Back to results
US 6,782,755 B2Granted
Surface-micromachined pressure sensor and high pressure application
AssigneesCalifornia Institute of Technology, Schlumberger Technology Corporation
InventorsYu-Chong Tai, Yong Xu, Fukang Jiang
Life of this patent
Estimating the term…
Abstract
A surface-micromachined high-pressure sensor, formed by forming a cavity using a sacrificial layer. The sacrificial layer can be reflowed to make the edges of the cavity more rounded. The material that is used for the diaphragm can be silicon nitride, or multiple layers including silicon nitride and other materials. The pressure sensor is intended to be used in high pressure applications, e.g. pressure is higher than 6000, 10,000 or 30,000 P.S.I.
Claims27
A device, comprising:
- a substrate;
- and
- a surface micromachined pressure sensor, formed on said substrate, and formed to be capable of sensing pressures that are greater than 6000 psi;
- wherein said pressure sensor includes a diaphragm material, and a plurality of strain sensitive resistors, formed in said diaphragm material;
- wherein said strain sensitive resistors are piezoresistors;
- and
- a vacuum cavity, under said diaphragm material, said cavity having a depth that is based on overpresaure protection characteristics.
4 more elements
A device, comprising:
- a substrate;
- and
- a surface micromachined pressure sensor, formed on said substrate, and formed to be capable of sensing pressures that are greater than 6000 psi;
- wherein said surface micromachined pressure sensor includes a diaphragm layer, formed from a silicon nitride layer;
- and
- at least one additional resistor, formed on an area other than said diaphragm layer, but formed on said substrate, said at least one additional resistor being sized to compensate for an offset voltage.
3 more elements
A device, comprising:
- a substrate;
- and
- a surface micromachined pressure sensor, formed on said substrate, and formed to be capable of sensing pressures that are greater than 6000 psi;
- an over pressure protection part, integral with said device, and protecting said device against pressures which are higher than a designed-for specified amount.
1 more element
A device, comprising:
- a substrate;
- a surface micromachined pressure sensor, formed on said substrate, and capable of sensing pressures greater than 6000 psi, said pressure sensor including a deformable diaphragm, coupled to said substrate, and connected at least around a perimeter thereof to said substrate, and separated from said substrate to form a cavity under said diaphragm between said diaphragm and said substrate, said deformable diaphragm having an outer perimeter size which is less than 100 microns, and having a thickness which is greater than three microns.
A device, comprising:
- a substrate;
- and
- a surface micromachined pressure sensor, having a deformable membrane formed adjacent said substrate, said membrane having an outer size from edge to edge which is less than 100 microns, and having a thickness that is capable of withstanding a pressure that is greater than at least 6000 psi.
Dependencies are inferred from the claim text.