Mother pixel arrangement structure and micro display device

Abstract

The present application relates to a kind of mother pixel arrangement structure and micro display device.The mother pixel arrangement structure includes driving backplate and multiple subpixels;Two subpixels in different pixel layers are located in: the inside of one subpixel in upper pixel layer is opened light transmission hole and constitutes light transmission pixel, the periphery of the light transmission hole of light transmission pixel forms peripheral light emitting area, the projection area of light transmission hole on driving backplate is second projection area, another subpixel in lower pixel layer is associated pixel, the projection area of associated pixel on driving backplate is first projection area, first projection area and second projection area at least partially overlap, so that associated pixel emits light at least partially via the light transmission hole of light transmission pixel shoots out.The present application also discloses a kind of micro display device, the present application can effectively improve the light efficiency and reliability of display device, also can make its light type meet the demand of different application scenarios.

Description

Mother pixel arrangement structure and micro display device Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a mother pixel arrangement structure and 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 results in a complex overall structure, significant loss of light-emitting area for each pixel, and difficulty in adjusting the light-emitting area, hindering optimal light distribution. Furthermore, the overall device consumes more power, which is detrimental to the reliability and stability of the LED display. 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, this invention provides a mother pixel arrangement structure, comprising:

[0005] Drive backplane;

[0006] Multiple sub-pixels, at least two of the sub-pixels are located in different pixel layers; all the pixel layers are stacked sequentially from bottom to top above the driving backplate;

[0007] In two sub-pixels located in different pixel layers, one of the sub-pixels in the upper pixel layer has a light-transmitting hole inside to form a light-transmitting pixel. The periphery of the light-transmitting hole of the light-transmitting pixel forms a peripheral light-emitting area. The projection area of ​​the light-transmitting hole on the driving backplate is a second projection area. The other sub-pixel in the lower pixel layer is a related pixel. The projection area of ​​the related pixel on the driving backplate is a first projection area. The first projection area and the second projection area at least partially overlap, so that the light emitted by the related pixel is at least partially emitted through the light-transmitting hole of the light-transmitting pixel.

[0008] In one embodiment of the present invention, the overlapping area of ​​the first projection area and the second projection area is not less than 1 / 2 of the area of ​​the first projection area.

[0009] In one embodiment of the present invention, the first projection area is completely located inside the second projection area.

[0010] In one embodiment of the present invention, the light-transmitting pixel and the associated pixel are both arranged coaxially.

[0011] In one embodiment of the invention, at least two associated pixels located in different pixel layers are both located below the same light-transmitting hole of the light-transmitting pixel.

[0012] In one embodiment of the invention, the light-transmitting pixel is arranged off-axis with at least one of the associated pixels below it.

[0013] In one embodiment of the present invention, the same light-transmitting pixel is provided with multiple light-transmitting holes, and the associated pixel and the light-transmitting hole of the light-transmitting pixel correspond one-to-one.

[0014] In one embodiment of the present invention, the light-transmitting pixel is surrounded by an outer air gap.

[0015] In one embodiment of the present invention, the light-transmitting pixel is further surrounded by a partition wall, and there is an outer air gap between the light-transmitting pixel and the surrounding partition wall.

[0016] In one embodiment of the present invention, an inner air gap is provided inside the light-transmitting pixel.

[0017] In one embodiment of the invention, at least two sub-pixels located in different pixel layers emit different colors.

[0018] The present invention also discloses a micro-display device, characterized in that: it includes at least one mother pixel, each mother pixel includes multiple sub-pixels, and each mother pixel adopts the mother pixel arrangement structure described in any of the above claims.

[0019] In one embodiment of the present invention, the bottom end of each of the multiple sub-pixels located in different pixel layers of the mother pixel is electrically connected to a corresponding first type of electrode contact, and the top ends of the multiple sub-pixels are interconnected through a top conductive layer and electrically connected to a corresponding second type of electrode contact to form a top common electrode structure, wherein the polarities of the first type of electrode contact and the second type of electrode contact are opposite.

[0020] In one embodiment of the present invention, in the top common polarity structure, among the two sub-pixels located in different pixel layers, one sub-pixel is the light-transmitting pixel and the other sub-pixel is the associated pixel. The bottom end of the light-transmitting pixel is electrically connected to the corresponding first type of electrode contact through a non-common polarity conductive element. The non-common polarity conductive element connected to the light-transmitting pixel is located on the periphery of the associated pixel.

[0021] In one embodiment of the present invention, the periphery of the associated pixel has an insulating fill area, and the non-common conductive element to which the light-transmitting pixel is connected passes through the insulating fill area.

[0022] In one embodiment of the present invention, the periphery of the associated pixel has a compound semiconductor region, and the non-common conductive element to which the light-transmitting pixel is connected passes through the compound semiconductor region.

[0023] In one embodiment of the invention, the compound semiconductor region is annular, and the associated pixel is surrounded inside the corresponding compound semiconductor region.

[0024] In one embodiment of the present invention, the associated pixel is surrounded by a plurality of compound semiconductor regions, which are circumferentially distributed.

[0025] In one embodiment of the invention, the periphery of the associated pixel is further surrounded by a peripheral air gap, the peripheral air gap being located between the associated pixel and the surrounding compound semiconductor region.

[0026] In one embodiment of the present invention, in the top common electrode structure, at least one pixel layer is a type II pixel layer, and the bottom end of the sub-pixel in the type II pixel layer is electrically connected to the corresponding first type electrode contact through a bottom conductive layer, and the bottom surface of the sub-pixel in the type II pixel layer is completely covered by the bottom conductive layer.

[0027] In one embodiment of the present invention, the pixel layer where the light-transmitting pixel is located is the type II pixel layer, and the bottom end of the light-transmitting pixel in the type II pixel layer is electrically connected to the corresponding non-common conductive element through a bottom conductive layer.

[0028] In one embodiment of the present invention, the bottom conductive layer is a metal bonding layer, and a first peripheral metal fence and a first inner metal fence are formed above the bottom conductive layer of the light-transmitting pixel in the type-II pixel layer. The light-transmitting pixel in the type-II pixel layer is surrounded by the first peripheral metal fence, and the light-transmitting hole is surrounded by the first inner metal fence.

[0029] In one embodiment of the present invention, at least one pixel layer is a type-1 pixel layer, and the bottom ends of each sub-pixel in the type-1 pixel layer are each electrically connected to a corresponding first-type electrode contact through an independent conductive block, wherein the conductive block corresponds one-to-one with the first-type electrode contact; wherein the conductive block has an electrical contact area for electrically connecting to the bottom end of the corresponding sub-pixel in the type-1 pixel layer, and the area of ​​the electrical contact area is smaller than the area of ​​the bottom surface of the corresponding sub-pixel in the type-1 pixel layer to which it is electrically connected.

[0030] In one embodiment of the present invention, the bottom end of the sub-pixel in the type-1 pixel layer is electrically connected to its corresponding conductive block through a metal reflective layer.

[0031] In one embodiment of the present invention, the pixel layer where the light-transmitting pixel is located is the type I pixel layer, and the bottom end of the light-transmitting pixel in the type I pixel layer is electrically connected to the corresponding non-common conductive element through the metal reflective layer and the conductive block in sequence.

[0032] In one embodiment of the present invention, an outer reflective portion and an inner reflective portion are formed above the metal reflective layer of the light-transmitting pixel in the type-pixel layer, the outer reflective portion surrounds the periphery of the light-transmitting pixel in the type-pixel layer, and the inner reflective portion surrounds the interior of the light-transmitting hole.

[0033] In one embodiment of the present invention, in the top common polarity structure, a display area is divided on the driving back plate, all the mother pixels constitute a pixel array, the projection of the pixel array on the driving back plate is located inside the display area, the second type of electrode contact is provided inside the display area, and / or the second type of electrode contact is provided outside the display area, the second type of electrode contact is electrically connected to the top conductive layer at the top of the multiple sub-pixels through a common polarity conductive element.

[0034] In one embodiment of the present invention, in the top common polarity structure, the top of each of the sub-pixels located in different pixel layers of the mother pixel is provided with a separate top conductive layer without sharing it, and the top conductive layers in the same pixel layer are all located on the upper part of the electrically connected sub-pixels.

[0035] In one embodiment of the present invention, in the top common polarity structure, the top of each of the sub-pixels of at least two different pixel layers in the mother pixel is provided with a separate top conductive layer without sharing it, and the common polarity conductive element includes an interconnecting conductive portion, and two adjacent top conductive layers are interconnected through the interconnecting conductive portion to achieve electrical connection.

[0036] In one embodiment of the present invention, in the top common polarity structure, at least two of the sub-pixels in the mother pixel share a top conductive layer, and the sub-pixels sharing a top conductive layer are respectively located in different pixel layers.

[0037] In one embodiment of the present invention, in the top common electrode structure, the bottom end of the common electrode conductive element is in direct contact with the corresponding second type of electrode contact.

[0038] In one embodiment of the present invention, the top of each of the multiple sub-pixels located in different pixel layers in the mother pixel is electrically connected to a corresponding second type of electrode contact through a top conductive layer, and the bottom ends of the multiple sub-pixels are electrically interconnected and connected to a first type of electrode contact to form a bottom common electrode structure, wherein the polarities of the first type of electrode contact and the second type of electrode contact are opposite.

[0039] In one embodiment of the present invention, in the bottom common polarity structure, among the two sub-pixels located in different pixel layers, one sub-pixel is the light-transmitting pixel and the other sub-pixel is the associated pixel. The bottom end of the light-transmitting pixel and the bottom end of the associated pixel are electrically connected to each other through a common polarity conductive element. The common polarity conductive element connected to the light-transmitting pixel is located on the periphery of the associated pixel.

[0040] In one embodiment of the present invention, the periphery of the associated pixel has an insulating fill area, and the common conductive element to which the light-transmitting pixel is connected passes through the insulating fill area.

[0041] In one embodiment of the present invention, the periphery of the associated pixel has a compound semiconductor region, and the common conductive element to which the light-transmitting pixel is connected passes through the compound semiconductor region.

[0042] In one embodiment of the present invention, the top conductive layer of the associated pixel is electrically connected to the corresponding second type of electrode contact through a non-common conductive element, and the top conductive layer of the top conductive layer of the associated pixel is electrically connected to the corresponding non-common conductive element after passing through the light-transmitting hole of the light-transmitting pixel.

[0043] In one embodiment of the present invention, in the bottom common electrode structure, a display area is divided on the driving back plate, all the mother pixels constitute a pixel array, the projection of the pixel array on the driving back plate is located inside the display area, the first type of electrode contact is provided inside the display area, and / or the first type of electrode contact is provided outside the display area.

