Sensor core and pressure sensor

Abstract

The application provides a sensor core and a pressure sensor. The pressure sensor comprises a core body, and the core body comprises a pressure-sensitive unit. The pressure-sensitive unit is distributed along a first dimension. The pressure-sensitive unit generates different deformations at at least two different positions along the first dimension according to pressure applied to the pressure-sensitive unit, and further generates a pressure electric signal. The core body extends along the first dimension on one side of the pressure-sensitive unit, and forms a stress isolation portion and a core connecting portion. The stress isolation portion is located between the core connecting portion and the pressure-sensitive unit. The core connecting portion is provided with at least one core connecting point. The core connecting point is electrically connected to the pressure-sensitive unit to transmit the pressure electric signal. In a working state, the core connecting portion is used for connecting a sensor base. The application can eliminate the component and transmission of the deformation stress along the first dimension as much as possible, thereby eliminating the influence of the deformation stress on the pressure-sensitive unit and ensuring the measurement accuracy of the pressure sensor.

Description

Technical Field

[0001] This application relates to the field of sensor technology, specifically a sensor core and a pressure sensor. Background Technology

[0002] Pressure sensors based on semiconductor manufacturing technology are typically a few millimeters or even smaller and are widely used in pressure measurement and testing equipment such as smart pressure gauges, pressure transmitters, and pressure calibrators. Based on different piezoelectric conversion principles, common pressure sensors include piezoelectric pressure sensors, resonant pressure sensors, and piezoresistive sensors.

[0003] A pressure sensor may be a packaged module containing a built-in sensor core, or it may be used in conjunction with a pressure measurement structure such as a pressure module. In the latter case, all or part of the pressure sensor may be integrated with the pressure measurement structure, such as... Figure 1 As shown, a typical pressure sensor, used to fix the sensor core, includes a sensor base 010. A pressure-sensing channel 020 is provided on the sensor base 010 to transmit the pressure to be measured. The sensor core 030 is placed flat on the sensor base 010 and sealed and fixed to the sensor base 010 around the pressure-sensing channel 020. The pressure-sensing surface 041 of the pressure-sensitive element 040 faces the pressure-sensing channel 020. During operation, the pressure to be measured is transmitted to the pressure-sensing surface 041 of the pressure-sensitive element 040 through the pressure-sensing channel 020. The pressure-sensitive element 040 generates a corresponding pressure electrical signal according to the magnitude of the pressure to be measured.

[0004] The material forming the sensor base is generally stainless steel or other metals and their alloys, used to provide greater compressive strength. This type of material generally has a relatively large coefficient of thermal expansion. The material forming the sensor core is generally silicon or its compounds, which has a relatively small coefficient of thermal expansion. As a result, when the ambient temperature changes, the temperature-induced deformation of the pressure-sensitive element is relatively small, while the temperature-induced deformation of the sensor base is relatively large. Since there is a fixed connection between the sensor base and the sensor core, the aforementioned inconsistent temperature-induced deformation will generate deformation stress between the sensor base and the sensor core, thereby creating tension / compression on the pressure-sensitive element and interfering with the pressure measurement accuracy of the sensor core.

[0005] To address the aforementioned technical problems, there are two main improvement paths for existing technologies:

[0006] One, hardware improvement, use soft glue to fix the sensor base and the sensor core, soft glue can absorb deformation stress, reduce stress transmission, but generally, soft glue has low compressive strength, easy to denature at high temperature and other problems, easy to fail under high pressure (7 MPa and above), on site (may exist 70℃ and above high temperature) and other conditions;

[0007] Two, software improvement, additional temperature sensor in the pressure measurement structure, after getting pressure electric signal from pressure sensor, according to the measurement value of temperature sensor and pre-set calibration data, the pressure measurement result is compensated, but generally, due to the deformation interference is the mixed stress of two materials, the interference change is nonlinear, the error change brought by this is also nonlinear, it is difficult to give enough accurate and reliable calibration data. SUMMARY

[0008] The technical problem to be solved: due to the different thermal expansion coefficients between the sensor base and the sensor core, after the environmental temperature changes, the two will produce deformation stress based on the fixed connection relationship, form the stretching / compression of the pressure sensitive element, affect the measurement accuracy of the pressure sensor, and the existing technical solutions cannot well solve the foregoing technical problems.

[0009] A sensor core for a pressure sensor, comprising a core body, the core body comprising a pressure sensitive unit;

[0010] The pressure sensitive unit is distributed at least along a first dimension, and different deformations of the pressure sensitive unit at at least two different positions in the first dimension are caused according to the pressure applied on the pressure sensitive unit, thereby generating a pressure electric signal;

[0011] The core body extends along the first dimension on one side of the pressure sensitive unit, forming a stress isolation part and a core connecting part, the stress isolation part is located between the core connecting part and the pressure sensitive unit, at least one core wiring point is provided on the core connecting part, and the core wiring point is electrically connected to the pressure sensitive unit to transmit the pressure electric signal;

[0012] In the working state, the core connecting part is used to connect the sensor base, so that the core body is fixedly arranged in the pressure sensor.

[0013] Preferably, the core body comprises a pressure sensitive layer, a first substrate and a second substrate, the pressure sensitive layer comprises the pressure sensitive unit, the pressure sensitive layer and the first substrate have the same distribution in the first dimension, the second substrate has a distribution at least covering the first substrate in the first dimension, one side of the first substrate is bonded to the pressure sensitive layer, and the other side of the first substrate is bonded to the second substrate.

[0014] Preferably, the second substrate forms an insulating fixed body at the position of the core connecting part, the insulating fixed body is used for adapting and fixing with the sensor base; the first substrate and at least part of the pressure sensitive layer have a first thermal expansion coefficient, the second substrate has a second thermal expansion coefficient, the second thermal expansion coefficient is greater than or equal to the first thermal expansion coefficient, and does not exceed three times of the first thermal expansion coefficient.

[0015] Preferably, the pressure sensitive layer has a first thickness, the first substrate has a second thickness, the second substrate has a third thickness, the second thickness is greater than the first thickness, and the third thickness is not less than the sum of the first thickness and the second thickness.

[0016] Preferably, the core connecting part is provided with a support mounting hole at a core connecting surface, the core connecting surface and the first dimension are perpendicular to each other, the support mounting hole is formed by at least the second substrate, is used for inserting a support column, the inner diameter of the support mounting hole is adapted to the support column, the axial direction of the support mounting hole is distributed along the first dimension and is located in the core connecting part.

[0017] Preferably, the pressure sensitive unit has a first pressure sensing surface and a second pressure sensing surface on two sides, a first pressure sensing cavity is provided between the first substrate and the first pressure sensing surface, the pressure sensitive unit generates the pressure electric signal according to the relative pressure of the first pressure sensing cavity and the second pressure sensing surface; the support mounting hole is a blind hole and is communicated with the first pressure sensing cavity, and is used for introducing pressure medium into the first pressure sensing cavity through a through hole in the support column.

[0018] Preferably, the surface of the core body forms a core lead structure, the core lead structure is continuous to the core connecting point and / or the pressure sensitive unit, one end of a core lead wire is connected to the pressure sensitive unit, the other end of the core lead wire is connected to the core connecting point, and at least part of the core lead wire is insulatively attached to the core lead structure, so that at least part of the core lead wire is continuously fixed to the core body.

[0019] A pressure sensor, comprising a core body and a sensor base;

[0020] The core body comprises a pressure sensitive unit, the pressure sensitive unit is distributed along at least a first dimension, and generates different deformations at at least two different positions along the first dimension according to the pressure applied on the pressure sensitive unit, thereby generating a pressure electric signal, the core body is stretched along the first dimension at least on one side of the pressure sensitive unit, forming a stress isolation part and a core connecting part, the stress isolation part is located between the core connecting part and the pressure sensitive unit, the core connecting part is provided with at least one core connecting point, and the core connecting point is electrically connected to the pressure sensitive unit.

[0021] The sensor base has a base fixing surface which is located on one side of the core body and perpendicular to the first dimension, the core connecting part is fixedly connected to the base fixing surface, and the sensor base is further provided with an output connector which is electrically connected to the core connecting point through a base connecting part to transmit the pressure electric signal.

[0022] Preferably, the core body comprises a pressure sensitive layer, a first substrate and a second substrate, the pressure sensitive layer comprises the pressure sensitive unit, the pressure sensitive layer and the first substrate have the same distribution in the first dimension, the second substrate has a distribution at least covering the first substrate in the first dimension, one side of the first substrate is bonded to the pressure sensitive layer, and the other side of the first substrate is bonded to the second substrate.

[0023] Preferably, the second substrate forms an insulating fixing body at the position of the core connecting part, the insulating fixing body is adaptively fixed to the base fixing surface, the first substrate and at least part of the pressure sensitive layer have a first thermal expansion coefficient, the second substrate has a second thermal expansion coefficient, at least part of the sensor base has a third thermal expansion coefficient, the second thermal expansion coefficient is greater than or equal to the first thermal expansion coefficient and does not exceed three times the first thermal expansion coefficient, and the third thermal expansion coefficient is greater than the second thermal expansion coefficient.

[0024] Preferably, the pressure sensitive layer has a first thickness, the first substrate has a second thickness, and the second substrate has a third thickness, the second thickness is greater than the first thickness, and the third thickness is not less than the sum of the first thickness and the second thickness.

