CN211553167U

CN211553167U - Packaging structure of micro differential pressure module

Info

Publication number: CN211553167U
Application number: CN202020447018.7U
Authority: CN
Inventors: 肖素艳
Original assignee: Memsensing Microsystems Suzhou China Co Ltd
Current assignee: Memsensing Microsystems Suzhou China Co Ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2020-09-22
Anticipated expiration: 2030-03-31

Abstract

The utility model discloses an encapsulation structure of differential pressure module belongs to differential pressure measurement technical field. The utility model provides a packaging structure of differential pressure module includes differential pressure sensor module, differential pressure sensor module includes the substrate, first temperature measurement mechanism, micro-heater and second temperature measurement mechanism, be provided with gaseous miniflow way in the differential pressure sensor module, gaseous miniflow way forms inlet port and venthole on the surface of differential pressure sensor module, first temperature measurement mechanism, micro-heater and second temperature measurement mechanism pass through the semiconductor technology integration on the substrate, and set up in gaseous miniflow way along the air current direction equidistant in proper order. The gas micro-channel of the packaging structure of the micro-differential pressure module based on the thermal flow principle has high air resistance, so that the application range is improved, the size and the cost of the whole packaging structure are reduced by realizing packaging through a semiconductor process, and the reliability is improved.

Description

Packaging structure of micro differential pressure module

Technical Field

The utility model relates to a little differential pressure measures technical field, especially relates to an encapsulation structure of little differential pressure module.

Background

With the rapid development of electronic technology, the measurement and control of micro differential pressure are more and more widely applied to electronic devices and household appliances. At present, the micro differential pressure module, which is a main component used for measuring micro differential pressure in the market, mainly includes two types, wherein one type is mechanical type, and the micro differential pressure module is commonly used in household appliances such as gas water heaters, wall-mounted furnaces and the like as a protection device for ensuring normal operation of the household appliances. The micro differential pressure module mainly comprises a skin membrane for separating a positive pressure cavity from a negative pressure cavity, and when a pressure source exists, the skin membrane positioned in front of the positive pressure cavity and the negative pressure cavity can move, so that a micro switch is triggered to achieve the purpose of opening and closing. The mechanical wind pressure switch has low precision, and the coating film is easy to be polluted and aged, and has poor reliability and stability, so that the frequency of the wind pressure switch having faults is very high.

Another differential pressure module is a differential pressure sensor based on pressure sensitive principle, which is commonly used in electronic cigarettes to ensure proper smoke volume. In electronic cigarette applications, the amount of smoke is often determined by the amount of differential pressure created by the amount of suction drawn by the user, which is typically less than 500 Pa. The differential pressure sensor based on pressure sensitivity has poor zero stability, and particularly has low sensitivity and poor measurement accuracy when measuring ultra-low differential pressure below 500 Pa.

In addition to the two structures, a third micro differential pressure module for measuring micro differential pressure based on a thermal flow principle is also available on the market, and although the micro differential pressure module can overcome the defects of the two micro differential pressure modules, the structure adopts a low air resistance structure and a method for directly measuring flow, and is only suitable for micro differential pressure measurement of clean gas. In addition, the micro differential pressure module based on the thermal flow principle is large in size during packaging, so that the cost is increased, and the consistency and the reliability of products are reduced.

Therefore, how to provide a package structure of a micro-differential pressure module based on the thermal flow principle, which can overcome the above-mentioned shortcomings, is a technical problem that needs to be solved at present.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a packaging structure of differential pressure module not only has high gas resistance nature, and application range is wider, and the size is little, with low costs, the reliability is high.

To achieve the purpose, the utility model adopts the following technical proposal:

a packaging structure of a micro differential pressure module comprises:

the micro differential pressure sensor module is internally provided with a gas micro channel, and the gas micro channel forms an air inlet and an air outlet on the surface of the micro differential pressure sensor module;

the micro differential pressure sensor module further comprises a substrate, a first temperature measuring mechanism, a micro heater and a second temperature measuring mechanism, wherein the first temperature measuring mechanism, the micro heater and the second temperature measuring mechanism are integrated on the substrate through a semiconductor process and are sequentially arranged in the gas micro channel at equal intervals along the gas flow direction.

Preferably, the micro differential pressure sensor module further comprises a cover plate, the cover plate is buckled on the top of the substrate, part of the gas micro flow channel is located in the cover plate, and the gas inlet and the gas outlet are formed in the surface of the cover plate or the substrate.

Preferably, the substrate is provided with a first micro-channel and a second micro-channel in a penetrating manner along the height direction;

the cover plate and form the third microchannel between the top surface of substrate, first microchannel third microchannel and second microchannel communicate in proper order and form gaseous microchannel, first temperature measurement mechanism the micro heater with second temperature measurement mechanism sets up along the air current direction is equidistant in the third microchannel.

Preferably, a first micro-channel and a second micro-channel are arranged on the substrate, one end of the first micro-channel forms the air inlet hole on the left side wall of the substrate, the other end of the first micro-channel penetrates through the top surface of the substrate, one end of the second micro-channel forms the air outlet hole on the right side wall of the substrate, and the other end of the second micro-channel penetrates through the top surface of the substrate;

Preferably, the gas microchannel is provided between the substrate and the cover plate, and the gas inlet hole is formed on one side wall of the cover plate, and the gas outlet hole is formed on the other side wall of the cover plate.

Preferably, the encapsulation structure of the micro differential pressure module further includes:

the base plate, the substrate sets up on the base plate, the interval is provided with fourth miniflow channel and fifth miniflow channel on the base plate, the one end of fourth miniflow channel with gaseous miniflow channel the inlet port intercommunication, the other end with the air inlet intercommunication of differential pressure module's packaging structure, the one end of fifth miniflow channel with gaseous miniflow channel the venthole intercommunication, the other end with differential pressure module's packaging structure's gas outlet intercommunication.

a base plate, the substrate disposed on the base plate.

the base plate, the substrate sets up on the base plate, the substrate with the juncture of base plate is provided with two at least breachs to form inlet port with the venthole.

