{"title":"Low melting point thermal interface material","authors":"R. Webb, J. Gwinn","doi":"10.1109/ITHERM.2002.1012519","DOIUrl":null,"url":null,"abstract":"A high performance thermal interface material has been developed that consists of a 25 /spl mu/m coating of low-melting-temperature alloy (LMTA) tinned on each side of a 50 /spl mu/m copper substrate. The alloy has a melting point below the maximum CPU operating temperature. Steady-state tests per ASTM D-5470 show 0.058 K-cm/sup 2//W at 138 kPa contact pressure. Contact pressures as small as 34 kPa are permissible. Thermal cycling tests (1000 cycles) show negligible performance degradation, if the temperature is cycled less than 12 K above the melting point. Thermal cycling 20 K above the melting point results in degradation due to formation of a low thermal conductivity intermetallic alloy at the LMTA-copper interface. Removal and replacement of the LMTA results in negligible increase in interface resistance. Manufacturing methods are discussed, and a concept for the application of LMTA to the CPU-heatsink interface is presented. The LMTA alloy offers performance competitive with the best thermal grease, without the \"messy\" disadvantages of thermal grease.","PeriodicalId":299933,"journal":{"name":"ITherm 2002. Eighth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (Cat. No.02CH37258)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"29","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ITherm 2002. Eighth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (Cat. No.02CH37258)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/ITHERM.2002.1012519","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 29
Abstract
A high performance thermal interface material has been developed that consists of a 25 /spl mu/m coating of low-melting-temperature alloy (LMTA) tinned on each side of a 50 /spl mu/m copper substrate. The alloy has a melting point below the maximum CPU operating temperature. Steady-state tests per ASTM D-5470 show 0.058 K-cm/sup 2//W at 138 kPa contact pressure. Contact pressures as small as 34 kPa are permissible. Thermal cycling tests (1000 cycles) show negligible performance degradation, if the temperature is cycled less than 12 K above the melting point. Thermal cycling 20 K above the melting point results in degradation due to formation of a low thermal conductivity intermetallic alloy at the LMTA-copper interface. Removal and replacement of the LMTA results in negligible increase in interface resistance. Manufacturing methods are discussed, and a concept for the application of LMTA to the CPU-heatsink interface is presented. The LMTA alloy offers performance competitive with the best thermal grease, without the "messy" disadvantages of thermal grease.