High-temperature co-fired ceramic pressure sensor

Abstract

The pressure sensor may include: a base having an inner surface formed of a high temperature co-fired ceramic (HTCC) material; a flexure plate formed of an HTCC material over the base surface, the flexure plate including an inner surface facing the base surface, and an outer surface; and a spacer having a thickness and implemented between the base and the flexplate to define a space between the inner surface of the base and the flexplate. The pressure sensor may also include first and second electrodes implemented on the inner surface of the base and the inner surface of the flexplate, respectively, to form a capacitor such that deflection of the flexplate due to pressure applied to the outer surface of the flexplate results in a detectable change in capacitance of the capacitor.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 513,853, filed July 14, 2023, entitled “HIGH TEMPERATURE CO-FIREDCERAMIC PRESSURE SENSOR,” the disclosure of which is incorporated herein by reference in its entirety and expressly combined. Technical Field

[0003] This application relates to high-temperature co-fired ceramic pressure sensors. Background Technology

[0004] A pressure sensor may include a base and a deformable portion relative to the base, thereby providing a gap and associated capacitance between them. If the deformable portion moves relative to the base portion due to applied pressure, the resulting change in capacitance can be measured. Therefore, the applied pressure can be measured from the capacitance. Summary of the Invention

[0005] In some embodiments, this application relates to a pressure sensor comprising: a base formed of a high-temperature co-fired ceramic (HTCC) material and including an inner surface; a flexural plate formed of HTCC material and positioned above a surface of the base, wherein the flexural plate includes an inner surface and an outer surface facing the surface of the base; and a spacer having a thickness and formed between the base and the flexural plate to define a space between the inner surface of the base and the inner surface of the flexural plate. The pressure sensor further includes a first electrode and a second electrode respectively formed on the inner surfaces of the base and the flexural plate to form a capacitor, such that a detectable change in the capacitance of the capacitor occurs due to deflection of the flexural plate caused by pressure applied to the outer surface of the flexural plate.

[0006] In some embodiments, the HTCC material of the base may be the same as the HTCC material of the flexural plate. In some embodiments, the HTCC materials of the base and the flexural plate may include a polycrystalline phase HTCC material. In some embodiments, the polycrystalline phase HTCC material may include alumina, such as at least 96% alumina.

[0007] In some embodiments, the spacer may be formed of HTCC material. In some embodiments, the base, the flexural plate, and the spacer may be formed from a plurality of pre-fired HTCC pieces and joined together to provide an indistinguishable joint interface. In some embodiments, the base, the flexural plate, and the spacer may be formed from individual corresponding pieces of pre-fired HTCC. In some embodiments, the base and the spacer may be formed from a single piece of pre-fired HTCC, and the flexural plate may be formed from another piece of pre-fired HTCC. In some embodiments, the base may be formed from a single piece of pre-fired HTCC, and the flexural plate and the spacer may be formed from another piece of pre-fired HTCC. In some embodiments, a first portion of the base and the spacer may be formed from a single piece of pre-fired HTCC, and a second portion of the flexural plate and the spacer may be formed from another piece of pre-fired HTCC.

[0008] In some embodiments, the plurality of HTCCs can be joined by co-firing the plurality of HTCCs. Co-firing joining between the plurality of HTCCs may include interdiffusion of elements between the joined HTCCs.

[0009] In some embodiments, the spacer may be formed from unburned HTCC on the inner surface of the base, and the base and the flexural plate may be formed from corresponding pre-burned HTCC pieces. The base, the flexural plate, and the spacer may be co-fired together.

[0010] In some embodiments, this application relates to a method for manufacturing a pressure sensor. The method includes forming or providing a base assembly comprising a 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 flexural assembly comprising a pre-fired ceramic material, an inner surface, and an outer surface, and forming a second electrode on the inner surface of the flexural assembly. The method also includes co-firing the flexural assembly with the base assembly to provide a spacer whose thickness defines the space between the inner surface of the base assembly and the inner surface of the flexural assembly, and such that the first and second electrodes form a capacitor, such that the flexural assembly flexes due to pressure applied to the outer surface of the flexural assembly, resulting in a detectable change in the capacitance of the capacitor.

[0011] In some embodiments, the pre-fired ceramic material of the flexural assembly can be formed by a high-temperature firing process, and the pre-fired ceramic material of the base assembly can also be formed by a high-temperature firing process.

[0012] In some embodiments, the pre-fired ceramic material of the base assembly may be the same as the pre-fired ceramic material of the flexural assembly. In some embodiments, the pre-fired ceramic materials of the base assembly and the flexural assembly may include polycrystalline phase high-temperature co-fired ceramic (HTCC) materials. The polycrystalline phase HTCC material may include alumina, such as at least 96% alumina.

[0013] In some embodiments, the spacer may be formed of a high-temperature co-fired ceramic (HTCC) material. In some embodiments, the base assembly, the flexural assembly, and the spacer may be formed from a plurality of pre-fired HTCC pieces and joined together to provide an indistinguishable joint interface. In some embodiments, the base assembly, the flexural assembly, and the spacer may be formed from individual corresponding pieces of pre-fired HTCC. In some embodiments, the base assembly including the spacer may be formed from a single piece of pre-fired HTCC, and the flexural assembly may be formed from another piece of pre-fired HTCC. In some embodiments, the base assembly may be formed from a single piece of pre-fired HTCC, and the flexural assembly including the spacer may be formed from another piece of pre-fired HTCC. In some embodiments, the base assembly having a first portion of the spacer may be formed from a single piece of pre-fired HTCC, and the flexural assembly having a second portion of the spacer may be formed from another piece of pre-fired HTCC.

[0014] For the purpose of summarizing this application, certain aspects, advantages, and novel features of the invention have been described herein. It should be understood that not all such advantages may be achieved according to any particular embodiment of the invention. Therefore, the invention may be embodied or practiced in a manner that realizes or optimizes one or more advantages as taught herein, without necessarily realizing other advantages as taught or suggested herein. Attached Figure Description

[0015] Figure 1A A side sectional view of the pressure sensor 100 is shown, and Figure 1B and Figure 1C As shown Figure 1A The sectional view shown. Figure 2A and Figure 2B It shows how it can be used Figure 1A An example of a pressure sensor used to measure pressure.

[0016] Figure 3A A first example of a capacitive pressure sensor is shown.

[0017] Figure 3B A second example of a capacitive pressure sensor is shown.

[0018] Figure 3C A third example of a capacitive pressure sensor is shown.

[0019] Figure 3D A fourth example of a capacitive pressure sensor is shown.

[0020] Figure 3E The fifth example of a capacitive pressure sensor is shown.

[0021] Figures 4A to 4C It shows the relationship with Figure 3A , Figure 3B and Figure 3C Examples related to the first, second, and third examples.

[0022] Figures 4D to 4G It shows the relationship with Figure 3D and Figure 3E Examples related to the fourth and fifth examples.

