Hard chrome plating manufacturers analyze the delamination of plating during the plating process of printed circuit boards. Hard chrome plating manufacturers analyze the delamination of plating during the plating process of printed circuit boards.
During the PCB plating process, there are many holes in the masking of the dry film. Many customers believe that after the hole is broken, the film temperature and pressure should be increased to enhance the bonding force. In fact, this view is incorrect because the temperature and pressure are too high. The solvent of the resist layer is excessively volatilized, so that the dry film becomes brittle and thin, and it is easy to be broken through the hole during development. We always have to maintain the toughness of the dry film. Therefore, after the occurrence of the hole, the introduction of the mold plating can be done from the following points. improve:
Exposure energy is high or low Under the irradiation of ultraviolet light, the photoinitiator that absorbs the light energy decomposes into a radical to initiate the photopolymerization of the monomer to form a bulk molecule which is insoluble in the solution of the dilute alkali. When the exposure is insufficient, due to incomplete polymerization, during the development process, the film swells and becomes soft, resulting in unclear lines or even falling off of the film, resulting in poor bonding of the film to copper; if overexposed, it may cause development difficulties, and also during the electroplating process. The warp peeling occurs in the middle to form a plating. So it is important to control the exposure energy.
After the surface of copper is treated, the cleaning time is not too long, because the cleaning water also contains certain acidic substances. Although its content is weak, the surface plating of the mold reminds that the influence on the surface of the copper cannot be taken lightly. The cleaning should be carried out strictly according to the time specified in the process specification. .
The main reason for the gold layer falling off the surface of the nickel layer is the problem of surface treatment of nickel. A poor surface activity of nickel metal is difficult to obtain a satisfactory effect. The surface of the nickel coating is prone to produce a passivation film in the air. If not treated properly, the gold layer is separated from the surface of the nickel layer. If the plating is performed improperly, the gold layer will be detached from the surface of the nickel layer, that is, peeled off. The reason for the second aspect is that after the activation, the cleaning time is too long, causing the nickel surface to regenerate the passivation film layer, and then performing gold plating, which inevitably causes the coating to fall off.
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Http://news.chinawj.com.cn Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn
