用扩散理论解释激光选择性催化的原理(英文)

An Explanation of the Mechanism for Laser Induced Selective Activation Using Diffusion Theory

激光选择性催化(LISA)技术可用于高分子的选择性电镀,本文主要研究了Pd/Sn催化系统在这个过程中的原理.实验表明在催化后的清洗步骤对电镀的选择性有很大影响,由于激光处理后在高分子表面产生了多孔结构,相对于在未被激光处理的表面上,Pd/Sn催化胶团需要更长的时间才能被清洗掉.本文中,采用扩散理论描述催化和清洗后在样品表面催化胶团的浓度分布,其中催化胶团在多孔介质中的扩散系数是研究的难点.采用NanosightR颗粒检测仪器测量胶粒的尺寸,用AliconaInfiniteFocus显微镜对激光处理后的表面多孔结构进行了测量和表征.最后测得催化胶团的浓度百分比曲线,可用于表征催化和清洗时间对浓度的影响.

Laser induced selective activation （LISA） is a technique for selective plating of polymers. A palladium and tin activation system is used before electroless copper plating. The mechanism of the se- lective activation is the main focus of this paper. Due to the porous structure of the LISA surface, acti- vation colloids need longer time to be rinsed away than that for a non-laser-machined surface. It is found in experiments that the rinsing step after the activation has a significant influence on the selec- tivity of the plating. In the present work, the diffusion theory is used to describe distribution of activa- tion colloid concentration after activation and rinsing, and it is found that the diffusivity of the activa- tion colloids in porous medium is the main challenge. The size of colloids is measured by a Nanosight~ system. The porosity of the laser machined surface is described based on the measurements by an Ali- cona~ InfiniteFoeus~ microscope. Finally the concentration percentage curve for the activation colloids is obtained and used to illustrate the effect of the rinsing and activation time on the concentration.