CN112396979B

CN112396979B - Back plate and LED panel

Info

Publication number: CN112396979B
Application number: CN202011267643.4A
Authority: CN
Inventors: 李兰艳
Original assignee: TCL Huaxing Photoelectric Technology Co Ltd
Current assignee: TCL Huaxing Photoelectric Technology Co Ltd
Priority date: 2020-11-13
Filing date: 2020-11-13
Publication date: 2022-07-12
Anticipated expiration: 2040-11-13
Also published as: CN112396979A

Abstract

The application provides a backboard and an LED panel, wherein in the backboard, a driving substrate comprises a substrate and a conductive pad arranged on the substrate; the buffer layer is arranged on the driving substrate, an opening is formed in the buffer layer, and the conducting pad is exposed out of the opening; the buffer layer comprises a retaining wall which is arranged around the opening; the reflecting layer is arranged on the driving substrate, and the reflecting layer is positioned on one side of the retaining wall far away from the opening. This application is through setting up the barricade around the opening to when carrying out the spout seal technology of reflection stratum, avoid the material overflow of reflection stratum to the exposed conducting pad of opening.

Description

Back plate and LED panel

Technical Field

The application relates to a display technology, in particular to a back plate and an LED panel.

Background

In the manufacture of Mini-LED or Micro-LED substrates, it is usually necessary to form a white oil layer on the substrate. The white oil process generally adopts a silk-screen process or a jet printing process. The screen printing process has high precision, but the substrate is directly contacted, so the substrate is easily scratched, and the metal layer is short-circuited; the spray printing process can avoid direct contact with the substrate and can effectively avoid scratching the substrate, but the printing precision of the spray printing process is difficult to guarantee, white oil is easy to overflow to a bonding pad area bound with the LED, the bonding pad is oxidized and discolored, the tin is abnormally fed, and the LED cannot be normally printed.

Disclosure of Invention

The embodiment of the application provides a backboard and an LED panel, and aims to solve the technical problem that when an existing LED substrate is provided with a white oil reflecting layer by adopting a jet printing process, white oil is easy to overflow into a pad area.

The embodiment of the present application provides a back plate, it includes:

a driving substrate including a base and a conductive pad disposed on the base;

the buffer layer is arranged on the driving substrate, an opening is formed in the buffer layer, and the opening exposes the conducting pad; the buffer layer comprises a retaining wall, and the retaining wall is arranged around the opening; and

the reflecting layer is arranged on the driving substrate, and is positioned on one side of the retaining wall away from the opening.

In the backplane of the embodiment of the present application, the conductive pad includes a reflective metal layer, and the retaining wall is disposed to overlap with a portion of the reflective metal layer.

In the back plate of the embodiment of the present application, the retaining wall has an undercut structure, and the undercut structure extends towards the direction of the retaining wall; the width of the undercut structure is gradually reduced from the driving substrate to the retaining wall;

the reflective layer extends into the undercut structure.

In the back plate of the embodiment of the application, the buffer layer comprises a main body part, a channel is arranged between the main body part and the retaining wall, and the channel is arranged around the retaining wall;

the reflective layer is disposed at least on the body portion and extends into the channel.

In the back sheet according to the embodiment of the present application, the buffer layer includes a base layer and a pore structure and/or flexible particles disposed in the base layer.

In the back sheet according to the embodiment of the present application, the flexible particles have a flexibility greater than that of the base layer.

In the backing plate of the embodiments of the present application, the hole structure includes a gas space.

In the back plate of the embodiment of the present application, the hole structure further includes a housing, and the housing wraps the gas space.

In the back plate of the embodiment of the present application, a hole is disposed on one side of the base layer close to the reflective layer, and the hole is communicated with the gas space.

In the backplane according to the embodiment of the present disclosure, the material of the buffer layer includes a photoresist material.

