Low stress polymer die attach adhesive for plastic packages

摘要: Silver filled epoxy is the most common type of adhesive used to attach Si chips metal leadframes in plastic packages. However, with attachment larger die sizes (2 cm length on side or larger) thin copper lead frames now coming into routine use, current adhesives were not reliable for these applications. Major technical issues materials are: stress-induced fracture; delamination at molding and post molding; device failures under pressure cooker tests thermal shock tests; thermal/hydrolytic stability adhesive; narrow processing window. A novel thermoset cyanate ester die-attach paste has been developed address above issues. The suitable use conventional dispensing equipment. This material can be cured less than 60 seconds 200/spl deg/C does generate any appreciable weight loss during cure. As a result, same fast cure profile utilized all sizes. In this paper, we review chemical physical characteristics its functional performance as media. combination lower modulus rigidity, about 400 MPa (vs. 1000 Mpa epoxies) temperatures well 300/spl given excellent strength, even deg/C, imparting very low stress die. Our data indicated level sensitive curing methods such fast-curing heater block slower-curing box oven. also change after long term high temperature 150/spl cycles between -65/spl deg/C. >