JP2015138825A - Thermal insulation structure of electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal insulation structure of an electronic device which enables the achievement of a relatively high thermal insulation effect while suppressing the rise in manufacturing costs.SOLUTION: A thermal insulation structure of an electronic device comprises: a substrate with a heating part mounted thereon; a housing for enclosing the substrate; and a thermal insulation sheet disposed in position in an inner face of the housing to be opposed to the heating part with a gap held between the thermal insulation sheet and the heating member. The thermal insulation sheet includes: a metal layer stuck to the inner face of the housing through a bonding layer; and a surface layer laminated over the metal layer. The surface layer is composed of a transparent resin layer laminated over the metal layer directly or through a second bonding layer. The surface layer has a thickness of 1-10 μm.

Description

  The present invention relates to a heat shield structure for an electronic device.

  The temperature inside the equipment rises due to the heat generated with the increase in the density of electronic equipment and the reduction of the heat dissipation area due to the downsizing of the electronic equipment, resulting in a decrease in product life, malfunctions, and low-temperature burns. It has become. In particular, thin electronic devices such as smartphones, tablet-type personal digital assistants, and laptop computers may be used in contact with parts of the user's body (for example, palms and thighs), so low-temperature burn countermeasures can be taken. It is important.

“Low-temperature burn” is a phenomenon in which muscles, blood, etc. are necrotic when touching the same part of the skin for a long time even at a relatively low temperature. It is said that the onset is caused by contact at 46 ° C. for 0.5 to 1 hour and at 50 ° C. for 2 to 3 minutes.
For this reason, a heat dissipation sheet is generally provided between an electronic component that generates heat (hereinafter referred to as “heat generating component”) and a housing in order to prevent a user from getting a low-temperature burn while using the electronic device.

  One type of such heat dissipation sheet is a heat shield sheet. Aluminum foil is mainly used, and the temperature of the outer surface of the housing reflects the radiant heat from the heat generating components by sticking the aluminum foil through the adhesive layer on the inner surface of the housing facing the heat generating components. The rise was suppressed (prior art 1).

  Further, in Patent Document 1, in a thin electronic device having a substrate on which a heat generating component is mounted and a housing for housing the substrate, a heat insulating sheet having a multilayer structure is provided at a position facing the heat generating component on the inner surface of the housing. A pasted heat shield structure has been proposed (prior art 2).

  The heat shield sheet in the prior art 2 is laminated on the heat insulating sheet via a heat insulating sheet attached to the inner surface of the casing of the electronic device via an adhesive layer and a first adhesive layer such as a double-sided tape or an adhesive. The heat conductive sheet and a protective layer laminated on the heat conductive sheet via a second pressure-sensitive adhesive layer such as a double-sided tape or a pressure-sensitive adhesive, and are disposed to face the heat-generating component with a gap.

  In the heat shielding sheet, a non-woven fabric or a foam resin is used as the heat insulating sheet, a pyrolytic graphite sheet is used as the heat conductive sheet, and a PET film or an aluminum sheet is used as the protective layer.

JP 2012-151196 A

  The heat shield sheet described in the prior art 2 has a six-layer structure in which an adhesive layer, a heat insulating sheet, a first pressure-sensitive adhesive layer, a heat conductive sheet, a second pressure-sensitive adhesive layer, and a protective layer are sequentially laminated from the housing side. is there. Since the heat shielding sheet has a large number of layers, the number of manufacturing steps is large, the material cost is increased, and an expensive pyrolytic graphite sheet is used as the heat conductive sheet, which increases the manufacturing cost.

  This invention is made | formed in view of such a subject, and it aims at providing the thermal-insulation structure of the electronic device which can obtain a comparatively high thermal-insulation effect, suppressing the raise in manufacturing cost.

