Pressure sensor and pressure sensing device

Abstract

The embodiment of the invention discloses a pressure sensor and a pressure sensing device, relates to the technical field of micro-electronic machinery, and at least can improve the frequency stability. The pressure sensor comprises a first resonance module and a second resonance module which are independently arranged. Under the action of the same pressure, differential signals are formed between signals generated by the first resonance module and signals generated by the second resonance module; each of the first resonance module and the second resonance module comprises at least two resonance units. The resonance unit comprises a resonance structure. The resonant structure comprises a first resonant beam and at least two second resonant beams which are connected with each other. In the same resonance module, the resonance structures of at least two resonance units are connected along a first direction; and the vibration directions of the resonance structures of the two adjacent resonance units are opposite. Some embodiments of the present disclosure provide a pressure sensor for measuring pressure.

Description

Technical Field

[0001] This disclosure relates to the field of microelectromechanical technology, and in particular to a pressure sensor and pressure sensing device. Background Technology

[0002] Micro-Electro-Mechanical System (MEMS) pressure sensors are miniature devices with pressure detection capabilities fabricated using MEMS technology. They are mainly divided into three categories: piezoresistive, capacitive, and resonant, and can be applied in fields such as consumer electronics and industrial production. Among them, resonant MEMS pressure sensors have advantages such as high measurement accuracy and good performance, and have been widely used.

[0003] In related technologies, resonant MEMS pressure sensors include a resonant structure disposed on a pressure-sensitive membrane. Under external pressure, the pressure-sensitive membrane deforms, generating stress. This stress is transmitted to the resonant structure, causing a change in its stiffness, which in turn changes its resonant frequency. Therefore, the magnitude of the external pressure can be reflected by the change in the resonant frequency.

[0004] In some implementations, resonant MEMS pressure sensors suffer from low frequency stability, which can affect the performance of the pressure sensor. Summary of the Invention

[0005] Some embodiments of this disclosure provide a pressure sensor and pressure sensing device, at least for improving frequency stability.

[0006] In a first aspect, a pressure sensor is provided. The pressure sensor includes independently arranged first and second resonant modules; under the same pressure, a differential signal is formed between the signals generated by the first and second resonant modules. Both the first and second resonant modules include at least two resonant units. Each resonant unit includes a resonant structure. The resonant structure includes a first resonant beam and at least two second resonant beams connected together. The at least two second resonant beams are respectively arranged on both sides of the first resonant beam in a first direction, which is the vibration direction of the resonant structure. Within the same resonant module, the resonant structures of at least two resonant units are connected along the first direction; the vibration directions of the resonant structures of two adjacent resonant units are opposite.

[0007] Understandably, on the one hand, by subtracting the resonant frequencies corresponding to the first and second resonant modules, a frequency change value directly related to pressure can be obtained, and this frequency change value is twice the frequency change value generated by a single resonant module, which can improve the sensitivity of the pressure sensor. Alternatively, the resonant frequencies corresponding to the first and second resonant modules can be summed to obtain a superimposed frequency value independent of pressure. This superimposed frequency value can be used for temperature compensation of the pressure sensor, reducing the influence of temperature on the resonant frequency and improving frequency stability. On the other hand, when the vibration directions of the resonant structures of two adjacent resonant units are opposite, the two adjacent resonant units can respectively sense two induced signals, one positive and one negative. Thus, by subtracting the two induced signals, common-mode interference signals in the two induced signals can be eliminated, improving the signal-to-noise ratio of the pressure sensor output signal. Furthermore, at least two resonant units in the same resonant module can form a dynamically balanced resonance, preventing the in-plane dynamic balance center of mass from moving with the vibration of the resonant structure. This reduces losses and couples the resonant structures of at least two resonant units into a whole, further improving frequency stability. On the other hand, the large vibration and out-of-plane stiffness of the second resonant beam can be utilized to increase the out-of-plane torsional stiffness and out-of-plane translational stiffness of the resonant structure. This can prevent the out-of-plane torsional mode of the resonant structure from appearing in low-order modes, making the frequency generated by the resonant unit more stable and further improving frequency stability.

[0008] Optionally, the pressure sensor includes a first substrate structure, which includes a first pressure-sensitive membrane, a first resonant module, and a second resonant module. The first pressure-sensitive membrane includes a central portion and a peripheral portion surrounding the central portion. Of the first and second resonant modules, one is located on one side of the central portion, and the other is located on one side of the peripheral portion.

[0009] Optionally, under the same pressure, one of the first resonant modules and the other of the second resonant module will generate tensile stress and compressive stress, respectively.

[0010] Optionally, the resonant unit further includes: a driving electrode, disposed on one side of the resonant structure in the first direction and disposed opposite to a portion of the resonant structure; the driving electrode is used to supply a driving signal to the resonant unit. In the same resonant module, the driving electrodes and resonant structures of at least two resonant units are alternately arranged along the first direction; in two adjacent resonant units, the driving signal supplied to the driving electrode of one unit and the driving signal supplied to the driving electrode of the other unit form a differential signal.

[0011] Optionally, the resonant unit further includes: a driving electrode, disposed on one side of the resonant structure in the first direction and disposed opposite to a portion of the resonant structure; the driving electrode is used to supply a driving signal to the resonant unit. In the same resonant module, in two adjacent resonant units, the driving electrode of one is disposed close to or far from the driving electrode of the other; the driving signal supplied to the driving electrodes of at least two resonant units is the same signal.

[0012] Optionally, both the first resonant module and the second resonant module further include: a coupling structure disposed between adjacent resonant units; the coupling structure includes: a first connecting portion and a second connecting portion connected and spaced apart along a first direction. The first connecting portion is connected to the resonant structure of the resonant unit disposed on one side of the coupling structure; the second connecting portion is connected to the resonant structure of the resonant unit disposed on the other side of the coupling structure.

[0013] Optionally, either the extension direction of the second resonant beam and the first resonant beam is perpendicular to the thickness direction of the pressure sensor and intersects with the first direction.

[0014] Optionally, the resonant unit further includes a driving electrode and a sensing electrode, the driving electrode, the resonant structure, and the sensing electrode being spaced apart along a first direction. The resonant structure further includes a driving portion and a sensing portion, respectively arranged on both sides of a first resonant beam and at least two second resonant beams in the first direction; the driving electrode is at least partially opposite to the driving portion; the sensing electrode is at least partially opposite to the sensing portion. Wherein, the driving electrode includes a first comb tooth portion, the driving portion includes a second comb tooth portion, the first comb tooth portion and the second comb tooth portion are complementary; and / or, the sensing electrode includes a third comb tooth portion, the sensing portion includes a fourth comb tooth portion, the third comb tooth portion and the fourth comb tooth portion are complementary.

[0015] Optionally, the pressure sensor includes a first substrate structure. The first substrate structure includes a first substrate, a first insulating layer, and a device layer stacked along the thickness direction of the pressure sensor. The device layer includes a first resonant module and a second resonant module. The first insulating layer includes an opening on one side of the resonant structure of the first and second resonant modules. The device layer also includes multiple anchor blocks, with anchor blocks connected to both ends of the first resonant beam and both ends of the second resonant beam. The driving electrode, the sensing electrode, and the multiple anchor blocks are respectively connected to the first insulating layer.

