CN112133208A

CN112133208A - LED display module and manufacturing method thereof, LED display screen and manufacturing method thereof

Info

Publication number: CN112133208A
Application number: CN202010742716.4A
Authority: CN
Inventors: 张汉春; 江忠永
Original assignee: Hangzhou Multi Color Optoelectronics Co ltd
Current assignee: Hangzhou Multi Color Optoelectronics Co ltd
Priority date: 2020-07-29
Filing date: 2020-07-29
Publication date: 2020-12-25

Abstract

The application discloses an LED display module and a manufacturing method thereof, and an LED display screen and a manufacturing method thereof. The LED display module comprises a PCB board; the LEDs are positioned on the first surface of the PCB and are electrically connected with the PCB, and each group of LED chips form pixel points; the isolation gate is positioned on the first surface of the PCB, and each pixel point is separated by the isolation gate; and the packaging layer is positioned on the first surface of the PCB and covers each LED. This LED display module separates each pixel through adopting the isolated gate structure, alleviates the crosstalk problem between the adjacent pixel to improve display effect.

Description

LED display module and manufacturing method thereof, LED display screen and manufacturing method thereof

Technical Field

The invention relates to the field of semiconductor packaging, in particular to an LED display module and a manufacturing method thereof, and an LED display screen and a manufacturing method thereof.

Background

In recent years, LED (Light-Emitting Diode) displays are being developed toward high resolution, which makes the number of pixels per unit area more and more. The conventional smd (surface Mounted devices) LED device adopts a patch method to assemble an LED display screen, so that the current requirement of high resolution display cannot be met. Specifically, as the devices are smaller, the packaging difficulty of a single chip device is increased, and the corresponding cost is increased; and as the number of patches increases in geometric order of magnitude, the assembly efficiency is lower; when the distance between the LEDs is smaller, particularly when the point distance is less than 800um, the difficulty of the surface mounting process is higher and higher, and the cost of the surface mounting is higher and higher; after the small-spacing SMD device patches are formed into a module, the edge of the module is very easily damaged by extrusion and friction in the installation and transportation processes, so that the maintenance cost of the small-spacing LED screen is sharply increased.

Therefore, for the LED display screen with fine pitch (P0.8 or less), the development trend is cob (chip On board) integrated package. On one hand, the COB LED display module can be used as an independent display unit and applied to mobile phones, vehicle-mounted display and wearable display equipment; on the other hand, an LED large screen such as an LED television can be obtained by splicing COB LED display modules.

The development of the conventional COB LED product still has a plurality of problems so far, so that the conventional COB LED product cannot be popularized and used in a large range. Specifically, when the pixel pitch is smaller than 800um (micro pitch), the front mounted chip cannot meet the requirement, and a flip chip is required. Meanwhile, as the distance between the chips of the adjacent pixels is short, when the display is carried out, the luminous light rays of the LEDs can influence each other, the light crosstalk phenomenon is obvious, the definition of a screen is poor, and the display effect is greatly influenced.

Disclosure of Invention

In view of this, the invention provides an LED display module and a manufacturing method thereof, an LED display screen and a manufacturing method thereof, so as to improve the display effect of the screen.

According to a first aspect of the present invention, there is provided an LED display module, comprising: a PCB board; the LED display device comprises a PCB, a plurality of groups of LED chips and a plurality of control circuits, wherein the plurality of groups of LED chips are positioned on the first surface of the PCB and are electrically connected with the PCB, and each group of LED chips form a pixel point; the isolation gate is positioned on the first surface of the PCB, and each pixel point is separated by the isolation gate; and the packaging layer is positioned on the first surface of the PCB and covers each LED chip.

Preferably, the isolation fence is made of plastic and is formed by injection molding.

Preferably, the isolation gate is of an integral structure or a split structure.

Preferably, the isolation gate comprises a plurality of grids arranged in an array, and each grid separates adjacent pixel points.

Preferably, the height of the isolation grid from the first surface of the PCB is greater than the height of each LED chip from the first surface of the PCB.

Preferably, the height of the isolation gate from the first surface of the PCB board is not greater than the thickness of the encapsulation layer.

Preferably, the height of the isolation gate ranges from 0.1 to 0.5 mm.

Preferably, the grid width of the isolation gate is not less than 0.1 mm.

Preferably, the color of the isolation gate includes black.

Preferably, the LED lamp further comprises a control chip located on a second surface of the PCB or in the PCB, and electrically connected with each LED chip through the PCB, wherein the second surface of the PCB is opposite to the first surface.

Preferably, the pixel point comprises 1, 2 or 3 of the LED chips.

Preferably, the color of the LED chip in the pixel point includes one, two or three of red, green and blue.

