Shin-etsu Chemical Co., Ltd.

Takita Patent & Engineering

Tokio Sekiya

Takehide Okami

Takeshi Hashimoto

Noboru Shimamoto

Akio Nakano

Tomokazu Washio

A reduction of the surface tackiness of a low-hardness thermally conductive silicone rubber sheet is performed by coating an organohydrogenpolysiloxane oil evenly on a resin film, and pasting together the oil-coated side of the resin film and an addition-cured low-hardness thermally conductive silicone rubber sheet having an Asker C hardness of from 1 to 80. Pasting can be done, for example, by passage between two rolls to supply the organohydrogenpolysiloxane oil to the surface of the silicone rubber sheet. Then, in only the surface part of the sheet, a cross-linking reaction is caused to reduce the tackiness of the sheet surface.

Method of reducing surface tackiness of low-hardness thermally conductive silicone rubber sheet

Thermally conductive composite sheets which comprise a silicone rubber layer which contains thermally conductive fillers and has an Asker C hardness from 5 to 50, and a porous reinforcing material layer which has pores of at least 0.3 mm in diameter and is incorporated within the silicone rubber layer. The thermally conductive composite sheets of the present invention are superior in thermal conductivity and flexibility (for contact towards the electronic parts and so on) and are suitable for mass production and for the assembly process of electronic instruments. Therefore, utilization of the thermally conductive composite sheets enables the effective production of electronic instruments wherein performance degradation caused by heat hardly occurs.

Thermally conductive composite sheets and manufacturing method thereof

A heat conductive BN filler having a cohesive factor of 3-50% is provided. An electrically insulating/heat dissipating sheet is obtained by mixing the BN filler with an organopolysiloxane and a crosslinking agent, shaping the resulting silicone rubber composition into a sheet form, followed by vulcanization. Without special orienting means, the BN particles are oriented in the sheeting step such that their a-axis is perpendicular to the sheet surface.

Heat conductive BN filler and electrically insulating/heat dissipating

The composite silicone rubber sheet comprises a thermal conductive silicone rubber layer, both surfaces of which are tacky, containing a thermal conductive filler such as aluminum oxide and having a Asker C hardness of 5 to 50 and a thickness of 0.4 mm or less; at least one reinforcing sheet such as glass cloth arranged within said silicone rubber layer; and a releasable protective sheet such as a release paper covered on at least one tacky surface of said silicone rubber layer. Since the composite silicone rubber sheet is superior in thermal conductivity and has a good flexibility and tackiness, when used as a heat dissipating insulation sheet, the composite silicone rubber sheet has the advantages of being superior in adherence, free of oil-bleeding, suitable for mass-production, and capable of not lowering workability in assembling electronic parts and the like. The composite silicone rubber sheet is thin and lightweight and has a superior thermal conductivity, so that it can be used in the heat dissipation of a display panel for mounting on motor vehicles, railway vehicles or aircrafts.

Thermal conductive composite silicone rubber sheet

An anti-dust gel sheet characterized in being formed from layers of a silicone gel, having a penetration of 20-130 after curing, coated on both sides of a sheet like reinforcing material is disclosed. Since the sheet has a suitable penetration, damage of the sheet does not easily occur and it can therefore be used repeatedly.

Anti-dust gel sheet

Disclosed is a heat conductive silicone rubber composition comprising a cross-linkable organopolysiloxane composition and a filler, with the filler being magnesium oxide treated so as to have a hydrophobic surface and having a content of from 30 to 70% by volume in the composition.

Heat conductive silicone rubber composition

The invention provides an electrically insulating spacer sheet of a silicone rubber used as sandwiched between a heat-generating electric or electronic device or unit, e.g. power transistor, and a heat radiator capable of dissipating the heat with improved heat conductivity. Different from conventional ones, the inventive spacer sheet has coating layers on both surfaces formed of a non-volatile flowable or deformable silicone material so that the condition of adhesive contacting can be greatly improved and the resistance against thermal flow across the spacer sheet can be decreased very much.

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Gunma-ken, Japan

Tokio Sekiya