| 摘要 |
PURPOSE:To smooth resin-sealed molding by a method wherein recessed parts provided directly in the tie bars of a lead frame each constitute an air vent between the parting face of a top force and a bottom force. CONSTITUTION:A resin-sealed molding is performed using a lead frame 1. At this time, there is a need to constitute air vents between the parting part of a top force and a bottom force, but recessed parts 8 provided in tie bars 3 of the lead frame 1 ful-fill this duty. That is, the width (l2) of the recessed parts 8 is set smaller than that of the tie bars 3 and also is set smaller than a width (l) in which a tie bar cut is performed in the latter process. The depth (h2) is set in the same as the depth of 0.01-0.05 mm of the air vent structure, which is set in the metal mold. Moreover, whether the recessed parts 8 are installed in all the tie bars 3 of the lead frame 1 or they are installed in some ones of them is arbitrarily decided and whether the recessed parts are installed only on one side os the top and bottom forces or they are installed on both sides of the forces is arbitrarily decided.
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