CN111983849A

CN111983849A - LED backlight module

Info

Publication number: CN111983849A
Application number: CN202010795406.9A
Authority: CN
Inventors: 刘俊领; 杨一峰
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2020-08-10
Filing date: 2020-08-10
Publication date: 2020-11-24

Abstract

An LED backlight module comprises a substrate with a first side and a second side which are opposite, a plurality of LED light sources arranged on the first side in an array mode, a metal layer arranged on the second side and a heat conduction layer, wherein the metal layer comprises grid patterns, the heat conduction layer comprises first heat conduction sheets, the LED light sources correspond to grids of the metal layer, and the first heat conduction sheets are arranged in the grids and correspond to the LED light sources. The metal layer with the metal grid patterns and the supporting legs with certain heights is formed at the positions, corresponding to the LED welding positions, of the back surface of the substrate, and heat conducting layers are arranged in the metal grid and on the four sides of the supporting legs, so that the heat conducting area is increased, and the heat radiating effect of the LED backlight module is improved by utilizing the regional temperature gradient.

Description

LED backlight module

Technical Field

The application relates to the technical field of display, in particular to an LED backlight module.

Background

Compared with liquid crystal display technology and OLED (Organic Light-Emitting Diode) display technology, Micro-LED (Micro Light-Emitting Diode) display technology has the advantages of fast reaction, high color gamut, high PPI (Pixel Density), low energy consumption and the like, but has more technical difficulties and complex technology, particularly the key technology mass transfer technology and the Micro-formation of LED particles form the technical bottleneck, and Mini-LED (sub-millimeter Light-Emitting Diode) is used as a product combining Micro-LED and a back plate, has the characteristics of high contrast, high color rendering performance and the like which can be compared with OLED, has the cost slightly higher than that of liquid crystal displays and only about six-fold of OLED displays, and is easier to implement compared with Micro-LED and OLED displays.

The manufacture of the Mini-LED back plate is a key factor for determining whether a product is reliable, and relates to the LED bonding effect, subsequent aging verification and the like, and the heat dissipation problem of the MiniLED display which is researched or partially sold in the industry exists all the time. When the LED emits light, the PN junction generates certain heat which is removed through convection and heat conduction scattering, however, because the LED works for a long time with high brightness, the heat dissipation is untimely, and then the problems of line aging, LED burning, brightness attenuation, service life reduction and the like of the Mini LED are caused. The existing improvement scheme has the problems of strengthening heat dissipation in the aspect of LED manufacturing structures or enhancing heat dissipation effect in module structures, but the existing improvement scheme has the problems of cost limitation, unobvious improvement effect or module thickness increase and the like.

Therefore, the structure of the existing Mini-LED backplane is to be improved.

Disclosure of Invention

The embodiment of the application provides an LED backlight module to solve the technical problems that in the existing LED backlight module, because LEDs work for a long time and at high brightness, heat dissipation is untimely, LED circuits are aged, brightness is attenuated, the service life is shortened, and LED luminous display is influenced.

In order to solve the above problems, the technical scheme provided by the invention is as follows:

the embodiment of the application provides an LED backlight module, which comprises a substrate, a plurality of LED light sources, a metal layer and a heat conduction layer, wherein the substrate comprises a first side and a second side which are opposite to each other; the LED light source corresponds to the grid of the metal layer, and the first heat conducting fin is arranged in the grid and corresponds to the LED light source.

In at least one embodiment of the present application, the metal layer further includes a supporting leg connected to the grid line of the metal layer, and the supporting leg protrudes from the surface of the grid pattern.

In at least one embodiment of the present application, the supporting legs are disposed corresponding to the LED light source.

In at least one embodiment of the present application, the height of the supporting feet is 0.5cm to 10 cm.

In at least one embodiment of the present application, an included angle between the supporting legs and a plane of the substrate is 90 degrees to 160 degrees.

In at least one embodiment of the present application, the heat conductive layer further includes a second heat conductive sheet disposed on the supporting leg surface.

In at least one embodiment of the present application, the second heat conduction sheet is disposed on an inner side surface of the supporting leg.

In at least one embodiment of the present application, the first thermally conductive sheet and the second thermally conductive sheet are each a graphite sheet.

In at least one embodiment of the present application, an orthographic area of the LED light source on the substrate is smaller than an orthographic area of the first heat conductive sheet corresponding to the LED light source on the substrate.

In at least one embodiment of the present application, the metal layer is a single layer structure or a multi-layer structure.

