Micro LED micro display chip and manufacturing method thereof

Abstract

The present application provides a Micro LED micro display chip and a manufacturing method thereof. The Micro LED micro display chip includes: a driving panel; a plurality of LED units arranged on the driving panel, the plurality of LED units having a plurality of LED tables corresponding to each other, and each LED unit can be driven individually by the driving panel; a fence structure having a plurality of grid holes, the plurality of grid holes are respectively arranged around the plurality of LED tables, and a recessed area is formed between the LED tables and the corresponding grid holes; a first transmissive reflective layer, arranged on the fence structure, the first transmissive reflective layer transmits the first color light emitted by the LED unit and reflects other color lights, and a cavity structure is formed between the first transmissive reflective layer and the corresponding LED unit; a wavelength conversion layer, arranged on the first transmissive reflective layer, the wavelength conversion layer includes a plurality of first wavelength conversion units, and the first wavelength conversion unit converts the first color light emitted by the corresponding LED into the second color light.

Description

Technical Field

[0001] The present application relates to the field of LED display technology, and more specifically, to a Micro LED micro display chip and a method for manufacturing the same. Background Art

[0002] With the emergence of Micro LED display technology, miniaturization and high resolution of display devices such as augmented reality (AR) display devices, virtual reality (VR) display devices, near-eye display (NED) and head up display (HUD) devices have become possible.

[0003] However, during the operation of the Micro LED micro display chip, the heat generated by the LED will cause the wavelength conversion material to age faster, resulting in a shorter lifespan of the Micro LED micro display chip. Summary of the invention

[0004] The present application provides a Micro LED micro display chip and a method for manufacturing the same. The various aspects involved in the present application are introduced below.

[0005] In a first aspect, a Micro LED micro display chip is provided, comprising: a driving panel; a plurality of LED units arranged on the driving panel, the plurality of LED units having a plurality of LED tables corresponding to each other, and each of the LED units can be driven individually by the driving panel; a fence structure having a plurality of grid holes, the plurality of grid holes being respectively arranged around the plurality of LED tables, and a recessed area being formed between the LED tables and the corresponding grid holes; a first transmissive reflective layer being arranged on the fence structure, the first transmissive reflective layer transmitting a first color light emitted by the LED unit and reflecting other color lights, and a cavity structure being formed between the first transmissive reflective layer and the corresponding LED unit; a wavelength conversion layer being arranged on the first transmissive reflective layer, the wavelength conversion layer comprising a plurality of first wavelength conversion units, and the first wavelength conversion unit converting the first color light emitted by the corresponding LED unit into a second color light.

[0006] In some possible implementations, the display chip includes: the first transmissive reflective layer is provided with a plurality of groups of through holes, each group of the through holes includes one or more through holes, each group of the through holes is circumferentially arranged around the edge of the corresponding grid hole, the through holes penetrate the first transmissive reflective layer, and the through holes extend into the interior of the grid hole.

[0007] In some possible implementations, the Micro LED micro display chip further includes: a reflective layer, at least disposed on a side wall of the grid hole, and the reflective layer is capable of heat conduction.

[0008] In some possible implementations, the through hole is filled with a heat-conducting metal unit, and the heat-conducting metal unit is connected to the reflective layer on the side wall of the corresponding grid hole to perform heat conduction.

[0009] In some possible implementations, the Micro LED micro display chip further includes: a protective layer covering the side walls and the top surface of the LED table.

[0010] In some possible implementations, the fence structure includes a first fence structure and a second fence structure, the first transmissive reflective layer is arranged between the first fence structure and the second fence structure, the LED unit is arranged on a first side of the first transmissive reflective layer, the wavelength conversion unit is arranged on the opposite side of the first side of the first transmissive reflective layer, and the wavelength conversion layer is filled in the corresponding grid holes formed by the second fence structure.

[0011] In some possible implementations, the Micro LED micro display chip further includes: a second transmissive reflective layer, disposed on the wavelength conversion layer, wherein the second transmissive reflective layer reflects the first color light and transmits other color lights.

[0012] In some possible implementations, the wavelength conversion layer further includes a plurality of second wavelength conversion units, and the second wavelength conversion units convert the first color light emitted by the corresponding LED unit into a third color light.

[0013] In some possible implementations, the Micro LED micro display chip further includes: a plurality of micro lenses, each of which has a light-emitting curved surface, and is disposed above the wavelength conversion layer, and is used to gather and / or collimate the light emitted by the corresponding LED unit.

[0014] In some possible implementations, the cavity is filled with gas.

[0015] In a second aspect, a method for manufacturing a Micro LED micro display chip is provided, comprising: providing a driving panel; forming a plurality of LED units on the driving panel, the plurality of LED units having a plurality of LED tables corresponding to each other, and each of the LED units can be driven individually by the driving panel; forming a fence structure having a plurality of grid holes, the plurality of grid holes being respectively arranged around the plurality of LED tables, and a recessed area being formed between the LED tables and the corresponding grid holes; forming a first transmissive reflective layer on the fence structure, the first transmissive reflective layer transmitting a first color light emitted by the LED unit and reflecting other color lights, and a cavity structure being between the first transmissive reflective layer and the corresponding LED unit; forming a wavelength conversion layer on the first transmissive reflective layer, the wavelength conversion layer comprising a plurality of first wavelength conversion units, the first wavelength conversion unit converting the first color light emitted by the corresponding LED unit into a second color light.

[0016] In some possible implementations, the forming of the fence structure having a plurality of grid holes includes: forming a first layer fence structure having a plurality of first grid holes, the plurality of first grid holes being respectively arranged around the plurality of LED countertops, and a recessed area being formed between the LED countertops and the corresponding first grid holes; the method further includes: forming the first transmission and reflection layer on the first layer fence structure; forming a second layer fence structure having a plurality of second grid holes on the first transmission and reflection layer; and forming the wavelength conversion layer on the second layer fence structure, the wavelength conversion layer being filled in the second grid holes.

[0017] In some possible implementations, before forming the first transmissive reflective layer on the first-layer fence structure, the method further includes: forming a sacrificial layer on the first-layer fence structure, the sacrificial layer filling the corresponding first grid holes; the forming of the first transmissive reflective layer on the fence structure includes: forming the first transmissive reflective layer on the sacrificial layer; after forming the first transmissive reflective layer on the sacrificial layer, the method further includes: corroding and eliminating the sacrificial layer to form the cavity structure between the first transmissive reflective layer and the corresponding LED unit.

