Backlight module and display module

Abstract

This application provides a backlight module and a display module. The backlight module includes a housing and a lamp source, a light guide plate, and a flexible circuit board located within the housing. Along a first direction, the lamp source is located at a first end of the light guide plate and is electrically connected to the flexible circuit board. A portion of the flexible circuit board is located on the side of the light guide plate near the bottom of the housing. Along a second direction perpendicular to the first direction, the flexible circuit board has a first side with the lamp source and a second side facing away from the lamp source. The first side is bonded to the light guide plate with a first double-sided adhesive, which covers the portion of the first side excluding the lamp source. The second side has a thermal functional layer, which is a heat dissipation layer, a heat insulation layer, or a composite layer formed by both. The thermal functional layer is bonded to the second side of the flexible circuit board. The second end of the light guide plate, away from the lamp source, is bonded to the bottom of the housing with a second double-sided adhesive. The thermal functional layer on the second side of the flexible circuit board is used to accelerate heat dissipation or provide heat insulation, thereby solving the problem of heat generation at the lamp port of the backlight module.

Description

Technical Field

[0001] This application relates to the technical field of backlight components, and in particular to a backlight module and a display module. Background Technology

[0002] In LCD modules, since the LCD panel itself does not emit light, a backlight assembly is required. To meet the need for thinner and lighter LCD modules, the LEDs (Light Emitting Diodes) in the backlight are typically side-lit. Furthermore, to minimize bezels, the backlight uses a reverse assembly design, where the LED_FPC (Light Emitting Diode Flexible Printed Circuit) is fixed below the light guide plate. During a drop, this reverse assembly structure is prone to the light guide plate separating from the LED_FPC, resulting in light leakage from the LED openings. Furthermore, the separation can cause the light guide plate to shift and impact the LEDs, leading to LED failure, or the light guide plate to shift and impact the metal frame, causing the light guide plate to crack. Summary of the Invention

[0003] The purpose of this application is to provide a backlight module and a display module to solve the problem that the light guide plate and LED_FPC are prone to separate during a drop. The specific technical solution is as follows:

[0004] This application provides a backlight module, comprising a housing and a lamp source, a light guide plate, and a portion of a flexible circuit board located within the housing. Along a first direction, parallel to the long side of the plane containing the light guide plate, the lamp source is disposed at a first end of the light guide plate and electrically connected to the flexible circuit board. The flexible circuit board is partially located on the side of the light guide plate near the bottom of the housing. Along a second direction, perpendicular to the plane containing the light guide plate, the flexible circuit board has a first side and a second side arranged opposite to each other. The first side is the side near the lamp source, and the second side is the side away from the lamp source. The first side is bonded to the light guide plate with a first double-sided adhesive, which covers the portion of the first side excluding the lamp source. The second side has a thermal functional layer, which is a heat dissipation layer, a heat insulation layer, or a composite layer formed by both. The thermal functional layer is bonded to the second side of the flexible circuit board. The second end of the light guide plate away from the lamp source is bonded to the bottom of the housing with a second double-sided adhesive.

[0005] According to the backlight module provided in the first aspect of this application, it may also have the following technical features:

[0006] In some embodiments, the flexible circuit board includes a first cover film, a first adhesive layer, a first electroplated copper layer, a first copper foil layer, a substrate layer, a second copper foil layer, a second electroplated copper layer, a second adhesive layer, and a second cover film stacked sequentially. The first cover film is located on the first side, and the second cover film is located on the second side. The first electroplated copper layer has a first trace layer and a first ground layer formed by etching. The first trace layer and the first ground layer are insulated from each other, and the first ground layer is disposed around the first trace layer. The second electroplated copper layer has a second ground layer formed by etching. The second cover film and the second adhesive layer have at least one first opening, which is a first copper leakage area, and the first opening is disposed opposite to the second ground layer. The first ground layer and / or the second ground layer are electrically connected to the ground pin of the flexible circuit board.

[0007] In some embodiments, the extension direction of the first window is parallel to the extension direction of the second ground layer, and they are spaced apart.

[0008] In some embodiments, the first cover film and the first adhesive layer include a plurality of second openings, the second openings being second copper leakage areas, the second copper leakage areas having pads, and the lamp source being electrically connected to the pads.

[0009] In some embodiments, the flexible circuit board includes at least one first conductive hole, and the first ground layer and the second ground layer are electrically connected through the first conductive hole.

