超低热阻触变型导热硅脂的制备与性能研究  

Preparation and Properties of Ultra Low Thermal-Resistance Thixotropic Thermal Silicone Grease

作　　者：林菊香 LIN Juxiang(Shenzhen Faymo Technology Co.,Ltd.,Shenzhen 518100,China)

机构地区：[1]深圳市飞墨科技有限公司,广东深圳518100

出　　处：《有机硅材料》2023年第6期28-35,共8页Silicone Material

摘　　要：以聚二甲基硅氧烷、不同粒径的球形氧化铝以及偶联剂等为原料制备导热硅脂,探讨了不同的填料复配比例、不同粒径分布以及粉体改性加工工艺对导热硅脂基本性能与老化等性能的影响。采用黏度为100 mPa·s和500 mPa·s搭配的聚二甲基硅氧烷为基础聚合物,不同粒径的球形氧化铝的搭配以及粉体改性工艺,并对大粒径粉体进行筛除卡断处理,使其粒径分布集中,选择粒径分布窄的球形氧化铝作为导热绝缘填料,在兼具良好流淌特性的前提下,提升硅油与填料的质量比至1∶14.14,制得热导率3.23 W/(m·K),热阻低至0.083℃·cm^(2)/W的触变型导热硅脂。该导热硅脂黏度低,流变性能好,满足印刷工艺要求的同时,具有渗油率低及抗垂流开裂特性,且其经过高温老化、高温高湿老化以及冷热循化冲击老化1000 h后热阻增加小于5%,满足长期使用的可靠性要求。Using polydimethylsiloxane,spherical alumina with different particle sizes and coupling agents as raw materials,the effects of processing on different filling ratios,distribution of particle size and powder modification on the basic properties and aging properties of thermal conductive silicone grease were discussed.The polydimethylsiloxane with viscosity of 100 mPa·s and 500 mPa·s as the base polymer,the spherical alumina with different particle sizes and powder modification process,and the screening treatment on large particle size powder to concentrate their particle size distribution,spherical alumina with narrow particle size distribution was selected as the thermal insulation filler,and the filling ratio of silicone oil and filler was increased to 1∶14.14 under the premise of good flowing characteristics.The thixotropic thermal conductive silicone grease was prepared with the thermal conductivity of 3.23 W/(m·K),and the thermal resistance became as low as 0.083℃·cm^(2)/W.The obtained thixotropic thermal grease has low viscosity,good rheological property,and meets the requirements in printing process.At the same time,it had low oil permeability and vertical cracking resistance,and its thermal resistance increased by less than 5%after high temperature aging,high temperature and high humidity aging and cold-hot circulation impact aging for 1000 h,meeting the reliability requirements for ongterm use.

关 键 词：导热硅脂 超低热阻 触变性 抗垂流开裂 低渗油率 

分 类 号：TQ324.21[化学工程—合成树脂塑料工业]