JP5635322B2 - Electronics - Google Patents

Description

  The present invention relates to an electronic device including an electronic element that generates heat. The electronic apparatus of the present invention is suitable as a backlight device for a liquid crystal display device.

Liquid crystal display devices are widely used as display devices for personal computers and televisions. A recent liquid crystal display device includes a backlight device that makes light incident from the back side of the liquid crystal display panel.
There are two types of backlight devices: a direct type with light sources arranged on the back side of the liquid crystal display panel and a side light method (edge method) with light sources arranged on the side of the light guide plate. The sidelight method is superior in that it can be made thinner.
The sidelight type backlight device is also referred to as a light guide plate method, and is a method in which a light guide plate made of a transparent resin is disposed on the back side of a liquid crystal display panel, and light is incident from the side surface of the light guide plate. Further, in the sidelight type backlight device, a reflector is often disposed on the back side of the light guide plate.

As a light source used in a sidelight type backlight device, a cold cathode tube or a light emitting diode (LED) is known.
Heretofore, light sources using light-emitting diodes have been used mainly in small electronic devices such as personal digital assistants and mobile phone devices because they have a relatively small amount of light, and large electronic devices such as monitor devices. Then, a cold cathode tube having a large light quantity has been adopted.
However, in recent years, the technology of light-emitting diodes has advanced, so-called high-intensity light-emitting diodes have been developed, and light-emitting diodes are being adopted in large electronic devices such as large liquid crystal televisions.

However, the high-intensity light emitting diode has a problem that it generates a large amount of heat. In the sidelight type backlight device, the light emitting diodes are intensively arranged in a part. Therefore, when the backlight device is continuously used for a long time, there is a problem that the temperature of the light emitting diode itself excessively rises and the light emitting state of the light emitting diode becomes unstable.
Further, the side end face of the light guide plate is excessively heated by the light emitting diodes, and the light guide plate is distorted to cause variations in brightness and brightness of the liquid crystal display panel.

Therefore, in a sidelight type backlight device using a light emitting diode, it is necessary to suppress a temperature rise by the light emitting diode. In the prior art, a cooling fin is provided on the back surface of the case of the backlight device, and a structure in which heat generated by the light emitting diode is radiated to the outside by the cooling fin is employed.
That is, a large number of light emitting diodes are mounted side by side on a substrate, and the substrate is fixed to the inside of the case using a mounting bracket or the like. If necessary, a heat transfer sheet is interposed between the mounting bracket and the inside of the case.
In addition to the light emitting diodes, a reflector, a light guide plate, and a liquid crystal display panel are arranged inside the case.
Cooling fins are attached to the outside of the case. The heat generated by the light emitting diode is conducted to the case via the mounting bracket and the heat transfer sheet, and is released from the cooling fins to the atmosphere.

JP 2006-156324 A

However, the sidelight type backlight device of the prior art has a problem that the outer shape is large because the cooling fin is provided outside the case. In addition, as the amount of heat generated by the light emitting diode increases, there is a problem that the fins become larger and the entire apparatus must be further enlarged.
Accordingly, the present invention focuses on the problems of the prior art, and an object of the present invention is to provide an electronic device in which the cooling fins can be reduced in size, the cooling fins can be omitted, and the overall shape can be reduced in size.

An invention according to claim 1 for solving the above-described problem is provided in an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is arranged on the frame. The graphite film is provided on the side where the temperature is substantially increased by the heat generated by the electronic element, and the graphite film is provided such that one end side thereof does not contact the frame and the other end side contacts the frame. The electronic device is arranged on a substrate, and the substrate is fixed to a frame via a substrate holding member .

The present invention relates to an electronic device in which an electronic element is arranged on a frame. In an electronic device in which the electronic element is arranged on a frame, heat generated by the electronic device is conducted to the back side of the frame. Here, in the electronic device of the present invention, since the graphite film is provided on the back side of the frame, the heat transmitted to the back side of the frame is widely diffused to the back side of the frame by the graphite film. In addition, since the graphite film is provided on the back side of the frame and at the “site where the temperature is substantially increased by the heat generated by the electronic element”, the location where the heat from the electronic element accumulates intensively, etc. Can be cooled. As a result, in the electronic device of the present invention, the heat generated by the electronic device is efficiently dissipated, and excessive temperature rise in the electronic device itself or in the vicinity thereof is suppressed.
Examples of the “electronic element” include a power transistor, an IC, and the like in addition to a light emitting diode described later. A transformer is also included in the “electronic element”.
An “electronic device” is an electrical device to which these “electronic elements” are attached.
The “back side” of the frame refers to a side other than the front side of the frame.

The “site where the temperature is substantially increased by the heat generated by the electronic device” where the graphite film is provided refers to a site that is affected by the heat generated by the electronic device. For example, the part where the heat transfer of the electronic element is directly applied is included in the "part where the temperature is substantially increased by the heat generated by the electronic element". For example, the vicinity of the electronic element and the vicinity thereof are included in the “part where the temperature is substantially increased by the heat generated by the electronic element” as long as the part is affected by the heat generated by the electronic element. For example, when the electronic element is provided on the frame via a pedestal or the like, as long as the part is affected by the heat generation of the electronic element, the place where the pedestal etc. is in contact and the vicinity thereof are “the electronic element is generated. It is included in the “site where the temperature is substantially increased by heat”.
In addition, even if it is not in the immediate vicinity of the electronic element or in the vicinity thereof, it is included in the “part where the temperature is substantially increased by the heat generated by the electronic element” as long as the part is affected by the heat generation of the electronic element. That is, the “site where the temperature is substantially increased by the heat generated by the electronic device” is not limited to the vicinity of the electronic device or the vicinity thereof, and is not limited to the location where heat from the electronic device is concentrated.
Conversely, even in the immediate vicinity of an electronic element, a portion that is not affected by the heat generation of the electronic element because it is thermally isolated or the like is “the temperature rises substantially by the heat generated by the electronic element. It is not included in “part”.
In the present invention, the graphite film is provided such that one end side thereof does not contact the frame and the other end side contacts the frame.
In the present invention, the electronic element is disposed on the substrate, and the substrate is fixed to the frame via the substrate holding member. Therefore, heat generated from an electronic element such as a light emitting diode is transmitted to the frame via the substrate holding member, and is further conducted to the back side of the frame. And it is diffused widely on the back surface side of the frame by the graphite film provided on the back surface side of the frame.

The electronic apparatus according to claim 1, comprising a holding member connected to the housing for covering the frame or frame, at least part of a region which is not in contact with the frame in the graphite film is held by the holding member It may be a structure (claim 2 ).

According to a third aspect of the present invention, in an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is disposed on the frame, the electronic element is located on the back side of the frame. A graphite film is provided at a portion where the temperature is substantially increased by the generated heat, and has a casing covering the frame. The graphite film is disposed across the frame and the casing, and the electronic element is disposed on the substrate. The electronic device is characterized in that the substrate is fixed to the frame via a substrate holding member .

A fourth aspect of the present invention is the electronic device according to any one of the first to third aspects, wherein a part of the graphite film forms a rib-like convex portion.

  In the electronic device of the present invention, a part of the graphite film provided on the back side of the frame forms a rib-like convex portion, so that the contact area between the graphite film and air is large. Therefore, heat dissipation from the graphite film is performed more efficiently.

According to a fifth aspect of the present invention, in an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is arranged on the frame, the electronic element is located on the back side of the frame. A graphite film is provided at a site where the temperature is substantially increased by generated heat, a part of the graphite film forms a rib-like convex portion, and the thickness of the graphite film is 10 to 300 μm, the thermal conductivity of the graphite film, 1200 W / mK or more der is, the electronic elements are disposed on the substrate, the substrate is an electronic device, characterized in that fixed to the frame via the substrate holding member is there.

According to a sixth aspect of the present invention, in the electronic device according to the fourth or fifth aspect, the convex portion has a cylindrical shape in which both ends in the length direction are open to form a gap portion. It is.

  In the electronic device of the present invention, since the convex portion has a cylindrical shape to form a void portion, air can pass through the convex portion (void portion). Therefore, heat dissipation from the convex portion is performed more efficiently.

There are a plurality of convex portions, and they may be arranged in parallel to each other (claim 7 ).

In the above electronic apparatus, the shape of the frame is arbitrary, and it may be a single plate or may have a bent portion. Moreover, a box-shaped thing may be sufficient. That frame includes a back plate portion, which may be one having a upstanding peripheral wall portion from the back plate portion (claim 9). In this case, both the back plate portion and the peripheral wall portion constitute part of the back side of the frame. The method of providing the graphite film is arbitrary, and may be provided only on one of the back plate portion and the peripheral wall portion. The graphite film may be provided across the back plate portion and the peripheral wall portion of the frame (claim 8 ).

Substrate holding member may be attached to the back plate portion of the frame (claim 10)

  When the substrate holding member is attached to the back plate portion of the frame, the graphite film is desirably provided on the back side of the back plate portion.

Substrate holding member may be attached to the peripheral wall of the frame (claim 11)

  When the substrate holding member is attached to the peripheral wall portion of the frame, the graphite film is desirably provided on the back side of the peripheral wall portion.

Substrate holding member is elongated, its sectional shape may be generally quadrilateral (claim 12).

Substrate holding member is elongated, its sectional shape may be a substantially L-shape (claim 13).

It is recommended that the present invention be applied to a backlight device. That is, according to the invention described in claim 14 , the electronic device is a backlight device, and includes a light guide plate and a reflection plate disposed on one surface side of the light guide plate, the electronic element is a light emitting diode, Located on the side of the light guide plate, the graphite film straddles the back surface portion of the frame corresponding to the portion where the substrate holding member is attached and the back surface portion of the frame corresponding to the portion where the light guide plate is attached it is provided an electronic device according to any one of claims 1 to 13, characterized in.

The invention according to claim 15 is an electronic device having an electronic element that generates heat when energized and a frame, wherein the electronic element is disposed on the back side of the frame. A graphite film is provided at a site where the temperature is substantially increased by the generated heat. The graphite film is provided such that one end side thereof does not contact the frame and the other end side contacts the frame. The portion forms a rib-like convex portion, and the convex portion is an electronic device characterized in that a gap is formed by forming a cylindrical shape with both ends in the length direction being open.
The invention according to claim 16 has a holding member connected to the frame or a casing covering the frame, and at least a part of a region of the graphite film not in contact with the frame is held by the holding member. The electronic apparatus according to claim 15, wherein the electronic apparatus is an electronic apparatus.
The invention according to claim 17 is an electronic device having an electronic element that generates heat when energized, and a frame, wherein the electronic element is disposed on the back side of the frame. A graphite film is provided at a portion where the temperature is substantially increased by the generated heat, and has a casing that covers the frame. The graphite film is arranged across the frame and the casing, and a part of the graphite film is A rib-like convex part is formed, and the convex part is an electronic device characterized in that a gap is formed by forming a cylindrical shape whose both ends in the length direction are open.

The invention according to claim 18 is an electronic apparatus comprising an electronic element that generates heat when energized and a frame, wherein the electronic element is disposed on the frame. A graphite film is provided at a site where the temperature is substantially increased by generated heat, a part of the graphite film forms a rib-like convex portion, and the thickness of the graphite film is 10 to 300 μm, In the electronic device, the thermal conductivity of the graphite film is 1200 W / mK or more, and the convex portion has a cylindrical shape with both ends in the length direction being open to form a void portion. is there.
The invention according to claim 19 is the electronic device according to any one of claims 15 to 18, wherein there are a plurality of convex portions and they are arranged in parallel to each other.
The invention according to claim 20 is an electronic device having an electronic element that generates heat when energized and a frame, wherein the electronic element is disposed on the frame, on the back side of the frame. A graphite film is provided at a site where the temperature is substantially increased by generated heat, a part of the graphite film forms a rib-like convex portion, and the thickness of the graphite film is 10 to 300 μm, The thermal conductivity of the graphite film is 1200 W / mK or more, the frame has a back plate portion and a peripheral wall portion rising from the back plate portion, and the graphite film straddles the back plate portion and the peripheral wall portion of the frame. It is an electronic device characterized by being provided.
The invention according to claim 21 is the electronic device according to any one of claims 15 to 19, wherein the frame has a back plate portion and a peripheral wall portion rising from the back plate portion.

The invention according to claim 22 is the electronic apparatus according to any one of claims 1 to 21 , wherein the electronic element is a light emitting diode.

  In the electronic device of the present invention, the electronic element is a light emitting diode. That is, the heat generated by the light emitting diode is widely diffused to the back side of the frame by the graphite film.

The invention according to claim 23 is the electronic device according to any one of claims 1 to 22 , wherein the graphite film is provided with an adhesive layer or an adhesive layer on one side.

  In the present invention, the graphite film is provided with an adhesive layer or an adhesive layer on one side, so the graphite film can be easily attached to the back of the frame.

The invention according to claim 24 is the electronic apparatus according to any one of claims 1 to 23 , wherein the graphite film is provided with a resin layer on one side.

  When the invention in which an adhesive layer or the like is provided on one side of the graphite film is used in combination, the adhesive layer or the like is provided on one side of the graphite film, and a resin layer is provided on the other side. In the present invention, since the resin layer is provided on one side of the graphite film, the graphite film is protected.

  The electronic device of the present invention has a high heat dissipation effect of the electronic element, and the performance is stable. Moreover, since the members required for heat radiation are small, there is an effect that the overall shape can be reduced in size.

