Display panel and method for manufacturing display panel

Abstract

The present application provides a display panel comprising: a transparent substrate; a plurality of electrode blocks, each of which is positioned on the transparent substrate and has a light-transmitting slit; a plurality of conductive adhesive blocks, each of which is applied to a surface of an electrode block away from the transparent substrate and partially embedded in a light-transmitting slit of an electrode block; and a plurality of micro-light-emitting diodes, each of which is secured to an electrode block via an adhesive block and electrically connected to the electrode block. The present application also provides a method for manufacturing the display panel.

Description

Technical Field

[0001] The present application relates to the field of display, and in particular to a display panel and a method for preparing the display panel. Background Art

[0002] In the current display technology, micro-light emitting diodes (LEDs) have the characteristics of high brightness and low power consumption, and the micro-LED display panels use self-luminous technology, which has better color performance. In the current production process of micro-LED display panels, non-uniform overflow of adhesive materials will occur during the mass transfer process, resulting in short circuits or skewed micro-LED grains. During the detection and repair process, it is necessary to perform lighting detection on the micro-LED, that is, to power on the micro-LED and detect whether the micro-LED is emitting light. For vertical micro-LEDs, the lighting detection needs to be performed after the upper electrode block is set. If an abnormality is detected, the repair process requires the upper electrode block to be removed, which is costly and difficult to repair. Summary of the Invention

[0003] In one aspect, the present application provides a display panel, comprising:

[0004] Transparent substrate;

[0005] A plurality of electrode blocks, each of which is provided with a light-transmitting slit, is located on the transparent substrate;

[0006] a plurality of conductive adhesive blocks, each adhesive block being coated on a surface of an electrode block away from the transparent substrate, and each adhesive block being partially embedded in a light-transmitting slit of an electrode block;

[0007] A plurality of micro light emitting diodes are provided, each of which is fixed on an electrode block via an adhesive block and electrically connected to the electrode block.

[0008] A height difference is formed between the light-transmitting slit and the electrode block, so that the adhesive block is partially embedded in the light-transmitting slit during the binding process, which helps to avoid overflow of excess adhesive material; at the same time, since the light-transmitting slit increases the contact area between the adhesive block and the electrode block, it helps to improve the adhesion between the micro LED and the electrode block, reduce the resistance of the adhesive block, and thus help to improve the quality of binding.

[0009] In one embodiment, the slit pattern formed by the light-transmitting slits on each of the electrode blocks is partially covered by one of the micro LEDs.

[0010] In one embodiment, the electrode block is made of an opaque conductive material.

[0011] The slit pattern formed by the light-transmitting slit on an opaque electrode block is partially covered by a micro LED, which is conducive to detecting whether the micro LED is emitting light through the uncovered part of the light-transmitting slit during the lighting detection process.

[0012] In one embodiment, the micro-LED is a horizontal micro-LED or a vertical micro-LED.

[0013] Another aspect of the present application provides a method for manufacturing a display panel, comprising:

[0014] providing a transparent substrate;

[0015] forming a plurality of electrode blocks on the transparent substrate;

[0016] A light-transmitting slit is provided on each of the electrode blocks;

[0017] Applying adhesive on the surface of each electrode block away from the transparent substrate;

[0018] A plurality of micro LEDs are transferred onto the transparent substrate, so that each of the micro LEDs is fixed on an electrode block by the adhesive, and the adhesive is partially embedded in the light-transmitting slit of the electrode block.

[0019] The adhesive is partially embedded in the light-transmitting slit of the electrode block, which helps to prevent the micro LED die from tilting during the binding process.

[0020] In one embodiment, the step of transferring the plurality of micro LEDs onto the transparent substrate further includes making the micro LEDs partially cover the light-transmitting slits.

[0021] In one embodiment, after transferring the plurality of micro-LEDs onto the transparent substrate, the preparation method further comprises:

[0022] energizing the plurality of micro LEDs through the electrode block;

[0023] Through the light-transmitting slits, it is detected whether the plurality of micro LEDs emit light.

[0024] In one embodiment, each of the micro LEDs includes a lower electrode located on a side close to the transparent substrate and an upper electrode located on a side away from the transparent substrate.

[0025] In one embodiment, the step of energizing the electrode block is specifically:

[0026] A probe is used to energize the upper electrode of each of the micro-LEDs.

