A light-emitting diode module and a preparation method thereof

Abstract

The present invention discloses a light-emitting diode module and a preparation method thereof, including a circuit board. The light-emitting diode module further includes: a red light chip, a green light chip, and a blue light chip sequentially arranged on the circuit board; the green light chip is arranged between the red light chip and the blue light chip. The red light chip, the green light chip, and the blue light chip all include a P-type electrode, a conductive layer, a P-type semiconductor layer, a light-emitting layer, an N-type semiconductor layer, a transparent conductive layer, and an N-type electrode sequentially stacked on the circuit board. The red light chip and the blue light chip are provided with a first total reflection layer on the side wall far from the green light chip, and a second total reflection layer is respectively provided between the N-type semiconductor layer and the transparent conductive layer in the red light chip and the blue light chip, and is arranged in a preset area of the red light chip and the blue light chip far from the green light chip. The present invention can solve the technical problem that in the prior art, there is more light emission from the edges of the red light chip and the blue light chip, resulting in poor light uniformity of the light-emitting diode module.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a light-emitting diode module and a preparation method thereof. Background Art

[0002] An LED (Light Emitting Diode) is a semiconductor device that emits light by releasing energy when carriers recombine. LED chips have many advantages such as low power consumption, pure chromaticity, long life, small size, fast response time, energy conservation and environmental protection. With the continuous development of LED chips, in recent years, a new display technology, Micro LED (Micro Light Emitting Diode), has begun to develop. It mainly miniaturizes, thins, and arrays LEDs. Its size is in the micron range. Due to its small size and volume, it can be arranged more densely together, thereby greatly improving the resolution. Moreover, it has the self-luminous characteristic and occupies a certain market in terms of high brightness, high contrast, fast response, and power saving.

[0003] Currently, the RGB light-emitting diode module applied in micro light-emitting diodes is formed by arranging red LED chips, green LED chips, and blue LED chips according to certain rules. The light emitted by the red LED chips, green LED chips, and blue LED chips in the RGB light-emitting diode module is mixed to form the light emitted by the RGB light-emitting diode module. Since the photosensitivity of the human eye's visual nerves to light of various different wavelengths is different, it is most sensitive to green light and less sensitive to red and blue light. Therefore, the green LED chips in the RGB light-emitting diode module are located in the middle position between the red LED chips and the blue LED chips. However, when the RGB light-emitting diode module needs to emit light with a reddish or bluish color, the light emitted by the red LED chips and the blue LED chips on both sides is more, and the light-emitting center will shift towards the red LED chips and the blue LED chips on both sides, resulting in poor light uniformity of the light emitted by the RGB light-emitting diode module and affecting the resolution of the RGB light-emitting diode module.

[0004] Therefore, the existing light-emitting diode modules generally have the technical problem that more light is emitted from the edges of the red chips and the blue chips, resulting in poor light uniformity of the light emitted by the light-emitting diode module. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, an object of the present invention is to provide a light-emitting diode module and a preparation method thereof, aiming to solve the technical problem in the prior art that more light is emitted from the edges of the red chips and the blue chips, resulting in poor light uniformity of the light emitted by the light-emitting diode module.

[0006] One aspect of the present invention provides a light-emitting diode module, including a circuit board. The light-emitting diode module further includes:

[0007] A red light chip, a green light chip, and a blue light chip sequentially disposed on the circuit board;

[0008] The green light chip is disposed between the red light chip and the blue light chip. The red light chip, the green light chip, and the blue light chip each include a P-type electrode, a conductive layer, a P-type semiconductor layer, a light-emitting layer, an N-type semiconductor layer, a transparent conductive layer, and an N-type electrode that are sequentially stacked on the circuit board;

[0009] The red light chip and the blue light chip are provided with a first total reflection layer on the side wall away from the green light chip. A second total reflection layer is respectively provided between the N-type semiconductor layer and the transparent conductive layer in the red light chip and the blue light chip. The second total reflection layer covers a part of the N-type semiconductor layer and is disposed in a preset area away from the green light chip in the red light chip and the blue light chip, so that most of the light at the edge is emitted from the light-emitting area close to the green light chip after being reflected and refracted by the first total reflection layer and the second total reflection layer. Compared with the prior art, the beneficial effect of the present invention is that: through a light-emitting diode module provided by the present invention, a first total reflection layer is provided on the side wall of the red chip and the blue chip away from the green chip, so that most of the light emitted from the side wall is emitted from the light-emitting area close to the green light chip after being reflected or refracted. And a second total reflection layer is respectively provided between the N-type semiconductor layer and the transparent conductive layer in the red chip and the blue chip. The second total reflection layer covers a part of the N-type semiconductor layer and is disposed in a preset area away from the green light chip in the red light chip and the blue chip, so that most of the light emitted from the edge is emitted from the light-emitting area close to the green light chip after being reflected or refracted. A first total reflection layer is provided on the side wall of the red chip and the blue chip away from the green chip, and a second total reflection layer is provided in the preset area of the N-type semiconductor layer, reducing the light emitted from the edges of the red light chip and the blue light chip, enhancing the light-emitting intensity in the area close to the green light chip, and weakening the light-emitting intensity in the area away from the green light chip, which is beneficial to promoting the light-emitting center of the overall light-emitting diode module to be away from the edge areas of the red light chip and the blue light chip, improving the light-emitting efficiency at the central position, and thus improving the light-emitting uniformity of the light-emitting diode module. Thereby solving the technical problem that the red light chip and the blue light chip have too much light emitted from the edge, resulting in poor light-emitting uniformity of the light-emitting diode module.