In the backplane according to the embodiment of the present application, the driving substrate further includes a first metal layer, an insulating layer, a second metal layer, and a passivation layer sequentially disposed on the substrate, the second metal layer includes the conductive pad, and the opening penetrates through the passivation layer.

The application also relates to an LED panel, which comprises an LED chip and the back plate of any one of the above embodiments; the LED chip is arranged on the back plate.

According to the back plate and the LED panel, the retaining wall is arranged around the opening, so that when the spray printing process of the reflecting layer is carried out, the material of the reflecting layer is prevented from overflowing to the exposed conductive pad of the opening; in addition, the main body part of the buffer layer is arranged on the driving substrate, so that the driving substrate is protected when the silk-screen printing process of the reflecting layer is carried out.

Drawings

In order to more clearly illustrate the embodiments of the present application, the drawings used in the embodiments will be briefly described below. The drawings in the following description are only some embodiments of the present application, and it will be obvious to those skilled in the art that other drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic top view of a backplate according to a first embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of a back plate according to a first embodiment of the present application;

FIG. 3 is a schematic cross-sectional view of a back plate according to a second embodiment of the present application;

FIG. 4 is a schematic top view of a third embodiment of a backplate of the present application;

FIG. 5 is a schematic cross-sectional view of a third embodiment of the backing plate of the present application;

FIG. 6 is another schematic cross-sectional view of a third embodiment of the present application;

FIG. 7 is a schematic view of a buffer layer of a back sheet according to a third embodiment of the present application;

FIG. 8 is a schematic cross-sectional view of a back plate according to a fourth embodiment of the present application;

FIG. 9 is a schematic view of a buffer layer of a back sheet according to a fourth embodiment of the present application;

fig. 10 is a schematic structural diagram of an LED panel according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It should be apparent that the described embodiments are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "above" the second feature may comprise the first and second features being in direct contact, or the first and second features being not in direct contact but in contact with each other through another feature therebetween.

Referring to fig. 1 and 2, fig. 1 is a schematic top view of a backplate according to a first embodiment of the present application; fig. 2 is a schematic cross-sectional structural diagram of a back plate according to a first embodiment of the present application.

The embodiment of the present application provides a back plate 100, which includes a driving substrate 11, a buffer layer 12, and a reflective layer 13. The buffer layer 12 is disposed on the driving substrate 11. The reflective layer 13 is disposed on the driving substrate 11.

The driving substrate 11 includes a base 111, and a first metal layer 112, an insulating layer 113, a second metal layer 114, and a passivation layer 115 sequentially disposed on the base 111. The driving substrate 11 further includes other film layers such as an active layer and a planarization layer. Since the hierarchical structure of the driving substrate 11 is prior art, it is not described herein in detail. Specifically, the second metal layer 114 includes a conductive pad 114 a.

The buffer layer 12 has an opening 12a, and the opening 12a exposes the conductive pad 114 a. The buffer layer 12 includes a retaining wall 121, and the retaining wall 121 is disposed around the opening 12 a. The opening 12a penetrates the buffer layer 12 and the passivation layer 115.

The reflective layer 13 is located on a side of the retaining wall 121 far away from the opening 12 a.

The backplate 100 of the first embodiment is provided with the retaining wall 121 around the opening 12a to prevent the material of the reflective layer 13 from overflowing to the conductive pad 114a exposed by the opening during the inkjet process of the reflective layer 13.

The opening 12a has a shape in vertical section in a wide-top and narrow-bottom structure, such as an inverted trapezoid. This arrangement facilitates rapid bonding of the LED chip to the pad 114a through the opening 12a during subsequent bonding.

Optionally, the conductive pad 114a includes a reflective metal layer. The retaining wall 121 is disposed to overlap with a portion of the reflective metal layer. Note that, in the present first embodiment, the "overlapping setting" is an indirect overlapping setting.

Because the retaining wall 121 and the reflective metal layer are overlapped, in the subsequently manufactured LED panel, light emitted by the LED chip passes through the retaining wall 121 to be radiated to the reflective metal layer, and is reflected by the reflective metal layer, so that the light utilization rate of the LED panel is improved.

