MicroLED pixels and microLED array panels

Abstract

A micro-LED pixel includes: a first light-emitting platform; a second light-emitting platform disposed above the first light-emitting platform; and a third light-emitting platform disposed above the second light-emitting platform, wherein at least a portion of the third light-emitting platform completely covers the second light-emitting platform; and the first light-emitting platform, the second light-emitting platform, and the third light-emitting platform do not contact each other.

Description

Technical Field

[0001] This disclosure generally relates to microdisplay technology, and more particularly to micro-light-emitting diodes (LEDs) and micro-LED array panels. Background Technology

[0002] Typically, a traditional microLED pixel consists of three or more microLED mesa arranged side by side to form a microLED panel. These three or more microLED mesa can emit light of different colors.

[0003] To reduce the size of microLED pixels, a microLED pixel may include a plurality of microLED mesas formed perpendicularly to a common central axis. The microLED mesas defines a light-emitting area, and electrodes of the microLED mesas are formed on an outer panel outside the light-emitting area of ​​the microLED pixel. However, the outer panel may increase the size of the microLED pixel.

[0004] Therefore, the microLED pixel structure needs further improvement to reduce its size and increase the light-emitting area. Summary of the Invention

[0005] An embodiment of this disclosure provides a micro-LED pixel. The micro-LED pixel includes: a first light-emitting platform; a second light-emitting platform disposed above the first light-emitting platform; and a third light-emitting platform disposed above the second light-emitting platform, wherein at least a portion of the third light-emitting platform completely covers the second light-emitting platform; and the first light-emitting platform, the second light-emitting platform, and the third light-emitting platform do not contact each other.

[0006] Embodiments of this disclosure provide a microLED array panel. The microLED array panel includes a plurality of the aforementioned microLED pixels, wherein the plurality of microLED pixels are arranged in an array.

[0007] Embodiments of this disclosure provide a microLED array panel. The microLED array panel includes a plurality of the aforementioned microLED pixels, wherein each microLED pixel further includes a top conductive layer continuously formed on the top surface of a first light-emitting platform, the top surface of a second light-emitting platform, and the top surface of a third light-emitting platform, and the top conductive layers of each of the plurality of microLED pixels are interconnected.

[0008] Embodiments of this disclosure provide a microLED array panel. The microLED array panel includes a plurality of the aforementioned microLED pixels, wherein each microLED pixel further includes an integrated circuit (IC) backplane disposed at the bottom of the microLED pixel, and the IC backplanes of the plurality of microLED pixels are interconnected. Attached Figure Description

[0009] The embodiments and aspects of this disclosure are described in the following detailed description and accompanying drawings. The features shown in the figures are not drawn to scale.

[0010] Figure 1 A structural diagram of an exemplary microLED pixel is shown, illustrating some embodiments according to this disclosure.

[0011] Figure 2 Some embodiments based on this disclosure are shown. Figure 1 The diagram shows a top view of the microLED pixel structure.

[0012] Figure 3 Some embodiments based on this disclosure are shown. Figure 2 The diagram shows the cross-sectional structure of the micro-LED pixel along the A-A' direction.

[0013] Figure 4 Some embodiments based on this disclosure are shown. Figure 2 The diagram shows the cross-sectional structure of the micro-LED pixel along the B-B' direction.

[0014] Figure 5 Some embodiments based on this disclosure are shown. Figure 2 The diagram shows the cross-sectional structure of the micro-LED pixel along the C-C' direction.

[0015] Figure 6 Some embodiments based on this disclosure are shown. Figure 2 The diagram shows a cross-sectional view of the micro-LED pixel structure along the D-D' direction.

[0016] Figure 7 A top view structural diagram of an exemplary microLED array panel according to some embodiments of the present disclosure is shown.

[0017] Figure 8 Some embodiments based on this disclosure are shown. Figure 7 Another top view of the exemplary microLED array panel shown, excluding the top conductive layer and top contact structure.

[0018] Figure 9 Some embodiments based on this disclosure are shown. Figure 7 The diagram shows a cross-sectional view of the micro-LED array panel along the E-E' direction.

[0019] Figure 10 Some embodiments based on this disclosure are shown. Figure 7 The diagram shows a cross-sectional view of the micro-LED array panel along the F-F' direction.

[0020] Figures 11 to 17Top view structural diagrams of different exemplary microLED pixels according to some embodiments of this disclosure are shown. Detailed Implementation

[0021] Reference will now be made specifically to exemplary embodiments. Examples of these exemplary embodiments are illustrated in the accompanying drawings. The following description refers to the drawings, wherein, unless otherwise stated, the same numbers in different figures denote the same or similar elements. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with the present invention. Rather, these implementations are merely examples of apparatuses and methods consistent with aspects of the invention recounted in the appended claims. Specific aspects of this disclosure are described in more detail below. If any terminology and definitions provided herein conflict with those incorporated by reference, the terminology and definitions provided herein shall prevail.

