高热导率Ag-AlN/聚丙烯酸酯导电胶黏剂的制备与性能

分别采用无钯化学镀法和溶液聚合法制备了Ag-AlN和聚丙烯酸酯胶黏剂,并采用超声辅助溶液共混法制备了高热导率Ag-AlN/聚丙烯酸酯导电胶黏剂。采用XRD、EDS和SEM等对Ag-AlN的结构进行分析。结果表明:经过高温和酸性清洗液清洗等处理, AlN表面的杂质被除去,并且在AlN表面形成致密的Al₂O₃层,采用无钯化学镀法制备的Ag-AlN具有优异的电导率和热导率,其电导率由AlN的10-13 S/cm提高到了7.06×102 S/cm,热导率由AlN的170 W/(m·K)提高到了230 W/(m·K)。经过计算, Ag-AlN表面的Ag镀层质量分数约为13%, Ag镀层的厚度约为80 nm。当导电胶黏剂中Ag-AlN填料的质量分数为50%时, Ag-AlN/聚丙烯酸酯导电胶黏剂的电导率为1.9 S/cm,热导率为3.1 W/(m·K)。 

Preparation and properties of Ag-AlN/acrylate electrically conductive adhesives with high thermal conductivity

Ag-AlN was prepared by electroless plating with Pd-free activation method and the acrylate adhesive was prepared by solution polymerization method. The Ag-AlN/acrylate electrically conductive adhesives with high thermal conductivity were prepared by ultrasound-assisted solution blending method. The structures of Ag-AlN were characterized by XRD, EDS and SEM etc. The results indicate that after the high temperature and cleaning by acid cleaning fluid, the impurities on surface of AlN is removed and dense Al₂O₃ layer forms on surface of AlN. The Ag-AlN prepared by electroless plating with Pd-free activation method has good electrical and thermal conductivity. The electrical conductivity of Ag-AlN reaches 7.06×10² S/cm from 10^-13 S/cm of AlN and the thermal conductivity reaches 230 W/(m·K) from 170 W/(m·K) of AlN. According to the calculation, the mass fraction of Ag layer on surface of Ag-AlN is 13%, the thickness of Ag layer is about 80 nm, and when the mass fraction of Ag-AlN filler in conductive adhesive is 50%, the electrical conductivity of Ag-AlN/acrylate electrically conductive adhesives is 1.9 S/cm, and thermal conductivity reaches 3.1 W/(m·K).