[0018] In some possible implementations, the corroding and eliminating the sacrificial layer includes: forming a plurality of groups of through holes on the first transmissive reflective layer, each group of the through holes including one or more through holes, each group of the through holes being circumferentially arranged around the edge of the corresponding first grid hole, the through holes penetrating the first transmissive reflective layer, and the through holes extending to the inside of the first grid hole; and injecting a corrosive liquid into the corresponding first grid hole through each group of the through holes to corrode and eliminate the sacrificial layer.

[0019] In some possible implementations, before forming the first transmissive reflective layer on the first fence structure, the method further includes: forming a first reflective layer on the first fence structure, the first reflective layer being at least disposed on a side wall of the first grid hole, and the first reflective layer being capable of heat conduction.

[0020] In some possible implementations, the method further includes: filling a heat-conducting metal unit in the through hole, the upper surface of the heat-conducting metal unit is flush with the upper surface of the first transmissive reflective layer, and the heat-conducting metal unit is connected to the corresponding first reflective layer for heat conduction; after forming a second layer of fence structure having a plurality of second grid holes on the first transmissive reflective layer, the method further includes: forming a second reflective layer on the second layer of fence structure, the second reflective layer being at least arranged on the side walls of the second grid holes; wherein the second reflective layer is connected to the corresponding heat-conducting metal unit for heat conduction.

[0021] In some possible implementations, the method further includes: forming a second transmissive reflective layer on the wavelength conversion layer, wherein the second transmissive reflective layer reflects the first color light and transmits other color lights.

[0022] In some possible implementations, the method further includes: forming a plurality of microlenses on the second transmissive reflective layer, the microlenses having a light-emitting curved surface, the microlenses covering corresponding second grid holes, and the microlenses being used to gather and / or collimate light emitted by the LED unit.

[0023] The embodiment of the present application provides a Micro LED micro display chip, including: a driving panel; a plurality of LED units arranged on the driving panel, the plurality of LED units having a plurality of LED tables corresponding to each other, and each LED unit can be driven separately by the driving panel; a fence structure having a plurality of grid holes, the plurality of grid holes being arranged around the plurality of LED tables respectively, and a recessed area being formed between the LED tables and the corresponding grid holes; a first transmissive reflective layer being arranged on the fence structure, the first transmissive reflective layer transmitting the first color light emitted by the LED unit and reflecting other color lights, and a cavity structure being formed between the first transmissive reflective layer and the corresponding LED unit; a wavelength conversion layer being arranged on the first transmissive reflective layer, the wavelength conversion layer including a plurality of first wavelength conversion units, and the first wavelength conversion unit converting the first color light emitted by the corresponding LED into a second color light. The present solution arranges a cavity structure between the wavelength conversion unit and the corresponding LED unit, so that each wavelength conversion unit is arranged at intervals from the corresponding LED unit, thereby helping to reduce or limit the heat generated by the LED unit from being transferred to the corresponding wavelength conversion unit, thereby helping to delay the aging of the wavelength conversion layer and improve the life of the Micro LED micro display chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the cross-sectional structure of a Micro LED micro display chip provided by related technology.

[0025] Figure 2 yes Figure 1 A cross-sectional view of the Micro LED micro display chip along the AA cutting line is shown in FIG.

[0026] Figure 3 It is a schematic diagram of the cross-sectional structure of a Micro LED micro display chip provided in an embodiment of the present application.

[0027] Figure 4 yes Figure 3 Schematic diagram of the structure of the top view of the first transmissive reflective layer shown in FIG.

[0028] Figure 5 It is a flow chart of the method for manufacturing a Micro LED micro display chip provided in an embodiment of the present application.

[0029] Figure 6 yes Figure 5 A possible implementation method for manufacturing a Micro LED micro display chip is shown in FIG.

[0030] Figure 7-Figure 19 yes Figure 3 The cross-sectional structure diagram of the Micro LED micro display chip at different preparation stages is shown in FIG. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0032] It should be specially noted that in the description of the present application, the terms "on", "over", "above", and "over" should be interpreted in the broadest sense, meaning that the description containing these terms is interpreted as "a component may be set on another component in direct contact, or there may be intermediate components or layers between the components."

[0033] In addition, for ease of description, the present application may also use spatially relative terms such as "under", "beneath", "under", "on", "above", "above", "lower", "upper", etc. to describe the relationship of one element or component to another element or component shown in the drawings. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90° or at other orientations), and the spatially relative descriptors used in the present application should be interpreted accordingly.

[0034] The term "layer" as used in this application refers to a portion of a material that includes an area having a certain thickness. A layer may extend over the entire underlying or superstructure, or may extend over a localized area of ​​the underlying or superstructure. In addition, a layer may be an area of ​​a homogeneous or inhomogeneous continuous structure whose thickness is less than the thickness of the continuous structure. For example, a layer may be located between the top and bottom surfaces of the continuous structure or between any pair of horizontal planes therebetween. A layer may extend horizontally, vertically and / or along a tapered surface.

[0035] In recent years, Micro LED has attracted widespread attention due to its low power consumption, fast response, long life, and high light efficiency. Micro LED display technology is a self-luminous display technology that integrates arrayed micron-level LED units (also called LED units) on an active addressing drive panel to achieve individual control and lighting to output display images.

[0036] Micro LED display has many advantages such as self-luminescence, high efficiency, low power consumption, high integration, high stability, etc. It is small in size, highly flexible, easy to disassemble and merge, and can be applied to any existing display application from small to large size.

[0037] Micro LED is also known as micro light emitting diode. The size of Micro LED is 0.1-10 microns. With the emergence of MicroLED display technology, the miniaturization and high resolution of display devices such as augmented reality (AR) display devices, virtual reality (VR) display devices, near-eye display (NED) and head up display (HUD) devices have become possible.

[0038] In the related art, a Micro LED micro display chip generally includes a driving panel, a plurality of LED units, and a fence structure having a plurality of grid holes. The plurality of LED units are arranged on one side surface of the driving panel, the fence structure is arranged on the side surface of the driving panel facing the LED units, and the plurality of grid holes correspond to each other to accommodate the plurality of LED units. Figure 1 Provide explanation.

[0039] Figure 1 This is a cross-sectional structural diagram of a Micro LED micro display chip. Figure 2 yes Figure 1 A cross-sectional view of the Micro LED micro display chip along the AA section line. Figure 1 As shown, the first Micro LED micro display chip 100 may include a first driving panel 110, a plurality of first LED units 120 and a first fence structure 130 having a plurality of grid holes.

