Piezoelectric vibration sensor module

Abstract

The present invention provides a piezoelectric vibration sensor module, which includes a damping substrate cover and a damping substrate base, a mass block, a piezoelectric cantilever arm, a fixed frame, and a charge (voltage) amplifier; wherein the mass block is suspended between the damping substrate cover and the damping substrate base through the piezoelectric cantilever arm, and the mass block receives external vibration signals, thereby driving the vibration of the piezoelectric cantilever arm, generating a piezoelectric sensing signal, forming a vertical piezoelectric vibration sensor module, realizing a vertical stop function, and improving the impact resistance of the piezoelectric vibration sensor module; at the same time, multiple open module units are superimposed and combined with the damping substrate base, multiple piezoelectric sensing signals are superimposed, and signal amplification is achieved through the charge (voltage) amplifier, thereby exponentially improving the sensitivity and reliability of the piezoelectric vibration sensor module, reducing process complexity, and saving wafer production costs.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-electromechanical systems, and in particular to a piezoelectric vibration sensor module. Background Art

[0002] Vibration monitoring is a key technology in modern industry and scientific research, crucial for health assessment, fault diagnosis, and predictive maintenance of equipment and buildings. As a core component of monitoring systems, the performance of vibration sensors directly impacts the accuracy and reliability of monitoring results. Vibration sensors can be categorized as piezoelectric, capacitive, and inertial. Piezoelectric vibration sensors offer advantages in sensitivity, frequency range, electronic noise, high-temperature resistance, and manufacturing cost. Traditional piezoelectric vibration sensors consist of a mass, a piezoelectric sensing element (e.g., a quartz crystal or piezoelectric ceramic), and a base. These sensors are bulky and heavy, often requiring additional signal processing circuitry, which increases system complexity and cost, making them less economical for small-batch production. The development of MEMS technology has revolutionized the field of vibration sensors. MEMS vibration sensors utilize microelectromechanical systems (MEMS) technology to integrate miniaturized mechanical structures and circuitry on a single chip, achieving miniaturization, intelligence, and cost-effectiveness. This has rapidly become a research hotspot for vibration sensors both domestically and internationally.

[0003] Piezoelectric vibration sensors utilize the bending piezoelectric effect of piezoelectric material D31 (lateral displacement mode of piezoelectric material) and are extremely susceptible to environmental vibration, impact, and high-frequency resonance, which can cause excessive displacement of the mass block and cause sensor failure. At the same time, a larger frequency detection range usually requires the device to have a higher resonant frequency, resulting in lower sensitivity and affecting the sensor's monitoring of tiny signals.

[0004] Therefore, how to provide a piezoelectric vibration sensor to solve the problems existing in the existing technology, improve the high sensitivity and high stability of the sensor, and enable it to accurately and in real time detect vibration signals in complex and changeable application scenarios has become an important technical problem that needs to be urgently solved by technical personnel in this field.

[0005] It should be noted that the above introduction to the technical background is merely intended to provide a clear and complete description of the technical solutions of this application and facilitate understanding by those skilled in the art. Simply because these solutions are described in the background technology section of this application, it should not be assumed that the above technical solutions are well known to those skilled in the art. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a piezoelectric vibration sensor module for solving the problem of how to improve the reliability and sensitivity of the sensor and reduce the production cost in the prior art.

[0007] To achieve the above objectives and other related objectives, the present invention provides a piezoelectric vibration sensor module, comprising:

[0008] A damping substrate, comprising a damping substrate cover and a damping substrate base; a fixing frame, disposed between the damping substrate cover and the damping substrate base, with a vibration cavity defined between the fixing frame, the damping substrate cover, and the damping substrate base;

[0009] a piezoelectric cantilever arm, the piezoelectric cantilever arm being connected to the fixed frame and being located in the vibration cavity;

[0010] A mass block is connected to the piezoelectric cantilever arm and suspended in the vibration cavity, the mass block includes a first end and a second end arranged opposite to each other, a first distance h1 is defined between the first end of the mass block and the damping substrate cover, and a second distance h2 is defined between the second end of the mass block and the damping substrate base.

[0011] Optionally, the maximum displacement distance of the mass block under the fracture strength of the piezoelectric cantilever arm is recorded as D100, 80% of D100 is recorded as D80, the range of the first distance h1 is D80≤h1≤D100, and the range of the second distance is D80≤h2≤D100.

[0012] Optionally, the damping substrate cover is provided with an electrical rewiring electrically connected to the piezoelectric cantilever arm; the piezoelectric vibration sensor module also includes a coupling layer, which is located between the damping substrate cover and the fixed frame and realizes the electrical connection between the damping substrate cover and the fixed frame.

[0013] Optionally, the piezoelectric cantilever arm includes a cantilever arm supporting layer and a piezoelectric layer. The thickness of the piezoelectric cantilever arm is in the range of 10 to 100 μm, and the thickness of the piezoelectric layer is in the range of 0.1 to 10 μm.

[0014] Optionally, the material of the piezoelectric layer includes one of aluminum nitride, lithium niobate, lead zirconate titanate and lithium tantalate.

[0015] Optionally, the piezoelectric cantilever arm, the mass block and the fixed frame are integrally formed by a semiconductor process.

[0016] Optionally, the piezoelectric vibration sensor module further includes a charge amplifier or a voltage amplifier electrically connected to the piezoelectric cantilever arm.

[0017] Optionally, the damping substrate cover, the fixed frame, the piezoelectric cantilever arm and the mass block form an open module unit, the piezoelectric vibration sensor module includes a damping substrate base and at least two stacked open module units, and adjacent open module units are electrically connected.

[0018] Optionally, the electrical connection between adjacent open-type module units includes series connection or parallel connection.

[0019] Optionally, the material of the damping substrate includes one of low temperature co-fired ceramics (LCLL), FR-4, copper, aluminum, and high temperature co-fired ceramics (HTCC).

[0020] As described above, the present invention provides a piezoelectric vibration sensor module, which includes a damping substrate cover and a damping substrate base, a mass block, a piezoelectric cantilever arm, a fixed frame, and a charge (voltage) amplifier; wherein the mass block is suspended between the damping substrate cover and the damping substrate base through the piezoelectric cantilever arm, and the mass block receives external vibration signals, thereby driving the vibration of the piezoelectric cantilever arm, generating a piezoelectric sensing signal, forming a vertical piezoelectric vibration sensor module, realizing a vertical stop function, and improving the impact resistance of the piezoelectric vibration sensor module; at the same time, multiple piezoelectric vibration sensor units are superimposed, multiple piezoelectric sensing signals are superimposed, and signal amplification is achieved through the charge (voltage) amplifier, which exponentially improves the sensitivity and reliability of the piezoelectric vibration sensor module, reduces the process complexity, and saves the wafer cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figures 1 to 3 Shown is a schematic diagram of the three-dimensional structure of the piezoelectric vibration sensor module of the present invention.

[0022] Figures 4 to 6 Schematic diagrams of the cross-sectional structure of the piezoelectric vibration sensor module along the AA direction in different states are shown according to the first embodiment of the present invention.

[0023] Figures 7 and 8 Shown is a schematic cross-sectional structure diagram of a piezoelectric vibration sensor module according to a second embodiment of the present invention.

[0024] Figures 9 and 10 Shown is a schematic diagram of the electrical connections of the piezoelectric vibration sensor module of the present invention.

[0025] Description of Reference Numerals

[0026] 100 Damping base plate base

[0027] 110 electrical leads

[0028] 120 amplifier

[0029] 121 Charge Amplifier

[0030] 122 Voltage Amplifier

[0031] 130 bulge

[0032] 200 fixed frame

[0033] 300 Piezoelectric Cantilever Arm

[0034] 400 mass blocks

[0035] 500 coupling layers

[0036] 600 Damping Base Plate Cover

[0037] 700 Vibration Chamber

[0038] 800 open module unit DETAILED DESCRIPTION

[0039] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0040] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0041] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] Example 1

[0043] See Figures 1 to 6 In order to solve the problems existing in the existing technology, improve the reliability and high stability of piezoelectric vibration sensors, and enable them to accurately and real-time detect vibration signals in complex and changing application scenarios, refer to Figures 1 and 2 is a schematic diagram of the three-dimensional structure of the piezoelectric vibration sensor module of the present invention, Figure 3 Display as Figure 1 and Figure 2Schematic diagram of the three-dimensional structure inside the piezoelectric vibration sensor module. Specifically, the piezoelectric vibration sensor module includes:

[0044] Damping substrate (not labeled), fixed frame 200 , piezoelectric cantilever arm 300 and mass block 400 .

