Microdisplay device

Abstract

This invention relates to a microdisplay device, comprising a driving backplane and multiple pixel layers, wherein a mother pixel includes multiple sub-pixels; the top of each sub-pixel is electrically connected to a corresponding second type of electrode contact via a top conductive layer, and the bottom ends of the multiple sub-pixels are interconnected via bottom conductive layers and then electrically connected to corresponding first type of electrode contacts to form a bottom common electrode structure; wherein the axes of all sub-pixels in the mother pixel do not coincide; in two sub-pixels located in different pixel layers, the bottom conductive layers of the two sub-pixels are interconnected via a common electrode conductive element, and one side of a sub-pixel in the lower pixel layer is provided with at least one non-light-emitting unit to form a unit body, wherein one non-light-emitting unit in the unit body is passed through by the common electrode conductive element. This invention can improve the luminous efficiency and reliability of the microdisplay device.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a microdisplay device. Background Technology

[0002] Microdisplay devices, characterized by their small size, high resolution, and high brightness, can be applied in numerous fields such as AR / VR devices, automotive displays, medical detection, and smart wearables. Micro-LED and Micro-OLED technologies, in particular, have seen widespread development in recent years. Micro-LED technology, with its advantages of high efficiency, low power consumption, high density, and high stability, is considered one of the most promising next-generation display and light-emitting devices. In the field of microdisplays, to further ensure pixel size and density, multi-color stacking integration is required for color displays. Multi-layer stacked LED devices typically have a driving backplane (with driving circuitry) and multiple layers above it. Pixels are arranged in each layer, and each pixel needs to be electrically connected to the driving backplane. This complex structure results in significant light loss for each pixel, hindering optimal light distribution. Poor heat dissipation also makes LED microdisplay devices prone to overheating, leading to reduced luminous efficiency and shorter lifespan, which negatively impacts their stability and reliability. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to improve the light efficiency and reliability of micro-display devices in the prior art.

[0004] To address the aforementioned technical problems, the present invention provides a microdisplay device, comprising,

[0005] A drive backplate, wherein a first type of electrode contact and a second type of electrode contact with opposite polarities are provided on the drive backplate.

[0006] Multiple pixel layers, all of which are stacked sequentially from bottom to top above the driving backplate;

[0007] A mother pixel, wherein the mother pixel comprises a plurality of sub-pixels, and at least two of the sub-pixels are located in different pixel layers;

[0008] The top of each sub-pixel is electrically connected to the corresponding second type of electrode contact through a top conductive layer, and the bottom ends of multiple sub-pixels are interconnected through a bottom conductive layer and electrically connected to the corresponding first type of electrode contact to form a bottom common electrode structure.

[0009] Wherein, the axes of all the sub-pixels in the mother pixel do not coincide;

[0010] In addition, in two sub-pixels located in different pixel layers, the bottom conductive layers of the two sub-pixels are interconnected by a common conductive element. In this case, one of the sub-pixels in the lower pixel layer has at least one non-light-emitting unit on one side, which together form a unit body. One of the non-light-emitting units in the unit body is passed through by the common conductive element, so that the lower part of the common conductive element is electrically connected to the bottom conductive layer of the sub-pixel in the unit body, and the upper part is electrically connected to the bottom conductive layer of the other sub-pixel in the upper pixel layer.

[0011] In one embodiment of the present invention, the non-light-emitting unit is a compound semiconductor or an insulating medium.

[0012] In one embodiment of the present invention, the projection areas of all the sub-pixels in the mother pixel on the driving backplate are completely non-overlapping.

[0013] In one embodiment of the present invention, the projection area of ​​the non-light-emitting unit in the unit body through which the common conductive element passes on the driving back plate is a first projection area, the projection area of ​​the sub-pixel in the unit body on the driving back plate is a second projection area, and the projection area of ​​another sub-pixel above which the common conductive element in the unit body is electrically connected on the driving back plate is a third projection area. The second projection area is located outside the first projection area, and the third projection area is located inside or outside the first projection area.

[0014] In one embodiment of the present invention, the bottom conductive layer is provided at the bottom end of the unit body, and the sub-pixels and the non-light-emitting units in the unit body share the bottom conductive layer.

[0015] In one embodiment of the present invention, the bottom conductive layer is a metal bonding layer, and an outer metal fence is formed on the upper part of the bottom conductive layer at the bottom end of the unit body, the outer metal fence surrounding the periphery of the unit body.

[0016] In one embodiment of the invention, the outer metal fence and the outer wall of the surrounding unit are insulated from each other.

[0017] In one embodiment of the present invention, a bottom ohmic contact layer is further provided between the bottom end of the unit body and the bottom conductive layer at the bottom end.

[0018] In one embodiment of the present invention, the top conductive layer of each sub-pixel is electrically connected to the corresponding second type of electrode contact via a non-common conductive element.

[0019] In one embodiment of the present invention, a first insulating filling area is provided on the periphery of the unit body, and the top conductive layer of the sub-pixel in the unit body is electrically connected to the corresponding second type electrode contact through a non-common conductive element passing through the first insulating filling area.

[0020] In one embodiment of the present invention, the bottom end of the non-common conductive element is in direct contact with the corresponding second type of electrode contact.

[0021] In one embodiment of the present invention, an insulating gap is provided between the top of the non-light-emitting unit in the unit body and the bottom conductive layer of the adjacent sub-pixel above it.

[0022] In one embodiment of the present invention, the top of the non-light-emitting unit in the unit body is in direct contact with the bottom conductive layer of the adjacent sub-pixel above it.

[0023] In one embodiment of the present invention, the sub-pixels in the unit body and the adjacent non-light-emitting units are separated by a first slot, the first slot having an air gap or being filled with a first filler to form a solid structure.

[0024] In one embodiment of the present invention, the unit body has a plurality of non-light-emitting units, and the first partition groove is also formed between two adjacent non-light-emitting units and is separated by the first partition groove.

[0025] In one embodiment of the present invention, the unit body has a plurality of non-light-emitting units, and the plurality of non-light-emitting units are interconnected as one unit.

[0026] In one embodiment of the invention, the top of the sub-pixel is in contact with an electrically connected top conductive layer, or the top of the sub-pixel and at least a portion of its sidewalls are in contact with an electrically connected top conductive layer.

[0027] In one embodiment of the present invention, a top ohmic contact layer is provided at the top of the sub-pixel, and the top of each sub-pixel is in contact with the corresponding top conductive layer through the top ohmic contact layer.

[0028] In one embodiment of the present invention, the top conductive layer is separately provided at the top of each of the sub-pixels located in different pixel layers in the mother pixel, and the top conductive layer in the same pixel layer is located above the electrically connected sub-pixels.

[0029] In one embodiment of the invention, at least two sub-pixels located in different pixel layers emit different colors.

[0030] In one embodiment of the present invention, a lens is provided above the uppermost sub-pixel, and the lens covers at least one of the sub-pixels in the parent pixel.

