Device for coating the wall of holes in electrical printed circuit boards or multilayer printed circuit boards

摘要

In a device for coating the wall of holes in electrical printed circuit boards or multilayer printed circuit boards (3), the objects which are to be treated are moved forwards by a transportation system (6), horizontally aligned underneath the level (13) of a treatment liquid. Located underneath the movement path of the printed circuit boards or multilayer printed circuit board (3) is a flow guide box (16) which is divided by partition walls (20, 21) into a plurality of chambers (17, 18, 19). Seen in the movement direction of the printed circuit boards or multilayer printed circuit board (3), the chambers (17, 18, 19) are alternately connected to the pressure side and the suction side of a pump which conveys the treatment liquid. The top of the chambers (17, 18, 19) is formed by a perforated plate (24) which has a large number of apertures (25) which are distributed over the entire surface of the perforated plate (24). In this way, the printed circuit boards (3) alternately have a laminar flow applied to them over a large area from below and are sucked into a laminar flow over a large area from below essentially throughout the entire time during which they are passing through the treatment liquid. As a result of the long action time achieved in this way for the flows whose direction alternates, and as a result of the relatively low flow speeds which can be achieved at the same time in this case, the through-holes which are present in the printed circuit boards or multilayer printed circuit boards (3) are on the one hand completely and reliably ... Original abstract incomplete. <IMAGE>