[0044] In one embodiment of the present invention, in the bottom common polarity structure, the top of each of the sub-pixels located in different pixel layers of the mother pixel is individually provided with the top conductive layer, and the top conductive layer in the same pixel layer is located above the electrically connected sub-pixels.

[0045] In one embodiment of the invention, at least one of the top conductive layers is electrically connected to a metal reinforcement located above or below the electrically connected top conductive layer.

[0046] 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.

[0047] 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.

[0048] The technical solution of the present invention has the following advantages compared with the prior art:

[0049] The mother pixel arrangement structure and microdisplay device described in this invention help reduce the obstruction of the light-emitting surface of the lower sub-pixels, ensure the effective light-emitting area of ​​the lower sub-pixels, reduce energy waste, and thus achieve the best light distribution effect. This can effectively improve the light efficiency and reliability of the display device, and also make its light pattern meet the needs of different application scenarios. Attached Figure Description

[0050] 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.

[0051] Figure 1 is a schematic diagram of the structure of the first micro-display device of the present invention (two-layer structure);

[0052] Figure 2 is a schematic diagram (top view) of the arrangement of sub-pixels in the microdisplay device shown in Figure 1.

[0053] Figure 3 is a magnified view of part M1 in Figure 1;

[0054] Figure 4 is a schematic diagram of the structure of the second type of micro-display device of the present invention (three-layer structure).

[0055] Figure 5 is a schematic diagram (top view) of the arrangement of sub-pixels in the microdisplay device shown in Figure 4.

[0056] Figure 6 is a schematic diagram of the structure of the third type of micro-display device of the present invention;

[0057] Figure 7 is a schematic diagram of the structure of the fourth micro-display device of the present invention;

[0058] Figure 8 is a schematic diagram of the structure of the fifth micro-display device of the present invention;

[0059] Figure 9 is a magnified view of part M2 in Figure 8;

[0060] Figure 10 is a schematic diagram of the structure of the sixth micro-display device of the present invention;

[0061] Figure 11 is a structural schematic diagram of the seventh micro-display device of the present invention (with an added metal reinforcement).

[0062] Figure 12 is a schematic diagram of the structure of the eighth micro-display device of the present invention;

[0063] Figure 13 is a schematic diagram of the structure of the ninth micro-display device of the present invention;

[0064] Figure 14 is a schematic diagram of the structure of the tenth micro-display device of the present invention;

[0065] Figure 15 is a magnified view of a portion of M3 in Figure 14;

[0066] Figure 16 is a schematic diagram (top view) of the distribution of the display area in this invention.

[0067] Figure 17 is a schematic diagram (top view) of the connection between the peripheral electrode contact area and the interface in this invention.

[0068] Figure 18 is a schematic diagram of a structure in which the top conductive layer is set independently in the first pixel layer;

[0069] Figure 19 is a schematic diagram of another structure in which the top conductive layer is set independently in the first pixel layer;

[0070] Figure 20 is a magnified view of a portion of M4 in Figure 19;

[0071] Figure 21 is a schematic diagram of the structure of the eleventh micro-display device of the present invention;

[0072] Figure 22 is a schematic diagram of the structure of the twelfth micro-display device of the present invention;

[0073] Figure 23 is a schematic diagram of the thirteenth micro-display device of the present invention;

[0074] Figure 24 is a schematic diagram of a structure of the micro-display device of the present invention when it has a lens;

[0075] Figure 25 is a schematic diagram of another structure of the micro-display device of the present invention when it has a lens;

[0076] Explanation of reference numerals in the instruction manual:

[0077] 10. Drive backplane; 101. First type of electrode contact; 102. Second type of electrode contact; 103. Display area; 104. Peripheral electrode contact area; 105. Interface;

[0078] 20. First pixel layer;

[0079] 30. Second pixel layer;

[0080] 40. Third pixel layer;

[0081] 50. Subpixel; 501. Light-transmitting aperture; 502. Peripheral light-emitting area; 503. Channel;

[0082] 60. Top conductive layer;

[0083] 70. Bottom conductive layer;

[0084] 80. Non-common conductive components;

[0085] 90. Common conductor; 901. Interconnecting conductor;

[0086] 110. Insulation filling area;

[0087] 120. Compound semiconductor region;

[0088] 130. First inner metal fence; 140. First outer metal fence; 150. First insulating layer; 160. Second insulating layer; 180. Bottom ohmic contact layer; 190. Metal reinforcement; 210. Outer air gap; 220. Inner air gap; 250. Lens; 260. Partition wall; 270. Conductive block; 2701. Electrical contact area; 280. Metal reflective layer; 2801. Outer reflective part; 2802. Inner reflective part; Detailed Implementation

[0089] 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.

[0090] 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.

[0091] 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.

[0092] Traditional LED devices using multi-layer stacking have complex overall structures, resulting in significant loss of light-emitting area for each pixel. This makes it difficult to adjust the light-emitting area and achieve optimal light distribution. Furthermore, the overall device consumes more power, which is detrimental to the reliability and stability of the LED display device. In view of this, this application provides a micro-display device to improve the above-mentioned problems, thereby better ensuring the photoelectric performance and reliability of the LED display device.

[0093] 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.

[0094] 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:

[0095] Table 1. Material Table of Film Layers for Compound Semiconductors

[0096]

[0097] The structure of the microdisplay device of this application will be further described below with reference to the following specific embodiments.

[0098] Example 1

[0099] Referring to 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] The micro-display device - LED display device in this embodiment includes a mother pixel, which includes a driving backplate 10 and a plurality of sub-pixels 50.

[0104] 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 and the driving circuit is realized, thereby driving the sub-pixel to emit light, so that each sub-pixel can be driven individually and emit light independently.

[0105] The aforementioned driving backplane 10 includes, but is not limited to, a CMOS (Complementary Metal Oxide Semiconductor) driving backplane.

[0106] 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 50 using the driving backplate 10.

[0107] 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.

[0108] Referring to Figures 1 and 2, the micro-display device in this embodiment includes a driving backplate 10 and two pixel layers. Each pixel layer is provided with sub-pixels 50, and at least two sub-pixels are located in different pixel layers. All pixel layers are stacked sequentially from bottom to top above the driving backplate 10.

[0109] The mother pixel in the microdisplay device includes multiple sub-pixels 50, which adopt the following mother pixel arrangement structure, which includes a driving backplate 10 and multiple sub-pixels 50, with sub-pixels of different emission colors located in different pixel layers.

[0110] In two sub-pixels 50 located in different pixel layers, one sub-pixel 50 in the upper pixel layer has a light-transmitting hole 501 inside to form a light-transmitting pixel. The periphery of the light-transmitting hole 501 of the light-transmitting pixel forms a peripheral light-emitting area 502. The projection area of ​​the light-transmitting hole 501 on the driving backplate 10 is the second projection area. The other sub-pixel 50 in the lower pixel layer is a related pixel. The projection area of ​​the related pixel on the driving backplate 10 is the first projection area. The first projection area and the second projection area at least partially overlap, so that the light emitted by the related pixel is at least partially emitted through the light-transmitting hole 501 of the light-transmitting pixel without being blocked. This increases the effective light-emitting area of ​​the lower sub-pixel 50-related pixel, which is beneficial to achieving the best light distribution effect. As shown in Figure 1, the direction of the dashed arrow in the figure is the light-emitting direction of the sub-pixel 50-related pixel in the first layer.

[0111] It is understandable that the interior of the light-transmitting hole 501 in the light-transmitting pixel can be filled with transparent material, as long as the light emitted from the sub-pixel below can be emitted through the light-transmitting hole.

[0112] For example, as shown in Figure 1, the structure has two pixel layers, namely a first pixel layer 20 and a second pixel layer 30 from bottom to top. 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 an associated pixel, and the sub-pixel 50 in the second pixel layer 30 is a light-transmitting pixel with a light-transmitting hole 501. The light emitted by the lower associated pixel is at least partially emitted through the light-transmitting hole 501 of the upper light-transmitting pixel, thereby minimizing the obstruction of the light-emitting surface of the lower sub-pixel 50, which helps to improve the light emission intensity of the overall device and thus improve efficiency.

[0113] Alternatively, as exemplified in the structure shown in Figure 4, there are three pixel layers, from bottom to top: a first pixel layer 20, a second pixel layer 30, and a third pixel layer 40. Each of these layers has a sub-pixel 50. The sub-pixel 50 in the third pixel layer 40 is a light-transmitting pixel with a light-transmitting aperture 501. The sub-pixel 50 in the first pixel layer 20 is a related pixel, and the sub-pixel 50 in the second pixel layer 30 is also a related pixel. For the first pixel layer 20 and the third pixel layer 40, the first pixel layer... Light emitted from associated pixels in pixel layer 20 is at least partially emitted through the light-transmitting aperture 501 of the light-transmitting pixel in the third pixel layer 40; for the second pixel layer 30 and the third pixel layer 40, light emitted from associated pixels in the second pixel layer 30 is at least partially emitted through the light-transmitting aperture 501 of the light-transmitting pixel in the third pixel layer 40; thereby minimizing the obstruction of the light-emitting surface of the lower sub-pixel 50, which is beneficial to improving the light emission intensity of the overall device and thus improving efficiency; as shown in Figure 4, the direction of the dashed arrow in the figure is the light emission direction of the sub-pixel 50-associated pixel in the first and second layers.

[0114] The light emitted by the lower associated pixel is at least partially emitted through the light-transmitting hole 501 of the upper light-transmitting pixel, thereby minimizing the obstruction of the light-emitting surface of the lower sub-pixel, which helps to improve the light emission intensity of the overall device and thus improve efficiency.

[0115] It is understood that in this embodiment, the "peripheral light-emitting area" is an area that can emit light after being powered on. The so-called "associated pixel" refers to a sub-pixel associated with the "light-transmitting pixel", and the light emitted by the associated pixel is at least partially emitted through the light-transmitting hole of its associated light-transmitting pixel.

[0116] Furthermore, in this embodiment, the projection area of ​​sub-pixels 50 on the driving backplate refers to the entire area surrounded by the outer edge of the projection. For example, the projection area of ​​a light-transmitting pixel 50 with a light-transmitting hole on the driving backplate 10 refers to the entire area surrounded by the outer edge of the projection, including the area where the light-transmitting hole is located. The projection area of ​​associated pixels on the driving backplate is the first projection area, which also refers to the entire area surrounded by the outer edge of its projection.

