Abstract: Recesses (72), surface contours, contact tip modifications (52, 56), and/or other methods of ensuring pressure between a bottom surface (50) of a test plate (5) and top surfaces (52) of electrical contacts (18) are employed to enhance cleaning of the top surfaces (52) of the electrical contacts (18) to promote reliable measurements of DUTs (14).

Abstract: An apparatus for accurately locating a micro-electronic chip in a chip-holding cavity for visual testing, the chip having at least a front wall and a pair of opposed, spaced-apart side walls, wherein the front wall meets with each of the side walls to form opposed, spaced-apart first and second front edges, comprising a cavity side wall formed to juxtapositionally abut at least one of the side walls of the chip, the cavity side wall having formed therein a depression creating a shadow projecting forward from the depression, wherein the first front edge of the chip forms a border of the shadow to form an objectively measurable contrast in grayness between the shadow and the chip.

Abstract: An apparatus for accurately locating a micro-electronic chip in a chip-holding cavity for visual testing, the chip having at least a front wall and a pair of opposed, spaced-apart side walls, wherein the front wall meets with each of the side walls to form opposed, spaced-apart first and second front edges, comprising a cavity side wall formed to juxtapositionally abut at least one of the side walls of the chip, the cavity side wall having formed therein a depression creating a shadow projecting forward from the depression, wherein the first front edge of the chip forms a border of the shadow to form an objectively measurable contrast in grayness between the shadow and the chip.

Abstract: One or more concentric rings of component seats are rotatable about the rings' center. The seats are uniformly angularly spaced and the rings are incrementally rotated, the increment of rotation being the angular space between adjacent seats. The rings are inclined at an angle and a stream of components is poured onto the rings as they are rotating. Stationary fences adjacent to outboard sides of the seats, confine unseated components to tumble randomly, due to gravity, over empty seats passing through arcs of the rings' rotation paths. The random tumbling results in seated components. In the paths of the rotating rings are electrical contactors for coupling the components to a tester. Preferably there are five contactor stations to permit five different kinds of tests to be performed simultaneously. Tested components pass beneath an ejection manifold which defines a plurality of ejection holes which register with a set of seats each time the ring is rotated an increment.