Why does the copper plate of the PCB board blister?

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PCB causes some factors in the quality of the board during production and processing:

1. PCB substrate "CCL" process problem; especially for some thin substrates, (generally 0.8mm or less), because the substrate rigidity is poor, it is not appropriate to use the brush machine to brush the board, this may not be possible Effectively remove the protective layer specially treated in order to prevent oxidation of the copper foil on the board surface during the production process. Although the layer is thinner, the brush plate is easier to remove, but there is a great difficulty in chemical treatment, so it is important to control the production and processing. In order to avoid the problem of blistering of the board caused by poor bonding between the copper foil of the board surface and the chemical copper; this problem may also cause blackening and browning when the thin inner layer is blackened, and the color is not Both, partial black browning is not a problem.

Double-layer Aluminum Based PCB

2. PCB copper sinking plate is bad: the pressure of the pre-sinking plate is too large, causing the hole to deform and brush out the copper foil round hole or even the hole to leak the substrate, so that it will be in the process of copper plating and soldering Causes foaming of the orifice; even if the brushing plate does not cause leakage of the substrate, the excessively heavy brushing plate will increase the roughness of the copper of the orifice, so that the copper foil is likely to be excessively coarsened during the microetching roughening process. Phenomenon, there will be a certain quality hazard; therefore, we must pay attention to the control of the brushing process, the process parameters of the brush plate can be adjusted to the best through the wear scar test and water film test.

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3. PCB washing problem: Because the copper plating treatment has to undergo a lot of chemical syrup treatment, all kinds of acid-base and non-polar organic solvents and other solvents are more, the board surface is not washed, especially the copper-plating adjustment degreasing agent will not only cause crossover. Contamination, at the same time, may cause partial treatment of the board surface or poor treatment effect, uneven defects, causing some problems in bonding; therefore, attention should be paid to strengthening the control of water washing, mainly including cleaning water flow, water quality, washing Time, and control of the dripping time of the board; especially in the winter, the temperature is lower, the washing effect will be greatly reduced, and more attention should be paid to the control of the washing.

In the case that some of the plants in the winter are not heated, it is necessary to pay special attention to the charging of the plates in the production process, especially the plating tank with air agitation, such as copper and nickel; Add a warm water washing tank (water temperature is about 30-40 degrees) to ensure good compaction of the initial deposition of the nickel layer.
In the actual production process, there are many reasons for causing foaming on the surface of the board. Now we can only do a brief analysis. For different manufacturers, the technical level of the equipment may cause blistering caused by different reasons. The specific situation should be analyzed in detail, and it is not possible to generalize ;