Patent ID: 8193644

Claim:
An electronic assembly adapted for bonding top packaged ICs thereon to form a package on package (PoP) device, comprising: a bottom package substrate having a substrate top surface and a molded IC die bonded thereto, said molded IC die defining a mold cap height, said substrate top surface having substrate contact pads lateral to said molded IC die; an interposer substrate having bottom metal land pads on a bottom side of said interposer substrate and top metal land pads on a top side of said interposer substrate, interposer vias for connecting said top metal land pads to said bottom metal land pads, and an open receptacle region formed through said interposer substrate; wherein said substrate top surface is positioned relative to said interposer so that said molded IC die is within said open receptacle region to align said bottom metal land pads and said substrate contact pads, and an underfill layer between said substrate top surface and said bottom side of said interposer substrate, wherein a step height comprising said mold cap height minus a height of said top metal land pads is between minus 0.1 mm and plus 0.2 mm.