Thus, according to the present invention, the substrate having the mounted heat generating component, the housing for housing the substrate, and the inner surface of the housing facing the heat generating component and disposed with a gap from the heat generating member. With a thermal insulation sheet,
The heat shield sheet is composed of a metal layer attached to the inner surface of the housing via a bonding layer, and a surface layer laminated on the metal layer,
The surface layer is composed of a transparent resin layer laminated directly on the metal layer or via a second bonding layer,
Provided is a heat shield structure for an electronic device, wherein the surface layer has a thickness of 1 to 10 μm.

    In the heat shield structure of the electronic device of the present invention, heat from the heat generating component is not transmitted to the heat shield sheet mainly as heat conduction or convection, but radiant heat radiated from the heat generating component is transmitted to the heat shield sheet. A part of the radiant heat from the heat generating component is transmitted through the transparent resin layer, hits the metal layer and is reflected to the heat generating component side, and a part of the radiant heat from the heat generating component is absorbed by the transparent resin layer. Further, part of the absorbed energy of the transparent resin layer that has absorbed the radiant heat is radiated to the heat generating component side as radiant heat.

At this time, since the surface of the metal layer is covered with the transparent resin layer, the metal layer surface is prevented from being oxidized and a high reflectance over a long period of time is maintained. In addition, radiant heat is hardly absorbed by the transparent resin layer having a thickness of 10 μm or less and is transparent, and most of the absorbed energy absorbed by the transparent resin layer is radiated as radiation energy from the surface of the transparent resin layer.
According to the heat shielding structure of the electronic device of the present invention, the local temperature rise on the outer surface on the opposite side of the heat shielding sheet pasting region on the inner surface of the housing is suppressed to be lower than that in the related art 1 due to such an action.

In addition, since the heat shield sheet in the present invention has a three-layer or four-layer structure, the number of layers is reduced as compared with the prior art 2, and an expensive material such as a pyrolytic graphite sheet is not used. Can achieve a significant cost reduction.
Thus, according to the heat shield structure of the electronic device of the present invention, a high heat shield effect can be obtained while suppressing an increase in manufacturing cost.

  Furthermore, according to the heat insulating structure of the electronic device of the present invention, the use of the insulating transparent resin layer prevents a problem that the heat insulating sheet is short-circuited even if it contacts the heat-generating component.

It is an expanded sectional view which shows Embodiment 1 of the heat insulation structure of the electronic device which concerns on this invention. It is a graph which shows a temperature change at the time of the space | gap of 1.0 mm of Example 2, 4 and Comparative Examples 2-4. It is a graph which shows the relationship between the surface layer thickness in Example 1, 2, 4 and Comparative Examples 2-4 when the space | gap is 1.0 mm, and average temperature. It is a graph which shows the relationship between temperature and the time when low temperature burns occur.

The heat-insulating structure for an electronic device according to the present invention includes a substrate having a mounted heat-generating component, a housing that houses the substrate, a position on the inner surface of the housing that faces the heat-generating component, and the heat-generating member. With a heat shield sheet arranged with a gap,
The heat shield sheet is composed of a metal layer attached to the inner surface of the housing via a bonding layer, and a surface layer laminated on the metal layer,
The surface layer is composed of a transparent resin layer laminated directly on the metal layer or via a second bonding layer,
The surface layer has a thickness of 1 to 10 μm.

  The electronic device targeted by the present invention is, for example, a thin electronic device such as a smartphone, a tablet-type portable information terminal, or a notebook computer, and the heat shielding structure of the present invention is suitably employed for such a thin electronic device.

In the present invention, the metal resin laminate of the metal layer and the transparent resin layer constituting the heat shield sheet is, for example, laminated on the metal sheet via an adhesive or an adhesive, or on the transparent resin film It can be manufactured by a known technique such as vapor deposition of a metal film.
Moreover, it attaches in the state which at least one part of the heat shield sheet contacted directly or indirectly to the housing inner surface. In this case, by applying an adhesive or a pressure-sensitive adhesive to at least a part of the surface of the metal layer opposite to the transparent resin layer, the metal layer is in direct or indirect contact with the inner surface of the housing and is displaced. It can be fixed without doing.

