WO2004030099A1 - Surface mounted electrical components and method for mounting an d retaining same - Google Patents

Surface mounted electrical components and method for mounting an d retaining same Download PDF

Info

Publication number
WO2004030099A1
WO2004030099A1 PCT/US2003/030444 US0330444W WO2004030099A1 WO 2004030099 A1 WO2004030099 A1 WO 2004030099A1 US 0330444 W US0330444 W US 0330444W WO 2004030099 A1 WO2004030099 A1 WO 2004030099A1
Authority
WO
WIPO (PCT)
Prior art keywords
retentive
hole
pin
solder composition
solder
Prior art date
Application number
PCT/US2003/030444
Other languages
French (fr)
Inventor
Yakov Belopolsky
Original Assignee
Fci Americas Technology, Inc.
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 Fci Americas Technology, Inc. filed Critical Fci Americas Technology, Inc.
Priority to AU2003276991A priority Critical patent/AU2003276991A1/en
Publication of WO2004030099A1 publication Critical patent/WO2004030099A1/en

Links

Classifications

    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00Apparatus or processes for manufacturing printed circuits
    • H05K3/30Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
    • H05K3/341Surface mounted components
    • H05K3/3415Surface mounted components on both sides of the substrate or combined with lead-in-hole components
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00Apparatus or processes for manufacturing printed circuits
    • H05K3/30Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
    • H05K3/3447Lead-in-hole components
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means 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
    • H01L2224/10Bump connectors; Manufacturing methods related thereto
    • H01L2224/15Structure, shape, material or disposition of the bump connectors after the connecting process
    • H01L2224/16Structure, shape, material or disposition of the bump connectors after the connecting process of an individual bump connector
    • H01L2224/161Disposition
    • H01L2224/16151Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/16221Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/16225Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001Technical content checked by a classifier
    • H01L2924/00014Technical content checked by a classifier the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/09Shape and layout
    • H05K2201/09209Shape and layout details of conductors
    • H05K2201/09654Shape and layout details of conductors covering at least two types of conductors provided for in H05K2201/09218 - H05K2201/095
    • H05K2201/09781Dummy conductors, i.e. not used for normal transport of current; Dummy electrodes of components
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10613Details of electrical connections of non-printed components, e.g. special leads
    • H05K2201/10621Components characterised by their electrical contacts
    • H05K2201/10659Different types of terminals for the same component, e.g. solder balls combined with leads
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10613Details of electrical connections of non-printed components, e.g. special leads
    • H05K2201/10621Components characterised by their electrical contacts
    • H05K2201/10734Ball grid array [BGA]; Bump grid array
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/04Soldering or other types of metallurgic bonding
    • H05K2203/047Soldering with different solders, e.g. two different solders on two sides of the PCB
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/16Inspection; Monitoring; Aligning
    • H05K2203/167Using mechanical means for positioning, alignment or registration, e.g. using rod-in-hole alignment
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00Apparatus or processes for manufacturing printed circuits
    • H05K3/22Secondary treatment of printed circuits
    • H05K3/24Reinforcing the conductive pattern
    • H05K3/244Finish plating of conductors, especially of copper conductors, e.g. for pads or lands
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00Apparatus or processes for manufacturing printed circuits
    • H05K3/30Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/303Surface mounted components, e.g. affixing before soldering, aligning means, spacing means
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00Apparatus or processes for manufacturing printed circuits
    • H05K3/30Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
    • H05K3/341Surface mounted components
    • H05K3/3431Leadless components
    • H05K3/3436Leadless components having an array of bottom contacts, e.g. pad grid array or ball grid array components
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00Apparatus or processes for manufacturing printed circuits
    • H05K3/30Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
    • H05K3/3457Solder materials or compositions; Methods of application thereof
    • H05K3/3463Solder compositions in relation to features of the printed circuit board or the mounting process
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50Manufacturing or production processes characterised by the final manufactured product
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49002Electrical device making
    • Y10T29/49004Electrical device making including measuring or testing of device or component part
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49002Electrical device making
    • Y10T29/49117Conductor or circuit manufacturing
    • Y10T29/49121Beam lead frame or beam lead device
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49002Electrical device making
    • Y10T29/49117Conductor or circuit manufacturing
    • Y10T29/49124On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/4913Assembling to base an electrical component, e.g., capacitor, etc.
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49002Electrical device making
    • Y10T29/49117Conductor or circuit manufacturing
    • Y10T29/49124On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/4913Assembling to base an electrical component, e.g., capacitor, etc.
    • Y10T29/49131Assembling to base an electrical component, e.g., capacitor, etc. by utilizing optical sighting device
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49002Electrical device making
    • Y10T29/49117Conductor or circuit manufacturing
    • Y10T29/49124On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/4913Assembling to base an electrical component, e.g., capacitor, etc.
    • Y10T29/49144Assembling to base an electrical component, e.g., capacitor, etc. by metal fusion
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49002Electrical device making
    • Y10T29/49117Conductor or circuit manufacturing
    • Y10T29/49124On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/49147Assembling terminal to base
    • Y10T29/49149Assembling terminal to base by metal fusion bonding
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49002Electrical device making
    • Y10T29/49117Conductor or circuit manufacturing
    • Y10T29/49124On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/49155Manufacturing circuit on or in base
    • Y10T29/49165Manufacturing circuit on or in base by forming conductive walled aperture in base
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49002Electrical device making
    • Y10T29/49117Conductor or circuit manufacturing
    • Y10T29/49204Contact or terminal manufacturing
    • Y10T29/49208Contact or terminal manufacturing by assembling plural parts
    • Y10T29/49222Contact or terminal manufacturing by assembling plural parts forming array of contacts or terminals

