A display panel, a preparation method thereof, and an electronic device

Abstract

The present application relates to a display panel, a preparation method thereof, and an electronic device. Since an adhesive layer is formed on the chip carrier surface through the protection block array, during the die bonding process, not only can the chip electrodes be bonded to the electrodes on the board through the bonding material, but also the LED chips can be bonded by the adhesive layer provided on the driving substrate. The adhesive force of the adhesive layer on the epitaxial layer of the LED chip is utilized to increase the tensile force received by the LED chip in the direction towards the driving substrate. By increasing the physical bonding reliability between the LED chip and the driving substrate, the reliability of the electrical connection between the chip electrodes and the electrodes on the board is improved, and the quality of the display panel is enhanced.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a display panel, a preparation method thereof, and an electronic device. Background Art

[0002] During the preparation process of a display panel, a huge number of LED chips need to be transferred to a driving substrate and die-bonded. In the die-bonding process, bonding materials such as solder paste and silver glue can be used to fix the LED chips to the driving substrate while realizing the electrical connection between the LED chips and the driving substrate. However, due to the small die-bonding thrust of the LED chips, it is easy to cause the connection between the LED chips and the driving substrate to be damaged, resulting in dead pixels. Especially during the transportation of the display panel, because of frequent collisions, the LED chips may also fall off the driving substrate, affecting the reliability of the display panel.

[0003] Therefore, how to improve the reliability of the bonding between the LED chips and the driving substrate and enhance the quality of the display panel is an urgent problem to be solved at present. Summary of the Invention

[0004] In view of the deficiencies of the above related technologies, the purpose of the present application is to provide a display panel, a preparation method thereof, and an electronic device, aiming to solve the problem of low bonding reliability between the LED chips and the driving substrate in the display panel.

[0005] The present application provides a display panel, including:

[0006] A driving substrate;

[0007] Multiple LED chips;

[0008] A bonding material; and

[0009] An adhesive layer;

[0010] Wherein, a display driving circuit and an on-board electrode electrically connected to the display driving circuit are provided on the driving substrate, and the bonding material is configured to electrically connect the chip electrode of the LED chip and the on-board electrode; multiple LED chips and the adhesive layer are both disposed on the chip-bearing surface of the driving substrate, and the covering area of the adhesive layer includes the area between two on-board electrodes corresponding to the LED chips, and the side of the adhesive layer away from the driving substrate is bonded to the side of the epitaxial layer of the LED chip facing the driving substrate.

[0011] In the preparation of the above display panel, since an adhesive layer is provided on the chip-bearing surface of the driving substrate, during the die bonding process, not only can the chip electrodes and the electrodes on the board be bonded through the bonding material, but also the LED chips can be bonded through the adhesive layer provided on the driving substrate. The adhesive force of the adhesive layer on the epitaxial layer of the LED chip is used to increase the pulling force on the LED chip in the direction towards the driving substrate. By increasing the physical bonding reliability between the LED chip and the driving substrate, the reliability of the electrical connection between the chip electrodes and the electrodes on the board is improved, and the quality of the display panel is enhanced.

[0012] Optionally, the adhesive layer is a black adhesive layer.

[0013] In the preparation of the above display panel, the adhesive layer provided on the driving substrate is a black adhesive layer. Therefore, this can avoid the problem of affecting the display effect of the display panel due to the reflection of the driving substrate surface, and can achieve the encapsulation blackening of the display panel.

[0014] Optionally, the adhesive layer is adhesively bonded to the sides of the chip electrodes and the bonding material at the same time.

[0015] In the preparation of the above display panel, since the adhesive layer not only bonds to the side of the LED chip epitaxial layer facing the driving substrate, but also bonds to the sides of the chip electrodes and the bonding material, this can further improve the bonding reliability between the LED chip and the driving substrate.

[0016] Based on the same inventive concept, the present application also provides an electronic device, including a processor and the display panel of any one of the above, and the display panel is communicatively connected to the processor.

[0017] Based on the same inventive concept, the present application also provides a display panel preparation method for preparing the display panel of any one of the foregoing, including:

[0018] A protection block array is provided on the chip-bearing surface of the driving substrate. A plurality of electrodes on the board are provided in the chip-bearing surface, and the electrodes on the board are configured to electrically connect the chip electrodes of the LED chips and the display driving circuit of the driving substrate. The protection block array is composed of a plurality of protection blocks, and each protection block respectively covers one side of an electrode on the board away from the driving substrate;

[0019] A patterned adhesive layer is formed on the chip-bearing surface through the protection block array;

[0020] The protection block array on the electrodes on the board is removed, and a bonding material is provided on the electrodes on the board;

[0021] Align the chip electrodes of the transferred LED chips with the electrodes on the board, and bond the chip electrodes to the electrodes on the board through the bonding material. After bonding, the side of the adhesive layer away from the driving substrate is adhesively bonded to the side of the LED chip epitaxial layer facing the driving substrate.

[0022] In the above display panel manufacturing method, since the adhesive layer is formed on the chip carrier surface through the protection block array, during the die bonding process, not only can the chip electrodes be bonded to the electrodes on the board through the bonding material, but also the LED chips can be bonded by the adhesive layer provided on the driving substrate. The adhesive force of the adhesive layer on the epitaxial layer of the LED chip is used to increase the tensile force received by the LED chip in the direction towards the driving substrate. By increasing the physical bonding reliability between the LED chip and the driving substrate, the reliability of the electrical connection between the chip electrodes and the electrodes on the board is improved, and the quality of the display panel is enhanced.

[0023] Optionally, setting the protection block array on the chip carrier surface of the driving substrate includes:

[0024] Setting a positive photoresist layer on the chip carrier surface;

[0025] Patterning the photoresist layer through a first photolithography mask to form a protection block array.

