CN114608664A

CN114608664A - Micro differential pressure sensor assembly and electronic equipment

Info

Publication number: CN114608664A
Application number: CN202210219121.XA
Authority: CN
Inventors: 谢国伟; 颜培力; 夏颖; 朱伟琪; 金怡
Original assignee: Shanghai Sirui Technology Co ltd
Current assignee: Shanghai Sirui Technology Co ltd
Priority date: 2022-03-08
Filing date: 2022-03-08
Publication date: 2022-06-10
Also published as: CN219495335U; CN219532146U; CN116067445A

Abstract

The application provides a little differential pressure sensor subassembly and electronic equipment. The micro-differential pressure sensor assembly comprises a substrate, a Micro Electro Mechanical System (MEMS) module, a processor and an MOS tube. The MEMS module comprises a first temperature detection unit, a second temperature detection unit and a heating unit, wherein the first temperature detection unit, the second temperature detection unit and the heating unit are all arranged in a sensing area of the MEMS module. In this scheme, the treater is based on the difference in temperature of first temperature detecting element, second temperature detecting element, can realize the high sensitive detection of flow. In addition, the processor can control the effective current value of the controlled module through the MOS tube based on the temperature difference, and the accuracy and the reliability of controlling the controlled module are improved.

Description

Micro differential pressure sensor assembly and electronic equipment

Technical Field

The application relates to the technical field of sensors, in particular to a micro differential pressure sensor assembly and electronic equipment.

Background

At present, two types of micro differential pressure sensors are available, one type of differential pressure sensor is based on a pressure sensitive principle, the technology is mature and widely applied, but the zero stability is poor, and the problem of poor measurement precision exists when the technology is applied to measuring ultra-low differential pressure, such as measuring the differential pressure lower than 500Pa in an electronic cigarette. The other is a micro differential pressure sensor based on the thermal flow principle, which has high measurement accuracy, but has large package size and large power consumption, and is not convenient to be installed in small-sized electronic equipment such as electronic cigarettes.

Disclosure of Invention

The application aims to provide a micro differential pressure sensor assembly and electronic equipment, which are beneficial to realizing high-precision flow detection in small-sized electronic equipment.

In order to achieve the above object, the technical solution provided by the present application includes:

in a first aspect, a micro differential pressure sensor assembly is provided, which includes a substrate, and a micro electro mechanical system MEMS module, a processor and a MOS transistor all disposed on the substrate; the MEMS module comprises a first temperature detection unit, a second temperature detection unit and a heating unit, wherein the first temperature detection unit, the second temperature detection unit and the heating unit are all arranged in a sensing area of the MEMS module; the processor is used for controlling the effective current value of the controlled module through the MOS tube according to the temperature difference sensed by the first temperature detection unit and the second temperature detection unit, wherein the temperature difference is formed when the heating unit operates and fluid flows through the sensing area of the MEMS module, and the MOS tube is used as a control switch of the controlled module.

In the above embodiment, the processor can realize highly sensitive detection of the flow rate based on the temperature difference between the first temperature detection unit and the second temperature detection unit. In addition, the processor can control the effective current value of the controlled module through the MOS tube based on the temperature difference, and the accuracy and the reliability of controlling the controlled module are improved.

With reference to the first aspect, as an optional implementation manner, the micro differential pressure sensor assembly further includes an insulating encapsulation structure disposed on the substrate, where the insulating encapsulation structure encapsulates the MEMS module, the processor, and the MOS transistor, and the sensing region of the MEMS module is exposed to the insulating encapsulation structure.

In the above embodiment, the insulating packaging structure can protect the MEMS module, the processor, and the MOS transistor, and in addition, the sensing region of the MEMS module is exposed to the outside, which facilitates sensing of fluid flow.

With reference to the first aspect, as an optional implementation manner, the insulating packaging structure has a trench, and the sensing region of the MEMS module is located at a bottom of the trench and exposed to the outside.

In the above embodiment, the sensing region is located at the bottom of the trench, so that the trench of the insulating package structure can protect the sensing region of the MEMS module, and the sensing region is not easily damaged by external force. In addition, the grooves can conduct flow of fluid, so that the fluid can pass through the sensing area of the MEMS module under the flow guiding effect of the grooves, and the detection precision is improved.

With reference to the first aspect, as an optional implementation manner, the micro differential pressure sensor assembly further includes a casing disposed on the substrate, and configured to cover the insulating encapsulation structure, and a cavity is disposed between the casing and the insulating encapsulation structure;

the shell is provided with a first through hole and a second through hole which are communicated with the cavity, the shell and the insulating packaging structure form a channel for fluid to flow through the first through hole, the second through hole and the cavity, and the sensing area is located in the shell and in the channel.

