CN115373180A

CN115373180A - Backlight module and display device

Info

Publication number: CN115373180A
Application number: CN202211035716.6A
Authority: CN
Inventors: 陈扬; 余强; 李玉成; 康光林; 黄盈; 沈亚群; 龙永; 陈强; 吴欣欣
Original assignee: BOE Technology Group Co Ltd; Chongqing BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chongqing BOE Optoelectronics Technology Co Ltd
Priority date: 2022-08-26
Filing date: 2022-08-26
Publication date: 2022-11-22

Abstract

The embodiment of the disclosure provides a backlight module and a display device, relates to the technical field of display, and is used for reducing the risk of light attenuation and increase of the backlight module. The backlight module comprises a back plate, a light guide plate and a flexible circuit board. The backplate includes the supporting part and is located the slot part of supporting part one side, and the slot part is including consecutive first daughter board, second daughter board and third daughter board, and one side that the second daughter board was kept away from to first daughter board links to each other with the supporting part, and the third daughter board sets up with first daughter board relatively. The light guide plate is arranged on the supporting part, and part of the light guide plate is positioned between the first sub-plate and the third sub-plate. The flexible circuit board is at least partially positioned between the light guide plate and the third sub-board and fixedly connected with the light guide plate. The backlight module is used for providing a light source for the LCD panel.

Description

Backlight module and display device

Technical Field

The disclosure relates to the technical field of display, in particular to a backlight module and a display device.

Background

Liquid crystal display devices are popular among users because of their advantages such as small size, high brightness, power saving, and low radiation. The liquid crystal display device comprises a backlight module for providing backlight and a display panel for displaying pictures. The backlight module comprises a backlight source, a light guide plate, a back plate and a plurality of optical diaphragms.

In the related art, the backlight source includes a flexible circuit board and a plurality of Light Emitting Diode (LED) lamp beads. The backlight module can be divided into a front backlight module and a back backlight module according to the installation position classification of the flexible circuit board, the light guide plate and the back plate. In the reverse-group backlight module, the flexible circuit board is positioned on one side of the light guide plate close to the optical membranes, the flexible circuit board is fixedly connected with the back plate, and the LED lamp beads are positioned on one side of the light guide plate close to the second sub-plate.

Wherein, the light guide plate is heated the inflation after shrink, and the clearance of lamp pearl and light guide plate increases, and backlight unit's light decay can grow.

Disclosure of Invention

An object of the embodiments of the present disclosure is to provide a backlight module and a display device, for reducing the risk of light attenuation increase of the backlight module.

In order to achieve the above purpose, the embodiments of the present disclosure provide the following technical solutions:

in one aspect, a backlight module is provided. The backlight module comprises a back plate, a light guide plate and a flexible circuit board. The backplate includes the supporting part and is located the slot part of supporting part one side, and the slot part is including consecutive first daughter board, second daughter board and third daughter board, and the one end that the second daughter board was kept away from to first daughter board links to each other with the supporting part, and the third daughter board sets up with first daughter board relatively. The light guide plate is arranged on the supporting part, and part of the light guide plate is positioned between the first sub-plate and the third sub-plate. The flexible circuit board is at least partially positioned between the light guide plate and the third sub-board and fixedly connected with the light guide plate.

In the display backlight module, the back plate comprises a supporting part and a groove part positioned on one side of the supporting part. The supporting portion is used for supporting the light guide plate, and the groove portion is used for shading light. The first sub-board, the second sub-board and the third sub-board are connected in sequence, one side of the first sub-board far away from the second sub-board is connected with the supporting portion, and the third sub-board is arranged opposite to the first sub-board, so that the first sub-board, the second sub-board and the third sub-board form a groove portion. The light guide plate is arranged on the supporting part and is partially positioned between the first sub-plate and the third sub-plate, and the light guide plate can convert the linear light source into the surface light source. At least part of the flexible circuit board is positioned between the light guide plate and the third sub-plate and is fixedly connected with the light guide plate. Under the condition that the light guide plate is heated to expand or is cooled to shrink, the light guide plate and the flexible circuit board move synchronously, and therefore the risk of light attenuation increase of the backlight module can be reduced.

In some embodiments, the light guide plate includes a first sub-portion and a second sub-portion. The first sub-portion is at least partially located between the first sub-board and the third sub-board. The second sub-part is arranged on the supporting part and connected with the first sub-part. The surface of the first sub-part far away from the first sub-plate is closer to the plane where the first sub-plate and the supporting part are located than the surface of the second sub-part far away from the supporting part. The flexible circuit board is located on one side, away from the first sub-board, of the first sub-portion and fixedly connected with the surface, away from the first sub-board, of the first sub-portion.

In some embodiments, the surface of the flexible circuit board away from the first sub-portion is flush with the surface of the second sub-portion away from the support portion.

In some embodiments, a flexible wiring board includes a routing portion and a shading portion. The wire routing part is positioned between the first sub-board and the third sub-board and is fixedly connected with the light guide plate. The shading part is positioned on one side of the routing part, which is far away from the second sub-board, and is connected with the routing part, and one end of the shading part, which is far away from the routing part, extends out of the groove part. The backlight module also comprises a plurality of optical diaphragms which are arranged in a stacked manner, wherein the plurality of optical diaphragms are positioned on one side of the light guide plate, which is far away from the supporting part, and are positioned on one side of the third sub-plate, which is far away from the second sub-plate; edge portions of the plurality of optical films near the third sub-sheet overlap edge portions of the light shielding portion away from the routing portion.

In some embodiments, the trace portion includes a first insulating layer, a first conductive layer, a substrate layer, a second conductive layer, and a cover film, which are sequentially stacked, wherein the first insulating layer is closer to the light guide plate than the cover film. The shading part comprises an extension layer and a reflecting layer, the extension layer and the cover film or the base material layer are integrally arranged, and the reflecting layer is arranged on one side of the extension layer close to the light guide plate.

In some embodiments, edge portions of the plurality of optical patches proximate the third sub-sheet overlap the light-reflecting layer.

In some embodiments, in a case where the light guide plate includes the first sub-portion and the second sub-portion, an end of the light shielding portion, which is away from the wire trace portion, is flush with an end of the second sub-portion, which is close to the first sub-portion.

In some embodiments, the flexible wiring board includes a ground conductive portion located on a side of the flexible wiring board adjacent to the third sub-board. The backlight module further comprises a grounding structure, and the grounding structure is electrically connected with the grounding conductive part and the third sub-board.