[0026] Optionally, the photoresist layer is a positive photoresist layer, and the first photolithography mask includes a first sub-mask and a second sub-mask. The first sub-mask includes a plurality of alternately arranged light-shielding rows and a plurality of light-transmitting rows, and the positions of the light-shielding rows correspond to the electrode rows on the board of the driving substrate. The second sub-mask includes a plurality of alternately arranged light-shielding columns and a plurality of light-transmitting columns, and the positions of the light-shielding columns correspond to the electrode columns on the board of the driving substrate. Patterning the photoresist layer through the first photolithography mask to form a protection block array includes: patterning the photoresist layer through the first sub-mask and the second sub-mask in sequence to form a protection block array.

[0027] Optionally, forming a patterned adhesive layer on the chip carrier surface through the protection block array includes:

[0028] Coating black glue in the non-board electrode area of the chip carrier surface through the protection block array to form an adhesive layer.

[0029] In the above display panel manufacturing method, the adhesive layer provided on the driving substrate is a black glue layer. Therefore, this can avoid the problem of affecting the display effect of the display panel due to the reflection of the driving substrate surface, and can achieve the encapsulation blackening of the display panel.

[0030] Optionally, removing the protection block array of the board electrode row and setting the bonding material on the board electrode includes:

[0031] Patterning the protection block array through a second photolithography mask to remove a partial area of the protection block;

[0032] Setting the bonding material in the exposed area of the board electrode;

[0033] Remove the remaining area of the protection block.

[0034] In the above method for preparing a display panel, since the entire area of the protection block array is not removed at one time during the process of removing the bonding material on the protection block array, but only a partial area is removed first to expose the partial area of the electrode on the board to carry the bonding material, and then the remaining area of the protection block is removed after the bonding material is set. In this way, the bonding material can be limited to the partial area of the electrode on the board, so as to form a gap between the side of the bonding material and the side of the adhesive layer, facilitating the subsequent filling of the adhesive layer into this gap during the process of pressure-induced deformation, and thus bonding to the sides of the chip electrode and the bonding material, further improving the reliability of the combination of the LED chip and the driving substrate.

[0035] Optionally, patterning the protection block array through a second photolithography mask plate to remove a partial area of the protection block includes:

[0036] Patterning the protection block array through a second photolithography mask plate to remove the middle area of the protection block and retain the edge area of the protection block;

[0037] Removing the remaining area of the protection block includes:

[0038] Removing the edge area of the protection block through a third photolithography mask plate.

[0039] In the above method for preparing a display panel, since the middle area of the protection block is removed first and its edge area is retained during the process of removing the protection block array, the bonding material can be located in the middle area of the electrode on the board, and the gap space is evenly distributed around the bonding material. In this way, when the black glue layer undergoes pressure-induced deformation and interacts with the side of the chip electrode, the problem that the chip electrode tilts due to uneven force in different directions will not occur, and it can ensure that the LED chip is always set upright on the driving substrate. Description of the Drawings

[0040] Figure 1 It is a schematic diagram showing the change of a process state of die bonding of a display panel in the related art shown in the present application;

[0041] Figure 2 It is a schematic flow diagram of a method for preparing a display panel provided in an optional embodiment of the present application;

[0042] Figure 3 It is a schematic diagram showing the change of a process state of a method for preparing a display panel provided in an optional embodiment of the present application;

[0043] Figure 4 It is a schematic flow diagram of a method for forming a protection block array by using a photodecomposable glue provided in an optional embodiment of the present application;

[0044] Figure 5a It is a schematic structural diagram of a first photolithography mask provided in an alternative embodiment of the present application;

[0045] Figure 5b It is a schematic structural diagram of another first photolithography mask provided in an alternative embodiment of the present application;

[0046] Figure 6 It is a schematic process diagram of removing a protection block array and setting a bonding material provided in an alternative embodiment of the present application;

[0047] Figure 7 It is a schematic diagram of the change in the process state of removing a protection block array and setting a bonding material provided in an alternative embodiment of the present application;

[0048] Figure 8 It is a schematic structural diagram of a display panel provided in another alternative embodiment of the present application;

[0049] Figure 9 It is a schematic diagram of the change in the process state of a display panel manufacturing method provided in yet another alternative embodiment of the present application;

[0050] Figure 10 It is a schematic process diagram of a display panel manufacturing method provided in yet another alternative embodiment of the present application.

[0051] Explanation of reference numerals:

[0052] 11 - Driving substrate; 110 - On - board electrode; 12 - Bonding material; 13 - LED chip; 130 - Chip electrode; 21 - Driving substrate; 210 - Chip - carrying surface; 211 - On - board electrode; 22 - Array of protection blocks; 220 - Protection block; 23 - Adhesive layer; 24 - LED chip; 240 - Chip electrode; 25 - Bonding material; 30 - Hot press head; 50a - First photolithographic mask; 50b - First photolithographic mask; 501b - First sub - mask; 502b - Second sub - mask; 51 - Translucent film; 52 - Non - translucent film; 53 - Light - blocking row; 54 - Light - transmitting row; 55 - Light - blocking column; 56 - Light - transmitting column; 70 - Second photolithographic mask; 71 - Third photolithographic mask; 80 - Display panel; 81 - Driving substrate; 810 - Chip - carrying surface; 811 - On - board electrode; 82 - LED chip; 820 - Chip electrode; 83 - Adhesive layer; 84 - Bonding material; 91 - Driving substrate; 910 - Chip - carrying surface; 911 - On - board electrode; 92 - Photodecomposable glue layer; 931 - First photoresist mask; 9311 - First sub - mask; 9312 - Second sub - mask; 932 - Second photolithographic mask; 933 - Third photolithographic mask; 94 - Array of protection blocks; 940 - Protection block; 95 - Black glue layer; 96 - Bonding material; 97 - LED chip; 100 - Hot press head. Detailed implementation manners

