WO2015119434A1

WO2015119434A1 - Light emitting diode (led) array and display device

Info

Publication number: WO2015119434A1
Application number: PCT/KR2015/001176
Authority: WO
Inventors: Kye Hoon Lee; Dae Kuen YANG; Nae Won Jang
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2014-02-06
Filing date: 2015-02-05
Publication date: 2015-08-13
Also published as: KR20150092924A

Abstract

Disclosed herein are a Light Emitting Diode (LED) array, and a display device. LED packages may be packaged based on Chip On Board (COB) technology to configure an LED array for a backlight unit. The LED array includes: a printed circuit board (PCB) having a length; a plurality of LED packages packaged in a plurality of rows along a longitudinal direction of the PCB; a partition wall formed between neighboring rows among the plurality of rows, in the longitudinal direction of the PCB; and a phosphor applied on each row to cover the row.

Description

LIGHT EMITTING DIODE (LED) ARRAY AND DISPLAY DEVICE

Embodiments of the present disclosure relate to a display device, and more particularly, to a display device with a backlight unit of a light emitting diode (LED) array.

A display device which is used in a monitor of a computer, a TeleVision (TV), or the like includes an Organic Light Emitting Display (OLED), a Vacuum Fluorescent Display (VFD), a Field Emission Display (FED), a Plasma Display Panel (PDP), and a Liquid Crystal Display (LCD), wherein the OLED, VFD, FED, and PDP can themselves emit light, and the LCD requires a light source since itself cannot emit light.

An LCD includes two substrates including field-generating electrodes, and a liquid crystal layer having dielectric anisotropy, interposed between the two substrates. The LCD displays a desired image by applying a voltage to the field-generating electrodes to form an electrical field in the liquid crystal layer, and changing the voltage to adjust the intensity of the electrical field and thus adjust transmittance of light passing through the liquid crystal layer.

The LCD includes a data driver to receive image data, to generate data signals of pixels, and to supply the data signals to the corresponding data lines of a liquid crystal panel, a gate driver to generate and supply gate signals such that the pixels of the liquid crystal panel are driven line by line, and a backlight unit disposed on the rear part of the liquid crystal panel and configured to provide light .

The backlight unit uses, as a light source, a Cold Cathode Fluorescent Lamp (CCFL), an External Electrode Fluorescent Lamp (EEFL), or an LED. Particularly, the LED is widely used as a light source for a backlight unit since it has advantages of high optical efficiency, slimming, and low consumption power.

As LEDs for a backlight unit, LED packages are generally used which produce white light by combining blue LED chips with yellow phosphors. The color of light that is emitted from the LED packages can be determined by chromaticity coordinates defined in the Commission International d'Eclairage (CIE).

A backlight unit with LED packages is manufactured generally using Surface Mount Technology (SMT). Since the SMT requires a lead frame structure, it needs a complicated configuration and many processing stages, which leads to an increase of manufacturing cost. Furthermore, since the SMT adds thermal resistance of a lead frame, the lifetime of the LED packages is reduced due to an excessive temperature increase of the LED packages.

Therefore, it is an aspect of the present disclosure to provide a Light Emitting Diode (LED) array for a backlight unit, in which LED packages are packaged based on Chip On Board (COB) technology.

Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure.

In accordance with one aspect of the present disclosure, a Light Emitting Diode (LED) array includes: a printed circuit board (PCB) having a length; a plurality of LED packages packaged in a plurality of rows along a longitudinal direction of the PCB; a partition wall formed between neighboring rows among the plurality of rows, in the longitudinal direction of the PCB; and a phosphor applied on each row to cover the row.

An LED chip of each LED package may be electrically connected to pads of the PCB through wires.

A rear surface of an LED chip of each LED package may be electrically connected to pads of the PCB.

The plurality of LED packages may be packaged based on Chip On Board (COB) technology on the PCB.

In accordance with another aspect of the present disclosure, a Light Emitting Diode (LED) array includes: a Printed Circuit Board (PCB) having a length; a plurality of LED packages packaged in a plurality of rows along a longitudinal direction of the PCB; and a plurality of phosphors having different colors and respectively applied on the plurality of rows, wherein the phosphors are individually applied on the plurality of LED packages.

The individually applying of the phosphors on the plurality of LED packages may include discontinuously applying the phosphors on and around the plurality of LED packages such that the phosphors individually cover the plurality of LED packages.

The individually applying of the phosphors on the plurality of LED packages may include coating the surfaces of the plurality of LED packages with the phosphors.

Upper surfaces of LED chips of the plurality of LED packages may be individually coated with the phosphors.

Rear surfaces of LED chips of the plurality of LED packages may be electrically connected to pads of the PCB.

In accordance with another aspect of the present disclosure, a Light Emitting Diode (LED) array includes: a Printed Circuit Board (PCB) having a length; a plurality of LED packages packaged in a row along a longitudinal direction of the PCB; and a plurality of phosphors having different colors and alternately applied on the plurality of LED packages packaged in the row.

The phosphors may be discontinuously applied on and around the plurality of LED packages such that the phosphors individually cover the plurality of LED packages.

The phosphors may be individually coated on the surfaces of the plurality of LED packages.

In accordance with another aspect of the present disclosure, a display device includes: a Light Emitting Diode (LED) array including a Printed Circuit Board (PCB) having a length, a plurality of LED packages packaged in a plurality of rows along a longitudinal direction of the PCB, a partition wall formed in the longitudinal direction of the PCB between neighboring rows among the plurality of rows, and a phosphor applied on each row to cover the row; a light guide panel configured to convert point light irradiated from each LED package into surface light; and a Liquid Crystal Display (LCD) panel configured to receive the surface light through the light guide panel, and to display an image.

In accordance with another aspect of the present disclosure, a display device includes: a Light Emitting Diode (LED) array including a Printed Circuit Board (PCB) having a length, a plurality of LED packages packaged in a plurality of rows along a longitudinal direction of the PCB, and a plurality of phosphors having different colors and respectively applied on the plurality of rows, wherein the phosphors are individually applied on the plurality of LED packages; a light guide panel configured to convert point light irradiated from each LED package into surface light; and a Liquid Crystal Display (LCD) panel configured to receive the surface light through the light guide panel, and to display an image.

In accordance with another aspect of the present disclosure, a display device includes: a Light Emitting Diode (LED) array including a Printed Circuit Board (PCB) having a length, a plurality of LED packages packaged in a row along a longitudinal direction of the PCB, and a plurality of phosphors having different colors and alternately applied on the plurality of LED packages packaged in the row; a light guide panel configured to convert point light irradiated from each LED package into surface light; and a Liquid Crystal Display (LCD) panel configured to receive the surface light through the light guide panel, and to display an image.

These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 illustrates a display device according to an embodiment of the present disclosure;

FIG. 2 is an exploded perspective view of the display device illustrated in FIG. 1;

FIG. 3 illustrates an arrangement state of Light Emitting Diode (LED) packages and a light guide panel;

FIG. 4 is a block diagram of a control system of a display device according to an embodiment of the present disclosure;

FIG. 5 illustrates a structure of LED packages according to an embodiment of the present disclosure;

FIG. 6 illustrates LED arrays according to various embodiments of the present disclosure;

FIG. 7 illustrates an LED array according to a first embodiment of the present disclosure;

FIG. 8 illustrates an LED array according to a second embodiment of the present disclosure;

FIG. 9 illustrates an LED array according to a third embodiment of the present disclosure;

FIG. 10 illustrates an LED array according to a fourth embodiment of the present disclosure;

FIG. 11 illustrates an LED array according to a fifth embodiment of the present disclosure;

FIG. 12 illustrates an LED array according to a sixth embodiment of the present disclosure;

FIG. 13 illustrates an LED array according to a seventh embodiment of the present disclosure;

FIG. 14 illustrates an LED array according to an eighth embodiment of the present disclosure;

FIG. 15 illustrates an LED array according to a ninth embodiment of the present disclosure; and

FIG. 16 illustrates an LED array according to a tenth embodiment of the present disclosure.