[0022] Embodiments of this disclosure provide a microLED pixel having staggered light-emitting platforms to reduce one or more cross-sectional dimensions of the microLED pixel.

[0023] Figure 1 A structural diagram of an exemplary microLED pixel 100 according to some embodiments of this disclosure is shown. Figure 1 As shown, the micro-LED pixel 100 includes three light-emitting platforms spaced apart and staggered in the vertical direction. For example, a first light-emitting platform 110 is located at the bottom, a second light-emitting platform 120 is located above the first light-emitting platform 110, and a third light-emitting platform 130 is located above the second light-emitting platform 120. The top surface of the first light-emitting platform 110 is lower than the bottom surface of the second light-emitting platform 120, and the top surface of the second light-emitting platform 120 is lower than the bottom surface of the third light-emitting platform 130. That is, the first light-emitting platform 110, the second light-emitting platform 120, and the third light-emitting platform 130 are spaced apart, i.e., they do not contact each other.

[0024] As can be seen from the micro-LED pixel 100 above, at least a portion of the three light-emitting platforms can overlap. For example, at least a portion of the second light-emitting platform 120 covers, i.e., overlaps but does not contact, at least a portion of the first light-emitting platform 110, or at least a portion of the third light-emitting platform 130 covers, i.e., overlaps but does not contact, at least a portion of the first light-emitting platform 110 or at least a portion of the second light-emitting platform. Meanwhile, another portion of the second light-emitting platform 120 does not cover the first light-emitting platform 110, or another portion of the third light-emitting platform 130 does not cover the second light-emitting platform 120 or the first light-emitting platform 110. (See reference...) Figure 1In this embodiment, a portion of the third light-emitting platform 130 covers a portion of the second light-emitting platform 120, and a portion of the second light-emitting platform 120 covers a portion of the first light-emitting platform 110. Another portion of the first light-emitting platform 110 is not covered by the second light-emitting platform 120 or the third light-emitting platform 130, and another portion of the second light-emitting platform 120 is not covered by the third light-emitting platform 130.

[0025] Each light-emitting mesa (i.e., 110, 120, and 130) includes a top electrode and a bottom electrode. For example, the top electrode is located on the top surface of the light-emitting mesa, and the bottom electrode is located on the bottom surface of the light-emitting mesa. In some embodiments, the microLED pixel 100 also includes a set of conductive bottom pads. Figure 1 As shown, a set of conductive bottom pads includes: a first bottom pad 111 of a first light-emitting platform 110, disposed below the first light-emitting platform 110; a second bottom pad 121 of a second light-emitting platform 120, disposed below the portion of the second light-emitting platform 120 that does not cover the first light-emitting platform 110; and a third bottom pad 131 of a third light-emitting platform 130, disposed below the portion of the third light-emitting platform 130 that does not cover either the second light-emitting platform 120 or the first light-emitting platform 110. That is, the second bottom pad 121 is disposed below a portion of the second light-emitting platform 120 and is not covered by the first light-emitting platform 110. The third bottom pad 131 is disposed below a portion of the third light-emitting platform 130 and is not covered by either the first light-emitting platform 110 or the second light-emitting platform 120. The first bottom pad 111, the second bottom pad 121, and the third bottom pad 131 do not contact each other. In some embodiments, the microLED pixel 100 also includes an integrated circuit (IC) backplane (…). Figure 1 (not shown), and the first bottom pad 111, the second bottom pad 121 and the third bottom pad 131 are each disposed on the IC backplane.

[0026] Therefore, each light-emitting mesa can be connected to a bottom pad beneath its own bottom surface. For the microLED pixel 100, all bottom pads can be located below the light-emitting area formed by the first light-emitting mesa 110, the second light-emitting mesa 120, and the third light-emitting mesa 130. Therefore, the bottom pads do not require an external area, and because at least a portion of the three light-emitting mesas overlaps, the cross-sectional size of the microLED pixel 100 is reduced.

