A Simulative Study on Invar Electrodeposition with Electroplating Tank

• Main Authors: Yu-Chih Lee, 李有植
• Other Authors: 張厚謙
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/vry29z

碩士 === 國立中興大學 === 化學工程學系所 === 107 === Nowadays, the fine metal mask required by the industry, deposited by Invar plating with a low thermal expansion coefficient and the thickness should be less than 30 μm with a unit plating deposition area of 200×700 mm2. Using the software to simulate the deposition thickness of 30 microns or less as the target, we can explore the experimental parameters’ relationship between deposition thickness and uniformity. As an experimental design proposal, we can shorten the time for experiment and have effect of saving energy and reducing environmental pollution. This study used COMSOL Multiphysics 5.3 finite element method to combine with microfluidic and electrodeposition modules for the simulation of electroplated Invar deposition. The geometry of plating tank is to set up two parallel plates for anode and cathode, seven nozzles with left and right symmetry for inlet, top coverless for overflow as a simple device. The depth analysis of the cathode surface is carried out to investigate the thickness of the Invar deposition on the cathode surface under controlling laminar flow, secondary current distribution, current density, charge transfer coefficient and inlet fluid flow rate. After that, using the experimental design of the response surface to select the optimal physical parameters. Finally, one or both side baffles are added to the nozzle of the plating tank to compare the influence of the geometric factors on the fluid flow rate and the deposition thickness. The results show that deposition thickness of the Invar was mainly affected by the current density. Influenced by the current density and the charge transfer coefficient, the deposition uniformity becomes better as the average deposition thickness increases. Besides, comparing the effect of flow field and deposition thickness between cathode and ahode by adding baffles on both sides of the nozzle or not. According to the results, adding a baffle helps to increase the fluid flow rate 128.6% between cathode and anode, enhancing the deposition thickness 1.2%. While adding a double-sided baffle can direct the fluid to the cathode, making the velocity distribution stable and increasing the fluid flow rate 236.7%, enhancing the deposition thickness of Invar.