LIGA process

LIGA is the short cut for the german language designation Lithographie, Galvanik, Abformung. 

It is a process to produce micro-detailed geometrical structures and micromechanical devices. The process has been evolutionary developped from fotolithograpy. Geometrical structures can bei produced with a minimum distance of 0,2 µm and an aspect ratio of up to 50.

The substrate is a material which will be treated by the etching process, preferably silicon, beryllium, copper or titanium.

  1. If the substrate is not conductive it will be coated by an electroconductive layer.
  2. The substrate or the electroconduvtive layer will be completely covered by a thick fotoresist, preferably a thich positive resist.
  3. The fotoresist is illuminated by the desired structure.
  4. After the development process the conductive surface is exposed.
  5. Now by galvanic deposition additional metall grows in the areas exposed from the resist.
  6. After removing the fotoresist a profiled metallic structure remains.
  7. The resulting profiled metallic part can be used as a mould for moulding extremely detailed microstructured copies.