[0040] The first driving panel 110 may be a display substrate including a complementary metal-oxide-semiconductor (CMOS) silicon substrate or a thin film transistor (TFT) glass substrate. Exemplarily, the first driving panel 110 may include a first substrate and a plurality of driving circuits (not shown in the drawings) and a plurality of cathodes 112 located on a surface of one side of the first substrate. The plurality of driving circuits are electrically connected to the plurality of cathodes 112 in a one-to-one correspondence, and each driving circuit includes a CMOS device or a TFT device, etc.

[0041] The plurality of first LED units 120 are disposed at intervals from each other on a side surface of the first driving panel 110. The plurality of first LED units 120 may be distributed in an array.

[0042] The first fence structure 130 is located on a side surface of the first driving panel 110 facing the first LED unit 120. The first fence structure 130 has a plurality of target grid holes 131. The number of the target grid holes 131 can be set in a one-to-one correspondence with the plurality of first LED units 120. The plurality of target grid holes 131 can be respectively arranged around the plurality of LED countertops, so that a recessed area is formed between the LED countertops and the corresponding target grid holes 131. The recessed area can be bowl-shaped or trumpet-shaped.

[0043] At least one side wall of the first fence structure 130 is provided with a target light reflecting layer 132. The target light reflecting layer 132 plays a role of reflecting light and conducting heat. The target light reflecting layer 132 is made of a heat conducting material, such as a metal reflective material such as aluminum.

[0044] The first Micro LED micro display chip 100 may further include a bonding layer 140. The P-type semiconductor layer of the first LED unit 120 is adhered or bonded to the surface of the first driving panel 110 through the bonding layer 140, that is, the bonding may constitute a common anode of the first LED unit 120. Based on this, the first driving panel 110 may apply an anode voltage to the plurality of first LED units 120 through the bonding layer 140, and apply a cathode voltage to the plurality of first LED units 120 individually through the plurality of cathodes 112, so as to drive the plurality of first LED units 120 to emit light individually.

[0045] The first Micro LED micro display chip 100 may further include a first passivation layer 150 . The material of the first passivation layer 150 may include an inorganic material or an organic material.

[0046] The first Micro LED micro display chip 100 further includes an electrode layer 160, which is located on a surface of the first passivation layer 150 facing away from the first driving panel 110, and the electrode layer 160 may include a plurality of first electrodes 161. The plurality of first electrodes 161 are disposed between the plurality of first LED units 120 and the plurality of cathodes 112 in a one-to-one correspondence.

[0047] The first Micro LED micro display chip 100 further includes a first wavelength conversion layer 170 . The first wavelength conversion layer 170 is filled in the target grid holes 131 .

[0048] In some examples, the first wavelength conversion layer 170 includes three wavelength conversion units, and the three wavelength conversion units are filled in the target grid holes 131 accordingly. The three wavelength conversion units can convert the first color light emitted by the first LED unit 120 into the second color light, the third color light and the fourth color light respectively. For example, the first color light can be ultraviolet light, the second color light can be red light, the third color light can be green light, and the fourth color light can be blue light. In this way, the full-color display of the first Micro LED micro display chip 100 can be achieved. It should be understood that if the first color light is blue light, there is no need to fill the wavelength conversion unit in the corresponding grid hole emitting blue light.

[0049] During the long-term display process of the first Micro LED micro display chip 100, the first LED unit 120 generates heat. The heat generated by the first LED unit 120 accelerates the aging of the first wavelength conversion layer 170, thereby shortening the life of the Micro LED micro display chip.

[0050] Therefore, it is necessary to design a technical solution for a Micro LED micro display chip that delays the aging of the wavelength conversion layer. The Micro LED micro display chip in the embodiment of the present application is described in detail below in conjunction with the accompanying drawings.

[0051] Figure 3 Schematic diagram of the cross-sectional structure of a Micro LED micro display chip provided in the embodiment of the present application. Figure 3 The Micro LED micro display chip of the embodiment of the present application is described in detail. Figure 3 As shown, the Micro LED micro display chip 300 may include: a driving panel 310 , a plurality of LED units 320 , a fence structure 330 , a first transmissive reflective layer 360 and a wavelength conversion layer 370 .

[0052] The driving panel 310 may be a display substrate including a CMOS silicon substrate or a TFT glass substrate. Exemplarily, the driving panel 310 may include a first substrate and a plurality of driving circuits (not shown in the drawings) and a plurality of cathode contacts 312 located on a surface of one side of the first substrate. The plurality of driving circuits are electrically connected to the plurality of cathode contacts 312 in a one-to-one correspondence, and each driving circuit includes a CMOS device or a TFT device, etc.

[0053] The plurality of LED units 320 are arranged at intervals on one side of the driving panel 310. Generally, the plurality of LED units 320 may be distributed in an array.

[0054] The fence structure 330 is located on the side of the driving panel 310 facing the LED unit 320, that is, on the same side of the driving panel 310 as the LED unit 320. The fence structure 330 includes a plurality of grid holes 331, and the number of the grid holes 331 can be set in a one-to-one correspondence with the plurality of LED units 320. The plurality of grid holes 331 can be respectively arranged around the plurality of LED countertops, so that a recessed area is formed between the LED countertops and the corresponding grid holes 331, and the recessed area can be bowl-shaped or trumpet-shaped.

[0055] The fence structure 330 can prevent light crosstalk between the plurality of LED units 320. For example, the material of the fence structure 330 can be a light-absorbing material such as black photoresist, color photoresist, resin, etc.

[0056] In some implementations, the Micro LED micro display chip 300 may include a reflective layer 332. The reflective layer 332 at least covers the sidewall of the fence structure 330. The thermal conductivity of the reflective layer 332 may be, for example, 1 W / (m·K). The material of the reflective layer 332 may be, for example, a metal material such as aluminum. The reflective layer 332 can conduct heat to the driving panel 310 to quickly dissipate the heat.

[0057] The reflective layer 332 plays a role in reflecting light and conducting heat. The reflective layer 332 and the light emitting direction of the LED unit 320 usually have a certain angle. By setting the reflective layer 332 on the side wall of the fence structure 330, the reflective layer 332 can be used to reflect more light emitted by the LED unit 320 toward the light emitting direction of the LED unit 320, which helps to improve the light emitting efficiency and light brightness of the Micro LED micro display chip 300.