The invention has the beneficial effects that: the metal layer with the metal grid pattern and the supporting legs with certain heights is formed at the positions, corresponding to the LED welding positions, of the back surface of the substrate, and heat conducting layers are arranged in the metal grid and on the four sides of the supporting legs, so that the heat conducting area is increased, and the heat radiating effect of the LED backlight module is improved by utilizing the regional temperature gradient; the heat dissipation layer in the metal grid on the back of the substrate is in full contact with the substrate for heat conduction, so that a heat conduction path is reduced; the supporting legs with certain height can enable heat transferred by the LEDs to be in contact with air, the temperature of unit area is reduced, and the supporting legs are inclined by a certain angle, so that the opening area of the metal grid is increased, and the influence of heat dissipation inside the grid on each other is avoided.

Drawings

In order to illustrate the embodiments or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the invention, and it is obvious for a person skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic cross-sectional structure diagram of an LED backlight module according to an embodiment of the present disclosure;

FIG. 2 is a schematic cross-sectional view of a metal layer according to an embodiment of the present disclosure;

FIG. 3 is a top view of a metal layer provided in an embodiment of the present application;

fig. 4 is a schematic cross-sectional view of a heat conductive layer according to an embodiment of the present disclosure;

fig. 5 is a top view of a thermally conductive layer provided in embodiments 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 is to be understood that the embodiments described 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 the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

Referring to fig. 1, fig. 3 and fig. 5, an embodiment of the present invention provides an LED backlight module 100, which includes a substrate 10, a plurality of LED light sources 20, a metal layer 30 and a heat conductive layer 40.

Wherein the substrate 10 includes a first side 11 and a second side 12 disposed opposite to each other, the plurality of LED light sources 20 are disposed on the first side 11 of the substrate 10, and the metal layer 30 and the heat conductive layer 40 are disposed on the second side 12 of the substrate 10.

The metal layer 30 includes a grid pattern 32, and the LED light sources correspond to the grid of the metal layer 30.

The heat conduction layer 40 includes a first heat conduction sheet 41, the first heat conduction sheet 41 is located in the grid, and the first heat conduction sheet 41 is disposed corresponding to the LED light source 20, so that the area temperature gradient is utilized, the heat conduction area is increased, and the heat dissipation effect of the LED light source is improved.

In one embodiment, the metal layer further includes support legs 31, the support legs 31 are connected to the grid lines, and the support legs 31 protrude from the surface of the grid pattern 32.

The supporting legs 31 have a certain height to support a certain space, so that the heat energy transferred by the LED is fully contacted with the air, the heat dissipation space of the LED is increased, and the temperature per unit area is reduced.

In one embodiment, the supporting feet 31 are disposed corresponding to the LED light source 20. In other embodiments, the supporting foot 31 can be disposed at other necessary positions.

Specifically, the height of the supporting legs 31 can be 0.5-10 cm, and if the height is too high, the thickness of the whole module is increased, and if the height is too low, the heat dissipation effect is not ideal.

The supporting legs 31 may be arranged perpendicular to the substrate; the supporting legs 31 can also be arranged at a certain angle with the substrate 10, but it needs to be ensured that the opening formed by the supporting legs 31 is gradually increased along the direction away from the substrate 10, so that the mutual influence of the heat dissipation inside the grid is avoided, and the stability of the module can also be improved.

Specifically, the included angle α between the supporting leg 31 and the plane of the substrate 10 is 90 to 160 degrees.

The orthographic projections of the LED light sources 20 on the grid pattern 32 are all within one complete grid. The orthographic projection area of the LED light source 20 on the substrate 10 is smaller than the orthographic projection area of the first heat conduction sheet 41 corresponding to the LED light source 20 on the substrate 10, so that the first heat conduction sheet 41 is in full contact with the LED light source 20 to conduct heat, and the conduction path is reduced.

In one embodiment, the supporting legs 31 may be designed as a three-dimensional enclosure, and the side surfaces thereof may also be designed as a grid pattern to increase the heat dissipation direction.

In an embodiment, the heat conduction layer 40 may further include a second heat conduction sheet 42, and the second heat conduction sheet 42 is disposed on the surface of the supporting leg 31, so as to conduct the heat of the first heat conduction sheet 41 to the supporting leg 31 by using a temperature gradient.

Specifically, the second heat conduction sheet 42 is disposed on the inner side surface of the supporting leg 31, so as to conduct heat to the inner surface of the supporting leg 31, and then conduct away through the outer side of the supporting leg 31.

The metal layer 30 may have a single-layer structure or a multi-layer structure, that is, the grid pattern 32 and the supporting legs 31 may have a single-layer metal structure or a multi-layer metal structure.