[0045] The damping substrate includes a damping substrate cover 600 and a damping substrate base 100; the fixing frame 200 is arranged between the damping substrate cover 600 and the damping substrate base 100, and a vibration cavity 700 is provided between the fixing frame 200, the damping substrate cover 600 and the damping substrate base 100.

[0046] As examples, the damping substrate material includes low-temperature co-fired ceramic (LTCC), FR-4, copper, aluminum, and high-temperature co-fired ceramic (HTCC). The damping substrate provides mechanical damping and enhances mechanical stability for the piezoelectric vibration sensor module. The damping substrate is provided with electrical rewiring, which collects and conducts subsequent electrical signals.

[0047] Specifically, the material of the fixing frame 200 includes one of semiconductor materials, ceramic materials, metal materials and organic materials. The selection of materials usually depends on factors such as specific application requirements, material compatibility and cost-effectiveness.

[0048] As an example, to facilitate fabrication and utilize MEMS technology, the fixed frame 200 in this embodiment is made of semiconductor Si. The fixed frame 200 provides stable support for the piezoelectric cantilever arm 300, ensuring that the piezoelectric cantilever arm 300 can accurately move and respond when subjected to external vibration and acceleration.

[0049] As an example, the piezoelectric cantilever arm 300 is connected to the fixed frame 200 and is located in the vibration cavity 700 .

[0050] See Figure 4 In this embodiment, the piezoelectric cantilever arm 300 is located in the vibration cavity 700 , and the upper end of the piezoelectric cantilever arm 300 is connected to the upper part of the fixed frame 200 .

[0051] Specifically, the piezoelectric cantilever arm 300 includes a supporting cantilever arm layer (unlabeled) and a piezoelectric layer (unlabeled). The thickness range of the piezoelectric cantilever arm 300 is 10 to 100 μm, for example, 10 μm, 15 μm, 20 μm, 30 μm, 50 μm, 70 μm, 90 μm, 100 μm, or any value within this range. The thickness range of the piezoelectric layer is 0.1 to 10 μm, for example, 0.1 μm, 0.5 μm, 1.5 μm, 2 μm, 4 μm, 7 μm, 9 μm, 10 μm, or any value within this range.

[0052] Furthermore, the material of the piezoelectric layer includes one of aluminum nitride, lithium niobate, lead zirconate titanate and lithium tantalate. In this embodiment, the piezoelectric material used by the piezoelectric cantilever arm 300 is aluminum nitride.

[0053] For example, see Figure 3 The piezoelectric cantilever arm 300 can be distributed in an umbrella shape around the mass block 400, and the piezoelectric cantilever arm 300 has a hollowed-out shape. In some other embodiments, the piezoelectric cantilever arm 300 can also be hollowed-out in a square shape or other shapes to ensure that one end can be connected to the fixed frame 200.

[0054] The mass block 400 is connected to the piezoelectric cantilever arm 300 and is suspended in the vibration cavity 700. The mass block 400 includes a first end and a second end arranged opposite to each other. There is a first distance h1 between the first end of the mass block 400 and the damping substrate cover 600, and there is a second distance h2 between the second end of the mass block 400 and the damping substrate base 100.

[0055] Specifically, the maximum displacement distance of the mass block 400 under the fracture strength of the piezoelectric cantilever arm 300 is D 100 , D 100 80% of 80 The range of the first distance h1 is D 80 ≤h1≤D 100 , the range of the second distance h2 is D 80 ≤h2≤D 100 .

[0056] In this embodiment, the first distance h1 is 10 μm. This value can be achieved by providing protrusions 130 at the four corners of the damping substrate. Taking into account factors such as machining errors, installation accuracy, and margins of the mass block 400, the first distance h1 can be set to 15 μm. The value of the first distance h1 is designed based on a structure made of Si material. Similarly, the value of the second distance h2 is similar to the setting method of the first distance h1.

[0057] As an example, the mass block 400 may be a cylindrical mass block or a prismatic mass block. The mass block 400 is electrically connected to the piezoelectric cantilever arm 300 and is suspended in the vibration cavity 700 .

