WO2021102764A1

WO2021102764A1 - Display substrate and manufacturing method therefor

Info

Publication number: WO2021102764A1
Application number: PCT/CN2019/121381
Authority: WO
Inventors: 洪温振; 周充祐; 汪楷伦; 许时渊
Original assignee: 重庆康佳光电技术研究院有限公司
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2021-06-03
Also published as: CN111033762A

Abstract

A display substrate and a manufacturing method therefor. The display substrate comprises: a backplate (1) and a plurality of Micro-LED chips (2), wherein each of the Micro-LED chips (2) comprises a first electrode (21) and a second electrode (22); the backplate (1) is provided with recesses (11); the Micro-LED chips (2) are inserted in the recesses (11) to be electrically connected to the backplate (1) by means of the first electrodes (21) and the second electrodes (22). By providing the recesses (11) matching the first electrodes (21) and the second electrodes (22) on the backplate (1), when the Micro-LED chips (2) have defects, only the Micro-LED chips (2) having the defects need to be plugged out from the recesses (11), and one of the Micro-LED chips (2) not having the defect is inserted in the corresponding recess (11) again, so that the Micro-LED chips (2) are more convenient to replace, and the problem in the prior art that the chips (2) loosen and displace due to replacing the Micro-LED chips (2) by heating solder is overcome.

Description

Display substrate and manufacturing method thereof

Technical field

The invention belongs to the technical field of semiconductor optoelectronics, and particularly relates to a display substrate and a manufacturing method thereof.

Background technique

Micro-LED technology, namely LED miniaturization and matrix technology, has good stability, longevity, and operating temperature advantages, while also inheriting the advantages of LED low power consumption, color saturation, fast response speed, strong contrast, etc. , Micro-LED has higher brightness and lower power consumption, which makes Micro-LED have great application prospects. At present, most of the way of mounting Micro-LED chips on the backplane is to first install solder bumps at the corresponding electrode positions on the backplane. By aligning and connecting the electrodes of the Micro-LED chip with the solder bumps, the solder bumps will melt when heated. State, cooling and curing to realize the electrical connection between the Micro-LED chip and the backplane.

When one or more Micro-LED chips are defective and need to be replaced or transferred, it is usually necessary to heat the solder in a certain area, and the Micro LED chip is separated from the backplane through the melting of the solder. However, this method is difficult to heat only the solder under the defective Micro-LED chip, causing the solder under the Micro-LED chip adjacent to the defective Micro-LED chip to also melt, resulting in Micro-LED The chip is loose and shifted, which affects the light-emitting performance of the Micro-LED chip.

Therefore, the existing technology needs to be further improved.

Summary of the invention

In view of the above-mentioned shortcomings in the prior art, the purpose of the present invention is to provide a display substrate and a manufacturing method thereof, which overcomes the problem that the Micro-LED chip in the existing display substrate is electrically connected to the backplane through solder bumps. When the chip is defective, it is necessary to melt the solder block by heating to separate the defective Micro-LED chip from the backplane, which will easily cause the normal Micro-LED chip adjacent to the defective Micro-LED chip to loosen and shift, which affects its luminous performance Defects.

The first embodiment disclosed in the present invention is a display substrate, including a backplane and a plurality of Micro-LED chips, wherein the Micro-LED chip includes a first electrode and a second electrode; the backplane is provided with Groove; The Micro-LED chip is electrically connected to the backplane through the first electrode and the second electrode inserted into the groove.

In the display substrate, a conductive layer is provided on the inner wall of the groove.

The display substrate, wherein the groove includes a first groove and a second groove;

The first electrode is inserted into the first groove, and the cross-sectional shape of the first electrode is the same as the cross-sectional shape of the first groove;

The second electrode is inserted into the second groove, and the cross-sectional shape of the second electrode is the same as the cross-sectional shape of the second groove.

In the display substrate, the Micro-LED chip further includes a semiconductor layer.

The display substrate, wherein the semiconductor layer includes:

The first semiconductor layer;

An active layer provided on the first semiconductor layer;

A second semiconductor layer provided on the active layer.

In the display substrate, the first electrode is provided on the second semiconductor layer, and the second electrode is provided on the first semiconductor layer.

In the display substrate, the first electrode is a positive electrode, and the second electrode is a negative electrode.

In the display substrate, the first semiconductor layer is an N-type semiconductor layer, and the second semiconductor layer is a P-type semiconductor layer.

In the display substrate, the first electrode is a negative electrode, and the second electrode is a positive electrode.