[0010] According to one aspect of the above technical solution, a plurality of through holes are provided on the second total reflection layer, and the number of through holes per unit area gradually increases from the side away from the green light chip to the side close to the green light chip.

[0011] According to one aspect of the above technical solution, the transparent conductive layers in the red light chip and the blue light chip both include a first transparent conductive sub-layer, a second transparent conductive sub-layer connected to the first transparent conductive sub-layer, and a third transparent conductive sub-layer connected to the second transparent conductive sub-layer. The first transparent conductive sub-layer is disposed on the N-type semiconductor layer, the second transparent conductive sub-layer is disposed on the second total reflection layer, and the third transparent conductive sub-layer is disposed in the through hole and contacts the N-type semiconductor layer.

[0012] According to one aspect of the above technical solution, the area of the preset region accounts for 30%-50% of the area on the N-type semiconductor layer.

[0013] According to one aspect of the above technical solution, the reflectivity of the first total reflection layer and the second total reflection layer is greater than 97%.

[0014] According to one aspect of the above technical solution, the first total reflection layer and the second total reflection layer both include a DBR total reflection layer or a metal reflection layer.

[0015] According to one aspect of the above technical solution, the N-type electrodes in the red light chip and the blue light chip are both disposed above the first transparent conductive sub-layer.

[0016] According to one aspect of the above technical solution, the circuit board includes a circuit substrate, a circuit layer disposed on the circuit substrate, and a heat-conducting insulating layer disposed on the circuit layer. The red light chip, the green light chip, and the blue light chip are sequentially disposed on the heat-conducting insulating layer.

[0017] Another aspect of the present invention lies in providing a method for manufacturing a light-emitting diode module. The manufacturing method is used to manufacture any light-emitting diode module described in the above technology. The manufacturing method includes:

[0018] Providing a circuit board, a red light chip, a green light chip, and a blue light chip. Among them, the red light chip, the green light chip, and the blue light chip all include a P-type electrode, a conductive layer, a P-type semiconductor layer, a light-emitting layer, an N-type semiconductor layer, and a substrate that are sequentially stacked on the circuit board;

[0019] Removing the substrates in the red light chip, the green light chip, and the blue light chip;

[0020] Sequentially disposing the red light chip, the green light chip, and the blue light chip with the substrates removed on the circuit board, and the green light chip is disposed between the red light chip and the blue light chip;

[0021] Growing a first total reflection layer on the side walls of the red light chip and the blue light chip away from the green light chip;

[0022] A second total reflection layer is grown on a preset area on the N-type semiconductor layer in the red light chip and the blue light chip, and the preset area is arranged in an area of the red light chip and the blue light chip far from the green light chip;

[0023] A transparent conductive layer is deposited on the red light chip, the green light chip, and the blue light chip respectively;

[0024] An N-type electrode is respectively evaporated on the transparent conductive layer in the red light chip, the green light chip, and the blue light chip.

[0025] Further, after the step of growing a second total reflection layer on a preset area on the N-type semiconductor layer in the red light chip and the blue light chip, and the preset area is arranged in an area of the red light chip and the blue light chip far from the green light chip, the method further includes:

[0026] A plurality of through holes are etched on the second total reflection layer, wherein the number of the through holes per unit area gradually increases from a side far from the green light chip to a side close to the green light chip. Description of the Drawings

[0027] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0028] Figure 1 is a schematic structural diagram of a light emitting diode module in the first embodiment of the present invention;

[0029] Figure 2 is a schematic structural diagram of a red light chip in the first embodiment of the present invention;

[0030] Figure 3 is a top view of a second total reflection layer and an N-type semiconductor layer in the first embodiment of the present invention;

[0031] Figure 4 is a flowchart of a method for manufacturing a light emitting diode module in the sixth embodiment of the present invention;

[0032] Description of the Symbols of the Components in the Drawings

[0033] Circuit board 100, circuit substrate 110, circuit layer 120, thermally conductive insulating layer 130, red light chip 200, green light chip 210, blue light chip 220, P-type electrode 310, conductive layer 320, P-type semiconductor layer 330, light-emitting layer 340, N-type semiconductor layer 350, transparent conductive layer 360, first transparent conductive sub-layer 361, second transparent conductive sub-layer 362, third transparent conductive sub-layer 363, N-type electrode 370, first total reflection layer 410, second total reflection layer 420, via hole 421. Detailed implementation manners

[0034] To make the objectives, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific implementation manners of the present invention with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0035] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right", "upper", "lower", and similar expressions used herein are only for the purpose of illustration and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention.

