Surface Treatment
Chemical layer consists of a single-molecule thickness of hydrophobic material applied to the surface of a stencil or PCB. Using a self assembled monolayer nano coating changes the surface energy of the substrate to prevent solder paste or moisture from sticking. The molecules orient themselves spontaneously into a highly ordered structure during the application process.
This coating is typically only a few nanometers thick, making it invisible to the naked eye.
Stencil Application
Printing accuracy improves because the paste releases more easily from the treated aperture walls. When a stencil uses a self assembled monolayer nano coating, the underside of the foil stays cleaner for longer periods between wipe cycles. This reduction in paste smear prevents bridging between adjacent pads on fine pitch components.
The low surface energy ensures that the paste is pushed toward the pad rather than clinging to the tool.
Board Protection
Moisture resistance on the finished assembly comes from applying these coatings to the bare copper or solder mask. It does not interfere with the electrical contact or the solderability of the pads during the assembly process. This treatment keeps the board clean during storage and handling before the final components are placed.
