Thermal interface materials and methods for processing the same

Abstract

A thermal interface material is provided for use to fill a gap between surfaces in a thermal transfer system to transfer heat between the surfaces. The thermal interface material includes a base material and thermally conductive particles dispersed within the base material. The thermal interface material is conditioned under reduced pressure (e.g., prior to being placed in the gap between the surfaces, while being placed in the gap, after being placed in the gap, etc.) and, within about forty-eight hours or less of conditioning, the conditioned thermal interface material is either positioned in a container that inhibits ambient gas from contacting it (either alone or applied to the surfaces), or used to transfer heat between the surfaces. As such, the thermal interface material is substantially free of cracks following exposure to thermal cycling comprising a temperature change of at least about 100 degrees Celsius for at least about 10 cycles.

1 - 29 . (canceled) 
     
     
         30 . A thermal interface material suitable for use to fill a gap between at least two surfaces to transfer heat between the at least two surfaces, the thermal interface material comprising:
 a base material; and   thermally conductive particles dispersed within the base material;   wherein the thermal interface material is conditioned and/or subjected to reduced pressure, whereby operational reliability and/or resistance to crack formation during thermal cycling is improved for the thermal interface material.   
     
     
         31 . The thermal interface material of  claim 30 , wherein the thermal interface material is conditioned under reduced pressure less than ambient air pressure. 
     
     
         32 . The thermal interface material of  claim 30 , wherein the thermal interface is conditioned under reduced pressure between about 0.01 Torr and about 750 Torr. 
     
     
         33 . The thermal interface material of  claim 30 , wherein:
 at a first time period, the thermal interface material is substantially free of cracks following exposure of the thermal interface material to thermal cycling between a temperature of about −20 degrees Celsius and a temperature of about 160 degrees Celsius for at least about 10 cycles during use of the thermal interface material to fill a gap between at least two surfaces; and   at a second time period, after exposure of the thermal interface material to ambient air for at least about eight hours, the thermal interface material exhibits crack formation following exposure of the thermal interface material to thermal cycling between a temperature of about −20 degrees Celsius and a temperature of about 160 degrees Celsius for at least about 10 cycles during use of the thermal interface material to fill a gap between at least two surfaces.   
     
     
         34 . The thermal interface material of  claim 30 , wherein:
 the thermal interface material is conditioned under reduced pressure prior to use of the thermal interface material to fill the gap between the at least two surfaces to transfer heat between the at least two surfaces; or   the thermal interface material is conditioned under reduced pressure during use of the thermal interface material to fill the gap between the at least two surfaces to transfer heat between the at least two surfaces; or   the thermal interface material is conditioned under reduced pressure prior to, during, or after positioning of the thermal interface material to fill the gap between at least two surfaces to transfer heat between the at least two surfaces.   
     
     
         35 . The thermal interface material of  claim 30 , wherein the thermal interface material is either a thermally conductive putty, a thermally conductive grease, or a thermally conductive gap pad. 
     
     
         36 . The thermal interface material of  claim 30 , wherein the thermal interface material has been conditioned under reduced pressure, whereby within about forty-eight hours or less of conditioning the thermal interface material, the conditioned thermal interface material is either positioned in a container that inhibits ambient gas from contacting the conditioned thermal interface material or used to transfer heat between at least two thermal transfer surfaces in a thermal transfer system. 
     
     
         37 . The thermal interface material of  claim 36 , wherein within about twelve hours or less of conditioning the thermal interface material, the conditioned thermal interface material is either positioned in the container that inhibits ambient gas from contacting the conditioned thermal interface material or used to transfer heat between the at least two thermal transfer surfaces in the thermal transfer system. 
     
     
         38 . The thermal interface material of  claim 30 , wherein the thermal interface material is in a container that inhibits ambient gas from contacting the thermal interface material. 
     
     
         39 . The thermal interface material of  claim 38 , wherein the thermal interface material is conditioned under reduced pressure while in the container. 
     
     
         40 . A method for processing a thermal interface material to improve operational reliability of the thermal interface material when used to transfer heat between at least two thermal transfer surfaces, the method comprising conditioning the thermal interface material by subjecting the thermal interface material to reduced pressure. 
     
     
         41 . The method of  claim 40 , wherein conditioning the thermal interface material includes subjecting the thermal interface material to a vacuum of at least about  127  Torr to reduce pressure around the thermal interface material. 
     