[0023] Figures 5A to 5F It shows the relationship with Figure 3A Other examples related to the first example.

[0024] Figures 6A to 6C It shows the relationship with Figure 3A Other examples related to the first example.

[0025] Figures 7A to 7D It shows the relationship with Figure 3A Other examples related to the first example.

[0026] Figure 8A and Figure 8B Examples of capacitance change (ΔC) of two capacitive pressure sensors as a function of applied pressure are shown, based on the examples in Figures 5 to 7.

[0027] Figures 9A to 9F It shows the relationship with Figure 3B Other examples related to the second example.

[0028] Figures 10A to 10G It shows the relationship with Figure 3C Other examples related to the third example.

[0029] Figures 11A to 11F It shows the relationship with Figure 3D Other examples related to the fourth example.

[0030] Figures 12A to 12C It shows the relationship with Figure 3D Other examples related to the fifth example. Detailed Implementation

[0031] The headings provided herein (if any) are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.

[0032] Figure 1A A side sectional view of the pressure sensor 100 is shown, and Figure 1B and Figure 1C As shown Figure 1A The sectional view shown. Figure 2A and Figure 2B It shows how it can be used Figure 1A An example of a pressure sensor used to measure pressure.

[0033] refer to Figures 1A to 1C The pressure sensor 100 is shown to typically include a base portion 130, a deformable portion 110, and a support portion 120, the support portion 120 providing support for the deformable portion 110 relative to the base portion 130, thereby defining a volume 106. Therefore, the deformable portion 110 is shown to include an outer surface 112 for receiving forces associated with pressure (e.g., as shown in the image). Figure 2B (middle) and its inner surface 114 on which the first electrode 14 is disposed. The base portion 130 is shown to include a mounting for the pressure sensor 100 (e.g., as Figure 2B The outer surface 132 of the middle part and the inner surface 134 on which the second electrode 142A is disposed. The support portion 120 is shown as including the inner surface 122 that partially defines the volume 106.

[0034] Configured as described above, a gap dimension g is provided between the first electrode 141 and the second electrode 142, forming a parallel-plate capacitor with a capacitance value of C ≈ ε(A / g), where A is, for example, the area of ​​the second electrode 142, and g is the gap dimension between the first electrode 141 and the second electrode 142 (e.g., ...). Figure 1A (as shown), and ε is the dielectric constant of the region between the first electrode 141 and the second electrode 14. This region may be part of a volume 106 filled with a dielectric material such as air.

[0035] refer to Figures 1A to 1C The first electrode 141 is shown electrically connected to the conductive via 151, and the second electrode 142 is shown electrically connected to the conductive via 152. The protection electrode 143 is shown electrically connected to the conductive via 153; however, for the purposes of this discussion, this protection electrode 143 may or may not be used.

[0036] In some embodiments, the base portion 130, the support portion 120, and the deformable portion 110 may be formed of the same material to provide similar thermo / mechanical properties during temperature variations associated with the manufacture and / or operation of the pressure sensor 100. In some embodiments, this same material may be ceramic. In some embodiments, pressure sensing in high-temperature environments can be allowed by using a high-temperature co-fired ceramic (HTCC) material as the same material for the pressure sensor. As an example, HTCC may include alumina.

[0037] In some embodiments, the support portion 120 may begin as a continuous portion of one of the deformable portion 110 and the base portion 130, and be joined to the other of the deformable portion 110 and the base portion 130 by means of diffusion bonding, such as that produced by co-firing of the different portions.

[0038] In some embodiments, the support portion 120 may begin as a separate portion and be joined to the deformable portion 110 and the base portion 130 by a corresponding combination (such as diffusion bonding produced by co-firing of different portions).

[0039] refer to Figure 2A and Figure 2B , Figures 1A to 1C The pressure sensor 100 is shown mounted on surface 200 to allow measurement of pressure in the area surrounding surface 200. Figure 2A In this context, it is assumed that a base pressure exists in this region. Therefore, some base pressure will be applied to the pressure sensor 100, including pressure on the outer surface 112 of the deformable portion 110. In this state, the first electrode 141 and the second electrode 142 are shown separated by a gap size g0, thereby providing a corresponding capacitance C0.

[0040] exist Figure 2B In the diagram, the increased pressure is shown as applied to the pressure sensor 100, including increased pressure (depicted as force F) on the outer surface 112 of the deformable portion 110. In this state, the first electrode 141 and the second electrode 142 are shown separated by a reduced gap size g1, thereby providing increased capacitance C1.

[0041] refer to Figure 2A and Figure 2B It should be noted that in some applications, the capacitor cavity of the pressure sensor 100 may be connected to the atmosphere through, for example, through holes 152 and 153. Such through holes can thus serve as pressure interfaces to the atmosphere (such as ambient atmosphere or some reference pressure atmosphere).

[0042] It should also be noted that in some applications, a vacuum can be applied to the capacitor cavity of the pressure sensor 100, and the through holes 152 and 153 can be sealed. This configuration allows the pressure sensor 100 to measure absolute pressure values.

[0043] refer to Figure 2A and Figure 2B It should also be noted that in some applications, the pressure sensor 100 may or may not be mounted on a surface such as the depicted mounting surface 200.

[0044] In some applications, many industrial processes and applications require or expect pressure measurements in harsh environments. These harsh environments can include a wide range of temperatures and pressures, with rapidly fluctuating operating conditions. Pressure measurements may also be taken in corrosive environments or combustion chambers.

[0045] For the aforementioned applications, pressure sensors typically need to withstand these conditions without deterioration or failure, and also need to be able to accurately sense the pressure range encountered in a given application. Pressure sensors typically utilize various sensing methods, including piezoresistive, strain gauge, and capacitive sensors.

[0046] This article describes an example of a pressure sensor involving the use of parallel plate capacitance, where the distance between the parallel plates changes due to the applied pressure via the mechanical deflection of one of the plates, as described herein with reference to Figures 1 and 2. As stated herein, this capacitance is inversely proportional to the distance between the parallel plates; therefore, the gap between the plates and the mechanical properties of the plates are important design parameters.

[0047] Capacitive sensors can be made from a variety of materials and geometries based on the conditions of a given application (e.g., temperature range, pressure range, and environment). In some embodiments, alumina can be selected as a flexible membrane material for pressure sensors due to its ability to withstand high temperatures, high resistance, chemical inertness, and good mechanical properties.

[0048] To form a parallel plate structure, two halves can be fabricated, corresponding electrodes can be formed on these two halves, and the two components can be joined together. In some embodiments, the joining of alumina-based devices can be achieved using copper brazing, glass, and ceramic-glass hybrids, which are typically used in low-temperature co-fired ceramics (LTF). It should be noted that the temperature a given sensor will experience typically determines the materials used to join the two halves. However, joining different materials or using a second material to join the two halves can lead to stress in the device due to thermal expansion mismatch; and this stress can cause deterioration and / or failure of the mechanical seals and flexible plates during the fabrication and use of the device.

