Protected pressure sensor and method of making

Claim 3

The method of claim 1 wherein said diaphragm is formed adjacent to said second surface in the absence of substantial diaphragm material shrinkage.

Claim 4

The method of claim 1 wherein said step of pouring the flexible, poured-in-place diaphragm comprises providing a diaphragm poured from a flowable polymeric material.

Claim 5

The method of claim 2 wherein the step of pouring the flexible diaphragm material comprises providing a diaphragm poured from a fluorosilicone material which substantially retains its original volume upon setting.

Claim 6

The method of claim 2 wherein the step of pouring the flexible diaphragm material comprises providing a diaphragm poured from a dimethyl silicone material which substantially retains its original volume upon setting.

Claim 7

The method of claim 2 wherein the step of pouring the flexible diaphragm material comprises providing a diaphragm poured from a medical grade silicone "rubber" material which substantially retains its original volume upon setting.

Claim 8

The method of claim 1 further including the step of testing the pressure sensor element before filling the cavity.

Claim 9

The method of claim 7 further including the steps of adjusting the sensor element and calibrating the pressure element before sealing the cavity.

Claim 12

A measurand sensor produced by the method comprising the steps of: providing a body having in a first face thereof a cavity, wherein said cavity has a first interior surface for receiving a pressure sensor element and a second generally upward facing surface for supporting a diaphragm; mounting said pressure sensor on said first surface; filling at least part of said cavity around said pressure sensor element with a volume of pressure transfer material less than the volume of said cavity around said sensor element below said body face; and pouring a volume of flexible, pourable-in-place diaphragm material above said pressure transfer material sufficient to seal said cavity, wherein said first surface is substantially level with the first face, wherein said diaphragm material forms a substantially impermeable barrier having a first, outward facing surface and a second surface facing said pressure transfer material, and wherein said diaphragm material and said pressure transfer material are chemically incompatible and characterized by the absence of chemical interaction between the pressure transfer material and the diaphragm.

Claim 13

A measurand sensor produced by the method comprising the steps of: providing a body having in a first face thereof a cavity, wherein said cavity has a first interior surface for receiving a pressure sensor element and a second generally upward facing surface for supporting a diaphragm; mounting said pressure sensor on said first surface; filling at least part of said cavity around said pressure sensor element with a volume of pressure transfer material less than the volume of said cavity around said sensor element below said body face; and pouring a volume of flexible, pourable-in-place diaphragm material above said pressure transfer material sufficient to seal said cavity, wherein said first surface is substantially level with the first face, wherein said diaphragm material forms a substantially impermeable barrier having a first, outward facing surface and a second surface facing said pressure transfer material, and wherein said diaphragm material and said pressure transfer material are chemically incompatible and characterized by the absence of chemical interaction between the pressure transfer material and the diaphragm.

Claim 14

The sensor of claim 10 wherein said outward facing surface is level with the body first face within 5 mils.

Claim 15

The sensor of claim 10 wherein said outward facing surface is level with the body first face within 3 mils.

Claim 16

The sensor of claim 10 wherein said outward facing surface is level with the body first face within 1 mil.

Claim 17

A measurand sensor produced by the method comprising the steps of: providing a body having in a first face surface thereof a first recess of given cross section, bottomed peripherally by a first upward facing surface for supporting a diaphragm, and a second recess spaced from said first recess, said second recess being of smaller cross section than said first recess and being substantially bottomed by a second upward facing surface for supporting a pressure sensing element, wherein said first recess and said second recess form a unitary stepped cavity in said body face surface; mounting said pressure sensing element on said second surface; making electrical connections to said pressure sensing element; substantially filling said second recess below the face portion with a non-gaseous pressure transfer medium; and pouring a flexible diaphragm in contact with said pressure transfer medium and said first surface, wherein said first surface is substantially level with the first face, wherein said diaphragm material forms a substantially impermeable barrier having a first, outward facing surface and a second surface facing said pressure transfer material, and wherein said diaphragm material does not shrink upon curing thereof and characterized by the absence of chemical interaction between the pressure transfer material and the diaphragm.