In some embodiments, the ground structure comprises a resilient conductive mass. The elastic conductive block is positioned between the flexible circuit board and the third sub-board, one end of the elastic conductive block is electrically connected with the grounding conductive part, and the other end of the elastic conductive block is electrically connected with the third sub-board.

In some embodiments, the third sub-panel is provided with a first opening. The grounding structure comprises a conductive adhesive layer and a conductive block. The conductive adhesive layer is bonded with the surface, far away from the first sub-board, of the third sub-board, and covers the first opening. The conductive block is partially positioned in the first opening, one end of the conductive block is electrically connected with the grounding conductive part, and the other end of the conductive block is electrically connected with the conductive adhesive layer.

In some embodiments, a portion of the third sub-panel that is distal from the second sub-panel is recessed inward, forming the first opening. Backlight unit is still including a plurality of optical films that range upon range of setting, and at least one optical film includes main part and bellying, and the main part is located the third daughter board and keeps away from one side of second daughter board, and bellying one end links to each other with the main part, and at least part is located the second opening, and the bellying sets up with the conducting block side by side.

In some embodiments, the end portions of the protrusions and the conductive bumps that are close to each other are in contact with each other along the first direction. The first direction is parallel to the length extending direction of the third sub-board.

In some embodiments, the conductive adhesive layer is provided with an avoiding hole, and a part of the protruding portion is located in the avoiding hole.

In some embodiments, the backlight module further includes a supporting layer and an adhesive layer stacked on the supporting layer, and the adhesive layer is adhered to the conductive adhesive layer.

In another aspect, a display device is provided. The display device comprises the backlight module and the display panel according to any one of the embodiments.

The display device has the same structure and beneficial technical effects as the backlight module provided in some embodiments, and the description is omitted here.

Drawings

In order to more clearly illustrate the technical solutions in the present disclosure, the drawings needed to be used in some embodiments of the present disclosure will be briefly described below, and it is apparent that the drawings in the following description are only drawings of some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art according to the drawings. Furthermore, the drawings in the following description may be considered as schematic diagrams, and do not limit the actual size of products, the actual flow of methods, the actual timing of signals, and the like, involved in the embodiments of the present disclosure.

FIG. 1 is a block diagram of a display panel of some embodiments of the present disclosure;

FIG. 2 isbase:Sub>A further sectional view taken along section line A-A of FIG. 1;

FIG. 3 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 4 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 5 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 6 is a block diagram of a backlight of some embodiments of the present disclosure;

FIG. 7 is another block diagram of a backlight of some embodiments of the present disclosure;

FIG. 8 is yet another block diagram of a backlight of some embodiments of the present disclosure;

FIG. 9 is a cross-sectional view taken along section line B-B of FIG. 8;

FIG. 10 is a block diagram of a backing plate of some embodiments of the present disclosure;

FIG. 11 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 12 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 13 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 14 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 15 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 16 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 17 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 18 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 19A is a cross-sectional view taken along section line C-C of FIG. 18;

FIG. 19B is another cross-sectional view taken along section line C-C of FIG. 18;

FIG. 20 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 21 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 22 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 23 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

FIG. 24 isbase:Sub>A further cross-sectional view taken along section line A-A of FIG. 1;

fig. 25 is yet another cross-sectional view taken along section linebase:Sub>A-base:Sub>A of fig. 1.

Detailed Description

Technical solutions in some embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments provided by the present disclosure belong to the protection scope of the present disclosure.

Throughout the specification and claims, the term "comprising" is to be interpreted in an open, inclusive sense, i.e., as "including, but not limited to," unless the context requires otherwise. In the description of the specification, the terms "one embodiment," "some embodiments," "example" or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the disclosure. The schematic representations of the terms used above are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be included in any suitable manner in any one or more embodiments or examples.

In the following, the terms "first", "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present disclosure, "a plurality" means two or more unless otherwise specified.

In describing some embodiments, the expression "connected" and derivatives thereof may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more elements are in direct physical or electrical contact with each other.

"at least one of A, B and C" has the same meaning as "at least one of A, B or C" and includes the following combinations of A, B and C: a alone, B alone, C alone, a combination of A and B, A and C in combination, B and C in combination, and A, B and C in combination.

The use of "adapted to" or "configured to" herein means open and inclusive language that does not exclude devices adapted to or configured to perform additional tasks or steps.

As used herein, "substantially" includes the stated value as well as an average value that is within an acceptable range of deviation from the specified value, as determined by one of ordinary skill in the art in view of the measurement in question and the error associated with the measurement of the specified quantity (i.e., the limitations of the measurement system).

As used herein, "parallel," "perpendicular," includes the recited case and cases that approximate the recited case to within an acceptable range of deviation as determined by one of ordinary skill in the art in view of the measurement in question and the error associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallel and approximately parallel, where an acceptable deviation from approximately parallel may be, for example, within 5 °; "perpendicular" includes absolute perpendicular and approximately perpendicular, where an acceptable deviation from approximately perpendicular may also be within 5 °, for example.

It will be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present.

Example embodiments are described herein with reference to cross-sectional and/or plan views as idealized example figures. In the drawings, the thickness of layers and regions are exaggerated for clarity. Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, the exemplary embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the exemplary embodiments.

An embodiment of the present disclosure provides a display apparatus 1000, as shown in fig. 1, which is an apparatus or device for visually displaying electronic information. Illustratively, the display device 1000 may be a tablet computer, a notebook computer, a monitor, or a television.

In some embodiments, the display device 1000 includes the backlight assembly 100, the display panel 200, and the fixing tape 300.

As shown in fig. 2, the backlight module 100 includes a back plate 10, a light guide plate 20, a backlight 30, and a plurality of optical films 40 stacked one on another.

The back plate 10 includes a support portion 11 and a groove portion 12 located at one side of the support portion 11, the support portion 11 is used for supporting the light guide plate 20, and the groove portion 12 is used for shielding light emitted from the backlight 30. The slot 12 includes a first sub-board 121, a second sub-board 122, and a third sub-board 123 connected in sequence, one end of the first sub-board 121 far away from the second sub-board 122 is connected to the support portion 11, and the third sub-board 123 is disposed opposite to the first sub-board 121.

