Abstract: According to one aspect of the invention apparatus is provided for electrical testing of a substrate having a plurality of terminals. The apparatus includes a frame, a probe card, a translation device, an alignment device, and a holder. The probe card includes a probe card backing member and a plurality of probes extending from the probe card backing member and is secured to the frame. The translation device is secured to the frame. The alignment device is located on the translation device. The holder is capable of holding a substrate and is secured to the alignment device. The alignment device is operable to cause alignment movement of the holder past the probe card so that selected ones of the terminals are brought into alignment with selected ones of the probes. The translation device is operable to cause translational movement, transverse to the alignment movement, of the alignment device with the holder towards the probe card.

Abstract: An apparatus and method for positioning a wafer holding platform by moving it along a first set of axes concurrently through a path measured along a second set of axes. An apparatus of the present invention comprises a motor system to move the wafer holding stage and a motion control system to control the path of the wafer holding stage. The motor system constrains the wafer holding stage to a first two axes of movement, and the motion control system controls the path along a second two axes of movement. The first two axes and second two axes are located at angles from one another. The distance a wafer on the wafer holding stage is to be moved is measured along the second two axes. A method comprises constraining the movement of a wafer holding stage to a first and a second movement axes and controlling a path of the wafer holding stage along a third and a fourth movement axis. The present invention increases the speed of the wafer holding platform, thereby decreasing the time needed to test a wafer.

Abstract: The invention provides apparatus for testing a substrate having a plurality of terminals. The apparatus includes a frame, a first arrangement secured to the frame, a mounting arrangement secured to the frame, and a second arrangement secured to the mounting arrangement. One of the first and second arrangements is a holder capable of holding the substrate so that the terminals are located in the first plane. The other one of the first and second arrangements is a probe card including a probe card backing member and a plurality of probes extending from the probe card backing member, the probes having contact regions located in a second plane. The mounting apparatus includes at least a first member which is adjustable relative to the frame so as to pivot the second arrangement relative to the first arrangement between an orientation wherein there is an angle between the first and second planes and an orientation wherein the first and second planes are substantially parallel to one another.

Abstract: A system is disclosed for determining the rotational orientation of an object. An image of the object is digitally captured. The digital image is filtered through an edge detection operation to enhance the edge information contained in the image. The filtered image is rotated through a series of incremental angles to produce a series of rotated images. Each rotated image is projected onto an x-axis and y-axis defined by pixel grid axes defined by the original image. The projection of the rotated images produces projected pixel counts formed by the summation of pixel value differences of the x-axis and y-axis on the projected image. For each rotated image, a score corresponding to the sum of the difference of gray-scale values for adjacent projected pixels is computed. The scores for the projections of each rotated image are plotted on a score-angle graph. A curve which includes the highest score and the neighboring next highest scores is interpolated to determine the peak score.

Abstract: A system is disclosed for correcting for rotational errors in a linear motor system. A shunt resistor is coupled in parallel with a winding of a phase of a motor of the linear motor system to correct for rotational errors caused by differences in the magnetic characteristics of the motors comprising the linear motor system. Yaw error values for the motors are sequentially measured to determine the value of the shunt resistor, and its location on a winding of a phase motor of the linear motor system.

Abstract: An apparatus and method for positioning a first stage relative to a second stage. An apparatus of the present invention comprises a motor system to move the first and second stages relative to each other and a motion control system to control the path of the stage being moved. One stage has a continuous surface with a continuous magnetizable region. Nonmagnetizable regions are uniformly patterned within the magnetizable region. A method of the present invention involves the construction of a stage by etching a plurality of though holes in a sheet and affixing the sheet to the top surface of a foundation. The present invention improves the accuracy and speed of a positioning stage.

Abstract: An improved method and apparatus for automatically aligning a wafer prober to the bonding pads of a semiconductor device are provided. In one embodiment of one aspect of the invention, a pattern of contact electrodes is located using a low magnification image of a number of contact electrodes. A shape representative of a contact electrode point is then fitted to each of the number of contact electrodes using a high magnification image of the contact electrodes and a centroid of that fitted shape is determined. The position of the centroid is compared to the position of each of the number of pads, and the pads and contact electrodes are moved relative to each other to a position for contact between the pads and contact electrodes. Other aspects and other embodiments are also described.