[0053] To facilitate the understanding of this application, the following will describe this application more comprehensively with reference to the relevant drawings. The preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of this application more thorough and comprehensive.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of this application in this specification are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0055] Please refer to Figure 1 A schematic diagram showing the change in the process state of die - bonding of a display panel. During the die - bonding process of the display panel, usually, a driving substrate 11 with a display driving circuit is first provided, as shown in Figure 1 (a) of. On the surface of the driving substrate 11 for carrying the LED chip, a plurality of electrodes are provided, and these electrodes correspond to the chip electrodes in the LED chip. For the purpose of distinction from the chip electrodes, in the embodiments of this application, the electrodes located on the driving substrate 11 are referred to as "on - board electrodes". Subsequently, a bonding material 12 is provided on the on - board electrode 110, as shown in Figure 1As shown in (b), the bonding material 12 can be solder paste, silver glue, bonding metal, etc. Then, please refer to Figure 1 (c) of FIG. It is possible to align the chip electrodes 130 of the transferred LED chip 13 with the electrodes 110 on the board, and use the bonding material 12 to bond the chip electrodes 130 and the electrodes 110 on the board together by means of reflow soldering, hot pressing, etc.

[0056] It can be understood that after die bonding is completed, Figure 1 the LED chip 13 and the driving substrate 11 can only be combined through the bonding material 12. However, because the die bonding thrust of the LED chip 13 is small, during the packaging and transportation process, it is very easy for the connection between the chip electrodes 130 and the electrodes 110 on the board to be disconnected due to the display panel being collided, affecting the electrical performance of the LED chip 13 and causing dead pixels to appear on the display panel.

[0057] Based on this, the present application hopes to provide a solution that can solve the above technical problems, and its detailed content will be elaborated in the subsequent embodiments.

[0058] An alternative embodiment of the present application:

[0059] This embodiment first provides a method for manufacturing a display panel. Please refer to Figure 2 and Figure 3 :

[0060] S202: Set an array of protection blocks on the chip-bearing surface of the driving substrate.

[0061] Please refer to Figure 3 As shown in (a) of FIG. First, a driving substrate 21 is provided. The driving substrate 21 can be a transparent substrate, such as a glass substrate, a sapphire substrate, etc., or a non-transparent substrate, such as an FPC (Flexible Printed Circuit) or a common PCB (Printed Circuit Board), etc.

[0062] The driving substrate 21 includes two surfaces, one of which is used to carry and set the LED chip 24. In this embodiment, the surface of the driving substrate 21 used to carry and set the LED chip 24 is called the "chip-bearing surface". A display driving circuit is provided on the driving substrate 21 ( Figure 3(not shown in the figure), the display driving circuit is used to electrically connect the LED chip 24 and the display driving chip, so that the LED chip 24 can work under the driving of the display driving chip. It should be noted that the display driving circuit is arranged on the driving substrate 21. The word "on" does not mean that the display driving circuit must be located on the surface of the driving substrate 21, nor does it mean that the display driving circuit is located above the driving substrate 21. As long as the display driving circuit is in contact with the driving substrate 21, it can be considered that the display driving circuit is arranged on the driving substrate 21. Therefore, in some examples, the display driving circuit can be arranged on the surface of the driving substrate 21, and in other examples, the display driving circuit can be arranged inside the driving substrate 21. The chip bearing surface 210 includes a plurality of on-board electrodes 211. On the one hand, the on-board electrodes 211 are electrically connected to the display driving circuit, and on the other hand, they are used to be electrically connected to the chip electrodes of the LED chip 24, so as to realize the electrical connection between the LED chip 24 and the display driving circuit. Optionally, the display driving circuit can be a TFT (Thin Film Transistor) driving circuit, that is, the driving substrate 21 is a TFT driving substrate, or the display driving circuit can also be a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor) driving circuit, that is, the driving substrate 21 is a MOS driving substrate.

[0063] Subsequently, a protection block array 22 is arranged on the chip bearing surface 210 of the driving substrate 21. As shown in (b) of Figure 3 , in this embodiment, the "protection block array" refers to a mask plate that covers the on-board electrodes 211. The protection block array 22 can be composed of a plurality of protection blocks 220. Each protection block 220 corresponds to an on-board electrode 211 and covers one side of an on-board electrode 211 away from the driving substrate 21. It should be understood that in this embodiment, the protection block 220 is arranged on the on-board electrode 211 mainly to avoid the adhesive layer 23 being arranged on the upper surface of the on-board electrode 211 when the adhesive layer 23 is arranged on the chip bearing surface 210 subsequently. Therefore, as long as the side of the on-board electrode 211 away from the driving substrate 21 can be covered and protected, the material and formation process of the protection block array 22 are not specifically limited in this embodiment. For example, in some examples of this embodiment, the protection block array 22 can be formed by photoresist. For example, in one example of this embodiment, the protection block array 22 includes positive photoresist. It can be understood that the protection block array 22 can be formed on the surface of other carriers first and then transferred and attached to the on-board electrode 211, or can be directly formed on the chip bearing surface 210.

[0064] It should be understood that, due to the huge number of upper-board electrodes 211 on the driving substrate 21, in this embodiment, the protection block array 22 is directly formed on the chip bearing surface 210. The following combines Figure 4 with the schematic process diagram shown in

[0065] S402: A positive photoresist layer is provided on the chip bearing surface.

[0066] First, a positive photoresist can be used to form a photoresist layer on the chip bearing surface 210. The photoresist layer can cover the entire area of the chip bearing surface 210, or at least cover the electrode setting area (the area where each upper-board electrode is concentratedly arranged) on the chip bearing surface 210.

[0067] S404: The photoresist layer is patterned through the first photolithography mask to form a protection block array.

[0068] Then, a part of the photoresist layer can be exposed through the first photolithography mask, so that in the subsequent process, a part of the photoresist layer can be removed and another part can be retained. It should be understood that the area of the photoresist layer on the chip bearing surface 210 that needs to be retained is the area located on the upper-board electrode 211, and the area that needs to be removed is the area outside the upper-board electrode 211. Therefore, the area of the first photolithography mask corresponding to the upper-board electrode 211 should be a light-shielding area, that is, a non-transmissive area, and the remaining areas are transmissive areas.

