A miniature light-emitting structure and display device

Abstract

This invention provides a miniature light-emitting structure and display device, relating to the field of semiconductor display manufacturing. The miniature light-emitting structure includes a first chip and a second chip. The first chip includes a bonding region and has multiple first protrusions distributed within the bonding region. During bonding, the second chip abuts against the first protrusions. The first chip has recesses spaced at intervals around the periphery of the bonding region, and the second chip has corresponding second protrusions that abut against the walls of the recesses during bonding. When bonding the first and second chips, in areas of greater stress, the first protrusions in these areas cannot continue to bring the chips closer together after abutting against the second chip; the pressure is borne by the first protrusions, preventing chip damage. The first and second chips can be bonded uniformly, thereby improving uneven brightness.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor display manufacturing, and in particular to a micro light-emitting structure and display device. Background Technology

[0002] Micro-LEDs (Micro Light Emitting Diodes) typically refer to micro-devices that shrink the size of LED chips to within 100 micrometers or even 50 micrometers, based on the traditional flip-chip LED structure. This miniaturization and arraying of RGB (red, green, and blue) Micro-LED chips (or chip arrays) are arranged according to specific rules on a TFT or CMOS board, allowing each chip to be addressed and individually driven to emit light, thus enabling full-color displays. Compared to current LED and OLED display devices, Micro-LEDs offer advantages such as faster response time, higher color gamut, higher PPI, higher brightness, and lower energy consumption.

[0003] Existing Micro-LED products suffer from uneven brightness. Utility Model Content

[0004] In order to solve the problems existing in the prior art, one of the objectives of this utility model is to provide a micro light-emitting structure.

[0005] This utility model provides the following technical solution: A micro-luminescent structure comprising: A first chip, the first chip including a bonding region, the first chip having a plurality of first protrusions disposed within the bonding region; and The second chip abuts against the first protrusion during bonding. The first chip has a recessed portion that is spaced apart on the periphery of the bonding area. The second chip has a corresponding second protrusion that abuts against the wall of the recessed portion during bonding.

[0006] As a further alternative to the micro-light-emitting structure, the first chip is an LED chip and the second chip is a driver chip.

[0007] As a further alternative to the micro-light-emitting structure, the bonding region is provided with a plurality of pixel electrodes, and the first protrusion is located between adjacent pixel electrodes.

[0008] As a further alternative to the micro-light-emitting structure, the height of the pixel electrode is H1, the height of the first protrusion is H2, and 0.4≤H2 / H1≤0.8.

[0009] As a further alternative to the micro-light-emitting structure, the width of the pixel electrode is W1, the width of the first protrusion is W2, and 0.3≤W2 / W1≤0.6.

[0010] As a further alternative to the micro-light-emitting structure, the height of the second protrusion is greater than the height of the first protrusion, and the end of the second protrusion away from the second chip is embedded in the corresponding recess.

[0011] As a further alternative to the micro-light-emitting structure, the height difference between the second protrusion and the first protrusion is less than the depth of the recess.

[0012] As a further alternative to the micro-light-emitting structure, the width of the recess is W3, and the width of the second protrusion is W4, where 0.3μm≤W3-W4≤0.6μm.

[0013] As a further alternative to the micro-light-emitting structure, the recesses are provided in multiple portions, and the multiple recesses are arranged around the bonding region.

[0014] Another objective of this invention is to provide a display device.

[0015] This utility model provides the following technical solution: A display device includes the aforementioned micro-light-emitting structure.

[0016] The embodiments of this utility model have the following beneficial effects: When bonding the first and second chips, the first protrusions within the bonding area of ​​the first chip abut against the second chip, limiting the relative movement of the two chips. Even in cases of uneven force causing excessive pressure on one or both sides of the chip, the first protrusions in the area of ​​greater force on the two chips, after abutting against the second chip, cannot continue to move closer together. The pressure is borne by the first protrusions, preventing chip damage. Simultaneously, other areas of the two chips can continue to be subjected to pressure until bonding is complete, meaning the first protrusions in other areas abut against the second chip. Therefore, the first and second chips in the aforementioned micro-light-emitting structure can be bonded uniformly, thereby improving the unevenness of brightness.

[0017] In addition, during bonding, the multiple recesses arranged around the bonding area and the corresponding second protrusions can fix the first chip and the second chip from different directions, making the first chip and the second chip less prone to displacement when heated, and further improving bonding accuracy.

[0018] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This diagram shows an overall structural schematic of a micro-luminescent structure provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of the first chip in a micro light-emitting structure provided by an embodiment of the present invention is shown.

[0021] Explanation of key component symbols: 100 - First chip; 101 - Bonding area; 110 - First protrusion; 120 - Pixel electrode; 130 - Recess; 200 - Second chip; 210 - Second protrusion. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] It should be noted that when an element is said to be "fixed" to another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is said to be "directly" on another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0024] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the template description is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] The inventors of this application have discovered that during chip bonding, uneven bonding force can easily occur due to the flatness of the equipment itself and the warpage of the chip. If the bonding pressure is too high, the areas of the chip subjected to greater force are more prone to damage. If the bonding pressure is too low, the areas of the chip subjected to less force are more prone to incomplete bonding, which in turn leads to problems such as the center being bright and the sides being dark, or one side being bright and the other side being dark, when the processed product is lit, affecting the display effect.

[0028] In addition, due to the limitations of traditional alignment technology (such as the diffraction limitation of optical alignment and the thermal expansion effect of mechanical alignment) and the influence of chip thermal expansion / thermal stress, the chip is prone to large displacement deviation, resulting in insufficient bonding accuracy, which in turn leads to a decrease in product yield and even pixel tandem, which will also affect the display effect.

[0029] To address the aforementioned technical problems, this embodiment provides a miniature light-emitting structure. Please refer to... Figure 1 The micro-light-emitting structure includes a first chip 100 and a second chip 200.

[0030] The first chip 100 includes a bonding region 101, and a plurality of first protrusions 110 are disposed on the first chip 100, which are distributed within the bonding region 101. Correspondingly, the second chip 200 abuts against the first protrusions 110 during bonding.

[0031] Among them, the first chip 100 is one of the LED chip and the driver chip, and the second chip 200 is the other of the LED chip and the driver chip.

[0032] When the first chip 100 and the second chip 200 are bonded, the first protrusion 110 distributed in the bonding area 101 of the first chip 100 abuts against the second chip 200, which can limit the relative movement distance of the first chip 100 and the second chip 200. Even if uneven force causes heavy pressure on one side or both sides of the chip, the first protrusion 110 in the area of ​​the two chips with greater force abuts against the second chip 200 and cannot continue to move closer. The pressure is shared by the first protrusion 110, preventing chip damage. At the same time, other areas of the two chips can continue to be subjected to pressure until the bonding is in place, that is, the first protrusion 110 in other areas abuts against the second chip 200. Therefore, the first chip 100 and the second chip 200 in the above-mentioned micro light-emitting structure can be bonded uniformly, thereby improving the unevenness of brightness.

[0033] For example, the first protrusion 110 is deposited or etched together with other structures on the first chip 100 during the fabrication process of the first chip 100, and the first protrusion 110 is cylindrical or cuboid in shape.

[0034] In some embodiments, the first chip 100 is an LED chip, and the second chip 200 is a driver chip.

[0035] At this time, the bonding area 101 of the first chip 100 is also the display area of ​​the first chip 100.

[0036] Please combine Figure 2 Furthermore, in some embodiments, the bonding region 101 is provided with a plurality of pixel electrodes 120, and the first protrusion 110 is located between adjacent pixel electrodes 120.

[0037] During bonding, the first protrusion 110 can directly support the surrounding pixel electrode 120, and share the pressure after the pixel electrode 120 is bonded to the pad on the driver chip, preventing damage to the pixel electrode 120 and the pad.

[0038] For example, the first protrusion is located between four adjacent pixel electrodes 120.

[0039] In some embodiments, the height of the pixel electrode 120 is H1, and the height of the first protrusion 110 is H2, satisfying 0.4≤H2 / H1≤0.8.

[0040] Understandably, by ensuring that the height of the first protrusion 110 is not less than 0.4 times the height of the pixel electrode 120, it is possible to ensure that the first protrusion 110 effectively supports the pixel electrode 120, and it is less likely that the pixel electrode 120 and the pad will be over-voltaged, resulting in a short circuit.