[0031] The technical solution of the present invention has the following advantages compared with the prior art:

[0032] The micro-display device described in this invention helps to reduce the obstruction of the light-emitting surface of the lower sub-pixel, ensure the effective light-emitting area of ​​the lower sub-pixel, reduce energy waste, and improve the heat dissipation capacity of the overall device. This effectively improves the luminous efficiency and reliability of the micro-display device and allows its light pattern to meet the needs of different application scenarios. Attached Figure Description

[0033] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0034] Figure 1 This is a schematic diagram of the structure of the first micro-display device of the present invention (two-layer structure);

[0035] Figure 2 yes Figure 1 A magnified view of a section at point M1;

[0036] Figure 3 yes Figure 1 The diagram shown is a schematic of the structure before the top conductive layer is fabricated.

[0037] Figure 4 This is a schematic diagram of the structure of the second type of microdisplay device of the present invention (two-layer structure).

[0038] Figure 5 yes Figure 4 A magnified view of a section at point M2;

[0039] Figure 6 yes Figure 4 The diagram shown is a schematic of the structure before the top conductive layer is fabricated.

[0040] Figure 7 This is a schematic diagram of the structure of the third type of microdisplay device of the present invention (two-layer structure);

[0041] Figure 8 yes Figure 7 A magnified view of a section at point M3;

[0042] Figure 9 This is a schematic diagram of the structure of the fourth type of microdisplay device of the present invention (three-layer structure).

[0043] Figure 10 yes Figure 9 A cross-sectional view of the microdisplay device shown from another angle;

[0044] Figure 11 This is a schematic diagram of the structure of the fifth type of microdisplay device of the present invention (three-layer structure).

[0045] Figure 12 This is a schematic diagram of the structure of the sixth type of microdisplay device of the present invention (three-layer structure).

[0046] Figure 13 This is a schematic diagram of the structure of the seventh micro-display device of the present invention (three-layer structure).

[0047] Figure 14 yes Figure 13 A magnified view of a section at point M4;

[0048] Figure 15 This is a schematic diagram of the structure of the eighth micro-display device of the present invention (two-layer structure).

[0049] Explanation of reference numerals in the instruction manual:

[0050] 10. Drive backplane; 101. Type I electrode contact; 102. Type II electrode contact;

[0051] 20. First pixel layer;

[0052] 30. Second pixel layer;

[0053] 40. Third pixel layer;

[0054] 50. Subpixel;

[0055] 60. Top conductive layer;

[0056] 70. Bottom conductive layer;

[0057] 80. Non-common conductive components;

[0058] 90. Common electrode conductive component;

[0059] 100. First insulation filling area;

[0060] 140. Outer metal fence; 150. First insulating layer; 160. Second insulating layer; 170. Top ohmic contact layer; 180. Bottom ohmic contact layer; 250. Lens; 260. Unit; 2601. Non-light-emitting unit; 270. Insulating interval area; 280. First slot; 2801. Air gap; 2802. First filler; 290. Filling hole; 300. Third insulating layer; Detailed Implementation

[0061] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present disclosure or its application or use.

[0062] In the description of this invention, it should be understood that the terms "vertical," "upper," "lower," "top," "side," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0063] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0064] Traditional LED display devices, employing multi-layer stacking, have complex overall structures, significant light loss in each pixel, and fail to achieve optimal light distribution. Furthermore, these devices consume more power and have poor heat dissipation, making them prone to overheating, which can lead to reduced luminous efficiency and shorter lifespan, compromising their stability and reliability. Therefore, this application provides a micro-display device to address these issues, thereby better ensuring the photoelectric performance and reliability of the LED display device.

[0065] It should be noted that in this invention, sub-pixels are generally obtained by etching a compound semiconductor layer. A compound semiconductor layer refers to a layer structure with a certain thickness prepared from a compound semiconductor material. Compound semiconductors typically refer to compounds formed from two or more elements, including crystalline inorganic compounds (such as III-V and II-VI compound semiconductors) and oxide semiconductors. The compound semiconductors involved in this application are mainly epitaxial materials for light-emitting diodes, such as InGaN ternary material systems or AlGaInP quaternary material systems, whose emission wavelengths can cover the entire spectrum from ultraviolet, visible, and infrared. Their substrate materials can be GaN, Si, SiC, Sapphire, GaAs, InP, etc.

[0066] Taking the Micro-LED field as an example, some compound semiconductor materials involved in this application are shown in Table 1. In some practical applications, the film layers of compound semiconductors are more complex, or there are cases where materials are used interchangeably. Typical compound semiconductors mainly include P-type semiconductor materials, N-type semiconductor materials, and MQW active quantum wells and other functional layers (barrier layers, confinement layers, waveguide layers, buffer layers, etc.) sandwiched between the two:

[0067] Table 1. Material Table of Film Layers for Compound Semiconductors

[0068]

[0069] The structure of the microdisplay device of this application will be further described below with reference to the following specific embodiments.

[0070] Example 1

[0071] See Figure 1 This embodiment discloses a multi-layer stacked micro-display device, including at least one mother pixel, each mother pixel having multiple (two or more) sub-pixels. The structure of the above-mentioned micro-display device is described in detail below. The structure shown in the figure only shows the case of one mother pixel. When there are multiple mother pixels, the internal structure of each mother pixel is basically the same.

[0072] In this invention, the micro-display device has a Z-direction, an X-direction, and a Y-direction, which are perpendicular to each other. The Z-direction is the stacking direction of each layer of sub-pixels, that is, the up and down direction, which can also be understood as the direction away from / closer to the driving backplate. Here, "height" or "up and down" or "top and bottom" are all in the Z-direction.

[0073] In this invention, "bottom end of sub-pixel" refers to the end of the sub-pixel that is close to the driving backplate, and "top end of sub-pixel" refers to the end of the sub-pixel that is away from (away from) the driving backplate.

[0074] It should be noted that the cross-sectional views in the XZ plane of the accompanying drawings of this invention can be schematic diagrams after cutting a single cross-section, or schematic diagrams after cutting multiple cross-sections in combination, to show the connection of different electrode contacts.

[0075] The LED display device in this embodiment includes a driving backplate 10 and a mother pixel, the mother pixel including a plurality of sub-pixels 50.

[0076] The driving backplate 10 is a component with a driving circuit. The first type of electrode contact 101 and the second type of electrode contact 102 are the lead-out terminals of the driving circuit, used to electrically connect the driving circuit and the sub-pixel 50. The sub-pixel 50 is a light-emitting element. Through the electrical connection between the driving backplate 10 and the sub-pixel 50, the connection between the sub-pixel 50 and the driving circuit is realized, thereby driving the sub-pixel 50 to emit light. This allows each sub-pixel 50 to be driven individually and emit light independently.

[0077] The aforementioned driving backplane 10 includes, but is not limited to, a CMOS (Complementary Metal Oxide Semiconductor) driving backplane.

[0078] The driving backplate 10 may be provided with a first type of electrode contact 101 and a second type of electrode contact 102. The polarities of the first type of electrode contact 101 and the second type of electrode contact 102 are opposite, with one being the anode and the other the cathode. Understandably, in order to prevent short circuits, the first type of electrode contact 101 and the second type of electrode contact 102 need to be insulated from each other. Through the provision of the first type of electrode contact 101 and the second type of electrode contact 102, the driving backplate 10 can be electrically connected to the sub-pixel 50, thereby controlling the light emission of each sub-pixel using the driving backplate 10.

