US 4,790,192 A · Silicon side by side coplanar pressure sensors

Abstract

A pressure sensor that provides for multiple diaphragm sensing regions in a side by side configuration which can be formed into a stacked monolithic batch fabricated form. The multiple pressure sensor can be constructed to sense differential or absolute pressure as desired. In preferred forms of the invention, the pressure inlets are all on the same side of the monolithic structure to easily isolate the corrosive pressure media from the sensing means, which as shown comprise strain gage sensors on the sensing diaphragms as well as from the conductors carrying signals from the sensing means. The variable strain gage resistors on the sensor diaphragms are segregated from the media in several differet ways using isolating layers. The stacked sensor configuration insures that the device can be batched fabricated so that a number of sensors can be formed on chips that are stacked and bonded together, and then separated into individual sensors.

Claims18

Dependent claims

A media-isolated multiple pressure sensor for providing outputs representing pressures of pressurized media coupled thereto, comprising:

a first layer having sensing means for providing the outputs disposed on a first surface thereof aligned with first and second cavities extending into the first layer from a second surface of the first layer opposite the first surface to form first and second pressure sensing diaphragms respectively in the first layer;
connection means electrically coupled to the sensing means and extending over a portion of the first surface for electrically coupling the outputs to a location spaced away from the sensor;
reference means coupled to the first surface for providing a media-free reference pressure to the first diaphragm;
and
mounting means sealingly affixed to the second surface surrounding the cavities for mounting the sensor, the mounting means having at least a first passageway therethrough for coupling the pressurized media to the diaphragms such that the sensing means and connection means are isolated from contact with the media.

2 more elements

A media isolated multiple pressure sensor for providing outputs representing pressures of fluid media coupled thereto comprising:

a first layer having first and second oppositely facing surfaces, and having cavities extending into the layer from the second surface to form first and second pressure sensing diaphragms respectively in the first layer, and sensing means disposed on the first surface aligned with the first and second cavities to sense deflections of the diaphragms as a result of pressure acting thereon;
connection means electrically coupled to the sensing means, respectively, and extending across a portion of the first surface for electrically coupling the outputs from the sensing means to remote circuitry;
a second layer mounted on the first surface of said first layer and providing a reference pressure to at least the first diaphragm, said second layer being spaced inwardly from the edge of the first layer in at least one portion of the first layer to expose a part of the first surface, said second layer being bonded to the first layer to seal around the first and second diaphragms;
said connection means extending outwardly to the exposed portion;
bonding pad means mounted on said one portion of the first surface;
and
a mounting layer mounted on the second surface of the first layer and sealingly bonded thereto to enclose the first and second cavities, and separate passageway means in said mounting layer opening to a surface of said mounting layer opposite from the first layer, said separate passageway means being coupled to the respective cavities.

4 more elements

Dependencies are inferred from the claim text.

Silicon side by side coplanar pressure sensors

Life of this patent

Silicon side by side coplanar pressure sensors

Life of this patent

Abstract

Claims18