Patent GB-1164036-A (GB)
Title: Machine for Automatically Testing and Orienting Miniature Semiconductor Chips
IPC: G01R31/01
Filed: 1967-08-29
Abstract: 1,164,036. Rotary conveyer. CORNING GLASS WORKS. 29 Aug., 1967 [31 Aug., 1966], No. 39421/67. Heading B8A. [Also in Division H1] An apparatus for correctly orienting and then electrically testing semi-conductor elements comprises a rotatably indexable turret carrying a plurality of vacuum supplied hollow needles with radially disposed axes, arranged to be movable along and rotatable about their axes, and orientation testing, electrical testing, reject, and magazine loading stations disposed successively in the direction of rotation of the turret adjacent its periphery, signals from the orientation testing station indicative of unsuitable orientation for electric testing causing it to be corrected by rotation of the needle carrying the element. In the illustrated arrangement a rectangular transistor chip is picked up at 68 (Fig. 1) by one of the needles and carried forward to orientation testing station 38 of which one of three possible incorrect orientations is sensed. One or more of three electromagnets is actuated by the sensing circuit (Fig. 30, not shown) to place associated pins 146, 148 in the path of a Geneva wheel 136 carried on the turret (Figs. 5 and 6) to rotate the needle via co-operating pinions 132, 104 on the wheel and needle holder in two stages to achieve correct orientation before the transistor chip is presented to electrical testing station 40. If the transistor fails the test a solenoid is operated to place a cam in the path of a shuttle valve carried by the turret, the valve operating to temporarily supply compressed air to the needle to blow the transistor into a vacuum supplied reject bin. The processes of testing and rejection are repeated at stations 44, 46, 48. Transistors passing all the electrical tests are carried round to magazine loading station 58. The magazine (Fig. 25, and Figs. 22-24, 26-28, not shown) consists of a carrier 314, with peripheral pockets for the chips, sandwicked between book member 300 and cover 308. The back and cover members are fixed by screws 346, 348 to peripherally toothed annular members 318 which are spring loaded into frictional engagement but are allowed a limited degree of relative angular movement under the control of a set of coil springs. The cover is provided with suitably shaped apertures (Fig. 28, not shown) through which chips can be fed in and out. The carrier is rotated stepwise in relation to the cover apertures as follows: Cover 308 is rocked forward a predetermined amount by engagement of a peripheral peg with a solenoid rocked arm while the back member is held stationary by engagement of a similar peg with a fixed abutment. During this movement pawls on the carrier ride over the teeth on the annular members but on the spring-controlled return movement they engage the teeth and the carrier is indexed forward. When the magazine 56 (Fig. 19) is full, as determined by a counter rotary solenoid 400 is actuated to rotate sleeve 364 via a linkage into a position where splines 371 are aligned with internal splines on the magazine so that the magazine is forced on to wire carrier 396 and replaced by another under the action of spring 372. To ensure proper filling of the magazines it is not indexed forward and the counter is rendered inoperative when the chip fails or no chip is presented at the first testing station.