Ceramic flat membrane double-sheet resistance type pressure core body

Abstract

The invention discloses a ceramic flat membrane double-sheet resistance type pressure core body, which belongs to the technical field of pressure sensing, is a flat membrane double-sheet type structure pressure sensing core body, and comprises a ceramic pressure sensing membrane, a Wheatstone bridge, a sealing layer, a ceramic base and a PIN needle, wherein the Wheatstone bridge comprises a strain resistor and a wire, is arranged on the surface of the ceramic pressure sensing diaphragm and is used for converting deformation of the ceramic pressure sensing diaphragm into a voltage signal; the sealing layer is used for sealing the ceramic pressure sensing diaphragm and the ceramic base into a whole; the PIN needle is arranged at the bottom of the ceramic base, is connected with a lead of the Wheatstone bridge and is used for outputting a voltage signal; moreover, the top of the ceramic base is provided with a deformation pit, and the two sides of the deformation pit are provided with double-lug structures. The resistance-type pressure core body is simple in structure, adopts the design of a flat-film double-piece structure, a double-lug structure, a zero-setting-free resistor and the like, and is beneficial to simplifying the production process, reducing the production and manufacturing cost and improving the anti-explosion performance and the pressure sensing sensitivity at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure sensing, and in particular to a ceramic flat-diaphragm double-sheet resistor type pressure core. Background Art

[0002] The pressure-sensitive core is the core pressure-sensitive element of the pressure sensor, which, like the human sensory organs, senses the pressure state of the measured medium. The resistive pressure core is a pressure-sensitive core manufactured using the piezoresistive effect. When the pressure-sensitive diaphragm is subjected to pressure and bends, the cross-sectional area and length of the Wheatstone bridge arm resistor change, resulting in a change in resistance. When a constant voltage or current signal is applied to the bridge, pressure changes input → resistance changes → bridge voltage signal output.

[0003] The structure of the existing resistive pressure core is relatively complex, the production process is complicated, and the production cost is high. At the same time, the anti-explosion performance and pressure sensitivity of the existing resistive pressure core also need to be improved. Summary of the Invention

[0004] In view of this, the present invention provides a ceramic flat-diaphragm double-piece resistive pressure core that solves at least some of the above-mentioned technical problems. The resistive pressure core has a simple structure and adopts a flat-diaphragm double-piece structure and other designs, which is conducive to simplifying the production process and reducing production costs, while also improving the anti-explosion performance and pressure sensitivity.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides a ceramic flat diaphragm double-piece resistive pressure core, which is a flat diaphragm double-piece structure pressure-sensitive core, comprising: a ceramic pressure-sensitive diaphragm, a Wheatstone bridge, a sealing layer, a ceramic base and a PIN needle; wherein:

[0007] The Wheatstone bridge includes a strain resistor and a wire, which is arranged on the surface of the ceramic pressure-sensitive diaphragm and is used to convert the deformation of the ceramic pressure-sensitive diaphragm into a voltage signal; the sealing layer is used to seal the ceramic pressure-sensitive diaphragm and the ceramic base into one body; the PIN pin is arranged at the bottom of the ceramic base and connected to the wire of the Wheatstone bridge, and is used to output a voltage signal.

[0008] Preferably, a deformation pit is provided on the top of the ceramic base.

[0009] Preferably, two ears are provided on both sides of the deformation pit.

[0010] Preferably, the ceramic base is dry pressed or injection molded.

[0011] Preferably, the sealing layer is a sealing glass, which is printed and coated on the ceramic surfaces of the ceramic pressure-sensitive diaphragm and the ceramic base, and the ceramic pressure-sensitive diaphragm and the ceramic base are sealed as one by sintering.

[0012] Preferably, the thickness of the ceramic base is 2 to 8 mm.

[0013] Preferably, the strain resistors and wires of the Wheatstone bridge are arranged on the surface of the ceramic pressure-sensitive diaphragm by screen printing or coating.

[0014] Preferably, the outer shape of the core is any one of the following: circular, square and octagonal.