In the present invention, the material of the metal layer of the heat shield sheet is preferably a metal having a high reflectance to radiant heat and a high thermal conductivity. For example, silver (Ag), copper (Cu), aluminum (Al), gold ( Au), platinum (Pt), rhodium (Rh), nickel (Ni), and the like, and copper or aluminum is preferable in view of cost.
The thickness of the metal layer is preferably a thickness compatible with thin film properties, high heat shielding effect, and excellent thermal diffusivity in the lateral direction, specifically preferably 10 to 100 μm, more preferably 25 to 75 μm, More preferably, it is 35-50 micrometers.

As a material for the transparent resin layer, a transparent resin having high radiation heat permeability and high heat resistance is preferable. For example, polyethylene terephthalate (PET), biaxially stretched polypropylene (OPP), polyethylene naphthalate (PEN), and the like. Can be mentioned.
The thickness of the transparent resin layer is preferably as thin as possible and can provide a high heat shielding effect, specifically 1 to 10 μm is preferable, 2.5 to 6 μm is more preferable, and 3.5 to 4. 5 μm is more preferable.

In the present invention, the thickness (total thickness) of the heat shield sheet is preferably 16 to 130 μm, more preferably 30 to 100 μm, and still more preferably 45 to 65 μm.
In the present invention, the distance of the gap between the heat shield sheet and the heat generating component is suitably a distance that the heat generating component is not too close and not too far from the heat shield sheet so as to obtain a high heat shield effect. Is 10 to 1000 μm.

  Hereinafter, embodiments of a heat shielding structure for an electronic device according to the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing Embodiment 1 of a heat shield structure for an electronic device according to the present invention.
As shown in FIG. 1, the heat insulating structure of the electronic device according to the present invention includes a substrate 1 having a mounted heat generating component 2, a housing 3 for housing the substrate 1, and a heat generating component on the inner surface of the housing 3. 2 and a heat shield sheet 10 affixed to the heat shield sheet affixing area A facing the heat shield sheet 10. In the heat shield structure of the electronic device, a gap G is provided between the heat shield sheet 10 and the heat generating component 2. That is, the gap L1 between the heat shield sheet pasting area A of the housing 3 and the heat generating component 2 is set wider than the thickness T of the heat shield sheet 10 so that the heat shield sheet 10 does not contact the heat generating component 2. Yes.

  The heat shield sheet 10 includes a metal layer 11 attached on the heat shield sheet attachment region A via the first bonding layer 12 and a transparent resin layer laminated on the metal layer 11 via the second bonding layer 14. 13 is a metal resin laminate. In the first embodiment, the heat shield sheet 10 has a thickness (total thickness) T of 42 to 82 μm.

In the first embodiment, copper or aluminum is used as the material of the metal layer 11, and the thickness T ₁ is 35 to 50 μm.
In the first embodiment, PET or OPP is used as the material of the transparent resin layer 13, and the thickness T ₃ is set to 3.5 to 4.5 μm.

As materials for the first and second bonding layers 12 and 14, acrylic, polyester, urethane, silicone, or rubber-based adhesives and adhesives are used in the first embodiment. The thickness T ₂ is 5 to 40 μm, and the thickness T ₄ of the second bonding layer 14 is 1.5 to 5.5 μm.

  In the case of the first embodiment, the first adhesive layer 12 is entirely laminated on one surface of the metal layer 11, but may be partially laminated as long as the necessary minimum bonding strength is ensured. In the case of the first embodiment, the second adhesive layer 14 is entirely laminated between the metal layer 11 and the transparent resin layer 13, but is partially laminated if the necessary minimum bonding strength is ensured. May be.

