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Use of Ultrasonics in the Nondestructive Testing and Evaluation of Metals
Published in Dale Ensminger, Leonard J. Bond, Ultrasonics, 2011
Dale Ensminger, Leonard J. Bond
Acoustic microscopy systems have now been developed to provide imaging at frequencies up to about 2 GHz, which give submicron resolution. Reviews of industrial applications, including some in the electronics industries, were provided in articles by Nikoonahad [155] and Gilmore et al. [156]. The second article considers systems covering the frequency range from 10 to 100 MHz. Acoustic microscopy is now recognized to be a powerful tool for the inspection of microstructures in electronic devices, and it is being employed to inspect chips, integrated circuits, flip-chip assemblies, ball-grid arrays, and layered assemblies for a wide variety of delaminations including die attachment and poor heat-sink attachment, for bond-line integrity, and to find voids and cracks that could cause in-service hotspots and failures [157]. An example of an image obtained with a commercial 50 MHz imaging system used to inspect for delaminations in an IC package is shown in Figure 8.33.
Techniques and Applications of Scanning Acoustic Microscopy in Bone Remodeling Studies
Published in Cornelius Leondes, Musculoskeletal Models and Techniques, 2001
Mark C. Zimmerman, Robert D. Harten, Sheu-Jane Shieh, Alain Meunier, J. Lawrence Katz
Presently, almost all acoustic microscopy uses the principle of reflection. When a sound wave is directed onto a large interface, it will be partially transmitted across the interface and partially reflected back toward its source. The reflected portion of the wave is used to determine the mechanical properties of the materials of the interface. The percentage of the wave reflected at the interface depends on the wave’s angle of incidence and the acoustic impedance differences of the materials that make up the interface. Snell’s law states that for a wave undergoing specular reflection, the angle of incidence equals the angle of reflection. In an acoustic microscope, the source of sound is a piezoelectric transducer which acts as a sender and receiver. Therefore, for the transducer to receive the maximum reflected signal, the transducer is oriented so that the incident wave strikes the interface perpendicularly. The path of the reflected wave thus will also be perpendicular to the interface.
Focused Beam Acoustic Microscopy
Published in J. David, N. Cheeke, Fundamentals and Applications of Ultrasonic Waves, 2017
Acoustic microscopy involves imaging the elastic properties of surface or subsurface regions using acoustic waves as well as measuring the mechanical properties on a microscopic scale. In most of the work done so far, this has involved focusing acoustic waves by an acoustic lens that is mechanically scanned over the field of view. Following the initial work of Sokolov [1], the real start of the field was the development of the scanning acoustic microscope (SAM) by Lemons and Quate in 1973 [2]. This was essentially an extension of the traditional focused C-scan ultrasonic imaging system, which is a broadband scanned ultrasonic imaging system using a spherical lens of high F number to image surface detail or defects in the interior of opaque samples.
3D reconstruction and characterization of reef limestone pores based on optical and acoustic microscopic images
Published in Marine Georesources & Geotechnology, 2022
Jinchao Wang, Chuanying Wang, Zengqiang Han, Yiteng Wang, Junpeng Zou
Deep microscopic images are mainly derived from acoustic microscopy. As a result of signal interference in the depth direction, acoustic microscopy images can reflect the acoustic response characteristics at different depths within a test sample. The pore profile texture information produced via acoustic microscopy is weak, so its principal value lies in its capacity to add depth accuracy to the pore profile.