[0015] Compared with the prior art, the technical solution of the present invention has at least the following beneficial technical effects:

[0016] 1. The present invention provides a ceramic flat membrane double-piece resistive pressure core, which adopts a flat membrane double-piece structure. The core structure is simple, compact and reasonable, which is convenient for simplifying the production process and reducing production costs.

[0017] 2. The present invention provides a ceramic flat-diaphragm double-piece resistive pressure core, in which the thickness of the ceramic base is 2 to 8 mm, ensuring high pressure resistance and greatly improving anti-explosion performance; a deformation pit is also provided on the top of the ceramic base, and a double-ear structure is provided on both sides of the deformation pit, which facilitates the precise guarantee of the deformation area diameter through the mold, which is beneficial to improving the pressure sensitivity and ensuring the consistency and reliability of the product.

[0018] 3. The present invention provides a ceramic flat-diaphragm double-piece resistive pressure core, the core shape can be circular, square, octagonal, etc., which improves the applicability of the finished sensor.

[0019] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0023] Figure 1 This is a schematic diagram of the front cross-sectional structure of a ceramic flat diaphragm double-plate resistive pressure core provided by the present invention.

[0024] Figure 2 This is a schematic side cross-sectional structure diagram of a ceramic flat diaphragm double-plate resistive pressure core provided by the present invention.

[0025] Figure 3 This is a schematic structural diagram of the ceramic pressure-sensitive diaphragm provided by the present invention.

[0026] Figure 4 This is a schematic diagram of the top structure of the ceramic base provided by the present invention.

[0027] Figure 5 This is a schematic diagram of the bottom structure of the ceramic base provided by the present invention.

[0028] Figure 6 This is a schematic diagram of the top view of the core body with a double-ear design provided by the present invention.

[0029] Figure 7 This is a schematic diagram of the top view of the core body adopting the non-binaural design provided by the present invention.

[0030] Among them, 1-ceramic pressure-sensitive diaphragm; 2-strain resistor; 3-wire; 4-sealing layer; 5-ceramic base; 6-PIN needle; 7-deformation pit; 8-double-ear structure. DETAILED DESCRIPTION

[0031] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0032] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "top," and "bottom" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the various serial numbers are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "connected," etc., should be understood in a broad sense. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection or an electrical connection; it may refer to a direct connection or an indirect connection through an intermediate medium; it may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0034] See also Figure 1-Figure 5 As shown, an embodiment of the present invention provides a ceramic flat diaphragm double-chip resistive pressure core, which is a flat diaphragm double-chip structure pressure-sensitive core, including: a ceramic pressure-sensitive diaphragm 1, a Wheatstone bridge, a sealing layer 4, a ceramic base 5 and a PIN needle 6; wherein:

[0035] In this embodiment, a thinner ceramic pressure-sensitive diaphragm 1 senses external pressure, while a thicker ceramic base 5 provides a solid backing, ensuring high pressure resistance and also leads to a fixed pin 6. A Wheatstone bridge circuit, comprising a strain gauge resistor 2 and a conductor 3, is positioned on the surface of the ceramic pressure-sensitive diaphragm 1 to convert its deformation into a voltage signal. A sealing layer 4 seals the ceramic pressure-sensitive diaphragm 1 to the ceramic base 5. A pin 6 is positioned at the bottom of the ceramic base 5 and connected to the Wheatstone bridge conductor 3, outputting a voltage signal externally or to a PAD. The core utilizes a flat-diaphragm, two-piece structure without bridge-circuit trimming resistors. This simple, compact, and rational structure facilitates simplified production processes and reduces manufacturing costs.

[0036] In an optional embodiment, the ceramic base 5 is manufactured by dry pressing or injection molding, followed by sintering and cold working. The thickness of the ceramic base 5 ranges from 2 to 8 mm, ensuring high pressure resistance. Compared to a core body with a thickness of less than 1.0 mm, the present invention significantly improves its burst strength. Furthermore, the sealing layer 4 is preferably a sealing glass, which is printed and coated onto the ceramic surfaces of the pressure-sensitive diaphragm 1 and the ceramic base 5 by screen printing or coating. The sealing glass is then sintered to tightly seal the pressure-sensitive diaphragm 1 and the ceramic base 5, ensuring reliability.