[0027] In some embodiments, the microLED pixel 100 includes one or more bottom electrical connection structures for conductively connecting a bottom electrode on the bottom surface of the light-emitting mesa to a conductive bottom pad. For example, a first bottom electrical connection structure may be provided to connect the bottom surface of the first light-emitting mesa 110 to the first bottom pad 111. In this embodiment, since the first light-emitting mesa 110 is located at the bottommost position, the first bottom electrical connection structure may be a bottom bonding layer or a bottom hole disposed between the bottom surface of the first light-emitting mesa 110 and the first bottom pad 111 to connect the first light-emitting mesa 110 and the first bottom pad 111. A second bottom electrical connection structure 122 is provided to connect the bottom surface of the second light-emitting mesa 120 to the second bottom pad 121. A third bottom electrical connection structure 132 is provided to connect the bottom surface of the third light-emitting mesa 130 to the third bottom pad 131. In some embodiments, the second bottom electrical connection structure 122 and the third bottom electrical connection structure 132 are through holes. The through holes are made of metal and may have a hollow structure. The second bottom electrical connection structure 122 and the third bottom electrical connection structure 132 are not in a conductive contact state.

[0028] In some embodiments, each of the light-emitting platforms (i.e., 110, 120, and 130) has a conical structure, meaning the top surface area of ​​the light-emitting platform is smaller than the bottom surface area, and each light-emitting platform has a symmetrical structure. In some embodiments, the top surface is a rectangle with a width (shorter side) and a length (longer side). The symmetrical structure is characterized by a length-perpendicular symmetry plane along the length direction and a width-perpendicular symmetry plane along the width direction. The length-perpendicular symmetry plane is perpendicular to the width-perpendicular symmetry plane, and the intersection of the length-perpendicular symmetry plane and the width-perpendicular symmetry plane is the vertical centerline of the light-emitting platform perpendicular to it. In some embodiments, the top surface is a square, i.e., the width and length are equal. It is understood that in this case, the width direction and the length direction can be interchanged, and can be referred to as the first direction and the second direction. Therefore, the length-perpendicular symmetry plane and the width-perpendicular symmetry plane can be interchanged, and can be referred to as the first vertical symmetry plane and the second vertical symmetry plane.

[0029] Figure 2 Some embodiments based on this disclosure are shown. Figure 1 The diagram shows a top view of the microLED pixel structure. Figure 2 As shown, with Figure 1 In this embodiment, the length vertical symmetry plane of the first light-emitting platform 110 is parallel to the length vertical symmetry plane of the third light-emitting platform 130, and is perpendicular to the length vertical symmetry plane of the second light-emitting platform 120.

[0030] Figures 3 to 6 An exemplary structure of a microLED pixel 100 according to some embodiments of the present disclosure is shown.

[0031] Figure 3 Some embodiments based on this disclosure are shown. Figure 2 The diagram shows a cross-sectional view of the micro-LED pixel 100 along the A-A' direction. Figure 4 Some embodiments based on this disclosure are shown. Figure 2 The diagram shows a cross-sectional view of the micro-LED pixel 100 along the B-B' direction. Figure 5 Some embodiments based on this disclosure are shown. Figure 2 The diagram shows a cross-sectional view of the micro-LED pixel 100 along the C-C' direction. Figure 6 Some embodiments based on this disclosure are shown. Figure 2 The diagram shows a cross-sectional view of the micro-LED pixel 100 along the D-D' direction.

[0032] Reference Figures 3 to 6 The microLED pixel 100 also includes a top conductive layer 160 formed on the top surface of the microLED pixel 100. For example... Figure 3As shown, a top conductive layer 160 is continuously formed on the first light-emitting mesa 110, the second light-emitting mesa 120, and the third light-emitting mesa 130, and is configured to connect to the top electrode of the first light-emitting mesa 110, the top electrode of the second light-emitting mesa 120, and the top electrode of the third light-emitting mesa 130. The top conductive layer 160 has a wavy structure and includes one or more recessed portions. In some embodiments, the top conductive layer 160 includes recessed portions (e.g., 161, 162, and 163) corresponding to each light-emitting mesa, to connect to each light-emitting mesa respectively. Since the three light-emitting mesa (i.e., 110, 120, and 130) are located at different positions in the vertical direction, the depths of the three recessed portions (e.g., 161, 162, and 163) are different. In some embodiments, the microLED pixel 100 also includes top electrical connection structures (e.g., 113, 123, and 133) for connecting the top electrode of the light-emitting mesa to the top conductive layer 160. For example, a first top electrical connection structure 113 is disposed on the top surface of the first light-emitting mesa 110 to connect to the top conductive layer 160. A second top electrical connection structure 123 is disposed on the top surface of the second light-emitting mesa 120 to connect to the top conductive layer 160. The top electrical connection structures (e.g., 113, 123, and 133) can act as ohmic contact layers. In some embodiments, the top electrical connection structures (e.g., 113, 123, and 133) are made of metal. In some embodiments, the top conductive layer 160 can directly contact the top surfaces of the three light-emitting mesas (i.e., 110, 120, and 130), thus eliminating the need for top electrical connection structures (e.g., 113, 123, and 133). In some embodiments, the top conductive layer 160 is transparent and has a light transmittance of not less than 70%. In some embodiments, the top conductive layer 160 is a TCO (transparent conductive oxide) layer, such as an ITO (indium tin oxide) layer, an AZO (antimony-doped zinc oxide) layer, an ATO (antimony-doped tin oxide) layer, an FTO (fluorine-doped tin oxide) layer, etc.

