Solder bar in the wave soldering machine welding process too much dross, the first thing to distinguish the composition of the dross is not normal. If the slag is black powder froth is normal, and tofu-like slag is not normal. For the generation of abnormal tin slag, summarize the following reasons.
1. Wave peak is too high, peak platform is too wide, double wave peak furnace is too close, and the choice of rotary pump and caused by.
Wave peak is too high, the solder from the peak down when the temperature reduction deviation is large, the solder mixed air rushed into the furnace caused by oxidation and semi-dissolution phenomenon, resulting in dross generation. Rotary pump did not do a good job of preventive measures, constantly press the dross into the furnace, back to the circle of the chain reaction plus excitement dross generation.
2. Wave soldering temperature is generally controlled relatively low, generally divided into 280 ℃ ± 5 ℃ (for lead-free SN-CU0.7 tin bars), this temperature is the most basic temperature required in the soldering process to achieve, the temperature is low tin can not reach a good dissolution, resulting in too much dross.
3. Man-made reasons. In the appropriate time to add tin is also very critical, the most appropriate time to add tin is always to keep the tin surface and the distance between the peak to the shortest.
4. Often clean up the tin slag, so that the peak of the fallen solder can enter the furnace as soon as possible, rather than staying on top of the slag, uneven heating, will also cause too much tin slag.
5. The usual clear tin furnace is also very critical. Long time no clear tin furnace, the impurity content in the furnace is high, is also one of the reasons for too much tofu-like tin dross.
It is recommended that regular clear tin furnace, about every six months or a year for a new tin more appropriate. (Change tin: that is, the wave soldering in the tin all clear out, clean each part of the tin furnace, and then install each part, add a new tin bar can be).
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