[0027] Partially covering the light-transmitting slit with a micro-LED facilitates detecting whether the vertical micro-LED is emitting light through the slit during the lighting test, avoiding the difficulty of directly detecting the micro-LED's light emission due to the large size of the probe. Using a probe to energize the upper electrode of each micro-LED for lighting test facilitates inspection before installing the electrode layer, optimizing the inspection process and avoiding the need to disassemble the electrode layer when replacing or repairing the micro-LED. This helps save costs, reduces the disassembly process, and reduces technical difficulty.

[0028] In one embodiment, the adhesive block is an ultraviolet bonding adhesive, and the steps of fixing each micro-LED on an electrode block via the adhesive are as follows:

[0029] Light is irradiated through the light-transmitting slit to cure the adhesive.

[0030] The light irradiation through the light-transmitting slits and the curing of the ultraviolet light-bonding adhesive are beneficial to optimizing the binding process and improving the binding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 FIG. 1 is a partial cross-sectional view of a display panel in an embodiment of the present application.

[0032] Figure 2 FIG. 1 is a top view of an electrode block in one embodiment of the present application.

[0033] Figure 3 This is a cross-sectional view of an electrode block and a micro-LED after being bound together in one embodiment of the present application.

[0034] Figure 4 This is a top view of the electrode block in other embodiments of the present application.

[0035] Figure 5 This is a flow chart of display panel preparation in one embodiment of the present application.

[0036] Figure 6 This is a schematic diagram of a principle for detecting a display panel in an embodiment of the present application.

[0037] Description of main component symbols

[0038] Display panel 100

[0039] Transparent substrate 10

[0040] Electrode block 30

[0041] Light transmission slit 31

[0042] Adhesive block 50

[0043] Micro LED 70

[0044] Lower electrode 71

[0045] Upper electrode 73

[0046] Insulation layer 40

[0047] Black Matrix 41

[0048] Planarization layer 80

[0049] Electrode layer 90

[0050] Connecting portion 91

[0051] Electrode portion 93

[0052] Probe a

[0053] Optical inspection machine b

[0054] Steps S1, S2, S3, S4, S5, S6, S7, S8

[0055] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0058] In order to further illustrate the technical means and effects adopted by this application to achieve the intended purpose, the following detailed description of this application is made in conjunction with the accompanying drawings and preferred implementation methods.

[0059] The “micro LED” or “micro light emitting diode” mentioned in this application refers to an inorganic light emitting diode with a size less than 50 μm.

[0060] This embodiment provides a display panel. Figure 1The display panel 100 includes a transparent substrate 10, a plurality of electrode blocks 30, a plurality of adhesive blocks 50, a plurality of micro-LEDs 70, an insulating layer 40, a black matrix 41, a planarization layer 80, and an electrode layer 90. The plurality of electrode blocks 30 are disposed on the transparent substrate 10, each having a light-transmitting slit 31. Adhesive blocks 50 are applied to the side of each electrode block 30 facing away from the transparent substrate 10, and are partially embedded in the light-transmitting slit 31. The micro-LEDs 70 are disposed on the side of the adhesive blocks 50 facing away from the electrode blocks 30, i.e., each micro-LED 70 is bonded to an electrode block 30 via an adhesive block 50. An insulating layer 40 is applied to the side of the transparent substrate 10 where the electrode blocks 30 are disposed, with the electrode blocks 30, adhesive blocks 50, and micro-LEDs 70 embedded in the insulating layer 40. The black matrix 41 is disposed on the side of the insulating layer 40 facing away from the transparent substrate 10, and the planarization layer 80 covers the insulating layer 40 and the black matrix 41. The electrode layer 90 penetrates the planarization layer 80 and is electrically connected to each micro LED 70 .

[0061] In this embodiment, the display panel 100 further includes a driver module (not shown), which can be an integrated circuit, a driver chip, or a combination of multiple chips. The driver module is electrically connected to each electrode block 30, for example, via metal wires, to transmit an electrical signal (e.g., a voltage signal) to each micro-LED 70 attached to the electrode block 30. The electrode layer 90 is a common cathode and is used to transmit the same voltage signal to the multiple micro-LEDs 70. The voltage signal transmitted by the driver module is different from the voltage signal transmitted by the electrode layer 90, so as to form a voltage difference between the two electrodes of the micro-LED 70, thereby driving the micro-LED 70 to emit light. Whether each micro-LED 70 emits light and the brightness of the light can be controlled by the driver module.

