WO2021031498A1

WO2021031498A1 - Vibration sensing apparatus

Info

Publication number: WO2021031498A1
Application number: PCT/CN2019/129221
Authority: WO
Inventors: 端木鲁玉; 李欣亮; 付博; 方华斌
Original assignee: 歌尔微电子有限公司
Priority date: 2019-08-22
Filing date: 2019-12-27
Publication date: 2021-02-25
Also published as: CN210513400U

Abstract

A vibration sensing apparatus, comprising a housing (6), an elastic element (7), a mass element (8), and a vibrations sensor. A cavity is formed in the housing (6); an air vent (603) is provided on the housing (6); the air vent (603) is configured to be in an opened state when assembling is performed on the vibration sensing apparatus, and to be in a closed state after the assembling of the vibration sensing apparatus is completed; the elastic element (7) is provided in the cavity; the mass element (8) is suspended in the cavity by means of the elastic element (7), and can move along with the elastic element (7) in the cavity so as to change pressure in the cavity; the vibration sensor is communicated with the cavity; the vibration sensor is configured to measure the pressure in the cavity or a pressure difference between different regions in the cavity. The vibration sensing apparatus facilitates improving the performance of a product and prolonging the service life of the product.

Description

Vibration sensing device

Technical field

The present invention relates to the technical field of vibration sensing, and more specifically, the present invention relates to a vibration sensing device.

Background technique

The existing vibration sensing device usually includes a housing and a mass arranged in the housing. The mass block is suspended inside the shell through the diaphragm. The housing has an open end. The substrate of the vibration sensor is hermetically connected to the open end. A MEMS chip and an ASIC chip are arranged on the side of the substrate opposite to the housing, and also a shell arranged outside the MEMS chip and the ASIC chip. The substrate has communication holes. The MEMS chip communicates with the inner cavity of the housing through the communication hole.

During work, the vibration sensing device is fixed on the equipment to be measured. When the device is working, the vibration is transmitted to the shell, which drives the shell to sound and vibrate. Since the mass has a set mass and the diaphragm has elasticity, the mass will vibrate relative to the shell. The vibration of the mass causes the volume of the chambers on both sides of the diaphragm to change. Since the inner cavity is airtight, the volume in the cavity will change, and the pressure in the cavity will change accordingly. When the MEMS chip senses the pressure change, it generates a corresponding electrical signal. The electrical signal is amplified by the ASIC chip and then transmitted to the external circuit. The external circuit collects the electrical signal. However, the existing vibration sensing device can usually only sense the pressure change of one chamber, and the sensing sensitivity is relatively low.

In addition, during the assembly process of the existing vibration sensing device, it is necessary to open a vent on the housing, which can maintain the internal and external pressure balance during reflow soldering, thereby avoiding product damage. After the assembly is completed, if the vent on the shell still exists, it will cause certain problems to the product, for example, it is very easy to cause external dust, dust, water, oil, etc. to enter the interior of the shell through the vent , This will have a great impact on the performance of the product and also reduce the service life of the product. Especially when the vacuum degree is low, the performance of the product will be greatly reduced.

Therefore, it is necessary to provide a new technical solution to solve the above technical problems.

Summary of the invention

An object of the present invention is to provide a new technical solution for a vibration sensing device.

According to one aspect of the present invention, there is provided a vibration sensing device, including:

A housing, a cavity is formed inside the housing, a vent is provided on the housing, and the vent is configured to be in an open state when the vibration sensing device is assembled. The device is closed after assembly;

An elastic element, the elastic element is arranged in the cavity;

A mass element, the mass element is suspended in the cavity by the elastic element, and can move in the cavity together with the elastic element to change the pressure in the cavity; and

A vibration sensor, the vibration sensor is in communication with the cavity, and the vibration sensor is configured to sense the pressure in the cavity or the pressure difference of different regions in the cavity.

Optionally, after the assembling of the vibration sensing device is completed, the vent is sealed by a glue.

Optionally, after the assembling of the vibration sensing device is completed, a plastic seal is used to form a plastic seal at the position of the air vent.

Optionally, the plastic sealing layer also covers the outer side of the housing and the vibration sensor.