  In the heat shield structure of Embodiment 1 configured as described above, the thickness of the heat shield sheet 10 is 42 to 82 μm, and the inner surface (heat shield sheet pasting region) of the housing 3 and the heat generating component 2 at this time The distance L1 between the gaps can be set to 0.1 to 1.0 mm, and the distance L2 of the gap G between the heat shield sheet 10 and the heat generating component 2 can be set to 18 to 958 μm.

(Embodiment 2)
In the heat shield sheet 10 of Embodiment 1 shown in FIG. 1, the second bonding layer 14 may be omitted. In this case, after the metal layer 11 is vapor-deposited on one surface of the transparent resin layer 13, the heat shielding sheet 10 is applied by applying the first bonding layer 12 to the surface of the metal layer 11 opposite to the surface on the transparent resin layer 13 side. Can be made.

(Embodiment 3)
In FIG. 1, the heat shield sheet affixing area A of the housing 3 is set at a position facing one heat-generating component 2, and a heat shield sheet 10 having a size slightly larger than the heat shield sheet affixing area A is attached to the housing 3. Although the case where it affixed was illustrated, this invention is not limited to this. For example, when a plurality of heat generating components are mounted on the substrate 1, there are a plurality of heat shielding sheet pasting areas, and therefore the heat shielding sheet has a size and shape that can cover the plurality of heat shielding sheet pasting areas with one sheet. May be formed.

<Preparation of acrylic adhesive>
n-butyl acrylate: 91 parts by weight, acrylic acid: 8 parts by weight, 2-hydroxyethyl methacrylate: 1 part by weight, polymerization initiator azobisisobutyronitrile (AIBN): 0.2 part by weight, and solvent (ethyl acetate , Toluene): 150 parts by weight were reacted in a nitrogen stream at 85 ° C. for 5 hours to obtain an acrylic pressure-sensitive adhesive having a resin content of 40% and a viscosity of 7000 Pa · s.

<Production of heat shield sheet>
Acrylic pressure-sensitive adhesive: 100 parts by weight of isocyanate-based cross-linking agent (Coronate (registered trademark) L-55E: manufactured by Nippon Polyurethane): 1 part by weight, and after stirring, defoamed to obtain an acrylic pressure-sensitive adhesive composition Obtained.
Next, an acrylic pressure-sensitive adhesive composition was applied to a release liner at a predetermined thickness, dried at 100 ° C. for 2 minutes, and then a copper foil (GTS: Furukawa) having a size of 60 mm × 30 mm and a thickness of 35 μm as a metal layer. The product was transferred to an electric industry Co., Ltd. to obtain “copper foil / acrylic adhesive layer / release liner”. This process was repeated to obtain “release liner / acrylic pressure-sensitive adhesive layer / copper foil / acrylic pressure-sensitive adhesive layer / release liner”.

  Then, one of the release liners is peeled off, and a PET film (Lumirror (registered trademark): manufactured by Toray Industries, Inc.) as a transparent resin layer is bonded to form “PET / acrylic adhesive layer (second bonding layer) / copper foil. / Acrylic pressure-sensitive adhesive layer (first bonding layer) / release liner "was prepared and cured at 40 ° C. for 3 days to obtain heat shield sheets of Examples 2 to 4 and Comparative Examples 3 to 4. In Examples 2-4 and Comparative Examples 3-4, the thickness of the PET film, the thickness of the acrylic adhesive layer between the PET film and the copper foil, and the thickness of the other acrylic adhesive layer are The thicknesses shown in Table 1 were set. Example 1 will be described later.

  An OPP film (Treffan (registered trademark): manufactured by Toray Industries, Inc.) was used in place of the PET film, and thermal insulation sheets of Example 5 and Comparative Example 5 were obtained in the same manner as in Examples 2-4. In Example 5 and Comparative Example 5, the thickness of the OPP film, the thickness of the acrylic pressure-sensitive adhesive layer between the OPP film and the copper foil, and the thickness of the other acrylic pressure-sensitive adhesive layer are shown in Table 1. Each was set to the indicated thickness.