Alternatively, the conductive pad 114a may have at least a two-layer structure, wherein the reflective metal layer is located at a side close to the retaining wall 121.

Alternatively, the conductive pad 114a may also be a single-layer structure, that is, the conductive pad 114a is formed by the reflective metal layer. The reflective metal may be silver or aluminum, etc.

When the reflective layer 13 is formed by a jet printing process, the process of manufacturing the back plate 100 of the first embodiment is as follows:

firstly, providing a substrate 111, and sequentially forming a first metal layer 112, an insulating layer 113, a second metal layer 114 and a passivation layer 115 on the substrate 111 to form a thin film transistor array structure, i.e. a driving substrate 11;

then, a photoresist is coated on the driving substrate 11 to form a photoresist layer. The photoresist layer is subjected to exposure, development, and baking processes to form the dam 121 and the opening 12 a.

Next, the reflective layer 13 is formed on the driving substrate 11 by a jet printing process.

And finally, cutting according to the product requirements.

This completes the process of manufacturing the backsheet 100 of the present first embodiment.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a backplane according to a second embodiment of the present application. The second embodiment of the present application provides a backplane 200 including a driving substrate 11, a buffer layer 12, and a reflective layer 13. The buffer layer 12 is disposed on the driving substrate 11. The reflective layer 13 is disposed on the driving substrate 11.

The backplate 200 of this second embodiment differs from the backplate 100 of the first embodiment in that: the retaining wall 121 has an undercut structure f1, and the undercut structure f1 extends towards the retaining wall 121. In the direction from the driving substrate 11 to the retaining wall 121, the width of the undercut structure f1 decreases.

The reflective layer 13 extends into the undercut structure f 1. Therefore, in the LED panel manufactured subsequently, light emitted from the LED chip is radiated to the reflective layer 13 in the undercut structure f1 through the retaining wall 121, and is reflected by the reflective layer 13, so that the light utilization rate of the LED panel is improved.

Referring to fig. 4 and 5, fig. 4 is a schematic top view of a back plate according to a third embodiment of the present application; fig. 5 is a schematic cross-sectional view of a back plate according to a third embodiment of the present application.

The third embodiment of the present application provides a back plate 300 including a driving substrate 11, a buffer layer 12, and a reflective layer 13. The buffer layer 12 is disposed on the driving substrate 11. The reflective layer 13 is disposed on the driving substrate 11.

The backsheet 100 of this third embodiment differs from the backsheet 100 of the first embodiment or the backsheet 200 of the second embodiment in that:

the buffer layer 12 further comprises a main body portion 122, a channel 12f is arranged between the main body portion 122 and the retaining wall 121, and the channel 12f is arranged around the retaining wall 121. The reflective layer 13 is disposed at least on the body portion 122 and extends into the channel 12 f.

As shown in fig. 5, when the back-plate 300 of the third embodiment forms the reflective layer 13 by a jet printing process, the fluid material is sprayed on the main portion 122 of the buffer layer 12 and overflows into the trench 12f and is blocked by the retaining wall 121, so as to avoid the fluid material overflowing onto the conductive pad 114a to cause defects. I.e. the reflective layer 13 covers the channel 12 f.

As shown in fig. 6, when the back sheet 300 of the third embodiment forms the reflective layer 13 by a screen printing process, a reflective material is formed on the buffer layer 12, the doctor blade is in contact with the buffer layer 12, and the buffer layer 12 absorbs the force applied thereto by the doctor blade, thereby protecting the driving substrate 11; in addition, the reflective material may also enter the channel 12f under the influence of the scraper.

In addition, in the process of the buffer layer 12, the retaining wall 121, the main body 122, the channel 12f and the opening 12a are formed by using the same mask.