It is a perspective view of the liquid crystal television of embodiment of this invention. It is the cross-sectional perspective view which cut | disconnected the main-body part of the liquid crystal television of FIG. 1 horizontally. It is an enlarged view of the end surface of FIG. 2, and shows the 1st form of this invention. It is a perspective view of the light emitting module used with the liquid crystal television of FIG. It is an expansion perspective view of the light emitting module of FIG. FIG. 5 is an enlarged exploded perspective view of the light emitting module of FIG. 4. It is the cross-sectional perspective view which observed the flame | frame used with the liquid crystal television of FIG. 1 from the back surface side. FIG. 4 is an enlarged view of an end surface corresponding to FIG. 3, showing a second embodiment of the present invention. FIG. 4 is an enlarged view of an end surface corresponding to FIG. 3, showing a third embodiment of the present invention. FIG. 4 is an enlarged view of an end surface corresponding to FIG. 3, showing a fourth embodiment of the present invention. FIG. 9 is an enlarged view of an end surface corresponding to FIG. 3, showing the fifth embodiment of the present invention. FIG. 10 is an enlarged view of an end surface corresponding to FIG. 3, showing a sixth embodiment of the present invention. FIG. 9 is an enlarged view of an end surface corresponding to FIG. 3, showing a seventh embodiment of the present invention. FIG. 10 is an enlarged view of an end surface corresponding to FIG. 3, showing an eighth embodiment of the present invention. It is the enlarged view of the end surface which shows the 9th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 10th form of this invention and corresponds to FIG. It is an enlarged view of the end surface which shows the 11th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 12th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 13th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 14th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 15th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 16th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 17th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 18th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 19th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 20th form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 21st form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 22nd form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 23rd form of this invention and corresponds to FIG. It is the enlarged view of the end surface which shows the 24th form of this invention and corresponds to FIG. It is an enlarged view of the end surface which shows the reference example relevant to this invention, and is equivalent to FIG. It is an enlarged view which shows the 1st form of this invention and shows the sticking condition of the graphite composite film at the time of seeing from the left side of FIG. It is the cross-sectional perspective view which showed the 25th form of this invention and observed the flame | frame from the back surface side. FIG. 36 is an enlarged view of a portion corresponding to FIG. 32, showing a twenty-fifth aspect of the present invention. FIG. 34 is an enlarged view of a portion corresponding to FIG. 32, showing a twenty-sixth aspect of the present invention. (A)-(c) is an enlarged view which shows the other shape of a convex part. FIG. 34 is an enlarged view of a portion corresponding to FIG. 32, showing a twenty-seventh aspect of the present invention. It is an expansion perspective view of the 1st modification of the light emitting module used with the liquid crystal television of embodiment of this invention. It is an expansion perspective view of the 2nd modification of the light emitting module used with the liquid crystal television of embodiment of this invention. It is sectional drawing which shows the laminated structure of a graphite composite film. It is a top view which shows the covering form of the edge part in a graphite composite film, (a) shows the case where 2 sides are covered, (b) shows the case where all 4 sides are covered.

  Embodiments of the present invention will be sequentially described below with reference to the drawings, but the present invention is not limited to these embodiments. For example, the numerical values such as the thickness and length of each member and the distance between the members are merely examples, and other numerical values can naturally be adopted.

The electronic apparatus of the present embodiment shown in FIG. The liquid crystal television 1 has a large screen with a width of 1000 mm and a length of 500 mm, and has a main body 2 and legs 3 as shown in FIG.
As shown in FIGS. 2 and 3, the main body 2 is entirely covered with a resin casing 5, and a liquid crystal display device 6 is built therein. The thickness of the housing 5 is 1.5 mm. 2 and the following drawings are shown in a state where the main body portion 2 is placed flat for drawing purposes. Therefore, FIG. 1 and FIG. 2 are 90 degrees different from each other.
In the present embodiment, the liquid crystal television 1 has the above screen size, but the present invention is not limited to this.

The main parts of the liquid crystal display device 6 are accommodated in a box-shaped frame 7 as shown in FIG. 3, for example. The frame 7 is made of aluminum, a thin steel plate or other metal having a thickness of 1 mm, and has a large area and is vertically raised from four sides of the square back plate 10 and the back plate 10. Further, it has four peripheral wall portions (only two sides 12 and 13 are shown in FIG. 3), and the front side (the upper side with reference to FIG. 3) is open. That is, in the present embodiment, the “back side” of the frame 7 is constituted by the back plate portion 10 and the four peripheral wall portions.
The lengths of the peripheral wall portions 12 and 13 in the direction from the front side of the frame 7 to the back plate portion 10 (vertical direction in FIG. 3) are 10 mm. The gap between the peripheral wall portion 12 of the frame 7 and the housing 5, that is, the distance from the surface of the housing 5 facing the peripheral wall portion 12 to the peripheral wall portion 12 is 45 mm.
Note that the shape of the back plate 10 may be other than a quadrangle. Further, the peripheral wall portion may not be raised vertically from the four sides of the back plate portion 10. The material of the frame 7 may be other than metal.

In a space surrounded by the back plate portion 10 of the frame 7 and four peripheral wall portions (only two sides 12 and 13 are shown in FIG. 3), components constituting the liquid crystal and the backlight are incorporated.
That is, a liquid crystal cell 15, a light collecting film (not shown), a prism film 16, a diffusion plate 17, a light guide plate 18 and a reflection plate 20 are laminated on the frame 7 in this order. The liquid crystal cell 15 is formed by sequentially laminating a polarizing film, glass, a liquid crystal material, a color filter glass, and another polarizing film in the same manner as a known one.
All of these members are rectangular and have a size of 1000 mm or more and 500 mm or more. The thickness of the liquid crystal cell 15 is 1.5 mm, the thickness of the prism film 16 is 0.2 mm, the thickness of the diffusion plate 17 is 2 mm, the thickness of the light guide plate 18 is 4 mm, and the thickness of the reflection plate 20 is 0.2 mm. is there. However, in the present invention, the shape of these members is not limited to a rectangle, and the size and thickness are not particularly limited.
The width of the overlapping portion of the casing 5 and the liquid crystal cell 15 on the open side (upper side in FIG. 3) of the frame 7 is 2 mm on the peripheral wall portion 12 side (the overlapping portion on the left side in FIG. 3) and the peripheral wall portion 13 side (FIG. 3). The overlapping part on the right side in FIG. That is, on the peripheral wall 13 side, the casing 5 overlaps with the liquid crystal cell 15 by 1 mm and the peripheral wall 13 by 1 mm (corresponding to the thickness of the frame 7), for a total of 2 mm.
In this embodiment, each film is installed on the frame 7 in a state where the reflection plate 20 is in contact with the inner surface of the back plate portion 10.

A light emitting module 22 is arranged along one side of the light guide plate 18 described above. The light emitting module 22 includes a substrate 25 and a substrate holding member 26 as shown in FIGS.
The ratio of the actual dimensions of each part of the light emitting module 22 is as shown in FIG. 4, and is a long object whose length is significantly longer than the cross-sectional area.
That is, the substrate holding member 26 is made by using a metal drawing material such as aluminum or mild steel, or by cutting or bending, and its cross-sectional shape is substantially L-shaped. More specifically, the height a and the width b of the substrate holding member 26 can both be about 4 to 7 mm, for example, and 6 mm in this embodiment. On the other hand, the total length c exceeds 1 m. However, the present invention is not limited to this embodiment, and the height a and the width b may be thinner, for example, less than 4 mm, and the total length c may be less than 1 m.

Since the cross-sectional shape of the substrate holding member 26 is substantially L-shaped as described above, it has a total of six surfaces except for the end surface.
That is, the substrate holding member 26 includes a bottom surface 37, a first back surface 38, a first top surface 40, a second back surface 41, and a second top surface 43 when the mounting surface of the substrate 25 is the front surface 36. Yes.
Here, the bottom surface 37 is a surface continuous with the front surface 36 and perpendicular to the front surface 36. The first back surface 38 is a surface that is continuous with the bottom surface 37 and parallel to the front surface 36. The first top surface 40 is a surface that is continuous with the first back surface 38 and parallel to the bottom surface 37. The second back surface 41 is a surface that is continuous with the first top surface 40 and is parallel to the front surface 36. The second top surface 43 is a surface that is continuous with the second back surface 41 and parallel to the bottom surface 37.
The lengths in the short direction of the first back surface 38, the first top surface 40, the second back surface 41, and the second top surface 43 are all 3 mm, but the present invention is not limited to this.
If there is no problem in function, the above six surfaces may not have the above-described vertical and parallel relationship.

The substrate 25 is obtained by printing a wiring on a resin plate 27 and soldering a large number of light emitting diodes 28 arranged in a row thereon. That is, in the liquid crystal television 1, a large number of light emitting diodes 28 are concentrated on the frame 7.
The thickness of the resin plate 27 is 1 mm, and the width is slightly smaller than the substrate holding member 26. The total length of the resin plate 27 is the same as that of the substrate holding member 26.
The light-emitting diode 28 has a regular quadrangular prism shape with a substantially square light-emitting surface, the light-emitting surface (surface facing the light guide plate 18) is 4 mm square, and the height (the length in the left-right direction in FIG. 3) is 3 mm. It is. In the present embodiment, 84 light emitting diodes are arranged in a row and soldered to the resin plate 27.
The thickness of the resin plate 27 and the size of the light emitting diode 28 are not limited to the above, and may be other sizes.

As described above, in this embodiment, the light guide plate 18 is a rectangular plate, and the light emitting module 22 is disposed along one of the long sides of the light guide plate 18. The side is a position to be a lower side when used as the liquid crystal television 1 as shown in FIG. In addition, about the light emitting module 22, what is necessary is just to be distribute | arranged to at least 1 side of the 4 sides of the light-guide plate 18, and is not limited to one of the long sides.
The shape and size of the light guide plate 18 are not particularly limited as long as the function can be exhibited.
The light emitting module 22 is fixed to the frame 7 with one surface of the substrate holding member 26 in contact with the inner surface of the back plate portion 10 of the frame 7. The light emitting module 22 is located along the end surface of one side of the light guide plate 18, and the light emitting diode 28 is close to the end surface of one side of the light guide plate 18. However, a 1 mm gap is provided between the light emitting diode 28 and the light guide plate 18.
In the present embodiment, there is also a gap G between the substrate holding member 26 and the peripheral wall portion 12 of the frame 7. The size of the gap G is 1 mm.

And as a structure peculiar to this embodiment, the graphite composite film 30 is affixed on the back surface side of the frame 7.
Here, as will be described later, the graphite composite film 30 is a laminate in which an adhesive layer or an adhesive layer is provided on one surface of the graphite film and a resin layer is provided on the other surface, and is a long ribbon-like member. . The resin layer is any layer selected from the group consisting of an insulating layer, an adhesive layer, and an adhesive layer.
That is, the graphite composite film 30 is a ribbon-shaped, long-shaped, or rectangular laminate having a width W of 50 mm and a length exceeding 1 m.
In addition, about the width | variety of a graphite film, it is preferable that it is the width | variety which can completely cover the mounting surface 31 which is a contact surface with the flame | frame 7 in the board | substrate holding member 26 from a heat dissipation viewpoint. For example, in this embodiment, when the width of the frame 7 is 1000 mm, the width of the graphite film is usually 20 mm or more, preferably 30 mm or more, more preferably 50 mm or more, further preferably 250 mm or more, and most preferably It is 500 mm or more. The width W of the graphite composite film 30 can also be selected according to the width of the graphite film.
In this embodiment, the graphite composite film 30 having a resin layer on one side is used, but a graphite composite film having no resin layer (having only an adhesive layer or an adhesive layer) may be used. That is, the presence or absence of the resin layer is arbitrary.

In the present embodiment, the graphite composite film 30 is affixed to a portion on the back side of the frame 7 where the light emitting diodes 28 as electronic elements are concentrated. This part is a part that is affected by the heat generated by the light emitting diode (electronic element) 28, and is a part that is substantially heated by the heat generated by the light emitting diode 28.
More specifically, the adhering position of the graphite composite film 30 in the width W direction is the back surface side (outer surface) of the frame 7, and the frame as shown in FIG. 7 is a position corresponding to a part of the light guide plate 18 directly below (directly behind) from the corner 32. Therefore, the attaching position of the graphite composite film 30 in the width W direction is a position that covers all of the portion corresponding to the installation surface 31 of the substrate holding member 26 and further covers the end surface of the light guide plate 18 from the tip of the light emitting module 22. . Here, the width of the graphite composite film 30 directly below (directly behind) the light guide plate 18 is preferably 200 mm or less, more preferably 50 mm or less, still more preferably 20 mm or less, and even more preferably 10 mm or less.

  Further, the longitudinal attachment position of the graphite composite film 30 extends over the entire length in the longitudinal direction of the back plate portion 10 of the frame 7 as shown in FIG. 7 (the entire length in the vertical direction in FIG. 7).

In the liquid crystal display device of the liquid crystal television 1 of the present embodiment, the light emitting module 22 is energized to emit light in the same manner as well-known, and the light enters from the end face of the light guide plate 18, and the liquid crystal cell from the surface of the light guide plate 18 15 is sent light.
At this time, the light emitting module 22 generates heat, and the heat at that time is conducted from the substrate 27 to the substrate holding member 26 and further transmitted from the installation surface 31 of the substrate holding member 26 to the frame 7. Then, the portion corresponding to the installation surface 31 of the substrate holding member 26 of the frame 7 is heated.

  Here, in this embodiment, the portion corresponding to the installation surface 31 of the substrate holding member 26 on the back surface of the frame 7 is all covered with the graphite composite film 30. Therefore, the rate at which heat is diffused through the graphite composite film 30 provided on the back surface of the frame 7 is increased, and the temperature of the rear surface of the frame 7 and corresponding to the installation surface 31 of the substrate holding member 26 is reduced. Let As a result, heat conduction from the light emitting module 22 through the substrate 27 and the substrate holding member 26 to the back surface of the frame 7 is smoothly performed, and the temperature of the light emitting module 22 is lowered. Therefore, the light emission state of the light emitting module 22 is stabilized and the life of the light emitting module 22 is extended. Further, as the temperature of the light emitting module 22 decreases, the temperature of the end surface of the light guide plate 18 decreases, and distortion of the light guide plate 18 is prevented.

In the embodiment described above (first embodiment), an L-shaped cross section of the substrate holding member 26 is employed. The cross-sectional shape of the substrate holding member 26 is arbitrary, and may be a quadrangle such as a square or a rectangle or a trapezoid. However, since the substrate holding member 26 exhibits a function of conducting heat generated by the light emitting module 22 to the frame 7, the cross-sectional shape should be selected in consideration of this function.
That is, from the viewpoint of efficiently conducting the heat generated by the light emitting module 22 to the installation surface 31, the cross-sectional shape of the substrate holding member 26 is preferably a shape having few missing portions. It is recommended that the shape be close to a square.
On the other hand, from the viewpoint of efficiently conducting heat from the substrate holding member 26 to the frame 7, it is desirable that the area of the installation surface 31 is large. From this viewpoint, the cross-sectional shape is an “L” shape, a right triangle. , Square, etc. are recommended.

