A Combined Pressure and Temperature Sensor without ... · 7 Kavlico DV Chip Dual Frequency-Output...
Transcript of A Combined Pressure and Temperature Sensor without ... · 7 Kavlico DV Chip Dual Frequency-Output...
A Combined Pressure and Temperature Sensorwithout External Temperature Probe
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Content
(1) Key P/T Sensor Specifications
(2) Patented Thin Film Technology
(3) Sensor Design for CO2 / R744 MACS
(4) Finite Element Modeling / Simulation
(5) Qualification Testing
(6) Other Thin Film Applications and Sensor products
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(1) Key P/T Sensor Specifications
Ø Pressure:Measurement Range0 to 170 BarAccuracy < ± 1,0% (F.Sp.)Response time 4 ms (t63)
Ø Temperature:Media -40°C to +180°CAccuracy ~ ± 3 KResponse time < 10 sec (t63)Ambient Temperature up to 135°C
Ø Electrical Interface: 3-pin LIN2.0, 3-pin PWM,4-pin P/T analog
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(2) Patented Thin Film Technology
Ø Thin Film Element on SST 1.4548.4Ø Sputtered Metal Strain GaugeØ TiON Strain Gauge with high K-Factor/ Gauge Factor:
K: TiON ~ 5 (CrNi ~ 1,1..2)K-Factor: dR/R= K * dl/l
Ø High Temperature Resistance (330°C)Ø Pressure Range: 25 to 3.000 Bar
6 mm
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(3) Sensor Design for CO2 / R744 MACS
Digital output: LIN2.0 or PWM(Temperature output embedded in signal)
Integrated Temp. feature: Less part complexity, higher reliability, less flow restriction and reduced leakage risk.
Long term stability, Rugged Design.Smallest possible thread interface: M10x1mm
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Exploded View / Cross Sectional
DV Chip
p,T
Connector
Flexwire
Component boardwith µC
Housing
Flexwire
Combined Sensor Assembly (p,T)
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Kavlico DV Chip
Dual Frequency-Output ASIC for Thin-Film and PRT Resistive type sensors:
Ø Ratiometric multiplexed frequency (digital) output for Sensor (Pressure-) and Temperature-data.
Ø Coarse gain and offset calibration via serial-interface, allowing wide range of sensors.
Ø Fine calibration by µP ; calibration coefficients to be stored in memory of µP.
Ø Extreme temperature range ( -50ºC to +200ºC ). Ø Low-Power (sleep mode and 3mA operational current)Ø Self-diagnostics and failure analysis.
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DV Chip placement on Thin Film Flexure
Accurate Temperature measurement independent fromambient temperature.Digital, non-susceptible output (temperature output embededin signal).
Solder or Conductive Epoxy Bumps on DV Chip
UnderfillAdhesive
Solder Conductive Epoxy Bumps or on Flexure Bridge Pads
Bridge pads
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Schematic
Thin Film
Strain
Gauge
DV chip Flexwire
Inter-connection
Micro Controller
LIN2.0
Transceiver
Out
Sensing(Sensor assy)
Conditioning(PC Board)
p T
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(4) Finite Element Modeling of P/T Sensor
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Effect of Chip on Diaphragm Stress and Deflection
0.00E+00
1.00E-03
2.00E-03
3.00E-03
4.00E-03
0 0.25 0.5 0.75 1
r/R
Def
lect
ion
(m
m)
No Chip Chip loaded
The influence of DV chip on the stress distribution and deflection of diaphragm is small
Condition: 180ºC temperature, 150 bar pressure
Rr
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Ambient Conditions: a) 25ºC still airb) 150ºC still air
150ºC air flow / 4.4 m/s
c) 135ºC still air
Thermal AnalysisImpact to electrical Components (PCB)
CO2 @ 200 kg/h and 180ºC or 165ºC
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a) Temperature Distributions after 5 Min. (25ºC Ambient Temperature)
Printed Circuit Board112~140ºC
25°C, Voo = 0m/s
Initial Fluid Temperature: 25ºC; Transient to 180ºC
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b) Temperature Distributions after 5 Min. (150ºC Ambient Temperature)
167~173ºC
Printed Circuit Board
166~172ºC
Initial Fluid Temperature: 25ºC; Transient to 180ºC
150°C, Voo = 0m/s 150°C, Voo = 4.4m/s
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Replace PCB
Mount the circuit board to components with low thermal conductivity (plastics) away from the metal housing.
ULTEM 2310 PolyetherimidePlastic Connector
Circuit Board
Stainless Steel 304L
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c) Design at 135ºC Ambient Temperature
141-144ºC
Printed Circuit Board Temperature
139-141ºC
CO2 Temperature
5 min of 180ºC
5 min of 165ºC
Initial Fluid Temperature: 135ºC; Transient to 180ºC and 165ºC
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Conclusions
Ø DV chip has negligible influence on the performance of sensor diaphragm / pressure sensor functionality.
Ø By connecting the circuit board to plastics and away from the metal housing, the circuit board temperature can be reduced to around
~ 140ºC under 135ºC ambient Temperature
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(5) Qualification Testing
ØLeackage test March 2008
Requirement <1,0 gram per year The test will be carried out at an external test lab, specialized on these kind of tests.
ØDesign validation test on sensor level
Start after sample build in July 2008Duration appr. 6 month.
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(6) Other Thin Film Application and Sensor Products:
ØDirect Fuel Injection / Common RailØIn-Cylinder PressureØTransmission / Break PressureØCompressed Natural Gas (CNG)ØTraction ControlØ(Mobile) Hydraulic Pressure / ControlsØHVAC / Hydraulic Machinery
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Thank you for your attention !
Contact:Mr. Markus ButenopDirector of Sales EuropeKAVLICO GmbH Potsdamer Str. 14D-32423 Minden (Ger.)Phone: +49 (0)571 3859 –171Fax.: +49 (0)571 3859 –119Email: [email protected]: www.kavlico.de / www.cst-sensors.com