US 11,667,825 B2
Thermally conductive sheet and method for producing the same
Hitoshi Shibuya, Aichi (JP)
Assigned to Fuji Polymer Industries Co., Ltd., Aichi (JP)
Appl. No. 16/961,882
Filed by Fuji Polymer Industries Co., Ltd., Nagoya (JP)
PCT Filed Oct. 2, 2019, PCT No. PCT/JP2019/038909
§ 371(c)(1), (2) Date Jul. 13, 2020,
PCT Pub. No. WO2020/179115, PCT Pub. Date Sep. 10, 2020.
Claims priority of application No. JP2019-041943 (JP), filed on Mar. 7, 2019.
Prior Publication US 2021/0214600 A1, Jul. 15, 2021
Int. Cl. C09K 5/14 (2006.01); C08J 5/18 (2006.01); C08K 3/22 (2006.01); C08K 7/18 (2006.01); C08K 9/06 (2006.01); H01L 23/373 (2006.01); H01L 33/64 (2010.01)
CPC C09K 5/14 (2013.01) [C08J 5/18 (2013.01); C08K 3/22 (2013.01); C08K 7/18 (2013.01); C08K 9/06 (2013.01); C08J 2383/04 (2013.01); C08K 2003/2227 (2013.01); C08K 2201/001 (2013.01); C08K 2201/005 (2013.01); H01L 23/3737 (2013.01); H01L 33/641 (2013.01)] 10 Claims
 
1. A thermally conductive sheet comprising:
a matrix resin; and
thermally conductive particles,
wherein the thermally conductive particles consist of alumina particles,
a content of the alumina particles is 400 to 3000 parts by mass with respect to 100 parts by mass of the matrix resin component,
the alumina particles with an average particle size of 30 to 100 μm are 50 vol % or more and the alumina particles with an average particle size of less than 30 μm are 33 to 50 vol % with respect to 100 vol % of the total amount of the alumina particles,
the alumina particles with an average particle size of 30 to 100 μm are spherical in shape,
the alumina particles with an average particle size of less than 30 μm are irregular in shape,
the matrix resin in the thermally conductive sheet is cross-linked,
a polymer viscosity of the matrix resin component after a crosslinking reaction in the absence of the alumina particles is 500 Pa·s or less at 25° C.,
a thermal conductivity of the thermally conductive sheet is 2.0 W/m·K or more, and
when the thermally conductive sheet with an initial thickness of 1.5 mm is compressed at a compression rate of 5.0 mm/min to measure a 50% compressive load value, a maximum load value is 100 kPa or more and a load value after 1 minute is more than 0 kPa and 100 kPa or less.