PCB circuit board manufacturers in the PCB after the immersion gold process, due to the nickel surface roughness, resulting in the visual observation of the gold after the chemical gold is manifested in the gold surface roughness. This failure mode of product reliability there is a greater risk of potential failure risk in the client to carry out the soldering may appear on the tin bad. Some people are not very clear about the cause of the roughness, and there are several possible potential failure causes:
1、Potions performance factors, especially in the new tank is very easy to appear. This kind of failure can only find the potion manufacturers with the improvement, mainly from the proportion of M agent, D agent additive, plating activity and other aspects of the adjustment to improve.
2, nickel bath deposition rate is too fast, by adjusting the composition of the nickel bath solution, the deposition rate will be adjusted to the specifications required by the pharmaceutical companies in the value.
3, nickel tank potion aging or organic pollution is serious, according to the potion business requirements for regular tank.
4, nickel tank precipitation nickel plating is serious, timely arrangement of nitrate tank and the new tank.
5、Protection current is too high, check whether the anti-dissipation device is working properly and check whether the plated parts are touching the tank wall, if any, correct it in time.
On the other hand, the imbalance of the nickel vat will also lead to loose or rough deposition, the main reason for rough deposition is that the accelerator is too high or the stabilizer is too little, as to how to improve, you can add stabilizer to the experimental beaker, according to the 1m/L, 2m/L, 3m/L to do a comparative experiment. Through comparison, we can find that the nickel surface gradually becomes bright, as long as we can find the appropriate ratio of stabilizer to the nickel cylinder can be test plate and re-production.
By adjusting the light agent or current density can improve the copper surface roughness produced by electroplating, for the copper surface unclean can be considered to improve the way of grinding plate or horizontal micro-etching, in order to solve the copper surface due to unclean caused by the roughness of the gold surface; as for the sunken gold line, horizontal micro-etching can not obviously change its roughness.