| 摘要 |
PURPOSE:To prevent generation of a crack in a substrate of hybrid module by a method wherein the diameter of a terminal pad and quantity of solder material are prescribed, and thickness of the solder material on the terminal pad is held at about 0.04mm. or less on the average, or the terminal pad is fixed to the substrate interposing an insulating layer between them. CONSTITUTION:A crack is generated because the solder material draws the substrate according to the difference of thermal expansion to be generated when they are cooled after welding is finished. When average thickness of the solder materisl on the terminal pad is held at 0.04mm. or less considering the diameter of terminal pad, quantity of the solder material, volume of gap inside of a through hole, volume of the terminal, etc., the crack is not generated in the substrate. When unevenness of thickness of substrate, the diameter of pad are considered, the larger the diameter of pad becomes, the easier thickness of the solder material can be controlled. And when the area A of substrate at the pad part/the area B of solder at the outside circumferential part is held at 6 or more, no crack is generated. At the case when short-circuit between the terminal pad 8 and the adjoining pattern 10 is generated by enlargement of the diameter of terminal pad, the terminal pad 3 is provided interposing an insulating layer 9 between the substrate, and at the case when the pad is to be provided by butt welding, no crack is generated in the substrate 1 by changing the shape of the terminal 2 and prescribing the solder material 5. |
