A method and device for evaluating inhomogeneous deformations in a first wafer bonded by molecular adhesion to a second wafer. This evaluation method includes the steps of making at least one reading of a plurality of measurement points, the reading corresponding to a surface profile of the first wafer along a predefined direction and over a predefined length, computing a second derivative from the measurement points of the surface profile and evaluating a level of inhomogeneous deformations in the first wafer according to the second derivative.

Systems and methods for testing a component, such as a battery, of a host device include transmitting one or more input acoustic signals into at least a portion of the host device, through input transducers coupled to the host device. One or more response signals generated in response to the one or more input acoustic signals are detected through recording transducers coupled to the host device. The one or more response signals are stored and compared with reference signals or datasets. One or more physical characteristics of the component or battery are analyzed based on the comparison.

The transformer fault detection apparatus includes an integrated sensor unit for sensing signals through a plurality of sensors located on each of upper and lower drain valves in a transformer. A first possible discharge area calculation unit calculates a first possible discharge area estimated to be a location of a partial discharge source of the transformer, based on arrival times of signals sensed by different sensors located on the upper drain valve. A second possible discharge area calculation unit calculates a second possible discharge area estimated to be the location of the partial discharge source, based on arrival times of signals sensed by different sensors located on the lower drain valve. A final possible discharge area calculation unit calculates a final possible discharge area, based on an overlapping area between the first and second possible discharge areas.

A method for testing a lifetime of a surface state carrier of a semiconductor, including the following steps, 1) a narrow pulse light source is used to emit a light pulse, and coupled to an interior of a near-field optical probe, and the near-field optical probe produces a photon-generated carrier on a surface of a semiconductor material under test through excitation. 2) The excited photon-generated carrier is concentrated on the surface of the semiconductor material, and recombination is conducted continuously with a surface state as a recombination center. 3) A change in a lattice constant is produced due to an electronic volume effect, a stress wave is produced, and a signal of the stress wave is detected in a high-frequency broadband ultrasonic testing mode. 4) Fitting calculation is conducted on the signal of the stress wave to obtain the lifetime of the surface state carrier τ.sub.c.

A method and system for detecting imperfections on a surface of a touchscreen of an electrical device, comprising: swiping a test object, such as a fingertip, a fingernail or a pin, along at least a portion of the touchscreen; producing, by the touchscreen, an electric signal indicative of the test object's contact with the touchscreen; receiving an acoustic signal by an acoustic sensor, during the swipe of the test object along the touchscreen; analyzing, by a processor, at least one of the electric signal and received acoustic signal; and determining existence of imperfections on the touchscreen's surface based on the analysis.

Embodiments disclosed herein include diagnostic substrates and methods of using such substrates. In an embodiment, a diagnostic substrate comprises a substrate, and a device layer over the substrate. In an embodiment, the diagnostic substrate further comprises a resonator in the device layer. In an embodiment, the resonator comprises a cavity, a cover layer over the cavity, and electrodes within the cavity for driving and sensing resonance of the cover layer. In an embodiment, the diagnostic substrate further comprises a reflector surrounding a perimeter of the resonator.

A method for in-situ and nonintrusive detection of one or more of bond-wire lift-off or surface degradation in insulated-gate bipolar transistor modules of a power switching device includes transmitting an ultrasonic soundwave from at least one transmitter, receiving, using at least one receiver, a reflected soundwave from the at least one insulated-gate bipolar transistor module, the reflected soundwave being a portion of the transmitted ultrasonic soundwave, using the controller to determine the frequency and amplitude of the received soundwaves, and comparing at least one of the frequency of the received soundwaves or the amplitude of the received soundwaves to known base characteristics for a new insulated-gate bipolar transistor module to determine a state of health for a power switching device including the insulated-gate bipolar transistor module being measured.

Systems and methods for prediction of state of charge (SOH), state of health (SOC) and other characteristics of batteries using acoustic signals, includes determining acoustic data at two or more states of charge and determining a reduced acoustic data set representative of the acoustic data at the two or more states of charge. The reduced acoustic data set includes time of flight (TOF) shift, total signal amplitude, or other data points related to the states of charge. Machine learning models use at least the reduced acoustic dataset in conjunction with non-acoustic data such as voltage and temperature for predicting the characteristics of any other independent battery.

A method of detecting sub-surface voids in a sample comprises positioning a probe adjacent to a first point on the sample, emitting an ultrasonic wave from the probe towards the sample, moving the probe towards the sample, measuring a shear force amplitude of a reflection of the ultrasonic wave at the probe as the probe moves towards the sample, creating an approach curve by plotting the measured shear force amplitude of the reflection of the ultrasonic wave as a function of a distance between the probe and the sample, and determining whether a sub-surface void exists at the first point on the sample based on a slope of the approach curve.

Systems and methods for prediction of state of charge (SOH), state of health (SOC) and other characteristics of batteries using acoustic signals, includes determining acoustic data at two or more states of charge and determining a reduced acoustic data set representative of the acoustic data at the two or more states of charge. The reduced acoustic data set includes time of flight (TOF) shift, total signal amplitude, or other data points related to the states of charge. Machine learning models use at least the reduced acoustic dataset in conjunction with non-acoustic data such as voltage and temperature for predicting the characteristics of any other independent battery.