Application of C-mode Scanning Acoustic Microscopy in Packaging

Abstract

The reliability of integrated circuit (IC) packages depends in many respects on their mechanical integrity. The effect of structural weaknesses caused by poor bonding, voids, microcracks or delaminations may not be evident in the electrical performance characteristics, but may cause premature failure. C-mode scanning acoustic microscopy (C-SAM) is an excellent tool for non-destructive failure analysis of IC packages. It has exhibited good sensitivity to interface anomalies such as poor bonding, delamination, voids, cracks, and foreign material inclusions. The non-destructive ultrasonic test method using C-SAM is a common detection method for delamination or crack failures in semiconductors with reliable and relatively accurate results. This paper will demonstrate the effectiveness of C-SAM at non-destructively analysis from A-Scan, B-Scan, C-Scan and T-Scan respectively. And the capability of C-SAM in detecting IC surface corrosion will be also illustrated.

Primary Creep in Sn3.8Ag0.7Cu Solder. Part I: Theory, Experiments, and Data Reduction

“…Each casting was scanned by non-destructive C-mode scanning acoustic microscopy (C-SAM) to inspect for voids, cracks, and foreign material inclusions. 13 The gauge section was machined with a CNC lathe to give a 6 mm shoulder fillet radius that transitioned to a 12.7 mm diameter straight cylindrical cross-section along the balance of the tensile specimen. The ends were machined flat and soldered to copper rods (60 mm long and 12.7 mm diameter).…”

Ultra-long metal nanowire arrays on solid substrate with strong bonding

“…The adhesion strength between them is 38.4 MPa (3.84 kN/cm 2 ) which is regarded as strong bonding [ 26 ]. Although it is not recommended that the value reported here be compared directly with those obtained by different testing methods, this interface is still much stronger than the strongest bonding of CNT arrays on Si substrate, which showed a strength of 30 to 110 N/cm 2 by a compression shear test [ 27 , 28 ]. Also, the sample was fractured at the interface of Au/Ti thin film and Si wafer (see Figure S1b in Additional file 1 ), suggesting comparatively stronger bonding between the nanowires and Au/Ti film than that of between Au/Ti film and Si wafer.…”

Measuring thickness based on the grayscale value of C-mode SAM images

“…A remarkable area of application of this equipment is in failure analysis, since delaminations or inhomogenities inside the observed samples are easy to detect and locate. Power electronic components are forming a special group among inspectable samples, as a delamination or crack in the die attach layer significantly reduces the reliability of the component [1,2].…”