Laser Micro Machining

1. By: Chandrakanth B

2. •Introduction
•Working principle
•classification
•application
•Advantage and disadvantage
• safety
•Case study
•References
Introduction

3.  Laser micromachining: cutting, drilling, welding, or
other modification in order to achieve small features.
 Micro machining implies that parts are made to the
size of 1 to 999 µm. However Micro also means very
small in the fields of machining, manufacture of small
parts are not easy.
Introduction

4. Continued...
•Lasers have been in use in various industrial sectors
such as the automotive and aerospace industries for
many years performing cutting, welding and
materials processing tasks.
•More recently, there has been an upsurge in the
micro engineering applications of lasers where pulsed
lasers, in particular, have played a major role in the
development of numerous micro-systems technology
(MST) areas.

5. Working Principle

6. • A laser machine consists of the laser, mirrors for beam
guidance, a focusing optic and a positioning system.
• The laser beam is focused onto the work piece and can
be moved relative to it.
• The laser machining process is controlled by switching
the laser on and off, changing the laser pulse energy
and other laser parameters and by positioning either
the work piece or the laser focus.
Continued...

7. Continued...
• Laser is emitted from the source is passed through
the energy attenuator. After it is passed through the
beam homogenizer to homogenize the beam.
• The target illuminator and machine vision controls
the beam to the focusing lens. The lens is moved by
precision motion stages. The beam is then falls on
the work piece and the machining takes place.

8. Types of Laser Micro Machining
1. Direct writing. 2. Mask Projection

9. Process
Parameters
Effect
Wavelength,
Focal length of lens
Feature size
Beam shape Feature shape
Beam energy,
Pulse width
Size of heat affected
zone
Depth of focus Aspect ratio
Continued...

10. Practical
Resolution
Limit
Attainable
Aspect
Ratio*
Taper Undesirable
Side Effects
Status of
Technology
Development
Excimer
Laser
5 mm >100:1 yes Recast Layer low
CO2 Laser 200 mm 100:1 yes
Recast Layer,
Burring,
Thermal
high
Nd:YAG 50 mm 100:1 yes
Recast Layer,
Burring,
Thermal
high
EDM 100 mm 20:1 No Surface finish moderate
Chemical Etch
250 mm 1:1.5 Yes Undercutting moderate
Mechanical Ø 100 mm 10:1 No Burring moderate
Comparison of Available Machining Methods

11. For drilling micro holes, laser beam drilling
technique is used.
Applications
High speed drilling of
20µm holes in 50µm
thick foil
Cutting of 1mm
tube
100µm wide v-
grooves

12. Laser Micro machining technique finds application in the
manufacture of micro channels and micro holes in integrated
chips and microchips.
Micro holes on integrated chips Micro channels on integrated chips
Continued...

13. Surface micro machining is characterized by the fabrication of
micro mechanical structures from thin deposited thin films.
Continued...

14. Used in machining threads in a single polyfibre and also used
to give taper to the fiber.
Continued...

15. •Easy capability of being automated
•Straightforward process monitoring
•Forceless and contactless machining
•Minor heat-affected zone
•Marginal modifications to the microstructure
•Machining free of burr and bulging
•High flexibility regarding design of tiny structures
•High machining speed
•High precision
•Constant machining quality
•No additional tooling costs by wear
•No solvent chemicals used
•Material removal rate controllable down to the
nanometer scale
Advantages

16. •The equipment required for micro machining is very
costly than other cutting processes.
•Need highly skilled persons to operate micro machining
systems.
•Material limitations (including crystalline and reflective
materials)
•Reflected laser light can present a safety hazard
Disadvantages

17. •High intensity ultraviolet and infrared light hazardous
to the eyes (cornea) and skin
•All manufacturers required by law to design and
certify compliance with U.S. Code
•During normal operation of the equipment
Interlocked protective housing is must.
•Required safety labels, inspections and record
keeping.
Safety

18. Mechanical safety
• Large motion control systems may pose mechanical
hazards to people
• Mechanical guards
• Machine must be checked regularly

19. •Lethal high voltages in the laser head
•Electrical safety covers
•Qualified service personnel only
Electrical safety
•Toxic and corrosive fluorine and chlorine gases
•Compressed gas cylinders need proper handling
Material safety

20. •Micro machining technology not only provides a new
manufacturing route for existing products, but also
allows the creation of completely new products.
•The surface micro machining technology
predominates at the present state & this trend will
continue in the future.
•Nano is the buzz word of the moment. Thus the
transition from Micro-Electro-Mechanical-Systems
(MEMS) to Nano-Electro-Mechanical systems (NEMS)
is taking place in present technology
Conclusion

21. •Advancements in Laser Micro machining Techniques-
By Nadeem Rizvi and Paul Apte.
•Laser Micromachining – By Udo Klotzbach, Andres
Fabian Lasagni, Michael Panzner and Volker Franke.
•www.resonetics.com
•Internet(wikepedia,google etc)
References

22. Thank you