Acceleration sensing chip, acceleration sensor and electronic equipment

Abstract

The embodiment of the invention discloses an acceleration sensing chip, an acceleration sensor and electronic equipment, and relates to the technical field of mechano-electronics. The acceleration sensing chip comprises a mass block, a base, a cantilever, a first stop part and a second stop part. The base ring is arranged around the mass block. The cantilevers are connected to the two sides of the mass block in the first direction respectively and further connected with the base. In the second direction, a distance is formed between the cantilever and the mass center of the mass block. The plurality of first stop parts are respectively connected with the base and are respectively positioned on two sides of the mass block along the first direction; in the second direction, a part of the first stopping part is arranged above the mass block at intervals. The plurality of second stop parts are respectively connected to two sides of the mass block along the third direction; in the second direction, a part of the second stopping part is arranged above the base in a spaced mode. The first backstop part and the second backstop part are matched with the base, so that comprehensive backstop on impact in the Z direction, the X direction and the Y direction can be realized, and the comprehensive impact resistance and reliability of the acceleration sensing chip are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical electronics, and in particular to an acceleration sensing chip, an acceleration sensor and an electronic device. BACKGROUND

[0002] With the increasing richness of functions of electronic devices, accelerometers / acceleration sensors (ACC) are increasingly widely used in electronic devices. A micro-electromechanical systems (MEMS) acceleration sensor is a sensor that uses a movable mass to measure acceleration. According to the detection principle of the MEMS acceleration sensor, the MEMS acceleration sensor can be mainly divided into a capacitive type, a piezoresistive type, a piezoelectric type, and the like.

[0003] Among them, the MEMS acceleration sensor of the capacitive type can convert the measured acceleration into a change in the capacitance of a capacitor. Specifically, the movable mass in the MEMS acceleration sensor can constitute a movable plate of a variable capacitor. When the MEMS acceleration sensor is impacted, the mass is subjected to acceleration and generates displacement, the gap or the facing area between the movable plate and the fixed plate changes, resulting in a change in the capacitance of the variable capacitor. After detecting this change, the size of the acceleration can be calculated.

[0004] However, in the case where the MEMS acceleration sensor is subjected to a large impact force, the internal structure of the MEMS acceleration sensor is prone to breakage or tearing, resulting in failure of the MEMS acceleration sensor and reducing the reliability of the MEMS acceleration sensor. SUMMARY

[0005] Embodiments of the present application provide an acceleration sensing chip, an acceleration sensor and an electronic device, for improving the reliability of the acceleration sensing chip, the acceleration sensor and the electronic device to which the acceleration sensing chip is applied.

[0006] To achieve the above object, the embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, an acceleration sensing chip is provided, which is for example a MEMS acceleration sensing chip of the capacitive type. The acceleration sensing chip can include a mass, a base, a plurality of suspension arms, a plurality of first stop portions, a plurality of second stop portions, and an electrode layer. The mass is electrically conductive. The electrode layer is spaced apart from the mass in a second direction; and the electrode layer is further connected to the base. The mass can serve as a movable plate, and the electrode layer can serve as a fixed plate, and the two together constitute a variable capacitor.

[0008] The bases are arranged around the mass block in a spaced manner. A plurality of cantilever arms are respectively connected to opposite sides of the mass block along a first direction, and are respectively connected to the bases. Along a second direction, a center of mass of each cantilever arm and a center of mass of the mass block have a spacing. A plurality of first stop portions are respectively connected to the bases. Along the first direction, the plurality of first stop portions are respectively located on opposite sides of the mass block, and along the second direction, a part of each first stop portion is arranged above the mass block in a spaced manner. A plurality of second stop portions are respectively connected to opposite sides of the mass block along a third direction. Along the second direction, a part of each second stop portion is arranged above the bases in a spaced manner. The first direction and the third direction are perpendicular to each other and are parallel to a reference plane defined by the bases and the mass block, and the second direction is perpendicular to the first direction and the third direction.

[0009] The acceleration sensing chip provided by some embodiments of the present application has a plurality of first stop portions connected to the bases and arranged on opposite sides of the mass block along a first direction, and a part of each first stop portion extends above the mass block, so that each first stop portion and the mass block partially overlap along a second direction and have a certain spacing. In this way, when the acceleration sensing chip is subjected to a large impact downward along the second direction, the first stop portions can effectively stop the movement of the mass block upward along the second direction, limit the movement range of the mass block along the second direction (Z direction), and thus protect the cantilever arms from being broken.

[0010] Furthermore, a plurality of second stop portions are arranged on opposite sides of the mass block along a third direction and connected to the mass block, and a part of each second stop portion extends above the bases, so that each second stop portion and the bases partially overlap along the second direction and have a certain spacing. In this way, when the acceleration sensing chip is subjected to a large impact upward along the second direction, and during the movement of the second stop portions downward along the second direction with the mass block, the bases can effectively stop the movement of the second stop portions, thus effectively stopping the movement of the mass block downward along the second direction, limiting the movement range of the mass block along the second direction (Z direction), and thus protecting the cantilever arms from being broken.

[0011] In addition, by limiting the relative position between the center of mass of the mass block and the center of mass of the cantilever, the application can form a seesaw structure when the acceleration sensing chip is subjected to a large impact in the first direction, and can effectively stop the rotation of the mass block by the first stopper during the rotation of the mass block, limit the rotation range of the mass block, and further protect the cantilever without the need to set an additional stop structure. In addition, the application can also form a seesaw structure when the acceleration sensing chip is subjected to a large impact in the third direction, and can effectively stop the rotation of the mass block by the second stopper and the base during the rotation of the mass block, limit the rotation range of the mass block, and further protect the cantilever without the need to set an additional stop structure.

[0012] In this way, the impact in the first direction (Y direction), the second direction (Z direction) and the third direction (X direction) can be fully stopped, and the resistance of the acceleration sensing chip to the impact in the first direction, the second direction and the third direction can be improved, the failure of the acceleration sensing chip caused by the fracture of the cantilever can be avoided, the reliability of the acceleration sensing chip (such as impact resistance and drop resistance) can be improved, and the reliability of the acceleration sensor and the electronic device using the acceleration sensing chip can be improved. In addition, the reuse of the first stopper and the second stopper can make the structure of the acceleration sensing chip simpler and easier to manufacture, which is beneficial to reduce the cost.

[0013] In a possible design of the first aspect, the plurality of first stoppers can be conductive. At least one first stopper is connected to the electrode layer and has an integrated structure. In this way, the structure of the acceleration sensing chip and the manufacturing process can be simplified, the number of layers of the structure in the acceleration sensing chip can be reduced, the thickness of the acceleration sensing chip can be reduced, and the space-saving advantage of the acceleration sensing chip can be further ensured. In addition, the structural stability between the electrode layer and the first stopper connected thereto can be improved, and the reliability of the acceleration sensing chip can be improved.

[0014] In a possible design of the first aspect, the mass block and the base are arranged on the same layer. And / or, the cantilever, the plurality of first stoppers, the plurality of second stoppers and the electrode layer are arranged on the same layer. In this way, the mass block and the base can be formed simultaneously in one patterning process, and / or the cantilever, the electrode layer, the plurality of first stoppers and the plurality of second stoppers can be formed simultaneously in one patterning process, which is beneficial to simplify the manufacturing process of the acceleration sensing chip. In addition, the number of layers of the structure in the acceleration sensing chip can be reduced, the thickness of the acceleration sensing chip can be reduced, and the space-saving advantage of the acceleration sensing chip can be further ensured.

[0015] In a possible design manner of the first aspect, the acceleration sensing chip comprises: a support layer, an isolation layer and a functional layer which are stacked along the second direction. The mass block and the base are located on the support layer, the cantilever, the plurality of first stop portions, the plurality of second stop portions and the electrode layer are located on the functional layer. In this way, the acceleration sensing chip provided by the embodiments of the present application can be prepared by a smaller number of film layers, and on the basis of achieving detection of acceleration and comprehensive stopping of impacts along the first direction, the second direction and the third direction, the number of film layers can be reduced, the thickness of the acceleration sensing chip can be reduced, the structure of the acceleration sensing chip can be simplified, and the space saving advantage of the acceleration sensing chip can be ensured.

[0016] In a possible design manner of the first aspect, along the first direction, the at least one cantilever located on one side of the mass block is connected with the at least one cantilever located on the other side of the mass block and forms an integral structure. In this way, the structural stability of the connected cantilevers and the mass block and the base can be improved, and the structural stability and reliability of the acceleration sensing chip can be improved.

[0017] In a possible design manner of the first aspect, the plurality of cantilevers are respectively located on opposite sides of the plurality of first stop portions along the third direction, and the plurality of second stop portions are respectively located on opposite sides of the plurality of cantilevers along the third direction. In this way, on the one hand, the spacing between two adjacent cantilevers along the third direction can be increased, so that the mass block is more stable and is less likely to shake; on the other hand, the design difficulty of the cantilevers, the first stop portions and the second stop portions can be simplified, and the structural symmetry can be improved.

[0018] In a possible design manner of the first aspect, along the first direction, the ratio of the effective stiffness of the at least one first stop portion located on one side of the mass block to the effective stiffness of the at least one first stop portion located on the other side of the mass block ranges from 1:2 to 2:1. In this way, the difference between the effective stiffness of the first stop portions located on opposite sides of the mass block can be smaller. In the case that the acceleration sensing chip is subjected to a larger positive or negative impact along the first direction, the stress of the first stop portions located on opposite sides of the mass block can be more balanced, so that better stopping effect and higher structural stability can be achieved.

[0019] In a possible design manner of the first aspect, along the first direction, the ratio of the effective size of the at least one first stop portion located on one side of the mass block in the third direction to the effective size of the at least one first stop portion located on the other side of the mass block in the third direction ranges from 1:2 to 2:1. In this way, the difference between the effective lengths of the first stop portions located on opposite sides of the mass block can be reduced, and the difference between the effective stiffness of the first stop portions located on opposite sides of the mass block can be reduced.

[0020] In a possible design manner of the first aspect, the ratio of the effective stiffness of the at least one second stop portion on one side of the mass to the effective stiffness of the at least one second stop portion on the other side of the mass ranges from 1:2 to 2:1 in the third direction. In this way, the difference in the effective stiffness of the second stop portions on opposite sides of the mass can be small. In the case of a large positive or negative impact on the acceleration sensing chip in the third direction, the forces on the second stop portions on opposite sides of the mass can be balanced, so that a better stopping effect and higher structural stability can be achieved.

[0021] In a possible design manner of the first aspect, the ratio of the effective size of the at least one second stop portion on one side of the mass in the first direction to the effective size of the at least one second stop portion on the other side of the mass in the first direction ranges from 1:2 to 2:1 in the third direction. In this way, the difference in the effective length of the second stop portions on opposite sides of the mass can be reduced, and the difference in the effective stiffness of the second stop portions on opposite sides of the mass can be reduced.

[0022] In a possible design manner of the first aspect, the base has a first side opposite to the mass, and the mass has a second side opposite to the base. The acceleration sensing chip has a plurality of grooves, which are formed on the first side and / or the second side, and the depth direction of each groove is parallel to the first direction. In the second direction, the grooves are below the cantilevers. In this way, the length of the cantilevers can be effectively increased, which can reduce the influence of etching errors of the support layer or the isolation layer on the length of the cantilevers, that is, increase the tolerance of etching errors of the support layer or the isolation layer in the first direction; on the other hand, the rigidity of the cantilevers can be reduced, which is conducive to achieving the stopping of lateral (that is, the first direction and / or the third direction) impact; on the other hand, the resonant frequency of the acceleration sensing chip can be reduced, and the signal-to-noise ratio of the acceleration sensing chip can be improved.

[0023] In a possible design manner of the first aspect, the number of grooves below different cantilevers is the same in the second direction. In this way, the difference in the length of different cantilevers can be reduced, which is conducive to balancing the forces on different cantilevers and improving the structural stability of the acceleration sensing chip.

[0024] In a possible design manner of the first aspect, the depths of the grooves are the same. In this way, the design difficulty of the acceleration sensing chip can be reduced; and the lengths of different cantilevers can be equal, which is conducive to further balancing the forces on different cantilevers and improving the structural stability of the acceleration sensing chip.

[0025] In a possible design of the first aspect, in the second direction, a portion of the first stopper above the mass is provided with at least one first communication structure. The first communication structure communicates a gap between the first stopper and the mass. In this way, in the process of manufacturing the acceleration sensing chip, the fluid can contact the membrane layer below the first stopper through the first communication structure, facilitate lateral etching of the membrane layer below the first stopper, and facilitate outflow of the fluid.

[0026] In a possible design of the first aspect, in the second direction, a portion of the electrode layer above the mass is provided with at least one second communication structure. The second communication structure communicates a gap between the electrode layer and the mass. In this way, in the process of manufacturing the acceleration sensing chip, the fluid can contact the membrane layer below the electrode layer through the second communication structure, facilitate lateral etching of the membrane layer below the electrode layer, and facilitate outflow of the fluid.

[0027] In a possible design of the first aspect, the acceleration sensing chip further includes a first protective layer. The first protective layer covers at least one side surface of the plurality of first stoppers close to the mass and at least one side surface of the plurality of second stoppers close to the base. A gap is formed between the first protective layer and the base and between the first protective layer and the mass. In this way, in the case that the acceleration sensing chip is subjected to a relatively large impact in the first direction, the second direction, or the third direction, the mass can contact the first stopper through the first protective layer, and a certain buffering effect is formed on the movement of the mass; or the second stopper can contact the base through the first protective layer, and a certain buffering effect is formed on the movement of the second stopper. In this way, the first stopper and the second stopper can be protected, stress concentration can be reduced or even avoided, the first stopper and / or the second stopper can be prevented from being damaged, and the reliability of the acceleration sensing chip is further improved.