  In the first embodiment described above, the substrate holding member 26 is installed on the back plate portion 10 of the frame 7, but the substrate holding member 26 may be installed on the peripheral wall portions 12, 13. When the substrate holding member 26 is installed on the peripheral wall portion 12 of the frame 7, the graphite composite film 30 is desirably attached to the back surface side of the peripheral wall portion 12 of the frame 7.

  The width W of the graphite composite film 30 is preferably wider from the viewpoint of widely diffusing heat. However, if the width W of the graphite composite film 30 is too wide, the graphite composite film 30 reaches the lower surface side (back surface side) of the reflecting plate 20 and the light guide plate 18, and the heat of the graphite composite film 30 is reduced to the frame 7. In some cases, the temperature of the light guide plate 18 is increased by being conducted from the back surface side to the light guide plate 18. Therefore, the width W of the graphite composite film 30 may be appropriately selected in consideration of the temperature of the light emitting module 22, the size of the light guide plate 18 and the like.

  Hereinafter, an example in which the configuration of each unit is changed will be described. In addition, the same number is attached | subjected to the member which exhibits the same function, and the duplicate description is abbreviate | omitted.

The main body of the liquid crystal television shown in FIG. 8 shows a second embodiment of the present invention.
The liquid crystal display device 35 according to the second embodiment is an example in which the substrate holding member 26 is brought into contact with the peripheral wall portion 12 as well as the back plate portion 10 of the frame 7. That is, the liquid crystal display device 35 shown in FIG. 8 employs the substrate holding member 26 having an L-shaped cross section as in the first embodiment. In the liquid crystal display device 35 of the second embodiment, the bottom surface 37 of the six surfaces of the substrate holding member 26 is in contact with the back plate portion 10 of the frame 7. Further, in the liquid crystal display device 35 of the present embodiment, the first back surface 38 of the substrate holding member 26 is brought into contact with the peripheral wall portion 12. The gap between the light emitting diode 28 and the light guide plate 18 is 2 mm.
Other configurations are the same as those of the first embodiment described above, and the graphite composite film 30 is on the back side of the back plate portion 10 of the frame 7 and directly below a part of the light guide plate 18 from the corner 32 of the frame 7 ( It is provided at a position corresponding to (back).
Note that the other end of the graphite composite film 30 may not be on the light guide plate 18. The graphite composite film 30 can also be provided on the peripheral wall portion 12.

The main body of the liquid crystal television shown in FIG. 9 shows a third embodiment of the present invention.
The liquid crystal display device 45 according to the third embodiment is an example in which the substrate holding member 46 has a rectangular cross-sectional shape. That is, the substrate holding member 46 has a rectangular cross section having a front surface 50, a bottom surface 47, a back surface 48, and a top surface 49. In the present embodiment, only the bottom surface 47 is in contact with the back plate portion 10 of the frame 7.
The length of the bottom surface 47 in the short direction (left-right direction in FIG. 9) is 3 mm. The gap between the back surface 48 of the substrate holding member 46 and the peripheral wall portion 12 of the frame 7 is 4 mm. The gap between the light emitting diode 28 and the light guide plate 18 is 1 mm.
Other configurations are the same as those of the first embodiment described above, and the graphite composite film 30 corresponds to the back side of the frame 7 and directly below (partly back) part of the light guide plate 18 from the corner 32 of the frame 7. In the position.
The other end side of the graphite composite film 30 may be a position that does not cover the light guide plate 18. The graphite composite film 30 can also be provided on the peripheral wall portion 12.

The main body of the liquid crystal television shown in FIG. 10 shows a fourth embodiment of the present invention.
An example in which the liquid crystal display device 51 according to the fourth embodiment has a rectangular cross section as the substrate holding member 46 and the substrate holding member 46 is fixed to the peripheral wall portion 12 of the frame 7 is shown. That is, the substrate holding member 46 has a rectangular cross section having a front surface 50, a bottom surface 47, a back surface 48, and a top surface 49. In the present embodiment, only the back surface 48 is brought into contact with the peripheral wall portion 12 of the frame 7. That is, there is no contact between the bottom surface 47 and the frame 7.
The gap between the bottom surface 47 and the back plate portion 10 of the frame 7 is 1 mm. The gap between the light emitting diode 28 and the light guide plate 18 is 5 mm.
Other configurations are the same as those of the first embodiment described above, and the graphite composite film 30 corresponds to the back side of the frame 7 and directly below (partly back) part of the light guide plate 18 from the corner 32 of the frame 7. In the position. In the present embodiment, the heat generated from the light emitting diode 28 is transmitted from the substrate holding member 46 to the peripheral wall portion 12, and is diffused by the graphite composite film 30 through the corner 32.
The other end side of the graphite composite film 30 may be a position that does not cover the light guide plate 18. The graphite composite film 30 can also be provided on the peripheral wall portion 12.

  In any of the fifth to twenty-first embodiments of the present invention described below, the graphite composite film protrudes outward from the corner 32 of the frame 7. The fifth to twenty-first embodiments of the present invention will be described sequentially.

The main body of the liquid crystal television shown in FIG. 11 shows a fifth embodiment of the present invention.
The liquid crystal display device 52 shown in FIG. 11 employs the substrate holding member 26 having an L-shaped cross section as in the first embodiment. The first embodiment is the same as the first embodiment in that only the bottom surface 37 of the substrate holding member 26 is in contact with the back plate portion 10 of the frame 7.
In the liquid crystal display device 52 of the fifth embodiment, the attaching position of the graphite composite film 53 is different from that of the first embodiment. That is, in the liquid crystal display device 52 of the fifth embodiment, one end side of the graphite composite film 53 protrudes outward from the corner 32 of the frame 7. One end side of the graphite composite film 53 is not in contact with the frame 7.
One end side (not in contact with the frame 7) of the graphite composite film 53 is not particularly supported and is in a free state. In the state where one end side of the graphite composite film 53 is stretched without sagging as shown in FIG. 11, the gap between the one end side end of the graphite composite film 53 and the housing 5 is 5 mm.
Further, the other end side of the graphite composite film 53 is located immediately below the light emitting die auto 28 (directly on the basis of the posture of FIG. 1), and completely covers the bottom surface 37 of the substrate holding member 26. The other end side of the graphite composite film 53 does not reach under the light guide plate 18, but may be a position reaching under the light guide plate 18. Conversely, the position may not be directly below the light emitting diode 28.
Other configurations are the same as those of the first embodiment.

The main body of the liquid crystal television shown in FIG. 12 shows a sixth embodiment of the present invention.
The liquid crystal display device 55 shown in FIG. 12 is a combination of the above-described second and fifth embodiments. That is, in the liquid crystal display device 55 of the sixth embodiment, the substrate holding member 26 having an L-shaped cross section is adopted, and the bottom surface 37 of the six surfaces of the substrate holding member 26 is brought into contact with the back plate portion 10 of the frame 7. The first back surface 38 is in contact with the peripheral wall portion 12.
One end side of the graphite composite film 53 protrudes outward from the corner 32 of the frame 7. Similarly to the fifth embodiment, one end side of the graphite composite film 53 is not particularly supported, and a gap between the one end side end portion and the housing 5 is 5 mm. The other end side of the graphite composite film 53 is located immediately below the light emitting die auto 28 and completely covers the bottom surface 37 of the substrate holding member 26. The other end side of the graphite composite film 53 does not reach under the light guide plate 18, but may be a position reaching under the light guide plate 18.
Other configurations are the same as those of the second embodiment described above.

The main body of the liquid crystal television shown in FIG. 13 shows a seventh embodiment of the present invention.
A liquid crystal display device 56 shown in FIG. 13 is a combination of the third and fifth embodiments. That is, in the liquid crystal display device 56 of the seventh embodiment, the substrate holding member 46 has a rectangular cross-sectional shape, and only the bottom surface 47 is in contact with the back plate portion 10 of the frame 7.
One end side of the graphite composite film 53 protrudes outward from the corner 32 of the frame 7. Similarly to the fifth embodiment, one end side of the graphite composite film 53 is not particularly supported, and a gap between the one end side end portion and the housing 5 is 5 mm. The other end side of the graphite composite film 53 is located immediately below the light emitting die auto 28 and completely covers the bottom surface 47 of the substrate holding member 46. The other end side of the graphite composite film 53 does not reach under the light guide plate 18, but may be a position reaching under the light guide plate 18.
Other configurations are the same as those of the third embodiment.

The main body of the liquid crystal television shown in FIG. 14 shows an eighth embodiment of the present invention.
In the liquid crystal display device 57 of the eighth embodiment, the substrate holding member 46 has a rectangular cross-sectional shape, and only the back surface 48 is in contact with the peripheral wall portion 12 of the frame 7. That is, there is no contact between the bottom surface 47 and the frame 7.
One end side of the graphite composite film 53 protrudes outward from the corner 32 of the frame 7. Similarly to the fifth embodiment, one end side of the graphite composite film 53 is not particularly supported, and a gap between the one end side end portion and the housing 5 is 5 mm. The other end side of the graphite composite film 53 is located between the front end of the light emitting die auto 28 and the light guide plate 18 and completely covers the bottom surface 47 of the substrate holding member 46. The other end side of the graphite composite film 53 does not reach under the light guide plate 18, but may be a position reaching under the light guide plate 18.
Other configurations are the same as those in the fourth embodiment.

The main body of the liquid crystal television shown in FIG. 15 shows a ninth embodiment of the present invention.
A liquid crystal display device 60 shown in FIG. 15 is a partial modification of the fifth embodiment. That is, in the liquid crystal display device 60 of the ninth embodiment, the substrate holding member 26 having an L-shaped cross section is adopted, and only the bottom surface 37 of the six surfaces of the substrate holding member 26 is in contact with the back plate portion 10 of the frame 7. I am letting.
One end side of the graphite composite film 53 protrudes outward from the corner 32 of the frame 7. That is, one end side of the graphite composite film 53 is not in contact with the frame 7. In this embodiment, unlike the fifth embodiment, one end of the protruding graphite composite film 53 is held by the holding member 62 and connected to the inner wall of the housing 5. That is, one end side of the graphite composite film 53 is held by the holding member 62 connected to the housing 5.
The holding member 62 is a rod-shaped member having a rectangular cross section, is supported by the inner wall of the housing 5, and projects toward the peripheral wall portion 12 of the frame 7. That is, the entire one longitudinal side surface of the holding member 62 is in contact with the inner wall of the housing 5. The length of the holding member 62 in the longitudinal direction is substantially the same as the length of the graphite composite film 53 in the longitudinal direction, and the holding member 62 is in contact with the entire one end side of the graphite composite film 53. The length of the holding member 62 in the short direction (left and right direction in FIG. 15) is smaller than the distance from the inner wall of the housing 5 to the peripheral wall portion 12 of the frame 7. Therefore, there is a gap between the holding member 62 and the peripheral wall portion 12. The material of the holding member 62 is not particularly limited as long as it can dissipate heat. For example, stainless steel (SUS), aluminum, ABS resin, and the like can be used.
According to the present embodiment, part of the heat is conducted to the housing 5 via the graphite composite film 53 and the holding member 62.
Similar to the fifth embodiment, the gap between one end of the graphite composite film 53 and the housing 5 is 5 mm. The length of the contact portion between the holding member 62 and the graphite composite film 53 (the contact length in the left-right direction in FIG. 15) is 10 mm.
The other end side of the graphite composite film 53 is located immediately below the light emitting die auto 28 and completely covers the bottom surface 37 of the substrate holding member 26. The other end side of the graphite composite film 53 does not reach under the light guide plate 18, but may be a position reaching under the light guide plate 18.
Other configurations are the same as those of the first embodiment.

  In the ninth embodiment shown in FIG. 15, the holding member 62 is a rod-shaped member having a rectangular cross-sectional shape, but may be a member having another shape. In addition, it is preferable that the part which contacts the graphite composite film 53 is flat. Further, the portion of the graphite composite film 53 between the corner 32 of the frame 7 and the holding member 62 may be stretched or slack.

A liquid crystal display device 63 shown in FIG. 16 shows a tenth embodiment of the present invention.
A liquid crystal display device 63 shown in FIG. 16 is a partial modification of the ninth embodiment. That is, in the liquid crystal display device 63 of the tenth embodiment, the substrate holding member 46 has a rectangular cross-sectional shape, and only the back surface 48 is brought into contact with the peripheral wall portion 12 of the frame 7.
Further, a position close to the center line of the graphite composite film 53 is located at the corner 32 of the frame 7, and one end side thereof protrudes to the housing 5 side. One end of the protruding graphite composite film 53 is held by the holding member 62 and connected to the inner wall of the housing 5 as in the ninth embodiment.
According to the present embodiment, part of the heat is conducted to the housing 5 via the graphite composite film 53 and the holding member 62.
The other end side of the graphite composite film 53 is located immediately below the light emitting die auto 28 and completely covers the bottom surface 47 of the substrate holding member 46. The other end side of the graphite composite film 53 does not reach under the light guide plate 18, but may be a position reaching under the light guide plate 18.
Other configurations are the same as those in the fourth embodiment.

  Also in the tenth embodiment, the holding member 62 is a rod-shaped member having a rectangular cross-sectional shape, but may be a member having another shape. Moreover, it is preferable that the part which contacts the graphite composite film 53 is flat. Further, the portion of the graphite composite film 53 between the corner 32 of the frame 7 and the holding member 62 may be stretched or slack.

A liquid crystal display device 65 shown in FIG. 17 shows an eleventh aspect of the present invention.
A liquid crystal display device 65 shown in FIG. 17 is an example in which a wide graphite composite film 66 is used. In the liquid crystal display device 65 shown in FIG. 17, the substrate holding member 26 having an L-shaped cross section is adopted, and only the bottom surface 37 of the six surfaces of the substrate holding member 26 is brought into contact with the back plate portion 10 of the frame 7. Yes.
Further, one end side of the graphite composite film 66 protrudes outward from the corner 32 of the frame 7. One end of the protruding graphite composite film 66 is held by the holding member 62 and connected to the inner wall of the housing 5 as in the ninth and tenth embodiments.
The other end side of the graphite composite film 66 reaches under the light guide plate 18 and completely covers the bottom surface 37 of the substrate holding member 26. That is, the other end side of the graphite composite film 66 is provided at a position corresponding to a part of the light guide plate 18 directly below (behind the back).
According to this embodiment, part of the heat is conducted to the housing 5 via the graphite composite film 66 and the holding member 62.
Other configurations are the same as those of the first embodiment.