[0049] It should be noted that the sensitivity of a capacitive pressure sensor is related to the gap between the two parallel plates. Generally, a smaller gap provides improved sensitivity.

[0050] In some embodiments, this application relates to a capacitive pressure sensor having a very small gap whose dimensions are controllable during manufacturing. In some embodiments, such a capacitive pressure sensor may include a high-temperature co-fired ceramic (HTCC) material to obtain improved thermal and mechanical properties compared to a capacitive pressure sensor having an LTCC material.

[0051] This article describes several examples of capacitive pressure sensors with the aforementioned properties. Figure 3A A first example of a capacitive pressure sensor is shown, and Figures 4A to 4C Figures 5 to 7 illustrate how this pressure sensor is manufactured. Figure 3B A second example of a capacitive pressure sensor is shown, and Figures 4A to 4C Figure 9 shows an example of how such a pressure sensor can be manufactured. Figure 3C A third example of a capacitive pressure sensor is shown, and Figures 4A to 4C Figure 10 shows an example of how such a pressure sensor can be manufactured. Figure 3D A fourth example of a capacitive pressure sensor is shown, and Figures 4D to 4G Figure 11 shows an example of how such a pressure sensor can be manufactured. Figure 3E A fifth example of a capacitive pressure sensor is shown, and Figures 4D to 4G Figure 12 shows an example of how such a pressure sensor can be manufactured.

[0052] Figure 3A In some embodiments, it is shown that Figures 1A to 1C The pressure sensor 100 can be formed from three independent pre-calcined alumina parts. More specifically, the pre-calcined alumina part assembly 200 may include: a first pre-calcined alumina part 201 configured as a deformable portion 110, a second pre-calcined alumina part 202 configured as a support portion 120, and a third pre-calcined alumina part 203 configured as a base portion 130.

[0053] exist Figure 3A In the example, the second pre-calcined alumina element 202 may also be referred to herein as a pre-calcined alumina gasket. In some embodiments, such a pre-calcined alumina gasket may have a thickness selected to provide a desired gap between parallel plates realized on the opposing surfaces of the first pre-calcined alumina element 201 and the third pre-calcined alumina element 203.

[0054] Figure 3B In some embodiments, it is shown that Figure 1A The pressure sensor 100 of Figure 10 can be formed from two separate pre-calcined alumina parts. More specifically, the assembly 200 of the pre-calcined alumina parts can include a first pre-calcined alumina part 211 configured as a deformable portion 110 and a second pre-calcined alumina part 212 configured to include a support portion 120 and a base portion 130.

[0055] Figure 3BAs shown in some embodiments, the support portion 120 of the second pre-calcined alumina member 212 can be formed by providing a recess of depth, such that the periphery of the recess provides the support portion 120. The depth of the recess can be selected to provide a desired gap between parallel plates on the opposing surfaces of the first pre-calcined alumina member 211 and the bottom surface of the recess of the second pre-calcined alumina member 212.

[0056] Figure 30 illustrates some embodiments. Figures 1A to 1C The pressure sensor 100 can be formed from two pre-fired alumina elements connected by unfired alumina spacers. More specifically, the alumina element assembly 200 can include a pre-fired alumina element 221 configured as a deformable portion 110, and an alumina assembly 222 configured to include a support portion 120 and a base portion 130.

[0057] refer to Figure 3C In some embodiments, the support portion 120 of the alumina assembly 222 may be formed from unfired alumina spacer screen printed on a prefired alumina component forming the base portion 130. It should be noted that in some embodiments, some or all of the unfired components may be fabricated using various ceramic manufacturing processes, such as dry pressing, tape casting, roll forming, etc. It should also be noted that thick-film screen printing can offer benefits including control over thickness and the ability to form thinner structures.

[0058] Figure 3C In some embodiments, the support portion 120 formed by the unburned alumina spacer is shown to provide a recess with a depth. Therefore, this depth of the recess, associated with the thickness of the unburned alumina spacer, can be selected to achieve a desired gap between the parallel plates on the opposing surfaces of the pre-burned alumina member 221 and the base portion 130 of the alumina assembly 200.

[0059] Figure 3D In some embodiments, it is shown that Figures 1A to 1C The pressure sensor 100 can be formed from two separate pre-fired alumina parts. More specifically, the pre-fired alumina part assembly 200 can include a first pre-fired alumina part 231 configured to include a deformable portion 110 and a support portion 120, and a second pre-fired alumina part 232 configured to include a base portion 130.

[0060] Figure 3DAs shown in some embodiments, the support portion 120 of the first pre-calcined alumina member 231 can be formed by providing a recess of depth, such that the periphery of the recess provides the support portion 120. The depth of the recess can be selected to achieve a desired gap between the parallel plates on the facing surfaces of the bottom plates of the recesses of the first pre-calcined alumina member 231 and the second pre-calcined alumina member 232. It should be noted that in some embodiments, when a reduced thickness of the flexural membrane (the deformable portion 110 of the first pre-calcined alumina member 231) is desired, to increase the amount of deflection compared to a thicker membrane under a given pressure, this can be achieved. Figure 3D Examples.

[0061] Figure 3E Figures 1a to 1b show some embodiments. Figure 1C The pressure sensor 100 can be formed from two separate pre-fired alumina parts. More specifically, the pre-fired alumina part assembly 200 can include a first pre-fired alumina part 241 configured to include a deformable portion 110 and a support portion 120, and a second pre-fired alumina part 242 configured to include a base portion 130 and a support portion 120.

[0062] Figure 3E As shown in some embodiments, a corresponding portion of the support portion 120 of the first pre-calcined alumina member 241 can be formed by providing a first recess of depth, such that the periphery of the first recess provides the corresponding portion of the support portion 120. Similarly, a corresponding portion of the support portion of the second pre-calcined alumina member 242 can be formed by providing a second recess of depth, such that the periphery of the second recess provides the corresponding portion of the support portion 120. In some embodiments, the depths of the first and second recesses can be selected to provide a desired gap between parallel plates formed on opposing surfaces of the bottom surfaces of the first recess of the first pre-calcined alumina member 241 and the second recess of the second pre-calcined alumina member 242.

[0063] Figures 4A to 4C and Figures 4D to 4G The first pre-fired alumina part (e.g.,) that can be used to manufacture a capacitive pressure sensor is shown. Figures 3A to 3C 201, 211, 221 and Figure 3D and Figure 3E of Figure 3D and Figure 3E The various process stages of (231, 241). More specifically, in Figures 4A to 4C Pre-fired alumina parts formed in the process can be used as Figures 3A to 3C The deformable part 110 in each of the three examples; and having in Figures 4D to 4G The pre-fired alumina parts with recesses formed during the process can be used as components that include deformable and support parts.

[0064] Figure 4A A side view of a pre-fired alumina ceramic disc 300 is shown, its thickness chosen to allow for disc deformation when the disc is supported on one side of its perimeter and subjected to pressure. The formation of such a pre-fired alumina ceramic disc and examples using other HTCC materials are described in more detail herein.