[0025] Preferably, the core connecting part is provided with a support mounting hole on the core connecting surface, the base fixing surface is provided with a support column, the core connecting part is fixedly connected to the base fixing surface, at least part of the support column is adaptively inserted into the support mounting hole; the core connecting surface and the base fixing surface are parallel; the support mounting hole is formed by at least the second substrate, the axial direction of the support mounting hole is distributed along the first dimension and all located in the core connecting part, and the support column and the support mounting hole are coaxial.

[0026] Preferably, the pressure sensitive unit has a first pressure sensing surface and a second pressure sensing surface on two sides, the sensor base forms a second pressure sensing cavity, the second pressure sensing surface of the pressure sensitive unit is exposed in the second pressure sensing cavity, a first pressure sensing cavity is provided between the first substrate and the first pressure sensing surface, the pressure sensitive unit generates the pressure electric signal according to the relative pressure of the first pressure sensing cavity and the second pressure sensing cavity; the support mounting hole is a blind hole and is communicated with the first pressure sensing cavity, the support column has a pressure guiding through hole in the middle, the sensor base has a first base pressure guiding opening, and the sensor base has a base pressure guiding channel communicated with the first base pressure guiding opening and the pressure guiding through hole, so that the pressure medium enters the first pressure sensing cavity through the first base pressure guiding opening.

[0027] Preferably, the surface of the core body forms a core lead structure, the core lead structure is continuous to the core connecting point and / or the pressure sensitive unit, one end of the core lead wire is connected to the pressure sensitive unit, the other end of the core lead wire is connected to the core connecting point, and at least part of the core lead wire is insulatively attached to the core lead structure, so that at least part of the core lead wire is continuously fixed to the core body.

[0028] Preferably, the sensor base is further provided with a base fixing groove on the base fixing surface, the inner contour of the base fixing groove is matched with the outer contour of the core connecting part, and the core connecting part is at least partially inserted into the base fixing groove.

[0029] Preferably, the pressure sensor further comprises a fastening bolt, the fastening bolt is threadedly connected to the sensor base, the core connecting part is provided with a fastening bolt hole matched with the fastening bolt, and the core connecting part is fixedly connected to the base fixing surface, including that one end of the fastening bolt is exposed to the inner side surface of the base fixing groove and is matched and abutted to the fastening bolt hole.

[0030] Preferably, the base connecting part comprises a connecting column, one end of the connecting column is exposed to one inner side surface of the base fixing groove and is arranged opposite to the fastening bolt, and the connecting column is matched and abutted to the core connecting point.

[0031] Advantages:

[0032] In the case that the pressure sensitive unit is distributed along the first dimension, the fixed point between the sensor core and the sensor base is at the end far from the pressure sensitive unit, and the other end of the sensor core is free, at this time, the fixed force between the sensor core and the sensor base is zero or very small in the first dimension, when the ambient temperature changes, if the temperature-induced relative deformation occurs between the sensor core and the sensor base, on the one hand, the deformation stress and the fixed force have the same transmission direction, therefore, the component of the deformation stress in the first dimension is almost zero, on the other hand, even if there is a little deformation stress, it will be absorbed by the stress isolation part in the transmission process, so as to eliminate the influence of the deformation stress on the pressure sensitive unit as much as possible, and the measurement accuracy of the pressure sensor is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A structure diagram of a pressure sensor in the prior art.

[0034] Figure 2 A resistance setting diagram of an example pressure sensitive unit.

[0035] Figure 3 A resistance setting diagram of an example pressure sensitive unit.

[0036] Figure 4 A resistance setting diagram of an example pressure sensitive unit.

[0037] Figure 5 A structure diagram of an example pressure sensor.

[0038] Figure 6 A structure diagram of an example pressure sensor.

[0039] Figure 7 A connection diagram of an example pressure sensor.

[0040] Figure 8 A structure diagram of another example pressure sensor.

[0041] Figure 9 A structure diagram of another example pressure sensor (package).

[0042] Figure 10 A structure diagram of a sensor core of still another example.

[0043] Figure 11 A structure diagram of a sensor core of still another example. Figure 10 An enlarged diagram of area A in the middle.

[0044] Figure 12 A structure diagram of a sensor shell of still another example.

[0045] Figure 13 A structure diagram of a pressure sensor of still another example.

[0046] Reference signs:

[0047] 010, (prior art) sensor base, 020, pressure lead channel, 030, (prior art) sensor core, 040, pressure sensitive element, 041, pressure sensitive surface;

[0048] 100, pressure sensitive layer, 110, pressure sensitive unit, 111, first pressure sensitive surface, 112, second pressure sensitive surface, 113, piezoresistive strip, 114, pressure sensitive connection circuit, 115, piezoresistive connection point, 120, insulation layer, 200, base layer, 210, first base, 211, first pressure sensitive cavity, 220, second base, 221, insulation fixed body, 300, core connection part, 310, core connection point, 320, core lead wire, 330, core pressure lead opening, 340, core pressure lead channel, 341, support mounting hole, 350, core connection surface, 360, fastening bolt hole, 400, stress isolation part, 500, sensor base (sensor housing), 510, base fixed surface, 520, output terminal, 530, base connection point, 531, electric connection wire, 532, connection post, 540, base mounting groove (base fixed groove), 541, base fixed ring, 542, base sealing ring, 543, second base pressure lead opening, 544, fastening bolt, 550, first base pressure lead opening, 560, base pressure lead channel, 561, support post, 562, pressure lead through hole, 571, second pressure sensitive cavity, 572, encapsulation pressure lead opening, 573, encapsulation pressure lead channel, 610, resistance measurement circuit, 620, signal processing unit. DETAILED DESCRIPTION

[0049] The technical solutions of the present application are described below based on the embodiments, but the technical solutions of the present application are not limited to these embodiments only. In the following detailed description of the technical solutions, some specific details are described in detail, and it should be understood that these details are not limitations to the protection scope of the present application. The description without these details can also fully understand the present application, and it can also be understood that these details are based on the non-creative modification, obvious changes, alternative of conventional technical means, etc. of the prior art.

[0050] In the description of the embodiments, unless explicitly stated or determined by those skilled in the art according to the relevant expressions that there is no meaning: the word "comprising" does not exclude other units or steps; the singular does not exclude the plural; the expressions "first XX", "second XX" and the like do not represent the limited number or selected order, if not explicitly stated in the embodiments, "first XX" and "second XX" can be an object or at least two different objects, that is, it includes two possible technical solutions, those skilled in the art can understand that if the first, second and the like individuals can only solve the technical problem independently, the first, second and the like in the scheme represent different specific entities, if part or all of the first, second and the like individuals can be a specific entity, and also can solve the technical problem, the scheme described in the embodiments includes this case, which should also belong to the scope intended to be protected by the present application; multiple structures, components, units can be integrated in the case of implementation, and a single structure, component, unit can be implemented by multiple specific entities in the case of implementation.

[0051] The embodiments give the main feasible scheme and the improvement scheme of the main feasible scheme, which can be understood that the main feasible scheme can independently solve the technical problem, combined with the improvement scheme can better solve the technical problem or solve the new technical problem, the combination of some improvement schemes can better solve the technical problem or solve the new technical problem, and the feasible way of these combinations is within the scope of the disclosed content of the embodiments.

[0052] In the embodiments and the technical scheme of the present application, some well-known technical features, common technical means and / or prior art may be indirectly referenced or implicitly contained, for example, the transmission of electrical signals on a structure with electrical conductivity (such as a metal shell, etc.), which implies that there is an insulating layer between the signal line transmitting electrical signals and the metal structure, and for example, for a pipeline transmitting pressure, it is generally realized by a certain pressure medium, which may be gas or liquid. Once there is a leak, the pressure will not be transmitted, so for the pipeline with the expression of communication or pressure transmission, it should be understood that there may be a pressure container or a sealed chamber in the pipeline, but in the area outside the necessary pressure transmission channel, such as the position communicating with the atmosphere, unless it is explicitly stated that the atmospheric channel is in gauge pressure, it should be in a sealed state. It can be understood that if some well-known technical features, common technical means and / or prior art do not contribute to the technical problems solved by the present application, and those skilled in the art have the motivation to combine these well-known technical features, common technical means and / or prior art with the embodiments without changing the purpose of the present application, it should be considered that these well-known technical features, common technical means and / or prior art are disclosed by the embodiments.

[0053] In the embodiments and the technical solutions of the present application, some materials or material properties may be described, for example, a structure layer is XX (material), and for example, a structure layer has an XX expansion coefficient, and the structure layer herein refers to the main body of the structure layer, and other structures or materials are allowed to be attached to the main body.

[0054] The pressure sensor may be applied in scenarios including but not limited to general pressure measurement, flow measurement, and other fields of measuring non-pressure physical quantities by using pressure measurement. The sensor in these fields should also be regarded as the pressure sensor in the embodiments.

