JP2013171932A - Heat radiator of electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiator of an electronic apparatus, in which a substrate is reliably connected to a sheet metal frame to materialize high shieldability and heat dissipation with respect to an integrated circuit on the substrate, and which can be thinned and can reduce the number of components used.SOLUTION: A first casing for fixing a substrate 108 on which an integrated circuit 110 is provided is combined with a second casing 2 for fixing a sheet metal frame 101 disposed face to face with the surface on which the integrated circuit 110 of the substrate 108 is provided face to face each other to form the electronic apparatus. The heat radiator in the electronic apparatus has the sheet metal frame 101, a shield sheet metal 102 disposed so as to surround the integrated circuit 110 fixed to the surface on the substrate side of the sheet metal frame, and a connection member 120 provided on the substrate and provided with heat conductivity and shieldability. The connection member 120 is connected to the shield sheet metal by fitting to the shield sheet metal 102, or changing the shape thereof, and the first casing is thereby combined with the second casing.

Description

  The present invention relates to a heat dissipation device for electronic equipment, and more particularly to a heat dissipation device for electronic equipment that enables efficient heat dissipation while maintaining a shielding effect.

  In portable terminals and the like that are becoming smaller in size, integrated circuits are densely mounted on a small substrate, and the temperature rise in the terminals due to the heat generated by each integrated circuit is large. For this reason, the circuit operation is affected, and heat countermeasures are indispensable in terminal design and manufacture. In other words, heat generation locations tend to be concentrated due to downsizing of the substrate, and a design for diffusing heat throughout the terminal is required.

  On the other hand, in such a terminal design, in order to avoid the influence of electromagnetic noise of each integrated circuit in the terminal, it is inevitable to mount the entire integrated circuit with a shield composed of a thin metal plate. Yes.

  Patent Document 1 discloses a heat dissipating device for an electronic device having a shield frame, a shield lid, and a substantially U-shaped graphite sheet. The shield frame covers the side surface of the heating element to electromagnetically shield the heating element. The shield lid is a lid for the shield frame and is provided with a slit. The combination of the shield frame and the shield lid maintains the function as a shield part. The substantially U-shaped graphite sheet penetrates the center shaft part through the slit of the shield lid, so that the bottom surface of the graphite sheet directly contacts the surface of the integrated circuit mounted inside the shield, and the top surface of the graphite sheet directly contacts the heat dissipation surface. Can be made. Therefore, the surface of the integrated circuit and the heat dissipation surface can be connected by a graphite sheet, and the thermal conductivity of the graphite sheet is used to diffuse the heat on the surface of the integrated circuit with high efficiency under a spatial spread. can do.

  FIG. 9 shows a related electronic device heat dissipation device. The first shield frame 312 covers the side surface of the heating element in order to electromagnetically shield the first integrated circuit 110 that is the heating element. The second shield frame 313 covers the side surface and the top surface of the heating element in order to electromagnetically shield the second integrated circuit 111 that is the heating element. The shield lid 913 is a lid for the first shield frame 312. A heat conductive sheet 914 is in contact with the upper portions of the shield lid 913 and the second shield frame 313. A sheet metal frame 101 that is a heat radiating portion is in contact with an upper portion of the heat conductive sheet 914.

JP 2010-258179 A

  A heating element such as a power supply circuit mounted on a mother board tends to warm the entire board through the board ground during circuit operation. Relaxing the temperature of the housing surface of the apparatus by connecting the substrate to a wide ground plane is an effective means of thermal diffusion. However, if the number of parts such as heat conductive sheets increases due to this connection, not only will it be disadvantageous for making the device thinner, but there will also be problems such as increased costs and increased man-hours for adding parts. Come. In the heat dissipating device disclosed in Patent Document 1 and the heat dissipating device of the related electronic device shown in FIG. 9, the thickness of the device increases because the graphite sheet and the heat conducting sheet are included in the device, respectively. There is a problem that the number of parts is increasing as well.

  A simplest configuration that can solve these problems is, for example, a shield cover in which the heat conductive sheet 914 is removed from the heat dissipating device of FIG. 9 and connected to the mother board 108 that is a heat source via a shield frame 312. In this configuration, 913 and the sheet metal frame 101 which is a heat radiating surface are in direct contact with each other. However, there may be a case where the mother substrate 108 is warped. In this case, the shield lid 913 and the sheet metal frame 101 are not completely parallel, and the two cannot be in surface contact with each other and are incompletely connected.

  In the present invention, the substrate and the sheet metal frame are securely connected to achieve high shielding performance and heat dissipation for the integrated circuit on the substrate, and the device can be thinned, and the heat dissipation device for electronic equipment with a small number of components. The purpose is to provide.

  A heat dissipation device for an electronic device according to the present invention fixes a first housing for fixing a substrate provided with an integrated circuit, and a sheet metal frame disposed to face a surface of the substrate provided with the integrated circuit. A heat dissipating device in an electronic device formed by coupling a second casing to face each other, wherein the integrated circuit is fixed to the sheet metal frame and the substrate side surface of the sheet metal frame And a connecting member provided on the substrate and having thermal conductivity and shielding properties, and the connecting member is fitted to the shielding sheet metal, or When the connecting member is deformed and connected to the shield metal plate, the first casing and the second casing are coupled.

  In the present invention, the substrate and the sheet metal frame are securely connected to achieve high shielding performance and heat dissipation for the integrated circuit on the substrate, and the device can be thinned, and the heat dissipation device for electronic equipment with a small number of components. Can be provided.

It is sectional drawing of the thermal radiation apparatus of the electronic device which concerns on the 1st Embodiment of this invention. It is a figure which shows the surface and the back surface of the mobile telephone which is an example of an electronic device. It is sectional drawing of the thermal radiation apparatus of the electronic device which concerns on the 2nd Embodiment of this invention. FIG. 4 is a top view of the mother substrate of FIG. 3. It is the figure explaining the front housing | casing of FIG. It is a flowchart of a heat dissipation route. It is sectional drawing of the heat radiating device of the electronic device which concerns on the 3rd Embodiment of this invention. It is sectional drawing of the heat radiating device of the electronic device which concerns on the 4th Embodiment of this invention. It is sectional drawing of the heat radiating device of the electronic device relevant to this invention.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

  FIG. 1 is a sectional view of a heat dissipation device for an electronic apparatus according to the first embodiment of the present invention. A sheet metal frame 101 is fixed to the front housing 100. A mother substrate 108 is fixed to the rear housing 109. A liquid crystal display 106 and a backlight unit 107 are fixed by a sheet metal frame 101 formed in a bowl shape, and a screen 105 made of tempered glass or acrylic or the like and a touch panel sensor glass 104 are attached from above. A shield metal plate 102 is welded to the metal plate frame 101. The shield metal plate 102 is disposed so as to surround the integrated circuits 110 and 111 on the mother substrate. A connection member 120 is provided on the mother substrate 108. The front front housing 100 and the rear housing 109 are coupled by connecting the connecting member 120 to the shield metal plate 102 or by deforming the connecting member 120 and connecting to the shield metal plate 102.

  The connecting member 120 has thermal conductivity and shielding properties. By surrounding the integrated circuits 110 and 111 on the mother substrate 108 with the sheet metal frame 101, the shield sheet metal 102, and the connection member 120, it is possible to shield the noise of the integrated circuits 110 and 111. On the other hand, by connecting the mother substrate 108 and the shield metal plate 102 with the connection member 120, the heat flowing into the mother substrate 108 from the integrated circuits 110 and 111 is dissipated to the sheet metal frame 101 via the connection member 120 and the shield metal plate 102. It is possible to

  Further, for example, parts such as the heat conductive sheet 914 and the shield cover 913 are not necessary as compared with the heat dissipating device of the related electronic device shown in FIG. 9, and the device is thinned by the thickness Y shown in FIG. And the number of components is reduced.

  FIG. 2 is a diagram illustrating a front surface (FIG. 2A) and a back surface (FIG. 2B) of a mobile phone which is an example of an electronic device. FIG. 1 corresponds to the XX section of FIG. The mobile phone 200 includes a touch panel 201, a liquid crystal display 106, a receiver 203, a microphone 204, and key buttons 205. A mother board 108 and a battery pack 207 are mounted inside the mobile phone 200.

  FIG. 3 is a cross-sectional view of a heat dissipation device for an electronic device according to the second embodiment of the present invention. As the connection member 120 in FIG. 1, first and second shield frames 312 and 313 are used. The first and second shield frames 312 and 313 are soldered to the ground of the mother board 108.

  FIG. 4 is a view of the mother substrate 108 of FIG. 3 as viewed from above. A first integrated circuit 110 and a second integrated circuit 111 are mounted on the substrate. In the case of a cellular phone, a power supply circuit, a high-frequency transmitter circuit, and a charging circuit are provided as integrated circuits. Since the first integrated circuit 110 and the second integrated circuit 111 are both heat sources and noise sources, the first and second shield frames 312 and 313 are surrounded by the first shield frame 312 and the second shield frame 313, respectively. For reasons such as resin sealing of the first integrated circuit 110, the first shield frame 312 has a top hole, and can be shielded by covering the hole from above. On the other hand, there is a structure in which the top hole is not opened like the second shield frame 313. First and second shield metal plates 403 and 404 are arranged at dotted line positions surrounding four sides of the first and second shield frames 312 and 313. The shield sheet metal may be inside and the shield frame outside. In addition, a connector 408 for connecting to devices such as a liquid crystal display and a touch panel, and a battery terminal 409 are mounted.

  FIG. 5 is a diagram illustrating the front casing 100 of FIG. A front casing 100 is formed by insert molding a mold 500 made of polycarbonate or the like and a sheet metal frame 101 (FIG. 5A), and the first and second shield sheet metals 403 and 404 are welded to the welding portion 103 thereto. (FIG. 5B).

  A projection 507 that is elastically deformed in a direction orthogonal to the side surface is formed on one side surface of the shield frame 505 and the shield sheet metal 102, and the shield frame 505 and the shield sheet metal 102 are fitted by the projection 507 (FIG. 5 ( c)).

  Alternatively, one of the shield frame 505 and the shield metal plate 102 has a protrusion 508 on the side surface, and the other has a hole 509 that fits into the protrusion 508 (FIG. 5D).

  FIG. 6 is a flowchart of the heat dissipation route. Here, the case where the heat radiation countermeasure of FIG. 3 is implemented, the case where the heat radiation countermeasure of FIG. 9 is implemented, and the case where the heat radiation sheet is removed from FIG.

  First, the first integrated circuit 110 and the second integrated circuit 111 in FIG. 4 start to operate (601). Then, the first integrated circuit 110 and the second integrated circuit 111 start to generate heat (602). Heat is transmitted to the ground of the mother substrate 108 through the solder balls of the first integrated circuit 110 and the second integrated circuit 111 (603).

  In the case of FIG. 3, since the shield frame 505 is soldered to the ground of the mother board 108, heat is sucked up (605). Next, heat is transferred to the shield metal plate 102 through the contact portion (606). Heat is transferred from the shield sheet metal to the sheet metal frame 101, and the heat spreads over a wide range (607). On the screen side, there are shielding objects such as an air layer, liquid crystal display, backlight, and touch panel on the way. Further, since heat escapes to the sheet metal frame 101, it is difficult for the heat to be transmitted to the rear casing that is directly touched by the hand.

  In the case of FIG. 9, it is possible to release heat to the sheet metal frame 101 as in the case of FIG. 3. (610), the speed until heat is transmitted deteriorates (611).

  When the heat conductive sheet 914 is removed from FIG. 9, there is no escape of heat and heat is transmitted to the surface of the shield frame on the back of the mother board, and the entire mother board is heated (612). Heat is transferred directly from the shield on the back of the mother board to the rear housing (613), and heat is transferred to the human hand.

  From the above, it can be seen that the configuration of FIG. 3 is the most suitable configuration as a heat dissipation measure.

  FIG. 7 is a cross-sectional view of a heat dissipation device for an electronic device according to the third embodiment of the present invention. With reference to this figure, another method for connecting the heat accumulated in the mother substrate 108 to the sheet metal frame 101 will be described. In the present embodiment, the metal fittings 712 are soldered and mounted on the mother board at regular intervals. The metal fitting 712 has a hole into which the tip of the shield metal plate 102 is inserted, and the hole extends from the entrance for receiving the tip of the shield metal plate 102 toward the back so that the metal fitting 712 and the shield metal plate 102 are fitted. The width is decreasing.

  FIG. 8 is a cross-sectional view of a heat dissipation device for an electronic device according to the fourth embodiment of the present invention. In this embodiment, the rubber 812 is soldered and connected to the ground 813 on the mother board 108. The rubber 812 can be deformed while being in contact with the tip of the shield metal plate 102.

  In the case of FIG. 7 and FIG. 8, when the mother substrate alone is used, a shield frame is not required around the integrated circuit, which is effective for rework when the integrated circuit fails.

  Note that the present invention is not limited to a mobile phone or a smartphone, but a notebook personal computer with a communication function, a PHS (Personal Handyphone System), a PDA with a communication function (Personal Data Assistant, or Personal Digital Assistant). It is also applicable to portable terminal devices such as equipment) and electronic dictionaries.

DESCRIPTION OF SYMBOLS 100 Front housing | casing 101 Sheet metal frame 102 Shield sheet metal 108 Mother board 110 1st integrated circuit 111 2nd integrated circuit 120 Connection member 312 1st shield frame 313 2nd shield frame 712 Hardware 812 Rubber 913 Shield lid 914 Thermal conduction Sheet

Claims (6)

A first casing for fixing a substrate provided with an integrated circuit and a second casing for fixing a sheet metal frame arranged to face the surface of the substrate provided with the integrated circuit are opposed to each other. A heat dissipation device in an electronic device formed by being combined,
The sheet metal frame;
A shield metal plate fixed to the substrate-side surface of the metal plate frame and arranged to surround the integrated circuit;
A connection member provided on the substrate and having thermal conductivity and shielding properties;
The first casing and the second casing are coupled to each other when the connecting member is fitted to the shield sheet metal or the connecting member is deformed and connected to the shield sheet metal. Equipment heat dissipation device.   The connection member is a shield frame fixed on the substrate so as to surround the integrated circuit on the inner or outer periphery of the shield sheet metal, and on the other side surface of the shield frame and the shield sheet metal, The heat dissipation device for an electronic device according to claim 1, wherein a protrusion that is elastically deformed in a direction orthogonal to the side surface is formed, and the shield frame and the shield sheet metal are fitted by the protrusion.   The connection member is a shield frame fixed on the substrate so as to surround the integrated circuit at an inner periphery or an outer periphery of the shield sheet metal, and one of the shield frame and the shield sheet metal has a protrusion on a side surface. The other is a heat dissipation device for an electronic device according to claim 1, wherein the other has a hole fitted into the protrusion.   The connection member is a metal fitting fixed on the substrate, and the metal fitting has a hole portion into which a tip end portion of the shield metal plate is inserted, and the hole portion is fitted with the metal plate and the shield metal plate. The heat dissipation device for an electronic device according to claim 1, wherein the width of the shield sheet metal is reduced from the inlet that receives the tip of the shield sheet metal toward the back.   The heat dissipation device for an electronic device according to claim 1, wherein the connection member is rubber fixed on the substrate, and the rubber is deformable while being in contact with a front end portion of the shield sheet metal. A heat dissipation device for an electronic device according to any one of claims 1 to 5,
The substrate;
The integrated circuit;
A front housing comprising the sheet metal frame;
A rear housing comprising the substrate,
The electronic device in which the front housing and the rear housing are coupled by the connection member being fitted to the shield metal plate or the connection member being deformed and connected to the shield metal plate.

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