According to a second aspect of the present invention, there is provided a method for manufacturing an LED display module, including: fixing a plurality of groups of LED chips on a first surface of a PCB, electrically connecting each LED chip with the PCB, and enabling each group of LED chips to form a pixel point; fixing an isolation gate on the first surface of the PCB, wherein each pixel point is separated by the isolation gate; and forming an encapsulation layer on the first surface of the PCB, wherein the encapsulation layer covers each LED chip.

Preferably, the thickness of the peripheral edge of the isolation gate is greater than or equal to the thickness of the middle of the isolation gate.

Preferably, the height of the isolation gate ranges from 0.1 to 0.5 mm.

Preferably, the grid width of the isolation gate is not less than 0.1 mm.

Preferably, the color of the isolation gate includes black.

Preferably, the pixel point comprises 1, 2 or 3 of the LED chips.

Preferably, the PCB board has a positioning hole, the barrier has a positioning pin matching with the positioning hole, the plurality of LED chips are fixed on the functional region of the PCB board, the positioning hole is located on the non-functional region of the PCB board, and the step of fixing the barrier on the first surface of the PCB board includes: placing the locating pin in the locating hole; and fixedly connecting the isolation gate with the first surface of the PCB by using fixing glue.

Preferably, the shape of the positioning hole comprises a circle and/or a polygon.

Preferably, the shape, size, number and position of the positioning pins correspond to the positioning holes.

Preferably, after the forming the encapsulation layer, the manufacturing method further includes: and cutting the edge of the LED display module to remove the non-functional area of the PCB, the positioning pin and the positioning hole.

Preferably, the method further comprises the following steps: and fixing a control chip on the second surface of the PCB or in the PCB, wherein the control chip is electrically connected with each LED chip through the PCB, and the second surface of the PCB is opposite to the first surface.

According to a third aspect of the invention, an LED screen is provided, which includes the LED display module set described above.

According to a fourth aspect of the invention, a manufacturing method of an LED screen is provided, which includes the manufacturing method of the LED display module described above.

According to the LED display module and the manufacturing method provided by the invention, the isolation grid structure is adopted to separate the pixel points, so that the problem of crosstalk between adjacent pixel points is solved, and the contrast of the LED display module can be improved.

Furthermore, the isolation gate is of an integrated structure, so that the process is simple and easy to realize, the manufacturing difficulty of the LED display module is reduced, and the production efficiency is improved.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the accompanying drawings of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description only relate to some embodiments of the present disclosure and do not limit the present disclosure.

Fig. 1 shows a schematic structural diagram of an LED display module according to an embodiment of the present invention.

Fig. 2a to 2f are sectional views of the manufacturing method for forming the LED display module according to the embodiment of the invention at various stages.

Fig. 3a is a top view of an embodiment of the present invention after a plurality of LED chips are formed on a first surface of a PCB board.

Figure 3b shows a top view of an isolation gate of an embodiment of the present invention.

Fig. 3c is a top view of an embodiment of the present invention forming an isolation gate on a first surface of a PCB.

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by like reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale. Moreover, certain well-known elements may not be shown in the figures.

In the following description, numerous specific details of the invention, such as structure, materials, dimensions, processing techniques and techniques of components, are set forth in order to provide a more thorough understanding of the invention. However, as will be understood by those skilled in the art, the present invention may be practiced without these specific details.

It will be understood that when a layer, region or layer is referred to as being "on" or "over" another layer, region or layer in describing the structure of the component, it can be directly on the other layer, region or layer or intervening layers or regions may also be present. Also, if the component is turned over, one layer or region may be "under" or "beneath" another layer or region.

As shown in fig. 1, the structure of the LED display module according to the embodiment of the present invention includes: PCB board 110, multiple groups of LED chips 120, isolation gate 130, encapsulation layer 140, and control chip 160. The PCB 110 has a first surface and a second surface opposite to each other. The plurality of sets of LED chips 120 are positioned on the first surface of the PCB board 110 and electrically connected to the PCB board 110. The isolation barrier 130 is located on the first surface of the PCB 110, each group of LED chips 120 is separated by the isolation barrier 130, wherein each group of LED chips 120 constitutes a pixel point, each pixel point includes 1, 2 or 3 LED chips, and the color of the LED chip in each pixel point (each group of LED chips 120) includes one, two or three combinations of red, green and blue. The encapsulation layer 140 is located on the first surface of the PCB board 110 and covers the isolation gate 130 and each of the plurality of sets of LED chips 120. The control chip 160 is electrically connected to each of the plurality of sets of LED chips 120 through the PCB board 110. In the present embodiment, the control chip 160 is located on the second surface of the PCB 110. In some other embodiments, the control chip 160 may also be located in the PCB board 110.

