LED pixel package

Abstract

To provide an LED pixel package and a method of manufacturing the LED pixel package.SOLUTION: The present invention provides an LED pixel package. The LED pixel package includes: a packaging substrate including a recessed groove; a drive circuit bare die provided in the recessed groove and having a top face of the bare die; LED dies provided in a front pixel area at intervals, each LED die including a light emission surface higher than the top face of the bare die; electrode pads arranged in the front pixel area at intervals; and a packaging rubber layer covering the drive circuit bare die, the LED dies and the electrode pads, the packaging rubber layer including a plurality of first transparent conductive patterns which each have one end connected to the drive circuit bare die and the other end connected to each LED die, and a plurality of second transparent conductive patterns which each have one end connected to the drive circuit bare die and the other end connected to each electrode pad. Thus, blocking of beams of the LED dies are avoided.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a package and a method for fabricating the package, and more particularly to an LED pixel package and a method for fabricating the LED pixel package. [Background technology]

[0002] With the development of technology, the size of light emitting diodes (LEDs) can be reduced, allowing them to be applied to more products, such as submillimeter light emitting diodes (Mini LEDs) or micro light emitting diodes (Micro LEDs) for display applications. In the process, a packaging substrate, a three-color LED die, and a driver chip are packaged into an LED pixel package, which can then be assembled and applied.

[0003] However, typically, the driver chip and the LED die are mounted on the surface of the packaging substrate and then electrically connected by wire bonding. This process makes it difficult to reduce the size of the LED pixel package, and also causes the top surface of the driver circuit to be higher than the light-emitting surface of the LED die, resulting in problems such as light blocking. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, those skilled in the art have improved the structure of LED pixel packages by stacking the LED die on top of the driver chip and then electrically connecting them using wire bonding, thereby solving the problems of size and light blocking. However, the problem with this vertical stacking is that heat generated by the LED die during operation is easily transferred to the driver chip, easily causing overheating damage to the device, affecting reliability and product lifespan. Furthermore, as the size of LED dies and LED pixel packages shrinks, the difficulty of the wire bonding process also increases, and LED pixel packages packaged after wire bonding have a certain thickness, which is disadvantageous for thinning.

[0005] In view of this, how to improve the structure of LED pixel packages to reduce thickness and avoid blocking the light rays of the LED die has become a problem that related companies are trying to solve. [Means for solving the problem]

[0006] To solve the above problems, the present invention provides an LED pixel package and a method for manufacturing the LED pixel package, which can achieve the purpose of reducing the thickness and avoiding the light from the LED die being blocked by the structural arrangement of the LED pixel package.

[0007] According to one embodiment of the present invention, there is provided an LED pixel package comprising: a packaging substrate including a front pixel region, a rear pixel region opposite the front pixel region, and a groove located in the front pixel region; a driving circuit bare die disposed in the groove and having a top surface of the bare die; a plurality of LED dies disposed at intervals in the front pixel region, each having a light-emitting surface higher than the top surface of the bare die; a plurality of electrode pads arranged at intervals in the front pixel region; and a packaging rubber layer disposed in the front pixel region to cover the driving circuit bare die, the plurality of LED dies, and the plurality of electrode pads, wherein the packaging rubber layer includes a plurality of first transparent conductive patterns, one end of which is connected to the driving circuit bare die and the other end of which is connected to each of the LED dies, and a plurality of second transparent conductive patterns, one end of which is connected to the driving circuit bare die and the other end of which is connected to each of the electrode pads.

[0008] In this way, the driving circuit bare die is placed in the groove and the light-emitting surface of the LED die is higher than the top surface of the bare die, thereby preventing the light from being blocked by the LED die, and the packaging rubber layer includes the first transparent conductive pattern and multiple second transparent conductive patterns, thereby reducing the thickness of the LED pixel package.

[0009] The LED pixel package according to the above embodiment may further include a plurality of driving circuit welding pads, a plurality of LED die welding pads, and a plurality of conductive parts, the plurality of driving circuit welding pads and the plurality of LED die welding pads being arranged at intervals in the backside pixel area, the packaging substrate further including a plurality of first vias and a plurality of second vias, each of the first vias penetrating the packaging substrate and connected to each LED die welding pad and each LED die, each of the second vias penetrating the packaging substrate and connected to each driving circuit welding pad and each electrode pad, and the plurality of conductive parts being filled in the plurality of first vias and the plurality of second vias, respectively.

