Practical Design of a High Frequency Phased-Array Acoustic Microscope Probe: A Preliminary Study

In pressure vessel and pipe inspection, ultrasonic nondestructive evaluation plays a pivotal role in both in-situ and laboratory examinations. Scanning acoustic microscopy (SAM) has been a well-recognized laboratory tool for both visualization and quantitative evaluation of pressure vessel and piping materials at the microscale since its invention in 1974. While there have been multiple advances in SAM over the past four decades, some issues still remain to be addressed. First, the measurement speed is limited by the mechanical movement of the acoustic lens and the sample stage. Second, a single-element transducer with an acoustic lens forms a predetermined beam pattern for a fixed focal length and incident angle, thereby limiting control of the inspection beam. Here, we propose to develop a phased-array probe as an alternative to overcome these issues. Preliminary studies to design a practical high-frequency phased-array acoustic microscope probe were explored. A linear phased-array, comprising 32 elements and operating at 5 MHz, was modeled using PZFlex, a finite element method software. This phased-array system was characterized in terms of electrical input impedance response, pulse-echo and impulse response, surface displacement profiles, mode shapes, and beam profiles. Details of the construction of the model and the results are presented in this paper. Development of a phased-array acoustic microscope probe will significantly enhance scanning acoustic microscopy techniques for detecting surface and subsurface defects and microstructural changes in laboratory samples of pressure vessel and piping materials.

Download Full-text

Implementation of a Rotational Ultrasound Biomicroscopy System Equipped with a High-Frequency Angled Needle Transducer — Ex Vivo Ultrasound Imaging of Porcine Ocular Posterior Tissues

10.32920/14637423.v1 ◽

2021 ◽

Author(s):

Tae-Hoon Bok ◽

Juho Kim ◽

Jinho Bae ◽

Chong Hyun Lee ◽

Dong-Guk Paeng

Keyword(s):

Ultrasound Imaging ◽

High Frequency ◽

Ex Vivo ◽

Focal Length ◽

Ultrasound Biomicroscopy ◽

Single Element ◽

High Frequency Ultrasound ◽

Scanning Angle ◽

Distance Range ◽

Minimal Incision

The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270° ~ 330° and at a distance range of 6 ~ 7 mm, whereas the tissues of the other eye were observed in relative angle range of 160° ~ 220° and at a distance range of 7.5 ~ 9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system.

Download Full-text

Implementation of a Rotational Ultrasound Biomicroscopy System Equipped with a High-Frequency Angled Needle Transducer — Ex Vivo Ultrasound Imaging of Porcine Ocular Posterior Tissues

10.32920/14637423 ◽

2021 ◽

Author(s):

Tae-Hoon Bok ◽

Juho Kim ◽

Jinho Bae ◽

Chong Hyun Lee ◽

Dong-Guk Paeng

Keyword(s):

Ultrasound Imaging ◽

High Frequency ◽

Ex Vivo ◽

Focal Length ◽

Ultrasound Biomicroscopy ◽

Single Element ◽

High Frequency Ultrasound ◽

Scanning Angle ◽

Distance Range ◽

Minimal Incision

The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270° ~ 330° and at a distance range of 6 ~ 7 mm, whereas the tissues of the other eye were observed in relative angle range of 160° ~ 220° and at a distance range of 7.5 ~ 9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system.

Download Full-text

Optimized integrated design of a high-frequency medical ultrasound transducer with genetic algorithm

SN Applied Sciences ◽

10.1007/s42452-021-04627-z ◽

2021 ◽

Vol 3 (6) ◽

Author(s):

Ali Babazadeh Khameneh ◽

Hamid Reza Chabok ◽

Hossein Nejat Pishkenari

Keyword(s):

High Frequency ◽

Focal Length ◽

Integrated Design ◽

Equivalent Circuit Model ◽

Single Element ◽

Optimized Design ◽

Medical Ultrasound ◽

Efficient Design ◽

Daunting Task ◽

Imaging Resolution

AbstractDesigning efficient acoustic stack and elements for high-frequency (HF) medical ultrasound (US) transducers involves various interrelated parameters. So far, optimizing spatial resolution and acoustic field intensity simultaneously has been a daunting task in the area of HF medical US imaging. Here, we introduce optimized design for a 50-MHz US probe for skin tissue imaging. We have developed an efficient design and simulation approach using Krimholtz, Leedom and Matthaei (KLM) equivalent circuit model and spatial impulse response method by means of Field II software. These KLM model and Field II software are integrated, and a GA algorithm is used to optimize the design of the US transducer to obtain the best imaging performance. As a result, a 50-MHz single element probe is effectively optimized with 5 mm acoustic focal length, 72 $$\upmu {\text{m}}$$ μ m lateral, and 42 $$\upmu {\text{m}}$$ μ m axial imaging resolution, with an enhancement in imaging resolution over the conventionally designed and simulated probe by 10%. This work has the potential to benefit many applications that require a fast, high-resolution and strong US focus in skin imaging.