[0055] Generally, the pressure sensor can be divided into absolute pressure measurement, gauge pressure measurement, and differential pressure measurement according to different types of measured pressure. In general, in the absolute pressure measurement, one pressure-sensitive surface of the pressure-sensitive element is located in a vacuum and sealed pressure chamber, and the other pressure-sensitive surface of the pressure-sensitive element is used to contact the measured pressure. In the gauge pressure measurement, one pressure-sensitive surface of the pressure-sensitive element is connected to the atmosphere or an atmospheric module, and the other pressure-sensitive surface of the pressure-sensitive element is used to contact the measured pressure. In the differential pressure measurement, one pressure-sensitive surface of the pressure-sensitive element is connected to high pressure in the measured pressure, and the other is connected to low pressure in the measured pressure. In the embodiments, if the specific application of the type of measured pressure is not specified, it can be understood that the corresponding pressure type can be further refined to obtain the corresponding sensor core and pressure sensor, and each further refinement is implicitly included in the solutions of the embodiments.

[0056] The pressure-sensitive unit is distributed at least along the first dimension, and different deformations of the pressure-sensitive unit at at least two different positions in the first dimension are generated according to the pressure applied to the pressure-sensitive unit, and then a pressure electric signal is generated. For ease of description, a pressure-sensitive unit suitable for a piezoresistive pressure sensor is given in the embodiments, and it can be understood that for other types of pressure sensors and their cores, the specific structure of the corresponding pressure-sensitive unit can be applied.

[0057] Specifically, the pressure sensitive unit is distributed at least along a first dimension, the pressure sensitive unit comprises a thin film which can be deformed according to pressure, generally, the thin film can be realized by bulk processing technology, for example, wet etching tetramethylammonium hydroxide TMAH and potassium hydroxide KOH, dry etching deep reactive ion etching DRIE, and for example, realized by surface processing technology. The thin film can be circular, rectangular or other shapes, four piezoresistive bars are arranged on the thin film to form a Wheatstone bridge, when there is relative pressure on both sides of the thin film (here, the relative pressure can be zero), the thin film generates a corresponding resistance signal according to the corresponding deformation, further, when the relative pressure on both sides of the thin film is not zero, the thin film deforms and the resistance changes, so that the voltage output of the Wheatstone bridge is unbalanced, so that the relative pressure value can be calculated by measuring the voltage output, the placement position of the piezoresistive bar affects the sensitivity of the pressure sensor and the electrical signal of the pressure sensor, generally, the piezoresistive bar is arranged at the edge area of the thin film as much as possible, but not excluded, the piezoresistive bar can also have other forms, for example Figure 2 As shown, the pressure sensitive unit 110 is a rectangle, has a first dimension distributed longitudinally and a second dimension distributed transversely, four piezoresistive bars 113 are arranged in a diamond shape, that is, there are two different piezoresistive bar 113 distribution areas in the first dimension, and two different piezoresistive bar 113 distribution areas in the second dimension, the piezoresistive bars are electrically connected to form a Wheatstone bridge, and for example Figure 3 As shown, the pressure sensitive unit 110 is a rectangle, has a first dimension distributed longitudinally and a second dimension distributed transversely, four piezoresistive bars 113 are arranged along the edges of the rectangle, that is, one piezoresistive bar 113 is arranged on each edge of the rectangle, the piezoresistive bars are electrically connected to form a Wheatstone bridge, and for example Figure 4 As shown, the pressure sensitive unit 110 is a rectangle, mainly has a first dimension distributed longitudinally, four piezoresistive bars 113 are arranged transversely, different piezoresistive bars 113 are arranged at different positions in the first dimension, the piezoresistive bars are electrically connected to form a Wheatstone bridge, there are other piezoresistive bar arrangement modes, which will not be illustrated one by one in this embodiment.

[0058] In this embodiment and other embodiments in the detailed description, if not explicitly stated, it should be understood that it can be applicable to any one of the foregoing various pressure sensitive unit implementation manners. The pressure sensitive unit of this embodiment has an arrangement manner that, according to the pressure applied on the pressure sensitive unit, the pressure sensitive unit produces different deformations at at least two different positions in the first dimension, and further produces a pressure electric signal; specifically, the pressure sensitive unit can have only a distribution in the first dimension, or have a distribution in two or more dimensions including the first dimension (for example, a rectangle); since the pressure sensitive unit has a distribution in the first dimension, when the pressure is actually applied on the pressure sensitive unit, this distribution can cause the deformations of the pressure sensitive unit at different positions to be possibly different, that is, at least different deformations at two or more different positions in the first dimension, and this deformation can be continuous or discrete; for a specific deformation, the pressure sensitive unit will produce a specific electric signal, that is, a pressure electric signal, and identifying the pressure electric signal can achieve the purpose of pressure measurement.

[0059] Based on the foregoing pressure sensitive unit, this embodiment gives a sensor core.

[0060] The sensor core for a pressure sensor includes a core body, and the core body includes a pressure sensitive unit 110. The pressure sensitive unit 110 is distributed at least along a first dimension, and according to the pressure applied on the pressure sensitive unit 110, the pressure sensitive unit 110 produces different deformations at at least two different positions in the first dimension, and further produces a pressure electric signal; the core body extends along the first dimension on one side of the pressure sensitive unit 110, forms a stress isolation portion 400 and a core connecting portion 300, the stress isolation portion 400 is located between the core connecting portion 300 and the pressure sensitive unit 110, and the core connecting portion 300 is provided with at least one core wiring point 310, and the core wiring point 310 is electrically connected to the pressure sensitive unit 110 to transmit the pressure electric signal; in the working state, the core connecting portion 300 is used to connect a sensor base 500, so that the core body is fixedly arranged in the pressure sensor.

[0061] Specifically, in some cases, as shown in Figure 5 、 Figure 6 and Figure 7 , the core body includes a pressure sensitive layer 100 and a first substrate 210.

[0062] The pressure sensitive layer 100 is distributed along the first dimension (up and down direction in the drawing), the pressure sensitive layer 100 forms a pressure sensitive unit 110 at a position close to the first end (upper end in the drawing) of the pressure sensitive layer 100, two sides of the pressure sensitive unit 110 form a first pressure sensing surface 111 (towards the left direction in the drawing) and a second pressure sensing surface 112 (towards the right direction in the drawing) respectively, the first pressure sensing surface 111 is provided with a piezoresistive strip 113, the first pressure sensing surface 111 is also provided with a very thin pressure sensing oxide layer (not shown in the drawing, if the pressure sensitive layer 110 is made of monocrystalline silicon material, the pressure sensing oxide layer can be silicon oxide), the pressure sensing oxide layer is provided with a pressure sensitive connection circuit 114, the pressure sensitive connection circuit 114 establishes electrical connection between each piezoresistive strip 113, and forms a Huygens path bridge.

[0063] The pressure sensitive layer 100 extends to one side of the first dimension at the position where the pressure sensitive unit 110 is formed, in the drawing, the pressure sensitive unit 110 is located at a position close to the first end of the pressure sensitive layer 100, and the pressure sensitive layer 100 extends from the pressure sensitive unit 110 to a position close to the second end (lower end in the drawing) of the pressure sensitive layer 100.

[0064] The first substrate 210 and the pressure sensitive layer 100 have the same distribution in the first dimension, the first substrate 210 is bonded and fixed to one side of the pressure sensitive layer 100 where the first pressure sensing surface 111 is located, generally, the first substrate 210 can have the same material as the pressure sensitive layer 100, for example, both are monocrystalline silicon, in some cases, the first substrate 210 can also be an oxide of the pressure sensitive layer 100, for example, the pressure sensitive layer 100 is monocrystalline silicon, and the first substrate 210 is silicon oxide; in the area where the pressure sensitive unit 110 is located, the first substrate 210 is also etched with a groove structure on the side facing the pressure sensitive layer 100, so that the first pressure sensing cavity 211 is formed between the first substrate 210 and the pressure sensitive layer 100.

[0065] The core body main body forms a core body connection part 300 at a position close to the second end of the core body main body, it can be understood that the pressure sensitive layer 100 and the first substrate 210 jointly extend at the second end of the two to form the core body connection part 300; the core body connection part 300 forms a core body wiring point 310 at the second end surface (the end surface where the lower end in the drawing is located, that is, the end surface where the second end is located) of the core body connection part 300, a core body lead-out wire 320 is arranged on the surface of the pressure sensitive layer 100, one end of the core body lead-out wire 320 is connected to the pressure sensitive unit 110, specifically, to the pressure sensitive connection circuit 114, the other end of the core body lead-out wire 320 is connected to the core body wiring point 310, the core body wiring point 310 is electrically connected to the pressure sensitive unit 110 through the core body lead-out wire 320, so as to lead out the resistance signal of the Huygens path bridge to the core body wiring point 310 to transmit the pressure electric signal.

[0066] The core body main body forms a stress isolation portion 400 between the core body connecting portion 300 and the pressure sensitive unit 110, and the stress isolation portion 400 is formed by the pressure sensitive layer 100 and the first substrate 210 extending together, similar to the core body connecting portion 300.

[0067] In the working state, the core body connecting portion 300 is used to connect the sensor base 500, so that the core body main body is fixed in the pressure sensor. The embodiment provides a pressure sensor with the sensor core body. The pressure sensor comprises the sensor base 500. The sensor base 500 has a base fixing surface 510. The base fixing surface 510 is located on one side of the core body main body and perpendicular to the first dimension. The core body connecting portion 300 is fixedly connected to the base fixing surface 510. The sensor base 500 is further provided with an output connector 520. The output connector 520 is electrically connected to the core body connecting point 310 through a base connecting member, so as to transmit the pressure electric signal.

