基于有限元分析的高性能耐高温导电胶的制备及性能研究

Preparation and properties of high-performance high-temperature conductive adhesive based on finite element analysis

针对目前导电胶基体在耐温性方面的瓶颈,选取耐高温、吸湿率低、热稳定性良好的氰酸酯作为基体,以银作为导电填料,通过COMSOL有限元仿真软件中APP开发器功能导入随机分布的导电颗粒代码,建立模型仿真,探究此新型导电胶中导电颗粒形状和大小对导电性的影响。研究结果表明,相比于银球导电胶,银片导电胶模拟的导电性能更好,当银的质量分数达到90%时,银片导电胶的电阻率比银颗粒导电胶低3个数量级。结合仿真结果,加入片状银粉,双马来酰亚胺作为增韧剂,二月桂酸二丁基锡作为固化剂,制备出银片导电胶,其电阻率随着银片含量增加而下降,在银片质量分数为50%~60%时迅速下降至43.9 mΩ·cm,之后变化平缓,胶粘的剪切强度在15 MPa以上,可以承受300℃的高温。

To address the bottleneck of conductive adhesive matrix for heat intolerance,cyanate ester was selected as the matrix for their high-temperature resistance,low moisture absorption rate,and good thermal stability.And silver was used as the conductive filler.Using APP developer function in COMSOL finite element simulation software,code was imported for randomly distributed conductive particle to establish simulation model,and the shape and size effect of conductive filler particles were explored in more detail for the new conductive adhesive.Compared with silver spheres,the simulated conductivity is better for silver sheet filled conductive adhesive.When the mass fraction of silver reaches 90%,the resistivity of silver sheet filled conductive adhesive is 3 orders of magnitude lower than that of silver sphere filled conductive adhesive.According to simulation results,silver flakes filled conductive adhesive was prepared using flake silver powders as filler,bismaleimide as tougheners,and dibutyltin dilaurate as acuring agent.The resistivity is gradually reduced at higher silver sheet content,which then rapidly drops to 43.9 mΩ·cm and becomes plateau at filler mass fraction of 50%-60%.The conductive adhesive has shear strength of above 15 MPa and can withstand high temperature of 300℃.