阅读说明：本技术 一种mems热式流速传感器封装装置 (MEMS (micro-electromechanical systems) thermal type flow velocity sensor packaging device ) 是由 李以贵 金敏慧 张成功 王保志 于 2020-11-27 设计创作，主要内容包括：本发明涉及一种MEMS热式流速传感器封装装置,包括封装盖体、封装隔板和封装基体,所述封装盖体设有放置薄膜驱动模块的第一腔体,以及放置MEMS热式流速传感器芯片的第二腔体,所述封装隔板设有与第一腔体对应的薄膜,以及与第二腔体对应的芯片流体通孔,所述封装基体设有流体凹槽、流体进口通道和流体出口通道,所述流体凹槽包括薄膜接触部和芯片接触部,所述薄膜接触部连通流体出口通道,所述芯片接触部连通流体进口通道,所述流体出口通道的截面面积小于薄膜的面积,所述芯片接触部与芯片流体通孔连通,所述封装盖体、封装隔板和封装基体依次固定连接。与现有技术相比,灵敏度高、反应速度快、体积更小、均一性好,且可用于腐蚀性气体的检测。(The invention relates to an MEMS (micro electro mechanical system) thermal type flow velocity sensor packaging device which comprises a packaging cover body, a packaging partition plate and a packaging base body, wherein the packaging cover body is provided with a first cavity for placing a film driving module and a second cavity for placing an MEMS thermal type flow velocity sensor chip, the packaging partition plate is provided with a film corresponding to the first cavity and a chip fluid through hole corresponding to the second cavity, the packaging base body is provided with a fluid groove, a fluid inlet channel and a fluid outlet channel, the fluid groove comprises a film contact part and a chip contact part, the film contact part is communicated with the fluid outlet channel, the chip contact part is communicated with the fluid inlet channel, the cross-sectional area of the fluid outlet channel is smaller than the area of the film, the chip contact part is communicated with the chip fluid through hole, and the packaging cover body, the packaging partition plate and the packaging base body are. Compared with the prior art, the method has the advantages of high sensitivity, high reaction speed, smaller volume and good uniformity, and can be used for detecting corrosive gas.)

1. The MEMS thermal type flow velocity sensor packaging device is characterized by comprising a packaging cover body (13), a packaging partition plate (15) and a packaging base body (23), wherein the packaging cover body (13) is provided with a first cavity (11) for placing a film driving module (9) and a second cavity (12) for placing an MEMS thermal type flow velocity sensor chip (7), the packaging partition plate (15) is provided with a film (14) corresponding to the first cavity (11) and a chip fluid through hole (16) corresponding to the second cavity (12), the packaging base body (23) is provided with a fluid groove (22), a fluid inlet channel (21) and a fluid outlet channel (24), the fluid groove (22) comprises a film contact part and a chip contact part, the film contact part is communicated with the fluid outlet channel (24), and the chip contact part is communicated with the fluid inlet channel (21), the cross-sectional area of the fluid outlet channel (24) is smaller than that of the thin film (14), the chip contact part is communicated with the chip fluid through hole (16), the packaging cover body (13), the packaging partition plate (15) and the packaging base body (23) are fixedly connected in sequence, fluid sequentially passes through the fluid inlet channel (21), the chip fluid through hole (16), the second cavity (12) and the fluid outlet channel (24), the thin film driving module (9) drives the thin film (14) to move, and the thin film (14) moves to enable the fluid outlet channel (24) to be opened or closed, so that the fluid in the second cavity (12) is in a balanced state.

2. The MEMS thermal flow rate sensor packaging device according to claim 1, wherein the package cover (13), the package partition plate (15) and the package base (23) are fixedly connected through bolts.

3. The package for a MEMS thermal flow rate sensor according to claim 1, wherein the thin film driver module (9) is a piezoelectric ceramic array.

4. The MEMS thermal flow rate sensor packaging device as claimed in claim 1, wherein a glass block (8) corresponding to the first cavity (11) is arranged above the packaging cover body (13), and the glass block (8) is fixedly connected with the packaging cover body (13).

5. A MEMS thermal flow rate sensor package according to claim 1 wherein the fluid outlet channel (24) extends to form a valve seat (18) at a membrane contact portion of the fluid recess (22), the height of the valve seat (18) being less than the depth of the fluid recess (22).

6. A MEMS thermal flow rate sensor package according to claim 1, wherein the membrane (14) has dimensions adapted to the dimensions of the cross-section of the first cavity (11), and the membrane contact has dimensions adapted to the dimensions of the membrane (14).

7. The package for a MEMS thermal flow rate sensor according to claim 1 wherein the membrane contact is provided with a gasket (17).

