Thermal conductive sheet

Abstract

A thermal conductive sheet contains a plate-like boron nitride particle. The proportion of the boron nitride particle content is 35 vol % or more, and the thermal conductivity in a direction perpendicular to the thickness direction of the thermal conductive sheet is 4 W/m·K or more.

1 . A thermal conductive sheet comprising a plate-like boron nitride particle, wherein
 the proportion of the boron nitride particle content is 35 vol % or more, and   the thermal conductivity in a direction perpendicular to the thickness direction of the thermal conductive sheet is 4 W/m·K or more.   
     
     
         2 . The thermal conductive sheet according to  claim 1 , wherein the boron nitride particle has an average particle size as measured by a light scattering method of 20 μm or more. 
     
     
         3 . The thermal conductive sheet according to  claim 1 , wherein no fracture is observed in the thermal conductive sheet when the thermal conductive sheet is evaluated in a bend test in conformity with the cylindrical mandrel method of JIS K 5600-5-1 with the test conditions below:
 Test Conditions:
 Test Device: Type I 
 Mandrel: diameter 10 mm 
 Bending Angle: 90 degrees or more 
 Thickness of the Thermal Conductive Sheet: 0.3 mm. 
   
     
     
         4 . The thermal conductive sheet according to  claim 1 , further comprising a resin component, wherein
 the resin component has a kinetic viscosity as measured by the kinetic viscosity test (temperature: 25° C.±0.5° C., solvent: butyl carbitol, solid content concentration: 40 mass %) in conformity with JIS K 7233 (bubble viscometer method) of 0.22×10 −4  to 2.00×10 −4  m 2 /s.