In the display substrate, the first semiconductor layer is a P-type semiconductor layer, and the second semiconductor layer is an N-type semiconductor layer.

In the display substrate, the height of the second electrode is greater than the sum of the thicknesses of the active layer and the second semiconductor layer.

The second embodiment disclosed in the present invention is a method for manufacturing a display substrate for manufacturing the above-mentioned display substrate, wherein the method for manufacturing a Micro-LED chip on the display substrate includes the following steps:

Forming a semiconductor layer on the substrate;

Forming a photoresist layer on the substrate and the semiconductor layer;

Exposing and developing the photoresist layer to remove the photoresist material corresponding to the position of the first electrode and the second electrode on the semiconductor layer;

A first electrode and a second electrode are formed on the semiconductor layer.

In the manufacturing method of the display substrate, the semiconductor layer includes a first semiconductor layer, a second semiconductor layer and an active layer, and the step of forming the semiconductor layer on the substrate includes:

Forming a first semiconductor layer on the substrate;

Forming an active layer on the first semiconductor layer;

A second semiconductor layer is formed on the active layer.

In the manufacturing method of the display substrate, the distance from the side of the photoresist layer away from the substrate to the substrate is greater than the distance from the side of the second semiconductor layer away from the substrate to the substrate.

The manufacturing method of the display substrate, wherein, after the step of forming the first electrode and the second electrode on the semiconductor layer, the method further includes:

The photoresist layer on the substrate and the semiconductor layer is removed.

Advantageous effects. The present invention provides a display substrate and a manufacturing method thereof. By providing grooves matching the first electrode and the second electrode on the backplane, the Micro-LED chip is inserted through the first electrode and the second electrode. It is electrically connected to the backplane in the groove. When the Micro-LED chip is defective, you only need to pull out the defective Micro-LED chip from the groove, and re-plug a non-defective Micro-LED chip to the corresponding In the groove, the replacement of the Micro-LED chip is convenient, which overcomes the problem of the loosening and displacement of the Micro-LED chip caused by the traditional replacement of the Micro-LED chip by heating the solder.

Description of the drawings

FIG. 1 is a schematic diagram of the structure of a display substrate provided by the present invention;

2 is a schematic diagram of the structure of the Micro-LED chip in the display substrate provided by the present invention;

Fig. 3 is a flowchart of a preferred embodiment of a method for manufacturing a Micro-LED chip provided by the present invention.

Detailed ways

In order to make the objectives, technical solutions, and advantages of the present invention clearer and clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not used to limit the present invention.

Since the Micro-LED chip in the existing display substrate is electrically connected to the backplane through the solder block, when the Micro-LED chip is defective, the solder block needs to be melted by heating to separate the defective Micro-LED chip from the backplane, which is easy to cause The normal Micro-LED chip adjacent to the defective Micro-LED chip is loosely displaced, which affects its luminous performance. In order to solve the above problems, the first embodiment of the present invention provides a display substrate, as shown in FIG. 1 and FIG. 2. The display substrate includes a backplane 1 and a plurality of Micro-LEDs arranged on the backplane 1. Chip 2. The Micro-LED chip 2 includes a first electrode 21 and a second electrode 22, the back plate 1 is provided with a groove 11, and the Micro-LED chip 2 passes through the first electrode 21 and the second electrode. 22 is inserted into the groove 11 to be electrically connected to the backplane 1. In specific implementation, the Micro-LED chip 2 is not electrically connected to the back plate 1 through solder, but is directly inserted into the groove 11 of the back plate 1 through the first electrode 21 and the second electrode 22 to realize the Micro-LED chip 2 The electrical connection between the LED chip 2 and the backplane 1. When one or more Micro-LED chips 2 are defective, you only need to pull out the defective Micro-LED chip 2 from the groove 11, and then plug a non-defective Micro-LED chip 2 into the corresponding groove. In the slot 11, the replacement of the Micro-LED chip 2 is convenient, and at the same time, the problem of the loosening and displacement of the Micro-LED chip caused by the traditional replacement of the Micro-LED chip by heating solder is overcome.

