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scanning acoustic microscopy

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Published: 01 August 2018
Fig. 7 Block diagram of a reflective-type scanning acoustic microscopy system that uses mechanical scanning of a highly focused transducer to investigate the surface zone of a sample at high magnification. CRT, cathode ray tube; B/W, black-and-white More
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Published: 01 August 2018
Fig. 14 50 MHz C-mode scanning acoustic microscopy reflection-mode micrograph of a carbon-fiber-reinforced plastic test sample. The ultrasound was focused near the top surface of the sample. Field of view: 19 × 14 mm More
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Published: 01 August 2018
Fig. 20 Scanning acoustic microscopy image at 180 MHz of the sample shown in Fig. 18 and Fig. 19 revealing features of the ceramic at and near the surface. Field of view: 1 × 1 mm More
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Published: 01 August 2018
Fig. 23 C-mode scanning acoustic microscopy reflection-mode image at 50 MHz made by setting the gate and focus to approximately 1 mm (0.04 in.) below the surface. The white circular spots correspond to individual pores located at this depth. Field of view: 30 × 30 mm More
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Published: 01 August 2018
Fig. 24 Scanning acoustic microscopy surface-mode image at 180 MHz made under conditions identical to Fig. 20 . In this image, the fine texture corresponds to porosity of the sample. Note the sharp contrast between the microstructure of this sample and that of Fig. 20 . Field of view: 1 × 1 More
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Published: 01 August 2018
Fig. 25 Scanning acoustic microscopy surface-mode image at 400 MHz of a manganese-zinc ferrite sample that was polished metallurgically but not chemically etched. The elastic property differences between the various phases of this material are responsible for the contrast shown in this image More
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Published: 01 August 2018
Fig. 26 Scanning acoustic microscopy image at 1.3 GHz of a polished but unetched manganese-zinc low-carbon steel. Darker regions indicate the presence of typical contaminants trapped in the metal. Courtesy of G.H. Thomas, Sandia National Laboratories More
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Published: 01 August 2018
Fig. 31 Schematic illustrating use of the C-mode scanning acoustic microscopy reflection technique to evaluate the die-attach bond between the silicon die and the ceramic package of a ceramic dual in-line package integrated circuit. With this technique, the ultrasound access to the bond layer More
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Published: 01 August 2018
Fig. 32 C-mode scanning acoustic microscopy reflection-mode image at 15 MHz of a plastic-encapsulated integrated circuit showing a suspicious area of the lead frame. In this image, the brightness of the image (toward white) represents the magnitude of the echoes from the interface More
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Published: 01 August 2018
Fig. 41 Edge effect in (a) C-mode scanning acoustic microscopy (C-SAM) and (b) scanning laser acoustic microscopy (SLAM). In the case of C-SAM, when the transducer is too close to the left edge of a sample having thickness t , the acoustic beam becomes cut off, and the echo signal does More
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Published: 01 August 2018
Fig. 33 Scanning laser acoustic microscopy (SLAM) through-transmission image produced at 10 MHz of the sample shown in Fig. 32 . In this image, the disbonded zones are presented as dark. Careful analysis of Fig. 33 indicates that the disbonded areas in black and white are larger than those More
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Published: 01 August 2018
Fig. 22 Scanning laser acoustic microscopy 100 MHz transmission acoustic image of the sample shown in Fig. 21 . At this higher frequency, textured variations in the sample are evident that may be due to micro (subresolution) porosity segregations, which cause differential absorption. Field More
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Published: 01 August 2018
Fig. 18 Low-frequency 10 MHz scanning laser acoustic microscopy image of a 25 mm (1 in.) diameter alumina test disk. The disk is very attenuating to ultrasound because of internal defects that cover approximately 75% of the area (dark zones). Field of view: 35 × 26 mm More
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Published: 01 August 2018
Fig. 21 Scanning laser acoustic microscopy image at 30 MHz of an alumina test disk similar in size to that shown in Fig. 18 . This sample was quite transparent to the ultrasound, as evidenced by the bright, relatively uniform appearance of the acoustic image. Field of view: 14 × 10.5 mm More
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Published: 01 August 2018
Fig. 28 Schematic illustrating use of the scanning laser acoustic microscopy through-transmission technique to evaluate the die-attach bond between the silicon die and the ceramic package More
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Published: 01 August 2018
Fig. 29 30 MHz transmission scanning laser acoustic microscopy image of a die-attach. The dark areas of the image correspond to little or no acoustic wave transmission due to the lack of bonding between the die and the ceramic. The white rectangle outlining the die is generated by an acoustic More
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Published: 01 August 2018
Fig. 30 Computer-analyzed scanning laser acoustic microscopy image of Fig. 29 in which the disbonds are clearly displayed as black More
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Published: 01 August 2018
Fig. 35 Scanning laser acoustic microscopy image at 200 MHz of tape-automated-bonded leads on an integrated circuit. The bright areas at the tips of each lead indicate good-quality bonds. Field of view: 1.75 × 1.3 mm More
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Published: 01 August 2018
Fig. 36 Scanning laser acoustic microscopy image at 200 MHz of tape-automated-bonded leads that are not of as uniform quality as those shown in Fig. 35 . The poor bonds are mechanically weak and are more likely to suffer from long-term reliability problems. Field of view: 1.75 × 1.3 mm More
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Published: 01 August 2018
Fig. 42 Scanning laser acoustic microscopy image at 30 MHz of a plastic-encapsulated ceramic capacitor having a significant defect that can cause long-term reliability problems. This defect is not evident by electrical testing. Field of view: 14 × 10.5 mm More