In the back sheet 300 of the third embodiment, as shown in fig. 7, the buffer layer 12 includes a base layer 12b and a hole structure 12c disposed in the base layer 12 b. The hole structure 12c includes a housing 12c1 and a gas space 12c 2. The enclosure 12c1 encloses the gas space 12c 2.

In the silk-screen printing process of the reflective layer 13, the scraper contacts the buffer layer 12, and the hole structure 12c has the effect of absorbing the acting force of the scraper, so that the scraper is prevented from damaging the driving substrate 11.

The gas space 12c2 is formed by decomposing a thermally and/or photolytically decomposable material into a gas. Therefore, the outer case 12c1 serves to protect and seal the gas space 12c2, so as to prevent the gas from breaking the base layer 12b, thereby ensuring the flatness of the surface of the buffer layer 12 and providing a flat base surface for the formation of the reflective layer 13.

Further, the "thermally decomposable and/or photodegradable material" is hereinafter simply referred to as "decomposable material".

In some embodiments, the buffer layer 12 includes flexible particles disposed within the base layer 12 b; i.e. the hole structure 12c is replaced by flexible particles. Wherein the flexible particles have a flexibility greater than that of the base layer 12 b. The flexible particles act as absorbing scrapers.

In some embodiments, the buffer layer 12 further comprises flexible particles disposed within the base layer 12 b; i.e. both the void structure 12c and the flexible particles are present in the base layer 12 b. Wherein the flexible particles have a flexibility greater than that of the base layer 12 b.

In the rear plate 300 of the third embodiment, the reflective layer 13 is formed on the buffer layer 12. The material of the reflective layer 13 may be white ink, or other reflective materials that can be used in a screen printing process.

Optionally, the material of the buffer layer 12 includes a photoresist material. Specifically, the material of the base layer 12b of the buffer layer 12 may be a photoresist material such as Polystyrene (PS) or soluble Polytetrafluoroethylene (PFA).

Optionally, the thickness of the buffer layer 12 is greater than or equal to 3 micrometers and less than or equal to 10 micrometers. It should be noted that, if the thickness of the buffer layer 12 is less than 3 micrometers, it does not have a good scratch-resistant effect; if the thickness of the buffer layer 12 is greater than 10 micrometers, on one hand, the cost is increased, and on the other hand, the LED chip is not conveniently bound.

When the reflective layer 13 is formed by a screen printing process, the process of manufacturing the back plate 300 according to the third embodiment is as follows:

then, a mixed material in which the photoresist is mixed with the particles is provided. The particles include the shell 12c1 and a decomposable material, the shell 12c1 encapsulating the decomposable material.

Next, the mixed material is coated on the driving substrate 11 to form a mixed material layer. Exposing, developing and baking the mixed material layer to form the retaining walls 121, the main body part 122, the openings 12a and the channels 12 f; and then decomposing the decomposable material in the particles to form the porous structure 12 c.

Next, the reflective layer 13 is formed on the buffer layer 12 by a screen printing process.

And finally, cutting according to the product requirements.

This completes the process of preparing the back sheet 300 of the present third embodiment.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a backplane according to a fourth embodiment of the present application.

The fourth embodiment of the present application provides a back plate 400 including a driving substrate 11, a buffer layer 12, and a reflective layer 13. The buffer layer 12 is disposed on the driving substrate 11. The reflective layer 13 is disposed on the driving substrate 11.

The back plate 400 of the fourth embodiment is different from the back plate 300 of the third embodiment in that: as shown in fig. 9, the base layer 12b is provided with an aperture 12d on a side thereof adjacent to the reflective layer 13. Optionally, at least a part of the hole structures 12c in the buffer layer 12 is connected to the pores 12 d. The apertures 12d serve to further absorb the force of the doctor blade against the buffer layer 12.