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

FIG. 1 illustrates a display device according to an embodiment of the present disclosure. As shown in FIG. 1, a display device 100 according to an embodiment of the present disclosure may be provided in which a display panel (for example, a Liquid Crystal Display (LCD) panel) is supported and protected by bezels 106. Below the bezels 106 may be provided stands 108 to support the display panel 102 vertically. Instead of the stands 108, a fixing unit to fix the display panel 102 on the wall may be provided.

FIG. 2 is an exploded perspective view of the display device 100 illustrated in FIG. 1. As shown in FIG. 2, the display device 100 may include an LCD panel 210 to display images, and a backlight unit 220 disposed on the rear part of the LCD panel 210 and configured to provide light to the LCD panel 210.

The LCD panel 210 may include a Thin Film Transistor (TFT) array substrate, a color filter substrate that faces the TFT array substrate and is bonded with the TFT array substrate in such a manner to maintain a uniform cell gap therebetween, and an LCD layer interposed between the TFT array substrate and the color filter substrate.

The backlight unit 220 may include a bottom cover 280 having a box shape whose upper side opens, a Printed Circuit Board (PCB) 251 disposed on a side of the bottom cover 280, a plurality of LED packages 252 mounted on the PCB 251, a light guide panel 260 aligned with the LED packages 252 and configured to convert point light into surface light, a plurality of optical sheets 230 disposed on the light guide panel 260 and configured to diffuse and concentrate light, and a reflection sheet 270 disposed below the light guide plate 260 and configured to reflect light passed through the light guide panel 260 toward the LCD panel 210. An LED array 250 may be configured by packaging the plurality of LED packages 252 on the PCB 251. According to an embodiment, the LED array 250 may be configured by arranging one or more rows of LED packages 252 on the PCB 251.

FIG. 3 illustrates an arrangement state of the LED packages 252 and the light guide panel 260. In FIG. 3, an area 302 defined by dotted lines is an area in which an image is actually displayed on the LCD panel 210 (see FIG. 2). If the individual LED packages 252 light on to irradiate light, point light of the LED packages 252 is converted into surface light by the light guide panel 260, and the surface light is irradiated to the area 302 of the LCD panel 210.

FIG. 4 is a block diagram of a control system of a display device according to an embodiment of the present disclosure. As shown in FIG. 4, a controller 402 may receive image signals, and generate control signals to produce an image of the received image signals. The control signals generated by the controller 402 may drive an LED driver 404. If the LED driver 404 is driven, the individual LED packages of an LED array 250 may light on to generate point light. The point light that is generated by the individual LED packages of the LED array 250 may be transferred to a light guide panel 260, and converted into surface light by the light guide panel 260.

FIG. 5 illustrates a structure of LED packages according to an embodiment of the present disclosure. FIG. 5A is a side sectional view of an LED package 252, and FIG. 5B is a perspective view of the LED package 252 shown in FIG. 5A. As shown in FIGS. 5A and 5B, a die-bonding material 502 may be applied on a PCB 251, and an LED chip 504 may be attached on the die-bonding material 502 through bonding. The LED chip 504 may be electrically connected to pads located adjacent to both sides of the LED chip 504 through conductive wires (for example, platinum wires) 506. If current flows through the pads 508, the wires 506, and the LED chip 504, the LED chip 504 may emit light. In order to protect the LED chip 504 and the wires 506, resin 510 may cover the entire of the LED chip 504 and the wires 506.

FIG. 5C shows a structure in which a plurality of LED packages 252 are connected to each other by a pattern 512 formed on the PCB 251. Some of the following description related to various embodiments of the present disclosure will be given based on a simplified structure of the LED packages 252, as shown in FIG. 5D.

FIG. 6 illustrates LED arrays according to various embodiments of the present disclosure. FIGS. 6A and 6B show an LED array 250 in which a plurality of LED packages 252 are arranged in two rows on a PCB 251. As shown in FIG. 6A, a partition wall 602 may be formed between the rows of the LED packages 252. The partition wall 602 will be described in more detail, later. FIG. 6B shows a circuit configuration of the LED array 250 shown in FIG. 6A. If driving currents I1 and I2 from an LED driver 404 are applied to the plurality of LED packages 252 connected in series, the LED packages 252 may light on to emit light.

FIGS. 6C and 6D show an LED array 250 in which a plurality of LED packages 252 are arranged in a row on a PCB 251. FIG. 6D shows a circuit configuration of the LED array 250 shown in FIG. 6C. In the row of the plurality of LED packages 252, the LED packages 252 may be connected in series to each other. When a driving current I3 from the LED driver 404 is applied to the plurality of LED packages 252 connected in series, the LED packages 252 may light on to emit light. In the embodiment of FIGS. 6C and 6D, since the LED packages 252 are arranged in a row, no partition wall is required unlike the embodiment of FIGS. 6A and 6B.

FIG. 7 illustrates an LED array according to a first embodiment of the present disclosure. FIG. 7A is a perspective view showing a part of an LED array 750 according to a first embodiment of the present disclosure, FIG. 7B is a cross-sectional view of the LED array 750 cut along a line A-A', according to the first embodiment of the present disclosure, and FIG. 7C is a top view of the LED array 750 according to the first embodiment of the present disclosure.

As shown in FIG. 7, the LED array 750 may be packaged by arranging a plurality of LED packages 752 in two rows on a PCB 751, wherein a partition wall 702 is formed between the rows of the LED packages 752. The PCB 751 may be a narrow, long flat plate. The length and width of the PCB 751 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 751 decide the number of LED packages 752 that can be packaged on the PCB 751, the PCB 751 may have a length and width enough to package a sufficient number of LED packages 752. The sufficient number of LED packages 752 may be a number of LED packages 752 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

In one side of the PCB 751 may be formed two

long grooves

706 and 708 along the longitudinal direction of the PCB 751. In each of the two

grooves

706 and 708, a plurality of LED packages 752 may be packaged in a row (electrically, in series) along the longitudinal direction (that is, the longitudinal direction of the PCB 751) of the

corresponding groove

706 or 708. Between the two

grooves

706 and 708 may be formed the partition wall 702. In other words, one side of the PCB 751 may be partitioned by the partition wall 702 to form two

grooves

706 and 708. The two

grooves

706 and 708 may be respectively filled with a green color phosphor 712 and a red color phosphor 714 in the state in which the plurality of LED packages 752 are packaged in the two

grooves

706 and 708. The green color phosphor 712 and the red color phosphor 714 that are respectively filled in the two

grooves

706 and 708 are not mixed with each other since they are separated by the partition wall 702. As such, the partition wall 702 of the LED array 750 according to the first embodiment of the present disclosure may be formed in the longitudinal direction of the PCB 751, that is, in the longitudinal direction of the LED array 750, thereby separating the two rows of the plurality of LED packages 752 from each other. The partition wall 702 may be integrated into the PCB 751 when the PCB 751 is fabricated. Alternatively, the partition wall 702 may be fabricated independently from the PCB 751 having no partition wall, and then attached on the PCB 751 to form the two

grooves

706 and 708.

As shown in FIG. 7C, an LED driver 704 may be packaged with the LED packages 752 on the PCB 751. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 704 may be mounted at another location than the PCB 751, and electrically connected to the plurality of LED packages 752 through a cable or the like.

In the LED array 750 according to the first embodiment of the present disclosure, forming the partition wall 702 in a longitudinal direction of the PCB 751 can obtain more advantages than forming the partition wall 702 in a width direction of the PCB 751, as follows.

First, the partition wall 702 can be easily formed since it is formed as one unit in the longitudinal direction of the PCB 751, as shown in FIG. 7A. If the partition wall 702 is formed in the width direction of the PCB 751 and the plurality of LED packages 752 are arranged in the longitudinal direction of the PCB 751, a plurality of partition walls having a small size need to be formed on the PCB 751, which requires a complicated process involving more processing stages and a longer fabrication time.

