Analysis of the formation process of the bonded area in the solid state bonding and its prediction

固相键合过程不仅受键合压力和温度的影响，还受表面粗糙度的影响。当摩擦表面相互挤压时，由于表面的粗糙度，在粘接界面上形成空洞。因此，我们不能在按压后立即实现充分的亲密接触(粘合)。在这项研究中，我们通过计算机模拟分析了孔洞收缩的过程。此外，我们还开发了在压力和温度的扩展条件下估算键合过程的算法。此外，我们还给出了考虑表面粗糙度散射的最佳键合条件的确定算法。主要研究结果如下：1)孔洞收缩过程受压力和温度的控制。孔洞收缩激活能由1n(T/tv)-(1/T)图得到，其中T是绝对温度，tv是达到一定体积的孔洞收缩所需的时间。2)当孔洞收缩主要由扩散控制时，时间Tv的应力指数n在-1~-0.3范围内(n不小于-1)。3)孔洞收缩受孔洞间距的影响较大。4)微细表面粗糙度的引入促进了粘接过程的进行。5)在键合过程中，孔洞之间的间距发生变化。这是由于表面粗糙度的散布造成的。这是准确估计的重叠过程的轮廓的衰减面。6)通过考虑空穴间距的变化，如果散射不是那么大，则可以估计完整的键合时间。7)研究发现，本文提出的算法是确定最佳键合条件的有力工具。8)通过实验验证了该算法的适用性。

The solid state bonding process is not only influenced by the bonding pressure and temperature but also by the surface roughness. When the faying surfaces are pressed each other, the voids dre formed on the bond-interface due to the surface roughness. Thus, we cannot achieve the full intimate contact (adhesion) immediately after pressing the faying surfaces. In this study, we analyzed the process of the void shrinkage by the computer simulations. Also, we developed the algorithm to estimate the bonding process under the extend conditions of the pressure and temperature. Besides, we produced the algorithm for determining the optimum bonding conditions by taking account of the scattering of the surface roughness. The main results obtained is as follows.1) the void shrinkage process is controlled by the pressure and temperature. the activation energy of the void shrinkage is obtained by 1n(T/t_v)-(1/T) plots, where T is the absolute temperature, and t_v the time required to attain the void shrinkage of a certain volume. 2) When the void shrinkage is dominantly controlled by the diffusion, the stress exponent n for the time tv is in the range of -1 to -0.3 ( n is not less than - 1 ). 3) The void shrinkage is largely influenced by the spacing between the voids. 4) The introduction of fine surface asperities promotes the bonding process. 5) The spacing between the voids changes during bonding. This is due to the scattering the surface roughness. This is exactly estimated by the overlap process of the profiles of the faying surfaces. 6) By taking account of the change in the void spacing, it is possible to estimate the complete bonding time if the scattering is not so large. 7) It is found that the algorithm developed in the present study is a powerful tool to determine the optimum bonding conditions. 8) the applicability of this algorithm is verified by the experiments.