[0117] The above structure forms a light-transmitting pixel by opening a light-transmitting hole 501 inside the upper sub-pixel 50, and places the lower sub-pixel 50 and its associated pixel below the light-transmitting hole 501 of the light-transmitting pixel. This allows the light emitted by the lower associated pixel to be emitted upward through the light-transmitting hole 501 of the upper light-transmitting pixel, thereby effectively reducing the obstruction of the light-emitting area of ​​the lower sub-pixel, increasing the effective light-emitting area of ​​the lower sub-pixel, and facilitating the achievement of optimal light distribution. At the same time, it also reduces the problem of light blocking and light absorption of the lower sub-pixel when the metal bonding layer is set at the bottom of the upper sub-pixel, thereby reducing the energy waste of the lower sub-pixel 50 and the phenomenon of the device temperature becoming too high due to energy loss being converted into heat, effectively increasing the light efficiency and reliability of the display device.

[0118] Furthermore, the sub-pixel distribution structure described above allows for more flexible design of the light-emitting area of ​​each sub-pixel layer, compensating for the shortcomings of certain sub-pixels being too bright or too dark. For example, by adjusting the size and position of the light-transmitting holes inside the light-transmitting pixels, the light-emitting position and size of the associated pixels below can be flexibly adjusted, thereby achieving adjustment of the light-emitting area and light-emitting region. This can be adapted to different application requirements and is more convenient for adjusting the light-emitting region. The above structure also facilitates the control of the sub-pixel positions, allowing the lower sub-pixels to be positioned differently than the upper sub-pixels, thereby controlling the light pattern of the multi-color stacked device to meet the different needs of XR (extended reality) applications.

[0119] In this embodiment, "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 subpixel" refers to the subpixels located above the lowermost subpixel, while "lower subpixel" is the subpixel located below the upper subpixel.

[0120] In some embodiments, the projection area of ​​the light-transmitting hole 501 on the driving back plate 10 is a second projection area, and the projection area of ​​the associated pixel on the driving back plate 10 is a first projection area. The overlapping area of ​​the first projection area and the second projection area is not less than 1 / 3 of the area of ​​the first projection area. For example, the overlapping area of ​​the first projection area and the second projection area is not less than 1 / 2 of the area of ​​the first projection area, or the overlapping area of ​​the first projection area and the second projection area is not less than 2 / 3 of the area of ​​the first projection area, etc.

[0121] Furthermore, the first projection area is completely located inside the second projection area, thereby minimizing the occlusion of the lower sub-pixel by the upper sub-pixel, so that the light emitted upward from the lower sub-pixel can be emitted from the light-transmitting hole of the upper sub-pixel, thus ensuring a better light output effect.

[0122] In some implementations, the associated pixel may or may not have an aperture 503 inside. For example, in the two-layer structure shown in FIG1, the sub-pixel 50 in the first pixel layer 20 is an associated pixel, and the associated pixel does not have an aperture 503 inside; in the three-layer structure shown in FIG2, the sub-pixel 50 in the first pixel layer 20 is an associated pixel, and the associated pixel has an aperture 503 inside; the sub-pixel 50 in the second pixel layer 30 is also an associated pixel, but the associated pixel does not have an aperture 503 inside.

[0123] In some implementations, the light-transmitting pixels and associated pixels are arranged coaxially.

[0124] For example, refer to Figures 1 and 2, where Figure 1 can be a cross-sectional view of the structure in Figure 2 along line AA. This structure is a two-layer structure. The first pixel layer 20 has a sub-pixel 50, which is an associated pixel. The second pixel layer 30 has another sub-pixel 50, which is a light-transmitting pixel. The associated pixel is located below the light-transmitting hole 501, and the light-transmitting pixel above it is coaxially arranged (the axes coincide). In Figure 2, the sub-pixel 50 in the first pixel layer 20 is denoted as i1, which is the associated pixel, and the first type of electrode contact 101 connected to it is denoted as c1. The sub-pixel 50 in the second pixel layer 30 is denoted as i2, which is the light-transmitting pixel, and the first type of electrode contact 101 connected to it is denoted as c2.

[0125] In some methods, at least two associated pixels located in different pixel layers are located below the same light-transmitting hole 501 of the light-transmitting pixel, so that the light emitted by multiple associated pixels is emitted from the same light-transmitting hole 501. This method can make the overall structure more compact and easier to arrange and process.

[0126] For example, referring to Figures 4 and 5, Figure 5 is a top view of the sub-pixel positions of the structure shown in Figure 4. The structure is a three-layer structure. The first pixel layer 20 has a sub-pixel 50, which is an associated pixel. The second pixel layer 30 has a sub-pixel 50, which is also an associated pixel. The third pixel layer 30 has a sub-pixel 50, which is a light-transmitting pixel. The associated pixels of the first and second layers are both located below the same light-transmitting hole 501 above. The light-transmitting pixel above and the two associated pixels below are coaxially arranged. In Figure 5, sub-pixel 50 located in the first pixel layer 20 is denoted as i1, which is an associated pixel, and the first type of electrode contact 101 connected to it is denoted as c1. Sub-pixel 50 located in the second pixel layer 30 is denoted as i2, which is an associated pixel, and the first type of electrode contact 101 connected to it is denoted as c2. Sub-pixel 50 located in the third pixel layer 40 is denoted as i3, which is a light-transmitting pixel, and the first type of electrode contact 101 connected to it is denoted as c3.

[0127] In other embodiments, the light-transmitting pixel and at least one associated pixel below it are arranged off-axis (the axes do not coincide).

[0128] When the axis is off-axis, the same light-transmitting pixel can be set with only one light-transmitting hole 501.

[0129] Alternatively, when the orientation is off-axis, the same light-transmitting pixel can be set with multiple light-transmitting holes 501, and the light-transmitting holes 501 of the associated pixels and the light-transmitting pixels correspond one-to-one.

[0130] Furthermore, in some alternative methods, the projections of the outgoing light rays through the corresponding light-transmitting holes 501 of the same light-transmitting pixel onto the driving backplate 10 do not overlap at all; or the projections of the outgoing light rays through the corresponding light-transmitting holes 501 of the same light-transmitting pixel onto the driving backplate 10 partially overlap.

[0131] In this embodiment, the shape of each sub-pixel 50 is not limited, and can be a circle, ellipse, polygon (triangle, trapezoid, rectangle, etc.) or other shapes.

[0132] For example, 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 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.

[0133] In some embodiments, referring to Figures 8-9, the light-transmitting pixel is surrounded by an outer air gap 210.

[0134] The aforementioned outer air gap 210 can be annular, such as a circular ring, a square ring, etc., and the specific shape is not limited.

[0135] By setting an air gap, it is easier for total internal reflection to occur when light is incident from the high-refractive-index sub-pixel corresponding film layer to the low-refractive-index air gap, thus achieving optical angle modulation, reducing the light emission divergence angle, achieving light collimation, and thereby improving the display brightness and light efficiency of the display device.

[0136] Furthermore, the light-transmitting pixel is surrounded by a partition wall 260, and there is an outer air gap 210 between the light-transmitting pixel and the outer partition wall 260.

[0137] The aforementioned partition wall 260 is made of compound semiconductor material.

[0138] In some embodiments, as shown in FIG10, the interior of the light-transmitting pixel is surrounded by an inner air gap 220.

[0139] In a specific configuration, as shown in Figure 10, the inner air gap 220 can surround the periphery of the light-transmitting hole 501 in the light-transmitting pixel.

[0140] Alternatively, after filling the light-transmitting hole 501 with a transparent medium, an inner air gap 220 can be provided inside the transparent medium;

[0141] The aforementioned inner air gap 220 can be annular, such as a circular ring, a square ring, etc., and the specific shape is not limited.

[0142] In some implementations, referring to FIG7, the periphery of the associated pixel is surrounded by a peripheral air gap 210.

[0143] This embodiment also discloses a micro-display device. Referring to Figures 1-5, the micro-display device includes at least one mother pixel, and each mother pixel includes multiple sub-pixels 50. Each mother pixel is arranged in the form of the mother pixel arrangement structure described above.

[0144] In some embodiments, the bottom of each of the multiple sub-pixels 50 located in different pixel layers of the mother pixel is electrically connected to a corresponding first type of electrode contact 101, and the top of the multiple sub-pixels 50 is electrically connected to a corresponding second type of electrode contact 102. The first type of electrode contact 101 and the second type of electrode contact 102 have opposite polarities, with one being an anode and the other being a cathode.

[0145] The first type of electrode contact 101 and the second type of electrode contact 102 are provided on the drive back plate 10 to serve as electrode terminals of the drive circuit inside the drive back plate.

[0146] In some embodiments, referring to FIG1, the periphery of the associated pixel has an insulating fill area 110, the interior of which is provided for interconnecting conductive elements to pass through, the top of which is electrically connected to the top or bottom of the light-transmitting pixel.

[0147] The insulating filling area 110 can be made of transparent filling material.

[0148] In other embodiments, referring to Figure 6, the periphery of the associated pixel has a compound semiconductor region 120, the interior of which is provided for interconnecting conductive elements to pass through. The top of the interconnecting conductive elements is electrically connected to the top or bottom of the light-transmitting pixel. This method can retain more compound semiconductor material, which has good thermal conductivity, thus improving the overall heat dissipation effect of the device.

[0149] The materials of the aforementioned interconnecting conductive components can be metals such as aluminum (Al), copper (Cu), and tungsten (W), as well as their corresponding adhesive or barrier layers, such as titanium (Ti), titanium nitride (TiN), tantalum nitride / copper (Ti / Cu), tantalum nitride / copper (TaN / Cu), etc.

[0150] In some implementations, at least two sub-pixels in a mother pixel located in different pixel layers emit different colors. For example, in a two-layer structure with two pixel layers, the sub-pixels in each pixel layer may emit the same color, while the sub-pixels in different pixel layers emit different colors. 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.

[0151] For example, in some implementations, the subpixels 50 in different pixel layers emit different colors to achieve a color configuration.

[0152] For example, in the two-layer structure, 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 instance, 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.

[0153] In this embodiment, each sub-pixel 50 can be made of inorganic compound semiconductor material.

[0154] In some implementations, a lens is provided above the uppermost sub-pixel 50, and the lens covers at least one sub-pixel 50 in the parent pixel. For example, a lens may cover one sub-pixel 50 or multiple sub-pixels 50.

[0155] The aforementioned lens 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.).

[0156] The mother pixel arrangement structure and microdisplay device of this embodiment help reduce the obstruction of the light-emitting surface of the lower sub-pixels, ensure the effective light-emitting area of ​​the lower sub-pixels, reduce energy waste, and thus achieve the best light distribution effect, which can effectively improve the luminous efficiency and reliability of LED display devices.

[0157] Example 2

[0158] Referring to Figures 1-5, this embodiment discloses a microdisplay device. In this microdisplay device, the bottom end of each of the multiple sub-pixels 50 located in different pixel layers of the mother pixel is electrically connected to a corresponding first-type electrode contact 101. The top ends of the multiple sub-pixels 50 are interconnected through a top conductive layer 60 and then electrically connected to a corresponding second-type electrode contact 102 to form a top common electrode structure. That is, the top conductive layers 60 of each sub-pixel 50 in the top common electrode structure are electrically connected together and electrically conductive to each other.

