用铜导电浆料替代传统的贵金属银浆料是电子浆料发展的重要方向之一。根据氧化锌压敏电阻器对导电浆料的工艺技术要求(烧结温度不能高于600℃,否则会造成器件压敏电性能降低),在铜导电浆料中添加适量银粉,制备了新型铜导电浆料,并将其印在氧化锌压敏基片表面,通过烧结处理得到导电铜膜。采用扫描电子显微镜观察导电铜膜的显微组织,采用四探针法测定导电铜膜的电阻,考察了铜粉种类、银添加量、银粉添加方式和烧结温度对导电铜膜性能的影响。结果表明,在铜导电浆料中添加质量分数4.5%的银粉,有助于提高浆料中铜粉的烧结活性,在烧结温度为600℃时可获得结合力和导电性良好的导电铜膜。银添加量一定时,与银粉相比,银包铜粉在浆料中的分布均匀性和连结性更好。

Replacing traditional precious metal silver paste with copper conductive paste is one of the important directions for the development of electronic paste.The technical requirements of the zinc oxide(ZnO) varistor for the conductor paste (sintering temperature can not be higher than 600℃,otherwise the varistor electrical performance of the device will be reduced),a suitable amount of Ag was added to the copper paste.The copper electrode paste was printed on the surface of the ZnO pressure-sensitive substrate,and subjected to sintering treatment to obtain a conductive copper film.The microstructure of conductive copper film was observed by scanning electron microscope,and the resistivity was measured by four-probe method.The effects of the type of copper powder,the amount of silver added and the addition method on the sintering process and the properties of the copper film were investigated.The results shown that adding 4.5wt% of Ag in the copper slurry can improve the sintering activity of the copper powder in the slurry,and obtained copper electrode film with good bonding and conductivity at a lower sintering temperature (600℃).Compared with silver-powder,silver coated copper powder had better distribution uniformity and connection in slurry when silver was added.