How to reduce tin dross during wave soldering

It is inevitable that the surface oxidation of tin liquid and the interaction of tin with other metals (mainly Cu) will produce some residues. One or two days of tin dross is equivalent to a month's wages for workers, which is not a small cost. So how can we reduce the dross or the solder in the dross? Some of the products of the same industry use the red glue process to open the dual-wave mode and the cheap tin bars, so the proportion of tin dross is relatively large. Is there a better way to reduce the proportion of tin dross? Is it possible to study a tool that can squeeze out the solder from the dross?

To reduce tin dross, you can start from the following aspects:

1. Choose high-quality tin bars, especially those with anti-oxidation function; add anti-oxidation oil or anti-oxidation powder to prevent oxidation; don’t ask suppliers who do not use recycled materials for reproduction;
2. The tin furnace is heated evenly. Try to fill up the tin as much as possible to keep the tin level and reduce the drop. The smaller the peak drop, the better. The wave should be lowered as far as possible when the work is done. Add tin bars to increase the tin level and maintain the height of the liquid level. Do not fish out with a little tin dross. If it does not affect the production, there is no need to fish all the time. If the liquid level is low, it is easier to accelerate oxidation than the high liquid level. Lower the height of the tin waterfall and reduce the amount of air contact.
3. When the tin dross floats on the surface, do not directly use a colander to fish it. Use a scraper to grind the tin dross into powder on the tin furnace wall. Squeeze the tin dross with a colander, which can also avoid some waste.
4. Various attempts: adding lard, refitting tin furnace, reducing powder, reducing oil, etc. The effect of reducing oil should be better. After use, the welding quality is good, and the tin dross is much less. You only need to salvage the tin dross once a week on Saturday.
5. Use nitrogen and fill nitrogen locally, but the equipment is very important. Many modified equipment is useless if it is not handled properly;
6. Add ge and phosphorus to the raw material tin rod. In fact, phosphorus (P) element is basically added by manufacturers, that is, there are many types, and the anti-oxidation effect is very good. The effect of germanium (GE) is very good in nitrogen furnace.
7. Use reducing agent, but most equipment manufacturers require not to use it. The reducing agent is more corrosive. Please verify carefully before using it. According to feedback, it will reduce the life of the tin furnace. After someone has used the reducing agent, the blades are corroded and the furnace is perforated.

The above factors that affect the generation of tin dross, according to different working conditions, different products made, speed, operating angle, etc., have different effects. To reduce tin dross, we must start with many aspects, and try to control these factors to reduce The generation of tin dross.