CN210775142U - Particle detection module - Google Patents

Abstract

A particle detection module, comprising: the base separates the bearing area of the air guide component from the laser setting area, and is assisted with the design of a gas flow channel, and finally, the driving circuit board covers the bottom surface of the base and the surface of the outer cover sealing the base, so that an air inlet channel is defined by an air inlet groove of the base, an air outlet channel is defined by an air outlet groove of the base, and the thickness of the particle sensor can be greatly reduced.

Description

Particle detection module

Technical Field

The present disclosure relates to a particle detection module, and more particularly, to a very thin particle detection module.

Background

By aerosol is meant solid particles or liquid droplets contained in a gas. Because of its very fine particle size, it is easy to enter the lungs of the human body through the nose hair in the nasal cavity, thus causing inflammation, asthma or cardiovascular diseases of the lungs, and if other pollutants adhere to the aerosol, it will further aggravate the harm to the respiratory system. In recent years, the problem of gas pollution is getting worse, especially the concentration data of fine suspended particles (for example, PM2.5) is often too high, and the monitoring of the gas suspended particle concentration is getting more and more important, but because the gas can flow along with the wind direction and the unstable wind quantity, and the gas quality monitoring station for detecting the suspended particles is mostly a fixed point at present, the current surrounding suspended particle concentration cannot be confirmed at all, so a micro-sized and portable gas detection module is needed for a user to detect the surrounding suspended particle concentration anytime and anywhere.

Please refer to fig. 1, which is a particle detecting module shown in taiwan patent application No. 107130404. The casing 11A of the conventional particle detection device 1A is limited by the size of the air guide 12A and the limitation of the internal air flow channel, and is difficult to reduce its volume, as shown in the air guide path indicated by the arrow in fig. 1, air needs to enter from the upper inlet and then enter the lower inlet, is detected and then is guided by the micro pump, and finally returns to the upper outlet to be discharged.

SUMMERY OF THE UTILITY MODEL

The main objective of the present disclosure is to provide a particle detection module, in which a driving circuit board is attached to a second surface of a base, and a first surface of the base is attached to an outer cover, so that an air inlet path is defined by an air inlet groove, and an air outlet path is defined by an air outlet groove, a laser module is disposed on the driving circuit board, and the driving circuit board directly covers the base, and separates a position of a piezoelectric actuator from a position of the laser module, thereby greatly reducing the thickness of the particle detection module.

One broad aspect of the present disclosure is a particle detection module, comprising: a base having: a first surface; a second surface opposite to the first surface; a laser setting area formed by hollowing from the first surface to the second surface; an air inlet groove which is formed by sinking from the second surface, is adjacent to the laser setting area, is provided with an air inlet, is communicated with the outside of the base and is provided with a light-transmitting window at the adjacent position of the laser setting area; the air guide assembly bearing area is formed by sinking from the second surface, communicated with the air inlet groove and communicated with a vent hole on the bottom surface; and an air outlet groove, which is recessed from the first surface to the bottom surface of the air guide assembly bearing area, is formed by hollowing the area of the first surface, which is not corresponding to the air guide assembly bearing area, from the first surface to the second surface, is communicated with the air vent, is provided with an air outlet and is communicated with the outside of the base; the piezoelectric actuator is accommodated in the air guide assembly bearing area; the driving circuit board is attached to the second surface of the base by the sealing cover; the laser assembly is positioned on the driving circuit board, is electrically connected with the driving circuit board, is correspondingly accommodated in the laser arrangement area, and emits light beams which penetrate through the light-transmitting window and form an orthogonal direction with the air inlet groove; a particle sensor which is positioned on the driving circuit board, electrically connected with the driving circuit board and correspondingly accommodated at the orthogonal direction position of the air inlet groove and the light beam projected by the laser component so as to detect the particles which pass through the air inlet groove and are irradiated by the light beam projected by the laser component; the outer cover covers the first surface of the base and is provided with a side plate, and the side plate is provided with an air inlet frame opening and an air outlet frame opening respectively corresponding to the air inlet and the air outlet of the base; the outer cover covers the first surface of the base, the driving circuit board covers the second surface of the base, so that the air inlet groove defines an air inlet path, the air outlet groove defines an air outlet path, the particle detection module has a length of 2 mm-4 mm, a width of 2 mm-4 mm and a thickness of 1 mm-3.5 mm, so that the piezoelectric actuator accelerates external gas to enter the air inlet path defined by the air inlet groove from the air inlet frame port, the particle concentration in the gas is detected through the particle sensor, the gas is guided through the piezoelectric actuator, is discharged into the air outlet path defined by the air outlet groove from the vent hole and is finally discharged through the air outlet frame port.

