Vantico Limited

Ulrich Lacher

Kurt Meier

Two sided printed circuit boards with very small rings surrounding the plated though holes can be produces by starting with a through-plated copper laminate, and coating it with a liquid negative electrodeposition photo-resist. The coated photo-resist is exposed to light through a mask set up so that the light does not shine on the through-platings. The non-crosslinked photo-resist is subsequently removed. A metal or a metal alloy resist is laid down by electrodeposition on those surfaces from which the non-crosslinked photo-resist has been removed. Finally, the crosslinked photoresist material is removed and the exposed copper laminate is treated with a copper-etching solution to completely remove the copper surface that has been uncovered.

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Inzlingen, Germany

Ulrich Lacher