Patent attributes
In a double side stack packaging a plurality of chips, a hole is formed in a substrate. A first chip is attached to a bottom surface of the substrate by using a thermo compression and is electrically interconnected to terminals formed at sidewall of the hole using a wire bonding. Next, an epoxy is coated on the substrate and the first chip and a first heat spreader is installed thereon and then the epoxy is cured. Thereafter, a second chip is attached to a top surface of the substrate by using the epoxy and is electrically interconnected to terminals formed on the substrate using the wire bonding. And then, an encapsulation resin is coated on the substrate and the first chip and a second heat spreader is installed thereon and then the epoxy is cured.