5. Micro-corrosion in pre-processing of copper precipitation and graphic electroplating
Micro-erosion will cause the hole leakage substrate, resulting in bubbling around the hole; The lack of micro erosion will also cause the lack of binding force, resulting in bubbling phenomenon; Therefore, the control of micro-corrosion should be strengthened. Generally, the micro-corrosion depth of copper precipitation pretreatment is 1.5-2 micron, and the micro-corrosion depth of graphic electroplating pretreatment is 0.3-1 micron. If possible, it is best to control the micro-corrosion thickness or corrosion rate by chemical analysis and simple experimental weighing method. Under normal circumstances, the surface of the micro etching is bright color, uniform pink, no reflection; If the color is not uniform, or reflective shows that there are quality hazards before processing; Pay attention to strengthen inspection; In addition, the copper content of the micro-etching tank, the temperature of the tank liquid, the loading capacity, and the content of the micro-etching agent are all items to be paid attention to.
6. Bad rework of sunk copper
Some copper or graphics after the rework board in the rework process because of poor plating, rework method is not correct or rework process micro erosion time control is not appropriate or other reasons will cause surface bubbling; The rework of the sunken copper plate can be directly reworked by pickling without corrosion if it is found that the sunken copper is not good on the line. It is best not to remove oil again, micro corrosion; For the plate that has been electrothickened, it should be now micro etching bath fading, pay attention to the time control, you can first use one or two plates to roughly calculate the fading time, to ensure the fading effect; After the plating is finished, a group of soft brushes are applied after the brush plate machine, and then the copper is sunk according to the normal production process, but the etching time should be halved or necessary adjustment.
7. The surface of the plate is oxidized during production
If the copper plate oxidizes in the air, it may not only cause no copper in the hole, the surface of the plate is rough, but also cause the surface of the plate to bubble; When the copper plate is stored in acid for too long, the surface of the plate will be oxidized, and the oxide film is difficult to remove. Therefore, in the production process, the copper plate should be timely thickened, not too long storage time, generally in 12 hours at the latest to finish thickening copper plating.
8. The activity of copper precipitation is too strong
The content of the three components in the new cylinder or tank of copper precipitation liquid is high, especially the copper content is too high, will cause the activity of the tank liquid is too strong, the chemical copper deposition is rough, hydrogen, cuprous oxide and so on in the chemical copper layer inclusions caused by too much coating physical quality decline and poor binding force defects; The following methods can be properly adopted: reducing the copper content (adding pure water into the tank liquid), including the three components, appropriately increasing the content of complexing agent and stabilizer, appropriately reducing the temperature of the tank liquid, etc.
9. Insufficient washing after development, too long placing time after development or too much dust in the workshop during graphics transfer will cause poor cleanliness of the board surface, and poor fiber treatment effect may cause potential quality problems.
10. Organic pollution, especially oil pollution, appears in the electroplating tank, which is more likely to occur for the automatic line.
11. Before copper plating, the acid tank should be replaced in time. Too much pollution in the tank liquid or too high copper content will not only cause the cleanliness of the board, but also cause defects such as rough board surface.
12. in winter, some factories in the production of tank liquid without heating, more special attention should be paid to the production process of charged plate into the tank, especially with air stirring plating tank, such as copper and nickel; For nickel cylinder in winter, it is best to add a heating water bath before nickel plating (water temperature is about 30-40 degrees), to ensure that the early deposition of nickel layer is dense.
In actual production process, cause the reason of the blister of the board surface is very much, the author can do brief analysis only, the blister phenomenon that causes different reason may appear to different manufacturer equipment technical level, specific situation should be specific analysis, cannot generalize, mechanically copy.