[0065] Figure 4B A side view of component 308 is shown, in which electrode 302 and electrical coupling tab 304 are formed on surface 306 of pre-fired alumina ceramic disk 300. Figure 40 shows... Figure 4B A plan view of component 308. In some embodiments, electrodes 302 and electrical coupling tabs 304 may be formed on the surface 306 of a pre-fired alumina ceramic disk 300 by a screen printing process, followed by a drying process.

[0066] Figure 4D A side view of a pre-fired alumina ceramic disk 310 is shown, having a thickness selected to allow for the formation of recesses, such that the deformable portion defined by the recesses is supported by the periphery of the recesses. The formation of such a pre-fired alumina ceramic disk and the use of other HTCC materials are described in more detail herein.

[0067] Figure 4E A side view of the stage is shown, in which a recess 319 is formed to provide a recess having a depth d10 from the upper surface 316 of the disk 310 to the bottom surface 311 of the recess 319. In some embodiments, such a recess can be formed by, for example, a dry pressing process or laser processing. The resulting recess is shown as being defined by the bottom surface 311 and a periphery surrounding the recess 319, wherein the periphery has a surface 316, which will be used for contact with a pre-fired alumina ceramic component including a base portion (e.g., Figure 3D 232 or Figure 3D Surface fit of 242).

[0068] exist Figure 4E In the example, conductive vias 313 and 315 are shown. More specifically, conductive via 313 is shown to extend from the bottom surface 311 of recess 311 to the other side of disk 310, and conductive via 315 is shown to extend from the peripheral surface 316 to the other side of disk 310. In some embodiments, such vias may be formed similarly to any of the example processes described herein.

[0069] Figure 4F Component 318 is shown, wherein electrodes 312 and electrical coupling tabs 314 are formed in Figure 4E On the bottom surface 311 of the recess 319 of the pre-fired alumina ceramic disc 310. Figure 4G It shows Figure 4FA plan view of component 318. In some embodiments, electrodes 312 and electrical coupling tabs 314 can be formed by a screen printing process on the bottom surface 311, followed by a drying process.

[0070] exist Figure 4F In the example, conductive path 317 is shown formed on the side of disk 310 opposite to surface 316 and recess 319. In some embodiments, such conductive path can be formed by a process similar to that used to form coupling tab 314, thereby providing an electrical connection between electrode 312 and the end of conductive via 315 at surface 316.

[0071] Example 1:

[0072] Figures 5 through 7 illustrate various views and stages of the process for manufacturing the base portion of a capacitive pressure sensor. This base portion can be, for example... Figure 1A The base portion 130. In some embodiments, the base portion formed in the examples of Figures 5 to 7 can be used as... Figure 3A The base portion 130 in the example.

[0073] Figure 5A A side view of a pre-fired alumina ceramic substrate 400 is shown, the thickness of which is chosen to provide basic functionality for a corresponding capacitive pressure sensor. This paper describes in more detail how such a pre-fired alumina ceramic substrate is formed and provides examples of using other HTCC materials.

[0074] Figure 5B The stage in which through-holes 401, 402, and 403 are formed to provide component 404 is illustrated. In some embodiments, such through-holes can be formed, for example, by mechanical or laser drilling through the ceramic substrate 400. In some embodiments, the substrate 400 can be formed using a dry pressing process, and this process can include forming through-holes 401, 402, and 403. In some embodiments, the substrate can be formed from a cast and rolled green ceramic strip, and the through-holes (such as through-holes 401, 402, and 403) can be stamped into such strip prior to the firing process.

[0075] Figure 5C A stage is shown, in which Figure 5B The through holes 401, 402, and 403 are filled with conductive material to form corresponding conductive through holes 411, 412, and 413. Figure 5C In the diagram, base electrode 406 and guard electrode 408 are shown to be formed on surface 410 of ceramic base 400 in order to form assembly 414.

[0076] exist Figure 5CIn the example, conductive vias 411, 412, and 413 can be formed, for example, by screen printing to fill vias 401, 402, and 403, followed by vacuuming to draw metallic ink into the vias and coat the surface of the vias. High-temperature metals such as platinum and tungsten can be used for such conductive vias to accommodate the high temperatures involved in diffusion bonding / co-firing processes.

[0077] In some embodiments, the base electrode 406 and the protective electrode 408 can be formed by a screen printing process on the surface 410 of the ceramic base 400, followed by a drying process. Thus, conductive via 412 is shown as electrically connected to the base electrode 406, conductive via 413 is shown as electrically connected to the protective electrode 408, and conductive via 411 is configured to become electrically connected to the deformable portion (e.g., when the deformable portion engages with the completed base portion) when the deformable portion is in contact with the deformable portion. Figure 4B and Figure 4C In the 302, the electrode is connected to the conductive contact 304.

[0078] exist Figure 5C In the example, it should be noted that a protective electrode may or may not be used.

[0079] Figure 5D A stage is shown, in which Figure 4B and Figure 4C Component 308 and Figure 5C The component 414 is assembled with the gasket component 500 therebetween to provide component 416. Figures 7A to 7D An example of how this gasket assembly 500 can be manufactured is shown.

[0080] refer to Figure 5D Component 308 is shown as including providing electrodes ( Figure 4B and Figure 4C Surface 306 of (302) is arranged such that a peripheral portion of surface 306 can engage with the first surface 501 of gasket assembly 500. Similarly, assembly 414 is shown to include providing electrodes ( Figure 5C Surface 410 of 406, 408) is such that the peripheral portion of surface 410 can engage with the second surface 502 of gasket assembly 500.

[0081] In some embodiments, at least the mating portion of the surface 306 of component 308, the first surface 501 and the second surface 502 of gasket component 500, and the surface 410 of component 414 may be configured to allow co-firing at high temperatures.

[0082] Figure 5E A stage is shown, in which Figure 5D Components 308, 500, and 414 are joined to provide component 422. More specifically, the first surface of gasket assembly 500 ( Figure 5D501) is shown engaging with surface 306 of component 308 to provide a first interface region 418, and the second surface 502 of gasket component 500 is shown engaging with surface 410 of component 414 to provide a second interface region 420. Figure 6A An enlarged view of interface areas 418 and 420 is shown.

[0083] refer to Figure 5E It should be noted that the electrode 302 of component 308 is now electrically connected to the conductive via 411 of component 414 through the conductive tab 304 of component 308 and the conductive via 511 of gasket component 500.

[0084] Figure 5F A stage is shown, in which Figure 5E Components 308, 500, and 414 have been co-fired at high temperature to provide component 428. This component (428) is similar to Figure 1A The capacitive pressure sensor 100; therefore, Figure 5F Component 428 in the code is also indicated as 100.

[0085] exist Figure 5F In the middle, previously respectively Figure 5E The regions of the first interface region 418 and the second interface region 420 are designated as bonding or co-firing regions 424 and 426. Figure 6B An enlarged view of the bonding or co-firing regions 424 and 426 is shown.