In a specific embodiment, in order to improve the electrical performance of the first electrode 21 and the second electrode 22 in contact with the groove 11, a conductive layer 12 is further provided on the inner wall of the groove 11, and the material of the conductive layer 12 may be Graphene, indium oxide, tin, zinc oxide, nickel, silver, aluminum, gold, platinum, palladium, magnesium, tungsten and other materials with good conductivity can have a single-layer structure or a multilayer structure. The conductive layer 12 is formed on the inner wall of the groove 11. When the first electrode 21 and the second electrode 22 are inserted into the groove 11, the first electrode 21 and the second electrode 22 are connected to the conductive layer 12 Direct contact, thereby improving the electrical performance of the display substrate.

In a specific embodiment, the first electrode 21 and the second electrode 22 are columnar, and the shape of the cross section can be set as required, such as a rectangle, a circle, and the like. The material of the first electrode 21 and the second electrode 22 can be one or more of metals or alloys such as indium, zinc, nickel, silver, aluminum, gold, platinum, palladium, magnesium, tungsten, etc., and a single layer can be used. The metal structure can also be a multi-layer metal structure.

In a specific embodiment, in order to achieve the stability of the electrical connection between the Micro-LED chip 2 and the backplane 1, the shape of the groove 11 needs to match the first electrode 21 and the second electrode 22. In a specific embodiment, the groove 11 includes a first groove 111 and a second groove 112. When the Micro-LED chip 2 and the backplane 1 are electrically connected, the first electrode 21 is inserted in In the first groove 111, the second electrode 22 is inserted into the second groove 112, and the cross-sectional shape of the first groove 111 is the same as the cross-sectional shape of the first electrode 21 Similarly, the cross-sectional shape of the second groove 112 is the same as the cross-sectional shape of the second electrode 22. For example, the cross-sectional shape of the first electrode 21 and the first groove 111 is a circle, and the cross-sectional shape of the second electrode 22 and the second groove 112 is a rectangle. In order to enable the first electrode 21 and the second electrode 22 to be inserted into the first groove 111 and the second groove 112, and the first electrode 21 and the second electrode 22 are in the first groove 111 and the second groove 112 are not easy to loosen, the cross-sectional size of the first electrode 21 is slightly smaller than the cross-sectional size of the first groove 111, and the cross-sectional size of the second electrode 22 is slightly smaller than the first groove 111. The cross-sectional size of the two grooves 112.

In a specific embodiment, the Micro-LED chip 2 further includes a semiconductor layer 23, and the first electrode 21 and the second electrode 22 are disposed on the semiconductor layer 23. The semiconductor layer 23 includes a first semiconductor layer 231, an active layer 232 disposed on the first semiconductor layer 231, and a second semiconductor layer 233 disposed on the active layer 232. The materials of the first semiconductor layer 231, the active layer 232, and the second semiconductor layer 233 can be set according to the actual requirements of the Micro-LED chip. For example, the first semiconductor layer 231 and the second semiconductor layer 233 are P-type and N-type nitrides. The gallium layer, the active layer 232 is a gallium nitride multiple quantum well layer.

In a specific embodiment, the first electrode 21 is disposed on the side of the second semiconductor layer 233 away from the active layer 232, and the second electrode 22 is disposed on the first semiconductor layer 231 and the active layer 232. The contact surface of the active layer 232. The first electrode 21 and the second electrode 22 are one of a positive electrode and a negative electrode, respectively, and the first semiconductor layer 231 and the second semiconductor layer 233 are an N-type semiconductor layer and a P-type semiconductor layer, respectively. One of the layers.

In a specific embodiment, the sides of the first electrode 21 and the second electrode 22 away from the semiconductor layer 23 may be on the same level or on different levels, that is, the first electrode 21 The side away from the semiconductor layer 23 may be higher or lower than the side away from the semiconductor layer 23 of the second electrode 22. The depth of the first groove 111 may be higher, lower or equal to the height of the first electrode 21, and the depth of the second groove 112 may be higher, lower or equal to the height of the first electrode 21. height. In a specific embodiment, the sides of the first electrode 21 and the second electrode 22 away from the semiconductor layer 23 are on the same horizontal plane, and the first groove 111 and the second groove 112 are on the same level. The depth is the same and the height is the same as the height of the first electrode 21, so that a stable electrical connection between the Micro-LED chip 2 and the backplane 1 is realized.

In a specific embodiment, the first electrode 21 is a positive electrode, and the second electrode 22 is a negative electrode. Correspondingly, the first semiconductor layer 231 is an N-type semiconductor layer, and the second semiconductor layer 233 is a P-type semiconductor layer. In actual use, after the display panel is energized, voltage is applied to the first electrode 21 on the Micro-LED chip 2, and the second semiconductor layer 233, that is, the holes in the forward P region will continuously swim to the first semiconductor layer 231 That is, the N region, and the electrons in the first semiconductor layer 231, that is, the N region move relative to the holes to the second semiconductor layer 233, that is, the P region. The electrons and holes combine with each other to excite photons and generate light energy. When electrons flow from the anode to the cathode, the Micro-LED chip 2 emits light of different colors from ultraviolet to infrared.

