The choice of PCBA through tin during PCBA processing is also crucial. In the through-hole plug-in process, the PCB board is not good for tin penetration, and it is easy to cause problems such as virtual soldering, tin cracking, and even missing parts.
We should understand these two points about PCBA through tin:
1. PCBA through tin requirements
According to the IPC standard, PCBA through-hole solder joints generally require more than 75% tin soldering. That is to say, the soldering of the surface inspection of the panel surface is not less than 75% of the hole height (board thickness), PCBA Through tin is suitable for 75%-100%. The plated through hole is connected to the heat dissipation layer or the heat dissipation layer that plays a role in heat dissipation. PCBA tin penetration requires more than 50%.
Second, the factors affecting PCBA through tin
PCBA poor tin penetration is mainly affected by factors such as materials, wave soldering process, flux, and manual soldering.
Specific analysis of factors affecting PCBA through tin:
1. Materials
Tin melted at high temperature has a strong permeability, but not all welded metals (PCB boards, components) can penetrate into it. For example, aluminum metal, its surface will generally form a dense protective layer automatically, and the internal molecules The difference in structure also makes it difficult for other molecules to penetrate. Second, if there is an oxide layer on the surface of the welded metal, it will also prevent the penetration of molecules. We generally use flux treatment or gauze brush to clean.