[0028] In a possible design of the first aspect, the acceleration sensing chip further includes a second protective layer. The second protective layer covers at least a portion of a surface of the mass opposite to the plurality of first stoppers and at least a portion of a surface of the base opposite to the plurality of second stoppers. A gap is formed between the second protective layer and the first stopper and between the second protective layer and the second stopper. In this way, in the case that the acceleration sensing chip is subjected to a relatively large impact in the first direction, the second direction, or the third direction, the mass can contact the first stopper through the second protective layer, and a certain buffering effect is formed on the movement of the mass; or the second stopper can contact the base through the second protective layer, and a certain buffering effect is formed on the movement of the second stopper. In this way, the first stopper and the second stopper can be protected, stress concentration can be reduced or even avoided, the structure of the first stopper and / or the second stopper can be prevented from being damaged, and the reliability of the acceleration sensing chip is further improved.

[0029] In one possible design approach, the accelerometer chip includes both a first protective layer and a second protective layer. The first protective layer covers at least the surfaces of the plurality of first stops near the mass block and the surfaces of the plurality of second stops near the base. The second protective layer covers at least the surfaces of the mass block facing the plurality of first stops and the surfaces of the base facing the plurality of second stops. A gap exists between the first and second protective layers. This provides further protection for the first and second stops, significantly reducing stress concentration and greatly improving the reliability of the accelerometer chip.

[0030] In one possible design approach, along the second direction, the ratio of the spacing between the first and second protective layers to the spacing between the mass block and the first stop is greater than or equal to 1:2. This ensures that the first and second protective layers can provide protection for the first and second stop portions, while also ensuring that the mass block and the second stop portions have sufficient movement distance to guarantee the sensitivity of the acceleration sensing chip.

[0031] In one possible design approach, the accelerometer chip has a first axis of symmetry and a second axis of symmetry. The first axis of symmetry extends along a first direction, and the second axis of symmetry extends along a third direction. The accelerometer chip is symmetrical about both the first and second axes of symmetry. This allows for a more balanced force distribution on different cantilever arms, resulting in a more balanced stopping effect for different first or second stop sections, which improves structural stability and achieves better stopping performance.

[0032] Secondly, an accelerometer chip is provided, which is, for example, a capacitive MEMS accelerometer chip. The accelerometer chip includes a first sensor chip and a second sensor chip. The first sensor chip includes the accelerometer chip as described in any design embodiment of the first aspect, and the second sensor chip includes the accelerometer chip as described in any design embodiment of the first aspect. The first and second sensor chips are disposed opposite to each other, the base of the first sensor chip and the base of the second sensor chip are connected, and the mass block of the first sensor chip and the mass block of the second sensor chip are connected.

[0033] The technical effects of the acceleration sensing chip provided in some embodiments of this application can be seen in the technical effects of different design methods in the first aspect, which will not be repeated here.

[0034] Furthermore, the electrode layer of the first sensing chip, the two connected mass blocks, and the electrode layer of the second sensing chip can constitute a variable capacitor. The electrode layers of the first and second sensing chips can serve as a differential output, making the relationship between the movement amplitude (or movement distance) of the two connected mass blocks and the total capacitance of the variable capacitor tend to change linearly. This maintains good linearity even when the movement amplitude of the two connected mass blocks is large, which is beneficial for improving the sensitivity of the acceleration sensing chip.

[0035] In the second possible design approach, the area of ​​the mass block and electrode layer facing each other in the first sensing chip is equal to the area of ​​the mass block and electrode layer facing each other in the second sensing chip. This helps to further improve the linearity between the movement amplitude (or movement distance) of the two connected mass blocks and the total capacitance of the variable capacitor, thereby further improving the sensitivity of the acceleration sensing chip.

[0036] In the second possible design approach, the first and second sensing chips have a connection interface. The first and second sensing chips are symmetrical about the connection interface. This helps to reduce the design and fabrication difficulty of the accelerometer chip and improve its fabrication efficiency.

[0037] Thirdly, an acceleration sensor is provided, comprising: an acceleration sensing chip as described in either the first or second aspect, and an application-specific integrated circuit (ASIC) chip. The ASIC chip is electrically connected to the acceleration sensing chip.

[0038] Fourthly, an electronic device is provided, comprising: an acceleration sensor and a circuit board as described in any of the designs in the third aspect. The circuit board is electrically connected to the acceleration sensor.

[0039] The technical effects of any of the design methods in the third or fourth aspects can be found in the technical effects of different design methods in the first aspect, and will not be repeated here. Attached Figure Description

[0040] Figure 1 A structural diagram of an electronic device provided in an embodiment of this application;

[0041] Figure 2 A partial structural diagram of an electronic device provided in an embodiment of this application;

[0042] Figure 3 A partial structural diagram of another electronic device provided in an embodiment of this application;

[0043] Figure 4 A partial structural diagram of another electronic device provided in an embodiment of this application;

[0044] Figure 5 A partial structural diagram of another electronic device provided in an embodiment of this application;

[0045] Figure 6 A structural diagram of an acceleration sensor chip provided in an embodiment of this application;

[0046] Figure 7a for Figure 6 The diagram shows a cross-sectional view of the accelerometer chip along the N1-N1' direction.

[0047] Figure 7b for Figure 6 The diagram shows a cross-sectional view of the accelerometer chip along the N2-N2' direction.

[0048] Figure 7c for Figure 6 The diagram shows a cross-sectional view of the accelerometer chip along the M-M' direction.

[0049] Figure 8 This is a structural diagram of another acceleration sensor chip provided in an embodiment of this application;

[0050] Figure 9a for Figure 8 The diagram shows a cross-sectional view of the accelerometer chip along the N1-N1' direction.

[0051] Figure 9b for Figure 8 The diagram shows a cross-sectional view of the accelerometer chip along the N2-N2' direction.

[0052] Figure 9c for Figure 8 The diagram shows a cross-sectional view of the accelerometer chip along the M-M' direction.

[0053] Figure 10 for Figure 8 The diagram shows a cross-sectional view of an accelerometer chip subjected to a downward impact along the second direction, along the N1-N1' direction.

[0054] Figure 11 for Figure 8 The diagram shows a cross-sectional view of an accelerometer chip subjected to a positive impact along the first direction, along the N1-N1' direction.

[0055] Figure 12 for Figure 8 The diagram shows a cross-sectional view of an accelerometer chip subjected to an upward impact along the second direction, along the M-M' direction.

[0056] Figure 13 for Figure 8The diagram shows a cross-sectional view of an accelerometer chip subjected to a positive impact along a third direction, along the M-M' direction.

[0057] Figure 14a A structural diagram of a support layer provided in an embodiment of this application;

[0058] Figure 14b A structural diagram of a support layer and an isolation layer provided in an embodiment of this application;

[0059] Figure 15 A structural diagram of another acceleration sensing chip provided in an embodiment of this application;

[0060] Figure 16a for Figure 15 The diagram shows a cross-sectional view of the accelerometer chip along the N-N' direction.

[0061] Figure 16b for Figure 15 The diagram shows a cross-sectional view of the accelerometer chip along the M-M' direction.

[0062] Figure 17a A partial structural diagram of an acceleration sensing chip provided in an embodiment of this application;

[0063] Figure 17b A partial structural diagram of another acceleration sensing chip provided in an embodiment of this application;

[0064] Figure 18a A partial structural diagram of another acceleration sensing chip provided in an embodiment of this application;

[0065] Figure 18b A partial structural diagram of another acceleration sensing chip provided in an embodiment of this application;

[0066] Figure 19 A structural diagram of another acceleration sensing chip provided in an embodiment of this application;

[0067] Figure 20a for Figure 8 Another cross-sectional view of the accelerometer chip along the N1-N1' direction is shown.

[0068] Figure 20b for Figure 8 Another cross-sectional view of the accelerometer chip along the M-M' direction is shown.

[0069] Figure 21a for Figure 8 The diagram shows another cross-sectional view of the accelerometer chip along the N1-N1' direction;

[0070] Figure 21b forFigure 8 The diagram shows another cross-sectional view of the accelerometer chip along the M-M' direction;

[0071] Figure 22a A structural diagram of another acceleration sensing chip provided in an embodiment of this application;

[0072] Figure 22b A structural diagram of another acceleration sensing chip provided in an embodiment of this application;

[0073] Figure 22c A structural diagram of another acceleration sensing chip provided in an embodiment of this application;

[0074] Figure 23a A cross-sectional view of an acceleration sensing chip along a second direction and a third direction, provided in an embodiment of this application;

[0075] Figure 23b A cross-sectional view of an acceleration sensing chip along a first direction and a second direction, provided in an embodiment of this application;

[0076] Figure 24a - Figure 24e The diagram shows the structural diagrams corresponding to each step in the fabrication method of an acceleration sensor chip provided in this application embodiment.

[0077] Figure 25a - Figure 25c The diagram shows the structural steps of another method for fabricating an acceleration sensor chip provided in this application. Detailed Implementation

[0078] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application are within the scope of protection of this application.

[0079] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. "At least one" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, and c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. "a and / or b" includes the following three combinations: only a, only b, and a combination of a and b. "Spacing" refers, for example, to the minimum distance between two adjacent structures.

[0080] Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" are not necessarily different. Meanwhile, in the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of terms such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding.

[0081] In describing some embodiments, the term "connection" and its derivative expressions are used. The term "connection" should be interpreted broadly; for example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, the use of "based on" implies openness and inclusivity, because processes, steps, calculations, or other actions "based on" one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0082] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error 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 range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0083] In this application embodiment, the terms "upper," "lower," "left," and "right" are not limited to the orientation of the components schematically placed in the accompanying drawings. It should be understood that these directional terms can be relative concepts used for description and clarification, and can vary accordingly depending on the orientation of the components in the accompanying drawings. In the drawings, for clarity, the thickness of layers and regions is exaggerated, and the dimensional proportions between the parts in the illustrations do not reflect actual dimensional proportions. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, exemplary embodiments should not be construed as being limited to the shapes of the areas shown in this application, but rather include shape deviations due to, for example, manufacturing. For example, an etched area shown as rectangular would typically have a curved feature. Therefore, the areas shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0084] Furthermore, the architecture and scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of architecture and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0085] This application provides an electronic device that can acquire vibration signals. This electronic device can be applied to various communication systems or protocols, such as Global System for Mobile Communication (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), General Packet Radio Service (GPRS), and Long Term Evolution (LTE).

[0086] The aforementioned electronic devices include, for example, consumer products, home products, automotive products, wearable products, financial terminal products, communication products, and intelligent detection products. For instance, these electronic devices can be various types of headphones such as true wireless stereo (TWS) headphones, open-air true wireless stereo (OWS) headphones, and hearing aids (HA); they can also be mobile phones, tablets, smart wearable products (e.g., smartwatches, smart bracelets), extended reality (XR) devices, inertial navigation systems, supplemental inflatable restraint systems (SRS) devices, smart door locks, stethoscopes, helmets, handheld devices, and fluid pressure gauges; and they can also be key components mounted on interior car windows to detect external voices and facilitate human-vehicle interaction. Among these, the aforementioned XR devices include, for example, virtual reality (VR) devices, augmented reality (AR) devices, or mixed reality (MR) devices. This application does not impose any special restrictions on the specific form of the terminal device described above.

[0087] The following uses TWS earphones as an example to illustrate the electronic device provided in the embodiments of this application. This should not be considered as a specific limitation on the structural form of the electronic device.

[0088] Combination Figure 1 and Figure 2 The electronic device 1000 mainly includes a housing 100, and components such as a circuit board 200, a battery, a microphone module, a speaker, and a Bluetooth module disposed within the housing 100. The battery powers the electronic device 1000, the microphone module picks up voice signals, the speaker plays voice signals, and the Bluetooth module communicates with external terminals. For example, the battery, microphone module, speaker, and Bluetooth module can be mounted on the circuit board 200 by soldering, bonding, or binding, and are electrically connected to the circuit board 200. The circuit board 200 can be a printed circuit board (PCB).

[0089] For example, such as Figure 2 As shown, the aforementioned electronic device 1000 may further include a processor 300 mounted on the circuit board 200. The processor 300 is used to process the electrical signals it receives.

[0090] Understandably, during voice interaction, one often encounters call scenarios with severe background noise, such as in bars, venues, or in windy and rainy environments. This background noise interferes with voice interaction, severely impacting its quality and making it difficult for the recipient to hear clear speech, thus affecting normal voice communication.

[0091] The aforementioned microphone module is an important component in the electronic device 1000 for picking up voice signals, and the noise filtering function of the microphone module has a crucial impact on the quality of voice interaction.

[0092] In some products, the voice pickup module includes an accelerometer 400, which is electrically connected to the circuit board 200 and used to acquire the acceleration of the component under test. In this case, the voice pickup bone sensor unit (VPU) of the aforementioned accelerometer 400 can be used to acquire the user's audio signal to improve noise filtering.

[0093] In some products, the aforementioned accelerometer sensor 400 is equipped with a microphone (MIC). In this case, a combination of voice pickup bone conduction and microphone can be used to acquire bone conduction signals of skull vibration when the user speaks, and to acquire air conduction signals in conjunction with the microphone. Then, the processor 300 can perform appropriate (adaptive) filtering on the bone conduction signals and air conduction signals to filter out environmental noise and output high-quality uplink call data.

[0094] For example, the aforementioned accelerometer 400 can be a MEMS accelerometer, and has a relatively small size (e.g., less than or equal to 10 mm). 3 It has the characteristics of being suitable for wearable products, high signal-to-noise ratio (SNR) (e.g., above 58 dBA, or even above 75 dBA), low total noise equivalent acceleration (TNEA), and limited bandwidth.

[0095] in, Figure 3 , Figure 4 and Figure 5 The structures of one type of accelerometer are illustrated below, and those skilled in the art will understand that... Figure 3 - Figure 5 The architecture of the accelerometer shown is not intended to limit the accelerometer, which may include, for example... Figure 3 - Figure 5 The components shown may have more or fewer components, or they may be combined. Figure 3 - Figure 5Some of the components shown, or those that can be combined with Figure 3 - Figure 5 The component arrangements shown are different.

