Alex

The big difference between a laser cut stencil and a etched stencil is the
surface of the walls inside the openings. In the direction of the flow of
the solderpaste during the printing process the laser cut stencil has a
smoother surface than a etched stencil. Additionaly, the openings of etched
stencils have kind of a double cone shape leaving a slight "nose". This
gives over all a better results in the depods, because with etched stencils
part of the solderdepot ( along the walls ) will stay in the stencil when
the stencil is lifted off. However, several prining investigations im our
lab showed, that printing down to a pitch of 0.5mm is well possible with
etched stencils. You might have to consider slightly wider openings than
with a laser cut stencil. The difference is the price. The price of a
etched stencil is determined by the size of the stencil, independend of how
many holes are etched. The price of a laser cut stecil is calculated by the
number of holes that have to be cut. Therefore, the price gap is not
constant but depends on the application.

Best regards

Guenter Grossmann


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