| LIGA, a German
acronym for lithography (X-ray LIthographie) , electroforming
(Galvanoformung) and molding (Abformtechnik), is a micro
technology that was developed in the early 1980s by the
team lead by Erwin Willy Becker and Wolfgang Ehrfeld at
the Institute for Nuclear Process Engineering (Institut
für Kernverfahrenstechnik IKVT) at the Karlsruhe Nuclear
Research Center in Germany.
In LIGA process, a mold insert is created by X-ray
lithography followed by micro electroforming. The mass
production is carried out by micro casting, micro injection
or micro hot embossing processes.
Because of X-ray’s high energy and collimation, the
resulting micro mold has distinct features such as high
aspect ratio (> 50 or more), submicron precision
and low surface roughness (< 30 nano meters).
There are today three different types of LIGA technologies,
differing in the radiation and preform used:
X-Ray LIGA, the original LIGA technology, utilizes X-Rays
produced by a synchrotron.
UV-LIGA using ultraviolet light, typically from a mercury
lamp, and special resists such as SU-8.
Silicon-LIGA using deep reactive ion etched silicon
as preform.
|