Preferably, the air inlet and the air outlet are both disposed on the substrate.

Preferably, the fourth micro flow channel is communicated with the air inlet through a first pipeline; and/or

And the fifth micro-channel is communicated with the air outlet through a second pipeline.

the shell is buckled on the base plate, the micro differential pressure sensor module is located in the shell, an air cavity is formed between the inner wall of the shell and the outer wall of the micro differential pressure sensor module and comprises an air inlet cavity and an air outlet cavity which are isolated from each other, the shell is provided with the air inlet and the air outlet, the air inlet is communicated with the air inlet cavity, and the air outlet is communicated with the air outlet cavity.

Preferably, the housing comprises a top shell, the top shell is buckled above the base plate, a separation plate for separating the air inlet cavity from the air outlet cavity is arranged in the top shell, and the air inlet and the air outlet are both positioned on the top shell and on two sides of the separation plate.

Preferably, the isolation plate is a U-shaped plate, the U-shaped plate comprises a transverse plate and vertical plates convexly arranged at two ends of the transverse plate, the transverse plate is positioned between the top surface of the cover plate and the top wall of the top shell, and the two vertical plates are respectively positioned between the substrate, two coplanar side walls of the cover plate and two inner side walls of the top shell; or

The division board is the plate structure, the plate structure be located the differential pressure sensor module with between the export of fifth miniflow channel, just the roof of plate structure, two lateral walls respectively with roof, two inside wall sealing connection in the roof shell, the diapire of plate structure with the top surface sealing connection of base plate.

Preferably, the shell comprises a top shell and a bottom shell, the top shell is buckled above the base plate, the micro differential pressure sensor module is located in the top shell, the bottom shell is buckled below the base plate, the top shell and the outer wall of the micro differential pressure sensor module form the air inlet cavity, the inner space of the bottom shell forms the air outlet cavity, a channel for communicating the air inlet cavity with the air outlet cavity is formed in the base plate, the air inlet is formed in the top shell, and the air outlet is formed in the bottom shell.

Preferably, the fourth micro flow channel is a U-shaped flow channel, and includes a first vertical flow channel, a first transverse flow channel and a second vertical flow channel, which are connected in sequence, the first vertical flow channel is communicated with the air inlet of the gas micro flow channel, and the second vertical flow channel is communicated with the air inlet of the packaging structure of the micro differential pressure module; and/or

The fifth micro flow channel is a U-shaped flow channel and comprises a third vertical flow channel, a second transverse flow channel and a fourth vertical flow channel which are sequentially connected, the third vertical flow channel is communicated with the air outlet of the gas micro flow channel, and the fourth vertical flow channel is communicated with the air outlet of the packaging structure of the micro differential pressure module.

Preferably, the substrate is provided with a cavity.

Preferably, a sixth micro flow channel is disposed on the substrate, and the sixth micro flow channel penetrates through the substrate and is communicated with the cavity.

Preferably, the pore size of the fourth micro flow channel is not more than 0.5 mm; and/or

The aperture of the fifth micro-channel is not more than 0.5 mm; and/or

The airflow impedance of the fourth micro-channel is not less than 3 kPa/sccm; and/or

The gas flow resistance of the fifth micro flow channel is not less than 3 kPa/sccm.

The utility model has the advantages that:

the utility model provides an encapsulation structure of differential pressure module, this encapsulation structure of differential pressure module includes differential pressure sensor module, differential pressure sensor module includes the substrate, first temperature measurement mechanism, micro-heater and second temperature measurement mechanism, be provided with gaseous miniflow way in the differential pressure sensor module, gaseous miniflow way forms inlet port and venthole on the surface of differential pressure sensor module, first temperature measurement mechanism, micro-heater and second temperature measurement mechanism pass through the semiconductor technology integration on the substrate, and set up in gaseous miniflow way along the air current direction equidistant in proper order. This packaging structure of differential pressure module based on hot type flow principle is through being provided with gaseous microchannel in differential pressure sensor module, and gaseous microchannel has high gas resistance to application range has been improved, and through semiconductor technology with first temperature measurement mechanism, microheater and the integration of second temperature measurement mechanism on the substrate, reduced whole packaging structure's size and cost, improved the reliability.

Drawings

Fig. 1 is a first cross-sectional view of a package structure of a micro differential pressure module according to an embodiment of the present invention;

fig. 2 is a second cross-sectional view of a package structure of a micro differential pressure module according to an embodiment of the present invention;

fig. 3 is a cross-sectional view of a package structure of a micro differential pressure module according to an embodiment of the present invention, taken along a direction a-a in fig. 1;

fig. 4 is a schematic structural diagram of a package structure of a micro differential pressure module according to an embodiment of the present invention, in which a partition plate is a flat plate;

fig. 5 is a schematic structural diagram of a first micro differential pressure module according to a second embodiment of the present invention, in which a bottom shell is disposed;

fig. 6 is a second schematic structural view illustrating a bottom case of the packaging structure of the micro differential pressure module according to the second embodiment of the present invention;

fig. 7 is a cross-sectional view of a package structure of a micro differential pressure module according to a third embodiment of the present invention;

fig. 8 is a cross-sectional view of an encapsulation structure of a micro differential pressure module according to a fourth embodiment of the present invention.

In the figure:

1. a substrate; 101. a cavity; 2. a cover plate; 3. a gas microchannel; 301. a first microchannel; 302. a second microchannel; 303. a third microchannel; 4. a micro-heater; 5. a first temperature measuring mechanism; 6. a second temperature measuring mechanism; 7. a substrate; 701. a fourth microchannel; 702. a fifth microchannel; 703. a sixth microchannel; 8. a top shell; 9. a separator plate; 10. an air inlet cavity; 11. an air outlet cavity; 12. an air inlet; 13. an air outlet; 14. a bottom shell.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example one

The embodiment provides an encapsulation structure of a micro differential pressure module, which is a main component of a micro differential pressure measurement device for accurately measuring micro differential pressure based on a thermal flow principle. Compared with a micro differential pressure module based on a thermal flow principle in the prior art, the packaging structure of the micro differential pressure module provided by the embodiment has the advantages of high air resistance, wide application range, small packaging size, low cost and higher product consistency and reliability.