Download Full-text

Application of Scanning Acoustic Microscopy to Electric and Electronic Parts

ISTFA 2000: Conference Proceedings from the 26th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2000p0303 ◽

2000 ◽

Author(s):

C. Miyasaka ◽

B. R. Tittmann

Keyword(s):

Surface Roughness ◽

Background Noise ◽

Spherical Aberration ◽

Current Trend ◽

Acoustic Microscopy ◽

Scanning Acoustic Microscopy ◽

Acoustic Microscope ◽

Acoustic Lens ◽

Electronic Parts ◽

Scanning Acoustic Microscope

Abstract Ever since the invention of the scanning acoustic microscope (SAM), a key objective has been the enhancement of the resolution in an interior image. Thus, an acoustic lens that can form an interior image with a shear wave has been designed. The use of this lens gives benefits such as an increase of lateral resolution in the interior image, a reduction in background noise caused by surface roughness, and a reduction of spherical aberration. Significantly, with the current trend towards microminiaturization of microelectronic packages, acoustic microscopy with higher resolution and removal of surface roughness can play an important role in diagnostic examinations and failure analysis. In this paper, applications for the lens in microelectronic IC packages will be summarized.

Download Full-text

The dance of the nanobubbles: detecting acoustic backscatter from sub-micron bubbles using ultra-high frequency acoustic microscopy

Nanoscale ◽

10.1039/d0nr05390b ◽

2020 ◽

Vol 12 (41) ◽

pp. 21420-21428

Author(s):

Michael J. Moore ◽

Filip Bodera ◽

Christopher Hernandez ◽

Niloufar Shirazi ◽

Eric Abenojar ◽

...

Keyword(s):

High Frequency ◽

Acoustic Microscopy ◽

Acoustic Backscatter ◽

Agarose Gel ◽

Acoustic Microscope ◽

Ultra High Frequency

Detection of the motion of individual nanobubbles and microbubbles in an agarose gel using an ultra-high frequency acoustic microscope.

Download Full-text

Biological Acoustic Microscopy - Living Cells at 37°C and Fixed Cells in Cryogenic Liquids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053565 ◽

1982 ◽

Vol 40 ◽

pp. 174-177

Author(s):

J.A. Hildebrand ◽

D. Rugar ◽

C.F. Quate

Keyword(s):

High Frequency ◽

Acoustic Microscopy ◽

Single Element ◽

Acoustic Image ◽

Acoustic Reflection ◽

Glass Substrates ◽

Acoustic Images ◽

Cryogenic Liquids ◽

Chick Heart ◽

Coupling Medium

The scanning reflection acoustic microscope uses high frequency sound to create images with sub-micron resolution. A single-element sapphire lens focuses sound to a diffraction-limited spot in a liquid coupling medium. With the object placed near the focus, the spot of sound is mechanically scanned while the magnitude of the acoustic reflection is recorded for each point on the object. The resulting acoustic image is bright in areas of large acoustic reflection and dark in areas of small acoustic reflection. Acoustic images of biological cells contain information on cellular viscous, elastic and topographic properties. This paper presents acoustic images of living and fixed chick heart fibroblasts grown on glass substrates.

