Automatic multilayer ceramic (mlc) screening machine

Abstract

Vertically displaceable green sheet support fixtures are borne by respective horizontally movable carriages traveling on common rails between respective dual loading stations and a common unloading station, through separate intermediate screening stations, with the carriages movable in opposite directions and out of phase stationwise. The carriages have fixedly coupled thereto, horizontally movable trailers which bear trays of stacked green sheets for selective transfer of the uppermost green sheet to a loading head at the loading station while the carriage borne fixture itself is at a screening station for paste screening of a prior transferred green sheet. Masks employed in screen printing at the screening station are removed from the screening station console and placed in a cleaning chamber for solvent removal of residual screening paste and are air dried prior to return to the screening station console. During cleaning of a dirty mask, a second clean mask is automatically presented at the station to eliminate throughput-loss. The fixture is vertically displaceable on the carriage and its height incrementally varied depending upon green sheet thickness variation. Accelerated vertical separation of the carriage borne green sheet from the mask is effected subsequent to initial slow incremental separation therebetween.