[0010] The LED pixel package according to the above embodiment may further include a protective layer covering the packaging rubber layer.

[0011] In the LED pixel package according to the above embodiment, the packaging substrate may be made of a transparent material.

[0012] In the LED pixel package according to the above embodiment, each of the first transparent conductive patterns and each of the second transparent conductive patterns may be indium tin oxide.

[0013] According to another embodiment of the present invention, there is provided a method for manufacturing an LED pixel package, the method including the steps of: providing an integrated circuit wafer including a packaging substrate, a plurality of driving circuit bare dies, a plurality of LED pixel groups, and a plurality of electrode pad groups; the packaging substrate including a plurality of front pixel areas and a plurality of grooves respectively located in the front pixel areas, each of the driving circuit bare dies being disposed in a respective groove and having a bare die top surface; each of the LED pixel groups including a plurality of LED dies disposed in each of the front pixel areas and arranged at intervals, each of the LED dies having a light-emitting surface higher than the top surface of the respective bare die; and each of the electrode pad groups being disposed in each of the front pixel areas; applying packaging rubber to the plurality of front pixel areas so as to cover the plurality of driving circuit bare dies, the plurality of LED pixel groups, and the plurality of electrode pad groups; and forming a plurality of trenches in the packaging rubber and covering the plurality of transparent conductive rubber thereon. a transparent conductive pattern forming step of flowing current into the trenches to form a plurality of first transparent conductive pattern groups and a plurality of second transparent conductive pattern groups to form a packaging rubber and a packaging rubber layer, each first transparent conductive pattern group corresponding to a respective front pixel area and including a plurality of first transparent conductive patterns, each first transparent conductive pattern of each first transparent conductive pattern group having one end connected to the driving circuit bare die of the respective front pixel area and the other end connected to a respective LED die of the respective front pixel area, each second transparent conductive pattern group corresponding to a respective front pixel area and including a plurality of second transparent conductive patterns, each second transparent conductive pattern of each second transparent conductive pattern group having one end connected to the driving circuit bare die of the respective front pixel area and the other end connected to a respective electrode pad of the electrode pad group of the respective front pixel area; and a cutting step of cutting the integrated circuit wafer to separate the plurality of front pixel areas to form a plurality of LED pixel packages.

[0014] The method for manufacturing the LED pixel package according to the above embodiment may further include a protective layer forming step, which is performed before the cutting step, for covering the packaging rubber layer with a protective layer.

[0015] In the method for fabricating an LED pixel package according to the above embodiment, the packaging substrate may be made of a transparent material.

[0016] In the method for fabricating an LED pixel package according to the above embodiment, each of the first transparent conductive patterns and each of the second transparent conductive patterns may be indium tin oxide.

[0017] In the method for fabricating the LED pixel packages according to the above embodiments, the integrated circuit wafer may further include a plurality of driving circuit welding pad groups, a plurality of LED die welding pad groups, and a plurality of conductive parts; the packaging substrate may further include a plurality of back pixel areas opposite each of the front pixel areas, each of the driving circuit welding pad groups and each LED die welding pad group being arranged at intervals in each of the back pixel areas; the packaging substrate may further include a plurality of first via groups and a plurality of second via groups, each of the first via groups including a plurality of first vias penetrating the packaging substrate and connected to each of the LED die welding pads and each of the LED dies; each of the second via groups including a plurality of second vias penetrating the packaging substrate and connected to each of the driving circuit welding pads and each of the electrode pads; and the conductive parts are filled in the plurality of first vias and the plurality of second vias, respectively. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic front view of an LED pixel package according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional schematic diagram illustrating the LED pixel package of the embodiment of FIG. 1. [Figure 3] 4 is a block flow chart illustrating a method for fabricating an LED pixel package according to another embodiment of the present invention. [Figure 4] 4 is a manufacturing flowchart illustrating a method for manufacturing the LED pixel package of the embodiment of FIG. 3. [Figure 5] 4A to 4C are cross-sectional schematic diagrams illustrating a method for fabricating the LED pixel package of the embodiment of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. For clarity, many practical details will be described in the following description. However, the reader should understand that these practical details are not used to limit the present invention. That is, in some embodiments of the present invention, these practical details are not necessary. In addition, to simplify the drawings, some conventional structures and elements are simply and diagrammatically shown in the drawings, and overlapping elements may be represented by the same or similar numbers.

