Could solder paste manufacturers briefly discuss the importance of solder powder?

Tin powder is one of the most important raw materials for processing and manufacturing solder paste. It is stable in the air, but the prerequisite is to store it properly. Once it is not stored properly, tin powder is prone to oxidation, especially in a humid environment. It is an extremely important material in the electronics industry. Tin is one of the minerals with a relatively high degree of development and utilization among non-ferrous metals in China at present, and is widely used in industries such as metallurgy, electronics, electrical appliances, chemical engineering, building materials, machinery and food packaging. With the continuous development of lead-free trends worldwide, electronic product manufacturers will apply more tin powder materials to their products. Meanwhile, with the continuous enhancement of environmental awareness, the non-toxic and environmentally friendly properties of tin powder will be increasingly applied in packaging fields such as medicine, chemical engineering, light industry, food, health care, and artworks. The importance of tin powder is becoming increasingly evident. Below, the solder paste manufacturer will explain it to you:

The surface of tin powder is significantly a silvery white, smooth and soft metal(Cubic crystal system and cubic crystal system)It is flexible. It has multiple solubility properties. It is readily soluble in concentrated hydrochloric acid, sulfuric acid, aqua regia, concentrated nitric acid, and hot caustic soda solutions. It is slowly soluble in cold dilute hydrochloric acid, dilute nitric acid, hot dilute sulfuric acid, and cold caustic soda solutions. It dissolves even more slowly in acetic acid. Melting point:231.9°C(lit.)Boiling point:2270°C(lit.)Density:7.3Solubility:H2O:insoluble.

In addition to the significant difference in the composition list of tin powder, the size of the tin powder particles also varies. The smaller the tin powder, the less likely it is to be printed on the circuit board from the steel plate. Moreover, it is not advisable to leave residue at the edge of the steel plate's cut, which is beneficial for improving the printing capacity of fine-pitch workpieces and can relatively obtain the amount of solder paste printed for consistency inspection. Moreover, smaller tin powder can also enhance its own collapse resistance, and the actual wetting effect is also better.

However, the particles of tin powder are not necessarily the smaller the better. Compared with solder paste containing impurities, solder paste with smaller tin powder is more prone to oxidation. This is why nitrogen gas is generally needed during operation(N2)To reduce its oxidation rate and achieve an excellent tin uptake effect, these are all selected5When welding and processing parts with large welding pads (such as shielding frames) at or above the number. The principle of its production is that the smaller the tin powder, the larger the area it has come into contact with the air, and the more prone it is to oxidation. When choosing solder paste, it is not the case that the smaller the particles of the solder powder, the better. Instead, the choice should be based on the actual needs of the product. At the same time, the standard deviation of impurities in the solder paste should also be stipulated.

MostsmtIt is widely adopted in welding processing3Tin powder is used for fine spacing or small pad bonding4Tin powder, the finer the tin powder, the more expensive it is. The finer the powder, the more complex the production and processing technology will be, and the more difficult it is to process.

Tin powder comes in two shapes: spherical and oval. The spherical type is easy to print, has a small surface area, a low oxidation degree, and the solder joints are shiny. The oval shape is slightly inferior. Based on the above judgment, we can clearly understand that tin powder has different compositions, various impurities of different sizes, and changes in appearance. Any of these characteristics can have adverse effects on the production process of solder paste, the final usage method of solder paste, solderability, product quality, etc. Therefore, it is advisable to select and purchase itSolder pasteWhen doing so, one must always be attentive and want to understand about itSMTFor any other questions regarding solder paste in surface mount technology, please feel free to come and consult us!