[0058] The first transmissive reflective layer 360 is disposed on the fence structure 330 , and transmits the first color light emitted by the LED unit 320 and reflects other color lights. A cavity 390 (or cavity structure) is formed between the first transmissive reflective layer 360 and the corresponding LED unit 320 .

[0059] In some embodiments, the first transmissive reflective layer 360 may be a distributed Bragg reflector (DBR) dielectric layer made of inorganic materials. The DBR is formed by stacking inorganic materials with high and low refractive indices, and can reflect light upward and increase brightness. Since inorganic materials have poor thermal conductivity, the first transmissive reflective layer 360 can play a role in heat insulation.

[0060] In some implementations, the cavity 390 is filled with gas. The thermal conductivity of gas is low, usually less than 0.5 W / (m·K). For example, at normal temperature and pressure, the thermal conductivity of air is about 0.0257 W / (m·K). In some embodiments, the cavity 390 is filled with an inert gas, which can further improve the thermal insulation effect because the thermal conductivity of the inert gas is lower. In other embodiments, the cavity 390 is filled with air, which can simplify the manufacturing process.

[0061] The wavelength conversion layer 370 is disposed on the first transmissive reflective layer 360 , and the wavelength conversion layer 370 includes a plurality of first wavelength conversion units, and the first wavelength conversion unit converts the first color light emitted by the corresponding LED unit 320 into the second color light.

[0062] In some implementations, the wavelength conversion layer 370 may include a plurality of first wavelength conversion units, a plurality of second wavelength conversion units, and a plurality of third wavelength conversion units. The LED unit 320 emits a first color light, and the first wavelength conversion unit converts the first color light into a second color light. The second wavelength conversion unit converts the first color light into a third color light. The third wavelength conversion unit converts the first color light into a fourth color light.

[0063] For example, the first color light may be ultraviolet light, the second color light may be red light, the third color light may be green light, and the fourth color light may be blue light. In this way, full-color display of the Micro LED micro display chip 300 can be achieved. It should be understood that if the first color light is blue light, the wavelength conversion unit does not need to be filled in the grid hole 331 that emits blue light.

[0064] In some implementations, the wavelength conversion layer 370 includes three wavelength conversion units, RGB, and the first wavelength conversion unit may be any one of the three wavelength conversion units, RGB. If the first wavelength conversion unit is an R wavelength conversion unit, the second color light is red light; if the first wavelength conversion unit is a G wavelength conversion unit, the second color light is green light; if the first wavelength conversion unit is a B wavelength conversion unit, the second color light is blue light.

[0065] In some implementations, the Micro LED micro display chip 300 may further include a bonding layer ( Figure 3 ) and a passivation layer 340.

[0066] In the common anode configuration, the anode contacts 314 of all LED units 320 are connected together and connected to the positive power supply. Each cathode contact 312 is provided in the driving panel 310, and each cathode contact 312 is electrically connected to the N-type semiconductor 313. The anode contact 314 can be connected to the P-type semiconductor 315, and the P-type semiconductor 315 is attached or bonded to the driving panel 310 through a bonding layer, that is, the bonding can constitute a common anode of the LED units 320. Based on this, the driving panel 310 can apply an anode voltage to the multiple LED units 320 through the bonding layer, and apply a cathode voltage to the multiple LED units 320 individually through the multiple cathode contacts 312, so as to drive the multiple LED units 320 to emit light individually.

[0067] In some implementations, a passivation layer 340 may be deposited on the sidewall surface of the LED unit 320 to prevent the LED unit 320 from being damaged by etching. The material of the passivation layer 340 includes inorganic materials or organic materials, and the inorganic materials include any one or a combination of SiO2, Al2O3, ZrO2, TiO2, Si3N4, and HfO2; the organic materials include any one or a combination of black matrix photoresist, color filter photoresist, polyimide, barrier glue (BANK), overcoat glue, near-ultraviolet negative photoresist, and styrene.

[0068] It can be seen from the above content that the present solution sets a cavity structure between the wavelength conversion unit and the corresponding LED unit, so that each wavelength conversion unit is spaced apart from the corresponding LED unit 320, thereby helping to reduce or limit the heat generated by the LED unit 320 from being conducted to the corresponding wavelength conversion unit, thereby helping to delay the aging of the wavelength conversion layer 370 and improving the service life of the Micro LED micro display chip.

[0069] In some implementations, the cavity 390 can be made by removing material. It is understood that before forming the cavity 390, a sacrificial layer ( Figure 3 In some implementations, the sacrificial layer in the grid hole 331 may be corroded and hollowed out by a corresponding corrosive solution to form a cavity 390 of a hollow structure.

[0070] In some implementations, the first transmissive reflective layer 360 is provided with a plurality of groups of through holes, each group of through holes includes one or more through holes, and each group of through holes is circumferentially arranged around the edge of the corresponding grid hole 331. As an example, see Figure 4 (It should be noted that Figure 3 yes Figure 4 ). It should be noted that the through hole penetrates the first transmissive reflective layer 360, and the through hole extends to the inside of the grid hole 331, so that the etching liquid can flow into the grid hole 331 through the through hole. Further, the sacrificial layer in the grid hole 331 is corroded and hollowed out by the etching liquid to form a cavity 390 with a hollow structure.

[0071] In some implementations, after the cavity 390 is formed, a heat-conducting metal unit may be filled in the through hole, and the heat-conducting metal unit is connected to the reflective layer 332 on the side wall of the corresponding grid hole 331 for heat conduction.

[0072] In some implementations, in order to prevent the corrosive liquid from corroding the multiple LED units 320, the Micro LED micro display chip 300 may further include a protective layer 350. The protective layer 350 covers the sidewalls and the top surface of the LED table, and the protective layer 350 is used to prevent corrosion from damaging the multiple LED units 320 during the process of forming the cavity 390. The material of the protective layer 350 may include silicon dioxide ( )、Alumina( ), silicon nitride, etc. The first transflective layer 360 is spaced apart from the protective layer 350 by the cavity 390 , that is, there is a gap between the first transflective layer 360 and the protective layer 350 .

[0073] In some implementations, the fence structure 330 includes a first fence structure 3301 and a second fence structure 3302, the first transmissive reflective layer 360 is disposed between the first fence structure 3301 and the second fence structure 3302, the LED unit 320 is disposed on a first side of the first transmissive reflective layer 360, the wavelength conversion unit is disposed on the opposite side of the first side of the first transmissive reflective layer 360, and the wavelength conversion layer 370 is filled in the second grid holes 3312 formed by the corresponding second fence structure 3302. That is, the wavelength conversion layer 370 is disposed on the first transmissive reflective layer 360 and is filled in the corresponding second grid holes 3312; the LED unit 320 is disposed in the first grid holes 3311.