[0036] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0037] Embodiment 1

[0038] Please refer to Figures 1-3, shown is a light-emitting diode module provided by the first embodiment of the present invention. The light-emitting diode module includes a circuit board 100, which includes a circuit substrate 110, a circuit layer 120 disposed on the circuit substrate 110, and a thermally conductive insulating layer 130 disposed on the circuit layer 120. The circuit substrate 110 is used to support and carry the chips, the circuit layer 120 is used to control the conduction of the chips, and the thermally conductive insulating layer 130 is used to dissipate heat from the chips.

[0039] Among them, a red light chip 200, a green light chip 210, and a blue light chip 220 are sequentially disposed on the circuit board 100; since RGB are the three primary colors of light, and various colors are obtained by changing the three color channels of red (R), green (G), and blue (B) and their superposition with each other, an RGB light-emitting diode module requires a red light chip 200, a green light chip 210, and a blue light chip 220. The red light chip 200, the green light chip 210, and the blue light chip 220 are arranged and combined according to certain rules. Because the visual nerves of the human eye have different sensitivities to light of different wavelengths, being most sensitive to green light and less sensitive to red and blue light, the green light chip 210 is disposed between the red light chip 200 and the blue light chip 220 to ensure that the light emitted by the green light chip 210 has better uniformity, which is beneficial to the light uniformity of the light-emitting diode module. The red light chip 200, the green light chip 210, and the blue light chip 220 each include a P-type electrode 310, a conductive layer 320, a P-type semiconductor layer 330, a light-emitting layer 340, an N-type semiconductor layer 350, a transparent conductive layer 360, and an N-type electrode 370 that are sequentially stacked on the circuit board 100. Among them, the P-type electrode 310 and the N-type electrode 370 are used to inject current, the conductive layer 320 and the transparent conductive layer 360 are used to expand the current, the P-type semiconductor layer 330 is used to provide holes to the light-emitting layer 340, and the N-type semiconductor layer 350 is used to provide electrons to the light-emitting layer 340, so that electrons and holes recombine radiatively in the light-emitting layer 340 to achieve the light-emitting effect of the light-emitting diode. In addition, different colors of light can be emitted because different materials of the P-type semiconductor layer 330, the light-emitting layer 340, and the N-type semiconductor layer 350 are used in the chips.

[0040] The red light chip 200 and the blue light chip 220 are provided with a first total reflection layer 410 on the side wall far away from the green light chip 210. The first total reflection layer 410 can block the light of the red light chip 200 and the blue light chip 220 from diverging out from the side wall far away from the green light chip 210, so that most of the light is emitted from the light-emitting area close to the green light chip 210 after being reflected or refracted by the first total reflection layer 410, reducing the light emission from the edges of the red light chip 200 and the blue light chip 220, enhancing the light-emitting intensity in the area close to the green light chip 210, and weakening the light-emitting intensity in the area far away from the green light chip 210, which is conducive to promoting the light-emitting center of the overall light-emitting diode module to be far away from the edge areas of the red light chip 200 and the blue light chip 220, improving the light-emitting efficiency at the central position, and thus improving the light-emitting uniformity of the light-emitting diode module.

[0041] In addition, a second total reflection layer 420 is respectively provided between the N-type semiconductor layer 350 and the transparent conductive layer 360 in the red light chip 200 and the blue light chip 220. The second total reflection layer 420 covers a part of the N-type semiconductor layer 350 and is provided on the preset areas of the red light chip 200 and the blue light chip 220 far away from the green light chip 210. When the second total reflection layer 420 is provided on the preset areas of the red light chip 200 and the blue light chip 220, the second total reflection layer 420 is provided on the side close to the first total reflection layer 410 and is connected to the first total reflection layer 410. The preset areas of the red light chip 200 and the blue light chip 220 are covered by the second total reflection layer 420, which will reflect or refract the light heading for edge light emission and most of the light is emitted from the light-emitting area close to the green light chip 210, reducing the light emission from the preset areas and further reducing the edge light emission, enhancing the light-emitting intensity in the area close to the green light chip 210, and weakening the light-emitting intensity in the area far away from the green light chip 210, further improving the light-emitting efficiency at the central position, and thus improving the light-emitting uniformity of the light-emitting diode module and improving the resolution of the displayed image.

[0042] Furthermore, the area of the preset area accounts for 30%-50% of the area on the N-type semiconductor layer 350 to improve the light-emitting uniformity of the light-emitting diode module. When the area of the preset area exceeds 50%, the area of the non-preset area will be too small, affecting the light-emitting area of the front sides of the red light chip 200 and the blue light chip 220, resulting in too small a light-emitting area of the light-emitting diode module and a darker light source at the edge position, affecting the light-emitting uniformity; when the area of the preset area is lower than 30%, although the light on the side wall is reflected and refracted out, the light at the edge position is not completely blocked, that is, there is more light at the edge that is not reflected or refracted by the second total emission layer to the central position. When the light-emitting diode module needs to emit light that is biased towards red or blue, the light-emitting center will shift towards the red light chip 200 and the blue light chip 220 on both sides, resulting in poor light-emitting uniformity of the light-emitting diode module.

