Vertical High-speed Electroplating Copper Additive And Performance Research On Printed Circuit Boards

With the improvement of science and technology,vertical continuous plating(VCP)line is widely used in printed circuit board industry.VCP plating line relative to the traditional gantry line,due to continuous transmission transmission,with a strong ability to burn and copper uniform and good.Therefore,the plating copper agent to a higher demand,that is,when the cathode current density is high,through-hole coating to have a better ability to deep plating,and through-hole coating to meet the reliability of electrical signal transmission.At present,the domestic electroplating syrup in the cathode high current density deep plating capacity is generally low.Therefore,this subject is based on the VCP line process characteristics,research and application in the VCP line plating copper agent.In the Hull and Harlem trough the initial screening of acidic copper plating agent basic formula.After the parameters were optimized,the concentration of brightener was 10 ~ 40 mg/L,the leveling agent concentration was 50 ~ 200 mg/L and the concentration of inhibitor was 100 ~ 1000 mg/L.At the cathode current density of 3.5 A/dm~2,the test sample thickness is 2.0 mm,the hole diameter is 0.3 mm,the plating capacity of the coating is up to 70%,and the analysis method of the agent is established by cyclic voltammetry.for performing the magnification simulation experiment.The simulation experiment was carried out by simulating the VCP trunking to study the reliability of the copper layer of the optical system.The results show that the deep plating capacity can be 64.26% when the thickness of the cathode is 4.0 mm/dm~2,the thickness is 2.0 mm and the aspect ratio is 10:1,which solves the problem of thinner copper plating.Coating thermal shock resistance at 288? temperature,immersion tin after the third non-porous copper fracture.The morphology of the copper layer was enlarged by scanning electron microscopy,and no crystal was formed.The copper layer was compact.Electroplating copper foil elongation rate of more than 20%.The study on the stability mechanism of the copper plating agent shows that the consumption rate of the brightener and the leveling agent is slowed down by adding the opening stabilizer to the bath during the dynamic plating process.At the same time,it was found that the addition of aldehydes had some accelerated coating effect on the bottom of the copper plating layer at the bottom corner of the blind plate.The optimized parameters of the electroplated copper cylinder were as follows: 100 g/L copper sulfate pentahydrate,200 g/L sulfuric acid,60 mg/L chloride ion,15 mg/L polybisulfide Propane sulfonate(SPS),200 mg/L Polyethylene glycol(PEG8000),200 mg/L inhibitor Polyethylene oxide and propylene oxide copolymer(50HB),100 mg / L leveling agent L2,1.0g/L aldehyde compound,the jet pressure of 30 to 50 Hz,the bath temperature of 20 to 26°C,where in the leveling agent L2 is a nitrogen-containing heterocyclic derivative.In the VCP production line trial copper plating agent,coating reliability results show that the cathode current density 3.0 A/dm~2,the appearance of the coating board surface bright,copper surface thickness of 1.0 mil,the lowest point of copper at least 0.7 mil or more,Which solves the problem of thinner porosity of the through-hole coating at high current density.In the blind hole at the bottom of the corner without crab foot phenomenon,to achieve a blind hole to solve the bath.Copper plating layer in the temperature of 288? dip tin three times without copper fracture,electrolytic copper foil elongation of 20% or more,the acidic copper plating agent can be applied to the printed circuit board VCP line trial.