| 摘要 |
<p>PURPOSE:To alleviate warpage stress of a memory card by providing slits at an arbitrary interval on a circuit board, and reducing linear expansion coefficient difference between the board and epoxy resin. CONSTITUTION:The outer periphery of an electronic module 3 in which electronic components 2 are mounted on a circuit board 1 formed with slits 8 at an arbitrary interval is covered with a sheath case 4 molded of ABS resin, and epoxy resin is filled from a small hole 5 formed at the sidewall of the case 4. After a space between the inner wall of the case 4 and the module 3 is filled with epoxy resin, the resin is heated at a temperature of predetermined conditions to be cured. Thermal expansion of the board 1 generated at the time of heating is alleviated by the slits formed on the board 1, and a warpage stress generated due to linear expansion coefficient difference between the epoxy resin and the board is reduced.</p> |
