CN111816649A

CN111816649A - LED display module and manufacturing method thereof, LED display screen and manufacturing method thereof

Info

Publication number: CN111816649A
Application number: CN202010741965.1A
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: 2020-10-23

Abstract

The application discloses an LED display module and a manufacturing method thereof, an LED display screen and a manufacturing method thereof. The LED display module comprises a PCB board; the LED chips are positioned on the first surface of the PCB and are electrically connected with the PCB; the packaging layer is positioned on the first surface of the PCB and covers each LED chip; and the panel is positioned on the surface of the packaging layer, wherein the surface of the packaging layer close to the panel is a polished surface. The surface of the packaging layer is planarized, so that the thickness difference of the LED display module is reduced, the panel is arranged on the surface of the LED module, the surface appearance consistency of the LED module is improved, and the display effect is improved.

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 moving toward high resolution, which makes the number of pixels per unit area increasing. 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 lower the assembly efficiency; 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, the large LED screen can be obtained by splicing the COB LED display modules, such as an LED television.

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, the uniformity of the surface of the COB LED product is not good due to the existence of the patchwork and mosaic phenomena. Because COB LED display module is single lamp pearl, the lamp pearl of unifying more relatively, the product size increases a lot, and the simple adoption mould pressing is moulded plastics, along with the change of mould surface appearance and the fluctuation of glue prescription, can't guarantee to mould plastics completely the colour on back lamp plate surface unanimously, after assembling into the display screen, the nonconformity of surface colour can be enlargied, appears similar "mosaic" phenomenon, influences the display effect. Moreover, due to the fact that the thickness of the PCB fluctuates by +/-10%, the tolerance of different injection molds is added, and after injection molding, the thickness tolerance of the lamp panel can be accumulated and amplified, so that the height unevenness of the lamp panel is prominent, the abutted seams exist, and the display effect is 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 LED display module and the LED display screen.

According to a first aspect of the present invention, there is provided an LED display module, comprising: a PCB board; the LED chips are positioned on the first surface of the PCB and are electrically connected with the PCB; the packaging layer is positioned on the first surface of the PCB and covers each LED chip; and the panel is positioned on the surface of the packaging layer.

Preferably, the surface of the packaging layer close to the panel is a polished surface.

Preferably, the panel comprises: the substrate is positioned on the packaging layer; and the coating layer is coated and/or evaporated and/or sprayed on the substrate.

Preferably, the coating layer is doped with a dye to change the color and transmittance of the panel.

Preferably, the coating layer is doped with a scattering agent.

Preferably, the coating layer is subjected to atomization or antireflection treatment.

Preferably, the substrate is a glass substrate or a flexible plastic substrate or a semi-transparent matte substrate.

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

Preferably, the method further comprises the following steps: and the lamp panel interface is positioned on the second surface of the PCB.

Preferably, the panel is a translucent matte panel or a glass panel or a flexible plastic panel.

According to a second aspect of the present invention, there is provided a method for manufacturing an LED display module, comprising: fixing a plurality of LED chips on a first surface of a PCB, and electrically connecting each LED chip with the PCB; forming an encapsulation layer on the first surface of the PCB, wherein the encapsulation layer covers each LED chip; planarizing the surface of the packaging layer to enable the thickness sum of the packaging layer and the PCB to be within a preset range; and forming a panel on the surface of the packaging layer.

Preferably, the step of forming the panel comprises: coating a transparent adhesive on the surface of the packaging layer after the planarization treatment; placing the panel on the adhesive; and curing the adhesive.

Preferably, the method of curing the adhesive comprises: heat curing, UV curing, and room temperature curing.

Preferably, the coating layer is doped with a scattering agent.

Preferably, the substrate comprises a glass substrate or a flexible plastic substrate or a semi-transparent matte substrate.

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.

Preferably, the method further comprises the following steps: and cutting the edges of the panel, the packaging layer and the PCB so as to adjust the size of the LED display module to a preset size.

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

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

According to the LED display module and the manufacturing method provided by the invention, the surface of the packaging layer is subjected to planarization treatment, and the panel is arranged on the surface of the packaging layer, so that the advantages of flatness and no chromatic aberration of the LED display module are ensured, the thickness difference of the LED display module is reduced, the surface appearance consistency of the LED module is increased, the seamless assembly of the LED display module is finally realized, and the superior consistency of the surfaces of the LED display module and the LED display screen is ensured.

In addition, the surface of the packaging layer is subjected to planarization treatment and the panel is arranged, so that the contrast of the LED display module and the LED display screen can be improved.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the 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 showing the manufacturing method of forming the LED display module according to the embodiment of the present invention at various stages.

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, a plurality of LED chips 120, encapsulation layer 140, panel 150, and control chip 160. The PCB 110 has a first surface and a second surface opposite to each other. The plurality of LED chips 120 are positioned on the first surface of the PCB board 110 and electrically connected to the PCB board 110. The encapsulation layer 140 is positioned on the first surface of the PCB board 110 and covers each LED chip 120. The panel 150 is located on the surface of the encapsulation layer 140. The control chip 160 is electrically connected to each of the 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. The LED display module further includes a lamp panel interface 111 located on the second surface of the PCB 110.

In the present embodiment, the surface of the encapsulation layer 140 close to the panel 150 is a polished surface.

In some embodiments, the panel 150 comprises a substrate and a coating layer coated and/or evaporated and/or sprayed on the substrate, wherein the coating layer may be doped with a dye to change the color and transmittance of the coating layer, or doped with a scattering agent to change the optical properties of the coating layer, or atomized or anti-reflected to achieve a high contrast effect on the surface; the substrate material can be a glass substrate, a flexible plastic substrate, a semitransparent matte substrate and the like. In alternative embodiments, the panel 150 is not coated and is a translucent matte panel, a glass panel, a flexible plastic panel, or the like.