[0016] Optionally, the resonant unit further includes a driving electrode and a sensing electrode, wherein the driving electrode, the resonant structure, and the sensing electrode are spaced apart along a first direction. The pressure sensor further includes: a plurality of first conductive bumps; the plurality of first conductive bumps includes: a conductive bump connected to the driving electrode, a conductive bump connected to the resonant structure, and a conductive bump connected to the sensing electrode.

[0017] Optionally, the pressure sensor includes a first substrate structure and a second substrate structure. The first substrate structure includes a device layer, a first insulating layer, and a first substrate stacked together; a first groove is formed on the surface of the first substrate away from the first insulating layer, and a first resonant module and a second resonant module are disposed on the device layer and on one side of the first groove. The second substrate structure is disposed opposite to and bonded to the first substrate structure, and the second substrate structure includes a second insulating layer and a second substrate stacked along a direction away from the first substrate structure. The surface of the second substrate away from the second insulating layer is a flat surface; or, a second groove is formed on the surface of the second substrate away from the second insulating layer, and the second groove is at least partially opposite to the first groove.

[0018] Secondly, a pressure sensing device is provided. The pressure sensing device includes a pressure sensor provided by the above-described technical solution.

[0019] The beneficial effects that the pressure sensing device provided in some embodiments of this disclosure can achieve are the same as the beneficial effects that the pressure sensor provided in the above-described technical solution can achieve, and will not be repeated here. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of embodiments of this disclosure and form part of the embodiments of this disclosure, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings: Figure 1 A structural diagram of a device layer provided for some embodiments of this disclosure; Figure 2 A structural diagram of a device layer provided for further embodiments of this disclosure; Figure 3A Structural diagrams of device layers provided in some embodiments of this disclosure; Figure 3B Structural diagrams of the driving electrodes and driving portions provided for some embodiments of this disclosure; Figure 4 A structural diagram of a pressure sensor provided for some embodiments of this disclosure; Figure 5 A structural diagram of a pressure sensor provided for further embodiments of this disclosure; Figure 6 Structural diagrams of a first resonant module and a second resonant module provided for some embodiments of this disclosure; Figure 7 A structural diagram of a first substrate structure provided for some embodiments of this disclosure; Figure 8 A structural diagram of a first substrate structure provided for further embodiments of this disclosure; Figure 9 A structural diagram of a second substrate structure provided for some embodiments of this disclosure; Figure 10 A structural diagram of a second substrate structure provided for further embodiments of this disclosure; Figure 11 A structural diagram of a pressure detection structure provided for further embodiments of this disclosure; Figure 12 A flowchart illustrating the fabrication process of a first substrate structure provided for some embodiments of this disclosure; Figure 13 A flowchart illustrating the fabrication process of a second substrate structure provided for some embodiments of this disclosure; Figure 14 A structural diagram of a pressure sensing device provided for some embodiments of this disclosure; Figure 15 This is a structural diagram of an electronic device provided for some embodiments of the present disclosure. Detailed Implementation

[0021] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0022] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0023] In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0024] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable deviation range, which is determined by those skilled in the art taking into account the measurement under discussion and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable deviation range for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable deviation range for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable deviation range for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0025] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of the embodiments disclosed herein, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] It should be noted that, in the accompanying drawings of this disclosure, for example, 1 / 2 indicates structure / line / direction 1, structure / line / direction 2, which can be referenced to that structure / line / direction. Figure 6 In this context, Y1 / Y2 represents the extension direction Y1 of the first resonant beam and the extension direction Y2 of the second resonant beam, both of which can be represented by this direction. Examples of 11~1 appearing in the accompanying drawings of this disclosure indicate that component 11 belongs to component 1. For example, in the attached drawings... Figure 1 In the figure, 1131~113 indicates that the inductive sub-electrode 1131 belongs to the inductive sub-electrode 113. Other similar reference numerals appearing in the figure also follow the above explanation.

[0028] In some examples, resonant MEMS pressure sensors incorporate a resonant structure on the pressure-sensitive diaphragm. This structure vibrates in a specific direction under the influence of a driving signal, generating a corresponding signal (e.g., an electrical signal). The frequency of this signal (i.e., the resonant frequency) is affected by the stiffness of the resonant structure. Under external pressure, the pressure-sensitive diaphragm deforms, generating stress (e.g., tensile stress). This stress is transmitted to the resonant structure on the diaphragm, causing a change in its stiffness and consequently, a change in the resonant frequency. Therefore, the magnitude of the external pressure sensed by the pressure sensor can be reflected by the change in the resonant frequency.

[0029] As mentioned in the background, in some cases, the frequency stability of resonant MEMS pressure sensors needs to be improved, which may affect the performance of the pressure sensors.

[0030] Based on this, in order to improve the frequency stability of the pressure sensor, some embodiments of this disclosure provide a pressure sensor 100. For example... Figure 1 and Figure 6 As shown, the pressure sensor 100 includes: a first resonant module M1 and a second resonant module M2, which are independently arranged; under the same pressure, a differential signal is formed between the signals generated by the first resonant module M1 and the second resonant module M2. Both the first resonant module M1 and the second resonant module M2 include at least two resonant units 110. Each resonant unit 110 includes a resonant structure 111. The resonant structure 111 includes: a first resonant beam 1111 connected to each other and at least two second resonant beams 1112. The at least two second resonant beams 1112 are respectively arranged on both sides of the first resonant beam 1111 in a first direction X, where the first direction X is the vibration direction of the resonant structure 111. In the same resonant module M, the resonant structures 111 of at least two resonant units 110 are connected along the first direction X; the vibration directions of the resonant structures 111 of two adjacent resonant units 110 are opposite.

[0031] Here, the pressure sensor 100 includes an independently configured first resonant module M1 and a second resonant module M2, meaning that the first resonant module M1 and the second resonant module M2 included in the pressure sensor 100 are spaced apart, and the two resonant modules M can independently receive drive signals and independently output detection signals.

[0032] The differential signal formed between the signals generated by the first resonant module M1 and the second resonant module M2 means that the resonant frequencies corresponding to the first resonant module M1 and the second resonant module M2 increase and decrease respectively, and the magnitude of the frequency increase is the same as the magnitude of the frequency decrease.

[0033] For example, such as Figure 1As shown, the resonant structure 111 includes a first resonant beam 1111 and two second resonant beams 1112 connected to each other. The two second resonant beams 1112 are respectively arranged on both sides of the first resonant beam 1111 in the first direction X.

[0034] For example, such as Figure 1 As shown, the first resonant beam 1111 and the two second resonant beams 1112 can be connected by a connecting beam 1115 extending along the first direction X.

[0035] In some examples, such as Figure 1 As shown, both the first resonant module M1 and the second resonant module M2 include two resonant units 110, and the vibration directions of the resonant structures 111 of the two resonant units 110 are opposite.

[0036] Here, the vibration directions of the resonant structures 111 of the two adjacent resonant units 110 are opposite. This can be understood as the two adjacent resonant units 110 moving towards each other or moving away from each other during the operation of the pressure sensor 100. For example, with Figure 1 Taking the direction shown as an example, there are two resonant units 110 connected along the first direction X. The pressure sensor 100 includes at least the following two working states: In the first working state, the resonant structure 111 of the resonant unit 110 on the left vibrates to the left, and the resonant structure 111 of the resonant unit 110 on the right vibrates to the right. The two move in opposite directions and vibrate in opposite directions. In the second working state, the resonant structure 111 of the resonant unit 110 on the left moves to the right, and the resonant structure 111 of the resonant unit 110 on the right vibrates to the left. The two move towards each other and vibrate in opposite directions.

