Injection Molding Techniques for the Fabrication of MEMS Elements

Abstract

For mass production of MEMS parts, processes that reproduce features on plastics, especially injection molding, are effective. These products have the following threefold geometric performance requirements (Fig.1).

• (a) Reproduction of micro-features: Precise reproduction of micro-features with dimensions in the range of 100 nano-meter to 1 micro-meter and tolerances in about 1/10 of those dimensions is necessary.

• (b) Reproduction of overall shape: The overall enclosing shapes of reproduced parts have dimensions in the range of 1mm to 10mm, with flatness, perpendicularity, or parallelism tolerance in the range of 1 to 10 micro-meters. These tolerances have to be met.

• (c) Uniformity of internal structure: Internal structure of the reproduced parts have to be uniform. In other words the part should be free of difference in local density of the filling material, residual stress, local concentration or directional variation in magnet particles, fibers, or gas bubbles.