[0074] In the embodiment of the present application, a gas insulation layer with a relatively low thermal conductivity (i.e., the gas filled in the cavity 390) is disposed between the first transmissive reflective layer 360 and the plurality of LED units 320. The wavelength conversion layer 370 in the second grid hole 3312 is spaced from the LED units 320 by the gas insulation layer, thereby helping to reduce or limit the heat generated by the LED units 320 from being conducted to the wavelength conversion layer 370, thereby helping to delay the aging of the wavelength conversion layer 370 and improve the life of the Micro LED micro display chip 300.

[0075] In some implementations, see again Figure 3 The Micro LED micro display chip 300 may further include a second transmissive reflective layer 380. The second transmissive reflective layer 380 is disposed on the wavelength conversion layer, and the second transmissive reflective layer 380 reflects the first color light and transmits other color lights.

[0076] It should be understood that the plurality of LED units 320 can emit a first color light, and the first transmissive reflective layer 360 can transmit the first color light and reflect other color lights. The first color light includes, but is not limited to, any one of red light, green light, blue light, yellow light or ultraviolet light. After the first color light passes through the first wavelength conversion unit of the wavelength conversion layer 370, the first color light can be converted into a second color light, and the conversion material of the first wavelength conversion unit belongs to one of the RGB color conversion materials. For example, the first color light is blue light, and the second color light can be red light or green light. The first transmissive reflective layer 360 can transmit blue light and reflect red light and green light. The second transmissive reflective layer 380 can reflect the first color light and transmit the second color light.

[0077] The embodiment of the present application can improve the brightness of the Micro LED micro display chip 300 and optimize the light output effect by setting the first transmissive reflective layer 360. Furthermore, by setting a double-layer projection reflective layer (i.e., the first transmissive reflective layer 360 and the second transmissive reflective layer 380), the brightness of the Micro LED micro display chip 300 can be further improved and the light output effect can be better optimized.

[0078] It should be noted that if the LED unit 320 emits blue light (i.e., the first color light is blue light), there is no need to fill the wavelength conversion unit in the second grid hole 3312 corresponding to the blue light, and the area of ​​the second transmissive reflective layer 380 covering the second grid hole 3312 emitting blue light needs to be hollowed out so that the second transmissive reflective layer 380 can transmit the blue light.

[0079] In some implementations, the corresponding hollow area of ​​the second transmissive reflective layer 380 can be filled with a transparent material, so that the flatness and light transmittance of the second transmissive reflective layer 380 can be taken into account (that is, the transparent material area of ​​the second transmissive reflective layer 380 can transmit blue light). In addition, it is also helpful for the subsequent preparation of lenses to form a light-gathering effect.

[0080] In some implementations, the Micro LED micro display chip 300 further includes a plurality of micro lenses 381, and the plurality of lenses 381 are arranged one-to-one corresponding to the plurality of LED units 320. The micro lenses 381 have a light-emitting curved surface, and the micro lenses 381 are arranged above the wavelength conversion layer 370, and the micro lenses 381 are used to gather and / or collimate the light emitted by the corresponding LED unit 320.

[0081] In some implementations, the reflective layer 332 may include a first reflective layer 3321 and a second reflective layer 3322. It should be understood that the first reflective layer 3321 at least covers the sidewalls of the first fence structure 3301. The second reflective layer 3322 at least covers the sidewalls of the second fence structure 3302. The first reflective layer 3321 and the second reflective layer 3322 may be connected by a heat-conducting metal unit filled in the through hole for heat conduction.

[0082] Combination of the above Figures 1 to 4 The device embodiment of the present application is described in detail. Figures 5 to 19 The method embodiment of the present application is described in detail. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, so the parts not described in detail can refer to the previous device embodiment.

[0083] Figure 5 Schematic diagram of the method for manufacturing a Micro LED micro display chip provided in an embodiment of the present application. Figure 5As shown, the method may mainly include steps S510 to S550, which are described in detail below.

[0084] It should be pointed out that the size of the serial numbers of the steps in the embodiments of the present application does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0085] In step S510, a driving panel is provided.

[0086] The driving panel may be a display substrate including a CMOS silicon substrate or a TFT glass substrate. A plurality of LED units may be distributed in an array.

[0087] In step S520, a plurality of LED units are formed on the driving panel, the plurality of LED units having a plurality of LED mesas corresponding to each other, and each LED unit can be driven individually by the driving panel.

[0088] In step S530, a fence structure having a plurality of grid holes is formed, wherein the plurality of grid holes are respectively arranged around a plurality of LED countertops, and recessed areas are formed between the LED countertops and the corresponding grid holes.

[0089] In some implementations, after forming a fence structure having a plurality of grid holes, the method further includes: forming a reflective layer on the fence structure. The reflective layer at least covers the side wall of the fence structure. The thermal conductivity of the reflective layer may be, for example, 1 W / (m·K). The material of the reflective layer may be, for example, a metal material such as aluminum. The reflective layer can conduct heat to the drive panel to quickly dissipate the heat.

[0090] In step S540, a first transflective layer is formed on the fence structure, the first transflective layer transmits the first color light emitted by the LED unit and reflects other color lights, and a cavity structure is formed between the first transflective layer and the corresponding LED unit.

[0091] In some embodiments, the first transmissive reflective layer may be a DBR dielectric layer made of inorganic materials. The DBR is formed by stacking inorganic materials with high and low refractive indices, and can reflect light upward and increase brightness. Since inorganic materials have poor thermal conductivity, the first transmissive reflective layer can play a role in heat insulation.

[0092] In some implementations, there is an air gap between the first transmissive reflective layer and the corresponding LED unit. That is, the cavity structure is filled with gas. The thermal conductivity of the gas is low, usually less than 0.5 W / (m·K). For example, at normal temperature and pressure, the thermal conductivity of air is about 0.0257 W / (m·K). In some embodiments, the cavity is filled with an inert gas, which can further improve the thermal insulation effect due to the lower thermal conductivity of the inert gas. In other embodiments, the cavity is filled with air, which can simplify the manufacturing process.

[0093] In step S550, a wavelength conversion layer is formed on the first transmissive reflective layer, wherein the wavelength conversion layer includes a plurality of first wavelength conversion units, and the first wavelength conversion unit converts the first color light emitted by the corresponding LED unit into the second color light.