[0086] refer to Figures 5A to 5F , Figure 6A and Figure 6B It should be noted that the HTCC process allows the resulting capacitive pressure sensor to operate at higher temperatures than LTCC devices (e.g., ~1000°C vs. ~600°C). This HTCC pressure sensor also eliminates or significantly reduces stress caused by intermaterial thermal expansion mismatch during manufacturing by fabricating the ceramic component of the sensor from alumina ceramic with polymorphic phase properties. In some embodiments, 96% alumina ceramic material can be used for the ceramic component. It should be noted that in some embodiments, the ceramic component of the HTCC pressure sensor may include other ceramic materials with polymorphic phase properties.

[0087] In some embodiments, the ceramic component of the HTCC pressure sensor may be formed of other ceramic materials with suitable mechanical and electrical properties, including but not limited to zirconium oxide, aluminum nitride, silicon nitride, beryllium oxide, and zirconium oxide toughened alumina (ZTA).

[0088] In some embodiments, the ceramic component for the HTCC pressure sensor can be formed using ceramic processing methods such as dry pressing, roll forming, or tape casting, and then fired at high temperature to produce a dense, impermeable ceramic with the desired mechanical strength and electrical properties.

[0089] In some embodiments, conductive electrodes and dielectric electrodes may be screen-printed onto the corresponding alumina portions and then dried.

[0090] As described in this article, the bonding of ceramic components in an HTCC pressure sensor can be achieved through co-firing at high temperatures. Devices produced by this high-temperature bonding process can operate at 1000°C in reducing or oxidizing atmospheres.

[0091] refer to Figure 6A In the enlarged view, it should be noted that in the first interface region 418 and the second interface region 420, the corresponding mating surfaces (306 and 501 for the first interface region 418 and 410 and 502 for the second interface region 420) are configured to allow co-firing boundaries 417, 419. When this co-firing is completed, and as... Figure 6B As shown, the first co-fired boundary 417 and the second co-fired boundary 419 are no longer distinguishable in the corresponding bonding regions 424 and 426, and the resulting ceramic structure 102 is essentially a single piece.

[0092] Figure 6C A photograph shows a cross-sectional view of the ceramic structure 102 of an actual HTCC pressure sensor manufactured according to the examples in Figures 4 to 7. This HTCC pressure sensor is manufactured as follows.

[0093] Manufacturing HTCC capacitive pressure sensor components, which include a 0.040" (inch) thick bottom alumina plate. Figure 5A 400), alumina spacer gasket (0.010-0.015" thick) Figure 7A 510) and alumina flexible plates (0.010-0.015" thick) Figure 4A (300 in the middle). Spacer gaskets and flexible plates are manufactured by laser cutting 96% alumina substrates with a thickness of ~0.010-0.015". 0.040" thick 96% alumina substrates are laser-cut into bottom alumina plates.

[0094] All the aforementioned alumina components are pre-fired to a density >98%. Conductive electrodes are screen-printed and dried onto the flexure and substrate, and a dielectric layer is printed on top of the conductive electrodes on the substrate to prevent possible short circuits of the sensor under high pressure.

[0095] The three pre-fired alumina parts were then stacked and co-fired at 1600°C for 4 hours, with weights placed on top of the stack to promote bonding.

[0096] exist Figure 6C The fracture cross-section of the obtained HTCC pressure sensor device in the photograph shows excellent bonding in bonding regions 424 and 426, where the bonding boundary is indistinguishable.

[0097] Figures 7A to 7D The various stages of the process that can manufacture a gasket assembly are illustrated. As described herein, such a gasket assembly may also be referred to as a gasket, spacer, or gasket spacer. This gasket spacer is described as being in... Figure 5D Used in the example.

[0098] Figure 7A A side view is shown of a pre-fired alumina ceramic spacer 510 with a thickness selected to provide assembly and capacitance gap functionality for a corresponding capacitive pressure sensor. This document describes in more detail how such a pre-fired alumina ceramic spacer is formed and examples using other HTCC materials.

[0099] Figure 7B The stage in which through-holes 520 are formed to provide component 522 is illustrated. In some embodiments, such through-holes can be formed, for example, by mechanical or laser drilling through ceramic spacers 510. As described herein, through-holes can be formed by green body forming processes including dry pressing. Furthermore, casting and roll forming processes can be used to produce flexible green ceramic films or green ceramic strips, which may have through-holes stamped therein, followed by high-temperature firing to produce dense ceramic with through-holes. It should be noted that green ceramic refers to ceramic components prior to firing or sintering. Green ceramic components typically contain binders and plasticizers added to the powder to enable the powder to be formed into various shapes and to provide sufficient mechanical strength for handling and processing, e.g., via stamping processes.

[0100] Figure 7C A stage is shown in which a hole 504 is formed through a ceramic spacer 510 to provide assembly 524. In some embodiments, such a hole can be formed by, for example, a mechanical punching operation or a laser cutting operation.

[0101] Figure 7D A stage is shown, in which Figure 7C The via 520 is filled with a conductive material to form a conductive via 511 in order to provide component 500. In some embodiments, such conductive vias can be formed by, for example, a screen printing operation. It should be noted that component 500 is similar to Figure 5D The component 500, and therefore can be used to provide component and capacitor gap functions for the corresponding capacitive pressure sensor.

[0102] In some embodiments, the gasket spacer assembly manufactured in the manner described above may be equipped with a selective thickness to control the gap between the two electrodes of the corresponding capacitive pressure sensor. As described herein, this gap between the electrodes may depend on the material applied to the deformable or flexible assembly ( Figure 4B and Figure 4C The pressure of 308) varies, thus allowing the measurement of the capacitance value C ≈ ε (A / g).

[0103] In some embodiments, the flexural assembly ( Figure 4B and Figure 4C The amount of deflection of 308 in the figure, and the corresponding change in capacitance (where it is assumed that there is no capacitance change in the undeflected configuration under no applied pressure), can depend on design parameters such as the lateral dimensions and thickness of the deflected component. For example, Figure 8A and Figure 8B The diagram illustrates the capacitance change (ΔC) as a function of applied pressure for two capacitive pressure sensors manufactured according to examples from Figures 5 to 7, where the flexural plates have thicknesses of 350 µm and 500 µm, respectively. It can be seen that the thicker flexural plate (500 µm) flexes less, resulting in a smaller change in the gap dimension (g) and consequently, a smaller capacitance change (ΔC) compared to the other flexural plate (350 µm).

[0104] Example 2:

[0105] Figures 9A to 9F The various stages of a process for manufacturing a pre-fired alumina part for a capacitive pressure sensor are illustrated. This alumina part can provide, for example... Figure 1A The base and support portions 130, 120. In some embodiments, in Figures 9A to 9F The alumina parts formed in the examples can be used as Figure 3B The example shows the second pre-fired alumina part 212.

