Blistering on PCB surface is one of the common quality defects in the production process of PCB. Because of the complexity of PCB production process and process maintenance, especially in chemical wet treatment, it is difficult to prevent blistering on PCB surface. The blistering of PCB surface is actually the problem of poor adhesion of PCB surface, and then it is the surface quality problem of PCB surface, which includes two aspects:

PCB surface cleanliness;

The micro roughness (or surface energy) of PCB surface; All the blistering problems on the board surface can be summarized as the above reasons. The adhesion between the coatings is poor or too low, and it is difficult to resist the coating stress, mechanical stress and thermal stress generated in the subsequent production and processing process and assembly process, resulting in different degrees of separation between the coatings.

Talking about the cause of blistering on the surface of copper plated circuit board!

Micro etching in PCB copper deposition pretreatment and pattern electroplating pretreatment: excessive micro etching will cause leakage of substrate at the orifice and blistering around the orifice; Insufficient micro etching will also cause insufficient bonding force and cause blistering; It is uniform pink without reflection; In addition, the copper content of the micro etch tank, the temperature of the tank liquid, the load, the content of micro etchant and so on are all items that should be paid attention to.

PCB surface cleanliness;

The micro roughness (or surface energy) of PCB surface; All the blistering problems on the board surface can be summarized as the above reasons. Mechanical stress and thermal stress, etc., eventually lead to different degrees of separation between coatings.

Talking about the cause of blistering on the surface of copper plated circuit board!

The activity of PCB copper precipitation solution is too strong: the content of three components in the newly opened cylinder or bath solution is too high, especially the copper content is too high, which will cause too strong activity of the bath solution, rough chemical copper deposition, excessive inclusion of hydrogen, cuprous oxide, etc. in the chemical copper layer, resulting in the decline of the physical quality of the coating and the reduction of the temperature of the bath solution. In the production process, the copper plate should be thickened in time. It should not be stored for too long. Generally, the thickening and copper plating should be completed within 12 hours at the latest. It's best not to remove oil again and cause slight corrosion; For the plates that have been electrically thickened, the micro etching groove should be faded now. Pay attention to the time control. You can roughly measure the fading time with oneortwo plates to ensure the fading effect; After the plating is removed, a group of soft grinding brushes behind the brush machine shall be used for light brushing, and then the copper shall be deposited according to the normal production process, but the etching and micro etching time shall be halved or adjusted as necessary.