[0058] Furthermore, the piezoelectric cantilever arm 300, the mass 400, and the fixed frame 200 can be integrally formed using a semiconductor process. In this embodiment, a layer of piezoelectric material is deposited on a single crystal silicon-on-insulator (SOI) wafer (not labeled). The SOI wafer comprises a top silicon layer, an insulating layer, and a base silicon layer. An etching process is then performed to form the piezoelectric cantilever arm 300 structure within the piezoelectric material and the top silicon layer. The base silicon layer is then back-etched to form the mass 400. In other embodiments, the piezoelectric cantilever arm 300, the mass 400, and the fixed frame 200 can also be formed using other processes. In this embodiment, the mass 400 is a cylindrical mass, and the piezoelectric cantilever arm is an umbrella-shaped cantilever arm corresponding to the cylindrical mass structure. In other embodiments, the mass 400 is a prismatic structure, and the piezoelectric cantilever arm is an umbrella-shaped cantilever arm corresponding to the prismatic structure; these will not be described in detail here.

[0059] As an example, in order to make the connection between the damping substrate and the fixed frame 200 more stable, the piezoelectric vibration sensor module is further provided with a coupling layer 500 to increase stability; the coupling layer 500 is located between the damping substrate and the fixed frame 200 and realizes the electrical connection between the damping substrate and the piezoelectric cantilever arm 300, that is, the coupling layer 500 transmits the electrical signal generated by the vibration of the mass block 400 to the damping substrate through the piezoelectric cantilever arm 300, thereby enhancing the signal transmission of the damping substrate.

[0060] Furthermore, the material of the coupling layer 500 includes gold-aluminum, aluminum-germanium, copper-tin, etc.

[0061] Example 2

[0062] See Figures 7 to 10 In order to further improve the sensitivity of the piezoelectric vibration sensor, this embodiment proposes a piezoelectric vibration sensor module. The difference between this embodiment and Example 1 is that the piezoelectric vibration sensor module of this embodiment includes multiple opening module units 800. The piezoelectric vibration sensor module is specifically introduced below.

[0063] See Figure 7The piezoelectric vibration sensor module includes a damping substrate base 100 and a plurality of open module units 800, wherein adjacent open module units 800 are electrically connected. The plurality of open module units 800 include a damping substrate cover plate 600, a fixed frame 200, a piezoelectric cantilever arm 300, and a mass block 400. The plurality of damping substrate cover plates 600 and the damping substrate base 100 are arranged in sequence in a vertical direction to form a damping substrate.

[0064] As an example, the damping substrate material includes low-temperature co-fired ceramic (LTCC), FR-4, copper, aluminum, and high-temperature co-fired ceramic (HTCC). The damping substrate provides mechanical damping and enhances mechanical stability for the piezoelectric vibration sensor module. That is, when the piezoelectric vibration sensor is subjected to large vertical displacements in the positive and negative directions, the damping substrate can prevent mechanical damage caused by large-scale vibration and impact. In addition, the damping substrate is provided with electrical rewiring to enable subsequent collection and conduction of electrical signals.

[0065] The fixing frame 200 is arranged between the damping substrate cover 600 and the damping substrate base 100, and a vibration cavity 700 is provided between the fixing frame 200, the damping substrate cover 600 and the damping substrate base 100; the electrical connection method of adjacent open-type module units 800 includes series connection or parallel connection.

[0066] Specifically, the material of the fixing frame 200 includes one of semiconductor materials, ceramic materials, metal materials and organic materials. The selection of materials usually depends on factors such as specific application requirements, material compatibility and cost-effectiveness.

[0067] As an example, to facilitate fabrication and utilize MEMS technology, the fixed frame 200 in this embodiment is made of semiconductor Si. The fixed frame 200 provides stable support for the piezoelectric cantilever arm 300, ensuring that the piezoelectric cantilever arm 300 can accurately move and respond when subjected to external vibration and acceleration. The damping substrate and the fixed frame can be connected by metal bonding or gluing.

[0068] As an example, the piezoelectric cantilever arm 300 is connected to the fixed frame 200 and is located in the vibration cavity 700 .