[0043] Further, the first total reflection layer 410 and the second total reflection layer 420 may be the same or different, but the reflectivity of both the first total reflection layer 410 and the second total reflection layer 420 is greater than 97%, so that all the light rays at the edge are reflected or refracted and most of them exit from the light-emitting area close to the green light chip 210, avoiding the absorption of light by the first total reflection layer 410 and the second total reflection layer 420, resulting in a decrease in the overall light intensity and brightness of the light-emitting diode module and affecting the user experience. Both the first total reflection layer 410 and the second total reflection layer 420 include a DBR total reflection layer or a metal reflection layer. The DBR total reflection layer is composed of two material layers with significantly different refractive indices stacked. The materials include one or any combination of SiO2, Si3N4, TiO2, MgF2, CaF2, SrF2, BaF2, ZnSe, ZnS, ZrO2, and Al2O3. The material of the metal reflection layer includes any one of Ag, Au, and Al to form a high-reflection thin film layer.

[0044] Among them, a plurality of through holes 421 are provided on the second total reflection layer 420. The function of the through holes 421 is to allow light to pass through the through holes 421 and exit, ensuring the light color uniformity in the preset area, and avoiding the second total reflection layer 420 from reflecting or refracting all the light back. There is no light emitted from the red chip or the blue chip in the preset area, resulting in uneven mixing of the light in the preset area and forming color differences.

[0045] Further, the number of the through holes 421 per unit area gradually increases from the side far from the green light chip 210 to the side close to the green light chip 210, that is, on the preset area from the side far from the green light chip 210 to the side close to the green light chip 210, the area of the second total reflection layer 420 covering the N-type semiconductor layer 350 gradually decreases, so that the light output intensity of the preset area gradually increases from the side far from the green light chip 210 to the side close to the green light chip 210, which is beneficial to the overall light-emitting center of the light-emitting diode module approaching the side of the green light chip 210 and improving the light output uniformity of the light-emitting diode module.

[0046] In practical applications, the preset region includes a first preset region, a second preset region, a third preset region, a fourth preset region, and a fifth preset region. The areas of the first to fifth preset regions are equal. The first to fifth preset regions are arranged from the side far away from the green light chip 210 to the side close to the green light chip 210. In this embodiment, the preset region accounts for 50% of the area on the N-type semiconductor layer 350. The area ratio of the second total reflection layer 420 on the first preset region is 100%, the area ratio of the second total reflection layer 420 on the second preset region is 90%, the area ratio of the second total reflection layer 420 on the third preset region is 60%, the area ratio of the second total reflection layer 420 on the fourth preset region is 30%, and the area ratio of the second total reflection layer 420 on the fifth preset region is 10%.

[0047] In addition, the transparent conductive layer 360 in the red light chip 200 and the blue light chip 220 both includes a first transparent conductive sub-layer 361, a second transparent conductive sub-layer 362 connected to the first transparent conductive sub-layer 361, and a third transparent conductive sub-layer 363 connected to the second transparent conductive sub-layer 362. The first transparent conductive sub-layer 361 is disposed on the non-preset region of the N-type semiconductor layer 350, the second transparent conductive sub-layer 362 is disposed on the second total reflection layer 420, and the third transparent conductive sub-layer 363 is disposed in the through hole 421 and contacts the N-type semiconductor layer 350 to expand the current in the preset region, that is, to enable the current to be evenly diffused to the N-type semiconductor layer 350 under the preset region and the non-preset region, avoiding the situation that there is no transparent conductive layer 360 on the N-type semiconductor layer 350 in the preset region and the uneven current distribution on the N-type semiconductor layer 350, which may cause uneven light emission of the light-emitting layer 340 and affect the light extraction efficiency. At the same time, since the second transparent conductive sub-layer 362 is disposed on the second total reflection layer 420 and the third transparent conductive sub-layer 363 is disposed in the through hole 421, the light is not blocked from emitting, and the light can pass through the through hole 421, the third transparent conductive sub-layer 363, and the second transparent conductive sub-layer 362 and emit out.

[0048] Furthermore, the N-type electrodes 370 of the red light chip 200 and the blue light chip 220 are both disposed on the first transparent conductive sub-layer 361 to prevent the N-type electrodes 370 from being disposed on the second transparent conductive sub-layer 362 and affecting the light emission from the through hole 421.

[0049] Compared with the prior art, a light-emitting diode module provided in this embodiment has the following beneficial effects: Through the light-emitting diode module provided by the present invention, a first total reflection layer is provided on the side walls of the red chip and the blue chip away from the green chip, so that most of the light emitted from the side walls is reflected or refracted and then emitted from the light-emitting area close to the green chip. And a second total reflection layer is respectively provided between the N-type semiconductor layer and the transparent conductive layer in the red chip and the blue chip. The second total reflection layer covers a part of the N-type semiconductor layer and is provided in a preset area of the red chip and the blue chip away from the green chip, so that most of the light emitted from the edge is reflected or refracted and then emitted from the light-emitting area close to the green chip. A first total reflection layer is respectively provided on the side walls of the red chip and the blue chip away from the green chip, and a second total reflection layer is respectively provided in the preset areas of the N-type semiconductor layer, reducing the edge light emission of the red chip and the blue chip, enhancing the light emission intensity in the area close to the green chip, and weakening the light emission intensity in the area far from the green chip, which is beneficial to promoting the light-emitting center of the overall light-emitting diode module to be away from the edge areas of the red chip and the blue chip, improving the light-emission efficiency at the central position, and thus improving the light-emission uniformity of the light-emitting diode module. Thereby solving the technical problem that the edge light emission of the red chip and the blue chip is large, resulting in poor light-emission uniformity of the light-emitting diode module.

