Why is rosin used in soldering? What are the functions of rosin?

In soldering, it is well known that rosin is merely a flux during the process.The functions of flux can be summarized as follows: "assisting heat conduction", "removing oxides", "reducing the surface tension of the material to be welded", "removing oil stains on the surface of the material to be welded and increasing the welding area", "preventing re-oxidation", etc. So, what role will rosin play in the process?Now, let's take a look together with JJY solder Paste Manufacturer:

Rosin generally increases the fluidity of solder and is a flux. Solder paste is only used when soldering iron parts and other items that are difficult to solder. It can remove oxides from the surface of metals and is corrosive, making it a corrosive agent.
　Rosin is the oil that flows out of the trunk of a pine tree. After being melted at high temperatures into a water-like state and dried, it turns into a solid block (without a fixed melting point). Its color is dark yellow to dark red. It is an important chemical raw material. In daily life, it is mainly used as a flux in circuit board soldering.
　　In terms of Musical Instruments, rosin is applied to the bow hairs of stringed instruments such as erhu, violin and morin Khuur to increase the friction between the bow hairs and the strings. Rosin serves as an anti-slip agent for ballet learning.
　　Solder paste is accompaniedSMTA new type of welding material that emerged as The Times require. Solder paste is a complex system, which is a paste composed of solder powder, flux and other additives.

Solder pasteAt room temperature, it has a certain degree of viscosity and can initially bond electronic components in the predetermined position. At the soldering temperature, as the solvent and some additives evaporate, the components to be soldered are soldered together with the printed circuit pads to form a permanent connection.

It can be seen from this that the rosin in the flux has the following characteristics:

1Low corrosiveness: Rosin is neutral and will not corrode circuit components or soldering iron tips.

2Removal of oxide film: Rosin undergoes a reduction reaction with other substances in the flux, thereby removing the oxide film.

3Prevent re-oxidation: After rosin melts, it floats on the surface of the solder, forming an isolation layer to prevent the welding surface from re-oxidizing.

4Reduce the surface tension of the solder: Increase the fluidity of the solder, which helps the solder to wet the sheet.

5Reduce the probability of false soldering: The melting of rosin makes the solder joints more substantial, thereby reducing the probability of false soldering.

6Make the weld points brighter and fuller.

For everyone, maintaining the brightness of the solder joint is the most important thing. Although rosin can remove impurities at the solder joint, keep the fluidity of the solder and the good characteristics of the solder joint, if you still have any questions, you are welcome to consult Shenzhen JJY Industrial Technology Co., LTD. Let's learn and grow together! The solder wire, solder paste and solder rods of JJY brand are always waiting for partners to come and take them together.