Analysis of problems in PCB preprocessing

PCB pretreatment process greatly affects the progress and processes in the program quality, the processing program, PCB machine, material, and other conditions can cause the problem to do some analysis, to achieve a more effective operation.

1. will use the process of pre processing equipment, such as: inner front treatment line, electroplating copper pretreatment line, D/F, welding (welding)...... Wait。

2 to PCB hard solder (solder) before the processing line for example (manufacturers vary): brush group *2 - > - > > > cold water washing and pickling and drying section, sun disc knife - > > > a collection plate material receiving plate.

3., the general use of brush wheel for #600, #800 steel brush, which will affect the roughness of the surface, thereby affecting the ink and copper surface adhesion. And the brush wheel used for a long time, if not to be products were about to put, easy to produce dog bone phenomenon, which causes the surface roughening of uneven deformation and even line after printing the copper and INK have different color shape, so the whole brush work. Brush brush marks to test before operation (D/F is required plus water break test), measuring the width of about 0 brush marks. 8~1. 2mm, as the product of other differences, update the brush, the brush wheel level should be corrected, and need regular Shu lubricating oil. If the brush is not boiling water, or spray pressure is too small not fan angles, it is easy to produce copper powder, copper powder will slightly cause micro short circuit test finished (dense line area) or high pressure test unqualified situation.

Another problem that arises earlier is the oxidation of the panel, which results in surface bubbles or cavitation after H/A.

1., the front of the solid water retaining roller wrong position, so that the acid into the water into the excess, if the number of water after the sink is insufficient or insufficient water injection, will lead to acid residues on the surface.

2., the water quality of the washing section is bad, or impurities will make the copper surface of foreign body attachment.

3 if the dry or water absorbent roller is saturated, will not be effective until the product will be on the water away, the residual water and residual water on the surface of the inner hole over subsequent air knife can not fully play a role, then the bubble is likely to lead hole edge, a tear shaped type state.

4., the plate temperature is still surplus, when the temperature of the plate will make the plate of copper surface oxidation.

In general, you can use the PH detector to monitor the water pH and infrared measurement surface discharge in Yu Wen, discharging and collecting plate is added between a Diego solar disc collection plate device makes the board cooling, wetting absorbent roller is provided, it is best to have two sets of water wheel alternatively clean air knife angle in the daily operation to be confirmed before, and pay attention to the drying section of air duct with no loss or damage situation.