[0068] The sensor base 500 forms the base fixing surface 510 on the first end surface (the end surface where the upper end is located in the figure). The core body connecting portion 300 is fixedly connected to the base fixing surface 510 on the second end surface. The specific fixed connection mode can be gluing, welding, bonding and the like. The mode can be determined according to the material of the second end surface forming the core body connecting portion 300 and the material of the base fixing surface 510.

[0069] The sensor base 500 is provided with a base connecting point 530 on the base fixing surface 510. When the core body connecting portion 300 is fixedly connected to the sensor base 500, the base connecting point 530 is abuttingly connected to the core body connecting point 310. At this time, the pressure electric signal generated by the Huygens path bridge on the pressure sensitive unit 110 is transmitted to the output connector 520 through the pressure sensitive connecting circuit 114, the core body lead-out line 320, the core body connecting point 310, the base connecting point 530 and a base connecting member (not shown in the figure), so as to output the pressure electric signal to the outside of the pressure sensor. In some cases, the output connector 520 is electrically connected to a resistance measurement circuit 610. The resistance measurement circuit 610 is used to supply power to the Huygens path bridge in the pressure sensor and measure the corresponding pressure electric signal, so as to convert it into a digital signal. The output end signal of the resistance measurement circuit 610 is connected to a signal processing unit 640. The signal processing unit 640 processes according to the range of the pressure sensor and the signal output range, so as to convert the electric signal measurement value into the corresponding pressure measurement value.

[0070] The embodiment further provides a pressure sensor, which can be wholly or partially combined with the sensor core body and the pressure sensor.

[0071] The pressure sensor comprises a sensor core body and a sensor base 500; the sensor core body comprises a pressure sensitive unit 110, the pressure sensitive unit 110 is distributed along a first dimension, the pressure sensitive unit 110 generates different deformations at at least two different positions along the first dimension according to the pressure applied on the pressure sensitive unit 110, and further generates a pressure electric signal, the sensor core body extends along the first dimension at least on one side of the pressure sensitive unit 110, and forms a stress isolation part 400 and a sensor core connecting part 300, the stress isolation part 400 is located between the sensor core connecting part 300 and the pressure sensitive unit 110, the sensor core connecting part 300 is provided with at least one sensor core connecting point 310, and the sensor core connecting point 310 is electrically connected to the pressure sensitive unit 110; the sensor base 500 has a base fixing surface 510, the base fixing surface 510 is located on one side of the sensor core body and perpendicular to the first dimension, the sensor core connecting part 310 is fixedly connected to the base fixing surface 510, and the sensor base 500 is further provided with an output connector 520, the output connector 520 is electrically connected to the sensor core connecting point 310 through a base connecting part, so as to transmit the pressure electric signal.

[0072] In some cases, as shown in Figure 8 The sensor core body comprises a pressure sensitive layer 100, a first substrate 210 and a second substrate 220, and the sensor core body is distributed along a first dimension (left-right direction in the figure), wherein the pressure sensitive layer 100 is distributed along the first dimension, the pressure sensitive layer 100 forms a pressure sensitive unit 110 at a middle region thereof, two sides of the pressure sensitive unit 110 form a first pressure sensitive surface 111 (towards the lower direction in the figure) and a second pressure sensitive surface 112 (towards the upper direction in the figure) respectively, and the specific implementation form of the pressure sensitive unit 110 can refer to the description of the sensor core and the like in the foregoing description, which will not be described herein again.

[0073] The pressure sensitive layer 100 extends to two directions of the first dimension at the position where the pressure sensitive unit 110 is formed, in the figure, the pressure sensitive layer 100 extends from the pressure sensitive unit 110 towards a first direction (left direction in the figure), and sequentially forms the stress isolation part 400 and the sensor core connecting part 300 at a position close to a first end (left end in the figure) of the sensor core body, and the pressure sensitive layer 100 also extends from the pressure sensitive unit 110 towards a second direction (right direction in the figure), i.e. extends towards the opposite direction of the first direction, the first direction and the second direction are two directions of the first dimension, thereby forming a structure (which can be symmetrical or not symmetrical) which extends to both sides with the pressure sensitive unit 110 as the center.

[0074] The first substrate 210 and the pressure sensitive layer 100 have the same distribution in the first dimension, the first substrate 210 is bonded and fixed on the side of the pressure sensitive layer 100 having the first pressure sensing surface 111, and the first substrate 210 is etched with a groove structure on the side facing the pressure sensitive layer 100 in the area where the pressure sensitive unit 110 is located, so that the first pressure sensing cavity 211 is formed between the first substrate 210 and the pressure sensitive layer 100, and the first substrate 210 is provided with a connecting through hole at the bottom of the groove structure, so as to connect the first pressure sensing cavity 211 to the position of the second substrate 220.

[0075] The second substrate 220 and the first substrate 210 have the same distribution in the first dimension, when one side of the first substrate 210 is bonded and fixed with the pressure sensitive layer 100, the second substrate 220 is bonded to the other side of the first substrate 210, so that the second substrate 220 and the pressure sensitive layer 100 are respectively located on the opposite sides of the first substrate 210, in some cases, the second substrate 220 can be selected to have the same or similar material as the first substrate 210, for example, when the first substrate 210 is selected to be monocrystalline silicon, the second substrate 220 can be selected to be glass or ceramic material; the second substrate 220 is also provided with a groove structure on the side facing the first substrate 210, one end of the groove structure extends in the first direction until it reaches the first end of the second substrate 220, so as to form an opening on the first end surface (the left end surface in the figure) of the second substrate 220, the other end of the groove structure extends in the second direction until it reaches the position of the connecting through hole of the first substrate 210; after the first substrate 210 and the second substrate 220 are bonded and fixed, the groove structure on the second substrate 220 and the first substrate 210 form a core pressure guiding channel 340, one end of the core pressure guiding channel 340 is communicated to the core pressure guiding port 330 on the first end surface of the core body, the other end of the core pressure guiding channel 340 is communicated to the first pressure sensing cavity 211 through the connecting through hole of the first substrate 210, the core pressure guiding port 330 is communicated to the first pressure sensing cavity 211 through the pressure transmission channel, when the pressure medium enters the core pressure guiding port 330, it can be transmitted to the first pressure sensing surface 111 in the first pressure sensing cavity 211 through the communication structure, and then be recognized and measured by the pressure sensitive unit 110.

[0076] The pressure sensitive layer 100, the first substrate 210 and the second substrate 220 jointly form a stress isolation part 400 and a core connecting part 300 on the side of the core body deviating to the first end, and the stress isolation part 400 is located between the pressure sensitive unit 110 and the core connecting part 300.

[0077] The sensor base 500 is provided with a base mounting groove 540 on the surface of the base fixing surface 510. Specifically, the sensor base 500 is provided with a first base pressure lead 550 and a second base pressure lead 543, and the sensor base 500 is further provided with a base pressure lead channel 560, one end of the base pressure lead channel 560 is communicated to the first base pressure lead 550, and the other end of the base pressure lead channel 560 is communicated to the second base pressure lead 543, the base pressure lead channel 560 realizes the communication relationship between the first base pressure lead 550 and the second base pressure lead 543, the first base pressure lead 550 is arranged on the outer side of the sensor base 500 and is used to communicate with the external pressure to be measured, and the second base pressure lead 543 is arranged at the groove bottom of the base mounting groove 540; the sensor base 500 is provided with a base wiring point 530 on the surface of the base fixing surface 510. Further, the base mounting groove 540 has a smaller circumferential profile at the position close to the groove bottom, and has a larger circumferential profile at the position close to the groove opening, forming a step or a gradually changing structure, and the base mounting groove 540 is further provided with a base sealing groove, the base sealing groove is located at the groove bottom of the base mounting groove 540 and surrounds the second base pressure lead 543, and the base sealing groove is provided with a base sealing ring 542, generally, the base sealing ring 542 adopts sealing glue or the like, which can improve the stability of the fixed connection on one hand and is also easy to manufacture on the other hand.

[0078] The core connecting part 300 and the sensor base 500 have a fixed connection relationship with each other, specifically, the circumferential profile of the first end face of the core connecting part 300 is matched with the smaller circumferential profile in the base mounting groove 540, so that the core connecting part 300 can be arranged in the base mounting groove 540, at this time, the first end face of the core connecting part 300 and the groove bottom of the base mounting groove 540 abut and press the base sealing ring 542, so that the base sealing ring 542 seals and isolates the inside and outside of the ring, and at the same time, a base fixing ring 541 can be sintered between the core connecting part 300 and the larger circumferential profile of the base mounting groove 540, the inner side of the base fixing ring 541 surrounds the core connecting part 300 and is fixed with the core connecting part 300, and the outer side of the base fixing ring 541 is fixed with the base mounting groove 540, so as to fixedly connect the core connecting part 300 to the sensor base 500; at the same time, the position of the core pressure lead 330 is opposite to the second base pressure lead 543 (allowing a certain manufacturing error), so as to establish a pressure transmission line from the first base pressure lead 550, the base pressure lead channel 560, the second base pressure lead 543, the core pressure lead 330, the core pressure lead channel 340 to the first pressure sensing cavity 211, when the pressure medium reaches the first base pressure lead 550, it can reach the first pressure sensing cavity 211 along the pressure transmission line, realizing the transmission of pressure.