[0079] Understandably, the two ends of sub-pixel 50 along the Z direction are the bottom and the top, respectively; the bottom and top of sub-pixel 50 are the two ends with opposite polarities. Sub-pixel 50 includes a P-type semiconductor layer, an active layer and an N-type semiconductor layer arranged sequentially along the Z direction. The active layer is used to emit light. The top of sub-pixel 50 is the end where the N-type semiconductor layer is located (or the end where the P-type semiconductor layer is located - anode), and the bottom is the end where the P-type semiconductor layer is located (or the end where the N-type semiconductor layer is located - cathode), which need to be connected to electrode contacts of different polarities respectively.

[0080] See Figures 1-2 This embodiment discloses a microdisplay device, including a driving backplate 10, a mother pixel, and two pixel layers;

[0081] The drive backplate 10 is provided with a first type of electrode contact 101 and a second type of electrode contact 102 with opposite polarities.

[0082] Two pixel layers are stacked sequentially from bottom to top above the driving backplate 10 to form a two-layer structure. The two stacked pixel layers are the first pixel layer 20 and the second pixel layer 30 from bottom to top.

[0083] The mother pixel has two sub-pixels 50, and the two sub-pixels 50 are located in different pixel layers;

[0084] The top of each of the two sub-pixels 50 is electrically connected to the corresponding second type electrode contact 102 through the top conductive layer 60, and the bottom of the two sub-pixels 50 is interconnected through the bottom conductive layer 70 and then electrically connected to the corresponding first type electrode contact 101 to form a bottom common electrode structure; that is, the bottom conductive layers 70 of each sub-pixel 50 in the bottom common electrode structure are electrically connected together and conduct electricity to each other.

[0085] In this design, the axes of all sub-pixels 50 in the mother pixel do not coincide (areo-axis), so as to reduce mutual occlusion between the upper and lower sub-pixels 50 and increase the effective light-emitting area.

[0086] And in two sub-pixels 50 located in different pixel layers: the bottom conductive layers 70 of these two sub-pixels 50 are interconnected by a common conductive element 90. In this case, one of the sub-pixels 50 in the lower pixel layer has at least one non-light-emitting unit 2601 on one side, which together constitutes a unit body 260. That is, the unit body 260 is mainly composed of a sub-pixel 50 and at least one non-light-emitting unit 2601 on one side of it. One of the non-light-emitting units 2601 in the unit body 260 is passed through by the common conductive element 90, so that the lower part of the common conductive element 90 is electrically connected to the bottom conductive layer 70 of the sub-pixel 50 in the unit body 260, and the upper part is electrically connected to the bottom conductive layer 70 of the other sub-pixel 50 in the upper pixel layer.

[0087] Specifically, such as Figure 2 As shown, a filling hole 290 can be formed in the corresponding non-light-emitting unit 2601, and a conductive material can be filled into the filling hole 290 to obtain the aforementioned common electrode conductive element 90. This allows the common electrode conductive element 90 to pass through the filling hole 290 of the corresponding non-light-emitting unit 2601, and the non-light-emitting unit 2601 to directly contact the hole wall of the filling hole 290. The material of the aforementioned common electrode conductive element 90 can be metals such as aluminum (Al), copper (Cu), and tungsten (W), and their corresponding adhesive or barrier layers, such as titanium (Ti), titanium nitride (TiN), tantalum nitride / copper (Ti / Cu), tantalum nitride / copper (TaN / Cu), etc.

[0088] Understandably, subpixel 50 is a light-emitting element that emits light when powered, while non-light-emitting unit 2601 is an element that does not emit light when powered. The axis of subpixel 50 can be understood as the geometric center line of that subpixel.

[0089] Furthermore, the non-light-emitting unit 2601 may be a compound semiconductor, or the non-light-emitting unit 2601 may be an insulating medium.

[0090] The above structure allows for better off-axis alignment of sub-pixels, effectively reducing occlusion of the lower sub-pixel's light-emitting surface and increasing its effective light-emitting area. This facilitates optimal light distribution and allows the light pattern of the multi-color stacked device to meet the diverse needs of XR (Extended Reality) applications; such as... Figure 1 As shown in the figure, the direction of the dashed arrow is the light emission direction of the first layer sub-pixel 50.

[0091] The above structure causes the upper and lower sub-pixels to be horizontally offset, effectively reducing the obstruction of the light-emitting area of ​​the lower sub-pixel. It also reduces the problem of the metal bonding layer blocking and absorbing light from the sub-pixel directly below when the metal bonding layer is placed at the bottom of the upper sub-pixel. This reduces the energy waste of the lower sub-pixel and the phenomenon of the device temperature becoming too high due to the conversion of energy loss into heat, effectively increasing the light efficiency and reliability of the display device.

[0092] When the non-light-emitting unit 2601 uses compound semiconductor, by setting the unit body 260, a portion of the compound semiconductor is reserved on one side of the sub-pixel 50 in the unit body 260 as a non-light-emitting area. This method retains the original compound semiconductor material to the greatest extent. The compound semiconductor material has a high thermal conductivity, which effectively improves the heat dissipation capacity of the overall device. This greatly avoids problems such as failure and malfunction caused by excessive heat accumulation and temperature rise during the operation of the LED device, and improves the stability and reliability of the LED display device. At the same time, the non-light-emitting unit 2601 can be passed through by the common electrode conductive component 90, which is also easier to manufacture and improves production efficiency.

[0093] Similarly, when the non-light-emitting unit 2601 uses an insulating medium (not shown in the figure), the insulating medium is set on one side of the sub-pixel 50 in the unit body 260 as a non-light-emitting area, which can also improve the heat dissipation capability of the overall device to a certain extent.

[0094] It should be noted that the non-light-emitting unit 2601 shown in the accompanying drawings of each embodiment is a compound semiconductor. If the non-light-emitting unit 2601 uses an insulating medium, the compound semiconductor can be replaced with an insulating medium.

[0095] As is understood, in this invention, "upper pixel layer" refers to the pixel layers located above the lowermost pixel layer, while "lower pixel layer" is the pixel layer located below the upper pixel layer. Similarly, "upper sub-pixel" refers to the sub-pixels located above the lowermost sub-pixel, while "lower sub-pixel" is the sub-pixel located below the upper sub-pixel.

[0096] The shape of each sub-pixel is not limited; it can be a circle, ellipse, polygon (triangle, trapezoid, rectangle, etc.) or other shapes.

[0097] In this embodiment, the sub-pixel 50 includes an N-type semiconductor layer, an active layer, and a P-type semiconductor layer arranged sequentially from top to bottom; the thickness of the sub-pixel 50 (the distance between the upper surface of the N-type semiconductor layer and the lower surface of the P-type semiconductor layer) is 0.1um to 5um; the width of the sub-pixel 50 (X direction) is 0.2um to 80um.

[0098] In some implementations, the projection areas of all sub-pixels 50 in the mother pixel on the driving back plate 10 do not overlap at all, so as to better reduce the occlusion of the light-emitting surface of the lower sub-pixel 50, increase the effective light-emitting area of ​​the lower sub-pixel 50, and facilitate the achievement of the best light distribution effect.

