微机电系统器件电镀镍厚度均匀性的模拟与改进

Simulation and improvement for thickness uniformity of electroplated nickel coating on metal components of micro-electro-mechanical system

微机电系统(MEMS)金属基器件经常存在电镀镍层厚度不均匀的问题,采用大型有限元分析软件ANSYS对电镀过程的电场分布进行建模分析。探讨了片内辅助阴极的线宽及其与微结构单元的距离对电镀层均匀性的影响。通过正交试验对片外辅助阴极相关的参数──挡板通孔直径、挡板与基底的距离、铜环壁厚及其与基底的距离进行优化,得到合理的电镀工艺条件。

In respect of the thickness nonuniformity of nickel coatings frequently occurred in electroplating on metal components of micro-electro-mechanical system(MEMS), the distribution of electric field during electroplating process was modeled and analyzed using ANSYS, a finite element analysis software. The effects of the size of in-chip auxiliary cathode and its spacing with respect to microelement on the uniformity of nickel coating were discussed. The parameters related to the out-chip axillary cathode including the size of through hole on baffle, the spacing between baffle and substrate, as well as the wall width of copper ring and its spacing with respect to substrate were optimized by orthogonal test, and suitable conditions for electroplating were obtained.