[0037] It should be understood that the resonant structure 111 is the part of the resonant unit 110 that vibrates. The frequency of the signal (e.g., electrical signal) generated by the vibration of the resonant structure 111 is the resonant frequency. The change in the resonant frequency can reflect the magnitude of the external pressure sensed by the pressure sensor 100.

[0038] Understandably, firstly, when a differential signal is formed between the signals generated by the first resonant module M1 and the second resonant module M2, one approach is to obtain a frequency change value directly related to pressure by subtracting the resonant frequencies corresponding to the first resonant module M1 and the second resonant module M2. This frequency change value is twice the frequency change value generated by a single resonant module M, thus improving the sensitivity of the pressure sensor 100. Secondly, the resonant frequencies corresponding to the first resonant module M1 and the second resonant module M2 can be summed to obtain a superimposed frequency value. This superimposed frequency value is independent of pressure and depends only on the intrinsic frequency of the resonant unit 110. Therefore, this superimposed frequency value can be used to characterize the detection temperature of the pressure sensor 100, and further used for temperature compensation of the pressure sensor 100, reducing the influence of temperature on the resonant frequency and improving frequency stability.

[0039] Secondly, in the same resonant module M, when the vibration directions of the resonant structures 111 of two adjacent resonant units 110 are opposite, the two adjacent resonant units 110 can respectively sense two positive and two negative sensing signals. In this way, by subtracting the two sensing signals, the common-mode interference signal in the two sensing signals can be eliminated. Thus, by reducing the influence of the basic detection capacitance and the common-mode interference signal, the signal-to-noise ratio of the output signal of the pressure sensor 100 can be improved.

[0040] Thirdly, in the same resonant module M, when the vibration directions of the resonant structures 111 of two adjacent resonant units 110 are opposite, and the resonant structures 111 of at least two resonant units 110 are connected along the first direction X, dynamic balance resonance can be formed between the at least two resonant units 110, so that the in-plane dynamic balance center of mass does not move with the vibration of the resonant structure 111. In this way, firstly, the loss can be reduced and the quality factor (Q value) of the resonant unit 110 can be improved; secondly, the resonant structures 111 of at least two resonant units 110 can be coupled into a whole. Thus, even if there is a slight asymmetry in the driving force and / or the resonant structure 111, the at least two resonant units 110 will only have one stable vibration mode and resonant frequency during operation, which can improve frequency stability.

[0041] Fourthly, when the resonant structure 111 also includes at least two second resonant beams 1112, compared to the case where the resonant structure 111 includes the first resonant beam 1111 but does not include the second resonant beam 1112, the out-of-plane torsional stiffness and out-of-plane translational stiffness of the resonant structure 111 can be increased by utilizing the characteristics of the vibration and out-of-plane stiffness of the second resonant beam 1112. Here, the out-of-plane direction can be understood as the thickness direction Z of the pressure sensor 100. In this way, the out-of-plane torsional mode shape of the resonant structure 111 can be avoided from appearing in the low-order mode, which can make the frequency generated by the resonant unit 110 more stable and further improve the frequency stability.

[0042] The embodiments disclosed herein do not limit the manner in which a differential signal is formed between the signals generated by the first resonant module M1 and the second resonant module M2.

[0043] The inventors of this application have discovered that the placement positions of the first resonant module M1 and the second resonant module M2 on the pressure-sensitive membrane affect the change in the resonant frequencies corresponding to the first resonant module M1 and the second resonant module M2. Therefore, by selecting the placement positions of the first resonant module M1 and the second resonant module M2 on the pressure-sensitive membrane, a differential signal can be formed between the signals generated by the first resonant module M1 and the second resonant module M2 under the same pressure.

[0044] In some embodiments, such as Figure 7 As shown, the pressure sensor 100 includes a first substrate structure 130, which includes a first pressure-sensitive membrane 101, a first resonant module M1, and a second resonant module M2. The first pressure-sensitive membrane 101 includes a central portion 101A and a peripheral portion 101B surrounding the central portion 101A. Of the first resonant module M1 and the second resonant module M2, one is located on one side of the central portion 101A, and the other is located on one side of the peripheral portion 101B.

[0045] For example, such as Figure 7 As shown, the first resonant module M1 is located on one side of the central part 101A, and the second resonant module M2 is located on one side of the peripheral part 101B.

[0046] For example, the first substrate structure 130 includes a first substrate 131, a first insulating layer 132, and a device layer 133 stacked along the thickness direction Z of the pressure sensor 100. In this case, a first groove Q1 can be formed on the surface of the first substrate 131 away from the first insulating layer 132 (see reference). Figure 4 The thickness of the first substrate 131 on one side of the first groove Q1 is made thinner to form the first pressure-sensitive film 101.

[0047] It should be noted that, although Figure 6 and Figure 7 The illustration shows a small gap between the first resonant module M1 and the second resonant module M2. However, the concept of this disclosure is not limited to this. In practical applications, the gap between the first resonant module M1 and the second resonant module M2 may be larger, for example, as shown in the diagram. Figure 8 The gap between the first resonant module M1 and the second resonant module M2 is shown to form a differential signal between the signals generated by the first resonant module M1 and the second resonant module M2 under the same pressure.

[0048] By utilizing the above settings, the difference in the placement positions of the first resonant module M1 and the second resonant module M2 on the pressure-sensitive membrane can be used to increase the resonant frequencies of the first resonant module M1 and the second resonant module M2, while decreasing them. The magnitude of the frequency increase is the same as the magnitude of the frequency decrease. This allows a differential output to be formed between the resonant frequencies of the two resonant modules M1. As described in the previous section, this can improve the sensitivity of the pressure sensor 100.

[0049] It should be understood that when the pressure sensor 100 includes a first resonant module M1 and a second resonant module M2, the types of stress experienced by the two resonant modules M may be the same or different. For example, both resonant modules M may be subjected to tensile stress.

[0050] In some embodiments, such as Figure 8 As shown, under the same pressure, in the first resonant module M1 and the second resonant module M2, one generates tensile stress and the other generates compressive stress.

[0051] For example, such as Figure 8 As shown, the first resonant module M1 is located on one side of the central portion 101A of the first pressure-sensitive membrane 101, and is subjected to tensile stress, which increases the resonant frequency; the second resonant module M2 is located on one side of the peripheral portion 101B of the first pressure-sensitive membrane 101, and is subjected to compressive stress, which decreases the resonant frequency.

[0052] By utilizing the different stress types experienced by the first resonant module M1 and the second resonant module M2, the resonant frequencies corresponding to the first resonant module M1 and the second resonant module M2 can be adjusted such that one increases and the other decreases, with the magnitude of the frequency increase being the same as the magnitude of the frequency decrease. This allows for a differential output between the resonant frequencies corresponding to the two resonant modules M1. As described in the preceding section, this can improve the sensitivity of the pressure sensor 100 and also enhance frequency stability.

[0053] In some embodiments, such as Figure 1 and Figure 6As shown, either the extension direction of the second resonant beam 1112 and the first resonant beam 1111 is perpendicular to the thickness direction Z of the pressure sensor 100 and intersects with the first direction X.

[0054] For example, the extension direction Y2 of the second resonant beam 1112 can be parallel to or intersect with the extension direction Y1 of the first resonant beam 1111, as long as it satisfies the requirement of being perpendicular to the thickness direction Z of the pressure sensor 100 and intersecting with the first direction X. In some examples, such as Figure 1 As shown, the extension direction Y2 of the second resonant beam 1112 is parallel to the extension direction Y1 of the first resonant beam 1111, and both are perpendicular to the first direction X.

