International Business Machines Corporation

James E Boyette, Jr

Michael Servedio

Jiann-Chang Lo

James Christopher Mahlbacher

James Michael Hammond

Robert Edward Brown

Hans-George H Kolan

Salvatore R Riggio, Jr

Wayne A Barringer

Ali Reza Taheri

Christian J Bunker

Guenter Schaefer

Christopher M Fleck

A scanning probe microscope having a probe attachment fixture, to which a probe assembly is removably attached during measurements, driven in an engagement direction, and a sample stage driven in scanning directions perpendicular to the engagement direction includes a buffer with a number of buffer stations within the sample stage. When the stage is driven so that one of the buffer stations is in alignment with the attachment fixture, and when the attachment fixture is driven in the engagement direction to be in proximity to the buffer station, the probe assembly is selectively transferred in either direction between the attachment fixture and the buffer station. In a preferred embodiment, probe assemblies are transferred on transfer pallets, and a stationary magazine is provided for storing these pallets, which are transferred in either direction between the magazine and the buffer.

Automatic probe replacement in a scanning probe microscope

A test system for applying electrical tests to circuits on flexible substrates includes a first transport system moving frames, each of which is configured for holding a single such flexible substrate, a loading station in which the substrates are individually loaded onto the frames, a testing station in which the electrical tests are applied, and an unloading station in which the substrates are removed from the frames. Within the testing station, each frame is disengaged from the first transport system and fastened to a second transport system, which moves the frame in a pattern causing a number of segments of the substrate within the frame to be placed between probe arrays adjacent each of the opposite sides of the substrate. These arrays are each aligned with visual markings on the adjacent side of the substrate, and the arrays are then moved into engagement with the substrate for the testing process. When testing of a particular substrate is complete, the frame is disengaged from the second transport system and fastened to the first transport system to be carried to the unloading station.

Apparatus and method for testing flexible circuit substrates

A dual contact probe tip is provided within a flying probe circuit tester to make separate electrical contacts with a circuit under test at two closely-spaced test points. The tip includes a mounting block having an attachment section attached to a carriage of the tester and a pair of flexible cantilever sections, with a probe pin extending from a distal end of each of these cantilever sections to make contact with the circuit. One electrical path is established through the conductive mounting block and one of the probe pins. The other probe pin is coated with an insulating material except for its point and for a surface to which a wire is soldered, so that the other electrical path is established through this other probe pin and the attached wire. Each probe pin is tapered toward its point, and the probe pins extend from the mounting block at an oblique angle toward one another.

Dual-contact probe tip for flying probe tester

An actuator providing Z-direction movement within a positioning system extends between an input stage and an output stage. A nut is mounted to rotate on the input stage in threaded engagement with a screw extending into the nut from the output stage. The nut is driven by a motor also mounted on the input stage. A plate attached to the output stage through a flexible leaf spring slides along the input stage in the Z-direction with movement of the output stage, preventing rotation of the output stage about the axis of the screw. Lateral positioning of the screw results from the threaded engagement of the screw and nut. The leaf spring is formed to provide a lateral pre-load force between the screw and nut.

Height stage for positioning apparatus

Disclosed is a Probe Positioning Actuator which is low in cost and mass, capable of high accelerations, relatively long stroke and compact packaging, as well as high in efficiency. The actuator assembly comprises a frame, and at least one pair of spaced apart, laterally extending, conductor carrying, flexible beams attached to the frame. A non-magnetic armature, substantially U-shaped in cross section, is attached adjacent or approximate the extended terminal ends of the beams, and a probe is attached to the base of the 'U' of the armature for contacting selected points in the electrical circuit associated with the device being tested. The heart of the actuator includes a coil mounted on the upstanding legs of the U-shaped armature and arranged so that the axis of the coil is perpendicular to the base of the armature but substantially parallel to the probe tip. This arrangement places the `motor` portion of the actuator adjacent the probe and permits accurate and repeatable, fast control of not only probe tip position but probe tip movement. To complete the motor portion of the actuator, means, carried by the frame create a magnetic field across the coil, whereby upon energization of the coil, deflection of the armature (and thus the beams) occurs, effecting movement of the probe tip into contact with selected portions of the device being tested.