In the above embodiment, the housing may cover the sensing region of the MEMS module to further protect the sensing region, so as to prevent the sensing region from being damaged by external force, thereby improving the reliability of the product.

With reference to the first aspect, as an optional embodiment, the first through hole and/or the second through hole is provided with a waterproof and breathable film.

In the above embodiment, the waterproof breathable film can allow gas to enter the housing for the MEMS module to achieve flow detection, and in addition, the waterproof breathable film can isolate and filter water mist and oil smoke to prevent water or other contaminants from affecting the detection accuracy of the MEMS module.

With reference to the first aspect, as an optional implementation manner, the MEMS module further includes a substrate and an insulating layer, the first temperature detecting unit, the second temperature detecting unit, and the heating unit are all disposed on the insulating layer, an edge portion of the insulating layer is disposed on the base plate through the substrate, the insulating layer, the substrate, and the base plate form a cavity, and the base plate is provided with a third through hole communicated with the cavity.

With reference to the first aspect, as an optional implementation manner, the MEMS module further includes a differential pressure detection unit disposed at the sensing region of the MEMS module;

the processor is further configured to control the heating unit to heat when receiving a target electrical signal sensed by the differential pressure detection unit, wherein the target electrical signal is an electrical signal generated by the differential pressure detection unit when sensing that a fluid flows through the sensing area.

In the above-described embodiment, the power consumption of the differential pressure detection unit is relatively lower than that of the heating unit. After the differential pressure detection unit is used for determining that the fluid flows, the heating unit is started to perform high-precision flow detection, so that the power consumption of the product is reduced, and the high precision and the low power consumption of the detection can be considered.

With reference to the first aspect, as an optional implementation manner, the differential pressure detection unit is a piezoresistive monitoring unit or a piezoelectric monitoring unit.

With reference to the first aspect, as an optional implementation manner, the first temperature detecting unit and the second temperature detecting unit are disposed at an interval in the sensing region of the MEMS module, and the heating unit is located between the first temperature detecting unit and the second temperature detecting unit.

In a second aspect, the present application further provides an electronic device, where the electronic device includes a controlled module and the micro differential pressure sensor assembly, and a MOS transistor in the micro differential pressure sensor assembly is connected to the controlled module and is used as a control switch of the controlled module.

With reference to the second aspect, as an optional implementation manner, the electronic device is an electronic cigarette, and the controlled module includes a tobacco tar heating module, wherein the processor is configured to control an operating state of the tobacco tar heating module through the MOS tube.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a micro differential pressure sensor assembly according to an embodiment of the present disclosure.

Fig. 2 is a second schematic structural diagram of a micro differential pressure sensor assembly according to an embodiment of the present disclosure.

Fig. 3a is a third schematic structural diagram of a micro differential pressure sensor assembly according to an embodiment of the present disclosure.

Fig. 3b is an exploded view of the micro differential pressure sensor assembly shown in fig. 3 a.

Fig. 4 is a fourth schematic structural diagram of a micro differential pressure sensor assembly according to an embodiment of the present disclosure.

Fig. 5 is one of cross-sectional views taken along the plane a-a in fig. 4.

Fig. 6 is a second cross-sectional view taken along the plane a-a in fig. 4.

Fig. 7 is a cross-sectional view of the a-a side of the micro differential pressure sensor assembly shown in fig. 4 after being provided with a water-resistant gas permeable membrane.

Fig. 8 is a schematic distribution diagram of electronic components disposed on a sensing region in a MEMS module according to an embodiment of the present disclosure.

Fig. 9 is a second schematic distribution diagram of electronic components disposed on a sensing region in a MEMS module according to an embodiment of the present disclosure.

Fig. 10 is a schematic diagram illustrating a connection between a micro differential pressure sensor assembly and a controlled module according to an embodiment of the present application.

Icon: 100-micro differential pressure sensor assembly; 110-a MEMS module; 111-a first temperature detection unit; 112-a second temperature detection unit; 113-a heating unit; 114-a sensing region; 115-an insulating layer; 116-a substrate; 120-a processor; 130-MOS tube; 140-a substrate; 141-third via holes; 150-a controlled module; 160-insulating packaging structure; 161-trenches; 170-a housing; 171-a first via; 172-second via; 181-waterproof and breathable film; 182-waterproof breathable film; 183-waterproof breathable film; 190-differential pressure detection unit; 191-a piezoelectric monitoring unit;

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. It should be noted that the terms "first," "second," and the like are used merely to distinguish one description from another, and are not intended to indicate or imply relative importance. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

Referring to fig. 1, the present application provides a micro differential pressure sensor assembly 100 that can be installed in a small-sized electronic device and can achieve high-precision fluid flow (or flow rate) detection. The fluid for detecting the differential pressure by the micro differential pressure sensor assembly 100 may be gas or liquid, and can be flexibly determined according to actual conditions.