[0094] In some implementations, the wavelength conversion layer may include a plurality of first wavelength conversion units, a plurality of second wavelength conversion units, and a plurality of third wavelength conversion units. The LED unit emits a first color light, and the first wavelength conversion unit converts the first color light into a second color light. The second wavelength conversion unit converts the first color light into a third color light. The third wavelength conversion unit converts the first color light into a fourth color light. For example, the first color light may be ultraviolet light, the second color light may be red light, the third color light may be green light, and the fourth color light may be blue light. In this way, a full-color display of the Micro LED micro-display chip can be achieved. It should be understood that if the first color light is blue light, then the corresponding grid hole emitting blue light does not need to be filled with a wavelength conversion unit.

[0095] From the above content, it can be seen that this solution sets a cavity structure between the wavelength conversion unit and the corresponding LED unit, so that each wavelength conversion unit is spaced apart from the corresponding LED unit, thereby helping to reduce or limit the heat generated by the LED unit from being conducted to the corresponding wavelength conversion unit, thereby helping to delay the aging of the wavelength conversion layer and improve the service life of the Micro LED micro display chip.

[0096] The method for manufacturing a Micro LED micro display chip in the embodiment of the present application is further described below in combination with some possible implementation methods of the embodiment of the present application.

[0097] Figure 6 yes Figure 5 A schematic flow chart of a possible implementation of the preparation method. Figure 7-Figure 19 yes Figure 3 A schematic diagram of a cross-sectional structure of a Micro LED microdisplay chip at different preparation stages. Taking the common anode structure as an example, Figure 6The preparation process method may include steps S6010 to S6130, which are described in detail below.

[0098] In step S6010, if Figure 7 As shown, a driving panel is provided. The driving panel 310 may be a display substrate including a CMOS silicon substrate or a TFT glass substrate. A plurality of LED units 320 may be distributed in an array.

[0099] In some implementations, the driving panel 310 may include a first substrate and a plurality of driving circuits (not shown in the drawings) located on a surface of one side of the first substrate, a plurality of cathode contacts 312, and a plurality of anode contacts 314. In some embodiments, the cathode contact 312 may be connected to the N-type semiconductor 313, and the anode contact 314 may be connected to the P-type semiconductor 315.

[0100] In the common anode configuration, the anode contacts 314 of all LED units 320 are connected together and connected to the positive power supply. Each cathode contact 312 is provided in the driving panel 310, and each cathode contact 312 is electrically connected to the N-type semiconductor 313. The anode contact 314 can be connected to the P-type semiconductor 315, and the P-type semiconductor 315 is attached or bonded to the driving panel 310 through a bonding layer, that is, the bonding can constitute a common anode of the LED units 320. Based on this, the driving panel 310 can apply an anode voltage to the multiple LED units 320 through the bonding layer, and apply a cathode voltage to the multiple LED units 320 individually through the multiple cathode contacts 312, so as to drive the multiple LED units 320 to emit light individually.

[0101] In step S6020, if Figure 8 As shown, a protection layer 350 is disposed outside the plurality of LED units 320 .

[0102] The protection layer 350 covers the sidewalls and the top surface of the LED table. The protection layer 350 is used to prevent corrosion from damaging the multiple LED units 320 during the subsequent process of forming the cavity 390 .

[0103] The material of the protective layer 350 may include silicon dioxide ( )、Alumina( ), silicon nitride, etc., and a combination of one or more thereof.

[0104] In step S6030, if Fig. 9 As shown, a first layer of fence structure 3301 is provided on a side of the driving panel 310 facing the LED unit 320 .

[0105] The first layer fence structure 3301 can be formed by photolithography or graphic morphology etching. The first layer fence structure 3301 can define a plurality of first grid holes 3311, and the plurality of first grid holes 3311 are respectively arranged around a plurality of LED tables, and a recessed area is formed between the LED tables and the corresponding first grid holes 3311. The cross-section of the recessed area can be a bowl-shaped structure, which can prevent the LED units 320 in the plurality of first grid holes 3311 from generating light crosstalk. Exemplarily, the material of the first layer fence structure 3301 can be a light-absorbing material such as black photoresist, color filter photoresist, polyimide, and organic resin.

[0106] In some implementations, the first fence structure 3301 may be set to be higher than the LED unit 320 by a certain preset dimension to ensure the thickness of the gas insulation layer (ie, the filling gas in the cavity 390).

[0107] In step S6040, if Fig.10 As shown, a first light reflecting layer 3321 is formed on the side wall of the first fence structure 3301 .

[0108] In some implementations, the entire surface of the first fence structure 3301 may be coated with a reflective layer to completely cover each area. The reflective layer on the LED table and the reflective layer on the first fence structure 3301 may be etched to obtain the first reflective layer 3321. Fig.11 shown.

[0109] The first light reflecting layer 3321 is made of a thermally conductive material to conduct heat.

[0110] In step S6050, a sacrificial layer 382 is disposed on the first fence structure 3301. The sacrificial layer 382 is correspondingly filled in the plurality of first grid holes 3311. Fig.12 shown.

[0111] In some implementations, the materials of the first transflective layer 360 and the sacrificial layer 382 are of different types, which is convenient for the subsequent removal of the sacrificial layer 382. If the first transflective layer 360 is an organic material, the sacrificial layer 382 can be made of an inorganic material; if the first transflective layer 360 is an inorganic material, the sacrificial layer 382 can be made of an organic material.

[0112] In step S6060, a first transmissive reflective layer 360 is disposed on the sacrificial layer 382, ​​such as Fig.13 shown.

[0113] The first transmissive reflective layer 360 transmits the first color light emitted by the LED unit 320 and reflects other color lights. For example, the first color light emitted by the LED unit 320 may be blue light, and the first transmissive reflective layer 360 can transmit the blue light and reflect red light and green light.

[0114] In some embodiments, the first transmissive reflective layer 360 may be a DBR dielectric layer made of an inorganic material.

[0115] In step S6070, see Figure 4 and Fig.14 A plurality of groups of through holes are provided on the first transmissive reflective layer 360 , each group of through holes includes one or more through holes, and each group of through holes is circumferentially arranged around the edge of the corresponding grid hole 331 .

[0116] It should be noted that the through hole penetrates the first transmissive reflective layer 360 and extends to the inside of the first grid hole 3311, so that the etching liquid can flow into the first grid hole 3311 through the through hole, so that the sacrificial layer 382 in the first grid hole 3311 can be corroded and eliminated by the etching liquid later.