[0062] Please also refer to Figure 2 and Figure 3, in this embodiment, the light-transmitting slit 31 forms a slit pattern on the electrode block 30. The slit pattern is in the shape of a "rice" character, that is, four light-transmitting slits 31 intersect at the geometric center of the electrode block 30, and an angle of 45° can be formed between any two adjacent light-transmitting slits 31. The bonding block 50 is provided at the center position of the slit pattern. The micro-LED 70 is provided on the bonding block 50 and partially covers the slit pattern. Part of the light-transmitting slit 31 is embedded by the bonding block 50. The slit pattern formed by the light-transmitting slits 31 forms a height difference with the electrode block 30, so that the light-transmitting slit can be used to accommodate part of the bonding block 50. The micro-LED 70 partially covers the slit pattern, and part of the slit space can be reserved, so that the extra bonding block 50 extends into the uncovered slit space, avoiding the non-uniform overflow of the bonding block 50 and the short circuit caused by the overflow. Since part of the bonding block 50 is embedded in the light-transmitting slit 31, the contact area between the bonding block 50 and the electrode block 30 is increased, thereby increasing the adhesion between the bonding block 50 and the electrode block 30, which is equivalent to improving the adhesion between the micro-LED 70 and the electrode block 30. At the same time, due to the increase in the contact area, the relative resistance value of the bonding block 50 is reduced, improving the ohmic contact between the micro-LED 70 and the electrode block 30.

[0063] Please refer to Figure 4 , in other embodiments, the slit pattern formed by the light-transmitting slit 31 on the electrode block 30 can also be an "S" shape (refer to Figure 4 Figure (A) therein), snowflake shape (refer to Figure 4 Figure (B) therein), "卍" shape (refer to Figure 4 Figure (C) therein), snake shape (refer to Figure 4 Figure (D) therein), corridor shape (refer to Figure 4 Figure (E) therein), stripe shape (refer to Figure 4 Figure (F) therein) or mesh shape (refer to Figure 4 Figure (G) therein) and other patterns partially covered by the micro-LED 70. That is, there is a part of the slit pattern that is not covered by the micro-LED 70, which is used to accommodate the extra part of the bonding block 50 when the bonding block 50 overflows.

[0064] Please refer to again Figure 1 , in this embodiment, the micro-LED 70 is a vertical micro-LED, that is, the micro-LED 70 includes a lower electrode 71 close to the electrode block 30 and an upper electrode 73 far from the electrode block 30. The lower electrode 71 and the upper electrode 73 are respectively located at the opposite upper and lower ends of the micro-LED 70. In other embodiments, the micro-LED 70 can also be a horizontal micro-LED, that is, the two electrodes of the micro-LED 70 are located at the same end of the micro-LED 70.

[0065] In this embodiment, the material of the transparent substrate 10 can be glass or other transparent materials.

[0066] In this embodiment, the electrode block 30 is made of a light-proof metal conductive material. In other embodiments, the electrode block 30 may also be made of other conductive materials such as transparent conductive oxides.

[0067] In this embodiment, the adhesive block 50 is a conductive light-curing adhesive. In other embodiments, the adhesive block 50 can also be a conductive bonding material such as silver glue, bonding adhesive, or flux.

[0068] In this embodiment, the insulating layer 40 is made of a dielectric material. A black matrix 41 is provided around each micro-LED 70 to separate the light emitted by each micro-LED 70 and prevent light mixing. The planarization layer 80 is made of an organic material and is used to adjust the height differences caused by the different functional layers on the display panel 100, preventing electric field interference and reducing power consumption.

[0069] In this embodiment, electrode layer 90 includes a connection portion 91 for electrically connecting to the upper electrode 73 of the micro-LED 70, and an electrode portion 93 disposed on the planarization layer 80. Electrode portion 93 is located within the coverage area of the black matrix 41. Connection portion 91 is made of indium tin oxide, while electrode portion 93 can be made of an opaque metallic conductive material. In other embodiments, connection portion 91 can be made of other transparent conductive materials.