[0055] By adopting the above settings, the effect of increasing the out-of-plane torsional stiffness and out-of-plane translational stiffness of the resonant structure 111 of the second resonant beam 1112 can be improved. Thus, as described in the previous part, the out-of-plane torsional mode of the resonant structure 111 can be avoided from appearing in the low-order mode, and the frequency generated by the resonant unit 110 can be made more stable, further improving the frequency stability.

[0056] The following will exemplarily describe other structures in the resonant unit 110.

[0057] In some embodiments, such as Figure 1 As shown, the resonant unit 110 also includes a driving electrode 112 and a sensing electrode 113, and the driving electrode 112, the resonant structure 111 and the sensing electrode 113 are arranged at intervals along the first direction X.

[0058] For example, the driving electrode 112 is used to input a driving signal to the resonant unit 110. For example, the sensing electrode 113 is used to output the signal generated by the resonant unit 110.

[0059] With this configuration, under the action of a driving signal (e.g., an AC driving signal), a periodic electrostatic force can be formed between the driving electrode 112 and the resonant structure 111 to drive the resonant structure 111 to vibrate, causing the gap between the resonant structure 111 and the sensing electrode 113 to change periodically, thereby causing the charge on the sensing electrode 113 to change periodically, thus generating a signal (e.g., an AC current signal) on the sensing electrode 113. By detecting the frequency of the signal, pressure can be detected.

[0060] In some embodiments, such as Figure 1As shown, the resonant structure 111 further includes a driving portion 1113 and a sensing portion 1114, which are respectively arranged on both sides of the first resonant beam 1111 and at least two second resonant beams 1112 in the first direction X; the driving electrode 112 is at least partially opposite to the driving portion 1113; and the sensing electrode 113 is at least partially opposite to the sensing portion 1114.

[0061] It should be understood that the driving part 1113 is the part of the resonant structure 111 used to receive the driving signal, and the sensing part 1114 is the part of the resonant structure 111 used to output the detection signal. When the driving part 1113 and the sensing part 1114 are respectively arranged on both sides of the first resonant beam 1111 and at least two second resonant beams 1112 in the first direction X, the relative area between the driving part 1113 and the driving electrode 112 can be larger, and the relative area between the sensing part 1114 and the sensing electrode 113 can also be larger. This is beneficial for improving the reliability of the driving signal input and the reliability of the detection signal output.

[0062] The embodiments of this disclosure do not limit the relative arrangement of the driving electrode 112 and the driving portion 1113, nor the relative arrangement of the sensing electrode 113 and the sensing driving portion 1113, as long as the requirement that the driving electrode 112 and the driving portion 1113 are at least partially opposite each other, and the sensing electrode 113 and the sensing portion 1114 are at least partially opposite each other, is met. For example, the driving electrode 112 and the driving portion 1113 may both be flat plates and arranged in parallel. The sensing electrode 113 and the sensing portion 1114 may both be flat plates and arranged in parallel.

[0063] In some embodiments, such as Figure 1 As shown, the driving electrode 112 includes a first comb tooth portion K1, and the driving portion 1113 includes a second comb tooth portion K2. The first comb tooth portion K1 and the second comb tooth portion K2 are complementary.

[0064] Here, the first comb tooth section K1 and the second comb tooth section K2 are complementary. It can be understood that the comb teeth of the first comb tooth section K1 can be embedded in the gap between the comb teeth of the second comb tooth section K2, and the comb teeth of the second comb tooth section K2 can be embedded in the gap between the comb teeth of the first comb tooth section K1.

[0065] The embodiments disclosed herein do not limit the shape of the first comb tooth portion K1 and the second comb tooth portion K2. For example, the first comb tooth portion K1 and the second comb tooth portion K2 can be serrated comb teeth, or they can be rectangular comb teeth or rounded comb teeth.

[0066] With the above configuration, the structural feature of the first comb tooth portion K1 and the second comb tooth portion K2 being interlocked can be utilized to make the relative area between the driving electrode 112 and the driving portion 1113 larger, which is beneficial to further improve the reliability of the driving signal access.

[0067] In some embodiments, such as Figure 1 As shown, the sensing electrode 113 includes a third comb tooth portion K3, and the sensing portion 1114 includes a fourth comb tooth portion K4. The third comb tooth portion K3 and the fourth comb tooth portion K4 are complementary.

[0068] For an understanding of the complementarity of the third comb tooth portion K3 and the fourth comb tooth portion K4, as well as the shapes of the third comb tooth portion K3 and the fourth comb tooth portion K4, please refer to the foregoing section, which will not be repeated here.

[0069] With the above configuration, the structural feature of the third comb tooth section K3 and the fourth comb tooth section K4 being interlocked can be utilized to make the relative area between the sensing electrode 113 and the sensing part 1114 larger, which is beneficial to further improve the reliability of the detection signal output.

[0070] In some embodiments, such as Figure 1 As shown, both the first resonant module M1 and the second resonant module M2 further include a coupling structure 120 disposed between adjacent resonant units 110. The coupling structure 120 includes a first connecting portion 121 and a second connecting portion 122 that are connected and spaced apart along a first direction X. The first connecting portion 121 is connected to the resonant structure 111 of the resonant unit 110 disposed on one side of the coupling structure 120; the second connecting portion 122 is connected to the resonant structure 111 of the resonant unit 110 disposed on the other side of the coupling structure 120.

[0071] For example, the coupling structure 120 is a rectangular structure, with the first connecting part 121 and the second connecting part 122 located on the long side of the rectangle, and the two are connected by a structure located on the short side of the rectangle.

[0072] With the above configuration, when the resonant structure 111 of two adjacent resonant units 110 vibrates, the coupling structure 120 can deform, and the first connecting part 121 and the second connecting part 122 can move closer to each other or move further away from each other. In this way, at least two resonant units 110 in the same resonant module M can form a dynamic balance resonance. Without affecting the vibration of the resonant structure 111 of the two adjacent resonant units 110 in opposite directions, the in-plane dynamic balance center of mass does not move with the vibration of the resonant structure 111. Thus, as mentioned in the previous part, firstly, it can reduce losses and improve the quality factor (Q value) of the resonant unit 110; secondly, it can couple the resonant structure 111 of at least two resonant units 110 in the same resonant module M into a whole, so that at least two resonant units 110 have only one stable vibration mode and resonant frequency during operation, which can further improve frequency stability.

[0073] It should be understood that, under the operating conditions of the pressure sensor 100, the vibration direction of the resonant structure 111 is related to the drive signal received by the resonant unit 110. The relationship between the drive signals of at least two resonant units 110 in the same resonant module M will be illustrated below with examples.

[0074] In some embodiments, such as Figure 2 As shown, the resonant unit 110 further includes a driving electrode 112, disposed on one side of the resonant structure 111 in the first direction X, and disposed opposite to a portion of the resonant structure 111. The driving electrode 112 is used to supply a driving signal to the resonant unit 110. In the same resonant module M, in two adjacent resonant units 110, the driving electrode 112 of one is disposed close to or far from the driving electrode 112 of the other. The driving electrode 112 is used to supply a driving signal to the resonant unit 110; the driving signal supplied to the driving electrodes 112 of at least two resonant units 110 is the same signal.

