Mini LED-RGB display device based on MEP packaging

Abstract

The invention discloses a Mini LED-RGB display device based on MEP packaging, and the device comprises an MEP packaging body, the MEP packaging body comprises a TOP substrate and a Bottom substrate, the upper surface of the TOP substrate is provided with a plurality of light-emitting wafer groups which are uniformly distributed in a rectangular array, an IC chip and heat-conducting liquid gold are disposed between the TOP substrate and the Bottom substrate, the TOP substrate and the Bottom substrate are welded together through alloy balls, and the TOP substrate and the Bottom substrate are welded together through the alloy balls. The lower surface of the Bottom substrate is embedded with a pin bonding pad, printed circuits are embedded in the TOP substrate and the Bottom substrate, and the light-emitting wafer group, the IC chip and the pin bonding pad are electrically communicated with one another through the printed circuits embedded in the TOP substrate and the Bottom substrate, so that a better geothermal management capability is obtained, the high-density printed circuits are ensured, and the service life of the light-emitting wafer group is prolonged. Therefore, the difficulty of the whole preparation process is reduced, and the yield is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of LED display, and particularly to a MiniLED-RGB display device based on MEP packaging. Background Art

[0002] As an advanced packaging technology, chip-level packages have the advantages of high brightness, low power consumption, strong compatibility, the ability to mix BINs to improve display consistency, and the ability to use current machine equipment, and are gradually applied to the display screen field.

[0003] Chip-level packaging is more challenging compared to traditional LED packaging. For example, the packaging size is smaller, the integration degree is higher, and the manufacturing process is more complex.

[0004] However, when packaging MiniLED chips at ultra-small pitches, only considering their electrical performance can no longer meet the requirements of product accuracy, yield, and reliability. It is necessary to consider the influence of multi-physical field effects such as electro-thermal-mechanical on the signal / power integrity and electromagnetic compatibility performance of the device during the design process. High integration and miniaturization mean that the power consumption per unit volume of MiniLED chips and the packaging structure increases significantly, which will exacerbate the Joule heating phenomenon caused by ohmic losses. It is necessary to simulate and test the temperature distribution of the packaged product in different environments; Joule heating will not only cause signal integrity problems such as signal attenuation and delay, but also cause deformation problems such as chip warping caused by thermal stress, seriously affecting the electrical performance of the device, and even damaging the circuit board and chips in extreme environments.

[0005] Therefore, in order to effectively address the thermal management problem of micro-pitch chips, it is necessary to study the electro-thermal-mechanical multi-physical field simulation design optimization technology to provide theoretical support and technical support for chip and thermal management device layout, multi-layer circuit board interconnection design, power-ground plane routing optimization, packaging material selection, etc., so as to ensure the signal and power integrity of the device. Summary of the Invention

[0006] The purpose of the present invention is to provide a MiniLED-RGB display device based on MEP packaging to improve the overall working efficiency in view of the above existing problems and deficiencies.

[0007] The present invention solves at least one of the following technical problems:

[0008] (1) Insufficient Layout space at ultra-small pitches and great difficulty in producing multi-layer high-density substrates;

[0009] (2) The power consumption per unit volume of MiniLED chips and the packaging structure increases significantly, which will cause signal integrity problems such as signal attenuation and delay.

[0010] The object of the present invention can be achieved by the following technical solutions: A MiniLED-RGB display device based on MEP packaging, comprising an MEP package body, the MEP package body includes a TOP substrate and a Bottom substrate, the upper surface of the TOP substrate is provided with a plurality of light-emitting wafer groups evenly distributed in a rectangular array, an IC chip and thermal liquid gold are provided between the TOP substrate and the Bottom substrate, the TOP substrate and the Bottom substrate are welded together by alloy balls, a pin pad is embedded in the lower surface of the Bottom substrate, and printed circuits are buried in both the TOP substrate and the Bottom substrate, and the light-emitting wafer groups, the IC chip and the pin pad are electrically connected to each other through the printed circuits buried in the TOP substrate and the Bottom substrate.