[0010] In some embodiments, the flexible circuit board includes a plurality of second conductive holes, and the second electroplated copper layer further has a second trace layer formed by etching, wherein the first trace layer and the second trace layer are electrically connected through the second conductive holes.

[0011] In some embodiments, the first double-sided adhesive has a clearance portion, which is opposite to the position of the light source; or the first double-sided adhesive is disposed in the area between the two boundary lines of the light source along the first direction and the boundary line on the same side of the flexible circuit board.

[0012] In some embodiments, the thermal functional layer at least covers the first copper leakage area.

[0013] In some embodiments, a protective layer is provided on the side of the thermal functional layer opposite to the light guide plate, and the protective layer is bonded to the thermal functional layer.

[0014] In some embodiments, the heat dissipation layer is formed by laminating a third double-sided adhesive and a heat dissipation material, or the heat dissipation layer is a heat dissipation adhesive layer; the heat insulation layer is formed by laminating the third double-sided adhesive and a heat insulation material; the heat insulation layer in the composite layer is disposed close to the second cover film, and the composite layer is formed by laminating the third double-sided adhesive, a heat insulation material, and a heat dissipation material, or the heat dissipation layer in the composite layer is disposed close to the second cover film, and the composite layer is formed by laminating a heat dissipation double-sided adhesive layer and a heat insulation material.

[0015] A second aspect of this application provides a display module, the display module including a display panel and the backlight module described above, the backlight module being disposed on the side of the display panel away from the display side.

[0016] Beneficial effects of the embodiments in this application:

[0017] The backlight module and display module provided in this application embodiment have a portion of the flexible circuit board located below the light guide plate. This reduces the distance the flexible circuit board extends beyond the first end of the light guide plate, thereby reducing the space occupied by the flexible circuit board in the bezel and facilitating a smaller bezel. The first side of the flexible circuit board is bonded to the light guide plate with a first double-sided adhesive, which secures the flexible circuit board. A thermal functional layer is provided on the second side of the flexible circuit board. This thermal functional layer is used to accelerate heat dissipation or provide heat insulation, thereby solving the problem of heat generation at the lamp port of the backlight module and improving the user experience.

[0018] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0020] Figure 1 A schematic diagram of the structure of the display module provided in one embodiment of this application;

[0021] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the first end of the display module.

[0022] Figure 3 This is a schematic diagram showing the cross-sectional structure of the second end of the module;

[0023] Figure 4 This is a schematic diagram of the structure of the first side of the flexible circuit board;

[0024] Figure 5This is a schematic diagram of the structure of the second side of the flexible circuit board;

[0025] Figure 6 This is a schematic diagram of the stacked structure of a flexible circuit board at one location;

[0026] Figure 7 This is a schematic diagram of the stacked structure of a flexible circuit board at another location;

[0027] Figure 8 Schematic diagrams of temperature observation on the side away from the flexible circuit board in Schemes 1 and 4;

[0028] Figure 9 A schematic diagram showing the temperature observation on the side where the flexible circuit board is attached for Schemes 1 and 4;

[0029] Figure 10 Schematic diagrams of temperature observation on the side away from the flexible circuit board in Schemes 2 and 4;

[0030] Figure 11 A schematic diagram showing the temperature observation on the side where the flexible circuit board is attached for Schemes 2 and 4;

[0031] Figure 12 Schematic diagrams of temperature observation on the side away from the flexible circuit board in Schemes 3 and 4;

[0032] Figure 13 A schematic diagram showing the temperature observation on the side where the flexible circuit board is attached for Schemes 3 and 4.

[0033] The attached figures are labeled as follows:

[0034] Display panel 100; array substrate 101; opposing substrate 102; optical adhesive 103; glass cover 104; upper polarizer 105; lower polarizer 106;

[0035] Backlight module 200; housing 201; lamp source 202; light guide plate 203; first end 203a; second end 203b;

[0036] Flexible circuit board 204; first side 204a; second window 204a1; second side 204b; first window 204b1; main body 204c; bent portion 204d; gold finger 204e; ground pin 204e1; first trace layer 2041; first ground layer 2042; second ground layer 2043; second trace layer 2044; first conductive hole 2045; second conductive hole 2046; pad 2047.