[0096] In some examples, such as Figure 3 As shown, the aforementioned accelerometer 400 may include a package substrate 10, an accelerometer chip 20, and an application-specific integrated circuit (ASIC) chip 30. The package substrate 10 has internal metal traces, and both the accelerometer chip 20 and the ASIC chip 30 may be disposed on and electrically connected to the package substrate 10. Optionally, the package substrate 10 may be a printed circuit board.

[0097] Furthermore, the accelerometer chip 20 is electrically connected, for example, to an application-specific integrated circuit (ASIC) chip 30. For example, such as... Figure 3 As shown, the accelerometer chip 20 and the application-specific integrated circuit (ASIC) chip 30 can be electrically connected via a flying wire connection. In this case, the active surfaces of the accelerometer chip 20 and the ASIC chip 30 are both, for example, facing upwards. The accelerometer sensor 400 may also include an adhesive layer (also called a glue layer) 40 bonded to the packaging substrate 10. The accelerometer chip 20 and the ASIC chip 30 are respectively bonded to the packaging substrate 10 through the adhesive layer 40.

[0098] Of course, the accelerometer chip 20 and the application-specific integrated circuit (ASIC) chip 30 can also be electrically connected in other ways. For example, both the accelerometer chip 20 and the ASIC chip 30 can be electrically connected to the packaging substrate 10 using a flip-chip method, so that the accelerometer chip 20 is indirectly electrically connected to the ASIC chip 30 through metal traces in the packaging substrate 10. Alternatively, the accelerometer chip 20 and the ASIC chip 30 can be electrically connected using a TSV (through-silicon via) process.

[0099] For example, such as Figure 3 As shown, the accelerometer 400 may further include an encapsulation cover 50, which can be snapped onto the accelerometer chip 20 and the application-specific integrated circuit (ASIC) chip 30, and is connected to the encapsulation substrate 10. The encapsulation cover 50 and the encapsulation substrate 10 can form a space for accommodating the accelerometer chip 20 and the ASIC chip 30, thereby protecting the accelerometer chip 20 and the ASIC chip 30 from the influence of external water, oxygen, and electromagnetic interference. The encapsulation cover 50 may be, for example, a metal cover. Of course, the accelerometer 200 may also be encapsulated using materials such as plastic sealant.

[0100] Continue reading Figure 3 The accelerometer 400 may also include a plurality of pads 60 disposed on the surface of the package substrate 10 away from the package cover plate 50. The package substrate 10 can be electrically connected to the circuit board 200 through the plurality of pads 60, thereby enabling the processor 300 on the circuit board 200 to transmit electrical signals to the accelerometer 400.

[0101] In this configuration, the accelerometer chip 20 can be indirectly connected to the device under test (e.g., the housing of a TWS earphone) via the packaging substrate 10 and the circuit board 200. When a user wears the TWS earphone and makes a call, the vibrations in the skull caused by the user's voice are transmitted sequentially through the earphone housing, the circuit board 200, and the packaging substrate 10 to the accelerometer chip 20. The accelerometer chip 20 can convert the acceleration of the device under test into a corresponding electrical signal and output it to the application-specific integrated circuit (ASIC) chip 30.

[0102] The dedicated integrated circuit chip 30 is used to process the electrical signals from the accelerometer chip 20, such as amplifying and filtering them. Furthermore, the dedicated integrated circuit chip 30 can transmit the processed electrical signals to the processor 300 in digital or analog form. In this way, the processor 300 can obtain the acceleration generated by the TWS earphone due to the vibration of the user's skull based on the electrical signals from the dedicated integrated circuit chip 30, and then convert the vibration of the user's skull into a corresponding voice signal based on this acceleration, realizing bone conduction technology for sound pickup.

[0103] In some examples, such as Figure 4 and Figure 5 As shown, the accelerometer 400 may also include a microphone 70, which is disposed on the packaging substrate 10 and located within the receiving space formed by the packaging substrate 10 and the packaging cover 50. By packaging the microphone 70 and the accelerometer chip 20 together, it is beneficial to improve the effective utilization of space and volume.

[0104] The setup between the microphone 70 and the accelerometer chip 20 can be varied. For example, such as... Figure 4 As shown, the microphone 70 and the accelerometer chip 20 are fabricated on the same wafer in the same patterning process, and they are integrated into a single structure. This simplifies the fabrication process of the microphone 70 and the accelerometer chip 20, improving fabrication efficiency. For example, as... Figure 5As shown, the microphone 70 and the accelerometer chip 20 are two independent chips, and they are stacked along the thickness direction of the packaging substrate 10. This not only reduces the limitation on the type of microphone 70 (for example, a traditional microphone can be used) and reduces development costs, but also helps to reduce the packaging area and facilitates the miniaturization design of the accelerometer sensor 400.

[0105] Continue reading Figure 5 In the case where the microphone 70 and the accelerometer chip 20 are stacked, the microphone 70 is located, for example, between the packaging substrate 10 and the accelerometer chip 20. Correspondingly, both the packaging substrate 10 and the circuit board 200 have through-holes H1, which are located below the microphone 70, exposing a portion of the microphone 70 so that the microphone 70 can collect the user's sound through the through-hole H1. Further, as... Figure 5 As shown, the accelerometer 400 may further include: an acoustic barrier 80 and a silicon fusion bond (SFB) layer 90. The acoustic barrier 80 is located between the microphone 70 and the accelerometer chip 20, and covers the side surface of the accelerometer chip 20 closest to the packaging substrate 10 to achieve acoustic isolation. The silicon fusion bond layer 90 is located between the microphone 70 and the acoustic barrier 80, and is an open annular shape to form an vent H2. The silicon fusion bond layer 90 is used to connect the microphone 70 and the acoustic barrier 80. The material of the silicon fusion bond layer 90 is, for example, the same as the material of the acoustic barrier 80. Optionally, the material of the acoustic barrier 80 may be silicon (Si) or glass, etc.

[0106] For example, microphone 70 is also electrically connected to application-specific integrated circuit chip 30. For example, as Figure 4 and Figure 5 As shown, the microphone 70 and the application-specific integrated circuit (ASIC) chip 30 can be electrically connected via a flying wire connection. In this case, the microphone 70 can be bonded to the packaging substrate 10, for example, via the adhesive layer 40. Of course, the microphone 70 and the ASIC chip 30 can also be electrically connected in other ways, which will not be elaborated here.

[0107] In this way, the dedicated integrated circuit chip 30 can also process the signal from the microphone 70 and transmit the processed electrical signal to the processor 300 in the form of a digital or analog signal. The processor 300 can then output high-quality uplink call data based on the electrical signal corresponding to the microphone 70 and the electrical signal corresponding to the accelerometer chip 20.

[0108] Alternatively, other structures in the electronic device 1000, such as angular velocity sensors, inertial measurement units (IMUs), or other MEMS sensors, can also be packaged together with the acceleration sensing chip 20 between the aforementioned packaging substrate 10 and packaging cover plate 50, which can bring space and cost benefits.

[0109] In some examples, the aforementioned accelerometer chip 20 typically has a movable mass and an elastic element connecting the mass. When the accelerometer sensor 400 is subjected to vibration (or impact, drop, etc.), the mass in the accelerometer chip 20 will displace under the action of inertial force (or acceleration). By measuring the inertial force acting on the mass and using Newton's second law, the acceleration value can be obtained.

[0110] Accelerometer chip 20 typically also includes a sensing element. Depending on the sensing element, the acceleration sensor chip 20 will have different detection principles. Based on this, acceleration sensor chips 20 can be mainly classified into capacitive, piezoresistive, and piezoelectric types. Below, this application embodiment uses a capacitive acceleration sensor chip 20 as an example for illustrative explanation.

[0111] Specifically, the capacitive accelerometer chip 20 can convert the measured acceleration into a change in the capacitance of a capacitor. Specifically, the movable mass in the accelerometer chip 20 can form a movable plate of a variable capacitor. When the accelerometer chip 20 is vibrated, causing the mass to displace under the action of acceleration, the gap or facing area between the movable plate and the fixed plate changes, resulting in a change in the capacitance of the variable capacitor. Detecting this change allows the calculation of the magnitude of the acceleration.

[0112] However, when the accelerometer chip 20 is subjected to a large impact force, the displacement of the mass block is large, and the internal structure (such as elastic element) used to connect the mass block in the accelerometer chip 20 is prone to breakage or tearing, which leads to the failure of the accelerometer chip 20 and reduces the reliability of the accelerometer chip 20.

[0113] In one possible implementation, the thickness or width of the elastic element could be increased, or a protective film or other structure could be added to protect the elastic element. However, this would cause the resonant frequency of the acceleration sensing chip to rise, which would be detrimental to reducing the total noise equivalent acceleration or improving the signal-to-noise ratio.

[0114] In other possible implementations, a stop structure or a buffer structure can be incorporated to limit the range of movement of the mass block. This protects the elastic element without increasing the resonant frequency of the accelerometer chip.

[0115] However, the setting of the stop structure or buffer structure can, on the one hand, usually only limit the range of movement of the mass block in a single direction. For example, it can only limit the range of movement along the arrangement direction of the mass block and the fixed electrode, or it can only limit the range of movement in the direction parallel to the plane where the fixed electrode is located. On the other hand, it will also increase the structural complexity of the acceleration sensor chip, for example, by increasing the number of film layers.

[0116] For example, along the arrangement direction of the mass block and the fixed electrode plate, an upper cover plate and a lower cover plate can be respectively provided on the upper and lower sides of the mass block. The upper cover plate can be used to block the upward movement of the mass block along the arrangement direction, and the lower cover plate can be used to block the downward movement of the mass block along the arrangement direction. This restricts the range of motion of the mass block and can prevent the elastic element from breaking or tearing.

[0117] However, both the upper and lower cover plates need to be bonded to the base to which the elastic element is connected, which undoubtedly increases the fabrication process steps of the accelerometer chip and its cost. Furthermore, the addition of the upper and lower cover plates increases the thickness of the accelerometer chip, for example, by at least 200 μm, negating its space-saving advantage. Additionally, the large spacing between the upper and lower cover plates along the arrangement of the mass and fixed electrode results in a large range of motion for the mass. Even with relatively small impacts on the accelerometer chip, the elastic element still experiences significant movement, which can easily lead to fatigue failure.

[0118] Based on this, some embodiments of this application provide an acceleration sensing chip, which can be a MEMS acceleration sensing chip and can be applied to the aforementioned acceleration sensor 400. Figure 6 and Figure 8 The diagrams show the structure of one type of accelerometer chip. Figure 7a , Figure 7b and Figure 7c They respectively indicated Figure 6 The diagram shows cross-sectional views of the accelerometer chip along different cross-sectional directions. Figure 9a , Figure 9b and Figure 9c They respectively indicated Figure 8 The diagram shows cross-sectional views of the accelerometer chip along different cross-sectional directions. Figure 10 , Figure 11 , Figure 12and Figure 13 The diagrams illustrate the effects of different impact directions. Figure 8 The diagram shows the cross-sectional structure of the accelerometer chip along different cross-sectional directions.

[0119] In some examples, such as Figure 6 and Figure 8 As shown, the accelerometer chip 20 includes: a mass block 1, a base 2, a cantilever 3, an electrode layer 4, a first stop portion 5, and a second stop portion 6. Further, the accelerometer chip 20 has a first direction Y, a second direction Z, and a third direction X. The first direction Y and the third direction X intersect (e.g., are perpendicular), and both are parallel to the reference plane defined by the mass block 1 and the base 2. The second direction Z is perpendicular to the first direction Y and the third direction X; that is, the second direction Z is perpendicular to the reference plane defined by the mass block 1 and the base 2.

[0120] The aforementioned mass block 1 has a polyhedral structure, such as a cube or cuboid, etc., and this embodiment of the application does not limit this. For example, the mass block 1 is conductive, that is, the material of the mass block 1 includes conductive materials, and the mass block 1 is capable of transmitting electrical signals.

[0121] The structure of the base 2 described above includes various types and can be configured according to actual product requirements. For example, such as... Figure 6 and Figure 8 As shown, base 2 is a hollow frame structure. For example, the structure of base 2 includes, but is not limited to, a hollow polygonal frame structure, a hollow circular frame structure, and a hollow elliptical frame structure. Among them, the hollow polygonal frame structure includes, for example, a hollow triangular frame structure, a hollow rectangular frame structure, and a hollow hexagonal frame structure.

[0122] Continue reading Figure 6 and Figure 8 The base 2 is arranged in a ring around the mass block 1 at intervals. That is, the mass block 1 is located in the area enclosed by the base 2 and is surrounded by the base 2; and there is a gap between the mass block 1 and the base 2, and the two are not in direct contact.

[0123] The number of cantilever arms 3 mentioned above is multiple. Optionally, the number of cantilever arms 3 can be two, three, four, or even more. Further, the number of cantilever arms 3 can be an even number. Figure 6 and Figure 8 All four cantilever arms are shown.

[0124] like Figure 6 and Figure 8 As shown, the aforementioned multiple cantilever arms 3 are located on opposite sides of the mass block 1 along the first direction Y. For example, in Figure 6 and Figure 8In the structure shown, a portion of the multiple cantilever arms 3 are located above the mass block 1, while another portion of the multiple cantilever arms 3 are located below the mass block 1. The number of cantilever arms 3 located on opposite sides of the mass block 1 along the first direction Y can be the same or different. For example, as... Figure 6 and Figure 8 As shown, along the first direction Y, the number of cantilever 3 on opposite sides of mass block 1 is the same, and there are two of them.