Definitions

  • the present invention relates to surface mounted electrical components having improved retentive properties, and methods for mounting and retaining electrical components on substrates.
  • PGA pin grid arrays
  • BGA ball grid arrays
  • CGA's column grid arrays
  • LGA's land grid array
  • ball grid arrays utilize a grid or array of solder bumps or balls arranged on one side of an electrical component to effectuate electrical and mechanical connection with a printed board.
  • the ball attachment sites are typically referred to as lands or pads.
  • Solder past is disposed on the lands (and/or on the balls), such as through screening or masking techniques, and the electrical component is then positioned on the board so that the balls and lands are registered.
  • the board is then processed at an elevated temperature sufficient to cause the solder and at least a portion or all of the solder ball to flow and fuse with the underlying land/pad to form the electrical interconnection. See, for example, U.S. Pat. No. 6,325,644 assigned to the assignee of this patent, and patents within that patent, all of which is incorporated by reference herein.
  • Locator pins extending from the electrical component may be employed to facilitate the initial alignment of the electrical component.
  • the locator pins are inserted into through holes located in the board at locations along the periphery of the array of lands/pads. Pin diameters may be slightly larger than the corresponding through hole diameters so that an interference fit is achieved. Alternatively, the pin diameters may be smaller than the through hole diameters. In this scenario, adhesive or solder paste may be applied in and around the through holes to help retain the electrical component on the substrate.
  • the BGA balls are allowed to float (that is, not rigidly restricted) during a reflow process resulting in self-alignment and ultimately a low stress solder joint. Component retention however may be compromised with this configuration when the board is manipulated before the reflow heat is substantially dissipated, or when the board is rotated so that additional electrical components can be mounted on other available surface areas with subsequent reflow steps.
  • the method comprises the steps of: disposing solder paste of a first solder composition into a retentive through hole of the substrate; inserting a retentive pin extending from the electrical component and having a relatively smaller diameter into the retentive through hole; subjecting the substrate to a first thermal cycle such that material associated with at least one of the retentive through hole and retentive pin migrates into the solder paste to create a mixed solder composition that has a higher melting point than the first solder composition; and then subjecting the substrate to a second thermal cycle having a peak temperature less than the melting point of said mixed solder composition.
  • a method for making an electronic assembly comprises the steps of: providing a circuit board including a retentive through hole having a wall; providing an electrical connector having a retentive pin extending therefrom, wherein the retentive pin has a diameter smaller than the retentive through hole and is made from a material comprising a precious metal; disposing solder paste of a first solder composition into the retentive through hole; inserting the retentive pin into the retentive through hole; and reflowing the solder paste such that at least some of the precious metal originally associated with the retentive pin migrates into the solder paste to create a mixed solder composition.
  • a method for mounting electrical components on opposing sides of a substrate comprises the steps of: providing a substrate including first and second sides and first and second retentive through holes; providing a first electrical component including a first retentive pin extending therefrom, wherein the first retentive pin has a diameter smaller than that of the first retentive through hole, and has plating material thereon; disposing solder paste of a first solder composition into said first retentive through hole; juxtaposing the first electrical component on the first side of the substrate, and inserting the first retentive pin into the first retentive through hole; heating the substrate such that at least a portion of the plating material migrates from the first retentive pin into the solder paste, wherein a mixed solder composition is created which has a higher melting point than that of said first solder composition; disposing solder paste of the first solder composition into the second retentive through hole; providing a second electrical component
  • an electronic assembly comprising a circuit board including a retentive through hole having a wall; an electrical component including a housing and retentive pin extending therefrom mounted on the circuit board, wherein the retentive pin is disposed within said retentive through hole and has a diameter less than that of the retentive through hole; and reflowed solder disposed in the retentive through hole and surrounding at least a portion of the retentive pin, wherein the reflowed solder includes material originally associated with at least one of the retentive pin and the retentive through hole wall, and wherein the reflowed solder has a melting point greater than a melting point of pure solder.
  • an electronic assembly comprising a circuit board including a retentive through hole; an electrical component including a housing and retentive pin extending therefrom mounted on the circuit board, wherein the retentive pin is disposed within the retentive through hole and has a diameter less than that of the retentive through hole; and reflowed solder disposed in the retentive through hole and surrounding the retentive pin, wherein at least about 0.5 % by weight of said reflowed solder is an additive comprising a precious metal.
  • an electronic assembly comprising a circuit board including a retentive through hole; an electrical component including a housing and retentive pin extending therefrom mounted on the circuit board, wherein the retentive pin is disposed within the retentive through hole, has a diameter less than that of the retentive through hole, and has plating material thereon; and reflowed solder disposed in the retentive through hole and surrounding the retentive pin, wherein the reflowed solder comprises at least about 0.5 % by weight of the plating material that has migrated from the retentive pin.
  • Figure 1 is a perspective view of an electronic component designed and configured for surface mounting to a substrate.
  • Figure 2 is a plan view of a circuit board including surface mounting lands.
  • Figure 3 is a partial side view of an electronic assembly embodiment provided by the present invention showing an electronic connector mounted to a circuit board including ball grid array interconnections
  • Figure 4 is a partial perspective view of an electronic assembly embodiment provided by the present invention showing an electronic connector mounted to a circuit board including ball grid array interconnections and retentive pins disposed in solder-filled through holes.
  • Figure 5 is a partial cross-sectional view of an electronic component retentive pin disposed in a substrate retentive through hole with solder surrounding the retentive pin.
  • Figure 6 is a partial perspective view of an electronic assembly embodiment provided by the present invention including electronic components surface mounted to both sides of a circuit board.
  • an electrical component 10 in the form of a connector including housing 20, an array of solder balls 21 extending from a housing lower surface 22, and retentive pins 25 extending from housing lower surface 22 and spaced apart from solder balls 21.