[0075] For example, such as Figure 2 As shown, there are two resonant units 110 connected along the first direction X, and the driving electrodes 112 of the two resonant units 110 are positioned far apart from each other. At this time, the sensing electrodes 113 of the two resonant units 110 are positioned close to each other.

[0076] For example, such as Figure 2 As shown, when the sensing electrodes 113 of the two resonant units 110 are arranged close to each other, and the resonant structure 111 also includes a connecting beam 1115, the sensing electrodes 113 of the two resonant units 110 may each include two sensing sub-electrodes 1131, and the two sensing sub-electrodes 1131 are arranged on both sides of the connecting beam 1115.

[0077] Here, the driving signal connected to the driving electrode 112 of at least two resonant units 110 is the same signal, which means that the driving signals connected to the driving electrode 112 of at least two resonant units 110 have the same intensity and frequency, and there is basically no phase difference between the two driving signals.

[0078] By configuring it as described above, the vibration directions of the resonant structures 111 of two adjacent resonant units 110 can be opposite. Thus, as described earlier, the frequency stability of the pressure sensor 100 can be improved. Furthermore, when the driving signals connected to the driving electrodes 112 of at least two resonant units 110 are the same, the variety of driving signals connected to the pressure sensor 100 is reduced, which to some extent simplifies the structural complexity of the control circuit coupled to the pressure sensor 100 and reduces errors and interference caused by signal deviations.

[0079] In some embodiments, such as Figure 1 and Figure 3A As shown, the resonant unit 110 further includes a driving electrode 112, disposed on one side of the resonant structure 111 in the first direction X, and disposed opposite to a portion of the resonant structure 111; the driving electrode 112 is used to input a driving signal to the resonant unit 110. In the same resonant module M, the driving electrodes 112 and resonant structures 111 of at least two resonant units 110 are alternately disposed along the first direction X; in two adjacent resonant units 110, the driving signal input to the driving electrode 112 of one unit forms a differential signal with the driving signal input to the driving electrode 112 of the other unit.

[0080] For example, such as Figure 1 As shown, there are two resonant units 110 connected along the first direction X. In the same resonant unit 110, the driving electrode 112 is located on the left side of the resonant structure 111, and the sensing electrode 113 is located on the right side of the resonant structure 111. The driving electrode 112 and the resonant structure 111 of the two resonant units 110 are alternately arranged along the first direction X, and the resonant structure 111 and the sensing electrode 113 of the two resonant units 110 are alternately arranged along the first direction X.

[0081] For example, such as Figure 1 As shown, when the resonant structure 111 also includes a connecting beam 1115, the sensing electrode 113 on the left side may include two sensing sub-electrodes 1131, which are arranged on both sides of the connecting beam 1115. The driving electrode 112 on the right side may include two driving sub-electrodes 1121, which are arranged on both sides of the connecting beam 1115.

[0082] Here, in two adjacent resonant units 110, the driving signal connected to the driving electrode 112 of one unit and the driving signal connected to the driving electrode 112 of the other unit form a differential signal. This means that the driving signals connected to the two adjacent resonant units 110 have the same intensity and frequency, and there is an nπ phase difference between the two driving signals, where n is a positive integer.

[0083] As one possible implementation, when the driving electrode 112 includes a first comb tooth portion K1 and the driving portion 1113 includes a second comb tooth portion K2, the driving signals connected to the driving electrodes 112 of the two adjacent resonant units 110 can be voltage signals, respectively. and The formulas for both are shown in equations (1) and (2) below. The driving force of both driving voltage signals acting on the resonant structure 111 is F, and the formula for calculating F is shown in equation (3) below. Wherein, V DC V represents the DC voltage component. AC The values ​​represent the AC voltage component, h represents the thickness of the first comb portion K1 and the second comb portion K2 (i.e., the thickness of the driving electrode 112 and the driving portion 1113, for example, equal to the thickness of the device layer 133), N represents the number of comb teeth in the first comb portion K1 and the second comb portion K2, ε0 represents the vacuum dielectric constant, and ε r The relative permittivity is represented by g, and the gap between the comb teeth is represented by g (see reference). Figure 3B By setting it up in this way, a differential signal can be formed between the driving signals connected to the driving electrodes 112 of two adjacent resonant units 110.

[0084] (1) (2) (3) By configuring the above, the vibration directions of the resonant structures 111 of two adjacent resonant units 110 can be opposite. Thus, as described earlier, the frequency stability of the pressure sensor 100 can be improved. Furthermore, when a differential signal is formed between the drive signals connected to the drive electrodes 112 of two adjacent resonant units 110, differential driving of the two adjacent resonant units 110 can be achieved, further improving frequency stability. For example, when using a DC voltage plus AC voltage driving method, differential processing can retain only the fundamental frequency drive component, without any harmonic drive component. This eliminates the influence of the harmonic drive signal on the resonant frequency, further improving frequency stability.

[0085] The following will provide an exemplary description of the arrangement of the resonant unit 110 in the pressure sensor 100.

[0086] In some embodiments, combined with Figure 1 ,like Figure 3A , Figure 4 and Figure 5 As shown, the pressure sensor 100 includes a first substrate structure 130. The first substrate structure 130 includes a first substrate 131, a first insulating layer 132, and a device layer 133 stacked along the thickness direction Z of the pressure sensor 100. The device layer 133 includes a first resonant module M1 and a second resonant module M2. The first insulating layer 132 includes an opening H on one side of the resonant structure 111 of the first resonant module M1 and the second resonant module M2. The device layer 133 also includes a plurality of fixing anchors 114, with fixing anchors 114 connected to both ends of the first resonant beam 1111 and both ends of the second resonant beam 1112. The driving electrode 112, the sensing electrode 113, and the plurality of fixing anchors 114 are respectively connected to the first insulating layer 132.

[0087] In some examples, the first substrate structure 130 includes an SOI substrate in which a device layer 133, a first insulating layer 132, and a first substrate 131 are formed. This arrangement can improve the integration of the device layer 133, the first insulating layer 132, and the first substrate 131.

[0088] For example, the first resonant beam 1111, at least two second resonant beams 1112, and a plurality of fixed anchor blocks 114 are integrally formed in the device layer 133. When the resonant structure 111 includes a driving portion 1113 and a sensing portion 1114, the driving portion 1113, the sensing portion 1114, the first resonant beam 1111, at least two second resonant beams 1112, the plurality of fixed anchor blocks 114, and any connecting beams 1115 that may be present can be integrally formed in the device layer 133.

[0089] For example, the fixed anchor block 114 connected to the first resonant beam 1111 can be configured to provide a fixing function for the first resonant beam 1111. The fixed anchor block 114 connected to the second resonant beam 1112 can be configured to provide a fixing function for the second resonant beam 1112.

[0090] Through the above configuration, the first insulating layer 132 can achieve an insulating connection between the device layer 133 and the first substrate 131. Furthermore, when the first insulating layer 132 includes an opening H on one side of the first resonant module M1 and the second resonant module M2, the opening H can form at least a portion of the resonant cavity of the resonant structure 111, preventing insufficient space in the resonant cavity from affecting the vibration of the resonant structure 111. In addition, by connecting the driving electrode 112, the sensing electrode 113, and the multiple fixed anchor blocks 114 to the first insulating layer 132, the first insulating layer 132 can provide support for the driving electrode 112, the sensing electrode 113, and the multiple fixed anchor blocks 114, thereby providing support for the resonant unit 110.