[0106] Figure 9A A side view is shown of a pre-fired alumina ceramic substrate 600 with a thickness selected to provide basic functionality for a corresponding capacitive pressure sensor. This document describes in more detail how such a pre-fired alumina ceramic substrate is formed and examples of using other HTCC materials.

[0107] Figure 9B The stage in which through holes 601, 602, and 603 are formed to provide component 604 is shown. In some embodiments, such through holes can be formed, for example, by mechanical or laser drilling through the ceramic substrate 600.

[0108] Figure 9CA stage is shown in which a recess 606 is formed on one side of a ceramic base 600 to provide assembly 614. In some embodiments, such a recess can be formed by, for example, a dry pressing process or laser processing. The resulting recess is shown as being defined by a bottom surface 608 at a selected depth g and a recess wall 610. The periphery around the recess 606 is shown as including elements for use with... Figure 4B and Figure 4C The surface 306 of component 308 is mated with the surface 612.

[0109] It should be noted that, with Figure 9C The associated technology eliminates one component and one bonding interface compared to the first example in Figures 5-7. Therefore, in some implementations, the manufacture of the HTCC pressure sensor can be simplified, and associated costs can be reduced, while providing excellent control over the gap thickness based on the control of the recess depth.

[0110] Figure 9D It shows that Figure 9C The through holes 601, 602, and 603 are filled with conductive material to form corresponding conductive through holes 611, 612, and 613. In Figure 9D In the diagram, the base electrode 616 and the protective electrode 618 are shown to be formed on the surface 608 of the recess 606 in order to form the assembly 624.

[0111] In some embodiments, the base electrode 616 and the protective electrode 618 can be formed by a screen printing process on the bottom surface 608 of the recess 606, followed by a drying process. Therefore, conductive via 622 is shown as electrically connected to the base electrode 616, conductive via 623 is shown as electrically connected to the protective electrode 618, and conductive via 621 is configured to become electrically connected to the deformable portion (e.g., ...) when the deformable portion engages with the completed base portion. Figure 4B and Figure 4C In the 302, the electrode is connected to the conductive contact 304.

[0112] exist Figure 9D In the example, note that a protective electrode may or may not be used.

[0113] Figure 9E A stage is shown, in which Figure 9D Component 624 and Figure 4B and Figure 4C Component 308 is assembled to provide component 628.

[0114] refer to Figure 9E Component 308 is shown to include surface 306, in which electrodes are provided ( Figure 4B and Figure 4C(302 in the text) such that the peripheral portion of surface 306 can engage with surface 612 of component 624. In some embodiments, at least the engaging portion of surface 306 of component 308 and surface 612 of component 624 can be configured to allow co-firing at high temperatures.

[0115] refer to Figure 9E The surface 612 of the base assembly 624 is shown to engage with the surface 306 of the assembly 308 to provide an interface region 626.

[0116] refer to Figure 9E It should be noted that the electrode 304 of component 308 is now electrically connected to the conductive via 621 of component 624 via the conductive tab 304 of component 308.

[0117] Figure 9F A stage is shown, in which Figure 9E Components 308 and 624 have been co-fired at high temperature to provide component 632. This component (632) is similar to Figure 1A The capacitive pressure sensor 100; therefore, Figure 9F Component 632 in the document is also indicated as 100.

[0118] exist Figure 9F In the middle, previously in Figure 9E The interface region 626 is designated as the bonding or co-firing region 630. The bonding or co-firing region 630 may resemble the bonding or co-firing regions described herein with reference to Figures 5 and 6. More specifically, co-firing at high temperatures can result in the co-firing region 630 having indistinguishable bonding boundaries (e.g., formed by...). Figure 9E The mating surfaces 306 and 612 are defined in the text, so that the resulting ceramic structure 102 is essentially a single piece.

[0119] Example 3:

[0120] Figures 10A to 10G This paper illustrates the various stages of a process for fabricating a capacitive pressure sensor using a pre-fired alumina ceramic substrate and a thick-film spacer. This alumina substrate and thick-film spacer can provide, for example... Figure 1A The base and support portions 130, 120. In some embodiments, in Figures 10A to 10G The alumina substrate and thick film spacer formed in the example can be used as the second pre-fired alumina part 222 in the example of FIG30.

[0121] Figure 10A A side view is shown of a pre-fired alumina ceramic substrate 700 with a thickness selected to provide basic functionality for a corresponding capacitive pressure sensor. This document describes in more detail how such a pre-fired alumina ceramic substrate is formed and examples of using other HTCC materials.

[0122] Figure 10B The stage in which through holes 711, 712, and 713 are formed to provide component 702 is shown. In some embodiments, such through holes can be formed, for example, by mechanical or laser drilling through the ceramic substrate 700.

[0123] Figure 10C A stage is shown in which a recess 704 is formed on one side of a ceramic substrate 700 to provide assembly 714. In some embodiments, such a recess may be formed by a thick film 710, for example, screen-printed along the periphery of a surface 706 of the ceramic substrate 700. The resulting recess is shown as a bottom surface defined by surface 706 at a selected depth. The thick film 710 is shown as including components for use with... Figure 4B and Figure 4C The surface 306 of component 308 mates with surface 708. In some embodiments, in addition to or instead of thick film screen printing, a support layer 710 for providing a gap with a desired thickness can be formed using a green ceramic gasket formed by dry pressing, casting, rolling, etc.

[0124] exist Figure 10C In one example, screen printing of the thick film 710 may include forming a through hole aligned with the through hole 711 of the ceramic substrate 700.

[0125] In some embodiments, the thick film 710 may be formed from unburned alumina material. In some embodiments, depending on the desired gap, this alumina material may be printed on either or both of the components (e.g., top plate and substrate).

[0126] Figure 10D A stage is shown, in which Figure 10C The through holes 711, 712, and 713 are filled with conductive material to form corresponding conductive through holes 721, 722, and 723. Figure 10D In the diagram, the base electrode 716 and the protective electrode 718 are shown to be formed on the surface 706 of the recess 704 in order to form the assembly 724.

[0127] In some embodiments, the base electrode 716 and the protective electrode 718 can be formed by a screen printing process on the base plate 706 of the recess 704, followed by a drying process. Therefore, the conductive via 722 is shown as electrically connected to the base electrode 716, the conductive via 723 is shown as electrically connected to the protective electrode 718, and the conductive via 721 is configured to be electrically connected to the deformable portion (e.g., when the deformable portion is engaged with the completed base portion) Figure 4B and Figure 4C In the 302, the electrode is connected to the conductive contact 304.

[0128] exist Figure 10DIn the example, note that a protective electrode may or may not be used.

[0129] Figure 10E A stage is shown, in which Figure 10D Component 724 will be with Figure 4B and Figure 4C The assembly of component 308. Component 308 is shown including surface 306, in which electrodes are provided ( Figure 4B and Figure 4C (302 in the text) such that the peripheral portion of surface 306 can engage with surface 708 of component 724. In some embodiments, at least the engaging portion of surface 306 of component 308 and surface 708 of component 724 can be configured to allow co-firing at high temperatures.