[0069] Continuing to take the photoresist layer as a positive photoresist layer as an example for illustration, in some examples of this embodiment, the first photolithography mask is composed of one sub-mask, and in other examples, the first photolithography mask can be composed of two or even more than two sub-masks:

[0070] Please refer to Figure 5aA schematic structural diagram of the first photolithography mask shown: The first photolithography mask 50a includes a light-transmitting film 51 and a light-blocking film 52, and the light-transmitting film 51 and the light-blocking film 52 together form a plane. The position of the light-blocking film 52 in the first photolithography mask 50a corresponds to the position of the on-board electrode 211 on the chip carrier surface 210. In some examples of this embodiment, when preparing the first photolithography mask 50a, multiple light-blocking films 52 can be prepared first, and then the multiple light-blocking films 52 are arranged according to the arrangement of the on-board electrodes 211 on the chip carrier surface 210. Then, a transparent adhesive is filled between the light-blocking films 52, and the transparent adhesive is used to form the light-transmitting film 51, and the individual light-blocking films 52 are combined together to form the first photolithography mask 50a. In some other examples, a photolithography mask layer can be provided first, and a release film is attached to one surface of the photolithography mask layer. Then, the photolithography mask layer is patterned according to the arrangement of the on-board electrodes 211 on the chip carrier surface 210 to form multiple light-blocking films 52. Since the release film is not patterned, the release film can be used to combine the multiple independent light-blocking films 52 together to form the first photolithography mask 50a.

[0071] Figure 5b A schematic structural diagram of the first photolithography mask 50b composed of two sub-masks is shown: The first photolithography mask 50b includes a first sub-mask 501b and a second sub-mask 502b. The first sub-mask 501b includes multiple alternately arranged light-blocking rows 53 and multiple light-transmitting rows 54. The positions of the light-blocking rows 53 correspond to the on-board electrode rows on the driving substrate 21. The second sub-mask includes multiple alternately arranged light-blocking columns 55 and multiple light-transmitting columns 56. The positions of the light-blocking columns 55 correspond to the on-board electrode columns on the driving substrate 21. The on-board electrode rows include a row of on-board electrodes 211 on the driving substrate 21, and the on-board electrode columns include a column of on-board electrodes 211 on the driving substrate 21. It can be understood that when using the first photolithography mask 50b including the first sub-mask 501b and the second sub-mask 502b, the two sub-masks need to be used separately, or rather, used successively, that is, first use one of them to expose the photoresist layer, and then use the other to further expose the photoresist layer. The use order of the two sub-masks can be arbitrary and is not specifically limited in this embodiment. In addition, after using one of the sub-masks to expose the photoresist layer, development can be carried out and then the other sub-mask can be used, or development can be carried out uniformly after two exposures.

[0072] S204: Form a patterned adhesive layer on the chip carrier surface through the protection block array.

[0073] After the protection block array 22 is disposed on the chip bearing surface 210, the adhesive layer 23 can be continuously formed on the chip bearing surface 210 through the protection block array 22. It can be understood that due to the presence of the protection block array 22, it can be ensured that the adhesive layer 23 is not disposed on the upper surface of the board electrode 211. At the same time, since the thickness of the adhesive layer 23 can be controlled when the adhesive layer 23 is disposed, the adhesive layer 23 does not cover the protection block 220 either. Therefore, the adhesive layer 23 formed through the protection block array 22 is a patterned layer structure. Please refer to Figure 3 of (c) and Figure 3 in (d).

[0074] In some examples of this embodiment, the adhesive can be disposed on the chip bearing surface 210 of the driving substrate 21 by means including but not limited to spin coating. For example, in one example, the adhesive can also be disposed on the chip bearing surface 210 by 3D printing to form the adhesive layer. Since the adhesive is disposed on the driving substrate by 3D printing, the process of disposing the adhesive layer is rapid, low-cost, and high-precision.

[0075] The display panel should ensure that the light emitted by the LED chip 24 can be efficiently emitted outside the display panel. However, at the same time, it should also prevent the light reflected from the area other than the LED chip 24 on the driving substrate 21 from penetrating outside the display panel and affecting the display effect. Therefore, in the related art, usually after the LED chip is die-bonded, a black glue layer needs to be uniformly disposed on the surface of the driving substrate 21 where the LED chip 24 is located. This black glue layer not only covers the idle area on the driving substrate 21, but also covers the LED chip 24. Although this can prevent the driving substrate 21 from reflecting light externally, it also affects the transmittance of the light emitted by the LED chip 24 and reduces the display performance of the display panel.

[0076] In some examples of this embodiment, the adhesive layer 23 can be formed by black glue. In this way, not only can the formed black glue layer play a role in bonding the LED chip 24, but also the encapsulation blackening is achieved by using the black glue layer, avoiding the problem of external light reflection of the driving substrate 21. Moreover, since the black glue layer in this embodiment is disposed on the driving substrate 21 prior to the LED chip 24 and does not cover the light-emitting surface of the LED chip 24, the encapsulation blackening solution in this embodiment does not affect the transmittance of the light emitted by the LED chip 24 and is beneficial to improving the display effect of the display panel.

[0077] Of course, in some other examples, other methods can also be adopted to achieve the encapsulation blackening of the display panel without affecting the light transmittance of the LED chip 24. For example, in one example, when preparing the driving substrate 21, the entire driving substrate 21 or the chip-bearing surface 210 of the driving substrate 21 can be made black. For example, black raw materials can be added when manufacturing the driving substrate 21. Or, the driving substrate 21 can be manufactured in a general manner. However, after the driving substrate is manufactured, a layer of black glue or a black film layer can be coated on the chip-bearing surface 210 of the driving substrate 21. When the chip-bearing surface 210 of the driving substrate 21 is black, directly using a transparent glue to form the bonding glue layer 23 can also ensure the encapsulation blackening.

