Rayleigh Waves in Scanning Acoustic Microscopy

Author(s):  
H. L. Bertoni
Author(s):  
Ingrid De Wolf ◽  
Ahmad Khaled ◽  
Martin Herms ◽  
Matthias Wagner ◽  
Tatjana Djuric ◽  
...  

Abstract This paper discusses the application of two different techniques for failure analysis of Cu through-silicon vias (TSVs), used in 3D stacked-IC technology. The first technique is GHz Scanning Acoustic Microscopy (GHz- SAM), which not only allows detection of defects like voids, cracks and delamination, but also the visualization of Rayleigh waves. GHz-SAM can provide information on voids, delamination and possibly stress near the TSVs. The second is a reflection-based photoelastic technique (SIREX), which is shown to be very sensitive to stress anisotropy in the Si near TSVs and as such also to any defect affecting this stress, such as delamination and large voids.


Author(s):  
Chiaki Miyasaka ◽  
Jikai Du ◽  
Bernhard R. Tittmann

The present article reports a technique to measure velocity of a biological specimen, wherein the thickness of the biological specimen and the diameter of the measurement area of the specimen are in the order of a few microns. The kidney was selected for the specimen as an example of the soft material. The kidney was thinly sliced by a microtome and located on a substrate. The thickness of the specimen was substantially 3 μm. For the substrate, fused quartz was used because its elastic properties are known and stable. The spherical acoustic lens was used to determine the position for the measurement. The frequencies of 400 and 600 MHz were used for the measurement and the visualization respectively. The generation of the Rayleigh waves in the above conditions was simulated by numerical calculations based on the wave propagation theory for layered media.


Author(s):  
Katherine V. Whittington

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.


Author(s):  
Bilal Abd-AlRahman ◽  
Corey Lewis ◽  
Todd Simons

Abstract A failure analysis application utilizing scanning acoustic microscopy (SAM) and time domain reflectometry (TDR) for failure analysis has been developed to isolate broken stitch bonds in thin shrink small outline package (TSSOP) devices. Open circuit failures have occurred in this package due to excessive bending of the leads during assembly. The tools and their specific application to this technique as well as the limitations of C-SAM, TDR and radiographic analyses are discussed. By coupling C-SAM and TDR, a failure analyst can confidently determine whether the cause of an open circuit in a TSSOP package is located at the stitch bond. The root cause of the failure was determined to be abnormal mechanical stress placed on the pins during the lead forming operation. While C-SAM and TDR had proven useful in the analysis of TSSOP packages, it can potentially be expanded to other wire-bonded packages.


Author(s):  
Li Na ◽  
Jawed Khan ◽  
Lonnie Adams

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.


Acoustics ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 3-10
Author(s):  
Hideki Kumagai ◽  
Kazuto Kobayashi ◽  
Sachiko Yoshida ◽  
Koji Yokoyama ◽  
Norio Hirota ◽  
...  

Scanning acoustic microscopy reveals information on histology and acoustic impedance through tissues. The objective of the present study was to investigate whether acoustic impedance values in the liver over time reflect the progression of steatohepatitis through different grades and stages, and whether this approach can visualize histologic features of the disease. Mice were divided into two groups: a control group and a steatohepatitis group prepared by keeping the mice on a methionine and choline-deficient diet for 56 weeks. The hepatic lobe was excised for measurement of impedance and observation of microscopic structure using a commercially available scanning acoustic microscopy system with a central frequency of 320 MHz. Scanning acoustic microscopy revealed that acoustic impedance through liver tissue with steatohepatitis temporarily decreased with the degree of fat deposition and then increased in parallel with the progression of inflammation and fibrosis. However, the acoustic images obtained did not allow discrimination of detailed microstructures from those seen using light microscopy. In conclusion, estimation of acoustic impedance appears to have potential clinical applications, such as for monitoring or follow-up studies.


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