Microengineering design and manufacture using the LIGA process

The need for design rules, new processes and methodologies for both the visualisation and analysis of microcomponents is outlined. Conventional planar microengineering has successfully resulted in producing transducer systems employing cantilevers and diaphragms. Artefacts possessing greater structural heights cannot be produced using this technology. The LIGA process, using X-ray radiation, is capable of producing microstructures in materials such as ceramics, polymers and electrodeposited metals having structural heights of up to 1000 μm and height-to-width aspect ratios of 100:1 to 1000:1. Where less stringent accuracy is required, visible radiation, such as UV and laser, may be used to form the structures. Optical LIGA has been used to produce fluidic valves, microwave couplers, microlens arrays and micro-optic devices. The basic steps in the design, processing and manufacture of LIGA components is described. Attention is drawn to the need to adapt existing finite element software in order to deal with components having small physical dimensions. LIGA microengineered components are handled on a laboratory scale using micromanipulators. A critical factor affecting the adoption of complex microengineered systems is the need for bulk handling and mass assembly techniques to be developed