[0033] In some embodiments, a top contact structure 180 is provided on the top conductive layer 160, and is configured to provide a contact on the top conductive layer 160. In some embodiments, the top contact structure 180 is connected to a top pad and is used for further connection to external circuitry. In some embodiments, the top pad is disposed on the IC backplane. In some embodiments, the top contact structure 180 is disposed at the edge of the microLED pixel 100 and around the periphery of the microLED pixel 100.

[0034] In some embodiments, the micro-LED pixel 100 also includes an optical isolation structure 140 disposed around the micro-LED pixel 100 and configured to prevent light from crossing between adjacent micro-LED pixels. In some embodiments, the top of the optical isolation structure 140 is equal to or higher than the top surface of the third emitting mesa 130, and the bottom of the optical isolation structure 140 is equal to or lower than the bottom surface of the first emitting mesa 110. Therefore, the optical isolation structure 140 can prevent light crossing between the emitting mesa of adjacent micro-LED pixels. It is understood that the optical isolation structure 140 is not connected to the emitting mesa (i.e., 110, 120, 130), the top conductive layer 160, and the IC backplane 190.

[0035] In some embodiments, the optical isolation structure 140 is reflective. In some embodiments, the material of the optical isolation structure 140 is metal.

[0036] In some embodiments, the microLED pixel 100 further includes a dielectric material 150 filled within the microLED pixel 100, that is, the dielectric material 150 fills at least partially the space defined by the IC backplane 190, the top conductive layer 160, and the optical isolation structure 140. More specifically, the dielectric material 150 fills the space between the first light-emitting mesa 110, the second light-emitting mesa 120, the third light-emitting mesa 130, the second bottom electrical connection structure 122, the third bottom electrical connection structure 132, the first bottom pad 111, the second bottom pad 121, the third bottom pad 131, the IC backplane 190, the top conductive layer 160, and the optical isolation structure 140. In some embodiments, the space defined by the IC backplane 190, the top conductive layer 160, and the optical isolation structure 140 may have a box structure. In some embodiments, the dielectric material 150 is selected from one or more of silicon oxide, silicon nitride, SiCN, SiNO, or Al2O3. In some embodiments, the dielectric material 150 is transparent.

[0037] With the above-described structure, the microLED pixels provided by the embodiments of this disclosure can achieve a good balance between high transmittance and size. Due to the staggered arrangement of the light-emitting mesa, a bottom connection structure can be provided under each light-emitting mesa, and at least a portion of the light-emitting mesa overlaps. Therefore, an external panel for electrode connection is unnecessary, thereby reducing the cross-sectional size of the microLED pixels with high transmittance.

[0038] Figure 7 A top view of an exemplary microLED array panel 700 according to some embodiments of the present disclosure is shown. Figure 8 Another top view of a microLED array panel 700 according to some embodiments of the present disclosure is shown, excluding the top conductive layer 160 and the top contact structure 180. (Refer to...) Figure 7and Figure 8 The microLED array panel 700 includes two or more microLED pixels 100 arranged in an array. In this embodiment, a 3×2 array is illustrated. Figure 7 As shown, the top view of each microLED pixel 100 can be rectangular, so two or more microLED pixels 100 can be arranged closely together.

[0039] Figure 9 Some embodiments based on this disclosure are shown. Figure 7 The cross-sectional structure of the micro-LED array panel 700 along the E-E' direction is shown. Figure 10 Some embodiments based on this disclosure are shown. Figure 7 The diagram shows a cross-sectional view of the micro-LED array panel 700 along the F-F' direction. Figure 9 and Figure 10 As shown, light crossing between adjacent microLED pixels can be prevented by optical isolation structure 140.

[0040] Reference Figure 9 and Figure 10 In some embodiments, the top conductive layers 160 of each of the plurality of microLED pixels 100 are interconnected. For example, the top conductive layers 160 are formed continuously on the top of the microLED array panel 700.