[0099] Furthermore, the following relationship exists between the non-light-emitting unit 2601 in unit body 260 and the two sub-pixels 50 interconnected by the common conductive member 90 through which the non-light-emitting unit 2601 passes (one being the sub-pixel 50 electrically connected to the lower end of the common conductive member 90 located in unit body 260, and the other being the sub-pixel 50 electrically connected to the upper end of the common conductive member 90):

[0100] The projection area of ​​the non-light-emitting unit 2601 in unit 260 that is passed through by the common conductive element 90 on the driving back plate 10 is the first projection area; the projection area of ​​the sub-pixel 50 in unit 260 on the driving back plate 10 is the second projection area; and the projection area of ​​the other sub-pixel 50 above the common conductive element 90 in unit 260 that is electrically connected to the driving back plate 10 is the third projection area.

[0101] One possible relationship is that the second projection area is located outside the first projection area, and the third projection area is located inside the first projection area, so that the two sub-pixels 50 interconnected by the common conductive element 90 do not overlap at all, thereby maximizing the light-emitting area of ​​the lower sub-pixel.

[0102] Another relationship is that the second projection area is located outside the first projection area, and the third projection area is located outside the first projection area, so that the second projection area and the third projection area do not overlap at all. This makes the two sub-pixels 50 interconnected by the common conductive element 90 completely non-overlapping, thereby maximizing the light-emitting area of ​​the lower sub-pixel.

[0103] In the bottom common-polarity structure, the top conductive layer is separately set at the top of each sub-pixel located in different pixel layers within the mother pixel. Specifically, the top conductive layer can be set in the following form:

[0104] In some configurations, the top conductive layer portion of a subpixel can be located on the side of the subpixel and extend to the bottom of the subpixel on that side. See [reference needed]. Figure 1 The way the top conductive layer 60 of the sub-pixel is set in the second pixel layer 30.

[0105] In other configurations, the top conductive layer 60 of at least one pixel layer is substantially located above the corresponding sub-pixel in the electrically connected pixel layer, that is, the top conductive layer of the sub-pixel is substantially located above the sub-pixel.

[0106] Furthermore, each sub-pixel in a different pixel layer within the mother pixel has a separate top conductive layer 60. This allows the top conductive layer (the top conductive layer electrically connected to the sub-pixel in the same pixel layer) to be located above the corresponding sub-pixel in that electrically connected pixel layer. Here, "above" refers to being located approximately near the top of the sub-pixel. The sub-pixel includes a P-type semiconductor layer, an active layer, and an N-type semiconductor layer arranged sequentially along the Z-direction (height direction). Therefore, "above" can be understood as ensuring that the lowest point of the top conductive layer is higher than the upper surface of the active layer in the sub-pixel. For example, see [reference needed]. Figure 15 In the first pixel layer, the entire top conductive layer 60 of the sub-pixel is located above the sub-pixel 50, or the entire top conductive layer 60 of the sub-pixel in the first pixel layer is located above the sub-pixel 50, with only a portion of it slightly below the top surface of the sub-pixel.

[0107] For example, a method for fabricating a top conductive layer 60 separately at the top of a sub-pixel 50 in the first pixel layer 20 includes: etching the sub-pixel in the first pixel layer 20, then backfilling the current pixel layer with an insulating medium, planarizing the top of the first pixel layer 20 after backfilling to expose the top of the sub-pixel, and then depositing the top conductive layer 60 to make it contact the exposed area of ​​the sub-pixel top to achieve electrical connection. Then, an insulating medium can be deposited again on top of the pixel layer and planarized again before stacking the upper pixel layer. The upper pixel layer can also be fabricated separately with the top conductive layer 60 in the same manner, i.e., after etching the sub-pixel, backfilling with an insulating medium, planarizing the top of the pixel layer after backfilling to expose the top of the sub-pixel, and then depositing the top conductive layer 60 to achieve electrical connection. In this process, the insulating medium can be a transparent material.

[0108] Specifically, in the two-layer structure, each sub-pixel in the first pixel layer 20 and the second pixel layer 30 has a separate top conductive layer 60, which is located above the sub-pixel in the pixel layer. The top conductive layer 60 of the sub-pixel in the first pixel layer 20 is electrically connected to the corresponding second type electrode contact 102 through a non-common conductive element 80 on one side, and the top conductive layer 60 of the sub-pixel in the second pixel layer 30 is electrically connected to another corresponding second type electrode contact 102 through a non-common conductive element 80 on the other side.

[0109] The above-described fabrication method allows the top conductive layer of a sub-pixel to be located at the top of the sub-pixel when the top conductive layer is set separately.

[0110] In some implementations, see Figures 1-2 A bottom conductive layer 70 is provided at the bottom of the unit body 260, and the sub-pixels 50 and non-light-emitting units 2601 in the unit body 260 share a bottom conductive layer 70. When there are multiple non-light-emitting units 2601 in the unit body 260, the sub-pixels 50 and all the non-light-emitting units 2601 in the unit body 260 can share a bottom conductive layer 70. This method is more conducive to fabrication and facilitates the electrical connection of the common electrode conductive component 90.

[0111] The aforementioned bottom conductive layer 70 can be a metal bonding layer. A peripheral metal fence 140 is formed on the upper part of the bottom conductive layer 70 at the bottom of the unit 260, surrounding the unit 260. That is, the sub-pixel 50 and the non-light-emitting unit 2601 in the unit 260 are both surrounded inside a peripheral metal fence 140. The pixel layer containing the unit 260 is stacked by bonding it to the driving backplane 10 or the adjacent pixel layer below it through the bottom metal bonding layer. The bonding method can be thermo-press bonding.

[0112] The aforementioned outer metal fence 140 can act as a reflector, thereby further preventing optical crosstalk between adjacent sub-pixels in the X direction.

[0113] Furthermore, there is insulation between the outer metal fence 140 and the outer wall of the surrounding unit 260. It is understood that the outer wall of unit 260 refers to the sidewall at the outer perimeter edge of unit 260.

[0114] Specifically, the outer metal fence 140 and the outer wall of the surrounding unit 260 are insulated and isolated by a second insulating layer 160. The outer wall of the unit 260 surrounded by the outer metal fence 140 is also covered by a first insulating layer 150, and the second insulating layer 160 is covered on the outside of the first insulating layer 150.

[0115] The materials of the first insulating layer 150 and the second insulating layer 160 can be the same.

[0116] For example, the first insulating layer 150 may be made of one or more materials selected from silicon oxide, aluminum oxide, silicon nitride, titanium oxide, hafnium oxide, tantalum oxide, niobium oxide, aluminum nitride, or gallium nitride;

[0117] In some designs, the thickness of the first insulating layer 150 can be 5 nm to 2 μm.

[0118] Preferably, the aforementioned outer metal fence 140 can be in the form of a ring structure.

[0119] In this design, the metal bonding layer at the bottom of the unit 260 and the outer metal fence 140 are integrally formed. The metal bonding layer will sputter to form the metal fence during the etching process, thereby achieving integral forming; or, the metal bonding layer at the bottom of the unit 260 and the outer metal fence 140 are separately set.

