Patent ID: 8513792

Claim:
A semiconductor assembly, comprising: a first semiconductor package having a plurality of inter-package contact pads on a top side and a plurality of second level interconnect (SLI) pads on a bottom side; and a planar stiffener having a first plurality of planar contact pads on a top side of the stiffener electrically connected to a second semiconductor package, and a second plurality of planar contact pads on a bottom side of the stiffener electrically connected to the inter-package contact pads of the first semiconductor package by a solder having a melt temperature wherein said stiffener has an adhesive on the bottom side of the stiffener which attaches said stiffener to the top side of the first semiconductor package, said adhesive having a glass transition temperature between 90° C.-180° C. and a cure temperature below said melt temperature; wherein said planar stiffener has a substrate comprising a polymeric core and an insulative plug material.