  Also in the eleventh embodiment, the holding member 62 is a rod-shaped member having a rectangular cross-sectional shape, but may be a member having another shape. Moreover, it is preferable that the part which contacts the graphite composite film 66 is flat. Further, the portion of the graphite composite film 66 between the corner 32 of the frame 7 and the holding member 62 may be stretched or slack.

A liquid crystal display device 70 shown in FIG. 18 shows a twelfth aspect of the present invention.
In the liquid crystal display device 70 shown in FIG. 18, the substrate holding member 26 having an L-shaped cross section is adopted, and only the bottom surface 37 of the six surfaces of the substrate holding member 26 is brought into contact with the back plate portion 10 of the frame 7. Yes.
The graphite composite film 71 is provided on the back surface side of the frame 7 from the back surface side of the back plate portion 10 to the back surface side of the peripheral wall portion 12 around the corner 32 portion. That is, the graphite composite film 71 is bent at the corner 32 and is provided across the back surface portion 10 and the peripheral wall portion 12 of the frame 7.
The width H of the graphite composite film 71 suspended on the peripheral wall portion 12 is half of the total width W of the graphite composite film 71. However, the width H can be appropriately selected in consideration of heat conduction of the heat generated by the light emitting module 22 to the light guide plate 18 and the like.
The other end of the graphite composite film 71 is located immediately below the light emitting die auto 28 and completely covers the bottom surface 37 of the substrate holding member 26. The other end side of the graphite composite film 71 does not reach the bottom of the light guide plate 18, but may be a position reaching the bottom of the light guide plate 18.
Other configurations are the same as those of the first embodiment.

A liquid crystal display device 72 shown in FIG. 19 shows a thirteenth embodiment of the present invention.
In the liquid crystal display device 72 shown in FIG. 19, the substrate holding member 46 has a rectangular cross-sectional shape, and the substrate holding member 46 is fixed to the peripheral wall portion 12 of the frame 7.
Similarly to the twelfth embodiment, the graphite composite film 71 is provided on the back surface side of the frame 7, bent at the corner 32, and provided from the back surface side of the back plate portion 10 to the back surface side of the peripheral wall portion 12. Yes. That is, the graphite composite film 71 is provided across the back surface portion 10 and the peripheral wall portion 12 of the frame 7.
The width H of the graphite composite film 71 suspended on the peripheral wall portion 12 is half of the total width W of the graphite composite film 71. However, the width H can be appropriately selected in consideration of heat conduction of the heat generated by the light emitting module 22 to the light guide plate 18 and the like.
The other end of the graphite composite film 71 is located immediately below the light emitting die auto 28 and completely covers the bottom surface 47 of the substrate holding member 46. The other end side of the graphite composite film 71 does not reach the bottom of the light guide plate 18, but may be a position reaching the bottom of the light guide plate 18.
Other configurations are the same as those in the fourth embodiment.

A liquid crystal display device 73 shown in FIG. 20 shows a fourteenth aspect of the present invention.
In the liquid crystal display device 73 shown in FIG. 20, the substrate holding member 46 has a rectangular cross-sectional shape, and the substrate holding member 46 is fixed to the peripheral wall portion 12 of the frame 7.
The graphite composite film 76 is provided on the back surface side of the frame 7 from the back surface side of the back plate portion 10 to the back surface side of the peripheral wall portion 12. That is, the graphite composite film 76 is provided across the back surface portion 10 and the peripheral wall portion 12 of the frame 7.
Similar to the eleventh embodiment, the other end side of the graphite composite film 76 is on the back side of the frame 7 and reaches a position corresponding to a part of the light guide plate 18 of the frame 7 (below the back). The bottom surface 47 of the member 46 is completely covered. That is, the width of the graphite composite film 76 is larger than the width of the graphite composite film 71 of the thirteenth aspect.
Other configurations are the same as those in the fourth embodiment.

A liquid crystal display device 75 shown in FIG. 21 shows a fifteenth aspect of the present invention.
In the liquid crystal display device 75 shown in FIG. 21, the substrate holding member 26 having an L-shaped cross section is adopted, and only the bottom surface 37 of the six surfaces of the substrate holding member 26 is brought into contact with the back plate portion 10 of the frame 7. Yes.
The graphite composite film 76 is provided on the back surface side of the frame 7 from the back surface side of the back plate portion 10 to the back surface side of the peripheral wall portion 12.
Similar to the eleventh embodiment, the other end side of the graphite composite film 76 is on the back side of the frame 7 and reaches a position corresponding to a part of the light guide plate 18 of the frame 7 (below the back). The bottom surface 37 of the member 26 is completely covered.
Other configurations are the same as those of the first embodiment.

A liquid crystal display device 77 shown in FIG. 22 shows a sixteenth aspect of the present invention.
In the liquid crystal display device 77 shown in FIG. 22, the substrate holding member 26 having an L-shaped cross section is adopted, and only the bottom surface 37 of the six surfaces of the substrate holding member 26 is brought into contact with the back plate portion 10 of the frame 7. Yes.
Further, the graphite composite film 78 is extremely wide and reaches the inner wall of the housing 5 through the corner 32 of the frame 7 from a position directly behind the light emitting die auto 28 on the back surface side of the frame 7 and further along the inner wall of the housing 5. It is pasted in a direction away from the liquid crystal display device 77. That is, the graphite composite film 78 is disposed across the frame 7 and the housing 5. The graphite composite film 78 is disposed at a position where the tip completely covers the bottom surface 37 of the substrate holding member 26 and does not reach the optical member such as the light guide plate 18.
The contact length between the graphite composite film 78 and the housing 5 can be appropriately selected in consideration of the amount of heat generated by the light emitting module 22 and the like.
Other configurations are the same as those of the first embodiment.

A liquid crystal display device 80 shown in FIG. 23 shows a seventeenth aspect of the present invention.
In the liquid crystal display device 80 shown in FIG. 23, the substrate holding member 46 having a rectangular cross section is employed, and the substrate holding member 46 is fixed to the peripheral wall portion 12 of the frame 7.
Similarly to the sixteenth embodiment, the graphite composite film 78 is extremely wide and reaches the inner wall of the housing 5 through the corner 32 of the frame 7 from the position on the back surface side of the frame 7 and immediately below the light emitting die auto 28. Further, it is attached along the inner wall of the housing 5 in a direction away from the liquid crystal display device 80. That is, the graphite composite film 78 is disposed across the frame 7 and the housing 5. Further, the graphite composite film 78 is arranged so that the tip thereof completely covers the bottom surface 47 of the substrate holding member 46 and does not reach the optical member such as the light guide plate 18.
The contact length between the graphite composite film 78 and the housing 5 can be appropriately selected in consideration of the amount of heat generated by the light emitting module 22 and the like.
Other configurations are the same as those in the fourth embodiment.

A liquid crystal display device 82 shown in FIG. 24 shows an eighteenth aspect of the present invention.
A liquid crystal display device 82 shown in FIG. 24 is a partial modification of the sixteenth embodiment. That is, in the liquid crystal display device 82 shown in FIG. 24, the substrate holding member 26 having an L-shaped cross section is adopted, and only the bottom surface 37 of the six surfaces of the substrate holding member 26 is brought into contact with the back plate portion 10 of the frame 7. ing.
Further, the graphite composite film 78 is extremely wide and reaches the inner wall of the housing 5 through the corner 32 of the frame 7 from a position directly behind the light emitting die auto 28 on the back surface side of the frame 7 and further along the inner wall of the housing 5. And pasted in a direction away from the liquid crystal display device 82. A holding member 83 similar to that in the ninth embodiment is provided at the tangent portion between the graphite composite film 78 and the inner wall of the housing 5 to hold the graphite composite film 78.
The contact length between the graphite composite film 78 and the housing 5 can be appropriately selected in consideration of the amount of heat generated by the light emitting module 22 and the like.
Other configurations are the same as those of the first embodiment.

  A liquid crystal display device 85 shown in FIG. 25 shows a nineteenth aspect of the present invention. In the present embodiment, the light emitting modules 22 are provided on two opposing sides of the light guide plate 18. A graphite composite film 53 is provided corresponding to the light emitting module 22. In the liquid crystal display device 85 shown in FIG. 25, the shape and attachment method of the light emitting module 22 and the shape and attachment form of the graphite composite film 53 are shown in the fifth form, but these forms are other forms. Can be arbitrarily selected.

A liquid crystal display device 86 shown in FIG. 26 shows a twentieth aspect of the present invention. In this embodiment, as in the fifth, sixth, seventh, eighth, ninth, tenth, eleventh, sixteenth, seventeenth, eighteenth and nineteenth aspects, a part of the graphite composite film is separated from the frame 7 (frame 7), and a hollow holding member (holding member) 90 that holds the hollow portion of the graphite composite film 53 is provided. The hollow holding member 90 is a rod-like member similar to the holding member 62 (FIG. 15 and the like). In the liquid crystal display device 86 shown in FIG. 26, the hollow holding member 90 is supported by a bracket 91 attached to the frame 7. That is, in this embodiment, the one end side of the graphite composite film 53 is held by the hollow holding member (holding member) 90 connected to the frame 7. The attachment method of the hollow holding member 90 is arbitrary, and the bracket 91 may be attached to the housing 5 side.
Other configurations are the same as those of the first embodiment.

A liquid crystal display device 92 shown in FIG. 27 shows a twenty-first mode of the present invention. Also in this embodiment, when a part of the graphite composite film is separated from the frame 7 as in the fifth, sixth, seventh, eighth, ninth, tenth, eleventh, sixteenth, sixteenth, seventeenth, eighteenth and nineteenth aspects. The projecting portion (holding member) 93 is provided on a part of the frame 7, and a part of the graphite composite film 53 is held by the projecting portion 93. That is, in the present embodiment, one end side of the graphite composite film 53 is held by the overhang portion (holding member) 93 connected to the frame 7. The overhang portion 93 is configured by a rod-like member similar to the holding member 62 (FIG. 15 and the like).
Other configurations are the same as those of the first embodiment.

As shown in FIGS. 3 and 8 to 27, in the above-described embodiment, the inner surface (surface on the reflecting plate 20 side) of the back plate portion 10 of the frame 7 is flat. It is not essential that the inner surface of the back plate 10 is flat.
For example, as shown in FIG. 28 (22nd form) and FIG. 29 (23rd form), the structure which has the step part 120 in the inner surface of the flame | frame 7, and the board | substrate holding member 121 is stored in the said step part 120 is employ | adopted. You can also
In the configuration of FIG. 28, the protruding end portion 123 of the substrate holding member 121 is in contact with the step wall 125 of the step portion 120, but there may be a gap between them as shown in FIG.
28, there is a gap between the substrate holding member 121 and the peripheral wall portion 12 of the frame 7, but the substrate holding member 121 may be in contact with the peripheral wall portion 12 of the frame 7 as shown in FIG. .
In the embodiment shown in FIGS. 28 and 29, the graphite composite film 130 is provided on the back plate portion 10 of the frame 7 as in the embodiment shown in FIG.

In the configuration shown in FIG. 28, the substrate holding member 121 has an “L” cross-sectional shape, and a part of the substrate holding member 121 includes a liquid crystal cell 15, a condensing film, a prism film 16, a diffusion plate 17, a conductive plate. It wraps around the back side of the light plate 18 and the reflection plate 20).
28 and 29, there is a slight gap between the upper surface 122 of the substrate holding member 121 and the reflection plate 20, but they may be in close contact with each other.

Further, when the temperature around the side portion 129 of the light guide plate 18 is excessively raised and this becomes a problem, the members constituting the liquid crystal (the liquid crystal cell 15, the light collecting film, the prism film 16, the diffusion plate 17) as shown in FIG. In addition, a graphite composite film 131 may be interposed between the light guide plate 18 and the reflection plate 20) and the frame 7.
That is, in the configuration shown in FIG. 30 (24th embodiment), not only the graphite composite film 130 is attached to the back side of the frame 7 but also the graphite composite film 131 is attached to the inside of the frame 7. . The graphite composite film 131 is between the member constituting the liquid crystal and the frame 7, and part thereof reaches the upper surface 122 of the substrate holding member 121 and is attached to the upper surface 122 of the substrate holding member 121.
Of course, the graphite composite film 131 may not reach the upper surface 122 of the substrate holding member 121. That is, the graphite composite film 131 may be provided only between the member constituting the liquid crystal and the frame 7.

In the configuration shown in FIG. 30, a shallow step portion 128 is formed inside the frame 7 and at a portion where the graphite composite film 131 is provided.
In the configuration shown in FIG. 30, the graphite composite film 131 is accommodated in the stepped portion 128 without any gap, but there may be a size between the two.
According to the configuration shown in FIG. 30, the heat around the side portion 129 of the light guide plate 18 is released to the frame 7 by the graphite composite film 131, and the temperature rise of the light guide plate 18 is mitigated.

  The structure itself in which the graphite composite film 131 is interposed between the member constituting the liquid crystal and the frame 7 has a remarkable effect of releasing the heat around the side portion 129 of the light guide plate 18. Therefore, this configuration is a technique that can be applied even when there is no graphite composite film 130 on the back side of the frame 7 as shown in FIG.

  In the embodiment shown in FIGS. 28 to 30, the graphite composite film 130 may be provided so as to straddle the back plate part 10 and the side wall part 12. Furthermore, the graphite composite film 130 may be provided only on the side wall portion 12.

  In the above-described embodiment, as illustrated in FIG. 7, the graphite composite film is uniformly attached to the surface of the back plate portion 10 and / or the side wall portion 12 of the frame 7, and there is no slack or wrinkles. In other words, the length in the longitudinal direction or the short side direction of the graphite composite film itself and the length in the longitudinal direction or the short side direction of the portion where the graphite composite film covers the back plate portion 10 and the like coincide with each other. . If the 1st form of FIG. 3 is demonstrated to an example, the attachment state of the flame | frame 7 and the graphite composite film 30 seen from the left side in FIG. 3 will become as shown in FIG. That is, there are no gaps or floats between the graphite composite film 30 and the frame 7 (back plate portion 10), and the surface of the attached graphite composite film 30 is uniform and has no irregularities.

