Young-Tae Lee Andong National University

1. Development of the silicon pressure sensor for measuring combustion gas pressure of automobile engine Young-Tae Lee Andong National University

2. Automobile engine Single crystal silicon High sensitivity High temperature High pressure Dielectric isolated piezoresistor High temperature SDB(Si/SiO2/Si-sub) structure Stainless steel packaging (two diaphragm) Pressure sensor for measuring combustion gas pressure 370℃ 600℃ Introduction

3. Environment Temperature: 1000℃ Pressure: 70 bar Automobile Engine

4. Engine Stainless steel diaphragm Semiconductor pressure sensor Glass base Combustion chamber Electrode Stainless steel package Pressure Sensor for Automobile Engine

5. Piezoresistor Diaphragm Electrode Pad(Al) Piezoresistor SiO2 Diaphragm High Temperature Pressure Sensor With SOI Structure

6. Diaphragm Y X α L W Shear Stress Type Piezoresistor( Single-element four-terminal piezoresistor)

7. Max. shear stress Max. shear stress Diaphragm Shear Stress Distribution

8. TAG D1200 D700 (1200ⅹ1200㎛2) Diaphragm (700ⅹ700 ㎛2) D2200 D1700 (2200ⅹ2200 ㎛2) (1700ⅹ1700 ㎛2) Piezoresistor Bonding Pad Sensor Design

9. SiO2 Si (a) Initial oxidation Diaphragm (100) (b) v-groove etching (c) Diaphragm etching Single crystal silicon Concentration: 5ⅹ1017 cm-3 (d) Ion implantation(Boron) Fabrication Process

10. Resist SiO2 (e) Si etching with RIE SiO2 CVD Single crystal silicon (f) SiO2 CVD and contact cut Contact Electrode Piezoresisitor Piezoresistor (g) Electrode formation Diaphragm Fabrication Process

11. SiO2 Piezoresistor V-groove Piezoresistor Pad Photograph of the Pressure Sensor

12. Pyrex glass Piezoresist Wire Pressure sensor chip Package Glass(bonding) Pressure Sensor Package

13. Characteristics of the Pressure Sensor D2200 D1700 D700

14. Temperature Characteristics of the Sensitivity

15. Long-term Stability

16. Characteristic Value Pressure Range 100 kPa Overpressure 200kPa Supply Voltage DC 5V Full Scale Span 92 mV (TYP) Sensitivity 183.6 ㎶/V kPa Linearity 1.3%FS Hysteresis 0.9%FS Measured Temperature 18∼370 ℃ Operating Temperature -40∼370 ℃ Temperature Effect on Full Scale Span 0.097 %FS/℃ Offset 4.8 mV Temperature Effect on Offset 0.026 %FS/℃ D2200-Specification

17. Silicon pressure sensor Glass base Stainless steel package Thermal Energy Diaphragm Oil or Gas Thermal resistance Temperature Distribution Analysis for Packaging

18. Transfer Oil Air Modeling (a) One diaphragm (b) Two diaphragm Air Oil Oil (c) Two diaphragm with transfer

19. 23 17 15 Engine(aluminum) Package(stainless steel) Oil Glass base 20 5 Pressure sensor Stainless steel diaphragm Units: mm 30℃ Model Size

20. Simulation condition Simulation tool: ANSYS 5.7.1 Simulation method: Linear thermal analysis(PLANE55) Material Properties for simulation

21. Temperature: 250-300℃ Engine(aluminum) Package(stainless steel) Oil Glass base 600℃ Stainless steel diaphragm Pressure sensor 30℃ One Diaphragm

22. Pressure sensor Oil Air Temperature: 100-150℃ Diaphragm Two Diaphragm

23. Transfer Two Diaphragm with Transfer

24. Pressure sensor Transfer Temperature: 150-200℃ Air Diaphragm Oil Two Diaphragm with Transfer

25. Pressure and temperature behavior in the combustion chamber of a 4-stroke engine http://www-mat.ee.tu-berlin.de/research/sic_sens/sic_sen3.htm Transient Thermal Analysis

26. Simulation condition Crank angle(deg.) -360 0 360 600 Temperature(℃) 300 30 80 40 5 45 Time(ms)

27. 600℃ 300℃ 600℃ 300℃ 30℃ 30℃ 1 cycle Simulation results(one diaphragm)

28. 3 cycle 2 cycle 1 cycle 5 cycle 6 cycle 4 cycle 7 cycle 9 cycle 8 cycle Simulation results(one diaphragm)

29. Silicon pressure sensor Oil Stainless diaphragm Pyrex glass 9 cycle Simulation results(9 cycle)