Driving backplane and display panel

Abstract

The application discloses a driving backboard and a display panel. The driving backboard comprises a substrate, a pad layer arranged on one side of the substrate and comprising a pad, and a connecting column arranged on the pad. The side surface of the connecting column is a slope surface, and the slope angle of the slope surface ranges from 30 degrees to 50 degrees. The application can avoid the phenomenon of dark spots after the light emitting element is electrically connected with the driving backboard.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a driving backplane and a display panel. Background Technology

[0002] Micro-LED display technology mainly includes epitaxial fabrication, integration, and driving technology. Among them, integration technology is the link between the other two technologies, effectively connecting the Micro-LED to the driving backplane.

[0003] However, the inventors of this application have discovered that after electrically connecting the Micro-LED to the driver backplane, dark spots often occur due to short circuits. Utility Model Content

[0004] This application provides a driver backplane and a display panel that can avoid dark spots that occur after the light-emitting element is electrically connected to the driver backplane.

[0005] A first aspect of this application provides a drive backplane, the drive backplane comprising: Substrate; A pad layer is disposed on one side of the substrate and includes pads; A connecting post is disposed on the pad and electrically connected to the pad, wherein the side of the connecting post is a sloped surface and the slope angle of the sloped surface is in the range of 30° to 50°.

[0006] The drive backplate further includes: An insulating layer is disposed on the side of the pad layer away from the substrate. The insulating layer has an opening corresponding to the pad. A portion of the surface of the pad away from the substrate is exposed in the opening. The connecting post is electrically connected to the pad through the opening. Preferably, the insulating layer is made of inorganic materials.

[0007] In the direction away from the substrate, the width of the pad decreases, and the distance between the orthogonal projection boundary of the opening on the substrate and the orthogonal projection boundary of the pad on the substrate ranges from 2 to 5 micrometers. Preferably, the orthographic projection of the connecting post on the substrate covers the orthographic projection of the opening on the substrate, and the orthographic projection of the connecting post on the substrate further extends beyond the orthographic projection of the opening on the substrate.

[0008] The pads are made of copper, and the connecting posts are made of tin.

[0009] The slope angle of the slope is in the range of 40° to 50°.

[0010] A second aspect of this application provides a display panel, the display panel comprising: Drive backplane as described in any of the above; The light-emitting element includes a light-emitting body and an electrode connected to the light-emitting body, wherein the electrode is electrically connected to the pad via the connecting post.

[0011] The pad layer includes a plurality of pads, the plurality of pads including a first pad and a second pad spaced apart, the connecting posts on the first pad and the second pad are respectively a first connecting post and a second connecting post, the light-emitting element includes a plurality of electrodes, the plurality of electrodes including a first electrode and a second electrode, the first electrode is electrically connected to the first pad through the first connecting post, and the second electrode is electrically connected to the second pad through the second connecting post; The first electrode and the second electrode have a first groove and a second groove respectively on their surfaces facing the drive back plate. The depth of the second groove is greater than the depth of the first groove. The second groove is filled with a target medium, which is located between the second electrode and the second connecting post.

[0012] The target medium is made of organic materials; Preferably, the material of the target medium includes photoresist.

[0013] Wherein, the surface of the target medium facing away from the light-emitting body is on the same plane as the bottom of the first groove; Preferably, the first electrode is a P-type electrode and the second electrode is an N-type electrode.

[0014] A filling layer is formed between the two connecting posts; Preferably, the material of the filler layer includes organic materials.

[0015] The beneficial effects are: the slope angle θ of the side of the connecting post is set to be in the range of 30°~50°, so that the side of the connecting post is relatively flat. Therefore, when the light-emitting element is bonded and electrically connected to the driving backplate, part of the force of the light-emitting element pressing the connecting post is inclined relative to the connecting post, thereby reducing the deformation of the connecting post, avoiding short circuits between the electrodes of the light-emitting element, and avoiding the dark spot phenomenon after the light-emitting element is electrically connected to the driving backplate. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of one embodiment of the drive backplane of this application; Figure 2 It is Figure 1 A schematic diagram of the structure when the driving backplate and the light-emitting element are bonded together; Figure 3 It is Figure 1 A schematic diagram of the structure after the driving backplate and the light-emitting element are bonded together; Figure 4 This is a schematic diagram of the structure of one embodiment of the display panel of this application; Figure 5 yes Figure 4 A schematic diagram of the structure of the light-emitting element; Figure 6 This is a schematic diagram of another embodiment of the display panel of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] It should be noted that the terms "first" and "second" in this application 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. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0019] See Figure 1 and Figure 2 , Figure 1This is a schematic diagram of one embodiment of the drive backplane of this application. Figure 2 It is Figure 1 The diagram shows the structure of the driving backplane and the light-emitting element being bonded together. The driving backplane 100 includes a substrate 111, a pad layer 120, and a connecting post 130.