[0117] In step S6080, if Fig.15 As shown, the etching liquid is injected into the corresponding first grid holes 3311 through each group of through holes, and the sacrificial layer 382 is corroded and eliminated by the etching liquid.

[0118] In step S6090, if Fig.16 As shown, a heat-conducting metal unit is filled in the through hole, and the heat-conducting metal unit is connected to the first light-reflecting layer 3321 on the side wall of the corresponding first grid hole 3311 for heat conduction.

[0119] By filling the thermally conductive metal unit in the through hole, a cavity 390 with a hollow structure can be formed between the first transmissive reflective layer 360 and the LED unit 320 .

[0120] The thermal conductivity of the thermally conductive metal unit is higher than the thermal conductivity of the material of the first transmissive reflective layer 360 , thereby improving the effect of heat conduction.

[0121] In step S6100, a second layer fence structure 3302 having a plurality of second grid holes 3312 is formed on the first transmissive reflective layer 360, and a second light reflecting layer 3322 is provided at least on the sidewall of the second layer fence structure 3302. The plurality of second grid holes 3312 correspond to the plurality of first grid holes 3311 one by one, such as Fig.17 shown.

[0122] The first light reflecting layer 3321 and the second light reflecting layer 3322 may be connected via a heat conductive metal unit filled in the through hole to conduct heat.

[0123] In step S6110, a wavelength conversion layer 370 is formed on the second fence structure 3302. Fig.18 shown.

[0124] The wavelength conversion layer 370 includes a plurality of first wavelength conversion units, and the first wavelength conversion unit converts the first color light emitted by the corresponding LED unit 320 into the second color light.

[0125] In some implementations, the wavelength conversion layer 370 may include a plurality of first wavelength conversion units, a plurality of second wavelength conversion units, and a plurality of third wavelength conversion units. The LED unit 320 emits a first color light, and the first wavelength conversion unit converts the first color light into a second color light. The second wavelength conversion unit converts the first color light into a third color light. The third wavelength conversion unit converts the first color light into a fourth color light.

[0126] For example, the first color light may be ultraviolet light, the second color light may be red light, the third color light may be green light, and the fourth color light may be blue light. In this way, full-color display of the Micro LED micro display chip 300 can be achieved. It should be understood that if the first color light is blue light, the wavelength conversion unit does not need to be filled in the grid hole 331 that emits blue light.

[0127] In some implementations, the wavelength conversion layer 370 includes three wavelength conversion units, RGB, and the first wavelength conversion unit may be any one of the three wavelength conversion units, RGB. If the first wavelength conversion unit is an R wavelength conversion unit, the second color light is red light; if the first wavelength conversion unit is a G wavelength conversion unit, the second color light is green light; if the first wavelength conversion unit is a B wavelength conversion unit, the second color light is blue light.

[0128] In step S6120, a second transmissive reflective layer 380 is disposed on the wavelength conversion layer 370. The second transmissive reflective layer 380 can transmit the second color light and reflect the first color light. Fig.19 shown.

[0129] It should be understood that the plurality of LED units 320 can emit a first color light, and the first transmissive reflective layer 360 can transmit the first color light and reflect other color lights. The first color light includes, but is not limited to, any one of red light, green light, blue light, yellow light or ultraviolet light. After the first color light passes through the first wavelength conversion unit of the wavelength conversion layer 370, the first color light can be converted into a second color light, and the conversion material of the first wavelength conversion unit belongs to one of the RGB color conversion materials. For example, the first color light is blue light, and the second color light can be red light or green light. The first transmissive reflective layer 360 can transmit blue light and reflect red light and green light. The second transmissive reflective layer 380 can reflect the first color light and transmit the second color light.

[0130] The embodiment of the present application can improve the brightness of the Micro LED micro display chip 300 and optimize the light output effect by setting the first transmissive reflective layer 360. Furthermore, by setting a double-layer projection reflective layer (i.e., the first transmissive reflective layer 360 and the second transmissive reflective layer 380), the brightness of the Micro LED micro display chip 300 can be further improved and the light output effect can be better optimized.

[0131] It should be noted that if the LED unit 320 emits blue light (i.e., the first color light is blue light), there is no need to fill the wavelength conversion unit in the second grid hole 3312 corresponding to the blue light, and the area of ​​the second transmissive reflective layer 380 covering the second grid hole 3312 emitting blue light needs to be hollowed out so that the second transmissive reflective layer 380 can transmit the blue light.

[0132] In some implementations, the corresponding hollow area of ​​the second transmissive reflective layer 380 can be filled with a transparent material, so that the flatness and light transmittance of the second transmissive reflective layer 380 can be taken into account (that is, the transparent material area of ​​the second transmissive reflective layer 380 can transmit blue light). In addition, it is also helpful for the subsequent preparation of lenses to form a light-gathering effect.

[0133] In step S6130, a plurality of micro lenses 381 are formed on the second transmissive reflective layer 380. The micro lenses 381 have a light-emitting curved surface. The micro lenses 381 cover the corresponding second grid holes 3312. The micro lenses 381 are used to gather and / or collimate the light emitted by the LED unit 320. Figure 3 shown.

[0134] It should be understood that the multiple lenses 381 are arranged in a one-to-one correspondence with the multiple LED units 320 .

[0135] In the embodiment of the present application, a gas insulation layer with a relatively low thermal conductivity (i.e., the gas filled in the cavity 390) is disposed between the first transmissive reflective layer 360 and the plurality of LED units 320. The wavelength conversion layer 370 in the second grid hole 3312 is spaced from the LED units 320 by the gas insulation layer, thereby helping to reduce or limit the heat generated by the LED units 320 from being conducted to the wavelength conversion layer 370, thereby helping to delay the aging of the wavelength conversion layer 370 and improve the life of the Micro LED micro display chip 300.

[0136] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A Micro LED micro display chip, characterized in that: include: Driver panel; A plurality of LED units are arranged on the driving panel, the plurality of LED units have a plurality of LED tables corresponding to each other, and each of the LED units can be driven individually by the driving panel; A fence structure having a plurality of grid holes, wherein the plurality of grid holes are respectively arranged around the plurality of LED countertops, and a recessed area is formed between the LED countertops and the corresponding grid holes; A first transmissive reflective layer, disposed on the fence structure, the first transmissive reflective layer transmits the first color light emitted by the LED unit and reflects other color lights, and a cavity structure is formed between the first transmissive reflective layer and the corresponding LED unit; A wavelength conversion layer, disposed on the first transmissive reflective layer, the wavelength conversion layer comprising a plurality of first wavelength conversion units, the first wavelength conversion units converting the first color light emitted by the corresponding LED unit into a second color light; The first transmissive reflective layer is provided with a plurality of groups of through holes, each group of the through holes includes one or more through holes, each group of the through holes is circumferentially arranged around the edge of the corresponding grid hole, the through holes penetrate the first transmissive reflective layer, and the through holes extend to the inside of the grid hole; Wherein, each group of through holes is a non-continuous hole structure circumferentially arranged around the edge of the grid holes.