Specifically, the mesh pattern 32 and the supporting legs 31 may be made of a metal material or an alloy material such as aluminum, copper, etc. having excellent thermal conductivity and ductility.

The first heat conducting sheet 41 and the second heat conducting sheet 42 may be graphite sheets, which have super strong heat conducting property, unique crystal grain orientation, and diffused heat dissipation along the horizontal direction, and the graphite sheets of the lamellar structure can adapt to any surface well, quickly dissipate heat of the heat source to achieve the purpose of uniform heat dissipation, shield the conductivity between the heat source and the component, and improve the performance of the consumer electronic product. The plane of the heat-conducting graphite sheet has ultrahigh heat-conducting performance within the range of 1700W/m-K, and the heat-conducting coefficient of the heat-conducting graphite sheet is 3-5 times that of copper (380W/m-K) and 9-11 times that of aluminum (160W/m-K). A graphite sheet can be used as the material of the first heat-conductive sheet and the second heat-conductive sheet.

The heat-conducting sheet may be formed in the mesh of the metal layer 30 and the side surface of the supporting leg 31 by means of spray printing or coating.

Specifically, referring to fig. 2 and 3, firstly, a metal grid pattern 32 and a supporting leg 31 are prepared on the back surface (second side 12) of the substrate 10, and an opening 101 formed by the supporting leg 31 and the corresponding grid pattern 32 is larger than the area of the soldering position 102 of the LED light source 20.

Referring to fig. 4 and 5, a graphite sheet material is then spray printed in the openings 101 formed by the supporting legs 31 and the corresponding grid patterns 32 and on the inner side surfaces of the supporting legs 31 by means of spray printing, so as to increase the heat conduction effect.

The substrate 10 may be a glass substrate or other backplane material.

The LED light source 20 may be a Mini LED or a Micro LED, and the LED backlight module 100 in the above embodiments may be applied to a liquid crystal display as a direct-type backlight source, may also be applied to a heat dissipation module structure of an LED backlight source display, and may also be applied to displays such as a Mini LED backlight source and a Micro LED.

The metal layer with the metal grid pattern and the supporting legs with certain heights is formed at the positions, corresponding to the LED welding positions, of the back surface of the substrate, and heat conducting layers are arranged in the metal grid and on the four sides of the supporting legs, so that the heat conducting area is increased, and the heat radiating effect of the LED backlight module is improved by utilizing the regional temperature gradient; the heat dissipation layer in the metal grid on the back of the substrate is in full contact with the substrate for heat conduction, so that a heat conduction path is reduced; the supporting legs with certain height can enable heat transferred by the LEDs to be in contact with air, the temperature of unit area is reduced, and the supporting legs are inclined by a certain angle, so that the opening area of the metal grid is increased, and the influence of heat dissipation inside the grid on each other is avoided.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

The LED backlight module provided in the embodiments of the present application is described in detail above, and the principle and the implementation of the present application are explained in the present application by applying specific examples, and the description of the embodiments above is only used to help understanding 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. An LED backlight module, comprising:

a substrate comprising opposing first and second sides;

a plurality of LED light sources arranged in an array on the first side;

a metal layer disposed on the second side, the metal layer including a mesh pattern; and

the heat conduction layer is arranged on the second side and comprises a first heat conduction sheet; wherein

The LED light source corresponds to the grid of the metal layer, and the first heat conducting fins are arranged in the grid and correspond to the LED light source.

2. The LED backlight module of claim 1, wherein the metal layer further comprises support legs connected to the grid lines of the metal layer, the support legs protruding from the surface of the grid pattern.

3. The LED backlight module of claim 2, wherein the support legs are disposed corresponding to the LED light sources.

4. The LED backlight module of claim 2, wherein the height of the supporting legs is 0.5cm to 10 cm.

5. The LED backlight module of claim 2, wherein an included angle between the supporting legs and the plane of the substrate is 90-160 degrees.

6. The LED backlight module of claim 2, wherein the heat conducting layer further comprises a second heat conducting sheet disposed on the supporting leg surface.

7. The LED backlight module of claim 6, wherein the second heat-conducting strip is disposed on an inner side surface of the supporting leg.

8. The LED backlight module of claim 6, wherein the first and second thermally conductive sheets are graphite sheets.

9. The LED backlight module according to claim 1, wherein an orthographic projection area of the LED light source on the substrate is smaller than an orthographic projection area of the first heat-conducting sheet corresponding to the LED light source on the substrate.

10. The LED backlight module according to claim 1, wherein the metal layer has a single-layer structure or a multi-layer structure.