In practical applications, the viscosity change of Solder Paste needs attention. Especially in high-temperature environments, excessively rapid viscosity drop will lead to stringing or irregular edges during the printing process, while excessively high viscosity can easily cause excessive printing pressure, resulting in the solder paste being squeezed out.

Wettability, one of the performance indicators of solder paste, is a key metric for determining whether the solder paste can adequately cover the pads. Solder paste with poor wettability tends to form voids or cold solder joints after heating, which not only affects electrical connections but may also lead to subsequent reliability issues.

The slump resistance of solder paste is equally important, especially when there is a long waiting time after printing. If the slump resistance is poor, the shape of the solder paste will change significantly, leading to misalignment during subsequent component placement and even the risk of bridging. Therefore, selecting the appropriate type of solder paste is crucial.

Metal content, as one of the core parameters of solder paste, is directly related to the electrical conductivity and mechanical strength after soldering. Excessively high metal content will increase costs and reduce fluidity, while excessively low content may result in insufficient Solder Joint Strength. Therefore, it must be matched according to specific process requirements.

In actual production, the storage and usage conditions of solder paste must also be strictly controlled. Temperature fluctuations, humidity changes, and exposure time after opening all affect its performance. Therefore, establishing a reasonable management process can effectively prevent an increase in defect rates caused by solder paste deterioration.

The particle size and distribution uniformity of solder paste also affect the printing effect. Fine particles pass through stencil apertures more easily, but excessively fine particles may exacerbate oxidation, while coarse particles may clog the stencil. Therefore, the appropriate particle size specification must be selected based on equipment characteristics.

Finally, the Flux composition of solder paste determines its activity and the ease of cleaning its residues. Although highly active solder paste can improve wettability, it may corrode component leads, while weakly active solder paste may not effectively remove the oxide layer. Therefore, a reasonable selection must be made based on actual process requirements.