[0050] Embodiment 2

[0051] A light-emitting diode module provided in the second embodiment of the present invention is different from the light-emitting diode module in the first embodiment in that:

[0052] The preset area accounts for 40% of the area on the N-type semiconductor layer. Under the same other conditions, the area ratio of the second total reflection layer on the first preset area is 100%, the area ratio of the second total reflection layer on the second preset area is 90%, the area ratio of the second total reflection layer on the third preset area is 60%, the area ratio of the second total reflection layer on the fourth preset area is 30%, and the area ratio of the second total reflection layer on the fifth preset area is 10%.

[0053] Embodiment 3

[0054] A light-emitting diode module provided in the third embodiment of the present invention is different from the light-emitting diode module in the first embodiment in that:

[0055] The preset area accounts for 30% of the area on the N-type semiconductor layer. With other conditions being the same, the area ratio of the second total reflection layer on the first preset area is 100%, the area ratio of the second total reflection layer on the second preset area is 90%, the area ratio of the second total reflection layer on the third preset area is 60%, the area ratio of the second total reflection layer on the fourth preset area is 30%, and the area ratio of the second total reflection layer on the fifth preset area is 10%.

[0056] Embodiment 4

[0057] A light-emitting diode module provided by the fourth embodiment of the present invention. The difference between the light-emitting diode module in this embodiment and the light-emitting diode module in the first embodiment is that:

[0058] The area ratio of the second total reflection layer on the first preset area is 100%, the area ratio of the second total reflection layer on the second preset area is 95%, the area ratio of the second total reflection layer on the third preset area is 70%, the area ratio of the second total reflection layer on the fourth preset area is 40%, the area ratio of the second total reflection layer on the fifth preset area is 20%. With other conditions being the same, the preset area accounts for 50% of the area on the N-type semiconductor layer.

[0059] Embodiment 5

[0060] A light-emitting diode module provided by the fifth embodiment of the present invention. The difference between the light-emitting diode module in this embodiment and the light-emitting diode module in the first embodiment is that:

[0061] The area ratio of the second total reflection layer on the first preset area is 90%, the area ratio of the second total reflection layer on the second preset area is 75%, the area ratio of the second total reflection layer on the third preset area is 50%, the area ratio of the second total reflection layer on the fourth preset area is 20%, the area ratio of the second total reflection layer on the fifth preset area is 0%. With other conditions being the same, the preset area accounts for 50% of the area on the N-type semiconductor layer.

[0062] Comparative Example 1

[0063] A light-emitting diode module provided by the first comparative example of the present invention. The difference between the light-emitting diode module in this comparative example and the light-emitting diode module in the first embodiment is that:

[0064] The red light chip and the blue light chip have the same structure as the green light chip, and there is no first total reflection layer and second total reflection layer.

[0065] Please refer to Table 1 below, which shows the corresponding parameters of the above-mentioned Embodiments 1 to 5 and Comparative Example 1 of the present invention.

[0066] Table 1

[0067]

[0068] It should be noted that the light-emitting diode module devices prepared in the first to fifth embodiments and the first comparative example are prepared under the same process conditions.

[0069] Combined with the data of the first to fifth embodiments and the first comparative example, it can be seen that a first total reflection layer is respectively provided on the side walls of the red light chip and the blue light chip away from the green light chip, and a second total reflection layer is respectively provided on the preset regions on the N-type semiconductor layer, which will improve the brightness uniformity, reduce the light emission from the edges of the red light chip and the blue light chip, and avoid the poor light emission uniformity of the light-emitting diode module caused by excessive light emission from the edges of the red light chip and the blue light chip.

[0070] Combined with the data of the first, second, and third embodiments, it can be seen that as the area of the preset region gradually increases, the uniformity of the light-emitting diode module gradually increases. Therefore, the second total reflection layer can reflect or refract the light at the edge and most of the light exits from the light-emitting region near the green light chip, reducing the light emission from the preset region, further reducing the edge light emission, enhancing the light emission intensity in the region near the green light chip, weakening the light emission intensity in the region far from the green light chip, further improving the light emission efficiency at the center position, and thus improving the light emission uniformity of the light-emitting diode module.

[0071] Combined with the data of the first, fourth, and fifth embodiments, it can be seen that the area ratio of the second total reflection layer on the preset region gradually decreases from the side away from the green light chip to the side close to the green light chip. When the coefficient of the decrease in the area ratio of the second total reflection layer is too large, that is, the number of through holes is too large, its brightness uniformity drops from 98% to 93%. When the number of through holes is too large, more light exits from the through holes on the preset region, which will cause more light emission from the edges of the red light chip and the blue light chip away from the green light chip. When the light-emitting diode module needs to emit light of a reddish or bluish color, the light-emitting center will shift towards the red light chip and the blue light chip on both sides, resulting in poor light emission uniformity of the light-emitting diode module; when the coefficient of the decrease in the area ratio of the second total reflection layer is too small, that is, the number of through holes becomes smaller, its brightness uniformity drops from 98% to 95%. When the number of through holes is small, less light is emitted from the red chip or blue chip above the preset region, resulting in uneven mixing of the light in the preset region and poor light emission uniformity of the light-emitting diode module.

