Abstract: Apparatus for forming a disc envelope from a prepunched, flexible, plastic blank having two sections connected at the heads thereof and containing a drive hole at the same location in each section. The drive holes are located on respective hubs which are located at the same position on respective folding plates. The end edge of a mandrel is pressed against the blank in the area between the two sections while the folding plates are moved from a horizontal to a vertical position pulling the drive holes taut on the hubs and thereby locating the center fold between the two sections of the blank flap folding apparatus and sealing apparatus are attached to and swing into operating position with the respective folding plates to form the side flap folds and seal the folded flaps.

Abstract: The flexible disk envelope is formed from a flexible plastic prepunched blank having two connected sections. One section of the blank has side flaps extending from the opposite side edges. The blank is folded about an end of a mandrel so that the side flaps extend beyond the side edges of the mandrel. The mandrel holds the plastic blank section having the flaps extending therefrom against the bottom surface of a plate. The mandrel has raised edge portions running along the side edges on the outward facing surface thereof. The side flaps are folded around the adjacent edge of the mandrel in an outward folding direction by folding blades which are driven about pivot means to guide the folding blades in an arcuate path.

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.

Abstract: A horizontally movable slide bears a two section, continuously extending horizontally inclined, steep and shallow sloped cam slot controlling the vertical rise and fall of a cam follower driven support fixture for supporting a ceramic green sheet in underlying contact with a stencil mask in an automatic MLC screening machine. An apertured positioning flag moves horizontally with the slide and past a vertical height digital position encoder assembly and a mask separate encoder assembly. The positioning encoder assembly provides an electrical signal for controlling an actuator mechanism 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.

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.