Claims
- 1. A thermal interface material for bonding substrates, the thermal interface material is characterized by a reflow temperature that is less than about 350° C., by a thermal conductivity of at least about 15 W/mK, and by consisting essentially of:
a. a solder having a melting temperature that is less than about 300° C. and consisting essentially of:
i. a bonding component selected from the group consisting of indium, an indium-tin alloy, a gold-tin alloy and mixtures thereof; ii. optionally, a thermal conductivity enhancement component having a thermal conductivity that is at least about 100 W/mK; and iii. an intrinsic oxygen getter selected from the group consisting of rare earth metals, alkali metals, alkaline-earth metals, refractory metals, zinc, and mixtures and alloys thereof; and b. a CTE modifying component having a coefficient of thermal expansion that is less than about 10 μm/m° C.
- 2. The thermal interface material as set forth in claim 1 having a reflow temperature that is less than about 250° C. and by having a thermal conductivity of at least about 20 W/mK.
- 3. The thermal interface material as set forth in claim 1 having a reflow temperature that is less than about 200° C. and by having a thermal conductivity of at least about 30 W/mK.
- 4. The thermal interface material as set forth in claim 1 wherein the bonding component is indium.
- 5. The thermal interface material as set forth in claim 1 wherein the CTE modifying component is selected from the group consisting of beryllium oxide, aluminum oxide, aluminum nitride, silicon carbide, silicon dioxide, copper-tungsten alloys, low expansion iron-nickel alloys, low expansion ceramic powders, low expansion glass powders and mixtures thereof.
- 6. The thermal interface material as set forth in claim 1 wherein the solder is about 30% to about 90% by volume of the thermal interface material and the CTE modifying component is about 10% to about 70% by volume of the thermal interface material.
- 7. The thermal interface material as set forth in claim 1 wherein the solder is about 50% to about 90% by volume of the thermal interface material and the CTE modifying component is about 10% to about 50% by volume of the thermal interface material.
- 8. The thermal interface material as set forth in claim 1 wherein the thermal conductivity enhancement component is selected from the group consisting of silver, copper, gold and mixtures and alloys thereof.
- 9. The thermal interface material as set forth in claim 1 wherein the alkali metals are selected from the group consisting of lithium, sodium and potassium and mixtures and alloys thereof, the alkaline earth metals are selected from the group consisting of magnesium and calcium and mixtures and alloys thereof, the refractory metals are selected from the group consisting of titanium, zirconium, hafnium, tantalum, vanadium and niobium and mixtures and alloys thereof, the rare earth metals are selected from the group consisting of lanthanum, cerium, praseodymium, samarium, neodymium, europium, gadolinium, terbium, dysprosium and ytterbium and mixtures and alloys thereof.
- 10. The thermal interface material as set forth in claim 1 wherein bonding component is indium or the indium-tin alloy and the total concentration of refractory metals in the solder is less about 10% by weight, the total concentration of rare earth metals in the solder is less about 5% by weight, and the total concentration of alkali metals, alkaline-earth metals and zinc is less than about 20% by weight.
- 11. The thermal interface material as set forth in claim 1 wherein bonding component is the gold-tin alloy and the total concentration of refractory metals in the solder is less than about 5% by weight, the total concentration of refractory metals is less than about 3% by weight, and the total concentration of alkali metals, alkaline-earth metals and zinc is less than about 10% by weight.
- 12. A thermal interface material for bonding substrates, the thermal interface material comprising a solder that comprises gold, a second metal selected from the group consisting of tin, silicon, germanium and mixtures and alloys thereof and an intrinsic oxygen getter selected from the group consisting of rare earth metals, alkali metals, alkaline-earth metals, refractory metals, zinc, and mixtures and alloys thereof.
- 13. The thermal interface material as set forth in claim 12 wherein the solder comprises about 75 to about 85% by weight gold and about 15 to about 25% by weight tin, or the solder comprises at least about 90% by weight gold and about 1 to about 5% by weight silicon, or the solder comprises at least about 80% by weight gold and about 5 to about 15% by weight germanium.
- 14. The thermal interface material as set forth in claim 13 wherein the total concentration of refractory metals in the solder is less than about 5% by weight, the total concentration of refractory metals is less than about 3% by weight, and the total concentration of alkali metals, alkaline-earth metals and zinc is less than about 10% by weight.
- 15. A thermal interface material for bonding substrates, the thermal interface material is characterized by having a reflow temperature that is less than about 350° C. and by having a thermal conductivity of at least about 15 W/mK, the thermal interface material consisting essentially of:
a solder consisting essentially of indium, about 0.5 to about 2% by weight of titanium and about 0.1 to about 2% by weight of misch metal, wherein the concentration of the solder ranges from about 30% to about 90% by volume of the thermal interface material; and a CTE modifying component selected from the group consisting of beryllium oxide, aluminum oxide, aluminum nitride, silicon carbide, silicon dioxide, copper-tungsten alloys, low expansion iron-nickel alloys, low expansion ceramic powders, low expansion glass powders and mixtures thereof, wherein the concentration of the thermal interface material ranges from about 10% to about 70% by volume of the thermal interface material.
