1. The thixotropic agent is used to make the
solder paste have good thixotropy, that is to say, in the specified shear force and temperature environment, the viscosity can drop sharply, so that the solder paste can smoothly open the template and have good film release performance. However, after removing the shear force, we can recover to ensure a higher consistency of the solder paste. There is no doubt that the printing performance of the solder paste is largely determined by the thixotropic characteristics of the solder paste itself.
2. The mixing of various types of auxiliary materials above depends on the consistency of the solder paste. Soldering paste with high viscosity can form a good printing shape and greatly reduce the collapse, but it is not suitable for passing through the template, which is easy to block holes or drag wires, leaving hidden dangers for future reflow soldering, such as false soldering and tombstones etc., it is also prone to defects such as tin balls and short circuits.
3. In the high-precision SMT process, it is necessary not only that the solder paste can print a good shape, but also that the solder paste can pass through the template with small openings smoothly, and that the consistency of the solder paste should be before and after printing ( 4~8h) to keep stable, otherwise it will be difficult to guarantee the safety and reliability of multiple printings. Especially for the printing of fine-pitch SMC/SMD, the solder paste must be stirred sufficiently to effectively ensure that the consistency of the solder paste reaches the value required by the quality, so as to ensure the quality of the printed product.
4. It can become an industrial thixotropic raw material, and now mainly includes the following castor oil, carnauba wax, etc.
So far, I believe that most people have fully understood the properties that must be paid attention to when choosing Ze solder paste, and fully understand the influence of solder paste thixotropy on solder paste printing performance.