The light guide plate 20 is disposed on the supporting portion 11 and partially disposed on the first sub-plate 121, the light guide plate 20 is partially disposed between the first sub-plate 121 and the third sub-plate 123, and the light guide plate 20 is used for converting a linear light source into a surface light source.

The backlight 30 includes a flexible circuit board 31 and LED beads 32 located on one side, and the LED beads 32 are attached to the flexible circuit board 31 by using Surface Mount Technology (SMT).

The plurality of optical films 40 are located on a side of the light guide plate 20 away from the supporting portion 11 and on a side of the third sub-plate 123 away from the second sub-plate 122, and the plurality of optical films 40 and the third sub-plate 123 have a distance therebetween.

Illustratively, the plurality of optical films 40 includes a first diffusion sheet, a prism sheet, and a second diffusion sheet, which are sequentially stacked. The first diffusion sheet is closer to the light guide plate 20 than the second diffusion sheet. The plurality of optical films 40 may make the brightness of the light emitted from the light guide plate 20 to the display panel more uniform.

The backlight module 100 further includes a light-shielding tape 50. The light shielding tape 50 is partially located between the flexible circuit board 31 and the third sub-board 123, and is located on a side of the second sub-board 122 close to the plurality of optical films 40. An end of the light shielding tape 50 remote from the second sub-board 122 protrudes out of the groove portion 12. Edge portions of the plurality of optical films 40 adjacent to the third sub-sheet 123 overlap edge portions of the light shielding tape 50 remote from the second sub-sheet 122.

The backlight module 100 further includes a display panel bearing layer 5, and the display panel bearing layer 5 is located on one side of the third sub-board 123 far away from the first sub-board 121 and is fixedly connected to the third sub-board 123.

The display panel 200 further includes a first glass substrate 210, a second glass substrate 220, a first polarizer 230, and a second polarizer 240.

The first glass substrate 210 is partially located on a side of the display panel bearing layer 5 away from the third sub-board 123, and is fixedly connected to the display panel bearing layer 5.

The second glass substrate 220 is located on a side of the first glass substrate 210 away from the display panel carrier layer 5, and is fixedly connected to the first glass substrate 210.

The first polarizer 230 is located on a side of the first glass substrate 210 away from the second glass substrate 220, and is fixedly connected to the first glass substrate 210.

The second polarizer 240 is located on a side of the second glass substrate 220 away from the first glass substrate 210, and is fixedly connected to the second glass substrate 220.

The fixing tape 300 is disposed along the edge of the second polarizer 240 and surrounds the back plate 10, the display panel carrier layer 5, the first glass substrate 210 and the second glass substrate 220.

In some embodiments, the backlight module 100 may be divided into a front backlight module 100 and a back backlight module 100 according to the installation location classification of the back plate 10, the light guide plate 20 and the flexible circuit board 31 in the backlight module 100.

Specifically, in the positive backlight unit, the flexible circuit board is partially located between the light guide plate and the first sub-plate, the flexible circuit board is fixedly connected with the light guide plate, and the LED lamp beads are located on one side, close to the second sub-plate, of the light guide plate. The backlight module further includes a first adhesive layer (not shown in the figure) for adhering the flexible circuit board and the light guide plate.

Specifically, in the reverse backlight module, at least a portion of the flexible printed circuit is located between the light guide plate and the third sub-plate and is fixedly connected to the third sub-plate. The LED lamp beads are located on one side, close to the second sub-board, of the light guide plate.

In the reverse backlight module, the shading adhesive tape is also used for bonding the light guide plate and the flexible circuit board. The material of the light shielding tape includes a conductive material. In this way, the flexible wiring board is electrically connected to the third sub-board 123 through the light shielding tape, that is, the flexible wiring board is grounded.

Wherein, in reverse group backlight unit 100, light guide plate 20 is heated the inflation, and light guide plate 20 can drive the flexible line way board of fixed LED lamp pearl 32 and move to the direction that is close to second daughter board 122, and when light guide plate 20 recovered to original position, light guide plate 20 and LED lamp pearl 32 apart from the increase, lead to backlight unit 100's light decay increase.

In order to solve the above problem, as shown in fig. 2, the flexible printed circuit 31 in the embodiment of the present disclosure is at least partially located between the light guide plate 20 and the third sub-board 123, and the flexible printed circuit 31 is fixedly connected to the light guide plate 20. Like this, under light guide plate 20 is under the condition of thermal expansion or the shrink of catching a cold, light guide plate 20 and LED lamp pearl 32 synchronous motion can reduce the risk of the increase of the distance between LED lamp pearl 32 and the light guide plate 20, and then can reduce the risk that backlight unit 100 optical attenuation increases.

Meanwhile, when the flexible printed circuit 31 needs to be removed from the groove 12 (for example, the flexible printed circuit 31 is damaged and the electrical analysis of the flexible printed circuit 31 is needed. Or the flexible printed circuit 31 needs to be replaced), the light guide plate 20 is moved, and the light guide plate 20 can drive the flexible printed circuit 31 to be removed from the groove 12, so that the flexible printed circuit 31 can be detached more easily and conveniently. The flexible wiring board 31 can be removed from the groove portion 12 without touching the flexible wiring board 31, and thus the risk of damage to the flexible wiring board 31 can be reduced.

Illustratively, the first adhesive layer is used to bond the light guide plate 20 and the flexible wiring board 31.

In some embodiments, as shown in fig. 3 (for convenience of illustrating the positional relationship of the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 3), the light guide plate 20 includes a first sub-portion 21 and a second sub-portion 22.

The first sub-portion 21 is at least partially located between the first sub-plate 121 and the third sub-plate 123.

The second sub-portion 22 is disposed on the supporting portion 11 and connected to the first sub-portion 21. The surface of the first sub-portion 21 away from the first sub-portion 121 is closer to the plane where the first sub-portion 121 and the supporting portion 11 are located than the surface of the second sub-portion 22 away from the supporting portion 11. The flexible circuit board 31 is located on a side of the first sub-portion 21 away from the first sub-board 121, and is fixedly connected to a surface of the first sub-portion 21 away from the first sub-board 121. Thus, the distance between the flexible circuit board 31 and the third sub-board 123 is increased, so that the light guide plate 20 and the flexible circuit board 31 can be conveniently moved into the groove 12, the assembly difficulty of the backlight module 100 can be reduced, and the thickness of the backlight module 100 can be reduced.

