Titanium Based MEMS Packaging

1
Titanium Based MEMS Packaging
MEMS
Tyler Vestal Mentor Payam Bozorgi Advisor Noel
Macdonald Mechanical Engineering
2
What are MEMS and why must they be packaged?

• Micro-Electro-Mechanical Systems
• Eye, Brain, and Arm in a single device
• Isolation from environment
• Particles
• Humidity
• pH

A HP Labs researcher holds the prototype skin
patch technology, demonstrating
the size and scale of the prototype
(Credit HP)
MEMS
A MEMS Package
3
Inkjet Printer
4
The Goal gtgtgt Titanium
GOLD

• Package using Titanium instead of Silicon
• Stronger
• Less Reactive
• Bio-Compatible
• Problems Arise
• Dicing (cutting)
• Melting Point (High)
• Solution gtgtgt Gold
• Lower MP

The Design
MEMS
Width

• Four Widths to Test
• 200 mm
• 500 mm
• 1000 mm
• 2000 mm

TITANIUM
5
Measure Polish

• The Burr
• Measure with the Profilometer
• Polish the Titanium Square

Polishing
Profilometer
6
Process the Titanium

• Clean the samples
• Acetone
• Methanol
• Apply Photo Resist
• Two Types
• Mask Samples and Expose Them
• Develop
• Add Gold
• Strip the Photo Resist

7
Packaging
GOLD
Cross-Section View
Ti
Top View
Thermo- Compression
8
Bond Strength Test

• Use tensile machine to pull apart the package
• Measure bonding strength between Ti substrate and
  lid

Tensile Machine
9
Uniformity of Bonding
Examples of Samples

• Analyze samples after Tensile Test under
  microscope
• Smooth
• Portion did not bond
• Rough
• Portion did bond
• Hermiticity Level
• Helium gas test

ROUGH
SMOOTH
10
Results

• Larger widths
• More local contact points
• Smaller widths
• Not enough surface touched

Tensile Machine F vs d
FORCE (N)
5 4 3 2 1
Breaking Point
F
G
30 40 50 60 70 80 90 100
GAP (mm)
11
Analysis
B

• Using point B we can calculate Bond strength
• Not Strong
• Less than 5 N
• Under microscope we see that bonding is not
  uniform
• Not well sealed

• Gold Bonding is not a good method for packaging
• Hermiticity level is not high
• Lengthy Process
• Complicated Method
• Expensive

12
Future of Ti-Based MEMS Packaging

• Using a laser to weld the pieces of Ti
• Payams Ph.D. Dissertation
• The applications of Ti-based MEMS
• Drug delivery
• Deep sea
• Puts MEMS in Harsh environments
• Not Gold Bonding!

13
My Time in AR

• Learned what being a scientist is like
• Patience
• power outages and mistakes
• Presentations

• Lab Technique
• Clean room protocol
• Scientists have fun
• Payam has lots of friends

14
Acknowledgements

• Payam Bozorgi
• My mentor
• Leila Jirari
• My Boat Building Partner
• Noel Macdonald
• Mentors advisor
• All the AR Staff

15
QUESTION SLIDES

• ANTICIPATE QUESTIONS AND PREPARE SLIDES FOR THEM