| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the occurrence of disconnection in a lead frame even when the lead frame is subjected to ultrasonic vibrations in bonding the lead frame to a heat radiating plate by forming the connections between support bars and dam bars and connecting thin striations on the lead frame in broad shapes so that the connections may be reinforced. SOLUTION: Firstly, a lead frame 1a is formed by punching a copper base belt-like material such as the A194, etc., or an iron-based belt-like material such as the A42, etc., with a press or by etching the material. In forming the lead frame 1a, the connections between support bars 4 and dam bars 6 and connecting thin striations 2 on the lead frame 1a are formed in broad square shapes 18. When the connections are formed in the square shapes 18 which are broader than the bars 4 and 6, the strengths of the connections are sufficiently reinforced. Therefore, the occurrence of disconnection in the lead frame 1a can be prevented when vibrations are applied to the lead frame 1a at the time of bonding the lead frame 1a to a heat radiating plate by ultrasonic bonding, because the weak sections of the frame 1a are sufficiently reinforced and the mechanical strengths of the sections are increased.</p> |
