Norinao Kouma

A 2-axis comb-driven micromirror array for 3D MEMS switches

Presents a new architecture of a 2-axis comb-driven micromirror array that combines a large deflection angle in a stationary operation, a low drive voltage, and easy scalability for a 3D MEMS switch. By using an SOI wafer with 100-/spl mu/m thick top and bottom Si layers and a 1-/spl mu/m buried oxide layer and, bulk micromachining with DRIE, we fabricated a 2-axis comb-driven micromirror array with a V-shaped torsion bar and comb teeth. The V-shaped torsion bar that has an optimized spring constant that enables both a large rotational angle and a low drive voltage without creating the undesired pull-in motion of the comb teeth. To implement a 2-axis tilt motion, we fabricated a gold bump for creating a gap under the comb teeth on the electrode substrate and mounted the mirror array substrate onto the electrode substrate by using the flip-chip-transfer technique. We fabricated an 80/spl times/80 switch chip and achieved a +/-5 degree rotation of the 2-axis stationary operation with a 60-V drive voltage.

A full-time accelerated vertical comb-driven micromirror for high speed 30-degree scanning

This paper presents a new structure and driving method for a vertical comb-driven micromirror which enables full-time acceleration and mechanical 30-degree scanning with a 4-mm long mirror. Its optimal application is as a scanning mirror for laser beam printers, replacing polygon mirrors which have technical limits in relation to scanning speed.

A multi-chip directly mounted 512-MEMS-mirror array module with a hermetically sealed package for large optical cross-connects

A 512 MEMS mirror array module with a hermetically sealed package for large optical cross-connects is constructed by using newly developed multi-chip direct mounting (MCDM) technology and is demonstrated to enable a plusmn5 degree rotation of the two-axis stationary operation under a drive voltage of 160 V, while having a high resonance frequency of 2 kHz

A multi-step DRIE process for a 128 /spl times/ 128 micromirror array

A multi-step DRIE process for fabricating a vertical comb-driven micromirror array with five different heights was developed. This process was used to fabricate a dual-axis 128 /spl times/ 128 micromirror array with a high resonance frequency.