| 摘要 |
PURPOSE:To manufacture the titled device by a photoetching method by determining the penetrating degree of a through hole formed in a thick portion of a plate, and controlling an etching. CONSTITUTION:Resist patterns 26, 28 having different shapes are formed on upper and lower surfaces of a metal plate 10, with the patterns as masks, the plate is etched, and a lead frame 30 having a thick portion and a thinner portion than the thick portion is manufactured. In this case, the penetrating degree of a through hole 32 formed in the thick portion is determined to control an etching. The plate 10 as a starting material may use a flat plate having the same thickness as the thick portion or a plate having a step. Since the hole 32 for mounting on the thick heat sink portion 30a is formed, the hole can be used as a through hole for controlling etching conditions. Thus, an accurate lead frame can be manufactured by a photoetching method. |
