586
Y. Li and D. Goyal
18.3.2 High Resolution Non-destructive Imaging Techniques
for 3D Microelectronic Packages
High resolution non-destructive imaging techniques are crucial for defect screening
and identification in complex 3D packages. Fundamental details along with application demonstrations of four commonly used non-destructive imaging techniques,
Scanning Acoustic microscopy (SAM), Infrared (IR) Imaging, 2D X-ray radiography, and 3D X-ray computed tomography (CT) are provided in this section.
Table 18.2 summarizes the resolution, capability, Pros, and Cons of the four techniques. The non-destructive imaging techniques with high resolution, large field of
view, and short TPT could be employed to directly detect failures without any fault
isolation. They are also utilized as in-line monitoring tools for defect inspection. The
high resolution non-destructive imaging techniques with relatively smaller field of
view and longer TPT could be applied after failure isolation to reveal defects causing
the electrical failures.
18.3.2.1 Scanning Acoustic Microscopy (SAM)
Scanning Acoustic Microscopy (SAM) has been widely used to non-destructively
detect voids in various packaging materials and delamination at multiple interfaces in
packages [18–21]. As illustrated in Fig. 18.11, the acoustic transducer (piezoelectric
element) excited by an extremely short electrical discharge transmits an ultrasonic
Table 18.2 Pros and Cons of high resolution non-destructive imaging techniques for 3D packages
(Adapted from Refs. [3, 13, 31, 32, 35, 44])
Non-destructive
imaging
technique
Resolution (μm) a Capability
Pros
Cons
SAM
~1
Air gap
(Delamination,
voids)
Short TPT; Low
cost
Not sensitive to
vertical cracks
IR imaging
~1
Die crack, defects Real time, low
cost
Not sensitive to
delamination
2D X-ray
radiography
~5
Defects in
interconnects and
traces
Real time; Low
cost
Projective
images; Not for
organic packing
materials
3D X-ray CT
<1
Defects in
interconnects and
traces
3D imaging;
Higher resolution
Long TPT; High
cost; Small field
of view; Not for
organic packing
materials
a Rough estimation in optimized condition, actual resolution depends on different equipment and
setup
Y. Li and D. Goyal
18.3.2 High Resolution Non-destructive Imaging Techniques
for 3D Microelectronic Packages
High resolution non-destructive imaging techniques are crucial for defect screening
and identification in complex 3D packages. Fundamental details along with application demonstrations of four commonly used non-destructive imaging techniques,
Scanning Acoustic microscopy (SAM), Infrared (IR) Imaging, 2D X-ray radiography, and 3D X-ray computed tomography (CT) are provided in this section.
Table 18.2 summarizes the resolution, capability, Pros, and Cons of the four techniques. The non-destructive imaging techniques with high resolution, large field of
view, and short TPT could be employed to directly detect failures without any fault
isolation. They are also utilized as in-line monitoring tools for defect inspection. The
high resolution non-destructive imaging techniques with relatively smaller field of
view and longer TPT could be applied after failure isolation to reveal defects causing
the electrical failures.
18.3.2.1 Scanning Acoustic Microscopy (SAM)
Scanning Acoustic Microscopy (SAM) has been widely used to non-destructively
detect voids in various packaging materials and delamination at multiple interfaces in
packages [18–21]. As illustrated in Fig. 18.11, the acoustic transducer (piezoelectric
element) excited by an extremely short electrical discharge transmits an ultrasonic
Table 18.2 Pros and Cons of high resolution non-destructive imaging techniques for 3D packages
(Adapted from Refs. [3, 13, 31, 32, 35, 44])
Non-destructive
imaging
technique
Resolution (μm) a Capability
Pros
Cons
SAM
~1
Air gap
(Delamination,
voids)
Short TPT; Low
cost
Not sensitive to
vertical cracks
IR imaging
~1
Die crack, defects Real time, low
cost
Not sensitive to
delamination
2D X-ray
radiography
~5
Defects in
interconnects and
traces
Real time; Low
cost
Projective
images; Not for
organic packing
materials
3D X-ray CT
<1
Defects in
interconnects and
traces
3D imaging;
Higher resolution
Long TPT; High
cost; Small field
of view; Not for
organic packing
materials
a Rough estimation in optimized condition, actual resolution depends on different equipment and
setup