[0069] See Figure 7 In this embodiment, the piezoelectric cantilever arm 300 is located in the vibration cavity 700 , and the upper end of the piezoelectric cantilever arm 300 is connected to the upper part of the fixed frame 200 .

[0070] Specifically, the piezoelectric cantilever arm 300 includes a supporting cantilever arm layer (unlabeled) and a piezoelectric layer (unlabeled). The thickness range of the piezoelectric cantilever arm 300 is 10 to 100 μm, for example, 10 μm, 15 μm, 20 μm, 30 μm, 50 μm, 70 μm, 90 μm, 100 μm, or any value within this range. The thickness range of the piezoelectric layer is 0.1 to 10 μm, for example, 0.1 μm, 0.5 μm, 1.5 μm, 2 μm, 4 μm, 7 μm, 9 μm, 10 μm, or any value within this range.

[0071] Furthermore, the material of the piezoelectric layer includes one of aluminum nitride, lithium niobate, lead zirconate titanate and lithium tantalate. In this embodiment, the piezoelectric material used by the piezoelectric cantilever arm 300 is aluminum nitride.

[0072] For example, see Figure 3 The piezoelectric cantilever arm 300 can be distributed in an umbrella shape around the mass block 400, and the piezoelectric cantilever arm 300 has a hollowed-out shape. In some other embodiments, the piezoelectric cantilever arm 300 can also be hollowed-out in a square shape or other shapes to ensure that one end can be connected to the fixed frame 200.

[0073] The mass block 400 is connected to the piezoelectric cantilever arm 300 and is suspended in the vibration cavity 700. The mass block 400 includes a first end and a second end that are oppositely disposed. Figure 4 There is a first distance h1 between the first end of the mass block 400 and the damping substrate cover 600 , and there is a first distance h2 between the second end of the mass block 400 and the damping substrate base 100 .

[0074] Specifically, the maximum displacement distance of the mass block 400 under the fracture strength of the piezoelectric cantilever arm 300 is D 100 , D 100 80% of 80 The range of the first distance h1 is D 80 ≤h1≤D 100 , the range of the second distance h2 is D 80 ≤h2≤D 100 .

[0075] In this embodiment, the first distance h1 is 10 μm, which can be achieved by providing protrusions 130 at the four corners of the damping substrate. Taking into account factors such as the processing error, installation accuracy and margin of the mass block 400, the first distance h1 can be set to 15 μm. The value of the first distance h1 described here is designed under the structure based on Si material; similarly, the value of the second distance h2 is the same.

[0076] The first distance h1 is set in a similar manner.

[0077] As an example, the mass block 400 may be a cylindrical mass block or a prismatic mass block, wherein the mass block 400 is electrically connected to the piezoelectric cantilever arm 300 and is suspended in the vibration cavity 700 .

[0078] For details, see Figure 5 and Figure 6 By setting the moving distance of the mass block 400 at 100% of the fracture strength of the piezoelectric cantilever arm 300, the problem of mechanical fracture of the piezoelectric cantilever arm 300 during movement can be further reduced, thereby realizing the stopping function of the piezoelectric vibration sensor module in the vertical direction and improving the impact resistance of the sensor.

[0079] Furthermore, the piezoelectric cantilever arm 300, the mass 400, and the fixed frame 200 are integrally formed using a semiconductor process. In this embodiment, a layer of piezoelectric material is deposited on a single crystal silicon-on-insulator (SOI) wafer (not labeled). The SOI wafer comprises a top silicon layer, an insulating layer, and a base silicon layer. An etching process is performed to form the piezoelectric cantilever arm 300 structure within the piezoelectric material and the top silicon layer. The base silicon layer is then back-etched to form the mass 400. In other embodiments, the piezoelectric cantilever arm, the mass 400, and the fixed frame 200 may also be formed using other processes. In this embodiment, the mass 400 is cylindrical, and the piezoelectric cantilever arm is an umbrella-shaped cantilever arm corresponding to the cylindrical mass 400 structure. In other embodiments, the mass 400 is a prismatic structure, and the piezoelectric cantilever arm is an umbrella-shaped cantilever arm corresponding to the prismatic structure; these will not be described in detail here.