[0120] For example, the aforementioned metal bonding layer can be a combination of metal materials, such as nickel (Ni), tin (Sn), gold (Au), copper (Cu), aluminum (Al), indium tin oxide (ITO), etc. For example, the metal bonding layer can be one or more of the following combinations: Ni and Sn, Au and Sn, Cu and Sn, Au and In, Au and Au, Al and Al, Cu and Cu, or ITO and ITO. The metal bonding layer and the driving backplate 10 may also include an adhesive layer (made of Cr, Ti, Ni, etc.) and a depletion barrier layer (made of Ni, Pt, Cu, etc.). The metal bonding layer on the pixel layer and the driving backplate 10 can be symmetrical or asymmetrical.

[0121] In some preferred embodiments, the aforementioned metal bonding layer can be a multilayer structure stacked sequentially along the height direction, with the layers from bottom to top being a Cr layer (adhesion layer), a Pt layer (barrier depletion layer), an Au layer, a Sn layer, and an Au layer, with thicknesses of 10 nm, 50 nm, 100 nm, 150 nm, and 50 nm, respectively.

[0122] In some embodiments, a bottom ohmic contact layer 180 is provided between the bottom end of the unit body 260 and the bottom conductive layer 70 at the bottom end, the bottom ohmic contact layer 180 being made of a conductive material.

[0123] For example, the bottom ohmic contact layer 180 can be one or more of transparent conductive films such as indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium tin oxide (IGZO), and aluminum-doped zinc oxide (AZO), or one or more of conductive metal materials such as nickel (Ni), chromium (Cr), gold (Au), silver (Ag), zinc (Zn), rhodium (Rh), beryllium (Be), and aluminum (Al), or a composite structure composed of transparent metal oxides and metals; the thickness of the bottom ohmic contact layer 180 is in the range of 1 nm to 500 nm.

[0124] Understandably, in addition to the sub-pixels 50 inside unit 260, other sub-pixels 50 can also have an outer metal fence 140 set around them. For example, in Figures 1-2 In the structure shown, the sub-pixel 50 in the second pixel layer 30 is also surrounded by a peripheral metal fence 140. The peripheral metal fence 140 of the sub-pixel 50 and the top conductive layer 60 of the sub-pixel 50 are insulated from each other by a third insulating layer 300.

[0125] In some implementations, the top conductive layer 60 at the top of each sub-pixel 50 is electrically connected to the corresponding second type electrode contact 102 via a non-common conductive element 80.

[0126] For example, in Figure 1 In the two-layer structure shown, each of the first pixel layer 20 and the second pixel layer 30 has a sub-pixel 50. The sub-pixel 50 in the first pixel layer 20 is located in the unit body 260. The top conductive layer 60 of the sub-pixel 50 in the first pixel layer 20 is electrically connected to the second type electrode contact 102 on the left through the non-common conductive member 80 on the left. The top conductive layer 60 of the sub-pixel 50 in the second pixel layer 30 is electrically connected to the second type electrode contact 102 on the right through the non-common conductive member 80 on the right.

[0127] The material of the non-common conductive component 80 can be the same as that of the common conductive component 90.

[0128] Furthermore, a first insulating filling area 100 is provided on the periphery of the unit body 260, and the top conductive layer 60 of the neutron pixel 50 of the unit body 260 is electrically connected to the corresponding second type electrode contact 102 through a non-common conductive element 80 passing through the first insulating filling area 100. That is, the non-common conductive element 80 is located on the periphery of the unit body 260.

[0129] For example, the filling material used in the first insulating filling region 100 may be one or more of silicon oxide, silicon nitride, silicon carbide (SiC), silicon carbon nitride (SiCN), silicon phosphosilicate glass (PSG), borosilicate glass (BPSG), or polyimide.

[0130] The first insulating filling area 100 mentioned above uses a transparent filling material.

[0131] In the specific preparation process, a non-common conductive component 80 can be formed by opening a filling in the insulating filling area and filling the filling hole with conductive material.

[0132] In some implementations, see Figures 1-2 The sub-pixel 50 in unit 260 and the adjacent non-light-emitting unit 2601 are separated by a first slot 280. The first slot 280 has an air gap 2801 inside to form a hollow structure. Furthermore, a first insulating layer 150 is provided between the first slot 280 and the internal air gap 2801.

[0133] Or, see Figures 4-5 The first septum 280 is filled with a first filler 2802 to form a solid structure.

[0134] The first filler 2802 is an insulating medium; or, the first filler 2802 can also be made of metal. In this case, the inner wall of the first partition 280 and the metal material inside it need to be insulated.

[0135] In some embodiments, the minimum dimension of the first partition 280 along the width direction (X direction) needs to be greater than 0, and the maximum dimension of the first partition 280 along the width direction (X direction) is 0.02um to 10um. This width should not be too large. The larger the width, the more compound semiconductor material is removed, which is less conducive to heat dissipation. If the width is too small, the effective separation of pixel units cannot be achieved, and it is also not conducive to the subsequent processes.

[0136] When the unit body 260 has multiple non-light-emitting units 2601, the arrangement of each non-light-emitting unit 2601 is as follows:

[0137] One type is where the unit body 260 has multiple non-light-emitting units 2601, and a first partition 280 is formed between adjacent non-light-emitting units 2601 and they are separated by the first partition 280. For example, see [reference needed]. Figure 9 The first pixel layer has a unit 260 body, which has one sub-pixel 50 and two non-light-emitting units 2601. A first slot 280 is also formed between two adjacent non-light-emitting units 2601, and an air gap is formed inside the first slot 280. See also... Figure 11 The unit 260 of the first pixel layer 20 has a sub-pixel 50 and two non-light-emitting units 2601. A first slot 280 is also formed between two adjacent non-light-emitting units 2601, and the first slot 280 has a first filler 2802 inside to form a solid structure.

[0138] Understandably, in unit cell 260, sub-pixels 50 and each light-emitting unit are arranged sequentially along the X direction.

[0139] Another type is where unit 260 has multiple non-light-emitting units 2601, which are interconnected. For example, see [reference needed]. Figure 11 The unit 260 of the first pixel layer 20 has a sub-pixel 50 and a non-light-emitting unit 2601 interconnected together.

[0140] In this embodiment, the top of the sub-pixel 50 is in contact with the corresponding top conductive layer 60 to achieve electrical connection, such as... Figure 1 As shown, the top of the sub-pixel 50 can be made to contact only the top conductive layer 60 for electrical connection; at this time, the top of the sub-pixel 50 can be exposed only in part or completely, and the exposed area can be made to contact the corresponding top conductive layer 60 to achieve electrical connection.

[0141] In some embodiments, the top conductive layer 60 is a transparent conductive layer to facilitate light transmission, allowing light emitted from the lower sub-pixel 50 to pass through the top conductive layer 60 and shine upwards. This transparent conductive layer can be one or more combinations of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum-doped zinc oxide (AZO), Al-doped indium tin oxide, Ag-doped indium tin oxide, and Au-doped indium tin oxide.

[0142] In some implementations, see Figures 13-14 Each sub-pixel 50 has a top ohmic contact layer 170 at its top. The top of each sub-pixel 50 is electrically connected to its corresponding top conductive layer 60 through the top ohmic contact layer 170. The aforementioned top ohmic contact layer 170 is a conductive layer.

