CN211604646U - A micro light-emitting diode display and its detection device - Google Patents

Abstract

The utility model relates to a semiconductor technology field, concretely relates to little emitting diode display and detection device thereof, its display includes: the display device comprises a display back plate, wherein more than one group of metal welding disc assemblies are arranged on the display back plate, the surface of each group of metal welding disc assemblies is connected with a metal pad at the lower end of a micro light-emitting diode chip through conductive adhesive, shading photoresistors are respectively arranged on two sides of each metal welding disc assembly, packaging structures are covered above the micro light-emitting diode chip and the shading photoresistors, and the conductive adhesive is light-cured conductive adhesive and is doped with metal materials; the utility model discloses a little emitting diode display has greatly reduced the complexity that carries out the replacement to miniature luminous little emitting diode chip through the improvement of its structure, has greatly improved the production efficiency of display, has brought the guarantee for the quick volume production of display screen.

Description

A micro light-emitting diode display and its detection device

technical field

The utility model relates to the technical field of light emitting diodes, in particular to a micro light emitting diode display and a detection device applied to the micro light emitting diode display.

Background technique

Micro LED (Micro LED), that is, LED miniaturization and matrix technology, it has good stability, life, and advantages in operating temperature, but also inherits the low power consumption, color saturation, and fast response speed of LED. , strong contrast and other advantages, it has great application prospects.

Making a display screen from micro LEDs is the mainstream development direction of display devices in the future; in the existing manufacturing process of micro LED displays, micro LED chips need to be generated on the growth substrate first; and then through mass transfer Transfer to display backplane and bond to secure. In the prior art, after the miniature light-emitting diode chip is bonded to the display backplane, it is necessary to conduct a power-on test on the miniature light-emitting diode chip; if there is no problem, the subsequent packaging process can be performed. However, in the prior art, the testing process is set after the bonding process. If a damaged micro LED chip is found in the display backplane at this time, the damaged micro LED chip needs to be debonded, and then the damaged micro LED chip can be debonded. The replacement greatly affects the production efficiency of the display, and brings a great obstacle to the rapid mass production of the display.

Utility model content

In order to overcome the above-mentioned defects, the purpose of the present invention is to provide a micro-LED display which is convenient to replace defective chips and a detection device applied to the micro-LED display.

The purpose of this utility model is to achieve through the following technical solutions:

The utility model relates to a micro light-emitting diode display, which comprises:

A display backplane, which is provided with more than one group of metal pad components, and the surfaces of each group of the metal pad components are connected to the metal pads at the lower end of the micro-LED chip through conductive glue, and the metal pads are welded Two sides of the disk assembly are respectively provided with light-shielding photoresist, the micro-LED chip and the light-shielding photoresist are covered with a package structure, and the conductive adhesive is a light-curing conductive adhesive, which is doped with metal materials.

In the present invention, the metal pad assembly is composed of two metal pads, which are a positive electrode pad and a negative electrode pad respectively.

In the present invention, an electrode is provided on the upper end of the micro-LED chip, and the electrode is connected with the packaging structure.

In the present invention, the encapsulation structure comprises: a first encapsulation layer, a second encapsulation layer, a third encapsulation layer and a fourth encapsulation layer arranged in sequence from bottom to top; the first encapsulation layer covers the micro above the light-emitting diode chip and the light-shielding photoresist.

The utility model is a detection device applied to the above-mentioned micro-LED display, which is characterized by comprising: a carrier substrate, on which more than one electrode structure is arranged, and each of the electrode structures is used for connected with one of the micro-LED chips.

In the present invention, the carrying substrate is provided with a boss, and the electrode structure covers the boss.

In the present invention, a power source is connected to the carrier substrate, and the power source is used for supplying power to the electrode structure.

The micro-LED display of the utility model uses conductive adhesive to temporarily fix the display backplane and the micro-LED chips, and then detects the micro-LED chips temporarily fixed on the display backboard, and only after the detection and repair are completed. The display backplane and the micro-LED chip are bonded, and by improving the above-mentioned structure of the display, the complexity of replacing the micro-LED chip is greatly reduced. The display cooperates with the detection, which greatly improves the production efficiency of the display, and brings a guarantee for the rapid mass production of the display.

Description of drawings

For ease of description, the present invention is described in detail by the following preferred embodiments and accompanying drawings.