[0078] S206: Remove the protection block array on the board electrode and set the bonding material on the board electrode.

[0079] After the bonding glue layer 23 is set on the chip-bearing surface 210, the protection block array 22 can be removed to expose the surface of the board electrode 211 away from the driving substrate 21. Then, the bonding material 25 is set in the exposed area of the board electrode 211. Please refer to Figure 3 (e) and (f) of. Since the bonding material 25 has conductivity, solder paste, silver glue, bonding metal, etc. can be used as the bonding material 25 in this embodiment.

[0080] In some examples of this embodiment, when removing the protection block array 22, the protection block array 22 can be directly removed at one time, that is, all the protection blocks 220 covering each board electrode 211 are removed at one time. In some other examples, when removing the protection block array 22, it is carried out in stages. For example, please refer to Figure 6 a schematic flow chart of removing the protection block array and setting the bonding material shown in, and Figure 7 a schematic diagram of the process state change shown in:

[0081] S602: Pattern the protection block array through the second photolithography mask to remove part of the area of the protection block.

[0082] As Figure 7 shown in (a) and (b) of, the second photolithography mask 70 is mainly used to remove part of the area of the protection block 220 to expose part of the area of the surface of the board electrode 211 away from the driving substrate 21. In some examples of this embodiment, when patterning the protection block array 22 through the second photolithography mask 70, the area on one side of the protection block 220 can be selected to be removed, such as the left area or the right area, or the front area or the rear area. In some other examples, the middle area of the protection block 220 can be selected to be removed, and the edge area of the protection block 220 is reserved.

[0083] S604: Set the bonding material in the area where the electrode on the board is exposed.

[0084] After removing a partial area of the protection block 220, a partial area of the electrode 211 on the board away from one side of the driving substrate 21 will be exposed. At this time, the bonding material 25 can be set in the exposed area of the electrode 211 on the board. Please refer to Figure 7 (c) of. The bonding material 25 can also be set by means of 3D printing. This setting method has high precision and high speed. It can be understood that compared with the method of removing the area on one side of the protection block 220, in the solution of removing the middle area of the protection block 220, it can be ensured that the bonding material 25 is in a relatively middle area on the electrode 211 on the board. In this way, when the chip electrode 240 of the LED chip 24 is combined with the bonding material 25, the distances between the chip electrode 240 and the surrounding adhesive layers 23 are not much different. When the adhesive layer 23 is deformed under pressure, the times when the adhesive layer 23 in all directions contacts the chip electrode 240 are naturally not much different. In this way, the problem that the chip electrode 240 is inclined or deformed due to the action of only the adhesive layer 23 on one side can be avoided. In other words, this method of setting the bonding material 25 in the middle area of the electrode 211 on the board can ensure that the LED chip 24 is set in the driving substrate 21 in an upright posture.

[0085] S606: Remove the remaining area of the protection block.

[0086] After the bonding material 25 is set, the remaining area of the protection block 220 remaining on the electrode 211 on the board can be removed. In some examples, when removing the remaining area of the protection block 220, a mask plate may not be used and it can be directly removed; in some other examples, considering that the exposure process of removing the photoresist has a certain impact on the properties of the adhesive layer 23, for example, it may cause the black glue to be completely cured. Therefore, even if all the remaining protection blocks 220 on the electrode 211 on the board are removed, a mask plate will still be selected. In some examples of this embodiment, such as Figure 7 (d) and (e) of, the remaining area of the protection block can be removed through the third photolithography mask plate 71. In Figure 7 (d), because the middle area of the protection block 220 was removed by the second photolithography mask plate 70 before, the edge area of the protection block 220 is removed through the third photolithography mask plate 71.

[0087] S208: Align the chip electrode of the transferred LED chip with the electrode on the board, and bond the chip electrode to the electrode on the board through the bonding material. After bonding, the side of the adhesive layer away from the driving substrate is bonded to the side of the LED chip epitaxial layer facing the driving substrate.

[0088] After removing the protection block array 22 and setting the bonding material on the on-board electrode 211, the LED chip 24 can be transferred onto the driving substrate 21, and the chip electrode 240 of the transferred LED chip 24 can be aligned with the on-board electrode 211, as shown in Figure 3 (g) in the figure. Subsequently, pressure can be applied to the LED chip 24 towards the driving substrate 21, as shown in Figure 3 (h) in the figure. The LED chip 24 can be pressed by the thermal head 30, so that the bonding material 25 bonds the chip electrode 240 and the on-board electrode 211 together. At the same time, the side of the epitaxial layer of the LED chip 24 facing the driving substrate 21 is bonded to the adhesive layer 23. Of course, those skilled in the art can understand that the device for applying pressure to the LED chip 24 is not limited to the thermal head 30.

[0089] Generally, a display panel needs to perform color display. Therefore, the LED chips 24 transferred and fixed on the driving substrate 21 can include chips of the three primary colors of RGB. In some other examples of this embodiment, in addition to the LED chips of red, green, and blue, LED chips capable of emitting other colors of light can also be provided. For example, LED chips capable of emitting indigo light, LED chips capable of emitting yellow light, etc. The LED chips 24 in this embodiment include but are not limited to Micro-LED (micro LED), Mini-LED (mini LED), or OLED (Organic Light-Emitting Diode, organic light-emitting diode), etc. In addition, in this embodiment, the LED chip 24 can be a flip-chip LED chip or a vertical structure LED chip.

