EP-4739987-A1 - HIGH TEMPERATURE CO-FIRED CERAMIC PRESSURE SENSOR

Abstract

A pressure sensor can include a base formed from high-temperature co-fired ceramic (HTCC) material with an inner surface, a flexure plate formed from HTCC material and positioned over the surface of the base, with the flexure plate including an inner surface that faces the surface of the base and an outer surface, and a spacer having a thickness and implemented between the base and the flexure plate to define a space between the inner surfaces of the base and flexure plate. The pressure sensor can further include first and second electrodes implemented on the inner surfaces of the base and the flexure plate, respectively, to form a capacitor, such that flexing of the flexure plate due to pressure applied to the outer surface of the flexure plate results in a detectable change in capacitance of the capacitor.

Inventors

• HUTCHINGS, Kent
• WANG, ZUOYI
• LIN, ROBERT
• ZHANG, III, Qingqi
• GALVAN, Antonio
• MORGAN, Cody

Assignees

• Bourns, Inc.

Dates

Publication Date

20260513

Application Date

20240714

Claims (20)

1. 1. A pressure sensor comprising: a base formed from high-temperature co-fired ceramic (HTCC) material and including an inner surface; a flexure plate formed from HTCC material and positioned over the surface of the base, the flexure plate including an inner surface that faces the surface of the base and an outer surface; a spacer having a thickness and implemented between the base and the flexure plate to define a space between the inner surfaces of the base and flexure plate; and first and second electrodes implemented on the inner surfaces of the base and the flexure plate, respectively, to form a capacitor, such that flexing of the flexure plate due to pressure applied to the outer surface of the flexure plate results in a detectable change in capacitance of the capacitor.
2. 2. The pressure sensor of Claim 1 , wherein the HTCC material of the base is same as the HTCC material of the flexure plate.
3. 3. The pressure sensor of Claim 2, wherein the HTCC material of the base and the flexure plate includes polymorphic phase HTCC material.
4. 4. The pressure sensor of Claim 3, wherein the polymorphic phase HTCC material includes alumina.
5. 5. The pressure sensor of Claim 4, wherein the polymorphic phase HTCC material includes at least 96% alumina.
6. 6. The pressure sensor of Claim 1 , wherein the spacer is formed from HTCC material.
7. 7. The pressure sensor of Claim 6, wherein the base, the flexure plate and the spacer are formed from a plurality of pieces of pre-fired HTCC and joined together to provide no discernible joint interface(s).
8. 8. The pressure sensor of Claim 7, wherein the base, the flexure plate and the spacer are formed from separate respective pieces of pre-fired HTCC.
9. 9. The pressure sensor of Claim 7, wherein the base and the spacer are formed from a single piece of pre-fired HTCC, and the flexure plate is formed from another piece of pre-fired HTCC.
10. 10. The pressure sensor of Claim 7, wherein the base is formed from a single piece of pre-fired HTCC, and the flexure plate and the spacer are formed from another piece of pre-fired HTCC.
11. 11 . The pressure sensor of Claim 7, wherein the base and a first portion of the spacer are formed from a single piece of pre-fired HTCC, and the flexure plate and a second portion of the spacer are formed from another piece of pre-fired HTCC.
12. 12. The pressure sensor of Claim 7, wherein the plurality of pieces of HTCC are joined by co-firing of the plurality of pieces of HTCC.
13. 13. The pressure sensor of Claim 12, wherein the co-fired joint between the plurality of pieces of HTCC includes interdiffusion of elements between the HTCC pieces joined together.
14. 14. The pressure sensor of Claim 1 , wherein the spacer is formed from an unfired HTCC on the inner surface of the base.
15. 15. The pressure sensor of Claim 14, wherein the base and the flexure plate are formed respective pieces of pre-fired HTCC.
16. 16. The pressure sensor of Claim 15, wherein the base, the flexure plate and the spacer are joined by co-firing.
17. 17. A method for manufacturing a pressure sensor, the method comprising: forming or providing a base assembly including pre-fired ceramic material and an inner surface; forming a first electrode on the inner surface of the base assembly; forming or providing a flexure assembly including pre-fired ceramic material, an inner surface and an outer surface; forming a second electrode on the inner surface of the flexure assembly; and co-firing the flexure assembly with the base assembly to provide a spacer having a thickness to define a space between the inner surfaces of the base assembly and the flexure assembly, and such that the first and second electrodes form a capacitor, such that flexing of the flexure assembly due to pressure applied to the outer surface of the flexure assembly results in a detectable change in capacitance of the capacitor.
18. 18. The method of Claim 17, wherein the pre-fired ceramic material of the flexure assembly is formed by a high-temperature firing process, and the pre-fired ceramic material of the base assembly is formed by a high-temperature firing process.
19. 19. The method of Claim 17, wherein the pre-fired ceramic material of the base assembly is same as the pre-fired ceramic material of the flexure assembly.
20. 20. The method of Claim 19, wherein the pre-fired ceramic material of the base assembly and the flexure assembly includes polymorphic phase high-temperature co-fired ceramic (HTCC) material.