Fig. 1 is the working principle schematic diagram of embodiment 1 of the production detection method of the present utility model;

2 is a schematic diagram of the working principle of step S101 in Embodiment 1 of the present invention;

3 is a schematic diagram of the working principle of step S102 in Embodiment 1 of the present invention;

4 is a schematic diagram of the working principle of step S103 in Embodiment 1 of the present invention;

5 is a schematic diagram of the working principle of step S104 in Embodiment 1 of the present invention;

6 is a schematic diagram of the working principle of step S105 in Embodiment 1 of the present invention;

7 is a schematic diagram of the working principle of step S107 in Embodiment 1 of the present invention;

8 is a schematic diagram of the working principle of Embodiment 2 of the production detection method of the present invention;

9 is a schematic diagram of the working principle of step S201 in Embodiment 2 of the present invention;

10 is a schematic diagram of the working principle of step S202 in Embodiment 2 of the present invention;

11 is a schematic diagram of the working principle of step S203 in Embodiment 2 of the present invention;

12 is a schematic diagram of the working principle of step S204 in Embodiment 2 of the present invention;

13 is a schematic diagram of the working principle of step S205 in Embodiment 2 of the present invention;

14 is a schematic diagram of the working principle of step S208 in Embodiment 2 of the present invention;

15 is a schematic diagram of the working principle of step S209 in Embodiment 2 of the present invention;

16 is a schematic diagram of the structure and principle of Embodiment 3 of the micro-LED display of the present invention;

17 is a schematic diagram of the structure and principle of Embodiment 4 of the micro-LED display of the present invention;

FIG. 18 is a schematic structural principle diagram of Embodiment 5 of the detection device of the micro-LED display of the present invention.

Detailed ways

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

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise" etc. Or the positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operation, so it cannot be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined as "first", "second" may expressly or implicitly include one or more of said features. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a connectable connection. Disconnect the connection, or connect it in one piece. It can be a mechanical connection or an electrical connection. It can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication between two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

The technical scheme of the utility model is suitable for flip-chip displays and displays mounted with vertical structure chips.

Example 1

Hereinafter, a method for producing and detecting a flip-chip display will be described in detail to describe a method for producing and detecting a micro-LED display of the present invention. Please refer to FIG. 1 to FIG. 7 , which includes:

S101. Provide a display backplane and provide metal pad assembly on the display backplane

A display backplane 101 is provided, and the display backplane 101 is a thin film transistor (TFT, Thin FilmTransistor) backplane; and two or more metal pad components 104 are arranged on the display backplane 101, wherein each metal The pad component 104 is composed of two metal pads, which are a positive electrode pad and a negative electrode pad respectively; the metal pads are composed of titanium Ti, gold Au, tin Sn, copper Cu, indium In, silver Ag, platinum Pt, One or several metals among chromium Cr and nickel Ni are formed by coating, exposing, developing, etching and stripping.

S102. Provide conductive glue on the surface of the metal pad assembly

Conductive adhesive 110 is coated on the surfaces of the positive electrode pad and the negative electrode pad; in this embodiment, the conductive adhesive 110 is used to temporarily fix the transferred micro-LED chip on the display backplane, and is connected with the display backplane The board is electrically connected; preferably, the conductive adhesive 110 is a photocurable conductive adhesive, the main body of the conductive adhesive 110 includes: epoxy resin, silicone, and the main body is doped with metal, and the metal includes: silver Ag, One or several combinations of nickel Ni and copper Cu.

S103. Transfer and temporarily fix the micro-LED chip on the display backplane

The plurality of micro-LED chips 103 are transferred onto the metal pad assembly 104 by the transfer device 201 by a mass transfer method, and the two metal pads 105 at the lower ends of the plurality of micro-LED chips 103 are respectively connected to the positive electrode pads and the metal pads 105 . The negative electrode pads are butted; apply appropriate downward pressure, then release the micro-LED chip 103 and remove the transfer device 201, so that the metal pad at the lower end of the micro-LED chip is in contact with the surface of the metal pad assembly and conducts electricity The adhesive 110 is temporarily fixed; the conductive adhesive 110 will temporarily fix the micro-LED chip 103, and provide electrical connection between the micro-LED chip 103 and the display backplane 101; wherein, the mass transfer method includes but is not limited to precision Grab, selective release, self-assembly and transfer or a combination of the above.

S104. Determine whether there is a defective chip

A detection device is provided, the detection device is electrically connected with the micro-LED chips, and the electrical properties of a plurality of the micro-LED chips are measured. A path is formed between the disk assembly and the electrode structure, and electrical measurement is performed. According to the electrical measurement results, it is determined whether there is a defective chip 103a in all the temporarily fixed micro-LED chips; The chip is taken out from the display backplane and replaced; if there is no defective chip, step S106 is performed to bond the metal pad and the metal pad assembly.