Drawings

Fig. 1 is a perspective view of a particle detecting module in the prior art.

Fig. 2A is a perspective view of the particle detecting module.

Fig. 2B is a perspective view of the particle detecting module according to another angle.

Fig. 2C is an exploded perspective view of the particle detection module according to the present disclosure.

Fig. 3A is a perspective view of the base.

Fig. 3B is a perspective view of the base at another angle.

Fig. 4 is a perspective view of the base housing the laser assembly and the particle sensor.

Fig. 5A is an exploded perspective view of the piezoelectric actuator in combination with a base.

Fig. 5B is a perspective view of the piezoelectric actuator in combination with a base.

Fig. 6A is an exploded perspective view of the piezoelectric actuator.

Fig. 6B is an exploded perspective view of the piezoelectric actuator from another angle.

FIG. 7A is a cross-sectional view of a piezoelectric actuator bonded to a gas guide bearing region.

Fig. 7B and 7C are schematic views illustrating the operation of the piezoelectric actuator of fig. 7A.

Fig. 8A-8C are schematic diagrams of the gas path of the particle detection module.

Fig. 9 is a schematic diagram of the path of the beam emitted by the laser assembly.

Fig. 10A is a schematic cross-sectional view of a microelectromechanical pump.

Fig. 10B is an exploded view of the microelectromechanical pump.

Fig. 11A to 11C are schematic views illustrating the operation of the mems pump.

Fig. 12 is a schematic view of a particle monitoring module set applied to a miniaturized portable electronic device.

FIG. 13 is a schematic diagram of a particle monitoring module embedded in a miniaturized mobile device.