In the case where the light guide plate 20 includes the first sub-portion 21 and the second sub-portion 22, the first adhesive layer is used to bond the flexible circuit board 31 and the first sub-portion 21.

Exemplarily, as shown in fig. 4 (for convenience of illustrating the positional relationship of the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 4), the surface of the flexible circuit board 31 away from the first sub-portion 21 is flush with the surface of the second sub-portion 22 away from the supporting portion 11. Alternatively, as shown in fig. 6, the flexible circuit board 31 is far from the surface of the first sub-part 21, and is far from the plane where the third sub-board 123 and the supporting part 11 are located, compared with the surface of the second sub-part 22 far from the supporting part 11.

Flush includes both absolute flush and approximately flush, and "approximately" includes the stated values as well as average values that are within an acceptable deviation range for the particular value, as determined by one of ordinary skill in the art in view of the measurement in question and the error associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

The light shielding tape 50 in the related art may absorb light emitted from the light guide plate 20 from the space between the third sub-sheet 123 and the plurality of optical films 40, resulting in an insufficient amount of light emitted from the light guide plate 20.

In some embodiments, to solve the above problem, as shown in fig. 5 (in order to facilitate showing the position relationship of the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 5), the flexible printed circuit 31 includes a trace portion 311 and a light shielding portion 312.

The wire trace portion 311 is located between the first sub-board 121 and the third sub-board 123, and is fixedly connected to the light guide plate 20. The LED lamp beads 32 are fixedly connected with the routing part 311.

The light shielding portion 312 is located on a side of the routing portion 311 away from the second sub-board 122, the light shielding portion 312 is connected to the routing portion 311, and one end of the light shielding portion 312 away from the routing portion 311 protrudes out of the groove 12. The edge portions of the plurality of optical films 40 close to the third sub-plate 123 overlap the edge portions of the light shielding portions 312 far from the routing portion 311, the light shielding portions 312 may reflect the light emitted from the light guide plate 20 from the space between the third sub-plate 123 and the plurality of optical films 40, thereby increasing the light emitting amount of the light guide plate 20, and the light shielding portions 312 may reduce the risk of light loss caused by the emission of part of the light in the light guide plate 20 from the space between the third sub-plate 123 and the plurality of optical films 40. Thus, the light-shielding tape 50 in the related art can be eliminated, and the process related to the light-shielding tape 50 in the backlight module 100 can be eliminated, so that the production speed of the backlight module 100 can be improved. The thickness of the backlight assembly 100 can also be reduced.

Illustratively, the length of the region where the plurality of optical films 40 and the light shielding portion 312 overlap each other in the second direction X may be 0.8mm. The second direction X is parallel to the direction in which the support portions 11 and the first sub-plate 121 are arranged.

Exemplarily, as shown in fig. 5, in a case where the light guide plate 20 includes the first sub-part 21 and the second sub-part 22, the first sub-part 21 overlaps with an edge portion of the plurality of optical films 40 adjacent to the third sub-plate 123 near an edge of the second sub-part 22, and exemplarily, a length of a region where the plurality of optical films 40 overlap with the first sub-part 21 in the second direction X may be 0.8mm. One end of the light shielding portion 312 away from the wire trace portion 311 is flush with one end of the second sub-portion 22 close to the first sub-portion 21. The surface of the light shielding portion 312 away from the first sub-portion 21 is flush with the surface of the second sub-portion 22 away from the supporting portion 11, so that the risk of the plurality of optical films 40 being lifted up by the light shielding portion 312 can be reduced.

Parallel absolute and approximately parallel, "approximately" includes the stated case as well as cases that approximate the stated case to within an acceptable range of deviation as determined by one of ordinary skill in the art in view of the measurement in question and the error associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, the acceptable range of deviation from near-parallel may be, for example, within 5 °;

in some embodiments, as shown in fig. 6 and 7, the trace portion 311 includes a first insulating layer 3111, a first conductive layer 3112, a substrate layer 3113, a second conductive layer 3114 and a cover film 3115, which are sequentially stacked, wherein the first insulating layer 3111 is closer to the light guide plate 20 than the cover film 3115.

The material of the first insulating layer 3111 may include silicon nitride (SiNx), aluminum oxide (Al 2O 3), or silicon oxide (SiO 2), and embodiments of the present disclosure are not enumerated one by one.

The material of the first conductive layer 3112 may include Aluminum (AL), silver (Ag), or copper (Cu), and embodiments of the present disclosure are not enumerated. Illustratively, the material of the first conductive layer 3112 includes copper.

The material of the substrate layer 3113 may include Polyethylene Terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyphenylene Sulfone resin (PPSU), or Polymethyl Methacrylate (PMMA), which is not illustrated in the embodiments of the present disclosure.

The material of the second conductive layer 3114 may be the same as that of the first conductive layer 3112, so that the material identity of the flexible printed circuit 31 can be improved, and the cost of the flexible printed circuit 31 can be reduced.

The material of the cover film 3115 may be the same as that of the first insulating layer 3111.

The light shielding portion 312 includes an extended layer 3121 and a light reflecting layer 3122. As shown in fig. 6, the extended layer 3121 is provided integrally with the cover film 3115; alternatively, as shown in fig. 7, the extended layer 3121 is provided integrally with the base material layer 3113.

The reflective layer 3122 is disposed on a side of the extension layer 3121 adjacent to the light guide plate 20. The material of the light reflective layer 3122 may include at least one of white oil and white paint. The material of the white oil may include epoxy resin, polytetrafluoroethylene resin, titanium dioxide or dipropylene glycol methyl ether, and embodiments of the present disclosure are not listed. The light reflective layer 3122 may also include a reflective sheet.

In some embodiments, edge portions of the plurality of optical films 40 near the third sub-sheet 123 overlap the light reflecting layer 3122. In this way, the light reflective layer 3122 can reduce the risk of light loss caused by a portion of the light in the light guide plate 20 being emitted from the space between the third sub-sheet 123 and the plurality of optical films 40.

The light guide plate 20 and the flexible wiring board 31 are fixedly connected together, so that the flexible wiring board 31 is not in contact with the third sub-board 123, and the flexible wiring board 31 cannot be grounded.