     
         42 . The method of  claim 41 , wherein subjecting the thermal interface material to a vacuum of at least about 127 Torr includes subjecting the thermal interface material to a vacuum of at least about 127 Torr for at least about 5 minutes. 
     
     
         43 . The method of  claim 40 , wherein conditioning the thermal interface material includes conditioning the thermal interface material includes reducing pressure around the thermal interface material to a pressure below ambient air pressure. 
     
     
         44 . The method of  claim 40 , wherein conditioning the thermal interface material includes conditioning the thermal interface material includes reducing pressure around the thermal interface material to between about 0.01 Torr and about 750 Torr. 
     
     
         45 . The method of  claim 40 , wherein conditioning the thermal interface material improves operational reliability and/or resistance to crack formation of the thermal interface material during thermal cycling. 
     
     
         46 . The method of  claim 40 , wherein the thermal interface material is substantially free of cracks following exposure to thermal cycling comprising a temperature change of at least about 100 degrees Celsius for at least about 10 cycles. 
     
     
         47 . The method of  claim 40 , wherein the thermal interface material is substantially free of cracks following exposure to thermal cycling comprising a temperature change of at least about 100 degrees Celsius for at least about 10 cycles during use of the thermal interface material to transfer heat between at least two thermal transfer surfaces. 
     
     
         48 . The method of  claim 40 , further comprising inhibiting ambient gas from contacting the conditioned thermal interface material within about forty-eight hours or less of conditioning the thermal interface material. 
     
     
         49 . The method of  claim 40 , further comprising inhibiting ambient gas from contacting the conditioned thermal interface material within about twelve hours or less of conditioning the thermal interface material. 
     
     
         50 . The method of  claim 49 , wherein inhibiting ambient gas from contacting the conditioned thermal interface material includes sealing the conditioned thermal interface material in a container. 
     
     
         51 . The method of  claim 40 , further comprising packaging the conditioned thermal interface material in a container configured to inhibit ambient gas from contacting the conditioned thermal interface material. 
     
     
         52 . The method of  claim 51 , further comprising shipping the thermal interface material in the container to an end user. 
     
     
         53 . The method of  claim 40 , further comprising using the conditioned thermal interface material to transfer heat between at least two thermal transfer surfaces in a thermal transfer system within about forty-eight hours or less of conditioning the thermal interface material. 
     
     
         54 . The method of  claim 40 , further comprising using the conditioned thermal interface material to transfer heat between at least two thermal transfer surfaces in a thermal transfer system within about twelve hours or less of conditioning the thermal interface material. 
     
     
         55 . The method of  claim 40 , wherein conditioning the thermal interface material by subjecting the thermal interface material to reduced pressure comprises removing entrained gas from the thermal interface material. 
     
     
         56 . The method of  claim 40 , further comprising installing the thermal interface material to a thermal transfer system, and wherein conditioning the thermal interface material by subjecting the thermal interface material to reduced pressure includes:
 conditioning the thermal interface material prior to installing the thermal interface material to the thermal transfer system; or   conditioning the thermal interface material while installing the thermal interface material to the thermal transfer system; or   conditioning the thermal interface material after installing the thermal interface material to the thermal transfer system.   
     
     
         57 . A thermal interface material processed in accordance with the method of  claim 40 . 
     
     
         58 . A thermal interface material suitable for use to fill a gap between at least two surfaces to transfer heat between the at least two surfaces, the thermal interface material comprising:
 a base material; and   thermally conductive particles dispersed within the base material;   wherein the thermal interface material is conditioned under reduced pressure; and/or   wherein the thermal interface material is configured such that:
 at a first time period, the thermal interface material will be substantially free of cracks following exposure of the thermal interface material to thermal cycling between a temperature of about −20 degrees Celsius and a temperature of about 160 degrees Celsius for at least about 10 cycles during use of the thermal interface material to fill a gap between at least two surfaces; and 
 at a second time period, after exposure of the thermal interface material to ambient air for at least about eight hours, the thermal interface material will exhibit crack formation following exposure of the thermal interface material to thermal cycling between a temperature of about −20 degrees Celsius and a temperature of about 160 degrees Celsius for at least about 10 cycles during use of the thermal interface material to fill a gap between at least two surfaces.