Description of the reference numerals

1A: particle detection device

11A: shell body

12A: air guide piece

1: base seat

100: particle detection module

11: first surface

12: second surface

13: laser setting area

14: air inlet groove

14 a: air inlet

14 b: light-transmitting window

15: air guide assembly bearing area

15 a: vent hole

15 b: positioning notch

16: air outlet groove

16 a: air outlet

16 b: first interval

16 c: second interval

17: light trapping region

17 a: optical trap structure

2: piezoelectric actuator

2A: portable electronic device

21: air injection hole sheet

210: suspension plate

211: hollow hole

212: connecting piece

213: voids

22: cavity frame

23: actuating body

231: piezoelectric carrier plate

2311: piezoelectric pin

232: tuning the resonator plate

233: piezoelectric plate

24: insulating frame

25: conductive frame

251: conductive pin

252: conductive electrode

26: resonance chamber

27: airflow chamber

2 a: MEMS pump

21 a: first substrate

211 a: inflow hole

212 a: first surface

213 a: second surface

22 a: first oxide layer

221 a: confluence channel

222 a: confluence chamber

23 a: second substrate

231 a: silicon wafer layer

2311 a: actuating part

2312 a: outer peripheral portion

2313 a: connecting part

2314 a: fluid channel

232 a: second oxide layer

2321 a: vibration chamber

233 a: silicon layer

2331 a: perforation

2332 a: vibrating part

2333 a: fixing part

2334 a: third surface

2335 a: the fourth surface

24 a: piezoelectric component

241 a: lower electrode layer

242 a: piezoelectric layer

243 a: insulating layer

244 a: upper electrode layer

3: driving circuit board

3A: mobile device

4: laser assembly

5: particle sensor

6: outer cover

61: side plate

61 a: air inlet frame port

61 b: air outlet frame port

7 a: first volatile organic compound sensor

7 b: second volatile organic compound sensor

D: distance of light trap

H: thickness of

L: length of

W: width of

Detailed Description

Embodiments that embody the features and advantages of this disclosure will be described in detail in the description that follows. It will be understood that the present disclosure is capable of various modifications without departing from the scope of the disclosure, and that the description and drawings are to be regarded as illustrative in nature, and not as restrictive.

Referring to fig. 2A to 2C, a particle detecting module 100 is provided, which includes a base 1, a piezoelectric actuator 2, a driving circuit board 3, a laser assembly 4, a particle sensor 5 and a cover 6; the driving circuit board 3 is covered and attached to the second surface 12 of the base 1, the laser assembly 4 is disposed on the driving circuit board 3 and electrically connected to the driving circuit board 3, the particle sensor 5 is also disposed on the driving circuit board 3 and electrically connected to the driving circuit board 3, the outer cover 6 covers the base 1 and is attached to the first surface 11 of the base 1, the outer cover 6 has a side plate 61, and the side plate 61 has an air inlet frame port 61a and an air outlet frame port 61 b.

Referring to fig. 3A and 3B, the substrate 1 has a first surface 11, a second surface 12, a laser installation region 13, an air inlet groove 14, an air guide device bearing region 15 and an air outlet groove 16, the first surface 11 and the second surface 12 are two surfaces disposed oppositely, the laser installation region 13 is formed by hollowing from the first surface 11 toward the second surface 12, the air inlet groove 14 is formed by recessing from the second surface 12 and is adjacent to the laser installation region 13, the air inlet groove 14 is provided with an air inlet 14a communicated with the outside of the substrate 1 and corresponding to the air inlet frame opening 61a of the cover 6, and two side walls penetrate through a light-transmitting window 14B and are communicated with the laser installation region 13; therefore, the first surface 11 of the base 1 is covered by the cover 6, and the second surface 12 is covered by the driving circuit board 3, so that the air inlet channel 14 defines an air inlet path.

The air guide assembly bearing area 15 is formed by the second surface 12 in a concave mode, is communicated with the air inlet groove 14, and penetrates through a vent hole 15a at the bottom face; the air outlet groove 16 is provided with an air outlet 16a, the air outlet 16a is arranged corresponding to the air outlet frame port 61b of the outer cover 6, the air outlet groove 16 comprises a first section 16b formed by the first surface 11 corresponding to the vertical projection region of the air guide assembly bearing region 15 in a concave manner, and a second section 16c formed by hollowing out the first surface 11 to the second surface 12 in a region extending from the vertical projection region of the non-air guide assembly bearing region 15, wherein the first section 16b is connected with the second section 16c to form a section difference, the first section 16b of the air outlet groove 16 is communicated with the air vent 15a of the air guide assembly bearing region 15, and the second section 16c of the air outlet groove 16 is communicated with the air outlet 16 a; therefore, when the first surface 11 of the base 1 is covered by the cover 6 and the second surface 12 is covered by the driving circuit board 3, the air-out trench 16 defines an air-out path.

Fig. 4 is a schematic diagram of the base accommodating the laser assembly and the particle sensor, the laser assembly 4 and the particle sensor 5 are both disposed on the driving circuit board 3 and in the base 1, and the driving circuit board 3 is omitted from fig. 3 for clarity of description in order to clarify the positions of the laser assembly 4 and the particle sensor 5 and the base 1; referring to fig. 4 and fig. 2C, the laser assembly 4 is accommodated in the laser installation region 13 of the base 1, the particle sensor 5 is accommodated in the air inlet groove 14 of the base 1 and aligned with the laser assembly 4, the laser assembly 4 corresponds to the light transmission window 14b for the laser light emitted by the laser assembly 4 to pass through, so that the laser light irradiates into the air inlet groove 14, and the path of the light beam emitted by the laser assembly 4 passes through the light transmission window 14b and forms an orthogonal direction with the air inlet groove 14.