[0037] First cover film a1; first adhesive layer a2; first electroplated copper layer a3; first copper foil layer a4; substrate layer a5; second copper foil layer a6; second electroplated copper layer a7; second adhesive layer a8; second cover film a9;

[0038] Thermal functional layer 205; First double-sided adhesive 206; Second double-sided adhesive 207; Light-blocking adhesive 208; Brightness-enhancing film 209; Upper brightness-enhancing film 209a; Lower brightness-enhancing film 209b; Diffuser 210; Reflective film 211; Main FPC 212; Copper foil 213; COF 214; Edge-binding mylar 215; Padding sheet 216; Outer shell 217; First direction X; Second direction Y. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0040] When the backlight module 200 adopts a reverse assembly structure, i.e., the LED_FPC is fixed under the light guide plate 203, it does not need to avoid the light enhancement sheet 209 and the diffuser sheet 210. This helps to reduce the bezel size. However, if the backlight module 200 is accidentally dropped, the light guide plate 203 is prone to separating from the LED_FPC. Separation of the light guide plate 203 from the LED_FPC can not only cause light leakage from the lamp opening, but also cause the light guide plate 203 to hit the LED, resulting in LED failure. It can even cause the light guide plate 203 to hit the iron frame, resulting in the light guide plate 203 breaking.

[0041] To address the above technical problems, this application provides a display module, such as... Figure 1 As shown, the display module includes a display panel 100 and a backlight module 200, with the backlight module 200 located on the side of the display panel 100 away from the display side. This display module can be a display screen or a component of an electronic device. The electronic device may include a mobile phone, a car navigation system, a monitor, a laptop computer, a tablet computer, or a television, etc.

[0042] Taking a liquid crystal display panel 100 as an example, the backlight module 200 is located on one side of the liquid crystal display panel 100. The liquid crystal display panel 100 may include, for example, an array substrate 101 and a counter substrate 102, with liquid crystal disposed between the array substrate 101 and the counter substrate 102. When powered on, the backlight module 200 emits light, which, after converging and diffusing, is emitted to the liquid crystal display panel 100. The liquid crystal in the liquid crystal display panel 100 can then control the degree of light transmission to display an image.

[0043] Specifically, a lower polarizer 106 is provided on the side of the array substrate 101 away from the opposing substrate 102, and an upper polarizer 105 and a glass cover plate 104 are sequentially provided on the side of the opposing substrate 102 away from the array substrate 101. The glass cover plate 104 and the upper polarizer 105 are bonded together by optical adhesive 103.

[0044] like Figures 1-3 As shown, the backlight module 200 includes a housing 201 and a lamp source 202, a light guide plate 203, and a flexible circuit board 204 located within the housing 201. Along a first direction X, which is parallel to the long side of the plane containing the light guide plate 203, the lamp source 202 is located at the first end 203a of the light guide plate 203 and is electrically connected to the flexible circuit board 204. A portion of the flexible circuit board 204 is located on the side of the light guide plate 203 near the bottom of the housing 201. Along a second direction Y, which is perpendicular to the plane containing the light guide plate 203, the flexible circuit board 204 has a first side 204a and a second side 204b arranged opposite to each other. The first side 204a is the side closest to the lamp source 202, and the second side 204b is the side away from the lamp source 202. The first side 204a is bonded to the light guide plate 203 by a first double-sided adhesive 206, which covers the portion of the first side 204a except for the lamp source 202. The second side 204b is provided with a thermal functional layer 205, which is a heat dissipation layer, a heat insulation layer, or a composite layer formed by a heat dissipation layer and a heat insulation layer. The thermal functional layer 205 is bonded to the second side 204b of the flexible circuit board 204. The second end 203b of the light guide plate 203 away from the lamp source 202 is bonded to the bottom of the housing 201 by a second double-sided adhesive 207.

[0045] In this embodiment, a portion of the flexible circuit board 204 is located on the side of the light guide plate 203 near the bottom of the housing 201, that is, a portion of the flexible circuit board 204 is located below the light guide plate 203. This reduces the distance by which the flexible circuit board 204 extends beyond the first end 203a of the light guide plate 203, thereby reducing the space occupied by the flexible circuit board 204 in the frame, which is beneficial for reducing the frame size. The first side 204a of the flexible circuit board 204 is bonded to the light guide plate 203 by the first double-sided adhesive 206, which serves to fix the flexible circuit board 204.

[0046] The first double-sided adhesive 206 covers the portion of the first side 204a of the flexible circuit board 204 excluding the light source 202. In one embodiment, a clearance portion may be provided on the first double-sided adhesive 206, with the clearance portion positioned opposite to the light source 202. By providing the clearance portion on the first double-sided adhesive 206, the light source 202 is not covered by the first double-sided adhesive 206, allowing the light emitted by the light source 202 to illuminate the light guide plate 203. The light is then transmitted through the light guide plate 203 to the display panel 100, such as the liquid crystal display panel 100, which cannot emit light independently, and the backlight module 200 is used to illuminate the screen.