S105. Take out the bad chip from the display backplane and replace it

If there is a defective chip, the position of the defective chip 103a on the display backplane 101 will be located, and then the repairing device 203 will be used to remove the located defective chip 103a from the display backplane 101, and the normal The micro-LED chip 103 is placed in this position to replace the micro-LED chip 103 .

S106. Bonding Metal Pad and Metal Pad Assembly

The two metal pads 105 at the lower end of the micro-LED chip 103 are respectively bonded to the positive electrode pad and the negative electrode pad, so that the micro-LED chip 103 is fixed on the display backplane 101 . The metals used for bonding include but are not limited to: tin Sn/gold Au, silver Ag/indium In, indium In/nickel Ni, tin Sn/copper Cu, tin Sn/silver Ag, gold Au/indium In.

S107. Curing conductive adhesive by light

The conductive adhesive 110 is cured by light; in this embodiment, the conductive adhesive 110 is a photocurable conductive adhesive, and the conductive adhesive 110 is cured by light to prevent the liquid conductive adhesive 110 from affecting subsequent processes and equipment.

S108. Installation package structure

A light-shielding photoresist 102 is coated on both sides of the metal pad assembly 104 on the display backplane 101 , and the light-shielding photoresist 102 is disposed on both sides of the micro-LED chip 103 , and then is placed on the micro-LED chip 103 . The upper ends of the light-emitting diode chip 103 and the light-shielding photoresist 102 are covered with a package structure to form a display. Specifically, the first encapsulation layer 106 , the second encapsulation layer 107 , the third encapsulation layer 108 , and the fourth encapsulation layer 109 are sequentially covered on the upper end of the micro-LED chip 103 . The refractive index of the first encapsulation layer 106 is greater than that of the second encapsulation layer 107 , and the refractive index of the second encapsulation layer 107 is greater than that of the third encapsulation layer 108 .

Example 2

A production and detection method of a micro-LED display of the present invention will be specifically described below by taking a production detection method of a vertical structure chip display as an example, please refer to FIG. 8 to FIG. 15 , which includes:

S201. Provide a display backplane and provide metal pad assembly on the display backplane

A display backplane 101 is provided, and the display backplane 101 is a thin film transistor backplane; and more than two metal pad components 104 are arranged on the display backplane 101, wherein each metal pad component 104 is composed of A metal pad consists of one or more metals selected from titanium Ti, gold Au, tin Sn, copper Cu, indium In, silver Ag, platinum Pt, chromium Cr, and nickel Ni through glue coating, exposure , developed, etched, and formed after stripping.

S202. Provide conductive glue on the surface of the metal pad assembly

Conductive adhesive 110 is coated on the surface of the metal pad; in this embodiment, the conductive adhesive 110 is used to temporarily fix the transferred micro-LED chips on the display backplane, and is connected with the display backplane 101 It is electrically conductive; preferably, the conductive adhesive 110 is a photocurable conductive adhesive, the main body of the conductive adhesive 110 includes: epoxy resin, silicone, and the main body is doped with metal, and the metal includes: silver Ag, nickel One or several combinations of Ni, Cu and Cu.

S203. Transfer and temporarily fix the micro-LED chip on the display backplane

The plurality of micro-LED chips 103 are transferred onto the metal pad assembly 104 by the transfer device 201 by a mass transfer method, and the metal pads 105 at the lower ends of the plurality of micro-LED chips 103 are in contact with the metal pads; applying Appropriate downward pressure, then release the micro-LED chips 103 and remove the transfer device 201, so that the metal pads on the lower ends of the plurality of micro-LED chips are abutted with the surface of the metal pad assembly and temporarily fixed by the conductive glue 110 ; The conductive adhesive 110 will temporarily fix the plurality of micro-LED chips 103, and provide electrical connection for the plurality of micro-LED chips 103 and the display backplane 101; wherein, the mass transfer method includes but not limited to precise grasping Extraction, selective release, self-assembly and transfer, or a combination of the above methods.

S204. Determine whether there is a defective chip

A detection device 202 is provided, the detection device 202 is connected to a plurality of the micro-LED chips, and the electrical properties of the plurality of micro-LED chips are measured. A path is formed between the metal pad assembly and the electrode structure, and electrical measurement is performed, and according to the electrical measurement results, it is determined whether there is a defective chip 103a in all the temporarily fixed micro-LED chips; if there is a defective chip 103a, proceed to the step In S205, the defective chip is taken out from the display backplane and replaced; if there is no defective chip, step S206 is performed to bond the metal pad and the metal pad assembly.

