Plastic encapsulated IC package and method of designing same

Abstract

A method for designing an IC package having a plastic encapsulated portion and a lead frame portion that are bonded together at a bonding interface includes selecting material candidates for each of the plastic encapsulated portion and the lead frame portion to obtain possible material combinations. A peeling stress and a shear stress at the bonding interface for each possible material combination is determined. A design material combination from all of the possible material combinations is then selected based on a singularity parameter and stress intensity factors of the peeling stress and the shear stress. To enhance the IC package, a circular fillet feature having a radius is added to a singularity point at the bonding interface of the IC package to reduce the stress at the singularity point. The value of the radius is determined from a predefined range of radii based on the singularity parameter and stress intensity factors of the peeling stress and the shear stress at the singularity point for each of the radii.

Dependencies are inferred from the claim text.