[0020] In this specification, when an element (or mechanism, module, etc.) is "connected," "placed," or "coupled" to another element, it may mean that the element is directly connected, directly placed, or directly coupled to the other element, or that the element is indirectly connected, indirectly placed, or indirectly coupled to the other element, meaning that the other element is interposed between the element and the other element. On the other hand, when an element is "directly connected," "directly placed," or "directly coupled" to another element, it means that the other element is not interposed between the element and the other element. Terms such as "first," "second," and "third" are used only to describe different elements or components and do not limit the elements / components themselves, so a "first element / component" may be read as a "second element / component." Furthermore, the combinations of elements / components / mechanisms / modules in this specification are not generally known, common, or known combinations in this field. Whether the elements / components / mechanisms / modules themselves are known does not determine whether the combinations would be easily achieved by a person skilled in the art.

[0021] Please refer to Figures 1 and 2. Figure 1 is a front schematic view showing an LED pixel package 100 according to one embodiment of the present invention, and Figure 2 is a cross-sectional schematic view showing the LED pixel package 100 of the embodiment of Figure 1. Please note that for clarity of the drawing, no cross-sectional lines are drawn in the cross-sectional view of the present invention. The LED pixel package 100 includes a packaging substrate 110, a driving circuit bare die 120, a plurality of LED dies 140, and a plurality of electrode pads 130.

[0022] The packaging substrate 110 may include a front pixel region 111, a rear pixel region 112, and a groove 113. The rear pixel region 112 is opposite the front pixel region 111, and the groove 113 is located in the front pixel region 111. The driving circuit bare die 120 is disposed in the groove 113 and has a bare die top surface 121. The LED dies 140 are disposed at intervals in the front pixel region 111 of the packaging substrate 110, and each LED die 140 has a light-emitting surface 141 higher than the bare die top surface 121. The electrode pads 130 are disposed at intervals in the front pixel region 111. The packaging rubber layer 150 is disposed in the front pixel region 111 of the packaging substrate 110 to cover the driving circuit bare die 120, the LED dies 140, and the electrode pads 130, and includes a plurality of first transparent conductive patterns 151 and a plurality of second transparent conductive patterns 152. Each first transparent conductive pattern 151 has one end connected to the driving circuit bare die 120 and the other end connected to each LED die 140. Each second transparent conductive pattern 152 has one end connected to the driving circuit bare die 120 and the other end connected to each electrode pad 130.

[0023] Therefore, by placing the driving circuit bare die 120 in the groove 113 and making the light-emitting surface 141 of the LED die 140 higher than the top surface 121 of the bare die, it is possible to avoid blocking the light from the LED die 140. In addition, by making the packaging rubber layer 150 include the first transparent conductive pattern 151 and the second transparent conductive pattern 152, it is possible to reduce the thickness of the LED pixel package 100.

[0024] 1 and 2, the packaging substrate 110 may be made of a transparent material and have a rectangular plate shape. The packaging substrate 110 may have a groove 113 formed therein, which is sized to accommodate the driving circuit bare die 120. The electrode pads 130 may be provided on the packaging substrate 110 in a well-known manner, and the details of this portion are not the focus of the present invention and will not be described separately.

