Upload
maciej-sobocinski
View
30
Download
0
Embed Size (px)
Citation preview
PERFORMANCE OF LTCC EMBEDDED SIC GAS SENSORS.
1
Maciej Sobocinski; Lida Khajavizadeh; Mike Andersson;Anita Lloyd Spetz; Jari Juuti; Heli Jantunen
Microelectronics and Material Physics Laboratories / Maciej Sobocinski 05/01/2023
SILICON CARBIDE GAS SENSORS
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
2
Ingemar Lundström et al. (2006)
• Emerged in 1990s• Sensitive to H2, NH3 CO and O2
• Sensing based on changes in VGS
• Operate at high temperatures• Chemically inert material• Used in:
• Combustion control• Ammonia slip control• NOx catalyst recovery• other
TRADITIONAL PACKAGING
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
3
Mike Andersson et al. (2013)
NASA (2013)
Mike Andersson et al. (2013)
Traditional packaging includes:• Die attachment• Wire bonding• Encapsulation through
brazing etc
Max temperature 350 °C
State of the art packing includes:• Die attachment• Thick wire bonding• Ceramic
encapsulation
Max Temperature: 500 °C
LOW TEMPERATURE CO-FIRED CERAMIC
• Cornerstone of modern electronics• Presented in the 80s of XX century• Dielectric tapes and functional thick film pastes
Benefits of LTCC Fast prototyping Parallel processing Durable, hermetic, resistant Relatively cheap
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
4
©IMST
©TDK-EPC
HERAEUS HERALOCK 2000
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
5
Ceramic powder and low melting point glass
Ceramic powder and low melting point glass
Refractory ceramic
Lautzenhiser, F., Amaya, E. & Hochheimer, T., 2004. Self-constrained low temperature glass-ceramic unfired tape for microelectronics and methodes for making and using the same. US Patent nr US 2003/0087136 A1.Rabe, T., Schiller, W., Hochheimer, T., Modes, C., & Kipka, A. (2005). Zero Shrinkage of LTCC by Self-Constrained Sintering. International Journal of Applied Ceramic Technology, 2(5), 374-382.
ONE-STEP PACKAGING
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
6
INTEGRATION THROUGH CO-FIRING
SiC insertion
Lamination:– 75 º C– 10 MPa pressure
Co-firing:– 865 º C– 30’ in peak T
THE EMBEDDED STRUCTURES
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
7
Electric via
Gate area
Electric via
Gate area
QUALITY OF INTEGRATION
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
8
Small cracks in the
passivationS D
G
Remains of via
connections
ELECTRICAL RESPONSE OF THE STRUCTURES
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
9
• Fully functional MOSFET device• Slight changes in threshold voltage and saturation current
└ Typical for SiC transistor devices exposed to high temperature
GAS SENSING 1
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
10
• 3 minute pulses of CO• 100 ppm to 1000 ppm• 200 °C
GAS SENSING 2
0 20 40 60 80 100 120 1402
2.2
2.4
2.6
2.8
3
As-processedLTCC packaged
Time [min]
Sens
or S
igna
l [V
]
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
11
• 5 minute pulses of Ammonia in 6% O2 in N2
• 25 ppm steps from 25 ppm to 175 ppm and back to 25 ppm• Operating temperature: 300 °C
GAS SENSING 3
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
12
0 25 50 75 100 125 150 175 2000
0.02
0.04
0.06
0.08
0.1
0.12
As-processed LTCC-packagedAs-processed LTCC-packagedAs-processed LTCC-packagedAs-processed LTCC-packaged
NH3 concentration [ppm]
Rel
ativ
e se
nsor
res
pons
e [Δ
V/V
0]
Carrier gas comp: 6% O2 in N2
Operation temp: 300 °C
SUMMARY
• One-step packaging through co-firing is feasible for SiC MOSFET gas sensors• Co-fried structures retain their electrical properties with
small changes• Gas sensing is still present and output signals are
comparable to not packaged structures
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
13
05/01/2023Microelectronics and Material Physics Laboratories / Maciej Sobocinski
14
THANK YOU FOR YOUR ATTENTION!