In the present embodiment, the isolation grid 130 includes a plurality of grids arranged in an array, each grid surrounding a corresponding group of LED chips 120 to isolate adjacent pixel points. The height of the isolation barrier 130 from the first surface of the PCB board 110 is greater than the height of each of the LED chips 120 of each group from the first surface of the PCB board 110. The height of the isolation gate 130 from the first surface of the PCB 110 is not greater than the thickness of the encapsulation layer 140. The isolation barrier 130 is made of plastic and is formed by injection molding, and the isolation barrier 130 is of an integral structure or a split structure. In some embodiments, the height of the isolation gate 130 ranges from 0.1 to 0.5mm, and the grid width d of the isolation gate 130 is not less than 0.1mm, which is the minimum applicable to COB modules with P0.5 dot pitch. The color of the isolation gate 130 includes black or other color having high light absorption efficiency.

However, the embodiments of the present invention are not limited thereto, and those skilled in the art may perform other settings on the size and color of the isolation barrier 130 as needed.

The manufacturing method starts with a PCB 110, the PCB 110 having a functional area 10 and a non-functional area 20, as shown in fig. 2 a.

In this step, the control chip 160 is fixed to the functional region 10 corresponding to the second surface 101b of the PCB 110.

In the present embodiment, the first surface 101a of the PCB 110 forms a plurality of pads 103 in the functional region 10, and the first surface 101a of the PCB 110 forms a plurality of positioning holes 102 in the non-functional region. In some specific embodiments, the shape of the positioning hole comprises a polygon and/or a circle.

Further, a plurality of sets of LED chips 120 are fixed on the first surface 101a of the PCB board 110, and each LED chip of each set of LED chips 120 is electrically connected to the PCB board 110, as shown in fig. 2 b.

In this step, for example, a solder paste is printed on the plurality of pads 103, and then each of the plurality of sets of LED chips 120 is sequentially fixed on the corresponding pad 103.

In the present embodiment, the plurality of sets of LED chips 120 are arranged on the first surface of the PCB 110 in an array, as shown in fig. 3a, wherein each set of LED chips 120 (each pixel point) includes three LED chips of red, green, and blue colors.

Further, the isolation barrier 130 is fixed on the first surface of the PCB 110, and each group of LED chips 120 is separated by the isolation barrier 130, as shown in fig. 2c, that is, adjacent pixel points are separated by the isolation barrier 130. The isolation gate 130 has a plurality of grids 130a arranged in an array, as shown in fig. 3 b.

In this embodiment, the isolation gate 130 has a plurality of positioning pins 131, and the shape, size, number and position of the positioning pins 131 correspond to the positioning holes of the PCB 110. The thickness of the peripheral edge 132 of the isolation gate 130 is greater than or equal to the thickness of the middle for ensuring the strength of the isolation gate 130 and preventing deformation, and the height of the peripheral edge 132 needs to be less than or equal to the height of the subsequently formed encapsulation layer 140. The positioning pins 131 and the peripheral edge 132 are located at positions corresponding to the non-functional area 20 of the PCB 110. The size and color design of the isolation gate 130 can be referred to the description of fig. 1, and are not described herein again.

In this step, for example, an adhesive (fixing glue) is coated on the first surface of the PCB 110 and/or the barrier 130, and then the positioning pins 131 are used for positioning, so that the positioning pins 131 are inserted into the positioning holes 102 of the PCB 110, and the barrier 130 is fixed on the first surface of the PCB 110 by the adhesive. After the isolation barrier 130 is fixed on the first surface of the PCB 110, each group of LED chips 120 is located in the corresponding grid 130a, as shown in fig. 3 c.

In some other embodiments, the isolation grid 130 is provided with a self-adhesive (fixing adhesive), and the isolation grid is fixed directly by the positioning pins 131 in this step and then bonded.

Further, an encapsulation layer 140 is formed on the first surface of the PCB board 110, and the encapsulation layer 140 covers each LED chip in each group of LED chips 120, as shown in fig. 2 d.

Further, the edge of the LED display module is cut, as shown in fig. 2 e.

In this step, the non-functional region 20 of the LED display module is cut according to the size, and the positioning pins 131, the positioning holes 102, and the peripheral edges 132 of the isolation bars 130 are removed in this step.

Further, at least two LED display modules are spliced as required to form a display screen, as shown in fig. 2 f.

