Etching plant for printed circuit boards - using squeegee rollers to remove surplus etchant from boards

摘要

Device for liq. treatments, esp. the etching of printed circuit boards which travel on a conveyor through the treatment zone(s). The novelty is the use of =2 squeegee rollers aligned at 90 degrees to the direction in which the boards travel and between which the boards pass so tht at least part of the treatment liq. is removed. In the pref. plant, two pairs of squeegee rollers are located one behind the other, at least one roll in a pair being driven either by its own motor or a gear drive obtd. from the gear box driving the conveyor. Normally, the boards carry a substantial amt. of treatment liq. out of a treatment zone; the liq. is valuable and in a large etching plant the drag-out can total 9 kg of Cu per day. The invention reduces this loss.