- 16. A thermal interface material for bonding substrates, the thermal interface material is characterized by having a reflow temperature that is less than about 350° C. and by having a thermal conductivity of at least about 15 W/mK, the thermal interface material consisting essentially of:
a solder consisting essentially of indium, about 1% by weight of titanium and about 0.2% by weight of misch metal, wherein the concentration of the solder ranges from about 30% to about 90% by volume of the thermal interface material; and a CTE modifying component selected from the group consisting of beryllium oxide, aluminum oxide, aluminum nitride, silicon carbide, silicon dioxide, copper-tungsten alloys, low expansion iron-nickel alloys, low expansion ceramic powders, low expansion glass powders and mixtures thereof, wherein the concentration of the CTE modifying component ranges from about 10% to about 70% by volume of the thermal interface material.
- 17. An active solder that wets metallic and nonmetallic surfaces at a temperature below about 300° C. without extrinsic fluxing, the active solder comprising bonding component selected from the group consisting of indium, an indium-tin alloy, an gold-tin alloy and mixtures thereof, and an intrinsic oxygen getter selected from the group consisting of alkali metals, alkaline-earth metals, refractory metals, rare earth metals and zinc and mixtures and alloys thereof.
- 18. The active solder as set forth in claim 17 wherein the bonding component is indium or the indium-tin alloy and the total concentration of the refractory metals is less than about 10% by weight, the total concentration of the rare earth metals is less than about 5% by weight, and the total concentration of the alkali metals, alkaline-earth metals and zinc is less than about 20% by weight.
- 19. The active solder as set forth in claim 17 wherein the bonding component is indium or the indium-tin alloy and the intrinsic oxygen getter is about 0.5 to about 2% by weight titanium and about 0.1 to about 2% by weight misch metal.
- 20. The active solder as set forth in claim 17 wherein the bonding component is indium or the indium-tin alloy and the intrinsic oxygen getter is about 1% by weight titanium and about 0.2% by weight misch metal.
- 21. The active solder as set forth in claim 17 wherein the bonding component is the gold-tin alloy and the gold-tin alloy comprises about 77 to about 83% by weight gold and about 17 to about 23% by weight tin, and the total concentration of refractory metals in the solder is about 0.5 to about 1.5% by weight, the total concentration of alkali metals is about 0.1 to about 0.5% by weight, the total concentration of alkaline-earth metals is about 0.1 to about 0.5% by weight, and the total concentration of zinc is about 0.1 to about 0.5% by weight.
- 22. An electronic device package comprising:
a. a semiconductor substrate having a front surface and a back surface; b. an electronic device on the front surface of the semiconductor substrate; c. a heat sink component having a front surface and a back surface; and d. a thermal interface material bonding the back surface of the semiconductor substrate to the front surface of the heat sink component, the thermal interface material being characterized by a reflow temperature that is less than about 350° C., by a thermal conductivity of at least about 15 W/mK, and by consisting essentially of a solder having a melting temperature that is less than about 300° C. and a CTE modifying component having a coefficient of thermal expansion that is less than about 10 μm/m° C., wherein the solder consists essentially of:
i. a bonding component selected from the group consisting of indium, an indium-tin alloy, a gold-tin alloy and mixtures thereof; ii. optionally, a thermal conductivity enhancement component having a thermal conductivity that is at least about 100 W/mK; and iii. an intrinsic oxygen getter selected from the group consisting of rare earth metals, alkali metals, alkaline-earth metals, refractory metals, zinc, and mixtures and alloys thereof.
- 23. The electronic device package as set forth in claim 22 wherein the CTE modifying component has a coefficient of thermal expansion that is less than about 8 μm/m° C.
- 24. The electronic device package as set forth in claim 22 wherein the thermal interface material comprises about 30% to about 90% by volume of the solder and about 10% to about 70% by volume of the CTE modifying component.
- 25. The electronic device package as set forth in claim 22 wherein the thermal interface material comprises about 50% to about 90% by volume of the solder and about 10% to about 50% by volume of the CTE modifying component.
- 26. The electronic device package as set forth in claim 22 wherein the thermal interface material is characterized by a reflow temperature below about 250° C.
- 27. The electronic device package as set forth in claim 22 wherein the thermal interface material is characterized by a reflow temperature below about 200° C.
- 28. The electronic device package as set forth in claim 22 wherein the thermal interface material is characterized by a bulk thermal conductivity of at least about 20 W/mK.
- 29. The electronic device package as set forth in claim 22 wherein the thermal interface material is characterized by a bulk thermal conductivity of at least about 30 W/mK.
