Generally, solder paste has a certain shelf life. The unopened printed solder paste can be kept for about a week at room temperature, but it also depends on whether the solder paste formula of different manufacturers is stable, and it will be scrapped in a few days. Syringe solder paste is usually placed at room temperature, depending on the internal vacuum degree, and it is recommended not to exceed 3 days.
Suzhou Duma Technology (a school-run enterprise of Changzhou University of Science and Technology) solder paste is placed at room temperature for 2 weeks, and it will not affect the welding quality if it is opened for 24 hours.