1. What is activity
Active solder paste
refers to solder paste with added active agent. Adding active agent to solder paste is conducive to soldering. The main activity in lead-free solder paste refers to the material added with active agent. It can assist heat conduction in the SMT welding process, remove metal oxides on circuit boards and electronic components, reduce the surface tension of the welded material, and remove impurities such as oil stains on the surface of the welded material. It can increase the welding area on electronic components and circuit boards. The addition of the active agent adds to the soldering performance of the solder paste. It is a very important component of lead-free solder paste. Whether it is producing leaded or lead-free solder paste, manufacturers will add varying amounts of active agents to it.
2. why not add more
The activity of lead-free solder paste is mainly to help the solder paste provide corrosion to the oxides on the circuit board after melting. The better the activity of the solder paste, the more corrosive it is. In the SMT process, the circuit board with the electronic components pasted will pass through the reflow oven, and the active agent added by the lead-free solder paste manufacturer will play a role in the circuit. The metal oxides of the boards and electronic components are corroded, so that the metals on the electronic components and circuit boards show their original appearance. At this time, after the metal components in the solder paste are melted, the pins of the electronic components can be welded to the circuit board. Since the activity of the solder paste has a great direct relationship with the added active agent, many people will suggest that Why don't you add enough active agent in lead-free solder paste at one time? You have to wait until the solder paste is not active enough in the actual soldering process to increase it. From the above analysis, it is not difficult to see the activity of the solder paste. It is the corrosiveness of the solder paste. If a lot of active agents are added to the solder paste at one time, the corrosion performance of the solder paste will be greatly improved. If too much corrosive agent is added to the solder paste, it will damage the circuit board and shorten the Over the life of the soldered circuit board, the results will be more than worth the loss.