[0025] The driving circuit bare die 120 is an unpackaged integrated circuit and may include a bare die body 122 and a plurality of pin welding pads 123, 124. The top surface 121 of the bare die is the upper surface of the bare die body 122, and the pin welding pads 123, 124 may be arranged at intervals on the top surface 121 of the bare die. When the driving circuit bare die 120 is installed in the groove 113, the top surface 121 of the bare die may be flush with the pixel surface of the front pixel area 111, and thus the pin welding pads 123, 124 may protrude from the pixel surface. The number of pin welding pads 123 may correspond to the number of LED dies 140 and be used to electrically connect to the LED dies 140, and the pin welding pads 123 are used to drive the outputs of the LED dies 140. The number of pin welding pads 124 may correspond to the number of electrode pads 130 and may be used to electrically connect to the electrode pads 130, and the pin welding pads 124 may be used as, but are not limited to, a power supply positive electrode, a power supply negative electrode, a main display data output, a main display data input, a sub-display data output, and a sub-display data input.

[0026] The number of LED dies 140 may be three, and the three LED dies 140 may emit light of different colors, such as red, blue, and yellow. Each LED die 140 may have a vertical LED die structure and include a die body 142 and a die upper electrode 143. The die upper electrode 143 may be provided above the die body 142, and a die substrate (not shown) of the die body 142 may be metal and directly used as a die lower electrode. Therefore, the die body 142 may be directly welded to the front pixel region 111 of the packaging substrate 110. In other embodiments, for the LED die, the die lower electrode may be separately provided below the die body, which is useful for welding the LED die to the front pixel region, and is not limited to the above disclosure.

[0027] The LED pixel package 100 may further include a plurality of driving circuit welding pads 170, a plurality of LED die welding pads 160, and a plurality of conductive parts 180. The driving circuit welding pads 170 and the LED die welding pads 160 may be arranged at intervals in the back pixel area 112 of the packaging substrate 110. The packaging substrate 110 may further include a plurality of first vias 114 and a plurality of second vias 115, each of the first vias 114 penetrating the packaging substrate 110 and connecting to each LED die welding pad 160 and each LED die 140, each of the second vias 115 penetrating the packaging substrate 110 and connecting to each driving circuit welding pad 170 and each electrode pad 130, and the conductive parts 180 filling the first vias 114 and the second vias 115, respectively.

[0028] Specifically, a first via 114 and a second via 115 may be fabricated in the packaging substrate 110 during the process, and since both the first via 114 and the second via 115 penetrate the packaging substrate 110, conductive vias (VIAs) can be formed after filling with the conductive portion 180, and can be electrically connected to the elements located in the front pixel region 111 and the back pixel region 112. Therefore, the LED die welding pad 160 can be electrically connected to the LED die 140, and the driving circuit welding pad 170 can be electrically connected to the driving circuit bare die 120. In this way, the LED pixel package 100 can then be electrically connected to other elements via the driving circuit welding pad 170 and the LED die welding pad 160.

[0029] When fabricating the packaging rubber layer 150, packaging rubber may be applied to the front pixel region 111 first, and then a plurality of trenches may be formed through a lithography process to correspond to the electrode pads 130, the pin welding pads 123 and 124, and the on-die electrodes 143. Then, the first transparent conductive pattern 151 and the second transparent conductive pattern 152 may be fabricated. In the embodiment of FIGS. 1 and 2, the first transparent conductive pattern 151 and the second transparent conductive pattern 152 may be fabricated by filling the trenches with transparent conductive rubber (e.g., indium tin oxide), so that the first transparent conductive pattern 151 and the second transparent conductive pattern 152 may be indium tin oxide, and light blocking can be avoided.

[0030] In the process, transparent conductive rubber may be applied on the packaging rubber and allowed to flow into the trenches, and then unnecessary portions may be removed by a lithography process, so that the first transparent conductive pattern 151 includes two first connecting sections 151a and 151b and a first middle section 151c, and the second transparent conductive pattern 152 includes two second connecting sections 152a and 152b and a second middle section 152c. The first connecting sections 151a and 151b are respectively connected to the pin welding pad 123 and the on-die electrode 143, the first middle section 151c is connected between the first connecting section 151a and the first connecting section 151b, the second connecting sections 152a and 152b are respectively connected to the pin welding pad 124 and the electrode pad 130, and the second middle section 152c is connected between the second connecting section 152a and the second connecting section 152b, completing the electrical connection.

[0031] The LED pixel package 100 may further include a protective layer 190 covering the packaging rubber layer 150. This can achieve the effect of protecting the first transparent conductive pattern 151 and the second transparent conductive pattern 152.

