Silver-to-silver bonded IC package having two ceramic substrates exposed on the outside of the package
First Claim
1. A method, comprising:
- (a) attaching a sintered silver pad of a first Direct Metal Bonded (DMB) ceramic substrate assembly to a layer of silver that covers a backside of a semiconductor die such that a silver-to-silver bond is formed between the first DMB ceramic substrate and the die, wherein the die comprises the layer of silver on the backside of the die, and wherein the die further comprises a plurality of sintered silver pads on a frontside of the die; and
(b) attaching a plurality of sintered silver pads of a second DMB ceramic substrate assembly to the plurality of sintered silver pads on the frontside of the semiconductor die such that a plurality of silver-to-silver bonds is formed between the second DMB ceramic substrate assembly and the die.
3 Assignments
0 Petitions
Accused Products
Abstract
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.
9 Citations
20 Claims
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1. A method, comprising:
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(a) attaching a sintered silver pad of a first Direct Metal Bonded (DMB) ceramic substrate assembly to a layer of silver that covers a backside of a semiconductor die such that a silver-to-silver bond is formed between the first DMB ceramic substrate and the die, wherein the die comprises the layer of silver on the backside of the die, and wherein the die further comprises a plurality of sintered silver pads on a frontside of the die; and (b) attaching a plurality of sintered silver pads of a second DMB ceramic substrate assembly to the plurality of sintered silver pads on the frontside of the semiconductor die such that a plurality of silver-to-silver bonds is formed between the second DMB ceramic substrate assembly and the die. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method, comprising:
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depositing a layer of silver onto a backside of a semiconductor die using an evaporative deposition process; printing silver nanoparticle paste onto selected portions of a frontside of the semiconductor die; sintering the silver nanoparticle paste on the frontside of the semiconductor die to form a plurality of sintered silver pads; forming a silver-to-silver bond between a first Direct Metal Bonded (DMB) ceramic substrate and the semiconductor die by attaching a sintered silver pad of the first DMB ceramic substrate to the layer of silver on the backside of the semiconductor die; and forming a plurality of silver-to-silver bonds between a second DMB ceramic substrate and the semiconductor die by attaching a plurality of sintered silver pads of the second DMB ceramic substrate to the plurality of sintered silver pads on the frontside of the semiconductor die. - View Dependent Claims (17, 18, 19, 20)
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Specification