[0090] It can be understood that since the cross-sectional area of the chip electrode 240 is generally smaller than that of the on-board electrode 211, after the LED chip 24 is placed on the on-board electrode 211, there will be a gap between the chip electrode 240 and the adhesive layer 23. Moreover, in some of the foregoing examples, by removing the protection block array 22 in stages, a certain gap is also ensured between the bonding material 25 and the adhesive layer 23. Therefore, when pressure is applied to the LED chip 24 towards the driving substrate 21, the incompletely cured adhesive layer 23 has a deformation space, and it can fill the space between its side and the side of the chip electrode 240 under the extrusion action, so as to bond with the side of the chip electrode 240; or, the adhesive layer 23 can also fill the space between its side and the side of the bonding material 25 under the extrusion action, so as to bond with the side of the bonding material 25. In some other examples, after the adhesive layer 23 deforms, it can bond with the side of the chip electrode 240 and the side of the bonding material 25 at the same time.

[0091] It should be understood that in order to deform the adhesive layer 23, it should be ensured that during the process of applying pressure to the LED chip 24, the pressure can be conducted from the LED chip 24 to the adhesive layer 23. Therefore, in this embodiment, the sum of the height h1 of the on-board electrode 211, the height h2 of the bonding material 25, and the height h3 of the chip electrode 240 (hereinafter referred to as the "total height") should be not much different from the thickness d of the adhesive layer 23. Among them, the height h3 of the chip electrode 240 refers to the shortest distance from the free end of the chip electrode 240 to its epitaxial layer, and the height h1 of the on-board electrode 211 refers to the shortest distance from the free end of the on-board electrode 211 to the surface of the driving substrate 21.

[0092] When the thickness of the adhesive layer 23 is greater than the total height, that is, d > h1 + h2 + h2, the value of d - (h1 + h2 + h2) should be less than or equal to the maximum deformable height s1 of the adhesive layer 23. Once d - (h1 + h2 + h2) > s1, it will occur that the adhesive layer 23 has been compressed and deformed to the extreme, but the chip electrode 240 of the LED chip 24 still cannot contact the bonding material 25, and it is impossible to be electrically connected to the on-board electrode 211 through the bonding material 25.

[0093] When the thickness of the adhesive layer 23 is less than the total height, that is, d < h1 + h2 + h2, the value of (h1 + h2 + h2) - d should be less than or equal to the maximum deformable height s2 of the bonding material 25. Once (h1 + h2 + h2) - d > s2, it will occur that the bonding material 25 has been compressed and deformed to the extreme, but the epitaxial layer of the LED chip 24 has never been able to contact the adhesive layer 23, resulting in the pressure applied to the LED chip 24 not being able to be conducted to the adhesive layer 23. The adhesive layer 23 can neither bond to the epitaxial layer of the LED chip 24 nor be deformed and bonded to the sides of the chip electrode 240 and the bonding material 25. In this case, the adhesive layer 23 will not be able to improve the bonding force between the LED chip 24 and the driving substrate 21.

[0094] In the display panel manufacturing method provided in this embodiment, since during the process of manufacturing the display panel, an adhesive layer is first provided on the chip-bearing surface of the driving substrate, and then the LED chip is transferred and fixed, the LED chip can be bonded to the adhesive layer, and the adhesive layer can provide an additional bonding force to the LED chip and the driving substrate, enhancing the firmness of the LED chip die bonding and improving the quality of the display panel.

[0095] Moreover, since the adhesive layer can be a black glue layer, the adhesive layer can not only provide adhesion to the LED chip but also realize the encapsulation blackening of the display panel. Compared with the solution of additionally providing a black glue layer to cover the LED chip and the driving substrate after the LED chip die bonding, it can improve the light transmittance of the LED chip and enhance the display effect of the display panel.

[0096] Another optional embodiment of the present application:

[0097] This embodiment provides a display panel. Please refer to Figure 8 a schematic structural diagram of the display panel shown:

[0098] The display panel 80 includes a driving substrate 81, multiple LED chips 82, an adhesive layer 83, and a bonding material 84. The driving substrate 81 includes a chip-bearing surface 810, in which a plurality of on-board electrodes 811 are provided. On the one hand, the on-board electrodes 811 are electrically connected to the display driving circuit on the driving substrate 81, and on the other hand, they are used to be electrically connected to the chip electrodes 820 of the LED chips 82 provided in the chip-bearing surface 810, so as to realize the electrical connection between the LED chips 82 and the display driving circuit. The bonding material 84 includes but is not limited to solder paste, silver glue, and bonding metal, etc., which is used to realize the fixed connection between the chip electrodes 820 and the on-board electrodes 811 while realizing their electrical connection.

[0099] The adhesive layer 83 covers the chip-bearing surface 810, and the covering area of the chip-bearing surface 810 by it includes the area between two on-board electrodes corresponding to the LED chip 82, and the side of the adhesive layer 83 away from the driving substrate is bonded to the side of the epitaxial layer of the LED chip 82 facing the driving substrate 81. Through the adhesion of the adhesive layer 83 to the LED chip 82, the combination between the LED chip 82 and the driving substrate 81 is not limited to the binding force provided by the bonding material 84, but also includes the adhesive force of the adhesive layer 83 to the two, which improves the reliability of the physical connection and electrical connection between the LED chip 82 and the driving substrate 81, and reduces the probability of disconnection between the chip electrodes 820 and the on-board electrodes 811 and the probability of the LED chip 82 falling off from the driving substrate 81.

[0100] In some examples of this embodiment, the adhesive layer 83 not only adheres to the epitaxial layer of the LED chip 82, but can also adhere to at least one of the sides of the chip electrode 820 and the bonding material 84. In some examples, the adhesive layer 83 can be simultaneously adhered to the side of the chip electrode 820 and the side of the bonding material 84.

[0101] In some examples of this embodiment, the adhesive layer 83 is a black glue layer formed by black glue. In still other examples, the chip-bearing surface 810 of the driving substrate 81 is black, but the adhesive layer 83 is a transparent glue layer.

[0102] In some examples, the display panel 80 can be prepared by using the display panel preparation method provided in any of the foregoing examples. For the details of the preparation process of the display panel 80, please refer to the introduction of the foregoing examples, which will not be elaborated here.