In some embodiments, in order to solve the above problem, the flexible wiring board 31 includes a ground conductive part 33, and the ground conductive part 33 is located on a side of the flexible wiring board 31 close to the third sub-board 123. Backlight unit 100 still includes ground structure 60, and ground structure 60 is connected with ground connection electrically conductive part 33 and third daughter board 123 electricity, and like this, flexible line way board 31 ground connection can reduce static or the risk that heavy current leads to LED lamp pearl 32 to damage.

As shown in fig. 8 and 9, the ground conductive part 33 is: the cover film 3115 is formed with at least one second opening 2, and the second opening 2 exposes a region of the second conductive layer 3114.

In some embodiments, as shown in FIG. 10, the third sub-panel 123 is provided with a first opening 1231, and the first opening 1231 is matched with the second opening 2.

In some embodiments, as shown in fig. 11 (for convenience of showing the positional relationship of the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 11), the grounding structure 60 includes an elastic conductive block 61, the elastic conductive block 61 is located between the flexible circuit board 31 and the third sub-board 123, one end of the elastic conductive block 61 is electrically connected to the grounding conductive portion 33, and the other end is electrically connected to the third sub-board 123. The flexible wiring board 31 is electrically connected to the third sub-board 123 through the elastic conductive pieces 61, i.e., the flexible wiring board 31 is grounded.

Illustratively, the elastic conductive piece 61 may include conductive foam. When installing the electrically conductive bubble cotton, place the cotton one end of electrically conductive bubble in second opening 2 earlier, electrically conductive bubble cotton and second conducting layer 3114 fixed connection, for example: glue is applied to one end of the conductive foam, and then the end of the conductive foam applied with the glue is bonded to the second conductive layer 3114. And then pressing the other end of the conductive foam, compressing the conductive foam, moving the conductive foam and the flexible circuit board 31 into the groove part 12, and contacting the other end of the conductive foam with the third sub-board 123 to complete the grounding of the flexible circuit board 31.

In some embodiments, as shown in fig. 12, in the case where the third sub-board 123 is provided with the first opening 1231, one end of the conductive foam is placed at the second opening 2 and is adhered to the second conductive layer 3114, and the other end is in contact with the edge of the first opening 1231, so that the flexible wiring board 31 is grounded.

In some embodiments, as shown in fig. 13, the elastic conductive block 61 includes a first conductive portion 611 and a second conductive portion 612. The first conductive part 611 is located between the third sub-board 123 and the flexible circuit board 31, the first conductive part 611 is located at the second opening 2, the second conductive part 612 is located on one side of the first conductive part 611 close to the third sub-board 123, an orthographic projection of the first conductive part 611 on the third sub-board 123 is located within a range of an orthographic projection of the second conductive part 612 on the third sub-board 123, and a space is formed between a boundary of the orthographic projection of the second conductive part 612 on the third sub-board 123. Therefore, the contact area between the elastic conductive block 61 and the third sub-plate 123 can be increased, the pressure applied to the third sub-plate 123 can be reduced, and the service life of the third sub-plate 123 can be prolonged.

In some embodiments, as shown in fig. 14, in the case that the third sub-board 123 is provided with the first opening 1231, the second opening 2 is orthographically projected on the third sub-board 123, is located within an orthographically projected range of the second conductive part 612 on the third sub-board 123, and is spaced from an orthographically projected boundary of the second conductive part 612 on the third sub-board 123, that is, the first opening 1231 is orthographically projected on the third sub-board 123, is located within an orthographically projected range of the second conductive part 612 on the third sub-board 123, and is spaced from an orthographically projected boundary of the second conductive part 612 on the third sub-board 123. The second opening 2 is orthographically projected on the third sub-board 123, is located within an orthographically projected range of the display panel bearing layer 5 on the third sub-board 123, and is spaced from a boundary of the orthographically projected range of the display panel bearing layer 5 on the third sub-board 123.

In some embodiments, as shown in fig. 15, an end of the elastic conductive block 61 away from the second sub-board 122 is provided with a fourth opening 613. The at least one optical film 40 includes a main portion 41 and a protrusion portion 42, the main portion 41 is located on a side of the third sub-board 123 away from the second sub-board 122, one end of the protrusion portion 42 is connected to the main portion, and at least a portion of the protrusion portion is located at the fourth opening 613, and the fourth opening 613 is configured to limit the movement of the protrusion portion 42 along the first direction Y, so that the risk of damage caused by collision of the at least one optical film 40 with the back plate 10 along the first direction Y can be reduced. The first direction Y is perpendicular to the second direction X. In order to facilitate the display of the positional relationship between the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 12 and 13.

In the case where the elastic conductive block 61 includes the first conductive portion 611 and the second conductive portion 612, as shown in fig. 16, one end of the first conductive portion 611 remote from the second sub-board 122 is provided with a fourth opening 613. The protrusion 42 is at least partially located within the fourth opening 613.

In some embodiments, as shown in fig. 17 (for convenience of illustrating the positional relationship of the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 17), in the case that the third sub-panel 123 is provided with the first opening 1231. The ground structure 60 includes a conductive paste layer 62 and a conductive bump 63.

The conductive adhesive layer 62 is adhered to the surface of the third sub-board 123 far away from the first sub-board 121, and covers the first opening 1231.

The conductive block 63 is partially located in the first opening 1231, and has one end electrically connected to the grounding conductive portion 33 and the other end electrically connected to the conductive adhesive layer 62. The flexible printed circuit 31 is electrically connected to the third sub-board 123 through the conductive bumps 63 and the conductive adhesive layer 62, i.e. the flexible printed circuit 31 is grounded. In the reliability cold-thermal shock test, the conductive adhesive layer 62 can provide a support for the flexible circuit board 31 at the first opening 1231, so as to reduce the risk of warping of the flexible circuit board 31 (the thickness is less than or equal to 0.1 mm), and further reduce the risk of light leakage of the backlight module 100.

For example, the material of the conductive block 63 may include a conductive adhesive, such that one end of the conductive block 63 is adhered to the ground conductive part 33 and the other end is adhered to the conductive adhesive layer 62 through the first opening 1231.

Illustratively, the material of the conductive block and the material of the second conductive layer 3114 may be the same, such that one end of the conductive block is in contact with the ground conductive portion 33 and the other end is in contact with the conductive adhesive layer 62 through the first opening 1231.

