STELA

The STELA is an integrated circuit testing equipment made by IPRS Băneasa [1].

The I.P.R.S. Băneasa Full Line Condensed Catalog (1990) describes it as equipment for the automatic sorting of integrated circuits, with one or two workplaces, manually and/or mechanically operated, for either final or wafer tests (the mechanical system is available for final testing only) [1]. Testing is computer controlled, by a CORAL 4030 minicomputer (DEC soft compatible) connected to each workplace through one connector with 18 output lines and 14 input lines plus logical ground; the interactive software supports sorting, debugging and the development of programs for new IC types [1].

At each workplace the basic test equipment consists of the interface to the fixed voltage supplies and the programmable data acquisition system, and a dedicated measure-head; with the available measure-heads the following parameters were obtained under real working conditions: a minimal current of 50 pA, a maximal slew-rate of 50 V/µs, a maximal voltage offset of 0.5 mV and a maximal gain of 100 dB [1]. The one-test time and the measuring accuracy are given by the measure-head, the typical one-test time being about 50 ms [1].

The I.C. handler, a final sorting mechanical system, loads the test socket automatically with circuits from a ten-sleeve input and distributes them into five electric classes; the output has five tracks of ten sleeves each plus one track for mechanically rejected circuits [1]. The handling time per circuit is 0.6 s, and with a typical sorting time of „1… s” (the character after the 1 is not legible on the scan) the machine yields 2000 circuits per hour [1]. A note adds that the HP 9825 computer, together with the HP 98032A interface, is fully compatible with the basic test equipment and with the final sorting mechanical system [1].