The Key To Cold-pressed Pin Solder Joints Lies In The Surface Quality Of The Solder Wire And The Soldering Surface.

In the female crimp contact soldering process, the core of solder joints does not rely on complex equipment, but rather focuses on two basic elements: the solder wire and the surface to be soldered. The alloy composition and purity of the solder wire determine the fluidity and wettability of the molten solder. The cleanliness of the surface to be soldered, the state of the tin plating, or the degree of oxide layer affects the wetting and adhesion of the solder to the male crimp contact substrate.

When the solder wire melts under heat, its molten material flows into the solder joint area, forming a metallic bond with the pad or lead. If there are oxides, residual grease, or dirt on the surface of the pad before soldering, it will interfere with the diffusion and wetting process between metals, leading to cold solder joints, false solder joints, or unstable contact resistance. On the other hand, if the solder wire contains impurities or has an unsuitable alloy melting point, it may also cause poor solder joints, solder balls, bridging, or uneven solder surface.

Therefore, when managing solder joint quality, priority should be given to controlling the quality of the solder wire material and the surface treatment process. Proper storage of the solder wire is essential to prevent moisture and oxidation, and to maintain the consistency of the solder wire composition. For the soldering surfaces, clean them, remove oxidation, and if necessary, pre-tin-plat or roughen the surface to improve wettability and bonding.