scholarly journals Correction for Laforsch et al., An acoustic microscopy technique reveals hidden morphological defenses in Daphnia, PNAS 2004 101:15911-15914

2004 ◽  
Vol 102 (2) ◽  
pp. 515-515
Keyword(s):  
Acoustic Microscopy ◽  
Microscopy Technique ◽  
Morphological Defenses

scholarly journals An acoustic microscopy technique reveals hidden morphological defenses in Daphnia

2004 ◽  
Vol 101 (45) ◽  
pp. 15911-15914 ◽  
Author(s):  
C. Laforsch ◽  
W. Ngwa ◽  
W. Grill ◽  
R. Tollrian
Keyword(s):  
Acoustic Microscopy ◽  
Microscopy Technique ◽  
Morphological Defenses

Backside Application of Acoustic Micro Imaging (AMI) on Plastic Ball Grid Array (PBGA) and Plastic Quad Flat Pack (PQFP) Packages

2004 ◽  
Author(s):  
Luis A. Curiel ◽  
Andrew J. Komrowski ◽  
Daniel J.D. Sullivan
Keyword(s):  
Ball Grid Array ◽  
Acoustic Microscopy ◽  
Electronic Packages ◽  
Nondestructive Technique ◽  
Molding Compound ◽  
Microscopy Technique ◽  
Plastic Ball ◽  
Die Surface ◽  
Plastic Ball Grid Array ◽  
Bond Pads

Abstract Acoustic Micro Imaging (AMI) is an established nondestructive technique for evaluation of electronic packages. Non-destructive evaluation of electronic packages is often a critical first step in the Failure Analysis (FA) process of semiconductor devices [1]. The molding compound to die surface interface of the Plastic Ball Grid Array (PBGA) and Plastic Quad Flat Pack (PQFP) packages is an important interface to acquire for the FA process. Occasionally, with these packages, the standard acoustic microscopy technique fails to identify defects at the molding compound to die surface interface. The hard to identify defects are found at the edge of the die next to the bond pads or under the bonds wires. This paper will present a technique, Backside Acoustic Micro Imaging (BAMI) analysis, which can better resolve the molding compound to die surface interface at the die edge by sending the acoustic signal through the backside of the PBGA and PQFP packages.

Quantitative Short-pulse Acoustic Microscopy and Application to Materials Characterization

2000 ◽  
Vol 6 (1) ◽  
pp. 59-67
Author(s):  
Theodore E. Matikas
Keyword(s):  
Elastic Property ◽  
Acoustic Waves ◽  
Short Pulse ◽  
Surface Acoustic Waves ◽  
Tone Burst ◽  
Acoustic Microscopy ◽  
Near Surface ◽  
Microscopy Technique ◽  
Setup Phase ◽  
Additional Reference

Abstract A new acoustic microscopy method was developed for providing near-surface elastic property mapping of a material. This method has a number of advantages over the traditional V(z) technique. First, it enables one to perform measurements in an automated mode that only requires user intervention in the setup phase. This automated mode makes it feasible to obtain quantitative microscopy images of the elastic property over an area on the material being tested. Also, it only requires a conventional ultrasonic system operating in pulsed mode for collecting the data, rather than a specialized tone-burst system, which is needed in the traditional quantitative scanning acoustic microscopy technique. Finally, unlike the traditional method, the new experimental process does not require calibration of the systems electronics or additional reference data taken under hard-to-duplicate identical conditions from a material that does not exhibit surface acoustic waves.

High-resolution picosecond acoustic microscopy for non-invasive characterization of buried interfaces

2006 ◽  
Vol 21 (5) ◽  
pp. 1204-1208 ◽  
Author(s):  
Shriram Ramanathan ◽  
David G. Cahill
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Integrated Circuit ◽  
Acoustic Waves ◽  
Spot Size ◽  
Acoustic Microscopy ◽  
Microscopy Technique ◽  
Fundamental Limitations ◽  
Buried Interfaces ◽  
Advanced Packaging

Non-destructive investigation of buried interfaces at high-resolution is critical for integrated circuit and advanced packaging research and development. In this letter, we present a novel non-contact microscopy technique using ultrahigh frequency (GHz range) longitudinal acoustic pulses to form images of interfaces and layers buried deep inside a silicon device. This method overcomes fundamental limitations of conventional scanning acoustic microscopy by directly generating and detecting the acoustic waves on the surface of the sample using an ultrafast pump-probe optical technique. We demonstrate our method by imaging copper lines buried beneath a 6-μm silicon wafer; the lateral spatial resolution of 3 μm is limited by the laser spot size. In addition to the high lateral spatial resolution, the technique has picosecond (ps) time resolution and therefore will enable imaging individual interconnect layers in multi-layer stacked devices.

Moisture Migration and Cracking in Plastic Quad Flat Packages (PQFPs)

1997 ◽  
Vol 119 (2) ◽  
pp. 85-88 ◽  
Author(s):  
S. A. Taylor ◽  
K. Chen ◽  
R. Mahajan
Keyword(s):  
Equilibrium Composition ◽  
Acoustic Microscopy ◽  
Infrared Heating ◽  
Moisture Migration ◽  
Molding Compound ◽  
Microscopy Technique ◽  
Ir Heating ◽  
Compound Material ◽  
Temperature Heat ◽  
Heating Test

Moisture migration in PQFPs (plastic quad flat packages) was investigated analytically and experimentally. Coupons made of the molding compound material were exposed to humid air for an extended time to determine its equilibrium moisture composition as a function of environmental moisture level. An IR (infrared) heating test was designed to simulate the high-temperature heat reflow process when PQFPs are soldered on computer boards. The C-SAM (C-mode Scanning Acoustic Microscopy) technique was employed to measure the delaminated areas. All packages failed after IR heating when the moisture content in PQFPs was higher than 60 percent of the equilibrium composition.

Non-invasive high-resolution acoustic microscopy technique using embedded nanostructures

2007 ◽  
Vol 1019 ◽  
Author(s):  
Daniel Wulin ◽  
Shriram Ramanathan
Keyword(s):  
High Resolution ◽  
Acoustic Waves ◽  
High Frequency ◽  
Acoustic Microscopy ◽  
Biological Applications ◽  
Acoustic Oscillations ◽  
Non Invasive ◽  
Microscopy Technique ◽  
First Time

AbstractAn opto-acoustic system capable of operating at frequencies greater than 1 GHz with novel biological applications is proposed for the first time. Metallic spheres with radii on the order of hundreds of nanometers dispersed inside a bio-matrix can be used to generate in-situ ultra-high frequency acoustic waves whose normal mode frequencies can be calculated using Lamb's theory for acoustic oscillations of elastic spheres. The frequency and amplitude of the resulting acoustic waves can be related to the physical properties of the metallic spheres and the surrounding bio-matrix: the acoustic waves produced by the metallic spheres are well-suited to high resolution acoustic imaging. We anticipate that our approach will open up new nanoscale techniques to study cells non-invasively.

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