Uneven surface after lead-free solder paste spot soldering? Why does this situation occur?

Lead-free solder pasteUneven surface after spot welding? We believe that many manufacturers will encounter such similar problems. The occurrence of such situations is caused by various circumstances. Now, JJY solder Paste Manufacturer will provide you with a detailed understanding:

Why does this situation occur?

The content of tin. If the tin content is too low, the solder joint will not be bright. As long as the tin content is50%Above, the solder joints will be very bright.(sn63/37The effect is the best),Lead-free solder, tin-copper alloysn99.3cu0.7)Tin, silver, coppersn99Ag0.3cu0.7The alloy has very bright solder joints, and the silver content is3.0%When it comes to this, the solder joints are not very bright. However, this lead-free solder is relatively expensive and is generally not used in factories.

There were also some problems that occurred during the process. The solder paste was too dry. When the solder paste was dry, the soldering effect was also poor and would be granular. Therefore, it is necessary to ensure the wettability of the solder paste. If the electronic components are not cleaned thoroughly and there are residues left, the solder paste should not come into direct contact with the circuit board during soldering, which may cause protrusions and result in an uneven finish after soldering.

Many people find that the circuit boards after soldering have granular phenomena when using lead-free solder paste for surface mount. These are all caused by such problems. On the other hand, it is also due to the flux. This aspect also needs everyone to pay attention to. If you want to learn more about soldering, please keep following JJY Solder Paste Factory and leave a message online to interact with us.