- 30. The electronic device package as set forth in claim 22 wherein the electronic device package is characterized by an interfacial heat transfer coefficient between the back surface of the semiconductor substrate and the thermal interface material that is greater than about 50 W/cm2° C.
- 31. The electronic device package as set forth in claim 22 wherein the electronic device package is characterized by an interfacial heat transfer coefficient between the back surface of the semiconductor substrate and the thermal interface material that is greater than about 500 W/cm2° C.
- 32. The electronic device package as set forth in claim 22 wherein the CTE modifying component is selected from the group consisting of beryllium oxide, aluminum oxide, aluminum nitride, silicon carbide, silicon dioxide, copper-tungsten alloys, low expansion iron-nickel alloys, low expansion ceramic powders, low expansion glass powders and mixtures thereof.
- 33. The electronic device package as set forth in claim 22 wherein the thermal conductivity enhancement component is selected from the group consisting of silver, copper, gold and mixtures and alloys thereof.
- 34. The electronic device package as set forth in claim 22 wherein the alkali metals are selected from the group consisting of lithium, sodium and potassium and mixtures and alloys thereof, the alkaline earth metals are selected from the group consisting of magnesium and calcium and mixtures and alloys thereof, the refractory metals are selected from the group consisting of titanium, zirconium, hafnium, tantalum, vanadium and niobium and mixtures and alloys thereof, the rare earth metals are selected from the group consisting of lanthanum, cerium, praseodymium, samarium, neodymium, europium, gadolinium, terbium, dysprosium and ytterbium and mixtures and alloys thereof.
- 35. The electronic device package as set forth in claim 22 wherein the solder consists essentially of indium, about 0.5 to about 2% by weight of titanium and about 0.1 to about 2% by weight of misch metal.
- 36. The electronic device package as set forth in claim 22 wherein the solder consists essentially of indium, about 1% by weight of titanium and about 0.2% by weight of misch metal.
- 37. An electronic device package comprising:
a semiconductor substrate having a front surface and a back surface; an electronic device on the front surface of the semiconductor substrate; a lid having a front surface and a back surface and a recess for receiving an insert; the insert being sized and shaped to fit within the recess in the lid, the insert having a front surface, a back surface, a surface in contact with the lid and a coefficient of thermal expansion that is between about that of the lid and about that of the semiconductor substrate; and a first thermal interface material bonding the back surface of the semiconductor substrate to at least a portion of the front surface of the insert.
- 38. The electronic device package as set forth in claim 37 wherein the recess in the lid extends inward from the front surface of the lid to a point between the front surface and the back surface of the lid.
- 39. The electronic device package as set forth in claim 37 wherein the recess in the lid extends inward from the front surface of the lid to the back surface of the lid.
- 40. The electronic device package as set forth in claim 37 wherein the insert is compression mounted in the lid.
- 41. The electronic device package as set forth in claim 37 wherein the entire back surface of the semiconductor substrate is bonded to the front surface of the insert by the first thermal interface material.
- 42. The electronic device package as set forth in claim 37 comprising:
a heat exchanger having a front surface and back surface; and a second thermal interface material for bonding at least a portion of the front surface of the heat exchanger to the back surface of the lid.
- 43. The electronic device package as set forth in claim 42 wherein the second interface material bonds the back surface of the insert to the front surface of the heat exchanger.
- 44. The electronic device package as set forth in claim 42 wherein the semiconductor substrate comprises silicon, the lid comprises copper, the heat exchanger comprises aluminum, the insert is selected from the group consisting of beryllium oxide, aluminum oxide, aluminum nitride, silicon carbide, silicon dioxide, copper-tungsten alloys, low expansion iron-nickel alloys, low expansion ceramic powders, low expansion glass powders and mixtures thereof, and the first and second thermal interface materials comprise a solder selected from the group consisting of indium, tin, gold, bismuth, lead, silicon, germanium, copper, silver, lithium, sodium, potassium, magnesium, calcium, titanium, zirconium, hafnium, tantalum, vanadium, niobium, lanthanum, cerium, praseodymium, samarium, neodymium, europium, gadolinium, terbium, dysprosium, zinc and mixtures and alloys thereof.
- 45. The electronic device package as set forth in claim 44 wherein the first and second thermal interface materials comprise a CTE modifying component selected from the group consisting of beryllium oxide, aluminum oxide, aluminum nitride, silicon carbide, silicon dioxide, copper-tungsten alloys, low expansion iron-nickel alloys, low expansion ceramic powders, low expansion glass powders and mixtures thereof.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/293,457, filed May 24, 2001 and U.S. Provisional Application No. 60/306,218, filed Jul. 18, 2001.
Provisional Applications (2)
|
Number |
Date |
Country |
|
60293457 |
May 2001 |
US |
|
60306218 |
Jul 2001 |
US |