  However, the present invention is not limited to this embodiment. In the twenty-fifth to twenty-seventh embodiments described below, the length of the graphite composite film to be attached is given a margin, and the surface is uneven in the state after being attached.

33 and 34 show a twenty-fifth embodiment of the present invention. The twenty-fifth embodiment is obtained by changing only the method of attaching the graphite composite film 140 in the first embodiment (FIG. 3).
In the present embodiment, the length in the longitudinal direction of the graphite composite film 140 is longer than the length in the longitudinal direction of the graphite composite film 30 employed in the first embodiment. In the present embodiment, a rib-like shape extending in the width direction of the graphite composite film 140 is applied to the graphite composite film 140 attached to the back plate portion 10 of the frame 7 by using this margin of length (length difference). A plurality of convex portions 142 are formed.
The plurality of convex portions 142 are arranged in parallel and at equal intervals.

As shown in FIG. 34, the convex portion 142 has a hollow rectangular or U-shaped cross section, and protrudes substantially perpendicularly from the surface of the graphite composite film 140. The convex portion 142 has rising portions 143 and 145 and a back wall portion 146.
The convex portion 142 has a cylindrical shape in which both ends in the length direction are open to form a gap portion 147. More specifically, the gap portion 147 is formed by a space surrounded by the rising portions 143 and 145, the back wall portion 146, and a part of the back plate portion 10.
The height h of the rising portions 143 and 145 is 10 mm. The distance i between the rising portion 143 and the rising portion 145 is 5 mm. An interval (pitch) L between adjacent convex portions 142 is 50 mm.
According to this embodiment, the convex part 142 can function as a heat radiation fin, and a high heat radiation effect is obtained. Furthermore, a heat dissipation effect due to air passing through the gap 147 is also obtained. Note that when the liquid crystal display device is used, the length direction of the convex portion 142 (the width direction of the graphite composite film 140) is the vertical direction (the vertical direction), so that the air in the gap portion 147 escapes upward. Cheap.

  FIG. 35 shows a twenty-sixth aspect of the present invention. The twenty-sixth form is common to the twenty-fifth form (FIGS. 33 and 34) in many respects, the height h of the rising parts 143 and 145 is 5 mm, and the interval (pitch) L between adjacent convex parts 142 is 25 mm. The number of convex portions 142 is the same as that of the 25th embodiment except that the number of the convex portions 142 is twice that of the 25th embodiment. Also in this embodiment, the convex part 142 can function as a cooling fin, and a high heat dissipation effect is obtained. Furthermore, a heat dissipation effect due to air passing through the gap 147 is also obtained.

In the twenty-fifth and twenty-sixth embodiments, the cross-sectional shape of the convex portion 142 is rectangular or U-shaped, but other shapes may be used. For example, a U shape as shown in FIG. 36A or a triangular shape (mountain shape) as shown in FIG. Further, as shown in FIG. 36C, the base portions of the rising portions may be brought close to each other, and the gap portion 147 may be formed only by portions substantially corresponding to the rising portion and the back wall portion. According to the example of FIG. 36C, the heat radiation effect by the convex portion 142 is obtained while maintaining the contact area between the back plate portion 10 and the graphite composite film 140 substantially the same as that of the first embodiment (FIG. 3). Can do.
The convex portions 142 shown in FIGS. 36A to 36C also have a cylindrical shape whose both ends in the length direction are open, and thereby a gap portion 147 is formed.

FIG. 37 shows a twenty-seventh aspect of the present invention. Also in the twenty-seventh embodiment, as in the twenty-fifth and twenty-sixth embodiments, a rib-like protrusion extending in the width direction of the graphite composite film 140 using the graphite composite film 140 having a longer length in the longitudinal direction than the first embodiment. A plurality of portions 148 are formed. The plurality of convex portions 148 are arranged in parallel and at equal intervals.
In the present embodiment, the rising portions 143 and 145 of the convex portion 148 are in close contact with each other, and there is no gap. That is, the distance i between the rising portion 143 and the rising portion 145 is substantially 0 mm.
Similarly to the twenty-sixth embodiment, the height h of the rising portions 143 and 145 of the convex portion 148 is 5 mm, the interval (pitch) L between the adjacent convex portions 148 is 25 mm, and the number of convex portions 148 is 2 in the twenty-fifth embodiment. Is double.
According to this embodiment, the convex part 148 can function as a heat radiation fin, and a high heat radiation effect is obtained. In addition, since the graphite composite film 140 has an adhesive layer or an adhesive layer on one surface as will be described later, it is easy to make the rising portions 143 and 145 adhere and adhere to each other.

  The length in the longitudinal direction of the graphite composite film 140 may be appropriately selected depending on the number, size, cross-sectional shape, presence or absence of voids, and the like, and there is no particular upper limit. As one example, if the length of the graphite composite film 30 (first embodiment, FIG. 3) in the longitudinal direction (that is, the length when the convex portions 142 and 148 are not provided) is 1000 mm, the graphite composite The length of the film 140 in the longitudinal direction can be, for example, 1.1 times (1100 mm, length difference: 100 mm) to 2 times (2000 mm, length difference: 1000 mm), and 1.3 times ( 1300 mm, length difference: 300 mm) to 1.5 times (1500 mm, length difference: 500 mm). Of course, as long as the convex parts 142 and 148 can be provided, it may be 2 times or more, or 1.1 times or less.

In the 25th to 27th embodiments, the height h of the rising portions 143 and 145, the distance i between the rising portion 143 and the rising portion 145, and the interval (pitch) L between the adjacent convex portions 142 and 148 are as follows. The present invention is not limited to the above example, and can be appropriately selected in consideration of the configuration of the liquid crystal display device. You may change the value of h and i for every convex part 142,148.
Further, the interval (pitch) L between the adjacent convex portions 142 and 148 may not be constant. That is, the convex parts 142 and 148 do not need to be arranged at equal intervals. Moreover, it does not need to be mutually parallel.
Furthermore, only one protrusion 142, 148 may be provided.

  In the 25th to 27th embodiments, as shown in FIG. 33, the convex portions 142 and 148 are provided uniformly over substantially the entire surface of the graphite composite film 140. 148 may be provided. For example, the convex portions 142 and 148 may be provided only in a portion where heat is intensively radiated or a portion where the heat radiation effect is high.

  In the 25th to 27th embodiments, the convex portions 142 and 148 extend in the width direction of the graphite composite film 140, but the convex portions 142 and 148 may extend in the longitudinal direction of the graphite composite film 140. However, it may extend in an oblique direction.

  In the 25th to 27th forms, the configuration other than providing the convex portions 142 and 148 is the same as that of the first form (FIG. 3), but of course, even in forms other than the first form, The graphite composite film can be provided with convex portions as employed in the 25th to 27th forms.

  In the embodiment described above, the back side of the frame is flat and has no cooling fins. However, the present invention does not deny the attachment of the cooling fins, and the cooling fins may be attached to the rear surface of the frame or other parts.

  In the above-described embodiment, the substrate holding members 26 and 46 are directly attached to the inner surface of the frame 7, but a heat conductive sheet may be interposed therebetween. For example, it is also desirable to interpose a graphite composite film between the two.

In the above-described embodiment, the L-shaped and rectangular cross-sectional shapes of the substrate holding members 26 and 46 are exemplified, but the present invention does not exclude other cross-sectional shapes.
From the viewpoint of securing a larger contact area between the substrate holding member and the frame, a substrate holding member 96 having a triangular cross-sectional shape as shown in FIG. 38 or a screen-like substrate holding member 97 as shown in FIG. It can also be adopted.

  In the above-described embodiment, the graphite film is in contact with at least the back plate portion 10 of the frame 7, but an embodiment in which the graphite film is not in contact with the back plate portion 10 of the frame 7 is also possible. For example, in the form shown in FIGS. 3, 8 to 17, 22 to 27, 34, 35, and 37, the graphite film may be in contact with the peripheral wall portion 12 instead of the back plate portion 10 of the frame 7.

  Next, the structure of the graphite composite film 30, 53, 66, 71, 76, 78, 130, 131, 140 used in the above embodiment will be described. In the following description, the graphite composite film 30 is taken as an example, but the structures of the graphite composite sheets 53, 66, 71, 76, 78, 130, 131, and 140 are exactly the same.

As shown in FIG. 40, the graphite composite film 30 is a laminate in which an adhesive layer or adhesive layer 102 is provided on one surface of the graphite film 101, and a resin layer 103 is provided on the other surface.
The graphite constituting the graphite film 101 is prepared by heat-treating a polymer film (hereinafter referred to as “polymer system”), and is prepared by compressing expanded graphite (hereinafter referred to as “natural system”). Any of the above may be used. In the case of a polymer system, the polymer compound to be graphitized is not particularly limited, and a polymer graphite film can be obtained by carbonizing and graphitizing a conventionally used polymer compound. In the case of natural systems, conventionally known manufacturing techniques can be applied, for example, by immersing natural graphite in a mixed solution of sulfuric acid and nitric acid, then heating and compressing the expanded graphite layer. it can. As thickness of the graphite film 101, 10-300 micrometers, for example, Preferably 20-60 micrometers is employable.

The pressure-sensitive adhesive layer or adhesive layer 102 is laminated on one surface of the graphite film 101. As a member constituting the adhesive layer or the adhesive layer 102, for example, an adhesive film made of an acrylic resin can be cited. As the thickness of the pressure-sensitive adhesive layer or the adhesive layer, for example, 3 to 200 μm, preferably 3 to 100 μm, more preferably 3 to 30 μm, and further preferably 5 to 15 μm can be employed.
The resin layer 103 is laminated on the other surface of the graphite film 101. Examples of the member constituting the resin layer 103 include a PET protective film having an adhesive layer or an adhesive layer on one side. As the thickness of the resin layer 103, for example, 3 to 200 μm, preferably 3 to 100 μm, more preferably 3 to 30 μm can be employed.

  The graphite composite film 30 is laminated such that the pressure-sensitive adhesive layer or adhesive layer 102 and the resin layer 103 are laminated so as to protrude slightly from the end of the graphite film 101, that is, to cover the end 105 of the graphite film 101. Alternatively, the end portion 105 of the graphite film may be aligned with the end portion of the adhesive layer or the adhesive layer 102 or the resin layer 103 and may be laminated so as not to protrude outward. When covering the end portion 105 of the graphite film 101, for example, two opposing sides 105b and 105d of the graphite film 101 may be covered as shown in FIG. 41 (a), or FIG. As shown, all four sides 105a to 105d of the graphite film 101 may be covered.

Hereinafter, sagging of the graphite composite film used in the present invention will be described.
The sag measurement of the graphite composite film can be performed according to the sag test described in JIS C2151. As a test piece, a piece of graphite film is slowly pulled out from a roll of graphite film with a minimum tension necessary for rewinding. The place to take out the test piece at this time is from the vicinity of the center of the roll winding (for example, if it is 40 m, three test pieces are taken out from the vicinity of 20 m from the end of winding).

  Two bars parallel to each other are set apart by 1500 mm in the horizontal direction, and a graphite film test piece of about 2 m is placed on the two bars. The tension applied to the film is 20 g weight per 1 cm width of the film. The deviation of the distance between the suspension line drawn by the film cross section and the horizontal line is measured with reference to the horizontal line in contact with the central portion in the width direction of the film at the center position between the two bars. The measurement is performed three times, and the median value is adopted as the sag value. The measurement location is the end, center, and 30 mm from the end.

  “(Sag value at the end) − (sag value at the center)” is calculated (hereinafter, this value is referred to as “A”). The measurement at the extreme end is performed for both the left and right sides, and the average value is taken as one measurement value. The sag measurement at the extreme end is performed on three test pieces, and the median value is adopted as the sag value.

  Similarly, “(sag value at the end portion) − (sag value at a point 30 mm from the end portion)” is also calculated.

  In general, the A value ((sag value at the end) − (sag value at the center)) of the film is correlated with the width W of the film. For example, when the film width W is small, A is small. Therefore, when A of the film having a small width and the film having a large width have the same value, it can be said that the waviness of the film having a large width is improved. Therefore, in order to evaluate the sag of the film regardless of the width W of the film, the sag of the graphite composite film is evaluated by a value “A / W” obtained by dividing A by W.

  “A / W” of the graphite composite film used in the present invention is preferably 0.05 to 0.4, more preferably 0.1 to 0.3, and still more preferably 0.1 to 0.2. That is, if A / W is 0.05 to 0.4, wrinkles are unlikely to occur when the frame is attached to the frame. Since the end portion is slightly slacker than the center portion, the strain generated when bonding is relaxed by the slack portion, and development of wrinkles is prevented.

  The sag of the graphite composite film can be controlled by controlling the sag of the graphite film. The sag of the graphite film occurs because the degree of freedom of the film is large when it is graphitized, and it tends to stretch in the plane direction. Therefore, the sag of the film is suppressed by suppressing the degree of freedom of the film during graphitization. Can be suppressed. Therefore, as a method for suppressing sagging, for example, a method of winding and graphitizing a carbonized film when performing graphitization can be considered. It is also effective to wind up the graphitized film after once graphitizing and then heat-treat it again to a temperature of 2400 ° C. or higher.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

  First, a method for producing a graphfight film, a method for measuring physical properties, a method for producing a graphite composite film, and an optical member used in Examples will be described.

1. Manufacture of graphite film [1]
A polyimide film (trade name: Apical AH, manufactured by Kaneka Corporation) having a thickness of 75 μm, a width of 500 mm, and a length of 35 m is wound around a cylindrical graphite inner cylinder having an outer diameter of 100 mm and a length of 600 mm. An outer cylinder was put on. In this state, it was set sideways in the electric furnace, and was subjected to carbonization treatment at a heating rate of 2 ° C./min up to 1400 ° C. in a nitrogen atmosphere. Next, the obtained roll-like carbonized film was set sideways in the graphitization furnace (in a state where the inner cylinder was floated by a support), and graphitized to 2700 ° C. at a heating rate of 5 ° C./min. After cooling, the graphite film obtained by this graphitization treatment was again wound around the inner cylinder having an outer diameter of 100 mm so as not to loosen. In this state, it was set sideways in the graphite furnace and again graphitized to 2900 ° C. The obtained heat-treated film was subjected to compression treatment (in the thickness direction, a load of 80 kgf / cm ² was applied and pressed with a press machine) to obtain a polymer graphite film having a thickness of 40 μm. Hereinafter, this graphite film was referred to as “graphite film A1”.
The graphite film A1 was employed in Examples 1-6, 13-20, 22-28, 34-49.