[0103] This embodiment further provides an electronic device, which can be a mobile terminal such as a mobile phone, a tablet computer, a notebook computer, a palm computer, a personal digital assistant (PDA), a portable media player (PMP), a navigation device, a wearable device, a smart bracelet, a pedometer, etc. including a display panel, or a fixed terminal such as a digital TV, a desktop computer, etc. including a display panel. In addition to the display panel, the electronic device further includes a processor communicatively connected to the display panel, and the processor can control the display of the display panel.

[0104] It can be understood that in addition to the processor and the display panel, the electronic device may further include components such as an RF (Radio Frequency) unit, a WiFi module, an audio output unit, a sensor, an interface unit, a memory, etc.

[0105] For the display panel and the electronic device provided in this embodiment, since an adhesive layer is provided on the chip-bearing surface of the driving substrate, the adhesive layer can more firmly fix the LED chip on the driving substrate while providing a bonding force between the bonding material and the chip electrode and the electrode on the board, improving the reliability of the physical connection between the LED chip and the driving substrate. At the same time, the reliability of the electrical connection between the LED chip and the driving substrate can be ensured through the reliable physical connection between the LED chip and the driving substrate, enhancing the quality of the display panel.

[0106] Another optional embodiment of this application:

[0107] To make the structural details of the foregoing display panel and the process of the display panel manufacturing method clearer to those skilled in the art, this embodiment will continue to be described with examples. Please refer to Figure 9 and Figure 10 :

[0108] S1002: Provide a driving substrate.

[0109] Please refer to Figure 9 as shown in (a) of , the driving substrate 91 can be a glass substrate, whose upper surface is the chip-bearing surface 910, and in the chip-bearing surface 910, there are a plurality of electrodes 911 on the board, and the electrodes 911 on the board are electrically connected to the display driving circuit provided in the driving substrate 91.

[0110] S1004: Form a positive photodecomposable adhesive layer on the chip-bearing surface of the driving substrate.

[0111] Please refer to Figure 9(b). In this embodiment, a photoresist layer 92 can be disposed on the chip bearing surface 910 by spin coating. Since a positive photoresist is used, the formed photoresist layer 92 will dissolve after being exposed to light.

[0112] S1006: Pattern the photoresist layer through the first photolithography mask to form a protection block array.

[0113] In this embodiment, the first photoresist mask 93 includes two sub-masks, as shown in Figure 9 (c) and (d): The first sub-mask 9311 includes a plurality of alternately arranged light-shielding rows and a plurality of light-transmitting rows, and the positions of the light-shielding rows correspond to the on-board electrode rows on the driving substrate. The second sub-mask 9312 includes a plurality of alternately arranged light-shielding columns and a plurality of light-transmitting columns, and the positions of the light-shielding columns correspond to the on-board electrode columns on the driving substrate.

[0114] In the process of patterning the photoresist layer 92 through the first photolithography mask 931, the photoresist layer 92 can be first exposed through the first sub-mask 9311, and then the photoresist layer 92 can be exposed through the second sub-mask 9312. After two exposures, the photoresist layer 92 in the exposed part is uniformly developed to obtain a protection block array 94. In some other examples, the second sub-mask 9312 can also be used first, and then the first sub-mask 9311.

[0115] S1008: Set a black glue layer on the chip bearing surface by 3D printing.

[0116] The protection block array 94 is composed of a plurality of protection blocks 940, and each protection block 940 covers an on-board electrode 911. In this embodiment, the cross-sectional area of the protection block 940 is slightly larger than the cross-sectional area of the on-board electrode 911. Therefore, it is required that the area of the light-shielding region jointly formed by the first sub-mask 9311 and the second sub-mask 9312 in the first photoresist mask 93 is slightly larger than the cross-sectional area of the on-board electrode 911.

[0117] Under the cover of the protection block array 94, a black glue layer 95 can be set on the chip bearing surface 910 by 3D printing. Please refer to Figure 9 (e) and (f). The upper surface of the black glue layer 95 is flush with the upper surface of the protection block 940. At the same time, the thickness of the black glue layer 95 needs to be approximately the sum of the heights of the on-board electrode 911, the subsequent bonding material 96 to be set, and the chip electrode.

[0118] S1010: Pattern the protection block array through the second photolithography mask to remove the middle area of the protection block.

[0119] After the black glue layer 95 is formed, the remaining photoresist layer 92 can be secondarily patterned through the second photolithography mask 932, that is, the protection block array is patterned, so as to remove the middle area of the protection block 940 and retain the edge area of the protection block 940. Please Figure 9 (g) of Figure 9 (h) of

[0120] In this embodiment, the second photolithography mask 932 can be composed of one sub-mask or two or more sub-masks. Among them, the area of a single light-transmitting area in the second photolithography mask 932 is slightly smaller than the cross-sectional area of the on-board motor 911.

[0121] S1012: Set the bonding material in the middle area of the on-board electrode by 3D printing.

[0122] After removing the middle area of the protection block 940, the bonding material 96 can be set in the exposed area of the on-board electrode 911, such as Figure 9 (i) of. Optionally, in some examples, the bonding material 96 can be set by 3D printing, and in some other examples, it can be set by dispensing.

[0123] S1014: Remove the edge area of the protection block through the third photolithography mask.

[0124] After the bonding material 96 is set, the remaining protection block 940 on the on-board electrode 911 can be removed through the third photolithography mask 933, Figure 9 (j) and (k) of. The third photolithography mask 933 can block the black glue layer 95 to prevent the black glue layer 95 from curing prematurely.

[0125] S1016: Transfer the LED chip and align the chip electrode of the LED chip with the on-board electrode.

[0126] After removing all areas of the protection block array 94, the LED chip 97 can be transferred onto the driving substrate, the chip electrode of the LED chip 97 is aligned with the on-board electrode 911, and the LED chip 97 is placed on the on-board electrode 911, Figure 9 (l) of.