[0070] This embodiment also provides a method for preparing a display panel. Figure 5 , a method for preparing a display panel includes:

[0071] Step S1: providing a transparent substrate;

[0072] Step S2: forming a plurality of electrode blocks on the transparent substrate;

[0073] Step S3: forming a light-transmitting slit on each of the electrode blocks;

[0074] Step S4: applying an adhesive block on the surface of each electrode block away from the transparent substrate;

[0075] Step S5: transferring a plurality of micro LEDs onto the transparent substrate, such that each micro LED is fixed to an electrode block via an adhesive block;

[0076] Step S6: providing an insulating layer between each group of electrode blocks and micro-LEDs, and providing a black matrix on the insulating layer;

[0077] Step S7: energizing the plurality of micro LEDs through the electrode blocks;

[0078] Step S8: detecting whether the plurality of micro LEDs are emitting light through the light-transmitting slits.

[0079] In this embodiment, step S2 further includes providing a driving module, and electrically connecting each electrode block to the driving module.

[0080] In this embodiment, the method for forming the light-transmitting slit in step S3 may be photolithography, laser engraving, or other methods that can form the light-transmitting slit on the electrode block.

[0081] In this embodiment, the adhesive is applied in step S4 by dispensing, with the adhesive partially covering the light-transmitting slits 31. In step S5, the micro-LEDs 70 are transferred to the transparent substrate 10 by transferring each micro-LED 70 onto the adhesive on each electrode block 30. Due to the gravity of the micro-LEDs 70 themselves, the adhesive is partially pressed into the light-transmitting slits 31. In one embodiment, a certain amount of pressure can be applied to the micro-LEDs 70 during transfer to the electrode blocks 30. This allows the overflowing adhesive to enter the light-transmitting slits 31 under pressure, preventing the micro-LEDs 70 from skewing after bonding due to uneven diffusion of the adhesive.

[0082] In this embodiment, the adhesive applied in step S4 is a UV-curable adhesive. In step S5, each micro-LED 70 is fixed to an electrode block 30 via the adhesive by irradiating the transparent substrate 10 with ultraviolet light from a side away from the electrode block 30. The ultraviolet light passes through the light-transmitting slits 31 and irradiates the adhesive, causing it to solidify into a bonded block 50, thus completing the bonding process. In other embodiments, the adhesive may be silver glue or a crystal-curable adhesive. In this case, thermal curing may be used to solidify the adhesive into a bonded block 50, completing the bonding process.

[0083] In this embodiment, step S5 also includes making the micro LED 70 partially cover the light-transmitting slit 31, that is, there is a part of the light-transmitting slit 31 that is not covered by the micro LED 70, and the part of the light-transmitting slit 31 that is not covered by the micro LED 70 is transparent, and the micro LED 70 can be lit and detected through the light-transmitting slit 31, that is, executing steps S7 and S8.

[0084] See also Figure 6In this embodiment, step S7 further includes energizing the top electrode 73 of each micro-LED 70 using a probe a. Specifically, probe a applies a test voltage to the top electrode 73 of each micro-LED 70, thereby creating a voltage difference between the top electrode 73 and the bottom electrode 71 of each micro-LED 70, driving the micro-LED 70 to emit light. Step S8 specifically involves positioning an optical inspection machine b on the side of the transparent substrate 10 away from the micro-LEDs 70, pointing toward the micro-LEDs 70 electrically connected to probe a. When power is applied to the micro-LEDs 70, optical inspection machine b can detect whether the micro-LEDs 70 emit light through the light-transmitting portion of the light-transmitting slits 31, thereby inspecting the quality of the micro-LEDs 70. Because the micro-LEDs 70 are sized between 1 and 50 μm, the cross-section of the probe tip is much larger than the micro-LEDs 70. This makes it difficult to detect light emission from the top electrode 73 side of the micro-LEDs 70 when power is applied. Therefore, light emission from the micro-LEDs 70 can be detected from the other side of the display panel 100 through the light-transmitting slits 31. In this embodiment, a probe is used to energize the upper electrode 73 of the micro-LED 70, allowing the micro-LED 70 to be illuminated before the electrode layer 90 is installed. This avoids the need to disassemble the electrode layer 90 when replacing or repairing the micro-LED 70, thereby saving costs, simplifying the disassembly and assembly process, and reducing technical difficulty. In other embodiments, the optical inspection machine b can also be located on the side of the transparent substrate 10 close to the micro-LED 70 to receive light from the micro-LED 70 that is not blocked by the probe a. That is, the optical inspection machine b can be located at any position on the same side as the probe a that can receive light emitted by the micro-LED 70. In this way, the micro-LED 70 can also be illuminated before the electrode layer 90 is installed.

