Abrasive Machining

The Micro Abrasive Jet (MAJ) machining process erodes the target material by use of fine abrasive particles blasted at a high velocity.

This process allows for very precise and accurate control of material removal rate. Non-machined areas are covered using a protective mask created by a photolithography step.

The material removal mechanism is based on propagation and intersection of cracks generated by the impact of abrasive particles on the brittle materials.

Applications of abrasive machining include:

  • Shallow depth cut on ceramic materials
  • Trenches for micro-medical applications
  • Mesas to reduce the surface area of chuck and other semiconductor components
  • Reference cavities for pressure sensors
  • Thru-holes for air and chemical flow
  • Cavities for mechanical locations

Advantages include:

  • Minimal tooling cost
  • Quick turnaround for prototyping and development work
  • Feature sizes down to 100µm and featured depths to just a few microns are possible
  • Feature location and dimensional tolerances down to +/-25 microns are possible
  • Multiple features can be machined in one operation
  • Very high pattern densities are possible
  • Features can be of any 2D shape: square, round, designed shapes, and connected channels
  • Masks are made directly out of CAD files reducing the risk of pattern error
  • The process generates no heat and does not change the material properties of the work-piece
  • Process works well with mettalized parts

Limitations:

  • Unlike vertical side walls produced by ultrasonic machining, abrasive blasting machined features have tapered sidewalls ranging from 18 to 26˚, depending on several factors
  • Maximum aspect ratio to 3:1 (Thickness:Diameter)