As shown in fig. 1 to 3, the package structure of the micro differential pressure module includes a micro differential pressure sensor module. The micro differential pressure sensor module is a main measurement unit of an encapsulation structure of the micro differential pressure module, and specifically comprises a substrate 1, a micro heater 4, a first temperature measurement mechanism 5 and a second temperature measurement mechanism 6. Be provided with gaseous microchannel 3 in the differential pressure sensor module, the one end of gaseous microchannel 3 forms the inlet port on the surface of differential pressure sensor module, the other end forms the venthole on the surface of differential pressure sensor module, the inlet port of gaseous microchannel 3 can regard as the air inlet 12 of the packaging structure of whole differential pressure module to use, also can communicate with the air inlet 12 of the packaging structure of differential pressure module through other passageways, the venthole of gaseous microchannel 3 can regard as the gas outlet 13 of the packaging structure of whole differential pressure module to use, also can communicate with the gas outlet 13 of the packaging structure of differential pressure module through other passageways. The first temperature measuring mechanism 5, the micro-heater 4, and the second temperature measuring mechanism 6 are integrated on the substrate 1 by a semiconductor process, and are arranged in the gas microchannel 3 at equal intervals in the gas flow direction inside the gas microchannel 3.

When no gas flows through the gas micro-channel 3 of the micro differential pressure sensor module, the temperature around the micro-heater 4 is distributed symmetrically, and the temperature values of the first temperature measuring mechanism 5 and the second temperature measuring mechanism 6 which are positioned at the upstream and the downstream of the micro-heater 4 are equal. After the gas enters the gas micro-channel 3, the gas sequentially passes through the first temperature measuring mechanism 5, the micro-heater 4 and the second temperature measuring mechanism 6, and based on the heat conduction principle, when the gas passes through the surface of the micro-heater 4, part of heat is taken away due to the flow of the gas, so that temperature fields on two sides of the micro-heater 4 along the direction of the gas channel are changed, and the temperature on two sides of the micro-heater 4 is asymmetric. That is, when there is an air flow passing through the micro-heater 4, the temperatures measured at the first temperature measuring mechanism 5 and the second temperature measuring mechanism 6 are different with a temperature difference therebetween. Also, based on the principle of heat conduction, the greater the flow rate of the gas flowing across the surface of the micro-heater 4, the more significant the asymmetry of the temperatures measured at the first temperature measuring mechanism 5 and the second temperature measuring mechanism 6, and the temperature difference has a fixed functional relationship with the flow rate. The measurement principle of the existing thermal flowmeter is based on the functional relationship, which is related to the measurement circuit connected to the first temperature measurement mechanism 5 and the second temperature measurement mechanism 6, and is the prior art, and is not described herein again.

Because the gas micro-channel 3 of the micro-differential pressure sensor module adopts a micro-channel with high air resistance, the flow velocity passing through the surface of the micro-heater 4 is extremely low, and the performance of resisting the pollution of oil smoke, particles, water vapor and the like can be greatly improved. Compared with other structures, the composite material has better pollution resistance, so that the application range is not limited to the application of clean gas media and clean environment, and the composite material is particularly suitable for the application that the micro-differential pressure of certain oil stain, particles and water vapor is lower than 500Pa, such as electronic smoke volume control, air pressure control of a gas water heater and a wall-mounted boiler, air purifier filter screen detection, HVAC (heating, ventilation and air conditioning) and the like, and the application range of the whole structure is greatly enlarged. In addition, the packaging structure integrates the first temperature measuring mechanism 5, the micro-heater 4 and the second temperature measuring mechanism 6 on the substrate 1 by adopting a semiconductor process, so that the size and the cost of the whole packaging structure are reduced, and the consistency and the reliability of the whole structure are improved.

In addition, the micro differential pressure measuring device of the packaging structure comprising the micro differential pressure module needs to be matched with a temperature difference flow velocity conversion unit and a flow velocity pressure conversion unit to obtain a specific value of the measured micro differential pressure. Specifically, a control program and a measurement circuit including the above functional relationship are provided in the temperature difference/flow rate conversion unit, the temperature difference/flow rate conversion unit is electrically connected to both the first temperature measurement mechanism 5 and the second temperature measurement mechanism 6, and the control program is operated to obtain the flow rate of the gas in the gas microchannel 3 corresponding to the temperature difference between the first temperature measurement mechanism 5 and the second temperature measurement mechanism 6. Namely, the gas flow rate can be obtained through the temperature asymmetry, and when the temperature difference between the first temperature measuring mechanism 5 and the second temperature measuring mechanism 6 is larger, a larger gas flow rate can be obtained; and a smaller flow rate of the air flow can be obtained as the temperature difference between the first temperature measuring means 5 and the second temperature measuring means 6 is smaller. Since the control program can be a control program in an existing thermal flow meter, which is the prior art, it is not described herein again.

The flow velocity pressure conversion unit can obtain the micro-pressure difference between the air inlet hole and the air outlet hole of the gas micro-channel 3 corresponding to the obtained gas flow velocity according to the energy conservation principle, namely, the micro-pressure difference between the air inlet 12 of the packaging structure of the micro-pressure difference module and the air outlet 13 of the packaging structure of the micro-pressure difference module. The formula of the energy conservation principle is as follows:

wherein ρ, g and h are fixed values, v is the flow velocity of the air flow, and P represents a micro differential pressure. The micro differential pressure can be obtained according to the energy conservation principle and the gas flow velocity, and when the gas flow velocity flowing through the gas micro flow channel 3 is larger, the micro differential pressure between the gas inlet 12 and the gas outlet 13 is larger; and the smaller the flow rate of the gas flowing through the gas microchannel 3, the smaller the differential pressure between the gas inlet 12 and the gas outlet 13.