[0091] The following example illustrates the interconnection between the resonant unit 110 and the control circuit. However, it should be understood that the concept of this disclosure is not limited thereto.

[0092] In some embodiments, combined with Figure 5 ,like Figure 1 As shown, the pressure sensor 100 further includes: a plurality of first conductive bumps 134; the plurality of first conductive bumps 134 include: a conductive bump 1341 connected to the driving electrode 112, a conductive bump 1342 connected to the resonant structure 111, and a conductive bump 1343 connected to the sensing electrode 113.

[0093] For example, such as Figure 5 As shown, when the pressure sensor 100 includes a first substrate structure 130, which includes a first substrate 131, a first insulating layer 132, and a device layer 133, a plurality of first conductive bumps 134 may be disposed on the side of the device layer 133 away from the first insulating layer 132.

[0094] For example, two conductive bumps 1341 are connected to the driving electrode 112, respectively connected to both ends of the driving electrode 112. For example, two conductive bumps 1343 are connected to the sensing electrode 113, respectively connected to both ends of the sensing electrode 113. For example, one conductive bump 1342 is connected to the resonant structure 111, which can be connected to the end of the first resonant beam 1111 or the second resonant beam 1112. When the device layer 133 also includes a fixing anchor 114, the conductive bump 1342 connected to the resonant structure 111 can be electrically connected to one of the fixing anchors 114.

[0095] For example, the conductive bump 1341 connected to the drive electrode 112 can be further coupled to the drive signal pin of the pressure sensor 100. For example, the conductive bump 1342 connected to the resonant structure 111 can be further coupled to the ground pin of the pressure sensor 100. For example, the conductive bump 1343 connected to the sensing electrode 113 can be further coupled to the output signal pin of the pressure sensor 100.

[0096] This disclosure does not limit the material, shape, size, etc. of the first conductive bump 134. Exemplarily, the material of the first conductive bump 134 may include at least one of CrAu, CrNiAu, and TiPtAu. Exemplarily, the shape of the first conductive bump 134 may be square, rectangular, circular, or elliptical. Exemplarily, the side length or diameter of the first conductive bump 134 may range from 50μm to 100μm, for example, 50μm, 60μm, 70μm, 80μm, or 100μm.

[0097] With the above configuration, the conductive bump 1341 connected to the driving electrode 112 can be configured to supply a driving signal to the driving electrode 112, the conductive bump 1342 connected to the resonant structure 111 can be configured to supply a reference voltage signal (e.g., a ground signal) to the resonant structure 111, and the conductive bump 1343 connected to the sensing electrode 113 can be configured to output the signal sensed by the sensing electrode 113. Thus, the control circuit can control and sense the resonant unit 110.

[0098] In some examples, such as Figure 4 and Figure 9 As shown, the pressure sensor 100 also includes a second substrate structure 140, which includes a second substrate 141 and a second insulating layer 142 stacked together, and a plurality of second conductive bumps 143 penetrating the second insulating layer 142 and contacting the second substrate 141, wherein a first conductive bump 134 is connected to a second conductive bump 143.

[0099] This disclosure does not limit the material, shape, size, etc. of the second conductive bump 143. Exemplarily, the material of the second conductive bump 143 may include at least one of CrAu, CrNiAu, and TiPtAu. Exemplarily, the shape of the second conductive bump 143 may be square, rectangular, circular, or elliptical, and the second conductive bump 143 and the first conductive bump 134 may have the same shape. Exemplarily, the side length or diameter of the second conductive bump 143 may range from 50μm to 100μm, for example, 50μm, 60μm, 70μm, 80μm, or 100μm.

[0100] In some examples, such as Figure 4 and Figure 10 As shown, the second substrate structure 140 further includes a plurality of conductive pillars 144 penetrating the second substrate 141, and a second conductive bump 143 is connected to a conductive pillar 144.

[0101] With the above configuration, the first conductive bump 134, the second conductive bump 143 and the conductive post 144 can form a signal transmission channel, which can realize the coupling between the resonant unit 110 and the control circuit, so as to realize the control circuit to control and sense the resonant unit 110.

[0102] In some embodiments, such as Figure 4 As shown, the pressure sensor 100 includes a first substrate structure 130 and a second substrate structure 140. The first substrate structure 130 includes a device layer 133, a first insulating layer 132, and a first substrate 131 stacked together. A first groove Q1 is formed on the surface of the first substrate 131 away from the first insulating layer 132. A first resonant module M1 and a second resonant module M2 are disposed on the device layer 133 and on one side of the first groove Q1. The second substrate structure 140 is disposed opposite to and bonded to the first substrate structure 130. The second substrate structure 140 includes a second insulating layer 142 and a second substrate 141 stacked together in a direction away from the first substrate structure 130.

[0103] It should be understood that when a first groove Q1 is formed on the surface of the first substrate 131 away from the first insulating layer 132, the thickness of the first substrate 131 on one side of the first groove Q1 is relatively thin, allowing the formation of a first pressure-sensitive film 101. By disposing the first resonant module M1 and the second resonant module M2 on the device layer 133 and on one side of the first groove Q1, the first resonant module M1 and the second resonant module M2 can be disposed on one side of the first pressure-sensitive film 101. Thus, the stress generated by the deformation of the first pressure-sensitive film 101 can be transmitted to the resonant structure 111 of the first resonant module M1 and the second resonant module M2.

[0104] like Figure 5 As shown, by setting the second substrate structure 140 opposite to and bonded to the first substrate structure 130, a cavity can be formed between the second substrate structure 140 and the first substrate structure 130, and the first pressure-sensitive membrane 101, the first resonant module M1 and the second resonant module M2 can be disposed on one side of the cavity.

[0105] Exemplarily, the material of the second insulating layer 142 may include at least one of SiO2, SiN, and glass. Exemplarily, the second insulating layer 142 may provide electrical insulation, thereby insulating the second substrate 141 from the structure located on one side thereof.

[0106] In some examples, combined Figure 4 ,like Figure 5 As shown, the first substrate structure 130 and the second substrate structure 140 are bonded together by an annular bonding body 150. Exemplarily, the bonding body 150 includes: a solder layer 151, a first connection pattern 152 disposed between the solder layer 151 and the first substrate structure 130, and a second connection pattern 153 disposed between the solder layer 151 and the second substrate structure 140.

[0107] For example, the material of solder layer 151 may include tin-based solder or indium-based solder. For instance, the material of solder layer 151 may be SnAgCu (SAC). For example, the thickness of solder layer 151 may be 20μm, 30μm, 40μm, 44μm, 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm, etc.

[0108] Exemplarily, the material of the first connection pattern 152 may include at least one of CrAu, CrNiAu, and TiPtAu. Exemplarily, the shape of the first connection pattern 152 may be a square annulus or a circular annulus. Exemplarily, the width of the first connection pattern 152 is greater than or equal to 600 μm, for example, 600 μm, 650 μm, 700 μm, 750 μm, or 900 μm. Exemplarily, along a direction parallel to the first substrate 131, the distance between the outer edge of the first connection pattern 152 and the edge of the first substrate structure 130 is greater than or equal to 50 μm, for example, 50 μm, 60 μm, 70 μm, 80 μm, or 90 μm. Exemplarily, along a direction parallel to the first substrate 131, the distance between the inner edge of the first connection pattern 152 and the first pressure-sensitive film 101 is greater than or equal to 50 μm, for example, 50 μm, 60 μm, 70 μm, 80 μm, or 90 μm.

