US20050017368A1 - Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps - Google Patents

Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps Download PDF

Info

Publication number
US20050017368A1
US20050017368A1 US10/921,497 US92149704A US2005017368A1 US 20050017368 A1 US20050017368 A1 US 20050017368A1 US 92149704 A US92149704 A US 92149704A US 2005017368 A1 US2005017368 A1 US 2005017368A1
Authority
US
United States
Prior art keywords
redistribution layer
layer trace
pad
electrically conductive
trace
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/921,497
Inventor
Atila Mertol
Senol Pekin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
LSI Corp
Bell Semiconductor LLC
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US10/921,497 priority Critical patent/US20050017368A1/en
Publication of US20050017368A1 publication Critical patent/US20050017368A1/en
Assigned to LSI CORPORATION reassignment LSI CORPORATION MERGER (SEE DOCUMENT FOR DETAILS). Assignors: LSI SUBSIDIARY CORP.
Assigned to BELL SEMICONDUCTOR, LLC reassignment BELL SEMICONDUCTOR, LLC ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD., BROADCOM CORPORATION
Assigned to CORTLAND CAPITAL MARKET SERVICES LLC, AS COLLATERAL AGENT reassignment CORTLAND CAPITAL MARKET SERVICES LLC, AS COLLATERAL AGENT SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BELL NORTHERN RESEARCH, LLC, BELL SEMICONDUCTOR, LLC, HILCO PATENT ACQUISITION 56, LLC
Assigned to BELL SEMICONDUCTOR, LLC, BELL NORTHERN RESEARCH, LLC, HILCO PATENT ACQUISITION 56, LLC reassignment BELL SEMICONDUCTOR, LLC RELEASE BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: CORTLAND CAPITAL MARKET SERVICES LLC
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/10—Bump connectors ; Manufacturing methods related thereto
    • H01L24/11—Manufacturing methods
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
    • H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/52—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames
    • H01L23/522—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
    • H01L23/525—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body with adaptable interconnections
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/52—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames
    • H01L23/522—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
    • H01L23/528—Geometry or layout of the interconnection structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/02—Bonding areas; Manufacturing methods related thereto
    • H01L2224/04—Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L2224/05—Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H01L2224/05001—Internal layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/02—Bonding areas; Manufacturing methods related thereto
    • H01L2224/04—Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L2224/05—Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H01L2224/05001—Internal layers
    • H01L2224/0501—Shape
    • H01L2224/05016—Shape in side view
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/02—Bonding areas; Manufacturing methods related thereto
    • H01L2224/04—Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L2224/05—Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H01L2224/05001—Internal layers
    • H01L2224/0502—Disposition
    • H01L2224/05022—Disposition the internal layer being at least partially embedded in the surface
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/02—Bonding areas; Manufacturing methods related thereto
    • H01L2224/04—Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L2224/05—Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H01L2224/0554—External layer
    • H01L2224/0556—Disposition
    • H01L2224/05571—Disposition the external layer being disposed in a recess of the surface
    • H01L2224/05572—Disposition the external layer being disposed in a recess of the surface the external layer extending out of an opening
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/12—Structure, shape, material or disposition of the bump connectors prior to the connecting process
    • H01L2224/13—Structure, shape, material or disposition of the bump connectors prior to the connecting process of an individual bump connector
    • H01L2224/13001—Core members of the bump connector
    • H01L2224/13099—Material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
    • H01L23/31—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape
    • H01L23/3107—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape the device being completely enclosed
    • H01L23/3114—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape the device being completely enclosed the device being a chip scale package, e.g. CSP
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/02—Bonding areas ; Manufacturing methods related thereto
    • H01L24/04—Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L24/05—Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01013—Aluminum [Al]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01029—Copper [Cu]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01033—Arsenic [As]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/013—Alloys
    • H01L2924/014—Solder alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/14—Integrated circuits