The temperature difference flow velocity conversion unit and the flow velocity pressure conversion unit can be both controllers, the controllers can be centralized or distributed controllers, for example, the controllers can be a single-chip microcomputer or be formed by a plurality of distributed single-chip microcomputers, and specific control programs can be operated in the single-chip microcomputers, so that relevant parameters such as airflow velocity v and micro differential pressure p can be obtained quickly and accurately.

As shown in fig. 1, in the present embodiment, the micro differential pressure sensor module further includes a cover plate 2. The substrate 1 and the cover plate 2 are packaged together at the wafer level, thereby forming a micro differential pressure sensor module. Specifically, the substrate 1 is a bulk structure made of silicon material, and a first micro flow channel 301 and a second micro flow channel 302 are arranged on the substrate in a penetrating manner along the height direction. Alternatively, the first micro flow channel 301 and the second micro flow channel 302 are disposed throughout in the height direction of the substrate 1. Further optionally, the first micro fluidic channel 301 and the second micro fluidic channel 302 are cylindrical channels arranged in parallel. The columnar passage is easy to manufacture and convenient for gas circulation.

The cover plate 2 is snapped on top of the substrate 1 and a third microchannel 303 is formed between the cover plate 2 and the top surface of the substrate 1. Specifically, the cover plate 2 is a cover-shaped structure made of silicon material, a U-shaped groove structure formed by a silicon micromachining semiconductor process is arranged on the lower bottom surface of the cover plate 2, and a third microchannel 303 is formed between the inner top wall and the inner side wall of the groove structure and the top surface of the substrate 1. The first micro-channel 301 and the second micro-channel 302 are connected to the two ends of the third micro-channel 303, and the first micro-channel 301, the third micro-channel 303 and the second micro-channel 302 are connected in sequence to form a gas micro-channel 3 for gas to flow through. In this embodiment, the first micro flow channel 301 and the second micro flow channel 302 have the same shape and are symmetrically disposed at two ends of the third micro flow channel 303, and any one of the first micro flow channel 301 and the second micro flow channel 302 can be used as an inlet channel or an outlet channel for gas to enter the gas micro flow channel 3. For convenience of description, in the present embodiment, the first micro flow channel 301 serves as an inlet channel, and the second micro flow channel 302 serves as an outlet channel.

In the present embodiment, the first temperature measuring mechanism 5, the micro-heater 4, and the second temperature measuring mechanism 6 are disposed in the third micro flow channel 303 at equal intervals in the direction of the air flow inside the package structure of the micro differential pressure module. In the present embodiment, the first temperature measurement mechanism 5 is provided near the first microchannel 301, and the second temperature measurement mechanism 6 is provided near the second microchannel 302. Alternatively, the first temperature measuring mechanism 5, the micro-heater 4, and the second temperature measuring mechanism 6 are all provided on the top surface of the substrate 1. Further alternatively, in the present embodiment, both the first temperature measurement mechanism 5 and the second temperature measurement mechanism 6 are temperature sensors.

Optionally, in order to realize the encapsulation of the encapsulation structure of the micro differential pressure module and further improve the anti-pollution performance of the encapsulation structure of the micro differential pressure module, the encapsulation structure of the micro differential pressure module further includes a substrate 7. As shown in fig. 1, the substrate 7 has a plate-like structure in a rectangular parallelepiped shape, and may be made of a PCB of FR4 grade or a ceramic material. The micro differential pressure sensor module is arranged on the substrate 7, and the air inlet and the air outlet of the gas micro channel 3 can also be arranged at the junction of the substrate 7 and the substrate 1. Specifically, at least two notches may be provided at the interface of the substrate 1 and the base plate 7 to form the air inlet hole and the air outlet hole. Alternatively, the notch may be separately provided on the substrate 1 or the base plate 7, or may be simultaneously provided on the substrate 1 and the base plate 7 to form the air inlet hole and the air outlet hole by splicing.

In this embodiment, in order to facilitate the air flow to enter and exit the micro differential pressure sensor module, a fourth micro channel 701 and a fifth micro channel 702 are disposed on the substrate 7, and one end of the fourth micro channel 701 is communicated with the air inlet of the gas micro channel 3, and the other end is communicated with the air inlet 12 of the packaging structure of the micro differential pressure module; and one end of the fifth micro flow channel 702 is communicated with the air outlet of the gas micro flow channel 3, and the other end is communicated with the air outlet 13 of the packaging structure of the micro differential pressure module.

In the present embodiment, the fourth micro flow channel 701 and the fifth micro flow channel 702 both have high gas resistance, the gas flow resistance of the fourth micro flow channel 701 is not less than 3kPa/sccm, and the gas flow resistance of the fifth micro flow channel 702 is not less than 3 kPa/sccm. Alternatively, the pore size of the fourth micro flow channel 701 is not greater than 0.5mm, for example, may be 0.1mm, 0.2mm, or 0.5 mm; the pore size of the fifth fluidic channel 702 is not greater than 0.5mm, and may be, for example, 0.1mm, 0.2mm, or 0.5mm, so that the fourth fluidic channel 701 and the fifth fluidic channel 702 have high air resistance.

Optionally, as shown in fig. 1, the fourth micro flow channel 701 is a U-shaped flow channel, so that the airflow needs to turn several times in the fourth micro flow channel 701 before entering the first micro flow channel 301, so that the foreign matters in the airflow can be blocked by the bent inner wall of the fourth micro flow channel 701, and the contamination resistance of the packaging structure of the micro differential pressure module is further improved. Specifically, the fourth micro flow channel 701 is sequentially connected to a first vertical flow channel, a first horizontal flow channel, and a second vertical flow channel, the first vertical flow channel is communicated with the air inlet of the gas micro flow channel 3, and the second vertical flow channel is communicated with the air inlet 12 of the packaging structure of the micro differential pressure module. Of course, in other embodiments, the fourth fluidic channel 701 may be a serpentine channel with more corners or other shaped channels.