[0143] Furthermore, a top ohmic contact layer 170 is also provided at the top of the non-light-emitting unit 2601 in the unit body 260, and the ohmic contact layer at the top of the sub-pixel 50 in the unit body 260 and the top ohmic contact layer 170 of the non-light-emitting unit 2601 are insulated from each other.

[0144] In some embodiments, a lens 250 is provided above the uppermost sub-pixel 50, and the lens 250 covers at least one sub-pixel 50 in the parent pixel. For example, the lens 250 can cover all sub-pixels 50 in different pixel layers of the parent pixel at the same time, or the sub-pixels 50 and the lens 250 can be in one-to-one correspondence, so that each sub-pixel 50 is covered by its own lens 250.

[0145] The lens 250 mentioned above is made of insulating material and can be made of materials such as silicon oxide, silicon nitride, aluminum oxide, silicate glass, silicone, electron beam photoresist (PMMA, SU8, etc.).

[0146] exist Figure 1 In the two-layer structure shown, when the lens 250 is fabricated, an insulating dielectric layer can be backfilled on the upper part of the second pixel layer 30, and the backfilled dielectric layer can be patterned and etched to form the lens 250.

[0147] Alternatively, the lens 250 can be prepared by filling with an insulating dielectric material, planarizing it (CMP process), and then patterning it with a coating.

[0148] In some embodiments, to enhance current spreading capability, at least one top conductive layer 60 is electrically connected to a metal reinforcement.

[0149] The aforementioned metal reinforcement can be located above or below the corresponding top conductive layer 60. The metal reinforcements in different mother pixels can be shared or used independently by their respective mother pixels.

[0150] In some implementations, the unit 260 is completely covered by the corresponding lens 250. That is, when the lens 250 is set, it needs to cover not only the sub-pixels 50 in the unit 260, but also the non-light-emitting unit 2601, so as to achieve overall coverage of the unit 260.

[0151] In some embodiments, the driving backplate 10 is divided into display areas, all parent pixels form a pixel array, the projection of the pixel array on the driving backplate 10 is located inside the display area, the first type of electrode contact 101 is provided inside the display area, and / or the first type of electrode contact 101 is provided outside the display area.

[0152] In some implementations, at least two sub-pixels 50 located in different pixel layers within a mother pixel have different emission colors. For example, in a two-layer structure with two pixel layers, the emission colors of sub-pixels in each pixel layer may be the same, and the emission colors of sub-pixels in different pixel layers may be different. Alternatively, one pixel layer may have two sub-pixels with different emission colors, while another pixel layer may have a sub-pixel whose emission color is different from that of at least one sub-pixel in the first layer.

[0153] For example, in some implementations, the sub-pixels 50 in different pixel layers of a multi-layer stacked structure emit different colors to achieve a color configuration.

[0154] For example, in Figure 1 In the two-layer structure shown, the sub-pixels 50 in the first pixel layer 20 and the second pixel layer 30 emit different colors to achieve a dual-color configuration. For example, the emission colors of each sub-pixel 50 from bottom to top are red and green, or they could be red and blue, or green and blue, etc.

[0155] In this embodiment, each sub-pixel 50 can be made of inorganic compound semiconductor material.

[0156] The microdisplay device of this embodiment helps to reduce the obstruction of the light-emitting surface of the lower sub-pixel, ensure the effective light-emitting area of ​​the lower sub-pixel, reduce energy waste, and also improve the heat dissipation capacity of the overall device, thereby effectively improving the light efficiency and reliability of the microdisplay device.

[0157] Example 2

[0158] In this embodiment, the pixel layer where unit 260 is located and the adjacent pixel layer above it can be configured in the following way:

[0159] First type: See reference Figures 1-2 An insulating gap 270 is provided between the top of the non-light-emitting unit 2601 in unit cell 260 and the bottom conductive layer 70 of the adjacent sub-pixel 50 above it. For example... Figure 1 As shown in the figure, the direction of the dashed arrow is the light emission direction of the first layer sub-pixel 50.

[0160] When preparing, refer to Figure 3For the pixel layer containing unit 260, after unit 260 is fabricated, insulating material is filled around unit 260 to form a first insulating filling region 100, and its top is planarized. The top surface of the first insulating filling region 100 after planarization is higher than the top surface of unit 260, and the higher insulating region forms an insulating gap region 270. Then, an upper pixel layer is stacked on top of the current pixel layer. At this time, the top of the non-light-emitting unit 2601 in unit 260 and the bottom conductive layer 70 of the adjacent sub-pixel 50 are separated by a certain distance by the insulating gap region 270, thus obtaining... Figure 3 After the structure shown is completed, the top conductive layers 60 are then fabricated to obtain... Figure 1 The structure shown.

[0161] The second type: See reference Figures 4-5 In unit cell 260, the top of the non-light-emitting unit 2601 is in direct contact with the bottom conductive layer 70 of the adjacent sub-pixel 50 above it. For example... Figure 4 As shown in the figure, the direction of the dashed arrow is the light emission direction of the first layer sub-pixel 50.

[0162] When preparing, refer to Figure 6 For the pixel layer containing unit 260, after unit 260 is fabricated, insulating material is filled around unit 260 to form a first insulating filling region 100, and its top is planarized. The top surface of the first insulating filling region 100 after planarization is flush with the top surface of unit 260, that is, the insulating material above the top surface of unit 260 is directly removed and the surface is directly planarized to the top surface of unit 260. At this time, there is no longer an insulating gap region 270 above unit 260. Then, the upper pixel layer is stacked on top of the current pixel layer. At this time, the top of the non-light-emitting unit 2601 in unit 260 is in direct contact with the bottom conductive layer 70 of the adjacent sub-pixel 50 above. Figure 6 After the structure shown is completed, the top conductive layers 60 are then fabricated to obtain... Figure 4 The structure shown.

[0163] Example 3

[0164] In this embodiment, the top of the sub-pixel 50 is in contact with the corresponding top conductive layer 60 to achieve electrical connection. The electrical connection can take the following forms:

[0165] The first type: such as Figure 1 As shown, only the top of the sub-pixel 50 is in contact with the electrically connected top conductive layer 60; at this time, only a part of the top of the sub-pixel 50 may be exposed or fully exposed, and the exposed area may be in contact with the corresponding top conductive layer 60 to achieve electrical connection.

[0166] The second type: See reference Figures 7-8This arrangement ensures that the top edge and at least a portion of the sidewalls of the sub-pixel 50 are in contact with the electrically connected top conductive layer 60. In this case, in addition to exposing the top edge j1 of the sub-pixel 50, at least a portion of the sidewalls j2 of the sub-pixel 50 are also exposed, thus forming an exposed area that contacts the corresponding top conductive layer 60 to achieve electrical connection. This method increases the electrical contact area, facilitates current spread, and enhances current conduction capability.

[0167] Understandably, in specific settings, one sub-pixel 50 in the mother pixel can use the first electrical connection method, while other sub-pixels 50 use the second electrical connection method, or all sub-pixels 50 can use the same electrical connection method. The specific choice can be made according to actual needs.

