High pressure sensing applications require a variety of design considerations to address the technical challenges that pressure of 500 psi and more can impose on the sensor. One of the main differentiating choices that a supplier has to consider is the technology used to detect pressure variations. However, this is just the start. By attending this special, free 1-hour webinar, you will gain a better understanding of the key factors necessary to make the best choice for your high pressure sensing application, including: 1.) The detailed packaging requirements for these potentially dangerous applications 2.) The design details that experts have taken into account to simplify applying high pressure sensors 3.) Key specifications that impact the successful application of high pressure sensors

1. Choosing the Right Sensor
for Measuring High
Pressure

2. Before We Start
This webinar will be available afterwards at
designworldonline.com & email
Q&A at the end of the presentation
Hashtag for this webinar: #DWwebinar

3. Presenters
Moderator
Randy Frank
Karmjit Sidhu
Ian Abbott
Design World
American Sensor Technologies
TERPS, GE Energy
Marek Wlodarczyk Wendell McCulley
Optrand
InterMEMS

4. Choosing the right sensor
for measuring high
pressure
Karmjit S. Sidhu
American Sensor Technologies Inc
Www.astsensor.com

5. Design considerations for high pressure sensors
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Hermetic seal against media
Rugged and durable
Wide media compatibility
Wide operating temperature range
High cyclic life
High proof and burst pressure ratings
Long term stability
Low non repeatable errors - hysteresis and no repeatability
High degree of compensation

6. Typical high pressure applications
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Hydraulics - 500PSI to 15000PSI
Oil & Gas - 500PSI to 20000PSI
Diesel injection - up to 45000PSI
Compressed Hydrogen - 2500PSI to 15000PSI
High pressure oxygen - up to 6000PSI
Water jet cutting - up to 72000PSI
Gas chromatography - 500PSI to 20000PSI
CNG systems - up to 4000PSI
Fire suppression systems - 500PSI to 3000PSI
Refrigeration - 500PSI to 1000PSI
Filtration

7. Krystal Bond Technology for high pressure
• One piece design - no welds, no O-rings, no fluid filling
• High temperature inorganic bonding of silicon to metals
• Wetted materials - 17-4PH and 316L stainless steels, Inconel 718, Hastelloy
C276, Titanium CP4
• Low operating strain
• Thick membrane
• High output of 40mV/V
• No p-n junctions - stable over wide temperature
• Very low EMI interference

8. Cross section of Krystal Bond Sensor

9. Silicon sensing elements glass bonded to
stainless steel diaphragm

16. Fiber-Optic
Pressure Sensors
for
Environments

17. Schematic Diagram of Optrand
Fiber Optic-Based Pressure Sensor
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18. High-Pressure High-Temperature
Pressure Sensor Key Specifications
Pressure Range:
Burst Pressure: > 4 range
Tip temp.:
Conditioner temp.:
Accuracy:
Frequency range
Dynamic Sensor:
Static-Dynamic:
Service life:
0-150, 0-250, 0-350, 0-3000 bar
-40oC to 380oC (480oC)
-40oC to 125oC (140oC)
1-2% FSO
0.1(1) Hz to 20 (60) kHz
0 Hz to 20 kHz
0.5B -5B pressure cycles,
10k30k hours
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19. Pressure Sensors Targeting Internal
Combustion Engines
• Dynamic sensors for use in (1) engine R&D and (2)
production gasoline, diesel, natural gas, jet fuel engines
used in passenger car, light- and heavy-duty truck, offhighway, marine, gen-set, ship, locomotive, or light aircraft
applications
• Two versions offered:
o Signal conditioner connected to sensor head by ruggedized
~few meter-long fiber optic cable; targeting engine R&D and
large engines
o Signal conditioner located on top of sensor head; targeting
automotive OE applications
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20. Sensors Targeting Harsh Environment
Industrial and Turbine Applications
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• 480 C-rated static-dynamic sensor for turbines
• 420oC-rated static pressure sensors for Plastic Melts with
flush mounted diaphragms as small as 1mm in diameter
with M4x0.6 thread
• 380oC-rated all fiber optic static-dynamic pressure sensor
with fiber optic cable up to hundreds meters-long for
monitoring of industrial circuit breakers and transformers
• 280oC-rated all fiber optic static-dynamic pressure AND
temperature sensor in one package with fiber optic cable
up to ~1 Km for oil-gas exploration, geothermal well &
volcano monitoring
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21. Current Sensor Packages
F1.8mm
M8x1
M4x0.6
M3x0.5
M4x0.6
M12x1.25
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22. Wendell McCulley
President