Optionally, in this embodiment, the fifth micro flow channel 702 is also designed as a U-shaped flow channel to improve the contamination resistance of the packaging structure of the micro differential pressure module when the second micro flow channel 302 is used as the air inlet channel. Specifically, as shown in fig. 1, the fifth micro flow channel 702 is a U-shaped flow channel, and includes a third vertical flow channel, a second horizontal flow channel, and a fourth vertical flow channel that are connected in sequence, where the third vertical flow channel is communicated with the air outlet of the gas micro flow channel 3, and the fourth vertical flow channel is communicated with the air outlet 13 of the packaging structure of the micro differential pressure module. Of course, in other embodiments, the fifth fluidic channel 702 may be a serpentine channel with more corners or other shaped channels. The fourth micro flow channel 701 and the fifth micro flow channel 702 may have the same or different shapes, preferably the same shape, so as to have symmetry, thereby improving the convenience of use of the packaging structure of the micro differential pressure module. The pore diameters of the fourth micro flow channel 701 and the fifth micro flow channel 702 may be the same or different, and are set as required.

Further, the packaging structure of the micro differential pressure module further comprises a housing, the housing is a cubic box-shaped structure made of metal or plastic, and the housing is used for further packaging the packaging structure of the micro differential pressure module and can be packaged with the substrate 7 by bonding or an SMT method. In the present embodiment, as shown in fig. 1, the housing includes a top case 8, the top case 8 is fastened on the substrate 7, and the micro differential pressure sensor module is located in the accommodating space formed by the top case 8 and the substrate 7.

In this embodiment, an air cavity is formed between the inner wall of the top case 8 and the outer wall of the micro differential pressure sensor module, the air cavity includes an air inlet cavity 10 and an air outlet cavity 11 which are isolated from each other, and the top case 8 is provided with an air inlet 12 communicated with the air inlet cavity 10 and an air outlet 13 communicated with the air outlet cavity 11. One end of the fourth micro flow channel 701 is communicated with the air inlet cavity 10, and the other end is communicated with the first micro flow channel 301; one end of the fifth microchannel 702 is in communication with the outlet chamber 11, and the other end is in communication with the second microchannel 302. Alternatively, as shown in fig. 2, the air inlet 12 and the air outlet 13 may be provided on the top case 8 along the x-axis. Of course, in other embodiments, as shown in fig. 4, the air inlet 12 and the air outlet 13 may be arranged along the y-axis or the z-axis of the top case 8 according to requirements. Or the air inlet 12 and the air outlet 13 may be provided on the substrate 7 as required.

Through setting up the shell to form air inlet chamber 10 and play gas cavity 11, thereby can make gaseous through air inlet 12 get into behind the air inlet chamber 10, get into fourth microchannel 701, first microchannel 301, third microchannel 303, second microchannel 302 and fifth microchannel 702 in proper order, get into afterwards and go out from gas outlet 13 behind the gas cavity 11, whole process gas tightness is good, is favorable to improving measurement accuracy.

Of course, besides the case forming the air inlet cavity 10 and the air outlet cavity 11, a first pipeline may be directly arranged between one end of the fourth micro channel 701 and the air inlet 12 of the packaging structure of the micro differential pressure module, and the fourth micro channel 701 and the air inlet 12 of the packaging structure of the micro differential pressure module are communicated through the first pipeline; and a second pipeline can be directly arranged between one end of the fifth micro-channel 702 and the air outlet 13 of the packaging structure of the micro-differential pressure module, and the fifth micro-channel 702 and the air outlet 13 of the packaging structure of the micro-differential pressure module are communicated through the second pipeline.

In order to isolate the air cavity, forming an inlet cavity 10 and an outlet cavity 11, a partition plate 9 is provided in the air cavity, as shown in figure 1. In this embodiment, can adopt the division board 9 that is the U type, specifically, as shown in fig. 1, division board 9 that is the U type includes the diaphragm and the protruding riser of establishing at the diaphragm both ends, and the diaphragm is located between the top surface of apron 2 and the roof of top shell 8, and two risers are located the both sides of differential pressure sensor module respectively to be located respectively between the substrate 1 of differential pressure sensor module, two common lateral walls of apron 2 and two inside walls of top shell 8. In this embodiment, a partition plate 9 in a U-shape is provided in the middle of the air chamber.

Of course, other shapes of the partition plate 9 may be used instead of the U-shaped partition plate 9, for example, as shown in fig. 4, the partition plate 9 is disposed on the base plate 7 and on the same side of the substrate 1 and the cover plate 2 in a flat plate structure using the partition plate 9 in a flat plate structure. It should be noted that, at this time, the isolation plate 9 needs to be disposed between the outlet of the fifth micro flow channel 702 and the substrate 1 and the cover plate 2, and the top wall and the two side walls of the isolation plate 9 are hermetically connected with the inner top wall and the two inner side walls of the top case 8, respectively, and the bottom wall of the isolation plate 9 is hermetically connected with the top surface of the base plate 7. The hermetic connection here means that no gas passes through the gap between the partition plate 9 and the base plate 7 and the gap between the partition plate 9 and the top case 8, thereby ensuring the insulating effect.