[0168] In some embodiments, the top conductive layer 60 is a transparent conductive layer to facilitate light transmission, allowing light emitted from the lower sub-pixel to pass through the top conductive layer and shine upwards. This transparent conductive layer can be one or more combinations of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum-doped zinc oxide (AZO), Al-doped indium tin oxide, Ag-doped indium tin oxide, and Au-doped indium tin oxide.

[0169] Example 4

[0170] See Figures 9-14 The main difference between this embodiment and embodiment one is that the micro-display device in this embodiment has three pixel layers. All pixel layers are stacked sequentially from bottom to top above the driving backplate. At this time, the structure is a three-layer structure. The mother pixel has three sub-pixels 50. The three pixel layers are, from bottom to top, the first pixel layer 20, the second pixel layer 30 and the third pixel layer 40.

[0171] The top of each of the three sub-pixels 50 is electrically connected to the corresponding second type electrode contact 102 through the top conductive layer 60, and the bottom of the three sub-pixels 50 is interconnected through the bottom conductive layer 70 and electrically connected to the first type electrode contact 101 to form a bottom common electrode structure.

[0172] In this design, the axes of all sub-pixels 50 in the mother pixel do not coincide (areo-axis), so as to reduce mutual occlusion between the upper and lower sub-pixels 50 and increase the effective light-emitting area.

[0173] And in two sub-pixels 50 located in different pixel layers: the bottom conductive layers 70 of these two sub-pixels 50 are interconnected by a common conductive element 90. In this case, one side of a sub-pixel 50 in the lower pixel layer is provided with at least one non-light-emitting unit 2601, which together constitutes a unit body 260. That is, the unit body 260 is mainly composed of a sub-pixel 50 and at least one non-light-emitting unit 2601 on one side of it. The non-light-emitting unit 2601 is a compound semiconductor. One non-light-emitting unit 2601 in the unit body 260 is passed through by the common conductive element 90, so that the lower part of the common conductive element 90 is electrically connected to the bottom conductive layer 70 of the sub-pixel 50 in the unit body 260, and the upper part is electrically connected to the bottom conductive layer 70 of the other sub-pixel 50 in the upper pixel layer.

[0174] For example, see Figures 9-10 The first pixel layer 20 and the second pixel layer 30 both have unit bodies 260, and the corresponding sub-pixels 50 are all sub-pixels 50 in unit bodies 260. The third pixel layer 40 is set with a sub-pixel 50. For two sub-pixels 50 in the first pixel layer 20 and the third pixel layer 40, the bottom conductive layers 70 of these two sub-pixels 50 are interconnected by a common conductive element 90. The common conductive element 90 is divided into two segments, one segment is located in the second pixel layer 30, and the other segment is located in the first pixel layer 20 and passes through a non-light-emitting unit 2601 in the unit body 260. For two sub-pixels 50 in the first pixel layer 20 and the second pixel layer 30, the bottom conductive layers 70 of these two sub-pixels 50 are interconnected by a common conductive element 90. The common conductive element 90 is located in the first pixel layer 20 and passes through a non-light-emitting unit 2601 in the unit body 260. For two sub-pixels 50 in the second pixel layer 30 and the third pixel layer 40, the bottom conductive layers 70 of these two sub-pixels 50 are interconnected by a common conductive element 90. The common conductive element 90 is located in the second pixel layer 30 and passes through a non-light-emitting unit 2601 in the unit body 260.

[0175] In some embodiments, a bottom conductive layer 70 is provided at the bottom end of the unit body 260, and the sub-pixels 50 and non-light-emitting units 2601 in the unit body 260 share a bottom conductive layer 70.

[0176] In some embodiments, the sub-pixel 50 in the unit body 260 and the adjacent non-light-emitting unit 2601 are separated by a first slot 280, and the first slot 280 has an air gap 2801 inside to form a hollow structure; further, a first insulating layer 150 is provided between the first slot 280 and the internal air gap 2801.

[0177] Alternatively, the first groove 280 may be filled with a first filler 2802 to form a solid structure, wherein the first filler 2802 is an insulating medium.

[0178] For example, see Figure 9 and Figure 11 Both the first pixel layer 20 and the second pixel layer 30 have unit cells 260, and the corresponding sub-pixels 50 are all sub-pixels 50 in unit cells 260. The unit cell 260 in the first pixel layer 20 has one sub-pixel 50 and two non-light-emitting units 2601, and they share a bottom conductive layer 70 at the bottom. The sub-pixel 50 in the unit cell 260 in the first pixel layer 20 and the adjacent non-light-emitting unit 2601 are separated by a first slot 280, and the first slot 280 has an air gap 2801 inside. The unit cell 260 in the second pixel layer 30 has one sub-pixel 50 and one non-light-emitting unit 2601, and they share a bottom conductive layer 70 at the bottom. The sub-pixel 50 in the unit cell 260 in the second pixel layer 30 and the adjacent non-light-emitting unit 2601 are separated by a first slot 280, and the first slot 280 has an air gap 2801 inside.

[0179] Or, see Figures 12-13 In the first pixel layer 20, the sub-pixel 50 in the unit body 260 and the adjacent non-light-emitting unit 2601 are separated by the first slot 280 and the first slot 280 is filled with the first filler 2802 to form a solid structure; in the second pixel layer 30, the sub-pixel 50 in the unit body 260 and the adjacent non-light-emitting unit 2601 are separated by the first slot 280 and the first slot 280 is filled with the first filler 2802 to form a solid structure.

[0180] When the unit body 260 has multiple non-light-emitting units 2601, the arrangement of each non-light-emitting unit 2601 is as follows:

[0181] One type is where the unit body 260 has multiple non-light-emitting units 2601, and a first partition 280 is formed between adjacent non-light-emitting units 2601 and they are separated by the first partition 280. For example, see [reference needed]. Figure 9 The unit 260 in the first pixel layer 20 has a sub-pixel 50 and two non-light-emitting units 2601, and there is also a first slot 280 between the two non-light-emitting units 2601.

[0182] Understandably, in unit cell 260, sub-pixels 50 and each light-emitting unit are arranged sequentially along the X direction.

[0183] Another type is where unit 260 has multiple non-light-emitting units 2601, which are interconnected. For example, see [reference needed]. Figure 11The unit 260 in the first pixel layer 20 has a non-light-emitting unit 2601 that is integrally set.

[0184] In some implementations, the top conductive layer 60 at the top of each sub-pixel 50 is electrically connected to the corresponding second type electrode contact 102 via a non-common conductive element 80.

[0185] In some embodiments, the bottom end of the non-common conductive element 80 is in direct contact with the corresponding second type electrode contact 102.

[0186] For example, in Figure 9 In the three-layer structure shown, each of the first pixel layer 20, the second pixel layer 30, and the third pixel layer 40 has one sub-pixel 50. The sub-pixels 50 in the first and second layers are located in their corresponding unit cells 260. The top conductive layer 60 of the sub-pixel 50 in the first pixel layer 20 is electrically connected to the left-side second-type electrode contact 102 via the left-side non-common conductive element 80. The top conductive layer 60 of the sub-pixel 50 in the third pixel layer 40 is electrically connected to the right-side second-type electrode contact 102 via the right-side non-common conductive element 80. (See reference...) Figure 10 In the second pixel layer 30, the top conductive layer 60 of the sub-pixel 50 is electrically connected to the corresponding second type electrode contact 102 through the non-common conductive element 80 on the right.