Claim 18

A measurand sensor produced by the method comprising the steps of: providing a body having in a first face surface thereof a first recess of given cross section, bottomed peripherally by a first upward facing surface for supporting a diaphragm, and a second recess spaced from said first recess, said second recess being of smaller cross section than said first recess and being substantially bottomed by a second upward facing surface for supporting a pressure sensing element, wherein said first recess and said second recess form a unitary stepped cavity in said body face surface; mounting said pressure sensing element on said second surface; making electrical connections to said pressure sensing element; substantially filling said second recess below the face portion with a non-gaseous pressure transfer medium; and pouring a flexible diaphragm in contact with said pressure transfer medium and said first surface, wherein said first surface is substantially level with the first face, wherein said diaphragm material forms a substantially impermeable barrier having a first, outward facing surface and a second surface facing said pressure transfer material, and wherein said diaphragm material does not shrink upon curing thereof and characterized by the absence of chemical interaction between the pressure transfer material and the diaphragm.

Claim 19

The sensor of claim 14 wherein said outward facing surface is level with the body first face within 5 mils.

Claim 20

The sensor of claim 14 wherein said outward facing surface is level with the body first face within 3 mils.

Claim 21

The sensor of claim 14 wherein said outward facing surface is level with the body first face within 1 mil.

Claim 22

The measurand sensor, comprising: a) a body having in a first face surface thereof a first recess of given cross section, bottomed peripherally by means for supporting a diaphragm comprising a first upward facing surface, and a second recess displaced from said first recess, said second recess being of smaller cross section than said first recess and being substantially bottomed by a second upward facing surface for supporting a pressure sensing element, wherein said first recess and said second recess form a unitary stepped cavity in said body face surface, b) signal communicating electrical pathways into said cavity, c) a sensing element connected to the communicating pathways, and d) a non-hardening flexible diaphragm which is pourable in place, e) means for i) isolating said sensing element from said measurand, ii) for transferring said measurand to said element, and iii) for supporting said diaphragm, comprising a non-hardening pressure transfer medium, wherein the pressure transfer medium and the diaphragm material are both unbonded and chemically incompatible, and said pressure transfer medium and said diaphragm material are capable of transferring said measurand to said sensing element.

Claim 23

The measurand sensor, comprising: a) a body having in a first face surface thereof a first recess of given cross section, bottomed peripherally by means for supporting a diaphragm comprising a first upward facing surface, and a second recess displaced from said first recess, said second recess being of smaller cross section than said first recess and being substantially bottomed by a second upward facing surface for supporting a pressure sensing element, wherein said first recess and said second recess form a unitary stepped cavity in said body face surface, b) signal communicating electrical pathways into said cavity, c) a sensing element connected to the communicating pathways, and d) a non-hardening flexible diaphragm which is pourable in place, e) means for i) isolating said sensing element from said measurand, ii) for transferring said measurand to said element, and iii) for supporting said diaphragm, comprising a non-hardening pressure transfer medium, wherein the pressure transfer medium and the diaphragm material are both unbonded and chemically incompatible, and said pressure transfer medium and said diaphragm material are capable of transferring said measurand to said sensing element.

Claim 24

The sensor of claim 18, wherein the diaphragm is fluorosilicone based material.

Claim 25

The sensor of claim 18, wherein the diaphragm is dimethyl silicone based material.

Claim 26

The sensor of claim 18, further including means for transferring a second measurand to the sensing element.

Claim 27

The sensor of claim 18, wherein the sensing element comprises a solid state sensor element.

Claim 28

The sensor of claim 18 wherein said first recess is of a lesser volume than said second cavity.

Claim 29

The sensor of claim 18 wherein the volume of said first recess substantially includes the diaphragm material.

Claim 30

The sensor of claim 18 wherein said diaphragm forms a substantially impermeable barrier having an outward facing surface and an inward facing surface facing and supported by said pressure transfer medium at its center and by said first upward facing surface at its periphery.

Claim 31

The sensor of claim 25 wherein said outward facing surface is recessed below the body first face.

Claim 32

The sensor of claim 25 wherein said outward facing surface is substantially level with the body first face.

Claim 33

The sensor of claim 25 wherein said outward facing surface is level with the body first face within 5 mils.

Claim 34

The sensor of claim 25 wherein said outward facing surface is level with the body first face within 3 mils.

Claim 35

The sensor of claim 25 wherein said outward facing surface is level with the body first face within 1 mil.

Claim 36

The sensor of claim 21 wherein said body includes a second face opposite said first face, and said means for communicating a second measurand to the sensing element includes an aperture in said second face and a communicating passageway into said second recess.

Claim 37

The sensor of claim 18, wherein the pressure transfer medium is a dimethyl silicone based material.

Claim 38

The sensor of claim 18, wherein the pressure transfer medium is a fluorosilicone material.

Claim 39

The sensor of claim 18, further including an opaquing agent to isolate the sensing element from light.