Optionally, the vibration sensor includes a packaging structure with a containing cavity formed by a substrate and a housing, and a MEMS chip and an ASIC chip housed in the containing cavity and fixedly arranged on the substrate;

The housing has an open end, the substrate is hermetically connected to the open end of the housing, the substrate is provided with a through hole that communicates the back cavity of the MEMS chip with the cavity, and the MEMS chip Connect with the ASIC chip.

Optionally, the housing includes a side wall arranged around the MEMS chip and the ASIC chip, and a bottom plate opposite to the substrate;

A metalized through hole is provided in the sidewall, and a pad is provided on the bottom plate, and the pad and the ASIC chip are electrically connected through the metalized through hole.

Optionally, there are multiple pads.

Optionally, the MEMS chip includes a substrate and a sensing film, and the substrate is a hollow structure;

The sensing film is disposed at one end of the substrate and covers the hollow structure, the hollow structure forms the back cavity, and the other end of the substrate is fixedly connected to the substrate;

The sensing film is provided with first air-permeable micropores.

Optionally, the mass element is attached to the surface of the elastic element, and second air-permeable micropores are jointly provided on the mass element and the elastic element.

Optionally, the elastic element is an elastic diaphragm.

In the vibration sensing device provided by the embodiment of the present invention, a vent is provided on the housing. By properly setting the opening and closing of the vent, the internal and external air pressure can be effectively balanced during the assembly phase, and the product can also be isolated during the use phase. The inner cavity and the external environment prevent foreign matter from entering the inner cavity, which helps to improve the performance of the product and prolong the service life of the product. In addition, the vibration sensor also has the characteristics of high sensitivity for sensing vibration.

Through the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings, other features and advantages of the present invention will become clear.

Description of the drawings

The drawings constituting a part of the specification describe the embodiments of the present invention, and together with the specification are used to explain the principle of the present invention.

Fig. 1 is a schematic structural diagram of a vibration sensing device according to an embodiment of the present disclosure.

Fig. 2 is a schematic structural diagram of another vibration sensing device according to an embodiment of the present disclosure.

Description of reference signs:

1: substrate; 101: through hole; 2: housing; 201: bottom plate; 202: side wall; 203: containing cavity; 3: MEMS chip; 301: sensing membrane; 302: first air-permeable micropore; 303: back cavity; 304: substrate; 4: ASIC chip; 5: pad; 6: housing; 601: first chamber; 602: second chamber; 603: vent; 7: elastic element; 8: mass element; 9 : The second air-permeable micropore; 10: the plastic sealing layer; 11: the colloid.

detailed description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless specifically stated otherwise, the relative arrangement of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention.

The following description of at least one exemplary embodiment is actually only illustrative, and in no way serves as any limitation to the present invention and its application or use.

The technology and equipment known to those of ordinary skill in the relevant fields may not be discussed in detail, but where appropriate, the technology and equipment should be regarded as part of the specification.

In all the examples shown and discussed herein, any specific value should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiment may have different values.

It should be noted that similar reference numerals and letters indicate similar items in the following drawings, so once a certain item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

According to an embodiment of the present invention, a vibration sensing device is provided. The vibration sensing device may be a bone voiceprint sensing device, an environment sensing device, or the like. As shown in Figs. 1 and 2, the vibration sensing device includes: a housing 6, an elastic element 7, a mass element 8, and a vibration sensor.

The housing 6 has an open end. A cavity is formed inside the housing 6. For example, the material of the housing 6 is metal, plastic or PCB board. The shape of the housing 6 is a cylindrical shape, a rectangular parallelepiped, or the like. Those skilled in the art can flexibly adjust according to actual needs, and there is no limitation on this.

In addition, a vent 603 is provided in the housing 6. The vent 603 has a ring structure, for example. In the production of the vibration sensing device, especially in the process of assembling the vibration sensing device, the housing 6 is provided with a vent 603. At this time, the vent 603 should be in an open state. The reason is that in the process of assembling the vibration sensing device, the welding process is usually involved, and the gas inside the cavity will change in pressure during welding. At this time, if there is no open air vent 603, it will cause The phenomenon of uneven pressure inside the cavity. That is, opening the air vent 603 can maintain uniform pressure inside and outside the cavity during welding, which can prevent damage to the product and affect the quality of the product. After the vibration sensing device is assembled, especially when the vibration sensing device is used, it is necessary to close the vent 603 to prevent external dust, dust and other particles, or water, oil, etc. from entering the cavity Inside the body, thus affecting the performance and service life of the product. However, it should be noted that when closing the vent 603, it is necessary to avoid a situation where the air pressure inside and outside the cavity is too different. For example, the pressure in the cavity can be controlled at 0.01-10 atmospheres.