The backlight module 100 further includes a support layer 70 and an adhesive layer 80, the support layer 70 is located on a side of the conductive adhesive layer 62 away from the third sub-board 123, and the adhesive layer 80 is located between the support layer 70 and the conductive adhesive layer 62. The adhesive layer 80 is used to adhere the support layer 70 and the conductive adhesive layer 62. The support layer 70, the adhesive layer 80, and the conductive glue layer 62 form a display panel carrier layer 5, and the display panel carrier layer 5 is configured to support the first glass substrate 210.

The material of the supporting layer 70 may include Polyethylene Terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyphenylene Sulfone resin (PPSU), or Polymethyl Methacrylate (PMMA), which is not exemplified in the embodiments of the present disclosure. Illustratively, the material of the support layer 70 includes PET.

In some embodiments, as shown in fig. 10, a portion of the boundary of the third sub-board 123 away from the second sub-board 122 is recessed inward to form the first opening 1231, i.e., the boundary of the first opening 1231 coincides with the boundary of the third sub-board 123 away from the second sub-board 122.

As shown in fig. 18, the at least one optical film 40 includes a main portion 41 and a protruding portion 42, the main portion 41 is located on a side of the third sub-board 123 far from the second sub-board 122, one end of the protruding portion 42 is connected to the main portion and at least partially located in the first opening 1231, the protruding portion 42 is located side by side with the conductive block 63, and the conductive block 63 is configured to limit the movement of the protruding portion 42 along the first direction Y, so that the risk that the at least one optical film 40 moves along the first direction Y and collides with the backplate 10 to be damaged can be reduced. The first direction Y is perpendicular to the second direction X. In fig. 17, the display panel 200 and the fixing tape 300 are not shown in order to show the position relationship of the film layers of the backlight module 100.

Exemplarily, as shown in fig. 19A (for convenience of showing the position relationship of the display panel carrier layer 5, the trace portion 311, and the conductive block 63, the back plate 10 and the display panel 200 fixing tape 300 are not shown in fig. 19A), the protruding portion 42 is arranged side by side with the conductive block 63 along the first direction Y, and the protruding portion 42 is located at the left side of the conductive block 63.

Exemplarily, as shown in fig. 19B (for convenience of illustrating the position relationship of the display panel carrier layer 5, the routing portion 311 and the conductive block 63, the back plate 10 and the display panel 200 fixing tape 300 are not shown in fig. 19B), the protruding portion 42 is disposed side by side with the conductive block 63 along the first direction Y, and the protruding portion 42 is located at the right side of the conductive block 63.

As shown in fig. 19A and 19B, the end portions of the protruding portions and the conductive pieces 62 where the conductive pieces 63 are close to each other are in contact with each other in the first direction Y, so that the conductive pieces 63 can restrict the movement of the protruding portions 42 in the first direction Y. Wherein.

In some embodiments, as shown in fig. 19A and 19B, the conductive adhesive layer 62 is provided with an avoiding hole 621, and a portion of the protruding portion 42 is located in the avoiding hole 621.

It should be noted that: in the case that the protrusion 42 is far from the surface of the light guide plate 20 and is closer to the light guide plate 20 than the surface of the third sub-plate 123 is far from the light guide plate 20, the avoiding hole 621 may not be formed in the conductive adhesive layer 62. Alternatively, in the case that the surface of the protrusion 42 away from the light guide plate 20 is flush with the surface of the third sub-plate 123 away from the light guide plate 20, the avoiding hole 621 may not be provided in the conductive adhesive layer 62.

In some embodiments, as shown in fig. 18, the backlight module 100 further includes a reflective layer 90, and the reflective layer 90 is located between the supporting portion 11 and the light guide plate 20.

It is to be understood that the embodiments of the present disclosure are not limited thereto, and that the above-described embodiments may be arbitrarily combined in some possible cases.

Exemplarily, as shown in fig. 20, the flexible wiring board 31 is partially located between the light guide plate 20 and the first sub-board 121, and is adhered to the light guide plate 20.

The light shielding tape 50 is partially located between the third sub-board 123 and the flexible wiring board 31, and is located on one side of the second sub-board 122 close to the plurality of optical films 40. An end of the light shielding tape 50 remote from the second sub-board 122 protrudes out of the groove portion 12. An edge portion of the plurality of optical films 40 adjacent to the first sub-sheet 121 overlaps an edge portion of the light shielding tape 50 remote from the second sub-sheet 122.

The conductive foam is located between the flexible circuit board 31 and the third sub-board 123, and between the second sub-board 122 and the light-shielding tape 50, one end of the conductive foam is connected with the grounding conductive part 33, and the other end is connected with the third sub-board 123.

Illustratively, as shown in fig. 21, the first sub-portion 21 is at least partially located between the first sub-portion 121 and the third sub-portion 123, and the second sub-portion 22 is disposed on the supporting portion 11 and connected to the first sub-portion 21. The surface of the first sub-part 21 far away from the first sub-part 121 is closer to the plane where the first sub-part 121 and the supporting part 11 are located than the surface of the second sub-part 22 far away from the supporting part 11.

The flexible circuit board 31 is partially located between the first sub-portion 21 and the first sub-plate 121, and the flexible circuit board 31 is adhered to the surface of the first sub-portion 21.

The light shielding tape 50 is partially located between the third sub-board 123 and the flexible wiring board 31 and located on a side of the second sub-board 122 close to the plurality of optical films 40. An end of the light shielding tape 50 remote from the second sub-board 122 protrudes out of the groove portion 12, and edge portions of the plurality of optical films 40 near the first sub-board 121 overlap edge portions of the light shielding tape 50 remote from the second sub-board 122.

Illustratively, as shown in fig. 11, the first sub-portion 21 is at least partially located between the first sub-portion 121 and the third sub-portion 123, and the second sub-portion 22 is disposed on the supporting portion 11 and connected to the first sub-portion 21. The surface of the first sub-part 21 far away from the first sub-part 121 is closer to the plane where the first sub-part 121 and the supporting part 11 are located than the surface of the second sub-part 22 far away from the supporting part 11. The first sub-portion 21 is adjacent to an edge of the second sub-portion 22, and overlaps with an edge portion of the plurality of optical films 40 adjacent to the third sub-plate 123.

