Abstract: A method and apparatus permitting accurate and repeatable steps of location and alignment of flimsy sheets during their transfer. A preferred embodiment comprises a sheet handler and method for aligning unfired ceramic green sheets used in multi-layer ceramic semiconductor packages. The thin flexible sheets are square or rectangular in shape and are provided with holes accurately punched in each corner thereof for alignment purposes. The sheets are moved by a vacuum input transfer head into orientation with a porous registration surface of an alignment fixture. The sheet is then trapped between opposed pressure zones emanating from the input transfer head and through the porous registration surface, respectively. With the sheet stabilized between the pressure zones four bullet-nosed alignment pins are raised from the registration surface into contact with the holes in the corners of the green sheet, thereby accurately aligning the sheet with respect to the alignment fixture.

Abstract: A vacuum pick up and transfer head adapted for handling flimsy sheets of material such as spacer sheet and uncured ceramic sheet commonly referred to as green sheet. The vacuum transfer head is of generally rectangular configuration having a sheet contacting lip having vacuum slots formed through the periphery thereof to hold the sheets in place by vacuum pressure. The center of the sheet contacting face is recessed whereby, with a sheet in place and acting as a diaphragm, a central vacuum chamber is also defined. A series of check valves are provided to control application of vacuum and positive pressure to the green sheet for picking the sheet up, retaining it and stripping it. A plurality of probes are provided in the handling head, adapted to selectively project through the sheet contacting surface for detecting green sheet and/or spacer sheet utilized inbetween layers of green sheet.