Kinemetrics, Inc.

California Institute of Technology

Other

Pike, William Thomas

Syms, Richard

William Thomas Pike

Ian Standley

Martin B Barmatz

Henry W Jackson

John D Mai

Nasser K Budraa

Richard Syms

Amadej Trnkoczy

An accelerometer or a seismometer using an in-plane suspension geometry having a suspension plate and at least one fixed capacitive plate. The suspension plate is formed from a single piece and includes an external frame, a pair of flexural elements, and an integrated proof mass between the flexures. The flexural elements allow the proof mass to move in the sensitive direction in the plane of suspension while restricting movement in all off-axis directions. Off-axis motion of the proof mass is minimized by the use of intermediate frames disbursed within and between the flexural elements. Intermediate frames can include motion stops to prevent further relative motion during overload conditions. The device can also include a dampening structure, such as a spring or gas structure that includes a trapezoidal piston and corresponding cylinder, to provide damping during non-powered states. The capacitive plate is made of insulating material. A new method of soldering the capacitive plate to the suspension plate is also disclosed.

Fabrication process and package design for use in a micro-machined seismometer or other device

A method of attaching two wafers in a seismometer comprising the steps of forming a patterned wetting metal layer on a first wafer and forming a plurality of cavities mirroring the pattern of the wetting metal layer on the first wafer. The steps further include pouring a plurality of solder balls on the surface of an alignment wafer, pouring off excess solder balls, aligning the first wafer with the alignment wafer, and connecting the first wafer with the alignment wafer. The solder balls are immobilized on the wetting metal layer by performing a partial reflow onto the wetting metal layer and removing the alignment wafer. The first and second wafers are aligned so that each solder ball is immobilized between the first and second wafer. The wafers are then bonded together.

An accelerometer or a seismometer using an in-plane suspension geometry having a suspension plate and at least one fixed capacitive plate. The suspension plate is formed from a single piece and includes an external frame, a pair of flexural elements, and an integrated proof mass between the flexures. The flexural elements allow the proof mass to move in the sensitive direction in the plane of suspension while restricting movement in all off-axis directions. Off-axis motion of the proof mass is minimized by the use of intermediate frames disbursed within and between the flexural elements. Intermediate frames can include motion stops to prevent further relative motion during overload conditions. The device can also include a dampening structure, such as a spring or gas structure that includes a trapezoidal piston and corresponding cylinder, to provide damping during non-powered states.

Micro-machined suspension plate with integral proof mass for use in a seismometer or other device

Bonding of MEMs materials is carried out using microwave. High microwave absorbing films are placed within a microwave cavity, and excited to cause selective heating in the skin of the material. This causes heating in one place more than another. Thereby minimizing the effects of the bonding microwave energy.

Microwave bonding of MEMS component

Bonding of materials such as MEMS materials is carried out using microwaves. High microwave absorbing films are placed within a microwave cavity containing other less microwave absorbing materials, and excited to cause selective heating in the skin depth of the films. This causes heating in one place more than another. This thereby minimizes unwanted heating effects during the microwave bonding process.

Microwave bonding of thin film metal coated substrates

The present invention is a seismometer/velocimeter, and can be also made to function as an accelerometer. The invention comprises an in-plane suspension geometry combined with a transverse periodic-sensing-array position transducer. The invention can incorporate a feedback actuator of magnetic design, incorporating fixed magnets and planar coils on the surface of the proof mass allowing for much lower noise than an equivalent electrostatic actuator without requiring high voltages. The invention may also have a dual-axis configuration by using two sets of springs. The nested suspensions allow the proof mass to move in two orthogonal directions. A three-axis configuration is possible by combining the dual-axis version with sensing and actuation of the proof mass motion out of the plane. The position sensing for the out-of-plane motion can be made using schemes common in existing state-of-the-art sensors. Actuation for the sensors may be electrostatic or electromagnetic in each of the axis.

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London, United Kingdom

William Thomas Pike