[0159] Among them, the polarities of the first type of electrode contact 101 and the second type of electrode contact 102 are opposite.

[0160] In this embodiment, the mother pixels can all be arranged in the form of the mother pixel arrangement structure described in Embodiment 1.

[0161] In some implementations, in the top common polarity structure, among the two sub-pixels 50 located in different pixel layers, one sub-pixel 50 is a light-transmitting pixel and the other sub-pixel 50 is an associated pixel. The bottom end of the light-transmitting pixel is electrically connected to the corresponding first type electrode contact 101 through a non-common polarity conductive element 80. The non-common polarity conductive element 80 connected to the light-transmitting pixel is located on the periphery of the associated pixel.

[0162] For example, the microdisplay device shown in Figure 1 is a top common electrode structure, which is a two-layer structure with a first pixel layer 20 and a second pixel layer 30. The first pixel layer 20 is provided with a sub-pixel 50, which is an associated pixel. The second pixel layer 30 is provided with a sub-pixel 50, which is a light-transmitting pixel. The bottom end of the light-transmitting pixel is electrically connected to the corresponding first type electrode contact 101 through a non-common electrode conductive member 80, and the non-common electrode conductive member 80 connected to the light-transmitting pixel is located on the periphery of the associated pixel.

[0163] Alternatively, the microdisplay device shown in Figure 4 is a top common-polarity structure, which is a three-layer structure with a first pixel layer 20, a second pixel layer 30, and a third pixel layer 40. The first pixel layer 20 has a sub-pixel 50, which is an associated pixel. The second pixel layer 30 has a sub-pixel 50, which is also an associated pixel. The third pixel layer 40 has a sub-pixel 50, which is a light-transmitting pixel. The bottom of the light-transmitting pixel is electrically connected to the corresponding first-type electrode contact 101 through a non-common-polarity conductive element 80, and the non-common-polarity conductive element 80 connected to the light-transmitting pixel is located on the periphery of the corresponding associated pixel below.

[0164] Understandably, "non-common conductive element 80" refers to the conductive element that provides non-common electrical connection for sub-pixel 50.

[0165] The material of the aforementioned non-common conductive component 80 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.

[0166] The aforementioned 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.

[0167] In some embodiments, referring to FIG1, the periphery of the associated pixel has an insulating fill region 110, the interior of which is for interconnecting conductive elements to pass through. In the top common polarity structure, the interconnecting conductive elements are non-common polarity conductive elements 80.

[0168] That is, the periphery of the associated pixel has an insulating filling area 110, and the non-common conductive element 80 connected to the light-transmitting pixel (that is, it passes through the insulating filling area 110 of the periphery of the associated pixel. In the top common structure, the bottom end of the light-transmitting pixel is electrically connected to the corresponding first type electrode contact 101 through the non-common conductive element 80.

[0169] The above structure can be fabricated using the following method: an insulating filling region 110 is formed by filling the periphery of the associated pixel with insulating material, allowing the non-common conductive element 80 to directly pass through the insulating filling region 110. In the top common structure, the non-common conductive element 80 can also directly pass through the insulating filling region 110 and then directly contact the corresponding first type electrode contact 101 to achieve electrical connection.

[0170] For example, the filling material used in the insulating filling area 110 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.

[0171] Furthermore, the insulating filling area 110 can be made of a transparent filling material.

[0172] In other embodiments, referring to FIG6, the periphery of the associated pixel has a compound semiconductor region 120, the interior of which is provided for interconnecting conductors to pass through. In the top common structure, the interconnecting conductors are non-common conductors 80.

[0173] That is, the periphery of the associated pixel has a compound semiconductor region 120, and the non-common conductive element 80 to which the light-transmitting pixel is connected passes through the compound semiconductor region 120. In the top common structure, the bottom end of the light-transmitting pixel is electrically connected to the corresponding first type electrode contact 101 through the non-common conductive element 80.

[0174] This method can retain more compound semiconductor materials, which have good thermal conductivity, thus improving the overall heat dissipation effect of the device.

[0175] Understandably, the compound semiconductor region 120 penetrated by the non-common conductive element 80 does not emit light when energized.

[0176] Furthermore, the compound semiconductor region 120 is ring-shaped, and the associated pixel is surrounded inside the corresponding compound semiconductor region 120, thereby better isolating the associated pixel from other peripheral conductive components and avoiding leakage caused by metal atoms diffusing to the sidewalls of the associated pixel.

[0177] Alternatively, the associated pixel is surrounded by multiple compound semiconductor regions 120, which are distributed circumferentially.

[0178] In some embodiments, referring to FIG7, the periphery of the associated pixel is further surrounded by a peripheral air gap 210, which is located between the associated pixel and the peripheral compound semiconductor region 120.

[0179] In some embodiments, referring to Figures 8-9, the light-transmitting pixels are also surrounded by an outer air gap 210.

[0180] In this embodiment, the driving backplate 10 is divided into a display area 103, and all the mother pixels constitute a pixel array. The projection of the pixel array on the driving backplate 10 is located inside the display area 103, which means that the display area 103 is the area where the pixel array projection is located.

[0181] The second type of electrode contact 102 can be configured in the following ways:

[0182] The second type of electrode contact 102 is provided only inside the display area 103;

[0183] Alternatively, the second type of electrode contact 102 can be provided only on the periphery of the display area 103. For example, as shown in FIG16, a peripheral electrode contact area 104 is provided on the periphery of the display area 103, and the second type of electrode contact 102 can be provided within the peripheral electrode contact area 104; as shown in FIG17, an interface 105 is also provided on the periphery of the display area 103, and the peripheral electrode contact area 104 can be electrically connected to the interface 105.

[0184] Alternatively, second type electrode contacts 102 may be provided both outside and inside the display area 103.

[0185] In some embodiments, the aforementioned top common electrode structure also includes a common electrode conductor 90, through which the second type of electrode contact 102 is electrically connected to the top conductive layer 60 at the top of multiple sub-pixels to achieve top common electrode.

[0186] The common electrode conductive element 90 can be located inside or outside the display area.

[0187] In some embodiments, referring to Figure 22, in the aforementioned top common electrode structure, the bottom end of the common electrode conductor 90 is in direct contact with the corresponding second type electrode contact 102.

[0188] In some embodiments, the top conductive layer 60 in the top common electrode structure can be arranged in the following manner:

[0189] The first type: at least two sub-pixels 50 in the mother pixel share a top conductive layer 60, and the sub-pixels 50 that share a top conductive layer 60 are located in different pixel layers.

[0190] For example, the microdisplay device shown in FIG1 is a top common-polarity structure, which is a two-layer structure, having a first pixel layer 20 and a second pixel layer 30, wherein the sub-pixels 50 in the first pixel layer 20 and the second pixel layer 30 share a top conductive layer 60; or, the microdisplay device shown in FIG3 is a top common-polarity structure, which is a three-layer structure, having a first pixel layer 20, a second pixel layer 30 and a third pixel layer 40, wherein the sub-pixels 50 in the first pixel layer 20, the second pixel layer 30 and the third pixel layer 40 share a top conductive layer 60.

[0191] In some embodiments, the above-described top common electrode structure also includes a common electrode conductor 90, through which the second type of electrode contact 102 is electrically connected to the top conductive layer 60 at the top of multiple sub-pixels to achieve top common electrode.

[0192] In this configuration, at least two sub-pixels in the mother pixel share a top conductive layer 60, and the common electrode conductive element 90 is in direct contact with the shared top conductive layer 60 to achieve electrical connection; or, the common electrode conductive element 90 is not in direct contact with the shared top conductive layer 60, but is electrically connected to the shared top conductive layer 60 through a transition conductive element.

[0193] The second method: Each sub-pixel located in a different pixel layer in the mother pixel has a separate top conductive layer 60 at its top and they do not share the same layer (see Figures 18-25 for the pixel layer structure with a separate top conductive layer 60).

[0194] That is, the top of each sub-pixel in different pixel layers of the mother pixel is set with a separate top conductive layer 60 instead of sharing it, and they can be interconnected with each other through a common conductive component.

[0195] Furthermore, the top conductive layer (the top conductive layer electrically connected to the sub-pixel in the same pixel layer) is located above the corresponding sub-pixel in the electrically connected pixel layer. Here, "above" means 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. Therefore, "above" can be understood as the lowest point of the top conductive layer being higher than the upper surface of the active layer in the sub-pixel. For example, referring to Figure 18, the entire top conductive layer 60 of the sub-pixel in the first pixel layer is located above the sub-pixel 50. Or, referring to Figure 19, 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 slightly lower portion of the top conductive layer area on the outer periphery of the sub-pixel's sidewall.

[0196] For example, referring to Figure 21, in a two-layer structure with two pixel layers, a top conductive layer 60 can be separately provided at the top of the sub-pixel 50 in the first pixel layer 20, and a top conductive layer 60 can also be separately provided at the top of the sub-pixel 50 in the second pixel layer 30. The two top conductive layers 60 can be interconnected by an interconnecting conductive part 901, which is part of a common conductive member 90.

[0197] or;

[0198] In a three-layer structure with three pixel layers, a top conductive layer 60 can be separately provided at the top of the sub-pixel 50 in the first pixel layer 20, and a top conductive layer 60 can also be separately provided at the top of the sub-pixel 50 in the second pixel layer 30 and the third pixel layer 40. The three top conductive layers 60 can be interconnected through a common conductive element 90.

[0199] The method for fabricating a separate top conductive layer 60 at the top of sub-pixel 50 in the first pixel layer includes: etching sub-pixels in the first pixel layer 20, then backfilling the current pixel layer with an insulating medium, planarizing the top of the first pixel layer 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 for electrical connection. Then, an insulating medium can be deposited again on top of the pixel layer and planarized again. Then, the upper pixel layer is stacked. The upper pixel layer can also have its top conductive layer 60 fabricated separately using the same method, i.e., after etching sub-pixels, insulating medium is backfilled, and after backfilling, planarization is performed on the top of the pixel layer to expose the top of the sub-pixel, and then the top conductive layer 60 is deposited to achieve electrical connection. In this process, the insulating medium can be entirely transparent.

[0200] The above-described preparation method also ensures that in a sub-pixel with a separate top conductive layer, the top conductive layer of the sub-pixel is basically located at the top of the sub-pixel.

[0201] In this context, at least two sub-pixels of different pixel layers in the mother pixel are each provided with a separate top conductive layer 60 without sharing one. The common conductive component 90 includes an interconnect conductive part 901. The two adjacent top conductive layers 60 of the upper and lower layers are interconnected through the interconnect conductive part 90 to achieve electrical connection. For details, please refer to Figures 12-23.

