| 摘要 |
PROBLEM TO BE SOLVED: To prevent a top sheet 35 of a piezoelectric actuator jointed with a bump electrode 103 of a flexible flat cable 40 from being separated at a part weak in jointing strength between a surface electrode 93 and an external electrode 95 by stretching and contracting the width 103 of the bump electrode 103 of the flexible flat cable 40 caused by fluctuation of temperature. SOLUTION: The peripheral edge of the external electrode 95 with a thick thickness is arranged more inside than the peripheral edge of a wide width part 93a of the surface electrode 93 with a thin thickness on a jointing terminal 91 for an individual electrode formed on the surface of the top sheet 35. When pressing under heating is performed under a condition where the bump electrode 103 of the flexible flat cable 40 is faced on the top face of the external electrode 95, the solder alloy is melted to cover the surface of the external electrode 95 and the surface more inside than the peripheral edge of the wide width part 93a. A dimension W5 from the peripheral edge of the wide width part 93a to the peripheral edge of the external electrode 95 is set as large as possible so that the thickness of a fillet part 103a of the solder alloy solidified (the bump electrode 103) and the diameter of the cross-section of the fillet part 103a can be made large. COPYRIGHT: (C)2005,JPO&NCIPI
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