[0041] In addition, by ensuring that the height of the first protrusion 110 is no more than 0.8 times the height of the pixel electrode 120, it is possible to avoid inadequate bonding between the pixel electrode 120 and the pad due to the first protrusion 110 being too high.

[0042] Optionally, the ratio of the height of the first protrusion 110 to the height of the pixel electrode 120 can be 0.4, 0.5, 0.6, 0.7, 0.8 or any value between 0.4 and 0.8.

[0043] In some embodiments, the width of the pixel electrode 120 is W1, and the width of the first protrusion 110 is W2, satisfying 0.3≤W2 / W1≤0.6.

[0044] Understandably, making the width of the first protrusion 110 not less than 0.3 times the width of the pixel electrode 120 can ensure that the first protrusion 110 has sufficient support strength, that is, ensure that the first protrusion 110 can share the pressure with the surrounding pixel electrodes 120, thereby ensuring the support effect of the first protrusion 110 on the pixel electrode 120.

[0045] Furthermore, since the first protrusion 110 is deposited or etched together with other structures on the first chip 100, the width of the first protrusion 110 is not greater than 0.6 times the width of the pixel electrode 120, which can avoid the subsequent indium balling process being affected by the first protrusion 110 occupying too much space.

[0046] Optionally, the ratio of the width of the first protrusion 110 to the width of the pixel electrode 120 can be 0.3, 0.4, 0.5, 0.6 or any value between 0.3 and 0.6.

[0047] In some other embodiments, the first chip 100 is a driver chip, and the second chip 200 is an LED chip. In this case, the plurality of first protrusions 110 disposed on the first chip 100 correspond to the display area of ​​the second chip 200.

[0048] Please refer to it again. Figure 1In some embodiments, a recess 130 is provided on the first chip 100, and a corresponding second protrusion 210 is provided on the second chip 200. The height of the second protrusion 210 is greater than the height of the first protrusion 110, and one end of the second protrusion 210 away from the second chip 200 is embedded in the corresponding recess 130.

[0049] During the bonding process of the first chip 100 and the second chip 200, as the first chip 100 and the second chip 200 move closer to each other, the end of the second protrusion 210 away from the second chip 200 is first embedded in the corresponding recess 130 to play a fixing role, so that the first chip 100 and the second chip 200 are less likely to shift when heated, thereby improving the bonding accuracy.

[0050] Understandably, the height of the second protrusion 210 is greater than the height of the first protrusion 110 to ensure that the second protrusion 210 is first embedded in the corresponding recess 130, and then the first protrusion 110 abuts against the second chip 200.

[0051] For example, the second protrusion 210 is deposited or etched together with other structures on the first chip 100 during the fabrication process of the first chip 100, and the second protrusion 210 is cylindrical or cuboid in shape.

[0052] Please refer to the following: Figure 1 and Figure 2 Furthermore, in some embodiments, multiple recesses 130 are provided, and the multiple recesses 130 are arranged around the bonding region 101.

[0053] During bonding, the multiple recesses 130 arranged around the bonding area 101 and the corresponding second protrusions 210 can fix the first chip 100 and the second chip 200 from different directions, making the first chip 100 and the second chip 200 less prone to displacement when heated, and further improving bonding accuracy.

[0054] For example, the bonding region 101 is square. There are four recesses 130, which are located at the four apex corners of the bonding region 101.

[0055] At this time, the four recessed parts 130 and the corresponding second protrusions 210 also serve as mark points, which are the alignment and identification points of the CCD camera before and during bonding.

[0056] In some embodiments, the height difference between the second protrusion 210 and the first protrusion 110 is less than the depth of the recess 130.

[0057] When the first protrusion 110 abuts against the second chip 200, the distance between the first chip 100 and the second chip 200 is equal to the height of the first protrusion 110. Correspondingly, the second protrusion 210 is embedded in the corresponding recess 130, and the distance by which the second protrusion 210 is embedded in the recess 130 is equal to the height difference between the second protrusion 210 and the first protrusion 110.

[0058] Since the height difference is less than the depth of the recess 130, the second protrusion 210 does not contact the bottom surface of the inner wall of the recess 130. That is to say, the second protrusion 210 does not provide support for the first chip 100 and the second chip 200, thus avoiding affecting the bonding of the first chip 100 and the second chip 200.