Second, a pattern 710 can be easily formed on the PCB 751. Forming the partition wall 702 in the longitudinal direction of the PCB 751, as shown in FIG. 7, may provide an additional advantage that a simple pattern 710 can be formed on the PCB 751 when the plurality of LED packages 752 are arranged in two rows (or in three rows or more). That is, forming a simple pattern 710 such as a straight line is enough to connect the plurality of LED packages 752 arranged in two rows and separated by the partition wall 702 in series to each other. The simple structure of the pattern 710 can be seen from FIG. 7C. However, if the partition wall 702 is formed in the width direction of the PCB 751, a plurality of LED packages and a plurality of partition walls are alternately arranged in parallel such that neighboring LED packages are separated by a partition wall (since a plurality of LED packages and a plurality of partition walls are alternately arranged in the longitudinal direction of the PCB 751). Accordingly, in the case of forming partition walls in the width direction of the PCB 751, a complex pattern of making detours of a plurality of partition walls has to be considered in order to electrically connect a plurality of LED packages to each other. However, the LED array 750 according to the first embodiment of the present disclosure does not need to consider such a complex pattern of making detours of a plurality of partition walls.

Accordingly, in the LED array 750 according to the first embodiment of the present disclosure as shown in FIG. 7A, by forming a partition wall in the longitudinal direction of the PCB 751, it is possible to easily form the partition wall 702 and the pattern 710 on the PCB 751.

FIG. 8 illustrates an LED array according to a second embodiment of the present disclosure. FIG. 8A is a perspective view showing a part of an LED array 850 according to a second embodiment of the present disclosure, FIG. 8B is a cross-sectional view of the LED array 850 cut along a line A-A', according to the second embodiment of the present disclosure, and FIG. 8C is a top view of the LED array 850 according to the second embodiment of the present disclosure.

As shown in FIG. 8, the LED array 850 may be packaged by arranging a plurality of LED packages 852 in two rows on a PCB 851. The PCB 851 may be a narrow, long flat plate. The length and width of the PCB 851 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 851 decides the number of LED packages 852 that can be packaged on the PCB 851, the PCB 851 may have a length and width enough to package a sufficient number of LED packages 852. The sufficient number of LED packages 852 may be a number of LED packages 852 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

On the PCB 851, the plurality of LED packages 852 may be packaged in rows (electrically, in series) along the longitudinal direction (that is, the longitudinal direction of the PCB 851) of the PCB 851. In the LED array 850 according to the second embodiment of the present disclosure, as shown in FIG. 8, no partition wall may be formed between the rows of the LED packages 852. Instead of forming a partition wall,

phosphors

812 and 814 may be discontinuously (that is, individually) applied on the plurality of LED packages 852. Individually applying the

phosphors

812 and 814 means applying the

phosphor

812 or 814 on each LED package 852 and a predetermined area around the LED package 852, as shown in FIG. 8B. Individually applying the

phosphor

812 or 814 may be, as described above with reference to FIG. 5, applying the

phosphor

812 or 814 to a predetermined thickness to cover the LED chip 504, or applying the

phosphor

812 or 814 to a predetermined thickness to cover the resin 510 applied to protect the LED chip 514 and the wires 506. In FIG. 8, the phosphor 812 may be a green color phosphor, and the phosphor 814 may be a red color phosphor.

As shown in FIG. 8C, an LED driver 804 may be packaged together with the LED packages 852 on the PCB 851. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 804 may be mounted at another location than the PCB 851, and electrically connected to the plurality of LED packages 852 through a cable or the like.

According to the second embodiment of the present disclosure, individually applying the

phosphors

812 and 814 on the plurality of LED packages 852 without forming a partition wall between the rows of the LED packages 852 can provide advantages as follows.

First, the

phosphors

812 and 814 may be less used. By individually applying the

phosphors

812 and 814 on the plurality of LED packages 852, as shown in FIG. 8, the

phosphors

812 and 814 may be much less used to cover the LED packages 852 than the case of applying phosphors on the entire rows of the LED packages 852.

Second, since there is no need to form a partition wall, cost reduction can be achieved. That is, since there is no need to form a partition wall, cost for forming a partition wall may be reduced, a manufacturing process may be simplified, and manufacturing cost may be reduced.

Third, the size of the LED array 850 may be reduced since no space for a partition wall is needed. If a partition wall is formed on the PCB 851, the thickness of the LED array 850 increases by the thickness of the partition wall. However, according to the second embodiment of the present disclosure as shown in FIG. 8, since no partition wall is formed, the LED array 850 may be implemented with a thin thickness. Also, when no partition wall is formed, the width of the PCB 851 may be reduced by the area of a partition wall so that the width of the LED array 850 may be reduced accordingly, which enables the LED array 850 to be applied to a thin light guide panel.

FIG. 9 illustrates an LED array according to a third embodiment of the present disclosure. FIG. 9A is a perspective view showing a part of an LED array 950 according to a third embodiment of the present disclosure, FIG. 9B is a cross-sectional view of the LED array 950 cut along a line A-A', according to the third embodiment of the present disclosure, and FIG. 9C is a top view of the LED array 950 according to the third embodiment of the present disclosure.

As shown in FIG. 9, the LED array 950 may be packaged by arranging a plurality of LED packages 952 in two rows on a PCB 951. The PCB 951 may be a narrow, long flat plate. The length and width of the PCB 951 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 951 decide the number of LED packages 952 that can be packaged on the PCB 951, the PCB 951 may have a length and width enough to package a sufficient number of LED packages 952. The sufficient number of LED packages 952 may be a number of LED packages 952 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

On the PCB 951, a plurality of LED packages 952 may be packaged in rows (electrically, in series) along the longitudinal direction (that is, the longitudinal direction of the PCB 951) of the PCB 951. In the LED array 950 according to the third embodiment of the present disclosure, as shown in FIG. 9, no partition wall may be formed between the rows of the LED packages 952. Instead of forming a partition wall, parts (for example, upper parts) of the surfaces of the LED packages 952 may be coated with

phosphors

912 and 914. Coating with the

phosphors

912 and 914 means coating a part (for example, a upper part) of the surface of each LED package 952 with the

phosphor

912 or 914, as shown in FIG. 9B. Coating with the

phosphor

812 or 814 may be, as described above with reference to FIG. 5, thinly coating a part (for example, a upper part) of the surface of the LED chip 504 with the

phosphor

912 or 914, or thinly coating, with the

phosphor

912 or 914, a part (for example, a upper part) of the surface of the resin 510 applied to protect the LED chip 514 and the wires 506. In FIG. 9, the phosphor 912 may be a green color phosphor, and the phosphor 914 may be a red color phosphor.

As shown in FIG. 9C, an LED driver 904 may be packaged together with the LED packages 952 on the PCB 951. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 904 may be mounted at another location than the PCB 951, and electrically connected to the plurality of LED packages 892 through a cable or the like.

According to the third embodiment of the present disclosure, coating parts (for example, upper parts) of the surfaces of the LED packages 952 with the

phosphors

912 and 914 without forming a partition wall between the rows of the LED packages 952 can provide advantages as follows.

First, the

phosphors

912 and 914 may be less used. By coating parts of the surfaces of the plurality of LED packages 952 with the

phosphors

912 and 914, as shown in FIG. 9, the

phosphors

912 and 914 may be much less used to coat the LED packages 952 than the case of applying phosphors on the entire rows of the LED packages 952. Also, the

phosphors

912 and 914 may be much less used to coat the plurality of LED packages 952 than the case of individually applying the

phosphors

912 and 914 on the plurality of LED packages 952.

Third, the size of the LED array 950 may be reduced since no space for a partition wall is needed. If a partition wall is formed on the PCB 951, the thickness of the LED array 950 increases by the thickness of the partition wall. However, according to the third embodiment of the present disclosure as shown in FIG. 9, since no partition wall is formed, the LED array 950 may be implemented with a thin thickness. Also, when no partition wall is formed, the width of the PCB 951 may be reduced by the area of a partition wall so that the width of the LED array 950 may be reduced accordingly, which enables the LED array 950 to be applied to a thin light guide panel.