[0127] S1018: Apply pressure to the LED chip towards the driving substrate using a hot press head.

[0128] Subsequently, the LED chip 97 can be pressed downward towards the driving substrate 91 using the hot press head 100. Please refer to Figure 9(m), so that the bonding material 96 melts, bonding the chip electrode to the electrode 911 on the board. At the same time, the black glue layer 95 is bonded to the epitaxial layer of the LED chip 97. Further, after the black glue layer 95 contacts the epitaxial layer of the LED chip 97, the pressure applied to the LED chip 97 is conducted to the black glue layer 95, and the black glue layer 95 will deform under pressure, so as to fill the gap between it and the chip electrode and the bonding material 96, thereby bonding the side surface of the chip electrode to the side surface of the bonding material 96. It is undoubtedly that after pressing, the height of the black glue layer 95 will be slightly lower.

[0129] In the display panel manufacturing method provided in this embodiment, by providing double bonding forces between the LED chip and the driving substrate through the black glue and the bonding material, the problem of easy detachment of the LED chip caused by insufficient die bonding force of the LED chip is avoided. At the same time, the setting of the black glue layer can also achieve the encapsulation blackening of the display panel and improve the display effect of the display panel. In addition, because there is a black glue layer between the two chip electrodes of the LED chip, the black glue layer can be used to achieve electrical isolation between the two chip electrodes of the LED chip, avoiding problems such as short circuit of the LED chip.

[0130] It should be understood that the application of this application is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of this application.

Claims

1. A display panel, characterized in that, Comprising: A driving substrate; Multiple LED chips; Bonding material; And An adhesive layer; Wherein, in an initial state, a protection block array is arranged on a chip-bearing surface of the driving substrate, a plurality of on-board electrodes are arranged in the chip-bearing surface, the on-board electrodes are configured to electrically connect a chip electrode of an LED chip and a display driving circuit of the driving substrate, the protection block array is composed of a plurality of protection blocks, and each protection block respectively covers a surface of one of the on-board electrodes away from the driving substrate; The adhesive layer is formed on the chip-bearing surface through the protection block array; Before arranging the bonding material, the protection block array is patterned through a second photolithography mask plate to remove a partial area of the protection blocks; Bonding material is arranged in an area where the on-board electrodes are exposed; the remaining area of the protection blocks is removed; The multiple LED chips and the adhesive layer are both arranged on the chip-bearing surface of the driving substrate, and a covering area of the adhesive layer includes an area between two on-board electrodes corresponding to the LED chips, and a side of the adhesive layer away from the driving substrate is bonded to a side of an epitaxial layer of the LED chip facing the driving substrate.

2. The display panel according to claim 1, wherein The adhesive layer is a black glue layer.

3. The display panel according to claim 1 or 2, characterized in that, The adhesive layer is simultaneously bonded to sides of the chip electrode and the bonding material.

4. An electronic device, characterized in that, Comprising a processor and a display panel according to any one of claims 1-3, the display panel being communicatively connected to the processor.

5. A method for manufacturing a display panel, which is used to manufacture the display panel according to any one of claims 1-3, characterized in that, Comprising: A protection block array is arranged on a chip-bearing surface of a driving substrate, a plurality of on-board electrodes are arranged in the chip-bearing surface, the on-board electrodes are configured to electrically connect a chip electrode of an LED chip and a display driving circuit of the driving substrate, the protection block array is composed of a plurality of protection blocks, and each protection block respectively covers a surface of one of the on-board electrodes away from the driving substrate; A patterned adhesive layer is formed on the chip-bearing surface through the protection block array; The protection block array on the on-board electrodes is removed, and bonding material is arranged on the on-board electrodes; The chip electrode of the transferred LED chip is aligned with the on-board electrode, and the chip electrode is bonded to the on-board electrode through the bonding material. After bonding, a side of the adhesive layer away from the driving substrate is bonded to a side of an epitaxial layer of the LED chip facing the driving substrate; Wherein, removing the protection block array on the on-board electrodes and arranging bonding material on the on-board electrodes includes: The protection block array is patterned through a second photolithography mask plate to remove a partial area of the protection blocks; Bonding material is arranged in an area where the on-board electrodes are exposed; The remaining area of the protection blocks is removed.

6. The method for manufacturing a display panel according to claim 5, wherein The arranging a protection block array on a chip-bearing surface of a driving substrate includes: A positive photoresist layer is arranged on the chip-bearing surface; The photoresist layer is patterned through a first photolithography mask plate to form a protection block array, and a light-shielding area of the first photolithography mask plate corresponds to the on-board electrodes.

7. The method for manufacturing a display panel according to claim 6, wherein The first photolithography mask plate includes a first sub-mask plate and a second sub-mask plate, The first sub-mask includes a plurality of alternately arranged light-blocking rows and a plurality of light-transmitting rows, and the positions of the light-blocking rows correspond to the on-board electrode rows on the driving substrate. The second sub-mask includes a plurality of alternately arranged light-blocking columns and a plurality of light-transmitting columns, and the positions of the light-blocking columns correspond to the on-board electrode columns on the driving substrate. Performing patterning on the photoresist layer through the first photolithography mask to form a protection block array includes: sequentially performing patterning on the photoresist layer through the first sub-mask and the second sub-mask to form a protection block array.

8. The method for manufacturing a display panel according to claim 5, wherein, Forming a patterned adhesive layer on the chip carrier surface through the protection block array includes: Coating a black adhesive in the non-on-board electrode area of the chip carrier surface through the protection block array to form the adhesive layer.

9. The method for manufacturing a display panel according to claim 5, wherein, Performing patterning on the protection block array through the second photolithography mask to remove a partial area of the protection block includes: Performing patterning on the protection block array through the second photolithography mask to remove the middle area of the protection block and retain the edge area of the protection block. Removing the remaining area of the protection block includes: Removing the edge area of the protection block through the third photolithography mask.

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