JP2006165156A - Thermally conductive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve electric insulating performance in a thermally conductive sheet with respect to the thermally conductive sheet to be used for heat dissipation countermeasures of a heat-generating electronic component such as an LSI. <P>SOLUTION: The thermally conductive sheet 1 has a configuration in which a plurality of small pieces 6 having different sizes and made of a graphite sheet are mixed into an insulating sheet 5 made of a resin. Thus, since the small pieces of graphite sheet are each independently disposed in the insulating sheet, the electric insulating performance can be ensured while utilizing high thermally conductive performance of the graphite sheet. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat conductive sheet used as a heat dissipation measure for heat generating electronic components such as LSI.

  Generally, heat generating electronic components such as LSIs used in hard disks and ICs used in power amplifiers have an adverse effect on products using them as the temperature rises. The heat conductive sheet is provided between the members.

  Therefore, this heat conduction sheet is required to disperse the heat generated locally from the heat-generating electronic component efficiently and over a wide range. Conventionally, carbon having two-dimensional bonding is considered to have such an effect and heat conduction. A graphite sheet with improved properties was used.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
Japanese Patent Laid-Open No. 10-3301177

  However, since the graphite sheet has a structure in which carbon is two-dimensionally bonded, its electrical insulation is low, and it easily interferes electrically with heat-generating electronic components and electronic components that form an electric circuit in the vicinity thereof. There was a problem.

  Then, this invention aims at solving such a problem and improving the electrical insulation in a heat conductive sheet.

  In order to achieve this object, in the present invention, in particular, the heat conductive sheet is configured such that a plurality of small pieces made of graphite sheets are mixed in an insulating sheet made of resin.

  According to this configuration, while utilizing the high thermal conductivity of the graphite sheet, the individual graphite sheet pieces are independently arranged in the insulating sheet, so that electrical insulation can be secured.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross section of a heat conductive sheet 1 according to the present invention. As shown in FIG. 2, a heat generating electronic component 2 such as an IC used in an LSI or a power amplifier and a heat radiating member 3 serving as a heat sink are shown. The heat dissipation effect is enhanced by transferring heat to the heat radiating member 3 while quickly diffusing the heat generated locally from the heat generating electronic component 2 to the in-plane region of the heat conductive sheet 1.

  Among such electronic devices that require the heat generating electronic component 2, in mobile electronic devices such as mobile phones and laptop computers, the performance of the hard disk, the size of the liquid crystal monitor, and the size and height of the device itself are reduced. While being advanced, high-density mounting and high-speed response of various electronic components 4 including the heat-generating electronic component 2 have progressed, and the heat conducting sheet 1 has not only a high heat dissipation effect, but also the heat-generating electronic component 2 and the surrounding electrons. High electrical insulation properties that prevent electrical interference with the component 4 are required.

  Therefore, as shown in FIG. 1, the heat conductive sheet 1 in this embodiment has a structure in which a plurality of pieces of graphite sheet 6 are mixed inside an insulating sheet 5 made of an insulating resin such as silicon, and the heat generating electronic component 2. The heat conductivity from the heat dissipation member 3 to the heat dissipating member 3 and the electrical insulation of the heat generating electronic component 2 and the surrounding electronic component 4 are compatible. The graphite sheet is obtained by carbonizing an organic resin sheet such as polyimide at a temperature of 1200 ° C. or higher, and then graphitizing at a temperature of 2600 ° C. or higher. As shown in FIG. A multi-layered structure having high thermal conductivity in the carbon bonding plane.

  That is, by configuring the heat conductive sheet 1 as shown in FIG. 1, a small piece 6 made of a graphite sheet is covered with an insulating resin that forms the insulating sheet 5, and high heat conduction that is a function of each is obtained. However, since the graphite sheet mixed into the insulating sheet 5 is fragmented, each small piece 6 has electrical conductivity. Since the individual small pieces 6 are separated by the insulating resin forming the insulating sheet 5 and are independent, the structure has a higher electrical insulating property.

  In addition, in order to ensure electrical insulation in the heat conductive sheet 1, in addition to the configuration in which small pieces 6 made of a graphite sheet are mixed in the insulating sheet 5, heat conduction such as natural graphite and ceramics is performed on the insulating sheet 5. It is conceivable that a highly powdery or granular material is mixed, but when the insulating sheet 5 is mixed with a powdery or granular material, the powdery or granular material itself has thermal conductivity by itself. However, since the individual powders or granules in the heat conductive sheet 1 become independent by the insulating resin forming the insulating sheet 5, heat transfer in the in-plane direction of the heat conductive sheet 1 becomes dull. End up.

  On the other hand, when the graphite sheet small piece 6 is mixed in the insulating sheet 5, the small piece 6 itself has a two-dimensional expanse and has a heat conduction effect within the range. High thermal conductivity can be obtained as compared with a mixture containing particles.

  Further, the small pieces 6 can be interposed between the large pieces 6 by making the sizes of the plurality of pieces 6 made of the graphite sheet mixed in the insulating sheet 5 different, and the graphite sheet in the heat conductive sheet 1 can be interposed. Thus, the distribution density of the plurality of small pieces 6 is increased, and the thermal conductivity of the heat conductive sheet 1 can be increased.

  The present invention relates to a heat conductive sheet, has an effect of ensuring high heat conductivity and electrical insulation, and is particularly useful for an electronic device that requires a heat generating electronic component.

Sectional drawing of the heat conductive sheet in one Embodiment of this invention The figure which showed the electronic equipment using the heat conduction sheet typically Schematic diagram of the graphite sheet used for the heat conductive sheet

Explanation of symbols

1 Thermal conductive sheet 5 Insulating sheet 6 Small piece

Claims (1)

A heat conducting sheet comprising a plurality of small pieces of graphite sheets mixed in an insulating sheet made of resin.

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