[0072] In summary, a first total reflection layer is respectively provided on the side walls of the red light chip and the blue light chip away from the green light chip, and a second total reflection layer is respectively provided on the preset regions on the N-type semiconductor layer, reducing the light emission from the edges of the red light chip and the blue light chip, improving the light emission uniformity of the light-emitting diode module, and avoiding the poor light emission uniformity of the light-emitting diode module caused by excessive light emission from the edges of the red light chip and the blue light chip.

[0073] Example VI

[0074] Please refer to Figure 4 , which shows a method for preparing a light-emitting diode module provided by the sixth embodiment of the present invention. The preparation method includes steps S10 - S16:

[0075] Step S10, provide a circuit board, a red light chip, a green light chip, and a blue light chip. Among them, the red light chip, the green light chip, and the blue light chip each include a P-type electrode, a conductive layer, a P-type semiconductor layer, a light-emitting layer, an N-type semiconductor layer, and a substrate that are sequentially stacked on the circuit board;

[0076] Among them, the circuit board includes a circuit substrate, a circuit layer provided on the circuit substrate, and a thermally insulating layer provided on the circuit layer. The circuit substrate is used to support and carry the chips, the circuit layer is used to control the conduction of the chips, and the thermally insulating layer is used to dissipate heat from the chips. In addition, since RGB are the primary colors of light and various colors are obtained by changing the three color channels of red (R), green (G), and blue (B) and their superposition with each other, an RGB light-emitting diode module requires a red light chip, a green light chip, and a blue light chip.

[0077] Step S11, remove the substrates of the red light chip, the green light chip, and the blue light chip;

[0078] Among them, the red light chip, the green light chip, and the blue light chip need to emit light from the direction facing the substrate, so the substrate needs to be removed to achieve flip-chip light emission. In this example, the substrates of the red light chip, the green light chip, and the blue light chip are removed by laser lift-off technology.

[0079] Step S12, sequentially arrange the red light chip, the green light chip, and the blue light chip with the substrates removed on the circuit board, and arrange the green light chip between the red light chip and the blue light chip;

[0080] Among them, since the visual nerves of the human eye have different sensitivities to light of various wavelengths, being most sensitive to green light and less sensitive to red and blue light, the green light chip is arranged between the red light chip and the blue light chip to ensure better uniformity of the light emitted by the green light chip, which is beneficial to the light uniformity of the light-emitting diode module.

[0081] Step S13, grow a first total reflection layer on the side walls of the red light chip and the blue light chip away from the green light chip;

[0082] Among them, the first total reflection layer can block the light of the red light chip and the blue light chip from diverging out from the side wall far away from the green light chip, so that most of the light is emitted from the light-emitting area close to the green light chip after being reflected or refracted by the first total reflection layer, reducing the edge light emission of the red light chip and the blue light chip, which is beneficial to promoting the light-emitting center of the overall light-emitting diode module to be far away from the edge areas of the red light chip and the blue light chip, improving the light-emitting efficiency at the central position, and thus improving the light-emitting uniformity of the light-emitting diode module. The reflectivity of the first total reflection layer is greater than 97% to emit most of the light from the edge after all the light is reflected or refracted from the light-emitting area close to the green light chip, avoiding the absorption of light by the first total reflection layer, resulting in a decrease in the overall light intensity and brightness of the light-emitting diode module and affecting the user experience. The first total reflection layer includes a DBR total reflection layer or a metal reflection layer. The DBR total reflection layer is composed of two material layers with relatively large refractive index differences stacked. The materials include one or more of SiO2, Si3N4, TiO2, MgF2, CaF2, SrF2, BaF2, ZnSe, ZnS, ZrO2, and Al2O3 in any combination. The material of the metal reflection layer includes any one of Ag, Au, and Al to form a high-reflection thin film layer.

[0083] The DBR total reflection layer can be prepared by methods such as magnetron sputtering, evaporation deposition, or chemical vapor deposition. In this example, the evaporation deposition method is used, and a DBR total reflection layer with an ABAB structure is formed by alternately laminating a TiO2 thin film layer and a SiO2 thin film layer. In an environment where the pressure is set to be less than 7×10 -6 torr, the temperature is set to 120 - 200 °C, and the TiO2 thin film layer and the SiO2 thin film layer are alternately evaporated. The single-layer thickness is controlled between 10 - 60 nm. The total thickness of the DBR is determined by the number of ABAB layers and the single-layer thickness. The more layers, the thicker the single-layer thickness, and the higher the reflectivity.

[0084] The metal reflection layer can be formed by evaporation coating, magnetron sputtering, or ion plating. In this example, in an environment where the pressure is set to be less than 7×10 -6 torr, the temperature is set to 200 - 300 °C, 30 - 60 sccm of argon gas is introduced, and the sputtering power supply power is set at 3000 - 9000 W to sputter and form an Al metal reflection layer.