For example, the micro-differential pressure sensor assembly 100 may be disposed at a mouthpiece portion of an electronic cigarette for detecting whether a user inhales through the mouthpiece portion of the electronic cigarette. If the suction nozzle part of the electronic cigarette is detected to suck air, the tobacco tar heating module of the electronic cigarette is controlled to start heating through the micro differential pressure sensor assembly 100 so as to be used by a user. If the suction of the suction nozzle part of the electronic cigarette is not detected, the tobacco tar heating module of the electronic cigarette is controlled not to operate through the micro-differential pressure sensor assembly 100, so that the heating is stopped.

In the present embodiment, the Micro differential pressure sensor assembly 100 may include a MEMS (Micro-Electro-Mechanical System) module, a processor 120, a MOS transistor 130, and a substrate 140. The MEMS module 110, the processor 120, and the MOS transistor 130 are independent devices and are relatively independently disposed on the substrate 140, and the micro differential pressure sensor assembly 100 has a good integration level, which is beneficial to the miniaturization design of products (e.g., electronic cigarettes).

The MEMS module 110 may include a first temperature detection unit 111, a second temperature detection unit 112, and a heating unit 113. The first temperature detecting unit 111, the second temperature detecting unit 112 and the heating unit 113 are disposed in a sensing region 114 of the MEMS module 110. Illustratively, the sensing region 114 of the MEMS module 110 may be the region of the dashed box shown in fig. 1.

Referring to fig. 8, the first temperature detecting unit 111 and the second temperature detecting unit 112 may be disposed at an interval in the sensing region 114 of the MEMS module 110, and the heating unit 113 is disposed between the first temperature detecting unit 111 and the second temperature detecting unit 112.

In the present embodiment, when no fluid flows in the sensing region 114 of the MEMS module 110, the temperature difference between the temperatures sensed by the first temperature detecting unit 111 and the second temperature detecting unit 112 is 0 ℃. When the fluid flows through the sensing region 114 in a predetermined direction, the temperature difference between the temperatures sensed by the first temperature detecting unit 111 and the second temperature detecting unit 112 is not 0 ℃.

The designated direction may be a direction in which the first temperature detection unit 111 points to the second temperature detection unit 112, or a direction in which the second temperature detection unit 112 points to the first temperature detection unit 111, and may be flexibly determined according to actual conditions, as long as it can be ensured that when no fluid flows in the sensing region 114, the temperature difference between the temperatures sensed by the first temperature detection unit 111 and the second temperature detection unit 112 is 0 ℃, and when fluid flows, the temperature difference between the temperatures sensed by the first temperature detection unit 111 and the second temperature detection unit 112 is not 0 ℃.

For example, referring to fig. 8 again, the distances between the first temperature detecting unit 111 and the second temperature detecting unit 112 and the heating unit 113 are the same or close to the same, which is favorable for ensuring that the temperature difference between the temperatures sensed by the first temperature detecting unit 111 and the second temperature detecting unit 112 is 0 ℃ when no fluid flows in the sensing region 114.

For example, when the micro differential pressure sensor assembly 100 operates, the heating unit 113 may be heated after being energized, and the first and second

temperature detection units

111 and 112 may sense an ambient temperature. If there is a fluid flowing through the sensing region 114 in the direction shown in fig. 9 (or fig. 5 to 8), the temperature sensed by the first temperature detecting unit 111 is lower than the temperature sensed by the second temperature detecting unit 112, and at this time, the processor 120 may calculate a temperature difference between the temperatures sensed by the first temperature detecting unit 111 and the second temperature detecting unit 112, where the temperature difference is not zero. If no fluid flows (for example, the first temperature detection unit 111 and the second temperature detection unit 112 are located in the closed space), the temperature difference between the temperatures sensed by the first temperature detection unit 111 and the second temperature detection unit 112 is 0 ℃.

Referring to fig. 10, the first temperature detecting unit 111, the second temperature detecting unit 112 and the heating unit 113 are all connected to the processor 120, and the first temperature detecting unit 111 and the second temperature detecting unit 112 can send the sensed temperature data to the processor 120. The processor 120 may control the operation state of the heating unit 113, for example, the processor may control the heating unit 113 to heat, or stop heating.