FIG. 10 illustrates an LED array according to a fourth embodiment of the present disclosure. FIG. 10A is a perspective view showing a part of an LED array 1050 according to a fourth embodiment of the present disclosure, FIG. 10B is a side sectional view of the LED array 1050 according to the fourth embodiment of the present disclosure, FIG. 10C is a sectional view of the LED array 1050 cut along a line A-A', according to the fourth embodiment of the present disclosure, and FIG. 10D is a top view of the LED array 1050 according to the fourth embodiment of the present disclosure.

In the LED array 1050 according to the fourth embodiment of the present disclosure, by overturning LED chips 1064 of LED packages 1052 to cause electrical contacts 1066 of the LED chips 1064 to contact pads 1068, as shown in FIG. 10B, the LED chips 1064 may be electrically connected to the pads 1068. That is, without using platinum wires (for example, the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1064 and the pads 1068, the LED chips 1064 may be directly connected to the pads 1068.

As shown in FIG. 10, the LED array 1050 according to the fourth embodiment of the present disclosure may be packaged by arranging a plurality of LED packages 1052 in two rows on a PCB 1051, wherein a partition wall 1002 is formed between the rows of the LED packages 1042. The PCB 1051 may be a narrow, long flat plate. The length and width of the PCB 1051 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 1051 decide the number of LED packages 1052 that can be packaged on the PCB 1051, the PCB 1051 may have a length and width enough to package a sufficient number of LED packages 1052. The sufficient number of LED packages 1052 may be a number of LED packages 1052 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

In one side of the PCB 1051 may be formed two

long grooves

1006 and 1008 in the longitudinal direction of the PCB 1051. In each of the two

grooves

1006 and 1008, a plurality of LED packages 1052 may be packaged in a row (electrically, in series) along the longitudinal direction (that is, the longitudinal direction of the PCB 1051) of the

corresponding groove

1006 or 1008. Between the two

grooves

1006 and 1008 may be formed the partition wall 1002. In other words, one side of the PCB 1051 may be partitioned by the partition wall 1002 to form two

grooves

1006 and 1008. The two

grooves

1006 and 1008 may be respectively filled with a green color phosphor 1012 and a red color phosphor 1014 in the state in which the plurality of LED packages 1052 are packaged in the two

grooves

1006 and 1008. The green color phosphor 1012 and the red color phosphor 1014 that are respectively filled in the two

grooves

1006 and 1008 are not mixed with each other since they are separated by the partition wall 1002. As such, the partition wall 1002 of the LED array 1050 according to the fourth embodiment of the present disclosure may be formed in the longitudinal direction of the PCB 1051, that is, in the longitudinal direction of the LED array 1050, thereby separating the two rows of the plurality of LED packages 1052 from each other. The partition wall 1002 may be integrated into the PCB 1051 when the PCB 1051 is fabricated. Alternatively, the partition wall 1002 may be fabricated independently from the PCB 1051 having no partition wall, and then attached on the PCB 1051 to form two

grooves

1006 and 1008.

As shown in FIG. 10D, an LED driver 1004 may be packaged with the LED packages 1052 on the PCB 1051. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 1004 may be mounted at another location than the PCB 1051, and electrically connected to the plurality of LED packages 1052 through a cable or the like.

In the LED array 1050 according to the fourth embodiment of the present disclosure, forming the partition wall 1002 in the longitudinal direction of the PCB 1051 can obtain more advantages than forming partition walls in the width direction of the PCB 1051, as follows.

First, the partition wall 1002 can be easily formed since it is formed as one unit in the longitudinal direction of the PCB 1051, as shown in FIG. 10A. If a partition wall is formed in the width direction of the PCB 1051 and a plurality of LED packages are arranged in the longitudinal direction of the PCB 1051, a plurality of partition walls having a small size need to be formed on the PCB 1051, which requires a complicated process involving more processing stages and a longer fabrication time.

Second, a pattern 1010 can be easily formed on the PCB 1051. Forming the partition wall 1002 in the longitudinal direction of the PCB 1051, as shown in FIG. 10, may provide an additional advantage that a simple pattern 1010 can be formed on the PCB 1051 when a plurality of LED packages 1052 are arranged in two rows (or in three rows or more). That is, forming a simple pattern 710 such as a straight line is enough to connect the plurality of LED packages 1052 arranged in two rows and separated by the partition wall 1002 in series to each other. The simple structure of the pattern 1010 can be seen from FIG. 10C. However, if partition walls are formed in the width direction of the PCB 1051, the plurality of LED packages and the plurality of partition walls are alternately arranged in parallel such that neighboring LED packages are separated by a partition wall (since a plurality of LED packages and a plurality of partition walls are alternately arranged in the longitudinal direction of the PCB 1051). Accordingly, in the case of forming partition walls in the width direction of the PCB 1051, a complex pattern of making detours of a plurality of partition walls needs to be considered in order to electrically connect a plurality of LED packages to each other. However, the LED array 1050 according to the fourth embodiment of the present disclosure does not need to consider such a complex pattern of making detours of a plurality of partition walls.

Third, the number of process stages may be reduced, and manufacturing cost may be reduced. In the LED array 1050 according to the fourth embodiment of the present disclosure, since the LED chips 1064 are directly connected to the pads 1068 without using wires (for example, platinum wires such as the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1064 and the pads 1068, a process for connecting wires can be omitted, and the number of components and manufacturing cost may be reduced since wires are not needed.

Accordingly, in the LED array 1050 according to the fourth embodiment of the present disclosure as shown in FIG. 10A, by forming a partition wall in the longitudinal direction of the PCB 1051 instead of the width direction of the PCB 1051, the partition wall 1002 and the pattern 1010 may be easily formed on the PCB 1051. Also, the number of process stages and manufacturing cost may be reduced since the LED chips 1064 are directly connected to the pads 1068.

FIG. 11 illustrates an LED array according to a fourth embodiment of the present disclosure. FIG. 11A is a perspective view showing a part of an LED array 1150 according to a fifth embodiment of the present disclosure, FIG. 11B is a side sectional view of the LED array 1150 according to the fifth embodiment of the present disclosure, FIG. 11C is a sectional view of the LED array 1150 cut along a line A-A', according to the fifth embodiment of the present disclosure, and FIG. 11D is a top view of the LED array 1150 according to the fifth embodiment of the present disclosure.

In the LED array 1150 according to the fifth embodiment of the present disclosure, by overturning LED chips 1164 of LED packages 1152 to cause electrical contacts 1166 of the LED chips 1164 to contact pads 1168, as shown in FIG. 11B, the LED chips 1164 may be electrically connected to the pads 1168. That is, without using platinum wires (for example, the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1164 and the pads 1168, the LED chips 1164 may be directly connected to the pads 1168.

As shown in FIG. 11, the LED array 1150 according to the fifth embodiment of the present disclosure may be packaged by arranging a plurality of LED packages 1152 in two rows on a PCB 1151. The PCB 1151 may be a narrow, long flat plate. The length and width of the PCB 1151 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 1151 decide the number of LED packages 1152 that can be packaged on the PCB 1151, the PCB 1151 may have a length and width enough to package a sufficient number of LED packages 1152. The sufficient number of LED packages 1152 may be a number of LED packages 1152 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

On the PCB 1151, a plurality of LED packages 1152 may be packaged in rows (electrically, in series) along the longitudinal direction (that is, the longitudinal direction of the PCB 1151) of the PCB 1151. In the LED array 1150 according to the fifth embodiment of the present disclosure, as shown in FIG. 11, no partition wall may be formed between the rows of the LED packages 1152. Instead of forming a partition wall,

phosphors

1112 and 1114 may be discontinuously (that is, individually) applied on the plurality of LED packages 1152. Individually applying the

phosphors

1112 and 1114 means applying the

phosphor

1112 or 1114 on each LED package 1152 and a predetermined area around the LED package 1152, as shown in FIG. 11C. Individually applying the

phosphor

1112 or 1114 may be, as described above with reference to FIG. 5, applying the

phosphor

1112 or 1114 to a predetermined thickness to cover the LED chip 504, or applying the

phosphor

1112 or 1114 to a predetermined thickness to cover the resin 510 applied to protect the LED chip 514 and the wires 506. In FIG. 11, the phosphor 1112 may be a green color phosphor, and the phosphor 1114 may be a red color phosphor.

