Flux Paste Uses, Flux Paste Ingredients.

What does flux paste do? What's included? In today's rapidly developing society, flux paste has become an indispensable flux and is widely used in many fields, such as electronics, digital, mobile, medical and other industries. So what does flux paste do in industry? And how to judge and buy? The editor of Jiajinyuan solder paste manufacturer will discuss with you below:

The role of flux paste:

1.Removal of surface oxides Due to the oxygen contained in the atmosphere, all kinds of substances are actually encapsulated by a layer of oxides, the thickness of which is about 2×10-9~2×10-8m. During soldering, the oxide film will inevitably hinder the wetting of the base metal by the solder, resulting in the inability of soldering to proceed properly. Therefore, flux must be applied to the surface of the base metal to reduce the oxide on the surface of the base metal, thereby eliminating the oxide film. In addition, the high temperature of welding tends to oxidize the surface of the welding material, and the flux paste helps to inhibit this oxidation process.

2.Improved soldering performance Flux paste removes oxides from the soldering surface. During the soldering process, a layer of oxide can easily form on the surface of the metal, which will prevent the solder from bonding well with the metal being welded. The active ingredient in the flux reacts chemically with these oxides and removes them, providing a clean interface between the solder and the metal, making the solder stronger and more reliable. For example, in the soldering of printed circuit boards (PCBs), if the oxide on the surface of the copper foil is not removed, the solder joints are prone to quality problems such as false soldering, and flux paste can effectively avoid this.

3.Reducing the surface tension of the material The surface tension of the substance will affect the quality of the weld, and another function of flux paste is to reduce the tension of the material. The surface tension of the molten solder prevents it from diffusing to the surface of the base metal, affecting the normal wetting process. When the flux is applied to the surface of the molten solder, the surface tension of the liquid solder is reduced, and the wetting performance is significantly improved.

4.Reducing Soldering Surface Tension Flux paste helps to reduce the surface tension of the solder. When no flux paste is added, the solder is difficult to spread on the solder surface due to its high surface tension. The flux paste allows the solder to flow and fill better between the pins of the component being soldered and the PCB pad, ensuring that the solder is evenly distributed throughout the soldering area. This is especially important for the soldering of small electronic components (e.g., surface mount components, SMD) to ensure that each solder joint can be soldered well, improving the success rate and quality of soldering.

<!--[if !supportLists]-->5.<!--[endif]-->Protecting the soldering surface Flux paste can also play a certain protective role during the soldering process. It forms a protective film on the welding surface to prevent the metal surface from being oxidized again during the welding process. This protective film can continue to function after the welding is completed, improving the durability and stability of the solder joint to a certain extent, and reducing the risk of failure of the solder joint due to oxidation during subsequent use.

<!--[if !supportLists]-->6.<!--[endif]-->Auxiliary heat transfer Flux paste has some thermal conductivity and can assist in the transfer of heat in the soldering area. During the soldering process, the heat provided by the soldering iron or other heating equipment needs to be efficiently transferred to the various parts being soldered to ensure that the solder is fully melted and a good soldering result is achieved. The presence of flux paste allows the heat to be distributed more evenly in the soldering area, making the entire soldering process more efficient and stable.

Flux paste plays an extremely important role in many aspects of the electronic soldering process, including improving soldering performance, reducing surface tension, protecting soldering surfaces, and aiding heat transfer, and is one of the key factors in ensuring the quality of electronic soldering.

Main components of flux:

 A. ACTIVATION: THIS COMPONENT IS MAINLY USED TO REMOVE OXIDIZING SUBSTANCES ON THE SURFACE OF PCB COPPER FILM PADS AND WELDING PARTS OF PARTS, AND HAS THE EFFECT OF REDUCING THE SURFACE TENSION OF TIN AND LEAD;

 B. THIXOTROPIC: This ingredient is mainly used to adjust the viscosity and printing performance of solder paste to prevent tailing and adhesion during the printing process;

 C. Resin (RESINS): This component is mainly used to enhance the adhesion of solder paste, and has the effect of protecting and preventing PCB re-oxidation after soldering, which is very important for part fixing;

 D. Solvent: This component is the solvent of the flux component, which plays a uniform role in the stirring process of the solder paste, and has a certain impact on the life of the solder paste.

The importance of flux paste in modern industry is self-evident, and its application is not limited to the above-mentioned fields such as electronics. In today's era of intelligent manufacturing, the role of flux paste is becoming more and more prominent as electronic products develop in the direction of smaller and more sophisticated. For example, in the manufacture of emerging wearable devices, such as smartwatches and health monitoring bracelets, where the internal circuit connections are extremely delicate, flux ensures the quality of these tiny solder joints, as these devices require highly integrated circuit connections in a limited space.

When judging and purchasing flux paste, there are many aspects to consider. First of all, from the role of flux paste, it is necessary to look at its ability to remove oxides. Simple tests, such as applying a small amount of flux paste to a sheet of metal with a slight oxide layer, can be used to see if it can reduce or disappear the oxide layer in a short period of time. For the index of improving soldering performance, you can refer to its application case in similar PCB soldering to understand whether it can effectively avoid problems such as virtual soldering.

When buying flux paste, also consider the quality of its ingredients. The degree of activity of the activator is directly related to the effect of removing the oxidizing substance, and if the activator is of poor quality, it may not be able to effectively remove the oxide from the weld part. The ratio of thixotropic agent is also critical, and an inappropriate thixotropic agent content may lead to various problems in the printing process, such as tailing, adhesion, etc. The quality of the resin affects the adhesion of the solder paste and the protective effect on the PCB, and the stability of the solvent has a non-negligible impact on the life of the solder paste.

At the same time, it is necessary to pay attention to the credibility and qualification of the manufacturer. Manufacturers like Jia Jinyuan, which has a wealth of successful research and development cases of chemical raw materials, are more likely to ensure product quality when producing flux paste. Because they have accumulated rich experience in the long-term production process, they know how to optimize the ratio of various ingredients to meet the needs of different users. In addition, manufacturers who cooperate with electronic raw material manufacturers for mutual benefit can obtain better quality raw materials, which is also an important factor in ensuring the quality of flux paste. In short, when choosing flux paste, it is necessary to comprehensively consider its role, composition and manufacturer and other factors to ensure the welding quality in industrial production.

Suzhou Nofil flux manufacturers carry out mutually beneficial cooperation with electronic raw material manufacturers, and also produce solder wire, solder rod, solder paste and flux paste for other enterprises; Rich successful cases of research and development of chemical raw material products, build quality with strength, and base ourselves on the market with integrity.