The choice of PCBA through tin during PCBAprocessing is also crucial. In the through-hole plug-in process, the PCB boardis not good for tin penetration, and it is easy to cause problems such asvirtual soldering, tin cracking, and even missing parts.

We should understand these two points aboutPCBA through tin:

1. PCBA through tin requirements

According to the IPC standard, PCBAthrough-hole solder joints generally require more than 75% tin soldering. Thatis to say, the soldering of the surface inspection of the panel surface is notless than 75% of the hole height (board thickness), PCBA Through tin issuitable for 75%-100%. The plated through hole is connected to the heatdissipation 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 throughtin

PCBA poor tin penetration is mainlyaffected by factors such as materials, wave soldering process, flux, and manualsoldering.

Specific analysis of factors affecting PCBAthrough tin:

1. Materials

Tin melted at high temperature has a strongpermeability, but not all welded metals (PCB boards, components) can penetrateinto it. For example, aluminum metal, its surface will generally form a denseprotective layer automatically, and the internal molecules The difference instructure also makes it difficult for other molecules to penetrate. Second, ifthere is an oxide layer on the surface of the welded metal, it will alsoprevent the penetration of molecules. We generally use flux treatment or gauzebrush to clean.