[0020] The substrate 111 serves as a support and protector in the drive backplane 100. It can be flexible, for example, the material of the substrate 111 is polyimide (PI), or the substrate 111 is a multilayer structure with alternating organic and inorganic layers. Of course, the substrate 111 can also be rigid, for example, the material of the substrate 111 can be glass or metal. In summary, this application does not limit the structure of the substrate 111.

[0021] A pad layer 120 is disposed on one side of the substrate 111 and includes pads 121. An array layer 112 is further disposed between the substrate 111 and the pad layer 120. The array layer 112 includes a driving circuit. After the light-emitting element 10 is transferred to the driving backplane 100 and electrically connected to the driving backplane 100, the driving circuit drives the light-emitting element 10 to emit light. Simultaneously, the pads 121 are electrically connected to the driving circuit in the array layer 112 to realize signal transmission between the light-emitting element 10 and the driving circuit. The pad layer 120 includes multiple pads 121, which are spaced apart. Each pad 121 includes a first pad and a second pad, which are spaced apart. After bonding, the first pad and the second pad are electrically connected to the first electrode and the second electrode of the light-emitting element 10, respectively.

[0022] Connecting posts 130 are disposed on and electrically connected to pads 121. In one embodiment, each pad 121 is provided with a connecting post 130. The side surface of the connecting post 130 is a sloped surface, and the slope angle θ of the sloped surface ranges from 30° to 50°. Specifically, the connecting post 130 is used to realize the electrical connection between the light-emitting element 10 and the pad 121, and its material can be solder. In the direction away from the substrate 111, the width of the connecting post 130 gradually decreases, that is, the side surface of the connecting post 130 is inclined relative to the substrate 111 and is a sloped surface, and the angle (i.e., slope angle θ) formed between the side surface of the connecting post 130 and the substrate 111 ranges from 30° to 50°, for example, specifically 30°, 40°, or 50°.

[0023] When the slope angle θ of the side of the connecting post 130 is greater than 50°, for example, the slope angle θ is in the range of 70°~80°, or the slope angle θ is 90°, because the side of the connecting post 130 is relatively steep, when the light-emitting element 10 is bonded and electrically connected to the driving back plate 100, the force of the light-emitting element 10 pressing the connecting post 130 is almost entirely perpendicular to the connecting post 130, resulting in a large deformation of the connecting post 130, for example, the deformation of the connecting post 130 is between 0 micrometers and 4 micrometers. If the light-emitting element 10 is misaligned relative to the driving back plate 100 during the transfer process and the misalignment is greater than 5 micrometers, the electrodes of the light-emitting element 10 will further compress and pull the connecting post 130 to deform, which will cause a short circuit between the electrodes of the light-emitting element 10, resulting in the light-emitting element 10 being unable to emit light and forming a dark spot phenomenon.

[0024] In this application, the slope angle θ of the side of the connecting post 130 is set to be in the range of 30°~50°, making the side of the connecting post 130 relatively gentle. Therefore, when the light-emitting element 10 is bonded and electrically connected to the driving backplate 100, part of the force exerted by the light-emitting element 10 on the connecting post 130 is inclined relative to the connecting post 130 (e.g., ...). Figure 2 (As shown by the red arrow in the middle), thereby reducing the deformation of the connecting post 130, preventing short circuits between the electrodes of the light-emitting element 10, and avoiding dark spots that may appear after the light-emitting element 10 is electrically connected to the driving backplate 100 (such as...). Figure 3 (As shown).

[0025] In one embodiment, the slope angle θ formed between the side of the pad 121 and the substrate 111 is in the range of 40° to 50°, for example, 40°, 45°, or 50°. This angle range can prevent the slope angle θ from being too small, resulting in too small a contact area between the electrode of the light-emitting element 10 and the pad 121, and can also prevent the slope angle θ from being too large, resulting in too large a deformation of the connecting post 130 during the bonding process. It should be noted that this application does not impose a specific limitation on the size of the slope angle θ, as long as it is within the range of 30° to 50°, and can be selected and set according to actual needs.

[0026] In one embodiment, the pad 121 is made of copper, and the connecting post 130 is made of tin.

[0027] Specifically, copper is a common metal that is readily available and has good electrical conductivity. Setting the material of pad 121 to copper can reduce costs and ensure good signal transmission. Tin is a common solder, and setting the material of connecting post 130 to tin can ensure a good electrical connection between the light-emitting element 10 and the driving backplane 100.

