填充碳纳米管各向同性导电胶的性能

制备了以碳纳米管(CNTs) 和镀银碳纳米管(SCCNTs) 为导电填料的各向同性导电胶, 研究了它们的电学性能、力学性能及抗老化性能, 并与传统的以微米量级的银粒子作为导电填料的导电胶的性能进行比较。研究发现: CNTs 作为导电填料时, 在填料体积分数为31 %时出现体积电阻率的最低值2. 4 ×10-3Ω·cm; 在填料体积分数为23 %时导电胶表现出最好的抗剪切性能。在填料体积分数同为28 %时, 填充SCCNTs 导电胶具有最低的体积电阻率2. 2 ×10-4Ω·cm; 填充CNTs 和SCCNTs 显示出比填充微米量级银粒子导电胶高的抗剪切强度(19. 6 MPa) 。在85 ℃、RH 85 %环境下经过1000h 老化测试结果表明: 填充SCCNTs 或CNTs 导电胶体积电阻率的变化和剪切强度的变化均不超过10 %; 而填充微米量级银粒子导电胶在老化后体积电阻率的变化和抗剪切强度的变化分别达到350 %和120 %。

Properties of isotropical conductive adhesives f illed with carbon nanotubes

Two kinds of isot ropical conductive adhesives ( ICA) were developed by using carbon nanotubes (CNTs)and silver coated carbon nanotubes (SCCNTs) as conductive fillers. The elect rical , mechanical and aging propertiesof the above ICAs were investigated and compared with those of conventional ICA filled with 1μm average-sized Agparticles. The result s indicated that the percolation threshold of bulk resistivity reaches 2. 4 ×10-3Ω·cm for ICAwith 31 % filler content of CNTs and the shear st rength of ICA with 23 % filler content of CNTs approaches themaximum value. At the same filler content of 28 % , the ICAs filled with SCCNTs show the lowest conductive resistivity of 212 ×10-4Ω·cm and the ICAs filled with both CNTs and SCCNTs exhibit higher shear st rength of 19. 6MPa. The result s of aging properties tested under the conditions of 85 ℃, RH85 % for 1000h showed that the shif t sof both bulk resistivity and shear st rength do not exceed 10 % for the ICAs filled with both CNTs and SCCNTs ,while the shif t s of conductive resistivity and shear st rength are 350 % and 120 % , respectively , for ICA filled withmicro-sized Ag particles.