[0037] In an alternative embodiment, see Figure 4As shown, a deformation pit 7 is provided on the top of the ceramic base 5, which is convenient for accurately ensuring the diameter of the deformation area through the mold, thereby ensuring that the sensitivity of the product is highly consistent; preferably, a double-ear structure 8 is also provided on both sides of the deformation pit 7. In the present invention, a double-ear design is adopted on both sides of the pit, and the strain resistor 2 and the sealing glass are kept away from the air, avoiding the chemical and physical effects of the glass during firing (there is also glass in the strain resistor, and the glass of the strain resistor and the sealing glass will react chemically), and also expands the pressure sensing range, further improves the pressure sensitivity, and reduces the peripheral size of the product.

[0038] In an alternative embodiment, see Figure 3 As shown, the strain resistor 2 and the wire 3 of the Wheatstone bridge are preferably provided on the surface of the ceramic pressure-sensitive diaphragm 1 by screen printing or coating, which is a simple and efficient process and saves time.

[0039] In an alternative embodiment, see Figure 5 As shown, the PIN needle 6 is provided at the bottom of the ceramic base 5 and is preferably potted with conductive silver glue to connect to the Wheatstone bridge.

[0040] In an optional embodiment, the outer shape structure of the core body is any one of the following: a circular structure, a square structure, and an octagonal structure, which has good applicability and can also be customized according to customer needs.

[0041] The following describes the production process of the resistance pressure core in the prior art and the ceramic flat membrane double-plate resistance pressure core of the present invention:

[0042] The process of making a resistance pressure core in the prior art is as follows:

[0043] Elastic diaphragm printed conductors -> Elastic diaphragm printed resistors -> Ceramic base printed sealing materials -> Ceramic base printed conductors -> Ceramic base printed zero-adjustable resistors -> Ceramic base printed encapsulation layer -> Co-firing -> Laser resistance trimming -> Ceramic base printed resin protective layer -> Probe implantation -> Testing.

[0044] In a specific embodiment, the process of a ceramic flat diaphragm double-plate resistive pressure core of the present invention is as follows:

[0045] Print and burn the wires on the elastic diaphragm (i.e., ceramic pressure-sensitive diaphragm) --> Print and burn the resistors on the elastic diaphragm --> Print and burn the sealing material on the ceramic base --> Combine and burn --> Glue and insert the pins --> Test.

[0046] Obviously, the process of the ceramic flat membrane double-piece resistive pressure core in the present invention is simpler, greatly reducing the process, which is conducive to reducing production costs and improving production efficiency. In addition, the ceramic flat membrane double-piece resistive pressure core produced by this process has improved explosion resistance, sensitivity and consistency. In addition, the existing resistive pressure core is provided with a bridge circuit adjustment resistor (zero adjustment resistor), and the preparation requires laser resistance adjustment to correct the zero voltage output to 0V. After the resistance adjustment, the resistance is easily affected by the external environment and the accuracy deviation; the ceramic flat membrane double-piece resistive pressure core of the present invention adopts a zero adjustment resistor design, which does not require subsequent resistance adjustment and correction, and is also convenient for significantly reducing the process and reducing production costs.

[0047] The present invention also conducted multiple sensitivity comparisons between binaural design and non-binaural design. The core structures of binaural design and non-binaural design are shown in Figure 6 and Figure 7 The comparison results are shown in Table 1:

[0048] Table 1 Sensitivity measurements using binaural design and non-binaural design

[0049] Sensitivity of real sequence number 1# 2# 3# 4# 5# Sensitivity unit Binaural design 2.98 2.96 2.99 3.12 2.99 mV / V Non-binaural design 2.47 2.51 2.39 2.55 2.64 mV / V

[0050] It can be seen from Table 1 that in the five actual measurements, the sensitivity of the binaural design is higher than that of the non-binaural design.

