Adhesives with thermal conductivity enhanced by mixed silver fillers
AssigneeDiemat, Inc.
InventorsTerence L Hartman, Stavros Anagnostopoulos, Peter Crudele
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Abstract
A thermally conductive adhesive comprises a mixture of at least two types of silver particles including a second type having a surface area to mass ratio in the range of 0.59 m2/g to 2.19 m2/g and a tap density in the range of 3.2 to 6.9 g/cm3 and a first type having a surface area to mass ratio of 0.05 to 0.15 m2/g and a tap density in the range of about 4.7 to 8.2 g/cm3. According to certain embodiments of the invention the first type of silver particles includes oblong silver particles. The thermally conductive adhesive further comprises a binder, and optionally a solvent.
Claims15
A thermally conductive adhesive comprising:
- a liquid epoxy resin as a binder contained in an amount of 3% by weight to 15% by weight based on the thermally conductive adhesive;
- a first silver powder including oblong particles and having a first surface area to mass ratio between 0.05 and 0.15 m2/g;
- and
- a second silver powder having a second surface area to mass ratio between 0.59 and 2.19 m2/g,
- wherein the total amount of the first silver powder and the second silver powder is at least 85% by weight based on the thermally conductive adhesive and the weight ratio of the first silver powder to the second silver powder is from 30/70 to 50/50.
A method of making a thermally conductive adhesive comprising:
- providing a liquid epoxy resin as a binder contained in an amount of 3% by weight to 15% by weight based on the thermally conductive adhesive;
- providing a first silver powder including oblong particles and having a first surface area to mass ratio between 0.05 and 0.15 m2/g;
- providing a second silver powder having a second surface area to mass ratio between 0.59 and 2.19 m2/g;
- and
- combining said binder, said first silver powder and said second silver powder,
- wherein the total amount of the first silver powder and the second silver powder is at least 85% by weight based on the thermally conductive adhesive and the weight ratio of the first silver powder to the second silver powder is from 30/70 to 50/50.
An apparatus comprising:
- a first part;
- a second part;
- a thermally conductive adhesive bonding said first part to said second part, wherein said thermally conductive adhesive includes:
- a liquid epoxy resin as a binder contained in an amount of 3% by weight to 15% by weight based on the thermally conductive adhesive;
- a first silver powder including oblong particles and having a first surface area to mass ratio between 0.05 and 0.15 m2/g;
- and
- a second silver powder having a second surface area to mass ratio between 0.59 and 2.19 m2/g,
- wherein the total amount of the first silver powder and the second silver powder is at least 85% by weight based on the thermally conductive adhesive and the weight ratio of the first silver powder to the second silver powder is from 30/70 to 50/50.
Dependencies are inferred from the claim text.