It should be noted that the gas generated by the decomposable material after decomposition breaks the base layer 12b to form the pores 12 d. Due to the different depths of the decomposable material in the base layer 12b, the decomposable material at different depths are subjected to different binding forces; therefore, when the decomposable material is decomposed into gas, the internal pressure of the gas space 12c2 is greater than the binding force of the base layer 12b, so as to break through the base layer 12b and form the pores 12 d; if the internal pressure of gas space 12c2 is less than the binding force of substrate 12b to it, gas space 12c2 is completely bound within substrate 12 b.

In the back plate 400 of this fourth embodiment, the hole structure 12c may include a housing 12c 1. The housing 12c1 is provided with an opening which is formed by being burst by gas.

Additionally, in some embodiments, the aperture structure 12c may also include only the gas space 12c 2. The decomposable material is decomposed into a gas to form the gas space 12c2, wherein the gas breaks the surface of the base layer 12b to form the pores 12d in the base layer 12 b.

In addition, the fourth embodiment only shows a schematic structural diagram of forming the reflective layer 13 by using a screen printing process, but is not limited thereto. However, when the reflective layer 13 is formed by the inkjet printing process in the fourth embodiment, the reflective layer 13 may not cover the retaining wall 121.

Referring to fig. 10, fig. 10 is a schematic structural diagram of an LED panel according to an embodiment of the present application. The embodiment of the present application also relates to an LED panel 1000, which includes an LED chip EL and a back plate BL. The LED chip EL is disposed on the back plate BL. The back plate BL is the back plate (100, 200, 300, 400) described in any of the above embodiments.

It should be noted that the LED is a light emitting diode chip. Which may be Mini-LED, Mirco-LED or other LED.

According to the back plate and the LED panel, the retaining wall is arranged around the opening, so that when the jet printing process of the reflecting layer is carried out, the material of the reflecting layer is prevented from overflowing to the exposed conductive pad of the opening; in addition, the main body part of the buffer layer is arranged on the driving substrate, so that the driving substrate is protected when the silk-screen printing process of the reflecting layer is carried out.

The backplane and the LED panel provided in the embodiments of the present application are described in detail above, and specific examples are applied in the description to explain the principle and the implementation of the present application, and the description of the embodiments above is only used to help understand the technical solution and the core idea of the present application; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. A backing sheet, comprising:

a driving substrate including a base and a conductive pad disposed on the base;

the reflection stratum, the reflection stratum sets up on the drive base plate, just at least part on reflection stratum is located the barricade is kept away from open-ended one side, the reflection stratum is located the open-ended outside.

2. The backplane according to claim 1, wherein the conductive pad comprises a reflective metal layer, and the dam is disposed to overlap a portion of the reflective metal layer.

3. The back plate as claimed in claim 1, wherein the retaining wall has an undercut structure extending in a direction of the retaining wall; the width of the undercut structure is gradually reduced from the driving substrate to the retaining wall;

the reflective layer extends into the undercut structure.

4. The back plate of claim 1, wherein the buffer layer comprises a main body portion, a channel is disposed between the main body portion and the retaining wall, and the channel is disposed around the retaining wall;

5. The backsheet according to claim 4, wherein the buffer layer comprises a base layer and a pore structure and/or flexible particles arranged within the base layer.

6. The backsheet according to claim 5, wherein the flexible particles have a flexibility greater than the flexibility of the base layer.

7. The backing plate of claim 5 wherein the hole structure comprises a gas space.

8. The backplate of claim 7, wherein the hole structure further comprises a housing that surrounds the gas space.

9. A backsheet according to claim 7 or 8, wherein the substrate is provided with apertures at a side thereof adjacent to the reflective layer, said apertures communicating with the gas space.

10. The backsheet according to claim 1, wherein the material of the buffer layer comprises a photoresist material.

11. The backplate of claim 1, wherein the driving substrate further comprises a first metal layer, an insulating layer, a second metal layer and a passivation layer sequentially disposed on the substrate, the second metal layer comprises the conductive pad, and the opening penetrates through the passivation layer.

12. An LED panel comprising LED chips and the backsheet according to any one of claims 1 to 11; the LED chip is arranged on the back plate.