High thermal conductive laminates for large current

In order that resins such as laminates may be made resistant to heat arising from the higher voltage or larger current of power device, it is necessary to make them highly thermally conductive. To make resins highly thermally conductive, it is usual to use a compound with inorganic filler. However, the thermal conductivity of matrix resins is low compared to that of ceramics. To achieve high thermal conductivity, it is necessary to use a large number of fillers. On the other hand, if the resin itself, which is a matrix, is highly thermally conductive, the thermal conductivity of compound resin can be efficiently improved. We have found that the thermal conductivity of the resin itself can be improved with the ordered structure of liquid crystal epoxy resin, which contains a mesogen group in the main chain. In this report, attention was paid to the resin that showed a smectic liquid crystal phase with higher regularity in order to improve molecular regularity in this ordered structure. In result, the thermal conductivity of this resin was 2.3 times that of usual epoxy resin and 1.4 times that of liquid crystal epoxy resin that shows a nematic phase. With laminates using this smectic-phase resin, a thermal conductivity of 11.4 W/m-K maximum was achieved.