[0130] Figure 10F A stage is shown in which the surface 708 of the base assembly 724 is shown to engage with the surface 306 of the assembly 308 to provide the assembly 726.

[0131] refer to Figure 10F It should be noted that the electrode 304 of component 308 is now electrically connected to the conductive via 721 of component 724 via the conductive tab 304 of component 308.

[0132] Figure 10G A stage is shown, in which Figure 10E Components 308 and 724 have been co-fired at high temperature to provide component 728. This component (728) is similar to Figure 1A The capacitive pressure sensor 100; therefore, Figure 10G Component 728 in the code is also indicated as 100.

[0133] exist Figure 10G In this context, the bonding or co-firing region between surface 306 of component 308 and surface 708 of thick film 710 can resemble the co-firing region described herein with reference to Figures 5 and 6. More specifically, co-firing at high temperatures can result in the co-firing region having indistinguishable bonding boundaries (e.g., by...). Figure 10F The mating surfaces 306 and 708 are defined in the text, so that the resulting ceramic structure 102 is essentially a single piece.

[0134] Example 4:

[0135] Figures 11A to 11F It shows that it is possible to manufacture something with similar characteristics. Figure 3D The example configuration of the capacitive pressure sensor illustrates the various stages of the process.

[0136] Figure 11AA side view of a pre-fired alumina ceramic substrate 800 is shown. The thickness of the alumina ceramic substrate 800 is selected to provide basic functionality for the corresponding capacitive pressure sensor. This article describes in more detail how such a pre-fired alumina ceramic substrate is formed and provides examples of using other HTCC materials.

[0137] Figure 11B The diagram illustrates the stages in which through-holes 811, 812, and 813 are formed from surface 802 to the surface on the other side in order to provide component 804. In some embodiments, such through-holes can be formed, for example, by mechanical or laser drilling through the ceramic substrate 800. In some embodiments, the substrate 800 can be formed using a dry pressing process, and this process can include forming through-holes 811, 812, and 813. In some embodiments, the substrate can be formed from a rolled and compacted green ceramic strip, and the through-holes (such as through-holes 811, 812, and 813) can be punched into such strip prior to the firing process.

[0138] Figure 11C A stage is shown, in which Figure 11B The through holes 811, 812, and 813 are filled with conductive material to form corresponding conductive through holes 821, 822, and 823. Figure 11C In the diagram, base electrode 816 and protective electrode 818 are shown formed on surface 802 of ceramic base 800 to form assembly 824.

[0139] exist Figure 11C In the example, conductive vias 821, 822, and 823 can be formed, for example, by screen printing to fill vias 811, 812, and 813, followed by vacuuming to draw metallic ink into the vias and coat the surface of the vias. High-temperature metals such as platinum and tungsten can be used for such conductive vias to accommodate the high temperatures involved in diffusion bonding / co-firing processes.

[0140] In some embodiments, the base electrode 816 and the protective electrode 818 can be formed by a screen printing process on the surface 802 of the ceramic base 800, followed by a drying process. Therefore, conductive via 822 is shown as electrically connected to the base electrode 816, conductive via 823 is shown as electrically connected to the protective electrode 818, and conductive via 821 is configured to... Figure 4F and Figure 4G (318) becomes electrically connected to the deformable part (e.g., when it is joined with the completed base portion) Figure 4F and Figure 4G The electrode in 312).

[0141] exist Figure 11C In the example, it should be noted that a protective electrode may or may not be used.

[0142] Figure 11D A stage is shown, in which Figure 4F and Figure 4G Component 318 and Figure 11C Component 824 is assembled. At this stage, component 318 is shown to include a surface 316 for engaging with surface 802 of component 824.

[0143] Figure 11E It shows that Figure 11D The components 318 and 824 are engaged in a stage to provide component 826. More specifically, surface 316 of component 318 is shown engaging with surface 802 of component 802 to provide an interface area.

[0144] refer to Figure 11E It should be noted that the electrodes of component 318 ( Figure 4F and Figure 4G (312) Now through this article reference Figure 4F and Figure 4G The described conductive structure is electrically connected to the conductive via 821 of component 824.

[0145] Figure 11F A stage is shown, in which Figure 11E Components 318 and 824 have been co-fired at high temperature to provide component 828. This component (828) is similar to Figure 1A The capacitive pressure sensor 100; therefore, Figure 11F Component 828 in the code is also indicated as 100.

[0146] Example 5:

[0147] Figures 12A to 12C It shows that it is possible to manufacture something with similar characteristics. Figure 3E The example configuration of the capacitive pressure sensor illustrates the various stages of the process.

[0148] Figure 12A It shows something similar to Figure 4F and Figure 4G Example component 318' and similar Figure 9D The example is a stage of component 624'. In this stage, component 318' is shown to include a surface 316' for engaging with surface 612' of component 624'.

[0149] It should be noted that Figure 12A Component 318' can be with Figure 11D Component 318 may be the same or different. Similarly, Figure 12A Component 624' may or may not be with Figure 9DThe same applies to component 624. In some embodiments, the depth of the recess in each of components 318' and 324' can be selected to provide desired flexural characteristics of component 318' and / or desired gap between the opposing electrodes of components 318' and 324'.

[0150] Figure 12B A stage is shown, in which Figure 12A Components 318' and 624' are engaged to provide component 9. More specifically, surface 316' of component 318' is shown engaging with surface 612' of component 624' to provide an interface area.

[0151] Figure 12C A stage is shown, in which Figure 12B Components 318' and 624' have been co-fired at high temperature to provide component 902. This component (902) is similar to Figure 1A The capacitive pressure sensor 100; therefore, Figure 12C Component 902 in the diagram is also indicated as 100.

[0152] It should be noted that conventional HTCC devices typically involve screen-printing metal circuitry and electrodes onto a green ceramic component, laminating or bonding them together, and then co-firing the green ceramic component at high temperature to form the device. In the various examples of HTCC devices described herein, the fabrication of such devices involves different methods, including utilizing pre-fired ceramic components (e.g., Figure 3A , 3B Instead of green (unfired) ceramic parts, this manufacturing process involves sintering the parts and then co-firing the pre-fired parts to form HTCC devices, which involves two high-temperature cycles.

[0153] It should also be noted that, as described herein, the “co-firing” of the aforementioned pre-fired components at high temperatures can result in diffusion bonding or diffusion-like bonding between the two pre-fired components. For the purposes of description, such co-firing bonding of two pre-fired components can include the interdiffusion of elements between the two components bonded at high temperatures.

[0154] It should also be noted that the aforementioned co-firing of pre-fired ceramic components at high temperatures can include many benefits, including overcoming the challenge that co-firing of green ceramic components typically results in some or all of the ceramic components deforming during firing. Another challenge that can be overcome includes manufacturing components with internal channels and / or cavities, which can be difficult due to the tendency of the cavities to collapse. However, with the co-firing of pre-fired components, the formation of internal channels and / or cavities may be less challenging.