[0032] Please refer to Figures 3, 4 and 5. Figure 3 is a block flowchart showing a method S100 for fabricating an LED pixel package according to another embodiment of the present invention, Figure 4 is a fabrication flowchart showing the method S100 for fabricating an LED pixel package of the embodiment of Figure 3, and Figure 5 is a cross-sectional schematic view showing the method S100 for fabricating an LED pixel package of the embodiment of Figure 3. The method S100 for fabricating an LED pixel package includes an integrated circuit wafer providing step S110, a packaging rubber applying step S120, a transparent conductive pattern forming step S130 and a cutting step S150.

[0033] In the integrated circuit wafer providing process S110, an integrated circuit wafer W1 is provided. The integrated circuit wafer W1 includes a packaging substrate 210, a plurality of driving circuit bare dies 220, a plurality of LED pixel groups, and a plurality of electrode pad groups. The packaging substrate 210 includes a plurality of front pixel regions 211 and a plurality of grooves 213 located in each of the front pixel regions 211. Each driving circuit bare die 220 is disposed in the groove 213 and has a top surface of the bare die (not shown in Figures 3 to 5). Each LED pixel group is disposed in each front pixel region 211 and includes a plurality of LED dies 240 arranged at intervals. Each LED die 240 has a light-emitting surface (not shown in Figures 3 to 5) that is higher than the top surface of the respective bare die. Each electrode pad group is disposed in each front pixel region 211.

[0034] In the packaging rubber application step S120, packaging rubber 253 is applied to the front pixel areas 211 of the packaging substrate 210 so as to cover the driving circuit bare dies 220, the LED pixel groups, and the electrode pad groups.

[0035] In the transparent conductive pattern formation process S130, multiple trenches 254 are formed in the packaging rubber 253 and coated with transparent conductive rubber 255, and the transparent conductive rubber 255 may flow into the multiple trenches 254 to form multiple first transparent conductive pattern groups and multiple second transparent conductive pattern groups, thereby forming the packaging rubber 253 and the packaging rubber layer 250. Each first transparent conductive pattern group corresponds to each front pixel region 211 and includes a plurality of first transparent conductive patterns 251, each of which has one end connected to the driving circuit bare die 220 of each front pixel region 211 and the other end connected to each LED die 240 of each front pixel region; each second transparent conductive pattern group corresponds to each front pixel region 211 and includes a plurality of second transparent conductive patterns 252, each of which has one end connected to the driving circuit bare die 220 of each front pixel region 211 and the other end connected to each electrode pad 230 of each electrode pad group of each front pixel region 211.

[0036] In the cutting step S150, the integrated circuit wafer W1 is cut to separate the plurality of front pixel regions 211, thereby forming a plurality of LED pixel packages 200.

[0037] In addition, the method for manufacturing an LED pixel package S100 may further include a protective layer forming step S140, which is performed before the cutting step S150, for covering the packaging rubber layer 250 with a protective layer 290.

[0038] 3 and 4, in the integrated circuit wafer providing step S110, the provided integrated circuit wafer W1 already includes elements other than the packaging rubber layer 250 and the protective layer 290, and also has the driving circuit bare die 220 and LED pixel groups already provided thereon. After that, the packaging rubber layer 250 may be fabricated by a lithography process. Therefore, the integrated circuit wafer W1 may further include a plurality of driving circuit welding pad groups, a plurality of LED die welding pad groups, and a plurality of conductive portions (not shown in FIGS. 3 to 5). The packaging substrate 210 further includes a plurality of rear pixel areas 212, and each driving circuit welding pad group and each LED die welding pad group is arranged at an interval in each rear pixel area 212. The packaging substrate 210 may further include a plurality of first via groups and a plurality of second via groups, each of which includes a plurality of first vias (not shown in Figures 3 to 5) that penetrate the packaging substrate 210 and are connected to each LED die welding pad (not shown in Figures 3 to 5) of each LED die welding pad group and each LED die 240, and each of the second via groups includes a plurality of second vias (not shown in Figures 3 to 5) that penetrate the packaging substrate 210 and are connected to each drive circuit welding pad (not shown in Figures 3 to 5) of each drive circuit welding pad group and each electrode pad 230, and the plurality of conductive portions are filled in the plurality of first vias and the plurality of second vias, respectively.