Definitions

  • the present invention relates generally to the design of flip-chip packages used in the manufacture of integrated circuits. More specifically, but without limitation thereto, the present invention relates to metal redistribution layer traces in an integrated circuit die.
  • microelectronic packaging An important issue in microelectronic packaging is reliability. Technologies for microelectronic packaging are developed not only to manufacture microelectronic packages at low cost, but also to ensure that the performance of the microelectronic packages will not deteriorate over their service life.
  • a critical factor in determining the service life of an integrated circuit is the redistribution of current through the metal redistribution layer of the integrated circuit die.
  • the metal redistribution layer is a conductive layer formed on a surface of the die in which traces are formed that connect various signals and power between the die and I/O pads formed on the surface of the die. The I/O pads connect the signals between the traces and the package substrate through solder bumps.
  • the current density reaches a maximum that may shorten the useful life of the integrated circuit.
  • the peaking of the current density at the junctions of the traces and the I/O pads and in the solder bumps is generally referred to as current crowding. It has been discovered that current crowding results in the deterioration of not only the trace junctions, which decreases the wafer level reliability, but also the solder bumps, which decreases the package level reliability.
  • a multi-level redistribution layer trace reduces current crowding in solder bumps of an integrated circuit package.
  • a multi-level redistribution layer trace for an integrated circuit die includes a redistribution layer trace formed on the integrated circuit die in each of a plurality of electrically conductive layers and an I/O pad formed at a termination of the redistribution layer trace so that the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.
  • a method of making a multi-level redistribution layer trace of an integrated circuit die includes the steps of forming a redistribution layer trace on the integrated circuit die in each of a plurality of electrically conductive layers, and forming an I/O pad at a termination of the redistribution layer trace so that the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.
  • a multi-level redistribution layer trace of an integrated circuit die includes a redistribution layer trace formed on the integrated circuit die in one or more electrically conductive layers, and a slot formed in the redistribution layer trace to divide the current flow horizontally at an electrical junction between a termination of the redistribution layer trace and an I/O pad.
  • a method of making a multi-level redistribution layer trace of an integrated circuit die includes the steps of forming a redistribution layer trace on the integrated circuit die in one or more electrically conductive layers, and forming a slot in the redistribution layer trace to divide the current flow horizontally at an electrical junction between a termination of the redistribution layer trace and an I/O pad.
  • FIG. 1 illustrates a cross-sectional view of a conventional flip chip package of the prior art
  • FIG. 2 illustrates a cross-sectional view of a conventional redistribution layer trace in the flipchip package of FIG. 1 ;
  • FIG. 3A illustrates a finite element model of a conventional narrow redistribution layer trace corresponding to FIG. 2 ;
  • FIG. 3B illustrates a finite element model of a conventional wide redistribution layer trace corresponding to FIG. 2 ;
  • FIG. 4 illustrates a computer simulation of current crowding in a solder bump resulting from the conventional redistribution layer trace of FIG. 3A ;
  • FIG. 5 illustrates a cross-sectional view of a multi-level redistribution layer trace according to an embodiment of the present invention
  • FIG. 6 illustrates a finite element model of a narrow multi-level redistribution layer trace corresponding to FIG. 5 ;
  • FIG. 7 illustrates a finite element model of a wide multi-level redistribution layer trace corresponding to FIG. 5 ;
  • FIGS. 8A and 8B illustrate a top view of two tapered multi-level redistribution layer traces corresponding to FIG. 5 ;
  • FIG. 9 illustrates a computer simulation of current crowding in a solder bump resulting from the redistribution layer trace of FIG. 6 ;
  • FIG. 10 illustrates a flow chart of a method of making a multi-level redistribution layer trace of an integrated circuit die according to an embodiment of the present invention
  • FIG. 11 illustrates a finite element model of a slotted multi-level redistribution layer trace according to an embodiment of the present invention
  • FIG. 12 illustrates a flow chart of a method of making a slotted redistribution layer trace of an integrated circuit die according to an embodiment of the present invention.
  • FIG. 13 illustrates a plot of maximum current density vs. passivation opening diameter in a solder bump resulting from the conventional narrow trace of FIG. 3A , the conventional wide redistribution layer trace of FIG. 3B , and the multi-level redistribution layer trace of FIG. 6 .
  • Electromigration is the mass transport of atoms in die interconnects and solder bumps of a microelectronic package. Since the invention of the first integrated circuits in the 1960's, electromigration has been a major problem. As package size and I/O pad dimensions decrease with higher density technologies, reliability may be comprised if measures are not taken to mitigate electromigration. Also, with the implementation of a metal redistribution layer made of copper instead of aluminum, the maximum current density capability of the metal redistribution layer doubles from about 4 ⁇ 10 ⁇ 3 amperes per square micron to about 8 ⁇ 10 ⁇ 3 amperes per square micron. The higher current density in the metal redistribution layer results in a correspondingly higher current density in the die interconnects and the solder bumps.
  • Solder bumps are especially prone to failures due to high current crowding in the area near the junctions between the termination of the redistribution layer traces and the I/O pads. Reducing the maximum current density by improving the distribution of current at junctions between the termination of the redistribution layer traces and the I/O pads can significantly increase the reliability of the solder bumps and consequently that of the integrated circuit.
  • a multi-level redistribution layer trace reduces current crowding in solder bumps of an integrated circuit package.
  • a multi-level redistribution layer trace for an integrated circuit die includes a redistribution layer trace formed on the integrated circuit die in each of a plurality of electrically conductive layers and an I/O pad formed at a termination of the redistribution layer trace so that the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.
  • FIG. 1 illustrates a cross-sectional view of a conventional flipchip package of the prior art. Shown in FIG. 1 are a die 102 , first level interconnects 104 , and a package substrate 106 .
  • the first level interconnects 104 are solder bumps formed between the die 102 and the package substrate 106 .
  • FIG. 2 illustrates a cross-sectional view of a conventional redistribution layer trace in the flipchip package of FIG. 1 . Shown in FIG. 2 are a die 102 , a solder bump 104 , under bump metallurgy (UMB) 202 , a passivation opening 204 , an I/O pad 206 , a redistribution layer trace 208 , and an I/O pad height 210 .
  • UMB under bump metallurgy
  • the solder bump 104 is electrically connected to the I/O pad 206 by the under bump metallurgy (UMB) 202 .
  • the I/O pad 206 is formed on the metal redistribution (metal-R) layer of the die 102 at the termination of the redistribution layer trace 208 .
  • the metal redistribution layer is an electrically conductive layer formed on the surface of the die 102 that distributes signals and power between the die 102 and the solder bumps 104 , and is formed according to well known chemical deposition techniques such as evaporation, sputtering, and screen printing.
  • the I/O pad 206 and the redistribution layer trace 208 are formed in the metal redistribution layer by removing selected portions of the metal redistribution layer according to well known photolithography techniques.
  • the I/O pad height 210 extends to the bottom of the redistribution layer trace 208 , forming an electrical junction between the termination of the redistribution layer trace 208 and the I/O pad 206 in the metal redistribution layer.
  • the passivation opening 204 is an opening formed by removing an area around the edge of the I/O pad 206 in a passivation layer formed on the die 102 that protects the metal redistribution layer from contaminants.
  • the passivation opening 204 exposes the I/O pad 206 so that the under bump metallurgy 202 may be formed on the I/O pad 206 .
  • the solder bump 104 is then formed on the I/O pad 206 according to well-known techniques.
  • the under bump metallurgy 202 is formed on the I/O pad 206 through the passivation opening 204 typically has three layers (not shown): an upper layer for promoting adhesion to the solder bump 104 , a middle layer for limiting diffusion between the solder bump 104 and the I/O pad 206 , and a lower layer for bonding the under bump metallurgy 202 to the I/O pad 206 .
  • the upper layer may be made of copper
  • the middle layer may be made of nickel
  • the lower layer may be made of the same metal as the I/O pad 206 , for example, aluminum or copper.
  • the solder bump 104 may be formed on the under bump metallurgy 202 , for example, by a solder reflow process according to well-known techniques.
  • FIG. 3A illustrates a finite element model of a conventional narrow redistribution layer trace corresponding to FIG. 2 . Shown in FIG. 3A are solder bumps 104 , I/O pads 206 , and a conventional narrow redistribution layer trace 302 .
  • FIG. 3B illustrates a finite element model of a wide conventional redistribution layer trace corresponding to FIG. 2 . Shown in FIG. 3B are solder bumps 104 , I/O pads 206 , and a conventional wide redistribution layer trace 304 .
  • FIG. 4 illustrates a computer simulation of current crowding in a solder bump resulting from the conventional redistribution layer trace of FIG. 3A .
  • Shown in FIG. 4 are a solder bump 104 , an under bump metallurgy 202 , a passivation opening 204 , a low current crowding area 402 , medium current crowding areas 404 , and high current crowding areas 406 .
  • the current density is low as illustrated by the low current crowding area 402 except on the side of the solder bump 104 near the electrical junction of the I/O pad 206 and the termination of the redistribution layer trace 302 in FIG. 3 .
  • the current density increases near the electrical junction of the I/O pad 206 and the termination of the redistribution layer trace 302 as illustrated by the medium current crowding areas 404 , and reaches a maximum along the junction of the passivation opening and the under bump metallurgy 202 as illustrated by the high current crowding areas 406 .
  • the maximum value of the current density is 1.07 ⁇ 10 ⁇ 4 amperes per square micron (millionth of a meter).
  • FIG. 5 illustrates a cross-sectional view of a narrow multi-level redistribution layer trace according to an embodiment of the present invention. Shown in FIG. 5 are a die 102 , a solder bump 104 , under bump metallurgy 202 , a passivation opening 204 , a redistribution layer trace 502 , an I/O pad 503 , an I/O pad height 504 , electrically conductive layers 506 , 508 and 510 , insulating layers 512 and 514 , and a termination offset 516 .
  • FIG. 2 generally applies to FIG. 5 , except that multiple electrically conductive layers 506 , 508 and 510 are formed on the die 102 to distribute signals and power between the die 102 and the solder bumps 104 instead of the single metal redistribution layer shown in FIG. 2 .
  • the electrically conductive layers 506 , 508 and 510 may be formed according to the same well-known techniques used to form the single metal redistribution layer shown in FIG. 2 .
