Poor tin in the wave soldering process is unacceptable shortcomings in the solder joints only partially tin, then what causes this defect happen, and today we analyze the reasons and ways to improve as follows:

External pollutants such as oil, grease, wax, etc. caused by poor tin-staining, such contaminants are usually available solvent cleaning, and sometimes when printing anti-flux stained.

SILICONOIL is usually used for mold release and lubrication, usually found on the baseplate and parts. SILICONOIL is not easy to clean. Be careful when using it. Especially when it is made of anti-oxidation oil, it can cause evaporation. Substrate caused by bad tin.

Poor storage conditions or problems in the substrate process oxidize, and soldering flux can cause poor tinning if tin can not be removed. After two times of tin, this problem can be solved.

Wave soldering flux method is not correct, resulting in unstable or inadequate foam pressure, resulting in a high degree of uneven foam or uneven so that the substrate part is not stained with flux.

Insufficient tin time or inadequate tin temperature can cause poor tinning because the tin needs sufficient temperature and time to be WETTING. Usually, the solder temperature should be higher than the melting temperature between 50 ° C and 80 ° C, and the total time for tinting should be about 3 seconds. Paste viscosity. There is also a case of poor local tin-stained, tin-poor and similar to the difference is that the local tin-poor will not be exposed copper foil surface, only a thin layer of tin can not form a full solder joints.