Resin sheet having controlled thermal conductivity distribution, and method for manufacturing the same

Abstract

A resin sheet has a single composition, and changes in thermal conductivity according to an area. The resin sheet includes a region having a thermal conductivity that is greater than an average value of a thermal conductivity of an entirety of the resin sheet by 1 W/mK or more. A method for manufacturing a resin sheet includes: forming a resin composition into a molded body having a sheet shape, the resin composition containing a filler having magnetic anisotropy; performing magnetic field orientation on the filler by using a bulk superconductor magnet in one or a plurality of predetermined portions of the molded body; and forming a region having a thermal conductivity that is greater than an average value of a thermal conductivity of an entirety of the resin sheet by 1 W/mK or more, in the one or the plurality of predetermined portions.

1 . A resin sheet that has a single composition and that changes in thermal conductivity according to an area, wherein
 a region exists that has a thermal conductivity that is greater than an average value of a thermal conductivity of an entirety of the resin sheet by 1 W/mK or more.   
     
     
         2 . The resin sheet according to  claim 1 , wherein a minimum unit area of the region having the thermal conductivity that is greater than the average value of the thermal conductivity of the entirety of the resin sheet by 1 W/mK or more is 0.2 cm 2  or more. 
     
     
         3 . The resin sheet according to  claim 1 , wherein an area of the region having the thermal conductivity that is greater than the average value of the thermal conductivity of the entirety of the resin sheet by 1 W/mK or more is from 1 to 50% of an area of the entirety of the resin sheet. 
     
     
         4 . The resin sheet according to  claim 1 , wherein the region having the thermal conductivity that is greater than the average value of the thermal conductivity of the entirety of the resin sheet by 1 W/mK or more includes a portion having a thermal conductivity of 5 W/mK or more. 
     
     
         5 . The resin sheet according to  claim 1 , wherein a region having a thermal conductivity of 5 W/mK or more and a region having a thermal conductivity of 2 W/mK or more are included in both. 
     
     
         6 . The resin sheet according to  claim 1 , wherein one or a plurality of regions exists that is spaced apart from an outer peripheral edge of the resin sheet, is surrounded by a closed loop, and has a thermal conductivity of 5 W/mK or more. 
     
     
         7 . The resin sheet according to  claim 6 , wherein a minimum thermal conductivity of the one or the plurality of regions surrounded by the closed loop is different from a maximum thermal conductivity of a region outside the one or the plurality of regions by 3 W/mK or more. 
     
     
         8 . A resin sheet that is obtained by cutting off the one or the plurality of regions according to  claim 6 , the one or the plurality of regions having a thermal conductivity of 5 W/mK or more and being surrounded by the closed loop. 
     
     
         9 . The resin sheet according to any one of  claim 1 , wherein the resin sheet includes a cured product of a resin composition containing a filler having magnetic anisotropy. 
     
     
         10 . The resin sheet according to  claim 9 , wherein the filler having the magnetic anisotropy has been oriented in a thickness direction of the resin sheet. 
     
     
         11 . The resin sheet according to  claim 9 , wherein the filler having the magnetic anisotropy includes at least one filler selected from the group consisting of a carbon fiber, an alumina fiber, an aluminum nitride whisker, a metal nanowire, a carbon nanotube, a boron nitride nanotube, scaly boron nitride, plate-like aggregated boron nitride, scaly graphite, graphene and plate-like alumina. 
     
     
         12 . The resin sheet according to  claim 1 , wherein a resin component of the resin sheet includes silicone resin or epoxy resin. 
     
     
         13 . The resin sheet according to  claim 1 , wherein a thickness of the resin sheet is 20 mm or less. 
     
     
         14 . A method for manufacturing a resin sheet, the method comprising:
 forming a resin composition into a molded body having a sheet shape, the resin composition containing a filler having magnetic anisotropy;   performing magnetic field orientation on the filler having the magnetic anisotropy by using a bulk superconductor magnet in one or a plurality of predetermined portions of the molded body; and   forming a region having a thermal conductivity that is greater than an average value of a thermal conductivity of an entirety of the resin sheet by 1 W/mK or more, in the one or the plurality of predetermined portions.   
     
     
         15 . The method for manufacturing a resin sheet according to  claim 14 , wherein the resin composition includes a liquid resin composition, the liquid resin composition is applied onto a film, the magnetic field orientation is performed on one or a plurality of predetermined portions of a body coated with the liquid resin composition, and the liquid resin composition is cured.