  • Each of solder balls 21 is coupled to an end of one of a plurality of conventional terminals (not shown) that reside within housing 20. Opposing ends of the terminals can be engaged by an electrical component, such as, for example, an integrated chip or mating electrical connector.
  • Electrical connector 10 is suitable for surface mounting to a substrate, such as the printed circuit board 40 shown in Figure 2.
  • Printed circuit board 40 includes a first side 42, an array of lands or pads 41 disposed on side 42 that correspond to the array of solder balls 21, and retentive through holes 45 that are designed and configured to accept retentive pins 25.
  • solder paste 50 is first applied to lands or pads 41, and in and/or around retentive through holes 45. Numerous techniques readily understood by one skilled in the art, such as, for example screen-printing, screening or masking, may be used to apply the solder paste.
  • Solder paste 50 is preferably a eutectic alloy of tin and lead having a melting point of approximately 183 degrees Celsius. Electrical connector 10 is placed in juxtaposition with board 40, with individual solder balls 21 roughly aligned with corresponding individual lands or pads 41 by inserting retentive pins 25 into the solder containing retentive through holes 45. The board/component assembly is then reflowed (subjected to a thermal cycle) preferably in a stationary or belt type furnace that employs convection or radiation heat sources. The solder reflow may be performed in an environment selected from a group comprising dry nitrogen, forming gas or hydrogen.
  • the reflow process typically includes a thermal cycle that subjects the board-component assembly to a peak temperature (or temperature at or above the melting point of the solder paste) for a time period between 15 and 150 seconds.
  • the reflow process is conventional and well documented in the literature.
  • retentive pins 25 preferably have a diameter 26 that is smaller than the diameter 46 of the retentive through holes, such that the component being surface mounted to the board is allowed to float.
  • the pin diameters 26 may be approximately 0.9 mm and the corresponding through hole diameters 46 approximately 1.1 mm; although the specific diameters and difference between the two diameters may be greater or smaller than this. This configuration promotes self-aligning of balls 21 with lands 41, and results in a low stress solder joint.
  • the present invention provides method embodiments to improve the retention of mounted electrical components employing retentive pins having diameters less than the through hole diameters, by altering the solder composition within the retentive through holes 45 during or after the initial component mounting.
  • retentive pins 25 are plated with materials including precious metals such as gold, palladium, platinum, silver, rhodium, iridium, osmium, ruthenium, and rhenium.
  • the precious plating material migrates from retentive pins 25 and into solder paste 50 residing within retentive through holes 45, thereby creating a mixed solder composition that includes an additive made up of the plating material. Due to the presence of the additive, the melting point of the mixed solder composition is higher than the melting point of the original solder composition (i.e., melting point of pure solder). The melting point of the mixed solder composition should now preferably be at least 10 degrees Celsius higher than the melting point of the original (or first) composition. Accordingly, the board assembly may be further processed to a temperature at or above the melting point of the first solder composition and below the melting point of the mixed solder composition without concern that the mounted electrical component will become separated from the board.
  • a wall 47 (see Figure 5) of retentive through holes 45 may be plated with material that will migrate into the solder paste during or after an initial reflow process.
  • both the through hole walls 47 and the retentive pins 25 may be plated with similar or dissimilar materials for migration into the solder paste.
  • the migrated material may also originate from a base composition of the retentive pins and through hole walls, rather than from plating material overlying a similar base composition.
  • retentive pins 25 are the sole source of the migrating material.
  • retentive pins 25 are made from a lead-brass alloy base material, with a first plating layer of nickel at a thickness of from about 0.00127 to about 0.00635 mm, and a second plating layer of gold or palladium at a similar thickness.
  • a preferred method embodiment for mounting electrical components on opposing sides of a circuit board begins with a step of applying solder paste 50 to lands 41 and in and around retentive through holes 45 on side 42 of board 40.
  • the solder composition at this point preferably consists essentially of tin and lead.
  • first electrical component 10 is movably coupled to side 42 by inserting retentive pins 25 comprising a gold or palladium plating into the solder containing through holes 45.
  • Board 40 is then subjected to a first thermal cycle including a peak temperature of about 183 degrees Celsius to reflow solder paste 50.
  • the gold or palladium plating migrates from retentive pins 25 and into solder paste 50 residing within through holes 45.
  • the solder composition within through holes 45 now comprises tin, lead, and gold or palladium, and has a melting point higher than 183 degrees Celsius.
  • the amount of gold or palladium present in the reflowed solder will typically vary, with higher concentrations proximate retentive pins 25.
  • the gold or palladium (or other plating material) is present in the reflowed solder in an amount of at least about 0.5 % by weight.
  • board 40 is flipped and side 43 is prepared for mounting a second electrical component thereon.
  • solder paste 50 composition consisting essential of tin and lead
  • solder paste 50 composition used for mounting the electrical component 10 on board side 42 is now applied to lands 141 and in and around retentive holes 145 located on board side 43.
  • a second electrical component 110 (similar or dissimilar to component 10) comprising an array of solder balls 121 and retentive pins 125 is movably coupled to board 40 in a similar fashion to that of component 10.
  • Board 40 is subjected to a second thermal cycle including a peak temperature of about 183 degrees Celsius to reflow solder paste 50.
  • Retentive pins on the second electrical component 110 may or may not include materials that will migrate into the solder paste residing in retentive though holes 145.
  • a cost savings, via materials and processing, may be realized by not including a plating material on the retentive pins (or on the walls of through holes 145) extending from electrical component 110.
  • retentive pins on electrical component 110 are made with a material comprising a precious metal, then migration will likely occur during the second thermal cycle.
  • Table 1 includes parameters of two preferred embodiments along with the calculated solder compositional change after a first thermal cycle.
  • Un-plated retentive pins having a diameter of 0.90 mm were plated with gold or palladium at a thickness of approximately 0.0051 mm.
  • a eutectic tin-lead solder paste was applied in and around retentive holes extending through a board.
  • the retentive through holes had a diameter of 1.10 mm.
  • the plated retentive pins were inserted into the retentive through holes and the board subjected to a thermal cycle sufficient to reflow the solder paste.
  • the plating material diffuses all the way through the solder disposed within the retentive through holes. That is, the plating material presence in the solder is not isolated to the solder region nearest to the material source (retentive pin).
  • Table 2 illustrates that gold diffuses more effectively than palladium through the tin-lead solder once the material is leached off of the retentive pins.

