MEMS Pressure Sensor Packaging Design Solution Consideration: Overcoming Environmental Challenges from Harsh Environment

1. MEMS Pressure Sensor Packaging Design
Solution Consideration: Overcoming
Environmental Challenges from Harsh
Environment
Tom Nguyen, Founder & CEO of DunAn Sensing
Date: 10/16/2018

2. May-2014
● Entered Joint Venture Contract Agreement with DunAn Environmental Company – a leading HVAC
global supplier
● Established DunAn Sensing Technology Company in Hangzhou, China. Company will be mainly
augment design, and manufacturing of MEMS pressure sensors, transducers and transmitters for
industrial, HVAC/R and automotive applications
April 2013
● Silicon Valley startup led by a group of highly experienced
MEMS & Sensors industry veterans
● R&D team established to develop DURAsense® MEMS
pressure sensor die and package for harsh environment,
mainly focus on industrial, HVAC/R and automotive industries
Company Profile

3. Sensor solutions for everyday life
Lead the development and manufacturing of reliable,
accurate, and affordable sensors that contribute to the
success of our customers.
MISSION
VISION
Award Winning
DURASenseR

4. Tom Nguyen, Founder and Chief Executive Officer, has over 30 plus years of engineering, operations, and
business development experience in the MEMS and semiconductor industry. Before the founding of DunAn
Sensing, Mr. Nguyen is also the founder and CEO of Microlux Technology. He is also served as an Executive
Director of Engineering and Operations at S3C, Inc. a subsidiary of Nagano Keiki group companies a leading
manufacturer in industrial and automotive pressure sensors.
Prior to that, Mr. Nguyen held a variety of business development and technical management positions
over at Celerity Research, ICSensors, GE Novasensor, Integrated Sensor Solutions, Merit Sensor Systems, S3C
and Invensense. Where he designed, and developed many of the pressure sensors, accelerometer and
transducers products. Mr. Nguyen has published several technical papers relating to the testing and probing
of high density and high pin counts semiconductor devices using MEMS technology, and reliability testing of
MEMS pressure sensors for automotive industry. He is an author and co-author of more than 12 patents in
the wafer probe test and MEMS pressure sensor packaging technology.
Currently, Mr. Nguyen serves as Chief Executive Officer for DunAn Sensing, an advanced MEMS pressure
sensor packaging technology for harsh environment, and his goal and vision is to bring together both of his
MEMS & semiconductor expertise to bring the MEMS packaging technology roadmap to Lower Cost!

5. Contents
History of MEMS & Sensors Packaging Design
The Challenge and Important of MEMS Pressure Sensor Packaging Design for Harsh Environment
The Traditional MEMS Pressure Sensor Packaging Design
 MEMS die with Oil Filled
 Micro fuse, Bonded strain gauge
 Thin film deposition on strain gauge
 Ceramic Thick film
New Approach for MEMS Pressure Sensors Packaging Design for Harsh Environment
 MEMS base with No oil filled, No O-ring, No Welding and low cost
Advantage and Disadvantage
Conclusion

6. History of MEMS & Sensors
Packaging Design

7. MEMS & Sensor Products History

8.  Historically, packaging has been (and in many cases) overlooked in the overall design of the
“sensor-based system” solution
Sensors are only a part of the “solution”….
Packaging is a critical element frequently consuming from 50-75% of the total bill of materials
”BOM” based on the application.
 Harsh media applications have the tendency to drive packaging cost up
 Packaging (and testing) have been an afterthought…but rather…need to be considered in the early
part of the design process to optimize design for Manufacturing and Test (DoM&T) Principles
Sensor Packaging : Situational Analysis
In the courtesy of Roger Grace Associates

9. The Challenge and Important of MEMS & Sensor
Packaging Design for Harsh Environment

10. The Challenge and Important of MEMS Pressure Sensor Design
& Packaging for Harsh Environment
• In hash environment, quality and reliability of the pressure sensors are keys and required.
• The sensors operate in extremely hostile environments. The high temperature ranging
from -40°C to 150°C and the pressure sensors devices are exposed to
 Fuel, oil, gas
 Coolant & transmission fluid
 Walter, Salt water
 Chemically compatible with refrigerant fluids (R-410A, R-404A, refrigerant oils, acids
formed due to moisture contamination)
• All of the above media can clog the sensors and potentially degrade the performance, or
even defeat or worsen the performance of the pressure sensors.
 Accuracy, Reliability and Affordability are important!