Abstract: A method and apparatus for positioning rectilinearly a wafer holding platform by performing rotations in a positioning system. A method comprises coupling a first clamp to a wafer holding platform, decoupling a second clamp from the wafer holding platform, and rotating the first clamp to cause the wafer holding platform to be moved to a first position. Further couplings, decouplings, and rotations may be performed to achieve a rectilinear translation to a final position without a resultant rotation after the rectilinear translation. An apparatus of the invention comprises a first clamp having a first axis of rotation, a second clamp having a second axis of rotation, where the first axis and the second axis are not concentric. A wafer holding platform is independently couplable to the first clamp and to the second clamp and has a plurality of points on the wafer holding platform which are positionable at a plurality of X,Y locations by rotating independently the first and second clamps.

Abstract: A method involves capturing visual indicia as a digital image, isolating the visual indicia on the digital image, converting the visual indicia to image primitives, identifying and presenting the visual indicia. An apparatus contains a camera for capturing a visual image, a video-to-digital converter, and a computer with a processor, appropriate memory, and software.

Abstract: A tester for testing integrated circuits-containing semiconductor wafers or substrates, includes a vertically oriented performance board with. D/A converters mounted and pin connected immediately therebehind. A prober including a vertical array of connector pins mounts a vertical probe card and a vertically-mounted chuck on which a vertically-oriented wafer or substrate is held. One of the tester and prober are moved with respect to the other to dock and latch the tester and prober together. Simultaneously the array of connector pins is electrically connected to electrical connectors on the performance board and probe needles extending from a probe board on the probes are placed into test contact with contact pads on the integrated circuits on the wafer or substrate.

Abstract: An improved illumination method and apparatus for optical character recognition. A first light source is positioned such that light emitted from it strikes the surface at an angle of incidence. A detector is placed at the angle of reflection, such that specularly reflected light strikes the detector, providing bright field illumination. Additional light sources positioned at angles different from the first light source are disclosed to provide for high and low angle dark field illumination. Novel light guides which allow for a compact and economic system design are also disclosed. The disclosed system utilizes light sources and filters which greatly reduce the effect of environmental lighting on the optical character recognition process. A novel method to select the optimum light source and intensity is also disclosed.

Abstract: Light is supplied via a optical fiber to a probe head. The light exiting the optical fiber is focused to a point by a lens. Reflected light from an object at or near the focal point is reflected back through the lens and then focused to the source optical fiber or a second optical fiber located next the source optical fiber. The return signal is then detected in a detector module. By noting the characteristics of the response curve as the object is moved back and forth relative to the probe head, the position of the object can be determined. By performing this procedure over several points, a detailed topography map can be created. Additionally, the probe head can be scanned at a constant distance from the surface to produce an image of the surface as the response signal varies according to the surface's reflectivity.

Abstract: The ball bearing assembly has a total stroke range comprising a first portion where a clearance fit is applied and a second range where an interference fit is applied. The interference stroke range is used to, for example, carry a platform where precise alignment is necessary, and deflections or other movement of the platform must be minimized. Use of the ball bearing assembly to carry a platform holding a semiconductor wafer to be probed is illustrated. After each wafer is probed, the ball cage is reset such that any migration of the ball cage is eliminated so that the clearance and interference stroke ranges return to predetermined values. Further provided are means for rotationally resetting the ball cage, providing for even wear over the entire surfaces of the shaft and housing in their working zones to increase the useful lifetime of the assembly.

Abstract: A probe for testing an electrical circuit includes a dielectric support body and a pair of spring arms each having an inner end fixed to the support body and an outer end free to deflect with respect to the support body. Means for connecting the outer ends of the arms supports a probe tip having a point movable with the deflection of the arms into contact with a predetermined point on the electrical circuit to be tested. Means responsive to a signal provides for the deflection of the arms and the movement of the probe tip into contact with the chip. The arms have different lengths providing the probe tip with movement along a substantially straight line with respect to the plane of the electrical circuit.