Referring to fig. 10 again, the MOS transistor 130 may be a P-type MOS transistor, and the Gate (Gate, G) and the Source (Source, S) of the MOS transistor 130 may be connected to corresponding pins of the processor 120. The Drain (Drain, D) of the MOS transistor 130 can be connected to the controlled module 150. The source of the MOS transistor may also be connected to a power supply, which may be used to power the controlled module 150. Of course, the power source may also power other modules, for example, the heating unit 113, the processor 120, etc.

In this way, the processor 120 can control the level (voltage) of the gate of the MOS transistor 130 according to the temperature difference sensed by the first temperature detecting unit 111 and the second temperature detecting unit 112, so as to turn on or off the source and the drain of the MOS transistor 130. In addition, the processor 120 may also adjust the current magnitude between the MOS transistor and the controlled module 150 by adjusting the gate voltage of the MOS transistor.

Understandably, the processor 120 can control the source and the drain of the MOS transistor 130 to be periodically turned on and off, so as to implement power adjustment on the controlled module 150 through PWM (Pulse Width Modulation). Generally, the longer the source and drain of the MOS transistor 130 are turned on in a single period, the larger the effective current value of the controlled module 150 is, and the larger the operating power of the controlled module 150 is. The effective current value may be determined by a conventional calculation method, which is not described herein again. The temperature difference is formed when the heating unit 113 is operated and a fluid flows through the sensing region 114 of the MEMS module 110, and the MOS transistor 130 is used as a control switch of the controlled module 150.

For example, when the temperature difference is 0 ℃, the processor 120 controls the source and the drain of the MOS transistor 130 to be turned off, so that the controlled module 150 can be in an off state. When the temperature difference is not 0 ℃, the processor 120 controls the conduction of the source and the drain in the MOS transistor 130, so that the controlled module 150 can be in an operating state. The type and parameters of the MOS transistor 130 may be flexibly selected according to actual conditions, and the operating mode of the MOS transistor 130 is conventional technology, which is not described herein again.

In other embodiments, the processor 120 may directly adjust the voltage of the gate of the MOS transistor, so as to control the magnitude of the current output by the MOS transistor, so as to control the effective current value of the controlled module 150 without controlling the effective current value of the controlled module 150 through the time length of the periodic conduction.

In the above-described embodiments, the micro differential pressure sensor assembly is formed by integrating the MEMS module, the processor, and the MOS transistor on the substrate. The processor can realize the high-sensitivity detection of the flow based on the temperature difference of the first temperature detection unit and the second temperature detection unit. In addition, the processor can control the effective current value of the controlled module through the MOS tube based on the temperature difference, and the accuracy and the reliability of controlling the controlled module are improved.

For example, if the temperature sensed by the first temperature detecting unit 111 is higher than the temperature sensed by the second temperature detecting unit 112, the flow direction is: the fluid flows from the second temperature detection unit 112 to the first temperature detection unit 111. If the temperature sensed by the first temperature detecting unit 111 is lower than the temperature sensed by the second temperature detecting unit 112, the flow direction is: the fluid flows from the first temperature detecting unit 111 to the second temperature detecting unit 112. Based on this, in the electronic cigarette, the micro differential pressure sensor assembly 100 can detect the inhalation behavior and the exhalation behavior of the user. The inhaling action is inhaling from a suction nozzle of the electronic cigarette; the air-spitting behavior is that the user spits air to the suction nozzle of the electronic cigarette.

When the micro differential pressure sensor assembly 100 detects an air suction behavior, the tobacco tar heating module of the electronic cigarette is controlled to start heating; when the gas spitting behavior is detected, the tobacco tar heating module does not operate, or the heating module which is heating is controlled to stop operating so as to stop heating. Therefore, the accuracy of detecting the smoking behavior of the user can be improved, and the situation that the tobacco tar heating module continues to heat when the user exhales is avoided, so that the user experience is not influenced.

Referring to fig. 2, as an alternative embodiment, the micro differential pressure sensor assembly 100 may further include an insulating encapsulation structure 160 disposed on the substrate 140. The insulating encapsulation structure 160 encapsulates the MEMS module 110, the processor 120 and the MOS transistor 130, wherein the sensing region 114 of the MEMS module 110 is exposed from the insulating encapsulation structure 160.

When the insulating package structure 160 is disposed, the MEMS module 110, the processor 120, and the MOS transistor 130 may be plastic-packaged on the substrate 140 through a conventional plastic packaging process, so as to form the insulating package structure 160. Therein, the sensing region 114 of the MEMS module 110 needs to be exposed to the outside in order to sense the flow of the fluid more sensitively. In addition, the material of the insulating encapsulation structure 160 may be flexibly determined according to actual situations, and may be, but is not limited to, insulating plastic, insulating resin, insulating rubber, and the like.