[0079] The core connecting part 300 is further provided with a core connecting point 310, which is electrically connected to the pressure sensitive unit 110 through a core lead wire (not shown in the figure). The sensor base 500 is provided with an output connector 520 and a base connecting point 530, which are electrically connected through a base connecting member. An electric connecting wire 531 is respectively overlapped on the core connecting point 310 and the base connecting point 530, so as to realize the electrical connection between the core connecting point 310 and the base connecting point 530.

[0080] The embodiment further provides a pressure sensor packaging module (hereinafter referred to as a packaging module), which can be combined with the sensor core and the pressure sensor in whole or in part. It can be understood that in some cases, the pressure sensor can refer to the same object as the packaging module.

[0081] As shown in Figure 9 The packaging module includes a core body and a sensor shell 500.

[0082] The sensor shell 500 forms a second pressure sensing cavity 571 on its inner side. The sensor shell 500 is provided with a packaging pressure lead port 572 at its second end (the upper end in the figure, which can also be the left end, the right end, the lower end, etc. The second end herein can be any end of the sensor shell 500). The packaging pressure lead port 572 is connected to the second pressure sensing cavity 571 through a packaging pressure lead channel 573. The sensor shell 500 forms a sensor base 500 at its first end. In some cases, the sensor shell 500 and the sensor base 500 are integrally formed or at least sealingly connected, so that the second pressure sensing cavity 571 is in a sealed state at positions other than the packaging pressure lead port 572 when the sensor core is packaged. During operation, according to the purpose of the packaging module, if the packaging module is used for absolute pressure measurement, the second pressure sensing cavity 571 can be vacuumized, and the packaging pressure lead port 572 is sealed. If the packaging module is used for gauge pressure measurement, the second pressure sensing cavity 571 can be filled with standard atmospheric pressure, and the packaging pressure lead port 572 is sealed. The packaging pressure lead port 572 can also be connected to an atmospheric module that provides atmospheric pressure. The packaging pressure lead port 572 can also be directly connected to the external atmosphere. If the packaging module is used for differential pressure measurement, the packaging pressure lead port 572 can be connected to one of the differential pressures.

[0083] The sensor base 500 is provided with an output connector (not shown in the figure) and a first base pressure lead 550 on the outside of the sensor shell 500, and on the inside of the sensor shell 500, the sensor base 500 forms a base fixing surface 510, which is provided with a second base pressure lead 543 and a base connecting point (not shown in the figure), the second base pressure lead 543 and the first base pressure lead 550 are in communication with each other through a base pressure lead channel 560, and the output connector (not shown in the figure) is electrically connected to the base connecting point through a base connecting member. In order to adapt to the fixing of the core body, the second base pressure lead 543 and part of the base pressure lead channel 560 protrude from the base fixing surface 510, forming a tubular structure that penetrates into the second pressure sensing cavity 571, and the tubular structure is integrated with the sensor shell 500 or fixed with each other.

[0084] The core body main body comprises a pressure sensitive layer 100 and a substrate layer 200, the specific structure of the pressure sensitive layer 100 can refer to the foregoing related description of the embodiment, the substrate layer 200 can only comprise the first substrate in the foregoing embodiment, can also comprise the first substrate and the second substrate in the foregoing embodiment, and can also comprise other structures; the pressure sensitive layer 100 comprises a pressure sensitive unit 110, a first pressure sensing cavity 211 is formed between the substrate layer 200 and the pressure sensitive unit 110, the substrate layer 200 and the pressure sensitive layer 100 are bonded and fixed at a position around the first pressure sensing cavity 211, the core body pressure leading channel 340 is arranged in the substrate layer 200, and one end of the core body pressure leading channel 340 is communicated to the first pressure sensing cavity 211; the pressure sensitive unit 110 is distributed along a first dimension (a dimension formed in the upward and downward direction in the figure); the pressure sensitive layer 100 extends (i.e. extends downward) along the first dimension at the first end (the lower end in the figure) of the pressure sensitive unit 110 to form part of the stress isolation part 400, and the substrate layer 200 has a distribution covering the pressure sensitive layer 100 in the first dimension, specifically, the substrate layer 200 also extends along the first dimension to the first direction (the downward direction in the figure) at the position corresponding to the pressure sensitive unit 110, first, another part of the stress isolation part 400 is formed, which is different from the pressure sensitive layer 100, the substrate layer 200 continues to extend and forms the core body connecting part 300, the core body connecting part 300 is provided with a core body wiring point (not shown in the figure) and a core body pressure leading opening 330, wherein the core body pressure leading opening 330 is communicated to the core body pressure leading channel 340; in the packaging state, the second base pressure leading opening 543 and part of the base pressure leading channel 560 are inserted into the core body pressure leading opening 330 and part of the core body pressure leading channel 340, and the two have mutually matched inner and outer diameters, in some cases, further sealing can also be performed by using sealing glue and the like, so as to form sealing isolation of the first pressure sensing cavity 211 and the second pressure sensing cavity 571, at this time, the first pressure sensing surface 111 of the pressure sensitive unit 110 contacts the first pressure sensing cavity 211, the second pressure sensing surface 112 of the pressure sensitive unit 110 contacts the second pressure sensing cavity 571, the core body wiring point and the base wiring point are electrically connected, so that the output connector is electrically connected to the pressure sensitive unit 110.

[0085] In the working process, the external measurement circuit is electrically connected to the output connector, the packaging module is powered on, the pressure sensitive unit generates a corresponding pressure electric signal according to the relative pressure of the first pressure sensing cavity 211 and the second pressure sensing cavity 571, the pressure electric signal is measured, and a corresponding pressure measurement result can be obtained.

[0086] Based on the sensor core and the pressure sensor provided in the embodiment, when the working temperature and the calibration temperature are different, for example, the working temperature is higher than the calibration temperature, the sensor base and the core body are both expanded due to heat, wherein the sensor base generates a larger temperature-induced deformation due to a larger thermal expansion coefficient, and the core body generates a smaller temperature-induced deformation due to a smaller thermal expansion coefficient. The deformation stress caused by the different amplitudes of the temperature-induced deformations will be generated. In the first dimension direction, since the fixed connection position between the sensor base and the core body is limited to the core connection part at one end of the core body, the deformation stress is not distributed in the first dimension (for example Figure 5 and Figure 6 ), or the deformation stress is only slightly distributed in the first dimension and the distribution area is limited to the core connection part, thereby eliminating the influence of the deformation stress on the pressure-sensitive unit in the first dimension and improving the measurement accuracy of the pressure-sensitive unit.

[0087] Further, if the fixed connection position between the sensor base and the core body is distributed in the third dimension, the third dimension and the first dimension (i.e., the dimension in which the pressure-sensitive unit is distributed) are perpendicular to each other. At this time, when the third dimension generates deformation stress due to temperature-induced deformation, on the one hand, the deformation stress will be absorbed by the stress isolation part in the transmission process, on the other hand, the part of the pressure-sensitive unit that deforms according to the measured pressure is a film structure, which has a very small thickness, that is, the distribution size in the third dimension is very small, much smaller than the length of the fixed connection position described above, which makes the deformation stress, even if it is transmitted to the position of the pressure-sensitive unit, only a small proportion will be transmitted to the pressure-sensitive unit, and the other will be distributed to the base part. On the other hand, the third dimension is not the distribution direction of the pressure-sensitive unit, but the perpendicular direction of the distribution direction of the pressure-sensitive unit, which makes the stress of the third dimension have no or almost no influence on the measurement accuracy of the pressure-sensitive unit. Based on the above aspects, the scheme of the embodiment can greatly weaken or even eliminate the influence of the deformation stress of the fixed connection position on the measurement accuracy of the pressure-sensitive unit.

[0088] In the scheme of the embodiment, hard glue can be used between the core body and the sensor base, and there is no need to worry about the stress transmission problem. In some cases, the use of soft glue is also possible.

[0089] In the scheme of the embodiment, since the temperature-induced deformation stress in the first dimension is eliminated, and the materials of the core body are the same or similar, it can be considered that the temperature-induced deformation of the pressure-sensitive unit and the core body is linear or nearly linear (determined by the material itself). In this case, since the temperature-induced deformation changes linearly,

[0090] The foregoing technical solutions of the present embodiment can be improved as follows. The improved examples and the foregoing technical solutions of the present embodiment are combined with each other to further solve the technical problems, and the technical features of each technical solution can be arbitrarily combined according to the possibility, and such a combination solution meeting the technical purpose of solving the technical problems of the present application should also be regarded as disclosed by the present embodiment and its improved examples. Some improved examples can include two parts of technical features, one part is the necessary technical feature for solving the technical problem, and the other part is the technical feature for better solving the technical problem or irrelevant to solving the technical problem. It can be understood that, from the minimum limit of solving the technical problem, part of the features of each improved example can be combined into the foregoing technical solutions of the present embodiment alone, or part of the features of two or more improved examples can be combined into the foregoing technical solutions of the present embodiment, and such a possible combination should also be regarded as disclosed by the present embodiment and its improved examples.