[0085] In other embodiments, the electrode block 30 may be made of a transparent conductive material. In this case, the lighting detection process can be performed either through the light-transmitting slit 31 or directly through the electrode block 30. The micro-LEDs 70 may also be horizontal micro-LEDs. In this case, step S7 does not require the use of probe a to energize each micro-LED 70. Step S8 also does not require the detection of whether the micro-LEDs 70 are emitting light through the light-transmitting slit 31. In other words, the optical inspection machine b can also perform lighting detection on the side of the transparent substrate 10 closest to the micro-LEDs 70.

[0086] In this embodiment, lighting detection specifically involves energizing each micro-LED 70 and detecting its light emission using a probe a and an optical inspection device b. In other embodiments, three micro-LEDs 70 can be grouped together, each group comprising red, green, and blue micro-LEDs 70. Power can be applied to each group of micro-LEDs 70 at a time, and the light emission of each group can be directly detected. Sampling testing can also be performed, such as inspecting the light emission of one micro-LED 70 every three micro-LEDs 70, to determine the overall yield rate.

[0087] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present application and are not intended to limit the present application. As long as they are within the spirit of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.

Claims

1. A display panel, characterized in that: include: Transparent substrate; A plurality of electrode blocks, each of which is provided with a light-transmitting slit; a plurality of conductive adhesive blocks, each of the adhesive blocks being coated on a surface of the electrode block away from the transparent substrate, and each of the adhesive blocks being partially embedded in the light-transmitting slit of the electrode block; a plurality of micro light emitting diodes, each of the micro light emitting diodes being fixed to one of the electrode blocks via one of the adhesive blocks and being electrically connected to the electrode block; The light-transmitting slit is used to allow the light emitted by the corresponding micro-LED to be transmitted and emitted from a side of the transparent substrate away from the electrode block.

2. The display panel according to claim 1, wherein The slit pattern formed by the light-transmitting slits on each of the electrode blocks is partially covered by a micro-LED.

3. The display panel according to claim 1, wherein The electrode block is made of an opaque conductive material.

4. The display panel according to claim 1, wherein: The micro light emitting diode is a horizontal micro light emitting diode or a vertical micro light emitting diode.

5. A method for preparing a display panel, for preparing the display panel according to any one of claims 1 to 4, characterized in that: include: providing a transparent substrate; forming a plurality of electrode blocks on the transparent substrate; A light-transmitting slit is provided on each of the electrode blocks; Applying a conductive adhesive on the surface of each electrode block away from the transparent substrate; Transferring a plurality of the micro-LEDs onto the transparent substrate, such that each of the micro-LEDs is fixed to one of the electrode blocks by the adhesive, and the adhesive is partially embedded in the light-transmitting slits of the electrode blocks; The light-transmitting slit is used to allow the light emitted by the corresponding micro-LED to be transmitted and emitted from a side of the transparent substrate away from the electrode block.

6. The method for manufacturing a display panel according to claim 5, wherein: The step of transferring the plurality of micro-LEDs onto the transparent substrate further includes allowing the micro-LEDs to partially cover the light-transmitting slits.

7. The method for manufacturing a display panel according to claim 5, wherein: After transferring the plurality of micro-LEDs onto the transparent substrate, the preparation method further comprises: energizing the plurality of micro light emitting diodes through the electrode block; Through the light-transmitting slits, it is detected whether the plurality of micro-LEDs emit light.

8. The method for manufacturing a display panel according to claim 7, wherein: Each of the micro light emitting diodes includes a lower electrode located at a side close to the transparent substrate and an upper electrode located at a side away from the transparent substrate.

9. The method for manufacturing a display panel according to claim 8, wherein: The step of energizing the electrode block is specifically as follows: A probe is used to energize the upper electrode of each of the micro-LEDs.

10. The method for manufacturing a display panel according to claim 5, wherein: The adhesive is a UV-curable adhesive, and the steps of fixing each of the micro-LEDs on one of the electrode blocks by the adhesive are as follows: Light is irradiated through the light-transmitting slit to cure the adhesive.

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