23. High Pressure Presents some very
Special Considerations
Traditional packaging
•At first glance High Pressure Sensor packaging seems to be more forgiving than Low
Pressure.
•Die attach can be done with “Harder” materials with less effect on TCOffset.
•Overpressure however is a Big Issue.
•Do you choose to use less traditional packaging methods (e.g. NASA SSME)
•Topside Applied Pressure with RTV Die attach.
•Oil Filled with Stainless Steel Isolation Diaphragm
•May require a Ceramic or other material as an Interposer
•Common Mode Pressure Considerations

24. Provides Media Isolation, Must be strong enough to withstand High Hydrostatic
pressure, but must be flexible enough to take up Oil expansion over Temperature
Extremely hard to accurately Model the
Performance of Corrugated Diaphragms since
they are inherently Non-linear, and in the Large
Deflection Regime

25. Creative High Pressure packaging
Creative Electronics, Compensation
and Calibration
•Do you choose to use less traditional packaging methods (e.g. NASA SSME)
•Hard Eutectic Die Attach
•Metal or Nitride V-Ring Seals
•Must withstand cryogenic temperatures -425⁰F to 250⁰F
•Use of Materials with closely matched Temperature Coefficient of Expansion
•Electron Beam Welded
•Use of Integrated Strain Gauge to measure flexure of the overall Chip
•Correction of Pressure Sensor Measurand for Chip flexure.
•On Chip Thin film Laser Trimmable Resistors.

26. Backside Pressure Failure Mode
•Silicon is a mode 1 Fracture Material
•Silicon and glass are Pulled from the central region of the chip
•Looks similar to the hole a BB makes in glass
•Diameter is directly related to the Radius of transition from Tension to
Compression and can be controlled by judicious design.
•Design Choices depend on many considerations
•Slab Vs. Diaphragm Design
•Aspect Ratio

27. Two Different Design Realizations
for a 1000 PSI Pressure Sensor
(A Case Study)
The ideal location “Sweet Spot” for
the Piezoresistors is Very Different
•Both have the same Die Size and Thickness
•Both have the Same Diaphragm Edge Length to Thickness Aspect Ratio
•Both have Approximately the same Pressure Sensitivity.
•In the case of the Larger Diaphragm it is Completely off the Diaphragm.
•In the case of the Smaller Diaphragm it is just on the Diaphragm near the Edge.

28. Why do we Care?
In the World of High Pressure
Things are often Counter-Intuitive.
•The Larger Diaphragm is also thicker, and therefore must be more Robust,
Right?
•By choosing the smaller Diaphragm we can make the overall Die Size much
smaller, Right?
•For Backside Applied Pressure, the Large Diaphragm will Fail at much lower
Pressures.
•The Smaller Diaphragm needs to be part of a Large Die to support higher Burst
Pressure.

29. Summary
High Pressure Sensor Design
InterMEMS Inc. Capability
•Often Counter-Intuitive
•Highly Interdisciplinary requiring a Deep Knowledge of:
•Materials
•Fracture Mechanics
•Piezoresistivity
•Packaging
•Media Compatibility
•Still a bit of a Black Art
•Specific knowledge of High Pressure Sensor Design & Manufacturing
•Has the Tools necessary to develop high performance devices.
•Non-linear Large Deflection Finite Element Analysis (FEA)
•Process Modeling (SUPREM)
•Wafer Processing
•Packaging
•Excels in Design for Manufacturability

30. Questions?
American Sensor Technologies
Karmjit S. Sidhu
kssidhu@astsensors.com
TERPS, GE Energy
Ian Abbott
ian.abbott@ge.com
Design World
Optrand
Marek Wlodarczyk
president@optrand.com
Randy Frank
r.frank@ieee.org
InterMEMS
Wendell E. McCulley
wmcculley@intermems.com

31. Thank You
 This webinar will be available at designworldonline.com & email
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