The strength of Epson's MEMS fabrication technology is its excellent three-dimensional accuracy. MEMS are ordinarily fabricated using a semiconductor process for two-dimensional planar structures. However, Epson's silicon MEMS technology makes it possible to form complex 3D structures on silicon substrates to accurately produce things such as complex inkjet heads and tiny parts for wristwatches.
The silicon MEMS fabrication process can be used to completely penetrate a silicon substrate with a thickness of 100 microns or more, create complicated hollow structures, or freely create exquisitely accurate three-dimensional structures, depending on the functions required. Mechanical functions require production technology for controlling cross-sectional accuracy and designs engineered with precise stress calculations.
Thin-film control technology is essential for fabricating MEMS. Not only is it used in the formation of electrical circuits and sensors directly on silicon, it is also used in etching control and silicon-to-silicon bonding. This technology takes advantage of optical interference principles to also produce decorative coatings. One of Epson's strengths is the ability to skillfully use a variety of thin films.
For silicon MEMS parts to function, they must be carefully assembled with other parts or mounted in a circuit. As with semiconductor processes, this assembly requires extraordinary precision and accuracy. Epson utilizes know-how accumulated in its own watch assembly processes in technology used in the transport of thin, fragile silicon parts with a 3D structure.
Silicon MEMS technology has many promising future applications. For example, if tiny MEMS devices with integrated actuators and sensors can be achieved, micromachines that work in the human body may become a reality.