Research Of Electroless Copper Plating And Design Of Production Line

Electroless copper plating isn’t influenced by the size, shape and conductivityproperty of matrix. It is a very effective method to metalizing the surface of nonmetalmaterial and its industrial application is expanding. It is a hot topic for chemists andmaterials scientists. In this work, quantum chemistry calculation was used to selectnew palladium complexing agents. Surface bound palladium on polyimide wereprepared by a surface modification method.The factors influencing the deposition rate,the bath life and the brightness of the deposits were investigated. Based on thereplenishment of the bath components, the bath life was determinated. EDS, ESEMand XRD techniques were used to characterize the composition, surface and structureof deposits.Quantum chemistry calculation was used to select new palladium complexing agents.According to the plating leakage proportion during electroless copper plating,2-aminopyridine is the optimized complexing agent in activation solution. Theoptimized formulation of activation solution contained:2-aminopyridine1.2g/L,PdCl₂·2H₂O0.3g/L, NH₄Cl0.3g/L, pH=10.5Surface modification method was usedto prepare surface bound palladium on polyimide. The palladium have good catalyticactivity and have good adhesion with polyimide.The factors influencing the deposition rate, the stability and the brightness of thedeposits were studied. The results show that: the greater concertration of Cu²⁺, Ni²⁺,formaldehyde and potassium sodium tartrate, the higher deposition rate and lowerstability; selenium dioxide can make the deposits brighter; trace potassium rhodanidecan enhance the stability; trace2,2’-dipyridyl can enhance the stability, decrease thedeposition rate and increase the brightness of the deposits. With the increasement ofpH and temperature, the deposition rate become higher while the stability andbrightness of the deposits becomes lower. The optimized formulation of electrolesscopper plating solution contained12g/L copper sulfate,60g/L K–Na tartarate,8g/LEDTA disodium,1.2g/L nickel sulfate,16mL/L formaldehyde,1mg/L2,2’-dipyridyl,2mg/L potassium sulfocyanate,44mg/L selenium dioxide,12.5pH.The temperature was held at35℃. The deposition rate is0.032μm/min and the grainsize of copper deposit is26.4nm. The bath life is up to2.3cycles under addingcomponents according to required.Design electroless copper plating production line. Complete the selection of electroless copper plating equipment and calculate the cost. Design temperature, pHand concertration automatic control system by using universal control unit PLC ascontrol core. Design the process of removing the by-products in the electroless copperplating solution, the process of recovering Pd²⁺, the process of treating rinse water byelectrodialysis technology, chemical precipitation and solid phase extraction.