[0091] In the improved example one, the core body includes the pressure-sensitive layer 100, the first substrate 210, and the second substrate 220, the pressure-sensitive layer 100 includes the pressure-sensitive unit 110, the pressure-sensitive layer 100 and the first substrate 210 have the same distribution in the first dimension, the second substrate 220 has a distribution at least covering the first substrate 210 in the first dimension, one side of the first substrate 210 is bonded to the pressure-sensitive layer 100, and the other side of the first substrate 210 is bonded to the second substrate 220; the second substrate 220 forms the insulating fixed body 221 at the position of the core body connecting part 300, and the insulating fixed body 221 is used for adapting and fixing with the sensor base 500; the first substrate 210 and at least part of the pressure-sensitive layer 100 have a first thermal expansion coefficient, the second substrate 220 has a second thermal expansion coefficient, the second thermal expansion coefficient is greater than or equal to the first thermal expansion coefficient, and does not exceed three times of the first thermal expansion coefficient, and the improved example one can be combined with any of the foregoing technical solutions of the sensor core, the pressure sensor, and the packaging module of the present embodiment.

[0092] In the second improved example, the core body includes the pressure-sensitive layer 100, the first substrate 210, and the second substrate 220. The pressure-sensitive layer 100 includes the pressure-sensitive unit 110. The pressure-sensitive layer 100 and the first substrate 210 have the same distribution in the first dimension. The second substrate 220 has a distribution at least covering the first substrate 210 in the first dimension. One side of the first substrate 210 is bonded to the pressure-sensitive layer 100. The other side of the first substrate 210 is bonded to the second substrate 220. The second substrate 220 forms the insulating fixed body 221 at the position of the core connecting part 300. The insulating fixed body 221 and the base fixed surface 510 are adaptively fixed. The first substrate 210 and at least part of the pressure-sensitive layer 100 have a first thermal expansion coefficient. The second substrate 220 has a second thermal expansion coefficient. At least part of the sensor base 500 has a third thermal expansion coefficient. The second thermal expansion coefficient is greater than or equal to the first thermal expansion coefficient and does not exceed three times the first thermal expansion coefficient. The third thermal expansion coefficient is greater than the second thermal expansion coefficient. The second improved example can be combined with any of the sensor core, the pressure sensor, and the packaging module of the foregoing embodiments.

[0093] In the third improved example, the pressure-sensitive layer 100 has a first thickness. The first substrate 210 has a second thickness. The second substrate 220 has a third thickness. The second thickness is greater than the first thickness. The third thickness is not less than the sum of the first thickness and the second thickness. The third improved example can be combined with any of the sensor core, the pressure sensor, and the packaging module of the foregoing embodiments. The third improved example can also be combined with the first improved example (including the combination of the first improved example and other technical solutions) or the second improved example (including the combination of the second improved example and other technical solutions).

[0094] In the fourth improved example, the core connecting part 300 is provided with the support mounting hole 341 at the core connecting surface 350. The core connecting surface 350 is perpendicular to the first dimension. The support mounting hole 341 is formed at least by the second substrate 220 and is used for inserting the support column 561. The inner diameter of the support mounting hole 341 is adaptively matched with the support column 561. The axial direction of the support mounting hole 341 is distributed along the first dimension and is entirely located in the core connecting part 300. The fourth improved example can be combined with any of the sensor core, the pressure sensor, and the packaging module of the foregoing embodiments. The fourth improved example can also be combined with the first improved example (including the combination of the first improved example and other technical solutions), the second improved example (including the combination of the second improved example and other technical solutions), or the third improved example (including the combination of the third improved example and other technical solutions).

[0095] In the fifth improved example, the core connecting portion 300 is provided with a support mounting hole 341 on the core connecting surface 350, the base fixing surface 510 is provided with a support column 561, the core connecting portion 300 is fixedly connected to the base fixing surface 561, and at least part of the support column 561 is adapted to be inserted into the support mounting hole 341; the core connecting surface 350 is parallel to the base fixing surface 510; the support mounting hole 341 is formed by at least the second base 220, the axial direction of the support mounting hole 341 is distributed along the first dimension and all located in the core connecting portion 300, and the support column 561 is coaxial with the support mounting hole 341; the fifth improved example can be combined with any of the foregoing technical solutions of the sensor core, the pressure sensor and the packaging module, or combined with the first improved example (including the combination of the first improved example and other technical solutions), or combined with the second improved example (including the combination of the second improved example and other technical solutions), or combined with the third improved example (including the combination of the third improved example and other technical solutions).

[0096] In the sixth improved example, the pressure sensitive unit 110 has a first pressure sensing surface 111 and a second pressure sensing surface 112 on both sides, a first pressure sensing cavity 211 is arranged between the first base 210 and the first pressure sensing surface 111, the pressure sensitive unit 110 generates a pressure electric signal according to the relative pressure of the first pressure sensing cavity 111 and the second pressure sensing surface 112, the support mounting hole 341 is a blind hole and is communicated with the first pressure sensing cavity 211, and is used for introducing the pressure medium into the first pressure sensing cavity 211 through the through hole in the support column 561; the sixth improved example can be combined with the fourth improved example (including the combination of the fourth improved example and other technical solutions), or combined with the fifth improved example (including the combination of the fourth improved example and other technical solutions).

[0097] In the seventh improved example, the pressure sensitive unit 110 has a first pressure sensing surface 111 and a second pressure sensing surface 112 on both sides, the sensor base 500 surrounds a second pressure sensing cavity 571, the second pressure sensing surface 112 of the pressure sensitive unit 110 is exposed in the second pressure sensing cavity 571, a first pressure sensing cavity 211 is arranged between the first base 210 and the first pressure sensing surface 111, and the pressure sensitive unit 110 generates a pressure electric signal according to the relative pressure of the first pressure sensing cavity 211 and the second pressure sensing cavity 571; the support mounting hole 341 is a blind hole and is communicated with the first pressure sensing cavity 211, the middle part of the support column 561 is provided with a pressure introduction through hole 562, the sensor base 500 is provided with a first base pressure introduction port 550, and the sensor base 500 is provided with a base pressure introduction channel 560 which is communicated with the first base pressure introduction port 550 and the pressure introduction through hole 562, so that the pressure medium enters the first pressure sensing cavity 211 through the first base pressure introduction port 550; the seventh improved example can be combined with the fourth improved example (including the combination of the fourth improved example and other technical solutions), or combined with the fifth improved example (including the combination of the fourth improved example and other technical solutions).

[0098] In the eighth improved example, the surface of the core body is formed with a core lead structure, the core lead structure is continuous to the core connection point 310 and / or the pressure sensitive unit 110, one end of the core lead-out wire 320 is connected to the pressure sensitive unit 110, the other end of the core lead-out wire is connected to the core connection point 310, and at least part of the core lead-out wire 320 is attached to the core lead structure in an insulating manner, so that at least part of the core lead-out wire 320 is continuously fixed to the core body; the eighth improved example can be combined with any of the sensor core, the pressure sensor and the packaging module of the technical solutions of the foregoing embodiments, and can also be combined with any one of the first to seventh improved examples (including the combination of these improved examples and other technical solutions).

[0099] In the ninth improved example, the sensor base 500 is further provided with a base fixing groove 540 on the base fixing surface 510, the inner contour of the base fixing groove 540 is adapted to the outer contour of the core connecting part 300, and the core connecting part 300 is at least partially inserted into the base fixing groove 540; the pressure sensor (and / or the packaging module thereof) further comprises a fastening bolt 544, the fastening bolt 544 is threadedly connected to the sensor base 500, the core connecting part 300 is provided with a fastening bolt hole 360 adapted to the fastening bolt 544, and the core connecting part 300 is fixedly connected to the base fixing surface 510, including that one end of the fastening bolt 544 is exposed to the inner side surface of the base fixing groove 540 and is adapted to abut against the fastening bolt hole 360; the base connecting member comprises a connecting column 532, one end of the connecting column 532 is exposed to one inner side surface of the base fixing groove 540 and is arranged opposite to the fastening bolt 544, and the connecting column 532 is adapted to abut against the core connection point 310; the ninth improved example can be combined with any of the sensor core, the pressure sensor and the packaging module of the technical solutions of the foregoing embodiments, and can also be combined with any one of the first to eighth improved examples (including the combination of these improved examples and other technical solutions).

[0100] In the following, the foregoing improved examples are described in detail in combination with Figure 10 , Figure 11 , Figure 12 and Figure 13 .

[0101] The pressure sensor comprises a sensor housing 500 and a core body.

[0102] The whole of the core body is a cuboid, which is convenient for processing. The up-down direction in the figure is the first dimension. The core body is composed of the pressure-sensitive layer 100, the first substrate 210, and the second substrate 220 from left to right. The main material of the pressure-sensitive layer 100 and the first substrate 210 is monocrystalline silicon, and they have the same first thermal expansion coefficient. The main material of the second substrate 220 is glass (a material mainly composed of silicon oxide), and the second substrate 220 has a second thermal expansion coefficient. In this embodiment, the second thermal expansion coefficient is similar to the first thermal expansion coefficient, that is, the second thermal expansion coefficient is equal to or slightly greater than the first thermal expansion coefficient. The pressure-sensitive layer 100 and the first substrate 210 are bonded and fixed, and the first substrate 210 and the second substrate 220 are bonded and fixed. According to the direction of the figure, the left side of the first substrate 210 covers the right side of the pressure-sensitive layer 100, and the left side of the second substrate 220 covers the right side of the first substrate 210.