[0187] In this embodiment, the three-layer pixel structure can also adopt the structure of Embodiment 2 when setting the pixel layer where the unit body 260 is located and the adjacent pixel layer above it. That is, an insulating gap region 270 is provided between the top of the non-light-emitting unit 2601 in the unit body 260 and the bottom conductive layer 70 of the adjacent sub-pixel 50 above it; or, the top of the non-light-emitting unit 2601 in the unit body 260 is in direct contact with the bottom conductive layer 70 of the adjacent sub-pixel 50 above it.

[0188] In some implementations, see Figures 13-14 Each sub-pixel 50 has a top ohmic contact layer 170 at its top. The top of each sub-pixel 50 is electrically connected to its corresponding top conductive layer 60 through the top ohmic contact layer 170. The aforementioned top ohmic contact layer 170 is a conductive layer.

[0189] In some implementations, the sub-pixels 50 in different pixel layers of the multi-layer stacked structure emit different colors to achieve a color configuration.

[0190] For example, in the three-layer structure, the sub-pixels 50 in the first pixel layer 20, the second pixel layer 30, and the third pixel layer emit different colors to achieve a three-color configuration. For instance, the emission colors of the sub-pixels 50 from bottom to top are red, green, and blue, respectively.

[0191] In some implementations, see Figure 9 A lens 250 is provided above the sub-pixel 50 of the third layer, and the lens 250 covers at least one sub-pixel 50 in the parent pixel. For example, the lens 250 can cover all sub-pixels 50 of different pixel layers in the parent pixel at the same time, or the sub-pixels 50 and the lens 250 can be in one-to-one correspondence, so that each sub-pixel 50 is covered by its own lens 250.

[0192] All the above-mentioned optional technical solutions can be combined in any way to form optional embodiments of the present invention. That is, any number of embodiments can be combined to meet the needs of different application scenarios. All of these are within the protection scope of this application and will not be described in detail here.

[0193] It should be noted that the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A microdisplay device, characterized in that: include, A drive backplate, wherein a first type of electrode contact and a second type of electrode contact with opposite polarities are provided on the drive backplate. Multiple pixel layers, all of which are stacked sequentially from bottom to top above the driving backplate; A mother pixel, wherein the mother pixel comprises a plurality of sub-pixels, and at least two of the sub-pixels are located in different pixel layers; The top of each sub-pixel is electrically connected to the corresponding second type of electrode contact through a top conductive layer, and the bottom ends of multiple sub-pixels are interconnected through a bottom conductive layer and electrically connected to the corresponding first type of electrode contact to form a bottom common electrode structure. Wherein, the axes of all the sub-pixels in the mother pixel do not coincide; In addition, in two sub-pixels located in different pixel layers, the bottom conductive layers of the two sub-pixels are interconnected by a common conductive element. In this case, one of the sub-pixels in the lower pixel layer has at least one non-light-emitting unit on one side, which together form a unit body. One of the non-light-emitting units in the unit body is passed through by the common conductive element, so that the lower part of the common conductive element is electrically connected to the bottom conductive layer of the sub-pixel in the unit body, and the upper part is electrically connected to the bottom conductive layer of the other sub-pixel in the upper pixel layer.

2. The microdisplay device according to claim 1, characterized in that: The non-light-emitting unit is made of compound semiconductor or insulating medium.

3. The microdisplay device according to claim 1, characterized in that: The projection areas of all the sub-pixels in the mother pixel on the driving backplate are completely non-overlapping.

4. The microdisplay device according to claim 3, characterized in that: The projection area of ​​the non-light-emitting unit in the unit body that is passed through by the common electrode conductive element on the driving back plate is the first projection area. The projection area of ​​the sub-pixel in the unit body on the driving back plate is the second projection area. The projection area of ​​another sub-pixel above the common electrode conductive element in the unit body on the driving back plate is the third projection area. The second projection area is located outside the first projection area, and the third projection area is located inside or outside the first projection area.

5. The microdisplay device according to claim 1, characterized in that: The bottom conductive layer is provided at the bottom of the unit body, and the sub-pixels and the non-light-emitting units in the unit body share the bottom conductive layer.

6. The microdisplay device according to claim 5, characterized in that: The bottom conductive layer is a metal bonding layer, and an outer metal fence is formed on the upper part of the bottom conductive layer at the bottom of the unit body, which surrounds the perimeter of the unit body.

7. The microdisplay device according to claim 6, characterized in that: The outer metal fence and the outer wall of the surrounding unit are insulated from each other.

8. The microdisplay device according to claim 5, characterized in that: A bottom ohmic contact layer is also provided between the bottom end of the unit body and the bottom conductive layer at the bottom end.

9. The microdisplay device according to claim 1, characterized in that: The top conductive layer of each sub-pixel is electrically connected to the corresponding second type of electrode contact via a non-common conductive element.

10. The microdisplay device according to claim 9, characterized in that: The bottom end of the non-common conductive element is in direct contact with the corresponding second type of electrode contact.

11. The microdisplay device according to claim 9, characterized in that: The unit body has a first insulating filling area around its periphery, and the top conductive layer of the sub-pixel in the unit body is electrically connected to the corresponding second type of electrode contact through a non-common conductive element passing through the first insulating filling area.

12. The microdisplay device according to claim 1, characterized in that: An insulating gap is provided between the top of the non-light-emitting unit in the unit body and the bottom conductive layer of the adjacent sub-pixel above it.

13. The microdisplay device according to claim 1, characterized in that: The top of the non-light-emitting unit in the unit cell is in direct contact with the bottom conductive layer of the adjacent sub-pixel above it.

14. The microdisplay device according to claim 1, characterized in that: The sub-pixels in the unit body and the adjacent non-light-emitting units are separated by a first slot. The first slot has an air gap or is filled with a first filler to form a solid structure.

15. The microdisplay device according to claim 14, characterized in that: The unit body has multiple non-light-emitting units, and the first partition is formed between two adjacent non-light-emitting units and they are separated by the first partition.

16. The microdisplay device according to claim 14, characterized in that: The unit body has multiple non-light-emitting units, and the multiple non-light-emitting units are interconnected into one.

17. The microdisplay device according to claim 1, characterized in that: The top of the sub-pixel is in contact with the electrically connected top conductive layer, or the top of the sub-pixel and at least part of its sidewalls are in contact with the electrically connected top conductive layer.

18. The microdisplay device according to claim 1, characterized in that: The top of each sub-pixel is provided with a top ohmic contact layer, and the top of each sub-pixel is in contact with the corresponding top conductive layer through the top ohmic contact layer.

19. The microdisplay device according to claim 1, characterized in that: Each of the sub-pixels located in different pixel layers of the mother pixel has a separate top conductive layer at its top, and the top conductive layers in the same pixel layer are all located on top of the electrically connected sub-pixels.

20. The microdisplay device according to claim 1, characterized in that: At least two of the sub-pixels located in different pixel layers emit different colors.

21. The microdisplay device according to claim 1, characterized in that: A lens is provided above the uppermost sub-pixel, and the lens covers at least one of the sub-pixels in the parent pixel.

Images