In another specific embodiment, the first electrode 21 is a negative electrode, and the second electrode 22 is a positive electrode. Correspondingly, the first semiconductor layer 231 is a P-type semiconductor layer, and the second semiconductor layer 233 is an N-type semiconductor layer. In actual use, after power is applied to the display panel, a voltage is applied to the second electrode 22 on the Micro-LED chip 2, and the holes in the first semiconductor layer 231, that is the forward P region, will continuously swim to the second semiconductor layer 233 That is, the N region, and the electrons in the second semiconductor layer 233, that is, the N region move relative to the holes to the first semiconductor layer 231, that is, the P region. The electrons and holes combine with each other to excite photons and generate light energy. When electrons flow from the anode to the cathode, the Micro-LED chip 2 emits light of different colors from ultraviolet to infrared.

In a specific embodiment, the height of the second electrode 22 is greater than the sum of the thicknesses of the active layer 232 and the second semiconductor layer 233, because the second electrode 22 is disposed on the first semiconductor layer 231 That is, the distance from the side of the second electrode 22 away from the first semiconductor layer 231 to the first semiconductor layer 231 is greater than the distance from the side of the second semiconductor layer 233 away from the first semiconductor layer 231 to the first semiconductor layer 231 The distance of a semiconductor layer 231. The first electrode 21 is disposed on the second semiconductor layer 233, that is, the distance from the side of the first electrode 21 away from the first semiconductor layer 231 to the first semiconductor layer 231 is greater than that of the second semiconductor layer 231 The distance from the side of 233 away from the first semiconductor layer 231 to the first semiconductor layer 231 is to realize that the first electrode 21 and the second electrode 22 are inverted into the groove 11.

In the second embodiment of the present invention, a method for manufacturing a display substrate is also provided for manufacturing the above-mentioned display substrate. As shown in FIG. 3, the method for manufacturing a Micro-LED chip on the display substrate includes the following steps :

S1, forming a semiconductor layer on the substrate;

S2, forming a photoresist layer on the substrate and the semiconductor layer;

S3. Exposing and developing the photoresist layer to remove the photoresist material corresponding to the position of the first electrode and the second electrode on the semiconductor layer;

S4, forming a first electrode and a second electrode on the semiconductor layer.

In a specific embodiment, in order to manufacture the aforementioned Micro-LED chip, it is first necessary to form a semiconductor layer on the substrate. The substrate is a transparent substrate such as glass, quartz or sapphire. In a specific embodiment, the substrate is a sapphire substrate. The sapphire substrate has mature production technology, good stability, high mechanical strength, easy handling and cleaning, and Reusable and other advantages.

In a specific embodiment, the semiconductor layer includes a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer, and the step S1 specifically includes the steps:

S11, forming a first semiconductor layer on the substrate;

S12, forming an active layer on the first semiconductor layer;

S13, forming a second semiconductor layer on the active layer.

In a specific embodiment, a clean substrate is selected, a first semiconductor layer is formed on the substrate, then an active layer is formed on the first semiconductor layer, and finally a second semiconductor layer is formed on the active layer, thereby A semiconductor layer is formed on the substrate. The formation methods of the first semiconductor layer, the active layer, and the second semiconductor layer can be selected according to the actual requirements of the Micro-LED chip, such as vapor phase epitaxial growth, liquid phase epitaxial growth, and the like.

In a specific embodiment, after the semiconductor layer is formed on the substrate and before the photoresist layer is formed, the semiconductor layer needs to be etched to remove part of the active layer and the second semiconductor layer to expose the first semiconductor layer. Then, a photoresist layer is formed on the substrate, the first semiconductor layer, and the second semiconductor layer by coating or vapor deposition, and the distance from the side of the photoresist layer away from the substrate to the substrate is greater than that of the substrate. The distance from the side of the second semiconductor layer away from the substrate to the substrate is to protect the area on the semiconductor layer where the first electrode and the second electrode do not need to be formed. The photoresist layer is composed of photosensitive materials, the solubility changes when exposed to light, and can be removed by etching.