[0202] Furthermore, at least one top conductive layer 60 may be made to directly contact the electrically connected interconnect conductive portion 901 to achieve electrical connection; or, at least one top conductive layer 60 may not be in direct contact with the electrically connected interconnect conductive portion 901, but the top conductive layer 60 and the electrically connected interconnect conductive portion 901 may be electrically connected through a metal reinforcement.

[0203] In some embodiments, in the top common-polarity structure, at least one pixel layer is a type-II pixel layer. The bottom end of the sub-pixel 50 in the type-II pixel layer is electrically connected to the corresponding first-type electrode contact 101 through a bottom conductive layer 70, and the bottom surface of the sub-pixel 50 in the type-II pixel layer is completely covered by the bottom conductive layer 70. This method typically makes the area of ​​the bottom conductive layer 70 larger than the area of ​​the first-type electrode contact 101 electrically connected to it, so that the first-type electrode contact 101 and the bottom conductive layer 70 only need to make contact for conductivity, without the need for alignment. For example, in Figure 1, both pixel layers are type-II pixel layers, and in Figure 4, all three pixel layers are type-II pixel layers.

[0204] In some schemes, referring to Figure 1, a bottom ohmic contact layer 180 is also provided at the bottom of the sub-pixel 50 in the type II pixel layer, which is made of conductive material.

[0205] In the type II pixel layer, the bottom of the sub-pixel 50 is electrically connected through the bottom ohmic contact layer 180 and the bottom conductive layer 70.

[0206] 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.

[0207] Furthermore, among the two sub-pixels 50 located in different pixel layers, one sub-pixel 50 is a light-transmitting pixel and the other sub-pixel 50 is an associated pixel. The pixel layer where the light-transmitting pixel is located is a type II pixel layer. The bottom end of the light-transmitting pixel in the type II pixel layer is electrically connected to the corresponding non-common conductive element 80 through the bottom conductive layer 70.

[0208] The pixel layer containing the associated pixel can be a type II pixel layer or other types of pixel layers.

[0209] In some designs, the bottom conductive layer 70 may be a non-metallic conductive layer.

[0210] In some embodiments, referring to Figures 1 and 3, the bottom conductive layer 70 can be a metal bonding layer. A first peripheral metal fence 140 and a first inner metal fence 130 are formed above the bottom conductive layer 70 of the light-transmitting pixel in the type-II pixel layer, such that the light-transmitting pixel in the type-II pixel layer is surrounded by the first peripheral metal fence 140, and the light-transmitting hole 501 is surrounded by the first inner metal fence 130.

[0211] Understandably, there is insulation between the first outer metal fence 140 and the outer wall of the surrounding light-transmitting pixel. There is also insulation between the first inner metal fence 130 and the inner wall of the outer light-emitting area 502 of the light-transmitting pixel.

[0212] Specifically, a first insulating layer 150 can be applied to the outer wall of the light-transmitting pixel, so that the first peripheral metal fence 140 and the outer wall of the surrounding light-transmitting pixel are insulated and isolated by the first insulating layer 150. The first inner metal fence 130 and the inner wall of the peripheral light-emitting area 502 of the light-transmitting pixel are also insulated and isolated by the first insulating layer 150.

[0213] Understandably, the outer wall of sub-pixel 50 refers to the sidewall at the outer periphery of the sub-pixel. For example, if sub-pixel 50 is a light-transmitting pixel, and a light-transmitting hole 501 is opened inside the light-transmitting pixel, making the light-transmitting pixel ring-shaped, then the outer wall of the light-transmitting pixel refers to the outer wall of the ring. The inner wall of the peripheral light-emitting area 502 refers to the sidewall facing the inner light-transmitting hole 501, that is, the sidewall at its inner periphery. For example, if the peripheral light-emitting area 502 is ring-shaped, then the inner wall of the peripheral light-emitting area 502 refers to the inner wall of the ring.

[0214] 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;

[0215] In some designs, the thickness of the first insulating layer 150 can be 5 nm to 2 μm.

[0216] 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.

[0217] 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.

[0218] In one embodiment, the metal bonding layer at the bottom of the light-transmitting pixel and the first peripheral 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 light-transmitting pixel and the first peripheral metal fence 140 are separately set.

[0219] Similarly, the metal bonding layer at the bottom of the light-transmitting pixel and the first inner metal fence 130 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 light-transmitting pixel and the first inner metal fence 130 are separately set.

[0220] Both the first outer metal fence 140 and the first inner metal fence 130 can be ring-shaped.

[0221] In some embodiments, referring to Figures 1 and 3, to achieve insulation between the first peripheral metal fence 140 and the top conductive layer 60 of the upper sub-pixel 50, a second insulating layer 160 may be provided between the first peripheral metal fence 140 and the top conductive layer 60; the material of the second insulating layer 160 may be the same as that of the first insulating layer 150.

[0222] Understandably, when the upper sub-pixel and the lower adjacent sub-pixel share a top conductive layer 60, a second insulating layer 160 is provided between the first peripheral metal fence 140 of the upper sub-pixel and the shared top conductive layer 60.

[0223] In some embodiments, the periphery of associated pixels in a type-two pixel layer may also be surrounded by a first peripheral metal fence 140.

[0224] In some implementations, when there is no metal bonding layer at the bottom of the sub-pixel, the aforementioned first inner metal fence 130 and first outer metal fence 140 may also be provided.

[0225] In some embodiments, referring to FIG7, the periphery of the associated pixel in the type-two pixel layer has a compound semiconductor region 120, and the common conductor 90 to which the light-transmitting pixel is connected passes through the compound semiconductor region 120. The compound semiconductor region 120 is annular, and the associated pixel is surrounded inside the corresponding compound semiconductor region 120. The periphery of the associated pixel is also surrounded by a peripheral air gap 210, which is located between the associated pixel and the peripheral compound semiconductor region 120.

[0226] Furthermore, the aforementioned peripheral air gap 210 is provided between the first peripheral metal fence 140 surrounding the associated pixel in the type II pixel layer and the compound semiconductor region 120.

[0227] For example, in the top common-polarity structure shown in Figure 1, both the first pixel layer 20 and the second pixel layer 30 are type II pixel layers. In the second pixel layer 30, sub-pixel 50 is a light-transmitting pixel with a light-transmitting aperture 501. In the first pixel layer 20, sub-pixel 50 is an associated pixel. The light-transmitting pixel is surrounded by a first peripheral metal fence 140, and the light-transmitting aperture 501 is surrounded by a first inner metal fence 130. The associated pixel is also surrounded by a first peripheral metal fence 140. The bottom conductive layer 70 of the light-transmitting pixel is electrically connected to the corresponding first-type electrode contact 101 via a non-common-polarity conductive element 80 (interconnecting conductive element).

[0228] In some implementations, at least two subpixels located in different pixel layers emit different colors to achieve a color configuration.

[0229] For example, in a two-layer structure, 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 instance, the emission colors of each sub-pixel 50 from bottom to top are red and green, or red and blue, or green and blue, etc. Alternatively, one pixel layer has two sub-pixels with different emission colors; while in the other pixel layer, there is a sub-pixel whose emission color is different from that of at least one sub-pixel in the first layer.

[0230] In this embodiment, each sub-pixel 50 can be made of inorganic compound semiconductor material.

[0231] 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, one lens 250 can cover one sub-pixel 50, or it can cover multiple sub-pixels 50, as shown in Figures 24-25.

[0232] In some embodiments, referring to Figure 24, the bottom end of the lens 250 may be in direct contact with the top conductive layer 60; or, referring to Figure 25, the bottom end g1 of the lens 250 may be higher than the top surface of the top conductive layer 60.

[0233] The microdisplay device structure described above can be applied not only to a two-layer structure with two pixel layers, but also to a three-layer structure with three pixel layers, or to a structure with more than three layers.

[0234] The LED display device of this embodiment simplifies the electrical connection structure, making it easier to manufacture. It can flexibly adjust the light-emitting area and position of the sub-pixels, which helps to reduce the shading of the light-emitting surface of the lower sub-pixels, increases the effective light-emitting area of ​​the lower sub-pixels, helps to reduce energy waste, achieves the best light distribution effect, and makes its light pattern meet the needs of different application scenarios. At the same time, it also effectively improves the luminous efficiency and reliability of the display device.

[0235] Example 3

[0236] Referring to Figure 12, this embodiment discloses a micro-display device. The main difference between this embodiment and Embodiment 2 is that: at least one pixel layer is a type I pixel layer, and the bottom end of each sub-pixel 50 in the type I pixel layer is electrically connected to the corresponding first type electrode contact 101 through an independent conductive block 270. The conductive block 270 corresponds one-to-one with the first type electrode contact 101.

[0237] The conductive block 270 has an electrical contact area 2701 for electrical connection with the bottom end of the corresponding sub-pixel 50 in a pixel layer. The area of ​​the electrical contact area 2701 is smaller than the area of ​​the bottom surface of the corresponding sub-pixel in the pixel layer to which it is electrically connected, so it does not need to make full contact with the entire bottom surface of the sub-pixel.

[0238] In the above structure, a certain pixel layer adopts a type I pixel layer. The bottom of each sub-pixel 50 in the type I pixel layer is electrically connected to the corresponding first type electrode contact 101 through an independent conductive block 270. The conductive block 270 and the first type electrode contact 101 correspond one-to-one. This method helps to improve the bonding accuracy, thereby improving the resolution and display effect of the device.

[0239] In some embodiments, a metal reflective layer 280 is also provided at the bottom of the sub-pixel 50 in the type pixel layer, so as to electrically connect the metal reflective layer 280 and the corresponding conductive block 270.

[0240] Furthermore, the bottom end of the sub-pixel 50 in the type pixel layer is electrically connected to the electrical contact area 2701 of the corresponding conductive block 270 through the metal reflective layer 280.

[0241] Furthermore, in a type-1 pixel layer, the sub-pixel 50 is electrically connected to the metal reflective layer 280 only at its bottom end. In this case, only the bottom end of the sub-pixel 50 can be exposed to contact the metal reflective layer 280.

[0242] Alternatively, the bottom end and at least part of the sidewalls of the sub-pixel 50 in a pixel layer can be electrically connected to the metal reflective layer 280. In this case, the bottom end and part of the sidewalls of the sub-pixel 50 can be exposed and in contact with the metal reflective layer 280. This method further increases the contact area, thereby increasing the current injection capability.

[0243] Understandably, the aforementioned "sidewall" can be either the outer or inner sidewall of the sub-pixel 50. If the sub-pixel has a light-transmitting hole 501 inside, an inner sidewall will be formed; otherwise, only an outer sidewall will be formed. The exposure height of the sidewall for electrical contact should not be too large, so as to ensure that the sub-pixel sidewall does not short-circuit.

