Dry Solder Paste is usually manifested as increased viscosity, reduced fluidity, and the occurrence of stringing or missing printing during the printing process. These changes are directly reflected in the uniformity and coverage of solder joints, and will also adversely affect the subsequent Reflow Soldering melting process.

In practice, it is first necessary to confirm whether the solder paste has exceeded its shelf life, because solder paste beyond the recommended service life will lose its original viscosity and wettability due to the volatilization of Flux components. In this case, it is difficult to restore the original state even by stirring.

The temperature and humidity control of the Solder Paste Storage environment is equally critical. High temperature will accelerate solvent evaporation, while high humidity may cause solder paste oxidation or caking. Both conditions will significantly accelerate the drying speed of solder paste, so it must be managed in strict accordance with the storage conditions recommended by the manufacturer.

During the printing process, if insufficient squeegee pressure or excessive printing speed is found, it may also cause the solder paste to fail to spread sufficiently, resulting in a locally dried or uneven solder paste layer. This will not only affect the soldering quality, but also may cause short circuits or cold soldering problems in subsequent processes.

For solder paste that has already dried, you can try to improve its state by appropriate stirring, but be careful to avoid excessive stirring, otherwise it may damage the distribution of metal particles inside the solder paste and further reduce its solderability. If the solder paste has obvious caking or delamination, it should be immediately stopped and replaced.

In daily maintenance, regularly check the usage records and storage conditions of the solder paste, timely clean up the residual solder paste on the printing press, and ensure that it is sealed and stored after each use. These are effective measures to prevent solder paste from drying out, and can also reduce material waste and production costs.

For production lines that frequently encounter solder paste drying problems, the cause should be analyzed from the source, including whether the solder paste selection is appropriate, whether the equipment parameter settings are reasonable, and whether the operation process is standardized. Only by comprehensively optimizing each link can the process problems caused by solder paste drying be fundamentally solved.