直流电作用下铜在液态锡里的溶解动力学

Kinetics of Copper Dissolution in Liquid Tin by Direct Current

摘要:

近年来,施加电流(电场)作为一种辅助技术在材料加工和制备技术中得到了广泛的应用。本文采用浸入法实验,通过施加直流电作用,研究了513-573 K温度范围内铜在液态锡中的溶解动力学。对溶解后铜的溶解厚度以及Sn/Cu界面IMC层的厚度进行测量,对溶解激活能以及有效电荷Z_^*进行计算,采用Comsol Multiphysics软件对电流引起的液态锡中的温度分布和流场分布进行模拟。实验结果表明：施加直流电对铜在液态锡中的速率有显著的影响,随着电流密度增加,溶解速率增加,溶解激活能减小。电流的方向对铜的溶解和界面IMC层的生长也有影响,由于电迁移的作用,当电子流动的方向和铜的溶解方向一致时,溶解速率加快,界面IMC层的厚度变薄。在电流密度为240 A/cm_²时,铜在液态锡中的有效电荷Z_^*随着温度的增加逐渐减小。

Abstract:

In this article, the dissolution kinetics of copper in liquid Tin at temperatures in the range 513~573 K were investigated under the influence of a DC current by immersion method. After dissolution, the dissolution thickness and the thickness of IMC layer at Sn/Cu interface were measured and the dissolution activation energy and effective charge Z_^* were calculated. It is found that the current had a marked effect on the dissolution rate constant. Correspondingly, the application of the current significantly decreased the activation energy of dissolution. Similarly,the direction of the DC current was shown to have an effect on dissolution and the growth of IMC. When the electronic flow was in the direction of dissolution, a further increase in dissolution and a decrease in growth of IMC layer were observed and attributed to electromigration. When the current density was 240 A/cm_², the effective charge Z_^* decreased with the increased of temperature.