Abstract

Methods for mounting electrical components (10, 20) on a substrate (40) and securely retaining the components (10, 20) are described. The methods include altering solder paste compositions (50), interposed between component retentive pins (25) and retentive through holes (46), during a reflow process. Electronic assemblies including circuit boards (40) and electrical components (10) mounted thereto are also described. In one of the electronic assembly embodiments (10, 20), materials originally associated with a mounted electrical component (10, 20) migrate in solder paste coupling the electrical components (10, 20) to the circuit board (40).

Description

SURFACE MOUNTED ELECTRICAL COMPONENTS AND METHOD FOR MOUNTING AND STAINING SAME
FIELD OF THE INVENTION
, The present invention relates to surface mounted electrical components having improved retentive properties, and methods for mounting and retaining electrical components on substrates.
BACKGROUND OF THE INVENTION
Various methods of electrically connecting components such as connectors and integrated circuit devices to printed boards are well known in the art. Surface mount technology is increasingly being employed as cost-effective method. Examples of surface mount technology include pin grid arrays (PGA's), ball grid arrays (BGA's), column grid arrays (CGA's), and land grid array (LGA's). Generally with such methods, a solder paste is introduced between surfaces to be joined, the solder paste reflowed, and then cooled to form a mechanical and electrically conductive joint.
As the name implies, ball grid arrays (BGA's) utilize a grid or array of solder bumps or balls arranged on one side of an electrical component to effectuate electrical and mechanical connection with a printed board. The ball attachment sites are typically referred to as lands or pads. Solder past is disposed on the lands (and/or on the balls), such as through screening or masking techniques, and the electrical component is then positioned on the board so that the balls and lands are registered. The board is then processed at an elevated temperature sufficient to cause the solder and at least a portion or all of the solder ball to flow and fuse with the underlying land/pad to form the electrical interconnection. See, for example, U.S. Pat. No. 6,325,644 assigned to the assignee of this patent, and patents within that patent, all of which is incorporated by reference herein.
Locator pins extending from the electrical component may be employed to facilitate the initial alignment of the electrical component. The locator pins are inserted into through holes located in the board at locations along the periphery of the array of lands/pads. Pin diameters may be slightly larger than the corresponding through hole diameters so that an interference fit is achieved. Alternatively, the pin diameters may be smaller than the through hole diameters. In this scenario, adhesive or solder paste may be applied in and around the through holes to help retain the electrical component on the substrate.
By selecting locator pins with a relatively smaller diameter and applying solder within the through holes, the BGA balls are allowed to float (that is, not rigidly restricted) during a reflow process resulting in self-alignment and ultimately a low stress solder joint. Component retention however may be compromised with this configuration when the board is manipulated before the reflow heat is substantially dissipated, or when the board is rotated so that additional electrical components can be mounted on other available surface areas with subsequent reflow steps.
Accordingly, there is a need for a method of mounting electrical components on a substrate that provides for a low stress solder joint while effectively retaining the mounted components during ensuing double-sided handling and/or processing during a second reflow step.
SUMMARY OF THE INVENTION
Methods for mounting electrical components on substrates are provided by the present invention. In accordance with a first preferred embodiment of the present invention, there has now been provided a method for mounting and retaining an electrical component on a substrate that is subjected to at least two thermal cycles. The method comprises the steps of: disposing solder paste of a first solder composition into a retentive through hole of the substrate; inserting a retentive pin extending from the electrical component and having a relatively smaller diameter into the retentive through hole; subjecting the substrate to a first thermal cycle such that material associated with at least one of the retentive through hole and retentive pin migrates into the solder paste to create a mixed solder composition that has a higher melting point than the first solder composition; and then subjecting the substrate to a second thermal cycle having a peak temperature less than the melting point of said mixed solder composition.
In accordance with another preferred embodiment of the present invention, there has now been provided a method for making an electronic assembly. The method comprises the steps of: providing a circuit board including a retentive through hole having a wall; providing an electrical connector having a retentive pin extending therefrom, wherein the retentive pin has a diameter smaller than the retentive through hole and is made from a material comprising a precious metal; disposing solder paste of a first solder composition into the retentive through hole; inserting the retentive pin into the retentive through hole; and reflowing the solder paste such that at least some of the precious metal originally associated with the retentive pin migrates into the solder paste to create a mixed solder composition.
In accordance with yet another preferred embodiment of the present invention, there has now been provided a method for mounting electrical components on opposing sides of a substrate. The method comprises the steps of: providing a substrate including first and second sides and first and second retentive through holes; providing a first electrical component including a first retentive pin extending therefrom, wherein the first retentive pin has a diameter smaller than that of the first retentive through hole, and has plating material thereon; disposing solder paste of a first solder composition into said first retentive through hole; juxtaposing the first electrical component on the first side of the substrate, and inserting the first retentive pin into the first retentive through hole; heating the substrate such that at least a portion of the plating material migrates from the first retentive pin into the solder paste, wherein a mixed solder composition is created which has a higher melting point than that of said first solder composition; disposing solder paste of the first solder composition into the second retentive through hole; providing a second electrical component including a second retentive pin extending therefrom, wherein the second retentive pin has a diameter smaller than that of the second retentive through hole; juxtaposing the second electrical component on the second side of the substrate, and inserting the second retentive pin into the second retentive through hole; and heating the substrate to a temperature sufficient to reflow the first solder composition and below the melting point of the mixed solder composition.
Electronic assemblies are also provided by the present invention. In accordance with a preferred embodiment of the present invention, there has now been provided an electronic assembly comprising a circuit board including a retentive through hole having a wall; an electrical component including a housing and retentive pin extending therefrom mounted on the circuit board, wherein the retentive pin is disposed within said retentive through hole and has a diameter less than that of the retentive through hole; and reflowed solder disposed in the retentive through hole and surrounding at least a portion of the retentive pin, wherein the reflowed solder includes material originally associated with at least one of the retentive pin and the retentive through hole wall, and wherein the reflowed solder has a melting point greater than a melting point of pure solder.
In accordance with another preferred embodiment of the present invention, there has now been provided an electronic assembly comprising a circuit board including a retentive through hole; an electrical component including a housing and retentive pin extending therefrom mounted on the circuit board, wherein the retentive pin is disposed within the retentive through hole and has a diameter less than that of the retentive through hole; and reflowed solder disposed in the retentive through hole and surrounding the retentive pin, wherein at least about 0.5 % by weight of said reflowed solder is an additive comprising a precious metal.
In accordance with yet another preferred embodiment of the present invention, there has now been provided an electronic assembly comprising a circuit board including a retentive through hole; an electrical component including a housing and retentive pin extending therefrom mounted on the circuit board, wherein the retentive pin is disposed within the retentive through hole, has a diameter less than that of the retentive through hole, and has plating material thereon; and reflowed solder disposed in the retentive through hole and surrounding the retentive pin, wherein the reflowed solder comprises at least about 0.5 % by weight of the plating material that has migrated from the retentive pin.
These and various other features of novelty, and their respective advantages, are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of aspects of the invention, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of an electronic component designed and configured for surface mounting to a substrate. Figure 2 is a plan view of a circuit board including surface mounting lands.
Figure 3 is a partial side view of an electronic assembly embodiment provided by the present invention showing an electronic connector mounted to a circuit board including ball grid array interconnections
Figure 4 is a partial perspective view of an electronic assembly embodiment provided by the present invention showing an electronic connector mounted to a circuit board including ball grid array interconnections and retentive pins disposed in solder-filled through holes.
Figure 5 is a partial cross-sectional view of an electronic component retentive pin disposed in a substrate retentive through hole with solder surrounding the retentive pin.