[0011] As a further solution of the invention, a heat pipe is provided in the thermal liquid gold, and heat-conducting blocks are installed between adjacent IC chips on the heat pipe, and porous metal fillers and a refrigerant are provided in both the heat pipe and the heat-conducting blocks, and a plurality of cavities are provided in the porous metal fillers.

[0012] As a further solution of the invention, the cavities of the heat pipe are concentratedly distributed directly below the heat-conducting blocks and directly below the IC chips, and the cavities of the heat pipe are circular in horizontal cross-section and spindle-shaped in vertical cross-section.

[0013] As a further solution of the invention, the light-emitting wafer group includes RLED wafers, GLED wafers, BLED wafers and a common cathode electrode, and the RLED wafers, GLED wafers, BLED wafers and the common cathode electrode are distributed in a square array, and an equal-width wafer gap is maintained between each light-emitting wafer group.

[0014] As a further solution of the invention, the center point spacing between adjacent light-emitting wafer groups is at most 312.5 microns.

[0015] As a further solution of the invention, the length and width of the light-emitting wafer group are the same, and the length and width dimensions are at most 225 microns.

[0016] As a further solution of the invention, the size of the wafer gap is at most 87.5 microns.

[0017] As a further solution of the invention, it further includes a lamp board PCB, and the MEP package body is electrically connected to the lamp board PCB through the pin pad, and a plurality of MEP package bodies evenly distributed in a rectangular array are provided on the lamp board PCB, and a substrate interval is provided between adjacent MEP package bodies.

[0018] As a further solution of the invention, the size of the MEP package body is at most 15 mm, and both the TOP substrate and the Bottom substrate adopt bismaleimide triazine resin as the main material.

[0019] As a further aspect of the invention, the size of the substrate spacing is at most 120 microns.

[0020] Advantages of the present invention:

[0021] (1) By setting the structure of sandwiching and embedding the IC chip with the TOP substrate and the Bottom substrate, the circuit design of the present application forms a three-dimensional structure, thus avoiding the layout limitations on the two-dimensional plane, obtaining more layout space, and at the same time setting the printed circuits for functions according to different positions in the vertical direction, thereby increasing more functions and adjustment ranges, solving the problem that the IC devices on the back of each light-emitting unit cannot be arranged under the limitation of the ultra-small spacing between each light-emitting unit, exploring the physical limit of PCB-based LED displays, and accelerating the trend of the civilian market of micro-pitch LED displays;

[0022] (2) When assembling, it is welded together by alloy balls, which not only avoids the production difficulties of stacking multiple high-density substrates layer by layer, but also ensures the high-density printed circuits, thereby reducing the difficulty of the overall preparation process and improving the yield rate;

[0023] (3) Through the filled thermally conductive liquid gold, the heat generated by the light-emitting wafer group, the IC chip and each circuit is quickly and evenly conducted to the Bottom substrate, and then conducted to the outside, thereby obtaining better heat management capabilities, avoiding a series of problems caused by the thermal stress of heat accumulation of the light-emitting wafer group and the IC chip during the working process, and improving the overall service life;

[0024] (4) During operation, the heat conduction rate of the thermally conductive liquid gold is accelerated by the heat spreader and the heat conduction block. The porous metal filler enables the refrigerant to more fully and quickly absorb the heat from the light-emitting wafer group or the IC chip and other circuits. After the refrigerant absorbs heat, it undergoes a phase change and quickly moves to the side far from the heat absorption place. Subsequently, the refrigerant undergoes a phase change again to release the absorbed heat. The phase-changed refrigerant forms a capillary flow by virtue of the porous structure of the porous metal filler and moves back to the initial heat absorption place again, forming a cyclic fast heat conduction rate, further controlling the temperature of each heating object, and evenly conducting the heat to the Bottom substrate for further heat dissipation, so as to make the overall obtain the best heat dissipation effect, avoid heat accumulation, and facilitate the further heat dissipation process. Description of the Drawings

[0025] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the drawings.

