Polymer with solder pre-coated fillers for thermal interface materials

• US 7,036,573 B2
• Filed: 02/08/2002
• Issued: 05/02/2006
• Est. Priority Date: 02/08/2002
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Koning, Paul A., Hua, Fay, Deppisch, Carl L.
• Primary Examiner(s): DUONG, THO V
• Application Number:
  US10/071,471
• Publication Number:
  US 20030150604A1
• Time in Patent Office: 1,544 Days
• Field of Search: 165/185, 165/80.3, 165/905, 361/704, 361/705, 361/712, 428/147, 428/148, 257/772, 523/200, 523/210
• US Class Current: 165/185
• CPC Class Codes: F28F 13/00 Arrangements for modifying heat-transfer, e.g. increasing, decreasing F28F1/00 - F28F11/00 take precedence
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 23/3737 Organic materials with or without a thermoconductive filler
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/15312 being a pin array, e.g. PGA
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: Y10S 165/905 Materials of manufacture

Abstract

A thermal interface material made of a binder material and a fusible filler.

Claims

1. A thermal interface material, comprising:

a binder material; and

a fusible filler within the binder material, the fusible filler randomly positioned with respect to the binder material, wherein the fusible filler is selected from the group consisting of an indium alloy that includes silver in an approximate range of 1 to 20 percent by weight, a tin alloy that includes copper in an approximate range of 0.7 to 1.4 percent by weight, a tin alloy that includes silver in an approximate range of 1 to 5 percent by weight, a tin alloy that includes tin in an approximate range of 42 to 85 percent by weight and bismuth in an approximate range of 15 to 58 percent by weight, a tin alloy that includes silver in an approximate range of 3.0 to 4.0 percent by weight and copper in an approximate range of 0 to 1.7 percent by weight, a tin alloy that includes silver in an approximate range of 3 to 4 percent by weight and bismuth in an approximate range of 1 to 6 percent by weight, and a tin alloy that includes silver approximately 1 percent by weight and bismuth approximately 57 percent by weight;

a plurality of non-fusible particles having a mean diameter of approximately 25 microns, within the binder material, the non-fusible particles randomly positioned with respect to the binder material, the fusible filler coated onto the non-fusible particles wherein a volume percent of the fusible filler to non-fusible particles is in a range of approximately 10–

50 percent by volume of fusible filler, wherein the non-fusible particles are selected from the group consisting of ceramic fiber, graphite fibers, carbon fibers, aluminum oxides, zinc oxide, graphite, carbon nanotubes, and silicon carbide.

2. The thermal interface material of claim 1, wherein the binder material is a polymer.

3. The thermal interface material of claim 1, wherein the binder material acts as an adhesive.

4. The thermal interface material of claim 1, wherein the fusible filler is a solder alloy having a solidus temperature above 100°

C.

5. The thermal interface material of claim 1, wherein the fusible filler is 60–

95% by weight of the total weight of the thermal interface material.

6. The thermal interface material of claim 1, wherein the fusible filler has a melting temperature of approximately between 100–

250°

C.

7. The thermal interface material of claim 1, wherein the fusible filler is stable to oxygen at temperatures up to approximately 150°

C. and relative humidity up to approximately 90%.

8. The thermal interface material of claim 4, wherein the solder alloy has a solidus temperature below 250°

C.