A presentation on the uses of Excimer Laser Machining

1. Alap Parikh
09D10014
Tej Mulgaonkar
09010015
Jainik Dedhia
09010016
•Excimer Laser machining is a micro
machining technique using ultraviolet
laser.
•Excimer comes from Excited and
Diamer.
•This method is particularly used to
machine organic compounds.
•The beam mainly consists of a halide of
an inert gas.
Sankalp Kelshikar
09010017

2. Why Excimer Lasers?
• Very highly accurate beams can give surfaces accurate
up to 45nm.
• Does not cause heating of the work piece so there is
no loss of power.
• The material is removed from the work piece by
vaporization or fine chipping.
How it works..
The thyratron places 45 kV across
pre-ionization pins and
electrodes, creating a gas
plasma.
The electrons in the gas plasma
are accelerated by electric field.
The laser transition step is
initiated by photons produced by
spontaneous emission along the
laser axis.
Excited molecules are created by
inelastic collision with the
electrons.

3. The Fabrication of 3D Polymer Structures
• Polymer surfaces can be etched in air by means of
pulsed excimer lasers.
•Ablation techniques such as the gray scale and the
scanning contour mask used
Micromachining of Inorganic Dielectric
•Problems with usual machining
•low UV absorptivity
•formation of cracks
•contamination by ablation debris
On the other hand these materials are
very interesting for micro technologies
•Factors involved
•Two photon absorption
•Defect formation
•Plasma mediated ablation
•Structures with micrometer resolution can be produced applying the appropriate
mask imaging technique.

4. Fabrication of Micro-Structures
• Lower coefficients of friction. Useful in:
•piston rings of reciprocating engines
•high end automobiles or space vehicle bodies
•coating of low friction systems.
•Have greater surface areas. Used as:
•Catalytic surfaces in automobiles,
•Industrial catalysts,
•Heat sinks or heat radiators.
Refractive Surgery
• Laser Assisted In-situ Keratomileusis (LASIK)
• Differs from PRK (photoreactive Keratectomy) in
that first a microkeratome “planes” a hinged flap of
corneal tissue 8mm in diameter
• Vision covers more quickly and with less
discomfort since the surface cells are left in place on
the surface of the corneal flap.

5. Cost factor..
$
Electric Power at 3kW
Gas Consumption
Routine Parts (Optics, filters)
Total routine operating expenses
Laser Refurb (every 1 billion pulses or
approximately every year at 100 Hz)
Total laser operation and maintenance
Advantages
Very highly accurate beams can give surfaces accurate up to
45nm
Does not cause heating of the work piece so there is no
loss of power
The material is removed from the work piece by
vaporization or fine chipping
$600
$12000
$400
$13000
$17000
~$45000
Disadvantages
High performance electronic components require frequent
and costly maintenance
Laser gas is toxic and corrosive
Laser gas consumption is high and expensive
Changes in gas chemistry affect beam shape and quality
Components inside laser require routine replacement and
cleaning due to corrosiveness of the laser gas
Conclusion..
• Excimer laser machining has great levels of accuracy
• Quite expensive
• Not yet feasible as a mass manufacturing process
• Great scope for improvement of productivity
• Reduction of operation and maintenance cost is key
• Rise of use of ELM in industries and medical sector during the 90s