[0085] Step S14, grow a second total reflection layer on a preset area on the N-type semiconductor layer in the red light chip and the blue light chip. The preset area is located in the area of the red light chip and the blue light chip far away from the green light chip;

[0086] Among them, a second total reflection layer is provided on both the red light chip and the blue light chip in a preset area. The second total reflection layer is disposed on a side close to the first total reflection layer and is connected to the first total reflection layer. The preset areas of the red light chip and the blue light chip are both covered by the second total reflection layer, which will reflect or refract the light emerging towards the edge and most of the light will emerge from the light-emitting area close to the green light chip, reducing the light output from the preset area and further reducing the edge light output, enhancing the light intensity in the area close to the green light chip and weakening the light intensity in the area far from the green light chip, further improving the light output efficiency at the central position, thereby improving the light output uniformity of the light-emitting diode module, improving the uniformity of the light-emitting diode module and the resolution of the displayed image.

[0087] Furthermore, the area of the preset area accounts for 30%-50% of the area on the N-type semiconductor layer to improve the light output uniformity of the light-emitting diode module. The second total reflection layer can be the same as or different from the first total reflection layer. The reflectivity of the second total reflection layer needs to be greater than 97%, reflecting or refracting the light emerging towards the edge and most of the light will emerge from the light-emitting area close to the green light chip, reducing the light output from the preset area. The second total reflection layer all includes a DBR total reflection layer or a metal reflection layer. The DBR total reflection layer is composed of two material layers with relatively large refractive index differences stacked. The materials include one or any combination of SiO2, Si3N4, TiO2, MgF2, CaF2, SrF2, BaF2, ZnSe, ZnS, ZrO2, and Al2O3. The material of the metal reflection layer includes any one of Ag, Au, and Al to form a high-reflection thin film layer. Its preparation method is as in step S13.

[0088] In addition, a plurality of through holes are etched on the second total reflection layer. Among them, the number of the through holes per unit area gradually increases from the side far from the green light chip to the side close to the green light chip.

[0089] Specifically, the second total reflection layer is etched by ICP etching technology to form a plurality of through holes. In this example, the chamber pressure is set to 1-5 mTorr, the ICP power is set to 1000-2500 W, the RF power is set to 20-80 W, and the flow rate of BCl3 is introduced at 30-80 sccm, and through holes with different numbers are etched in the preset areas at different positions.

[0090] It should be noted that the function of the through holes is to allow light to pass through the through holes and emit out, ensuring the light color uniformity in the preset area, and preventing the second total reflection layer from reflecting or refracting all the light back. Without the light emitted by the red chips or blue chips in the preset area, the light mixing in the preset area will be uneven, resulting in color difference. The number of such through holes per unit area gradually increases from the side far away from the green light chip to the side close to the green light chip. That is, on the preset area from the side far away from the green light chip to the side close to the green light chip, the area of the second total reflection layer covering the N-type semiconductor layer gradually decreases, so that the light emission intensity in the preset area gradually increases from the side far away from the green light chip to the side close to the green light chip, which is beneficial to making the overall light-emitting center of the light-emitting diode module approach the side of the green light chip and improving the light emission uniformity of the light-emitting diode module.

[0091] Step S15: Deposit transparent conductive layers on the red light chip, the green light chip, and the blue light chip respectively.

[0092] Among them, the transparent conductive layers on the red light chip and the blue light chip both include a first transparent conductive sub-layer, a second transparent conductive sub-layer connected to the first transparent conductive sub-layer, and a third transparent conductive sub-layer connected to the second transparent conductive sub-layer. The first transparent conductive sub-layer is disposed on the non-preset area of the N-type semiconductor layer, the second transparent conductive sub-layer is disposed on the second total reflection layer, and the third transparent conductive sub-layer is disposed in the through hole and contacts the N-type semiconductor layer to expand the current in the preset area, that is, to enable the current to be evenly diffused to the N-type semiconductor layer under the preset area and the non-preset area, avoiding the situation that there is no transparent conductive layer on the N-type semiconductor layer in the preset area and the current distribution on the N-type semiconductor layer is uneven, resulting in uneven light emission of the light-emitting layer and affecting the light extraction efficiency. At the same time, the second transparent conductive sub-layer is disposed on the second total reflection layer, and the third transparent conductive sub-layer is disposed in the through hole, which will not block the light from emitting out, and the light can pass through the through hole, the third transparent conductive sub-layer, and the second transparent conductive sub-layer and emit out.

[0093] Step S16: Evaporate and deposit N-type electrodes on the transparent conductive layers on the red light chip, the green light chip, and the blue light chip respectively.

[0094] Among them, the N-type electrodes on the red light chip and the blue light chip are both disposed above the first transparent conductive sub-layer to prevent the N-type electrodes from being disposed on the second transparent conductive sub-layer and affecting the light emission from the through hole.

