Choosing suitable solder paste is very important for SMT, because it will directly affect the quality and reliability of welding.

Understand the application requirements: First, we should be clear about our application requirements. Different electronic products may need different types of solder paste, for example, high temperature application, low temperature application, high reliability requirements and so on will affect the selection of solder paste.

Suitable alloy composition: solder paste is usually composed of tin, lead and other alloy elements. Choosing suitable alloy composition is very important for welding temperature requirements and environmental protection requirements. For example, considering the non-environmental protection of lead-containing solder paste, we all use lead-free solder paste.

Particle size: The particle size of solder paste will affect the appearance and performance of solder joints. Generally, smaller particles can provide better solder joint appearance and reliability.

Fluidity: The fluidity of solder paste determines the performance of solder paste during reflow or wave soldering. Moderate fluidity helps to ensure the wetting and uniformity of solder joints, but excessive fluidity may lead to virtual welding or missing welding.

Melting point: The melting point of solder paste should be suitable for our welding process and components. High temperature welding may require solder paste with higher melting point, while low temperature application requires solder paste with lower melting point.

Oxidation resistance: solder paste should have good oxidation resistance during welding to avoid oxidation problems during welding.

Availability and suppliers: ensure that the selected solder paste is easily available in the market and supported by reliable suppliers.

Quality certification: Some solder pastes may have specific quality certification, for example, solder pastes that meet RoHS or other industry standards.

BQC uses two famous solder paste brands, Senju and Alpha, which have the properties of high-quality soldering and lead-free solder paste.