Figure 6 is a partial perspective view of an electronic assembly embodiment provided by the present invention including electronic components surface mounted to both sides of a circuit board.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention are directed to surface mounted electrical components having improved retentive properties and methods for making the same. Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to Figure 1, an electrical component 10 in the form of a connector is shown including housing 20, an array of solder balls 21 extending from a housing lower surface 22, and retentive pins 25 extending from housing lower surface 22 and spaced apart from solder balls 21. Each of solder balls 21 is coupled to an end of one of a plurality of conventional terminals (not shown) that reside within housing 20. Opposing ends of the terminals can be engaged by an electrical component, such as, for example, an integrated chip or mating electrical connector.
Electrical connector 10 is suitable for surface mounting to a substrate, such as the printed circuit board 40 shown in Figure 2. Printed circuit board 40 includes a first side 42, an array of lands or pads 41 disposed on side 42 that correspond to the array of solder balls 21, and retentive through holes 45 that are designed and configured to accept retentive pins 25. Referring to Figures 3 and 4, to mount electrical connector 10 to circuit board 40, solder paste 50 is first applied to lands or pads 41, and in and/or around retentive through holes 45. Numerous techniques readily understood by one skilled in the art, such as, for example screen-printing, screening or masking, may be used to apply the solder paste. Solder paste 50 is preferably a eutectic alloy of tin and lead having a melting point of approximately 183 degrees Celsius. Electrical connector 10 is placed in juxtaposition with board 40, with individual solder balls 21 roughly aligned with corresponding individual lands or pads 41 by inserting retentive pins 25 into the solder containing retentive through holes 45. The board/component assembly is then reflowed (subjected to a thermal cycle) preferably in a stationary or belt type furnace that employs convection or radiation heat sources. The solder reflow may be performed in an environment selected from a group comprising dry nitrogen, forming gas or hydrogen. The reflow process typically includes a thermal cycle that subjects the board-component assembly to a peak temperature (or temperature at or above the melting point of the solder paste) for a time period between 15 and 150 seconds. The reflow process is conventional and well documented in the literature.
Referring now to Figure 5, retentive pins 25 preferably have a diameter 26 that is smaller than the diameter 46 of the retentive through holes, such that the component being surface mounted to the board is allowed to float. For example, the pin diameters 26 may be approximately 0.9 mm and the corresponding through hole diameters 46 approximately 1.1 mm; although the specific diameters and difference between the two diameters may be greater or smaller than this. This configuration promotes self-aligning of balls 21 with lands 41, and results in a low stress solder joint.
After mounting the electrical connector 10 to board 40 (as can be seen in Figure 2), it may be desirable to further process the board/component assembly at temperatures above the melting point of solder paste 50 without affecting solder bonds previously formed. The present invention provides method embodiments to improve the retention of mounted electrical components employing retentive pins having diameters less than the through hole diameters, by altering the solder composition within the retentive through holes 45 during or after the initial component mounting. To alter the solder composition, retentive pins 25 are plated with materials including precious metals such as gold, palladium, platinum, silver, rhodium, iridium, osmium, ruthenium, and rhenium. During the first reflow (or shortly thereafter), at least a portion of the precious plating material migrates from retentive pins 25 and into solder paste 50 residing within retentive through holes 45, thereby creating a mixed solder composition that includes an additive made up of the plating material. Due to the presence of the additive, the melting point of the mixed solder composition is higher than the melting point of the original solder composition (i.e., melting point of pure solder). The melting point of the mixed solder composition should now preferably be at least 10 degrees Celsius higher than the melting point of the original (or first) composition. Accordingly, the board assembly may be further processed to a temperature at or above the melting point of the first solder composition and below the melting point of the mixed solder composition without concern that the mounted electrical component will become separated from the board.
In alternative embodiments, a wall 47 (see Figure 5) of retentive through holes 45 may be plated with material that will migrate into the solder paste during or after an initial reflow process. Or both the through hole walls 47 and the retentive pins 25 may be plated with similar or dissimilar materials for migration into the solder paste. The migrated material may also originate from a base composition of the retentive pins and through hole walls, rather than from plating material overlying a similar base composition. Preferably, retentive pins 25 are the sole source of the migrating material. In preferred embodiments, retentive pins 25 are made from a lead-brass alloy base material, with a first plating layer of nickel at a thickness of from about 0.00127 to about 0.00635 mm, and a second plating layer of gold or palladium at a similar thickness.
One instance where two or more reflow steps (two thermal cycles) may occur is when electrical components are mounted on both sides 42 and 43 of circuit board 40. A preferred method embodiment for mounting electrical components on opposing sides of a circuit board begins with a step of applying solder paste 50 to lands 41 and in and around retentive through holes 45 on side 42 of board 40. The solder composition at this point preferably consists essentially of tin and lead. Referring again to Figure 4, first electrical component 10 is movably coupled to side 42 by inserting retentive pins 25 comprising a gold or palladium plating into the solder containing through holes 45. Board 40 is then subjected to a first thermal cycle including a peak temperature of about 183 degrees Celsius to reflow solder paste 50. During the first thermal cycle, at least a portion of the gold or palladium plating migrates from retentive pins 25 and into solder paste 50 residing within through holes 45. The solder composition within through holes 45 now comprises tin, lead, and gold or palladium, and has a melting point higher than 183 degrees Celsius. The amount of gold or palladium present in the reflowed solder will typically vary, with higher concentrations proximate retentive pins 25. In preferred embodiments, the gold or palladium (or other plating material) is present in the reflowed solder in an amount of at least about 0.5 % by weight.
Referring now to Figure 6, board 40 is flipped and side 43 is prepared for mounting a second electrical component thereon. The same solder paste 50 composition (consisting essential of tin and lead) used for mounting the electrical component 10 on board side 42 is now applied to lands 141 and in and around retentive holes 145 located on board side 43. A second electrical component 110 (similar or dissimilar to component 10) comprising an array of solder balls 121 and retentive pins 125 is movably coupled to board 40 in a similar fashion to that of component 10. Board 40 is subjected to a second thermal cycle including a peak temperature of about 183 degrees Celsius to reflow solder paste 50. During the second thermal cycle, reflowed solder in retentive through holes 45 does not melt, and therefore, first electrical component 10 is securely held on board 40. Retentive pins on the second electrical component 110 may or may not include materials that will migrate into the solder paste residing in retentive though holes 145. A cost savings, via materials and processing, may be realized by not including a plating material on the retentive pins (or on the walls of through holes 145) extending from electrical component 110. Obviously, if retentive pins on electrical component 110 are made with a material comprising a precious metal, then migration will likely occur during the second thermal cycle. EXAMPLES Example 1:
Table 1 includes parameters of two preferred embodiments along with the calculated solder compositional change after a first thermal cycle.
Table 1
Figure imgf000011_0001
Example 2:
Un-plated retentive pins having a diameter of 0.90 mm were plated with gold or palladium at a thickness of approximately 0.0051 mm. A eutectic tin-lead solder paste was applied in and around retentive holes extending through a board. The retentive through holes had a diameter of 1.10 mm. The plated retentive pins were inserted into the retentive through holes and the board subjected to a thermal cycle sufficient to reflow the solder paste. Samples of the altered solder were taken at three positions, as shown in Figure 5: 1) proximate the retentive pin - PI; 2) proximate the wall of the retentive through hole- P3; and 3) an intermediate position - P2. The solder samples were analyzed via mass spectrometry. Table 2 shows the amount of plating material (% by weight) present in the solder after completing the thermal cycle. Table 2
Figure imgf000012_0001
As can be seen in Table 2, the plating material diffuses all the way through the solder disposed within the retentive through holes. That is, the plating material presence in the solder is not isolated to the solder region nearest to the material source (retentive pin). In addition, Table 2 illustrates that gold diffuses more effectively than palladium through the tin-lead solder once the material is leached off of the retentive pins.
It is to be understood that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure, manufacture of, and function of the invention, the disclosure is illustrative only. Accordingly, changes may be made in detail, especially in matters of shape, size and arrangement of structural features, as well as, sequences of manufacturing steps, within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims

What is claimed is:
1. A method for mounting and retaining an electrical component on a substrate that is subjected to at least two thermal cycles, the method comprising the steps of: a) providing a substrate including a retentive through hole having a wall; b) providing an electrical component having a retentive pin extending therefrom, said retentive pin having a diameter smaller than that of said retentive through hole; c) disposing solder paste of a first solder composition into said retentive through hole; d) inserting said retentive pin into said retentive through hole; e) subjecting said substrate to a first thermal cycle such that material associated with at least one of said retentive through hole wall and said retentive pin migrates into said solder paste to create a mixed solder composition which has a higher melting point than that of said first solder composition; f) subjecting said substrate to a second thermal cycle having a peak temperature less than the melting point of said mixed solder composition, whereby said retentive pin remains securely held in said retentive through hole.
2. The method of claim 1 , wherein the migrated material was originally plating material disposed on said retentive pin.
3. The method of claim 2, wherein the plating material comprises palladium.
4. The method of claim 2, wherein the plating material comprises gold.
5. The method of claim 1, wherein the migrated material was originally plating material disposed on said retentive through hole wall.
6. The method of claim 1 , wherein the migrated material includes plating material originally disposed on both of said retentive through hole wall and said retentive pin.
7. The method of claim 1, wherein the migrated material is present in an amount of at least about 0.5 % by weight at a solder location proximate said retentive through hole wall.
8. A method for making an electronic assembly, comprising the steps of: a) providing a circuit board including a retentive through hole having a wall; b) providing an electrical connector having a retentive pin extending therefrom, said retentive pin having a diameter smaller than that of said retentive through hole and being made from a material comprising a precious metal; c) disposing solder paste of a first solder composition into said retentive through hole; d) inserting said retentive pin into said retentive through hole; and e) reflowing said solder paste such that at least some of the precious metal originally associated with said retentive pin migrates into said solder paste to create a mixed solder composition.
9. The method of claim 8, wherein said mixed solder composition has a melting point that is at least about 10 degrees higher than that of said first solder composition.
10. The method of claim 8, wherein said first solder composition consists essentially of tin and lead.
11. The method of claim 8, wherein said precious metal is gold.
12. The method of claim 8, wherein said precious metal is palladium.
13. The method of claim 8, wherein the migrated material is distributed in a gradient in said mixed solder composition.
14. The method of claim 8, wherein said mixed solder composition at solder locations proximate said retentive through hole wall includes at least about 0.5 % by weight of migrated material.
15. The method of claim 8, wherein said mixed solder composition at solder locations proximate said retentive pin includes at least about 15 % by weight of migrated material.
16. A method for mounting electrical components on opposing sides of a substrate, the method comprising the steps of: a) providing a substrate including first and second sides and first and second retentive through holes; b) providing a first electrical component including a first retentive pin extending therefrom, said first retentive pin having a diameter smaller than that of said first retentive through hole, and having plating material thereon; c) disposing solder paste of a first solder composition into said first retentive through hole; d) juxtaposing said first electrical component on said first side of said substrate, and inserting said first retentive pin into said first retentive through hole; e) heating said substrate such that at least a portion of said plating material migrates from said first retentive pin into said solder paste, wherein a mixed solder composition is created which has a higher melting point than that of said first solder composition; f) disposing solder paste of said first solder composition into said second retentive through hole; g) providing a second electrical component including a second retentive pin extending therefrom, said second retentive pin having a diameter smaller than that of said second retentive through hole; h) juxtaposing said second electrical component on said second side of said substrate, and inserting said second retentive pin into said second retentive through hole; and i) heating said substrate to a temperature sufficient to reflow said first solder composition and below the melting point of said mixed solder composition.
17. The method of claim 16, wherein said first solder composition melting point is about 180 degrees Celsius.
18. The method of claim 16, wherein said mixed solder composition melting point is about 225 degrees Celsius.
19. The method of claim 16, wherein at least about 40% by volume of said plating material migrates from said retentive pins into said solder paste.
20. The method of claim 16, wherein said plating material comprises palladium.
21. The method of claim 16, wherein said plating material comprises gold.
22. The method of claim 16, wherein said second retentive pin is void of plating material.
23. An electronic assembly comprising: a circuit substrate including a retentive through hole having a wall; an electrical component including a housing and retentive pin extending therefrom mounted on said circuit substrate, wherein said retentive pin is disposed within said retentive through hole and has a diameter less than that of said retentive through hole; and a mixed solder composition in said retentive through hole and surrounding at least a portion of said retentive pin, said mixed solder composition including material originally associated with at least one of said retentive pin and said retentive through hole wall that migrated during a reflow process into a first solder composition disposed in said retentive through hole, wherein the mixed solder composition has a melting point greater than a melting point of said first solder composition.
24. The electronic assembly of claim 23, wherein the melting point of said mixed solder composition is greater than the melting point of said first solder composition by about 10 degrees Celsius.
25. The electronic assembly of claim 23, wherein said mixed solder composition at locations proximate said retentive pin includes at least about 10 % by weight of the material originally associated with at least one of said retentive pin and said retentive through hole wall.
26. The electronic assembly of claim 23, wherein said mixed solder composition at locations proximate said through hole wall includes at least about 0.5 % by weight of material originally associated with at least one of said retentive pin and said retentive through hole wall.
27. The electronic assembly of claim 23, wherein the material originally associated with at least one of said retentive pin and said retentive through hole wall was originally associated solely with said retentive pin.
28. The electronic assembly of claim 23, wherein the material originally associated with at least one of said retentive pin and said retentive through hole wall was originally associated with said through hole wall.
29. An electronic assembly comprising: a circuit substrate including a retentive through hole; an electrical component including a housing and retentive pin extending therefrom mounted on said circuit substrate, wherein said retentive pin is disposed within said retentive through hole and has a diameter less than that of said retentive through hole; and reflowed solder disposed in said retentive through hole and surrounding said retentive pin, wherein at least about 0.5 % by weight of said reflowed solder is an additive comprising a precious metal.
30. The electronic assembly of claim 29, wherein said precious metal is gold.
31. The electronic assembly of claim 29, wherein said precious metal is palladium.
32. An electronic assembly comprising: a circuit substrate including a retentive through hole; an electrical component including a housing and retentive pin extending therefrom mounted on said circuit substrate, wherein said retentive pin is disposed within said retentive through hole, has a diameter less than that of said retentive through hole, and has plating material thereon; and a mixed solder composition disposed in said retentive through hole and surrounding said retentive pin, wherein said mixed solder composition comprises at least about 0.5 % by weight of said plating material that has migrated from said retentive pin during a reflow process into a first solder composition disposed in said retentive through hole which comprised less than about 0.5% by weight of said plating material.
33. An electronic assembly comprising:
a circuit substrate including a retentive hole;
an electrical component mounted on said circuit substrate, said electrical component including a housing and a retentive structure extending therefrom, said retentive structure is disposed within said retentive hole; and
a mixed solder composition disposed in said retentive hole and surrounding said retentive structure, wherein said mixed solder composition comprises at least about 0.5% by weight of plating material that has migrated from at least one of said retentive hole and said retentive structure during a reflow process into a first solder composition disposed in said retentive through hole which comprised less than about 0.5% by weight of said plating material.
34. An electrical connector, comprising:
a housing;
a plurality of solder masses extending from a surface of said housing; and
at least one retentive structure for engaging a circuit substrate, said at least one retentive structure extending from said surface of said housing and being spaced apart from each of said plurality of solder balls, and being plated with a material which includes a precious metal.
PCT/US2003/030444 2002-09-26 2003-09-25 Surface mounted electrical components and method for mounting an d retaining same WO2004030099A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2003276991A AU2003276991A1 (en) 2002-09-26 2003-09-25 Surface mounted electrical components and method for mounting an d retaining same

