Joint results may vary even when the tool and solder remain unchanged, because substrates enter the process in different surface conditions. Oils, fingerprints, oxide films, residues, and storage history affect wetting. Surface preparation should be documented as part of the process.
Inspect the starting surface
Record coatings, plating, discoloration, oxidation, and contamination risk. If the substrate was stored for different periods or exposed to different environments, note that history.
Select compatible cleaning
Surface cleaning must suit the material, coating, and downstream process. Check compatibility and safety requirements before choosing a solvent or chemical. Some surfaces may need specified preparation, while others may be damaged by aggressive treatment.
Minimize recontamination
Use clean fixtures and handling tools, avoid touching the target area, and standardize the time between preparation and soldering. Keep storage and transport consistent.
Separate preparation from soldering variables
When troubleshooting poor wetting, do not change surface treatment and machine settings simultaneously if you need to isolate the cause. Prepare equivalent samples and compare them under one consistent soldering procedure.
Trying to improve wetting consistency? Tell Sonic4Lab your substrate materials, surface finish, cleaning method, and solder alloy to discuss useful variables to evaluate.