  • Each of the electrically conductive layers 506 , 508 and 510 is electrically insulated from one another, for example, by the insulating layers 512 and 514 .
  • the insulating layers 512 and 514 may be formed, for example, by depositing a layer of silicon oxide or silicon nitride on each of the electrically conductive layers 508 and 510 .
  • three electrically conductive layers 506 , 508 and 510 are formed on the die 102 and insulated from one another by the insulating layers 512 and 514 , however, any number of electrically conductive layers and insulating layers may be formed in the same manner to practice various embodiments of the present invention to suit specific applications. For example, only two electrically conductive layers insulated from each other by a single insulating layer may be formed in the same manner described above to practice the present invention to suit specific applications.
  • the redistribution layer trace 502 may be formed in each of the electrically conductive layers 506 , 508 and 510 according to well-known photolithography techniques. The redistribution layer trace 502 is terminated by the I/O pad 503 .
  • the I/O pad height 504 extends through each of the electrically conductive layers 506 , 508 and 510 to form an electrical junction between the I/O pad 503 and the termination of the redistribution layer trace 502 in each of the electrically conductive layers 506 , 508 and 510 .
  • the I/O pad 503 extends completely through all the electrically conductive layers 506 , 508 and 510 so that an electrical junction is formed between the redistribution layer trace 502 and the I/O pad 503 in each of the electrically conductive layers 506 , 508 and 510 on the die 102 without any intervening devices such as vias.
  • Previous methods for reducing current crowding such as disclosed by Smooha in U.S. Pat. No. 5,969,421, incorporated herein by reference, incorporate intervening vias between the contact pads and conductive layers in the package substrate.
  • Dividing the current among the multiple junctions of the I/O pad 503 with the redistribution layer trace 502 diffuses the current flow between the die 102 and the solder bump 104 over a wider area through the under bump metallurgy 202 , substantially reducing the maximum current density as well as the area of high current density in the solder bump 104 .
  • the current flow between the die 102 and the solder bump 104 may be further diffused by terminating the redistribution layer trace 502 at the I/O pad 503 in each of the electrically conductive layers 506 , 508 and 510 so that the termination of the redistribution layer trace 502 in one electrically conductive layer is vertically offset from the termination of the redistribution layer trace 502 in a preceding electrically conductive layer as indicated in FIG. 5 by the termination offset 516 .
  • the termination offset 516 may have a value ranging from zero to the diameter of the I/O pad 503 in accordance with various embodiments of the present invention to suit specific applications.
  • FIG. 6 illustrates a finite element model of a narrow multi-level redistribution layer trace corresponding to FIG. 5 .
  • Shown in FIG. 6 are a solder bump 104 , an I/O pad 503 , a redistribution layer trace 602 , and electrically conductive layers 506 and 508 .
  • the redistribution layer trace 502 is formed in two electrically conductive layers 506 and 508 that terminate respectively at the top and bottom of the I/O pad 503 , and the redistribution layer trace 502 has a width equal to one side of the octagonally shaped I/O pad 503 .
  • the shape of the I/O pad 503 is not a limiting factor of the present invention, however, and other geometrical shapes may be used for the I/O pad 503 in various embodiments to practice the present invention to suit specific applications.
  • FIG. 7 illustrates a finite element model of a wide multi-level redistribution layer trace corresponding to FIG. 5 .
  • Shown in FIG. 7 are a solder bump 104 , an I/O pad 503 , a redistribution layer trace 702 , and electrically conductive layers 506 and 508 .
  • the redistribution layer trace 702 is formed in two electrically conductive layers 506 and 508 that terminate respectively at the top and bottom of the I/O pad 503 , and the redistribution layer trace 502 has a width equal to the diameter of the octagonally shaped I/O pad 503 .
  • FIGS. 8A and 8B illustrate a top view of two tapered multi-level redistribution layer traces corresponding to FIG. 5 .
  • the tapered trace designs shown in FIG. 8 may be used to practice the present invention in various embodiments to further reduce the maximum current density in the solder bumps 104 to suit specific applications.
  • Shown in FIG. 8 are I/O pads 503 , a short tapered multi-level redistribution layer trace 802 and a long tapered multi-level redistribution layer trace 804 .
  • Both the fast tapered multi-level redistribution layer trace 802 and the slow tapered multi-level redistribution layer trace 804 include a tapered portion having an initial width substantially equal to the diameter of the I/O pad 503 .
  • the tapered portion extends from the termination of the redistribution layer trace at the I/O pad 503 to a termination of the tapered portion.
  • a straight portion having a width substantially equal to a final width of the tapered portion extends from the termination of the tapered portion.
  • the straight portion has a length of substantially zero.
  • FIG. 9 illustrates a computer simulation of current crowding in a solder bump resulting from the redistribution layer trace of FIG. 6 . Shown in FIG. 9 are a solder bump 104 , an under bump metallurgy 202 , a passivation opening 204 , a low current crowding area 902 , medium current crowding areas 904 , and a high current crowding area 906 .
  • the high current crowding area 906 of the multi-level redistribution layer trace of the present invention is smaller than the high current crowding areas 406 of the conventional redistribution layer trace illustrated in the computer simulation of FIG. 4 , and the maximum current density of the multi-level redistribution layer trace is only 0.9 ⁇ 10 ⁇ 4 amperes per square micron compared to 1.07 ⁇ 10 ⁇ 4 amperes per square micron for the conventional redistribution layer trace.
  • a method of making a multi-level redistribution layer trace of an integrated circuit die includes the steps of forming a redistribution layer trace on the integrated circuit die in each of a plurality of electrically conductive layers, and forming an I/O pad at a termination of the redistribution layer trace so that the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.
  • FIG. 10 illustrates a flow chart 1000 of a method of making a multi-level redistribution layer trace of an integrated circuit die according to an embodiment of the present invention.
  • Step 1002 is the entry point of the flow chart 1000 .
  • a redistribution layer trace is formed on the integrated circuit die in each of a plurality of electrically conductive layers according to well-known techniques.
  • the redistribution layer trace may have a narrow, wide, or tapered shape as described above to further diffuse the current flow between the under bump metallurgy and the solder bump.
  • an I/O pad is formed at a termination of the redistribution layer trace.
  • the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.
  • the termination of the redistribution layer trace at the I/O pad may be offset in each of the plurality of electrically conductive layers to further diffuse the current flow into the solder bump as described above.
  • step 1008 a passivation opening is formed on the I/O pad.
  • step 1010 an under bump metallurgy is formed on the passivation opening.
  • step 1012 a solder bump is formed on the under bump metallurgy.
  • Step 1014 is the exit point of the flow chart 1000 .
  • a multi-level redistribution layer trace of an integrated circuit die includes a redistribution layer trace formed on the integrated circuit die in one or more electrically conductive layers, and a slot formed in the redistribution layer trace to divide the current flow horizontally at an electrical junction between a termination of the redistribution layer trace and an I/O pad.
  • FIG. 11 illustrates a finite element model of a slotted redistribution layer trace according to embodiment of the present invention. Shown in FIG. 11 are solder bumps 104 , I/O pads 503 , a slotted multiple layer redistribution layer trace 1102 , electrically conductive layers 506 and 508 , and a slot 1104 .
  • the slot 1104 extends from the junction of the redistribution layer trace 1102 and the I/O pad 503 into the redistribution layer trace 1102 and may extend the entire length of the redistribution layer trace 1102 as shown in FIG. 11 . Alternatively, the slot 1104 may extend less than the entire length of the redistribution layer trace 1102 to practice the present invention in various embodiments to suit specific applications.
  • the redistribution layer trace 1102 may include additional slots formed in the same manner as described above to divide the current flow horizontally at the I/O pad 503 to practice the present invention in various embodiments to suit specific applications.
  • electrically conductive layers 506 and 508 While only two electrically conductive layers 506 and 508 are used to illustrate this example, a single electrically conductive layer may be used to divide the current flow horizontally at the I/O pad 503 to practice the present invention in various embodiments to suit specific applications. Alternatively, more than two electrically conductive layers may be used to practice the present invention in various embodiments to suit specific applications.
  • a method of making a multi-level redistribution layer trace of an integrated circuit die includes the steps of forming a redistribution layer trace on the integrated circuit die in one or more electrically conductive layers, and forming a slot in the redistribution layer trace to divide the current flow horizontally at an electrical junction between a termination of the redistribution layer trace and an I/O pad.
  • FIG. 12 illustrates a flow chart 1200 of a method of making a slotted redistribution layer trace of an integrated circuit die according to an embodiment of the present invention.
  • Step 1202 is the entry point of the flow chart 1200 .
  • a redistribution layer trace is formed on the integrated circuit die in at least one electrically conductive layer as described above.
  • an I/O pad is formed on the integrated circuit die that extends through each electrically conductive layer to form an electrical junction between the redistribution layer trace and the I/O pad in each electrically conductive layer as described above.
  • a slot is formed in the redistribution layer trace that extends into the redistribution layer trace from the electrical junction between the redistribution layer trace and the I/O pad in each at least one electrically conductive layer.
  • step 1208 a passivation opening is formed on the I/O pad.
  • step 1210 an under bump metallurgy is formed on the passivation opening.
  • step 1212 a solder bump is formed on the under bump metallurgy.
  • Step 1214 is the exit point of the flow chart 1200 .
  • FIG. 13 illustrates a plot of passivation opening diameter vs. maximum current density for the conventional narrow trace of FIG. 3A , the conventional wide redistribution layer trace of FIG. 3B , and the multi-level redistribution layer trace of FIG. 6 .
  • the passivation opening diameter is defined by the width of the intersection of the passivation 204 , the I/O pad 206 , and the first level interconnect 104 in FIG. 6 .
  • the points plotted in the plot of FIG. 13 correspond to the maximum current density of each corresponding redistribution layer trace design.
  • the conventional narrow redistribution layer trace has the highest maximum current density.
  • the conventional wide redistribution layer has the next highest maximum current density, and the multi-level redistribution layer trace of the present invention has the lowest maximum current density.