Understandably, the insulation package structure 160 can insulate the exposed pins of the MEMS module 110, the processor 120 and the MOS transistor 130, protect the MEMS module 110, the processor 120 and the MOS transistor 130, prevent the MEMS module 110, the processor 120 and the MOS transistor 130 from being short-circuited due to the exposed pins, and prevent the MEMS module 110, the processor 120 and the MOS transistor 130 from being damaged by external force.

Referring to fig. 2 again, the insulation package structure 160 may have a trench 161, and the sensing region 114 of the MEMS module 110 is located at the bottom of the trench 161 and exposed to the outside.

Understandably, trenches 161 penetrate through opposite ends of the insulating encapsulation structure 160 to serve as flow guiding grooves. Because the sensing region 114 is located at the bottom of the trench 161, the sensing region 114 is not easily damaged by external force, that is, the trench 161 can guide the fluid to improve the sensitivity and detection accuracy of the MEMS module 110 for sensing the fluid flow, and in addition, the sensing region 114 of the MEMS module 110 can be protected, which is beneficial to improving the reliability of the product.

Referring to fig. 3a and 3b, the micro differential pressure sensor assembly 100 may further include a housing 170 disposed on the substrate 140. Fig. 3a can be understood as a schematic view when the housing 170 covers the substrate 140, and fig. 3b can be understood as a schematic view when the housing 170 is separated from the substrate 140. The housing 170 is used to cover the insulating encapsulation structure 160, and a cavity (for the sake of distinction, referred to as a first cavity) is formed between the housing 170 and the insulating encapsulation structure 160. The housing 170 is provided with a first through hole 171 and a second through hole 172 penetrating the first cavity, and the housing 170 and the insulating package structure 160 form a channel for fluid to flow through the first through hole 171, the second through hole 172 and the first cavity, wherein the sensing region 114 is located in the housing 170.

In this embodiment, the shape of the housing 170 can be flexibly determined according to actual conditions. For example, referring to fig. 3b, the housing 170 may be a square cover having an opening, and the square cover is disposed on the substrate 140 through the opening.

The housing 170 may protect the sensing region 114 of the MEMS. The number and the arrangement position of the first through hole 171 and the second through hole 172 can be flexibly determined according to actual situations, as long as the sensing region 114 is exposed in the channel formed by the first through hole 171 and the second through hole 172, so that the sensing region 114 can sense whether fluid flows in the channel.

For example, referring to fig. 3b, the first through hole 171 may be disposed on a sidewall of the housing 170 and is used for communicating with a side port of the trench 161 of the insulation package structure 160, as shown in fig. 3 a. A second through hole 172 may be provided at the top of the housing 170 in communication with the first cavity in which the groove 161 is located.

In other embodiments, the first and second through

holes

171 and 172 may be disposed on two opposite side walls of the housing 170 and respectively communicate with both ends of the groove 161.

Referring to fig. 4, in the present embodiment, the housing 170 may be a cover plate for covering the trench 161 on the insulating encapsulation structure 160. The channel 161 and the cover plate may form a channel for fluid communication. The two outlets of the passage may be respectively a first through hole 171 and a second through hole 172. Wherein the cover may protect the sensing region 114 on the MEMS module 110.

Referring to fig. 4 and 5, in the present embodiment, the MEMS module 110 may include a substrate 116 and an insulating layer 115, the first temperature detecting unit 111, the second temperature detecting unit 112 and the heating unit 113 are disposed on the insulating layer 115, and an edge portion of the insulating layer 115 is disposed on the substrate 140 through the substrate 116. The substrate 116 may be a ring structure, the insulating layer 115, the substrate 116 and the base plate 140 form a cavity (the cavity is referred to as a second cavity), and the base plate 140 is provided with a third through hole 141 communicating with the second cavity.

In this embodiment, the first temperature detecting unit 111, the second temperature detecting unit 112 and the heating unit 113 are all disposed on the insulating layer 115, and the first temperature detecting unit 111, the second temperature detecting unit 112 and the heating unit 113 may not be exposed to the outside, so that the effects of water or pollutants are favorably isolated, and the anti-interference capability of the first temperature detecting unit 111 and the second temperature detecting unit 112 on the detection of the ambient temperature is improved.

After the heating unit 113 is heated, air in the second cavity below the insulating layer 115 expands, so that the difference between the upper and lower pressure of the insulating layer 115 is easily increased, and the third through hole 141 can be used for preventing the cavities on the upper and lower sides of the insulating layer 115 from generating pressure difference due to heating.