8. The package for a MEMS thermal flow rate sensor according to claim 1, wherein the fluid inlet channel (21) is connected to the fluid inlet (19), the fluid outlet channel (24) is connected to the fluid outlet (20), and the fluid inlet (19) and the fluid outlet (20) are both provided with external threads.

9. The package for a MEMS thermal flow rate sensor according to claim 1, wherein the film (14) is an aluminum nitride film.

10. The MEMS thermal flow rate sensor package device according to claim 1, wherein the package cover (13) is a stainless steel package cover, the package spacer (15) is a stainless steel package spacer, and the package base (23) is a stainless steel package base.

Technical Field

The invention relates to the field of MEMS sensor packaging, in particular to an MEMS thermal type flow velocity sensor packaging device.

Background

With the development of modern science and technology and the progress of productivity, the flow velocity measurement has more and deeper requirements in the aspects of aerospace, meteorology, biomedical treatment and the like. However, the conventional flow rate sensor has the disadvantages of large volume, easy influence of ambient temperature, and the like, and the application scenario is limited. In recent years, with the development of a Micro Electro Mechanical System (MEMS) processing technology, sensors are increasingly miniaturized, and a MEMS thermal flow velocity sensor prepared based on the MEMS technology has greatly improved performance, has the advantages of small volume, high sensitivity, high precision and the like, and is widely applied in various aspects.

The flow velocity sensor prepared by the MEMS processing technology generally needs to be packaged for practical application, the packaging of the MEMS thermal flow velocity sensor is a difficult problem all the time, the MEMS thermal sensor is mainly based on a thermal principle, the packaging material of the MEMS thermal sensor needs to meet certain heat conduction performance while protecting the sensor, the common MEMS flow velocity sensor is mostly packaged by ceramic or glass at present, the common MEMS flow velocity sensor is connected by common multipurpose adhesives, the uniformity, stability and consistency of the packaging technology are poor, and the material of the packaging technology cannot support the sensor for flow velocity detection of certain corrosive and active gases.

Disclosure of Invention

The present invention is directed to a package device for a MEMS thermal flow rate sensor, which overcomes the above-mentioned drawbacks of the prior art.

The purpose of the invention can be realized by the following technical scheme:

the utility model provides a MEMS hot type velocity of flow sensor packaging hardware, is including encapsulation lid, encapsulation baffle and encapsulation base member, the encapsulation lid is equipped with the first cavity of placing film drive module to and place the second cavity of MEMS hot type velocity of flow sensor chip, the encapsulation baffle is equipped with the film that corresponds with first cavity, and the chip fluid through-hole that corresponds with the second cavity, the encapsulation base member is equipped with fluid recess, fluid inlet passageway and fluid outlet passageway, the fluid recess includes film contact site and chip contact site, film contact site intercommunication fluid outlet passageway, chip contact site intercommunication fluid inlet passageway, the cross-sectional area of fluid outlet passageway is less than the area of film, chip contact site and chip fluid through-hole intercommunication, encapsulation lid, encapsulation baffle and encapsulation base member be fixed connection in proper order, and fluid loops through fluid inlet passageway, The chip fluid through hole, the second cavity and the fluid outlet channel, the film driving module drives the film to move, and the film moves to enable the fluid outlet channel to be opened or closed, so that the fluid in the second cavity is in a balanced state.

The packaging cover body, the packaging partition plate and the packaging base body are fixedly connected through bolts.

The film driving module is a piezoelectric ceramic array.

And a glass block corresponding to the first cavity is arranged above the packaging cover body and is fixedly connected with the packaging cover body.

The fluid outlet passage extends at the membrane contacting portion of the fluid recess to form a valve seat having a height less than the depth of the fluid recess.

The size of the thin film is adaptive to the size of the cross section of the first cavity, and the size of the thin film contact part is adaptive to the size of the thin film.

The film contact part is provided with a gasket.

The fluid inlet channel is communicated with the fluid inlet, the fluid outlet channel is communicated with the fluid outlet, and the fluid inlet and the fluid outlet are both provided with external threads.

The film is an aluminum nitride film.

The packaging cover body is a stainless steel packaging cover body, the packaging partition plate is a stainless steel packaging partition plate, and the packaging base body is a stainless steel packaging base body.

Compared with the prior art, the invention has the following advantages:

(1) fluid sequentially passes through the fluid inlet channel and the chip fluid through hole to enter the second cavity, the film driving module drives the film to move, and the film moves to enable the fluid outlet channel to be opened or closed, so that the fluid in the second cavity is in a balanced state, the fluid in the balanced state can enable the measuring result of the MEMS thermal flow rate sensor to be more accurate, and the MEMS thermal flow rate sensor has the advantages of high sensitivity, high reaction speed and the like.

