A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder. The system utilizes real time, automated ultrasonic inspection of a welding operation as the welds are being made by providing a transducer which follows a short distance behind the welding head. Reflected ultrasonic signals are analyzed utilizing computer based digital pattern recognition techniques to discriminate between good and flawed welds on a pass by pass basis. The system also distinguishes between types of weld flaws.

Concurrent ultrasonic weld evaluation system

A laser drilling control system utilizing photoacoustic feedback is described. The control system provides an accurate monitoring of the laser drilling of a multilayered printed circuit board thereby allowing uniform drilling through layers of different optical and photoacoustic properties by both analyzing the photoacoustic feedback signals received, and adjusting optimally the laser parameters such as pulse duration, wavelength, energy, pulse repetition rate, and the number of pulses, for each successive layer. The system also provides an end point detection which prevents underdrilling overheating, and overdrilling of underlying layers and associated damages. According to another aspect of this invention, the control system can be used as a sensitive misregistration detector for aligning the laser beam to a selected drill site for subsequent drilling at the selected drill site.

Laser drilling system utilizing photoacoustic feedback

A laser weld monitoring system capable of assessing a weld quality of welding using a pulsed laser is provided. The system includes at least one sensor capable of capturing a weld characteristic of welding using said pulsed laser. The weld characteristic has multiple attributes. The system also includes data acquisition and processing equipment adapted for storing and analyzing the weld characteristic. A user first performs multiple welds to capture at least one weld characteristic for each weld. The user then determines the weld quality of each weld, and runs at least one of a library of algorithms associated with the attributes on said at least one weld characteristic for each weld to generate a single value output for the associated attribute. The user selects an attribute indicative of the weld quality by correlating the single value outputs of said at least one algorithm with the weld qualities of the welds.

Laser weld monitor

A bearing failure judging apparatus correctly judges the type of the cause of a failure of a bearing by synthetically judging many factors found in a vibrating waveform of a vibration produced when a failure takes place in the bearing i.e. various features of the time-waveform; a localization of the amplitudes of the time-waveform, the periods of pulsating waves, a degree of the acuteness of the waveform depicted by its envelope, the presence or absence of the proper peak value in the frequency spectra, and a change of the waveform after a given time.

Bearing failure judging apparatus

Pulsed light sources, such as a flashlamp or laser, remove coatings from substrates via the ablation method. A photodetector circuit, sensing reflected light from the surface being ablated, provides a feedback signal that indicates the reflected color intensity of the surface being ablated. The boundary between the coatings or substrate surfaces is distinguished by a change in color intensity between an upper coating and an undercoating, e.g., between a topcoat of paint and a primer coat of paint, or between a coating and the substrate surface itself. The color intensity determination thus provides a measure relative to when one coating has been removed and another coating remains. The photodetector circuit is also useful for providing feedback information relative to the quality of a stripped work surface for quality control or other purposes.

Method and system for selective removal of material coating from a substrate using a flashlamp

Herein disclosed is a noncontact, nondestructive method for monitoring the quality of a high energy weld, e.g., laser beam weld. In accordance with the proposed method, an acoustic sensor (32) is positioned at a distance from the welding zone (34) and picks up airborne acoustic emission signals (33) associated with the laser welding process. These acoustic signals, propagating through the air space between the welding zone (34) and the sensor (32), are detected and analyzed (36,37) to determine the quality of the weld (FIG. 3).

Nondestructive real-time method for monitoring the quality of a weld

Detection of the existence, magnitude, and frequency of occurrence of a plurality of ESD events is achieved by using an envelope detector to process signals generated by ESD events and received by an antenna The ESD event detector includes an antenna for producing a signal waveform in response to electromagnetic fields incident thereupon, a demodulator coupled to the antenna for generating an envelope waveform that is related to the envelope of the signal waveform, a threshold window discriminator coupled to the demodulator for generating an indication signal if the envelope detected by the demodulator has a magnitude between a first and a second threshold, and a counter coupled to the threshold window discriminator for counting the number of indication signals received from the threshold window detector

Electrostatic discharge event detector

The disclosure is directed to a technique for monitoring signals emanating from a ceramic article (10) during a soldering operation. In order to determine whether the signals are stress wave emissions (SWE's) or noise the number of pulses (41) of the monitored signal having an amplitude exceeding a preset threshold (51), during a period of time, are counted. A count (62) proportional to the area under the envelope of the detected signal during the period of time is also made. A ratio of the count related to the area under the envelope to the pulse count is formed and compared to an empirically developed range of ratios which are indicative of a stress wave emission signal.

Method and apparatus for monitoring cracking using stress wave emission techniques

An automatic pull tester and an acoustic emission system are herein combined to analyze the failure modes of lead frames bonded to integrated circuits. By using a discriminant analysis technique, a specific failure mode can be determined in real-time by first measuring up to five variables during the pulling operation. The five variables that may be measured comprise acoustic emission signals of a first amplitude (AE1), acoustic emission signals of a second amplitude (AE2), the time elapsed until failure (Δt), the number (n) of acoustic emission bursts above a first threshold, to the peak pulling force at failure (Lmax). Next, the variables measured are incorporated into a plurality of predetermined functions, each function corresponding to one failure mode (FM1 to FM5). The failure mode of the bond is determined by selecting the function having the highest value (FIG. 4).

Method for determining lead frame failure modes using acoustic emission and discriminant analysis techniques

A connector assembly for removing static electricity generated in high-speed communication cable as a result of tribocharging is described. The invention is realized with a typical high-speed cable having a connector provided with a dissipative medium and at least one conductive pad. Static electricity on the jacket material of the cable induces a charge in the cable wires, which is bled to the pads via the dissipative medium. The charge on the pad is then grounded prior to or as the cable is connected to a cable jack.

Vito Palazzo

Papers

Nondestructive real-time method for monitoring the quality of a weld

Electrostatic discharge event detector

Method and apparatus for monitoring cracking using stress wave emission techniques

Method for determining lead frame failure modes using acoustic emission and discriminant analysis techniques

Connector assembly to eliminate or reduce ESD on high-speed communication cables