[0080] In this embodiment, the damping substrate cover 600, the fixed frame 200, the piezoelectric cantilever arm 300 and the mass block 400 constitute an open module unit 800; the piezoelectric vibration sensor module includes a damping substrate base 100 and at least two stacked open module units 800, and adjacent open module units 800 are electrically connected.

[0081] As an example, the piezoelectric vibration sensor module includes one damping substrate base 100 and three stacked opening module units 800 , and adjacent opening module units 800 are electrically connected.

[0082] Furthermore, the damping substrate cover 600 of the lower opening module unit 800 is electrically connected to the piezoelectric cantilever arm 300 of the upper opening module unit 800 .

[0083] Furthermore, the piezoelectric vibration sensor module further includes an amplifier 120 , and the amplifier 120 includes a charge amplifier 121 or a voltage amplifier 122 . The charge amplifier 121 or the voltage amplifier 122 is located on the damping substrate base 100 to achieve signal amplification.

[0084] As an example, in order to make the connection between the damping substrate and the fixed frame 200 more stable, the piezoelectric vibration sensor module can also be provided with a coupling layer 500; the coupling layer 500 is located between the damping substrate and the fixed frame 200 and realizes the electrical connection between the damping substrate and the piezoelectric cantilever arm 300, that is, the coupling layer 500 transmits the electrical signal generated by the vibration of the mass block 400 to the damping substrate through the piezoelectric cantilever arm 300, thereby enhancing the signal transmission of the damping substrate.

[0085] Generally, MEMS piezoelectric vibration sensor modules with a large frequency response range usually require a higher resonant frequency. The expression formula of resonant frequency f and sensitivity S is as follows:

[0086]

[0087]

[0088] When the resonant frequency of the MEMS piezoelectric vibration sensor module is required to be high, the device needs to have a smaller mass, that is, the size of the device is required to be smaller, and the smaller mass will lead to a decrease in the sensitivity of the device. In this embodiment, the multiple opening module units 800 of the piezoelectric vibration sensor module are stacked, and each of the opening module units 800 is stacked in the vertical direction through the coupling layer 500 and the damping substrate cover 600 to realize the stacking configuration in the vertical direction and the piezoelectric cantilever arm 300 of the electrical connection layer when receiving vibration excitation will produce deformation, and the signal is converted into an electrical signal, which is transmitted to the amplifier 120 through the electrical lead 110 provided on the damping substrate for signal amplification and output. Under the premise of not increasing the area in the horizontal plane (XY plane), the multiple opening module units 800 are stacked along the vertical (Z axis) direction, thereby achieving a multiple increase in the sensitivity of the piezoelectric vibration sensor module, optimizing the space utilization of the sensor, and enhancing the device's detection capability of vibration signals.

[0089] See Figure 8In this embodiment, the three opening module units 800 are stacked in the vertical direction. According to actual needs, the three opening module units 800 are connected in series or in parallel to achieve further amplification of charge or voltage and improve the sensitivity of the piezoelectric vibration sensor module; the piezoelectric vibration sensor module can allow the selection of an appropriate electrical connection method according to the type of the amplifier 120 to achieve optimal sensor performance; further, the material of the coupling layer 500 includes gold-aluminum, aluminum-germanium, copper-tin materials, etc.

[0090] Furthermore, when the charge amplifier 121 is used for charge amplification, the connection method of the piezoelectric vibration sensor module formed by stacking multiple opening module units 800 is as follows: Figure 9 The multiple opening module units 800 are stacked and the electrical signals are connected in parallel, and then connected to the charge amplifier 121. The charge amplifier 121 is placed on the damping substrate base 100 and connected to the electrical signal of the stacked structure through the electrical lead 110.

[0091] When the voltage amplifier 122 is used to amplify the voltage, the connection method of the piezoelectric vibration sensor module formed by stacking multiple opening module units 800 is as follows: Figure 10 The multiple opening module units 800 are stacked and the electrical signals are connected in series, and then connected to the voltage amplifier 122. The voltage amplifier 122 is placed on the damping substrate base 100 and is connected to the electrical signal of the stacked structure through the electrical lead 110. In addition, the stacked structure adopted by the piezoelectric vibration sensor module is to assemble N opening module units 800 through subsequent processing and can be stacked on each other by simultaneous bonding, thereby avoiding the temperature difference caused by the distributed bonding process affecting the performance of the device. In other embodiments, the processing and assembly can also be connected by gluing, while ensuring the consistency and reliability of the piezoelectric vibration sensor module, reducing the complexity of the process manufacturing, reducing the wafer cost, and improving the economic benefits.

