钢基体电沉积Cu、Ni膜的残余应力及其在线测量

Residual Stress and Its On-line Measurement in Cu and Ni Films on Plain Carbon Steel Substrates

采用电沉积法在碳素钢基片上分别沉积Cu膜和Ni膜,用数码相机拍摄沉积不同膜厚时基片的弯曲状况,并上传到计算机计算出薄膜内的平均残余应力及分布残余应力。结果表明:Cu膜和Ni膜的平均残余应力和分布残余应力均为拉应力;当膜厚较小时(0.5～3μm),Cu膜的平均残余应力和分布残余应力随膜厚的增加急剧降低,随着膜厚的进一步增加两种残余应力都趋于稳定;Ni膜的平均残余应力随着膜厚的增加而增加,分布残余应力总体趋势是随着膜厚的增加而增加。由实验结果可以认为Cu膜内的界面应力为拉应力而Ni膜内的界面应力为压应力,与基于Thomas-Fermi-Dirac-Cheng(TFDC)电子理论的判断结果一致。

Cu and Ni films were prepared by using electrodeposited technics.The photograph of substrates coated by Cu and Ni films with difference thickness were taken by using high pixel digital camera,and uploaded to computer.Average and distributed residual stresses in Cu and Ni films were calculated from measured data.The results show that average and distributed residual stresses in Cu and Ni films are tensile stress.Two types of stresses in Cu films decrease abruptly with the increase of the film thickness for the smaller thickness (0.5~3 μm) firstly,and then tend to be stable.Average residual stress in Ni films increases with thickness,and distributed residual stress in Ni flims increases with thickness on the whole.The types of their interfacial stress of test are the same as that of analysis based on Thomas-Feimi-Dirac-Cheng electron theory.