A Fundamental Study on the Copper Electroplating Method of Stress Analysis : Frequency-Dependence of Grain Growth and Slip-Initiation

Abstract

In the copper electroplating method of stress analysis, frequency effects of cyclic stresses on the proper stress τ_p for grain growth and slip-initiation in the copper plating foil, and τ_s for slip-initiation in the copper foil were investigated within the range of 1∼15 kHz. The following results were obtained : (1) The proper stress τ_p increases and grown grains appear finely with an increase in frequency. (2) τ_p depends on strain rate remarkably as compared with τ_s. (3) This is due to the fact that the grain growth in the plating foil is dominated by both the test period and strain rate for the slip in crystals, while the slip-initiation in the copper foil is dominated only by the strain rate. (4) The relation between τ_p for grain growth and the test period is represented by one curve, regardless of the frequency within 1∼150 Hz.