Referring to fig. 6, the MEMS module 110 further includes a differential pressure detection unit 190, and the differential pressure detection unit 190 is disposed in the sensing region 114 of the MEMS module 110. The processor 120 may control the heating unit 113 to heat upon receiving a target electrical signal sensed by the differential pressure detection unit 190, wherein the target electrical signal is an electrical signal generated by the differential pressure detection unit 190 when it is sensed that a fluid flows through the sensing region 114.

In the present embodiment, the differential pressure detecting unit 190 is an electronic component having lower power consumption than the heating unit 113. For example, the differential pressure detection unit 190 may be a piezoresistive monitoring unit or a piezoelectric monitoring unit 191.

In the present embodiment, the differential pressure detection unit 190 may preliminarily detect whether a fluid flows through the sensing surface of the MEMS module 110. When no fluid flows through the sensing region 114, the heating unit 113 is not operated to reduce power consumption. The processor 120 controls the operation of the heating unit 113 when the differential pressure detecting unit 190 outputs the target electric signal, and then performs high-precision detection of the magnitude of the differential pressure or the air flow by using the heating unit 113. In this way, the problem of high power consumption caused by the fact that the heating unit 113 needs to be continuously heated even when no fluid flows can be solved, and high-precision and low-power consumption detection of the flow can be achieved.

Understandably, the differential pressure detection unit 190 may be integrated on the MEMS module 110. For example, referring to fig. 6, the differential pressure detecting unit 190 may be disposed in the insulating layer 115, and may determine whether a fluid flows in the sensing region 114 by sensing whether the insulating layer 115 is deformed.

Referring to fig. 6 again, if the fluid in the trench 161 does not flow, the insulating layer 115 will not deform. If the fluid in the trench 161 flows to form a second cavity by the insulating layer 115, the substrate 116 and the substrate 140, the pressure difference between the second cavity and the trench 161 is changed, so that the insulating layer 115 is easily deformed. The piezoresistive monitoring unit and the piezoelectric monitoring unit 191 may generate corresponding electrical signals due to the deformation of the insulating layer 115. In this way, the processor 120 may determine whether the insulating layer 115 is deformed based on the electrical signal output by the piezoresistive monitoring unit or the piezoelectric monitoring unit 191.

Referring to fig. 4 and fig. 7, in the present embodiment, at least one of the first through hole 171, the second through hole 172, and the third through hole 141 may be provided with a waterproof breathable film. For example, the first through hole 171, the second through hole 172, and the third through hole 141 are respectively provided with a waterproof vent film 181, a waterproof vent film 182, and a waterproof vent film 183. The waterproof breathable film can allow air to permeate, and can filter and isolate water mist and oil smoke, so that the water mist, the oil smoke and the like are prevented from being attached to the sensing area 114, and the detection accuracy is improved.

Referring to fig. 6 and 9, fig. 9 can be seen as a schematic diagram of the distribution of the corresponding electronic components on the sensing region 114 in a top view. The piezoelectric monitoring unit 191 may be a ring structure and disposed on the insulating layer 115 of the MEMS module 110. The piezoelectric monitoring unit 191 may detect deformation or stress change of the insulating layer 115, and in the case where the insulating layer 115 is deformed or the stress change occurs, generate an electrical signal and output the electrical signal as a target electrical signal to the processor 120. The processor 120, upon receiving the target electrical signal, can determine that there is fluid flowing through the sensing region 114, and then control the heating unit 113 to start operating and heating.

The piezoresistive monitoring cells may be polysilicon piezoresistive strips, or single crystal silicon piezoresistive strips. For example, the piezoresistive monitoring units may be deployed by way of a wheatstone bridge. That is, the resistors in the wheatstone bridge are replaced with the piezoresistive strips in this embodiment to form a piezoresistive monitoring unit. The piezoresistive monitoring unit can change the resistance value when the insulating layer 115 is deformed or has a stress change, so as to change the magnitude of the output current, and the processor 120 can regard the change of the current as a target electrical signal.

The Piezoelectric monitoring unit 191 may be, but not limited to, a Piezoelectric film sensor, or a Piezoelectric ceramic (PTZ) sensor, and may generate an electrical signal in the case that the insulating layer 115 is deformed or a stress is changed.

The heating unit 113 may be, but is not limited to, a heating metal bar, a heating metal wire, a PN junction heater that can achieve heating, poly (mono) silicon heavily doped that can achieve heating, etc.

The first and second

temperature detection units

111 and 112 may be the same type or different types of temperature detection units. The temperature detecting unit may be, but is not limited to, a PN junction temperature sensor, a temperature sensor of a metal type sensitive to temperature, or the like.