[0092] In summary, the present invention provides a piezoelectric vibration sensor module, which includes a damping substrate cover and a damping substrate base, a mass block, a piezoelectric cantilever arm, a fixed frame, and a charge (voltage) amplifier; wherein the mass block is suspended in the vibration cavity by the piezoelectric cantilever arm, and the mass block receives external vibration signals, drives the vibration of the piezoelectric cantilever arm, generates a piezoelectric sensing signal, forms a vertical piezoelectric vibration sensor module, realizes a vertical stop function, and improves the impact resistance of the piezoelectric vibration sensor module; at the same time, multiple piezoelectric vibration sensor units are superimposed, multiple piezoelectric sensing signals are superimposed, and the signal is amplified by the charge (voltage) amplifier, which multiplies the sensitivity and reliability of the piezoelectric vibration sensor module, reduces the process complexity, and saves the wafer cost. Therefore, the present invention effectively overcomes the various shortcomings in the prior art and has a high industrial utilization value.

[0093] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A piezoelectric vibration sensor module, characterized in that: The piezoelectric vibration sensor module includes: A damping substrate, comprising a damping substrate cover and a damping substrate base; A fixed frame, the fixed frame being disposed between the damping substrate cover and the damping substrate base, and a vibration cavity being defined between the fixed frame, the damping substrate cover and the damping substrate base; a piezoelectric cantilever arm, the piezoelectric cantilever arm being connected to the fixed frame and being located in the vibration cavity, the damping substrate cover being provided with an electrical rewiring electrically connected to the piezoelectric cantilever arm; A mass block is connected to the piezoelectric cantilever arm and suspended in the vibration cavity. The mass block includes a first end and a second end arranged opposite to each other. A first distance h1 is defined between the first end of the mass block and the damping substrate cover, and a second distance h2 is defined between the second end of the mass block and the damping substrate base. The maximum displacement distance of the mass block under the fracture strength of the piezoelectric cantilever arm is recorded as D 100 , D 100 80% of 80 , the range of the first distance h1 is D 80 ≤h1≤D 100 , the range of the second distance h2 is D 80 ≤h2≤D 100 ; The fixed frame, the piezoelectric cantilever arm and the mass block are integrated by using MEMS technology; The damping substrate cover, the fixed frame, the piezoelectric cantilever arm and the mass block constitute an open module unit. The piezoelectric vibration sensor module also includes a damping substrate base and at least two stacked open module units, and adjacent open module units are electrically connected.

2. The piezoelectric vibration sensor module according to claim 1, wherein: The piezoelectric vibration sensor module further includes a coupling layer, which is located between the damping substrate cover and the fixed frame and realizes electrical connection between the damping substrate cover and the fixed frame.

3. The piezoelectric vibration sensor module according to claim 1, wherein: The piezoelectric cantilever arm includes a cantilever arm supporting layer and a piezoelectric layer. The thickness of the piezoelectric cantilever arm is in the range of 10 to 100 μm, and the thickness of the piezoelectric layer is in the range of 0.1 to 10 μm.

4. The piezoelectric vibration sensor module according to claim 3, wherein: The material of the piezoelectric layer includes one of aluminum nitride, lithium niobate, lead zirconate titanate and lithium tantalate.

5. The piezoelectric vibration sensor module according to claim 1, wherein: The piezoelectric cantilever arm, the mass block and the fixing frame are integrally formed by a semiconductor process.

6. The piezoelectric vibration sensor module according to any one of claims 1 to 5, characterized in that: The piezoelectric vibration sensor module further includes a charge amplifier or a voltage amplifier electrically connected to the piezoelectric cantilever arm.

7. The piezoelectric vibration sensor module according to claim 1, wherein: The electrical connection between the adjacent opening module units includes series connection or parallel connection.

8. The piezoelectric vibration sensor module according to claim 1, wherein: The material of the damping substrate includes one of low temperature co-fired ceramics (LCLL), FR-4, copper, aluminum, and high temperature co-fired ceramics (HTCC).

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