[0095] Compared with the prior art, the beneficial effect of a method for manufacturing a light-emitting diode module provided in this embodiment lies in that: through the method for manufacturing a light-emitting diode module provided by the present invention, a first total reflection layer is grown on the side walls of the red chip and the blue chip away from the green chip, so that most of the light emitted from the side walls is reflected or refracted and then emitted from the light-emitting region close to the green chip. And a second total reflection layer is grown in a preset region of the N-type semiconductor layer in the red chip and the blue chip. The second total reflection layer covers part of the N-type semiconductor layer, so that most of the light emitted from the edge is reflected or refracted and then emitted from the light-emitting region close to the green chip. Growing a second total reflection layer on the side walls of the red chip and the blue chip away from the green chip and in the preset region of the N-type semiconductor layer reduces the edge light emission of the red chip and the blue chip, enhances the light-emitting intensity in the region close to the green chip, and weakens the light-emitting intensity in the region far from the green chip, which is beneficial to promoting the overall light-emitting center of the light-emitting diode module to be away from the edge regions of the red chip and the blue chip, improving the light-emitting efficiency at the central position, and thus improving the light-emitting uniformity of the light-emitting diode module. Thereby, the technical problem that the edge light emission of the red chip and the blue chip is large, resulting in poor light-emitting uniformity of the light-emitting diode module is solved.

[0096] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0097] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A light-emitting diode module, comprising a circuit board, characterized in that, The light-emitting diode module further includes: A red light chip, a green light chip, and a blue light chip sequentially disposed on the circuit board; The green light chip is disposed between the red light chip and the blue light chip. The red light chip, the green light chip, and the blue light chip each include a P-type electrode, a conductive layer, a P-type semiconductor layer, a light-emitting layer, an N-type semiconductor layer, a transparent conductive layer, and an N-type electrode sequentially stacked on the circuit board; The red light chip and the blue light chip are provided with a first total reflection layer on the side wall away from the green light chip. A second total reflection layer is respectively provided between the N-type semiconductor layer and the transparent conductive layer in the red light chip and the blue light chip. The second total reflection layer covers a part of the N-type semiconductor layer and is disposed in a preset area of the red light chip and the blue light chip away from the green light chip, so that most of the light exits from the light-emitting area close to the green light chip after being reflected and refracted by the first total reflection layer and the second total reflection layer. A plurality of through holes are provided on the second total reflection layer, and the number of the through holes per unit area gradually increases from the side away from the green light chip to the side close to the green light chip.

2. The light emitting diode module according to claim 1, characterized in that, The transparent conductive layer in the red light chip and the blue light chip each includes a first transparent conductive sub-layer, a second transparent conductive sub-layer connected to the first transparent conductive sub-layer, and a third transparent conductive sub-layer connected to the second transparent conductive sub-layer. The first transparent conductive sub-layer is disposed on the N-type semiconductor layer, the second transparent conductive sub-layer is disposed on the second total reflection layer, and the third transparent conductive sub-layer is disposed in the through hole and is in contact with the N-type semiconductor layer.

3. The light-emitting diode module according to claim 1, characterized in that The area of the preset area accounts for 30%-50% of the area on the N-type semiconductor layer.

4. The light-emitting diode module according to claim 1, wherein The reflectivity of the first total reflection layer and the second total reflection layer is greater than 97%.

5. The light-emitting diode module according to claim 4, characterized in that The first total reflection layer and the second total reflection layer each include a DBR total reflection layer or a metal reflection layer.

6. The light-emitting diode module according to claim 2, wherein, The N-type electrodes in the red light chip and the blue light chip are both disposed on the first transparent conductive sub-layer.

7. The light-emitting diode module according to claim 1, characterized in that, The circuit board includes a circuit substrate, a circuit layer disposed on the circuit substrate, and a heat-conducting insulating layer disposed on the circuit layer. The red light chip, the green light chip, and the blue light chip are sequentially disposed on the heat-conducting insulating layer.

8. A method for preparing a light-emitting diode module, characterized in that, The preparation method is used to prepare the light-emitting diode module according to any one of claims 1-7. The preparation method includes: Providing a circuit board, a red light chip, a green light chip, and a blue light chip. Among them, the red light chip, the green light chip, and the blue light chip each include a P-type electrode, a conductive layer, a P-type semiconductor layer, a light-emitting layer, an N-type semiconductor layer, and a substrate sequentially stacked on the circuit board; Removing the substrates in the red light chip, the green light chip, and the blue light chip; Sequentially disposing the red light chip, the green light chip, and the blue light chip with the substrates removed on the circuit board, and the green light chip is disposed between the red light chip and the blue light chip; A first total reflection layer is grown on the side walls of the red light chip and the blue light chip away from the green light chip; A second total reflection layer is grown on a preset area on the N-type semiconductor layer in the red light chip and the blue light chip, and the preset area is arranged in the area of the red light chip and the blue light chip away from the green light chip; A plurality of through holes are etched on the second total reflection layer, wherein the number of the through holes per unit area gradually increases from the side away from the green light chip to the side close to the green light chip; Transparent conductive layers are deposited on the red light chip, the green light chip and the blue light chip respectively; N-type electrodes are respectively evaporated on the transparent conductive layers in the red light chip, the green light chip and the blue light chip.

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