30-07-2011, 03:10 PM
Presented by
Sudheesh K N
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Micromachining
Implies parts are made to the size of 1 to 999µm
By the definition micro engg: as the field where component sizes are a few millimeters
Important aspects
Unit removal
Equipment precision
Classification According to Machining phenomena
Removal by mechanical force
Removal by ablation
Removal by dissolution
Plastic deformation
Laser micro machining
Uses a power source (FS laser, Excimer laser) that emits a beam with very high quantum energy.
Laser Micromachining Process
Conceptual Solid Model of Laser Micromachining Setup
Advantages of Laser Micromachining
Non-contact machining
Very high resolution, repeatability and aspect ratios
Localized heating, minimal redeposition
No pre/post processing of material
Wide range of materials: fragile, ultra-thin and highly reflective surfaces
Process can be fully automated
Characteristics of Femtosecond Laser Micromachining
Very high peak powers in the range 1013W/cm2 provide for minimal thermal damage to surroundings
Very clean cuts with high aspect ratios
Sub-micron feature resolution
Minimal redeposition
Possible to machine transparent materials like glass, sapphire etc
Ultrashort Pulses vs. Long Pulse Micromachining
Femtosecond Laser Micromachining
Micromachining in 18μm Thick Aluminum Foil
Holes Drilled in 25μm Thick Brass Foil
Ablation Rate vs. Energy Density in 18m Thick Aluminum Foil
Optimization of Pulse Energy Required to Drill Holes
Automation of Laser Micromachining Process
Application of micromachining
Micro milling
Micro grinding
Chemical etching
Micro punching
Manufacturing of injection nozzles, Micro surgical tools, VLSI circuits
Conclusion
As regards micro machining, dimensions of the product is one of the good indicator of the levels of technology and request. However, the level of request from the industry varies widely.