[0155] Unless the context explicitly requires otherwise, throughout the specification and claims, the words “comprising,” “including,” etc., shall be understood to have an inclusive meaning, rather than an exclusive or exhaustive meaning; that is, in the sense of “including but not limited to.” As commonly used herein, the word “coupled” refers to two or more elements that are directly connected or connected via one or more intermediate elements. Furthermore, when used in this application, the words “in this document,” “above,” “below,” and similar terms shall refer to the application as a whole, and not to any particular part of the application. Where the context permits, singular or plural words used in the above detailed description may also include the plural or singular, respectively. The word “or” refers to a list of two or more items, and the word encompasses all of the following interpretations: any item in the list, all items in the list, and any combination of items in the list.

[0156] The above detailed description of embodiments of the present invention is not intended to be exhaustive or to limit the invention to the precise forms disclosed above. Although specific embodiments and examples of the invention have been described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as will be recognized by those skilled in the art. For example, although processes or blocks are presented in a given order, alternative embodiments may perform processes with steps in a different order, or employ systems with blocks in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and / or modified. Each of these processes or blocks may be implemented in various different ways. Moreover, although processes or blocks are sometimes shown as being executed serially, they may also be executed in parallel or at different times.

[0157] The teachings of this invention provided herein can be applied to other systems, not just those described above. Elements and actions of the various embodiments described above can be combined to provide further embodiments.

[0158] Although certain embodiments of the invention have been described, these embodiments are presented by way of example only and are not intended to limit the scope of this application. In fact, the novel methods and systems described herein can be implemented in many other forms; furthermore, various omissions, substitutions, and changes can be made to the form of the methods and systems described herein without departing from the spirit of this application. The appended claims and their equivalents are intended to cover such forms or modifications that fall within the scope and spirit of this application.

Claims

1. A pressure sensor, comprising: A base formed of high-temperature co-fired ceramic (HTCC) material and including an inner surface; A flexible plate formed of HTCC material and positioned above the surface of the base, the flexible plate including an inner surface and an outer surface facing the surface of the base; A spacer having a thickness and being realized between the base and the flexible plate to define the space between the inner surface of the base and the flexible plate; as well as A first electrode and a second electrode are respectively implemented on the inner surface of the base and the inner surface of the flexure plate to form a capacitor, such that the capacitance of the capacitor changes detectably due to the flexure plate flexing under pressure applied to the outer surface of the flexure plate.

2. The pressure sensor as described in claim 1, wherein, The HTCC material of the base is the same as that of the flexural plate.

3. The pressure sensor as described in claim 2, wherein, The HTCC material of the base and the flexural plate includes a polycrystalline phase HTCC material.

4. The pressure sensor as described in claim 3, wherein, The polycrystalline phase HTCC material includes alumina.

5. The pressure sensor as described in claim 4, wherein, The polycrystalline phase HTCC material comprises at least 96% alumina.

6. The pressure sensor as claimed in claim 1, wherein, The spacer is made of HTCC material.

7. The pressure sensor as described in claim 6, wherein, The base, the flexural plate, and the spacer are formed from a plurality of pre-fired HTCC parts and joined together to provide an indistinguishable joint interface.

8. The pressure sensor as claimed in claim 7, wherein, The base, the flexural plate, and the spacer are formed from pre-fired HTCC parts of individual corresponding components.

9. The pressure sensor as claimed in claim 7, wherein, The base and the spacer are formed from a single piece of pre-fired HTCC, and the flexural plate is formed from another piece of pre-fired HTCC.

10. The pressure sensor as claimed in claim 7, wherein, The base is formed from a single piece of pre-fired HTCC, and the flexural plate and the spacer are formed from another piece of pre-fired HTCC.

11. The pressure sensor as claimed in claim 7, wherein, The base and the first portion of the spacer are formed from a single piece of pre-fired HTCC, and the flexural plate and the second portion of the spacer are formed from another piece of pre-fired HTCC.

12. The pressure sensor as claimed in claim 7, wherein, The plurality of HTCC components are joined together by co-firing the plurality of HTCC components.

13. The pressure sensor as claimed in claim 12, wherein, The co-firing bonding between the plurality of HTCC parts includes the mutual diffusion of elements between the HTCC parts bonded together.

14. The pressure sensor as claimed in claim 1, wherein, The spacer is formed from unburned HTCC on the inner surface of the base.

15. The pressure sensor as claimed in claim 14, wherein, The base and the flexural plate are formed from corresponding pre-fired HTCC parts.

16. The pressure sensor as claimed in claim 15, wherein, The base, the flexural plate, and the spacer are joined by co-firing.

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; A first electrode is formed on the inner surface of the base assembly; Forming or providing a flexible assembly comprising pre-fired ceramic material, an inner surface, and an outer surface; A second electrode is formed on the inner surface of the flexural assembly; as well as The flexure assembly and the base assembly are co-fired to provide a spacer, the thickness of which defines the space between the inner surface of the base assembly and the inner surface of the flexure assembly, and such that the first electrode and the second electrode form a capacitor, such that the flexure assembly flexes due to pressure applied to the outer surface of the flexure assembly, resulting in a detectable change in the capacitance of the capacitor.

18. The method of claim 17, wherein, The pre-fired ceramic material of the flexural component is formed by a high-temperature firing process, and the pre-fired ceramic material of the base component is also formed by a high-temperature firing process.

19. The method of claim 17, wherein, The pre-fired ceramic material of the base assembly is the same as that of the pre-fired ceramic material of the flexural assembly.

20. The method of claim 19, wherein, The pre-fired ceramic materials of the base assembly and the flexural assembly include polycrystalline phase high-temperature co-fired ceramic (HTCC) materials.

21. The method of claim 20, wherein, The polycrystalline phase HTCC material includes alumina.

22. The method of claim 21, wherein, The polycrystalline phase HTCC material comprises at least 96% alumina.

23. The method of claim 17, wherein, The spacer is formed of high-temperature co-fired ceramic (HTCC) material.

24. The method of claim 23, wherein, The base assembly, the flexure assembly, and the spacer are formed from a plurality of pre-burnt HTCC elements and joined together to provide an indistinguishable joint interface.

25. The method of claim 23, wherein, The base assembly, the flexure assembly, and the spacer are formed from pre-fired HTCC parts of individual corresponding parts.

26. The method of claim 23, wherein, The base assembly including the spacer is formed from a single piece of pre-fired HTCC, and the flexural assembly is formed from another piece of pre-fired HTCC.

27. The method of claim 23, wherein, The base assembly is formed from a single piece of pre-fired HTCC, and the flexural assembly including the spacer is formed from another piece of pre-fired HTCC.

28. The method of claim 23, wherein, The base assembly having the first portion of the spacer is formed from a single piece of pre-fired HTCC, and the flexural assembly having the second portion of the spacer is formed from another piece of pre-fired HTCC.

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