[0125] like Figure 7b and Figure 9b The aforementioned multiple cantilever arms 3 are respectively connected to the mass block 1 and also to the base 2. The connection points between the cantilever arms 3 and the base 2 can be called anchor points. The relative positions of each cantilever arm 3 and the mass block 1 are fixed, and the relative positions of each cantilever arm 3 and the base 2 are also fixed. Each cantilever arm 3 can serve as a connection point between the mass block 1 and the base 2. The multiple cantilever arms 3 cooperate with each other to fix the mass block 1 to the base 2. Each cantilever arm 3 is elastic, and can undergo elastic deformation when the mass block 1 is displaced relative to the base 2. Optionally, each cantilever arm 3 can be a beam structure or a membrane structure.

[0126] Furthermore, such as Figure 7b As shown, along the second direction Z, there is a gap between the center of mass C1 of each cantilever 3 and the center of mass C2 of the mass block 1. For example, the center of mass C1 of each cantilever 3 is located in the same first plane, and the center of mass C2 of the mass block 1 is located in the second plane. Both the first and second planes are perpendicular to the second direction Z, and there is a gap between the first and second planes. For example, in Figure 7b In the middle, along the second direction Z, the first plane is located above the second plane.

[0127] Thus, when the accelerometer chip 20 is impacted along the second direction Z, the mass block 1 can move upward or downward relative to the base 2, and the cantilever 3 will be stretched. When the accelerometer chip 20 is impacted laterally along the first direction Y or the third direction X, the mass block 1 can rotate or tilt at a certain angle relative to the base 2, and the cantilever 3 will be twisted. The mass block 1 and the cantilever 3 form a seesaw-like structure.

[0128] For example, such as Figure 7a , Figure 7c , Figure 9a and Figure 9cAs shown, along the second direction Z, the electrode layers 4 are spaced apart above the mass block 1. That is, along the second direction Z, the electrode layers 4 are higher than the mass block 1, there is a gap between the lower surface of the electrode layers 4 and the upper surface of the mass block 1, and there is no contact between the electrode layers 4 and the mass block 1. Furthermore, the electrode layers 4 and the mass block 1 are partially opposite each other, the electrode layers 4 cover a portion of the mass block 1, and the orthographic projection of the electrode layers 4 on the reference plane and the orthographic projection of the mass block 1 on the reference plane partially overlap.

[0129] Combination Figure 6 and Figure 8 The electrode layer 4 is also connected to the base 2. Optionally, the electrode layer 4 can be directly connected to the base 2, or the electrode layer 4 can be connected to the base through other structures (such as the first stop). The relative position between the electrode layer 4 and the base 2 is fixed.

[0130] In this case, the electrode layer 4 and the mass block 1 can, for example, constitute a variable capacitor. The electrode layer 4 can serve as a fixed plate of the capacitor, the mass block 1 can serve as a movable plate of the capacitor, and the gas (e.g., air) filling the gap between the electrode layer 4 and the mass block 1 can serve as an insulating medium.

[0131] When the acceleration sensing chip 20 is subjected to an impact, the mass block 1 will be displaced by the acceleration a, which will cause the distance between the mass block 1 and the electrode layer 4 in the second direction Z to change. This will cause the capacitance of the capacitor formed by the mass block 1 and the electrode layer 4 to change. After detecting this change, the magnitude of the acceleration can be calculated.

[0132] In some examples, the number of the first stop portions 5 is multiple. Optionally, the number of first stop portions 5 can be two, three, four, or even more. Further, the number of first stop portions 5 can be an even number. Figure 6 and Figure 8 Both diagrams show the two first stop sections 5.

[0133] like Figure 7a and Figure 9a As shown, the aforementioned plurality of first stop portions 5 are respectively connected to and fixed on the base 2. The relative positions of each first stop portion 5 and the base 2 are fixed. Figure 6 and Figure 8A portion of each first stop 5 protrudes from the base 2 and extends into the area enclosed by the base 2. Along the second direction Z, portions of each first stop 5 are spaced apart above the mass block 1. That is, along the second direction Z, each first stop 5 is higher than the mass block 1, and there is a gap between the lower surface of the first stop 5 and the upper surface of the mass block 1; there is no contact between the first stop 5 and the mass block 1. Each first stop 5 covers a portion of the mass block 1. Figure 6 and Figure 8 As shown, the orthographic projections of each first stop 5 on the aforementioned reference plane and the orthographic projections of the mass block 1 on the aforementioned reference plane partially overlap.

[0134] It is understandable that, such as Figure 10 As shown, when the accelerometer chip 20 is subjected to a large impact downward along the second direction Z, the impact will be transmitted to the base 2 (or electrode layer 4), causing the base 2 to move with the impact. Due to inertia, the mass block 1 and the cantilever 3 connected to the mass block 1 will generate a large relative acceleration relative to the base 2 and move in the opposite direction relative to the base 2, that is, upward along the second direction Z. Since the first stop 5 and the mass block 1 partially overlap in the second direction Z, after the mass block 1 moves to the lower surface of the first stop 5, it will be blocked by the first stop 5 (e.g., ...). Figure 10 (As shown by the dashed circle in the diagram), this prevents the mass block 1 and the cantilever 3 from moving upwards significantly, thus avoiding the tearing of the cantilever 3.

[0135] The upward movement range of the mass block 1 along the second direction Z is determined by the distance between the lower surface of the first stop part 5 and the upper surface of the mass block 1. The distance between the lower surface of the first stop part 5 and the upper surface of the mass block 1 can be flexibly set according to actual product requirements.

[0136] Continue reading Figure 6 and Figure 8 Along the first direction Y, the plurality of first stop portions 5 are respectively located on opposite sides of the mass block 1. That is, a portion of the plurality of first stop portions 5 are located... Figure 6 and Figure 8 The upper side of the mass block 1 shown; another portion of the plurality of first stop portions 5, located on the upper side of the mass block 1 shown; Figure 6 and Figure 8 The mass block 1 shown is located on its lower side. The number of first stop portions 5 located on opposite sides of the mass block 1 may be equal or unequal.

[0137] When the accelerometer chip 20 is subjected to a large impact downward along the second direction Z, the aforementioned multiple first stop portions 5 can be used to form a stopping effect on both opposite sides of the mass block 1 along the first direction Y (e.g., Figure 10(As shown by the dashed circle in the diagram), this avoids a situation where one side of the mass block 1 along the first direction Y is blocked while the other side is not. This not only helps to keep the mass block 1 in balance, but also helps to make the forces on the cantilever 3 located on different sides of the mass block 1 more balanced.

[0138] Furthermore, such as Figure 11 As shown, when the accelerometer chip 20 is subjected to a large impact in the positive direction along the first direction Y, the impact will be transmitted to the base 2, causing the base 2 to move with the impact. Due to inertia, the mass block 1 and the cantilever 3 connected to the mass block 1 will generate a large relative acceleration relative to the base 2 and tend to move in the opposite direction relative to the base 2. However, since the multiple cantilever 3 are connected to opposite sides of the mass block 1 along the first direction Y, the mass block 1 will rotate or tilt at a certain angle, forming a seesaw-like structure. For example, in Figure 11 In the structure shown, the left side of mass block 1 is tilted upwards relative to its right side. Since the first stop 5 and mass block 1 partially overlap in the second direction Z, after the left side of mass block 1 rotates and tilts upwards to the lower surface of the left-side portion of the first stop 5, it will be blocked by that portion of the first stop 5 (e.g., ...). Figure 11 (As shown by the dashed circle in the diagram), this prevents the mass block 1 from rotating or tilting significantly, thus avoiding the tearing of the cantilever 3.

[0139] When the accelerometer chip 20 is subjected to a large impact in the negative direction along the first direction Y, the right side of the mass block 1 will tilt upward relative to its left side. Since the first stop 5 and the mass block 1 partially overlap in the second direction Z, after the right side of the mass block 1 rotates and tilts upward to the lower surface of the right side portion of the first stop 5, it will be blocked by that portion of the first stop 5, so that the mass block 1 will no longer rotate or tilt significantly, thereby preventing the cantilever 3 from breaking.

[0140] Here, when the accelerometer chip 20 is subjected to a large impact along the first direction Y, one side of the mass block 1 will tilt upwards and the other side will sink downwards in the first direction Y. This makes the capacitance change between the mass block 1 and the electrode layer 4 approach 0, which is beneficial to maintain capacitance balance and reduce the impact of crosstalk in the first direction Y on the sensitivity in the second direction Z.

[0141] In some examples, the number of the aforementioned second stop portions 6 is multiple. Optionally, the number of second stop portions 6 can be two, three, four, or even more. Further, the number of second stop portions 6 can be an even number. Figure 6 and Figure 8 The two second stop sections 6 are shown.

[0142] like Figure 7c andFigure 9c As shown, the aforementioned plurality of second stop portions 6 are respectively connected to and fixed to the mass block 1. The relative positions of each second stop portion 6 and the mass block 1 are fixed. Figure 6 and Figure 8 A portion of each second stop 6 protrudes from the mass block 1 and extends in the direction from the mass block 1 toward the base 2. Along the second direction Z, portions of each second stop 6 are spaced apart above the base 2. That is, along the second direction Z, each second stop 6 is higher than the base 2, and there is a gap between the lower surface of the second stop 6 and the upper surface of the base 2; there is no contact between the second stop 6 and the base 2. Each second stop 6 covers a portion of the base 2. Figure 6 and Figure 8 As shown, the orthographic projections of each second stop portion 6 on the aforementioned reference plane and the orthographic projections of the base 2 on the aforementioned reference plane partially overlap.

[0143] It is understandable that, such as Figure 12 As shown, when the accelerometer chip 20 is subjected to a large impact in the upward direction Z, the impact will be transmitted to the base 2, causing the base 2 to move with the impact. Due to inertia, the mass block 1, the cantilever 3 connected to the mass block 1, and the second stop 6 will generate a large relative acceleration relative to the base 2 and move in the opposite direction relative to the base 2, that is, downward in the second direction Z. Since the second stop 6 and the base 2 partially overlap in the second direction Z, after the second stop 6 moves with the mass block to the upper surface of the base 2, it will be blocked by the base 2 (e.g., ...). Figure 12 (As shown by the dashed circle in the diagram), this prevents the mass block 1 and the cantilever 3 from moving downwards significantly, thus avoiding the tearing of the cantilever 3.

[0144] The downward movement range of the mass block 1 along the second direction Z is determined by the distance between the lower surface of the second stop 6 and the upper surface of the base 2. The distance between the lower surface of the second stop 6 and the upper surface of the base 2 can be flexibly set according to actual product requirements.

[0145] Continue reading Figure 6 and Figure 8 Along a third direction X, the plurality of second stop portions 6 are located on opposite sides of the mass block 1. That is, a portion of the plurality of second stop portions 6 are located... Figure 6 and Figure 8 The mass block 1 shown is located to the left of the mass block 1; another portion of the plurality of second stop portions 6 is located at the left side of the mass block 1 shown in the figure. Figure 6 and Figure 8 The mass block 1 shown is located on the right side. The number of second stop portions 6 located on opposite sides of the mass block 1 may be equal or unequal.

[0146] When the accelerometer chip 20 is subjected to a large impact along the second direction Z upward, the aforementioned multiple second stop portions 6 can be used to form a stopping effect on both opposite sides of the mass block 1 along the third direction X (e.g., Figure 12 (As shown by the dashed circle in the diagram), this avoids a situation where one side of mass block 1 along the third direction X is blocked while the other side is not. This not only helps to keep mass block 1 in balance, but also helps to make the forces on the cantilever 3 located on different sides of mass block 1 more balanced.

[0147] Furthermore, such as Figure 13 As shown, when the accelerometer chip 20 is subjected to a large impact in the positive direction of the third direction X, the impact will be transmitted to the base 2, causing the base 2 to move with the impact. Due to inertia, the mass block 1, the cantilever 3 connected to the mass block 1, and the second stop 6 will generate a large relative acceleration relative to the base 2 and tend to move in the opposite direction relative to the base 2. However, since the multiple cantilever 3 are connected to opposite sides of the mass block 1 along the first direction Y, the mass block 1 will rotate at a certain angle, forming a seesaw-like structure. For example, in Figure 13 In the structure shown, the left side of mass block 1 is raised relative to its right side, and the right side of mass block 1 is lowered relative to its left side. Because the second stop 6 and the base 2 partially overlap in the second direction Z, after the lower surface of the right-side portion of the second stop 6 contacts the upper surface of the base 2, the right-side portion of mass block 1 is stopped from rotating and lowering (as shown). Figure 13 (As shown by the dashed circle in the diagram), this prevents the mass block 1 from rotating significantly, thus avoiding tearing the cantilever 3.

[0148] When the accelerometer chip 20 is subjected to a large impact in the negative direction of the third direction X, the right side of the mass block 1 will tilt upward relative to its left side, and the left side of the mass block 1 will sink downward relative to its right side. Since the second stop 6 and the base 2 partially overlap in the second direction Z, after the lower surface of the second stop 6 on the left side contacts the upper surface of the base 2, the left side of the mass block 1 is stopped from rotating downward, so that the mass block 1 no longer rotates significantly, thereby preventing the cantilever 3 from breaking.

[0149] Here, when the accelerometer chip 20 is subjected to a large impact along the third direction X, one side of the mass block 1 will tilt up (capacitance change, for example, +ΔC) and the other side will sink down (capacitance change, for example, -ΔC). This makes the capacitance change between the mass block 1 and the electrode layer 4 approach 0, which is beneficial to maintaining capacitance balance and reducing the impact of crosstalk in the third direction X on the sensitivity in the second direction Z.

[0150] Therefore, the accelerometer chip 20 provided in some embodiments of this application provides a plurality of first stop portions 5 connected to the base 2 on opposite sides of the mass block 1 along the first direction Y, and a portion of each first stop portion 5 extends upward toward the mass block 1 so that each first stop portion 5 and the mass block 1 partially overlap in the second direction Z and have a certain distance. In this way, when the accelerometer chip 20 is subjected to a large impact downward along the second direction Z, the first stop portions 5 can be used to effectively stop the movement of the mass block 1 upward along the second direction Z, limiting the range of movement of the mass block 1 upward along the second direction Z, thereby protecting the cantilever 3 and preventing the cantilever 3 from breaking.

