| 摘要 |
PURPOSE:To make an inner lead and an outer lead such that a cross section configuration of the inner lead on the side of an etched surface thereof and a cross section configuration of the outer lead on the side of an etched surface thereof are both substantially straight lines by forming a dummy pattern using a dummy pattern and etching the pattern. CONSTITUTION:A dummy pattern is provided on a predetermined print, and a dummy resist pattern 103 is provided between resist patterns 104 corresponding to an outer lead part 108 such that the degree of advance of etching is substantially the same as that of the inner lead part. An exposed part of a lead frame raw material 101 is etched from opposite surfaces thereof to form an etched recessed portion 106, and the etching is advanced to form a through-hole 106A in the recessed portion and force the lead frame raw material 107 under the dummy resist pattern 103 to disappear. Further, the etching is continued, and is stopped such that the width of elimination of the configuration of the cross section of the outer lead 108 on the side of the etched surface is substantially on the same straight line, whereby the configurations of the inner lead and the outer lead on the surface sides can be made straight. |