[0109] For example, in the process of fabricating the pressure sensor 100, the first connection pattern 152 and the first conductive bump 134 can be formed in the same step and their thicknesses can be substantially the same. This can improve the connection reliability between the first conductive bump 134 and the second conductive bump 143 and improve the bonding strength between the first connection pattern 152 and the solder layer 151.

[0110] Exemplarily, the material of the second connection pattern 153 may include at least one of CrAu, CrNiAu, and TiPtAu. Exemplarily, the shape of the second connection pattern 153 may be a square annulus or a circular annulus. Exemplarily, the width of the second connection pattern 153 is greater than or equal to 600 μm, for example, 600 μm, 650 μm, 700 μm, 750 μm, or 900 μm. Exemplarily, along a direction parallel to the first substrate 131, the distance between the outer edge of the second connection pattern 153 and the edge of the second substrate structure 140 is greater than or equal to 50 μm, for example, 50 μm, 60 μm, 70 μm, 80 μm, or 90 μm. Exemplarily, along a direction parallel to the first substrate 131, the distance between the inner edge of the second connection pattern 153 and the first pressure-sensitive film 101 is greater than or equal to 50 μm, for example, 50 μm, 60 μm, 70 μm, 80 μm, or 90 μm.

[0111] For example, the shape of the first connection pattern 152 and the shape of the second connection pattern 153 can both be the same as the shape of the solder layer 151.

[0112] In some embodiments, such as Figure 11 As shown, the surface of the second substrate 141 away from the second insulating layer 142 is a flat surface.

[0113] It should be understood that when the surface of the second substrate 141 away from the second insulating layer 142 is a flat surface, no groove is formed on the second substrate 141. In this case, the pressure sensor 100 includes a pressure-sensitive membrane, namely the first pressure-sensitive membrane 101.

[0114] With this configuration, the pressure sensor 100 can be an absolute pressure sensor 100, used to detect the pressure acting on the first pressure-sensitive membrane 101. Absolute pressure sensors can measure the absolute value of pressure changes and have the advantages of high accuracy and a large measurement range.

[0115] In some embodiments, such as Figure 5 As shown, a second groove Q2 is formed on the surface of the second substrate 141 that is away from the second insulating layer 142, and the second groove Q2 is at least partially opposite to the first groove Q1.

[0116] With the above configuration, a second pressure-sensitive membrane 102 is formed on one side of the second groove Q2 in the second substrate structure 140. Thus, the pressure sensor 100 can be a differential pressure sensor, which can be used to detect the pressure difference acting on the first pressure-sensitive membrane 101 and the second pressure-sensitive membrane 102. Differential pressure sensors have advantages such as direct pressure difference measurement, common-mode pressure cancellation, high detection accuracy, high frequency stability, and high resolution.

[0117] The following describes the fabrication method of pressure sensor 100 by taking pressure sensor 100 as a differential pressure type pressure sensor as an example.

[0118] In some embodiments, the method for manufacturing the pressure sensor 100 includes steps S1 to S3.

[0119] S1: Forming a first substrate structure 130. The first substrate structure 130 includes a first resonant module M1 and a second resonant module M2.

[0120] S2: Forming the second substrate structure 140.

[0121] S3: Bond the first substrate structure 130 and the second substrate structure 140 together.

[0122] In some examples, such as Figure 12 As shown, a first substrate structure 130 (i.e., S1) is formed, including S1.1 to S1.4.

[0123] S1.1: A first conductive bump 134 and a first connection pattern 152 are formed on the SOI substrate. The SOI substrate includes a first substrate 131, a first insulating layer 132, and a device layer 133 stacked together.

[0124] For example, the process of forming the first conductive bump 134 and the first connection pattern 152 can be a sputtering process or an evaporation process.

[0125] S1.2: Etch the surface of the first substrate 131 away from the first insulating layer 132 to form a first groove Q1, and form a first pressure-sensitive film 101 on the first substrate 131 disposed on one side of the first groove Q1.

[0126] For example, a dry etching process or a wet etching process can be used to form the first groove Q1.

[0127] Here, the shape of the first groove Q1 is not limited. For example, the first groove Q1 can be a rectangular groove.

[0128] S1.3: Etch device layer 133 to form the first resonant module M1 and the second resonant module M2 (see reference). Figure 6 ).

[0129] S1.4: Remove the first insulating layer 132 located on one side of the resonant structure 111 of the first resonant module M1 and the second resonant module M2.

[0130] For example, an acid etching process (e.g., hydrofluoric acid (HF) etching) is used to remove the first insulating layer 132 located on one side of the resonant structure 111 of the first resonant module M1 and the second resonant module M2.

[0131] For example, in the case where the pressure sensor 100 includes a first resonant module M1 and a second resonant module M2, in S1.4, the first insulating layer 132 on one side of the resonant structure 111 of the second resonant module M2 is also removed.

[0132] In some examples, such as Figure 13 As shown, a second substrate structure 140 (i.e., S2) is formed, including S2.1 to S2.4.

[0133] S2.1: A conductive pillar 144 is formed on the second substrate 141, penetrating the second substrate 141.

[0134] For example, the conductive pillar 144 is formed by filling a conductive material within a through-hole (e.g., a through-silicon via, TSV) that penetrates the second substrate 141.

[0135] S2.2: Deposit insulating material on the second substrate 141 to form a second insulating layer 142.

[0136] S2.3: Etch away the second insulating layer 142 located on one side of the second conductive bump 143 to be formed.

[0137] S2.4: Form the second conductive bump 143 and the second connection pattern 153.

[0138] For example, the process of forming the second conductive bump 143 and the second connection pattern 153 can be a sputtering process or an evaporation process.

[0139] S2.5: Etch the surface of the second substrate 141 away from the second insulating layer 142 to form the second groove Q2, and form the second pressure-sensitive film 102 on the second substrate 141 disposed on one side of the second groove Q2.

[0140] For example, a dry etching process or a wet etching process can be used to form the second groove Q2.

[0141] Here, the shape of the second groove Q2 is not limited. For example, the second groove Q2 can be a rectangular groove.

[0142] In some examples, such as Figure 13 As shown, the first substrate structure 130 and the second substrate structure 140 are bonded together (i.e., S3), including S3.1 to S3.2.

[0143] S3.1: A eutectic solder L is provided on the side of the second connection pattern 153 and the second conductive bump 143 away from the second substrate 141.

[0144] For example, a ball-mounting process is used to deposit eutectic solder L on the side of the second connection pattern 153 and the second conductive bump 143 away from the second substrate 141.

[0145] S3.2: The first substrate structure 130 is bonded to one side of the second substrate structure 140 to form a solder layer 151 disposed between the first connection pattern 152 and the second connection pattern 153, and a solder portion disposed between the first conductive bump 134 and the second conductive bump 143.

[0146] For example, the material of the solder section can be SnAgCu.

[0147] Understandably, the above method can be used to form a flip-chip integrated differential pressure sensor (e.g., a differential pressure resonant pressure sensor), and the above fabrication method is simple and can reduce the complexity of the process of forming the pressure sensor 100.

[0148] It should be noted that the above-listed preparation methods are examples of the preparation methods for the pressure sensor 100, and are not limitations on the preparation methods for the pressure sensor 100.

