JPH06268113A - Heat radiating member for electronic apparatus - Google Patents

Abstract

PURPOSE:To obtain a heat radiating member which can be strongly stuck to an electronic part, enclosure, etc., and has an efficient heat transferring effect without performing any special processing, lamination, etc. CONSTITUTION:The title member 10 is formed by enclosing a fibrous metallic material 11 formed by processing a metallic material into a fibrous state and entwining the fibrous metallic material and an inert gas 12 with which the voids between the entwined metallic material 11 are filled in a soft sheet-like outer bag 13 having a good thermal conductivity and an insulating property. The member 10 is set between heat-generating electronic parts, such as the semiconductor chip, resistor 2, etc., and an enclosure 4 and between the rear surface of a substrate 3 and the enclosure 4. The heat generated from the heat- generating electronic parts is transferred to the bag 13 directly or through the substrate 3 and further transferred to the metallic material 11. Finally, the heat is transferred to the enclosure 4 through the bag 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat dissipating member for use in an electronic device in which various electronic parts are housed in a housing and for transferring heat generated from the electronic parts to the housing.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 3 and 4, for example, various electronic components such as a semiconductor chip 1 and a resistor 2 are mounted on a printed wiring board 3 and housed in a housing 4.
For example, there are electronic devices such as a power supply unit and a motor driver unit.

In this type of electronic equipment, the heat generated from the heat-generating electronic components such as the semiconductor chip 1 and the resistor 2 is transferred to the outside by being transmitted to the housing 4 formed of aluminum or the like. Therefore, as a heat dissipation member for transmitting heat from the heat generating electronic component to the housing 4, for example,
The liquid heat sink 5 shown in FIG. 3 or the heat conductive sheet 8 shown in FIG. 4 is used.

First, the liquid heat sink 5 is a resin bag 7 filled with an electrically insulating liquid 6, and the liquid heat sink 5 is placed between the heat-generating electronic component on the surface of the substrate 3 and the housing 4. To place. The liquid 6 is convected by the heat from the heat-generating electronic component, and the heat is transferred to the housing 4.

The heat-conducting sheet 8 is made of heat-conductive plastic, rubber or the like. The heat-conducting sheet 8 is provided between the heat-generating electronic component on the surface of the substrate 3 and the housing 4. And between the back surface of the substrate 3 and the housing 4.
Heat from the heat-generating electronic component and the substrate 3 is transferred to the housing 4 via the heat conductive sheet 8.

[0006]

However, in the liquid heat sink 5, since the bag 7 filled with the liquid 6 is deformed, the liquid heat sink 5 has high adhesion to the heat-generating electronic components, the substrate 3 and the housing 4, and the like. Since the heat transfer is due to the convection of the liquid 6, a sufficient heat transfer effect cannot always be obtained. Also, heat from the back surface of the substrate 3 needs to be efficiently transferred to the housing 4, but the liquid heat sink 5 that uses heat transfer by convection of the liquid 6 transfers this heat to the substrate 3.
Almost no effect could be expected even if it was placed on the back surface of. Further, as a problem peculiar to the liquid heat sink 5 in which the bag 6 is filled with the liquid 6, there is a risk of leakage of the liquid 6 due to breakage of the bag 7.

On the other hand, the heat conduction sheet 8 has a higher heat conduction effect than the liquid heat sink 5 because it transfers heat between solids, but on the other hand, the precision of adhesion to the heat-generating electronic components, the substrate 3 and the housing 4 is high. Was hard to get. That is, in order to bring the heat conductive sheet 8 into close contact with electronic parts,
It was necessary to process (8a) or partially laminate (8b) according to the dimension.

Therefore, the present invention provides a heat dissipating member for electronic equipment, which can obtain high adhesion to electronic parts, housings, etc. without any special processing or lamination and can obtain an efficient heat conduction effect. The purpose is to provide.

[0009]

In order to achieve the above object, the present invention provides a heat dissipation member for an electronic device for transmitting heat generated from an electronic component inside a casing to the casing. A non-bulk metal material capable of changing its shape and a gas filled between the metal materials are sealed in a flexible outer bag having good heat conductivity and insulation.

It is preferable that the metal material is entwined with a fibrous metal material, and the gas is preferably an inert gas.

[0011]

According to the present invention configured as described above, the heat generated from the heat-generating electronic components such as the semiconductor chip and the resistor is
It is transmitted to the outer bag directly or through the substrate, is transmitted to the metal material, and is transmitted to the housing through the outer bag. The heat transfer by the metal material is not the heat transfer by the convection of the liquid but the heat transfer between the metal solids having a very high thermal conductivity, so that the heat transfer effect is extremely high. Further, the heat from the back surface of the substrate can be efficiently transferred to the housing.
However, since the heat dissipation member can be changed in shape by enclosing the metal material and the gas in the outer bag, the heat dissipation member is highly compatible with heat-generating electronic components, housings, etc. without performing dimension matching processing or partial lamination. Adhesion is obtained and there is no risk of liquid leakage.

