Patent GB-1265345-A (GB)
IPC: H01L21/677
Filed: 1969-09-24
Abstract: 1,265,345. Apparatus for handling individual articles in a stack. INTERNATIONAL BUSINESS MACHINES CORP. 24 Sept., 1969 [26 Sept., 1968], No. 47039/69. Heading B8C. An apparatus for handling articles, such as wafers 14 on which an integrated circuit is to be formed, comprises a magazine 10 having a number of article containers 11 supported therein in vertically stacked relation, an elevator 30 for indexing the stack in a vertical direction to bring the containers in turn to a predetermined removal position and automatic push-pull transport means 58, 59 which is movable in a horizontal direction for individually removing from, and returning to, the stack any selected container in the removal position. When locking means 20, on each sliding door 18, 19 forming opposite sides of the magazine 10, are released the doors remain stationary as the magazine 10 is moved downward on the elevator 30 which is indexed downwardly by a feed screw 36 driven by a stepping motor 37, the sides of the magazine being opened to expose the opposite sides of those containers 11 which descend below the removal position. The trays 11 are held in the magazine by a screw-down plate 26, each tray 11, Fig. 2, having pockets 12 to receive articles 14, openings 73 within the pockets 12, and two openings 48 each with a slot 49 to accommodate rods 31, 32 for guiding the elevator 30 and members which connect the upper ends of the rods 31, 32 to a support table 33. The base 17 of the elevator 30 has corresponding sets of openings 46, 47 which are closed to exclude dust &c. by cylindrical-shaped parts 50, carried by the doors 18, 19, when the latter are closed. The doors 18, 19 carry side tongs 39, Fig. 17, which locate the magazine 10 in a retention frame 29, the magazine being properly positioned when a notch in one of the tongs 39 co-operates with a pin 40<SP>1</SP> across one of the slots. Horizontal plates 41, which are carried by the doors 18, 19 across the tops of the tongs 39, rest upon the upper edge of the frame 29 and each carry four screws 43 which co-operate with the arms 44 of microswitches 45 the positions of which form a code to select which trays 11 are to be removed from the magazine. When a selected tray is to be removed the remainder of the trays above that selected are held by a pair of retainer arms 52, 53 which are urged inwardly, against springs, by solenoids (56, 57), Fig. 5 (not shown), to engage the bevelled edges 57<SP>1</SP> of the tray above the one selected, arms (70), Fig. 7 (not shown), actuating microswitches (68) and causing the descent of the elevator to stop after a predetermined number of lowering steps to provide a clearance between the selected tray and the one above it. The rounded end 59 of an arm 58, which is engaged in one of the openings 48 of the selected tray 11, is then moved forward by a carrier (60), Figs. 3, 4 (not shown), which is urged along a frame (61) by a fluid cylinder (63) to deposit the tray above an article lifter 71, Fig. 9, which has been properly orientated by a push-pull mechanism (72<SP>1</SP>) Fig. 10, not shown. Four pistons 72, with suction openings 83, are raised by a fluid motor 76 to project through the openings 73 and lift the wafers 14 from the tray and hold them while each one is engaged by a corresponding group of fingers 86 at the ends of braces 92 which are urged inwardly by a cam plate 94 as a glide housing 95 of an article handler 87 which supports the sets of braces 92, is moved downwardly under the control of a fluid motor 97, the suction to the piston openings 83 then being cut off as the pistons descend in the frame of the lifter 71. Fluid is then supplied to the cylinder (63) to cause retraction of the arm 58 which pulls the tray back into the magazine 10, the retaining arms 52, 53 then being retracted ready for the removal of another selected tray 11. The sequence of operations is repeated after the articles 14 have been dropped from the article handler 87 on to a carrier (115) which is advanced by a push-pull mechanism (118), Fig. 10 (not shown), to a position beneath the handler 87 as the lifter 71 is moved away from that position by the push-pull mechanism (115). A blow-off tube 117 distributes nitrogen against the articles as they are dropped on to the carrier 115 when the fingers 86 open and the handler 87 is raised to its original position, the carrier 115 then being carried by a conveyer (119) to transport the articles to a processing station.