[0103] The pressure-sensitive layer 100, the first substrate 210, and the second substrate 220 have the same distribution in the first dimension, which allows multiple core bodies to be made on the same piece of raw material. For example, multiple pressure-sensitive layers are made on the same piece of monocrystalline silicon material, and the same number of first substrates are made on another piece of monocrystalline silicon, and the same number of second substrates are made on a piece of glass material. The materials are bonded in the order of the pressure-sensitive layer 100, the first substrate 210, and the second substrate 220, and then cut, so that multiple core bodies can be obtained at one time. This is suitable for the manufacture of pressure sensor cores of several millimeters or less in size corresponding to this embodiment.

[0104] To realize electrical connection, a very thin insulating layer 120 is provided on the surface of the pressure-sensitive layer 100. The piezoresistive strip 113 can be provided with a piezoresistive connection point 115 on the insulating layer 120. Further, the core lead-out wire 320 can be printed on the pressure-sensitive layer 100 by 3D printing or other processes. The core lead-out wire 320 realizes electrical connection with the piezoresistive strip 113 by contacting the piezoresistive connection point 115, so that the core lead-out wire 320 and the pressure-sensitive layer 100 or the core body have a fixed connection relationship. Since the core lead-out wire 320 is very thin, this fixed connection relationship does not cause significant stress changes. On the other hand, this fixed connection relationship can ensure the reliability of the core lead-out wire 320 and avoid line failure caused by vibration and other reasons.

[0105] In view of the single-side fixing structure of the sensor core body in the embodiment, the pressure-sensitive layer 100, the first substrate 210 and the second substrate 220 have certain thickness design requirements. Specifically, in order to ensure that the pressure-sensitive unit 110 has sufficient measurement sensitivity, the pressure-sensitive layer 100 should be designed to be thin enough, i.e., the first thickness of the pressure-sensitive layer 100 should be as small as possible. Correspondingly, in order to form the pressure-sensitive cavity and other pressure-sensitive structures, the first substrate 210 has a second thickness, and the second thickness should be greater than the first thickness. In order to ensure that the entire sensor core body has sufficient fixing strength after being fixed, the second substrate 220 has a third thickness, and the third thickness should be greater than or equal to the sum of the first thickness and the second thickness. Such a design can take into account the pressure-sensing sensitivity, reasonable pressure-sensing structure and reliable fixing strength. In some cases, when selecting the material of the second substrate 220, a material with the highest possible compressive strength can be selected, i.e., the second substrate 220 has a second compressive strength, the sensor housing 500 (sensor base) has a third compressive strength, and the second compressive strength is not less than half of the third compressive strength.

[0106] In the first direction (the direction from top to bottom in the figure), the core body formed by the pressure-sensitive layer 100, the first substrate 210 and the second substrate 220 successively forms the pressure-sensitive unit 110, the stress isolation portion 400 and the core body connecting portion 300. In order to more clearly illustrate the relationship between the three positions, the figure uses dashed lines to roughly mark the three positions. The reason for using dashed lines is that, in the actual manufacturing process, the pressure-sensitive unit 110, the stress isolation portion 400 and the core body connecting portion 300 are integrally formed in the first dimension, so there is actually no structural distinction between the three.

[0107] Since the second substrate 220 is made of glass material, which is a material with good insulation effect, the second substrate 220 forms an insulating fixed body 221 at the position of the core body connecting portion 300. The insulating fixed body 221 is the main force structure for cooperating with the sensor housing 500 for fixing. The insulating fixed body 221 forms a fastening bolt hole 360 on the side opposite to the first substrate 210. The surface of the fastening bolt hole 360 is located on the surface of the insulating fixed body 221. The fastening bolt hole 360 is a blind hole, and its hole diameter and depth are matched with the fixing structure on the sensor housing 500.

[0108] In this embodiment, the sensor shell 500 is provided for packaging and fixing the sensor core (i.e. the core body), the sensor shell 500 is mainly made of stainless steel, the sensor base 500 is a part of the sensor shell 500 (fixed or integrated with each other), the sensor base 500 has a third thermal expansion coefficient, which is greater than the second thermal expansion coefficient of the second base 220; thus, a step transfer structure of temperature-induced deformation stress is formed, that is, the second base 220 and the insulation fixing body 221 formed thereby are the main structures fixedly connected with the sensor base 500, therefore, the deformation stress between them is relatively small, and at the same time, the deformation stress needs to pass through the first base 210 before being transmitted to the pressure-sensitive layer 100, which can absorb the deformation stress to a certain extent.

[0109] The core connecting part 300 and the sensor base 500 have a matching fixing structure.

[0110] The lower end surface of the core connecting part 300 forms a core connecting surface 350, and a support mounting hole 341 is formed in the core connecting surface 350. Correspondingly, the upper end surface of the sensor base 500 forms a base fixing surface 510, and a support column 561 is arranged on the base fixing surface 510. The support column 561 can be made of the same material as the sensor base 500. The outer diameter of the support column 561 matches the inner diameter of the support mounting hole 341. The core connecting surface 350 is parallel to the base fixing surface 510, and the support column 561 is coaxial with the support mounting hole 341, so that the support column 561 can be fitted into the support mounting hole 341. This fitting relationship directly limits the relative movement between the core body and the sensor shell 500 in the first dimension. As shown, most of the hole wall of the support mounting hole 341 is formed by the second base 220. The axial direction of the support mounting hole 341 is distributed along the first dimension and does not exceed the range of the core connecting part 300, so that the fixing stress caused by this fitting fixing structure is limited within the range of the core connecting part 300. According to the foregoing analysis, on the one hand, the transmission of the fixing stress is absorbed by the stress isolation part 400, and on the other hand, the core body is in a free state at the end close to the pressure-sensitive unit 110, so that the fixing stress cannot be transmitted to the pressure-sensitive unit 110, thereby ensuring the accuracy of pressure measurement.

[0111] The matching structure of the support column 561 and the support mounting hole 341 can also be used to transmit pressure medium. Specifically, the pressure sensitive unit 110 forms a first pressure sensing surface 111 and a second pressure sensing surface 112 on its left and right sides, and the pressure sensitive unit 110 generates a pressure electric signal according to the relative pressure of the first pressure sensing surface 111 and the second pressure sensing surface 112. In order to ensure the stability and reliability of pressure transmission, the sensor housing 500 (sensor base 500) encloses a second pressure sensing cavity 571. Specifically, the sensor housing 500 forms the second pressure sensing cavity 571 on its inner side, and is configured to fill the second pressure sensing cavity 571 with pressure medium. The sensor housing 500 is provided with a packaging pressure introduction port 572 at its upper part, and the packaging pressure introduction port 572 is connected to the second pressure sensing cavity 571 through a packaging pressure introduction channel 573. The packaging pressure introduction port 572 can be used to fill the second pressure sensing cavity 571 with reference pressure or vacuum. The core body forms a first pressure sensing cavity 221 in its interior. Specifically, the first pressure sensing cavity 221 is formed between the first pressure sensing surface 111 of the pressure sensitive unit 110 and the first base 210. The support mounting hole 341 is a blind hole extending upward until it is connected to the first pressure sensing cavity 221, forming a core pressure introduction channel 340. The core pressure introduction channel 340 and the support mounting hole 341 can be integrated or have the same structure. Corresponding to the core pressure introduction channel 340 and the support mounting hole 341, the middle part of the support column 561 is provided with a pressure introduction through hole 562, which penetrates the support column 561 from top to bottom, thereby forming an opening at the upper end of the support column 561 and being connected to a base pressure introduction channel 560 at the lower end of the support column 561. In some cases, if the support column 561 and the sensor base 500 are integrated, the pressure introduction through hole 562 and the base pressure introduction channel 560 can also be integrated or have the same structure. If the support column 561 and the sensor base 500 are separate structures, the pressure introduction through hole 562 and the base pressure introduction channel 560 are generally separate. The base pressure introduction channel 560 is connected to the outer side of the sensor base 500, forming a first base pressure introduction port 550. Through the above structure, when the pressure medium enters the first base pressure introduction port 550, it can pass through the base pressure introduction channel 560, the pressure introduction through hole 562, the support mounting hole 341, the core pressure introduction channel 340, and finally reach the first pressure sensing cavity 221.

[0112] The sensor base 500 is further provided with a base fixing groove 540 on the base fixing surface 510. This structure can also be referred to as a base mounting groove 540. If the first dimension is taken as the axial direction, the circumferential inner contour of the base fixing groove 540 is adapted to the circumferential outer contour of the core connecting part 300. In a preferred case, the length of the base fixing groove 540 in the first dimension is also the same as the length of the core connecting part 300 in the first dimension. Thus, the core connecting part 300 can be placed in the base fixing groove 540 in whole or in part as needed. In combination with the cooperation structure of the support column 561 and the support mounting hole 341, the guided assembly can be achieved in cooperation.

