| 摘要 |
PURPOSE:To prevent the occurrence of an erroneous operation in a semiconductor integrated circuit due to the fact that alpha rays contained in a package reach a semiconductor memory circuit cell by forming an alpha ray stopping layer on the inner surface of the package for containing the semiconductor memory circuit cells. CONSTITUTION:A polyimide resin layer having more than 30mum thick, a silicone resin layer having more than 50mum thick or a metallic layer 11 made of metal having relatively large atomic weight, e.g., tungsten, lead, etc. is formed on the inner surface of a ceramic package 5 having a recess 4. Alpha rays radiated from radioactive substance contained in a ceramic package 5 are stopped due to the layer 11 before reaching the memory circuit cell on a semiconductor integrated circuit chip 7. In this manner, the erroneous operation of the memory circuit element due to the alpha rays can be prevented in advance. The layer 11 can be formed also on the bottom 6 of the recess and on the inner surface of a cover plate 8 as required. |
