The electric characteristic of each of semiconductor chips formed on a semiconductor wafer substrate is measured while keeping probes contacted with electrode pads of the semiconductor chip. The wafer is mounted on a mount movable in directions X, Y, Z and .theta.. The array direction of the semiconductor chips on the wafer is positioned in the directions X and Y, in which the mount is moved, at an alignment position and the electrode pads of each of the chips are positioned relative to their corresponding probes at a measuring position. Information needed to carry out the positioning at the alignment position is stored as a first data and information needed to carry out the positioning at the measuring position is stored as a second data. The following three steps can be selectively conducted after the positioning at the measuring position. Measurement is conducted relative to the substrate at a first step. The positionings at the alignment and measuring positions are again automatically conducted relative to the substrate at a second step in response to the first and second data stored. The positionings at the alignment and measuring positions are again conducted relative to the substrate while storing first and second new data resulted from these re-positionings at a third step.
A system for probing both sides of a high density printed circuit board includes an open frame extending around the circuit board when it is held in a test position by a circuit board carrier. The frame includes two parallel rail structures extending above, and at opposite ends of, the circuit board in the test position. The frame also includes another two parallel rail structures extending below, and at opposite ends of, the circuit board. The upper and lower rail structures extend perpendicularly to one another, and are fastened together at the corners of the frame by means of compression bolt assemblies. Two gantry structures are moved in a first direction between the upper rail structures, while two other gantry structures are moved in a direction perpendicular to the first direction between the lower rail structures. A carriage moves along each gantry structure, and a probe is mounted on each carriage to be moved toward and away from the adjacent surface of the circuit board. The circuit board is moved by a board carrier between a position, outside the frame, in which it is loaded and unloaded, and the test position.
Apparatus for scanning an integrated circuit chip or other device under test (DUT) for defects and for visual alignment of chip electrical leads with leads of an electrical tester for testing the chip circuit(s). The apparatus provides an image forming system to provide a visually perceptible image of the chip for chip scanning and chip lead alignment. The apparatus also provides means to translate the chip in a plane containing the chip and rotate the chip about an axis perpendicular to that plane to facilitate alignment of the chip leads with the corresponding electrical tester leads. A computer or operator views the chip through the image forming system and controls chip translation and rotation for scanning and lead alignment for subsequent chip testing.
An electronic device test apparatus for testing IC chips (IC) by pushing their input/output terminals (HB) against contact units of a test head, provided with an IC moving system (410) for picking up and moving an IC chip (IC) at the front surface where input/output terminals (HB) are led out, a first camera for capturing an image of the front surface of an IC chip (IC) before being picked up, a second camera for capturing an image of a back surface of an IC chip (IC) after being picked up, and an image processing system for calculating the position of input/output terminals (HB) of an IC chip (IC) picked up by the IC moving system (410) from the image information captured by the first camera and second camera and identifying the relative position of the IC chip (IC) picked up by the IC moving system (410) with respect to a contact unit based on the results of calculation, wherein the IC moving system (410) corrects the position of the IC chip based on the relative position of the input/output terminals (HB) of the IC chip (IC) with respect to the contact unit identified by the image processing system.
