| 摘要 |
PURPOSE:To see that cracks do not occur in a ceramic base substance by arranging the constitution that the major part of a solder material may be replaced with a member which exists inside the solder material and has a thermal expansion coefficient smaller than that of the solder material. CONSTITUTION:The major part of a solder material 4 to solder a lead 3 terminal directly to the terminal 2 of a circuit pattern on the surface of a ceramic base substance 1 is replaced with a member which is put between the lead 2 lower end and the terminal 2 inside the solder material 4 and is smaller in thermal expansion coefficient than the solder material 4 and has the same outside diameter as that of the terminal 2 or a little smaller outside diameter than that outside diameter. Accordingly, when soldered to the terminal 2, the shrinkage stress which acts directly on the ceramic base substance, of the solder material 4 which cools and solidifies at the surface of the ceramic base substance 1 can be sharply weakened. Hereby, it can be soldered without causing cracks in the ceramic base substance 1. |