2. The Micro LED micro display chip according to claim 1, characterized in that: The Micro LED micro display chip also includes: The reflective layer is at least arranged on the side wall of the grid hole, and the reflective layer can conduct heat.

3. The Micro LED micro display chip according to claim 2, characterized in that: The through holes are filled with heat-conducting metal units, and the heat-conducting metal units are connected to the reflective layers on the side walls of the corresponding grid holes for heat conduction.

4. The Micro LED micro display chip according to claim 1, characterized in that: The Micro LED micro display chip also includes: The protective layer covers the side walls and the top surface of the LED table.

5. The Micro LED micro display chip according to claim 1, characterized in that: The fence structure includes a first fence structure and a second fence structure, the first transmissive reflective layer is arranged between the first fence structure and the second fence structure, the LED unit is arranged on a first side of the first transmissive reflective layer, the wavelength conversion unit is arranged on the opposite side of the first side of the first transmissive reflective layer, and the wavelength conversion layer is filled in the corresponding grid holes formed by the second fence structure.

6. The Micro LED micro display chip according to claim 1, characterized in that: The Micro LED micro display chip also includes: The second transmissive reflective layer is disposed on the wavelength conversion layer, and the second transmissive reflective layer reflects the first color light and transmits other color lights.

7. The Micro LED micro display chip according to claim 1, characterized in that: The wavelength conversion layer further includes a plurality of second wavelength conversion units, and the second wavelength conversion units convert the first color light emitted by the corresponding LED unit into a third color light.

8. The Micro LED micro display chip according to claim 1, characterized in that: The Micro LED micro display chip also includes: A plurality of micro lenses, each of which has a light-emitting curved surface, is disposed above the wavelength conversion layer, and is used to gather and / or collimate the light emitted by the corresponding LED unit.

9. The Micro LED micro display chip according to claim 1, characterized in that: The cavity is filled with gas.

10. A method for manufacturing a Micro LED micro display chip, characterized in that: include: Providing a drive panel; A plurality of LED units are formed on the driving panel, wherein the plurality of LED units have a plurality of LED tables corresponding to each other, and each of the LED units can be driven individually by the driving panel; Forming a fence structure having a plurality of grid holes, wherein the plurality of grid holes are respectively arranged around the plurality of LED countertops, and a recessed area is formed between the LED countertops and the corresponding grid holes; A first transmissive reflective layer is formed on the fence structure, wherein the first transmissive reflective layer transmits the first color light emitted by the LED unit and reflects other color lights, and a cavity structure is formed between the first transmissive reflective layer and the corresponding LED unit; forming a wavelength conversion layer on the first transmissive reflective layer, wherein the wavelength conversion layer comprises a plurality of first wavelength conversion units, and the first wavelength conversion units convert the first color light emitted by the corresponding LED unit into a second color light; The method further comprises: forming a plurality of groups of through holes on the first transmissive reflective layer, each group of the through holes comprising one or more through holes, each group of the through holes being circumferentially arranged around the edge of the corresponding grid hole, the through holes penetrating the first transmissive reflective layer, and extending to the inside of the grid hole; Wherein, each group of through holes is a non-continuous hole structure circumferentially arranged around the edge of the grid holes.

11. The method according to claim 10, characterized in that The forming of the fence structure having a plurality of grid holes comprises: Forming a first layer of fence structure having a plurality of first grid holes, wherein the plurality of first grid holes are respectively arranged around the plurality of LED tabletops, and a recessed area is formed between the LED tabletops and the corresponding first grid holes; The method further comprises: forming the first transmissive reflective layer on the first fence structure; forming a second layer of fence structure having a plurality of second grid holes on the first transmissive reflective layer; The wavelength conversion layer is formed on the second fence structure, and the wavelength conversion layer is filled in the second grid holes.

12. The method according to claim 11, characterized in that Before forming the first transmissive reflective layer on the first fence structure, the method further includes: forming a sacrificial layer on the first fence structure, wherein the sacrificial layer is filled in the corresponding first grid holes; The step of forming a first transmissive reflective layer on the fence structure comprises: forming the first transmissive reflective layer on the sacrificial layer; After forming the first transmissive reflective layer on the sacrificial layer, the method further includes: The sacrificial layer is corroded and eliminated to form the cavity structure between the first transmissive reflective layer and the corresponding LED unit.

13. The method according to claim 12, characterized in that The corroding and eliminating the sacrificial layer comprises: A corrosive liquid is injected into the corresponding first grid holes through each group of the through holes to corrode and eliminate the sacrificial layer.

14. The method according to claim 13, characterized in that Before forming the first transmissive reflective layer on the first fence structure, the method further includes: A first light reflecting layer is formed on the first layer of the fence structure. The first light reflecting layer is at least arranged on the side wall of the first grid hole. The first light reflecting layer can conduct heat.

15. The method according to claim 14, characterized in that The method further comprises: Filling a heat-conducting metal unit in the through hole, wherein the upper surface of the heat-conducting metal unit is flush with the upper surface of the first transmissive reflective layer, and the heat-conducting metal unit is connected to the corresponding first reflective layer for heat conduction; After forming a second layer of fence structure having a plurality of second grid holes on the first transmissive reflective layer, the method further comprises: forming a second light reflecting layer on the second fence structure, wherein the second light reflecting layer is at least arranged on the side wall of the second grid hole; Wherein, the second reflective layer is connected to the corresponding heat-conducting metal unit for heat conduction.

16. The method according to claim 11, characterized in that The method further comprises: A second transmissive reflective layer is formed on the wavelength conversion layer, the second transmissive reflective layer reflects the first color light and transmits other color lights.

17. The method according to claim 16, characterized in that The method further comprises: A plurality of micro lenses are formed on the second transmissive reflective layer, wherein the micro lenses have a light-emitting curved surface, cover corresponding second grid holes, and are used to gather and / or collimate the light emitted by the LED unit.

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