As shown in FIG. 11D, an LED driver 1104 may be packaged together with the LED packages 1152 on the PCB 1151. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 1104 may be mounted at another location than the PCB 1151, and electrically connected to the plurality of LED packages 1152 through a cable or the like.

According to the fifth embodiment of the present disclosure, individually applying the

phosphors

1112 and 1114 on the plurality of LED packages 1152 without forming a partition wall between the rows of the LED packages 1152 can provide advantages as follows.

First, the

phosphors

1112 and 1114 may be less used. By individually applying the

phosphors

1112 and 1114 on the plurality of LED packages 1152, as shown in FIG. 11, the

phosphors

1112 and 1114 may be much less used to cover the plurality of LED packages 1152 than the case of applying phosphors on the entire rows of the LED packages 1152.

Third, the size of the LED array 1150 may be reduced since no space for a partition wall is needed. If a partition wall is formed on the PCB 1151, the thickness of the LED array 1150 increases by the thickness of the partition wall. However, according to the fifth embodiment of the present disclosure as shown in FIG. 11, since no partition wall is formed, the LED array 1150 may be implemented with a thin thickness. Also, when no partition wall is formed, the width of the PCB 1151 may be reduced by the area of a partition wall so that the width of the LED array 1150 may be reduced accordingly, which enables the LED array 1150 to be applied to a thin light guide panel.

Fourth, the number of process stages may be reduced, and manufacturing cost may be reduced. In the LED array 1150 according to the fifth embodiment of the present disclosure, since the LED chips 1164 are directly connected to the pads 1168 without using wires (for example, platinum wires such as the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1164 and the pads 1168, a process for connecting wires can be omitted, and the number of components and manufacturing cost may be reduced since wires are not needed.

FIG. 12 illustrates an LED array according to a sixth embodiment of the present disclosure. FIG. 12A is a perspective view showing a part of an LED array 1250 according to a six embodiment of the present disclosure, FIG. 12B is a side sectional view of an LED package 1252 of the LED array 1250 according to the sixth embodiment of the present disclosure, FIG. 12C is a sectional view of the LED array 1250 cut along a line A-A', according to the sixth embodiment of the present disclosure, and FIG. 12D is a top view of the LED array 1250 according to the sixth embodiment of the present disclosure.

In the LED array 1250 according to the sixth embodiment of the present disclosure, by overturning LED chips 1264 of LED packages 1252 to cause electrical contacts 1266 of the LED chips 1264 to contact pads 1268, as shown in FIG. 12B, the LED chips 1264 may be electrically connected to the pads 1268. That is, without using platinum wires (for example, the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1264 and the pads 1268, the LED chips 1264 may be directly connected to the pads 1268.

As shown in FIG. 12, the LED array 1250 according to the sixth embodiment of the present disclosure may be packaged by arranging a plurality of LED packages 1252 in two rows on a PCB 1251. The PCB 1251 may be a narrow, long flat plate. The length and width of the PCB 1251 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 1251 decide the number of LED packages 1252 that can be packaged on the PCB 1251, the PCB 1251 may have a length and width enough to package a sufficient number of LED packages 1252. The sufficient number of LED packages 1252 may be a number of LED packages 1252 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

On the PCB 1251, a plurality of LED packages 1252 may be packaged in rows (electrically, in series) along the longitudinal direction of the PCB 1251. In the LED array 1250 according to the sixth embodiment of the present disclosure, as shown in FIG. 12, no partition wall may be formed between the rows of the LED packages 1252. Instead of forming a partition wall, parts (for example, upper parts) of the surfaces of the LED packages 1252 may be coated with

phosphors

1212 and 1214. Coating with the

phosphors

1212 and 1214 means coating a part (for example, a upper part) of the surface of each LED package 1252 with the

phosphor

1212 or 1214, as shown in FIG. 12C. Coating with the

phosphor

1212 or 1214 may be, as described above with reference to FIG. 5, thinly coating a part (for example, a upper part) of the surface of the LED chip 504 with the

phosphor

1212 or 1214, or thinly coating, with the

phosphor

1212 or 1214, a part (for example, a upper part) of the surface of the resin 510 applied to protect the LED chip 514 and the wires 506. In FIG. 12, the phosphor 1212 may be a green color phosphor, and the phosphor 1214 may be a red color phosphor.

As shown in FIG. 12D, an LED driver 1204 may be packaged together with the LED packages 1252 on the PCB 1251. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 1204 may be mounted at another location than the PCB 1251, and electrically connected to the plurality of LED packages 1292 through a cable or the like.

According to the sixth embodiment of the present disclosure, coating parts (for example, upper parts) of the surfaces of the LED packages 1252 with the

phosphors

1212 and 1214 without forming a partition wall between the rows of the LED packages 1252 can provide advantages as follows.

First, the

phosphors

1212 and 1214 may be less used. By coating parts of the surfaces of the LED packages 1252 with the

phosphors

1212 and 1214, as shown in FIG. 12, the

phosphors

1212 and 1214 may be much less used to cover the plurality of LED packages 1252 than the case of applying phosphors on the entire rows of the plurality of LED packages 1252. Also, the

phosphors

1212 and 1214 may be much less used to cover the plurality of LED packages 1252 than the case of individually applying phosphors on the plurality of LED packages 1252.

Third, the size of the LED array 1250 may be reduced since no space for a partition wall is needed. If a partition wall is formed on the PCB 1251, the thickness of the LED array 1250 increases by the thickness of the partition wall. However, according to the sixth embodiment of the present disclosure as shown in FIG. 12, since no partition wall is formed, the LED array 1250 may be implemented with a thin thickness. Also, when no partition wall is formed, the width of the PCB 1251 may be reduced by the area of a partition wall so that the width of the LED array 1250 may be reduced accordingly, which enables the LED array 1250 to be applied to a thin light guide panel.

Fourth, the number of process stages may be reduced, and manufacturing cost may be reduced. In the LED array 1250 according to the sixth embodiment of the present disclosure, since the LED chips 1264 are directly connected to the pads 1268 without using wires (for example, platinum wires such as the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1264 and the pads 1268, a process for connecting wires can be omitted, and the number of components and manufacturing cost may be reduced since wires are not needed.

FIG. 13 illustrates an LED array according to a seventh embodiment of the present disclosure. FIG. 13A is a perspective view showing a part of an LED array 1350 according to a seventh embodiment of the present disclosure, FIG. 12B is a sectional view of the LED array 1350 cut along a line A-A', according to the sixth embodiment of the present disclosure, and FIG. 13C is a top view of the LED array 1350 according to the sixth embodiment of the present disclosure.

As shown in FIG. 13, the LED array 1350 according to the seventh embodiment of the present disclosure may be packaged by arranging a plurality of LED packages 1352 in a row on a PCB 1351. The PCB 1351 may be a narrow, long flat plate. The length and width of the PCB 1351 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 1351 decide the number of LED packages 1352 that can be packaged on the PCB 1351, the PCB 1351 may have a length and width enough to package a sufficient number of LED packages 1352. The sufficient number of LED packages 1352 may be a number of LED packages 1352 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

On the PCB 1351, a plurality of LED packages 1352 may be packaged in a row (electrically, in series) along the longitudinal direction of the PCB 1351. In the LED array 1350 according to the seventh embodiment of the present disclosure, as shown in FIG. 13, no partition wall may be formed since the plurality of LED packages 1352 are packaged in a row. Instead of forming a partition wall,

phosphors

1312 and 1314 may be discontinuously (that is, individually) applied on the plurality of LED packages 1352. Individually applying the

phosphors

1312 and 1314 means applying the

phosphor

1312 or 1314 on each LED package 1352 and a predetermined area around the LED package 1352, as shown in FIG. 13B. Individually applying the

phosphor

1312 or 1314 may be, as described above with reference to FIG. 5, applying the

phosphor

1312 or 1314 to a predetermined thickness to cover the LED chip 504, or applying the

phosphor

1312 or 1314 to a predetermined thickness to cover the resin 510 applied to protect the LED chip 514 and the wires 506. In FIG. 13, the phosphor 1312 may be a green color phosphor, and the phosphor 1314 may be a red color phosphor.