[0047] In another embodiment, the application position of the first double-sided adhesive 206 can be controlled to avoid the light source 202. For example, the first double-sided adhesive 206 can be located in the area between the two boundary lines of the light source 202 along the first direction and the boundary line on the same side of the flexible circuit board 204.

[0048] A thermal functional layer 205 is provided on the second side 204b of the flexible circuit board 204. The thermal functional layer 205 is used to accelerate heat dissipation or heat insulation, thereby solving the problem of heat generation at the lamp port of the backlight module 200 and improving the user experience.

[0049] Specifically, the thermal functional layer 205 is a heat dissipation layer, such as graphite sheets, copper foil, aluminum foil, thermally conductive single-sided adhesive, thermally conductive double-sided adhesive, etc. The heat dissipation layer can accelerate the transfer of heat from one side of the flexible circuit board 204 to the outside, reducing the temperature at the lamp port of the backlight module 200 and solving the problem of overheating at the lamp port of the backlight module 200. Alternatively, the thermal functional layer 205 can be a heat insulation layer, such as a polymer heat insulation film, aerogel heat insulation film, etc. The heat insulation layer can reduce the speed of heat transfer to the lamp port, solving the problem of overheating at the lamp port of the backlight module 200. Or, when the thermal functional layer 205 is a composite layer formed by a heat dissipation layer and a heat insulation layer, it can both reduce the speed of heat transfer to the lamp port and quickly dissipate the heat transferred to the lamp port, thereby further solving the problem of overheating at the lamp port of the backlight module 200.

[0050] like Figure 2 As shown, the first end 203a of the light guide plate 203 is bonded to the flexible circuit board 204, while the flexible circuit board 204 is not bonded to the bottom of the housing 201. During the drop of the backlight module 200, the housing 201 will not exert a downward force on the flexible circuit board 204. Therefore, the flexible circuit board 204 and the light guide plate 203 are not easily separated, thus solving the problem of light leakage from the lamp opening due to separation during the drop. At the same time, the second end 203b of the light guide plate 203, as shown... Figure 3 As shown, the second end 203b and the first end 203a are opposite ends. The second end 203b is bonded to the bottom of the housing 201 by the second double-sided adhesive 207, which also serves to fix the light guide plate 203. On the one hand, in the whole machine drop test (directional vertical drop and roller drop), it can prevent light leakage caused by the separation of the light guide plate 203 from the flexible circuit board 204 due to the weight of the light guide plate 203, and also prevent the light guide plate 203 from cracking due to displacement. On the other hand, through the contact between the second side 204b of the flexible circuit board 204 and the heat-functional layer 205, it can effectively avoid the problem of overheating at the module lamp port, improve the optical quality of the backlight module 200, such as avoiding problems such as light leakage, lamp shadows, and yellowing, and improve the display effect of the display device.

[0051] The first double-sided adhesive 206 and the second double-sided adhesive 207 can be the same type of double-sided adhesive or different types of double-sided adhesive.

[0052] The housing 201 can be a metal housing 201, such as iron, steel, aluminum, copper, etc., which can form a path for static electricity discharge and reduce the damage caused by static electricity to the backlight module 200.

[0053] Figure 4 This is a schematic diagram of the structure of the first side 204a of the flexible circuit board 204. Figure 5 This is a schematic diagram of the second side 204b of the flexible circuit board 204. The flexible circuit board 204 includes a main body 204c, a bending portion 204d, and gold fingers 204e. The main body 204c is where the light source 202 is housed. The bending portion 204d connects the main body 204c and the gold fingers 204e. The gold fingers 204e are bent outside the housing 201 via the bending portion 204d, meaning a portion of the flexible circuit board 204 is located inside the housing 201. The housing 201 includes a bottom wall and a side wall connected to the bottom wall. The bottom wall and the side wall form a space to accommodate the light source 202, the light guide plate 203, and the flexible circuit board 204. The bottom of the housing 201 is the inner side of the bottom wall, which is the side that does not contact the outside.