[0026] Figure 1 It is a schematic diagram of the overall structure of the MEP package of the present invention;

[0027] Figure 2 It is Figure 1Cross-sectional side view of plane A-A in [Chinese];

[0028] Figure 3 Top view of the partial structure of the MEP package of the present invention;

[0029] Figure 4 Cross-sectional view of the overall structure of the present invention;

[0030] Figure 5 Top view of the partial structure of the present invention;

[0031] In the figure: 101, MEP package; 102, lamp board PCB; 201, TOP substrate; 202, light-emitting wafer group; 203, IC chip; 204, Bottom substrate; 205, pin pad; 206, heat sink plate; 207, heat-conducting block; 208, alloy ball; 209, heat-conducting liquid gold; 301, RLED wafer; 302, GLED wafer; 303, BLED wafer; 304, common cathode electrode; 305, wafer gap; 401, substrate spacing. Detailed implementation manners

[0032] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features and their effects of the present invention as follows.

[0033] Please refer to Figures 1-5 as shown: Embodiment 1:

[0034] A MiniLED-RGB display device based on MEP packaging includes an MEP package 101. The MEP package 101 includes a TOP substrate 201 and a Bottom substrate 204. The upper surface of the TOP substrate 201 is provided with a plurality of light-emitting wafer groups 202 evenly distributed in a rectangular array. An IC chip 203 and heat-conducting liquid gold 209 are provided between the TOP substrate 201 and the Bottom substrate 204. The TOP substrate 201 and the Bottom substrate 204 are welded together through alloy balls 208. The lower surface of the Bottom substrate 204 is embedded with pin pads 205. Printed circuits are buried in both the TOP substrate 201 and the Bottom substrate 204. The light-emitting wafer groups 202, the IC chip 203 and the pin pads 205 are electrically connected to each other through the printed circuits buried in the TOP substrate 201 and the Bottom substrate 204;

[0035] MEP is the abbreviation of "Moulded Embedded Package", which means "moulded embedded package";

[0036] When this embodiment works, by setting up the structure of clamping and embedding the IC chip 203 with the TOP substrate 201 and the Bottom substrate 204, the circuit design of this application forms a three-dimensional structure, thus avoiding the layout limitations on the two-dimensional plane and obtaining more layout space. At the same time, according to the different positions in the vertical direction, printed circuits for functions are set, thereby increasing more functions and adjustment ranges. During assembly, they are welded together by alloy balls 208, which not only avoids the production difficulties of stacking multiple high-density substrates layer by layer, but also ensures a high-density printed circuit, thus reducing the difficulty of the overall preparation process and improving the yield rate. Through the filled thermally conductive liquid gold 209, the heat generated by the light-emitting wafer group 202, the IC chip 203, and each circuit is quickly and evenly conducted to the Bottom substrate 204, and then conducted to the outside, thereby obtaining better thermal management capabilities, avoiding a series of problems caused by the thermal stress of heat accumulation in the light-emitting wafer group 202 and the IC chip 203 during the working process, and improving the overall service life.

[0037] Embodiment Two:

[0038] On the basis of Embodiment One, a heat spreader 206 is provided in the thermally conductive liquid gold 209. A heat conduction block 207 is installed between adjacent IC chips 203 on the heat spreader 206. Both the heat spreader 206 and the heat conduction block 207 are provided with porous metal fillers and refrigerant. The porous metal filler is provided with several cavities. The cavities of the heat spreader 206 are concentrated directly below the heat conduction block 207 and directly below the IC chip 203. The cavities of the heat spreader 206 are circular in the horizontal cross-section and spindle-shaped in the vertical cross-section.

[0039] When this embodiment works, the heat conduction rate of the thermally conductive liquid gold 209 is accelerated by the heat spreader 206 and the heat conduction block 207. The porous metal filler enables the refrigerant to more fully and quickly absorb the heat from the light-emitting wafer group 202 or the IC chip 203 and other circuits. After absorbing heat, the refrigerant undergoes a phase change and quickly moves to the side far from the heat absorption area. Subsequently, the refrigerant undergoes a phase change again to release the absorbed heat. The phase-changed refrigerant forms a capillary flow by virtue of the porous structure of the porous metal filler and moves back to the initial heat absorption area again, forming a cyclic fast heat conduction rate, further controlling the temperature of each heating object, and evenly conducting the heat to the Bottom substrate 204 for further heat dissipation, so as to obtain the best heat dissipation effect for the whole, avoid heat accumulation, and facilitate the further heat dissipation process.