[0113] Further, for fixation, the sensor base 500 is further provided with a fastening bolt 544 and a wiring post 532. The sensor base 500 is provided with a threaded hole for threadedly connecting the fastening bolt 544. One end of the fastening bolt 544 is exposed outside the sensor base 500 for assembly and maintenance. The other end of the fastening bolt 544 enters the bolt hole when threadedly connected. One opening of the aforementioned threaded hole is exposed on the surface of the base fixing groove 540. After further tightening, the other end of the fastening bolt 544 can be exposed in the base fixing groove 540. Further design is that the position of the fastening bolt 544 is directly opposite to the aforementioned insulating fixing body 221. Correspondingly, the insulating fixing body 221 is formed with a fastening bolt hole 360. The size and depth of the fastening bolt hole are matched with the fastening bolt 544. Thus, the insulating fixing body 221 and the support column 561 can form clamping on the second substrate 220. Further, the core connecting part 300 and the sensor base 500 are fixed to each other.

[0114] Further, the core wiring point 310 can adopt an elastic member or other elastic electric connection structure. In a preferred case, the core wiring point 310 and the fastening bolt hole 360 are located at opposite ends of the core body. Thus, when the support column 561 and / or the fastening bolt 544 form fixed limiting on the core connecting part 300, a leftward pushing force can be formed on the core wiring point 310. Correspondingly, the sensor base 500 further includes the wiring post 532. One end of the wiring post 532 is directly opposite to the core wiring point 310 and is exposed on the inner side of the base fixing groove 540. Thus, the wiring post 532 and the core wiring point 310 are abutted and connected.

[0115] The above description is only the preferred embodiment of the present application. On the basis of solving the technical problems, part of the technical features of the embodiment can be omitted or deformed into equivalent technical features. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A sensor core for use in a pressure sensor, characterized in that, It includes a core body, and the core body includes a pressure-sensitive unit; The pressure-sensitive units are distributed at least along the first dimension. Depending on the pressure applied to the pressure-sensitive units, the pressure-sensitive units undergo different deformations at at least two different positions in the first dimension, thereby generating pressure electrical signals. The core body extends along the first dimension on one side of the pressure-sensitive unit to form a stress isolation part and a core connecting part. The stress isolation part is located between the core connecting part and the pressure-sensitive unit. The core connecting part is provided with at least one core wiring point, which is electrically connected to the pressure-sensitive unit to transmit the pressure signal. In operation, the core connecting part is used to connect to the sensor base so that the core body is fixed inside the pressure sensor; The core body includes a pressure-sensitive layer, a first substrate, and a second substrate. The pressure-sensitive layer includes the pressure-sensitive unit. The pressure-sensitive layer and the first substrate have the same distribution in the first dimension. The second substrate has a distribution in the first dimension that at least covers the first substrate. One side of the first substrate is bonded to the pressure-sensitive layer, and the other side of the first substrate is bonded to the second substrate. The second substrate forms an insulating fixing body at the position of the core connection portion, the insulating fixing body being adapted and fixed to the sensor base; the first substrate and at least a portion of the pressure-sensitive layer have a first coefficient of thermal expansion, the second substrate has a second coefficient of thermal expansion, the second coefficient of thermal expansion being greater than or equal to the first coefficient of thermal expansion and not exceeding three times the first coefficient of thermal expansion.

2. The sensor core according to claim 1, characterized in that, The pressure-sensitive layer has a first thickness, the first substrate has a second thickness, the second substrate has a third thickness, the second thickness is greater than the first thickness, and the third thickness is not less than the sum of the first thickness and the second thickness.

3. The sensor core according to claim 1, characterized in that, The core connecting part has a support mounting hole on the core connecting surface. The core connecting surface is perpendicular to the first dimension. The support mounting hole is formed by at least the second base and is used to insert a support column. The inner diameter of the support mounting hole is adapted to the support column. The axial direction of the support mounting hole is distributed along the first dimension and is entirely located within the core connecting part. The pressure-sensitive unit has a first pressure-sensitive surface and a second pressure-sensitive surface on both sides, and a first pressure-sensitive cavity is provided between the first substrate and the first pressure-sensitive surface. The pressure-sensitive unit generates the pressure electrical signal according to the relative pressure between the first pressure-sensitive cavity and the second pressure-sensitive surface. The support mounting hole is a blind hole and is connected to the first pressure-sensing cavity, used to introduce pressure medium into the first pressure-sensing cavity through the through hole in the support column.

4. The sensor core according to claim 1, characterized in that, A core lead structure is formed on the surface of the core body. The core lead structure is continuous to the core connection point and / or the pressure-sensitive unit. One end of the core lead is connected to the pressure-sensitive unit, and the other end of the core lead is connected to the core connection point. At least a portion of the core lead is insulatedly attached to the core lead structure so that at least a portion of the core lead is continuously fixed to the core body.

5. A pressure sensor, characterized in that, Includes the core body and sensor base; The core body includes pressure-sensitive units distributed at least along a first dimension. Depending on the pressure applied to the pressure-sensitive units, the pressure-sensitive units undergo different deformations at at least two different positions along the first dimension, thereby generating a pressure electrical signal. The core body extends along the first dimension on at least one side of the pressure-sensitive units, forming a stress isolation portion and a core connecting portion. The stress isolation portion is located between the core connecting portion and the pressure-sensitive units. The core connecting portion is provided with at least one core wiring point, which is electrically connected to the pressure-sensitive units. The sensor base has a base fixing surface, which is located on one side of the core body and perpendicular to the first dimension. The core connecting part is fixedly connected to the base fixing surface. The sensor base is also provided with an output connector, which is electrically connected to the core connection point through a base connector to transmit the pressure signal. The core body includes a pressure-sensitive layer, a first substrate, and a second substrate. The pressure-sensitive layer includes the pressure-sensitive unit. The pressure-sensitive layer and the first substrate have the same distribution in the first dimension. The second substrate has a distribution in the first dimension that at least covers the first substrate. One side of the first substrate is bonded to the pressure-sensitive layer, and the other side of the first substrate is bonded to the second substrate. The second substrate forms an insulating fixing body at the position of the core connection part. The insulating fixing body is adapted and fixed to the base fixing surface. The first substrate and at least a portion of the pressure-sensitive layer have a first coefficient of thermal expansion. The second substrate has a second coefficient of thermal expansion. At least a portion of the sensor base has a third coefficient of thermal expansion. The second coefficient of thermal expansion is greater than or equal to the first coefficient of thermal expansion and does not exceed three times the first coefficient of thermal expansion. The third coefficient of thermal expansion is greater than the second coefficient of thermal expansion.

6. The pressure sensor according to claim 5, characterized in that, The pressure-sensitive layer has a first thickness, the first substrate has a second thickness, the second substrate has a third thickness, the second thickness is greater than the first thickness, and the third thickness is not less than the sum of the first thickness and the second thickness.

7. The pressure sensor according to claim 5, characterized in that, The core connecting part has a support mounting hole on the core connecting surface, and a support column is provided on the base fixing surface. The core connecting part is fixedly connected to the base fixing surface, including at least a portion of the support column being adapted to be inserted into the support mounting hole; the core connecting surface and the base fixing surface are parallel. The support mounting holes are formed at least by the second base, the axial direction of the support mounting holes is distributed along the first dimension and all are located within the core connection portion, and the support column and the support mounting holes are coaxial; The pressure-sensitive unit has a first pressure-sensitive surface and a second pressure-sensitive surface on both sides. The sensor base forms a second pressure-sensitive cavity. The second pressure-sensitive surface of the pressure-sensitive unit is exposed in the second pressure-sensitive cavity. A first pressure-sensitive cavity is provided between the first base and the first pressure-sensitive surface. The pressure-sensitive unit generates the pressure electrical signal according to the relative pressure between the first pressure-sensitive cavity and the second pressure-sensitive cavity. The support mounting hole is a blind hole and is connected to the first pressure-sensing cavity. The support column has a pressure-guiding through hole in the middle. The sensor base has a first base pressure-guiding port. The sensor base has a base pressure-guiding channel that connects the first base pressure-guiding port and the pressure-guiding through hole, so that the pressure medium enters through the first base pressure-guiding port and is transmitted to the first pressure-sensing cavity.

8. The pressure sensor according to claim 5, characterized in that, A core lead structure is formed on the surface of the core body. The core lead structure is continuous to the core connection point and / or the pressure-sensitive unit. One end of the core lead is connected to the pressure-sensitive unit, and the other end of the core lead is connected to the core connection point. At least a portion of the core lead is insulatedly attached to the core lead structure so that at least a portion of the core lead is continuously fixed to the core body.

9. The pressure sensor according to claim 5, characterized in that, The sensor base is further provided with a base fixing groove on the base fixing surface. The inner contour of the base fixing groove is adapted to the outer contour of the core connecting part. The core connecting part is at least partially inserted into the base fixing groove. The pressure sensor also includes a fastening bolt, which is threaded to the sensor base. The core connecting part has a fastening bolt hole adapted to the fastening bolt, and the core connecting part is fixedly connected to the base fixing surface. This includes the fastening bolt having one end protruding from the inner side of the base fixing groove and being adapted to abut against the fastening bolt hole; The base connector includes a terminal post, one end of which protrudes from an inner side of the base fixing groove and is disposed opposite to the fastening bolt. The terminal post is adapted to abut against the core connection point.

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