What are the 4 situations that may cause poor quality of the board surface during the production and processing of PCB circuit boards?
1. The problem of the substrate process of the circuit board manufacturer: especially for some thinner substrates (generally below 0.8mm), because the rigidity of the substrate is poor, it is not suitable to use a brushing machine to brush the board. This may not be able to effectively remove the protective layer specially treated to prevent the oxidation of the copper foil on the board surface during the production and processing of the substrate. It is important to pay attention to the control of processing, so as to avoid the problem of blistering on the board surface caused by the poor bonding between the copper foil of the board surface substrate and the chemical copper; this kind of problem will also exist blackening and browning when the thin inner layer is blackened Defective, uneven color, partial black and brown, etc.
2. Poor surface treatment caused by oil or other liquid contamination and dust pollution on the board surface during machining (drilling, lamination, edge milling, etc.)
3. Defective copper sinking brush plate: the pressure of the grinding plate before sinking copper is too large, causing the hole to deform and brush out the rounded corners of the copper foil at the hole or even the hole to leak the base material, which will cause Blistering phenomenon at the orifice; even if the brush plate does not cause leakage of the base material, the overweight brush plate will increase the roughness of the copper at the orifice, so the copper foil at this place is prone to excessive roughening during the micro-etching roughening process , There will also be certain quality hidden dangers; therefore, attention should be paid to strengthening the control of the brushing process, and the parameters of the brushing process can be adjusted to the optimum through the wear mark test and the water film test.
4. Water washing problem: Because the electroplating treatment of copper sinking needs to be treated with a large amount of chemical medicine, there are many kinds of acid and alkali and organic and other pharmaceutical solvents, and the surface of the board is not washed cleanly, especially the adjustment of degreaser for copper sinking will not only cause cross contamination , At the same time, it will also cause poor local treatment or poor treatment effect on the board surface, uneven defects, and cause some problems in the bonding force; therefore, attention should be paid to strengthening the control of water washing, mainly including the flow of washing water, water quality, Wash time.