The wire trace portion 311 is partially located between the light guide plate 20 and the third sub-plate 123, and is fixedly connected to the first sub-portion 21. LED lamp pearl 32 and walking portion 311 fixed connection. The light shielding portion 312 is located on a side of the wire trace portion 311 away from the second sub-board 122, and is connected to the wire trace portion 311, and an end of the light shielding portion 312 away from the wire trace portion 311 extends out of the groove 12 and is flush with an end of the first sub-portion 21 close to the second sub-portion 22. The light shielding portion 312 is away from the surface of the first sub-portion 21 and flush with the surface of the second sub-portion 22 away from the supporting portion 11.

The conductive foam is located between the flexible circuit board 31 and the third sub-board 123, one end of the conductive foam is connected with the grounding conductive part 33, and the other end of the conductive foam is connected with the third sub-board 123.

For example, as shown in fig. 22 (for convenience of illustrating the positional relationship of the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 21), the trace portion 311 is partially located between the light guide plate 20 and the third sub-plate 123, and is fixedly connected to the light guide plate 20. The LED lamp beads 32 are fixedly connected with the routing part 311. The light shielding portion 312 is located on a side of the wire trace portion 311 away from the second sub-board 122, and is connected to the wire trace portion 311, and one end of the light shielding portion 312 away from the wire trace portion 311 extends out of the groove 12. An edge portion of the plurality of optical films 40 close to the first sub-sheet 121 overlaps an edge portion of the light shielding portion 312 far from the second sub-sheet 122.

Illustratively, as shown in fig. 17, the first sub-portion 21 is at least partially located between the first sub-portion 121 and the third sub-portion 123, and the second sub-portion 22 is disposed on the supporting portion 11 and connected to the first sub-portion 21. The surface of the first sub-part 21 far away from the first sub-part 121 is closer to the plane where the first sub-part 121 and the supporting part 11 are located than the surface of the second sub-part 22 far away from the supporting part 11. The first sub-portion 21 is adjacent to the edge of the second sub-portion 22 and overlaps with the edge portions of the plurality of optical films 40 adjacent to the third sub-plate 123.

The routing portion 311 is partially located between the first sub-portion 21 and the third sub-portion 123, and is fixedly connected to the first sub-portion 21. The LED lamp beads 32 are fixedly connected with the routing part 311. The light shielding portion 312 is located on a side of the trace portion 311 away from the second sub-board 122 and connected to the trace portion 311, and an end of the light shielding portion 312 away from the trace portion 311 extends out of the groove 12 and is flush with an end of the first sub-portion 21 away from the second sub-portion 22. The light shielding portion 312 is away from the surface of the first sub-portion 21 and flush with the surface of the second sub-portion 22 away from the supporting portion 11.

The third sub-board 123 is provided with a first opening 1231. The conductive adhesive layer 62 is adhered to the surface of the third sub-board 123 far away from the first sub-board 121, and covers the first opening 1231. The conductive block 63 is located in the first opening 1231, and one end of the conductive block 63 is electrically connected to the grounding conductive portion 33, and the other end is electrically connected to the conductive adhesive layer 62.

The support layer 70 is located on a side of the conductive adhesive layer 62 far from the third sub-board 123, and the adhesive layer 80 is located between the support layer 70 and the conductive adhesive layer 62. The adhesive layer 80 is used to adhere the support layer 70 and the conductive adhesive layer 62. The support layer 70, the adhesive layer 80 and the conductive glue layer 62 form a display panel carrier layer 5, and the display panel carrier layer 5 is configured to support the first glass substrate 210.

Exemplarily, as shown in fig. 23 (for convenience of illustrating the positional relationship of the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 23), the flexible printed circuit 31 is at least partially located between the light guide plate 20 and the first sub-board 121, and is bonded to the light guide plate 20.

The light shielding tape 50 is partially located between the third sub-board 123 and the flexible wiring board 31 and located on a side of the second sub-board 122 close to the plurality of optical films 40. One end of the light shielding tape 50 remote from the second sub-board 122 protrudes out of the groove portion 12. An edge portion of the plurality of optical films 40 adjacent to the first sub-sheet 121 overlaps an edge portion of the light shielding tape 50 remote from the second sub-sheet 122.

The third sub-board 123 is provided with a first opening 1231. The conductive adhesive layer 62 is adhered to the surface of the third sub-board 123 far away from the first sub-board 121, and covers the first opening 1231. The conductive block 63 is located partially in the first opening 1231 and partially between the second sub-board 122 and the light shielding tape 50, one end of the conductive block 63 is electrically connected to the grounding conductive portion 33, and the other end is electrically connected to the conductive adhesive layer 62.

The support layer 70 is located on the side of the conductive adhesive layer 62 away from the third sub-board 123, and the adhesive layer 80 is located between the support layer 70 and the conductive adhesive layer 62. The adhesive layer 80 is used to adhere the support layer 70 and the conductive adhesive layer 62. The support layer 70, the adhesive layer 80, and the conductive glue layer 62 form a display panel carrier layer 5, and the display panel carrier layer 5 is configured to support the first glass substrate 210.

For example, as shown in fig. 24 (to facilitate showing the positional relationship of the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 24), the first sub-portion 21 is at least partially located between the first sub-portion 121 and the third sub-portion 123, and the second sub-portion 22 is disposed on the supporting portion 11 and connected to the first sub-portion 21. The surface of the first sub-part 21 far away from the first sub-part 121 is closer to the plane where the first sub-part 121 and the supporting part 11 are located than the surface of the second sub-part 22 far away from the supporting part 11.

The flexible circuit board 31 is at least partially located between the first sub-portion 21 and the first sub-board 121, and is bonded to the first sub-portion 21.

The light shielding tape 50 is partially positioned between the third sub-board 123 and the flexible wiring board 31 and on one side of the second sub-board 122. An end of the light shielding tape 50 remote from the second sub-board 122 protrudes out of the groove portion 12, and an orthographic projection of the plurality of optical films 40 on the reference surface overlaps with an orthographic projection of the light shielding tape 50 on the reference surface.

The third sub-board 123 is provided with a first opening 1231. The conductive adhesive layer 62 is connected to the surface of the third sub-board 123 away from the first sub-board 121. The conductive block 63 is located partially in the first opening 1231 and partially between the second sub-board 122 and the light shielding tape 50, one end of the conductive block 63 is electrically connected to the grounding conductive portion 33, and the other end is electrically connected to the conductive adhesive layer 62.