[0041] In some embodiments, the IC backplanes 190 of the plurality of microLED pixels 100 are interconnected. For example, the IC backplanes 190 may be continuously configured as the entire base plate of the microLED array panel 700. In some embodiments, the entire IC backplane 190 also includes a top pad (not shown), and a top conductive layer 160 is connected to the top pad. In some embodiments, external conductors are also provided for connecting the top contact structure 180 to the top pad.

[0042] return Figure 1 In some embodiments, the first light-emitting platform 110 is oriented along a first length direction D1, the second light-emitting platform 120 is oriented along a second length direction D2, and the third light-emitting platform 130 is oriented along a third length direction D3. In some embodiments, the vertical center line of the third light-emitting platform 130 is not aligned with the vertical center line of the second light-emitting platform 120. In this embodiment, the length vertical symmetry plane of the first light-emitting platform 110 is parallel to the length vertical symmetry plane of the third light-emitting platform 130, and both are perpendicular to the length vertical symmetry plane of the second light-emitting platform 120.

[0043] Figures 11 to 17Top views of different exemplary microLED pixels according to various embodiments of the present disclosure are shown. In such different embodiments, the first light-emitting platform 110, the second light-emitting platform 120, and the third light-emitting platform 130 may be arranged in different directions and have different dimensions.

[0044] Reference Figure 11 ,and Figure 1 The exemplary micro-LED pixels shown are consistent. In exemplary micro-LED pixel 100A, the first vertical symmetry plane 110A of the first light-emitting platform 110 is parallel to and perpendicular to the first vertical symmetry plane 130A of the third light-emitting platform 130, and is perpendicular to the first vertical symmetry plane 120A of the second light-emitting platform 120. The second vertical symmetry plane 110B of the first light-emitting platform 110 is aligned with the second vertical symmetry plane 130B of the third light-emitting platform 130, that is, the second vertical symmetry plane 110B of the first light-emitting platform 110 and the second vertical symmetry plane 130B of the third light-emitting platform 130 are coplanar. A portion of the third light-emitting platform 130 covers a portion of the second light-emitting platform 120, and a portion of the second light-emitting platform 120 covers a portion of the first light-emitting platform 110. Another portion of the first light-emitting platform is not covered by either the second light-emitting platform 120 or the third light-emitting platform 130, and another portion of the second light-emitting platform 120 is not covered by the third light-emitting platform 130. In this embodiment, each light-emitting platform may have an upward-facing light-emitting area that is not covered by other light-emitting platforms. Therefore, the luminous quality can be high, and the transmittance of the luminous mesa can be balanced.

[0045] Reference Figure 12 In the exemplary micro-LED pixel 100B, a portion of the second light-emitting platform 120 covers a portion of the first light-emitting platform 110, another portion of the second light-emitting platform 120 does not cover the first light-emitting platform 110, and another portion of the first light-emitting platform 110 is not covered by the second light-emitting platform 120. The third light-emitting platform 130 does not cover either the second light-emitting platform 120 or the first light-emitting platform 110. In this embodiment, both the second light-emitting platform 120 and the third light-emitting platform 130 can emit light without being covered by the other light-emitting platforms. More specifically, in Figure 12In this design, the first vertical symmetry plane 110A of the first light-emitting platform 110 is parallel to the first vertical symmetry plane 130A of the third light-emitting platform 130, and both are perpendicular to the first vertical symmetry plane 120A of the second light-emitting platform 120. The second vertical symmetry plane 110B of the first light-emitting platform 110 is aligned with the second vertical symmetry plane 130B of the third light-emitting platform 130, meaning they are coplanar. Since the third light-emitting platform 130 does not cover the second light-emitting platform 120 or the first light-emitting platform 110, it can be positioned at any location in the vertical direction, as long as it does not contact the first light-emitting platform 110 or the second light-emitting platform 120. For example, the third light-emitting platform 130 and the second light-emitting platform 120 can be positioned in the same plane. Therefore, the height of the micro-LED pixel 100B can be reduced.

[0046] Reference Figure 13 In the exemplary micro-LED pixel 100C, the first light-emitting platform 110 is completely covered by a portion of the second light-emitting platform 120. Another portion of the second light-emitting platform 120 does not cover the first light-emitting platform 110. The third light-emitting platform 130 does not cover either the second light-emitting platform 120 or the first light-emitting platform 110. More specifically, the first vertical symmetry plane 120A of the second light-emitting platform 120 is coplanar with the second vertical symmetry plane 110B of the first light-emitting platform 110, and further parallel to the first vertical symmetry plane 130A of the third light-emitting platform 130. The second vertical symmetry plane 120B of the second light-emitting platform 120 is coplanar with the second vertical symmetry plane 130B of the third light-emitting platform 130, and further parallel to the first vertical symmetry plane 110A of the first light-emitting platform 110. Since the third light-emitting platform 130 does not cover the second light-emitting platform 120 or the first light-emitting platform 110, the third light-emitting platform 130 can be positioned at any location in the vertical direction, as long as it does not contact the first light-emitting platform 110 or the second light-emitting platform 120. For example, the third light-emitting platform 130 and the second light-emitting platform 120 can be positioned in the same plane. Therefore, the height of the micro-LED pixel 100C can be reduced.