The laser assembly 4 emits a projection beam to enter the air inlet groove 14 through the light-transmitting window 14b, the projection beam irradiates suspended particles contained in the air inlet groove 14, when the beam contacts the suspended particles, the beam is scattered and generates a projection light spot, and the particle sensor 5 receives the projection light spot generated by scattering and calculates to obtain the related information of the particle size and the concentration of the suspended particles contained in the air. Wherein the particulate sensor 5 is a PM2.5 sensor.

Referring to fig. 5A and 5B, the piezoelectric actuator 2 is accommodated in the air guide device supporting region 15 of the base 1, the air guide device supporting region 15 is square, and four corners of the air guide device supporting region 15 are respectively provided with a positioning notch 15B, the piezoelectric actuator 2 is disposed in the air guide device supporting region 15 through the four positioning notches 15B, in addition, the air guide device supporting region 15 is communicated with the air inlet groove 14, when the piezoelectric actuator 2 is actuated, the air in the air inlet groove 14 is drawn into the piezoelectric actuator 2, and the air is introduced into the air outlet groove 16 through the vent holes 15A of the air guide device supporting region 15.

Referring to fig. 6A and 6B, the piezoelectric actuator 2 includes: an air injection hole plate 21, a cavity frame 22, an actuating body 23, an insulating frame 24 and a conductive frame 25.

The air hole plate 21 is made of a flexible material and has a suspension plate 210, a hollow hole 211 and a plurality of connecting members 212. The suspension plate 210 is a plate-shaped structure capable of bending and vibrating, and the shape and size of the suspension plate generally correspond to the inner edge of the air guide assembly carrying area 15, but not limited thereto, the shape of the suspension plate 210 may be one of square, circle, ellipse, triangle and polygon. The hollow hole 211 is formed through the center of the floating plate 210 for gas to flow through. In the present embodiment, the number of the connecting members 212 is four, and the number and the type of the connecting members are mainly corresponding to the positioning notches 15b of the air guide device carrying region 15, and each connecting member 212 and the corresponding positioning notch 15b form a snap structure for being snapped and fixed with each other, so that the piezoelectric actuator 2 can be disposed in the air guide device carrying region 15.

The cavity frame 22 is stacked on the air injection hole sheet 21, and the shape of the cavity frame corresponds to the air injection hole sheet 21, the actuating body 23 is stacked on the cavity frame 22, and a resonance chamber 26 is defined between the cavity frame 22 and the suspension sheet 210, the insulating frame 24 is stacked on the actuating body 23, the appearance of the actuating body is similar to that of the cavity frame 22, the conductive frame 25 is stacked on the insulating frame 24, the appearance of the conductive frame is similar to that of the insulating frame 24, the conductive frame 25 is provided with a conductive pin 251 and a conductive electrode 252, the conductive pin 251 extends outwards from the outer edge of the conductive frame 25, and the conductive electrode 252 extends inwards from the inner edge of the conductive frame 25. In addition, the actuator 23 further includes a piezoelectric carrier 231, an adjusting resonator plate 232 and a piezoelectric plate 233, the piezoelectric carrier 231 is stacked on the cavity frame 22, the adjusting resonator plate 232 is stacked on the piezoelectric carrier 231, the piezoelectric plate 233 is stacked on the adjusting resonator plate 232, the adjusting resonator plate 232 and the piezoelectric plate 233 are housed in the insulating frame 24, and the piezoelectric plate 233 is electrically connected to the conductive electrode 252 of the conductive frame 25, wherein the piezoelectric carrier 231 and the adjusting resonator plate 232 are made of conductive material, the piezoelectric carrier 231 has a piezoelectric pin 2311, the piezoelectric pin 2311 is connected to the conductive pin 251 and a driving circuit (not shown) on the driving circuit board 3 for receiving driving signals (driving frequency and driving voltage), and the driving signals can be formed by the piezoelectric pin 2311, the piezoelectric 231, the adjusting resonator plate 232, the piezoelectric plate 233, the conductive electrode 252, the conductive frame 25, The conductive pin 251 forms a loop, and the insulating frame 24 separates the conductive frame 25 from the actuator 23 to prevent short circuit, so that the driving signal is transmitted to the piezoelectric plate 233, and the piezoelectric plate 233 is deformed due to the piezoelectric effect after receiving the driving signal (driving frequency and driving voltage) to further drive the piezoelectric carrier plate 231 and adjust the resonator plate 232 to generate reciprocating bending vibration.