[0149] Combination Figure 1 ,like Figure 14 As shown, some embodiments of this disclosure also provide a pressure sensing device 200. The pressure sensing device 200 includes a pressure sensor 100 provided in the above-described technical solution. In some examples, the pressure sensing device 200 also includes a control circuit 210. The control circuit 210 is coupled to the first resonant module M1 and the second resonant module M2.

[0150] It should be understood that when the control circuit 210 is coupled to the first resonant module M1 and the second resonant module M2, the control circuit 210 can input a drive signal (e.g., a voltage signal) to the first resonant module M1 and the second resonant module M2, and can output the signals detected by the first resonant module M1 and the second resonant module M2 to the control circuit 210. In this way, control and sensing of the first resonant module M1 and the second resonant module M2 can be realized.

[0151] In some examples, the control circuit 210 is disposed on a circuit board (e.g., a printed circuit board, PCB), and the conductive post 144 (see reference) Figure 5 The pressure sensor 100 is connected to the circuit board via a wire bonding (WB) structure, thereby achieving coupling between the pressure sensor 100 and the control circuit 210.

[0152] In some examples, the pressure sensor 100 includes a circuit structure disposed in the second substrate 141, to which the control circuit 210 can be coupled, and further coupled to the first resonant module M1 and the second resonant module M2.

[0153] The beneficial effects that the pressure sensing device 200 provided in some embodiments of this disclosure can achieve are the same as the beneficial effects that the pressure sensor 100 provided in the above technical solution can achieve, and will not be repeated here.

[0154] like Figure 15 As shown, some embodiments of this disclosure also provide an electronic device 300. The electronic device 300 includes a housing 310 and a pressure sensing device 200 provided by the above-described technical solution disposed on the housing 310.

[0155] The beneficial effects that the electronic device 300 provided in some embodiments of this disclosure can achieve are the same as the beneficial effects that the pressure sensing device 200 provided in the above technical solution can achieve, and will not be repeated here.

[0156] In some examples, the electronic device 300 can be a mobile phone, a computer, or a portable electronic device, enabling the pressure sensor 100 to be applied in technical scenarios that require pressure measurement, such as automobiles and industrial manufacturing.

[0157] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A pressure sensor, characterized by The pressure sensor comprises: independent first and second resonant modules; under the same pressure, a differential signal is formed between the signals generated by the first and second resonant modules; each of the first and second resonant modules comprises at least two resonant units, each resonant unit comprises a resonant structure, and the resonant structure comprises a first resonant beam and at least two second resonant beams connected to each other, and the at least two second resonant beams are arranged on both sides of the first resonant beam in a first direction, which is the vibration direction of the resonant structure; in the same resonant module, the resonant structures of the at least two resonant units are connected in the first direction, and the vibration directions of the resonant structures of two adjacent resonant units are opposite.

2. The pressure sensor of claim 1, wherein, The pressure sensor comprises a first substrate structure, which comprises a first pressure-sensitive film, the first resonant module and the second resonant module; the first pressure-sensitive film comprises a central part and a peripheral part surrounding the central part, one of the first and second resonant modules is arranged on one side of the central part, and the other is arranged on one side of the peripheral part.

3. The pressure sensor of claim 1, wherein, Under the same pressure, one of the first and second resonant modules generates tensile stress, and the other generates compressive stress.

4. The pressure sensor of claim 1, wherein, The resonant unit further comprises a driving electrode arranged on one side of the resonant structure in the first direction and opposite to part of the resonant structure, and the driving electrode is used to input a driving signal to the resonant unit; in the same resonant module, the driving electrodes and resonant structures of the at least two resonant units are alternately arranged in the first direction, and the driving signal input by the driving electrode of one of the two adjacent resonant units forms a differential signal with the driving signal input by the driving electrode of the other.

5. The pressure sensor of claim 1, wherein, The resonant unit further comprises a driving electrode arranged on one side of the resonant structure in the first direction and opposite to part of the resonant structure, and the driving electrode is used to input a driving signal to the resonant unit; in the same resonant module, the driving electrodes of the two adjacent resonant units are arranged close to each other or away from each other, and the driving signals input by the driving electrodes of the at least two resonant units are the same signals.

6. The pressure sensor according to any one of claims 1 to 5, characterized in that The first and second resonant modules further comprise: a coupling structure arranged between the adjacent resonant units, the coupling structure comprises a first connecting part and a second connecting part connected to each other and arranged in the first direction; wherein the first connecting part is connected to the resonant structure of the resonant unit arranged on one side of the coupling structure, and the second connecting part is connected to the resonant structure of the resonant unit arranged on the other side of the coupling structure.

7. The pressure sensor according to any one of claims 1 to 5, wherein Either of the extension directions of the second resonant beam and the first resonant beam is perpendicular to the thickness direction of the pressure sensor and intersects the first direction.

8. The pressure sensor according to any one of claims 1 to 5, wherein The resonant unit further comprises a driving electrode and an inductive electrode, the driving electrode, the resonant structure and the inductive electrode are arranged at intervals along the first direction; The resonant structure further comprises a driving portion and an inductive portion, which are arranged on both sides of the first resonant beam and the at least two second resonant beams in the first direction respectively; the driving electrode is at least partially opposite to the driving portion; the inductive electrode is at least partially opposite to the inductive portion; The driving electrode comprises a first comb tooth portion, the driving portion comprises a second comb tooth portion, and the first comb tooth portion is complementary to the second comb tooth portion; and / or, The inductive electrode comprises a third comb tooth portion, the inductive portion comprises a fourth comb tooth portion, and the third comb tooth portion is complementary to the fourth comb tooth portion.

9. The pressure sensor of claim 8, wherein, The pressure sensor comprises a first substrate structure; The first substrate structure comprises a first substrate, a first insulating layer and a device layer which are arranged in a stacked manner along the thickness direction of the pressure sensor, and the device layer comprises the first resonant module and the second resonant module; The first insulating layer comprises an opening arranged on one side of the resonant structure of the first resonant module and the second resonant module; the device layer further comprises a plurality of fixed anchor blocks, both ends of the first resonant beam and both ends of the second resonant beam are connected with the fixed anchor blocks; The driving electrode, the inductive electrode and the plurality of fixed anchor blocks are connected with the first insulating layer respectively.

10. The pressure sensor according to any one of claims 1 to 5, wherein The resonant unit further comprises a driving electrode and an inductive electrode, the driving electrode, the resonant structure and the inductive electrode are arranged at intervals along the first direction; The pressure sensor further comprises a plurality of first conductive bumps; the plurality of first conductive bumps comprise conductive bumps connected with the driving electrode, conductive bumps connected with the resonant structure, and conductive bumps connected with the inductive electrode.

11. The pressure sensor according to any one of claims 1 to 5, wherein The pressure sensor comprises: A first substrate structure, the first substrate structure comprises a device layer, a first insulating layer and a first substrate which are arranged in a stacked manner; a surface of the first substrate away from the first insulating layer is formed with a first groove, the first resonant module and the second resonant module are arranged on the device layer and on one side of the first groove; and A second substrate structure arranged opposite to the first substrate structure and bonded, the second substrate structure comprises a second insulating layer and a second substrate which are arranged in a stacked manner away from the first substrate structure; The surface of the second substrate away from the second insulating layer is a flat surface; or The surface of the second substrate away from the second insulating layer is formed with a second groove, and the second groove is at least partially opposite to the first groove.

12. A pressure sensing device, characterized by The pressure sensor comprises any one of claims 1-11.

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