Further, as shown in fig. 1, a cavity 101 is disposed on the substrate 1, and the cavity 101 mainly plays a role of thermal isolation, so as to improve the detection sensitivity of the package structure of the micro differential pressure module and reduce power consumption. In the present embodiment, the cavity 101 is an inverted cup-shaped structure, commonly referred to as a "silicon cup". In this case, as shown in fig. 1, a sixth microchannel 703 needs to be provided on the substrate 7, and the sixth microchannel 703 needs to be provided so as to penetrate the substrate 7 and communicate with the cavity 101. The sixth micro flow channel 703 provided on the substrate 7 can balance the air pressure in the up-and-down direction of the thin film between the silicon cup and the micro heater 4, thereby preventing the thin film from being damaged due to unbalanced pressure. The pore diameter of the sixth micro flow channel 703 is not particularly limited, and is determined as required. Of course, in other embodiments, the silicon cup may be placed in a forward direction, and the communicating hole may be provided in the film between the silicon cup and the micro-heater 4 on the substrate 1 to achieve the same effect.

The packaging structure of the micro differential pressure module provided by the embodiment realizes packaging through a semiconductor process, specifically, the substrate 1 and the cover plate 2 form the micro differential pressure sensor module through wafer-level packaging, then the chip is bonded on the base plate 7, and finally the shell and the base plate 7 with the chip are packaged into the packaging structure of the micro differential pressure module. The packaging structure of the micro differential pressure module including the substrate 1, the cover plate 2, the base plate 7 and the housing in the embodiment is a symmetrical structure, and differential pressure can be measured bidirectionally. Due to the thermal flow principle, the packaging body assembly has extremely high sensitivity and precision in the range of 0- +/-500Pa of ultralow differential pressure, can sense the differential pressure lower than +/-0.1Pa, and has excellent zero point stability and almost no zero point drift. And a micro differential pressure sensor module provided with a micro flow channel is formed by adopting wafer level packaging, so that the size of a packaging body is effectively reduced, the volume production cost is greatly reduced, and the consistency and the reliability of the product are also obviously improved.

Example two

The present embodiment provides an encapsulation structure of a micro differential pressure module, and in the present embodiment, the encapsulation structure of the micro differential pressure module includes a micro differential pressure sensor module, a substrate 7 and a housing. In this embodiment, the micro differential pressure sensor module is a main measurement unit of the packaging structure of the micro differential pressure sensor module, and the micro differential pressure sensor module includes a substrate 1, a cover plate 2, a micro heater 4, a first temperature measurement mechanism 5, and a second temperature measurement mechanism 6. A gas micro-channel 3 is arranged in the micro-differential pressure sensor module, one end of the gas micro-channel 3 forms an air inlet hole on the surface of the micro-differential pressure sensor module, and the other end of the gas micro-channel forms an air outlet hole on the surface of the micro-differential pressure sensor module. The air inlet of the gas micro-channel 3 can be used as the air inlet 12 of the packaging structure of the whole micro-differential pressure module, and can also be communicated with the air inlet 12 of the packaging structure of the micro-differential pressure module through other channels, and the air outlet of the gas micro-channel 3 can be used as the air outlet 13 of the packaging structure of the whole micro-differential pressure module, and can also be communicated with the air outlet 13 of the packaging structure of the micro-differential pressure module through other channels.

The first temperature measuring mechanism 5, the micro-heater 4, and the second temperature measuring mechanism 6 are integrated on the substrate 1 by a semiconductor process, and are arranged in the gas microchannel 3 at equal intervals in the gas flow direction inside the gas microchannel 3. The specific structures of the substrate 1, the cover plate 2, the micro-heater 4, the first temperature measuring mechanism 5, and the second temperature measuring mechanism 6 may be the same as those of the components in the first embodiment, and are not described herein again.

The main difference between this embodiment and the first embodiment is the structure of the housing. Specifically, in this embodiment, the shell includes top shell 8 and

drain pan

14, and 8 spiral-lock of top shell are in the top of base plate 7, and the differential pressure sensor module is located inside top shell 8, and the drain pan 14 spiral-lock is in the below of base plate 7, forms air inlet cavity 10 between the outer wall of top shell 8 and differential pressure sensor module, and the inner space of drain pan 14 forms out gas cavity 11, is provided with the passageway that the intercommunication air inlet cavity 10 was admitted gas and is gone out gas cavity 11 on the base plate 7, and air inlet 12 sets up on top shell 8, and gas outlet 13 sets up on drain pan 14. The bottom shell 14 has the same structure as the outer shell, and is a rectangular shell, which is not described in detail herein.

Specifically, as shown in fig. 5, the bottom case 14 may be fastened under the substrate 7, and the fifth micro flow channel 702 may be disposed to penetrate through the substrate 7 and communicate with the inside of the bottom case 14, so as to be used as a channel for communicating the air inlet chamber 10 and the air outlet chamber 11. An air inlet 12 is provided on the top case 8 and an air outlet 13 is provided on the bottom case 14. Alternatively, the air inlet 12 and the air outlet 13 are located on the same side. In this structure, the gas flow enters the top case 8 from the gas inlet 12, flows into the gas microchannel 3 through the fourth microchannel 701 provided in a U-shape, then flows into the bottom case 14 through the fifth microchannel 702, and then flows out from the gas outlet 13.

In addition to the above structure, as shown in fig. 6, it is also possible to omit the fourth micro flow channel 701 formed on the substrate 7, redirect the first micro flow channel 301 formed on the substrate 1 to the top of the cover plate 2, make the opening of the first micro flow channel 301 upward, so that the airflow can enter the top case 8 from the air inlet 12, directly enter the gas micro flow channel 3 from the first micro flow channel 301 with the upward opening, then sequentially pass through the third micro flow channel 303 and the second micro flow channel 302, enter the fifth micro flow channel 702, and finally enter the bottom case 14 and then flow out from the air outlet 13. Of course, the first micro flow channel 301 may be diverted to the side of the cover plate 2, which is not described herein.

