| 摘要 |
PURPOSE:To accomplish an alpha-ray preventive measure of a high reliability at low cost by a method wherein insulating powder material is filled in an internal void of a ceramic package. CONSTITUTION:A screening action for X-rays is given to an internal void 1c of ceramic package 1 and insulating powder substrate 7, which can resist against the temperature at the time of airtight sealing with glass 2 of the low melting point, is filled in said void 1c. As an insulating powder substrate 7, flakes of CVD (chemical vapour deposition)-SiO2 film is suitable. |