[0028] It should be noted that this application does not impose specific restrictions on the materials of the pads 121 and the connecting posts 130, as long as they can achieve the conductivity function. For example, in other embodiments, the material of the pads 121 can be gold, and the material of the connecting posts 130 can include lead in addition to tin.

[0029] Continue reading Figure 1 In one embodiment, the drive backplane 100 further includes an insulating layer 140.

[0030] An insulating layer 140 is disposed on the side of the pad layer 120 away from the substrate 111. The insulating layer 140 has an opening 141 corresponding to the pad 121. A portion of the surface of the pad 121 away from the substrate 111 is exposed in the opening 141. At the same time, the connecting post 130 is electrically connected to the pad 121 through the opening 141.

[0031] Specifically, a portion of the surface of the pad 121 facing away from the substrate 111 is exposed in the opening 141, while another portion is covered by the insulating layer 140. It is understood that the connecting post 130 is disposed above the portion of the pad 121 exposed in the opening 141, thereby achieving electrical connection between the connecting post 130 and the pad 121. It is also understood that when there are multiple pads 121, the insulating layer 140 has multiple openings 141, each corresponding to a specific pad 121, with a portion of the surface of the pad 121 facing away from the substrate 111 exposed in the corresponding opening 141.

[0032] In one aspect, the insulating layer 140 can protect the pads 121, prevent the migration of metal ions from the pads, avoid short circuits, and prevent the pads 121 from being oxidized and corroded by external moisture. In another aspect, the insulating layer 140 can also withstand the extrusion pressure during the bonding process, preventing the connecting post 130 from being squeezed between the two pads 121 and causing a short circuit between the two pads 121.

[0033] In one embodiment, the material of the insulating layer 140 includes an inorganic material, such as at least one selected from silicon dioxide, silicon nitride, and silicon oxynitride. In one embodiment, the thickness of the insulating layer 140 ranges from 2600 angstroms to 2800 angstroms, for example, 2600 angstroms, 2700 angstroms, or 2800 angstroms. In short, this application does not limit the specific structure of the insulating layer 140.

[0034] Continue reading Figure 1 In one embodiment, the width of the pad 121 is reduced in the direction away from the substrate 111, and the distance L between the orthogonal projection boundary of the opening 141 on the substrate 111 and the orthogonal projection boundary of the pad 121 on the substrate 111 ranges from 2 micrometers to 5 micrometers.

[0035] It is understandable that, since the width of the pad 121 decreases in the direction away from the substrate 111, the orthogonal projection of the pad 121 on the substrate 111 is the orthogonal projection of the end of the pad 121 closest to the substrate 111 on the substrate 111.

[0036] During the bonding process, the connecting post 130 and the pad 121 form an alloy. This alloying process involves expansion and deformation, which can affect the adhesion between the insulating layer 140 and the pad 121, and may also cause cracks in the insulating layer 140. Ultimately, this can lead to ion migration from the pad 121 and a short circuit. Setting L to a range of 2 micrometers to 5 micrometers reduces the area of ​​alloy formation between the connecting post 130 and the pad 121, while increasing the contact area between the pad 121 and the insulating layer 140. This strengthens the connection between the pad 121 and the insulating layer 140, preventing the insulating layer 140 from splitting during the alloying process and preventing cracks from forming in the insulating layer 140, thus avoiding short circuits caused by ion migration.

[0037] The distance L between the orthographic projection boundary of the opening 141 on the substrate 111 and the orthographic projection boundary of the pad 121 on the substrate 111 can be 2 micrometers, 3 micrometers, 4 micrometers or 5 micrometers, etc., and can be selected and set according to actual needs.

[0038] In one embodiment, the cross-section of the pad 121 perpendicular to the substrate 111 is trapezoidal.

[0039] Continue reading Figure 1 In one embodiment, the orthographic projection of the connecting post 130 on the substrate 111 covers the orthographic projection of the opening 141 on the substrate 111, and the orthographic projection of the connecting post 130 on the substrate 111 further extends beyond the orthographic projection of the opening 141 on the substrate 111.

[0040] Specifically, the connecting post 130 covers the opening 141 and further covers a portion of the insulating layer 140, which ensures a stable connection between the light-emitting element 10 and the driving backplate 100.

[0041] See Figure 4 as well as Figure 5 In one embodiment of this application, the display panel includes a driving backplate 100 and a light-emitting element 200.

[0042] The drive backplane 100 has the same structure as the drive backplane 100 in any of the above embodiments, and can be found in the relevant content above, which will not be repeated here.