EXAMPLE III

The present embodiment provides an encapsulation structure of a micro differential pressure module, and in the present embodiment, the encapsulation structure of the micro differential pressure module includes a micro differential pressure sensor module, a substrate 7 and a housing. In this embodiment, the micro differential pressure sensor module is a main measurement unit of the packaging structure of the micro differential pressure sensor module, and the micro differential pressure sensor module includes a substrate 1, a cover plate 2, a micro heater 4, a first temperature measurement mechanism 5, and a second temperature measurement mechanism 6. A gas micro-channel 3 is arranged in the micro-differential pressure sensor module, one end of the gas micro-channel 3 forms an air inlet hole on the surface of the micro-differential pressure sensor module, and the other end of the gas micro-channel forms an air outlet hole on the surface of the micro-differential pressure sensor module.

The first temperature measuring mechanism 5, the micro-heater 4, and the second temperature measuring mechanism 6 are integrated on the substrate 1 by a semiconductor process, and are arranged in the gas microchannel 3 at equal intervals in the gas flow direction inside the gas microchannel 3.

In this embodiment, the structures of the first temperature measuring mechanism 5, the micro-heater 4 and the second temperature measuring mechanism 6 may be the same as those in the first embodiment, and therefore, the description thereof is omitted. The difference between the present embodiment and the first embodiment is: the micro differential pressure sensor module according to the present embodiment is different from the micro differential pressure sensor module according to the first embodiment in the formation of the gas micro flow channel 3.

Specifically, as shown in fig. 7, the substrate 1 is a bulk structure made of silicon material, a first micro flow channel 301 and a second micro flow channel 302 are disposed on the substrate 1, one end of the first micro flow channel 301 forms an air inlet hole on the left side wall of the substrate 1, the other end of the first micro flow channel runs through the top surface of the substrate 1, one end of the second micro flow channel 302 forms an air outlet hole on the right side wall of the substrate 1, and the other end of the second micro flow channel runs through the top surface of the substrate 1. The cover plate 2 is buckled on the top of the substrate 1, a third micro-channel 303 is formed between the cover plate 2 and the top surface of the substrate 1, the first micro-channel 301, the third micro-channel 303 and the second micro-channel 302 are sequentially communicated to form a gas micro-channel 3, and the first temperature measuring mechanism 5, the micro-heater 4 and the second temperature measuring mechanism 6 are arranged in the third micro-channel 303 at equal intervals along the gas flow direction.

In this embodiment, the gas enters the micro differential pressure sensor module from the air inlet formed on the left side wall of the substrate 1 through the first micro channel 301, flows into the third micro channel 303 along the first micro channel 301, sequentially passes through the first temperature measuring mechanism 5, the micro heater 4 and the second temperature measuring mechanism 6, flows out of the third micro channel 303, enters the second micro channel 302, and finally flows out of the entire micro differential pressure sensor module from the air outlet formed on the right side wall of the substrate 1 through the second micro channel 302.

Alternatively, the first micro flow channel 301 and the second micro flow channel 302 may be L-shaped channels, or curved channels.

In this embodiment, the substrate 7 and the housing may be disposed as required, and the structures of the substrate 7 and the housing may be the same as those in the first embodiment, or may be appropriately modified as required, which is not described herein again.

Example four

Specifically, as shown in fig. 8, the substrate 1 is a block structure made of a silicon material, the gas micro flow channel 3 is provided between the substrate 1 and the cover plate 2, and an air inlet hole is formed on one side wall of the cover plate 2 and an air outlet hole is formed on the other side wall of the cover plate. Alternatively, recessed structures may be provided on the top surface of the substrate 1 and the bottom surface of the cover plate 2, the two recessed structures being joined to form a gas microchannel 3 that allows gas to flow therethrough. The first temperature measuring mechanism 5, the micro-heater 4 and the second temperature measuring mechanism 6 are arranged in the gas micro-channel 3 formed by splicing the two concave structures at equal intervals along the gas flow direction.

In the embodiment, the gas enters the gas micro-channel 3 from the gas inlet, and flows out of the whole micro-differential pressure sensor module from the gas outlet after sequentially passing through the first temperature measuring mechanism 5, the micro-heater 4 and the second temperature measuring mechanism 6.

Alternatively, the gas micro flow channel 3 formed by splicing two concave structures and allowing gas to flow through can be a linear flow channel or a curved flow channel.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. The utility model provides an encapsulation construction of little differential pressure module which characterized in that includes:

the micro differential pressure sensor module is internally provided with a gas micro channel (3), and the gas micro channel (3) forms an air inlet and an air outlet on the surface of the micro differential pressure sensor module;

the micro differential pressure sensor module comprises a substrate (1), a first temperature measuring mechanism (5), a micro heater (4) and a second temperature measuring mechanism (6), wherein the first temperature measuring mechanism (5), the micro heater (4) and the second temperature measuring mechanism (6) are integrated through a semiconductor process on the substrate (1) and are sequentially arranged in the gas micro channel (3) at equal intervals along the gas flow direction.

2. The package structure of the micro differential pressure module according to claim 1, wherein the micro differential pressure sensor module further comprises a cover plate (2), the cover plate (2) is fastened on top of the substrate (1), part of the structure of the gas micro flow channel (3) is located in the substrate (1), part of the structure is located in the cover plate (2), and the gas inlet hole and the gas outlet hole are formed on the surface of the cover plate (2) or the substrate (1).

3. The encapsulation structure of the micro differential pressure module according to claim 2,

a first micro-channel (301) and a second micro-channel (302) penetrate through the substrate (1) along the height direction;

the apron (2) with form third microchannel (303) between the top surface of substrate (1), first microchannel (301) third microchannel (303) with second microchannel (302) communicate in proper order and form gas microchannel (3), first temperature measurement mechanism (5) micro heater (4) with second temperature measurement mechanism (6) are in along the equidistant setting of air current direction in third microchannel (303).