[0040] Embodiment Three:

[0041] On the basis of Embodiment 2, the light-emitting wafer group 202 includes an RLED wafer 301, a GLED wafer 302, a BLED wafer 303, and a common cathode electrode 304. The RLED wafer 301, the GLED wafer 302, the BLED wafer 303, and the common cathode electrode 304 are distributed in a square array, and an equal-width wafer gap 305 is maintained between each light-emitting wafer group 202;

[0042] If the distance between the centers of adjacent light-emitting wafer groups 202 is set as a, then a ≤ 312.5 microns;

[0043] Each light-emitting wafer group 202 has the same length and width, and if the length and width dimensions are set as b, then b ≤ 225 microns;

[0044] If the size of the wafer gap 305 is set as c, then c ≤ 87.5 microns;

[0045] If the size of the MEP package 101 is set as d, then d is an integer multiple of a;

[0046] Embodiment 4:

[0047] On the basis of Embodiment 3, it further includes a lamp board PCB 102. The MEP package 101 is electrically connected to the lamp board PCB 102 through a pin pad 205. A number of MEP packages 101 are evenly distributed in a rectangular array on the lamp board PCB 102. A substrate interval 401 is provided between adjacent MEP packages 101. If the size of the substrate interval 401 is set as e, then e ≤ 120 microns, and d ≤ 15 mm;

[0048] Both the TOP substrate 201 and the Bottom substrate 204 use bismaleimide triazine resin as the main material.

[0049] When the present invention is in use, the staff sets the structure of the TOP substrate 201 and the Bottom substrate 204 to clamp and embed the IC chip 203, so that the circuit design of the present application forms a three-dimensional structure, thereby avoiding the layout limitations on the two-dimensional plane, obtaining more layout space, and at the same time setting the printed circuit for functions according to different positions in the vertical direction, thereby increasing more functions and adjustment ranges, solving the problem that the IC devices on the back of each light-emitting unit cannot be arranged under the limitation of the ultra-small distance between each light-emitting unit, reaching the physical limit of the PCB-based LED display, and accelerating the trend of the civilian market of the layout of micro-pitch LED displays;

[0050] By welding each component together with the alloy ball 208, it not only skillfully avoids the production difficulties of the traditional process of stacking multiple high-density substrates layer by layer, but also ensures the stability and reliability of the high-density printed circuit, thereby greatly reducing the difficulty of the entire product preparation process and significantly improving the yield;

[0051] In traditional processes, the layer-by-layer stacking of multi-layer high-density substrates is an extremely complex and error-prone process. The alignment accuracy, welding quality, and material compatibility of each layer of the substrate need to be strictly controlled. A slight oversight can lead to problems such as short circuits, open circuits, or signal interference in the entire product. However, after adopting the alloy ball 208 welding technology, these problems are solved. The alloy ball 208 has excellent electrical conductivity and thermal stability, and can quickly and accurately connect each component together in a high-temperature environment to form an integrated whole. This not only reduces the number of welding points, decreases the impact of thermal stress during the welding process on the substrate, but also improves the welding efficiency and shortens the production cycle.

[0052] In high-density printed circuits, the alloy ball 208 can ensure a closer connection of the circuit and more stable signal transmission, thus meeting the requirements of high reliability, significantly improving the overall performance of electronic products, and at the same time making it possible for the products to be miniaturized and lightweight.

[0053] In summary, the application of the alloy ball 208 welding technology not only solves many problems in traditional processes, but also brings higher efficiency and better quality to the production of this invention.

[0054] Through the filled thermally conductive liquid gold 209, the heat generated by the light-emitting wafer group 202, the IC chip 203, and each circuit is quickly and evenly conducted to the Bottom substrate 204, and then conducted to the outside, thereby obtaining better thermal management capabilities, avoiding a series of problems caused by the thermal stress of heat accumulation in the light-emitting wafer group 202 and the IC chip 203 during operation, and improving the overall service life.