[0039] In the packaging rubber application process S120, a packaging rubber 253 may be applied, and then a trench 254 connected to the LED die 240, the driving circuit bare die 220, and the electrode pad 230 may be formed through processes such as exposure, development, and etching. In the transparent conductive pattern formation process S130, a transparent conductive rubber 255 may be applied, and the transparent conductive rubber 255 may flow into and fill the trench 254, and a transparent conductive film may be formed on the surface of the packaging rubber 253. Then, a portion of the transparent conductive film may be removed to cut off unnecessary electrical connections, and the first transparent conductive pattern 251 and the second transparent conductive pattern 252 may be formed. Finally, a protective layer 290 may be formed.

[0040] After the above steps are completed, the integrated circuit wafer W1 may be laser cut in a cutting step S150, so that the back pixel regions 212 (which also correspond to the front pixel regions 211) that are originally connected to each other may be separated from each other to form a plurality of LED pixel packages 200, as shown in FIG.

[0041] Although the present invention has been disclosed as described above in the embodiments, the above embodiments are not used to limit the present invention, and anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention is as defined by the claims attached below. [Explanation of symbols]

[0042] 100, 200: LED pixel package 110, 210: Packaging substrate 111, 211: Front pixel area 112, 212: rear pixel area 113, 213: groove 114: First via 115: Second via 120, 220: Drive circuit bare die 121: Top surface of bare die 122: Bare die body 123, 124: Pin welding pad 130, 230: Electrode pads 140, 240: LED die 141:Idemitsu surface 142: Die body 143: Electrode on die 150, 250: Packaging rubber layer 151, 251: First transparent conductive pattern 151a, 151b: First connection section 151c: First middle section 152, 252: second transparent conductive pattern 152a, 152b: second connection section 152c: Second middle section 160: LED die welding pad 170:Drive circuit welding pad 180: Conductive part 190, 290: Protective layer 253: Packaging rubber 254: Trench 255: Transparent conductive rubber S100: LED pixel package manufacturing method S110: Integrated circuit wafer provision process S120: Packaging rubber application process S130: Transparent conductive pattern formation process S140: Protective layer formation process S150: Cutting process W1: Integrated circuit wafer

Claims

1. 1. An LED pixel package comprising: a packaging substrate including a front pixel region, a rear pixel region opposite the front pixel region, and a recess located in the front pixel region; a drive circuit bare die provided in the groove and having a top surface of the bare die; a plurality of LED dies spaced apart from one another in the front pixel region, each including a light-emitting surface higher than a top surface of the bare die; a plurality of electrode pads arranged at intervals in the front pixel region; a packaging rubber layer provided in the front pixel area so as to cover the driving circuit bare die, the LED dies, and the electrode pads; Equipped with The packaging rubber layer is a plurality of first transparent conductive patterns, each having one end connected to the driving circuit bare die and the other end connected to each of the LED dies; a plurality of second transparent conductive patterns, each having one end connected to the driving circuit bare die and the other end connected to each of the electrode pads;

2. 2. The LED pixel package of claim 1, further comprising: a plurality of driving circuit welding pads, a plurality of LED die welding pads, and a plurality of conductive parts, wherein the plurality of driving circuit welding pads and the plurality of LED die welding pads are arranged at intervals in the backside pixel area; the packaging substrate further comprises a plurality of first vias and a plurality of second vias, wherein each of the first vias penetrates the packaging substrate and is connected to each of the LED die welding pads and each of the LED dies, and each of the second vias penetrates the packaging substrate and is connected to each of the driving circuit welding pads and each of the electrode pads, and the plurality of conductive parts are filled in the plurality of first vias and the plurality of second vias, respectively.

3. The LED pixel package according to claim 1 , further comprising a protective layer covering the packaging rubber layer.

4. The LED pixel package of claim 1 , wherein the packaging substrate is made of a transparent material.

5. 2. The LED pixel package according to claim 1, wherein each of the first transparent conductive patterns and each of the second transparent conductive patterns is indium tin oxide.

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