It should be noted that the non-agglomerate metallic material capable of changing its shape and the gas filled between the metallic materials ensure a predetermined volume occupied by the flexible outer bag. If a metal material entwined with a fibrous metal material is used, the weight can be further reduced and the volume can be secured, and the shape can be changed more easily. Furthermore, when an inert gas is used as the gas to be enclosed, the metal material can be prevented from being oxidized, as compared with the case where air is enclosed.
It is possible to select an inert gas with a higher thermal conductivity.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a heat dissipation member according to the present invention will be described below with reference to FIGS. In the electronic device using the heat dissipation member, components corresponding to those in the conventional example are designated by the same reference numerals and the description thereof will be omitted.

First, as shown in FIG. 1, in a housing 4 of an electronic device, between a housing 4 and a heat-generating electronic component such as a semiconductor chip 1 or a resistor 2 on the surface of a printed wiring board 3, and a print. The heat dissipation member 10 is arranged between the back surface of the wiring board 3 and the housing 4.

As shown in FIG. 2, the heat dissipating member 10 is formed by enclosing a fibrous metal material 11 and an inert gas 12 in an outer bag 13. The fibrous metal material 11 is, for example, a metal material such as aluminum or copper which is processed into a fibrous shape and entangled with each other, whereby the shape can be changed. The inert gas 12 is, for example, N ₂ or the like, and is filled between the fibrous metal materials 11. Furthermore, the outer bag 13
Is a flexible sheet-like bag having good thermal conductivity and insulation, and is made of, for example, polyimide resin.

According to the heat dissipating member 10 constructed as described above, the heat generated from the heat-generating electronic components such as the semiconductor chip 1 and the resistor 2 is transferred to the outer bag 13 directly or through the substrate 3, and the fiber It is transmitted to the metal member 11 and then transmitted to the housing 4 through the outer bag 13.

The heat transfer by the fibrous metal material 11 is not the heat transfer by the convection of the liquid such as the liquid heat sink 5 (see FIG. 3), but the heat transfer between the metal solids having a very high heat conductivity. Therefore, the heat conduction effect becomes extremely high. In addition, the heat from the back surface of the substrate 3 is also efficiently used by the housing 4
Can be transmitted to.

However, since the heat dissipation member 10 can be changed in shape by enclosing the fibrous metal material 11 and the inert gas 12 in the outer bag 13, the heat dissipation member 10 can be changed like the heat conduction sheet 8 (see FIG. 4). It is possible to obtain high adhesion to the heat-generating electronic component, the housing 4, etc. without performing dimension matching processing or partial lamination, and there is no risk of liquid leakage.

In this embodiment, since the metal material entwined with the fibrous metal material 11 is used, the weight can be further reduced and the volume can be secured, and the shape can be changed more easily. You can Furthermore, since the inert gas 12 is used as the gas to be enclosed, oxidation of the fibrous metal material 11 can be prevented as compared with the case where air is enclosed, and heat can be generated by selecting an inert gas having a higher thermal conductivity. The conduction effect can be further enhanced.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various effective modifications and applications are possible based on the technical idea of the present invention. . For example, as the metal material to be enclosed in the outer bag, other than the fiber metal material entangled in the embodiment, the same linear metal material entangled, the foil metal material is rolled and wrinkled Various modifications are possible.

[0021]

As described above, according to the present invention,
By enclosing the metal material and gas in the outer bag, the adhesion to the heat-generating electronic parts and the case is extremely high without any special processing or partial lamination. It is possible to obtain a heat dissipation member for an electronic device that exhibits the above.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an electronic device using a heat dissipation member according to an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of the heat dissipation member.

FIG. 3 is a cross-sectional view of an essential part of an electronic device using a conventional liquid heat sink.

FIG. 4 is a sectional view of an essential part of an electronic device using a conventional heat conductive sheet.

[Explanation of symbols]

 1 Semiconductor Chip 2 Resistor 3 Printed Wiring Board 4 Housing 10 Heat Dissipating Member 11 Fibrous Metal Material 12 Inert Gas 13 Outer Bag

Claims (3)

[Claims] 1. A heat-dissipating member for an electronic device for transmitting heat generated from an electronic component inside a housing to the housing, the non-bulk metal material capable of changing shape, and the metal. A heat-dissipating member for electronic equipment, characterized in that a gas filled between the materials is enclosed in a flexible outer bag having good thermal conductivity and insulation. 2. The heat dissipating member for electronic equipment according to claim 1, wherein the metal material is formed by entwining a fibrous metal material. 3. The heat dissipation member for an electronic device according to claim 1, wherein the gas is an inert gas.