11. The 4 Key Important Factors
• Media Compatibility: MEMS pressure sensor must be able to withstand the media,
such as: refrigeration, transmission oil, engine oil, gasoline, water, etc…
• Thermal stress: Severe temperature could cause damage, instability, drift and shift to
the sensor due to the effect of materials thermal coefficient of expansion.
• Mechanical stress: The mechanical instability, vibration and shock could cause damage
and reliability of MEMS pressure sensor and its components.
• ESD & EMI: Due to noisy environment, the pressure sensor must withstand the ESD and
EMI (electromagnetic interference)…
 High dielectric withstand voltage (1.8kV)
 High ESD immunity (+/-2kV, +/-8kV, +/-15kV)

12. Hostile Media Compatibility
• It is very important that the sensors must survive conditions below :
 Fuel, oil, gas, & transmission fluid
 Refrigeration, Coolant
 Walter, Salt water
 Corrosive media..
• For the test conditions: The pressure sensors must be tested with the above media at
extreme temperature range with a long duration typically about 3 to 6 months
• The devices must have passed the environmental test. No damage or anomalies are
found by visual inspection
• After environmental testing, the sensors must pass functional/parametric tests on all
required electrical and mechanical parameters .

13. The Traditional MEMS & Sensor
Packaging Design

14. SS Metal Diaphragm
MEMS Element
Spacer
Sensor Body
Silicon Oil fill cavity
Glass Filled Header
Oil Filled Sensor
SS Diaphragm & Welding
 millivolt (mV) output signal
 Problem at high temperature > 85C
 Poor repeatability & accuracy
 Long term stability
 Expensive & difficult for manufacturing
 High media resistance
MEMS Element

15. Microfuse Sensor
Metal diaphragm with strain gauges bonded to it.
 High media resistance
 Simple design / Assembly (welding)
 Low output signal
 Expensive & difficult for manufacturing
 Only high pressure ranges only
Poor repeatability & accuracy

16.  High media resistance
 Low output signal
 Poor repeatability and accuracy
 Expensive to make
Thin film fabrication process for pressure sensor
Note:
• PVD: Physical vapor deposition
• P-CVD Plasma chemical vapor deposition

17. Ceramic Thick Film Pressure Sensor
 Low output signal
 Low performance & limited pressure range
 Poor repeatability and accuracy
 Poor long term stability
 High media resistance
 Simple design
 Low Cost
Ceramic
Housing
Print thin
conductor
Print Solder
pads
Print Sensing
Resistors
Print Protective
Glass

18. New Approach for MEMS Pressure Sensor
Packaging Design for Harsh Environment

19. A New Approach
• Overcome the problem associated with the design of packages for harsh
environment and maintaining:
- Accuracy
- Reliability
- Affordability
• A New Approach for MEMS Pressure Sensor Packaging Design for Harsh
Environment meeting all of the above

20. Comped Board
Sensor Body
Sensor Element
•Sensor Body
•MEMS Element
•PCB Board
DunAn sensing
(Amplified Output: 0.5 to 4.5V)
Low manufacturing cost!
Copper Ring
Pressure
A New Approach of MEMS Pressure Sensor Packaging
Design for Harsh Environment
 Hostile media compatible
 Fully amplified output signal: 0.5-4.5V. 0- 10V or 4-20mA
 Simple design  low cost manufacturing
 No O-ring and No Welding
 High reliability, high accuracy and affordability
 Pressure range < 1000PSIBack side Entry MEMS die

21. A New Approach of MEMS Pressure Sensor Packaging
Design for Harsh Environment
Mold plastic
package
Housing
Color coded
plastic cap
Wires /
connector
DURAsense® Core
DURAsense® MEMS Sensor
 DURAsense® MEMS Sensorand DURAsense® Core
 Small size and light weight
 High volume production  low cost !
 Media compatible; Housing:Coppertube,Aluminum,StainlessSteelorBrass
 Electricalinterconnect: wireandsleeveorplasticmoldedconnector
 Fully amplified output signal: 0.5-4.5V. 0- 10V or 4-20mA
 No O-ring, high reliability, high accuracy and affordability

