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US 6,598,750 B2Granted
Micromachined membrane particle filter using parylene reinforcement
AssigneeCalifornia Institute of Technology
InventorsYu-Chong Tai, Xing Yang
Life of this patent
Estimating the term…
Abstract
A micromachined membrane particle filter is formed by making holes in a silicon and coating over the holes with Parylene.
Claims21
A micromachined membrane filter, comprising:
- a semiconductor base layer;
- a filter border comprising a filter material layer comprising a filter material disposed on at least a portion of the base layer;
- a grid comprising the filter material, the grid connected to the filter material layer and spanning a filter area defined by the filter border, the grid defining a plurality of openings with an opening factor of between about 37.3% and about 44.4%.
A method of forming a micromachined particle filter, comprising:
- forming a plurality of openings in a grid area of a filter layer so that an opening factor of the grid area is between about 37.3% and about 44.4%;
- and
- coating edges of the openings with a thickness of an overlayer material to achieve a desired filter pore size.
A method, comprising:
- forming a first layer on a first side of a semiconductor substrate;
- etching a second side opposite the first side of the semiconductor substrate, forming a thinned area of the semiconductor substrate;
- forming openings in the first layer across a grid area so that an opening factor of the first layer across the grid area is between about 37.3% and about 44.4%;
- and
- substantially removing the thinned area of the semiconductor substrate beneath the grid area of the first layer.
2 more elements
A method, comprising:
- depositing a first layer of silicon nitride of between one-half and one micron thick on a first side of a substrate including silicon;
- etching a second side opposite the first side of said substrate to form a thinned layer of substrate that is between 20 and 100 microns in width, supporting said silicon nitride first layer;
- forming openings in said silicon nitride first layer over a grid area so that an opening factor of the first layer across the grid area is between about 37.3% and about 44.4%, and wherein said openings are larger than a desired final filter pore size;
- and
- removing said thinned layer of substrate at least beneath the grid area.
2 more elements
Dependencies are inferred from the claim text.