PCB Producer in China: Surface treatment and characteristics of aluminum substrate PCB laminate

PATT CIRCUITS, PCB Producer in China shares

Skills requirements for aluminum substrates laminate

The most basic skill requirement for the manufacture of aluminum substrate copper clad laminate is the smooth and flat appearance, no scratches, pits, marks, non-gold presses, air holes, rolling strips and other obvious defects, the thickness is consistent, the wave level is controlled Within 1mm, the straightness is less than 2I; the structure is fine and uniform, without segregation and slag inclusion, the internal stress is divided into symmetry and uniformity; the roughness Ra value is less than 0.28, to ensure the fine and uniform electrolysis sand. At present, many of the plate-based materials used in China are 1050A, 1060 and so on.

Alkali wash

Generally, the aluminum substrate supplied by the aluminum processing plant has a certain amount of oil on the outside, and the oil and the oxide film have an influence on the disposal of the sand. In the production of the PS plate, the hot alkali is used to wash the aluminum plate for external treatment.

The alkali solution is generally used to remove the oxide film and the oil of the surface of aluminum substrate. The ratio of common degreasing liquid is: corrosion inhibitor such as sodium NaOH, and external surfactant such as sodium gluconate, fatty acid polyoxyethylene ether solubilization and complexation.

In addition to the temperature of the oil is generally controlled at about 55 ~ 60 ° C, the role of degreasing is related to the temperature of the solution. If the temperature is too high, the people will be seriously corroded by the aluminum substrate, so it is necessary to control the temperature.

At the moment of degreasing, it is necessary to conclude by careful comparison. Because it is related to a variety of different production lines. The reel production line is related to the speed of the production line. Take 4m/min as an example. It is necessary to remove this oil to 20s at the time of degreasing.

In addition to the oil, it is necessary to pay attention to timely update. Since many saponifications, emulsions and aluminum salts are formed during the degreasing process, their presence affects the degreasing effect and prevents the saponification and emulsification of the oil on the surface of the aluminum sheet. When the oil is not strong, it is necessary to update it in time. Generally, when the circulation is performed by the alkali pump, the degreasing liquid can adhere to a long time, and if it is not circulated, the update time is shortened.

The easiest way to see the degreasing effect is to use water. The surface water of the aluminum substrate with good degreasing effect can be evenly attached and scattered. If the water is poured, the surface of the aluminum substrate is water-like, which indicates that the degreasing effect is not good. The temperature of the degreasing should be kept in mind. If the temperature of the degreasing liquid is too low, it can constitute incomplete degreasing.

Pickling

In the production process, after the alkali washing, there is a nitric acid pickling process, the purpose of which is to remove the residual substance after the alkali washing and neutralize the remaining alkali liquid on surface of aluminum substrate. The mass concentration of the nitric acid solution is 5% to 10%. When preparing, carefully dilute the nitric acid into the water and mix well. In the process of pickling, the concentration of the solution should be carefully observed and compensated in time.

Coarsening

The roughening is to form a sand structure with a desired roughness on aluminum substrate. Coarsening can not only improve the affinity of the aluminum substrate for water, improve the surface moisture content of the aluminum substrate board, and avoid the dirty surface aluminum substrate; the appearance of the roughened surface can also improve the adhesion of the aluminum substrate to the sensitizer, thereby improving the printing durability of the aluminum substrate.

The roughened sand is composed of numerous peaks and valleys. Different sand structure has a great influence on the adhesion of the water-repellent photosensitive layer and has a great influence on the application of the PS plate aluminum substrate. Characterized by the characteristic parameters of the rough contour profile of the sand surface produced by the top surface roughness tester.

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