[0051] As can be seen from the above embodiments, the present invention provides a ceramic flat-diaphragm dual-piece resistive pressure core. Unlike conventional concave-diaphragm piezoresistive cores, the present invention adopts a flat-diaphragm dual-piece structural design. The pressure core structure is simple, compact, and rational, which facilitates a simplified production process and reduces manufacturing costs. The ceramic base has a thickness of 2 to 8 mm, making it durable and sturdy, ensuring high pressure resistance and providing a solid backing. Compared with a concave-diaphragm core with a thickness of less than 1.0 mm, its anti-blasting performance is significantly improved. Furthermore, a deformation pit design is incorporated into the ceramic base, facilitating precise determination of the deformation area diameter through the mold, thereby ensuring highly consistent product sensitivity. Furthermore, a double-ear structure is employed on either side of the pit, further enhancing pressure sensitivity and reducing the product's external dimensions. The present invention's ceramic flat-diaphragm dual-piece resistive pressure core also utilizes a zero-adjustment resistor design, eliminating the need for subsequent resistance adjustment, significantly simplifying the process and reducing manufacturing costs. Finally, the core structure is simple, and the shape can be circular, square, or octagonal, and can be customized to meet customer needs. The present invention helps improve the reliability, accuracy, and applicability of finished sensors.

[0052] The above is a detailed introduction to a ceramic flat diaphragm double-piece resistive pressure core provided by the present invention. In this embodiment, specific examples are used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scopes, and the content of this specification should not be understood as limiting the present invention.

[0053] This specification adopts a progressive description, and the same and similar parts between each implementation can be referenced. The unexplained parts of the embodiments of the present invention can be obtained from the corresponding product specifications or the existing technology in the field, and will not be described in detail.

[0054] It should be noted that the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0055] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this embodiment may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown in this embodiment, but is intended to conform to the widest scope consistent with the principles and novel features disclosed in this embodiment.

Claims

1. A ceramic flat membrane double-plate resistive pressure core, characterized in that: The core is a flat diaphragm double-piece structure, including: a ceramic pressure-sensitive diaphragm, a Wheatstone bridge, a sealing layer, a ceramic base and a PIN needle; wherein: The Wheatstone bridge includes a strain resistor and a wire, which is arranged on the surface of the ceramic pressure-sensitive diaphragm and is used to convert the deformation of the ceramic pressure-sensitive diaphragm into a voltage signal; the sealing layer is used to seal the ceramic pressure-sensitive diaphragm and the ceramic base into one body; the PIN pin is arranged at the bottom of the ceramic base and connected to the wire of the Wheatstone bridge, and is used to output a voltage signal.

2. The ceramic flat membrane double-plate resistive pressure core according to claim 1, characterized in that: A deformation pit is provided on the top of the ceramic base.

3. The ceramic flat membrane double-plate resistive pressure core according to claim 2, characterized in that: Two ears are provided on both sides of the deformation pit.

4. The ceramic flat membrane double-plate resistive pressure core according to claim 1, characterized in that: The ceramic base is dry pressed or injection molded.

5. The ceramic flat membrane double-plate resistive pressure core according to claim 1, characterized in that: The sealing layer is a sealing glass, which is printed and coated on the ceramic surfaces of the ceramic pressure-sensitive diaphragm and the ceramic base, and the ceramic pressure-sensitive diaphragm and the ceramic base are sealed as a whole by sintering.

6. The ceramic flat membrane double-plate resistive pressure core according to claim 1, characterized in that: The thickness of the ceramic base is 2 to 8 mm.

7. The ceramic flat membrane double-plate resistive pressure core according to claim 1, characterized in that: The strain resistors and wires of the Wheatstone bridge are arranged on the surface of the ceramic pressure-sensitive diaphragm by screen printing or coating.

8. The ceramic flat diaphragm double-plate resistive pressure core according to claim 1, characterized in that: The outer shape of the core is any of the following: round, square and octagonal.

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