Abstract

A multi-level redistribution layer trace reduces current crowding in solder bumps of an integrated circuit package. A multi-level redistribution layer trace for an integrated circuit die includes a redistribution layer trace formed on the integrated circuit die in each of a plurality of electrically conductive layers and an I/O pad formed at a termination of the redistribution layer trace so that the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers. The redistribution layer trace may also be slotted to divide current flow horizontally at the electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.

Description

    CROSS-REFERENCE TO RELATED APPLICATIONS
  • This is a divisional application of pending U.S. patent application Ser. No. 10/327,333 by Atila Mertol et al. for “MULTI-LEVEL REDISTRIBUTION LAYER TRACES FOR REDUCING CURRENT CROWDING IN FLIPCHIP SOLDER BUMPS”, filed on Dec. 20, 2002.
    • BACKGROUND OF THE INVENTION
  • 1. Field of the Invention
  • The present invention relates generally to the design of flip-chip packages used in the manufacture of integrated circuits. More specifically, but without limitation thereto, the present invention relates to metal redistribution layer traces in an integrated circuit die.
  • 2. Description of the Prior Art
  • An important issue in microelectronic packaging is reliability. Technologies for microelectronic packaging are developed not only to manufacture microelectronic packages at low cost, but also to ensure that the performance of the microelectronic packages will not deteriorate over their service life. A critical factor in determining the service life of an integrated circuit is the redistribution of current through the metal redistribution layer of the integrated circuit die. The metal redistribution layer is a conductive layer formed on a surface of the die in which traces are formed that connect various signals and power between the die and I/O pads formed on the surface of the die. The I/O pads connect the signals between the traces and the package substrate through solder bumps. In certain areas of the solder bumps near the junctions of the traces and the I/O pads, the current density reaches a maximum that may shorten the useful life of the integrated circuit. The peaking of the current density at the junctions of the traces and the I/O pads and in the solder bumps is generally referred to as current crowding. It has been discovered that current crowding results in the deterioration of not only the trace junctions, which decreases the wafer level reliability, but also the solder bumps, which decreases the package level reliability.
    • SUMMARY OF THE INVENTION
  • In one aspect of the present invention, a multi-level redistribution layer trace reduces current crowding in solder bumps of an integrated circuit package. In one embodiment, a multi-level redistribution layer trace for an integrated circuit die includes a redistribution layer trace formed on the integrated circuit die in each of a plurality of electrically conductive layers and an I/O pad formed at a termination of the redistribution layer trace so that the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.
  • In another aspect of the present invention, a method of making a multi-level redistribution layer trace of an integrated circuit die includes the steps of forming a redistribution layer trace on the integrated circuit die in each of a plurality of electrically conductive layers, and forming an I/O pad at a termination of the redistribution layer trace so that the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.
  • In a further aspect of the present invention, a multi-level redistribution layer trace of an integrated circuit die includes a redistribution layer trace formed on the integrated circuit die in one or more electrically conductive layers, and a slot formed in the redistribution layer trace to divide the current flow horizontally at an electrical junction between a termination of the redistribution layer trace and an I/O pad.
  • In yet another aspect of the present invention, a method of making a multi-level redistribution layer trace of an integrated circuit die includes the steps of forming a redistribution layer trace on the integrated circuit die in one or more electrically conductive layers, and forming a slot in the redistribution layer trace to divide the current flow horizontally at an electrical junction between a termination of the redistribution layer trace and an I/O pad.
    • DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
  • The present invention is illustrated by way of example and not limitation in the accompanying figures, in which like references indicate similar elements throughout the several views of the drawings, and in which:
  • FIG. 1 illustrates a cross-sectional view of a conventional flip chip package of the prior art;
  • FIG. 2 illustrates a cross-sectional view of a conventional redistribution layer trace in the flipchip package of FIG. 1;
  • FIG. 3A illustrates a finite element model of a conventional narrow redistribution layer trace corresponding to FIG. 2;
  • FIG. 3B illustrates a finite element model of a conventional wide redistribution layer trace corresponding to FIG. 2;
  • FIG. 4 illustrates a computer simulation of current crowding in a solder bump resulting from the conventional redistribution layer trace of FIG. 3A;
  • FIG. 5 illustrates a cross-sectional view of a multi-level redistribution layer trace according to an embodiment of the present invention;
  • FIG. 6 illustrates a finite element model of a narrow multi-level redistribution layer trace corresponding to FIG. 5;
  • FIG. 7 illustrates a finite element model of a wide multi-level redistribution layer trace corresponding to FIG. 5;
  • FIGS. 8A and 8B illustrate a top view of two tapered multi-level redistribution layer traces corresponding to FIG. 5;
  • FIG. 9 illustrates a computer simulation of current crowding in a solder bump resulting from the redistribution layer trace of FIG. 6;
  • FIG. 10 illustrates a flow chart of a method of making a multi-level redistribution layer trace of an integrated circuit die according to an embodiment of the present invention;
  • FIG. 11 illustrates a finite element model of a slotted multi-level redistribution layer trace according to an embodiment of the present invention;
  • FIG. 12 illustrates a flow chart of a method of making a slotted redistribution layer trace of an integrated circuit die according to an embodiment of the present invention; and
  • FIG. 13 illustrates a plot of maximum current density vs. passivation opening diameter in a solder bump resulting from the conventional narrow trace of FIG. 3A, the conventional wide redistribution layer trace of FIG. 3B, and the multi-level redistribution layer trace of FIG. 6.
  • Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
    • DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
  • One of the limiting factors of the service life of a microelectronic package is electromigration. Electromigration is the mass transport of atoms in die interconnects and solder bumps of a microelectronic package. Since the invention of the first integrated circuits in the 1960's, electromigration has been a major problem. As package size and I/O pad dimensions decrease with higher density technologies, reliability may be comprised if measures are not taken to mitigate electromigration. Also, with the implementation of a metal redistribution layer made of copper instead of aluminum, the maximum current density capability of the metal redistribution layer doubles from about 4×10−3 amperes per square micron to about 8×10−3 amperes per square micron. The higher current density in the metal redistribution layer results in a correspondingly higher current density in the die interconnects and the solder bumps.
  • Solder bumps are especially prone to failures due to high current crowding in the area near the junctions between the termination of the redistribution layer traces and the I/O pads. Reducing the maximum current density by improving the distribution of current at junctions between the termination of the redistribution layer traces and the I/O pads can significantly increase the reliability of the solder bumps and consequently that of the integrated circuit.
  • In one aspect of the present invention, a multi-level redistribution layer trace reduces current crowding in solder bumps of an integrated circuit package. In one embodiment, a multi-level redistribution layer trace for an integrated circuit die includes a redistribution layer trace formed on the integrated circuit die in each of a plurality of electrically conductive layers and an I/O pad formed at a termination of the redistribution layer trace so that the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.
  • FIG. 1 illustrates a cross-sectional view of a conventional flipchip package of the prior art. Shown in FIG. 1 are a die 102, first level interconnects 104, and a package substrate 106.
  • In FIG. 1, the first level interconnects 104 are solder bumps formed between the die 102 and the package substrate 106.
  • FIG. 2 illustrates a cross-sectional view of a conventional redistribution layer trace in the flipchip package of FIG. 1. Shown in FIG. 2 are a die 102, a solder bump 104, under bump metallurgy (UMB) 202, a passivation opening 204, an I/O pad 206, a redistribution layer trace 208, and an I/O pad height 210.
  • In FIG. 2, the solder bump 104 is electrically connected to the I/O pad 206 by the under bump metallurgy (UMB) 202. The I/O pad 206 is formed on the metal redistribution (metal-R) layer of the die 102 at the termination of the redistribution layer trace 208. The metal redistribution layer is an electrically conductive layer formed on the surface of the die 102 that distributes signals and power between the die 102 and the solder bumps 104, and is formed according to well known chemical deposition techniques such as evaporation, sputtering, and screen printing.
  • The I/O pad 206 and the redistribution layer trace 208 are formed in the metal redistribution layer by removing selected portions of the metal redistribution layer according to well known photolithography techniques. The I/O pad height 210 extends to the bottom of the redistribution layer trace 208, forming an electrical junction between the termination of the redistribution layer trace 208 and the I/O pad 206 in the metal redistribution layer.
  • The passivation opening 204 is an opening formed by removing an area around the edge of the I/O pad 206 in a passivation layer formed on the die 102 that protects the metal redistribution layer from contaminants. The passivation opening 204 exposes the I/O pad 206 so that the under bump metallurgy 202 may be formed on the I/O pad 206. The solder bump 104 is then formed on the I/O pad 206 according to well-known techniques.
  • The under bump metallurgy 202 is formed on the I/O pad 206 through the passivation opening 204 typically has three layers (not shown): an upper layer for promoting adhesion to the solder bump 104, a middle layer for limiting diffusion between the solder bump 104 and the I/O pad 206, and a lower layer for bonding the under bump metallurgy 202 to the I/O pad 206. By way of example, the upper layer may be made of copper, the middle layer may be made of nickel, and the lower layer may be made of the same metal as the I/O pad 206, for example, aluminum or copper.
  • The solder bump 104 may be formed on the under bump metallurgy 202, for example, by a solder reflow process according to well-known techniques.
  • FIG. 3A illustrates a finite element model of a conventional narrow redistribution layer trace corresponding to FIG. 2. Shown in FIG. 3A are solder bumps 104, I/O pads 206, and a conventional narrow redistribution layer trace 302.
  • FIG. 3B illustrates a finite element model of a wide conventional redistribution layer trace corresponding to FIG. 2. Shown in FIG. 3B are solder bumps 104, I/O pads 206, and a conventional wide redistribution layer trace 304.
  • FIG. 4 illustrates a computer simulation of current crowding in a solder bump resulting from the conventional redistribution layer trace of FIG. 3A. Shown in FIG. 4 are a solder bump 104, an under bump metallurgy 202, a passivation opening 204, a low current crowding area 402, medium current crowding areas 404, and high current crowding areas 406.
  • In FIG. 4, the current density is low as illustrated by the low current crowding area 402 except on the side of the solder bump 104 near the electrical junction of the I/O pad 206 and the termination of the redistribution layer trace 302 in FIG. 3. The current density increases near the electrical junction of the I/O pad 206 and the termination of the redistribution layer trace 302 as illustrated by the medium current crowding areas 404, and reaches a maximum along the junction of the passivation opening and the under bump metallurgy 202 as illustrated by the high current crowding areas 406. In this example, the maximum value of the current density is 1.07×10−4 amperes per square micron (millionth of a meter).
  • FIG. 5 illustrates a cross-sectional view of a narrow multi-level redistribution layer trace according to an embodiment of the present invention. Shown in FIG. 5 are a die 102, a solder bump 104, under bump metallurgy 202, a passivation opening 204, a redistribution layer trace 502, an I/O pad 503, an I/O pad height 504, electrically conductive layers 506, 508 and 510, insulating layers 512 and 514, and a termination offset 516.
