How to prevent lead-free solder paste from drying out?

How to preventLead-free solder pasteDry? Generally, the quality issues of this kind of product are not caused by the production control problems of the supplier, but rather by the unstable factors resulting from the design flaws of the solder paste itself. This is one of the reasons for the problems and dryness. Now, the solder paste manufacturer will explain

Lead-free solder paste is composed of solder powder and solder paste. Therefore, the quality and performance of the solder powder will affect the service life of the solder paste product, while the effectiveness of the solder paste is an important factor in determining whether it dries easily.

To formulate a reasonable catalytic activity system for solder paste and flux, two conditions must be met simultaneously: it should have good catalytic activity at the soldering temperature and be able to maintain inertness at room temperature. To achieve this goal, the active groups must be specially treated so that they do not show catalytic activity at room temperature. However, when the temperature is too high to a certain extent, they will gradually release catalytic activity. The effectiveness of solder paste refers to its physical and chemical properties remaining stable at room temperature, being less likely to crystallize or react with metals, etc.

The main function of solder paste is to remove the oxides on the surface of solder and solder joints. This is a chemical reaction process. To achieve this effect, the solder paste must be active. The catalytic active system of solder paste is the key to successful spot soldering. The stronger the catalytic activity, the stronger the ability to remove oxides, and vice versa. Due to its catalytic activity, the reaction between solder paste and tin powder always affects the storage and use of solder paste, but the response speed is very slow at low temperatures and appears very quickly at the soldering temperature.

For this reason, the response speed of lead-free solder paste and solder powder at room temperature depends on the product's service life. The active groups in the catalytic active system of solder paste that is easy to dry are usually more catalytically active at room temperature. So during the printing process, under the intervention of water vapor and oxygen, the response speed between solder paste and tin powder will also increase accordingly, resulting in drying.