Abstract:
An array apparatus has a micromachined SOI structure, such as a MEMS array, mounted directly on a class of insulative substrate, such as low temperature co-fired ceramic or a thermal-coefficient of expansion matched glass, in which is embedded electrostatic electrodes disposed in alignment with the individual MEMS elements, where the electrostatic electrodes are configured for substantial fanout. In a specific embodiment in order to compensate for differences in thermal-expansion characteristics between SOI and ceramic, a flexible mounting is effected by means of posts, bridges and/or mechanical elements which allow uneven expansion in x and y while maintaining z-axis stability. Methods according to the invention include fabrication steps wherein electrodes are fabricated to a post-fired ceramic substrate and coupled via traces through the ceramic substrate to driver modules.
Abstract:
In an electrostatically controlled deflection apparatus, such as a MEMS array having cavities formed around electrodes and which is mounted directly on a dielectric or controllably resistive substrate in which are embedded electrostatic actuation electrodes disposed in alignment with the individual MEMS elements, a mechanism is provided to mitigate the effects of uncontrolled dielectric surface potentials between the MEMS elements and the electrostatic actuation electrodes, the mechanism being raised electrodes relative to the dielectric or controllably resistive surface of the substrate. The aspect ratio of the gaps between elements (element height to element separation ratio) is at least 0.1 and preferably at least 0.5 and preferably between 0.75 and 2.0 with a typical choice of about 1.0, assuming a surface fill factor of 50% or greater. Higher aspect ratios at these fill factors are believed not to provide more than marginal improvement.
Abstract:
A MEMS device having a fixed element and a movable element wherein one or the other of the fixed element and the movable element has at least one radially-extended stop or overdeflection limiter. A fixed overlayer plate forms an aperture. The aperture is sized to minimize vignetting and may be beveled on the margin. Overdeflection limitation occurs during deflection before the movable element can impinge on an underlying electrode. The overdeflection limiter may be conveniently placed adjacent a gimbaled hinge.
Abstract:
In a folded three-dimensional free-space optical switch including a set of fibers and an optical system for producing collimated beamlets aligned to intersect an array of dual axis micromirrors of coplanar input and output mirror elements, and a folding mirror, the input and output micromirrors are arranged in a pattern wherein either the input or output mirror set is disposed along an annulus and wherein the complementary output or input mirror set is disposed within the annulus in order to globally minimize maximum tilt angles for a two-dimensional locus of tilt angles of the micromirror set. The beamlets are routed from assigned input fibers to corresponding input moveable mirrors to assigned output fibers via the static folding mirror and corresponding output moveable mirrors.
Abstract:
An array apparatus has a micromachined SOI structure, such as a MEMS array, mounted directly on a class of substrate, such as low temperature co-fired ceramic, in which is embedded electrostatic actuation electrodes disposed in substantial alignment with the individual MEMS elements, where the electrostatic electrodes are configured for substantial fanout and the electrodes are oversized such that in combination with the ceramic assembly are configured to allow for placement of the vias within a tolerance of position relative to electrodes such that contact is not lost therebetween at the time of manufacturing.