  • The description of FIG. 2 generally applies to FIG. 5, except that multiple electrically conductive layers 506, 508 and 510 are formed on the die 102 to distribute signals and power between the die 102 and the solder bumps 104 instead of the single metal redistribution layer shown in FIG. 2. The electrically conductive layers 506, 508 and 510 may be formed according to the same well-known techniques used to form the single metal redistribution layer shown in FIG. 2. Each of the electrically conductive layers 506, 508 and 510 is electrically insulated from one another, for example, by the insulating layers 512 and 514. The insulating layers 512 and 514 may be formed, for example, by depositing a layer of silicon oxide or silicon nitride on each of the electrically conductive layers 508 and 510. In this example, three electrically conductive layers 506, 508 and 510 are formed on the die 102 and insulated from one another by the insulating layers 512 and 514, however, any number of electrically conductive layers and insulating layers may be formed in the same manner to practice various embodiments of the present invention to suit specific applications. For example, only two electrically conductive layers insulated from each other by a single insulating layer may be formed in the same manner described above to practice the present invention to suit specific applications.
  • The redistribution layer trace 502 may be formed in each of the electrically conductive layers 506, 508 and 510 according to well-known photolithography techniques. The redistribution layer trace 502 is terminated by the I/O pad 503.
  • The I/O pad height 504 extends through each of the electrically conductive layers 506, 508 and 510 to form an electrical junction between the I/O pad 503 and the termination of the redistribution layer trace 502 in each of the electrically conductive layers 506, 508 and 510.
  • An important feature of the present invention is that the I/O pad 503 extends completely through all the electrically conductive layers 506, 508 and 510 so that an electrical junction is formed between the redistribution layer trace 502 and the I/O pad 503 in each of the electrically conductive layers 506, 508 and 510 on the die 102 without any intervening devices such as vias. Previous methods for reducing current crowding such as disclosed by Smooha in U.S. Pat. No. 5,969,421, incorporated herein by reference, incorporate intervening vias between the contact pads and conductive layers in the package substrate.
  • Current flowing through the redistribution layer trace 502 between the die 102 and the solder bump 104 is divided among each of the electrically conductive layers 506, 508 and 510 so that current flows between the I/O pad 503 and the die 102 through each of the junctions formed between the I/O pad 503 and the termination of the redistribution layer trace 502 in each of electrically conductive layers 506, 508 and 510. Dividing the current among the multiple junctions of the I/O pad 503 with the redistribution layer trace 502 diffuses the current flow between the die 102 and the solder bump 104 over a wider area through the under bump metallurgy 202, substantially reducing the maximum current density as well as the area of high current density in the solder bump 104.
  • The current flow between the die 102 and the solder bump 104 may be further diffused by terminating the redistribution layer trace 502 at the I/O pad 503 in each of the electrically conductive layers 506, 508 and 510 so that the termination of the redistribution layer trace 502 in one electrically conductive layer is vertically offset from the termination of the redistribution layer trace 502 in a preceding electrically conductive layer as indicated in FIG. 5 by the termination offset 516. The termination offset 516 may have a value ranging from zero to the diameter of the I/O pad 503 in accordance with various embodiments of the present invention to suit specific applications.
  • FIG. 6 illustrates a finite element model of a narrow multi-level redistribution layer trace corresponding to FIG. 5. Shown in FIG. 6 are a solder bump 104, an I/O pad 503, a redistribution layer trace 602, and electrically conductive layers 506 and 508. In this example, the redistribution layer trace 502 is formed in two electrically conductive layers 506 and 508 that terminate respectively at the top and bottom of the I/O pad 503, and the redistribution layer trace 502 has a width equal to one side of the octagonally shaped I/O pad 503. The shape of the I/O pad 503 is not a limiting factor of the present invention, however, and other geometrical shapes may be used for the I/O pad 503 in various embodiments to practice the present invention to suit specific applications.
  • FIG. 7 illustrates a finite element model of a wide multi-level redistribution layer trace corresponding to FIG. 5. Shown in FIG. 7 are a solder bump 104, an I/O pad 503, a redistribution layer trace 702, and electrically conductive layers 506 and 508. In this example, the redistribution layer trace 702 is formed in two electrically conductive layers 506 and 508 that terminate respectively at the top and bottom of the I/O pad 503, and the redistribution layer trace 502 has a width equal to the diameter of the octagonally shaped I/O pad 503.
  • FIGS. 8A and 8B illustrate a top view of two tapered multi-level redistribution layer traces corresponding to FIG. 5. The tapered trace designs shown in FIG. 8 may be used to practice the present invention in various embodiments to further reduce the maximum current density in the solder bumps 104 to suit specific applications. Shown in FIG. 8 are I/O pads 503, a short tapered multi-level redistribution layer trace 802 and a long tapered multi-level redistribution layer trace 804. Both the fast tapered multi-level redistribution layer trace 802 and the slow tapered multi-level redistribution layer trace 804 include a tapered portion having an initial width substantially equal to the diameter of the I/O pad 503. The tapered portion extends from the termination of the redistribution layer trace at the I/O pad 503 to a termination of the tapered portion. In the fast tapered multi-level redistribution layer trace 802, a straight portion having a width substantially equal to a final width of the tapered portion extends from the termination of the tapered portion. In the slow tapered multi-level redistribution layer trace 804, there is no straight portion, that is, the straight portion has a length of substantially zero.
  • FIG. 9 illustrates a computer simulation of current crowding in a solder bump resulting from the redistribution layer trace of FIG. 6. Shown in FIG. 9 are a solder bump 104, an under bump metallurgy 202, a passivation opening 204, a low current crowding area 902, medium current crowding areas 904, and a high current crowding area 906.
  • In FIG. 9, the high current crowding area 906 of the multi-level redistribution layer trace of the present invention is smaller than the high current crowding areas 406 of the conventional redistribution layer trace illustrated in the computer simulation of FIG. 4, and the maximum current density of the multi-level redistribution layer trace is only 0.9×10−4 amperes per square micron compared to 1.07×10−4 amperes per square micron for the conventional redistribution layer trace.
  • In another aspect of the present invention, a method of making a multi-level redistribution layer trace of an integrated circuit die includes the steps of forming a redistribution layer trace on the integrated circuit die in each of a plurality of electrically conductive layers, and forming an I/O pad at a termination of the redistribution layer trace so that the I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers.
  • FIG. 10 illustrates a flow chart 1000 of a method of making a multi-level redistribution layer trace of an integrated circuit die according to an embodiment of the present invention.
  • Step 1002 is the entry point of the flow chart 1000.
  • In step 1004, a redistribution layer trace is formed on the integrated circuit die in each of a plurality of electrically conductive layers according to well-known techniques. The redistribution layer trace may have a narrow, wide, or tapered shape as described above to further diffuse the current flow between the under bump metallurgy and the solder bump.
  • In step 1006, an I/O pad is formed at a termination of the redistribution layer trace. The I/O pad extends through each of the plurality of electrically conductive layers to form an electrical junction between the termination of the redistribution layer trace and the I/O pad in each of the plurality of electrically conductive layers. The termination of the redistribution layer trace at the I/O pad may be offset in each of the plurality of electrically conductive layers to further diffuse the current flow into the solder bump as described above.
  • In step 1008, a passivation opening is formed on the I/O pad.
  • In step 1010, an under bump metallurgy is formed on the passivation opening.
  • In step 1012, a solder bump is formed on the under bump metallurgy.
  • Step 1014 is the exit point of the flow chart 1000.
  • In a further aspect of the present invention, a multi-level redistribution layer trace of an integrated circuit die includes a redistribution layer trace formed on the integrated circuit die in one or more electrically conductive layers, and a slot formed in the redistribution layer trace to divide the current flow horizontally at an electrical junction between a termination of the redistribution layer trace and an I/O pad.
  • FIG. 11 illustrates a finite element model of a slotted redistribution layer trace according to embodiment of the present invention. Shown in FIG. 11 are solder bumps 104, I/O pads 503, a slotted multiple layer redistribution layer trace 1102, electrically conductive layers 506 and 508, and a slot 1104.
  • The slot 1104 extends from the junction of the redistribution layer trace 1102 and the I/O pad 503 into the redistribution layer trace 1102 and may extend the entire length of the redistribution layer trace 1102 as shown in FIG. 11. Alternatively, the slot 1104 may extend less than the entire length of the redistribution layer trace 1102 to practice the present invention in various embodiments to suit specific applications.
  • In this example, only one slot 1104 is shown in the redistribution layer trace 1102, however, the redistribution layer trace 1102 may include additional slots formed in the same manner as described above to divide the current flow horizontally at the I/O pad 503 to practice the present invention in various embodiments to suit specific applications.
  • While only two electrically conductive layers 506 and 508 are used to illustrate this example, a single electrically conductive layer may be used to divide the current flow horizontally at the I/O pad 503 to practice the present invention in various embodiments to suit specific applications. Alternatively, more than two electrically conductive layers may be used to practice the present invention in various embodiments to suit specific applications.
  • In yet another aspect of the present invention, a method of making a multi-level redistribution layer trace of an integrated circuit die includes the steps of forming a redistribution layer trace on the integrated circuit die in one or more electrically conductive layers, and forming a slot in the redistribution layer trace to divide the current flow horizontally at an electrical junction between a termination of the redistribution layer trace and an I/O pad.
  • FIG. 12 illustrates a flow chart 1200 of a method of making a slotted redistribution layer trace of an integrated circuit die according to an embodiment of the present invention.
  • Step 1202 is the entry point of the flow chart 1200.
  • In step 1204, a redistribution layer trace is formed on the integrated circuit die in at least one electrically conductive layer as described above.
  • In step 1206, an I/O pad is formed on the integrated circuit die that extends through each electrically conductive layer to form an electrical junction between the redistribution layer trace and the I/O pad in each electrically conductive layer as described above.
  • In step 1207, a slot is formed in the redistribution layer trace that extends into the redistribution layer trace from the electrical junction between the redistribution layer trace and the I/O pad in each at least one electrically conductive layer.
  • In step 1208, a passivation opening is formed on the I/O pad.
  • In step 1210, an under bump metallurgy is formed on the passivation opening.
  • In step 1212, a solder bump is formed on the under bump metallurgy.
  • Step 1214 is the exit point of the flow chart 1200.
  • FIG. 13 illustrates a plot of passivation opening diameter vs. maximum current density for the conventional narrow trace of FIG. 3A, the conventional wide redistribution layer trace of FIG. 3B, and the multi-level redistribution layer trace of FIG. 6. The passivation opening diameter is defined by the width of the intersection of the passivation 204, the I/O pad 206, and the first level interconnect 104 in FIG. 6.
  • The points plotted in the plot of FIG. 13 correspond to the maximum current density of each corresponding redistribution layer trace design. The conventional narrow redistribution layer trace has the highest maximum current density. The conventional wide redistribution layer has the next highest maximum current density, and the multi-level redistribution layer trace of the present invention has the lowest maximum current density.
  • Although the methods of the present invention illustrated by the flowchart descriptions above are described and shown with reference to specific steps performed in a specific order, these steps may be combined, sub-divided, or reordered without departing from the scope of the claims. Unless specifically indicated herein, the order and grouping of steps is not a limitation of the present invention.
  • While the invention herein disclosed has been described by means of specific embodiments and applications thereof, other modifications, variations, and arrangements of the present invention may be made in accordance with the above teachings other than as specifically described to practice the invention within the spirit and scope defined by the following claims.

Claims (2)

1. A multi-level redistribution layer trace for an integrated circuit die comprising:
a redistribution layer trace formed on the integrated circuit die in an electrically conductive layer of the integrated circuit die;
an I/O pad extending through the electrically conductive layer to form an electrical junction between the termination of the redistribution layer trace and the I/O pad; and
a slot formed in the redistribution layer trace to divide the current flow horizontally at the electrical junction.
2. A method of making a multi-level redistribution layer trace of an integrated circuit die comprising steps for:
forming a redistribution layer trace in an electrically conductive layer of the integrated circuit die;
forming an I/O pad on the integrated circuit die that extends through the electrically conductive layer to form an electrical junction between the redistribution layer trace and the I/O pad; and
forming a slot in the redistribution layer trace that extends into the redistribution layer trace from the electrical junction between the redistribution layer trace and the I/O pad.
US10/921,497 2002-12-20 2004-08-18 Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps Abandoned US20050017368A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/921,497 US20050017368A1 (en) 2002-12-20 2004-08-18 Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10/327,333 US6818996B2 (en) 2002-12-20 2002-12-20 Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps
US10/921,497 US20050017368A1 (en) 2002-12-20 2004-08-18 Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10/327,333 Division US6818996B2 (en) 2002-12-20 2002-12-20 Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps

Publications (1)

Publication Number Publication Date
US20050017368A1 true US20050017368A1 (en) 2005-01-27

Family

ID=32594226

Family Applications (2)

Application Number Title Priority Date Filing Date
US10/327,333 Expired - Lifetime US6818996B2 (en) 2002-12-20 2002-12-20 Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps
US10/921,497 Abandoned US20050017368A1 (en) 2002-12-20 2004-08-18 Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US10/327,333 Expired - Lifetime US6818996B2 (en) 2002-12-20 2002-12-20 Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps

Country Status (1)

Country Link
US (2) US6818996B2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090027137A1 (en) * 2003-11-12 2009-01-29 Fjelstad Joseph C Tapered dielectric and conductor structures and applications thereof
US20090072394A1 (en) * 2007-02-28 2009-03-19 Masanori Onodera Semiconductor device and method of manufacturing the same
US20090091019A1 (en) * 2003-11-17 2009-04-09 Joseph Charles Fjelstad Memory Packages Having Stair Step Interconnection Layers
US20100072615A1 (en) * 2008-09-24 2010-03-25 Maxim Integrated Products, Inc. High-Electrical-Current Wafer Level Packaging, High-Electrical-Current WLP Electronic Devices, and Methods of Manufacture Thereof
US8785244B2 (en) 2011-10-10 2014-07-22 Maxim Integrated Products, Inc. Wafer level packaging using a lead-frame
US8785248B2 (en) 2011-10-10 2014-07-22 Maxim Integrated Products, Inc. Wafer level packaging using a lead-frame

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3988710B2 (en) * 2003-03-05 2007-10-10 三菱電機株式会社 Joining method using metal electrodes
US7065721B2 (en) * 2003-07-28 2006-06-20 Lsi Logic Corporation Optimized bond out method for flip chip wafers
US7253528B2 (en) * 2005-02-01 2007-08-07 Avago Technologies General Ip Pte. Ltd. Trace design to minimize electromigration damage to solder bumps
US20080116584A1 (en) * 2006-11-21 2008-05-22 Arkalgud Sitaram Self-aligned through vias for chip stacking
TWI397983B (en) * 2008-12-31 2013-06-01 Ind Tech Res Inst Package carrier and bonding structure
US8350161B2 (en) * 2009-01-30 2013-01-08 Kycera Corporation Circuit board and structure using the same
US10685167B1 (en) * 2018-09-30 2020-06-16 Cadence Design Systems, Inc. System, method, and computer program product for displaying bump layout for manufacturing variations

