| 摘要 |
PURPOSE:To provide a molding material for sealing which is excellent in low stress and crack resistance and does not cause any soft error, containing silica contg. a specified amount of a radioactive impurity, a silicone resin contg. a specified amount of a radioactive impurity and a flame retarder having a specified X-ray dose. CONSTITUTION:Silica contg. not more than 1ppb (in terms of the amount of uranium) of a radioactive impurity (e.g., fused silica) is mixed with 1-50wt% silicone resin contg. not more than 1ppb (in terms of the amount of uranium) of a radioactive impurity, a flame retarder having not more than 0.2CPH/cm<2> in terms of X-ray dose (e.g., Sb2O3), and optionally, a filler other than silica (e.g., CaCO3), other resins (e.g., an epoxy resin), a curing agent, a curing accelerator, a crosslinking agent, a parting agent, a coupling agent, a colorant, etc. The mixture is kneaded, crushed and, as needed, granulated.
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