(2) Compared with the packages of other flow velocity sensors on the market, the package structure has smaller volume.

(3) The whole packaging process is simple and convenient, the packaging cover body, the packaging partition plate and the packaging base body are all prepared based on the traditional machining process, only bolt fixing is needed for fixing the packaging cover body, the packaging partition plate and the packaging base body, the operability is high, the uniformity is good, and batch production can be realized.

(4) The sensor is packaged by adopting stainless steel materials, so that the stability, reliability and corrosion resistance of the sensor are improved, and the sensor can be used for detecting certain corrosive gases and active gases (such as chlorine).

Drawings

FIG. 1 is a partial side view of a thin film drive module according to the present invention in an unpowered state;

FIG. 2 is a partial side view of the thin film drive module of the present invention in a powered state;

FIG. 3 is a schematic structural diagram of a package cover according to the present invention;

FIG. 4 is a schematic diagram of a package spacer according to the present invention;

FIG. 5 is a schematic structural diagram of a package substrate according to the present invention;

FIG. 6 is a schematic diagram of a MEMS flow rate sensor configuration according to an embodiment of the present invention;

reference numerals:

1 is a heating resistor; 2 is a temperature measuring resistor; 3 is a compensation resistor; 4 is a sensor chip cavity; 5 is a lead wire; 6 is a pin; 7 is an MEMS thermal flow velocity sensor chip; 8 is a glass block; 9 is a film driving module; 10 is a bolt hole; 11 is a first cavity; 12 is a second cavity; 13 is a packaging cover body; 14 is a film; 15 is a packaging separator; 16 is a chip fluid through hole; 17 is a gasket; 18 is a valve seat; 19 is a fluid inlet; 20 is a fluid outlet; 21 is a fluid inlet channel; 22 is a fluid groove; 23 is a packaging substrate; and 24 is a fluid outlet channel.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

Examples

The embodiment provides a packaging device of an MEMS thermal flow rate sensor, which includes a packaging cover 13, a packaging partition 15 and a packaging substrate 23, wherein the packaging cover 13 is provided with a first cavity 11 for placing a thin film driving module 9 and a second cavity 12 for placing a MEMS thermal flow rate sensor chip 7, the packaging partition 15 is provided with a thin film 14 corresponding to the first cavity 11 and a chip fluid through hole 16 corresponding to the second cavity 12, the packaging substrate 23 is provided with a fluid groove 22, a fluid inlet channel 21 and a fluid outlet channel 24, the fluid groove 22 includes a thin film contact portion and a chip contact portion, the thin film contact portion is communicated with the fluid outlet channel 24, the chip contact portion is communicated with the fluid inlet channel 21, the cross-sectional area of the fluid outlet channel 24 is smaller than the area of the thin film 14, the chip contact portion is communicated with the chip fluid through hole 16, the packaging cover 13, the packaging partition 15 and the packaging substrate 23 are sequentially and fixedly connected, the fluid passes through the fluid inlet channel 21, the chip fluid through hole 16, the second cavity 12 and the fluid outlet channel 24 in sequence, the film driving module 9 drives the film 14 to move, and the film 14 moves to open or close the fluid outlet channel 24, so that the fluid in the second cavity 12 is in a balanced state.

Specifically, the method comprises the following steps:

the package cover 13, the package spacer 15, and the package base 23 are fixedly connected by bolts.

The thin film driving module 9 is a lead zirconate titanate (PZT) piezoelectric ceramic array, which has the advantages of fast reaction speed, large acting force, and the like, and realizes the balance control of the fluid flow channel by applying and releasing appropriate voltage to the PZT piezoelectric ceramic array.

A glass block 8 corresponding to the first cavity 11 is arranged above the packaging cover 13, the glass block 8 is fixedly connected with the packaging cover 13, and the glass block 8 is a heat-resistant glass block.

The fluid outlet passage 24 extends to form the valve seat 18 at the membrane contacting portion of the fluid recess 22, the height of the valve seat 18 being less than the depth of the fluid recess 22.

The size of the film 14 is matched with that of the cross section of the first cavity 11, the size of the film contact part is matched with that of the film 14, the first cavity 11 is cylindrical, the second cavity 12 is cuboid, and the film 14 is circular; the purpose of the second cavity 12 being rectangular is to facilitate the testing of the external connection of the lead 5 of the MEMS thermal flow rate sensor chip 7.

The membrane contact portion is provided with a gasket 17, the gasket 17 ensuring gas tightness, the gasket 17 being a metal gasket.

