In the wave soldering process, how do we distinguish between what is the pinhole, what is the stomata, first of all we see from the surface of the external factors, the smaller the diameter of the pinhole is now on the surface, you can see the bottom. Pinholes and pores represent the bubbles in the solder joints, but they have not yet been expanded to the surface, most of which occur at the bottom of the substrate. The stomata are the larger holes in the solder joints, the interior of which is usually empty. The stomata are the large holes caused by the internal air being completely ejected. The reason for the formation of the stoma is that the solder has solidified during the time when the gas has not been completely removed, that is, the pinholes or the stoma are formed. Formed as follows:

1, wave soldering preheat temperature is too low, can not evaporate water vapor or solvent, once the substrate into the tin stove, instant contact with high temperature, resulting in a burst, it is necessary to increase the preheating temperature.

2, brightener plating solution: the use of a large number of brightener plating, the brightener and gold deposition at the same time, encountered high temperature volatility caused, especially gold-plated, use less brightener containing plating solution, of course, this To give back to the supplier.

3, wave soldering process organic pollutants: substrate and parts of the foot may produce gas and cause pinholes or pores, such contaminated materials from automatic plug-in machines, parts molding machines and poor storage and other factors. This problem is relatively simple as long as the solvent can be cleaned, if the source of the problem is found in silicone oil, you must consider changing the lubricant or release agent.

4. Wave soldering substrates contain moisture generated by plating solutions and similar materials. If substrates are made of cheaper materials, it is possible to breathe in such water vapor, which is caused by high heat evaporation during the soldering process. The solution is to place in the oven Bake at 120 ° C for two hours.