Citations (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4467345A (en) * 1980-10-23 1984-08-21 Nippon Electric Co., Ltd. Semiconductor integrated circuit device
US4514751A (en) * 1982-12-23 1985-04-30 International Business Machines Corporation Compressively stresses titanium metallurgy for contacting passivated semiconductor devices
US4654692A (en) * 1983-06-30 1987-03-31 Kabushiki Kaisha Toshiba Semiconductor device of resin-seal type
US4680610A (en) * 1983-11-30 1987-07-14 Siemens Aktiengesellschaft Semiconductor component comprising bump-like, metallic lead contacts and multilayer wiring
US5101261A (en) * 1988-09-09 1992-03-31 Texas Instruments Incorporated Electronic circuit device with electronomigration-resistant metal conductors
US5289036A (en) * 1991-01-22 1994-02-22 Nec Corporation Resin sealed semiconductor integrated circuit
US5329162A (en) * 1991-06-21 1994-07-12 Oki Electric Industry Co., Ltd. Semiconductor device having a conductor layer provided over a semiconductor substrate
US5382831A (en) * 1992-12-14 1995-01-17 Digital Equipment Corporation Integrated circuit metal film interconnect having enhanced resistance to electromigration
US5461260A (en) * 1994-08-01 1995-10-24 Motorola Inc. Semiconductor device interconnect layout structure for reducing premature electromigration failure due to high localized current density
US5470788A (en) * 1994-02-28 1995-11-28 International Business Machines Corporation Method of making self-aligned, lateral diffusion barrier in metal lines to eliminate electromigration
US5689139A (en) * 1995-09-11 1997-11-18 Advanced Micro Devices, Inc. Enhanced electromigration lifetime of metal interconnection lines
US5712510A (en) * 1995-08-04 1998-01-27 Advanced Micro Devices, Inc. Reduced electromigration interconnection line
US5739587A (en) * 1995-02-21 1998-04-14 Seiko Epson Corporation Semiconductor device having a multi-latered wiring structure
US5925931A (en) * 1996-10-31 1999-07-20 Casio Computer Co., Ltd. Semiconductor device having interconnect lines and connection electrodes formed in groove portions of an insulating layer
US5939790A (en) * 1996-04-09 1999-08-17 Altera Corporation Integrated circuit pad structures
US5962918A (en) * 1997-10-14 1999-10-05 Nec Corporation Semiconductor device having simple protective structure and process of fabrication thereof
US5969421A (en) * 1997-11-18 1999-10-19 Lucent Technologies Inc. Integrated circuit conductors that avoid current crowding
US6023100A (en) * 1997-07-23 2000-02-08 Advanced Micro Devices, Inc. Metallization stack structure to improve electromigration resistance and keep low resistivity of ULSI interconnects
US6081036A (en) * 1996-04-19 2000-06-27 Matsushita Electronics Corp. Semiconductor device
US6169326B1 (en) * 1996-05-16 2001-01-02 Hyundai Electronics Industries Co., Ltd. Metal wire of semiconductor device and method for forming the same
US6191481B1 (en) * 1998-12-18 2001-02-20 Philips Electronics North America Corp. Electromigration impeding composite metallization lines and methods for making the same
US20010042918A1 (en) * 1998-05-22 2001-11-22 Toshiharu Yanagida Semiconductor device and method of fabricating the same
US20010051426A1 (en) * 1999-11-22 2001-12-13 Scott K. Pozder Method for forming a semiconductor device having a mechanically robust pad interface.
US6346749B1 (en) * 1999-04-09 2002-02-12 Oki Electric Industry Co., Ltd. Semiconductor device
US6388269B1 (en) * 1999-03-25 2002-05-14 Nec Corporation Metal interconnection structure for evaluation on electromigration
US6417572B1 (en) * 1997-08-13 2002-07-09 International Business Machines Corporation Process for producing metal interconnections and product produced thereby
US6424014B2 (en) * 2000-02-25 2002-07-23 Oki Electric Industry Co,Ltd. Semiconductor element with electric field reducing device mounted therein for increasing dielectric strength
US6522021B2 (en) * 2000-06-29 2003-02-18 Kabushiki Kaisha Toshiba Semiconductor device
US20030046647A1 (en) * 2001-09-05 2003-03-06 Fujitsu Limited Wiring designing method
US20030049886A1 (en) * 2001-09-07 2003-03-13 Salmon Peter C. Electronic system modules and method of fabrication
US20030048256A1 (en) * 2001-09-07 2003-03-13 Salmon Peter C. Computing device with roll up components
US6548902B2 (en) * 2000-12-27 2003-04-15 Fujitsu Limited Semiconductor integrated circuit device, circuit design apparatus, and circuit design method
US6566758B1 (en) * 2001-11-27 2003-05-20 Sun Microsystems, Inc. Current crowding reduction technique for flip chip package technology
US20030122258A1 (en) * 2001-12-28 2003-07-03 Sudhakar Bobba Current crowding reduction technique using slots
US20040021232A1 (en) * 2002-08-05 2004-02-05 Senol Pekin Flip-chip ball grid array package for electromigration testing
US20040058520A1 (en) * 2002-09-20 2004-03-25 Burrell Lloyd G. Support structures for wirebond regions of contact pads over low modulus materials
US20040108592A1 (en) * 2002-12-05 2004-06-10 Taiwan Semiconductor Manufacturing Company Slot design for metal interconnects
US6897563B2 (en) * 2001-12-28 2005-05-24 Sun Microsystems, Inc. Current crowding reduction technique using selective current injection
US7065721B2 (en) * 2003-07-28 2006-06-20 Lsi Logic Corporation Optimized bond out method for flip chip wafers

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3239719A (en) 1963-07-08 1966-03-08 Sperry Rand Corp Packaging and circuit connection means for microelectronic circuitry
US3517278A (en) 1967-10-02 1970-06-23 Teledyne Inc Flip chip structure
US4603345A (en) 1984-03-19 1986-07-29 Trilogy Computer Development Partners, Ltd. Module construction for semiconductor chip
JPS62136865A (en) 1985-12-11 1987-06-19 Hitachi Ltd Module mounting structure
JP2533511B2 (en) 1987-01-19 1996-09-11 株式会社日立製作所 Electronic component connection structure and manufacturing method thereof
US5239448A (en) 1991-10-28 1993-08-24 International Business Machines Corporation Formulation of multichip modules
US5847936A (en) 1997-06-20 1998-12-08 Sun Microsystems, Inc. Optimized routing scheme for an integrated circuit/printed circuit board

Patent Citations (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4467345A (en) * 1980-10-23 1984-08-21 Nippon Electric Co., Ltd. Semiconductor integrated circuit device
US4514751A (en) * 1982-12-23 1985-04-30 International Business Machines Corporation Compressively stresses titanium metallurgy for contacting passivated semiconductor devices
US4654692A (en) * 1983-06-30 1987-03-31 Kabushiki Kaisha Toshiba Semiconductor device of resin-seal type
US4680610A (en) * 1983-11-30 1987-07-14 Siemens Aktiengesellschaft Semiconductor component comprising bump-like, metallic lead contacts and multilayer wiring
US5101261A (en) * 1988-09-09 1992-03-31 Texas Instruments Incorporated Electronic circuit device with electronomigration-resistant metal conductors
US5289036A (en) * 1991-01-22 1994-02-22 Nec Corporation Resin sealed semiconductor integrated circuit
US5329162A (en) * 1991-06-21 1994-07-12 Oki Electric Industry Co., Ltd. Semiconductor device having a conductor layer provided over a semiconductor substrate
US5382831A (en) * 1992-12-14 1995-01-17 Digital Equipment Corporation Integrated circuit metal film interconnect having enhanced resistance to electromigration
US5470788A (en) * 1994-02-28 1995-11-28 International Business Machines Corporation Method of making self-aligned, lateral diffusion barrier in metal lines to eliminate electromigration
US5760476A (en) * 1994-08-01 1998-06-02 Motorola, Inc. Interconnect run between a first point and a second point in a semiconductor device for reducing electromigration failure
US5461260A (en) * 1994-08-01 1995-10-24 Motorola Inc. Semiconductor device interconnect layout structure for reducing premature electromigration failure due to high localized current density
US5739587A (en) * 1995-02-21 1998-04-14 Seiko Epson Corporation Semiconductor device having a multi-latered wiring structure
US5712510A (en) * 1995-08-04 1998-01-27 Advanced Micro Devices, Inc. Reduced electromigration interconnection line
US5689139A (en) * 1995-09-11 1997-11-18 Advanced Micro Devices, Inc. Enhanced electromigration lifetime of metal interconnection lines
US5939790A (en) * 1996-04-09 1999-08-17 Altera Corporation Integrated circuit pad structures
US6081036A (en) * 1996-04-19 2000-06-27 Matsushita Electronics Corp. Semiconductor device
US6169326B1 (en) * 1996-05-16 2001-01-02 Hyundai Electronics Industries Co., Ltd. Metal wire of semiconductor device and method for forming the same
US5925931A (en) * 1996-10-31 1999-07-20 Casio Computer Co., Ltd. Semiconductor device having interconnect lines and connection electrodes formed in groove portions of an insulating layer
US6023100A (en) * 1997-07-23 2000-02-08 Advanced Micro Devices, Inc. Metallization stack structure to improve electromigration resistance and keep low resistivity of ULSI interconnects
US6417572B1 (en) * 1997-08-13 2002-07-09 International Business Machines Corporation Process for producing metal interconnections and product produced thereby
US5962918A (en) * 1997-10-14 1999-10-05 Nec Corporation Semiconductor device having simple protective structure and process of fabrication thereof
US5969421A (en) * 1997-11-18 1999-10-19 Lucent Technologies Inc. Integrated circuit conductors that avoid current crowding
US20010042918A1 (en) * 1998-05-22 2001-11-22 Toshiharu Yanagida Semiconductor device and method of fabricating the same
US6545355B2 (en) * 1998-05-22 2003-04-08 Sony Corporation Semiconductor device and method of fabricating the same
US6191481B1 (en) * 1998-12-18 2001-02-20 Philips Electronics North America Corp. Electromigration impeding composite metallization lines and methods for making the same
US6388269B1 (en) * 1999-03-25 2002-05-14 Nec Corporation Metal interconnection structure for evaluation on electromigration
US6346749B1 (en) * 1999-04-09 2002-02-12 Oki Electric Industry Co., Ltd. Semiconductor device
US6677236B2 (en) * 1999-04-09 2004-01-13 Oki Electric Industry Co., Ltd. Semiconductor device fabrication method for interconnects that suppresses loss of interconnect metal
US20010051426A1 (en) * 1999-11-22 2001-12-13 Scott K. Pozder Method for forming a semiconductor device having a mechanically robust pad interface.
US6803302B2 (en) * 1999-11-22 2004-10-12 Freescale Semiconductor, Inc. Method for forming a semiconductor device having a mechanically robust pad interface
US6424014B2 (en) * 2000-02-25 2002-07-23 Oki Electric Industry Co,Ltd. Semiconductor element with electric field reducing device mounted therein for increasing dielectric strength
US6522021B2 (en) * 2000-06-29 2003-02-18 Kabushiki Kaisha Toshiba Semiconductor device
US6548902B2 (en) * 2000-12-27 2003-04-15 Fujitsu Limited Semiconductor integrated circuit device, circuit design apparatus, and circuit design method
US6745378B2 (en) * 2001-09-05 2004-06-01 Fujitsu Limited Wiring designing method
US20030046647A1 (en) * 2001-09-05 2003-03-06 Fujitsu Limited Wiring designing method
US20030049886A1 (en) * 2001-09-07 2003-03-13 Salmon Peter C. Electronic system modules and method of fabrication
US6927471B2 (en) * 2001-09-07 2005-08-09 Peter C. Salmon Electronic system modules and method of fabrication
US20030048256A1 (en) * 2001-09-07 2003-03-13 Salmon Peter C. Computing device with roll up components
US6566758B1 (en) * 2001-11-27 2003-05-20 Sun Microsystems, Inc. Current crowding reduction technique for flip chip package technology
US20030098510A1 (en) * 2001-11-27 2003-05-29 Pradeep Trivedi Current crowding reduction technique for flip chip package technology
US20030122258A1 (en) * 2001-12-28 2003-07-03 Sudhakar Bobba Current crowding reduction technique using slots
US6897563B2 (en) * 2001-12-28 2005-05-24 Sun Microsystems, Inc. Current crowding reduction technique using selective current injection
US6700207B2 (en) * 2002-08-05 2004-03-02 Lsi Logic Corporation Flip-chip ball grid array package for electromigration testing
US20040021232A1 (en) * 2002-08-05 2004-02-05 Senol Pekin Flip-chip ball grid array package for electromigration testing
US20040058520A1 (en) * 2002-09-20 2004-03-25 Burrell Lloyd G. Support structures for wirebond regions of contact pads over low modulus materials
US6908841B2 (en) * 2002-09-20 2005-06-21 Infineon Technologies Ag Support structures for wirebond regions of contact pads over low modulus materials
US20040108592A1 (en) * 2002-12-05 2004-06-10 Taiwan Semiconductor Manufacturing Company Slot design for metal interconnects
US6940108B2 (en) * 2002-12-05 2005-09-06 Taiwan Semiconductor Manufacturing Co., Ltd. Slot design for metal interconnects
US7065721B2 (en) * 2003-07-28 2006-06-20 Lsi Logic Corporation Optimized bond out method for flip chip wafers