S205. Take out the bad chip from the display backplane and replace it

If there is a defective chip, the position of the defective chip 103a on the display backplane 101 will be located, and then the repairing device 203 will be used to remove the located defective chip 103a from the display backplane 101, and the normal The micro-LED chip 103 is placed in this position to replace the micro-LED chip 103 .

S206. Bonding Metal Pad and Metal Pad Assembly

The metal pad 105 at the lower end of the micro-LED chip 103 is bonded to the metal pad, so that the micro-LED chip 103 is fixed on the display backplane 101 . The metals used for bonding include but are not limited to: tin Sn/gold Au, silver Ag/indium In, indium In/nickel Ni, tin Sn/copper Cu, tin Sn/silver Ag, gold Au/indium In.

S207. Curing conductive adhesive by light

The conductive adhesive 110 is cured by light; in this embodiment, the conductive adhesive 110 is a photocurable conductive adhesive, and the conductive adhesive 110 is cured by light to prevent the liquid conductive adhesive 110 from affecting subsequent processes and equipment.

S208. Disposing electrodes on micro-LED chips

An electrode 111 is disposed on the upper end of the micro-LED chip 103, and the electrode 111 is made of indium tin oxide (ITO), a transparent conductive material.

S209. Installation package structure

A light-shielding photoresist 102 is coated on both sides of the metal pad assembly 104 on the display backplane 101 , and the light-shielding photoresist 102 is disposed on both sides of the micro-LED chip 103 , and then is placed on the micro-LED chip 103 . The upper ends of the light-emitting diode chip 103 and the light-shielding photoresist 102 are covered with a package structure to form a display. Specifically, the first encapsulation layer 106 , the second encapsulation layer 107 , the third encapsulation layer 108 , and the fourth encapsulation layer 109 are sequentially covered on the upper end of the micro-LED chip 103 . The refractive index of the first encapsulation layer 106 is greater than that of the second encapsulation layer 107 , and the refractive index of the second encapsulation layer 107 is greater than that of the third encapsulation layer 108 .

Example 3

A micro-LED display of the present invention will be specifically described below with an embodiment of a flip-chip display, please refer to FIG. 16 , which includes:

The display backplane 101 is provided with more than one group of metal pad assemblies 104 on the display backplane 101 , and each group of the metal pad assemblies 104 is composed of two metal pads, which are respectively a positive electrode pad and a negative electrode pad , and the metal pad component 104 is formed by patterning one or more metals selected from titanium Ti, gold Au, tin Sn, copper Cu, indium In, silver Ag, platinum Pt, chromium Cr, and nickel Ni. . And the surfaces of the positive electrode pad and the negative electrode pad are connected with the metal pad 105 at the lower end of the micro-LED chip 103 through the conductive glue 110; wherein, the conductive glue 110 is a light-cured conductive glue, and the main body of the conductive glue 110 includes: : epoxy resin, silicone, and its main body is doped with metal, and the metal includes: one or several combinations of silver Ag, nickel Ni, copper Cu. In this embodiment, by disposing the conductive adhesive 110 between the metal pads 105 and the metal pads, the micro-LED chips 103 before being bonded with the display backplane 101 can be temporarily fixed on the display backplane 101, which is convenient for After the detection, the defective chips are replaced. The two sides of the metal pad assembly 104 are respectively provided with light-shielding photoresist. The light-shielding photoresist 102 includes: a white photoresist or a black photoresist; Disposing the light-shielding photoresist 102 on the display backplane 101 can effectively prevent the occurrence of light leakage and light mixing in the display. A package structure is covered above the micro-LED chip 103 and the light-shielding photoresist. The encapsulation structure includes a first encapsulation layer 106, a second encapsulation layer 107, a third encapsulation layer 108, and a fourth encapsulation layer 109 that are sequentially covered from bottom to top; and the refractive index of the first encapsulation layer 106 is greater than that of the second encapsulation layer The refractive index of 107 and the refractive index of the second encapsulation layer 107 are greater than the refractive index of the third encapsulation layer 108 .