In the present embodiment, the processor 120 may be, but is not limited to, a Microprocessor Unit (MPU), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), and the like, and may be a device for Signal Processing.

The application also provides an electronic device. The electronics can include the controlled module 150 and the micro differential pressure sensor assembly 100 described in the embodiments above. The electronic device may be any small size device that requires flow (or fluid flow) detection.

The drain of the MOS transistor 130 may be connected to the controlled module 150. The micro differential pressure sensor assembly 100 can control the conduction of the source and the drain of the MOS transistor 130 by using the processor 120, so as to conduct the controlled module 150; alternatively, the source and the drain of the control MOS transistor 130 are disconnected, so that the controlled module 150 is turned off. The controlled module 150 as a controlled module can be flexibly determined according to actual conditions.

For example, referring to fig. 10, the electronic device may be an electronic cigarette, and the controlled module 150 is a tobacco tar heating module. The processor 120 may control the heating power of the soot heating module by conducting the MOS tube 130 for a long time in a unit time. The processor 120 may control the source and the drain of the MOS transistor 130 to be always turned on, and at this time, the heating power of the soot heating module may be maximized. Or, the processor 120 may control the source and the drain of the MOS transistor 130 to be turned on and off periodically, so as to implement power adjustment on the soot heating module. In one period, the duration of on or off can be flexibly determined according to the actual situation. The duration of the single period can be flexibly determined according to actual conditions, and for example, the single period can be shorter duration such as 500 milliseconds, 1 second and the like.

In this embodiment, the heating unit 113 may continuously heat during the operation, when an air flow passes through the sensing region 114 of the MEMS module 110, a temperature distribution of the insulating layer 115 may be changed, wherein a corresponding relationship exists between a temperature difference and an air flow, so the processor 120 may obtain the air flow by detecting the temperature difference between the first temperature detecting unit 111 and the second temperature detecting unit 112, and then adjust the periodic conduction duration of the source and the drain of the MOS transistor 130 based on the air flow, thereby adjusting the power of the soot heating module. For example, the greater the airflow, the longer the source and drain of the control MOS transistor 130 are conducting in a single cycle, so that the more power the soot heating module.

For example, when the micro differential pressure sensor assembly 100 is applied to the electronic cigarette, the micro differential pressure sensor assembly can be directly installed in an air passage of the electronic cigarette without an additional air passage design, so that the cost is saved. In addition, the piezoresistive or piezoelectric monitoring unit 191 is used as the differential pressure detection unit 190 with lower precision but low power consumption, so that the standby monitoring can be carried out for a long time; when the electronic cigarette works, the heating unit 113, the first temperature detection unit 111 and the second temperature detection unit 112 are used as a heat conduction type flow detection unit, and the gas flow, namely the size of the smoking force channel, can be detected with high sensitivity and high precision, so that the requirements of the electronic cigarette on low power consumption and high measurement precision are met.

Traditional electron cigarette adopts single flow sensor, and the resolution ratio is lower, and the resolution ratio of little differential pressure sensor subassembly 100 in this application embodiment is high, and it can be the linear relation to go out cigarette volume and smoking power way, in addition, the air current direction can be distinguished to first temperature detecting element 111 and second temperature detecting element 112's temperature size, if application in the electron cigarette, can discern and breathe in and blow the action, thereby the prevention is blown and is triggered the oil smoke heating module operation of electron cigarette by mistake, promote user experience and product reliability.

In the long-term use process of the traditional electronic cigarette, tobacco tar is accumulated and attached to the surface of the sensor in the form of atomized steam, so that the sensor chip is invalid, and whether fluid flow exists or not cannot be detected. In addition, the contamination of the sensor by the smoke can not be distinguished by adopting a single flow sensor.

In the present application, the piezoresistive monitoring unit or the piezoelectric monitoring unit 191 senses the change of the externally applied pressure through the stress change; the heat conduction type flow rate detection unit formed by the first temperature detection unit 111, the second temperature detection unit 112 and the heating unit 113 changes the temperature distribution of the sensing area 114 because the fluid flows through the sensing area 114, and the size of the passing air flow is obtained by monitoring the temperature change of the sensing area 114. Since the piezoresistive (or piezoelectric) and thermal conductive working principles are different and the sensitivity to oil stains is different, by comparing the output relationship between the piezoresistive monitoring unit and the temperature detecting unit (referring to the first temperature detecting unit 111 or the second temperature detecting unit 112), it can be determined whether the sensing area 114 or the MEMS module 110 is contaminated by the smoke. For example, in the case where the sensing region 114 is free from smoke contamination, the ratio of the current values output by the piezoresistive monitoring unit and the temperature detection unit is within a set range. If the ratio is not within the set range, it indicates that the sensing region 114 or the MEMS module 110 is contaminated by soot. The setting range may be flexibly determined according to actual conditions, and is not specifically limited herein.