Abstract: Testing of integrated circuit components of the silicon wafer type for grading purposes is accomplished by supporting the wafer matrix on a platform type work table which is indexed in an x-y coordinate fashion, with the work table being moved vertically to a test position such that the test probes make contact with a precise predetermined position corresponding to the precise location of that portion of the integrated circuit to be tested. The work table is movable vertically with reference to a predetermined axis and rotatable with respect thereto such that the surface of the table remains perpendicular to the reference axis. The chuck assembly for moving the table includes a housing having a bore whose center forms the axis, with a chuck plate mounted for sliding movement in the bore. The end of the chuck plate is in the form of a flanged spool which receives bearing-eccentric assembly for effecting vertical movement while permitting rotation of the spool and the attached chuck plate.

Abstract: A tool for testing the miniaturized circuitry of silicone wafer devices. A ring-shaped structure is supported on a casting or platform for movement along X and Z axes in a horizontal plane. A probe is suspended from the ring-shaped element for contact with a lead-in point of the circuitry on the device to be tested. The probe may be moved along the X and Z horizontal axes and a Y vertical axis relative to the ring, movement in the X and Z axes being controlled by a single lever which acts between the ring and the probe. Movement of the probe in the Y axis is controlled by a screw-type pressure-exerting device which also serves as a pivot point for movement of the probe along the horizontal axes. A high performance board is supported on the ring to act as a junction board so that the probes may be connected to a cable which runs around the ring. The cable extends radially therefrom at a location such that it may be connected to suitable external control circuitry.

Abstract: A probe for testing integrated circuit components which includes a dielectric support body, conductive arms supported by the body and with the arms including a longer arm and a shorter arm. The shorter arm is positioned above the longer arm in spaced relation thereto with each arm having an outer end connected to a conductive probe tip. The probe tip includes a downwardly positioned point for contact with a surface having an integrated circuit defined thereon and contact means are provided which cooperate with the arms and tip to transmit an electrical signal to the tip or receive a signal from the tip.

Abstract: A probe for testing integrated circuit components which includes a dielectric support body, conductive arms supported by the body and with the arms including a longer arm and a shorter arm. The shorter arm is positioned above the longer arm in spaced relation thereto with each arm having an outer end connected to a conductive probe tip. The probe tip includes a downwardly positioned point for contact with a surface having an integrated circuit defined thereon and contact means are provided which cooperate with the arms and tip to transmit an electrical signal to the tip or receive a signal from the tip. The probe tip includes a thin-walled bent tube that is secured to the probe. The bend in the thin-walled tube serves to frictionally hold a needle in the thin-walled tube because on insertion of a needle the tube will be resiliently straightened to create a frictional force between the tube and the needle.

Abstract: A positioning apparatus includes a platen and a head independently movable relative to the platen. First and second coils having a particular phase relationship are disposed relative to each other on the head are independently energized to produce first and second electromagnetic forces. These electromagnetic forces have varying characteristics for moving the head relative to the platen and constant characteristics for maintaining the head in a substantially fixed relationship to the platen. Abrupt changes from the variable to the constant characteristics of the applied electromotive forces allow inertial forces to impart a decaying oscillation of the head about the positional origin determined by the constant characteristics of the applied electromotive force.Oscillation of the head relative to the platen produces first and second back-electromotive force sinusoids in the first and second coils, respectively.

Abstract: Testing of integrated circuit components of the silicon wafer type is accomplished by a test probe assembly mounted on a support table, the latter being spaced vertically with respect to a platform on which the circuit components are placed. The test probe assembly, which includes a probe test unit, is mounted on the support in such a fashion that the test probe may be moved to a precise predetermined position corresponding to the precise location of that portion of the integrated circuit to be tested. This is accomplished by mounting the assembly housing such that it moves arcuately with respect to its support structure, while providing a slide unit within the housing which is movable vertically as well as axially with respect to the housing. Once the proper predetermined position has been determined and the test probe assembly adjusted such that the probe is properly aligned with the particular portion of the integrated circuit to be tested, the entire assembly is maintained in proper position.