The elastic element 7 is arranged in the cavity. The elastic element 7 is used to provide elastic restoring force for the mass element 8. The elastic element 7 may be an elastic diaphragm, for example. Of course, the elastic element 7 can also be other elastic elements known to those skilled in the art, and the present invention does not limit this.

In an example, the elastic element 7 includes an elastic part located in the middle part and an edge part arranged around the elastic part. The elastic part can be elastically deformed to provide elastic restoring force. The edge portion is used to connect with the inner wall of the housing 6. Thus, the entire elastic element 7 can be fixedly arranged in the cavity.

The mass element 8 is suspended in the cavity by the elastic element 7 and can move in the cavity together with the elastic element 7 to change the pressure in the cavity. In an example, the mass element 8 and the elastic part of the elastic element 7 are connected by an adhesive, so that the mass element 8 is firmly attached to the surface of the elastic element 7. Of course, the mass element 8 and the elastic element 7 can also be combined together in other ways known to those skilled in the art, which is not limited. In addition, the mass element 8 is a mass of a predetermined weight, and those skilled in the art can flexibly adjust the weight of the mass as required, and there is no limitation on this.

As shown in FIGS. 1 and 2, after the mass element 8 and the elastic element 7 are connected together, the cavity in the housing 6 can be divided into a first chamber 601 and a second chamber 602. Wherein, the first chamber 601 and the second chamber 602 both have a set volume. Seal the gas with a predetermined pressure in the two chambers. The gas can be, for example, air, nitrogen, inert gas, etc., and those skilled in the art can flexibly choose according to needs, and there is no restriction on this.

The mass element 8 and the elastic element 7 are jointly provided with second air-permeable micropores 9. The size of the second air-permeable micropores 9 is very small, belonging to the micron level. The second air-permeable micropores 9 can allow air to flow through, so that the air can pass through and then be discharged through the vent 603, which helps to balance the air pressure inside and outside the cavity. Those skilled in the art can appropriately adjust the number and position of the second air-permeable micro-holes 9 as needed, and there is no limitation on this.

In the present invention, the vibration sensor communicates with the cavity formed in the housing 6. The vibration sensor is configured to sense the pressure in the cavity or the pressure difference in different areas in the cavity. For example, a vibration sensor can be used to sense the pressure difference between the first chamber 601 and the second chamber 602. Among them, the vibration sensor can be, for example, an electric sensor, a piezoelectric sensor, an eddy current sensor, an inductive sensor, a capacitive sensor, etc. Those skilled in the art can choose flexibly according to needs, and there is no limitation on this.

The vibration sensing device provided by the embodiment of the present invention can obtain the pressure difference between the first chamber 601 and the second chamber 602 through the vibration sensor; and calculate the vibration state at the location of the vibration sensor through the pressure difference.

In use, the vibration sensing device is installed on the object to be detected, for example, a human joint, a robot joint, etc. The vibration of the object to be detected will drive the housing 6 to vibrate. Due to the combined action of the inertia of the mass element 8 and the elastic restoring force of the elastic element 7, the mass element 8 will vibrate relative to the housing 6. The vibration of the mass element 8 and the elastic element 7 causes the volume of the first chamber 601 and the second chamber 602 to change. Since both chambers are closed chambers, the first chamber 601 and the second chamber 602 The pressure of the gas inside will change.

In this example, the vibration sensor senses the pressure difference between the first chamber 601 and the second chamber 602, and converts the pressure difference into an electrical signal, such as a voltage signal, a current signal, or a capacitance signal. The electrical signal is calculated to obtain the vibration state of the object to be detected. For example, amplitude, vibration frequency, etc.