[0054] Figure 6 , Figure 7 This is a schematic diagram of the stacked structure of the flexible circuit board 204. The flexible circuit board 204 includes a first cover film a1, a first adhesive layer a2, a first electroplated copper layer a3, a first copper foil layer a4, a substrate layer a5, a second copper foil layer a6, a second electroplated copper layer a7, a second adhesive layer a8, and a second cover film a9 stacked sequentially. The first cover film a1 is located on the first side 204a, and the second cover film a9 is located on the second side 204b.

[0055] Among them, such as Figure 4 As shown, the first electroplated copper layer a3 has a first trace layer 2041 and a first ground layer 2042 formed by etching. The first trace layer 2041 and the first ground layer 2042 are insulated from each other, and the first ground layer 2042 is disposed around the first trace layer 2041. Figure 5 As shown, the second electroplated copper layer a7 has an etched second ground layer 2043; the second cover film a9 and the second adhesive layer a8 have at least one first opening 204b1, the first opening 204b1 being a first copper leakage area, and the first opening 204b1 being disposed opposite to the second ground layer 2043. The first ground layer 2042 and the second ground layer 2043 are electrically connected to the ground pin 204e1 of the flexible circuit board 204.

[0056] The first ground layer 2042 surrounds the first trace layer 2041. Optionally, the first ground layer 2042 is located within the perimeter of the flexible circuit board 204 and close to its perimeter, so that there is more space inside the first ground layer 2042 for the arrangement of the first trace layer 2041, which facilitates the manufacturing of the structure of the first ground layer 2042 and the first trace layer 2041 and helps to improve the manufacturing yield of the flexible circuit board 204.

[0057] The second ground layer 2043 can also be located within the perimeter of the flexible circuit board 204 and close to its perimeter, which facilitates the manufacturing of the second ground layer 2043 and helps to improve the manufacturing yield of the flexible circuit board 204.

[0058] Based on the cooperation of the first grounding layer 2042 and the second grounding layer 2043, without using the metal housing 201, static electricity can be discharged by directly or indirectly connecting the grounding pin 204e1 through the first grounding layer 2042 and the second grounding layer 2043, thereby reducing the damage caused by static electricity to the backlight module 200.

[0059] On the other hand, such as Figure 5 , Figure 7 As shown, by creating at least one first window 204b1 in the second cover film a9 and the second adhesive layer a8, the second electroplated copper layer a7 inside the second adhesive layer a8 is exposed. That is, the first window 204b1 corresponds to the first copper leakage area and is positioned opposite to the second ground layer 2043. Through the copper leakage from the second side 204b of the flexible circuit board 204, which contacts the thermal functional layer 205, the problem of overheating at the lamp port of the backlight module 200 can be effectively avoided, improving the optical quality of the backlight module 200 and the display effect of the display device. The number of first windows 204b1 can also be multiple, such as two, three, or four. The more first windows 204b1 there are, the larger the area for contact with the thermal functional layer 205, which is more conducive to effective heat dissipation.

[0060] In some embodiments, the first ground layer 2042 and the second ground layer 2043 are continuously arranged metal trace layers, generally in a U-shape. However, due to the presence of the gold finger 204e and the bend 204d, the first ground layer 2042 and the second ground layer 2043 are not strictly U-shaped. Figure 4 , Figure 5As shown, the shapes of the first ground layer 2042 and the second ground layer 2043 are not necessarily exactly the same. The first ground layer 2042 can be U-shaped, and the second ground layer 2043 also includes metal traces arranged at the bend 204d and the gold finger 204e, and electrically connected to the ground pin 204e1 at the gold finger 204e. In this case, the first ground layer 2042 is not directly electrically connected to the ground pin 204e1, but is indirectly electrically connected to the ground pin 204e1 through the second ground layer 2043.

[0061] Of course, the flexible circuit board 204 may include not only the ground pin 204e1, but also other pins, such as positive pins and negative pins.

[0062] In some embodiments, such as Figure 5 As shown, the extension direction of the first window 204b1 is parallel to the extension direction of the second grounding layer 2043, and they are spaced apart.

[0063] The extension direction of the first window 204b1 is the same as the extension direction of the second ground layer 2043, which makes the area of ​​the first copper leakage area exposed by the first window 204b1 larger, thereby increasing the contact area between the first copper leakage area and the thermal functional layer 205, improving the heat dissipation capacity of the flexible circuit board 204, and helping to solve the problem of heat generation at the lamp port of the backlight module 200.

