Question

What is solder paste? What are its chemical components?

Answer 1

Solder Paste (Chinese name: 锡膏 ), also known as solder paste, is a welding auxiliary material widely used in the field of electronic welding. It is mainly composed of tin powder (Sn powder) and some flux (Flux) mixed evenly in a certain proportion to form a paste. The main chemical components of solder paste include the following aspects:

1. Tin powder: Tin powder is the main solid component in solder paste, and its particle size and shape will directly affect the application performance and connection effect of solder paste. Tin powder is usually finely processed to ensure the uniformity of particle size and shape, thereby improving the performance of solder paste.

2. Flux: Flux plays a vital role in solder paste. It mainly contains resin, activator, solvent and other ingredients. The main functions of flux include improving the wettability of welding, preventing oxidation, regulating the fluidity of solder, etc., thereby helping to achieve high-quality and reliable welding connections.

3. Other additives: In addition to tin powder and flux, solder paste may also contain some other additives and auxiliaries, such as thermal stabilizers, to improve the fluidity, adhesion, oxidation resistance, corrosion resistance and other properties of solder paste. The type and content of these additives will vary depending on the specific application.

In general, the chemical composition of solder paste is complex and delicate, and the synergistic effect of various components achieves high-quality connections in electronic welding. Different types of solder paste formulas will vary according to different application requirements, so their chemical composition will also vary.

Answer 2

The chemical composition of solder paste mainly includes tin (Sn) as the main component, which usually accounts for the majority of the total mass. In addition, other elements may be included to improve its performance, such as:

* Silver (Ag) and copper (Cu), which can enhance the conductivity of solder paste.

* Lead (Pb) was a common ingredient in the past to improve fluidity and ductility, but modern solder pastes are more often formulated without lead to meet environmental and health requirements.

* Solder paste also contains flux, which is usually composed of resins, activators, thixotropic agents and solvents, which help clean pads, remove oxides, adjust viscosity and promote the soldering process.

In summary, the chemical composition of solder paste is complex and is designed to meet the various needs of electronic manufacturing and assembly processes.