In the vibration sensing device provided by the embodiment of the present invention, the housing 6 is provided with a vent 603. By reasonably setting the opening and closing of the vent 603, the internal and external air pressure can be effectively balanced during the assembly stage, and it can also be used Separate the inner cavity of the product from the external environment in stages to prevent foreign matter from entering the inner cavity, which helps to improve the performance of the product and prolong the service life of the product. Moreover, the inventor of the present invention found that in the prior art, the vibration sensor is usually only provided in the first chamber 601 or the second chamber 603, and at this time, only the pressure change of one chamber is sensed to detect the to-be-detected The vibration state of the object. In the embodiment of the present invention, the vibration sensor can sense the pressure difference between the first chamber 601 and the second chamber 602, and has the feature of high sensitivity for sensing vibration.

In an example, as shown in FIG. 1, when the air vent 603 on the housing 6 is closed, a plastic sealing method can be used. Specifically, the plastic sealing layer 10 is formed at the position of the air vent 603 by plastic sealing. At this time, the plastic sealing layer 11 directly covers the vent 603 to completely seal the vent 603. This design can play the role of dustproof, waterproof and oil-proof.

In addition, it should be noted that in this embodiment, only the vent 603 can be covered by plastic sealing, or the vibration sensing device can be plastic-encapsulated as a whole. When the vibration sensing device is plastic-encapsulated as a whole, the formed plastic sealing layer 10 covers the outer side of the housing 6 and the vibration sensor, and the plastic sealing layer 10 can protect the whole vibration sensing device from dust, water and oil.

In an example, as shown in FIG. 2, when sealing the air vent 603 on the housing 6, the air vent 603 can also be blocked by the glue 11. That is, the leak hole 603 is closed with the glue 11 in a way of blocking the hole. Among them, the glue 11 can use glue materials well known in the art. The blocked air vent 603 can isolate the inner cavity of the housing 6 from the external environment, so that it can prevent dust, water, and oil.

When the vent 603 is closed, the vibration sensing device can be applied to various atmospheric environments with a wide range of applications.

In the present invention, the vibration sensor and the housing 6 are connected together. Wherein, the shell 6 has a dish-shaped structure, one end of which is an open end, and the vibration sensor is connected to the open end of the shell 6 to close the open end of the shell 6.

The vibration sensor of the present invention, as shown in FIG. 1 and FIG. 2, includes a packaging structure with a housing cavity 203 formed by a substrate 1 and a housing 2, and a MEMS housed in the housing cavity 203 and fixedly arranged on the substrate 1. Chip 3 and ASIC chip 4. Among them, the substrate 1 is, for example, a PCB board. The substrate 1 is hermetically connected to the open end of the housing 6. In addition, a through hole 101 is provided on the substrate 1, and the through hole 101 is used to communicate the cavity in the housing 6 with the back cavity 303 in the MEMS chip 3. In this embodiment, the through hole 101 is a round hole, a square hole, etc., and those skilled in the art can flexibly adjust according to specific needs, and there is no limitation on this. The difficulty of opening the through hole 101 on the substrate 1 is small and the processing is easy.

The MEMS chip 3 includes a substrate 304 and a sensing film 301. The substrate 304 is a hollow structure. The sensing film 301 is, for example, a piezoelectric element, a capacitive element, a piezoresistive element, or the like. The sensing film 301 is disposed at one end of the substrate 304 and covers the hollow structure. The hollow structure forms a back cavity 303. The other end of the substrate 304 is fixedly connected to the substrate 1. The sensing film 301 is provided with first air-permeable micro holes 302.

In the process of assembling or packaging the entire vibration sensing device, a welding process is inevitably involved, for example, welding the housing 6 and the substrate 1 or welding the housing 2 and the substrate 1. The air flow generated during the welding process will remain in the cavity and the containing cavity 203. In order to facilitate the discharge of these air flows from the air vent 603, in this embodiment, a first vent 302 is provided on the sensing membrane 301, and the second vent 9 on the elastic element 7 and the mass element 8 can make the receiving cavity 203 The middle air flow smoothly flows into the cavity, and finally is smoothly discharged from the air vent 603.

It should be noted that the size of the first air-permeable micro-holes 302 is also very small, which also belongs to the micron level. Wherein, the number of first air-permeable micro-holes 302 can be set as one or multiple as required, and there is no limitation on this. In addition, the size of the first air-permeable micropores 302 can be the same as or different from the second air-permeable micropores 9.

