Kevin Kiarash Ahi - DMSMS 2015
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Transcript of Kevin Kiarash Ahi - DMSMS 2015
University of Connecticut
A Novel Approach for Enhancement of the
Resolution of Terahertz Measurements for Quality
Control and Counterfeit Detection
Center for Hardware Assurance and Engineering (CHASE)
Electrical and Computer Engineering Department
Kiarash Ahi and Mehdi Anwar
Presented at DMSMS Conference 2015
Phoenix, Arizona
All Rights Reserved 2
Counterfeit component classification
Counterfeit component classification and
comparison of X-ray and THz in detection of
counterfeit components
All Rights Reserved 3
Detection of recycled blacktopped components
20 21 22 23 24 25 26 27 28 29 300
0.05
0.1
0.15
0.2
0.25
X: 27.77
Y: 0.1394
Time Delay [ps]
Dete
cte
d P
uls
e M
ag
nit
ud
e [
au
]
X: 28.71
Y: 0.06609
X: 23.91
Y: 0.1047
16 17 18 19 20 21 22 23 24 25 26 270
0.05
0.1
0.15
0.2
0.25
0.3
X: 21.56
Y: 0.2727
Dete
cte
d P
uls
e M
ag
nit
ud
e [
au
]
Time Delay [ps]
X: 24.02
Y: 0.1371
X: 22.38
Y: 0.0742
X: 17.11
Y: 0.1235
20 21 22 23 24 25 26 27 28 29 300
0.05
0.1
0.15
0.2
0.25
X: 27.66
Y: 0.1439
Time Delay [ps]D
ete
cte
d P
uls
e M
ag
nit
ud
e [
au
]
X: 28.48
Y: 0.06966
17 18 19 20 21 22 23 24 25 26 270
0.05
0.1
0.15
0.2
0.25
X: 24.02
Y: 0.1644
Time Delay [ps]
Dete
cte
d P
uls
e M
ag
nit
ud
e [
au
]
X: 24.84
Y: 0.06998
Ref
lect
ed F
rom
th
e bla
ck-t
opped
mat
eria
l
(Top figure) Reflection of the THz pulse from the top surface of an
authentic IC;
(Bottom figure) Reflection of the THz pulse from the top surface of a
counterfeit IC.
Ref
lect
ed F
rom
the
ori
gin
al s
urf
ace
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Detection of recycled components
40 50 60 70 80 90 1000
0.02
0.04
0.06
0.08Reflected Pulse From a Contaminated Spot on the Surface of a Counterfeir IC
Time Delay [ps]
TH
z S
ign
al
[au
]
(b)
(c)
(a)
40 50 60 70 80 90 1000
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08Reflected Pulse From the Left Side (Not Sanded) of a Counterfeir IC
Time Delay [ps]
TH
z S
ign
al
[au
]
40 50 60 70 80 90 1000
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08Reflected Pulse From the Right Side (Sanded Side) of a Counterfeir IC
Time Delay [ps]
TH
z S
ign
al
[au
]
(a) Reflected THz pulse from the left side of the surface of a counterfeit sanded recycled
IC and vertical image of the IC under an optical microscope (b) Reflected THz pulse
from the right side of surface of a counterfeit sanded recycled IC the and vertical image
IC under an optical microscope; this side is thinner as a result of being sanded. (c) )
Reflected THz pulse from the contaminated spot of a recycled couterfeit IC.
More
del
ay
Dif
fere
nt
refl
ecti
on c
har
acte
rist
ic
Sanded
Contaminated
Normal
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Imaging with THz pulsed laser
The stepper motors are mounted to make uniform spot measurements possible in a 2D
plane in order to mak THz images
Y Stage
Stepper Motor X
Sta
ge
Ste
pp
er M
oto
r
Sample
Detector
Transmitter
All Rights Reserved 6
Detection of recycled components
THz reflection images on the left and optical images using a high resolution microscope on the right. (a)
Images of an authentic IC. (b) Images of a counterfeit recycled IC: the contaminated spot is obvious in
the THz image. This contamination is soldering paste which likely is used by counterfeiters during the
recycling process of the IC from its old circuit board. (c) Image of an IC which is sanded on one side.
The difference of the reflected THz pulse magnitude is obvious in the THz image.
Sanded
Contaminated
Authentic
Variance is
Higher on
the sanded
side! (a simple computer
code gives the
counterfeit IC!)
Contamination
is detected !
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Inspection of packaging materials: Detection of
Classes # 3, 4 and 6
Time delay
Attenuation
(a)
(b)
(c)
(a) Three ICs including two authentic and one counterfeit. (b) THz pulses in transmission from
these ICs. (c) Fourier spectrum of these pulses.
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Inspection of the die and bond wires: Detection
of Classes # 3 and 5
Two electronic chips one counterfeit and another authentic. THz and X-ray
transmission images of these ICs; the die geometry of the counterfeit IC (left
image) differs from the authentic one (right image).
THz is non-ionizing,
more accessible, faster,
cheaper and it can do
the work of X-ray!
Authentic Counterfeit
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Absorption characteristic of THz Beam
Exponential absorption characteristics of THz beam while passing through a
2.3 mm packaged IC is shown on the left. As it is shown in the right figure,
it’s the lower frequencies, roughly speaking sub 1.5 THz that are transmitted
into materials of IC packages and can be used for inspection purposes.
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Firs Method of Enhancement :
Enhancement of THz images
Using Peak Fitting (Simple)
The main idea: THz beam is a Gaussian beam and thus
hidden details can be revealed by Gaussian peak fitting!
