JP6204020B2 - Electronic device including thermal diffusion member and thermal diffusion member - Google Patents

Description

  The present invention relates to a heat diffusion member that diffuses heat from a heating element and an electronic device including the heat diffusion member.

  In recent years, portable information terminals such as smartphones (hereinafter simply referred to as “information terminals” or “electronic devices”) have become widespread, and users can easily use the information terminals anytime and anywhere. It is now possible to collect information and send information.

Accordingly, such information terminals have been improved in functionality, performance, and use for a long time in order to further improve convenience for users.
Specifically, the number of cores in a central processing unit (Central_Processing_Unit: hereinafter abbreviated as “CPU”) built in the information terminal is increased, or the operating clock frequency in the CPU is increased. Accordingly, large capacity batteries with large discharge current and charge current are used for information terminals.
As a result, heat generation in built-in components such as the CPU constituting the information terminal and a power supply circuit that controls charging / discharging of the large capacity battery increases, and accordingly, the heat generation causes a temperature rise in the information terminal.

  Therefore, efficient heat dissipation of the information terminal is important. That is, in order to efficiently dissipate heat, the information terminal conducts the heat generated by the heating element in the information terminal into the information terminal casing, and the conducted heat to the outside through the casing. Further dissipate. In order to efficiently dissipate heat, such an information terminal is advantageous in that it easily conducts heat to the housing and has a large area (housing surface area) with which the housing is in contact with outside air.

  However, if it is easy to conduct heat to the housing, a high heating element such as a CPU built in the information terminal has a casing portion in the vicinity thereof (hereinafter referred to as a “high heating element vicinity casing portion”). Since the high heat generating element is heated by radiant heat or conduction heat (hereinafter sometimes referred to simply as “heat”), the outer surface of the casing near the high heat generating element (hereinafter referred to as “the vicinity of the high heat generating element”). A so-called heat spot is generated in which the temperature in the “outer surface of the housing” is considerably higher than the temperature of the outer surface of the housing around the housing portion near the high heating element.

  As a result, when the skin such as the palm of the user keeps touching the heat spot for a long time, the skin that is continuously touching may cause, for example, a low-temperature burn.

  In addition, information terminals have been made thinner and lighter in order to improve their portability, and as a result, a casing surface area capable of efficiently radiating heat from the outer surface of the casing is secured. It has become difficult.

  A method for solving the problem caused by such a heat spot has been proposed as described below.

  Patent Document 1 discloses an electronic device including a heat diffusion member that uniformly and efficiently diffuses heat generated from a heat-generating component in a housing on the outer surface of the housing, a method of manufacturing the electronic device including the heat diffusion member, and heat diffusion Techniques relating to members are disclosed.

  The heat diffusing member 85 described in Patent Document 1 shown in FIG. 5 includes a heat diffusing layer 91, a heat insulating layer 92, and a heat conducting layer 93. FIG. 5 is a cross-sectional view of a related electronic device.

  The electronic device described in Patent Document 1 includes a casing 81, a printed wiring board 82, a heat generating component 83, a component 84, and a heat diffusing member 85.

  The heat diffusing member 85 is disposed so as to be sandwiched between the inner surface of the housing 81 and the heat generating component 83 mounted on the printed wiring board 82. The thermal diffusion layer 91 is a layer made of a high thermal conductivity member that easily conducts heat in the surface direction. The heat insulating layer 92 is a layer made of a low heat conductive member. The heat conductive layer 93 is a layer made of a high heat conductive member that easily conducts heat in the thickness direction.

  And in the technique described in patent document 1, the heat | fever transmitted from the heat-emitting component 83 contact | abutted to the thermal-diffusion layer 91 is spread | diffused to a surface direction. Then, the heat diffused in the surface direction is conducted in the thickness direction in the heat conductive layer 93 bonded to the heat diffusion layer 91 surface to surface. The heat conducted in the thickness direction is conducted to the housing 81.

  In the technique described in Patent Document 1, the heat generating component 83 is in contact with the heat diffusion layer 91 and is insulated between the heat diffusion layer 91 at a position facing the heat generating component 83 and the inner surface of the housing 81. A layer 92 is provided.

  Thus, in the technique described in Patent Document 1, the heat from the heat generating component 83 is insulated by the heat insulating layer 92, and thus is prevented from being directly conducted to the outer surface of the housing 81, thereby generating a heat spot. Is suppressed.

JP 2010-251386 A (page 6, paragraph number: 0030)

  However, if the electronic device described in Patent Document 1 is an information terminal such as a smartphone, and the information terminal includes a rechargeable battery, a normal rechargeable battery has a life (that is, a chargeable / dischargeable frequency limit). When the battery is exhausted, it needs to be replaced. For this purpose, a lid for taking in and out the battery is provided in the casing of the information terminal. As a result, there is a problem in that a heat diffusing member cannot be provided at the location of the battery lid, and sufficient heat dissipation cannot be performed.

  In other words, in the technique described in Patent Document 1, when the lid as described above is provided, the area of the inner surface of the casing 81 in contact with the heat conductive layer 93 is reduced, and the outer surface of the casing 81 is reduced. However, there is a problem that the heat radiation area for releasing heat is small and the heat radiation efficiency is lowered.

  The objective of this invention is providing the electronic device provided with the thermal diffusion member and thermal diffusion member which solve the problem mentioned above.

The thermal diffusion member of the present invention is
A member that is mounted on an electronic device including a housing in which a plurality of electronic components are mounted, and a lid that is provided on at least a part of the lower portion of the housing and is removable from the housing,
A high thermal conductivity layer having high thermal conductivity;
A low thermal conductivity layer superimposed on the high thermal conductivity layer and having a low thermal conductivity,
The low thermal conductive layer is contacted or adhered to the lower surface in the casing excluding the lid,
A high thermal conductive stretched portion obtained by stretching the high thermal conductive layer is brought into contact with or adhered to a structure provided inside the housing.

In addition, an electronic device provided with the heat diffusion member of the present invention,
A housing with a plurality of electronic components inside,
A lid provided on at least a part of the lower portion of the housing and removable from the housing;
A high thermal conductivity layer having high thermal conductivity;
A low thermal conductivity layer superimposed on the high thermal conductivity layer and having a low thermal conductivity,
The low thermal conductive layer is contacted or adhered to the lower surface in the casing excluding the lid,
A high thermal conductive stretched portion obtained by stretching the high thermal conductive layer is brought into contact with or adhered to a structure provided inside the housing.

  In the present invention, even if the structure of the electronic device housing includes a lid that allows a battery or the like to be taken in and out while suppressing the generation of heat spots on the outer surface of the housing of the electronic device. There is an effect that heat can be diffused.

It is sectional drawing which shows the 1st Embodiment of this invention. It is sectional drawing which represents notionally the structure of the thermal-diffusion member in the 1st Embodiment of this invention. It is sectional drawing which shows the 2nd Embodiment of this invention. It is sectional drawing which represents notionally the structure of the thermal-diffusion member in the 2nd Embodiment of this invention. 2 is a cross-sectional view of an electronic device described in Patent Document 1. FIG.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, for convenience of explanation, three-dimensional coordinate symbols are used in the figure.

<First Embodiment>
FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.
Referring to FIG. 1, in the present embodiment, an electronic device (hereinafter, “smartphone” will be described as an example) includes a housing 46, a touch panel unit 42, a display unit 41, a reinforcing frame 40, and a substrate. 48, a battery 49, a lid 50, the heating element 3, and the heat diffusion member 30.

  FIG. 2 is a sectional view conceptually showing the structure of the heat diffusing member 30 in the first embodiment.

  The thermal diffusion member 30 shown in FIG. 2 includes a high thermal conductive layer 11, a low thermal conductive layer 12, an adhesive layer 13, and an insulating layer 14. The high thermal conductive layer 11 is a member having a high thermal conductivity, for example, graphite (graphite) formed in a sheet shape. Further, the low thermal conductive layer 12 is a member having a low thermal conductivity, for example, a foamed material including silica glass fiber, ceramic or an air layer formed into a sheet shape. The material of the member mentioned above is an example, and the material of these members is not limited to the material mentioned above.

  The adhesive layer 13 is used when the high heat conductive layer 11 in the high heat conductive stretched portion described later is bonded to the reinforcing frame 40 or the like. The adhesive layer 13 is, for example, a sheet-like double-sided adhesive tape or a heat conductive adhesive in which an adhesive material is applied to both sides of a base material.

  The insulating layer 14 is included in the high thermal conductive layer 11, for example, a heating element 3 such as a CPU or a battery 49 in order to prevent a circuit from being short-circuited by a conductor such as graphite coming into contact with a component or a circuit. It is the layer which consists of an insulator provided in the side facing components, such as.

  Since the adhesive layer 13 and the insulating layer 14 are thin members, the adhesive layer 13 and the insulating layer 14 affect the thermal conductivity to and from the high thermal conductive layer 11 and the low thermal conductive layer 12. There is nothing.

  As shown in FIG. 2, in the portion other than the high heat conduction stretched portion of the heat diffusion member 30, the surface on the high heat conduction layer 11 side faces the heating element 3, and the low heat conduction layer 12 contacts the inner surface of the housing 46.

  Moreover, in the thermal diffusion member 30, the high heat conductive layer 11 is extended | stretched to the high heat conductive extending | stretching part.

  An adhesive layer 13 is provided on the upper surface side of the high thermal conductive layer 11 in the high thermal conductive stretched portion, and an insulating layer 14 is provided on the lower surface side of the high thermal conductive layer 11 in the high thermal conductive stretched portion.

  Next, the case where the heat-diffusion member 30 mentioned above is used for a smart phone is demonstrated using FIG.

  The three-dimensional coordinate symbol shown in FIG. 1 represents that the vertical direction of the smartphone is the Z axis, the horizontal direction is the X axis, and the thickness direction is the Y axis. That is, FIG. 1 represents an XY axis cross section of the smartphone.

  In FIG. 1, the low thermal conductive layer 12 of the heat diffusing member 30 is in contact with the inner surface of the housing 46 facing the heating element 3.

  Thereby, the heat from the heating element 3 is conducted to the high thermal conductive layer 11 as indicated by the thermal conduction 47 indicated by the arrow. However, the heat conducted to the high thermal conductive layer 11 is insulated by the low thermal conductive layer 12 and is not transmitted to the housing 46.

  For this reason, the temperature of the outer surface of the casing 46 in the vicinity of the heating element 3 does not increase. As a result, the occurrence of heat spots at locations facing the heating element 3 on the outer surface of the housing is suppressed.

  Thereby, even when the user holds and uses the smartphone for a long time, it is possible to prevent the user from suffering a low-temperature burn on the palm or the like.

  Further, the high thermal conductive extension portion (see FIG. 2) of the heat diffusing member 30 passes through the gap between the right side surface of the battery 49 and the left side surface of the substrate 48 so as to avoid the lid 50, and further reinforces the upper surface side of the battery 49. It extends through a gap with the frame 40.

  The heat diffusing member 30 is bonded to the reinforcing frame 40 by the adhesive layer 13 on the upper surface side of the high thermal conductive stretched portion of the heat diffusing member 30.

  At this time, the insulating layer 14 on the lower surface side of the high thermal conductive extension portion faces the battery 49. There may be a gap between the insulating layer 14 and the battery 49, or both may be in contact with each other.

  By providing such a heat diffusing member 30, heat from the heating element 3 is conducted to the high heat conductive layer 11 in the heat diffusing member 30, and the heat conducted to the high heat conductive layer 11 is further bonded to the high heat conductive stretched portion. It is transmitted to the layer 13, the reinforcing frame 40 and the display unit 41 and is diffused inside the smartphone.

  Here, the reinforcement frame 40 can use a high thermal conductivity, for example, a stainless steel material. The heat conducted to the reinforcing frame 40 is further conducted to the display unit 41. Further, the heat conducted to the reinforcing frame 40 is also conducted from the left and right sides of the reinforcing frame 40 to the housing 46.

  In the case of a smartphone that does not include the reinforcing frame 40, the high heat conductive layer 11 in the high heat conductive extension portion may be bonded to a structure such as the display unit 41 via the adhesive layer 13, for example.

  The material of the housing 46 may be at least one of metal, resin, and carbon fiber, or a combination of these materials.

  Moreover, the low thermal conductive layer 12 in the thermal diffusion member 30 may have heat resistance and flame retardancy. Moreover, when using a foam material as the low heat conductive layer 12, the low heat conductive layer 12 may have impact resistance, drop resistance, and noise resistance.

  In addition, as shown in FIG. 2, the high thermal conductive layer 11, the low thermal conductive layer 12, and the insulating layer 14 are integrated by adhering the side portions of these superimposed layers using an adhesive 15. Is possible.

  Further, as an example of the thickness of each layer constituting the thermal diffusion member 30, the high thermal conductive layer 11 is about 20 μm (micrometer), the low thermal conductive layer 12 is about 50 μm, the insulating layer 14 is about 10 μm, and the adhesive layer 13 is About 10 μm.

In other words, the heat diffusion member 30 has a substantially uniform thickness of, for example, 40 μm to 80 μm, and is thin and flexible. It can be folded.
The thickness of each layer constituting the heat diffusion member 30 described above and the thickness of the entire heat diffusion member 30 are examples, and are not limited to these thicknesses.

  Further, for example, the battery 49 and the power supply circuit that controls charging / discharging in the vicinity of the battery 49 may generate heat when charging / discharging. In that case, if the heat generated in the battery 49 is lower than the heat conducted from the heat generating element 3 to the high heat conducting extension portion, the heat from the heat generating element 3 is also conducted to components such as the battery 49.

  Further, a layer formed by stacking a plurality of high heat conductive sheets may be used as the high heat conductive layer 11 in accordance with the amount of heat generated by the heat from the heating element.

  Even if the present embodiment has a structure including a lid that allows a battery or the like to be taken in and out of the smartphone casing while suppressing the generation of heat spots on the outer surface of the smartphone casing, Has the effect of being able to diffuse.

  The reason is that the heat from the heating element 3 is insulated by the low thermal conductive layer 12 so that the heat is not transmitted to the outer surface of the housing 46, and the high thermal conductive stretched part and the reinforcing frame 40 are used. This is because the heat can be dissipated outside the smartphone.

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 3 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view conceptually showing the structure of the heat diffusion member 35 in the present embodiment.
Referring to FIG. 4, the thermal diffusion member 35 in this embodiment includes a high thermal conductive layer 11, a low thermal conductive layer 12, an insulating layer 14, and an adhesive layer 13. And the adhesion layer 13 is used for adhesion | attachment of the surfaces in each of these layers.

  In the following, the characteristic part of the present embodiment will be mainly described, and the same reference numerals are given to the same components as those of the first embodiment described above, and the configurations thereof are described. A duplicate description of the elements is omitted.

  In this embodiment, the heat diffusing member 35 is bonded to the insulating layer 14, the adhesive layer 13, the high thermal conductive layer 11, the adhesive layer 13, the low thermal conductive layer 12, and the adhesive in order from the side facing the heating element 3. Layer 13. In the heat diffusion member 35, the adhesive layer 13 on the side farthest from the heating element 3 adheres the heat diffusion member 35 to the inner surface of the housing 46.

  In addition, the high thermal conductive stretched portion of the thermal diffusion member 35 is composed of the adhesive layer 13, the high thermal conductive layer 11, the adhesive layer 13, and the insulating layer 14 in order from the side bonded to the reinforcing frame 40.

  Since the method for mounting the high thermal conductive stretched part on the smartphone is the same as that in the first embodiment, description thereof is omitted here.

  As described above, this embodiment has the same effect as that of the first embodiment.

  The reason is the same as that of the first embodiment.

3 Heating Element 11 High Thermal Conductive Layer 12 Low Thermal Conductive Layer 13 Adhesive Layer 14 Insulating Layer 15 Adhesive 30 Heat Diffusion Member 35 Thermal Diffusion Member 40 Reinforcement Frame 41 Display Unit 42 Touch Panel Unit 46 Housing 47 Thermal Conduction 48 Substrate 49 Battery 50 Lid 81 Case 82 Printed wiring board 83 Heat-generating component 84 Component 85 Heat diffusion member 91 Heat diffusion layer 92 Heat insulation layer 93 Heat conduction layer

Claims (10)

In a heat diffusing member mounted on an electronic device including a housing in which a plurality of electronic components are mounted, and a lid that is provided at least at a part of the lower portion of the housing and is removable from the housing,
A high thermal conductivity layer having high thermal conductivity;
A low thermal conductivity layer superimposed on the high thermal conductivity layer and having a low thermal conductivity,
The low thermal conductive layer is contacted or adhered to the lower surface in the casing excluding the lid,
A heat diffusing member, characterized in that a high heat conductive stretched portion that extends the high heat conductive layer and is bent substantially at right angles contacts or adheres to the electronic component or structure provided in the housing. 2. The thermal diffusion according to claim 1, wherein an adhesive is applied to a side surface portion of the superposed high thermal conductive layer and the low thermal conductive layer to join the high thermal conductive layer and the low thermal conductive layer. Element. The adhesive layer is provided between one surface of the high thermal conductive layer and the one surface of the low thermal conductive layer, and the high thermal conductive layer and the low thermal conductive layer are joined by the adhesive layer. The thermal diffusion member according to 1 or 2. The heat diffusing member according to claim 1, wherein the material of the high thermal conductive layer is graphite. The material of the low thermal conductive layer is a combination of at least two of a foam material containing silica glass fiber, ceramic or air layer, or a foam material containing silica glass fiber, ceramic and air layer. The heat diffusing member according to claim 1, wherein the heat diffusing member is a heat diffusing member. A housing with a plurality of electronic components inside,
A lid provided on at least a part of the lower portion of the housing and removable from the housing;
A high thermal conductivity layer having high thermal conductivity;
A low thermal conductivity layer superimposed on the high thermal conductivity layer and having a low thermal conductivity,
The low thermal conductive layer is contacted or adhered to the lower surface in the casing excluding the lid,
An electronic apparatus, wherein a high heat conductive stretched portion that extends the high heat conductive layer and is bent substantially at right angles contacts or adheres to the electronic component or structure provided in the housing. The electronic device according to claim 6, wherein a material of the housing is a combination of metal, resin, or carbon fiber, or at least two of metal, resin, and carbon fiber. The electronic apparatus according to claim 6, wherein the structure is a reinforcing frame or a display unit that supports the housing. 9. The electronic apparatus according to claim 6, wherein the material of the structure is a metal, a resin, or a carbon fiber, or a combination of at least two of a metal, a resin, and a carbon fiber. The lid is removed from the housing when the rechargeable battery is inserted into the housing or the rechargeable battery is taken out from the housing. Electronic equipment.

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