[0151] Furthermore, in this embodiment, multiple second stop portions 6 connected to the mass block 1 are provided on opposite sides along the third direction X, and a portion of each second stop portion 6 extends upward toward the base 2, so that each second stop portion 6 and the base 2 partially overlap in the second direction Z and have a certain distance. In this way, when the acceleration sensing chip 20 is subjected to a large impact upward along the second direction Z, and as the second stop portion 6 moves downward along the second direction Z with the mass block 1, the base 2 can effectively stop the movement of the second stop portion 6. In this way, the movement of the mass block 1 downward along the second direction Z is effectively stopped, limiting the range of movement of the mass block 1 downward along the second direction Z, thereby protecting the cantilever 3 and preventing the cantilever 3 from breaking.

[0152] Furthermore, by defining the relative position between the center of mass of mass 1 and the center of mass of cantilever 3 in this embodiment, not only can a seesaw-like structure be formed when the accelerometer chip 20 is subjected to a large impact along the first direction Y, but also the multiple first stop parts 5 can be used to effectively stop the rotational movement of mass 1 during its rotational movement, limiting the range of rotational movement of mass 1, thereby protecting cantilever 3 without the need for additional stop structures; moreover, when the accelerometer chip 20 is subjected to a large impact along the third direction X, a seesaw-like structure can be formed, and the multiple second stop parts 6 can be used to effectively stop the rotational movement of mass 1 during its rotational movement, limiting the range of rotational movement of mass 1, thereby protecting cantilever 3 without the need for additional stop structures.

[0153] This allows for comprehensive protection against impacts along the first direction Y, the second direction Z, and the third direction X, thereby improving the resistance of the accelerometer chip 20 to impacts along these directions. This prevents the accelerometer chip 20 from failing due to the breakage of the cantilever 3, improving its reliability (e.g., impact and drop resistance) and the reliability of the accelerometer sensor 400 and electronic device 1000 using the accelerometer chip 20. Furthermore, the reuse of the first stop portion 5 and the second stop portion 6 simplifies the structure of the accelerometer chip 20, making it easier to manufacture and reducing costs.

[0154] Furthermore, the accelerometer chip 20 provided in this embodiment replaces the upper and lower cover plates in one of the above-mentioned implementations with the first stop portion 5 and the second stop portion 6. This achieves good impact resistance while avoiding the addition of extra components (such as upper and lower cover plates). Moreover, on the one hand, the related bonding process steps can be omitted, improving the fabrication efficiency of the accelerometer chip 20 and reducing its cost; on the other hand, it avoids increasing the thickness of the accelerometer chip 20, ensuring its space-saving advantage; furthermore, in the second direction Z, by flexibly setting the distance between the first stop portion 5 and the mass block 1, and flexibly setting the distance between the second stop portion 6 and the base 2, the swing arm of the cantilever 3 can be limited to a relatively small range to reduce the impact of fatigue.

[0155] It is understandable that the relative positional relationship between the cantilever 3, the first stop 5 and the second stop 6 along the third direction X can be varied, and the specific position can be selected and set according to actual needs.

[0156] In some examples, such as Figure 6 and Figure 8 As shown, the aforementioned multiple cantilever arms 3 are respectively located on opposite sides of the multiple first stop portions 5 along the third direction X. That is, the multiple cantilever arms 3 can be divided into two groups, each group of cantilever arms 3 including, for example, at least two cantilever arms 3; along the third direction X, the multiple first stop portions 5 are located between the two groups of cantilever arms 3.

[0157] Furthermore, the aforementioned plurality of second stop portions 6 are respectively located on opposite sides of the aforementioned plurality of cantilever arms 3 along the third direction X. That is, the plurality of second stop portions 6 can be divided into two groups, each group of second stop portions 6 including, for example, at least one second stop portion 6; along the third direction X, the aforementioned plurality of cantilever arms 3 and the plurality of first stop portions 5 are located between the two groups of second stop portions 6.

[0158] Correspondingly, such as Figure 6 and Figure 8As shown, along the third direction X, at least one second stop 6, at least two cantilever 3, multiple first stop 5, at least two cantilever 3, and at least one second stop 6 are arranged in sequence.

[0159] In this way, on the one hand, the distance between two adjacent cantilever 3 along the third direction X can be increased, making the mass block 1 more stable and less prone to shaking; on the other hand, it helps to simplify the design of cantilever 3, first stop 5 and second stop 6 and improve the structural symmetry.

[0160] In some embodiments, the plurality of first stop portions 5 are conductive, that is, the material of each first stop portion 5 includes a conductive material and is capable of transmitting electrical signals. For example, as... Figure 8 and Figure 9a As shown, at least one first stop portion 5 is connected to the electrode layer 4 and forms an integral structure. That is, one, two, or even all of the aforementioned first stop portions 5 can be connected to the electrode layer 4 and form an integral structure.

[0161] The aforementioned plurality of first stop portions 5 and electrode layers 4 are, for example, patterned from the same conductive thin film. Furthermore, the electrode layer 4 and the first stop portions 5 connected thereto, forming an integral structure, are continuous and unbroken. The electrode layer 4 can be reused as a first stop portion, and the first stop portions 5 connected to the electrode layer 4 can be reused as an electrode layer.

[0162] This not only simplifies the structure and fabrication process of the accelerometer chip 20, but also reduces the number of structural layers in the accelerometer chip 20, which helps to reduce the thickness of the accelerometer chip 20 and further ensures its space-saving advantage; moreover, it can also improve the structural stability between the electrode layer 4 and the first stop portion 5 connected thereto, thereby improving the reliability of the accelerometer chip 20.

[0163] In some embodiments, combined with Figure 9a , Figure 9b and Figure 9c Mass block 1 and base 2 are arranged on the same layer. And / or, cantilever 3, electrode layer 4, multiple first stop parts 5 and multiple second stop parts 6 are arranged on the same layer.

[0164] Here, "same layer" refers, for example, to a layer structure formed using the same film deposition process to create a film layer for a specific pattern, and then using the same mask to form a single patterning process. Depending on the specific pattern, a single patterning process may include multiple etching processes, and the specific pattern in the formed layer structure may be continuous or discontinuous, and these specific patterns may also be at different heights or have different thicknesses.

[0165] In other words, the aforementioned mass block 1 and base 2 are patterned from the same thin film. This allows multiple structures, including mass block 1 and base 2, to be formed simultaneously in a single patterning process, simplifying the fabrication process of the accelerometer chip 20. Furthermore, it reduces the number of layers in the accelerometer chip 20, thus reducing its thickness and further ensuring its space-saving advantage.

[0166] And / or, the aforementioned cantilever 3, electrode layer 4, multiple first stop portions 5, and multiple second stop portions 6 are patterned from the same thin film. This allows multiple structures, including the cantilever 3, electrode layer 4, multiple first stop portions 5, and multiple second stop portions 6, to be formed simultaneously in a single patterning process, simplifying the fabrication process of the accelerometer chip 20. Furthermore, it reduces the number of layers in the accelerometer chip 20, thus reducing its thickness and further ensuring its space-saving advantage.

[0167] It is understandable that the aforementioned accelerometer chip 20 includes various types, such as surface-mount silicon accelerometer chips, piezoresistive / piezoelectric accelerometer chips, microphone-integrated accelerometer chips, and bulk silicon accelerometer chips. Among these, the detection principles of surface-mount silicon accelerometer chips, microphone-integrated accelerometer chips, and bulk silicon accelerometer chips are, for example, capacitive detection. Compared to surface-mount silicon accelerometer chips and microphone-integrated accelerometer chips, bulk silicon accelerometer chips have advantages such as simpler manufacturing processes, lower cost, and lower low-frequency transmission loss.

[0168] This application provides an illustrative example using a bulk silicon accelerometer chip 20 as an example. This accelerometer chip 20 can be fabricated on a silicon substrate using microfabrication processes. Therefore, the accelerometer chip 20 can be composed of multiple sequentially stacked film layers.

[0169] In some embodiments, combined with Figure 8 , Figure 14a and Figure 14b The accelerometer chip 20 may include a support layer 201, an isolation layer 202, and a functional layer 203. The support layer 201, isolation layer 202, and functional layer 203 may be stacked along a second direction Z. The support layer 201, isolation layer 202, and functional layer 203 may be formed by etching a silicon-on-insulator (SOI) structure, which helps reduce the stress on the accelerometer chip 20.

[0170] The aforementioned support layer 201 is mainly used for directly or indirectly connecting the packaging substrate 10 and providing support. The isolation layer 202 is mainly used to separate the support layer 201 and the functional layer 203 and provide a connection. The functional layer 203 is mainly used to perform a stopping function and a detection function.

[0171] like Figure 14a As shown, the aforementioned mass block 1 and base 2 are located on the support layer 201. Figure 8 As shown, the cantilever 3, electrode layer 4, each first stop portion 5, and each second stop portion 6 are located in the functional layer 203. During the fabrication of the acceleration sensing chip 20, the mass block 1 and the base 2 are formed by the same thin film etching, and the cantilever 3, electrode layer 4, each first stop portion 5, and each second stop portion 6 are formed by the same thin film etching.

[0172] For example, both the materials of the support layer 201 and the functional layer 203 are conductive, while the material of the isolation layer 202 is insulating. For instance, the materials of the support layer 201 and the functional layer 203 can be the same or different. Optionally, the material of at least one of the support layer 201 and the functional layer 203 includes, but is not limited to, silicon-based semiconductor materials. The material of the isolation layer 202 includes, but is not limited to, silicon oxide.

[0173] like Figure 14b As shown, the aforementioned isolation layer 202 includes, for example, a plurality of first connection patterns 202a and a plurality of second connection patterns 202b.

[0174] Combination Figure 14b , Figure 8 and Figure 9c The aforementioned plurality of first connection patterns 202a are located on the side surface of the mass block 1 near the functional layer 203. Furthermore, a portion of the plurality of first connection patterns 202a are located between the plurality of cantilever 3 and the mass block 1, respectively, for connecting the plurality of cantilever 3 and the mass block 1. Another portion of the plurality of first connection patterns 202a are located between the plurality of second stop portions 6 and the mass block 1, respectively, for connecting the plurality of second stop portions 6 and the mass block 1.

[0175] Combination Figure 14b , Figure 8 , Figure 9a and Figure 9bThe aforementioned plurality of second connection patterns 202b are located on one side surface of the base 2 near the functional layer 203. Furthermore, a portion of the plurality of second connection patterns 202b are located between the plurality of cantilever 3 and the base 2, respectively, for connecting the plurality of cantilever 3 and the base 2. Another portion of the plurality of second connection patterns 202b are located between the plurality of first stop portions 5 and the base 2, respectively, for connecting the plurality of first stop portions 5 and the base 2.

[0176] In this context, the upward or downward movement distance of mass block 1 along the second direction Z is, for example, equal to the thickness of the isolation layer 202. Thus, the movement range of mass block 1 is limited by the thickness of the isolation layer 202. By flexibly adjusting the thickness of the isolation layer 202, the movement range of mass block 1 can also be flexibly adjusted.

[0177] Because the isolation layer 202 can be made relatively thin, the range of movement of the mass block 1 will be relatively small. In this way, even if the accelerometer chip 20 is subjected to a small impact along the second direction Z, the movement of the mass block 1 can be restricted by the first stop 5 and the second stop 6, reducing the effects of fatigue.

[0178] In addition, such as Figure 15 As shown, the accelerometer chip 20 may also include a wiring layer 204, the material of which may include, for example, a metallic material. The wiring layer 204 is used to bring out the mass block 1 and the electrode layer 4.

[0179] For example, such as Figure 15 , Figure 16a and Figure 16bAs shown, the wiring layer 204 includes a filling portion 204a, a first lead 204b, and a second lead 204c. Taking an example where cantilever 3a and cantilever 3b are connected and form an integral structure, and the first stop portion 5 and electrode layer 4 are connected and form an integral structure, the accelerometer chip 20 may have at least one blind hole H3. The blind hole H3 penetrates the cantilever 3b and the first connection pattern 202a located below it, extending into the interior of the mass block 1. The filling portion 204a fills the blind hole H3, allowing the mass block 1 to be electrically connected to the cantilever 3b through the filling portion 204a. The first lead 204b is located on the base 2 and is separated from the base 2 by a second connection pattern 202b; one end of the first lead 204b contacts the cantilever 3b, and the other end is used for electrical connection to an external circuit. In this way, mass block 1 can be led out to the external circuit sequentially through filling part 204a, cantilever 3b and first lead 204b. Second lead 204c is located on base 2 and is separated from base 2 by a second connection pattern 202b; one end of second lead 204c contacts first stop part 5, and the other end of second lead 204c is used for electrical connection with external circuit. In this way, electrode layer 4 can be led out to external circuit through first stop part 5 and second lead 204c. Of course, wiring layer 204 can also have other configurations, which are not limited in this embodiment.

[0180] Therefore, the acceleration sensor chip 20 provided in this application embodiment can be formed by fabricating at least four film layers. It can reduce the number of film layers, reduce the thickness of the acceleration sensor chip 20, simplify the structure of the acceleration sensor chip 20, and ensure the space-saving advantage of the acceleration sensor chip 20, while achieving the detection of acceleration and the comprehensive blocking of impacts along the first direction Y, the second direction Z and the third direction X.

[0181] In some examples, such as Figure 8 As shown, along the first direction Y, at least one cantilever 3 located on one side of the mass block 1 is connected to at least one cantilever 3 located on the other side of the mass block 1 and forms an integral structure. For example, in Figure 8 In the structure shown, a cantilever 3a located between the first stop 5a and the second stop 6a is connected to a cantilever 3b located between the first stop 5b and the second stop 6a, and they form an integral structure.

