want to examine the internal features of an object without damaging that
object, one of the best ways to do so is with scanning acoustic microscopy
(SAM), also known as acoustic micro imaging (AMI). This is a non-destructive
technique that uses high-frequency sound waves – ultrasound – to generate an
we perform C-mode scans using technology from Sonoscan, Inc., we use that
manufacturer’s well-recognized trademark term for this technique: C-SAM®.
put, a C-mode scan produces a 2-dimensional image of ultrasound echoes that
arise from reflections at a specified depth. Here’s how it works:
transducer is used to generate a sound wave with a specific frequency chosen
for its compatibility with the component or material to be imaged. Typical
frequencies are in the 10 MHz to 300 MHz range.
sound wave interacts with the component being tested, a portion of that wave is
reflected at each interface while another portion of it is transmitted through
the interfaces. Both signals – reflected and transmitted – can be used to
produce images of the various interfaces present within the component.
is particularly sensitive to interfacial defects such as air gaps resulting
from delamination at the paddle, die, or leadframe, cracks, such as popcorn
cracks, and voids. For example, delamination of the mold compound from the
surface of the die or leadframe in a PEM creates a very thin air gap at the
interface. That thinness isn’t a problem, though: sound waves won’t travel
across an air gap, however small. So 100% of the ultrasound signal will be
reflected at the delamination, allowing a clear distinction to be made between
a good bond and a delaminated bond. The same holds true for any crack or void
in an otherwise solid component: the air gaps these defects create will reflect
the ultrasound signals and thus be clearly identified.
C-SAM® to scan a wide variety of part types, including PEMs,
capacitors, PCBs, and all sorts of hybrid devices. We also use it in a
comprehensive range of applications.
choose AcousTech for your C-SAM® inspections, you can expect a test
plan customized to your specific needs and clearly communicated in order to
assure meaningful results. You can expect a truly collaborative partnership,
too. Contact AcousTech if you have any
questions. And when you’re ready, Request a Quote.
We’re ready to serve you.
C-SAM® is a registered trademark of Sonoscan, Inc.