Silver-to-silver bonded IC package having two ceramic substrates exposed on the outside of the package

摘要

A packaged power device involves no soft solder and no wire bonds. The direct-bonded metal layers of two direct metal bonded ceramic substrate assemblies, such as Direct Bonded Aluminum (DBA) substrates, are provided with sintered silver pads. Silver nanoparticle paste is applied to pads on the frontside of a die and the paste is sintered to form silver pads. Silver formed by an evaporative process covers the backside of the die. The die is pressed between the two DBAs such that direct silver-to-silver bonds are formed between sintered silver pads on the frontside of the die and corresponding sintered silver pads of one of the DBAs, and such that a direct silver-to-silver bond is formed between the backside silver of the die and a sintered silver pad of the other DBA. After leadforming, leadtrimming and encapsulation, the finished device has exposed ceramic of both DBAs on outside package surfaces.

主权项

1. A packaged power device comprising:
a semiconductor die having a frontside and a backside, wherein the semiconductor die comprises a plurality of sintered silver pads disposed on the frontside, and wherein the semiconductor die further comprises layer of silver that covers substantially all of the backside; a first Direct Bonded Aluminum (DBA) substrate assembly comprising an aluminum island, wherein the first DBA substrate assembly further comprises a sintered silver pad disposed on the aluminum island, and wherein the sintered silver pad of the first DBA substrate assembly is silver-to-silver bonded to the layer of silver on the backside of the semiconductor die; a second DBA substrate assembly comprising a plurality of aluminum islands, wherein the second DBA substrate assembly further comprises a plurality of sintered silver pads disposed on the aluminum islands of the second DBA substrate assembly, and wherein each sintered silver pad of the second DBA substrate assembly is silver-to-silver bonded to a corresponding one of the plurality of sintered silver pads on the frontside of the semiconductor die; an amount of encapsulant that contacts both the first and the second DBA substrate assemblies so that the first and second DBA substrate assemblies and the amount of encapsulant together form a body portion of the packaged power device, wherein a surface of a ceramic substrate of the first DBA substrate assembly forms a first outside surface of the body portion, and wherein a surface of a ceramic substrate of the second DBA substrate assembly forms a second outside surface of the body portion; a first plurality of stamped metal package terminals, wherein each of the first plurality of terminals is attached to the first DBA substrate assembly; and a second plurality of stamped metal package terminals, wherein each of the second plurality of terminals is attached to the second DBA substrate assembly, and wherein the first and second pluralities of stamped metal package terminals together form a single row of in-line stamped metal package terminals.