Cleaning Sequence
Mechanical systems ensure the consistent removal of solder paste remnants from the apertures and underside of a printing screen during board assembly. Use of automated stencil cleaning prevents the accumulation of dried flux and lead-free alloys that otherwise restrict paste transfer efficiency. It relies on a combination of solvent application, vacuum extraction and lint-free paper wipes to maintain surface cleanliness.
Mechanical Operation
Solvents are applied across the entire width of the stencil while the internal wiper blade traverses the surface at a programmed velocity. A vacuum manifold removes excess liquid from the apertures to prevent bridging between fine-pitch pads on the subsequent printing cycle. This sub-system calculates the number of cycles between wet and dry passes to optimize material usage without compromising throughput speeds.
Wet wiping acts first to dissolve resins while dry passes finish the task by absorbing moisture and dislodging any trapped metal particles inside the holes.
Systematic Efficacy
Recovery units filter used solvents to extend the lifecycle of the chemicals before disposal becomes necessary. Proper integration of these modules reduces the manual labor required for maintenance during a high-volume production shift. Contamination levels on the bottom of the stencil decline sharply when the wiper tension remains calibrated to the specific thickness of the metal foil.
Regular intervals for cleaning reduce the occurrence of cold solder joints caused by insufficient volume.
