Abstract: A CWT-based method to calculate transmission coefficients of different Lamb waves using individual LEU signals. A neural network was trained to accurately predict WPDs based on the transmission coefficients of selected Lamb waves and the LEU signal energy. The method is capable of inspecting WPDs quickly along welds in thin structures.

Abstract: A CWT-based method to calculate transmission coefficients of different Lamb waves using individual LEU signals. A neural network was trained to accurately predict WPDs based on the transmission coefficients of selected Lamb waves and the LEU signal energy. The method is capable of inspecting WPDs quickly along welds in thin structures.

Abstract: Dynamic digital fringe projection (DDFP) techniques for measuring warpage. The DDFP technique generates a dynamic fringe pattern, in which a proper fringe intensity distribution is dynamically determined based on the surface reflectance of an unpainted sample in order to obtain better fringe image contrasts. The DDFP technique includes the automatic segmentation method to segment the chip package and PWB regions in an unpainted PWB assembly PWBA image. It also includes calibration methods to compensate the mismatches in coordinates and intensities between the projected and captured images.

Abstract: Dynamic digital fringe projection (DDFP) techniques for measuring warpage. The DDFP technique generates a dynamic fringe pattern, in which a proper fringe intensity distribution is dynamically determined based on the surface reflectance of an unpainted sample in order to obtain better fringe image contrasts. The DDFP technique includes the automatic segmentation method to segment the chip package and PWB regions in an unpainted PWB assembly PWBA image. It also includes calibration methods to compensate the mismatches in coordinates and intensities between the projected and captured images.

Abstract: A system and method for measuring various weld characteristics is presented. The system and method can comprise a means to measure penetration depth of butt welds in thin plates, for example, using laser generated ultrasounds. Superimposed line sources (SLS) can be used to generate narrowband ultrasounds. A signal processing procedure that combines wavenumber-frequency (k-?) domain filtering and synthetic phase tuning (SPT) is used to reduce the complexity of Lamb wave signals. The reflection coefficients for different wavelengths corresponding to each wave mode can be calculated. Regression analysis that can include stepwise regression and corrected Akaike's information criterion (AIC) can be performed to build prediction models that use the reflection coefficients as predictors.

Abstract: High speed autofocus interferometric inspection systems and methods are discussed in this Application. In accordance with some embodiments, an inspection system can generally include a laser module, an interferometer module, and a system controller. The laser can produce laser pulses to excite a device such as a silicon wafer, chip capacitor or chip packaged/silicon die containing a plurality of solder bumps into vibration. The interferometer module can be disposed to receive reflected laser energy from the device to sense vibration displacements created in the device with the laser pulses. The system controller to receive vibration data from the interferometer, the system controller configured to output a control signal for adjusting a relative distance and position between the laser module and the device. Other aspects, features, and embodiments are also claimed and discussed.

Abstract: A system and method for measuring various weld characteristics is presented. The system and method can comprise a means to measure penetration depth of butt welds in thin plates, for example, using laser generated ultrasounds. Superimposed line sources (SLS) can be used to generate narrowband ultrasounds. A signal processing procedure that combines wavenumber-frequency (k-?) domain filtering and synthetic phase tuning (SPT) is used to reduce the complexity of Lamb wave signals. The reflection coefficients for different wavelengths corresponding to each wave mode can be calculated. Regression analysis that can include stepwise regression and corrected Akaike's information criterion (AIC) can be performed to build prediction models that use the reflection coefficients as predictors.

Abstract: Non-contact microelectronic device inspection systems and methods are discussed and provided. Some embodiments include a method of generating a virtual reference device (or chip). This approach uses a statistics to find devices in a sample set that are most similar and then averages their time domain signals to generate the virtual reference. Signals associated with the virtual reference can then be correlated with time domain signals obtained from the packages under inspection to obtain a quality signature. Defective and non-defective devices are separated by estimating a beta distribution that fits a quality signature histogram of inspected packages and determining a cutoff threshold for an acceptable quality signature. Other aspects, features, and embodiments are also claimed and described.

Abstract: In-process weld geometry methods and systems are discussed, enabled, and provided. Some embodiments include in-process welding devices to compensate for error associated with detected weld penetration depth. Exemplary devices can generally include an ultrasonic energy source, an ultrasonic receiving sensor, and a controller. The ultrasonic energy source can be disposed to generate ultrasonic energy through a first specimen being welded to a second specimen. A weld seam can be used to join the first specimen to the second specimen. The ultrasonic sensor can be disposed on an opposite side of the weld seam from the ultrasonic energy source, and configured to detect ultrasonic energy propagated from the first specimen side of the weld seam to the second specimen side of the weld seam.

Abstract: A system and method for providing laser generated ultrasound technique utilizing superimposed line sources is presented. The system and method can generate narrowband Lamb waves with a dominant wavelength by superimposing signals of line sources at the pitch corresponding to the desired wavelength. The superposition can be performed in software after data are collected to permit flexibility in the wavelength selected. Selecting the dominant wavelength in signals can reduce signal complexity and the speeds and frequencies of wave modes with the selected wavelength can be determined through dispersion curves. One or more additional techniques including, but not limited to, two-dimensional Fourier transforms and wavelet analysis can be used to further reduce the complexity of the signals. The system and method can be used, for example, for defect detection in thin plates.

Abstract: A method for processing ultrasonic response signals collected from a plurality of measurement locations along a weld of a test sample to determine the presence of defects in the weld may include filtering an ultrasonic response signal from each measurement location to produce a plurality of filtered response signals for each measurement location, wherein each filtered response signal corresponds to specific types of defects. Thereafter, a plurality of energy distributions may be calculated for the weld based on the plurality of filtered response signals for each measurement location. The plurality of energy distributions may be compared to corresponding baseline energy distributions to determine the presence of defects in the weld.

