兼容性Cu^(2+)溶液改性EP基材催化铜导电线路沉积

Modification Epoxy Resin Substrate with Compatible Cu^(2+) Solution to Catalyze Copper Circuits Deposition

印制电路板(PCB)基材预设位置活化是选择性化学镀铜法制作导电线路的关键工艺。以乙酸铜为催化剂前驱体、硫脲为络合剂、双酚A二缩水甘油醚为环氧树脂(EP)预聚物、试剂593为固化剂和丙二醇甲醚为溶剂,设计出一种基于EP兼容的Cu^(2+)溶液,借助喷墨打印机把兼容性Cu^(2+)溶液印刷在EP基材表面,采用选择性化学镀铜法加成制备了铜导电线路。基于量子化学密度泛函理论,模拟兼容性Cu^(2+)溶液中硫脲分子与Cu^(2+)之间的络合反应,利用红外光谱和拉曼光谱对兼容性Cu^(2+)溶液中特殊官能团进行表征。结果表明:铜线路中晶粒结晶度良好且堆积致密,其电阻率低至2.62×10^(-6)Ω·cm;在改性层的帮助下,铜线路与EP基材之间的结合力达到5B级别。因此,EP基材兼容性改性催化铜导电线路沉积具有工艺简单、经济环保的优点,这对其他常用树脂基材兼容性改性加成制备PCB具有一定的参考价值。

The predesigned position activation of printed circuit board(PCB)substrates is the key process for manufacturing circuits by selective electroless copper plating.A compatible Cu^(2+)solution for epoxy resin(EP)substrate was designed with copper acetate monohydrate as a catalyst precursor,thiourea as a complexing agent,bisphenol A diglycidyl ether as a prepolymer of EP,reagent 593 as a curing agent,and 1-methoxy-2-propanol as a solvent.The compatible Cu^(2+)solution was printed on EP substrate surface by an inkjet printer.Copper circuits were additively fabricated by selective electroless copper plating.Based on quantum chemistry density functional theory,the complexation reactions between thiourea molecules and copper ions were simulated in the compatible Cu^(2+)solution.The special functional groups in the compatible Cu^(2+)solution were characterized by infrared spectroscopy and Raman spectroscopy.The results show that the resistivity of copper circuits is as low as 2.62×10^(-6)Ω·cm attributing to the good crystallization and dense accumulation of copper grains.The adhesion between copper circuit and EP substrate is up to 5B level with the help of the modified layer.Therefore,compatible modification EP substrate to catalyze copper circuits deposition has the advantages of simple process,economic and environmental-friendly,which provides a valuable reference for compatible modification on other common resin substrates in additive manufacturing of PCB.