996results about "Diode testing" patented technology

Structure and methods of determining the complete location of a buried short using voltage contrast inspection are disclosed. In one embodiment, a method includes providing a test structure having a PN junction thereunder; and using the PN junction to determine the location of the buried short using voltage contrast (VC) inspection. A test structure may include a plurality of test elements each having a PN junction thereunder, wherein a location of the buried short within the test structure can be determined using the PN junction and the VC inspection. The PN junction forces a change in illumination brightness of a test element including the buried short, thus allowing determination of the complete location of a buried short.

An illumination device and method is provided herein for controlling individual light emitting diodes (LEDs) in an LED illumination device, so that a desired luminous flux and a desired chromaticity of the device can be maintained over changes in drive current and temperature. According to one embodiment, the illumination device comprises a plurality of emission LEDs, a storage medium, an LED driver and receiver circuit and a control circuit. The storage medium may store a table of calibration values correlating forward voltage and drive current to chromaticity and luminous flux at a plurality of temperatures for each of the plurality of emission LEDs. The LED driver and receiver circuit may apply respective drive currents to the emission LEDs to produce substantially continuous illumination, and may periodically turn the emission LEDs off to measure operating forward voltages that develop across each emission LED. The control circuit may determine whether a target luminance setting or a target chromaticity setting for the illumination device has changed, and if so, may determine new respective drive currents needed to achieve the target luminance setting and the target chromaticity setting using the operating forward voltages measured across each emission LED, the table of calibration values and one or more interpolation techniques.

A picking-up and placement process for electronic devices comprising: (a) providing a first substrate having a plurality of electronic devices formed thereon, the electronic devices being arranged in an array, and each of the electronic devices comprising a magnetic portion; (b) selectively picking-up parts of the electronic devices from the first substrate via a magnetic force generated from an electric-programmable magnetic module; and (c) bonding the parts of the electronic devices picked-up by the electric-programmable magnetic module with a second substrate.

A quick attachment device for use in the repeated testing of diode light sources (30) includes a quick attachment module (10) having a fixed location with respect to a testing position (150) for the diodes (30), and a mounting assembly (20) on which each diode (30) is mounted during testing. The quick attachment module (10) includes a quick disconnect fastener and two locating pins (120a and 120b) for securing the mounting assembly (20) for testing, where the two locating pins (120a and 120b) have a locational transition fit connection with the mounting assembly (20). The mounting assembly (20) may further include a thermal-electric cooling device (260) for cooling the diode light sources (30) during testing.

Disclosed is a fault diagnosis method for a switch reluctance motor each-phase dual-master-switch power converter fly-wheel diode. Two electric current sensors are assembled and placed in an each-phase dual-master-switch power converter. One electric current sensor LEM 1 is used for detection of direct current bus lower master switch total current. The other electric current sensor LEM2 is used for detection of total current feedback by a direct current bus lower fly-wheel diode. An upper master switch diode and a lower master switch diode are controlled to be broken-over and turned off so that conditions that the upper fly-wheel diode is in short-circuit fault, the lower fly-wheel diode is in short-circuit fault, the upper and the lower fly-wheel diodes are all in short-circuit fault, the upper fly-wheel diode is in open-circuit fault, the lower fly-wheel diode is in open-circuit fault, or the upper and the lower fly-wheel diodes are all in open-circuit fault can be judged. The fault diagnosis method for the switch reluctance motor each-phase dual-master-switch power converter fly-wheel diode is precise in detection of fly-wheel diode fault, discrimination of fault modes and location of fault phases. Convenience is brought to implementation of fault-tolerant control of the fly-wheel diodes.