Patent ID: 6558500
Filing Date: 2003-05-06
Classification: C09J,H01L,Y10T

Abstract:
A method of producing a lead frame with a composite film attached, comprising steps of:placing a composite film over a lead frame, the composite film including a base film and an adhesive layer on at least one side of the base film, such that the composite film has the at least one adhesive layer, the composite film having a thickness of T (&mgr;m), the base film having an edge tearing strength of R (kg/20 mm), the at least one adhesive layer having a total thickness of A, and the base film having a thickness of B, T being related to R by a numerical formula R>0.6T-8 when T&lE;60, or by a numerical formula R&lE;28 when T>60, and A/B being 0.5 to 1.4, with one adhesive layer facing the lead frame, wherein the at least one adhesive layer is made of an adhesive having a broadening length of 2 mm or less; punching the composite film into a strip by using a punching metal mold; and pressing the strip to the lead frame with the punching metal mold at a pressure of 0.1 to 10 MPa for 0.1 to 5 seconds.