[0244] In some embodiments, a peripheral reflective portion 2801 is formed above the metal reflective layer 280 of the sub-pixel 50 in a type pixel layer.

[0245] In some embodiments, the pixel layer containing the light-transmitting pixel is a type I pixel layer, and the bottom of the light-transmitting pixel in the type I pixel layer is electrically connected to the corresponding non-common conductive element 80 through a metal reflective layer 280 and a conductive block 270 in sequence.

[0246] For example, referring to Figure 12, in the top common-polarity structure, both the first pixel layer 20 and the second pixel layer 30 are type-one pixel layers. Sub-pixels 50 in the second pixel layer 30 are light-transmitting pixels, and sub-pixels 50 in the first pixel layer 20 are associated pixels. The bottom of the light-transmitting pixel is electrically connected to the corresponding non-common-polarity conductive element 80 via a metal reflective layer 280 and a conductive block 270, and then electrically connected to the corresponding first-type electrode contact 101 via the non-common-polarity conductive element 80. Since the pixel layer containing the associated pixel is the bottommost pixel layer, the bottom of the associated pixel can be directly electrically connected to the corresponding first-type electrode contact 101 via the metal reflective layer 280 and the conductive block 270. In Figure 12, the direction of the dashed arrow indicates the light emission direction of the associated pixel in the first layer.

[0247] Furthermore, an outer reflective portion 2801 and an inner reflective portion 2802 are formed above the metal reflective layer 280 of the light-transmitting pixel in the type pixel layer. The outer reflective portion 2801 surrounds the outer periphery of the light-transmitting pixel in the type pixel layer, and the inner reflective portion 2802 surrounds the inner periphery of the light-transmitting hole 501.

[0248] The peripheral reflective portion 2801 is insulated from the outer wall of the surrounding light-transmitting pixel by a first insulating layer 150 to prevent short circuits and leakage at the side wall of the light-transmitting pixel. This arrangement allows the metal reflective layer 280 to surround the end of the light-transmitting pixel near the driving backplate 10 and its side wall, which can better reflect the light oriented towards the X direction back, so that most of the light emitted by the light-transmitting pixel can be emitted from above the light-transmitting pixel, thus enhancing the light efficiency.

[0249] Similarly, the inner reflective portion 2802 and the inner sidewall of the outer light-emitting area 502 of the light-transmitting pixel are insulated and isolated by the first insulating layer 150. The aforementioned inner reflective portion 2802 allows light emitted from the light-transmitting pixel into the light-transmitting hole 501 to be reflected back through the inner reflective portion 2802, thereby better reducing light loss in the outer light-emitting area 502.

[0250] Both the inner reflective portion 2802 and the inner reflective portion 2802 can be annular.

[0251] In some embodiments, a peripheral reflective portion 2801 is formed above the metal reflective layer 280 of the associated pixel in the type-1 pixel layer, and the peripheral reflective portion 2801 surrounds the periphery of the associated pixel in the type-1 pixel layer.

[0252] For example, referring to the top common-polarity structure shown in FIG12, the first pixel layer 20 and the second pixel layer 30 are both type I pixel layers. In the second pixel layer 30, the sub-pixel 50 is a light-transmitting pixel, and in the first pixel layer 20, the sub-pixel 50 is an associated pixel. The upper part of the metal reflective layer 280 of the light-transmitting pixel of the second layer has an outer reflective portion 2801 and an inner reflective portion 2802. The inner reflective portion 2802 is located inside the light-transmitting hole 501 of the light-transmitting pixel, and the outer reflective portion surrounds the periphery of the light-transmitting pixel. The upper part of the metal reflective layer 280 of the associated pixel of the first layer has an outer reflective portion 2801, and the outer reflective portion 2801 surrounds the periphery of the associated pixel.

[0253] In some embodiments, the microdisplay device has multiple pixel layers, such that other pixel layers are type II pixel layers; or, all pixel layers are type I pixel layers; or, all pixel layers are type II pixel layers.

[0254] In some embodiments, as shown in FIG12, in the top common-polarity structure, at least two sub-pixels 50 in the mother pixel share a top conductive layer 60, and the sub-pixels 50 sharing the top conductive layer 60 are located in different pixel layers. For example, in the two-layer structure shown in FIG12, both pixel layers are type-one pixel layers. The sub-pixel 50 in the second pixel layer 30 is a light-transmitting pixel, and the top conductive layer of the light-transmitting pixel is electrically connected to the top of the associated pixel in the first pixel layer 20 through a light-transmitting hole, so that both share a top conductive layer 60.

[0255] Alternatively, each sub-pixel in a different pixel layer within the parent pixel may have its own separate top conductive layer 60, without sharing one; that is, each sub-pixel in a different pixel layer within the parent pixel may have its own separate top conductive layer 60, without sharing one, and they may be interconnected via common conductive elements. For example, in the two-layer structure shown in Figures 21-25, both pixel layers are type-II pixel layers. In the second pixel layer 30, the sub-pixel 50 is a light-transmitting pixel, and the top conductive layer 60 of the light-transmitting pixel is electrically interconnected with the top conductive layer 60 of the associated pixel in the first pixel layer 20.

[0256] In some implementations, a lens is provided above the uppermost sub-pixel 50, and the lens covers at least one sub-pixel 50 in the parent pixel. For example, a lens may cover one sub-pixel 50 or multiple sub-pixels 50.

[0257] Example 4

[0258] Referring to Figures 13-15, this embodiment discloses a micro-display device. The main difference between this embodiment and Embodiment 2 is that the multiple sub-pixels 50 in the mother pixel adopt a bottom common electrode structure when connecting electrodes.

[0259] In this embodiment, the top of each of the multiple sub-pixels 50 located in different pixel layers in the mother pixel is electrically connected to the corresponding second type of electrode contact 102 through the top conductive layer 60. The bottom ends of the multiple sub-pixels 50 are electrically interconnected and connected to the first type of electrode contact 101 to form a bottom common pole structure. That is, the bottom ends of each sub-pixel 50 in the bottom common pole structure are electrically connected together and electrically conductive to each other.

[0260] Among them, the polarities of the first type of electrode contact 101 and the second type of electrode contact 102 are opposite.

[0261] In some embodiments, in the bottom common electrode structure, the bottom ends of sub-pixels 50 of different pixel layers are electrically connected through common electrode conductors 90; the top conductive layer 60 of each sub-pixel 50 is electrically connected to the corresponding second type electrode contact 102 through non-common electrode conductors 80.

[0262] As is understandable, "common conductive component 90" refers to the conductive component that provides common terminal electrical connection for sub-pixels. The material of the aforementioned common conductive component 90 can be metals such as aluminum (Al), copper (Cu), and tungsten (W), as well as their corresponding adhesive or barrier layers, such as titanium (Ti), titanium nitride (TiN), tantalum nitride / copper (Ti / Cu), tantalum nitride / copper (TaN / Cu), etc.

[0263] In some embodiments, referring to FIG13, in the bottom common-polarity structure, among the two sub-pixels 50 located in different pixel layers, one sub-pixel 50 is a light-transmitting pixel located in the second pixel layer 30, and the other sub-pixel 50 is an associated pixel located in the first pixel layer 20. The bottom ends of the light-transmitting pixel and the associated pixel are electrically connected through a common-polarity conductive element 90, which is located on the periphery of the associated pixel. In FIG12, the direction of the dashed arrow indicates the light-emitting direction of the associated pixel in the first layer.

[0264] In some embodiments, referring to FIG13, the periphery of the associated pixel has an insulating fill region 110, the interior of which is for interconnecting conductive elements to pass through. In the bottom common polarity structure, the interconnecting conductive elements are common polarity conductive elements 90.

[0265] That is, the periphery of the associated pixel has an insulating filling area 110, and the common electrode conductive element 90 connected to the light-transmitting pixel passes through the insulating filling area 110. In the bottom common electrode structure, the common electrode conductive element 90 connected to the light-transmitting pixel is electrically connected to the first type electrode contact 101 after passing through the insulating filling area 110.

[0266] In other embodiments, referring to Figures 14-15, the periphery of the associated pixel has a compound semiconductor region 120, and the interior of the compound semiconductor region 120 is through which interconnect conductors pass. In the bottom common structure, the interconnect conductor is a common conductor 90.

[0267] That is, the periphery of the associated pixel has a compound semiconductor region 120, and the common electrode conductive element 90 connected to the light-transmitting pixel passes through the compound semiconductor region 120. In the bottom common electrode structure, the common electrode conductive element 90 connected to the light-transmitting pixel is electrically connected to the first type electrode contact 101 after passing through the compound semiconductor region 120.

[0268] Understandably, the compound semiconductor region 120 penetrated by the common conductive element 90 does not emit light when energized.

[0269] Furthermore, the compound semiconductor region 120 is ring-shaped, and the associated pixel is surrounded inside the corresponding compound semiconductor region 120; thereby better isolating the associated pixel from other peripheral conductive components and avoiding leakage caused by metal atoms diffusing to the sidewalls of the associated pixel.

[0270] Referring to Figures 14-15, the periphery of the associated pixel may also be surrounded by a peripheral air gap 210; the compound semiconductor region 120 and the surrounding associated pixel have the aforementioned peripheral air gap 210.

[0271] In some embodiments, the top conductive layer 60 of the associated pixel is electrically connected to the corresponding second type electrode contact 102 through the non-common conductive element 80, and the top conductive layer 60 of the associated pixel is electrically connected to the corresponding non-common conductive element 90 after passing through the light-transmitting hole 501 of the light-transmitting pixel.

[0272] Understandably, the top conductive layer 60 of the associated pixel needs to be insulated from the light-transmitting pixel that is passed through to avoid short circuits in the light-transmitting pixel itself.

[0273] For example, referring to Figure 13, the microdisplay device has two pixel layers, namely a first pixel layer 20 and a second pixel layer 30. The sub-pixels 50 in the first pixel layer 20 are associated pixels, and the sub-pixels 50 in the second pixel layer 30 are light-transmitting pixels. The top conductive layer 60 of the light-transmitting pixels is electrically connected to the second type electrode contact 102 on the left through the non-common conductive element 80 on the left. The top conductive layer 60 of the lower associated pixels extends upward through the light-transmitting hole 501 of the upper light-transmitting pixel and is electrically connected to the second type electrode contact 102 on the right through the non-common conductive element 80 on the right.

[0274] In some embodiments, referring to FIG13, in the bottom common electrode structure, at least one pixel layer is a type II pixel layer, and the bottom end of the sub-pixel 50 in the type II pixel layer is electrically connected to the corresponding first type electrode contact 101 through the bottom conductive layer 70. The bottom surface of the sub-pixel 50 in the type II pixel layer is completely covered by the bottom conductive layer 70.