Miniature probe positioning actuator

A probe positioning apparatus for use in a probe testing system is disclosed. The probe positioning apparatus includes a probe tip, a probe actuator connected to the probe tip, a probe plate coupled to the probe actuator and a magnetic probe plate clamp that magnetically couples the probe plate. The magnetic coupling forms a slip plane that provides collision compliance for the probe positioning apparatus. One embodiment of the magnetic probe clamp uses a set of shoulder screws to provide quick attachment and release of the probe plate from the probe clamp. A second embodiment uses a magnetic shunt to disable the magnetic connection of the clamp from the probe plate.

Breakaway test probe actuator used in a probing apparatus

Probing system performance is improved by dynamically positioning a test probe at a test site during the gantry settling interval using a high performance secondary positioner to compensate for the inherent moving mass oscillational displacements. A primary positioner positions the gantry and its associated test probe to within a predetermined axis distance of the test site and a secondary positioner dynamically maintains the test probe at a target position corresponding to the test site during the settling interval by imparting compensating displacements to the test probe to counteract the displacement errors incurred as the primary positioner attempts to settle the gantry at the test site. Similarly, automatic machine tool performance is improved by dynamically positioning a work tool at a work site during the gantry settling interval using a high performance secondary positioner to compensate for the inherent moving mass oscillational displacements. A primary positioner positions the gantry and its associated work tool to within a predetermined axis distance of the work site and a secondary positioner dynamically maintains the work tool at a target position corresponding to the work site during the settling interval by imparting compensating displacements to the work tool to counteract the displacement errors incurred as the primary positioner attempts to settle the gantry at the work site.

High speed test probe positioning system

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.

Open frame gantry probing system

Disclosed is a Probe Positioning Actuator which is low in cost and mass, capable of high accelerations, relatively long stroke and compact packaging, as well as high in efficiency. The actuator assembly comprises a frame, and at least one pair of spaced apart, laterally extending, conductor carrying, flexible beams attached to the frame. A non-magnetic armature, substantially U-shaped in cross section, is attached adjacent or approximate the extended terminal ends of the beams, and a probe is attached to the base of the 'U' of the armature for contacting selected points in the electrical circuit associated with the device being tested. The heart of the actuator includes a coil mounted on the upstanding legs of the U-shaped armature and arranged so that the axis of the coil is perpendicular to the base of the armature but substantially parallel to the probe tip. This arrangement places the `motor` portion of the actuator adjacent the probe and permits accurate and repeatable, fast control of not only probe tip position but probe tip movement. To complete the motor portion of the actuator, means, carried by the frame create a magnetic field across the coil, whereby upon energization of the coil, deflection of the armature (and thus the beams) occurs, effecting movement of the prob into contact with selected portions of the device being tested.

A mechanism is provided for testing circuit traces extending along a flexible substrate, which is fed in a longitudinal direction between an upper plate and a lower plate. The upper plate includes a number of upper apertures extending across the flexible substrate and a number of upper segments, also extending across the flexible substrate, between adjacent apertures. The lower plate includes lower segments extending under the upper apertures and lower apertures extending under the upper segments. Two upper test probes are moved above the flexible substrate, while two lower test probes are moved under the flexible substrate. Tests are applied to both sides of the flexible substrate as the probes are brought into contact with test points in the areas accessible through the upper and lower apertures, with segments extending along the apertures on the opposite sides of the flexible substrate providing a backing surface for probe contact. A two-probe method may be used to determine the electrical characteristics of a circuit trace extending between test points, or a single-probe method may be used to determine the capacitance between a circuit trace and the plates. Circuit areas on the substrate are moved between the plates in a series of incremental motions to expose various points through the apertures as required to complete the testing process.

Testing fixture and method for circuit traces on a flexible substrate

A fixture is provided for locating open conditions within circuits and short conditions between adjacent circuits on a flexible substrate having circuits extending along each side, as well as individual circuits extending along both sides. In one station of the fixture, the flexible circuit extends against a conductive backing plate, and conductivity measurements, to detect open conditions, are made between two probes moving among test points on the first side of the substrate, which is opposite the backing plate, and between one of these probes and the conductive backing plate. The latter type of measurement is used particularly to detect an open condition in a via extending through the substrate. In another station of the fixture, the first side of the flexible circuit extends against a conductive backing plate having an insulating sheet adjacent to the substrate, conductivity measurements, to detect open conditions, are made between two test probes moving along a side of the substrate opposite this insulated conductive backing plate, and capacitance measurements, to detect short circuit conditions, are made between one of these probes and the insulated conductive backing plate.

Growing community of inventors

Delray Beach, FL, United States of America

James E Boyette, Jr