Deposition Performance
Metric of process capability identifies the percentage of the intended solder paste volume that successfully passes through a small stencil opening. Measuring micro aperture transfer efficiency allows manufacturers to quantify the performance of the printing process for fine pitch components. This value is the ratio of the actual volume measured by an inspection system to the theoretical volume of the aperture.
High values indicate a clean release with minimal residue left on the stencil walls.
Stencil Treatment
Surface treatment of the stencil significantly improves the release characteristics of the solder paste. Nano-coatings reduce the friction between the paste particles and the stainless steel walls, which directly increases the micro aperture transfer efficiency during high speed production. Without these treatments, the small surface area of the pad cannot provide enough pull to overcome the wall friction.
Consistent transfer volumes are necessary to prevent insufficient solder defects and head-in-pillow failures.
Inspection Logic
Automated systems compare the height and area of each paste deposit against the programmed stencil data. When the micro aperture transfer efficiency falls below a set threshold, the machine flags the board for rework. Maintaining a stable efficiency across the entire panel ensures that the final solder joints meet the structural requirements of workmanship standards.