The manufacturing method starts with a PCB board 110, the PCB board 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 board 110 is formed with a plurality of pads 103 corresponding to the functional regions 10.

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

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

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 120, as shown in fig. 2 c.

In this step, for example, the molding injection process is used to form the encapsulation layer 140, the material of the encapsulation layer 140 is, for example, a colloid, and the thickness of the surface of the encapsulation layer 140 after the complete injection molding cannot be guaranteed to be consistent with the change of the surface topography of the mold and the fluctuation of the glue formula, and is limited by the surface flatness of the PCB 110 itself, and the thickness of the PCB 110 has a thickness fluctuation of ± 10%, and after the molding injection process step, the thickness tolerance is cumulatively amplified, thereby causing the poor surface flatness of the encapsulation layer 140.

Further, the surface of the encapsulation layer 140 is planarized to make the thickness of the encapsulation layer 140 and the PCB 110 within a predetermined range, as shown in fig. 2 d.

In this step, for example, a grinding and polishing process is used to flatten the surface of the package layer 140, so as to eliminate the thickness inconsistency of the PCB 110 and the thickness inconsistency of the package layer 140, so that the sum of the thicknesses of the package layer 140 and the PCB 110 is within a predetermined range.

Further, a panel 150 is formed on the surface of the encapsulation layer 140, as shown in fig. 2 e.

In this step, for example, a transparent adhesive is first coated on the surface of the encapsulation layer 140, then the panel 140 is placed on the adhesive, and finally the adhesive is cured, so that the panel 150 is fixed on the surface of the encapsulation layer 140.

In this embodiment, the method of curing the adhesive includes: heat curing, UV curing, and room temperature curing. In some embodiments, the panel 150 comprises a substrate and a coating layer coated and/or evaporated and/or sprayed on the substrate, wherein the coating layer may be doped with a dye to change the color and transmittance of the coating layer, or doped with a scattering agent to change the optical properties of the coating layer, or atomized or anti-reflected to achieve a high contrast effect on the surface; the substrate material can be a glass substrate, a flexible plastic substrate, a semitransparent matte substrate, or the like. In alternative embodiments, the panel 150 is not coated and is a translucent matte panel, a glass panel, a flexible plastic panel, or the like.

Further, the edge of the LED display module is cut, as shown in fig. 2 f. In this step, the non-functional area 20 of the LED display module is cut according to the size requirement, and the functional area 10 is reserved.

In this step, the edges of the panel 150, the encapsulation layer 140 and the PCB 110 are cut to adjust the size of the LED display module to a predetermined size.

Furthermore, at least two LED display modules are spliced to form a display screen according to needs.

In addition, the planarization treatment is carried out on the surface of the packaging layer, and the panel is arranged, so that the contrast ratio of the LED display module and the LED display screen 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 chips are positioned on the first surface of the PCB and are electrically connected with the PCB;

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

and the panel is positioned on the surface of the packaging layer.

2. The LED display module of claim 1, wherein a surface of the encapsulation layer proximate to the faceplate is a polished surface.

3. The LED display module of claim 1, wherein the panel comprises:

the substrate is positioned on the packaging layer; and

and the coating layer is coated and/or evaporated and/or sprayed on the substrate.

4. The LED display module of claim 3, wherein the coating layer is doped with a dye to change the color and transmittance of the panel.

5. The LED display module of claim 3, wherein the coating layer is doped with a scattering agent.

6. The LED display module of claim 3, wherein the coating is atomized or anti-reflective.

7. The LED display module of claim 3, wherein the substrate is a glass substrate or a flexible plastic substrate or a semi-transparent matte substrate.

8. 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 with each LED chip through the PCB,

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

9. The LED display module of claim 1, further comprising:

and the lamp panel interface is positioned on the second surface of the PCB.

10. The LED display module of claim 1, wherein the panel is a translucent matte panel or a glass panel or a flexible plastic panel.

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

fixing a plurality of LED chips on a first surface of a PCB, and electrically connecting each LED chip with the PCB;

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

planarizing the surface of the packaging layer to enable the thickness sum of the packaging layer and the PCB to be within a preset range; and

and forming a panel on the surface of the packaging layer.

12. The manufacturing method of claim 11, wherein the step of forming the panel comprises:

coating a transparent adhesive on the surface of the packaging layer after the planarization treatment;

placing the panel on the adhesive; and

curing the adhesive.

13. The manufacturing method according to claim 12, wherein the method of curing the adhesive includes: heat curing, UV curing, and room temperature curing.

14. The method of manufacturing of claim 11, wherein the panel is a translucent matte panel or a glass panel or a flexible plastic panel.

15. The manufacturing method according to claim 11, wherein the panel comprises:

the substrate is positioned on the packaging layer; and

16. The method of manufacturing of claim 15, wherein the coating is doped with a dye to change the color and transmittance of the panel.

17. The method of manufacturing of claim 15 wherein the coating is doped with a scattering agent.

18. The manufacturing method according to claim 15, wherein the coating layer is subjected to atomization or antireflection treatment.

19. The manufacturing method according to claim 15, wherein the substrate comprises a glass substrate or a flexible plastic substrate or a translucent matte substrate.

20. The manufacturing method according to claim 11, 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.

21. The manufacturing method according to claim 11, further comprising:

and cutting the edges of the panel, the packaging layer and the PCB so as to adjust the size of the LED display module to a preset size.

22. An LED display screen comprising the LED display module of any one of claims 1 to 10.

23. A method for manufacturing an LED display screen, comprising the method for manufacturing an LED display module according to any one of claims 11 to 21.