PD 9251 Micro Electro Mechanical System Nov/Dec 2010 Question paper | ME Product Design and Development Question papers

M.E. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2010 

Elective 

 Product Design and Development 

PD 9251 — MICRO ELECTRO MECHANICAL SYSTEMS 

(Regulation 2009) 

Time : Three hours                                                                                          Maximum : 100 Marks

Answer ALL questions 

PART A — (10 × 2 = 20 Marks) 

1. Why is semiconductor preferred as substrate material in MEMS?
2. Distinguish between wet and dry etching.
3. State the need for packaging the chips.
4. List out different stacked die configurations.
5. Briefly explain the principle of operation of electrostatic scratch drive actuator  used in MEMS devices.
6. Differentiate System level modeling from Finite element modeling.
7. How is the pressure converted into electrical signal in pressure sensor?
8. Explain Archimedes principle.
9. List out varies types of accelerometer used in MEMS technology.
10. What is the principle of magnetic head type torque sensor?

PART B — (5 × 16 = 80 Marks) 

11. (a) (i) Enumerate various substrate and additive materials used in  MEMS. (10)
 (ii) Describe various steps in surface micro machining with neat sketches. (6)
Or
(b) (i) Describe various steps in LIGA process with a neat block diagram.  (10)
 (ii) Explain various deposition methods used in micro fabrication and explain any one. (6)

12. (a) (i) Describe various methods of die-attachment with neat sketches. (10)
 (ii) Describe the requirements of MEMS mechanical sensor packaging. (6)
Or
(b) (i) Discuss the salient features of standard IC packages. (10)
 (ii) List out various methods of electrical interconnects used in MEMS.  Describe any two. (6)

13. (a) List out various actuation methods used in MEMS. Describe the principles of any two methods with neat sketches.
Or
(b) Write short notes on the following :
 (i) Capacitive displacement technique (6)
 (ii) Smart sensors (5)
 (iii) MEMS simulation tools. (5)

14. (a) Explain the physics and dynamics of pressure sensing with neat  sketches.
Or
(b) Write short notes on the following :
 (i) Pressure sensor specifications. (8)
 (ii) Micro-machined silicon diaphragms. (8)
15. (a) Enumerate the working principle of Atomic force microscope and  scanning probes with neat sketches.
Or
(b) (i) Describe with a neat schematic diagram principle of variable gap capacitor force sensor. (8)
 (ii) Discuss the principle of micro machined gyroscope with neat sketch.  (8)