Chip on board wire bonding presents challenges to modern wire bonding technology which include smaller, closely spaced wire bond pads; bonding to soft substrates without special processing and pad construction; and diverse first bond and second bond metallurgies. These challenges are addressed by extensive bonding accuracy tests, a design of experiments approach for optimizing wire bond process...

This study investigates the different types of ultrasonic inspection, when applied to assess the impact damage in Carbon Fiber Reinforced Plastic CFRP laminates. The study surveys the two most used ultrasonic testing approaches first; namely the pulse-echo and the through-transmission modes. Then, the manuscript discusses and analyzes the enhanced ultrasonic testing methods that use the polar s...

This research verified the applicability and effectiveness of the ultrasonic monitoring of sediments stuck on the inner wall of polyvinyl chloride (PVC) pipes. For identifying the transmittance of acoustic energy and the speed of sound in the PVC material, the pulse-echo ultrasonic testing was conducted for PVC sheets of different thicknesses. To simulate the solidified sediment, the hot melt a...

Transmission loss and insertion loss measurements of building materials at audible frequencies are commonly made using plane wave tubes or as a panel between reverberant rooms. These measurements provide information for noise isolation control in architectural acoustics and in product development. Airborne ultrasonic sound transmission through common building materials has not been fully explor...

For inquiry of application of ultrasonic method [UT] possibilities at composite materials inspection specimens based on the carbon fibres that correspond to structure aircraft elements were designed and made. Applied specimens were made of different composite materials with various numbers of layers and various thicknesses. For simulation of delaminating in different layers of tested structure ...

The in-situ testing of early age concrete strength is crucial for determining the time of form removal from concrete elements, opening highways to traffic or applying of prestress to steel reinforcement. A nondestructive ultrasonic technique, which measures the reflection loss of ultrasonic transverse waves at a concrete-steel interface, is presented in this paper. The focus is to compare wave ...

Before a product can be developed, materials are the first step in the differentiation and engineering of matter. Therefore material constitutes the clay with which any human made product is built. Since the drawn of time, man has been using materials, but knowledge in this area is mainly based in experience. Today we have reached a revolutionary stage in the knowledge and the control of matter...

Certain microstructural features of materials, such as grain size in metals, porosity in ceramics, and structural phase compositions, are important for determining mechanical properties. Many of these microstructural features have been characterized by ultrasonic wave propagation measurements, such as wave velocity and attenuation. Real-time monitoring of ultrasonic wave propagation during the ...

In non destructive testing of materials, the ultrasonic imagery is a field in full rise. Indeed , more than one convivial representation of the results , the operations of detection , localization and sizing of the defects can be carried out automatically by the analysis of synthesized images. The problem breaks up in general into a phase of preprocessing to only limit the quantity of informati...

background: ultrasonic vibrations are used to remove a cemented post from a root canal requiring endodontic retreatment. various results have been reported from the studies that evaluated the effect of ultrasonic instruments in removing the posts cemented with resin cements. the aim of this study was to evaluate the effect of ultrasonic energy on the retention of prefabricated metal post cement...