2. Manufacture of graphite film [2]
A high-molecular graphite film having a thickness of 40 μm was obtained in the same manner as 1 described above except that the temperature increase rate of the first graphitization treatment was 2.5 ° C./min. Hereinafter, this graphite film was referred to as “graphite film A2”.
The graphite film A2 was employed in Examples 10 and 31.

3. Manufacture of graphite film [3]
A polymer graphite film having a thickness of 40 μm was obtained in the same manner as 1 described above except that the temperature raising rate of the carbonization treatment was 3 ° C./min. Hereinafter, this graphite film was referred to as “graphite film A3”.
The graphite film A3 was employed in Examples 11 and 32.

4). Manufacture of graphite film [4]
Except that the second graphitization treatment was omitted, a long roll-shaped polymer graphite film having a thickness of 40 μm was obtained in the same manner as 1 above. Hereinafter, this graphite film was referred to as “graphite film A4”.
The graphite film A4 was employed in Examples 12 and 33.

5. Manufacture of graphite film [5]
Except that a polyimide film (trade name: Apical AV, manufactured by Kaneka Co., Ltd.) having a thickness of 50 μm, a width of 500 mm, and a length of 50 m was used, a long roll polymer polymer graphite having a thickness of 25 μm was used. A film was obtained. Hereinafter, this graphite film was referred to as “graphite film B”.
The graphite film B was employed in Examples 7, 21, and 29.

6). Manufacture of graphite film [6]
A polyimide film (trade name: Apical AH, manufactured by Kaneka Corporation) with a thickness of 75 μm and 250 mm × 300 mm is sandwiched between graphite plates, and heated to 1400 ° C. at a heating rate of 2 ° C./min using an electric furnace. Carbonization treatment was performed. The carbonized film obtained by the carbonization treatment was sandwiched between graphite plates, and the temperature was raised to 2900 ° C. using a graphitization furnace to perform the graphitization treatment. The graphite film after graphitization was subjected to compression treatment (in the thickness direction, a load of 80 kgf / cm ² was applied and pressed with a press machine) to obtain a polymer graphite film (sheet-like) having a thickness of 40 μm. Hereinafter, this graphite film was referred to as “graphite film C”.
Graphite film C was employed in Example 8.

7). Manufacture of graphite film [7]
In the presence of an oxidizing agent (hydrogen peroxide, perchloric acid, etc.), sulfuric acid, nitric acid, etc. are inserted between natural scaly graphite layers, and the formed intercalation compound is rapidly heated at a high temperature of about 900 to 1200 ° C. It was decomposed and gasified, and the graphite was expanded by expanding the graphite layer by the gas pressure at this time. The expanded graphite obtained as described above was compression-preformed and then rolled with a roll to obtain a natural graphite film having a thickness of 100 μm. Hereinafter, this graphite film was referred to as “graphite film D”.
The graphite film D was employed in Examples 9 and 30.

8). Measurement of thermal conductivity of graphite film (1) Measurement of thermal diffusivity in the direction of the film surface by optical alternating current method Sample of graphite film cut to 4x40 mm, and using thermal alternating current method as a sample (LaserPit, ULVAC-RIKO) The thermal diffusivity α (m ² / s) was measured at 10 Hz in an atmosphere of 20 ° C. The higher the thermal diffusivity, the more the graphitization tends to progress.

(2) Thickness measurement Using a thickness gauge (HEIDENHAIN-CERTO, manufactured by HEIDENHAIN Co., Ltd.), a 10 mm × 250 mm graphite film was measured at a room temperature of 25 ° C., and 10 points were measured. The value was taken as thickness. Thickness variation was determined by measuring 10 arbitrary points in the film plane of 10 graphite films and making a difference from the average value.

(3) Density measurement The weight (g) of the graphite film was divided by the volume (cm ³ ) calculated by the product of the vertical, horizontal and thickness of the graphite film to calculate the density d (kg / m ³ ). The average value of the above (2) was adopted for the thickness of the graphite film. In addition, there exists a tendency for graphitization to advance, so that a density is high.

(4) Calculation of thermal conductivity The thermal conductivity λ (W / mK) of the graphite film was calculated by the following formula (I).
λ = αdC (I)
here,
λ: thermal conductivity (W / mK)
α: Thermal diffusivity (m ² / s)
d: Density (kg / m ³ )
C: Specific heat (J / kg · K)
Indicates.

  Table 1 shows the physical properties and the like of the obtained graphite films.

9.2 Manufacture of graphite composite film coated on 2 sides [1]
A double-sided tape (adhesive layer, adhesive layer) whose width is 40 mm wider than the width of each graphite film is bonded to one side of each rolled graphite film so that the graphite film does not protrude from the end of the double-sided tape. It was. The graphite film was slit into an arbitrary length at the center and used. As double-sided tape, DIC 8603TNW-10 (thickness 10 μm, Examples 1-14, 16-19, 21-33, 35, 36, 38, 39, 41, 43-49), or Teraoka 750F manufactured by Seisakusho (thickness 160 μm, Examples 15, 20, 34, 37, 40, 42 including a flame retardant) was used.
Subsequently, a polyethylene terephthalate tape (PET tape, resin layer) whose width is 40 mm wider than the width of each graphite film on the other surface (the surface opposite to the surface on which the double-sided tape is bonded) of each graphite film. The graphite film was bonded so that the graphite film did not protrude from the end of the PET tape. As a PET tape, 631S (thickness 30 μm) manufactured by Teraoka Seisakusho Co., Ltd. was used.
Thus, a graphite composite in which a double-sided tape (adhesive layer) is provided on one side of the graphite film, a PET tape (resin layer) is provided on the other side, and both ends of the graphite film are covered with the double-sided tape and the PET tape. A film was made.
Finally, slitting was performed so that the covering portions at both ends of the graphite composite film were 2 mm, and then cutting was performed to a length of 1000 mm in the MD direction (roll unwinding direction). As a result, a graphite composite film in which two sides of the graphite film were coated was produced.

10.2 Manufacture of graphite composite film with 2 sides coated [2]
A 200 mm × 260 mm sheet (sheet-like) graphite film (using graphite film C) was slit, and two 50 mm × 260 mm graphite films were prepared and joined by overlapping 2 mm so as to be 50 mm × 518 mm. A double-sided tape (adhesive layer) having a width of 90 mm was bonded to one side of the graphite film so that the graphite film did not protrude from the end of the double-sided tape. As a double-sided tape, DIC 8603TNW-10 (thickness 10 μm, not including a flame retardant) was used. Subsequently, a PET tape (resin layer) with a width of 90 mm is placed on the other surface of the graphite film (the surface opposite to the surface on which the double-sided tape is bonded), and the graphite film does not protrude from the end of the PET tape. Were pasted together. As a PET tape, 631S (thickness 30 μm) manufactured by Teraoka Seisakusho Co., Ltd. was used.
Thus, a graphite composite in which a double-sided tape (adhesive layer) is provided on one side of the graphite film, a PET tape (resin layer) is provided on the other side, and both ends of the graphite film are covered with the double-sided tape and the PET tape. A film was made.
Finally, slitting was performed so that the covering portions at both ends of the graphite composite film were 2 mm, and then cutting was performed to a length of 1000 mm in the MD direction (roll unwinding direction). As a result, a graphite composite film in which two sides of the graphite film were coated was produced.
This graphite composite film was employed in Example 8.

11. Manufacture of graphite composite film with uncoated end A double-sided tape (adhesive layer) with a width of 100 mm is applied to one side of a roll-shaped graphite film (using graphite film A1) with a width of 60 mm from the end of the double-sided tape. Bonding was performed so that the graphite film did not protrude. The graphite film was slit into an arbitrary length at the center and used. As a double-sided tape, DIC 8603TNW-10 (thickness 10 μm, not including a flame retardant) was used.
Subsequently, a PET tape (resin layer) with a width of 100 mm is placed on the other surface of the graphite film (the surface opposite to the surface on which the double-sided tape is bonded) so that the graphite film does not protrude from the end of the PET tape. Pasted together. As a PET tape, 631S (thickness 30 μm) manufactured by Teraoka Seisakusho Co., Ltd. was used.
Thus, a graphite composite in which a double-sided tape (adhesive layer) is provided on one side of the graphite film, a PET tape (resin layer) is provided on the other side, and both ends of the graphite film are covered with the double-sided tape and the PET tape. A film was made.
Finally, this graphite composite film was cut so that both ends were slit by 5 mm, and a graphite composite film having a width of 50 mm was produced. Further, the sheet was cut into a length of 1000 mm in the MD direction (roll unwinding direction). As a result, a graphite composite film in which the end of the graphite film was not coated was produced.
This graphite composite film was employed in Example 13.

12.4 Manufacture of Graphite Composite Film with Covered Sides After a roll-like graphite film with a width of 50 mm (using graphite film A1) is cut to 1000 mm, a double-sided tape with a width of 90 mm and a length of 1040 mm on one side The (adhesive layer) was bonded so that the graphite film did not protrude from the four sides of the double-sided tape (so as to cover all four sides of the graphite film). The graphite film was slit into an arbitrary length at the center and used. As a double-sided tape, DIC 8603TNW-10 (thickness 10 μm, not including a flame retardant) was used.
Subsequently, a PET tape (resin layer) having a width of 90 mm and a length of 1040 mm is placed on the other side of the graphite film (the side opposite to the side where the double-sided tape is bonded), and the graphite film is applied from the four sides of the double-sided tape. It stuck together so that it might not protrude (covering all four sides of a graphite film). As a PET tape, 631S (thickness 30 μm) manufactured by Teraoka Seisakusho Co., Ltd. was used.
Thus, a graphite composite in which a double-sided tape (adhesive layer) is provided on one side of the graphite film and a PET tape (resin layer) is provided on the other side, and all four sides of the graphite film are covered with the double-sided tape and the PET tape. A film was made.
Finally, slitting was performed so that the covering portion (four sides) of this graphite composite film was 2 mm. As a result, a graphite composite film in which all four sides of the graphite film were coated was produced.
This graphite composite film was employed in Example 14.

13. Materials and physical properties of optical members and the like Optical members having the following materials and physical properties were used.

  The electronic device which consists of a structure of each above-mentioned form was assembled, and the following experiment was conducted. About the size of a member etc., the size illustrated by description of said each form was employ | adopted as it was unless it indicated in particular.

[Example 1]
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 500 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

[Example 2]
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 250 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 3
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 100 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 4
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 5
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film A1 (width 30 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 6
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 20 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 7
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film B (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 8
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film C (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 9
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film D (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 10
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A2 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 11
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A3 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 12
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A4 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 13
Using a graphite composite film (no end coating, no flame retardant) coated on both sides of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 14
Using a graphite composite film (4-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 15
Using a graphite composite film (two-side coating, with flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 3 (first embodiment).

Example 16
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 8 (second embodiment).

Example 17
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 9 (third embodiment).

Example 18
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 10 (fourth embodiment).

Example 19
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 11 (fifth embodiment). Of the film width of 50 mm, the frame contact portion was 10 mm, and the protruding portion was 40 mm.

Example 20
As shown in FIG. 11 (fifth embodiment), an LED and a graphite film were attached to the graphite composite film in the same manner as in Example 19 except that the adhesive layer contained a flame retardant.

Example 21
An LED and a graphite film were attached as shown in FIG. 11 (fifth embodiment) in the same manner as in Example 19 except that the graphite film B (width 50 mm) was used instead of the graphite film A1.

[Example 22]
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 12 (sixth embodiment). Of the film width of 50 mm, the frame contact portion was 10 mm, and the protruding portion was 40 mm.

Example 23
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 13 (seventh embodiment). Of the film width of 50 mm, the frame contact portion was 10 mm, and the protruding portion was 40 mm.

Example 24
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 14 (eighth embodiment). Of the film width of 50 mm, the frame contact portion was 10 mm, and the protruding portion was 40 mm.

Example 25
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 100 mm), an LED and a graphite film were attached as shown in FIG. 15 (ninth embodiment). Of the film width of 100 mm, the frame contact portion was 10 mm and the protruding portion was 90 mm. Further, of the protruding portion of 90 mm, the contact portion with the holding member was 10 mm, and the hollow portion was 80 mm. The material of the holding member was stainless steel (SUS).

Example 26
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 15 (ninth embodiment). Of the film width of 50 mm, the frame contact portion was 10 mm, and the protruding portion was 40 mm. Further, out of the protruding portion 40 mm, the contact portion with the holding member was 10 mm, and the hollow portion was 30 mm. The material of the holding member was stainless steel (SUS).

Example 27
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film A1 (width 30 mm), an LED and a graphite film were attached as shown in FIG. 15 (ninth embodiment). Of the film width of 30 mm, the frame contact portion was 10 mm, and the protruding portion was 20 mm. Moreover, out of the protruding portion 20 mm, the contact portion with the holding member was 10 mm, and the hollow portion was 10 mm. The material of the holding member was stainless steel (SUS).

Example 28
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 17 (11th embodiment). Of the film width of 50 mm, the frame contact portion was 20 mm, and the protruding portion was 30 mm. Further, of the protruding portion of 30 mm, the contact portion with the holding member was 10 mm, and the hollow portion was 20 mm. The material of the holding member was stainless steel (SUS).

Example 29
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film B (width 50 mm), an LED and a graphite film were attached as shown in FIG. 15 (ninth embodiment). Of the film width of 50 mm, the frame contact portion was 10 mm, and the protruding portion was 40 mm. Further, out of the protruding portion 40 mm, the contact portion with the holding member was 10 mm, and the hollow portion was 30 mm. The material of the holding member was stainless steel (SUS).

Example 30
An LED and a graphite film were attached as shown in FIG. 15 (9th embodiment) in the same manner as in Example 26 except that the graphite film D (width 50 mm) was used instead of the graphite film A1.

Example 31
LED and graphite film were attached as shown in FIG. 15 (9th form) like Example 26 except having used graphite film A2 (width 50mm) instead of graphite film A1.

[Example 32]
An LED and a graphite film were attached as shown in FIG. 15 (9th embodiment) in the same manner as in Example 26 except that the graphite film A3 (width 50 mm) was used instead of the graphite film A1.

