Process for fabricating a crack resistant resin encapsulated semiconductor chip package

Claim 1

A fabrication process of a semiconductor package, comprising the steps of: (1) bonding a semiconductor chip to a first side of two surfaces of a lead frame with an adhesive member, (2) conductively connecting a second side of said two surfaces of said lead frame and said semiconductor chip via a wire; and (3) molding a molding compound so that the molding compound covers at least said semiconductor chip and a bonded part between the semiconductor chip and said frame, wherein said wire and said lead frame are connected at a position inside a shadow which is formed by projecting said semiconductor chip vertically on said second side of said lead frame; and said adhesive member is a composite adhesive sheet comprising a heat-resistant film and a coating layer of an adhesive applied on both major surfaces of the heat resistant film; and said adhesive member is make of polyimide or polyamide and includes a heat-resistant adhesive having a coming-out length of not more than 2 mm and a water absorption rate of not more than 3 wt %, (4) measuring the coming-out length of said adhesive, wherein the coming-out length is measured by the steps of: pressing a film of said adhesive having a size of 19 mm×50 mm with a thickness of 25 μm at 350° C. under 3 MPA for one minute; and measuring a coming-out length of said adhesive at a central part in the direction of the longer of the longer surface of said adhesive.

Claim 15

A method of selecting an adhesive for fabrication of a semiconductor package by bonding a semiconductor chip to lead frames, comprising measuring the coming-out length of an adhesive and a step of selecting an adhesive whose coming-out length is not longer than 2 mm and whose water absorption rate is not higher than 3% by weight, wherein said coming-out length is measured by steps of: pressing a film of said adhesive having a size of 19 mm×50 mm with a thickness of 25 μm at 350° C. under 3 MPa for one minute; and measuring a coming-out length of said adhesive at a central part in the direction of the longer surface of said adhesive film, and wherein said water absorption rate is measured by steps of: drying a film of said adhesive having a size of 50 mm×50 mm with a thickness of 25 μm at 100° C. for one hour; soaking the film in water of 23° C. for 24 hours; and calculating the water absorption rate of the adhesive from the weight difference of the film before and after being soaked in water.

Claim 16

A method of selecting an adhesive for fabrication of a semiconductor package by bonding a semiconductor chip to lead frames, comprising measuring the coming-out length of an adhesive and a step of selecting an adhesive whose coming-out length is not longer than 2 mm and whose water absorption rate is not higher than 3% by weight, wherein said coming-out length is measured by steps of: pressing a film of said adhesive having a size of 19 mm×50 mm with a thickness of 25 μm at 350° C. under 3 MPa for one minute; and measuring a coming-out length of said adhesive at a central part in the direction of the longer surface of said adhesive film, and wherein said water absorption rate is measured by steps of: drying a film of said adhesive having a size of 50 mm×50 mm with a thickness of 25 μm at 100° C. for one hour; soaking the film in water of 23° C. for 24 hours; and calculating the water absorption rate of the adhesive from the weight difference of the film before and after being soaked in water.