Surface bubbling is one of the common defects in PCB production process, because of the complexity of PCB production process, it is difficult to prevent the surface bubbling defects. So, what are the causes of PCB board surface bubbling?
1. The problem of base material processing. For some thinner substrate, because the substrate rigidity is poor, should not be used brush plate machine brush plate, so in the production and processing to pay attention to control, so as not to cause plate substrate copper foil and chemical copper binding force between the bad surface bubbling.
2. The surface of the plate in the process of machining (drilling, laminating, milling, etc.) caused by oil, or other liquid contaminated with dust on the surface, will cause the surface bubbling phenomenon.
3. Poor sink copper brush plate. The pressure of the grinding plate before sinking copper is too high, which causes the orifice to be deformed. In this way, the orifice bubbling will be caused in the process of plating and soldering.
4. Washing problem. Because sink copper electroplating to have to go through a large number of chemical solution treatment, all kinds of acid and alkali inorganic, organic and other pharmaceutical solvents more, not only will cause cross-pollution, but also cause local plate treatment, resulting in some problems in the binding force.
5. Microerosion in pretreatment of immersed copper and graphic electroplating pretreatment. Excessive microerosion will cause the hole to leak the base material and cause the bubbling around the hole.
6. The copper settling solution is too active. The content of the three components in the newly opened cylinder or bath of the copper deposit is high, which leads to the defects of the material quality and poor adhesion of the deposit.
7. The surface of the board is oxidized in the production process, which will also cause the surface to bubble.
8. Poor rework of copper sinking. Some of the copper plate in the rework process, due to poor plating, rework method is not correct or the rework process of micro erosion time control is not appropriate will cause surface bubbling.
9. Insufficient water washing after development, too long time after development or too much dust in the workshop during graphics transfer will cause potential quality problems;
10. The leaching tank before copper plating should be replaced in a timely manner, otherwise it will not only cause the surface cleanliness, but also cause the surface roughness and other defects.
11. Organic pollution, especially oil stains, occurs in the plating bath, which will cause surface bubbling.
12. Special attention should be paid to the electrically charged grooves of the plates in the production process, especially the plating grooves with air agitation.
Above is the PCB board surface bubbling cause analysis, hope to help the industry peers! In the actual production process, there are a lot of causes of plate bubbling, to specific analysis of the specific situation, must not be generalized.