[0275] In some designs, a bottom ohmic contact layer 180 is provided at the bottom of the sub-pixel 50 in the type II pixel layer. This bottom ohmic contact layer 180 is made of a conductive material.

[0276] In the type II pixel layer, the bottom of the sub-pixel 50 is electrically connected through the bottom ohmic contact layer 180 and the bottom conductive layer 70.

[0277] For example, the bottom ohmic contact layer 180 can be one or more of the following transparent conductive films: indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium tin oxide (IGZO), aluminum-doped zinc oxide (AZO), etc.; or it can be one or more of the following conductive metal materials: nickel (Ni), chromium (Cr), gold (Au), silver (Ag), zinc (Zn), rhodium (Rh), beryllium (Be), aluminum (Al); or it can be a composite structure composed of transparent metal oxide and metal. The thickness of the bottom ohmic contact layer 180 is 1 nm to 500 nm.

[0278] Furthermore, the pixel layer where the light-transmitting pixel is located is a type II pixel layer, and the bottom end of the light-transmitting pixel in the type II pixel layer is electrically connected to the common electrode conductive element 90 through the bottom conductive layer 70;

[0279] If the pixel layer containing the associated pixel is also a type II pixel layer, then the bottom conductive layer 70 at the bottom of the light-transmitting pixel and the bottom conductive layer 70 at the bottom of the associated pixel are electrically connected through a common conductive element 90.

[0280] In some embodiments, referring to FIG13, the bottom conductive layer 70 is a metal bonding layer, and a first peripheral metal fence 140 and a first inner metal fence 130 are formed above the bottom conductive layer 70 of the light-transmitting pixel in the type II pixel layer, such that the light-transmitting pixel in the type II pixel layer is surrounded by the first peripheral metal fence 140, and the light-transmitting hole 501 is surrounded by the first inner metal fence 130.

[0281] Understandably, there is insulation between the first outer metal fence 140 and the outer wall of the surrounding light-transmitting pixel. There is also insulation between the first inner metal fence 130 and the inner wall of the outer light-emitting area 502 of the light-transmitting pixel.

[0282] Specifically, a first insulating layer 150 can be applied to the outer wall of the light-transmitting pixel, so that the first peripheral metal fence 140 and the outer wall of the surrounding light-transmitting pixel are insulated and isolated by the first insulating layer 150. The first inner metal fence 130 and the inner wall of the peripheral light-emitting area 502 of the light-transmitting pixel are also insulated and isolated by the first insulating layer 150.

[0283] In one embodiment, the metal bonding layer at the bottom of the light-transmitting pixel and the first peripheral 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 light-transmitting pixel and the first peripheral metal fence 140 are separately set.

[0284] Similarly, the metal bonding layer at the bottom of the light-transmitting pixel and the first inner metal fence 130 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 light-transmitting pixel and the first inner metal fence 130 are separately set.

[0285] Both the first outer metal fence 140 and the first inner metal fence 130 can be ring-shaped.

[0286] In some embodiments, to achieve insulation between the first peripheral metal fence 140 of the upper sub-pixel 50 and its own top conductive layer 60, a second insulating layer 160 may be provided between the first peripheral metal fence 140 and the top conductive layer 60.

[0287] For example, referring to Figure 13, the microdisplay device has a bottom common polarity structure, having a first pixel layer 20 and a second pixel layer 30. Both the first pixel layer 20 and the second pixel layer 30 are type-II pixel layers. In the first pixel layer 20, the sub-pixel 50 is an associated pixel, and in the second pixel layer 30, the sub-pixel 50 is a light-transmitting pixel. The bottom conductive layer 70 of the light-transmitting pixel and the bottom conductive layer 70 of the associated pixel are electrically connected through a common polarity conductive element 90 to form a bottom common polarity structure. A first peripheral metal fence 140 surrounds the light-transmitting pixel in the second layer, and a first inner metal fence 130 surrounds the inside of the light-transmitting hole 501.

[0288] In some embodiments, in the bottom common polarity structure, among the two sub-pixels 50 located in different pixel layers, one sub-pixel 50 is a light-transmitting pixel and the other sub-pixel 50 is an associated pixel. The top conductive layer 60 of the light-transmitting pixel is electrically connected to the corresponding second type electrode contact 102 through a non-common polarity conductive element 80 located on the periphery of the associated pixel.

[0289] Furthermore, the top conductive layer 60 of the associated pixel is also electrically connected to the corresponding second type electrode contact 102 via another non-common conductive element 80, which is also located on the periphery of the associated pixel.

[0290] 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:

[0291] In some configurations, the top conductive layer portion of a subpixel can be located on the side of that subpixel.

[0292] In other configurations, the top conductive layer 60 of at least one pixel layer is completely above the corresponding sub-pixel in the electrically connected pixel layer, that is, the top conductive layer of the sub-pixel is completely above the sub-pixel.

[0293] Furthermore, the top conductive layer in the same pixel layer (the top conductive layer electrically connected to the sub-pixel in the same pixel layer) can be located completely above the corresponding sub-pixel in the electrically connected pixel layer; that is, the top conductive layer of the sub-pixel in the pixel layer is located completely above the sub-pixel.

[0294] In some embodiments, in the bottom common pole structure, the driving back plate 10 is divided into a display area 103, and all the mother pixels constitute a pixel array. The projection of the pixel array on the driving back plate 10 is located inside the display area, that is, the display area 103 is the area where the pixel array projection is located.

[0295] The first type of electrode contact 101 can be set in the following ways: the first type of electrode contact is set only inside the display area 103; or the first type of electrode contact 101 is set only outside the display area 103; or the first type of electrode contact 101 is set both inside and outside the display area 103.

[0296] 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:

[0297] In some configurations, the top conductive layer of a sub-pixel can be located on the side of the sub-pixel and extend to the bottom of the sub-pixel, as shown in the configuration of the top conductive layer 60 of the sub-pixel in the second pixel layer 30 of FIG13.

[0298] In other configurations, the top conductive layer (the top conductive layer electrically connected to the sub-pixel in the same pixel layer) can be located above the corresponding sub-pixel in the electrically connected pixel layer. Here, "above" means essentially located 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). In this case, the lowest point of the top conductive layer can be higher than the upper surface of the active layer in the sub-pixel. For example, the entire top conductive layer 60 of the sub-pixel can be located above the sub-pixel 50, or the entire top conductive layer 60 of the sub-pixel in the first pixel layer can be located essentially above the sub-pixel 50, with only a portion slightly lower than the top surface of the sub-pixel.

[0299] In some embodiments, in the bottom common electrode structure, the top conductive layer 60 of each sub-pixel is electrically connected to the corresponding second type electrode contact 102 through the corresponding non-common electrode conductive element 80, and the bottom end of the non-common electrode conductive element 80 and the corresponding second type electrode contact 102 can be in direct contact.

[0300] In some implementations, at least two subpixels located in different pixel layers emit different colors to achieve a color configuration.

[0301] For example, in a two-layer structure, 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 instance, the emission colors of each sub-pixel 50 from bottom to top are red and green, or red and blue, or green and blue, etc. Alternatively, one pixel layer has two sub-pixels with different emission colors; while in the other pixel layer, there is a sub-pixel whose emission color is different from that of at least one sub-pixel in the first pixel layer.

[0302] In some implementations, a lens is provided above the uppermost sub-pixel 50, and the lens covers at least one sub-pixel 50 in the parent pixel. For example, a lens may cover one sub-pixel 50 or multiple sub-pixels 50.

[0303] Example 5

[0304] In this embodiment, the microdisplay device also includes a metal reinforcement 190, and the top conductive layer 60 is electrically connected to the metal reinforcement 190 to increase the current spreading capability through the metal reinforcement.

[0305] In some approaches, the metal reinforcement 190 in different mother pixels can be shared or used independently by their respective mother pixels.

[0306] In either the top common polarity structure or the bottom common polarity structure, at least one top conductive layer 60 can be electrically connected to the metal reinforcement 190, and the metal reinforcement 90 can be located above or below the electrically connected top conductive layer 60.

[0307] In the top common-polarity structure: if at least two sub-pixels 50 in the mother pixel share a top conductive layer 60, and the sub-pixels sharing the top conductive layer 60 are located in different pixel layers, the shared top conductive layer 60 can be electrically connected to the metal reinforcement 190. The metal reinforcement 190 can be arranged in the following way:

[0308] The first method: Referring to Figure 11, the metal reinforcement 190 is located above the common top conductive layer 60;

[0309] The second method: the metal reinforcement 190 is located below the common top conductive layer 60;

[0310] Furthermore, the metal reinforcement 190 surrounds the periphery of a sub-pixel 50 below the shared top conductive layer 60.

[0311] In some embodiments, the light-transmitting pixels and associated pixels may share a top conductive layer 60, which is electrically connected to the metal reinforcement 190.

[0312] In the top common polarity structure: if the top of the sub-pixels of at least two different pixel layers in the mother pixel are each provided with a separate top conductive layer 60 and not shared, then at least one top conductive layer 60 can be electrically connected to the metal reinforcement 190. The metal reinforcement 190 can also be located above (see Figure 23) or below the electrically connected top conductive layer 60.

[0313] In the bottom common polarity structure, each of the sub-pixels located in different pixel layers of the mother pixel is provided with a separate top conductive layer 60, which allows at least one top conductive layer 60 to be electrically connected to the metal reinforcement 190. The metal reinforcement 190 can also be located above or below the electrically connected top conductive layer 60.

[0314] Example 6

[0315] In this embodiment, the top of the sub-pixel 50 is in contact with the top conductive layer 60 to achieve electrical connection, which can take the following forms:

[0316] The first method: Referring to Figures 1 and 18, only the top of the sub-pixel 50 is in contact with the electrically connected top conductive layer 60; in this case, only a part or all of the top of the sub-pixel can be exposed, and the exposed area can be in contact with the corresponding top conductive layer 60 to achieve electrical connection.

[0317] The second method, referring to Figures 19-20, involves making the top edge and at least part of the sidewalls of the sub-pixel 50 contact the electrically connected top conductive layer 60. In this case, in addition to exposing the top edge of the sub-pixel 50, at least part of its sidewalls 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.

[0318] Understandably, in specific settings, one sub-pixel of the mother pixel can use the first type of electrical connection, while other sub-pixels use the second type of electrical connection. Alternatively, all sub-pixels can use the same type of electrical connection. The choice can be made based on actual needs.

[0319] The microdisplay device structure described above can be applied not only to two-layer structures with two pixel layers, but also to three-layer structures with three pixel layers, and even to structures with more than three layers.