[0064] In some embodiments, such as Figure 4 As shown, the first cover film a1 and the first adhesive layer a2 include a plurality of second openings 204a1, the second openings 204a1 are second copper leakage areas, the second copper leakage areas are provided with pads 2047, and the lamp source 202 is electrically connected to the pads 2047.

[0065] By creating multiple second openings 204a1 in the first cover film a1 and the first adhesive layer a2, the first electroplated copper layer a3 inside the first adhesive layer a2 is exposed. That is, the second openings 204a1 correspond to the second copper leakage area and are positioned opposite to the first trace layer 2041, facilitating the electrical connection of the lamp source 202 to the first trace layer 2041 via the solder pads 2047. The lamp source 202 and the solder pads 2047 can be electrically connected via soldering, which improves connection stability.

[0066] The light source 202 can be an LED, such as mini-LED or Micro-LED.

[0067] like Figure 4 , Figure 5As shown, the flexible circuit board 204 includes at least one first conductive hole 2045, and the first ground layer 2042 and the second ground layer 2043 are electrically connected through the first conductive hole 2045. The electrical connection between the first ground layer 2042 and the second ground layer 2043 through the first conductive hole 2045 can reduce the space occupied by wiring and simplify the wiring difficulty, which is beneficial to reducing the overall size of the flexible circuit board 204.

[0068] like Figure 4 and Figure 5 As shown, the first grounding layer 2042 and the second grounding layer 2043 are arranged opposite to each other. Since they are arranged opposite each other, the first conductive hole 2045 can be directly formed as a vertical through hole, which reduces the opening area of ​​the first conductive hole 2045 and lowers the design difficulty of the first conductive hole 2045.

[0069] In some embodiments, such as Figure 5 As shown, the flexible circuit board 204 includes a plurality of second conductive holes 2046, and the second electroplated copper layer a7 also has a second trace layer 2044 formed by etching. The first trace layer 2041 and the second trace layer 2044 are electrically connected through the second conductive holes 2046.

[0070] In this embodiment, the second side 204b of the flexible circuit board 204 is also provided with a second wiring layer 2044. The first wiring layer 2041 and the second wiring layer 2044 are electrically connected through the second conductive hole 2046, which can reduce the space occupied by wiring and simplify the wiring difficulty, and is conducive to reducing the overall size of the flexible circuit board 204.

[0071] In some embodiments, the backlight module 200 further includes a reflective sheet 211 disposed on the side of the light guide plate 203 near the housing 201, and a diffuser sheet 210, a brightness enhancement sheet 209, and a light-shielding adhesive 208 disposed on the side of the light guide plate 203 away from the housing 201. The diffuser sheet 210, the brightness enhancement sheet 209, and the light-shielding adhesive 208 are arranged sequentially in a direction away from the housing 201. The brightness enhancement sheet 209 includes two sheets: an upper brightness enhancement sheet 209a and a lower brightness enhancement sheet 209b. The backlight module 200 also includes a housing 217, in which the diffuser sheet 210, the brightness enhancement sheet 209, the light-shielding adhesive 208, the light guide plate 203, the reflective sheet 211, the flexible circuit board 204, the light source, etc., are all located within the housing 217.

[0072] The display module also includes a main FPC 212, which is electrically connected to the display panel 100 via a COF 214 (Chip On Flex or Chip On Film). A copper foil 213 is provided on the side of the COF 214 furthest from the main FPC 212 to shield against radio frequency signal interference. The backlight module 200 has a mylar 215 for fixing the light-shielding adhesive 208 to the housing 201, preventing the adhesive from separating from the housing 201. A shim 216 is located between the backlight module 200 and the display panel 100 to fill the step difference between them.

[0073] In some embodiments, the thermal functional layer 205 at least covers the first copper leakage area.

[0074] To improve the heat dissipation or insulation effect of the thermal functional layer 205, the thermal functional layer 205 can cover the entire second side 204b of the flexible circuit board 204. The thermal functional layer 205 is in contact with the first copper leakage area, which reduces the intermediate heat transfer process on the one hand, and on the other hand, since copper itself has good thermal conductivity, it can accelerate the heat transfer rate to the thermal functional layer 205, thus improving the problem of heat generation at the lamp port of the backlight module 200.

[0075] In some embodiments, a protective layer is provided on the side of the thermal functional layer 205 facing away from the light guide plate 203, and the protective layer is bonded to the thermal functional layer 205. The protective layer is attached to the outside of the thermal functional layer 205, which can reduce the risk of the heat dissipation layer or heat insulation layer formed by heat dissipation material or heat insulation material falling off, and improve the service life of the thermal functional layer 205.