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090027137A1 (en) * 2003-11-12 2009-01-29 Fjelstad Joseph C Tapered dielectric and conductor structures and applications thereof
US7973391B2 (en) * 2003-11-12 2011-07-05 Samsung Electronics Co., Ltd. Tapered dielectric and conductor structures and applications thereof
US20090091019A1 (en) * 2003-11-17 2009-04-09 Joseph Charles Fjelstad Memory Packages Having Stair Step Interconnection Layers
US20090072394A1 (en) * 2007-02-28 2009-03-19 Masanori Onodera Semiconductor device and method of manufacturing the same
US9508651B2 (en) * 2007-02-28 2016-11-29 Cypress Semiconductor Corporation Semiconductor device and method of manufacturing the same
US11018105B2 (en) 2007-02-28 2021-05-25 Cypress Semiconductor Corporation Semiconductor device and method of manufacturing the same
US20100072615A1 (en) * 2008-09-24 2010-03-25 Maxim Integrated Products, Inc. High-Electrical-Current Wafer Level Packaging, High-Electrical-Current WLP Electronic Devices, and Methods of Manufacture Thereof
US8785244B2 (en) 2011-10-10 2014-07-22 Maxim Integrated Products, Inc. Wafer level packaging using a lead-frame
US8785248B2 (en) 2011-10-10 2014-07-22 Maxim Integrated Products, Inc. Wafer level packaging using a lead-frame

Also Published As

Publication number Publication date
US6818996B2 (en) 2004-11-16
US20040121522A1 (en) 2004-06-24

Similar Documents

Publication Publication Date Title
US8212357B2 (en) Combination via and pad structure for improved solder bump electromigration characteristics
US9741659B2 (en) Electrical connections for chip scale packaging
US6452270B1 (en) Semiconductor device having bump electrode
US20230307399A1 (en) Interconnect Structures, Packaged Semiconductor Devices, and Methods of Packaging Semiconductor Devices
US7285850B2 (en) Support elements for semiconductor devices with peripherally located bond pads
US8264078B2 (en) Metal wiring structures for uniform current density in C4 balls
US9536850B2 (en) Package having substrate with embedded metal trace overlapped by landing pad
TWI442524B (en) Flip chip package and semiconductor die
US7777333B2 (en) Structure and method for fabricating flip chip devices
US9093333B1 (en) Integrated circuit device having extended under ball metallization
US8063487B2 (en) Manufacturing method of semiconductor apparatus and semiconductor apparatus
US7208843B2 (en) Routing design to minimize electromigration damage to solder bumps
US20070087544A1 (en) Method for forming improved bump structure
US20020017553A1 (en) Structure of solder bumps with improved coplanarity and method of forming solder bumps with improved coplanarity
US6818996B2 (en) Multi-level redistribution layer traces for reducing current crowding in flipchip solder bumps
US20050285116A1 (en) Electronic assembly with carbon nanotube contact formations or interconnections
US11133259B2 (en) Multi-chip package structure having high density chip interconnect bridge with embedded power distribution network
JP2012507163A (en) Semiconductor device including reduced stress structure for metal pillars
US7518211B2 (en) Chip and package structure
CN109148409B (en) Semiconductor chip
US9059004B2 (en) Method for chip scale package and package structure thereof
US20040266160A1 (en) Parasitic capacitance-preventing dummy solder bump structure and method of making the same
US6501186B1 (en) Bond pad having variable density via support and method for fabrication
WO2010049087A2 (en) A semiconductor device including a reduced stress configuration for metal pillars
CN212342601U (en) Multi-chip ultrathin fan-out packaging structure

Legal Events

Date Code Title Description
AS Assignment

Owner name: LSI CORPORATION, CALIFORNIA

Free format text: MERGER;ASSIGNOR:LSI SUBSIDIARY CORP.;REEL/FRAME:020548/0977

Effective date: 20070404

Owner name: LSI CORPORATION,CALIFORNIA

Free format text: MERGER;ASSIGNOR:LSI SUBSIDIARY CORP.;REEL/FRAME:020548/0977

Effective date: 20070404

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION

AS Assignment

Owner name: BELL SEMICONDUCTOR, LLC, ILLINOIS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.;BROADCOM CORPORATION;REEL/FRAME:044886/0766

Effective date: 20171208

AS Assignment

Owner name: CORTLAND CAPITAL MARKET SERVICES LLC, AS COLLATERA

Free format text: SECURITY INTEREST;ASSIGNORS:HILCO PATENT ACQUISITION 56, LLC;BELL SEMICONDUCTOR, LLC;BELL NORTHERN RESEARCH, LLC;REEL/FRAME:045216/0020

Effective date: 20180124

AS Assignment

Owner name: BELL NORTHERN RESEARCH, LLC, ILLINOIS

Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:CORTLAND CAPITAL MARKET SERVICES LLC;REEL/FRAME:059723/0382

Effective date: 20220401

Owner name: BELL SEMICONDUCTOR, LLC, ILLINOIS

Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:CORTLAND CAPITAL MARKET SERVICES LLC;REEL/FRAME:059723/0382

Effective date: 20220401

Owner name: HILCO PATENT ACQUISITION 56, LLC, ILLINOIS

Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:CORTLAND CAPITAL MARKET SERVICES LLC;REEL/FRAME:059723/0382

Effective date: 20220401