[0182] This helps to improve the structural stability of the connected cantilever 3 and its relationship with the mass block 1 and the base 2, and in turn, improves the structural stability and reliability of the acceleration sensing chip 20.

[0183] It is understood that the above-mentioned mass block 1 and base 2 can be arranged in various ways. Optionally, mass block 1 can be a regular three-dimensional structure, or mass block 1 can be an irregular three-dimensional structure; base 2 can be a regular hollow frame structure, or base 2 can be an irregular hollow frame structure. The following is a schematic description of the arrangement of mass block 1 with reference to the accompanying drawings.

[0184] In some possible embodiments, the mass block 1 is a regular three-dimensional structure, and the base 2 is a regular hollow frame structure. For example, the mass block 1 can be a cube, cuboid, or cylindrical structure, etc., and the base 2 can be a hollow square frame structure, a hollow rectangular frame structure, or a hollow circular frame structure, etc.

[0185] by Figure 14b Taking the structure shown as an example, the mass block 1 is a cuboid structure, and the base 2 is a hollow rectangular frame structure. The base 2 has a first side A1 facing the mass block 1, which is, for example, the inner annular side of the base 2; the mass block 1 has a second side A2 facing the base 2, which is, for example, the outer annular side of the mass block 1.

[0186] Along the first direction Y, the distance L1 between the first side A1 and the second side A2 is, for example, the length of the cantilever 3. For example, along the first direction Y, the distances at different positions between the first side A1 and the second side A2 are equal. This ensures that the lengths of the different cantilever 3s are equal, which helps to balance the forces acting on the different cantilever 3s and helps to keep the mass block 1 in balance.

[0187] In other possible embodiments, such as Figure 17a and Figure 18a As shown, the accelerometer chip 20 has multiple grooves R, which are formed on the first side A1 of the base 2 and / or the second side A2 of the mass block 1. Furthermore, the depth direction of each groove R is parallel to the first direction Y.

[0188] In other words, such as Figure 17a As shown, all of the aforementioned grooves R can be formed on the first side surface A1 of the base 2, and these grooves R can be located on one side or opposite sides of the base 2 along the second direction Y. Alternatively, all of the grooves R can be formed on the second side surface A2 of the mass block 1, and these grooves R can be located on one side or opposite sides of the mass block 1 along the second direction Y. Or, as... Figure 18aAs shown, a portion of the multiple grooves R are formed on the first side A1 of the base 2, and this portion of the grooves R can be located on one side or opposite sides of the base 2 along the second direction Y; the remaining portion of the grooves R are formed on the second side A2 of the mass block 1, and the remaining portion of the grooves R can be located on one side or opposite sides of the mass block 1 along the second direction Y.

[0189] Furthermore, the groove R extends, for example, along the second direction Z, penetrating the mass block 1 or the base 2. Along the second direction Z, each groove R is located below a cantilever 3. Wherein, as... Figure 17b and Figure 18b As shown, a groove R can be provided below a cantilever 3, or two grooves R can be provided, depending on the actual needs.

[0190] For example, combining Figure 17a and Figure 17b A groove R is provided below the cantilever 3, and the groove R is formed on the first side surface A1. At this time, the length of the cantilever 3 is, for example, the distance between the bottom wall of the groove R and the second side surface A2 along the first direction Y.

[0191] For example, combining Figure 18a and Figure 18b Two grooves R are provided below the cantilever 3, and these two grooves R are respectively opened on the first side A1 and the second side A2. At this time, the length of the cantilever 3 is, for example, the distance between the bottom walls of the two grooves R along the first direction Y.

[0192] Therefore, after setting the groove R below the cantilever 3, the length of the cantilever 3 is, for example, the sum of the distance between the first side A1 and the second side A2 in the first direction Y, and the depth of the groove R located below the cantilever 3. This can effectively increase the length of the cantilever 3. On the one hand, it can reduce the influence of the etching error of the support layer 201 or the isolation layer 202 on the length of the cantilever 3, that is, increase the tolerance of the etching error of the support layer 201 or the isolation layer 202 in the first direction Y. On the other hand, it can reduce the rigidity of the cantilever 3, which is beneficial to achieving the stop of lateral (i.e., the first direction Y and / or the third direction X) impacts. Furthermore, it is beneficial to reduce the resonant frequency of the acceleration sensing chip 20 and improve the signal-to-noise ratio of the acceleration sensing chip 20.

[0193] In some examples, the number of grooves R located below different cantilever 3 along the second direction Z is the same. Optionally, one groove R is provided below each cantilever 3 along the second direction Z, or two grooves R are provided below each cantilever 3.

[0194] This reduces the difference in length between different cantilever arms 3, which helps to make the forces on different cantilever arms 3 more balanced and improves the structural stability of the acceleration sensing chip 20.

[0195] Among the aforementioned grooves R, the depth of each groove R can be the same or different. When the depth of each groove R is the same, on the one hand, it helps to reduce the design difficulty of the acceleration sensor chip 20; on the other hand, it allows the lengths of different cantilever arms 3 to be equal, which helps to further improve the force balance of different cantilever arms 3 and the structural stability of the acceleration sensor chip 20.

[0196] It is understood that, along the first direction Y, the arrangement of the plurality of first stop portions 5 on opposite sides of the mass block 1 includes various methods; along the third direction X, the arrangement of the plurality of second stop portions 6 on opposite sides of the mass block 1 includes various methods, which can be specifically set according to actual product requirements. The arrangement of the first stop portions 5 and the second stop portions 6 will be schematically explained below with reference to the accompanying drawings.

[0197] In some possible embodiments, such as Figure 8 and Figure 19 As shown, along the third direction X, there is at least one second stop portion 6 located on the left side of the mass block 1, and at least one second stop portion 6 located on the right side of the mass block 1. The number of second stop portions 6 located on opposite sides of the mass block 1 may be the same or different.

[0198] For example, such as Figure 8 As shown, along the third direction X, the number of second stop portions 6 located on opposite sides of the mass block 1 is the same, and there is one of each.

[0199] For example, such as Figure 19 As shown, along the third direction X, the number of second stop portions 6 located on opposite sides of the mass block 1 is different, and the number of second stop portions 6 located on the left side of the mass block 1 is two, while the number of second stop portions 6 located on the right side of the mass block 1 is three.

[0200] In some examples, the effective stiffness of at least one second stop 6 on one side of mass block 1 along the third direction X is in the range of 1:2 to 2:1 to the effective stiffness of at least one second stop 6 on the other side of mass block 1.

[0201] Wherein, along the third direction X, when there is only one second stop 6 on one side of the mass block 1, the effective stiffness refers to the stiffness of that one second stop 6; when there are multiple second stop 6 on one side of the mass block 1, the effective stiffness refers to the sum of the stiffness of the multiple second stop 6.

[0202] Optionally, along the third direction X, the ratio of the effective stiffness of at least one second stop 6 on one side of the mass block 1 to the effective stiffness of at least one second stop 6 on the other side of the mass block 1 can be 1:2, 4:5, 1:1, 6:5, 3:2 or 2:1, etc.

[0203] This configuration minimizes the difference in effective stiffness between the second stop portions 6 located on opposite sides of the mass block 1. When the acceleration sensor chip 20 experiences a large impact along the third direction X in either the positive or negative direction, the forces on the second stop portions 6 located on opposite sides of the mass block 1 are more balanced, facilitating better stopping performance and higher structural stability.

[0204] In some examples, the effective size of at least one second stop 6 on one side of mass block 1 in the first direction Y, along the third direction X, is in the range of 1:2 to 2:1 to the effective size of at least one second stop 6 on the other side of mass block 1 in the first direction Y.

[0205] Among them, such as Figure 8 As shown, when there is only one second stop 6 located on one side of the mass block 1 along the third direction X, the effective size refers to the size of that single second stop 6 in the first direction Y; when there are multiple second stop 6 located on one side of the mass block 1, the effective size refers to the sum of the sizes of the multiple second stop 6 in the first direction Y. For example, as... Figure 19 As shown, along the third direction X, there are two second stop portions 6 located on one side of the mass block 1. The effective size refers to the sum of the sizes of the two second stop portions 6 in the first Y direction X.

[0206] Optionally, along the third direction X, the effective dimension of at least one second stop 6 on one side of the mass block 1 in the first direction Y, and the effective dimension of at least one second stop 6 on the other side of the mass block 1 in the first direction Y, can be 1:2, 4:5, 1:1, 6:5, 3:2, or 2:1, etc.

[0207] Here, the dimension of the second stop portion 6 in the first direction Y is related to its stiffness. For example, the larger the dimension of the second stop portion 6 in the first direction Y, the greater its stiffness.

[0208] This configuration reduces the difference in effective length between the second stop portions 6 located on opposite sides of the mass block 1, thereby reducing the difference in effective stiffness between the second stop portions 6 located on opposite sides of the mass block 1. When the acceleration sensing chip 20 is subjected to a large impact in the positive or negative direction along the third direction X, the forces on the second stop portions 6 located on opposite sides of the mass block 1 can be more balanced, facilitating better stopping performance and higher structural stability.

[0209] In other possible embodiments, such as Figure 8 and Figure 19 As shown, along the first direction Y, there is at least one first stop portion 5 located on the upper side of the mass block 1, and at least one first stop portion 5 located on the lower side of the mass block 1. The number of first stop portions 5 located on opposite sides of the mass block 1 may be the same or different.

[0210] For example, such as Figure 8 As shown, along the first direction Y, the number of first stop portions 5 located on opposite sides of the mass block 1 is the same, and there is one of each.

[0211] For example, such as Figure 19 As shown, along the first direction Y, the number of first stop portions 5 located on opposite sides of the mass block 1 is different, and the number of first stop portions 5 located on the upper side of the mass block 1 is one, while the number of first stop portions 5 located on the lower side of the mass block 1 is two.

[0212] In some examples, along the first direction Y, the ratio of the effective stiffness of at least one first stop portion 5 on one side of the mass block 1 to the effective stiffness of at least one first stop portion 5 on the other side of the mass block 1 is in the range of 1:2 to 2:1. For details on "effective stiffness," please refer to the relevant explanation above; it will not be repeated here.

[0213] Optionally, along the first direction Y, the ratio of the effective stiffness of at least one first stop portion 5 on one side of the mass block 1 to the effective stiffness of at least one first stop portion 5 on the other side of the mass block 1 can be 1:2, 3:5, 1:1, 6:5, 9:5 or 2:1, etc.

[0214] This configuration minimizes the difference in effective stiffness between the first stop portions 5 located on opposite sides of the mass block 1. When the acceleration sensing chip 20 experiences a large impact along the first direction Y (positive or negative), the forces on the first stop portions 5 located on opposite sides of the mass block 1 are more balanced, facilitating better stopping performance and higher structural stability.

[0215] In some examples, along the first direction Y, the effective dimension of at least one first stop portion 5 located on one side of the mass block 1 in the third direction X is in the range of 1:2 to 2:1 with respect to the effective dimension of at least one first stop portion 5 located on the other side of the mass block 1 in the third direction X. For details on "effective dimension," please refer to the relevant explanation above; it will not be repeated here.

[0216] Optionally, along the first direction Y, the effective dimension of at least one first stop portion 5 located on one side of the mass block 1 in the third direction X, and the effective dimension of at least one first stop portion 5 located on the other side of the mass block 1 in the third direction X, can be 1:2, 3:5, 1:1, 6:5, 9:5, or 2:1, etc.

[0217] Here, the dimension of the first stop portion 5 in the third direction X is related to its stiffness. For example, the larger the dimension of the first stop portion 5 in the third direction X, the greater its stiffness.

[0218] This configuration reduces the difference in effective length between the first stop portions 5 on opposite sides of the mass block 1, thereby reducing the difference in effective stiffness between the first stop portions 5 on opposite sides of the mass block 1. When the acceleration sensing chip 20 is subjected to a large impact in the positive or negative direction along the first Y, the force on the first stop portions 5 on opposite sides of the mass block 1 can be more balanced, facilitating better stopping effect and higher structural stability.

[0219] It is understandable that when the accelerometer chip 20 is subjected to a large impact and effectively stops the movement of the mass block 1, the contact point between the first stop part 5 and the mass block 1 (e.g.) Figure 10 and Figure 11 (as shown by the dashed circle in the image), and the contact position between the second stop 6 and the base 2 ...). Figure 12 and Figure 13 As shown by the dashed circle in the diagram, stress concentration may occur, damaging the structure of the first stop 5 and / or the second stop 6.

[0220] Take, for example, an accelerometer chip 20 subjected to a large impact downwards along the second direction Z. Figure 10 As shown, during the upward movement of mass block 1 along the second direction Z, a surface contact is initially formed between mass block 1 and the first stop portion 5, that is, the upper surface of mass block 1 contacts the lower surface of the first stop portion 5. Subsequently, as mass block 1 moves upward along the second direction Z, the first stop portion 5 undergoes elastic deformation, and the portion of the first stop portion 5 covering mass block 1 tilts upward, causing the first stop portion 5 to contact the side of mass block 1 extending along the third direction X. This changes the contact from a surface to a line, resulting in stress concentration at the line contact location.

[0221] Based on this, in some embodiments, such as Figure 20a and Figure 20b As shown, the accelerometer chip 20 may also include a first protective layer 7.

[0222] Combination Figure 20a and Figure 20bThe first protective layer 7 covers at least the surface of each first stop 5 near the mass block 1 and the surface of each second stop 6 near the base 2. That is, a portion of the first protective layer 7 is located between each first stop 5 and the mass block 1 and is in contact with the lower surface of each first stop 5; another portion of the first protective layer 7 is located between each second stop 6 and the base 2 and is in contact with the lower surface of each second stop 6.