According to the LED display module and the manufacturing method thereof, the isolation grid structure is adopted to separate the pixel points, so that the problem of crosstalk between adjacent pixel points is solved, and the contrast of the LED display module can be improved.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

In accordance with the present invention, as set forth above, these embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An LED display module, comprising:

a PCB board;

the LED display device comprises a PCB, a plurality of groups of LED chips and a plurality of control circuits, wherein the plurality of groups of LED chips are positioned on the first surface of the PCB and are electrically connected with the PCB, and each group of LED chips form a pixel point;

the isolation gate is positioned on the first surface of the PCB, and each pixel point is separated by the isolation gate; and

and the packaging layer is positioned on the first surface of the PCB and covers each LED chip.

2. The LED display module of claim 1, wherein the barrier is plastic and injection molded.

3. The LED display module of claim 1, wherein the barrier is a unitary or split structure.

4. The LED display module of claim 1, wherein the isolation grid comprises a plurality of grids arranged in an array, each grid isolating adjacent pixel points.

5. The LED display module of claim 1, wherein the isolation grid has a height from the first surface of the PCB that is greater than a height of each of the LED chips from the first surface of the PCB.

6. The LED display module of claim 1, wherein the height of the isolation grid from the first surface of the PCB board is no greater than the thickness of the encapsulation layer.

7. The LED display module of claim 1, wherein the isolation barrier has a height ranging from 0.1 to 0.5 mm.

8. The LED display module of claim 4, wherein the grid width of the isolation grid is not less than 0.1 mm.

9. The LED display module of claim 1, wherein the color of the isolation barrier comprises black.

10. The LED display module of claim 1, further comprising a control chip located on the second surface of the PCB or in the PCB, electrically connected to each of the LED chips through the PCB,

wherein the second surface of the PCB board is opposite to the first surface.

11. The LED display module of claim 1, wherein said pixel site comprises 1, 2 or 3 of said LED chips.

12. The LED display module of claim 1, wherein the color of the LED chips in the pixel site comprises one, two, or three of red, green, and blue.

13. A manufacturing method of an LED display module comprises the following steps:

fixing a plurality of groups of LED chips on a first surface of a PCB, electrically connecting each LED chip with the PCB, and forming pixel points by each group of LED chips;

fixing an isolation gate on the first surface of the PCB, wherein each pixel point is separated by the isolation gate; and

and forming an encapsulation layer on the first surface of the PCB, wherein the encapsulation layer covers each LED chip.

14. The method of claim 13, wherein the isolation barrier is made of plastic and injection molded.

15. The method of claim 13, wherein the isolation gate is a unitary structure or a split structure.

16. The method of claim 13, wherein the isolation grid comprises a plurality of grids arranged in an array, each grid isolating adjacent ones of the pixel sites.

17. The method of claim 13, wherein the thickness of the peripheral edge of the isolation gate is equal to or greater than the thickness of the middle.

18. The method of manufacturing of claim 13, wherein the isolation grid has a height from the first surface of the PCB that is greater than a height of each of the LED chips from the first surface of the PCB.

19. The method of manufacturing of claim 13, wherein the isolation grid is no greater than the thickness of the encapsulation layer from the first surface of the PCB board.

20. The method of claim 13, wherein the isolation gate has a height ranging from 0.1 to 0.5 mm.

21. The method of claim 16, wherein the grid width of the isolation gate is not less than 0.1 mm.

22. The method of claim 13, wherein the isolation gate comprises black in color.

23. The method of manufacturing of claim 13, wherein the pixel site includes 1, 2, or 3 of the LED chips.

24. The method of manufacturing of claim 13, wherein the color of the LED chips in the pixel comprises one, two, or three of red, green, and blue.

25. The manufacturing method of claim 13, wherein the PCB board has positioning holes, the barrier grid has positioning pins matched with the positioning holes, the plurality of LED chips are fixed on the functional area of the PCB board, the positioning holes are located on the non-functional area of the PCB board,

the step of fixing the isolation gate on the first surface of the PCB board includes:

placing the locating pin in the locating hole; and

and fixedly connecting the isolation gate with the first surface of the PCB by using fixing glue.

26. The method of claim 25, wherein the shape of the alignment hole comprises a circle and/or a polygon.

27. The method of manufacturing of claim 25, wherein the locating pins correspond in shape, size, number, and location to the locating holes.

28. The fabrication method of claim 25, wherein after forming the encapsulation layer, the fabrication method further comprises: and cutting the edge of the LED display module to remove the non-functional area of the PCB, the positioning pin and the positioning hole.

29. The method of manufacturing of claim 13, further comprising:

fixing a control chip on the second surface of the PCB or in the PCB, wherein the control chip is electrically connected with each LED chip through the PCB,

wherein the second surface of the PCB board is opposite to the first surface.

30. An LED display screen comprising the LED display module of any one of claims 1 to 12.

31. A method for manufacturing an LED display screen, comprising the method for manufacturing an LED display module according to any one of claims 13 to 29.