Download Full-text

Numerical calculation and measurement for the focus field of concave spherical acoustic lens transducer

MATEC Web of Conferences ◽

10.1051/matecconf/201928305007 ◽

2019 ◽

Vol 283 ◽

pp. 05007

Author(s):

Jun Zhang ◽

Yi Chen ◽

Liuqing Yang

Keyword(s):

Wave Propagation ◽

Incident Angle ◽

Focal Length ◽

Sound Field ◽

Numerical Data ◽

Scanning System ◽

Acoustic Lens ◽

Wave Propagation Method ◽

The Relationship ◽

Important Basis

How to accurately calculate the sound field formed by acoustic lenses is an important basis for the design of acoustic lens transducers. The radiation sound field distribution of the physical model of acoustics lens is simulated by numerical methods, including the ray propagation method and the wave propagation method. The ray propagation method can only get the focal length without considering the wave characteristics property, while the wave propagation method takes into account the amplitude and phase factors of the wave, and by which the distribution of the whole sound field can be got. The relationship between the property of refractive wave and incident angle of incident wave is analyzed, and theoretical results of the distribution of the focal field are obtained. The actual sound field of the real transducer is measured by acoustic field scanning system, and the measured results of focal length and focal area are obtained. The comparison and analysis of the numerical data and measured data show that the wave propagation method can be used to predict the focus field of concave spherical acoustic lens transducer accurately and effectively.

Download Full-text

Failure Analysis of Flip-Chip Interconnections Through Acoustic Microscopy

ISTFA 1996: Conference Proceedings from the 22nd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa1996p0277 ◽

1996 ◽

Author(s):

O. Diaz de Leon ◽

M. Nassirian ◽

C. Todd ◽

R. Chowdhury

Keyword(s):

Failure Analysis ◽

Large Scale ◽

Flip Chip ◽

Ultrasonic Waves ◽

Acoustic Microscopy ◽

Acoustic Microscope ◽

Chip Technology ◽

Ball Joints ◽

Non Destructive ◽

Scanning Acoustic Microscope

Abstract Integration of circuits on semiconductor devices with resulting increase in pin counts is driving the need for improvements in packaging for functionality and reliability. One solution to this demand is the Flip- Chip concept in Ultra Large Scale Integration (ULSI) applications [1]. The flip-chip technology is based on the direct attach principle of die to substrate interconnection.. The absence of bondwires clearly enables packages to become more slim and compact, and also provides higher pin counts and higher-speeds [2]. However, due to its construction, with inherent hidden structures the Flip-Chip technology presents a challenge for non-destructive Failure Analysis (F/A). The scanning acoustic microscope (SAM) has recently emerged as a valuable evaluation tool for this purpose [3]. C-mode scanning acoustic microscope (C-SAM), has the ability to demonstrate non-destructive package analysis while imaging the internal features of this package. Ultrasonic waves are very sensitive, particularly when they encounter density variations at surfaces, e.g. variations such as voids or delaminations similar to air gaps. These two anomalies are common to flip-chips. The primary issue with this package technology is the non-uniformity of the die attach through solder ball joints and epoxy underfill. The ball joints also present defects as open contacts, voids or cracks. In our acoustic microscopy study packages with known defects are considered. It includes C-SCAN analysis giving top views at a particular package interface and a B-SCAN analysis that provides cross-sectional views at a desired point of interest. The cross-section analysis capability gives confidence to the failure analyst in obtaining information from a failing area without physically sectioning the sample and destroying its electrical integrity. Our results presented here prove that appropriate selection of acoustic scanning modes and frequency parameters leads to good reliable correlation between the physical defects in the devices and the information given by the acoustic microscope.

Download Full-text

Stacked Die Analysis Using C-mode Scanning Acoustic Microscope

ISTFA 2005: Conference Proceedings from the 31st International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2005p0189 ◽

2005 ◽

Author(s):

Li Na ◽

Jawed Khan ◽

Lonnie Adams

Keyword(s):

Data Acquisition ◽

Image Interpretation ◽

Acoustic Microscopy ◽

Scanning Acoustic Microscopy ◽

Acoustic Microscope ◽

Analysis Mode ◽

Scanning Acoustic Microscope

Abstract For stacked die package delamination inspection using C-mode acoustic microscope, traditional interface and thorough scan techniques cannot give enough of information when the delamination occurs in multi-interfaces, and echoes from adjacent interfaces are not sufficiently separated from each other. A thinner thickness in the stacked-die package could complicate C-mode scanning acoustic microscopy (CSAM) analysis and sometimes may lead to false interpretations. The first objective of this paper is to briefly explain the CSAM mechanism. Based on that, some of the drawbacks of current settings in detecting the delamination for stacked-die packages are presented. The last objective is to introduce quantitative B-scan analysis mode (Q-BAM) and Zip-Slice technologies in order to better understand and improve the reliability of detecting the delamination in stacked-die packages. Therefore, a large portion of this paper focuses on the Q-BAM and Zip-Slice data acquisition and image interpretation.

Download Full-text