4. The encapsulation structure of the micro differential pressure module according to claim 2,

a first micro-channel (301) and a second micro-channel (302) are arranged on the substrate (1), one end of the first micro-channel (301) forms the air inlet hole on the left side wall of the substrate (1), the other end of the first micro-channel penetrates through the top surface of the substrate (1), one end of the second micro-channel (302) forms the air outlet hole on the right side wall of the substrate (1), and the other end of the second micro-channel penetrates through the top surface of the substrate (1);

5. The encapsulation structure of the micro differential pressure module according to claim 2,

the gas micro-channel (3) is arranged between the substrate (1) and the cover plate (2), the gas inlet hole is formed on one side wall of the cover plate (2), and the gas outlet hole is formed on the other side wall of the cover plate (2).

6. The encapsulation structure of the micro differential pressure module according to claim 2 or 3, further comprising:

base plate (7), substrate (1) sets up on base plate (7), the interval is provided with fourth microchannel (701) and fifth microchannel (702) on base plate (7), the one end of fourth microchannel (701) with gaseous microchannel (3) the inlet port intercommunication, the other end with air inlet (12) the intercommunication of the packaging structure of differential pressure module, the one end of fifth microchannel (702) with gaseous microchannel (3) the outlet port intercommunication, the other end with packaging structure's of differential pressure module gas outlet (13) intercommunication.

7. The encapsulation structure of the micro differential pressure module according to claim 4 or 5, further comprising:

a base plate (7), the substrate (1) being arranged on the base plate (7).

8. The package structure of the micro differential pressure module according to claim 1, further comprising:

the air inlet structure comprises a base plate (7), wherein the substrate (1) is arranged on the base plate (7), and at least two notches are arranged at the junction of the substrate (1) and the base plate (7) to form the air inlet hole and the air outlet hole.

9. The encapsulation structure of the micro differential pressure module according to claim 6,

the air inlet (12) and the air outlet (13) are both arranged on the substrate (7).

10. The encapsulation structure of the micro differential pressure module according to claim 6,

the fourth micro-channel (701) is communicated with the air inlet (12) through a first pipeline; and/or

The fifth micro-channel (702) is communicated with the air outlet (13) through a second pipeline.

11. The package structure of the micro differential pressure module according to claim 6, further comprising:

the shell is buckled on the base plate (7), the micro differential pressure sensor module is located in the shell, an air cavity is formed between the inner wall of the shell and the outer wall of the micro differential pressure sensor module and comprises an air inlet cavity (10) and an air outlet cavity (11) which are mutually isolated, the shell is provided with the air inlet (12) and the air outlet (13), the air inlet (12) is communicated with the air inlet cavity (10), and the air outlet (13) is communicated with the air outlet cavity (11).

12. The encapsulation structure of the micro differential pressure module according to claim 11,

the shell comprises a top shell (8), the top shell (8) is buckled above the base plate (7), a separation plate (9) for separating the air inlet cavity (10) and the air outlet cavity (11) is arranged in the top shell (8), and the air inlet (12) and the air outlet (13) are both positioned on the top shell (8) and positioned on two sides of the separation plate (9).

13. The encapsulation structure of the micro differential pressure module according to claim 12,

the isolation plate (9) is a U-shaped plate, the U-shaped plate comprises a transverse plate and vertical plates convexly arranged at two ends of the transverse plate, the transverse plate is positioned between the top surface of the cover plate (2) and the top wall of the top shell (8), and the two vertical plates are respectively positioned between the substrate (1), two coplanar side walls of the cover plate (2) and two inner side walls of the top shell (8); or

The division board (9) is of a flat structure, the flat structure is located between the micro differential pressure sensor module and the outlet of the fifth micro flow channel (702), the top wall and the two side walls of the flat structure are respectively connected with the inner top wall and the two inner side walls of the top shell (8) in a sealing mode, and the bottom wall of the flat structure is connected with the top face of the substrate (7) in a sealing mode.

14. The encapsulation structure of the micro differential pressure module according to claim 11,

the shell includes top shell (8) and drain pan (14), top shell (8) spiral-lock is in the top of base plate (7), little differential pressure sensor module is located in top shell (8), drain pan (14) spiral-lock is in the below of base plate (7), top shell (8) with form between the outer wall of little differential pressure sensor module admit air chamber (10), drain pan (14) inner space forms go out air cavity (11), be provided with the intercommunication on base plate (7) admit air chamber (10) with go out the passageway in air cavity (11), air inlet (12) set up on top shell (8), gas outlet (13) set up on drain pan (14).

15. The encapsulation structure of the micro differential pressure module according to claim 6,

the fourth micro flow channel (701) is a U-shaped flow channel and comprises a first vertical flow channel, a first transverse flow channel and a second vertical flow channel which are sequentially connected, the first vertical flow channel is communicated with the air inlet of the gas micro flow channel (3), and the second vertical flow channel is communicated with the air inlet (12) of the packaging structure of the micro differential pressure module; and/or

The fifth micro flow channel (702) is a U-shaped flow channel and comprises a third vertical flow channel, a second transverse flow channel and a fourth vertical flow channel which are sequentially connected, the third vertical flow channel is communicated with the air outlet of the gas micro flow channel (3), and the fourth vertical flow channel is communicated with the air outlet (13) of the packaging structure of the micro differential pressure module.

16. The encapsulation structure of the micro differential pressure module according to claim 6,

a cavity (101) is arranged on the substrate (1).

17. The encapsulation structure of the micro differential pressure module according to claim 16,

the substrate (7) is provided with a sixth micro-channel (703), and the sixth micro-channel (703) penetrates through the substrate (7) and is communicated with the cavity (101).

18. The encapsulation structure of the micro differential pressure module according to claim 6,

the pore diameter of the fourth micro-channel (701) is not more than 0.5 mm; and/or

The pore diameter of the fifth micro-channel (702) is not more than 0.5 mm; and/or

The gas flow impedance of the fourth micro flow channel (701) is not less than 3 kPa/sccm; and/or

The gas flow impedance of the fifth micro flow channel (702) is not less than 3 kPa/sccm.