445results about "Bipolar transistor testing" patented technology

In an electrical circuit for testing electrical current using a plurality of precision resistors connected in parallel or in series, a range finder for receiving the current to be measured with the voltage drop across the range finder being indicative of a current sub-range for measurement. In a preferred embodiment, a range finder has a first bipolar transistor and a second bipolar transistor connected in parallel and in opposite polarity with the emitter and base of each transistor connected together whereby each transistor functions as an emitter-base diode.

The invention provides an IGBT aging state monitoring method and an IGBT aging state monitoring device. The IGBT aging state monitoring method comprises the steps of outputting a normal voltage through a voltage stabilization chip in a measurement circuit, and when a voltage stabilization chip control signal is in a high level, outputting a driving voltage by the measurement circuit for switching on a to-be-monitored IGBT; setting the voltage stabilization chip control signal to a low level, setting the output voltage of the voltage stabilization chip to zero, and when the gate voltage of the IGBT reduces to an on threshold voltage and the current which flows over the IGBT is zero, making the driving voltage slowly and continuously drop, intercepting a driving voltage waveform which is output from the measurement circuit and a corresponding collector electrode current waveform, obtaining the transmission characteristic curve of the to-be-monitored IGBT; and monitoring the aging state of the to-be-monitored IGBT through utilizing the on threshold voltage and a transconductance of the to-be-monitored IGBT as aging state characteristic quantities, wherein the on threshold voltage and the transconductance are extracted through the transmission characteristic curve. The IGBT aging state monitoring method and the IGBT aging state monitoring device have an advantage of quick and accurate monitoring on the aging state of the IGBT.

The invention discloses an IGBT online state monitoring method and measuring system based on Miller platform delay. One end of a drive signal pre-processing circuit is connected with one end of a controller through a time measuring circuit. The other end of the controller and the drive chip of an IGBT device drive circuit are connected. The drive chip is divided into two paths. One is connected with an IGBT device, and the other is connected with the drive signal pre-processing circuit. The drive signal pre-processing circuit extracts the Miller platform delay in a drive voltage signal of an IGBT turn-on process as the characteristic parameter of IGBT state monitoring to carry out initial state calibration and real-time online monitoring. The health and reliability of the IGBT device during an aging process are evaluated. According to the invention, online monitoring and parameter extraction do not affect the operation of a main circuit, and are sensitive to various typical failure modes; and the method and the system can be directly used for health monitoring and service life evaluation of the IGBT, and solve the problem of lack of effective characteristic parameters in the existing state monitoring technology of power electronic devices.

A jig for use in a semiconductor test of the present invention includes; a base on which a probe pin and an insulating material are provided such that the probe pin is surrounded by the insulating material in plan view; and a stage arranged to face a surface of the base on which the probe pin and the insulating material are provided. The stage is capable of receiving a test object placed on a surface facing the base. When the test object is placed on the stage and the base and the stage move in a direction in which they get closer to each other, the probe pin comes into contact with an electrode formed on the test object, and the insulating material comes into contact with both the test object and the stage.

The invention relates to a method for constructing a state evaluation and remaining life prediction model of an IGBT module. The method comprises the following steps: measuring electric heating parameters of the IGBT module under different aging degrees through testing; establishing a functional model of average crust thermal resistance change rate-average power cycle index and a functional modelof average saturation pressure drop change rate-average power cycle index of test samples of the IGBT module; evaluating the aging state of the IGBT module according to the above functional models, and expressing the aging state of the IGBT by a real number on the interval [0, 1] to obtain a state evaluation result; and establishing a calculation model of the remaining life of the IGBT module according to the state evaluation result. The method provided by the invention establishes mathematical models of electrical parameters, thermal parameters and power cycle indexes according to a power cycle accelerated aging test, and the models comprehensively consider the influence of electrical parameters and thermal parameters on the evaluation results to make up for the deficiency of single parameter evaluation, thereby accurately obtaining the aging state of the IGBT module under the condition of thermal resistance and saturation voltage drop of a certain crust.

A method for monitoring online condition of an IGBT module bonding wire comprises the following steps of step 1, building a full-bridge inverter circuit and a VCE online measurement circuit, and connecting both input terminals of the VCE online measurement circuit to the collector and emitter of the IGBT power module of the full-bridge inverter circuit to realize the connection between the full-bridge inverter circuit and the VCE online measurement circuit; step 2, establishing a three-dimensional data model of the healthy IGBT; step 3, establishing an IGBT three-dimensional data model of thebond wire break; step 4, optimizing the least squares support vector machine by a genetic algorithm; and step 5, using the optimized least squares support vector machine to evaluate the state of the 3D data model obtained in the steps 2 and 3. The method provided by the invention closely links the online monitoring and state evaluation, and helps to improve the health management mechanism of the IGBT module bonding wire.

An isolated insulated gate bipolar transistor (IGBT) gate driver is provided which integrates circuits, in-module, to support the measurements of threshold voltage, and collector-emitter saturation voltage of IGBTs. The measured gate threshold and collector-emitter saturation voltage can be used as precursors for state of health predictions for IGBTs. During the measurements, IGBTs are biased under specific conditions chosen to quickly elicit collector-emitter saturation and gate threshold information. Integrated analog-to-digital converter (ADC) circuits are used to convert measured analog signals to a digital format. The digitalized signals are transferred to a micro controller unit (MCU) for further processing through serial peripheral interface (SPI) circuits.

The present invention provides an inspection apparatus, which comprises probes for front side electrodes, probes for back side electrodes, and a chuck stage, wherein the probes for front side electrodes and the probes for back side electrodes are formed on the upper surface of the chuck stage, and the probe contact area electrically continues to the wafer holding area, and the probes for front side electrodes and the probes for back side electrodes are located leaving a distance in horizontal direction between them so that the probes for back side electrodes move relatively within the probe contact area when the probes for front side electrodes are moved relatively within the wafer under test by the movement of the chuck stage. According to the inspection apparatus of the present invention, it is possible to inspect characteristics of semiconductor devices having electrodes on both side of a wafer more accurately in wafer state.

A life estimation circuit includes a temperature detector configured to detect temperature of a power element unit, an inflection point detection unit configured to detect an inflection point of temperature variation in the power element unit based on an output signal from the temperature detector, an operation unit configured to determine an absolute value of a difference between the temperature of the power element unit at an inflection point detected this time and the temperature of the power element unit at an inflection point detected last time, a count circuit configured to count the number of times that the absolute value of the difference in temperature has reached a threshold temperature, and a signal generation unit configured to output, when a count value from the count circuit reaches a threshold number of times, an alarm signal indicating that the power element is about to reach the end of its life.