[0059] In some embodiments, the width of the recess 130 is W3 and the width of the second protrusion 210 is W4, satisfying 0.3μm≤W3-W4≤0.6μm.

[0060] Understandably, due to the existence of alignment error, when the width of the recess 130 is exactly the same as the width of the second protrusion 210, the second protrusion 210 and the recess 130 are not fully aligned, causing the second protrusion 210 to abut against the surface of the first chip 100, which in turn causes the first chip 100 and the second chip 200 to be crushed during bonding.

[0061] If the width of the recessed portion 130 is greater than the width of the second protrusion 210 by more than 0.3 μm, the influence of alignment error can be eliminated, ensuring that the second protrusion 210 can be smoothly embedded in the recessed portion 130.

[0062] Furthermore, by ensuring that the width of the recess 130 and the width of the second protrusion 210 are no more than 0.6 μm, the range of movement of the second protrusion 210 relative to the recess 130 can be limited, thus preventing the second protrusion 210 and the recess 130 from failing to provide a fixing function when they are engaged.

[0063] Optionally, the difference between the width of the recess 130 and the width of the second protrusion 210 can be 0.3μm, 0.4μm, 0.5μm, 0.6μm, or any value between 0.3μm and 0.6μm.

[0064] In summary, when bonding the first chip 100 and the second chip 200, as they approach each other, the second protrusion 210 first embeds into the corresponding recess 130, providing a fixing function. This prevents the first chip 100 and the second chip 200 from shifting when heated, thereby improving bonding accuracy and ultimately enhancing the display effect. Subsequently, the first chip 100 and the second chip 200 continue to approach each other until the first protrusion 110 abuts against the second chip 200, limiting the relative movement distance between them. During this process, even if uneven force causes uneven pressure on one or both sides of the chip, the first protrusion 110 in the area of ​​greater force on the two chips cannot continue to approach after abutting against the second chip 200. The pressure is shared by the first protrusion 110, preventing chip damage. At the same time, other areas of the two chips can continue to be subjected to pressure until bonding is complete. Therefore, the first chip 100 and the second chip 200 in the above-mentioned micro light-emitting structure can be bonded uniformly, thereby improving the unevenness of brightness and darkness, and thus improving the display effect.

[0065] This embodiment also provides a display device, including the above-described micro light-emitting structure.

[0066] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0067] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0068] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A micro-luminescent structure, characterized in that, include: A first chip, the first chip includes a bonding region, and the first chip is provided with a plurality of first protrusions, the plurality of first protrusions being distributed in the bonding region; as well as The second chip abuts against the first protrusion during bonding. The first chip has a recessed portion that is spaced apart on the periphery of the bonding area. The second chip has a corresponding second protrusion that abuts against the wall of the recessed portion during bonding.

2. The micro-light-emitting structure according to claim 1, characterized in that, The first chip is an LED chip, and the second chip is a driver chip.

3. The micro-light-emitting structure according to claim 2, characterized in that, The bonding region is provided with a plurality of pixel electrodes, and the first protrusion is located between adjacent pixel electrodes.

4. The micro-light-emitting structure according to claim 3, characterized in that, The height of the pixel electrode is H1, and the height of the first protrusion is H2, where 0.4 ≤ H2 / H1 ≤ 0.

8.

5. The micro-light-emitting structure according to claim 3, characterized in that, The width of the pixel electrode is W1, and the width of the first protrusion is W2, where 0.3 ≤ W2 / W1 ≤ 0.

6.

6. The micro-light-emitting structure according to any one of claims 1-5, characterized in that, The height of the second protrusion is greater than the height of the first protrusion, and the end of the second protrusion away from the second chip is embedded in the corresponding recess.

7. The micro-light-emitting structure according to claim 6, characterized in that, The height difference between the second protrusion and the first protrusion is less than the depth of the recess.

8. The micro-light-emitting structure according to claim 6, characterized in that, The width of the recess is W3, and the width of the second protrusion is W4, where 0.3μm≤W3-W4≤0.6μm.

9. The micro-light-emitting structure according to claim 6, characterized in that, The recessed portion is provided in multiple ways, and the multiple recessed portions are arranged around the bonding region.

10. A display device, characterized in that, Includes the microluminescent structure according to any one of claims 1-9.

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