[0223] There are gaps between the first protective layer 7 and the mass block 1, and between the first protective layer 7 and the base 2. That is, the first protective layer 7 does not contact the mass block 1 or the base 2. Along the second direction Z, there are also certain gaps between the first protective layer 7 and the mass block 1, and between the first protective layer 7 and the base 2. This ensures that the mass block 1 has upward movement space along the second direction Z, and that the second stop 6 has downward movement space along the second direction Z.

[0224] The materials of the first protective layer 7 mentioned above include, but are not limited to, polymeric materials, such as polyimide (PI) and parylene. The first protective layer 7 can provide a cushioning effect.

[0225] In this way, when the accelerometer chip 20 is subjected to a large impact along the first direction Y, the second direction Z, or the third direction X, the mass block 1 can contact the first stop part 5 through the first protective layer 7, thus buffering the movement of the mass block 1; or, the second stop part 6 can contact the base 2 through the first protective layer 7, thus buffering the movement of the second stop part 6. This can protect the first stop part 5 and the second stop part 6, reduce or even avoid stress concentration, prevent damage to the first stop part 5 and / or the second stop part 6, and further improve the reliability of the accelerometer chip 20.

[0226] For example, the first protective layer 7 may also cover the surface of the electrode layer 4 near the mass block 1, the surface of each cantilever 3 near the mass block 1, etc. Further, the first protective layer 7 may also cover the surfaces of each cantilever 3, the electrode layer 4, each first stop portion 5, and each second stop portion 6 away from the base 2. It can also be considered that all surfaces of the functional layer 203, except for the surface in contact with the isolation layer 202, are covered with the first protective layer 7.

[0227] In other embodiments, such as Figure 21a and Figure 21b As shown, the acceleration sensor chip 20 may also include a second protective layer 8.

[0228] Combination Figure 21a and Figure 21bThe second protective layer 8 covers at least the surfaces of the mass block 1 facing each of the first stop portions 5 and the surfaces of the base 2 facing each of the second stop portions 6. That is, a portion of the second protective layer 8 is located between the mass block 1 and each of the first stop portions 5 and is in contact with the upper surface of the mass block 1; another portion of the second protective layer 8 is located between the base 2 and each of the second stop portions 6 and is in contact with the upper surface of the base 2.

[0229] There are gaps between the second protective layer 8 and the first stop 5, and between the second protective layer 8 and the second stop 6. That is, the second protective layer 8 does not contact the first stop 5 or the second stop 6. Along the second direction Z, there are certain distances between the second protective layer 8 and the first stop 5, and between the second protective layer 8 and the second stop 6. This ensures that the mass block 1 has upward movement space along the second direction Z, and that the second stop 6 has downward movement space along the second direction Z.

[0230] The material of the second protective layer 8 includes, but is not limited to, polymeric materials, such as polyimide (PI) and parylene. The material of the second protective layer 8 can be the same as or different from that of the first protective layer 7. The second protective layer 8 provides cushioning.

[0231] In this way, when the accelerometer chip 20 is subjected to a large impact along the first direction Y, the second direction Z, or the third direction X, the mass block 1 can contact the first stop part 5 through the second protective layer 8, thus buffering the movement of the mass block 1; or, the second stop part 6 can contact the base 2 through the second protective layer 8, thus buffering the movement of the second stop part 6. This can protect the first stop part 5 and the second stop part 6, reduce or even avoid stress concentration, prevent damage to the structure of the first stop part 5 and / or the second stop part 6, and further improve the reliability of the accelerometer chip 20.

[0232] For example, the second protective layer 8 may also cover the surface of the mass block 1 opposite to the electrode layer 4, and the surface of the base 2 not covered by the second stop portion 6. Further, the second protective layer 8 may also cover the side surface of the mass block 1 and the side surface of the base 2. It can also be considered that all surfaces of the support layer 201, except for the surface in contact with the isolation layer 202, are covered by the second protective layer 8.

[0233] In some other embodiments, such as Figure 21a and Figure 21b As shown, the accelerometer chip 20 may also include a first protective layer 7 and a second protective layer 8. The locations of the first protective layer 7 and the second protective layer 8 are explained in the relevant description above and will not be repeated here.

[0234] Continue reading Figure 21a and Figure 21b There is a gap between the first protective layer 7 and the second protective layer 8. That is, the first protective layer 7 and the second protective layer 8 are not in contact. Along the second direction Z, there is a certain distance between the first protective layer 7 and the second protective layer 8. This ensures that the mass block 1 has room to move upward along the second direction Z, and ensures that the second stop part 6 has room to move downward along the second direction Z.

[0235] This provides further protection for the first stop 5 and the second stop 6, greatly reduces stress concentration, and significantly improves the reliability of the acceleration sensor chip 20.

[0236] For example, such as Figure 21a and Figure 21b As shown, along the second direction Z, the upper surface of the base 2 is flush with the upper surface of the mass block 1, and the lower surfaces of the first stop 5 and the second stop 6 are flush with each other. Correspondingly, the distance between the mass block 1 and the first stop 5 in the second direction Z is equal to the distance between the base 2 and the second stop 6 in the second direction Z.

[0237] Optionally, when the acceleration sensing chip 20 includes both a first protective layer 7 and a second protective layer 8, the ratio of the distance between the first protective layer 7 and the second protective layer 8 to the distance between the mass block 1 and the first stop portion 5 along the second direction Z is greater than or equal to 1:2.

[0238] That is, the sum of the thicknesses of the first protective layer 7 and the second protective layer 8 is less than or equal to the distance between the mass block 1 and the first stop portion 5. For example, the sum of the thicknesses of the first protective layer 7 and the second protective layer 8 can be equal to the distance between the mass block 1 and the first stop portion 5. wait.

[0239] In this way, it can be ensured that the first protective layer 7 and the second protective layer 8 can provide protection for the first stop 5 and the second stop 6, and it can also be ensured that the mass block 1 and the second stop 6 have sufficient movement distance to ensure the sensitivity of the acceleration sensing chip 20.

[0240] Optionally, the first protective layer 7 and / or the second protective layer 8 can be formed using a molecular deposition process. In this case, the outer surface of the accelerometer chip 20 is, for example, covered with a polymer material. Of course, the formation process of the first protective layer 7 and / or the second protective layer 8 is not limited to this.

[0241] Figure 22a , Figure 22b and Figure 22cThe diagrams also illustrate the structure of an acceleration pressure sensor chip.

[0242] In some embodiments of this application, such as Figure 22a , Figure 22b and Figure 22c As shown, along the second direction Z, the portion of the first stop 5 located above the mass block 1 has at least one first connecting structure 51. The orthographic projection of this at least one first connecting structure 51 onto the reference plane is, for example, located within the orthographic projection range of the mass block 1 onto the reference plane. The aforementioned first connecting structure 51 includes, but is not limited to, through holes (such as...). Figure 22a and Figure 22b As shown), trench (as shown) Figure 22c (as shown), grooves, and other structures.

[0243] The number of first connected structures 51 can be one or more. When there are multiple first connected structures 51, these multiple first connected structures 51 are arranged in an array, for example.

[0244] Furthermore, the aforementioned first connecting structure 51 connects the gap between the first stop portion 5 and the mass block 1.

[0245] In this way, during the fabrication of the accelerometer chip 20, fluid can contact the film layer located below the first stop portion 5 through the first connecting structure 51, facilitating lateral etching of the film layer below the first stop portion 5 and facilitating fluid outflow. This fluid may include, for example, an etchant or a etchant gas (hydrofluoric acid, HF).

[0246] In other embodiments of this application, such as Figure 22b and Figure 22c As shown, along the second direction Y, the portion of the electrode layer 4 disposed above the mass block 1 has at least one second connecting structure 41. The orthographic projection of this at least one second connecting structure 41 onto the reference plane is, for example, located within the orthographic projection range of the mass block 1 onto the reference plane. The aforementioned second connecting structure 41 includes, but is not limited to, through holes (such as...). Figure 22b As shown), trench (as shown) Figure 22c (as shown), grooves, and other structures.

[0247] The number of second connecting structures 41 can be one or more. When there are multiple second connecting structures 41, they are arranged in an array, for example.

[0248] Furthermore, the aforementioned second connecting structure 41 connects the gap between the electrode layer 4 and the mass block 1.

[0249] In this way, during the fabrication of the accelerometer chip 20, fluid can contact the film layer located below the electrode layer 4 through the second connecting structure 41, facilitating lateral etching of the film layer below the electrode layer 4 and allowing fluid to flow out. This fluid may include, for example, an etchant or a etchant gas (hydrofluoric acid, HF).

[0250] Optionally, the first connecting structure 51 and the second connecting structure 41 described above may be the same or different.

[0251] In some examples, such as Figure 22b and Figure 22c As shown, when the electrode layer 4 and the first stop portion 5 are connected and form an integral structure, the first connecting structure 51 and the second connecting structure 41 are, for example, the same, and the first connecting structure 51 can be reused as the second connecting structure 41.

[0252] This helps to improve the design regularity of the first connecting structure 51 and the second connecting structure 41, reduce the fabrication difficulty of the first connecting structure 51 and the second connecting structure 41, and improve the etching uniformity of the film layer located below the first stop portion 5 and the film layer located below the electrode layer 4.

[0253] Furthermore, in some examples, where the accelerometer chip 20 also includes a second protective layer 8, the second protective layer 8 is formed later than the gap between the mass block 1 and the first stop portion 5 and the electrode layer 4. Therefore, a portion of the second protective layer 8 can also fill the first connecting structure 51 and / or the second connecting structure 41, providing further protection for the first stop portion 5 and / or the electrode layer 4, effectively improving the reliability of the accelerometer chip 20.

[0254] In some possible embodiments, the acceleration sensing chip 20 is symmetrical. For example, as... Figure 8 As shown, the accelerometer chip 20 has a first axis of symmetry S1 and a second axis of symmetry S2. The first axis of symmetry S1 extends along a first direction Y, and the second axis of symmetry S2 extends along a third direction X. Furthermore, the accelerometer chip 20 is symmetrical about the first axis of symmetry S1 and about the second axis of symmetry S2. That is, the accelerometer chip 20 has XZ plane symmetry and YZ plane symmetry.

[0255] For example, mass block 1 is a cuboid structure, symmetrical about a first axis of symmetry S1 and about a second axis of symmetry S2. Base 2 is a hollow rectangular frame structure, symmetrical about a first axis of symmetry S1 and about a second axis of symmetry S2. Along the first direction Y, the number of cantilever arms 3 on opposite sides of mass block 1 is the same, and the different cantilever arms 3 have the same dimensional parameters; the cantilever arms 3 on opposite sides of mass block 1 are symmetrical about a first axis of symmetry S1 and about a second axis of symmetry S2. Along the first direction Y, the number of first stop portions 5 on opposite sides of mass block 1 is the same, and the different first stop portions 5 have the same dimensional parameters; the first stop portions 5 on opposite sides of mass block 1 are symmetrical about a first axis of symmetry S1 and about a second axis of symmetry S2. Along the third direction X, the number of second stop portions 6 on opposite sides of mass block 1 is the same, and the different second stop portions 6 have the same dimensional parameters; the second stop portions 6 on opposite sides of mass block 1 are symmetrical about a first axis of symmetry S1 and about a second axis of symmetry S2.

[0256] This allows for a more balanced force distribution on different cantilever arms 3, and a more balanced stopping effect on different first stop parts 5 or different second stop parts 6, which is beneficial for improving structural stability and achieving a better stopping effect.

[0257] Some embodiments of this application provide an acceleration sensing chip, which can be a MEMS acceleration sensing chip and can be applied to the aforementioned acceleration sensor 400. Figure 23a and Figure 23b The cross-sectional structural diagrams of an acceleration sensor chip along different cross-sectional directions are shown respectively.

[0258] In some embodiments, such as Figure 23a and Figure 23b As shown, the acceleration sensor chip 20 includes a first sensor chip 20a and a second sensor chip 20b disposed opposite each other. The first sensor chip 20a may include the acceleration sensor chip 20 described in any of the above embodiments, and the second sensor chip 20b may include the acceleration sensor chip 20 described in any of the above embodiments.

[0259] Continue reading Figure 23a and Figure 23b The base 2 of the first sensing chip 20a and the base 2 of the second sensing chip 20b are connected, as are the mass block 1 of the first sensing chip 20a and the mass block 1 of the second sensing chip 20b. The electrode layer 4, the first stop portion 5, and the second stop portion 6 of the first sensing chip 20a are located on the side of its base 2 away from the second sensing chip 20b. The electrode layer 4, the first stop portion 5, and the second stop portion 6 of the second sensing chip 20b are also located on the side of its base 2 away from the first sensing chip 20a.

[0260] Optionally, the first sensor chip 20a and the second sensor chip 20b are connected together using silicon fusion bonding. Of course, the first sensor chip 20a and the second sensor chip 20b can also be connected together using other processes, and this application embodiment does not limit this.

[0261] For example, two connected mass blocks 1 can move relative to two connected bases 2. When the accelerometer chip 20 is subjected to a large impact downwards in the second direction Z, the first stop portion 5 of the first sensor chip 20a and the second stop portion 6 of the second sensor chip 20b can cooperate to stop the movement of the two connected mass blocks 1. When the accelerometer chip 20 is subjected to a large impact upwards in the second direction Z, the second stop portion 6 of the first sensor chip 20a and the first stop portion 5 of the second sensor chip 20b can cooperate to stop the movement of the two connected mass blocks 1. When the accelerometer chip 20 is subjected to a large impact in the first direction Y, the first stop portion 5 of the first sensor chip 20a and the first stop portion 5 of the second sensor chip 20b can cooperate to stop the rotation or tilting of the two connected mass blocks 1. When the acceleration sensing chip 20 is subjected to a large impact along the third direction X, the second stop part 6 of the first sensing chip 20a and the second stop part 6 of the second sensing chip 20b can cooperate with each other to achieve the effect of stopping the rotation or tilt of the two connected mass blocks 1.