[0055] During operation, the heat conduction rate of the thermally conductive liquid gold 209 is accelerated through the heat spreader 206 and the heat conduction block 207. The porous metal filler enables the refrigerant to more fully and quickly absorb the heat from the light-emitting wafer group 202 or the IC chip 203 and other circuits. After absorbing heat, the refrigerant undergoes a phase change and quickly moves to the side far from the heat absorption area. Subsequently, the refrigerant undergoes a phase change again to release the absorbed heat. The phase-changed refrigerant forms a capillary flow by virtue of the porous structure of the porous metal filler and moves back to the initial heat absorption area again, forming a cyclic and rapid heat conduction rate, further controlling the temperature of each heat-generating object, and evenly conducting the heat to the Bottom substrate 204 for further heat dissipation, so as to enable the whole to obtain the best heat dissipation effect, avoid heat accumulation, and facilitate the further heat dissipation process.

[0056] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A MiniLED-RGB display device based on MEP packaging, characterized in that: The MEP package (101) comprises a TOP substrate (201) and a Bottom substrate (204); a plurality of light-emitting chip groups (202) uniformly distributed in a rectangular array are provided on the upper surface of the TOP substrate (201); an IC chip (203) and thermal conductive liquid gold (209) are provided between the TOP substrate (201) and the Bottom substrate (204); the TOP substrate (201) and the Bottom substrate (204) are welded together via an alloy ball (208); a pin pad (205) is embedded on the lower surface of the Bottom substrate (204); printed circuits are embedded in the TOP substrate (201) and the Bottom substrate (204); and the light-emitting chip group (202), the IC chip (203) and the pin pad (205) are electrically connected to each other via the printed circuits embedded in the TOP substrate (201) and the Bottom substrate (204).

2. According to claim 1, a MiniLED-RGB display device based on MEP packaging is characterized in that: A heat spreader (206) is provided in the heat conducting liquid gold (209), a heat conducting block (207) is installed on the heat spreader (206) and between adjacent IC chips (203), and porous metal fillers and refrigerants are provided in the heat spreader (206) and the heat conducting block (207), and a plurality of cavities are provided in the porous metal filler.

3. According to claim 2, a MiniLED-RGB display device based on MEP packaging is characterized in that: The cavity of the heat spreader (206) is concentratedly distributed directly below the heat conducting block (207) and directly below the IC chip (203), and the cavity of the heat spreader (206) is in the shape of a perfect circle in a horizontal section and in the shape of a spindle in a vertical section.

4. The MiniLED-RGB display device based on MEP packaging according to claim 1, characterized in that: The light-emitting chip group (202) comprises an RLED chip (301), a GLED chip (302), a BLED chip (303) and a common cathode electrode (304); the RLED chip (301), the GLED chip (302), the BLED chip (303) and the common cathode electrode (304) are distributed in a square array, and a chip gap (305) of equal width is maintained between each light-emitting chip group (202).

5. The MiniLED-RGB display device based on MEP packaging according to claim 4, characterized in that: The distance between the center points of adjacent light emitting chip groups (202) is at most 312.5 microns.

6. The MiniLED-RGB display device based on MEP packaging according to claim 4, characterized in that: The length and width of the light-emitting chip group (202) are consistent, and the length and width dimensions are at most 225 micrometers.

7. The MiniLED-RGB display device based on MEP packaging according to claim 4, characterized in that: The wafer gap (305) has a size of at most 87.5 microns.

8. The MiniLED-RGB display device based on MEP packaging according to claim 1, characterized in that: It also comprises a light board PCB (102), wherein the MEP package (101) is electrically connected to the light board PCB (102) via a pin pad (205), and the light board PCB (102) is provided with a plurality of MEP packages (101) evenly distributed in a rectangular array, and substrate spacers (401) are provided between adjacent MEP packages (101).

9. The MiniLED-RGB display device based on MEP packaging according to claim 8, characterized in that: The size of the MEP package (101) is at most 15 mm, and both the TOP substrate 201 and the Bottom substrate (204) use bismaleimide triazine resin as the main material.

10. The MiniLED-RGB display device based on MEP packaging according to claim 8, characterized in that: The size of the substrate spacing (401) is at most 120 microns.

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