The ASIC chip 4 is integrated on the substrate 1. The MEMS chip 3 is connected to the ASIC chip 4 through metal wires. The ASIC chip 4 is connected to the substrate 1 through metal wires. The ASIC chip 4 can be used to amplify the signal collected by the MEMS chip 3. Among them, the ASIC chip 4 can also be replaced by other signal amplifiers well known to those skilled in the art, and those skilled in the art can choose flexibly according to needs.

The housing 2 and the substrate 1 are fixedly connected. The housing 2 and the substrate 1 may enclose a receiving cavity 203, and the receiving cavity 203 may be used to house the MEMS chip 3 and the ASIC chip 4.

In an example, as shown in FIG. 1 and FIG. 2, the structure of the housing 2 includes a side wall 202 arranged around the MEMS chip 3 and the ASIC chip 4, and a bottom plate 201 opposite to the substrate 1. In addition, a plurality of pads 5 are provided on the outside of the bottom plate 201. For example, the number of pads 5 can be set to three, four or more as needed.

The bottom plate 201 is, for example, a circuit board or a metal plate, which is not limited.

A metalized through hole is provided in the sidewall 202, and a pad 5 is provided on the bottom plate 201, and the pad 5 and the ASIC chip 4 are electrically connected through the metalized through hole. When in use, solder the pad 5 directly to the external circuit.

In addition, the housing 2 and the substrate 1 can be fixed together by glue bonding or solder paste welding. Similarly, the substrate 1 and the housing 6 can also be fixed together by glue bonding or solder paste welding. Those skilled in the art can flexibly choose according to their needs, and there is no restriction on this.

Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration and not for limiting the scope of the present invention. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present invention. The scope of the invention is defined by the appended claims.

Claims

A vibration sensing device, characterized in that it comprises:

A housing, a cavity is formed inside the housing, a vent is provided on the housing, and the vent is configured to be in an open state when the vibration sensing device is assembled. The device is closed after assembly;

An elastic element, the elastic element is arranged in the cavity;

A mass element, the mass element is suspended in the cavity by the elastic element, and can move in the cavity together with the elastic element to change the pressure in the cavity; and

A vibration sensor, the vibration sensor is in communication with the cavity, and the vibration sensor is configured to sense the pressure in the cavity or the pressure difference of different regions in the cavity.
The vibration sensing device according to claim 1, wherein after the assembly of the vibration sensing device is completed, the vent is sealed by a glue.
The vibration sensing device according to claim 1, wherein after the assembly of the vibration sensing device is completed, a plastic sealing method is used to form a plastic sealing layer at the position of the air vent.
4. The vibration sensing device of claim 3, wherein the plastic encapsulation layer further covers the outer side of the housing and the vibration sensor.
The vibration sensing device according to claim 1, wherein the vibration sensor comprises a packaging structure with a containing cavity formed by a substrate and a housing, and a packaging structure that is housed in the containing cavity and fixedly arranged on the substrate MEMS chips and ASIC chips;

The housing has an open end, the substrate is hermetically connected to the open end of the housing, the substrate is provided with a through hole that communicates the back cavity of the MEMS chip with the cavity, and the MEMS chip Connect with the ASIC chip.
The vibration sensing device according to claim 5, wherein the housing comprises a side wall arranged around the MEMS chip and the ASIC chip, and a bottom plate opposite to the substrate;

A metalized through hole is provided in the sidewall, and a pad is provided on the bottom plate, and the pad and the ASIC chip are electrically connected through the metalized through hole.
7. The vibration sensing device of claim 6, wherein there are a plurality of the pads.
The vibration sensing device of claim 5, wherein the MEMS chip comprises a substrate and a sensing film, and the substrate is a hollow structure;

The sensing film is disposed at one end of the substrate and covers the hollow structure, the hollow structure forms the back cavity, and the other end of the substrate is fixedly connected to the substrate;

The sensing film is provided with first air-permeable micropores.
The vibration sensing device according to claim 1, wherein the mass element is attached to the surface of the elastic element, and second air-permeable micropores are jointly provided on the mass element and the elastic element .
The vibration sensing device according to claim 1, wherein the elastic element is an elastic diaphragm.