[0047] Reference Figure 14In the exemplary micro-LED pixel 100D, the second light-emitting platform 120 is completely covered by a portion of the third light-emitting platform 130. Another portion of the third light-emitting platform 130 does not cover the second light-emitting platform 120. The first light-emitting platform 110 is not covered by either the second light-emitting platform 120 or the third light-emitting platform 130. The first light-emitting platform 110 can emit light without being covered by other light-emitting platforms. More specifically, the first vertical symmetry plane 130A of the third light-emitting platform 130 is coplanar with the second vertical symmetry plane 120B of the second light-emitting platform 120, and further parallel to the first vertical symmetry plane 110A of the first light-emitting platform 110. The second vertical symmetry plane 110B of the first light-emitting platform 110 is coplanar with the second vertical symmetry plane 130B of the third light-emitting platform 130, and further parallel to the first vertical symmetry plane 120A of the second light-emitting platform 120. Since the first light-emitting platform 110 is not covered by the second light-emitting platform 120 or the third light-emitting platform 130, the first light-emitting platform 110 can be positioned at any location in the vertical direction, as long as it does not contact the second light-emitting platform 120 or the third light-emitting platform 130. For example, the first light-emitting platform 110 and the second light-emitting platform 120 can be positioned in the same plane. Therefore, the height of the micro-LED pixel 100D can be reduced.

[0048] Reference Figure 15 In the exemplary micro-LED pixel 100E, the second light-emitting platform 120 is completely covered by a portion of the third light-emitting platform 130, and a portion of the second light-emitting platform 120 covers a portion of the first light-emitting platform 110. A portion of the third light-emitting platform 130 also covers a portion of the first light-emitting platform 110. More specifically, the first vertical symmetry plane 130A of the third light-emitting platform 130 is coplanar with the second vertical symmetry plane 120B of the second light-emitting platform 120, and further parallel to the first vertical symmetry plane 110A of the first light-emitting platform 110. The second vertical symmetry plane 110B of the first light-emitting platform 110 is coplanar with the second vertical symmetry plane 130B of the third light-emitting platform 130, and further parallel to the first vertical symmetry plane 120A of the second light-emitting platform 120.

[0049] Reference Figure 16In the exemplary micro-LED pixel 100F, the third light-emitting platform 130 does not cover any portion of the second light-emitting platform 120 or the first light-emitting platform 110. A portion of the second light-emitting platform 120 covers a portion of the first light-emitting platform 110. More specifically, the first vertical plane of symmetry 110A of the first light-emitting platform 110 is parallel to the first vertical plane of symmetry 130A of the third light-emitting platform 130 and perpendicular to the first vertical plane of symmetry 120A of the second light-emitting platform 120. The second vertical plane of symmetry 110B of the first light-emitting platform 110 is parallel to the second vertical plane of symmetry 130B of the third light-emitting platform 130 and perpendicular to the second vertical plane of symmetry 120B of the second light-emitting platform 120. Figure 12 Compared to the microLED pixel 100B shown, in this embodiment, the emission area of ​​the third light-emitting platform 130 is reduced, and the emission area of ​​the first light-emitting platform 110 is increased. Since the third light-emitting platform 130 does not cover the second light-emitting platform 120 or the first light-emitting platform 110, the third light-emitting platform 130 can be positioned at any location in the vertical direction, as long as it does not contact the first light-emitting platform 110 or the second light-emitting platform 120. For example, the third light-emitting platform 130 and the second light-emitting platform 120 can be positioned in the same plane. Therefore, the height of the microLED pixel 100F can be reduced.

