The relationship between solder paste, solder paste, and solder paste

During the SMT pcb assembly placement process, we will often come into contact with three types of pastes, namely solder paste, solder paste and flux paste. The names of the three creams are all the same, but from a professional point of view, they will be very different. Let’s take a closer look today.


In fact, from a certain aspect, solder paste, solder paste and solder paste are the same thing, that is, solder paste, but the name is different, and the English name is solder paste.
However, there are many people who treat solder paste and flux paste as a product. In fact, solder paste is solder paste. Its main component is a paste-like object composed of metal alloy powder.
The flux paste is different, it mainly acts as a flux, and its main components are rosin, activator and solvent. A certain proportion of solder paste will be added to the solder paste during the manufacturing process.
The role of solder paste: alloy powder; complete the mechanical and electrical connection between the electronic components and the circuit board.

The role of solder paste:
1. The carrier of tin powder particles provides suitable rheology and wet strength, which facilitates the transfer of heat to the soldering area, reduces the surface tension of the solder, and prevents the reoxidation of the solder and the soldering surface during soldering.

2. Remove the soldering surface and the oxide layer of tin powder particles, and form a protective layer and a safe residue layer on the solder joint surface.

3. The ratio of the soldering paste can be arbitrarily matched with various solder powders (tin, silver, copper, bismuth, lead), and can also be matched with high, medium and low temperature solder powders (100-260) ℃. After being proportioned into solder paste, it has the advantages of good solderability, continuous printability, and less residue.
In summary, solder paste, solder paste, and flux paste actually refer to two products-solder paste and flux paste. It is also very simple to distinguish the three. The solder paste and the solder paste can be distinguished from the appearance color. The solder paste is yellowish, and the solder paste will be gray or black. This is because tin powder is added to the solder paste, and the soldering paste is just a simple paste that plays a role in soldering.
This is the difference and connection of the three. I hope this article can provide you with some references in the process of understanding the SMT PCB board patch process.