In the seventh embodiment of FIG. 13, since the LED packages 1352 are packaged in a row, a solution for applying a plurality of colors of phosphors is needed. In order to apply a plurality of colors of phosphors, in the LED array 1350 according to the seventh embodiment of the present disclosure, different colors of

phosphors

1312 and 1314 may be alternately applied on the plurality of LED packages 1352 that are packaged in a row. For example, a green color phosphor 1312 may be applied on oddnumbered LED packages 1352, and a red color phosphor 1342 may be applied on evennumbered LED packages 1352. Likewise, three or more colors of phosphors may be alternately applied on the plurality of LED packages 1352 that are packaged in a row.

As shown in FIG. 13C, an LED driver 1304 may be packaged together with the LED packages 1352 on the PCB 1351. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 1304 may be mounted at another location than the PCB 1351, and electrically connected to the plurality of LED packages 1392 through a cable or the like.

According to the seventh embodiment of the present disclosure, individually applying the

phosphors

1312 and 1314 on the plurality of LED packages 1352 without forming a partition wall between the plurality of LED packages 1352 arranged in a row can provide advantages as follows.

First, the

phosphors

1312 and 1314 may be less used. By individually applying the

phosphors

1312 and 1314 on the plurality of LED packages 1352, as shown in FIG. 13, the

phosphors

1312 and 1314 may be much less used to cover the plurality of LED packages 1352 than the case of applying phosphors on the entire rows of the plurality of LED packages 1352.

Third, the size of the LED array 1350 may be reduced since no space for a partition wall is needed. If a partition wall is formed on the PCB 1351, the thickness of the LED array 1350 increases by the thickness of the partition wall. However, according to the seventh embodiment of the present disclosure as shown in FIG. 13, since no partition wall is formed, the LED array 1350 may be implemented with a thin thickness. Also, when no partition wall is formed, the width of the PCB 1351 may be reduced by the area of a partition wall so that the width of the LED array 1350 may be reduced accordingly, which enables the LED array 1350 to be applied to a thin light guide panel.

Fourth, the width of the PCB 1351, that is, the width of the LED array 1350 may be reduced. By packaging the plurality of LED packages 1352 in a row, the width of the LED array 1350 may be significantly reduced. Accordingly, it is possible to apply the LED array 1350 to the light guide panel 260 having a thin thickness, resulting in a reduction in thickness of the display device 100. That is, the seventh embodiment of the present disclosure is advantageous in implementing a ultra-thin display device 100.

FIG. 14 illustrates an LED array according to an eighth embodiment of the present disclosure. FIG. 14A is a perspective view showing a part of an LED array 1450 according to an eighth embodiment of the present disclosure, FIG. 14B is a cross-sectional view of the LED array 1450 cut along a line A-A', according to the eighth embodiment of the present disclosure, and FIG. 14C is a top view of the LED array 1450 according to the eighth embodiment of the present disclosure.

As shown in FIG. 14, the LED array 1450 according to the eighth embodiment of the present disclosure may be packaged by arranging a plurality of LED packages 1452 in a row on a PCB 1451. The PCB 1451 may be a narrow, long flat plate. The length and width of the PCB 1451 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 1451 decide the number of LED packages 1352 that can be packaged on the PCB 1451, the PCB 151 may have a length and width enough to package a sufficient number of LED packages 1452. The sufficient number of LED packages 1452 may be a number of LED packages 1452 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

On the PCB 1451, a plurality of LED packages 1452 may be packaged in a row (electrically, in series) along the longitudinal direction of the PCB 1451. In the LED array 1450 according to the eighth embodiment of the present disclosure, as shown in FIG. 14, no partition wall may be formed since the plurality of LED packages 1452 are packaged in a row. Instead of forming a partition wall, parts (for example, upper parts) of the surfaces of the plurality of LED packages 1452 may be coated with

phosphors

1412 and 1414. Coating with the

phosphors

1412 and 1414 means coating a part (for example, a upper part) of the surface of each LED package 1452 with the

phosphor

1412 or 1414, as shown in FIG. 14B. Coating with the

phosphor

1412 or 1414 may be, as described above with reference to FIG. 5, thinly coating a part (for example, a upper part) of the surface of the LED chip 504 with the

phosphor

1412 or 1414, or thinly coating, with the

phosphor

1412 or 1414, a part (for example, a upper part) of the surface of the resin 510 applied to protect the LED chip 514 and the wires 506. In FIG. 14, the phosphor 1412 may be a green color phosphor, and the phosphor 1414 may be a red color phosphor.

In the seventh embodiment of FIG. 14, since the LED packages 1452 are packaged in a row, a solution for applying a plurality of colors of phosphors is needed. In order to apply a plurality of colors of phosphors, in the LED array 1450 according to the eighth embodiment of the present disclosure, different colors of

phosphors

1412 and 1414 may be alternately applied on parts of the surfaces of the plurality of LED packages 1452 that are packaged in a row. For example, a green color phosphor 1312 may be applied on oddnumbered LED packages 1452, and a red color phosphor 1342 may be applied on evennumbered LED packages 1452. Likewise, three or more colors of phosphors may be alternately applied on parts of the surfaces of the plurality of LED packages 1352 that are packaged in a row.

As shown in FIG. 14C, an LED driver 1404 may be packaged with the LED packages 1452 on the PCB 1451. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 1404 may be mounted at another location than the PCB 1451, and electrically connected to the plurality of LED packages 1452 through a cable or the like.

According to the eighth embodiment of the present disclosure, coating a part (for example, a upper part) of the surface of each of the LED packages 1452 that are arranged in a row, with the

phosphor

1412 or 1414, without forming a partition wall between the LED packages 1452 can provide advantages as follows.

First, the

phosphors

1412 and 1414 may be less used. By coating parts of the surfaces of the LED packages 1452 with the

phosphors

1412 and 1414, as shown in FIG. 14, the

phosphors

1412 and 1414 may be much less used to coat the LED packages 1452 than the case of applying phosphors on the entire rows of the LED packages 1452. Also, the

phosphors

1412 and 1414 may be much less used to coat the LED packages 1452 than the case of individually applying phosphors on the LED packages 952.

Third, the size of the LED array 1450 may be reduced since no space for a partition wall is needed. If a partition wall is formed on the PCB 1451, the thickness of the LED array 1450 increases by the thickness of the partition wall. However, according to the third embodiment of the present disclosure as shown in FIG. 14, since no partition wall is formed, the LED array 1450 may be implemented with a thin thickness. Also, when no partition wall is formed, the width of the PCB 951 may be reduced by the area of a partition wall so that the width of the LED array 1450 may be reduced accordingly, which enables the LED array 1450 to be applied to a thin light guide panel.

Fourth, the width of the PCB 1451, that is, the width of the LED array 1450 may be reduced. By packaging the plurality of LED packages 1452 in a row, the width of the LED array 1450 may be significantly reduced. Accordingly, it is possible to apply the LED array 1450 to the light guide panel 260 having a thin thickness, resulting in a reduction in thickness of the display device 100. That is, the seventh embodiment of the present disclosure is advantageous in implementing a ultra-thin display device 100.

FIG. 15 illustrates an LED array according to a ninth embodiment of the present disclosure. FIG. 15A is a perspective view showing a part of an LED array 1550 according to a ninth embodiment of the present disclosure, FIG. 15B is a side sectional view of an LED package 1552 of the LED array 1550 according to the ninth embodiment of the present disclosure, FIG. 15C is a sectional view of the LED array 1550 cut along a line A-A', according to the ninth embodiment of the present disclosure, and FIG. 15D is a top view of the LED array 1550 according to the ninth embodiment of the present disclosure.

In the LED array 1550 according to the ninth embodiment of the present disclosure, by overturning LED chips 1564 of LED packages 1552 to cause electrical contacts 1566 of the LED chips 1564 to contact pads 1568, as shown in FIG. 15B, the LED chips 1564 may be electrically connected to the pads 1568. That is, without using platinum wires (for example, the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1564 and the pads 1568, the LED chips 1564 may be directly connected to the pads 1568.

