高深径比通孔电镀铜的添加剂优化

以75 g/L CuSO4·5H2O、230 g/L硫酸和0.1 g/L十二烷基苯磺酸钠(SDBS)组成的溶液作为基础镀液,并以Cl-、聚乙二醇(PEG-10000)、聚二硫二丙烷磺酸钠(SPS)及2,2′-二硫代二吡啶(2-PDS)作为添加剂,在温度(23±2)℃、电流密度1.8 A/dm2和空气搅拌的条件下对印制电路板(PCB)上深径比为10∶1的通孔电镀铜。以深镀能力作为评价指标,通过正交试验对添加剂用量进行优化,得到较优的组合为:SPS 5 mg/L,PEG 250 mg/L,Cl- 60 mg/L,2-PDS 2 mg/L。采用该组合添加剂电镀通孔时,深镀能力高达112.9%,镀层均匀、细致、平整,抗热冲击性能良好,符合PCB生产对可靠性的要求。

Optimization of additives for copper electroplating of through holes with a high aspect ratio

The copper electroplating of through holes(THs)with a aspect ratio of 10:1 on print circuit board(PCB)was carried out in a bath basically comprising CuSO4·5H2O 75 g/L,sulfuric acid 230 g/L,and sodium dodecyl benzenesulfonate(SDBS)0.1 g/L with additives including Cl-,polyethylene glycol(PEG-10000),bis-(sodium sulfopropyl)-disulfide(SPS),and 2,2′-dithiopyridine(2-PDS)at temperature(22±3)℃and current density 1.7 A/dm2 under air agitation.The combination of additives was optimized through orthogonal test using throwing power as an evaluation indicator,i.e.SPS 5 mg/L,PEG 250 mg/L,Cl-60 mg/L,and 2-PDS 2 mg/L.The throwing power of the copper electroplating bath with the optimal combination of additives was up to 112.9%.The copper coatings obtained were uniform,compact,and smooth,and had good resistance to thermal shock,meeting the requirements of reliability for PCB application.