The fluid inlet channel 21 communicates with the fluid inlet 19, the fluid outlet channel 24 communicates with the fluid outlet 20, and the fluid inlet 19 and the fluid outlet 20 are each externally threaded.

The film 14 is an aluminum nitride film.

The fluid outlet channel 24, fluid inlet channel 21, package cover 13, package spacer 15, and package base 23 are made of SUS316/SUS316L stainless steel, all based on conventional machining.

The thermistor in the MEMS thermal flow rate sensor chip 7 of this embodiment is symmetrically distributed, and the heating resistor 1 is located in the middle, and 4 pairs of temperature measuring resistors 2 are respectively arranged on both sides with the heating resistor 1 as the center, and flow rate information is obtained by measuring the thermal temperature difference between the heating resistor 1 and the temperature measuring resistors 2, and the MEMS thermal flow rate sensor chip has the advantages of high sensitivity, large measurement range, small size, and the like. A compensation resistor 3 is respectively arranged at a position slightly far away from the heating resistor 1 and used for measuring the ambient temperature and carrying out environmental compensation; the work is based on the heat loss principle, and the preparation is based on the MEMS processing technology.

The following is a specific example:

fig. 6 shows an MEMS thermal flow rate sensor chip 7 of the present embodiment, which is prepared by selecting a glass substrate and spin-coating Polyimide (PI) as a protection layer; a heating resistor 1, a temperature measuring resistor 2 and a compensating resistor 3 are obtained by magnetron sputtering a Cr/Pt film on a PI protective layer; obtaining a lead 5 by electroplating metal Cu with the thickness of about 15um, and obtaining a pin 6 by electroplating metal Ni with the thickness of about 20 um; the method comprises the steps of spin-coating a polyimide support film with the thickness of about 8 microns, sputtering a Cr/Cu metal barrier layer, spin-coating polyimide with the thickness of about 20 microns as a substrate layer, etching the polyimide film by using reactive ions to obtain a sensor chip cavity 4, and stripping the sensor chip from a glass substrate to obtain the flexible MEMS thermal flow rate sensor chip 7 with the size of 9mmx7mmx30 um.

In fig. 3, there is a package cover 13 with dimensions 20mm x20mm x10 mm; the bolt hole 10 is about 3.8mm in diameter; the thickness of the thin film driving module 9 is 6mm, and the length and width are 3mmx10mm as an example, it is noted here that the piezoelectric effect of the thin film driving module 9 is mainly related to the thickness thereof, and the thin film driving module 9 of this embodiment can generate 6.5um deformation under the condition of 100V voltage; the size of the first cavity 11 is based on the size of the thin film driving module 9 contained therein, and similarly, the size of the MEMS flow rate sensor chip is based on the size of the second cavity 12; the glass block 8 is located above the film drive module 9 and has dimensions of about 5mm x 5mm x2 mm.

Fig. 4 shows a package spacer 15 with dimensions of 20mm x20mm x 0.15mm, a diameter of a film 14 corresponds to a diameter of a first cavity 11 on a package cover 13, the film 14 is made of aluminum nitride, a hole wall of a chip fluid through hole 16 is used for placing an MEMS thermal sensor chip, and a heating resistor 1, a temperature measuring resistor 2 and a compensation resistor 3 on the MEMS thermal sensor chip sense fluid for detection.

Fig. 5 shows a package base 23 having dimensions 20mm x20mm x10mm, the diameter of the gasket 17 corresponding to the dimensions of the membrane 14, it being noted that the gasket 17 is located at the membrane contact portion, the depth of the fluid groove 22 is about 0.2mm, the chip contact portion of the fluid groove 22 corresponds to the MEMS flow rate sensor chip of the package spacer 15, and the valve seat 18 is in the form of a hollow ring structure, the diameter of the inner ring of which is about 1-3mm the same as the outer diameter of the fluid outlet channel 24. The gas to be measured enters from the fluid inlet 19 and exits from the fluid outlet 20, and the fluid outlet channel 24 and the fluid inlet channel 21 are formed to have a diameter of about 1 to 3mm, and in particular, the fluid inlet 19 and the fluid outlet 20 are externally threaded.

The package cover 13, the package partition 15 and the package base 23 can be connected through four M2 hexagon socket head cap bolts and top-down bolt holes 10, the glass block 8 and the package cover 13 are connected through adhesive colloid, and the MEMS flow rate sensor chip is placed above the chip fluid through hole 16 on the package partition 15.

Fig. 1 shows the membrane 14 in a normal state and the fluid outlet channel 24 in an open state when the membrane drive module 9 is not powered.

In fig. 2, the membrane 14 is deformed in an expanded state upon application of a current, and the fluid outlet passage 24 is closed by the membrane 14 contacting the valve seat 18.