[0043] The light-emitting element 200 includes a light-emitting body 210 and an electrode 220 connected to the light-emitting body 210. The electrode 220 is electrically connected to the pad 121 through a connecting post 130.

[0044] In one embodiment, the display panel may be a Micro-LED display panel (Micro Light Emitting Diode). In other embodiments, the display panel may also be an LCD display panel (Liquid Crystal Display) or an OLED display panel (Organic Light-Emitting Diode), or other types of display panels. This application does not impose specific limitations on the type of display panel.

[0045] In one embodiment, the pad layer 120 includes a plurality of pads 121, the plurality of pads 121 including a first pad 121a and a second pad 121b spaced apart, the connecting posts on the first pad 121a and the second pad 121b being a first connecting post 130a and a second connecting post 130b, respectively; the light-emitting element 200 includes a plurality of electrodes 220, the plurality of electrodes 220 including a first electrode 220a and a second electrode 220b, the first electrode 220a being electrically connected to the first pad 121a through the first connecting post 130a, and the second electrode 220b being electrically connected to the second pad 121b through the second connecting post 130b; The first electrode 220a and the second electrode 220b are respectively provided with a first groove 221a and a second groove 221b on the surface facing the drive back plate 100. The depth of the second groove 221b is greater than the depth of the first groove 221a. The second groove 221b is filled with a target medium 230, which is located between the second electrode 220b and the second connecting post 130b.

[0046] Specifically, during the bonding process, the first electrode 220a is electrically connected to the first pad 121a through the first connecting post 130a, and the second electrode 220b is electrically connected to the second pad 121b through the second connecting post 130b, thereby realizing the electrical connection between the light-emitting element 200 and the driving backplane 100.

[0047] Due to the inherent properties of the light-emitting element 200, the depth of the second groove 221b on the second electrode 220b is greater than the depth of the first groove 221a on the first electrode 220a. Therefore, during the bonding process, the second connecting post 130b needs to fill a larger space than the first connecting post 130a. After bonding, the volume of the second connecting post 130b is larger than the volume of the first connecting post 130a. Consequently, the second connecting post 130b is prone to forming voids during the bonding process. When the display panel operates in a high-temperature and high-humidity environment, the presence of voids in the second connecting post 130b can easily cause the second electrode 220b to peel off from the second pad 121b, resulting in the light-emitting element 200 failing to emit light normally and forming a dark spot phenomenon.

[0048] In the above embodiment, the target medium 230 filled in the second groove 221b reduces the depth of the second groove 221b, which can reduce the height of the second connecting post 130b being pulled up during the bonding process, thereby improving or avoiding the formation of voids in the second connecting post 130b during the bonding process, and thus improving or avoiding the above-mentioned dark spot phenomenon.

[0049] In one embodiment, the first electrode 220a is a P-type electrode and the second electrode 220b is an N-type electrode. In other embodiments, the first electrode 220a may also be an N-type electrode and the second electrode 220b may be a P-type electrode. This application does not impose specific limitations on the types of the first electrode 220a and the second electrode 220b.

[0050] The target medium 230 can be an insulating material or a conductive material.

[0051] In one embodiment, the material of the target medium 230 includes an organic material. Specifically, organic materials are common in the display panel industry and have good leveling properties. Therefore, setting the material of the target medium 230 to be an organic material can reduce costs and also ensure the flatness of the target medium 230 in the second groove 221b, avoiding the formation of voids in the second connecting post 130b during the bonding process.

[0052] In one embodiment, the target medium 230 is made of photoresist. During the filling of the target medium 230 into the second groove 221b, a material layer can be formed over the entire surface first. This material layer is then exposed and developed, leaving only the material layer in the second groove 221b, thus obtaining the target medium 230 filled in the second groove 221b. Of course, in other embodiments, the target medium 230 can also be an organic material without photosensitive properties, or it can be an inorganic material. In short, this application does not limit the specific material of the target medium 230.

[0053] In one embodiment, the surface of the target medium 230 facing away from the light-emitting body 210 is on the same plane as the bottom of the first groove 221a.

[0054] Specifically, the surface of the target medium 230 facing away from the light-emitting body 210 is set to be on the same plane as the bottom of the first groove 221a, so that during the bonding process, the depth of the first groove 221a relative to the first connecting post 130a is equal to the depth of the second groove 221b relative to the second connecting post 130b, thereby avoiding the formation of voids in the first connecting post 130a and the second connecting post 130b during the bonding process.