[0050] Reference Figure 17 In the exemplary micro-LED pixel 100G, a portion of the third light-emitting platform 130 covers a portion of the second light-emitting platform 120. The first light-emitting platform 110 is not covered by either the second light-emitting platform 120 or the third light-emitting platform 130. More specifically, the first vertical plane of symmetry 110A of the first light-emitting platform 110 is parallel to the first vertical plane of symmetry 130A of the third light-emitting platform 130 and perpendicular to the first vertical plane of symmetry 120A of the second light-emitting platform 120. The second vertical plane of symmetry 110B of the first light-emitting platform 110 is parallel to the second vertical plane of symmetry 130B of the third light-emitting platform 130 and perpendicular to the second vertical plane of symmetry 120B of the second light-emitting platform 120. Figure 14 Compared to the micro-LED pixel 100D shown, the emitting area of ​​the first emitting platform 110 is reduced, while the emitting area of ​​the second emitting platform 120 is increased. Figure 16Compared to the micro-LED pixel 100F shown, the emission area of ​​the second light-emitting platform 120 is reduced, while the emission area of ​​the third light-emitting platform 130 is increased. Since the first light-emitting platform 110 is not covered by the second light-emitting platform 120 or the third light-emitting platform 130, the first light-emitting platform 110 can be positioned at any location in the vertical direction, as long as it does not contact the second light-emitting platform 120 or the third light-emitting platform 130. For example, the first light-emitting platform 110 and the second light-emitting platform 120 can be positioned in the same plane. Therefore, the height of the micro-LED pixel 100G can be reduced.

[0051] In some implementations, the top surface area of ​​the bottommost light-emitting platform is the largest among the three or more light-emitting platforms. In this embodiment, the top surface area of ​​the first light-emitting platform 110 is greater than the top surface areas of the second light-emitting platform 120 and the third light-emitting platform 130.

[0052] In some embodiments, the three or more light-emitting mesa include at least a red-emitting mesa configured to emit red light, a green-emitting mesa configured to emit green light, and a blue-emitting mesa configured to emit blue light. For example, the first light-emitting mesa 110 is a red-emitting mesa, the second light-emitting mesa 120 is a green-emitting mesa, and the third light-emitting mesa 130 is a blue-emitting mesa. In some embodiments, the first light-emitting mesa 110 is a red-emitting mesa, the second light-emitting mesa 120 is a blue-emitting mesa, and the third light-emitting mesa 130 is a green-emitting mesa.

[0053] Those skilled in the art will understand that there are many other arrangements for these three or more light-emitting mesa. The purpose of these arrangements is that each light-emitting mesa can be connected to an electrode located beneath it, without requiring an external panel. Therefore, the cross-sectional size of the microLED pixel can be reduced. In some embodiments, the arrangement of three or more light-emitting mesa forms a rectangular top surface. Therefore, the microLED pixels provided by the embodiments of this disclosure facilitate the assembly of microLED array panels with large light-emitting areas.

[0054] It should be noted that relational terms such as “first” and “second” in this document are used only to distinguish one entity or operation from another, and do not require or imply any actual relationship or order between these entities or operations. Furthermore, the words “including,” “having,” “containing,” and “comprising,” as well as other similar forms, are intended to be equivalent in meaning and are open-ended; one or more items following any of these words do not imply an exhaustive list of such one or more items, or that they are limited to only one or more listed items.

[0055] Unless otherwise specified, the term "or" as used herein includes all possible combinations except where it is impractical. For example, if a database is declared to include A or B, then unless otherwise specified or impractical, the database may include A, or B, or A and B. A second example is if a database is declared to include A, B, or C, then unless otherwise specified or impractical, the database may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C.

[0056] In the foregoing specification, numerous specific details have been described with reference to embodiments that may vary depending on the implementation. Certain adjustments and modifications may be made to the described embodiments. Other embodiments will be apparent to those skilled in the art in light of the specification and practice of the invention disclosed herein. The specification and embodiments are intended to be illustrative only, and the following claims indicate the true scope and spirit of the invention. It is also intended that the order of steps shown in the figures is for illustrative purposes only and is not intended to limit one to any particular order of steps. Therefore, those skilled in the art will understand that these steps may be performed in a different order when implementing the same method.

[0057] Exemplary embodiments have been disclosed in the accompanying drawings and description. However, many variations and modifications can be made to these embodiments. Therefore, although specific terms are used, they are used in a general and descriptive sense only and not for limiting purposes.

Claims

1. A micro-LED pixel, comprising: comprises: a first light emitting mesa; a second light emitting mesa disposed above the first light emitting mesa; and a third light emitting mesa disposed above the second light emitting mesa, wherein at least a portion of the third light emitting mesa completely covers the second light emitting mesa, and neither the second light emitting mesa nor the third light emitting mesa covers the first light emitting mesa; and the first light emitting mesa, the second light emitting mesa, and the third light emitting mesa do not contact each other. Each of the first light emitting mesa, the second light emitting mesa, and the third light emitting mesa has a symmetric structure having:

2. The micro-LED pixel of claim 1, wherein, a first vertical symmetry plane along a length direction; a second vertical symmetry plane along a width direction; and a vertical center line being an intersection of the first vertical symmetry plane and the second vertical symmetry plane. The vertical center line of the third light emitting mesa is not aligned with the vertical center line of the second light emitting mesa.