As shown in FIG. 15, the LED array 1550 according to the ninth embodiment of the present disclosure may be packaged by arranging a plurality of LED packages 1552 in a row on a PCB 1551. The PCB 1551 may be a narrow, long flat plate. The length and width of the PCB 1551 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 1551 decide the number of LED packages 1552 that can be packaged on the PCB 1551, the PCB 1551 may have a length and width enough to package a sufficient number of LED packages 1552. The sufficient number of LED packages 1552 may be a number of LED packages 1552 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

On the PCB 1551, a plurality of LED packages 1552 may be packaged in a row (electrically, in series) along the longitudinal direction of the PCB 1551. In the LED array 1550 according to the ninth embodiment of the present disclosure, as shown in FIG. 15, no partition wall may be formed since the plurality of LED packages 1552 are packaged in a row. Instead of forming a partition wall,

phosphors

1512 and 1514 may be discontinuously (that is, individually) applied on the plurality of LED packages 1552. Individually applying the

phosphors

1512 and 1514 means applying the

phosphor

1512 or 1514 on each LED package 1552 and a predetermined area around the LED package 1552, as shown in FIG. 15C. Individually applying the

phosphor

1512 or 1514 may be, as described above with reference to FIG. 5, applying the

phosphor

1512 or 1514 to a predetermined thickness to cover the LED chip 504, or applying the

phosphor

1512 or 1514 to a predetermined thickness to cover the resin 510 applied to protect the LED chip 514 and the wires 506. In FIG. 15, the phosphor 1512 may be a green color phosphor, and the phosphor 1514 may be a red color phosphor.

In the ninth embodiment of FIG. 15, since the LED packages 1552 are packaged in a row, a solution for applying a plurality of colors of phosphors is needed. In order to apply a plurality of colors of phosphors, in the LED array 1550 according to the ninth embodiment of the present disclosure, different colors of

phosphors

1512 and 1514 may be alternately applied on the plurality of LED packages 1552 that are packaged in a row. For example, a green color phosphor 1512 may be applied on oddnumbered LED packages 1552, and a red color phosphor 1542 may be applied on evennumbered LED packages 1552. Likewise, three or more colors of phosphors may be alternately applied on the LED packages 1552 that are packaged in a row.

As shown in FIG. 15D, an LED driver 1504 may be packaged with the LED packages 1552 on the PCB 1551. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 1504 may be mounted at another location than the PCB 1551, and electrically connected to the plurality of LED packages 1552 through a cable or the like.

According to the ninth embodiment of the present disclosure, individually applying the

phosphors

1512 and 1514 on the LED packages 852 arranged in a row, without forming a partition wall between the LED packages 1552 can provide advantages as follows.

First, the

phosphors

1512 and 1514 may be less used. By individually applying the

phosphors

1512 and 1514 on the plurality of LED packages 1552, as shown in FIG. 15, the

phosphors

1512 and 1514 may be much less used to cover the plurality of LED packages 1552 than the case of applying phosphors on the entire rows of the LED packages 1552.

Third, the size of the LED array 1550 may be reduced since no space for a partition wall is needed. If a partition wall is formed on the PCB 1551, the thickness of the LED array 1550 increases by the thickness of the partition wall. However, according to the ninth embodiment of the present disclosure as shown in FIG. 15, since no partition wall is formed, the LED array 1550 may be implemented with a thin thickness. Also, when no partition wall is formed, the width of the PCB 1551 may be reduced by the area of a partition wall so that the width of the LED array 1550 may be reduced accordingly, which enables the LED array 1550 to be applied to a thin light guide panel.

Fourth, the number of process stages may be reduced, and the number of elements and manufacturing cost may be reduced. In the LED array 1550 according to the ninth embodiment of the present disclosure, since the LED chips 1564 are directly connected to the pads 1568 without using wires (for example, platinum wires such as the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1664 and the pads 1568, a process for connecting wires can be omitted, and the number of components and manufacturing cost may be reduced since wires are not needed.

Fifth, the width of the PCB 1551, that is, the width of the LED array 1550 may be reduced. By packaging the plurality of LED packages 1552 in a row, the width of the LED array 1550 may be significantly reduced. Accordingly, it is possible to apply the LED array 1550 to the light guide panel 260 having a thin thickness, resulting in a reduction in thickness of the display device 100. That is, the seventh embodiment of the present disclosure is advantageous in implementing a ultra-thin display device 100.

FIG. 16 illustrates an LED array according to a tenth embodiment of the present disclosure. FIG. 16A is a perspective view showing a part of an LED array 1650 according to a tenth embodiment of the present disclosure, FIG. 16B is a side sectional view of an LED package 1652 of the LED array 1650 according to the tenth embodiment of the present disclosure, FIG. 16C is a sectional view of the LED array 1650 cut along a line A-A', according to the tenth embodiment of the present disclosure, and FIG. 16D is a top view of the LED array 1650 according to the tenth embodiment of the present disclosure.

In the LED array 1650 according to the tenth embodiment of the present disclosure, by overturning LED chips 1664 of LED packages 1652 to cause electrical contacts 1666 of the LED chips 1664 to contact pads 1668, as shown in FIG. 16B, the LED chips 1664 may be electrically connected to the pads 1668. That is, without using platinum wires (for example, the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1664 and the pads 1668, the LED chips 1064 may be directly connected to the pads 1668.

As shown in FIG. 16, the LED array 1650 according to the tenth embodiment of the present disclosure may be packaged by arranging a plurality of LED packages 1652 in a row on a PCB 1651. The PCB 1651 may be a narrow, long flat plate. The length and width of the PCB 1651 may correspond to those of the light guide panel 260 shown in FIG. 2. That is, since the length and width of the PCB 1651 decide the number of LED packages 1652 that can be packaged on the PCB 1651, the PCB 1651 may have a length and width enough to package a sufficient number of LED packages 1652. The sufficient number of LED packages 1652 may be a number of LED packages 1652 capable of irradiating an amount of light enough for sufficient light diffusion through the light guide panel 260.

On the PCB 1651, a plurality of LED packages 1652 may be packaged in a row (electrically, in series) along the longitudinal direction of the PCB 1651. In the LED array 1650 according to the tenth embodiment of the present disclosure, as shown in FIG. 16, no partition wall may be formed since the plurality of LED packages 1652 are packaged in a row. Instead of forming a partition wall, parts (for example, upper parts) of the surfaces of the plurality of LED packages 1652 may be coated with

phosphors

1612 and 1614. Coating with the

phosphors

1612 and 1614 means coating a part (for example, a upper part) of the surface of each LED package 1652 with the

phosphor

1612 or 1614, as shown in FIG. 16C. Coating with the

phosphor

1612 or 1614 may be, as described above with reference to FIG. 5, thinly coating a part (for example, a upper part) of the surface of the LED chip 504 with the

phosphor

1612 or 1614, or thinly coating, with the

phosphor

1612 or 1614, a part (for example, a upper part) of the surface of the resin 510 applied to protect the LED chip 514 and the wires 506. In FIG. 16, the phosphor 1612 may be a green color phosphor, and the phosphor 1614 may be a red color phosphor.

In the tenth embodiment of FIG. 16, since the LED packages 1652 are packaged in a row, a solution for applying a plurality of colors of phosphors is needed. In order to apply a plurality of colors of phosphors, in the LED array 1650 according to the tenth embodiment of the present disclosure, different colors of

phosphors

1612 and 1614 may be alternately applied on parts of the surfaces of the plurality of LED packages 1652 that are packaged in a row. For example, a green color phosphor 1612 may be applied on parts of the surfaces of oddnumbered LED packages 1652, and a red color phosphor 1642 may be applied on parts of the surfaces of evennumbered LED packages 1652. Likewise, three or more colors of phosphors may be alternately applied on parts of the surfaces of the plurality of LED packages 1652 that are packaged in a row.

As shown in FIG. 16D, an LED driver 1604 may be packaged together with the LED packages 1652 on the PCB 1651. However, as necessary in view of efficient use or insufficiency of an installation space for components, the LED driver 1604 may be mounted at another location than the PCB 1651, and electrically connected to the plurality of LED packages 1652 through a cable or the like.