[0055] Of course, in other embodiments, the surface of the target medium 230 away from the light-emitting body 210 and the bottom of the first groove 221a may not be on the same plane.

[0056] See Figure 4 In one embodiment, a filling layer 240 is formed between two adjacent connecting posts 130.

[0057] Specifically, before bonding the light-emitting element 200 to the driving backplate 100, a filler layer 240 covering the connecting post 130 is formed on the driving backplate 100. Then, the light-emitting element 200 is transferred to the driving backplate 100. At this time, the light-emitting element 200 can be pre-fixed to the driving backplate 100 through the filler layer 240, which can prevent the light-emitting element 200 from being misaligned. Then, the light-emitting element 200 and the driving backplate 100 are pressed together. In this pressing process, the electrode 220 of the light-emitting element 200 passes through the filler layer 240 and is electrically connected to the pad 121 through the connecting post 130. Finally, the filler layer 240 is disposed between two adjacent connecting posts 130.

[0058] In one embodiment, the filler layer 240 is made of an organic material. Organic materials have good leveling properties, which can ensure the flatness of the display panel. Since there is no need to pattern the filler layer 240, an organic material without photosensitive properties can be used. Specifically, the filler layer 240 can be made of materials such as polyimide (PI), polyamide, or benzocyclobutene (BCB). This application does not limit the specific material of the filler layer 240.

[0059] See Figure 6 In other embodiments, the filling layer 240 may not be provided.

[0060] Additionally, this application also includes a display device, which includes the display panel in any of the above embodiments. The display device may include a device with image processing capabilities, such as a mobile phone, desktop computer, laptop computer, tablet computer, vehicle display, wearable device, etc.

[0061] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A drive backplane, characterized in that, The drive backplate includes: Substrate; A pad layer is disposed on one side of the substrate and includes pads; A connecting post is disposed on the pad and electrically connected to the pad, wherein the side of the connecting post is a sloped surface and the slope angle of the sloped surface is in the range of 30° to 50°.

2. The drive backplane according to claim 1, characterized in that, The drive backplane further includes: An insulating layer is disposed on the side of the pad layer facing away from the substrate. The insulating layer has an opening corresponding to the pad. A portion of the surface of the pad facing away from the substrate is exposed in the opening. The connecting post is electrically connected to the pad through the opening.

3. The drive backplane according to claim 2, characterized in that, The insulating layer is made of inorganic materials.

4. The drive backplane according to claim 2, characterized in that, In the direction away from the substrate, the width of the pad decreases, and the distance between the orthographic projection boundary of the opening on the substrate and the orthographic projection boundary of the pad on the substrate ranges from 2 micrometers to 5 micrometers.

5. The drive backplane according to claim 2, characterized in that, The orthographic projection of the connecting post on the substrate covers the orthographic projection of the opening on the substrate, and the orthographic projection of the connecting post on the substrate further extends beyond the orthographic projection of the opening on the substrate.

6. The drive backplane according to claim 1, characterized in that, The pads are made of copper, and the connecting posts are made of tin.

7. The drive backplane according to claim 1, characterized in that, The slope angle of the slope is in the range of 40° to 50°.

8. A display panel, characterized in that, include: The drive backplate as described in any one of claims 1 to 7; The light-emitting element includes a light-emitting body and an electrode connected to the light-emitting body, wherein the electrode is electrically connected to the pad via the connecting post.

9. The display panel according to claim 8, characterized in that, The pad layer includes a plurality of pads, the plurality of pads including a first pad and a second pad spaced apart, the connecting posts on the first pad and the second pad being a first connecting post and a second connecting post, respectively; the light-emitting element includes a plurality of electrodes, the plurality of electrodes including a first electrode and a second electrode, the first electrode being electrically connected to the first pad through the first connecting post, and the second electrode being electrically connected to the second pad through the second connecting post; The first electrode and the second electrode have a first groove and a second groove respectively on their surfaces facing the drive back plate. The depth of the second groove is greater than the depth of the first groove. The second groove is filled with a target medium, which is located between the second electrode and the second connecting post.

10. The display panel according to claim 9, characterized in that, The target medium is made of organic materials.

11. The display panel according to claim 10, characterized in that, The material of the target medium includes photoresist.

12. The display panel according to claim 9, characterized in that, The surface of the target medium facing away from the light-emitting body is on the same plane as the bottom of the first groove.

13. The display panel according to claim 9, characterized in that, The first electrode is a P-type electrode, and the second electrode is an N-type electrode.

14. The display panel according to claim 8, characterized in that, A filling layer is formed between the two connecting posts.

15. The display panel according to claim 14, characterized in that, The filling layer is made of organic materials.

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