Optimise stencil printing with BECfinish

One possibility is our brushing process. As standard, our SMD stencils are brushed on both sides. This process allows us to reliably remove the cutting ridge as well as plasma residues left behind at laser-cut apertures. The brushing process creates two different surface topographies on the SMD stencil. While the underside (LP side) is smoothed, the squeegee blade side is slightly roughened.

BECchem: Through the chemical treatment of the stencil surface, we achieve a sustainable optimisation regarding the solder paste coming off the stencils' apertures. This results in an increased stencil durability, while reducing the cleaning cycles to the same extent. The pad edges are deburred and the surface roughness of the pad inner walls is smoothed significantly from a previous < 3 μm to subsequent < 1 μm. This creates a sharply contoured print. In addition, the surface treatment allows for easier removal of adhesive and paste from the pad aperture. This speeds up stencil cleaning considerably. The positive effects of the treatment persist throughout the entire service life of the treated SMD stencils.

In general, we recommend special treatment for small structures on the SMD stencil, such as those with a pitch of ≤ 0.65 mm, QFP/QFN, BGAs or μBGAs, as well as 0402 and 0201 patterns.

BECnano: On request, we will finish your SMD stencil with a nano-coating, for example. The high-quality stencil coating gives the stencil surface (printed circuit board side) fluxophobic properties (paste- and flux-repellent). This allows for a longer service life while reducing cleaning cycles.