When the processor 120 determines that the sensing region 114 or the MEMS module 110 is contaminated by the soot, the contaminated chip may be subjected to evaporation of the soot through physical heating, and the current value output by the temperature detection unit may be corrected and calibrated through a preset algorithm. The preset algorithm is that the current value of the temperature detection unit is corrected by utilizing the corresponding relation of the current value of the piezoresistive monitoring unit and the current values of the piezoresistive monitoring unit and the temperature detection unit when oil pollution exists, and then the temperature value sensed by the temperature detection unit is determined by utilizing the corrected current value. In this way, the accuracy of the airflow detection can be improved even when the sensing area 114 is contaminated with oil.

Through the above description of the embodiments, those skilled in the art will clearly understand that the present application can be implemented by hardware, and also by software plus a necessary general hardware platform.

In summary, in the present embodiment, the micro differential pressure sensor assembly is formed by integrating the MEMS module, the processor and the MOS transistor on the substrate. The processor can realize the high-sensitivity detection of the flow based on the temperature difference of the first temperature detection unit and the second temperature detection unit. In addition, the processor can control the effective current value of the controlled module through the MOS tube based on the temperature difference, and the accuracy and the reliability of controlling the controlled module are improved.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus, system, and method may be implemented in other ways. The apparatus, system, and method embodiments described above are illustrative only, as the flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. In addition, functional modules in the embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A micro differential pressure sensor assembly is characterized by comprising a substrate, and an MEMS module, a processor and an MOS tube which are independently arranged on the substrate;

the MEMS module comprises a first temperature detection unit, a second temperature detection unit and a heating unit, wherein the first temperature detection unit, the second temperature detection unit and the heating unit are all arranged in a sensing area of the MEMS module;

the processor is used for controlling the effective current value of the controlled module through the MOS tube according to the temperature difference sensed by the first temperature detection unit and the second temperature detection unit, wherein the temperature difference is formed when the heating unit operates and fluid flows through the sensing area of the MEMS module, and the MOS tube is used as a control switch of the controlled module.

2. The micro differential pressure sensor assembly of claim 1, further comprising an insulating encapsulation structure disposed on the substrate, the insulating encapsulation structure encapsulating the MEMS module, the processor, and the MOS transistors, wherein the sensing region of the MEMS module is exposed from the insulating encapsulation structure.

3. The micro differential pressure sensor assembly according to claim 2, wherein the insulating encapsulation structure has a trench, and the sensing region of the MEMS module is located at a bottom of the trench and exposed to the outside.

4. The micro differential pressure sensor assembly according to claim 2 or 3, further comprising a housing disposed on the substrate for covering the insulating encapsulation structure, and having a cavity therebetween;

5. The differential pressure sensor assembly of claim 4, wherein the first and/or second through-holes are provided with a water and gas permeable membrane.

6. The micro differential pressure sensor assembly according to claim 1, wherein the MEMS module further includes a substrate and an insulating layer, the first temperature detecting unit, the second temperature detecting unit and the heating unit are disposed on the insulating layer, an edge portion of the insulating layer is disposed on the base plate through the substrate, the insulating layer, the substrate and the base plate form a cavity, and the base plate is provided with a third through hole communicating with the cavity.

7. The micro differential pressure sensor assembly of claim 1, wherein the MEMS module further comprises a differential pressure detection cell disposed at the sensing region of the MEMS module;

8. The micro differential pressure sensor assembly of claim 7, wherein the differential pressure detection unit is a piezoresistive monitoring unit or a piezoelectric monitoring unit.

9. The micro differential pressure sensor assembly according to claim 1, wherein the first temperature detection unit and the second temperature detection unit are spaced apart from each other at the sensing region of the MEMS module, and the heating unit is located between the first temperature detection unit and the second temperature detection unit.

10. An electronic device, characterized in that the electronic device comprises a controlled module and the micro differential pressure sensor assembly as claimed in any one of claims 1 to 9, wherein a MOS transistor in the micro differential pressure sensor assembly is connected with the controlled module for being used as a control switch of the controlled module.

11. The electronic device of claim 10, wherein the electronic device is an electronic cigarette, and the controlled module comprises a tobacco tar heating module, wherein the processor is configured to control an operating state of the tobacco tar heating module via the MOS tube.