Description

HIGH TEMPERATURE CO-FIRED CERAMIC PRESSURE SENSOR CROSS-REFERENCE TO RELATED APPLICATION(S) [0001] This application claims priority to U.S. Provisional Application No. 63/513,853 filed July 14, 2023, entitled HIGH TEMPERATURE CO-FIRED CERAMIC PRESSURE SENSOR, the disclosure of which is hereby expressly incorporated by reference herein in its respective entirety. BACKGROUND Field [0002] The present disclosure relates to high temperature co-fired ceramic pressure sensors Description of the Related Art [0003] A pressure sensor can include a base portion and a deformable portion implemented relative to the base portion to thereby provide a gap therebetween and an associated capacitance. If the deformable portion moves relative to the base portion due to application of pressure, the resulting change in capacitance can be measured. Accordingly, the applied pressure can be measured from the measure capacitance. SUMMARY [0004] In some implementations, the present disclosure relates to a pressure sensor that includes a base formed from high-temperature co-fired ceramic (HTCC) material and including an inner surface, a flexure plate formed from HTCC material and positioned over the surface of the base, with the flexure plate including an inner surface that faces the surface of the base and an outer surface, and a spacer having a thickness and implemented between the base and the flexure plate to define a space between the inner surfaces of the base and flexure plate. The pressure sensor further includes first and second electrodes implemented on the inner surfaces of the base and the flexure plate, respectively, to form a capacitor, such that flexing of the flexure plate due to pressure applied to the outer surface of the flexure plate results in a detectable change in capacitance of the capacitor. [0005] In some embodiments, the HTCC material of the base can be same as the HTCC material of the flexure plate. In some embodiments, the HTCC material of the base and the flexure plate can include polymorphic phase HTCC material. In some embodiments, the polymorphic phase HTCC material can include alumina, such as at least 96% alumina. [0006] In some embodiments, the spacer can be formed from HTCC material. In some embodiments, the base, the flexure plate and the spacer can be formed from a plurality of pieces of pre-fired HTCC and joined together to provide no discernible joint interface(s). In some embodiments, the base, the flexure plate and the spacer can be formed from separate respective pieces of pre-fired HTCC. In some embodiments, the base and the spacer can be formed from a single piece of pre-fired HTCC, and the flexure plate can be formed from another piece of pre-fired HTCC. In some embodiments, the base can be formed from a single piece of pre-fired HTCC, and the flexure plate and the spacer can be formed from another piece of pre-fired HTCC. In some embodiments, the base and a first portion of the spacer can be formed from a single piece of pre-fired HTCC, and the flexure plate and a second portion of the spacer can be formed from another piece of pre-fired HTCC. [0007] In some embodiments, the plurality of pieces of HTCC can be joined by co-firing of the plurality of pieces of HTCC. The co-fired joint between the plurality of pieces of HTCC can include interdiffusion of elements between the HTCC pieces joined together. [0008] In some embodiments, the spacer can be formed from an unfired HTCC on the inner surface of the base, the base and the flexure plate can be formed respective pieces of pre-fired HTCC. The base, the flexure plate and the spacer can be joined by co-firing. [0009] In some implementations, the present disclosure relates to a method for manufacturing a pressure sensor. The method includes forming or providing a base assembly including pre-fired ceramic material and an inner surface, and forming a first electrode on the inner surface of the base assembly. The method further includes forming or providing a flexure assembly including pre-fired ceramic material, an inner surface and an outer surface and forming a second electrode on the inner surface of the flexure assembly. The method further includes co-firing the flexure assembly with the base assembly to provide a spacer having a thickness to define a space between the inner surfaces of the base assembly and the flexure assembly, and such that the first and second electrodes form a capacitor, such that flexing of the flexure assembly due to pressure applied to the outer surface of the flexure assembly results in a detectable change in capacitance of the capacitor. [0010] In some embodiments, the pre-fired ceramic material of the flexure assembly can be formed by a high-temperature firing process, and the pre-fired ceramic material of the base assembly can be formed by a high-temperature firing process. [0011] In some embodiments, the pre-fired ceramic material of the base assembly can be same as the pre-fired ceramic material of the fl