| 摘要 |
PURPOSE:To improve the hermetic sealability and bonding strength of a cap mounting structure for a semiconductor device by reducing the thickness of a periphery of a solder layer formed on the cap and preventing the production of voids in the solder when pressed and bonded to a ceramic base. CONSTITUTION:A solder layer 12 is formed on the inner surface of a cover 11 of Kovar. The layer 12 has a stepwise difference in the vicinity of each periphery, and the thickness of the periphery 12a is smaller than the other. When a cap 11 is placed on a ceramic base 1 and passed through a furnace while pressing the cap 11. The layer 12 of the cap is molten, pressed to be fusion-bonded to an Au-plated layer 10 and an Ni-plated layer 9, and the cap 11 is secured to the ceramic base. In this case, the layer 12 is contacted with a multilayer processing unit 7 at the inside 12b of the stepwise difference to be first molten, the molten part is gradually advanced toward the outer periphery, and fusion bonding is performed in directivity. In this manner, the air between the layer 12 and the unit 7 is removed from the inner periphery to the outer periphery through the gap 13 as the solder is molten, thereby preventing the production of voids, and improving the reliability of the device. |