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10/255,312 US6791845B2 (en) 2002-09-26 2002-09-26 Surface mounted electrical components
US10/255,312 2002-09-26

Publications (1)

Publication Number Publication Date
WO2004030099A1 true WO2004030099A1 (en) 2004-04-08

Family

ID=32029090

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2003/030444 WO2004030099A1 (en) 2002-09-26 2003-09-25 Surface mounted electrical components and method for mounting an d retaining same

Country Status (5)

Country Link
US (3) US6791845B2 (en)
CN (1) CN100394600C (en)
AU (1) AU2003276991A1 (en)
TW (1) TWI247561B (en)
WO (1) WO2004030099A1 (en)

Families Citing this family (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6791845B2 (en) * 2002-09-26 2004-09-14 Fci Americas Technology, Inc. Surface mounted electrical components
US20040198082A1 (en) * 2003-04-07 2004-10-07 Victor Zaderej Method of making an electrical connector
EP1643818A4 (en) * 2003-07-03 2006-08-16 Hitachi Ltd Module and method for fabricating the same
US7167375B2 (en) * 2004-01-16 2007-01-23 Motorola, Inc. Populated printed wiring board and method of manufacture
US7005742B2 (en) * 2004-02-05 2006-02-28 Texas Instruments Incorporated Socket grid array
JP2006339316A (en) * 2005-05-31 2006-12-14 Toshiba Corp Semiconductor device, mounting substrate therefor, and mounting method thereof
JP4995527B2 (en) * 2006-09-28 2012-08-08 日本電波工業株式会社 Piezoelectric oscillator for surface mounting
KR20090067249A (en) * 2007-12-21 2009-06-25 삼성전기주식회사 Printed circuit board and manufacturing method thereof
CN101568224B (en) * 2008-04-22 2012-01-25 鸿富锦精密工业(深圳)有限公司 Circuit board and electronic device having circuit board
DE102008041497A1 (en) * 2008-08-25 2010-03-04 Robert Bosch Gmbh Component with a mechanical contact and method for producing the component
CN102137549B (en) * 2010-01-26 2013-01-16 英业达股份有限公司 Electronic component layout method of circuit board with adhesive surfaces on both sides
US8210424B2 (en) * 2010-09-16 2012-07-03 Hewlett-Packard Development Company, L.P. Soldering entities to a monolithic metallic sheet
JP6236915B2 (en) * 2013-06-25 2017-11-29 富士電機株式会社 Soldering method and semiconductor device manufacturing method
US9564697B2 (en) * 2014-11-13 2017-02-07 Lear Corporation Press fit electrical terminal having a solder tab shorter than PCB thickness and method of using same
WO2016115205A1 (en) * 2015-01-15 2016-07-21 Fci Asia Pte. Ltd Separator for electrical assembly
DE102015214807A1 (en) * 2015-08-04 2017-02-09 Continental Automotive Gmbh PCB with pin-in-paste (PIP) mounting
US9627784B1 (en) * 2015-12-01 2017-04-18 International Business Machines Corporation Method and apparatus for strain relieving surface mount attached connectors
US11387033B2 (en) 2016-11-18 2022-07-12 Hutchinson Technology Incorporated High-aspect ratio electroplated structures and anisotropic electroplating processes
US11521785B2 (en) * 2016-11-18 2022-12-06 Hutchinson Technology Incorporated High density coil design and process
CN108346952B (en) * 2018-01-25 2020-11-24 番禺得意精密电子工业有限公司 Electric connector holder
CN110396708A (en) * 2019-08-07 2019-11-01 东莞市合航精密科技有限公司 A kind of corrosion resistance coating of silver combined plating

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5086966A (en) * 1990-11-05 1992-02-11 Motorola Inc. Palladium-coated solder ball
US5751556A (en) * 1996-03-29 1998-05-12 Intel Corporation Method and apparatus for reducing warpage of an assembly substrate
US5893725A (en) * 1996-06-24 1999-04-13 Intel Corporation C4 substrate contact pad which has a layer of NI-B plating