Thermal insulation sheet of Example 6 and Comparative Example 6 using polyester adhesive layer instead of acrylic adhesive layer as second bonding layer between PET film and copper foil in the same manner as Examples 2-4 Got. In Example 6 and Comparative Example 6, the thickness of the PET film, the thickness of the polyester-based adhesive layer (second bonding layer), and the thickness of the acrylic pressure-sensitive adhesive layer (first bonding layer) are shown in Table 1. Each thickness was set as shown in FIG.
The polyester-based adhesive composition used as the material for the polyester-based adhesive layer is a polyester-based adhesive (Dick Dry LX-500: manufactured by DIC Graphics Co., Ltd.): 100 parts by weight and a curing agent (KW-75 : DIC Graphics Co., Ltd.): 50 parts by weight, 200 parts by weight of ethyl acetate as a diluting solvent was added, and after stirring, the foam was removed.

In place of the acrylic adhesive layer as the second bonding layer between the PET film and the copper foil, a polyether-based adhesive layer was used, and the heat shield sheet of Example 7 was obtained in the same manner as in Examples 2-4. . In Example 7, the thickness of the PET film, the thickness of the polyether-based adhesive layer (second bonding layer), and the thickness of the acrylic pressure-sensitive adhesive layer (first bonding layer) are shown in Table 1. Each thickness was set.
The polyether-based adhesive composition used as the material for the polyether-based adhesive layer is a polyether-based adhesive (Dick Dry LX-401A: manufactured by DIC Graphics Corporation): 100 parts by weight of a curing agent ( SP-60: manufactured by DIC Graphics Co., Ltd.): 100 parts by weight, 250 parts by weight of ethyl acetate as a diluting solvent was added, and the mixture was stirred and degassed.

In place of the acrylic pressure-sensitive adhesive layer as the first bonding layer, a silicone pressure-sensitive adhesive layer was used, and a heat shield sheet of Example 8 was obtained in the same manner as in Examples 2 to 4. At this time, in Example 8, the thickness of the PET film, the thickness of the acrylic pressure-sensitive adhesive layer (second bonding layer), and the thickness of the silicone pressure-sensitive adhesive layer (first bonding layer) are shown in Table 1. Each thickness was set.
The silicone pressure-sensitive adhesive composition used as the material for the silicone-based pressure-sensitive adhesive layer is a silicone pressure-sensitive adhesive (TSR1512: manufactured by Momentive Performance Materials Japan GK): 100 parts by weight, and a curing agent (CR50: momentary). -Performance Materials Japan GK): 1 part by weight was added, stirred and degassed.

A heat-shielding sheet of Example 9 was obtained in the same manner as in Examples 2 to 4, using a rubber-based pressure-sensitive adhesive layer instead of the acrylic pressure-sensitive adhesive layer as the first bonding layer. At this time, in Example 9, the thickness of the PET film, the thickness of the acrylic pressure-sensitive adhesive layer (second bonding layer), and the thickness of the rubber-based pressure-sensitive adhesive layer (first bonding layer) are shown in Table 1. Each thickness was set.
Note that GR-1134 manufactured by Big Technos Co., Ltd. was used as the rubber-based pressure-sensitive adhesive composition as a material for the rubber-based pressure-sensitive adhesive layer.

  Instead of the copper foil as the metal layer, an aluminum foil (A1N30: manufactured by Nihon Foil Co., Ltd.) was used, and the heat shield sheets of Examples 11 and 12 and Comparative Examples 9 and 10 were used in the same manner as in Examples 2-4. Obtained. At this time, in Examples 11 and 12 and Comparative Examples 9 and 10, the thickness of the PET film, the thickness of the acrylic adhesive layer (second bonding layer), the thickness of the aluminum foil, the acrylic adhesive layer (first The thickness of one bonding layer was set to the thickness shown in Table 1.

  The polyester adhesive composition is applied to a release liner and dried to form a polyester adhesive layer (transparent resin layer), and then a copper foil (metal layer) is bonded to the polyester adhesive layer. On the opposite surface, an acrylic pressure-sensitive adhesive layer (first bonding layer) was laminated in the same manner as described above to obtain the heat shield sheet of Example 1. At this time, in Example 1, the thickness of the polyester-based adhesive layer, the thickness of the copper foil, and the thickness of the acrylic pressure-sensitive adhesive layer were set to the thicknesses shown in Table 1, respectively.

<Evaluation method of heat shield sheet>
An ABS case having a size of 95 mm × 55 mm, a height of 20 mm, and a thickness of 2 mm was used as the housing, and the heat shield sheet from which the release liner was peeled was attached to the inner surface of the ABS case. This heat shield sheet is that of the above-mentioned Examples and Comparative Examples.
On the other hand, a glass epoxy substrate to which a heater having a size of 50 mm × 25 mm (manufactured by Nippon Heater) was joined was disposed in the housing so that the heater faced the heat shield sheet. At this time, the gap distance L1 between the inner surface of the ABS case and the heater was set to 0.1 mm, 0.4 mm, and 1.0 mm (see FIG. 1).

  Heat the heater with the thermocouple attached to the outer surface of the ABS case opposite to the heat shield sheet, measure the temperature of the outer surface of the ABS case, and the average temperature after 20-40 minutes when the case outer surface temperature has stabilized Are shown in Table 2. At this time, the heater output was set to 3W and 1W.

  Further, as shown in Table 1, Comparative Example 1 in which no heat shielding sheet is provided, and Comparative Example 2 in which the heater output is set to 3 W and 1 W using a heat shielding sheet obtained by laminating only an acrylic pressure-sensitive adhesive layer on copper foil. 7 and Comparative Example 9 in which a heater output was set to 1 W using a heat shielding sheet obtained by laminating only an acrylic pressure-sensitive adhesive layer on an aluminum foil, the temperature was measured, and the results are shown in Table 2.

  Moreover, about each Example and each comparative example, the clearance gap between a heat shield sheet and a heater when the distance L1 of the space | gap between an ABS case inner surface and a heater is 0.1 mm, 0.4 mm, and 1.0 mm The distance L2 is shown in Table 3 (see FIG. 1).

In Table 2, “difference” refers to the temperature differences of Examples 1 to 9 and Comparative Examples 3 to 6 with respect to the temperature of Comparative Example 2, the temperature difference of Example 10 and Comparative Example 8 with respect to the temperature of Comparative Example 7, It means the temperature difference between Examples 11 and 12 and Comparative Example 10 with respect to the temperature of Comparative Example 9, and if these temperature differences are positive values, heat dissipation is inferior, and “Evaluation” is marked as I, with negative values. “Evaluation” is described as “II” because heat dissipation is excellent.

<Result>
Comparing Comparative Examples 1 and 2, in the case of Comparative Example 1 in which the heat shield sheet is not provided in the ABS case, the outer surface temperature of the housing is 80.0 ° C., whereas the heat shield sheet having a total thickness of 40 μm (bonding layer) The outer surface temperature of Comparative Example 2 provided with + metal layer was 71.8 ° C. That is, it was confirmed that the outer surface temperature of the casing can be lowered by 8.2 ° C. by the heat shielding sheet of Comparative Example 2, and that the heat shielding sheet having a simple structure is effective for suppressing the temperature rise.

  Next, with reference to Comparative Example 2, the results of Examples and Comparative Examples in which a transparent resin layer is laminated on the metal layer of the heat shield sheet used in Comparative Example 2 via the second bonding layer will be described.

FIG. 2 is a graph showing a change in temperature when the gaps of Examples 2 and 4 and Comparative Examples 2 to 4 are 1.0 mm, and FIG. It is a graph which shows the relationship between the surface layer thickness in case of 0 mm, and average temperature.
As shown in FIGS. 2 and 3, Examples 1, 2, and 4 in which a surface layer made of an acrylic pressure-sensitive adhesive layer and a PET film was laminated on a copper foil were compared without having a surface layer on the copper foil. The effect of suppressing the temperature rise was superior to that of Example 2. Moreover, the comparative examples 3 and 4 which made the thickness of the surface layer on copper foil thicker than 10 micrometers raised the temperature rather than the comparative example 2 which does not have a surface layer.

  Non-oxidized metal reflects heat rays with high efficiency, so if a material with high emissivity is laminated on the metal surface, it absorbs heat rays easily and contributes to temperature rise, and radiation energy from the surface layer also increases. This contributes to a decrease in temperature. That is, the temperature suppression effect is determined by the magnitude of absorbed energy and radiant energy.

  In the case of Examples 1, 2, and 4, where the thickness of the surface layer is as thin as 10 μm or less, the radiation energy is larger than the absorbed energy. Probably higher. On the other hand, in the case of Comparative Examples 3 and 4 where the thickness of the surface layer is thicker than 10 μm, it is considered that the temperature suppression effect is lower than that of Comparative Example 2 because the absorbed energy is larger than the radiant energy.

  This tendency was the same in Example 3, and the same was true when the gap distance L1 in Examples 1, 2, 4 and Comparative Examples 2 to 4 was 0.1 mm and 0.4 mm. Furthermore, it is the same even if it changes the material of a transparent resin layer, a 2nd joining layer, or a 1st joining layer like Examples 5-9 and Comparative Examples 5 and 6, Examples 10-12 and Comparative Examples 7- The result was the same even when the heater output was reduced as shown in FIG.

Fig. 4 is a graph showing the relationship between temperature and the time at which low temperature burns occur (from Kenji Sasaki "Never Burning Low Temperature Burns", NHK Today's Health 2003.1, 102-106).
From FIG. 4, it can be seen that the time at which low temperature burns occur exponentially decreases as the temperature of the heat source increases, and increases exponentially as the temperature of the heat source decreases.
Therefore, even if the surface temperature of a thin portable electronic device is reduced by only 1 ° C., it is a great advantage for suppressing low-temperature burns. Therefore, it can be said that the heat shielding effect by the heat shielding structure of the electronic device of the present invention is effective. .

  It should be understood that the disclosed embodiments and examples are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The heat insulation structure of the electronic device of the present invention is suitable for thin portable electronic devices such as smartphones, tablet personal digital assistants, and notebook personal computers.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Heat-emitting component 3 Housing | casing 10 Heat insulation sheet 11 Metal layer 12 1st joining layer 13 Transparent resin layer 14 2nd joining layer A Heat insulation sheet sticking area G Gap

Claims (5)

A substrate having a heat-generating component mounted thereon, a housing for housing the substrate, and a heat shield sheet disposed at a position facing the heat-generating component on the inner surface of the housing and with a gap from the heat-generating member,
The heat shield sheet is composed of a metal layer attached to the inner surface of the housing via a bonding layer, and a surface layer laminated on the metal layer,
The surface layer is composed of a transparent resin layer laminated directly on the metal layer or via a second bonding layer,
The thickness of the surface layer is 1 to 10 μm.   The heat shielding structure for an electronic device according to claim 1, wherein the gap is 10 to 1000 μm.   The heat shielding structure for an electronic device according to claim 1 or 2, wherein the heat shielding sheet has a thickness of 16 to 130 µm.   The heat shielding structure for an electronic device according to any one of claims 1 to 3, wherein the metal layer is made of copper or aluminum.   The heat-insulating structure for an electronic device according to any one of claims 1 to 4, wherein the transparent resin layer is made of polyethylene terephthalate or biaxially oriented polypropylene polyethylene.