Enabling Scanning Acoustic Microscopy Inspection of Materials Underneath the Chamfer of the Package

2013 ◽  
Author(s):  
Melanie S. Cajita ◽  
Marlyn C. Grancapal ◽  
Rudolf A. Sia
Keyword(s):  
Electronic Device ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
X Ray ◽  
Areas Of Interest ◽  
Copper Tape

Abstract This paper describes how scanning acoustic microscopy can be used to inspect materials under the chamfer of electronic device packages. The technique involves the use of copper tape to locate the areas affected by the chamfer during X-ray radiography. The results are then correlated with known critical package and assembly geometries to determine how far parallel lapping should proceed to ensure that the areas of interest will become observable under acoustic microscopy without interfering with the functionality of the device.

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

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.

Characterization of Stress at a Ceramic/Metal Joined Interface by the Vz Technique of Scanning Acoustic Microscopy

2002 ◽  
Vol 124 (3) ◽  
pp. 336-342 ◽  
Author(s):  
Chiaki Miyasaka ◽  
Bernard R. Tittmann ◽  
Shun-Ichiro Tanaka
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Wave Velocity ◽  
Dissimilar Materials ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wave Velocities

It is well known that the process of heating and then cooling dissimilar materials introduces considerable stress at and near the interface. In this article, first, the surface wave velocity distributions obtained with the Vz curve technique were found to compare well with residual stress distribution measured by the finely collimated X-ray diffraction technique. Second, a delamination was introduced at the interface. The Vz curve technique was then used again to measure the surface acoustic wave velocity along the interface. The defective specimens showed significantly different patterns of surface acoustic wave velocities. Thus, this study presents useful guidelines in discriminating between sound and defective ceramic/metal joints by scanning acoustic microscopy.

Scanning Acoustic Microscopy and x-ray Diffraction Investigation of Near Crack Tip Stresses

1999 ◽  
Vol 591 ◽  
Author(s):  
S. Sathish ◽  
R. W. Martin
Keyword(s):  
Rayleigh Wave ◽  
Crack Tip ◽  
Acoustic Velocity ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
X Ray Diffraction ◽  
Rayleigh Wave Velocity ◽  
X Ray ◽  
Wave Velocities ◽  
Velocity Images

ABSTRACTScanning Acoustic Microscopy has been used to measure and map the Rayleigh wave velocity and the Surface Skimming Longitudinal wave velocities near a crack tip in a sample of Ti-6AI-4V. X-ray diffraction measurements have been performed to map the stress in the same region of the sample. The differences in the contrast between the two acoustic velocity images and their sensitivity to stress are examined. Similarities between x-ray stress images and acoustic velocity images are discussed.

Failure Analysis of Broken Stitch Bonds in TSSOP Packages Using Scanning Acoustic Microscopy (SAM) and Time Domain Reflectometry (TDR)

2004 ◽  
Author(s):  
Bilal Abd-AlRahman ◽  
Corey Lewis ◽  
Todd Simons
Keyword(s):  
Failure Analysis ◽  
Mechanical Stress ◽  
Time Domain ◽  
Open Circuit ◽  
Time Domain Reflectometry ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Root Cause ◽  
Analysis Application

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.

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