| 摘要 |
<p>PROBLEM TO BE SOLVED: To increase adherence strength between an external electrode and a current collecting electrode so as to prevent the exfoliation of the external electrode, by increasing the area on which a fillet of a soldering layer is formed. SOLUTION: A current collecting electrode 5 is divided into four unit current collecting electrodes 5', and all of the unit current collecting electrodes 5' are electrically connected to an external electrode 7. The bottoms of thin wires 4 are electrically connected to an impurity diffused layer 2. Furthermore, a fillet 9 on solder 8 is formed, so as to cover the upper surface of a current collecting electrode 5 and the side of the external electrode 7. The larger the fillet 9 is, the larger the adherence strength between the external electrode 7 and the current collecting electrode 5 becomes. Since the current collecting electrode 5 is divided into four, a soldering layer 8 covers the bottom surface of the external electrode 7 at the ends of the unit current collecting electrodes 5'. The soldering layer 8 further covers the side walls of the unit current collecting electrodes 5' and the back of the external electrode 7 to form the fillet 9. Therefore, it is possible to increase the connecting strength between the external electrode and the current collecting electrode to prevent exfoliation of the external electrode.</p> |