Example 4

A micro-LED display of the present invention will be specifically described below with an embodiment of a vertical structure chip display, please refer to FIG. 17 , which includes:

The display backplane 101 is provided with more than one group of metal pad components 104 on the display backplane 101, each group of the metal pad components 104 is composed of a metal pad, and the metal pad component 104 is made of titanium Ti, One or several metals selected from gold Au, tin Sn, copper Cu, indium In, silver Ag, platinum Pt, chromium Cr, and nickel Ni are formed by patterning. And the surface of the metal pad is connected with the metal pad 105 at the lower end of the micro-LED chip 103 through the conductive glue 110; wherein, the conductive glue 110 is light-cured conductive glue, and the main body of the conductive glue 110 includes: epoxy resin , silicone, and its main body is doped with metal, and the metal includes: one or several combinations of silver Ag, nickel Ni, copper Cu. In this embodiment, by disposing the conductive adhesive 110 between the metal pads 105 and the metal pads, the micro-LED chips 103 before being bonded with the display backplane 101 can be temporarily fixed on the display backplane 101, which is convenient for After the detection, the defective chips are replaced. The two sides of the metal pad assembly 104 are respectively provided with light-shielding photoresist. The light-shielding photoresist 102 includes: a white photoresist or a black photoresist; Disposing the light-shielding photoresist 102 on the display backplane 101 can effectively prevent the occurrence of light leakage and light mixing in the display. The upper end of the micro-LED chip 103 is provided with an electrode 111, wherein the electrode 111 is made of indium tin oxide (ITO), a transparent conductive material, and a package structure is covered above the micro-LED chip 103 and the light-shielding photoresist. The encapsulation structure includes a first encapsulation layer 106, a second encapsulation layer 107, a third encapsulation layer 108, and a fourth encapsulation layer 109 that are sequentially covered from bottom to top; and the refractive index of the first encapsulation layer 106 is greater than that of the second encapsulation layer The refractive index of 107 and the refractive index of the second encapsulation layer 107 are greater than the refractive index of the third encapsulation layer 108 .

Example 5

A detection device applied to a micro-LED display of the present invention will be specifically described below with an embodiment, please refer to FIG. 18 , which includes:

A carrier substrate 2021, the carrier substrate 2021 is provided with one or more electrode structures 2022, the electrode structures 2022 are arranged on the lower surface of the carrier substrate 2021, and each of the electrode structures 2022 is used to interact with one of the micro-luminescence The diode chip 103 is connected to each other, and the carrier substrate 2021 is connected with a power source, and the power source is used to supply power to the electrode structure 2022; therefore, when detection is required, the electrode structure 2022 on the carrier substrate 2021 is connected to the micro-LED 103 Butt joint, and supply power to the micro-LED 103 to detect the micro-LED 103; the carrier substrate 2021 is provided with a boss 2023 protruding toward the lower surface thereof, and the electrode structure 2022 covers the boss On the stage 2023 , it makes the electrode structure 2022 more convenient for the connection of the micro-LED 103 .

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples", etc., is meant to incorporate the embodiments A particular feature, structure, material, or characteristic described or exemplified is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection of the utility model.

Claims (7)

1. A micro light emitting diode display, comprising:

the display back plate is provided with more than one group of metal welding disc assemblies, the surface of each group of metal welding disc assemblies is connected with a metal pad at the lower end of a micro light-emitting diode chip through conductive adhesive, shading photoresistors are respectively arranged on two sides of each metal welding disc assembly, packaging structures are covered above the micro light-emitting diode chip and the shading photoresistors, and the conductive adhesive is light-cured conductive adhesive.

2. The micro-led display of claim 1, wherein the metal pad assembly consists of two metal pads, a positive pad and a negative pad, respectively.

3. The micro-led display of claim 1, wherein the upper ends of the micro-led chips are provided with electrodes, and the electrodes are connected to the encapsulation structure.

4. A micro-led display according to any of claims 1-3, wherein the encapsulation structure comprises: the first packaging layer, the second packaging layer, the third packaging layer and the fourth packaging layer are sequentially arranged from bottom to top; the first packaging layer covers the micro light-emitting diode chip and the shading photoresistor.

5. A detection device applied to the micro-led display device of claim 1, comprising: the light-emitting diode chip comprises a bearing substrate, wherein more than one electrode structure is arranged on the bearing substrate, and each electrode structure is used for being connected with one micro light-emitting diode chip.

6. The detecting device for detecting the rotation of a motor rotor according to claim 5, wherein the carrying substrate is provided with a boss, and the electrode structure is covered on the boss.

7. The detecting device for detecting the rotation of a motor rotor according to claim 6, wherein a power supply is connected to the carrying substrate and is used for supplying power to the electrode structure.

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