Enhancement of the Images (Approach-1)
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The full vertical image based on conductivity
A code has been developed to convert the detected
THz pulse to the conductivity of each spot of the
object.
The full transmission vertical image The full vertical image based on conductivity
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Filtering the IC material, time domain filtering
Here our interest is to inspect the leads outside the IC packaging, so the
delayed signal is filtered out. For inspection of the leads inside the
packaging, the non-delayed signal has to be filtered out.
[m
m]
[mm]
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Low Pass Filter to filter the noise
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Averaging to decrease the random noise
Making a section by averaging three rows to
decrease the random noise even more
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Extracting the locations of the peaks by
Lorentzian
In every 5 pixels we have peaks. Each pixel is equal to 0.24 mm and 5x0.24= 1.2 mm.
Separation between leads are 1.2 mm. So this method leads to distinguishing the leads!
The leads are 0.3 mm wide. So according to Nyquist theory the SPF should be 0.15mm or less, but here the SPF is 1.9mm; which means that we improved the resolution 12.6 times higher than Nyquist limit.
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Example of the Applications
The missed bond wires and leads, inside and
outside the packaging of the IC can be detected.
Thus miss produced ICs in QC as well as recycled
counterfeit ICs can be detected.
An authentic IC A recycled counterfeit IC
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Second Method of Enhancement:
Enhancement of THz Images
Using our Advanced
Reconstruction Method
Enhancement of the Images (Approach-2)
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Results
0
50
100
150
200
250
050100150200250300350
X: 120
Y: 144
Z: 0.04834
X: 161
Y: 163
Z: 0.06585
X: 84
Y: 163
Z: 0.0532
X: 120
Y: 186
Z: 0.04963
Before
After
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Results
Before
After
The obtained measurements are as accurate as 0.02 mm !
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Results
The obtained measurements of the die of the IC are as
accurate as 0.02 mm !
Before
After
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The obtained dimensions after enhancement are
confirmed by high resolution X-ray image
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Above: left: X-ray image intensity diagram of bond wires. Right: X-ray image of
bond wires. ( in converted colors so that be consistent with THz images)
Bottom: Left: THz after enhancement. Right: THz before enhancement.
Results
Intensity [A
U]
THz Image Slice
After Enhancement
(Y axis is intensity)
THz Image Slice
Before Enhancement
Inverted X-ray
image of three
leads inside the
IC
The same inverted
X-ray image of
three leads inside
the IC (Y axis is
intensity this time )
Note: Resolution of X-ray is higher by nature and we use X-ray images as reference to prove
the validity of our reconstructed THz images.
[0
.0
5 m
m]
[0.05 mm]
Intensity [A
U]
Intensity [A
U]
[0.05 mm] [0.05 mm]
[0.05 mm]
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Results of Quality Metrics
SSIM´ MSE Spatial Accuracy
Original THz
image
136 0.1485 2.2 mm
Reconstructed
THz image
68 0.1078 0.2 mm
Improvement %50 %27.4 10 times higher
The quality of the reconstructed image is also
measured by the structural similarity (SSIM)
index and mean squared error (MSE). For this
purpose the reconstructed THz images of and
the original THz image, are given to MSE and
the SSIM whereas the reference image is
chosen to be the X-ray image.
*Since the images which are given to MSE and SSIM were small, 48×11 pixels, the values for MSE are small and the
values for SSIM are relatively high. Thus we defined SSIM´ to be (1-SSIM) ×104 for scaling the results of SSIM .
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References and Detailed Analysis
1. Kiarash Ahi, Mehdi Anwar, “Terahertz techniques for quality
control and counterfeit detection”, Accepted for the next issue of
International Journal of High Speed Electronics and Systems, 2016.
2. Kiarash Ahi, Mehdi Anwar, “Modeling and developing of terahertz
imaging equation and enhancement of the resolution of terahertz
images using deconvolution”, Accepted for Terahertz Physics,
Devices, and Systems X: Advanced Applications in Industry, May,
2016, Baltimore, Maryland, USA.
3. Kiarash Ahi, Mehdi Anwar, “Review of terahertz application for
characterization, inspection and quality control in near-field and far-
field”, Accepted for Terahertz Physics, Devices, and Systems X:
Advanced Applications in Industry, May, 2016, Baltimore, Maryland,
USA.
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References and Detailed Analysis
4. Kiarash Ahi, Mehdi Anwar, “Simulation of terahertz images from X-
ray images: a novel approach for verification of terahertz images and
identification of objects with fine details beyond terahertz resolution”
Accepted for Terahertz Physics, Devices, and Systems X: Advanced
Applications in Industry, May, 2016, Baltimore, Maryland, USA.
5. Kiarash Ahi, Navid Asadizanjani, Sina Shahbazmohamadi, Mark
Tehranipoor, Mehdi Anwar, “Terahertz characterization of electronic
components and comparison of terahertz imaging with x-ray imaging
techniques” Proc. SPIE 9483, Terahertz Physics, Devices, and Systems
IX: Advanced Applications in Industry, 94830K (May 13, 2015).
6. Kiarash Ahi, Navid Asadizanjani, Mark Tehranipoor, Mehdi Anwar,
“Authentication of electronic components by time domain THz
Techniques”, Connecticut Symposium on Microelectronics &
Optoelectronics (CMOC), Bridgeport, CT, April, 2015.
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References and Detailed Analysis
7. Kiarash Ahi, Navid Asadizanjani, Sina Shahbazmohamadi, Mark
Tehranipoor, Mehdi Anwar, “THZ Techniques: A Promising Platform
for Authentication of Electronic Components” , CHASE Conference
on Trustworthy Systems and Supply Chain Assurance, Storrs, CT,
April 8-9, 2015