3. The micro-LED pixel of claim 2, wherein, Neither the first vertical symmetry plane nor the second vertical symmetry plane of the third light emitting mesa is coplanar with the first vertical symmetry plane and the second vertical symmetry plane of the second light emitting mesa.

4. The micro-LED pixel of claim 2, wherein, The first vertical symmetry plane of the third light emitting mesa is parallel to the first vertical symmetry plane of the second light emitting mesa.

5. The micro-LED pixel of claim 4, wherein, The first vertical symmetry plane of the third light emitting mesa is coplanar with the first vertical symmetry plane of the second light emitting mesa.

6. The micro-LED pixel of claim 2, wherein, Further comprising an Integrated Circuit (IC) backplane, wherein first, second, and third bottom pads are independently disposed on the IC backplane, and the first, second, and third bottom pads are configured to be connected to bottom electrodes of the first, second, and third light emitting mesas, respectively.

7. The micro-LED pixel of claim 1, wherein, Further comprising a top conductive layer continuously formed on top surfaces of the first, second, and third light emitting mesas, and configured to connect top electrodes of the first, second, and third light emitting mesas.

8. The micro-LED pixel of claim 7, wherein, The top conductive layer comprises one or more recessed portions to be connected to the first, second, and third light emitting mesas, respectively.

9. The micro-LED pixel of claim 8, wherein, The top conductive layer is transparent, and has a light transmittance of no less than 70%.

10. The micro-LED pixel of claim 8, wherein, Further comprising a top contact structure disposed on the top conductive layer and configured to provide a contact for the top conductive layer.

11. The micro-LED pixel of claim 8, wherein, The top contact structure is disposed at a periphery of the micro LED pixel.

12. The micro-LED pixel of claim 11, wherein, Further comprising an optical isolation structure formed around the micro LED pixel.

13. The micro-LED pixel of claim 8, wherein, The optical isolation structure is reflective.

14. The micro-LED pixel of claim 13, wherein, A material of the optical isolation structure is metal.

15. The micro-LED pixel of claim 14, wherein, The optical isolation structure does not contact the top conductive layer, the first, second, and third light emitting mesas, the first, second, and third bottom pads, or the IC backplane.

16. The micro-LED pixel of claim 15, wherein, Further comprising a dielectric material filled in a space within the micro LED pixel.

17. The micro-LED pixel of claim 13, wherein, ​ 18. The micro-LED pixel of claim 17, wherein, The dielectric material is selected from one of silicon oxide, silicon nitride, SiCN, SiNO, or AI2O3.

19. The micro-LED pixel of claim 17, wherein, The dielectric material is transparent.

20. The micro-LED pixel of claim 1, wherein, The top surface area of the first light emitting mesa is greater than the top surface area of the second light emitting mesa and greater than the top surface area of the third light emitting mesa.

21. The micro-LED pixel of claim 1, wherein, The first light emitting mesa is configured to emit red light, the second light emitting mesa is configured to emit green light, and the third light emitting mesa is configured to emit blue light.

22. The micro-LED pixel of claim 1, wherein, The first light emitting mesa is configured to emit red light, the second light emitting mesa is configured to emit blue light, and the third light emitting mesa is configured to emit green light.

23. The micro-LED pixel of claim 2, wherein, The top surface of the first light emitting mesa, the top surface of the second light emitting mesa, and the top surface of the third light emitting mesa are rectangular.

24. A micro LED array panel, comprising: Comprising: A plurality of micro-LED pixels according to any one of claims 1 to 23, wherein the plurality of micro-LED pixels are arranged in an array.

25. A micro LED array panel, comprising: Comprising: A plurality of micro-LED pixels according to any one of claims 1 to 7 and 20 to 23, wherein the plurality of micro-LED pixels are arranged in an array; and wherein the micro-LED pixels further comprise a top conductive layer formed continuously on the top surface of the first light emitting mesa, the top surface of the second light emitting mesa, and the top surface of the third light emitting mesa, and the respective top conductive layers of the plurality of micro-LED pixels are interconnected.

26. A micro LED array panel, comprising: Comprising: A plurality of micro-LED pixels according to any one of claims 1 to 6 and 20 to 23, wherein the plurality of micro-LED pixels are arranged in an array; and wherein the micro-LED pixels further comprise an integrated circuit (IC) backplane disposed at the bottom of the micro-LED pixels, and the respective IC backplanes of the plurality of micro-LED pixels are interconnected.

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