[0076] Optionally, the heat dissipation layer can be formed by laminating a third double-sided adhesive with a heat dissipation material, or the heat dissipation layer can be a heat dissipation adhesive layer.

[0077] When the heat dissipation layer is composed of a third double-sided adhesive and a heat dissipation material, the third double-sided adhesive is used to bond the heat dissipation material and the second cover film a9 respectively. The protective layer has adhesive on one side to bond with the heat dissipation material, which prevents the heat dissipation material from falling off. The side of the protective layer facing the bottom of the housing 201 is free of adhesive to avoid the protective layer from bonding with the bottom of the housing 201. During the drop of the backlight module 200, the housing 201 does not exert a downward force on the flexible circuit board 204, so that the flexible circuit board 204 will not detach from the light guide plate 203 and cause light leakage from the lamp opening.

[0078] The heat dissipation layer is a heat dissipation adhesive layer. The adhesive side of the heat dissipation adhesive layer is bonded to the second cover film a9, and the adhesive-free side of the heat dissipation adhesive layer is bonded to the adhesive side of the protective layer. The side of the protective layer facing the bottom of the housing 201 is also an adhesive-free side to prevent the heat dissipation adhesive layer from bonding to the bottom of the housing 201. During the drop of the backlight module 200, the housing 201 does not exert a downward force on the flexible circuit board 204, thus preventing the flexible circuit board 204 from detaching from the light guide plate 203 and causing light leakage from the lamp opening.

[0079] Alternatively, the insulation layer may be formed by laminating a third double-sided adhesive and an insulation material. When the insulation layer is composed of a third double-sided adhesive and an insulation material, the third double-sided adhesive is used to bond the insulation material and the second cover film a9 respectively. The protective layer has adhesive on one side to bond with the insulation material, thereby preventing the insulation material from falling off.

[0080] Alternatively, the heat insulation layer in the composite layer is disposed close to the second cover film a9, and the composite layer is formed by laminating a third double-sided adhesive with heat insulation material and heat dissipation material; or, the heat dissipation layer in the composite layer is disposed close to the second cover film a9, and the composite layer is formed by laminating a heat dissipation double-sided adhesive layer and a heat insulation layer.

[0081] The heat insulation layer in the composite layer is formed by stacking a third double-sided adhesive and a heat insulation material. The composite layer is composed of a heat insulation layer and a heat dissipation material. The third double-sided adhesive is used to bond the heat insulation material and the second cover film a9 respectively. The protective layer has adhesive on one side to bond with the heat dissipation material, which prevents the heat dissipation material from falling off. The side of the protective layer facing the bottom of the housing 201 is not adhesive to avoid the protective layer from bonding with the bottom of the housing 201. During the drop of the backlight module 200, the housing 201 does not exert a downward force on the flexible circuit board 204, so that the flexible circuit board 204 will not detach from the light guide plate 203 and cause light leakage from the lamp opening.

[0082] The composite layer is composed of a heat-dissipating double-sided adhesive layer and a heat-insulating material, with the heat-dissipating double-sided adhesive layer positioned close to the second cover film a9. The heat-dissipating double-sided adhesive layer is bonded to both the second cover film a9 and the heat-insulating material. The protective layer has adhesive on one side, which is bonded to the heat-insulating material to prevent it from falling off. The side of the protective layer facing the bottom of the housing 201 is free of adhesive to prevent the protective layer from sticking to the bottom of the housing 201. During the drop of the backlight module 200, the housing 201 does not exert a downward force on the flexible circuit board 204, thus preventing the flexible circuit board 204 from detaching from the light guide plate 203 and causing light leakage from the lamp opening.

[0083] Scheme 1 uses thermal functional layer 205 as a third double-sided adhesive + heat insulation material + protective layer; Scheme 2 uses thermal functional layer 205 as a heat dissipation single-sided adhesive + protective layer; Scheme 3 uses thermal functional layer 205 as a heat dissipation double-sided adhesive + heat insulation material + protective layer; and Scheme 4 uses thermal functional layer 205 as a third double-sided adhesive + heat insulation material + heat dissipation material + protective layer. In all cases, the protective layer is a single-sided adhesive. Temperature observations were performed on both the side attached to the flexible circuit board 204 and the side facing away from the flexible circuit board 204. The observation results are shown in the table below. Figures 8-13 As shown:

[0084]

[0085] Compare the data in the table and Figures 8-13 The results showed that Scheme 4 was more effective than Scheme 2, Scheme 3 and Scheme 1 in solving the problem of overheating of the 200 lamp ports in the backlight module.

[0086] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0087] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0088] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A backlight module, characterized in that, The backlight module includes a housing and a single lamp source, a light guide plate, and a single flexible circuit board located within the housing. The light source is located at the first end of the light guide plate and is electrically connected to the flexible circuit board. The backlight module is positioned along a first direction that is parallel to the long side of the plane containing the light guide plate. The flexible circuit board portion is located on the side of the light guide plate near the bottom of the housing, along a second direction, which is perpendicular to the plane where the light guide plate is located. The flexible circuit board has a first side and a second side arranged opposite to each other. The first side is the side closer to the light source, and the second side is the side away from the light source. The first side is bonded to the light guide plate by a first double-sided adhesive, and the first double-sided adhesive covers the part of the first side except for the light source. The second side is provided with a thermal functional layer, which is a heat dissipation layer, a heat insulation layer, or a composite layer formed by a heat dissipation layer and a heat insulation layer, and the thermal functional layer is bonded to the second side of the flexible circuit board. The first end of the light guide plate is connected to the flexible circuit board on the side facing the housing, and the flexible circuit board is not bonded to the bottom of the housing; The second end of the light guide plate, away from the light source, is bonded to the bottom of the housing with a second double-sided adhesive to fix the light guide plate.

2. The backlight module of claim 1, wherein, The flexible circuit board includes a first cover film, a first adhesive layer, a first electroplated copper layer, a first copper foil layer, a substrate layer, a second copper foil layer, a second electroplated copper layer, a second adhesive layer, and a second cover film stacked sequentially, with the first cover film located on the first side and the second cover film located on the second side. The first electroplated copper layer has an etched first trace layer and a first ground layer, the first trace layer and the first ground layer are insulated from each other, and the first ground layer is disposed around the first trace layer; The second electroplated copper layer has a second ground layer formed by etching; The second cover film and the second adhesive layer have at least one first opening, the first opening being a first copper leakage area, and the first opening being disposed opposite to the second ground layer; The first ground layer and / or the second ground layer are electrically connected to the ground pin of the flexible circuit board.

3. The backlight module according to claim 2, characterized in that, The first window extends in a direction parallel to the extension direction of the second grounding layer, and is spaced apart.

4. The backlight module according to claim 2, characterized in that, The first cover film and the first adhesive layer include a plurality of second openings, the second openings being second copper leakage areas, the second copper leakage areas having pads, and the lamp source being electrically connected to the pads.

5. The backlight module according to claim 2, characterized in that, The flexible circuit board includes at least one first conductive hole, and the first ground layer and the second ground layer are electrically connected through the first conductive hole.

6. The backlight module according to claim 2, characterized in that, The flexible circuit board includes a plurality of second conductive holes, and the second electroplated copper layer also has a second trace layer formed by etching. The first trace layer and the second trace layer are electrically connected through the second conductive holes.

7. The backlight module according to any one of claims 2-6, characterized in that, The first double-sided adhesive tape has a clearance portion, which is positioned opposite to the light source. Alternatively, the first double-sided adhesive can be applied to the area between the two boundary lines of the light source along the first direction and the boundary line on the same side of the flexible circuit board.

8. The backlight module according to any one of claims 2-6, characterized in that, The thermal functional layer at least covers the first copper leakage area.

9. The backlight module according to any one of claims 2-6, characterized in that, The thermal functional layer has a protective layer on the side opposite to the light guide plate, and the protective layer is bonded to the thermal functional layer.

10. The backlight module according to any one of claims 2-6, characterized in that, The heat dissipation layer is formed by laminating a third double-sided adhesive and a heat dissipation material, or the heat dissipation layer is a heat dissipation adhesive layer; the composite layer includes a heat insulation layer, which is formed by laminating the third double-sided adhesive and a heat insulation material. The heat insulation layer in the composite layer is disposed close to the second cover film, and the composite layer is formed by laminating the third double-sided adhesive with heat insulation material and heat dissipation material; or, the heat dissipation layer in the composite layer is disposed close to the second cover film, and the composite layer is formed by laminating a heat dissipation double-sided adhesive layer and heat insulation material.

11. A display module, characterized in that, The display module includes a display panel and a backlight module as described in any one of claims 1-10, wherein the backlight module is disposed on the side of the display panel away from the display side.

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