Family Cites Families (62)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4217024A (en) 1977-11-07 1980-08-12 Burroughs Corporation Dip socket having preloading and antiwicking features
ZA826825B (en) 1981-10-02 1983-07-27 Int Computers Ltd Devices for mounting integrated circuit packages on a printed circuit board
CH650373A5 (en) 1982-07-16 1985-07-15 Jean Paul Strobel PRINTED CIRCUIT AND METHOD FOR MANUFACTURING THE CIRCUIT.
US4518112A (en) * 1982-12-30 1985-05-21 International Business Machines Corporation Process for controlled braze joining of electronic packaging elements
US4535955A (en) * 1983-03-31 1985-08-20 Morgan Construction Company Means for sensing an undesirable approach angle in a level wind coiler
US4647476A (en) 1984-03-05 1987-03-03 General Electric Company Insulating glass body with electrical feedthroughs and method of preparation
US4878611A (en) 1986-05-30 1989-11-07 American Telephone And Telegraph Company, At&T Bell Laboratories Process for controlling solder joint geometry when surface mounting a leadless integrated circuit package on a substrate
US4767344A (en) 1986-08-22 1988-08-30 Burndy Corporation Solder mounting of electrical contacts
US5029748A (en) * 1987-07-10 1991-07-09 Amp Incorporated Solder preforms in a cast array
JPH0228990A (en) 1988-07-19 1990-01-31 Seiko Epson Corp Mounting system of semiconductor device
CA2034703A1 (en) 1990-01-23 1991-07-24 Masanori Nishiguchi Substrate for packaging a semiconductor device
US5102829A (en) 1991-07-22 1992-04-07 At&T Bell Laboratories Plastic pin grid array package
US5261593A (en) 1992-08-19 1993-11-16 Sheldahl, Inc. Direct application of unpackaged integrated circuit to flexible printed circuit
US5363280A (en) 1993-04-22 1994-11-08 International Business Machines Corporation Printed circuit board or card thermal mass design
US5810607A (en) 1995-09-13 1998-09-22 International Business Machines Corporation Interconnector with contact pads having enhanced durability
US5831828A (en) 1993-06-03 1998-11-03 International Business Machines Corporation Flexible circuit board and common heat spreader assembly
US5772451A (en) 1993-11-16 1998-06-30 Form Factor, Inc. Sockets for electronic components and methods of connecting to electronic components
US5490040A (en) 1993-12-22 1996-02-06 International Business Machines Corporation Surface mount chip package having an array of solder ball contacts arranged in a circle and conductive pin contacts arranged outside the circular array
JP3228841B2 (en) 1994-10-26 2001-11-12 松下電器産業株式会社 Shield device
EP0738456A1 (en) 1994-11-09 1996-10-23 Blaupunkt-Werke GmbH Method of producing a feedthrough on a circuit board
US5637008A (en) 1995-02-01 1997-06-10 Methode Electronics, Inc. Zero insertion force miniature grid array socket
US5743009A (en) 1995-04-07 1998-04-28 Hitachi, Ltd. Method of making multi-pin connector
FR2735648B1 (en) 1995-06-13 1997-07-11 Bull Sa COOLING METHOD OF AN INTEGRATED CIRCUIT MOUNTED IN A HOUSING
US5691041A (en) 1995-09-29 1997-11-25 International Business Machines Corporation Socket for semi-permanently connecting a solder ball grid array device using a dendrite interposer
US5638008A (en) * 1995-10-30 1997-06-10 Cypress Semiconductor Corp. Method and apparatus for generating an asynchronously clocked signal in a synchronously clocked programmable device
CH693478A5 (en) 1996-05-10 2003-08-15 E Tec Ag Contact socket for detachable connection of IC to PCB
WO1997044859A1 (en) 1996-05-24 1997-11-27 Tessera, Inc. Connectors for microelectronic elements
US5984726A (en) 1996-06-07 1999-11-16 Hon Hai Precision Ind. Co., Ltd. Shielded electrical connector
US5735452A (en) 1996-06-17 1998-04-07 International Business Machines Corporation Ball grid array by partitioned lamination process
US5755595A (en) 1996-06-27 1998-05-26 Whitaker Corporation Shielded electrical connector
TW354200U (en) 1996-07-18 1999-03-01 Hon Hai Prec Ind Co Ltd Fastener for connector
SG71046A1 (en) 1996-10-10 2000-03-21 Connector Systems Tech Nv High density connector and method of manufacture
US5729896A (en) 1996-10-31 1998-03-24 International Business Machines Corporation Method for attaching a flip chip on flexible circuit carrier using chip with metallic cap on solder
US5796590A (en) 1996-11-05 1998-08-18 Micron Electronics, Inc. Assembly aid for mounting packaged integrated circuit devices to printed circuit boards
KR100268460B1 (en) 1996-12-07 2000-10-16 윤종용 Positioning device of surface mount semiconductor IC
US6183301B1 (en) 1997-01-16 2001-02-06 Berg Technology, Inc. Surface mount connector with integrated PCB assembly
US5742484A (en) 1997-02-18 1998-04-21 Motorola, Inc. Flexible connector for circuit boards
US5883782A (en) 1997-03-05 1999-03-16 Intel Corporation Apparatus for attaching a heat sink to a PCB mounted semiconductor package
US5919050A (en) 1997-04-14 1999-07-06 International Business Machines Corporation Method and apparatus for separable interconnecting electronic components
US5874776A (en) 1997-04-21 1999-02-23 International Business Machines Corporation Thermal stress relieving substrate
US5938451A (en) 1997-05-06 1999-08-17 Gryphics, Inc. Electrical connector with multiple modes of compliance
US5870272A (en) * 1997-05-06 1999-02-09 Medtronic Inc. Capacitive filter feedthrough for implantable medical device
TW321372U (en) 1997-05-16 1997-11-21 Molex Taiwan Co Ltd Electrical connector to block the EMI (Electromagnetic Interference)
US5876219A (en) 1997-08-29 1999-03-02 The Whitaker Corp. Board-to-board connector assembly
US5955888A (en) 1997-09-10 1999-09-21 Xilinx, Inc. Apparatus and method for testing ball grid array packaged integrated circuits
TW361737U (en) 1997-11-24 1999-06-11 Hon Hai Prec Ind Co Ltd Power connector assembly
US5888884A (en) 1998-01-02 1999-03-30 General Electric Company Electronic device pad relocation, precision placement, and packaging in arrays
US6037044A (en) 1998-01-08 2000-03-14 International Business Machines Corporation Direct deposit thin film single/multi chip module
JP2000049438A (en) * 1998-07-28 2000-02-18 Nec Kofu Ltd Surface mount component drop preventive structure and prevention of dropping thereof
US6203690B1 (en) * 1998-09-29 2001-03-20 International Business Machines Corporation Process of reworking pin grid array chip carriers
TW465146B (en) 1999-02-02 2001-11-21 Hon Hai Prec Ind Co Ltd Thermal expansion adjustment method of plate-shaped electronic devices and the structure thereof
TW433624U (en) 1999-04-06 2001-05-01 Hon Hai Prec Ind Co Ltd Electrical connector
US6116926A (en) 1999-04-21 2000-09-12 Berg Technology, Inc. Connector for electrical isolation in a condensed area
US6174198B1 (en) 1999-04-21 2001-01-16 Hon Hai Precision Ind. Co., Ltd. Electrical connector assembly
US6527587B1 (en) 1999-04-29 2003-03-04 Fci Americas Technology, Inc. Header assembly for mounting to a circuit substrate and having ground shields therewithin
US6243272B1 (en) * 1999-06-18 2001-06-05 Intel Corporation Method and apparatus for interconnecting multiple devices on a circuit board
US6529385B1 (en) * 1999-08-25 2003-03-04 Intel Corporation Component array adapter
TW531948B (en) * 1999-10-19 2003-05-11 Fci Sa Electrical connector with strain relief
JP2003518759A (en) 1999-12-20 2003-06-10 シンクォール・インコーポレーテッド Terminal pin with flange for DC / DC converter
JP3473566B2 (en) * 2000-08-31 2003-12-08 イビデン株式会社 Pin-up type printed circuit board
US6644985B2 (en) * 2001-02-16 2003-11-11 Fci Americas Technology, Inc. Ball attached zero insertion force socket
US6791845B2 (en) 2002-09-26 2004-09-14 Fci Americas Technology, Inc. Surface mounted electrical components

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5086966A (en) * 1990-11-05 1992-02-11 Motorola Inc. Palladium-coated solder ball
US5751556A (en) * 1996-03-29 1998-05-12 Intel Corporation Method and apparatus for reducing warpage of an assembly substrate
US5893725A (en) * 1996-06-24 1999-04-13 Intel Corporation C4 substrate contact pad which has a layer of NI-B plating

Also Published As

Publication number Publication date
CN100394600C (en) 2008-06-11
TWI247561B (en) 2006-01-11
US6791845B2 (en) 2004-09-14
US7535723B2 (en) 2009-05-19
US20040237298A1 (en) 2004-12-02
TW200414843A (en) 2004-08-01
US20040062015A1 (en) 2004-04-01
CN1706042A (en) 2005-12-07
AU2003276991A1 (en) 2004-04-19
US20040121626A1 (en) 2004-06-24
US7249411B2 (en) 2007-07-31

Similar Documents

Publication Publication Date Title
US7249411B2 (en) Methods for mounting surface-mounted electrical components
US5861663A (en) Column grid array or ball grid array pad on via
US5326936A (en) Mounting device for mounting an electronic device on a substrate by the surface mounting technology
US6179631B1 (en) Electrical contact for a printed circuit board
US6300578B1 (en) Pad-on-via assembly technique
US5017738A (en) Connecting apparatus
US5844316A (en) Fixture for handling and attaching conductive spheres to a substrate
US6333563B1 (en) Electrical interconnection package and method thereof
CA2267293C (en) High density connector and method of manufacture
US6079991A (en) Method for placing contact on electrical connector
JP2590450B2 (en) Method of forming bump electrode
US5941449A (en) Method of making an electronic package having spacer elements
US7537498B2 (en) Solder-bearing contacts and method of manufacture thereof and use in connectors
JP2005512335A (en) Ball grid array package
JP2001297812A (en) Modular electrical connector
US6881906B2 (en) Printed circuit board comprising a contact sleeve that is mounted thereon
US6272741B1 (en) Hybrid solder ball and pin grid array circuit board interconnect system and method
US20040003496A1 (en) Interposer to couple a microelectronic device package to a circuit board
GB2325354A (en) Electrical connector or connection with concave ball-receiving site
US5868304A (en) Socketable bump grid array shaped-solder on copper spheres
US20020061687A1 (en) Solder bearing grid array
US6012225A (en) Method of making surface mount pads
US6404047B1 (en) Socketable BGA package
EP1441417A2 (en) High density connector and method of manufacture
CA2404792C (en) High density connector and method of manufacture

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 20038208369

Country of ref document: CN

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 69(1) EPC (EPO FORM 1205A DATED 04.07.05).

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP