Abstract: A bond strength testing apparatus comprising a main body, a test tool mount for holding a test tool, and an axial drive mechanism including a screw and nut assembly. The drive mechanism couples the test tool mount to the main body and allows for relative movement between the test tool mount and the main body in an axial direction. A backlash control element is coupled to the main body and the test tool mount, and, in operation, biases the test tool mount relative to the main body in an axial direction. The backlash control element is switchable between a first state in which the test tool mount is biased in a first axial direction by the backlash control element, and a second state in which either the test tool mount is biased in a second axial direction by backlash control element, or the backlash control element applies no biasing force to test tool mount. The apparatus can be automated to apply the appropriate backlash control for a particular, selected test type.

Abstract: Shear test apparatus for gold and solder balls of a semiconductor substrate comprises a support element (21) on which is provided a piezo-electric crystal (24) in the direct shear load path. The crystal (24) may have a shield (25). The interface between shield and crystal, and crystal and support element may include an epoxy resin layer to distribute force and retain the components as a unit.

Abstract: A prosthetic ankle and foot combination has an ankle joint mechanism constructed to allow damped rotational movement of a foot component relative to a shin component. The mechanism provides a continuous hydraulically damped range of ankle motion during walking with dynamically variable damping resistances, and with independent variation of damping resistances in the plantarflexion and dorsiflexion directions. An electronic control system coupled to the ankle joint mechanism includes at least one sensor for generating signals indicative of a kinetic or kinematic parameter of locomotion and/or walking environment, the mechanism and the control system being arranged such that the damping resistances effective over the range of motion of the ankle are adapted automatically in response to such signals. Single and dual piston hydraulic damping arrangements are disclosed, including arrangements allowing independent heel-height adjustment.

Abstract: A method and apparatus for determining a mode of failure of a bond between an electrically conductive ball deposit and a substrate when breaking the ball deposit off of the substrate. The method and apparatus utilize tool force and displacement values to plot a force/displacement curve. The force/displacement curve is used to calculate the energy necessary to break the ball deposit off of the substrate. The energy value of a portion of a force/displacement curve is selected by reference to a peak force. In one preferred embodiment, this energy value is compared with a predetermined reference energy value to indicate a mode of failure. The peak force is preferably the maximum peak force, in the preferred embodiment, the method and apparatus distinguish between a ductile failure mode and a brittle failure mode.

Abstract: A device and method for tensile testing of the bond strength of an electrically conductive ball adhered to a substrate. A ball is gripped and moved at a speed in a direction substantially orthogonal to the plane of adherence. The substrate is abruptly halted by an abutment to impose a sudden load on the ball/substrate interface.

Abstract: A test apparatus for applying shear loads to a deposit on a substrate comprises a cantilevered shear tool (18) having a tip (24) for contact with the deposit, and a back face having a piezo-electric crystal thereon. In use, the back face is subject to a compressive force, as well as other forces, and a corresponding electrical output from said crystal which is proportional to those forces. In one embodiment, the portion of the shear tool which contacts the deposit is offset rearwardly from the front face of the shear tool to improve the accuracy of the signal produced by the piezo-electric crystal. The apparatus is useful in testing the strength of bonds between deposits and substrates typically found in semiconductor devices.

Abstract: Shear test apparatus for gold and solder balls of a semiconductor substrate comprises a support element (21) on which is provided a piezo-electric crystal (24) in the direct shear load path. The crystal (24) may have a shield (25). The interface between shield and crystal, and crystal and support element may include an epoxy resin layer to distribute force and retain the components as a unit.

Abstract: A method and apparatus for determining a mode of failure of a bond between an electrically conductive ball deposit and a substrate when breaking the ball deposit off of the substrate. The method and apparatus utilize tool force and displacement values to plot a force/displacement curve. The force/displacement curve is used to calculate the energy necessary to break the ball deposit off of the substrate. The energy value of a portion of a force/displacement curve is selected by reference to a peak force. In one preferred embodiment, this energy value is compared with a predetermined reference energy value to indicate a mode of failure. The peak force is preferably the maximum peak force, in the preferred embodiment, the method and apparatus distinguish between a ductile failure mode and a brittle failure mode.

Abstract: A method and apparatus for determining a mode of failure of a bond between an electrically conductive ball deposit and a substrate when breaking the ball deposit off of the substrate. The method and apparatus utilize tool force and displacement values to plot a force/displacement curve. The force/displacement curve is used to calculate the energy necessary to break the ball deposit off of the substrate. The energy value of a portion of a force/displacement curve is selected by reference to a peak force. In one preferred embodiment, this energy value is compared with a predetermined reference energy value to indicate a mode of failure. The peak force is preferably the maximum peak force, hi the preferred embodiment, the method and apparatus distinguish between a ductile failure mode and a brittle failure mode.

Abstract: Shear test apparatus for gold and solder balls of a semi-conductor substrate comprises a support element (21) on which is provided a piezo electric crystal (24) in the direct shear load path. The crystal (24) may have a shield (25). The interface between shield and crystal, and crystal and support element may include an epoxy resin layer to distribute force and retain the components as a unit.

Abstract: A test apparatus for applying shear loads to a deposit on a substrate comprises a cantilevered shear tool (18) having a tip (24) for contact with the deposit, and a back face having a piezo-electric crystal thereon. In use, the back face is subject to a compressive force, as well as other forces, and a corresponding electrical output from said crystal which is proportional to those forces. In one embodiment, the portion of the shear tool which contacts the deposit is offset rearwardly from the front face of the shear tool to improve the accuracy of the signal produced by the piezo-electric crystal. The apparatus is useful in testing the strength of bonds between deposits and substrates typically found in semiconductor devices.

Abstract: A tensile testing machine has a jaw which comprises a unitary ‘H’ section member having a cross piece (25) and two uprights (26). The cross piece is mounted to a cantilever beam which is supported on said test machine and has force measuring elements. A pneumatic actuator (20) applies tensile forces to the first ends of the jaw (23) via strands (22) to urge them apart. When first ends of the uprights are urged apart, their oppositely disposed second ends are urged together to grip a sample deposit (29) to be pulled off a substrate in a tensile test. In use, the jaws can be moved at speed, in the order of 500 mm/s to pull the deposit off of the substrate. The force required to pull the deposit off the substrate in this tensile test is measured by the force measuring elements on the beam (35).

Abstract: A device (10) for shear testing of very small protrusions of an electrical semi-conductor device includes a sensor (30) for detecting surface contact of a shear test tool (15). The lateral shear force transducer is also used to detect scrubbing forces as the tool is reciprocated on the substrate, so as to give accurate surface contact sensing of non-rigid substrates. After contact sensing, the test tool is stepped back to ensure the shear test is performed without dragging of the tool on the substrate.

Abstract: A method and apparatus for determining a mode of failure of a bond between an electrically conductive ball deposit and a substrate when breaking the ball deposit off of the substrate. The method and apparatus utilize tool force and displacement values to plot a force/displacement curve. The force/displacement curve is used to calculate the energy necessary to break the ball deposit off of the substrate. The energy value of a portion of a force/displacement curve is selected by reference to a peak force. In one preferred embodiment, this energy value is compared with a predetermined reference energy value to indicate a mode of failure. The peak force is preferably the maximum peak force, hi the preferred embodiment, the method and apparatus distinguish between a ductile failure mode and a brittle failure mode.

Abstract: A self-teaching lower limb prosthesis, for an above-knee amputee, including a dynamically adjustable joint movement control unit arranged to control operation of the joint automatically. A control unit electrically stores a target relationship between a kinetic or kinematic parameter of locomotion and walking speed. The relationship defines a number of values of the parameter associated with different walking speeds. The control unit generates monitoring signals representative of walking speed values and values of the parameter occurring at different walking speeds. An adjustment system adjusts the control unit automatically when the monitoring signals indicate deviation from the target relationship so as to bring the parameters close to that defined by the target relationship.

Abstract: A device and method permits absolute and relative calibration of a pull-test device for testing the mechanical strength of electrical bond deposits. The invention provides repeatable breaking of a test specimen such as a wire (11) indexable through an anvil (17). A test tool (12) is restrained against movement from the pull axis by a low friction support such as a roller (13). A rest (14) defines a start position. The test tool is moved against the test specimen to break the test specimen. A measuring device is provided to measure the force necessary to break the test specimen.

Abstract: Shear test apparatus for gold and solder balls of a semi-conductor substrate comprises a support element (21) on which is provided a piezo electric crystal (24) in the direct shear load path. The crystal (24) may have a shield (25). The interface between shield and crystal, and crystal and support element may include an epoxy resin layer to distribute force and retain the components as a unit.

Abstract: A prosthetic ankle and foot combination has an ankle joint mechanism constructed to allow damped rotational movement of a foot component relative to a shin component. The mechanism provides a continuous hydraulically damped range of ankle motion during walking with dynamically variable damping resistances, and with independent variation of damping resistances in the plantarflexion and dorsiflexion directions. An electronic control system coupled to the ankle joint mechanism includes at least one sensor for generating signals indicative of a kinetic or kinematic parameter of locomotion, the mechanism and the control system being arranged such that the damping resistances effective over the range of motion of the ankle are adapted automatically in response to such signals. Single and dual piston hydraulic damping arrangements are disclosed, including arrangements allowing independent heel-height adjustment.

Abstract: A device (10) for shear testing of very small protrusions of an electrical semi-conductor device includes a sensor (30) for detecting surface contact of a shear test tool (15). The lateral shear force transducer is also used to detect scrubbing forces as the tool is reciprocated on the substrate, so as to give accurate surface contact sensing of non-rigid substrates. After contact sensing, the test tool is stepped back to ensure the shear test is performed without dragging of the tool on the substrate.