| 摘要 |
PROBLEM TO BE SOLVED: To eliminate a thermal deformation by a method, wherein a circuit board on which a plurality of chips can be mounted is formed in such a way that a lead frame in which a first plated layer is formed on the whole face and a pattern connection part in which a second plated layer is formed are contained and a eutectic-point bonding layer for first and second plated layers is contained, so as to be formed between the first plated layer and the second plated layer. SOLUTION: A nickel-plated layer 20 and a second plated layer 30 are formed sequentially on a copper pattern at a printed-circuit board 10, and a first plated layer 50 is formed on a lead frame 40. The second plated layer 30 is faced with the first plated layer 50 and heated up to a eutectic point, their temperature is lowered down to the eutectic temperature or lower, their bonding faces are hardened, and a bonding layer 60 which has a strong bonding force is formed. When both plated layers are bonded at the eutectic temperature, their thermal deformations can be mostly eliminated. |