In a specific embodiment, after the photoresist layer is formed on the substrate and the semiconductor layer, the photoresist layer is exposed and developed to remove the photoresist material corresponding to the position of the first electrode and the second electrode on the semiconductor layer , To expose the semiconductor layer where the first electrode and the second electrode need to be formed, and then form the first electrode and the second electrode on the semiconductor layer, and remove the photoresist layer on the substrate and the semiconductor layer, thereby completing the Micro -Manufacturing of LED chips.

In summary, the present invention provides a display substrate and a manufacturing method thereof. The display substrate includes: a backplane and a plurality of Micro-LED chips arranged on the backplane; the Micro-LED chip includes a An electrode and a second electrode; the back plate is provided with a groove, and the Micro-LED chip is inserted into the groove through the first electrode and the second electrode to be electrically connected to the back plate . In this application, grooves matching the first electrode and the second electrode are provided on the back plate, and the Micro-LED chip is inserted into the groove through the first electrode and the second electrode to be electrically connected to the back plate. When the chip is defective, you only need to pull out the defective Micro-LED chip from the groove and re-insert a non-defective Micro-LED chip into the corresponding groove. The replacement of the Micro-LED chip is convenient and overcomes the traditional Micro-LED chip loosening and displacement caused by replacing the Micro-LED chip by heating the solder.

It should be understood that the system application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or changes can be made based on the above description, and all these improvements and changes shall fall within the protection scope of the appended claims of the present invention. .

Claims

A display substrate includes a backplane and a plurality of Micro-LED chips, wherein the Micro-LED chip includes a first electrode and a second electrode; the backplane is provided with a groove; the Micro-LED The chip is inserted into the groove and electrically connected to the back plate through the first electrode and the second electrode.
The display substrate according to claim 1, wherein the inner wall of the groove is provided with a conductive layer.
The display substrate of claim 2, wherein the groove comprises a first groove and a second groove;

The first electrode is inserted into the first groove, and the cross-sectional shape of the first electrode is the same as the cross-sectional shape of the first groove;

The second electrode is inserted into the second groove, and the cross-sectional shape of the second electrode is the same as the cross-sectional shape of the second groove.
The display substrate of claim 1, wherein the Micro-LED chip further comprises a semiconductor layer.
The display substrate of claim 4, wherein the semiconductor layer comprises:

The first semiconductor layer;

An active layer provided on the first semiconductor layer;

A second semiconductor layer provided on the active layer.
7. The display substrate of claim 5, wherein the first electrode is disposed on the second semiconductor layer, and the second electrode is disposed on the first semiconductor layer.
7. The display substrate of claim 6, wherein the first electrode is a positive electrode, and the second electrode is a negative electrode.
8. The display substrate of claim 7, wherein the first semiconductor layer is an N-type semiconductor layer, and the second semiconductor layer is a P-type semiconductor layer.
7. The display substrate of claim 6, wherein the first electrode is a negative electrode, and the second electrode is a positive electrode.
9. The display substrate of claim 9, wherein the first semiconductor layer is a P-type semiconductor layer, and the second semiconductor layer is an N-type semiconductor layer.
7. The display substrate of claim 6, wherein the height of the second electrode is greater than the sum of the thickness of the active layer and the second semiconductor layer.
A method for manufacturing a display substrate for manufacturing the display substrate according to any one of claims 1 to 11, wherein the method for manufacturing a Micro-LED chip on the display substrate comprises the following steps:

Forming a semiconductor layer on the substrate;

Forming a photoresist layer on the substrate and the semiconductor layer;

Exposing and developing the photoresist layer to remove the photoresist material corresponding to the position of the first electrode and the second electrode on the semiconductor layer;

A first electrode and a second electrode are formed on the semiconductor layer.
The method of manufacturing a display substrate according to claim 12, wherein the semiconductor layer comprises a first semiconductor layer, a second semiconductor layer and an active layer, and the step of forming the semiconductor layer on the substrate comprises:

Forming a first semiconductor layer on the substrate;

Forming an active layer on the first semiconductor layer;

A second semiconductor layer is formed on the active layer.
The method for manufacturing a display substrate according to claim 13, wherein the distance from the side of the photoresist layer far from the substrate to the substrate is greater than the distance from the side of the second semiconductor layer far from the substrate to the The distance of the substrate.
The method of manufacturing a display substrate according to claim 12, wherein after the step of forming the first electrode and the second electrode on the semiconductor layer, the method further comprises:

The photoresist layer on the substrate and the semiconductor layer is removed.