According to the tenth embodiment of the present disclosure, coating parts (for example, upper parts) of the surfaces of the plurality of LED packages 1652 with the

phosphors

1612 and 1614 without forming a partition wall between the LED packages 1652 arranged in a row may provide advantages as follows.

First, the

phosphors

1612 and 1614 may be less used. By coating parts of the surfaces of the LED packages 1652 with the

phosphors

1612 and 1614, as shown in FIG. 16, the

phosphors

1612 and 1614 may be much less used to coat the LED packages 1652 than the case of applying phosphors on the entire rows of the LED packages 1652. Also, the

phosphors

1612 and 1614 may be much less used to coat the plurality of LED packages 1652 than the case of individually applying phosphors on the plurality of LED packages 1652.

Third, the size of the LED array 1650 may be reduced since no space for a partition wall is needed. If a partition wall is formed on the PCB 1651, the thickness of the LED array 1650 increases by the thickness of the partition wall. However, according to the tenth embodiment of the present disclosure as shown in FIG. 16, since no partition wall is formed, the LED array 1650 may be implemented with a thin thickness. Also, when no partition wall is formed, the width of the PCB 1651 may be reduced by the area of a partition wall so that the width of the LED array 1650 may be reduced accordingly, which enables the LED array 1650 to be applied to a thin light guide panel.

Fourth, the number of process stages may be reduced, and manufacturing cost may be reduced. In the LED array 1650 according to the fifth embodiment of the present disclosure, since the LED chips 1664 are directly connected to the pads 1668 without using wires (for example, platinum wires such as the conductive wires 506 of FIG. 5) for electrical connections between the LED chips 1664 and the pads 1668, a process for connecting wires may be omitted, and the number of elements and manufacturing cost may be reduced since wires are not needed.

Fifth, the width of the PCB 1651, that is, the width of the LED array 1650 may be reduced. By packaging the plurality of LED packages 1552 in a row, the width of the LED array 1650 may be significantly reduced. Accordingly, it is possible to apply the LED array 1650 to the light guide panel 260 having a thin thickness, resulting in a reduction in thickness of the display device 100. That is, the seventh embodiment of the present disclosure is advantageous in implementing a ultra-thin display device 100.

Therefore, as described above, according to the embodiments of the present disclosure, since LED packages are packaged based on COB technology to configure an LED array for a backlight unit, the structure of the LED array may be simplified, the number of processing stages may be reduced, and the lifetime of the LED packages may be lengthened.

Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

Claims

A Light Emitting Diode (LED) array comprising:

a printed circuit board (PCB) having a length;

a plurality of LED packages packaged in a plurality of rows along a longitudinal direction of the PCB;

a partition wall formed between neighboring rows among the plurality of rows, in the longitudinal direction of the PCB; and

a phosphor applied on each row to cover the row.
The LED array according to claim 1, wherein an LED chip of each LED package is electrically connected to pads of the PCB through wires.
The LED array according to claim 1, wherein a rear surface of an LED chip of each LED package is electrically connected to pads of the PCB.
The LED array according to claim 1, wherein the plurality of LED packages are packaged based on Chip On Board (COB) technology on the PCB.
A Light Emitting Diode (LED) array comprising:

a Printed Circuit Board (PCB) having a length;

a plurality of LED packages packaged in a plurality of rows along a longitudinal direction of the PCB; and

a plurality of phosphors having different colors and respectively applied on the plurality of rows,

wherein the phosphors are individually applied on the plurality of LED packages.
The LED array according to claim 5, wherein an LED chip of each LED package is electrically connected to pads of the PCB through wires.
The LED array according to claim 6, wherein the individually applying of the phosphors on the plurality of LED packages comprises discontinuously applying the phosphors on and around the plurality of LED packages such that the phosphors individually cover the plurality of LED packages.
The LED array according to claim 6, wherein the individually applying of the phosphors on the plurality of LED packages comprises coating the surfaces of the plurality of LED packages with the phosphors.
The LED array according to claim 8, wherein upper surfaces of LED chips of the plurality of LED packages are individually coated with the phosphors.
The LED array according to claim 5, wherein rear surfaces of LED chips of the plurality of LED packages are electrically connected to pads of the PCB.
The LED array according to claim 10, wherein the individually applying of the phosphors on the plurality of LED packages comprises discontinuously applying the phosphors on and around the plurality of LED packages such that the phosphors individually cover the plurality of LED packages.
The LED array according to claim 10, wherein the individually applying of the phosphors on the plurality of LED packages comprises coating the surfaces of the plurality of LED packages with the phosphors.
The LED array according to claim 12, wherein upper surfaces of LED chips of the plurality of LED packages are individually coated with the phosphors.
The LED array according to claim 5, wherein the plurality of LED packages are packaged based on Chip On Board (COB) technology on the PCB.
A Light Emitting Diode (LED) array comprising:

a Printed Circuit Board (PCB) having a length;

a plurality of LED packages packaged in a row along a longitudinal direction of the PCB; and

a plurality of phosphors having different colors and alternately applied on the plurality of LED packages packaged in the row.
The LED array according to claim 15, wherein an LED chip of each LED package is electrically connected to pads of the PCB through wires.
The LED array according to claim 16, wherein the phosphors are discontinuously applied on and around the plurality of LED packages such that the phosphors individually cover the plurality of LED packages.
The LED array according to claim 16, wherein the phosphors are individually coated on the surfaces of the plurality of LED packages.
The LED array according to claim 18, wherein upper surfaces of LED chips of the plurality of LED packages are individually coated with the phosphors.
The LED array according to claim 15, wherein rear surfaces of LED chips of the plurality of LED packages are electrically connected to pads of the PCB.
The LED array according to claim 20, wherein the phosphors are discontinuously applied on and around the plurality of LED packages such that the phosphors individually cover the plurality of LED packages.
The LED array according to claim 20, wherein the phosphors are individually coated on the surfaces of the plurality of LED packages.
The LED array according to claim 22, wherein upper surfaces of LED chips of the plurality of LED packages are individually coated with the phosphors.
The LED array according to claim 15, wherein the plurality of LED packages are packaged based on Chip On Board (COB) technology on the PCB.
A display device comprising:

a Light Emitting Diode (LED) array including a Printed Circuit Board (PCB) having a length, a plurality of LED packages packaged in a plurality of rows along a longitudinal direction of the PCB, a partition wall formed between neighboring rows among the plurality of rows, in the longitudinal direction of the PCB, and a phosphor applied on each row to cover the row;

a light guide panel configured to convert point light irradiated from each LED package into surface light; and

a Liquid Crystal Display (LCD) panel configured to receive the surface light through the light guide panel, and to display an image.
The display device according to claim 25, wherein the plurality of LED packages are packaged based on Chip On Board (COB) technology on the PCB.
A display device comprising:

a Light Emitting Diode (LED) array including a Printed Circuit Board (PCB) having a length, a plurality of LED packages packaged in a plurality of rows along a longitudinal direction of the PCB, and a plurality of phosphors having different colors and respectively applied on the plurality of rows, wherein the phosphors are individually applied on the plurality of LED packages;

a light guide panel configured to convert point light irradiated from each LED package into surface light; and

a Liquid Crystal Display (LCD) panel configured to receive the surface light through the light guide panel, and to display an image.
The display device according to claim 27, wherein the plurality of LED packages are packaged based on Chip On Board (COB) technology on the PCB.
A display device comprising:

a Light Emitting Diode (LED) array including a Printed Circuit Board (PCB) having a length, a plurality of LED packages packaged in a row along a longitudinal direction of the PCB, and a plurality of phosphors having different colors and alternately applied on the plurality of LED packages packaged in the row;

a light guide panel configured to convert point light irradiated from each LED package into surface light; and

a Liquid Crystal Display (LCD) panel configured to receive the surface light through the light guide panel, and to display an image.
The display device according to claim 29, wherein the plurality of LED packages are packaged based on Chip On Board (COB) technology on the PCB.