22. Temp
Press. (MPa) 0 0.5 1 1.5 2 0 0.5 1 1.5 2 0 0.5 1 1.5 2 0 0.5 1 1.5 2 0 0.5 1 1.5 2
Min 0.01% -0.07% -0.20% -0.33% -0.54% 0.01% -0.10% -0.23% -0.34% -0.56% -0.04% -0.08% -0.19% -0.31% -0.51% -0.13% -0.10% -0.17% -0.25% -0.38% -0.27% -0.24% -0.33% -0.45% -0.66%
Max 0.22% 0.23% 0.16% 0.03% -0.16% 0.21% 0.18% 0.08% -0.05% -0.28% 0.18% 0.19% 0.08% -0.03% -0.24% 0.17% 0.18% 0.15% 0.07% -0.04% 0.14% 0.10% 0.04% -0.09% -0.28%
Average 0.12% 0.07% 0.00% -0.12% -0.28% 0.09% 0.02% -0.08% -0.21% -0.40% 0.07% 0.03% -0.07% -0.18% -0.37% 0.01% 0.04% 0.00% -0.08% -0.20% -0.10% -0.11% -0.18% -0.31% -0.48%
StDev 0.06% 0.08% 0.09% 0.09% 0.08% 0.05% 0.08% 0.08% 0.07% 0.06% 0.05% 0.07% 0.07% 0.07% 0.06% 0.07% 0.07% 0.08% 0.08% 0.09% 0.09% 0.08% 0.09% 0.08% 0.08%
UL 1.5% 1.5% 1.5% 1.5% 1.5% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.5% 1.5% 1.5% 1.5% 1.5%
LL -1.5% -1.5% -1.5% -1.5% -1.5% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.0% -1.5% -1.5% -1.5% -1.5% -1.5%
Cpk 8.07 6.01 5.50 5.19 5.14 5.67 4.32 3.75 3.53 3.25 5.64 4.62 4.21 3.88 3.44 4.54 4.35 4.17 3.73 3.09 5.48 5.88 5.17 4.83 3.98
8.07 6.01 5.53 6.07 7.54 5.67 4.32 4.42 5.37 7.62 5.64 4.62 4.86 5.59 7.42 4.54 4.35 4.17 4.38 4.67 6.26 6.81 6.58 7.35 7.79
9.48 6.63 5.50 5.19 5.14 6.78 4.47 3.75 3.53 3.25 6.52 4.91 4.21 3.88 3.44 4.63 4.71 4.18 3.73 3.09 5.48 5.88 5.17 4.83 3.98
Typical Accuracy Performance (%FS)
-20°C 0°C 25°C 80°C 120°C
-3.00%
-2.50%
-2.00%
-1.50%
-1.00%
-0.50%
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
3.00%
0 0.5 1 1.5 2 0 0.5 1 1.5 2 0 0.5 1 1.5 2 0 0.5 1 1.5 2 0 0.5 1 1.5 2
-20°C 0°C 25°C 80°C 120°C
ERROR(%FS)
PRESSURE (MPA)
TEMPERATURE (° C)
Accuracy Performance Typical Industry Limits DunAn Sensing Limits
Accuracy Results

23. Reliability Testing
Pressure Cycling 10M cycles with ATF, < 0.15% shift
Temperature Shock 360 cycles from -40C to 140C, < 0.4% shift
Temperature Cycle 44 cycles, <0.3% shift
Liberation with Temp
Cycle
Up to 20g, 24hours/axis, < 0.3% shift
EMI TEM cell, 30V/m, 1-1000MHz, deviation < 0.02%
Burst Pressure Typical > 1500psi

24. Samples: 96
Temperatures:
 -40, 0 , 25, 100, 135 °C
Pressures:
 0.05, 0.66, 1.28,1.89,2.5 MPa
Overall Duration
 3 months
Initial Final
MIN -1.18 -1.03
MAX 0.34 0.48
Average -0.22 -0.26
StDev 0.19 0.21
UL 1.5 1.5
LL -1.5 -1.5
Cpk 2.20 1.97
Average Shift of ~ 0.04 %FS
-50
0
50
100
150
200
250
300
350
-2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00
FREQUENCY
ERROR (%FS)
Performance before and after Full Qualification
Final Initial
LL UL
Accuracy Results
Before and After Qualification

25. CHARACTERISTICS/CAPABILITIES OF CURRENT
TECHNOLOGIES FOR HARSH MEDIUM
Thin-film on Strain
Gauge Sensor
Micro fuse
Sensor
Oil Filled
MEMS Sensor
Ceramic
capacitive Sensor
Ceramic
piezoresistive
Sensor
DURAsense®
MEMS Sensor
Measure Absolute Pressure NO NO YES YES OK YES
Measure Gauge Pressure YES YES YES YES YES YES
Very Low Pressure Range NO NO YES OK NO OK
Very High Pressure Range YES YES YES OK NO OK
Long Term Stability YES YES OK YES OK YES
High temperature > 100ºC OK OK NO YES OK YES
Repeatability OK OK YES OK OK YES
Accuracy OK OK YES OK OK YES
COST High High High Medium Medium LOW
Requirement fulfilled
YES /
Good
Requirement partly
fulfilled
OK /
Maybe
Requirement not
fulfilled
No /
Bad
DURAsense®
CORE

26. Conclusion
• We believe MEMS is the most widely used technology
• The challenge today is packaging and large scale production
• Packaging has to be done from the MEMS out keeping the package small
and affordable.
• Think outside the box and make packaging more reliable
• When designing the package also think about testing and large scale
production.

27. Thanks
Name: Tom Nguyen
email: tomnguyen@dunansensing.com
And please visit us at booth #419