tTo explain what I mean...sorry for my bad Engilsh... please find short " patchwork stencil" description from EPP Europe. http://www.epp-online.de/europe/-/article/16537487/15944614/Innovators-of-laser-processing-technology /art_co_INSTANCE_0000/maximized/
" A patchwork stencil family
The PatchWork version was originally designed in order to solve the issue with quite different solder paste volumes on PCB pads for very different components. "While other suppliers offer stencils with different thicknesses, we introduced a novel approach due to our patented stencil design". As Kleemann further explains, "We cut large apertures from the stencil metal sheet in the form of the components, produce a small piece of the appropriate thickness and weld this small item on the normal basis stencil." With this technology, every special component can therefore be provided with the solder amount needed. In principle, all pad volumes to be put on the stencil surface but differing from the base material thickness capability, say 150 µm, can be lowered (reduced thickness added) or amplified (with an inserted stencil piece of more thickness). This looks like a patchwork then, whereby the resulting stencil sheet thickness is guaranteed within ± 3 µm. Since the weald seam smoothly adjusts the level of the patches, the squeegee can closely accommodate to the outline.
...anybody have idea about welding so thin SS304 foils ? Up to now I've heard about electroformed nickel and chemically etched stepped stencils only...
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