Abstract: A method for processing ultrasonic response signals collected from a plurality of measurement locations along a weld to determine the presence of a defect in the weld may include filtering an ultrasonic response signal from each of the measurement locations to produce a filtered response signal for each of the measurement locations. Thereafter, an ultrasonic energy for each of the measurement locations is calculated with the corresponding filtered response signal. The ultrasonic energy for each measurement location is then compared to the ultrasonic energy of adjacent measurement locations to identify potential defect locations. When the ultrasonic energy of a measurement location is less than the ultrasonic energy of the adjacent measurement locations, the measurement location is a potential defect location. The presence of a defect in the weld is then determined by analyzing fluctuations in the ultrasonic energy at measurement locations neighboring the potential defect locations.

Abstract: Non-contact microelectronic device inspection systems and methods are discussed and provided. Some embodiments include a method of generating a virtual reference device (or chip). This approach uses a statistics to find devices in a sample set that are most similar and then averages their time domain signals to generate the virtual reference. Signals associated with the virtual reference can then be correlated with time domain signals obtained from the packages under inspection to obtain a quality signature. Defective and non-defective devices are separated by estimating a beta distribution that fits a quality signature histogram of inspected packages and determining a cutoff threshold for an acceptable quality signature. Other aspects, features, and embodiments are also claimed and described.

Abstract: A method for determining the type of a defect in a weld may include determining a defect location and a corresponding defect signal by analyzing ultrasonic response signals collected from a plurality of measurement locations along the weld. The defect signal and the plurality of defect proximity signals corresponding to ultrasonic response signals from measurement locations on each side of the defect location may then be input into a trained artificial neural network. The trained artificial neural network may be operable to identify the type of the defect located at the defect location based on the defect signal and the plurality of defect proximity signals and output the type of the defect located at the defect location. The trained artificial neural network may also be operable to determine a defect severity classification based on the defect signal and the plurality of defect proximity signals and output the severity classification.

Abstract: High speed autofocus interferometric inspection systems and methods are discussed in this application. In accordance with some embodiments, an inspection system can generally include a laser module, an interferometer module, and a system controller. The laser can produce laser pulses to excite a device such as a silicon wafer, chip capacitor or chip packaged/silicon die containing a plurality of solder bumps into vibration. The interferometer module can be disposed to receive reflected laser energy from the device to sense vibration displacements created in the device with the laser pulses. The system controller to receive vibration data from the interferometer, the system controller configured to output a control signal for adjusting a relative distance and position between the laser module and the device. Other aspects, features, and embodiments are also claimed and discussed.

Abstract: A method for processing ultrasonic response signals collected from a plurality of measurement locations along a weld to determine the presence of a defect in the weld may include filtering an ultrasonic response signal from each of the measurement locations to produce a filtered response signal for each of the measurement locations. Thereafter, an ultrasonic energy for each of the measurement locations is calculated with the corresponding filtered response signal. The ultrasonic energy for each measurement location is then compared to the ultrasonic energy of adjacent measurement locations to identify potential defect locations. When the ultrasonic energy of a measurement location is less than the ultrasonic energy of the adjacent measurement locations, the measurement location is a potential defect location. The presence of a defect in the weld is then determined by analyzing fluctuations in the ultrasonic energy at measurement locations neighboring the potential defect locations.

Abstract: A method for determining the type of a defect in a weld may include determining a defect location and a corresponding defect signal by analyzing ultrasonic response signals collected from a plurality of measurement locations along the weld. The defect signal and the plurality of defect proximity signals corresponding to ultrasonic response signals from measurement locations on each side of the defect location may then be input into a trained artificial neural network. The trained artificial neural network may be operable to identify the type of the defect located at the defect location based on the defect signal and the plurality of defect proximity signals and output the type of the defect located at the defect location. The trained artificial neural network may also be operable to determine a defect severity classification based on the defect signal and the plurality of defect proximity signals and output the severity classification.

Abstract: A method for processing ultrasonic response signals collected from a plurality of measurement locations along a weld of a test sample to determine the presence of defects in the weld may include filtering an ultrasonic response signal from each measurement location to produce a plurality of filtered response signals for each measurement location, wherein each filtered response signal corresponds to specific types of defects. Thereafter, a plurality of energy distributions may be calculated for the weld based on the plurality of filtered response signals for each measurement location. The plurality of energy distributions may be compared to corresponding baseline energy distributions to determine the presence of defects in the weld.

Abstract: Embodiments of inspection systems and methods are disclosed. One embodiment of an inspection system, among others, comprises logic configured to receive a reference signal and a target signal, the reference signal having first surface displacement information and the target signal having second surface displacement information, said logic configured to determine a correlation coefficient between the first surface displacement information and the second surface displacement information, the correlation coefficient indicating whether an inspected object exhibits a defect.

Abstract: The present disclosure relates to an object inspection system. The object inspection system comprises an ultrasound source capable of exciting the object to be tested with a stimulus such that the object vibrates at an ultrasound frequency, at least one optical fiber optically connected to the ultrasound source and adapted to be positioned with its exit end in close proximity to a surface of the object to be tested to deliver the stimulus to the object, a vibration sensing device adapted to sense the ultrasonic vibration displacements created in the object by the ultrasound source, and a system controller which receives the ultrasonic vibration data from the vibration sensing device. In a preferred arrangement, the object inspection system comprises a solder joint inspection system for testing the integrity of solder joints used to connect a computer chip to a printed circuit board.