For wave soldering, tin strip in the process of use said tin slag is too much, first of all, to distinguish whether the tin slag is normal, in general, black powder tin slag is normal, and tofu shaped tin slag is not normal. The reasons for abnormal tofu shaped tin residue are as follows:

① The main reason is the problem of crest furnace equipment: at present, the design of some crest furnaces on the market is not ideal, the crest is too high, the peak is too wide, the double crest furnace is too close and the selection of rotary pump caused by. When the wave crest is too high, the temperature reduction deviation is relatively large when the solder falls from the peak. The solder mixes with the air and rushes into the tin furnace, resulting in oxidation and semi-dissolution, resulting in the generation of tin slag. Rotary pump did not do a good job of preventive measures, constantly press the tin slag into the furnace, the chain reaction of ring plus excited tin slag produced.

② Wave soldering temperature is generally controlled relatively low, generally 280℃±5℃(for lead-free SN-CU0.7 tin bar), and this temperature is the most basic temperature required in the solder process, low temperature can not achieve a good dissolution of tin, indirectly resulting in too much tin slag.

③ Man-made relations, adding tin bar at the right time is also very critical, adding tin bar at the right time is always to keep the distance between the tin surface and the peak to the shortest.

④ There is no regular cleaning of the tin slag, so that the peak of the fall of the solder can enter the furnace as soon as possible, rather than stay on the tin slag, uneven heat, will also cause too much tin slag. The usual cleaning furnace is also very key. For a long time, there is no cleaning furnace, and the impurity content in the furnace is high, which is also one of the reasons for too much tin slag.

In order to solve the cause of excessive crest solder slag and excessive copper content, please clean the furnace regularly. It is more appropriate to change the new tin about every half year or a year.