Example 33
An LED and a graphite film were attached as shown in FIG. 15 (9th embodiment) in the same manner as in Example 26 except that the graphite film A4 (width 50 mm) was used instead of the graphite film A1.

Example 34
An LED and a graphite film were attached to the graphite composite film as shown in FIG. 15 (9th embodiment) in the same manner as in Example 26 except that the adhesive layer contained a flame retardant.

Example 35
An LED and a graphite film were attached as shown in FIG. 15 (9th embodiment) in the same manner as in Example 26 except that the material of the holding member was aluminum.

Example 36
An LED and a graphite film were attached as shown in FIG. 15 (9th embodiment) in the same manner as in Example 27 except that the material of the holding member was aluminum.

Example 37
An LED and a graphite film were attached as shown in FIG. 15 (9th embodiment) in the same manner as in Example 34 except that the material of the holding member was aluminum.

Example 38
An LED and a graphite film were attached as shown in FIG. 15 (9th embodiment) in the same manner as in Example 26 except that the material of the holding member was ABS resin.

Example 39
An LED and a graphite film were attached as shown in FIG. 15 (9th embodiment) in the same manner as in Example 27 except that the material of the holding member was ABS resin.

Example 40
An LED and a graphite film were attached as shown in FIG. 15 (9th embodiment) in the same manner as in Example 34 except that the material of the holding member was ABS resin.

Example 41
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film A1 (width 50 mm), an LED and a graphite film were attached as shown in FIG. 16 (tenth embodiment). Of the film width of 50 mm, the frame contact portion was 10 mm, and the protruding portion was 40 mm. Further, out of the protruding portion 40 mm, the contact portion with the holding member was 10 mm, and the hollow portion was 30 mm. The material of the holding member was stainless steel (SUS).

Example 42
As shown in FIG. 16 (tenth embodiment), an LED and a graphite film were attached to the graphite composite film in the same manner as in Example 41 except that the adhesive layer contained a flame retardant.

Example 43
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 30 mm), an LED and a graphite film were attached as shown in FIG. 21 (fifteenth embodiment). Of the film width of 30 mm, the frame (aluminum) back contact portion was 20 mm, and the frame side contact portion was 10 mm (all protruding portions).

Example 44
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 20 mm), an LED and a graphite film were attached as shown in FIG. 18 (a twelfth embodiment). Of the film width of 20 mm, the frame back contact portion was 10 mm, and the frame side contact portion was 10 mm (all protruding portions).

Example 45
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 30 mm), an LED and a graphite film were attached as shown in FIG. 20 (fourteenth embodiment). Of the film width of 30 mm, the frame back contact portion was 20 mm and the frame side contact portion was 10 mm (all protruding portions).

Example 46
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film A1 (width 20 mm), an LED and a graphite film were attached as shown in FIG. 19 (13th embodiment). Of the film width of 20 mm, the frame back contact portion was 10 mm, and the frame side contact portion was 10 mm (all protruding portions).

Example 47
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 30 mm), an LED and a graphite film were attached as shown in FIG. 22 (sixteenth embodiment). Of the film width of 30 mm, the frame contact portion was 10 mm, the hollow portion was 10 mm, and the housing (made of ABS resin) contact portion was 10 mm.

Example 48
Using a graphite composite film (two-side coating, no flame retardant) coated on both surfaces of a graphite film A1 (width 30 mm), an LED and a graphite film were attached as shown in FIG. 23 (17th embodiment). Of the film width of 30 mm, the frame contact portion was 10 mm, the hollow portion was 10 mm, and the housing (made of ABS resin) contact portion was 10 mm.

Example 49
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film A1 (width 30 mm), an LED and a graphite film were attached as shown in FIG. 24 (18th embodiment). Of the film width of 30 mm, the frame contact portion was 10 mm, the hollow portion was 10 mm, and the contact portion with the housing (made of ABS resin) and the holding member was 10 mm. The material of the holding member was stainless steel (SUS).

Example 50
Using a graphite composite film (two-side coating, no flame retardant) coated on both sides of a graphite film A1 (width 30 mm), an LED was attached as shown in FIG. 3 (first embodiment), and FIG. 34 (25th embodiment) ), 20 convex portions 142 were formed and a graphite film was attached (total length of graphite film A1 in the longitudinal direction: 1400 mm, area: 42000 mm ² ).

Example 51
Using a graphite composite film (two-sided coating, no flame retardant) coated on both sides of a graphite film A1 (width 30 mm), an LED was attached as shown in FIG. 3 (first embodiment), and FIG. 35 (26th embodiment) ) 40 convex portions 142 were formed and a graphite film was attached. (Total length of graphite film A1 in the longitudinal direction: 1400 mm, area: 42000 mm ² ).

Example 52
Using a graphite composite film (two-sided coating, no flame retardant) coated on both sides of a graphite film A1 (width 30 mm), an LED was attached as shown in FIG. 3 (first embodiment), and FIG. 37 (27th embodiment) ) 40 convex portions 148 were formed and a graphite film was attached (total length of graphite film A1 in the longitudinal direction: 1400 mm, area: 42000 mm ² ).

[Comparative Example 1]
The LED was mounted as shown in FIG. 3 (first embodiment) without using the graphite composite film.

[Comparative Example 2]
Without using the graphite composite film, the LED was attached as shown in FIG. 10 (fourth embodiment).

For each of the examples and comparative examples, the LED temperature and the maximum temperature of the liquid crystal surface were measured after 3 hours from the lighting of the LED. The input power per LED was 1W. The heat dissipation effect was evaluated in four stages: extremely excellent (A), excellent (B), normal (C), and bad (D). About Examples 50-52, it tested in the attitude | position in which the longitudinal direction of the convex parts 142 and 148 faces an up-down direction (top and bottom direction).
Furthermore, about each Example and the comparative example, the adhesiveness (holding force), workability, sticking property, and rework property of a graphite composite film were evaluated in the same four steps.

  First, the evaluation results of Examples 1 to 49 are shown in Tables 3 to 6.

  Below, consideration of the experimental result of Examples 1-49 is shown.

[Installation of graphite film and temperature reduction effect]
1. When the substrate holding member is in contact with only the frame peripheral wall portion As in Comparative Example 2 (corresponding to the case where no graphite film is provided in FIG. 10), the substrate holding member with the LED attached is attached to the frame peripheral wall portion. And the heat generated from the LED is transferred to the frame peripheral wall portion through the substrate and the substrate holding member. Subsequently, the heat transferred to the peripheral wall portion transfers through the frame, but the peripheral wall portion has a narrow width of 10 mm and hardly diffuses heat to the side opposite to the back plate portion. Moreover, since the heat transfer to the back plate portion side passes through the bent portion of the frame, the heat transfer becomes worse as compared with the case where heat is transferred through the straight portion. Furthermore, the material of the frame is aluminum, and the heat conductivity is not sufficient, so that heat cannot be diffused efficiently. For this reason, not much heat is transmitted to the optical member such as the light guide plate and the diffusion plate, and the liquid crystal surface temperature only rises to 56.7 ° C., but the heat concentrates around the substrate holding member. Has risen to 106.7 ° C.

  On the other hand, by disposing the graphite film on the back plate portion as in Example 18 (FIG. 10), the heat conductivity on the back plate portion is improved, and the heat transmitted to the back plate portion is quickly transmitted. It can diffuse and heat flow to the back plate is improved. Therefore, compared with the comparative example 2, in Example 18, LED temperature fell. Further, when the heat conducted to the back plate portion is conducted from the corner 32 (FIG. 10) of the frame back plate portion toward the light guide plate, the frame made of aluminum has low thermal conductivity, and the back plate The heat was concentrated near the corner 32 of the portion, and the temperature of the end of the optical member near the corner 32 was easy to rise, but by placing the graphite film on the back plate, the heat concentrated near the corner 32 was Since the graphite film diffuses to a lower temperature and closer to the center, it is considered that the local temperature rise is eliminated and the maximum temperature of the liquid crystal part is also lowered.

2. When the substrate holding member is in contact with only the frame back plate portion As in Comparative Example 1 (corresponding to the case where no graphite film is provided in FIG. 3), the substrate holding member to which the LED is attached is attached to the frame back plate portion. When attached and not in contact with the peripheral wall portion of the frame, the heat generated from the LED is transferred to the frame back plate portion through the substrate and the substrate holding member, and tends to diffuse over the entire frame surface. However, the material of the frame is aluminum, and the heat conductivity is not sufficient, so that heat cannot be efficiently diffused. Moreover, since the heat transfer to the frame peripheral wall portion passes through the bent portion of the frame, the heat transfer becomes worse as compared with the case of transferring heat to the straight portion. Further, the peripheral wall portion of the frame is as narrow as 10 mm, and the diffusion of heat to the frame peripheral wall portion side is small. Therefore, heat concentrates on the portion where the substrate holding member is attached, and the LED temperature rises. However, when compared with Comparative Example 2, since the concentration of heat around the LED is reduced in the configuration of Comparative Example 1, the temperature of the LED is lower than that of Comparative Example 2. On the other hand, the end of the optical member closer to the corner 32 (FIG. 3) is disposed near the substrate holding member where heat concentrates, so that the temperature rises extremely and accordingly, the maximum temperature of the liquid crystal surface Also rose to 71.3 ° C.

  From a comparison between Comparative Example 1 and Examples 1 to 15, it was found that when the graphite film was provided on the frame back plate, the LED temperature and the liquid crystal surface temperature were lowered as compared with the case where the graphite film was not provided. This is because the heat concentrated around the substrate holding member was diffused by the graphite film to the lower temperature part closer to the center, and the local temperature rise was prevented. It is considered that the end temperature of the optical member near 32 (reflected in the maximum temperature of the liquid crystal surface) decreased.

[Relationship between substrate holding member installation location and graphite film installation location]
From the comparison between Example 4 (FIG. 3) and Example 18 (FIG. 10), when the graphite film is disposed only on the frame back plate, the substrate holding member that transmits heat generated by the LED to the frame is the graphite of the frame. It was found that both the LED temperature and the maximum liquid crystal surface temperature can be lowered when the film is installed at the site where the film is disposed. This is considered to be because the heat generated from the LED could be efficiently transferred to the graphite film.

  Moreover, when Example 4 (FIG. 3) and Example 17 (FIG. 9) are compared, even if the board | substrate holding member is similarly installed in the installation part of the graphite film of a frame back plate part, a contact area with a flame | frame In Example 17 in which the LED is small, both the LED temperature and the liquid crystal surface temperature are increased compared to Example 4 having a large contact area. This is because the amount of heat transmitted to the graphite film is reduced due to the small contact area of the substrate holding member with the frame, and thus the heat generated in the LED is less likely to be diffused, and the LED temperature is considered to have increased. . In addition, since the substrate holding member is connected to the frame back plate, the heat generated by the LED is easily transferred to the optical member, and as the LED temperature rises, the temperature around the substrate holding member rises, holding the substrate. The temperature at the end of the optical member closer to the member has risen, and the maximum liquid crystal surface temperature has also risen somewhat.

  Furthermore, when Example 4 (FIG. 3) and Example 16 (FIG. 8) are compared, when the substrate holding member is connected to both the back plate part and the peripheral wall part of the frame as in Example 16, the LED temperature It was found that both the maximum liquid crystal surface temperature decreased. This is because heat was diffused by the graphite film by connecting to the frame back plate, and part of the heat was also transmitted to the peripheral wall by connecting the substrate holding member to the peripheral wall having a low temperature. This is probably because the temperature decreased.

[Position of graphite film]
From a comparison between Example 19 (FIG. 11) and Example 4 (FIG. 3), when the graphite film width is the same, it is better to dissipate heat from the corner 32 of the frame so as to protrude outside the frame as in Example 19. The effect was high. When the graphite film is installed so as not to protrude from the corner 32 of the frame as in the fourth embodiment, the heat generated from the LED is mainly diffused only to the optical member side. However, by arranging the graphite film so as to protrude from the corner 32 of the frame as in Example 19, heat can be transferred toward both ends (in the left-right direction in FIG. 11), so that heat can be diffused efficiently. it can. In addition to the graphite film, the heat generated from the LED is partially diffused by the frame. Therefore, a new heat transfer path can be provided by providing the graphite film on the portion outside the frame, which is very effective. Furthermore, by disposing the graphite film so as to protrude from the corner 32 of the frame, heat transfer to the outside of the frame is performed, and heat transfer to the optical member side can be suppressed as compared with the fourth embodiment. The temperature could be lowered. As a result, the maximum liquid crystal surface temperature could be lowered. Comparison between Example 16 (FIG. 8), Example 22 (FIG. 12), Example 17 (FIG. 9), Example 23 (FIG. 13), Example 18 (FIG. 10), and Example 24 (FIG. 14) The same result was obtained, and it was found that the heat dissipation effect was improved even when the location and shape of the substrate holding member were different.

  As for the part which protruded from the corner | angular 32 of the graphite film, when Example 25, 26, 27 (all are FIG. 15) was compared, it turns out that the one where the width | variety of the protruding part is large has a high heat dissipation effect.

  Moreover, when Example 26 (FIG. 15) and Example 28 (FIG. 17) are compared, it is the graphite film of the same width | variety, and both are arrange | positioned and protruded from the corner | angular 32 of the flame | frame, but the contact width of a flame | frame is sufficient. It was found that Example 26 with a small amount had a higher temperature reduction effect for both the LED temperature and the liquid crystal surface maximum temperature. In the case of Example 26, the graphite film in the contact portion with the frame does not reach the position of the optical member, but in Example 28, the graphite film in the contact portion with the frame reaches the position of the optical member. Some of the optical members are covered. From this, when the contact portion with the frame reaches the optical member as in Example 28, the heat generated from the LED is more easily carried to the position of the optical member through the graphite film as compared with Example 26. It has been found that it is effective to make the contact width of the graphite film to the frame up to a portion that does not reach the optical member. Moreover, also about LED temperature, the temperature of Example 26 was low, and it turned out that it is more effective to enlarge the heat conduction to the direction which protrudes from the corner | angular 32 rather than the heat conduction to the optical member side. . Since the heat transfer to the optical member side is also performed by the frame, the protrusion width of the graphite film outside the corner 32 that originally had no means of heat transfer is increased rather than increasing the width of the graphite film on the frame. It is considered that the heat radiation effect is further increased and the LED temperature is lowered.

[Connection of graphite film when graphite film is arranged so as to protrude from corner 32]
From a comparison between Example 26 (FIG. 15) and Example 21 (FIG. 11), it was found that the heat dissipation effect was enhanced when the graphite film protruding from the corner 32 was connected to the holding member. This is presumably because the heat transferred from the graphite film was transferred to the housing through the holding member and the holding member, so that the heat transfer became active and thermal diffusion occurred.

  As a material for connecting the graphite film protruding from the corner 32, aluminum (rather than the case of connecting to SUS (thermal conductivity: 16 W / mK) from comparison of Example 26 and Example 35 (both in FIG. 15). (Thermal conductivity: 237 W / mK) Although the LED temperature and the liquid crystal surface maximum temperature are both slightly lower, the heat dissipation effect is better when connected to a material with good thermal conductivity. I found it expensive. However, when Example 26 and Example 38 are compared, the LED temperature and the liquid crystal surface maximum are highest when connected to ABS with a thermal conductivity of 0.18 W / mK and when connected to SUS with a thermal conductivity of 16 W / mK. The temperature was almost the same. This is thought to be due to the effect of radiation in addition to heat transfer. In ABS with high emissivity, heat dissipation due to heat transfer is slightly lower than SUS, but heat dissipation due to radiation is higher than SUS. It is considered that the heat dissipation effect was almost the same.

  Further, from a comparison between Example 43 (FIG. 21), Example 44 (FIG. 18), and Example 27 (FIG. 15), the graphite film protruding from the corner 32 is disposed on the peripheral wall portion of the frame and the holding member. When connected, the liquid crystal surface maximum temperature and the LED temperature were almost the same value, and it was found that the same effect was obtained.

  Further, when the graphite film is disposed so as to straddle the back plate portion and the peripheral wall portion of the frame, the substrate holding member has a structure in which the substrate holding member is in contact with only the peripheral wall portion as in Example 45 (FIG. 20). Since it becomes the structure by which the graphite film is arrange | positioned in the connection location of a member, the heat | fever staying in the surrounding wall part can be efficiently spread | diffused to the backplate part side. When Example 24 (FIG. 14) is compared with Example 45, the width of the graphite film is wider in Example 24, but the efficiency of Example 45 is also lower because the LED temperature is lower. It can be seen that heat is diffused. However, the liquid crystal surface maximum temperature tends to increase, and it can be seen that the heat staying in the frame peripheral wall portion is carried to the optical member through the back plate portion and the liquid crystal surface temperature is rising. In this way, when the substrate holding member is in contact with only the frame peripheral wall portion, it is arranged so that the graphite film also covers the peripheral wall portion, compared with the case where the graphite film is disposed only on the back plate portion. It has been found that the LED temperature can be greatly reduced.

  Further, from a comparison between Example 47 (FIG. 22) and Example 27 (FIG. 15), it was found that the same effect can be obtained by connecting a graphite film protruding from the corner 32 to the casing.

  Further, when the graphite film protruding from the corner 32 was connected to both the casing and the holding member as in Example 49 (FIG. 24), it was connected only to the casing or only to the holding member. The heat dissipation effect was somewhat higher than in the case, but the temperature did not decrease significantly.

[Width of graphite film]
From the results of Examples 1 to 6, it was found that both the LED temperature and the liquid crystal surface temperature can be further decreased as the width of the graphite film is wider. This is because the heat generated from the LED can be transported to the vicinity of the central part where the temperature is lower by the graphite film, and the local temperature rise generated near the substrate holding member is prevented and the effect of equalization is improved. Therefore, it is considered that the temperature can be further reduced.
However, in the processability when laminating a PET tape or double-sided tape to a graphite film, wrinkles and the like tend to occur easily when the width is widened, and the degree of difficulty tends to increase. Similarly, when pasting on a frame or the like, the degree of difficulty tends to increase.

[Types of graphite film]
From the comparison between Example 7 and Example 4, the larger the thickness of the graphite film (40 μm), the higher the heat dissipation effect, but there was a sufficient heat dissipation effect even in the case of 25 μm. Moreover, regardless of the difference in thickness, in both examples, adhesion, workability, sticking property, and reworkability were good.

  From the comparison between Example 8 and Example 4, it was found that even when a single sheet (sheet-like) graphite film was used, there was a heat dissipation effect similar to that when a long graphite film was used. However, in the case of a sheet form, it cannot be created by “one connection”, so it is necessary to connect two graphite films, resulting in poor workability.

  From the comparison between Example 9 and Example 4, when the natural graphite film was used, the heat dissipation effect was slightly inferior compared with the case where the polymer graphite film was used. This is because the natural graphite film has a lower thermal conductivity of ¼ or less. In addition, natural graphite film is created by rolling and compacting expanded graphite powder, so the interlaminar strength is weak, and after bonding to a frame etc., the bonding position is changed, Even if it tried to peel off again, the interlayer of the graphite film was peeled off and could not be reworked.

[Sag of graphite film]
When Examples 4, 10, 11, and 12 were compared, there was no significant difference in heat dissipation due to the difference in the size of the slack “A / W” at the end of the graphite composite film. However, with respect to workability and pasting properties, Examples 10 and 12 were somewhat inferior to Examples 4 and 11. From this, it was found that the sagging at the end of the graphite composite film was not too large or too small, and had an appropriate value. This is because the center part of the graphite film is slightly longer than the edge part and is slack, so that `` strain '' which is a factor that develops into wrinkles when bonded together is relaxed by the slack part, This is because development can be prevented.

[Cover of edge of graphite film]
In Example 13 in which the end of the graphite film is not covered with PET tape and double-sided tape, Example 4 in which two sides of the graphite film are covered, or Example 14 in which all four sides of the graphite film are covered. Compared with, the heat dissipation effect gave the same effect, but the reworkability was slightly inferior. Since the graphite film has a layered structure in which graphite layers developed in the plane direction are stacked, there is a tendency that the layers are easily peeled by a force applied in the thickness direction. Therefore, if the graphite film is once bonded to the frame and then peeled off, if there is a coating on the edge, the force applied directly in the thickness direction of the graphite film can be eased by peeling off from the coated part Delamination is unlikely to occur. However, when the end portion of the graphite film is not covered, force is directly applied to the graphite film portion, so that the layers are easily peeled off during rework.

  In addition, the structure with all four sides covered must be cut one by one because the graphite film must be cut first when bonding with PET tape or double-sided tape. I can't. Therefore, it is necessary to perform operations such as alignment one by one, and workability is slightly inferior.

[Presence or absence of flame retardant in adhesive]
When a double-sided tape imparted with flame retardancy is used for the pressure-sensitive adhesive, it is necessary to increase the pressure-sensitive adhesive strength by increasing the thickness of the pressure-sensitive adhesive layer because the pressure-sensitive adhesive is inferior by blending the flame retardant. Therefore, from the comparison between Example 4 and Example 15, the heat transfer to the graphite film was slightly inferior and the LED temperature was slightly increased due to the contribution of the adhesive layer having low thermal conductivity. However, since the amount of heat transferred to the optical member is somewhat reduced due to a decrease in the amount of heat transferred to the graphite film, the maximum temperature of the liquid crystal surface is lowered.

  Next, the evaluation results of Examples 50 to 52 are shown in Tables 7 and 8.

As shown in Tables 7 and 8, Examples 50 to 52 provided with the convex portions all had higher heat dissipation effects than Examples 4 and 5 where the convex portions were not provided. In particular, the LED temperature was lowered to less than 80 ° C., and the heat dissipation effect was remarkable.
The adhesion (holding power), workability, sticking property, and reworkability of the graphite composite film were as good as in Examples 4 and 5.

  Considering the results of Tables 7 and 8, first, in Examples 50 to 52, the contact area between the graphite film and the air is increased by providing the protrusions, so that it is considered that the heat dissipation is improved. Moreover, in Examples 4 and 5, heat dissipation by heat diffusion in the surface direction was the main, but in Examples 50 to 52, heat dissipation was also performed in the height direction by the convex portions, so that heat dissipation was improved. Conceivable.

Regarding the area of the graphite film, although the area of Example 4 was larger (50000 mm ² ), Examples 50 to 52 had a higher heat dissipation effect. From this, it is shown that the heat dissipation effect of Examples 50 to 52 is higher than that of Example 5 due not only to the difference in area.

  Since Examples 50 and 51 have a higher heat dissipation effect than Example 52, it can be said that it is better to provide a gap when providing a convex portion. There is a possibility that the heat dissipation due to the convection effect is improved because the convex portion extends in the vertical direction (top-bottom direction).

  From the comparison between Example 50 and Example 51, when providing the convex part having the gap part, there are many convex parts having a low rising part height rather than providing a small number of convex parts having a high rising part height. It can be said that the installation is more effective.

1 LCD TV (electronic equipment)
7 Frame 18 Light guide plate 20 Reflector plate 25 Substrate 26 Substrate holding member 28 Light emitting diode 30 Graphite composite film 46 Substrate holding member 53, 66, 71, 76, 78 Graphite composite film 62, 83 Holding member 90 Hollow holding member (holding member)
93 Overhang (holding member)
96, 97 Substrate holding member 101 Graphite film 102 Adhesive layer, adhesive layer 103 Resin layer 121 Substrate holding member 130 Graphite composite film 140 Graphite composite film 142, 148 Convex portion

Claims (24)

In an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is arranged on the frame, the temperature is substantially increased by heat generated by the electronic element on the back side of the frame. A graphite film is provided at the site to
The graphite film is provided such that one end thereof does not contact the frame and the other end contacts the frame ,
The electronic device is arranged on a substrate, and the substrate is fixed to a frame via a substrate holding member .   The holding member connected to the frame or a casing covering the frame, wherein at least a part of the graphite film not in contact with the frame is held by the holding member. The electronic device described. In an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is arranged on the frame,
A graphite film is provided on the back surface side of the frame and substantially heated by the heat generated by the electronic element,
It has a housing that covers the frame, and the graphite film is placed across the frame and the housing ,
The electronic device is arranged on a substrate, and the substrate is fixed to a frame via a substrate holding member .   The electronic device according to claim 1, wherein a part of the graphite film forms a rib-like convex portion. In an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is arranged on the frame,
A graphite film is provided on the back surface side of the frame and substantially heated by the heat generated by the electronic element,
A part of the graphite film forms a rib-like convex part,
The graphite film has a thickness of 10 to 300 μm,
The thermal conductivity of the graphite film state, and are more 1200 W / mK,
The electronic device is arranged on a substrate, and the substrate is fixed to a frame via a substrate holding member .   The electronic device according to claim 4, wherein the convex portion has a cylindrical shape in which both ends in the length direction are open to form a gap portion.   The electronic apparatus according to claim 4, wherein there are a plurality of convex portions and are arranged in parallel to each other. The frame has a back plate part and a peripheral wall part rising from the back plate part,
6. The electronic apparatus according to claim 5, wherein the graphite film is provided across the back plate portion and the peripheral wall portion of the frame.   The electronic device according to claim 1, wherein the frame includes a back plate portion and a peripheral wall portion rising from the back plate portion. The electronic device according to any one of claims 1 to 9 substrate holding member is characterized by being attached to the back plate portion of the frame. The electronic device according to any one of claims 1 to 9 substrate holding member is characterized by being attached to the peripheral wall portion of the frame. Substrate holding member is elongated, the electronic device according to any one of claims 1 to 11, characterized in that the cross section is substantially square. Substrate holding member is elongated, the electronic device according to any one of claims 1 to 11, characterized in that the cross-sectional shape is substantially L-shaped. The electronic device is a backlight device, and includes a light guide plate and a reflection plate arranged on one side of the light guide plate, the electronic element is a light emitting diode, and the light emitting diode is disposed on a side of the light guide plate. The graphite film is provided across a back surface portion of the frame corresponding to a portion to which the substrate holding member is attached and a back surface portion of the frame corresponding to the portion to which the light guide plate is attached. Item 14. The electronic device according to any one of Items 1 to 13 . In an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is arranged on the frame, the temperature is substantially increased by heat generated by the electronic element on the back side of the frame. A graphite film is provided at the site to
  The graphite film is provided such that one end thereof does not contact the frame and the other end contacts the frame,
  Part of the graphite film forms a rib-like convex part,
  An electronic device, wherein the convex portion is formed in a cylindrical shape with both ends in the length direction being open to form a gap. The holding member connected to a frame or a casing covering the frame, wherein at least a part of the graphite film not in contact with the frame is held by the holding member. The electronic device described. In an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is arranged on the frame,
  A graphite film is provided on the back surface side of the frame and substantially heated by the heat generated by the electronic element,
  It has a housing that covers the frame, and the graphite film is placed across the frame and the housing,
  Part of the graphite film forms a rib-like convex part,
  An electronic device, wherein the convex portion is formed in a cylindrical shape with both ends in the length direction being open to form a gap. In an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is arranged on the frame,
  A graphite film is provided on the back surface side of the frame and substantially heated by the heat generated by the electronic element,
  A part of the graphite film forms a rib-like convex part,
  The graphite film has a thickness of 10 to 300 μm,
  The thermal conductivity of the graphite film is 1200 W / mK or more,
  An electronic device, wherein the convex portion is formed in a cylindrical shape with both ends in the length direction being open to form a gap. The electronic device according to claim 15, wherein there are a plurality of convex portions and they are arranged in parallel to each other. In an electronic device having an electronic element that generates heat when energized and a frame, and the electronic element is arranged on the frame,
  A graphite film is provided on the back surface side of the frame and substantially heated by the heat generated by the electronic element,
  A part of the graphite film forms a rib-like convex part,
  The graphite film has a thickness of 10 to 300 μm,
  The thermal conductivity of the graphite film is 1200 W / mK or more,
  The frame has a back plate part and a peripheral wall part rising from the back plate part,
  An electronic apparatus, wherein the graphite film is provided across the back plate portion and the peripheral wall portion of the frame. The electronic device according to claim 15, wherein the frame includes a back plate portion and a peripheral wall portion rising from the back plate portion. The electronic device according to any one of claims 1 to 21 electronic element characterized in that it is a light emitting diode. The electronic device according to any one of claims 1 to 22 , wherein the graphite film is provided with an adhesive layer or an adhesive layer on one side. The electronic device according to any one of claims 1 to 23 , wherein the graphite film is provided with a resin layer on one side.

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