[0320] The microdisplay devices of the above embodiments simplify the electrical connection structure, are easier to fabricate, effectively increase the effective light-emitting area of ​​the lower sub-pixels, and are more conducive to the best light distribution effect, thereby effectively improving the light efficiency and reliability of the display device.

[0321] 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.

[0322] 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 mother pixel arrangement structure, characterized in that: include, A driving backplate; multiple sub-pixels, at least two of which are located in different pixel layers; all the pixel layers are stacked sequentially from bottom to top above the driving backplate; among the two sub-pixels located in different pixel layers, one of the sub-pixels in the upper pixel layer has a light-transmitting hole inside to form a light-transmitting pixel, and the periphery of the light-transmitting hole of the light-transmitting pixel forms a peripheral light-emitting area, the projection area of ​​the light-transmitting hole on the driving backplate is a second projection area, the other sub-pixel in the lower pixel layer is a related pixel, the projection area of ​​the related pixel on the driving backplate is a first projection area, the first projection area and the second projection area at least partially overlap, so that the light emitted by the related pixel is at least partially emitted through the light-transmitting hole of the light-transmitting pixel.

2. The mother pixel arrangement structure according to claim 1, characterized in that: The overlapping area of ​​the first projection area and the second projection area is not less than 1 / 2 of the area of ​​the first projection area.

3. The mother pixel arrangement structure according to claim 2, characterized in that: The first projection area is completely located inside the second projection area.

4. The mother pixel arrangement structure according to claim 1, characterized in that: The light-transmitting pixels and the associated pixels are both arranged coaxially.

5. The mother pixel arrangement structure according to claim 4, characterized in that: At least two associated pixels located in different pixel layers are located below the same light-transmitting hole of the light-transmitting pixel.

6. The mother pixel arrangement structure according to claim 1, characterized in that: The light-transmitting pixel is arranged off-axis with at least one of the associated pixels below it.

7. The mother pixel arrangement structure according to claim 6, characterized in that: The same light-transmitting pixel is provided with multiple light-transmitting holes, and the associated pixel and the light-transmitting hole of the light-transmitting pixel correspond one-to-one.

8. The mother pixel arrangement structure according to claim 1, characterized in that: The light-transmitting pixels are surrounded by an outer air gap.

9. The mother pixel arrangement structure according to claim 8, characterized in that: The light-transmitting pixel is surrounded by a partition wall, and there is an outer air gap between the light-transmitting pixel and the surrounding partition wall.

10. The mother pixel arrangement structure according to claim 1, characterized in that: The light-transmitting pixel has an inner air gap.

11. The mother pixel arrangement structure according to claim 1, characterized in that: At least two of the sub-pixels located in different pixel layers emit different colors.

12. A microdisplay device, characterized in that: It includes at least one mother pixel, each mother pixel includes multiple sub-pixels, and each mother pixel adopts the mother pixel arrangement structure according to any one of claims 1-11.

13. The microdisplay device according to claim 12, characterized in that: The bottom of each of the multiple sub-pixels located in different pixel layers of the mother pixel is electrically connected to the corresponding first type of electrode contact. The tops of the multiple sub-pixels are interconnected through a top conductive layer and then electrically connected to the corresponding second type of electrode contact to form a top common electrode structure. The polarities of the first type of electrode contact and the second type of electrode contact are opposite.

14. The microdisplay device according to claim 13, characterized in that: In the top common polarity structure, among the two sub-pixels located in different pixel layers, one sub-pixel is the light-transmitting pixel and the other sub-pixel is the associated pixel. The bottom end of the light-transmitting pixel is electrically connected to the corresponding first type of electrode contact through a non-common polarity conductive element. The non-common polarity conductive element connected to the light-transmitting pixel is located on the periphery of the associated pixel.

15. The microdisplay device according to claim 13, characterized in that: The periphery of the associated pixel has an insulating fill area, and the non-common conductive component connected to the light-transmitting pixel passes through the insulating fill area.

16. The microdisplay device according to claim 13, characterized in that: The periphery of the associated pixel has a compound semiconductor region, and the non-common conductive element to which the light-transmitting pixel is connected passes through the compound semiconductor region.

17. The microdisplay device according to claim 16, characterized in that, The compound semiconductor region is ring-shaped, and the associated pixel is surrounded inside the corresponding compound semiconductor region.

18. The microdisplay device according to claim 16, characterized in that, The associated pixel is surrounded by a plurality of compound semiconductor regions, which are distributed circumferentially.

19. The microdisplay device according to claim 16, characterized in that: The associated pixel is further surrounded by a peripheral air gap, which is located between the associated pixel and the surrounding compound semiconductor region.

20. The microdisplay device according to claim 14, characterized in that: In the top common electrode structure, at least one pixel layer is a type II pixel layer. The bottom end of the sub-pixel in the type II pixel layer is electrically connected to the corresponding first type electrode contact through a bottom conductive layer. The bottom surface of the sub-pixel in the type II pixel layer is completely covered by the bottom conductive layer.

21. The microdisplay device according to claim 20, characterized in that: The pixel layer containing the light-transmitting pixel is the type II pixel layer, and the bottom end of the light-transmitting pixel in the type II pixel layer is electrically connected to the corresponding non-common conductive component through the bottom conductive layer.

22. The microdisplay device according to claim 21, characterized in that: The bottom conductive layer is a metal bonding layer. A first outer metal fence and a first inner metal fence are formed above the bottom conductive layer of the light-transmitting pixel in the type-II pixel layer. The light-transmitting pixel in the type-II pixel layer is surrounded by the first outer metal fence, and the light-transmitting hole is surrounded by the first inner metal fence.

23. The microdisplay device according to claim 14, characterized in that: At least one pixel layer is a type-1 pixel layer, and the bottom ends of each sub-pixel in the type-1 pixel layer are each electrically connected to a corresponding first-type electrode contact through an independent conductive block. The conductive block and the first-type electrode contact are one-to-one. The conductive block has an electrical contact area for electrically connecting to the bottom end of the corresponding sub-pixel in the type-1 pixel layer. The area of ​​the electrical contact area is smaller than the area of ​​the bottom surface of the corresponding sub-pixel in the type-1 pixel layer to which it is electrically connected.

24. The microdisplay device according to claim 23, characterized in that: The bottom of each sub-pixel in the type-1 pixel layer is electrically connected to its corresponding conductive block via a metal reflective layer.

25. The microdisplay device according to claim 24, characterized in that: The pixel layer containing the light-transmitting pixel is the type I pixel layer. The bottom of the light-transmitting pixel in the type I pixel layer is electrically connected to the corresponding non-common conductive component through the metal reflective layer and the conductive block in sequence.

26. The microdisplay device according to claim 24, characterized in that: Above the metal reflective layer of the light-transmitting pixel in the type-1 pixel layer, an outer reflective portion and an inner reflective portion are formed. The outer reflective portion surrounds the outer periphery of the light-transmitting pixel in the type-1 pixel layer, and the inner reflective portion surrounds the interior of the light-transmitting hole.

27. The microdisplay device according to claim 13, characterized in that: In the top common electrode structure, a display area is divided on the driving back plate, and all the mother pixels constitute a pixel array. The projection of the pixel array on the driving back plate is located inside the display area. The second type of electrode contact is provided inside the display area, and / or the second type of electrode contact is provided outside the display area. The second type of electrode contact is electrically connected to the top conductive layer at the top of multiple sub-pixels through a common electrode conductive element.

28. The microdisplay device according to claim 27, characterized in that: In the top common polarity structure, the top of each of the sub-pixels located in different pixel layers of the mother pixel is provided with a separate top conductive layer without sharing it, and the top conductive layer in the same pixel layer is located on the top of the electrically connected sub-pixels.

29. The microdisplay device according to claim 28, characterized in that: In the top common polarity structure, the top of each of the sub-pixels of at least two different pixel layers in the mother pixel is provided with a separate top conductive layer without sharing it. The common polarity conductive element includes interconnecting conductive parts, and two adjacent top conductive layers are interconnected through the interconnecting conductive parts to achieve electrical connection.

30. The microdisplay device according to claim 27, characterized in that: In the top common-polarity structure, at least two of the sub-pixels in the mother pixel share a top conductive layer, and the sub-pixels that share a top conductive layer are located in different pixel layers.

31. The microdisplay device according to claim 27, characterized in that: In the top common electrode structure, the bottom end of the common electrode conductive element is in direct contact with the corresponding second type of electrode contact.

32. The microdisplay device according to claim 12, characterized in that: The top of each of the multiple sub-pixels located in different pixel layers in the mother pixel is electrically connected to the corresponding second type of electrode contact through the top conductive layer. The bottom ends of the multiple sub-pixels are electrically interconnected and connected to the first type of electrode contact to form a bottom common electrode structure. The polarities of the first type of electrode contact and the second type of electrode contact are opposite.

33. The microdisplay device according to claim 32, characterized in that: In the bottom common-polarity structure, among the two sub-pixels located in different pixel layers, one sub-pixel is the light-transmitting pixel and the other sub-pixel is the associated pixel. The bottom ends of the light-transmitting pixel and the bottom ends of the associated pixel are electrically connected through a common-polarity conductive element. The common-polarity conductive element connected to the light-transmitting pixel is located on the periphery of the associated pixel.

34. The microdisplay device according to claim 33, characterized in that: The periphery of the associated pixel has an insulating fill area, and the common conductive element to which the light-transmitting pixel is connected passes through the insulating fill area.

35. The microdisplay device according to claim 33, characterized in that: The periphery of the associated pixel has a compound semiconductor region, and the common conductive element to which the light-transmitting pixel is connected passes through the compound semiconductor region.

36. The microdisplay device according to claim 33, characterized in that: The top conductive layer of the associated pixel is electrically connected to the corresponding second type electrode contact through a non-common conductive element, and the top conductive layer of the top conductive layer of the associated pixel is electrically connected to the corresponding non-common conductive element after passing through the light-transmitting hole of the light-transmitting pixel.

37. The microdisplay device according to claim 32, characterized in that: In the bottom common electrode structure, the driving back plate is divided into a display area, all the mother pixels constitute a pixel array, the projection of the pixel array on the driving back plate is located inside the display area, the first type of electrode contact is provided inside the display area, and / or the first type of electrode contact is provided outside the display area.

38. The microdisplay device according to claim 32, characterized in that: In the bottom common-polarity structure, the top of each of the sub-pixels located in different pixel layers of the mother pixel is individually provided with the top conductive layer, and the top conductive layer in the same pixel layer is located on the top of the electrically connected sub-pixels.

39. The microdisplay device according to any one of claims 13 or 32, characterized in that: At least one of the top conductive layers is electrically connected to a metal reinforcement located above or below the electrically connected top conductive layer.

40. The microdisplay device according to any one of claims 13 or 32, 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.

41. The microdisplay device according to claim 12, 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.

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