For example, as shown in fig. 25 (for convenience of showing the position relationship of the film layers of the backlight module 100, the display panel 200 and the fixing tape 300 are not shown in fig. 23), the trace portion 311 is located between the light guide plate 20 and the third sub-plate 123 and is fixedly connected to the first sub-portion 21. LED lamp pearl 32 and walking portion 311 fixed connection. The light shielding portion 312 is located on a side of the wire trace portion 311 away from the second sub-board 122, and is connected to the wire trace portion 311, and an end of the light shielding portion 312 away from the wire trace portion 311 extends out of the groove 12 and is flush with an end of the first sub-portion 21 close to the second sub-portion 22. The light shielding portion 312 is away from the surface of the first sub-portion 21 and flush with the surface of the second sub-portion 22 away from the supporting portion 11.

The third sub-board 123 is provided with a first opening 1231. The conductive adhesive layer 62 is adhered to the surface of the third sub-board 123 far from the first sub-board 121, and covers the first opening 1231. The conductive block 63 is located in the first opening 1231, and one end of the conductive block 63 is electrically connected to the grounding conductive portion 33, and the other end is electrically connected to the conductive adhesive layer 62.

The support layer 70 is located on the side of the conductive adhesive layer 62 away from the third sub-board 123, and the adhesive layer 80 is located between the support layer 70 and the conductive adhesive layer 62. The adhesive layer 80 is used to adhere the support layer 70 and the conductive adhesive layer 62. The support layer 70, the adhesive layer 80 and the conductive glue layer 62 form a display panel carrier layer 5, and the display panel carrier layer 5 is configured to support the first glass substrate 210.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art will appreciate that changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A backlight module, comprising:

the back plate comprises a supporting part and a groove part positioned on one side of the supporting part, the groove part comprises a first sub-plate, a second sub-plate and a third sub-plate which are sequentially connected, one end of the first sub-plate, which is far away from the second sub-plate, is connected with the supporting part, and the third sub-plate is arranged opposite to the first sub-plate;

the light guide plate is arranged on the supporting part, and part of the light guide plate is positioned between the first sub-plate and the third sub-plate;

and at least part of the flexible circuit board is positioned between the light guide plate and the third sub-plate and is fixedly connected with the light guide plate.

2. A backlight module according to claim 1, wherein the light guide plate comprises:

a first sub-portion located at least partially between the first sub-board and the third sub-board;

the second sub-part is arranged on the supporting part and is connected with the first sub-part;

the surface of the first sub-part, which is far away from the first sub-board, is closer to a plane where the first sub-board and the supporting part are located than the surface of the second sub-part, which is far away from the supporting part, and the flexible circuit board is located on one side of the first sub-part, which is far away from the first sub-board, and is fixedly connected with the surface of the first sub-part, which is far away from the first sub-board.

3. The backlight module as claimed in claim 2, wherein the surface of the flexible circuit board away from the first sub-portion is flush with the surface of the second sub-portion away from the supporting portion.

4. The backlight module according to any one of claims 1 to 3, wherein the flexible circuit board comprises:

the wiring part is positioned between the first sub-board and the third sub-board and is fixedly connected with the light guide plate;

the shading part is positioned on one side, away from the second sub-board, of the routing part and is connected with the routing part, and one end, away from the routing part, of the shading part extends out of the groove part;

the backlight module further comprises a plurality of optical films which are stacked, wherein the optical films are positioned on one side, away from the supporting part, of the light guide plate and positioned on one side, away from the second sub-plate, of the third sub-plate; the edge parts of the plurality of optical films close to the third sub-plate are overlapped with the edge parts of the light shielding parts far away from the wiring parts.

5. The backlight module according to claim 4, wherein the trace portion comprises a first insulating layer, a first conductive layer, a substrate layer, a second conductive layer and a cover film, which are sequentially stacked, wherein the first insulating layer is closer to the light guide plate than the cover film;

the shading part comprises an extension layer and a reflecting layer, the extension layer and the cover film or the base material layer are integrally arranged, and the reflecting layer is arranged on one side, close to the light guide plate, of the extension layer.

6. The backlight module according to claim 5, wherein edge portions of the plurality of optical films adjacent to the third sub-plate overlap the light reflecting layer.

7. The backlight module according to claim 4, wherein in the case that the light guide plate comprises a first sub-portion and a second sub-portion, an end of the light shielding portion away from the wire trace portion is flush with an end of the second sub-portion close to the first sub-portion.

8. The backlight module according to any one of claims 1 to 3, wherein the flexible printed circuit board comprises a ground conductive part, and the ground conductive part is located on a side of the flexible printed circuit board close to the third sub-board; the backlight module further comprises:

and a grounding structure electrically connected with the grounding conductive part and the third sub-board.

9. The backlight module according to claim 8, wherein the ground structure comprises:

and the elastic conductive block is positioned between the flexible circuit board and the third sub-board, one end of the elastic conductive block is electrically connected with the grounding conductive part, and the other end of the elastic conductive block is electrically connected with the third sub-board.

10. A backlight module according to claim 8, wherein the third sub-board is provided with a first opening; the grounding structure includes:

the conductive adhesive layer is adhered to the surface, far away from the first sub-board, of the third sub-board and covers the first opening;

and the part of the conductive block is positioned in the first opening, one end of the conductive block is electrically connected with the grounding conductive part, and the other end of the conductive block is electrically connected with the conductive adhesive layer.

11. A backlight module according to claim 10, wherein a portion of the third sub-plate away from the second sub-plate is recessed to form the first opening;

the backlight module further comprises a plurality of optical diaphragms which are arranged in a stacked mode, at least one optical diaphragm comprises a main body portion and a protruding portion, the main body portion is located on one side, away from the second daughter board, of the third daughter board, one end of the protruding portion is connected with the main body portion, at least part of the protruding portion is located in the first opening, and the protruding portion and the conducting blocks are arranged side by side.

12. A backlight module according to claim 11, wherein in the first direction, the protrusions contact ends of the conductive bumps adjacent to each other; wherein the first direction is parallel to a length extension direction of the third sub-board.

13. The backlight module according to claim 11, wherein the conductive adhesive layer is provided with an avoiding hole, and a portion of the protruding portion is located in the avoiding hole.

14. The backlight module according to claim 10, further comprising a supporting layer and an adhesive layer stacked on each other, wherein the adhesive layer is adhered to the conductive adhesive layer.

15. A display device, comprising the backlight module as claimed in any one of claims 1 to 14 and a display panel.