公开(公告)号：DE3168782D1

公开(公告)日：1985-03-21

申请号：DE3168782

申请日：1981-08-19

Applicant: IBM

Inventor： DAVIS GORDON ,  MUELLER WOLFGANG ,  REMSEM LAWRENCE PETER ,  STRICKER ALFRED ALOIS

IPC: B41F15/08 ,  H05K1/03 ,  H05K3/12 ,  H05K13/02 ,  H01L21/68

Abstract: A horizontally movable slide (64) bears a two section, continuously extending horizontally inclined, steep (66b) and shallow (66a) sloped cam slot controlling the vertical rise and fall of a cam follower (76) driven support fixture (38) for supporting a ceramic green sheet in underlying contact with a stencil mask in an automatic MLC screening machine. An apertured positioning flag (90) moves horizontally with the slide (64) and past a vertical height digital position encoder assembly (100) and a mask separate encoder assembly (102). The positioning encoder assembly (100) provides an electrical signal for controlling an actuator mechanism (80) causing slide movement, indicative of the desired final positioning height of the green sheet relative to the mask when the fixture is moving towards the mask. When the actuator mechanism (80) drives the slide (64) in the opposite direction, to lower the green sheet from the mask, the mask separate encoder assembly (102) produces a signal, in response to common positioning flag movement in the opposite direction with the slide to effect a change in speed of the actuator mechanism. This provides slow initial separation of the green sheet from the mask and final removal of the fixture from screening height, at a much more rapide rate.