| 摘要 |
PURPOSE:To improve the thermal conductivity, moisture resistance, etc., by adding magnesium oxide powder at a specified weight ratio to an electronic part-sealing resin composition based on an epoxy resin and a novolak phenolic resin as a curing agent. CONSTITUTION:The purpose sealing resin composition is obtained by mixing an epoxy resin (A) with a novolak phenolic resin (B) and 25-90wt% small- diameter magnesium oxide powder (C) of an average particle diameter >=60 mesh at a molar ratio of epoxy groups in component A to phenolic hydroxyl groups in component B of 0.1-10. If desired, a mold release, a flame retardant, a colorant, a cure accelerator, etc., may be added to the composition. Because of its large thermal conductivity, the obtained sealing resin composition shows excellent heat radiation and particularly effective when used in devices such as power semiconductors of a large power consumption.
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