[0262] In other words, the aforementioned acceleration sensing chip 20 can comprehensively stop impacts along the first direction Y, the second direction Z, and the third direction X, improving its resistance to impacts along these directions and preventing the cantilever 3 of the first sensing chip 20a and the cantilever 3 of the second sensing chip 20b from being torn off. This effectively improves the reliability of the acceleration sensing chip 20.

[0263] Furthermore, in the aforementioned acceleration sensing chip 20, the two connected mass blocks 1 are, for example, suspended, and the electrode layer 4 of the first sensing chip 20a and the electrode layer 4 of the second sensing chip 20b are, for example, electrically connected to electrode leads respectively.

[0264] In this configuration, the two connected mass blocks 1 can serve as intermediate electrodes, and the electrode layers 4 of the first sensing chip 20a and the second sensing chip 20b can each serve as fixed electrodes. The two connected mass blocks 1, the electrode layers 4 of the first sensing chip 20a, and the second sensing chip 20b can be considered as two capacitors connected in series. These two capacitors have, for example, the same charge, and the voltage across each capacitor is inversely proportional to its charge. When the two connected mass blocks 1 move along the second direction Z, the change in the gap between the mass block 1 and the electrode layer 4 in the first sensing chip 20a is the same as the change in the gap between the mass block 1 and the electrode layer 4 in the second sensing chip 20b.

[0265] In this way, the electrode layer 4 of the first sensing chip 20a and the electrode layer 4 of the second sensing chip 20b can be used as differential outputs, so that the relationship between the movement amplitude (or movement distance) of the two connected mass blocks 1 and the total capacitance of the two capacitors tends to change linearly. Even when the movement amplitude of the two connected mass blocks 1 is large, good linearity can be maintained, which is beneficial to improving the sensitivity of the acceleration sensing chip 20.

[0266] In some embodiments, such as Figure 23a and Figure 23b As shown, the area between the mass block 1 and the electrode layer 4 in the first sensing chip 20a is equal to the area between the mass block 1 and the electrode layer 4 in the second sensing chip 20b.

[0267] For example, the electrode layer 4 in the first sensing chip 20a and the area of ​​the second sensing chip 20b projected onto the reference plane are equal; the areas of the two connected mass blocks 1 projected onto the reference plane are equal.

[0268] When the two connected mass blocks 1 do not move, the capacitance of the capacitor formed by the two connected mass blocks 1 and the electrode layer 4 of the first sensing chip 20a, and the capacitance of the capacitor formed by the two connected mass blocks 1 and the electrode layer 4 of the second sensing chip 20b, are, for example, equal. When the two connected mass blocks 1 move, the change in capacitance of the capacitor formed by the two connected mass blocks 1 and the electrode layer 4 of the first sensing chip 20a, and the change in capacitance of the capacitor formed by the two connected mass blocks 1 and the electrode layer 4 of the second sensing chip 20b, are, for example, equal.

[0269] This helps to further improve the linearity between the movement amplitude (or movement distance) of the two connected mass blocks 1 and the total capacitance of the two capacitors, thereby further improving the sensitivity of the acceleration sensing chip 20.

[0270] In some embodiments, such as Figure 23a and Figure 23b As shown, the first sensing chip 20a and the second sensing chip 20b have a connection interface B. This connection interface B can be the surface of the first sensing chip 20a adjacent to the second sensing chip 20b, for example, it can be formed by the surfaces of the mass block 1 and the base 2 in the first sensing chip 20a adjacent to the second sensing chip 20b. Alternatively, the connection interface B can also be the surface of the second sensing chip 20b adjacent to the first sensing chip 20a, for example, it can be formed by the surfaces of the mass block 1 and the base 2 in the second sensing chip 20b adjacent to the first sensing chip 20a.

[0271] Continue reading Figure 23a and Figure 23b The first sensor chip 20a and the second sensor chip 20b are symmetrical about the connection interface.

[0272] For example, in the process of fabricating the acceleration sensor chip 20, multiple sensor chips with the same parameters can be fabricated on the same wafer, and then two sensor chips (i.e., the first sensor chip 20a and the second sensor chip 20b) can be connected back to back by means of silicon fusion bonding, etc., to obtain the acceleration sensor chip 20.

[0273] This helps to reduce the design and fabrication difficulty of the accelerometer chip 20 and improve the fabrication efficiency of the accelerometer chip 20.

[0274] Some embodiments of this application also provide two methods for fabricating an accelerometer chip, which are used to fabricate the accelerometer chip 20 described in any of the above embodiments. Of course, the fabrication methods for the accelerometer chip are not limited to these. For example, the fabrication methods used for the accelerometer chip 20 in the different embodiments described above are the same, the difference being that the etching removal area of ​​the film layer is different. The following uses… Figure 9c Taking the acceleration sensor chip 20 shown as an example, the fabrication method is illustrated.

[0275] The first method for fabricating an acceleration sensor chip includes, for example, S100a-S500a.

[0276] S100a, such as Figure 24a As shown, a substrate is provided. The substrate includes, for example, a substrate layer (HL) 2011, a buried oxide layer (BL) 2021 and a device layer (DL) 2031 sequentially stacked along the second direction Z.

[0277] For example, the above-mentioned substrate can also be referred to as a silicon-on-insulator structure.

[0278] S200a, combined with Figure 24a and Figure 24b According to the preset removal area, the device layer 2031 is etched to form the functional layer 203, resulting in multiple cantilever 3, electrode layer 4, multiple first stop portions, and multiple second stop portions 6. The removal area is related to... Figure 24b The blank areas are the same except for the multiple cantilever 3, electrode layer 4, multiple first stop parts and multiple second stop parts 6.

[0279] Functional layer 203 exposes a portion of buried oxide layer 2021, and then the exposed portion of buried oxide layer 2021 can be etched based on functional layer 203, for example, buried oxide layer 2021 can be over-etched.

[0280] S300a, such as Figure 24c As shown, the substrate 2011 is etched from the side of the substrate 2011 away from the functional layer 203 to define the mass block 1. For example, along the second direction Z, the thickness of the mass block 1 is less than the thickness of the substrate 2011.

[0281] S400a, combined with Figure 24c and Figure 24d The substrate 2011 was further etched using deep reactive ion etching (DRIE) to form the back cavity and the base 2. The back cavity exposed a portion of the buried oxide layer 2021.

[0282] S500a, combined with Figure 24d and Figure 24e From the side where the back cavity is located, a portion of the buried oxide layer 2021 exposed by the back cavity is etched to form an isolation layer 202. During this process, the etched buried oxide layer can be over-etched to connect the back cavity and the over-etched area.

[0283] The second method for fabricating an accelerometer chip includes, for example, S100b-S400b.

[0284] S100b, such as Figure 24a As shown, a substrate is provided. For details regarding the substrate, please refer to the description in S100a; it will not be repeated here.

[0285] S200b, combined with Figure 24a and Figure 25a According to the preset removal area, the device layer 2031 is etched to form a functional layer 203 and at least one connecting structure, resulting in multiple cantilever 3, electrode layer 4, multiple first stop portions, and multiple second stop portions 6. The connecting structure is, for example, a second connecting structure 41, and is formed on the electrode layer 4. The provision of the second connecting structure 41 facilitates fluid flow through the second connecting structure 41 to corrode the buried oxide layer 2021.

[0286] S300b, combined with Figure 25a and Figure 25b From the side of the substrate 2011 away from the functional layer 203, the substrate 2011 is etched to form a back cavity, a mass block 1, and a base 2. In the second direction Z, the thickness of the mass block 1 is, for example, less than the thickness of the base 2.

[0287] S400b, combined with Figure 25b and Figure 25c The buried oxide layer 2021 is etched from the side where the back cavity is located to form an isolation layer 202. During this process, the buried oxide layer 2021 can be over-etched to connect the back cavity and the second connecting structure 41.

[0288] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed herein should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An acceleration sensor chip, characterized by, The acceleration sensing chip comprises: a mass block, which is electrically conductive; a base, which is spaced around the mass block; a plurality of suspension arms, which are respectively connected to opposite sides of the mass block along a first direction, and are respectively connected to the base along a second direction, and have a spacing between the mass block and the center of mass of each suspension arm along the second direction; a plurality of first stoppers, which are respectively connected to the base along the first direction, and are respectively located on opposite sides of the mass block along the first direction, and have a portion of each first stopper spaced above the mass block along the second direction; a plurality of second stoppers, which are respectively connected to opposite sides of the mass block along a third direction, and have a portion of each second stopper spaced above the base along the second direction; an electrode layer, which is spaced above the mass block along the second direction, and is connected to the base; wherein the first direction and the third direction intersect and are both parallel to a reference plane determined by the base and the mass block, and the second direction is perpendicular to the first direction and the third direction.

2. The acceleration sensing chip according to claim 1, characterized in that The plurality of first stoppers are electrically conductive. At least one first stopper is connected to the electrode layer and has an integrated structure.

3. The acceleration sensing chip according to claim 1 or 2, characterized in that, The mass block and the base are arranged in the same layer; and / or The suspension arms, the plurality of first stoppers, the plurality of second stoppers, and the electrode layer are arranged in the same layer.

4. The acceleration sensing die of any one of claims 1-3, wherein, The acceleration sensing chip comprises a support layer, an isolation layer, and a functional layer arranged in layers along the second direction; The mass block and the base are located in the support layer; The suspension arms, the plurality of first stoppers, the plurality of second stoppers, and the electrode layer are located in the functional layer.

5. The acceleration sensing die of claim 4, wherein, Along the first direction, at least one suspension arm located on one side of the mass block is connected to at least one suspension arm located on the other side of the mass block and has an integrated structure.

6. The acceleration sensing die of any one of claims 1-5, wherein, The plurality of suspension arms are respectively located on opposite sides of the plurality of first stoppers along the third direction, and the plurality of second stoppers are respectively located on opposite sides of the plurality of suspension arms along the third direction.

7. The acceleration sensing die of any of claims 1-6, wherein, Along the first direction, the effective size of at least one first stopper located on one side of the mass block in the third direction is in a proportional range of 1:2-2:1 with the effective size of at least one first stopper located on the other side of the mass block in the third direction.

8. The acceleration sensing die of any one of claims 1-7, wherein, Along the first direction, the effective stiffness of at least one first stopper located on one side of the mass block is in a proportional range of 1:2-2:1 with the effective stiffness of at least one first stopper located on the other side of the mass block.

9. The acceleration sensing die of any of claims 1-8, wherein, Along the third direction, the effective size of at least one second stopper located on one side of the mass block in the first direction is in a proportional range of 1:2-2:1 with the effective size of at least one second stopper located on the other side of the mass block in the first direction.

10. The acceleration sensing die of any one of claims 1-9, wherein, The ratio of the effective stiffness of the at least one second stop portion on one side of the mass to the effective stiffness of the at least one second stop portion on the other side of the mass ranges from 1:2 to 2:1 along the third direction.

11. The acceleration sensing die of any of claims 1-10, wherein, The base has a first side surface opposite to the mass, and the mass has a second side surface opposite to the base; The acceleration sensing chip has a plurality of grooves, the plurality of grooves are formed on the first side surface and / or the second side surface, and the depth direction of each groove is parallel to the first direction; Along the second direction, the grooves are located below the cantilever arms.

12. The acceleration sensing die of claim 11, wherein, Along the second direction, the number of grooves located below different cantilever arms is the same.

13. The acceleration sensing die of claim 11 or 12, wherein, The depths of the grooves are the same.

14. The acceleration sensing die of any one of claims 1-13, wherein, Along the second direction, a portion of the first stop portion arranged above the mass is provided with at least one first communication structure; The first communication structure communicates the gap between the first stop portion and the mass.

15. The acceleration sensing die of any one of claims 1-14, wherein, Along the second direction, a portion of the electrode layer arranged above the mass is provided with at least one second communication structure; The second communication structure communicates the gap between the electrode layer and the mass.

16. The acceleration sensing die of any one of claims 1-15, wherein, The acceleration sensing chip further comprises: A first protective layer covering at least the side surface of the plurality of first stop portions close to the mass and the side surface of the plurality of second stop portions close to the base; A second protective layer covering at least the portion of the mass opposite to the plurality of first stop portions and the portion of the base opposite to the plurality of second stop portions; The first protective layer and the second protective layer have a gap therebetween.

17. The acceleration sensing die of claim 16, wherein, The ratio of the gap between the first protective layer and the second protective layer to the gap between the mass and the first stop portion along the second direction is greater than or equal to 1:

2.

18. The acceleration sensing die of any one of claims 1-17, wherein, The acceleration sensing chip has a first symmetry axis and a second symmetry axis, the first symmetry axis extends along the first direction, and the second symmetry axis extends along the third direction; The acceleration sensing chip is symmetrical about the first symmetry axis and symmetrical about the second symmetry axis.

19. An acceleration sensing chip, characterized by The acceleration sensing chip comprises: A first sensing chip comprising the acceleration sensing chip according to any one of claims 1-18; A second sensing chip comprising the acceleration sensing chip according to any one of claims 1-18; The first sensing chip and the second sensing chip are arranged opposite to each other, the base of the first sensing chip and the base of the second sensing chip are connected, and the mass of the first sensing chip and the mass of the second sensing chip are connected.

20. The acceleration sensing die of claim 19, wherein, The opposite area between the mass and the electrode layer in the first sensing chip is equal to the opposite area between the mass and the electrode layer in the second sensing chip.

21. The acceleration sensing die of claim 19 or 20, wherein, The first sensing chip and the second sensing chip have a connection interface; The first sensing chip and the second sensing chip are symmetrical about the connection interface.

22. An acceleration sensor, characterized by The acceleration sensor comprises: The acceleration sensing chip according to any one of claims 1-21; A special integrated circuit chip is electrically connected with the acceleration sensing chip.

23. An electronic device, comprising: The electronic device comprises: The acceleration sensor according to claim 22; A circuit board is electrically connected with the acceleration sensor.

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