As described above, the tuning resonator plate 232 is located between the piezoelectric plate 233 and the piezoelectric carrier plate 231, and serves as a buffer between the two, thereby tuning the vibration frequency of the piezoelectric carrier plate 231. Basically, the thickness of the tuning resonance plate 232 is larger than that of the piezoelectric carrier plate 231, and the thickness of the tuning resonance plate 232 is variable, thereby tuning the vibration frequency of the actuating body 23.

Referring to fig. 6A, 6B and 7A, a plurality of connecting members 212 define a plurality of gaps 213 between the floating plate 210 and the inner edge of the air guide supporting region 15 for air to flow through.

Referring to fig. 7A, the air injection hole piece 21, the cavity frame 22, the actuator 23, the insulating frame 24 and the conductive frame 25 are correspondingly stacked and disposed in the air guide supporting region 15, and an air flow chamber 27 is formed between the air injection hole piece 21 and a bottom surface (not labeled) of the air guide supporting region 15. The air flow chamber 27 communicates with the resonance chamber 26 between the actuating body 23, the cavity frame 22 and the floating plate 210 through the hollow hole 211 of the air injection hole plate 21. By controlling the vibration frequency of the gas in the resonant cavity 26 to be approximately the same as the vibration frequency of the floating plate 210, a Helmholtz resonance effect (Helmholtz resonance) can be generated between the resonant cavity 26 and the floating plate 210, so as to improve the gas transmission efficiency.

Referring to fig. 7B and 7C, which are schematic operation diagrams of the piezoelectric actuator of fig. 7A, as shown in fig. 7B, when the piezoelectric plate 233 moves to a direction away from the bottom surface of the air guide assembly carrying region 15, the floating plate 210 of the air injection hole plate 21 is driven to move in a direction away from the bottom surface of the air guide assembly carrying region 15, so as to expand the volume of the air flow chamber 27 sharply, the internal pressure thereof decreases to form a negative pressure, and the air outside the piezoelectric actuator 2 is sucked to flow in through the plurality of gaps 213 and enter the resonant chamber 26 through the hollow hole 211, so that the air pressure in the resonant chamber 26 increases to generate a pressure gradient. As shown in fig. 7C, when the piezoelectric plate 233 drives the suspension plate 210 of the air injection hole piece 21 to move toward the bottom surface of the air guide assembly carrying region 15, the gas in the resonant chamber 26 flows out rapidly through the hollow hole 211, and the gas in the gas flow chamber 27 is squeezed, so that the converged gas is injected rapidly and in large quantities in an ideal gas state close to bernoulli's law. The exhausted interior of the resonant chamber 26, which is below the equilibrium pressure, will again introduce gas into the resonant chamber 26, based on inertial principles. Therefore, by repeating the operations of fig. 7B and 7C, the piezoelectric plate 233 is vibrated in a reciprocating manner, and the vibration frequency of the gas in the resonance chamber 26 is controlled to be approximately the same as the vibration frequency of the piezoelectric plate 233, so as to generate the helmholtz resonance effect, thereby realizing high-speed and large-volume gas transmission.

Referring to fig. 8A to 8C, fig. 8A to 8C are schematic diagrams of gas paths of the particle detection module, referring to fig. 8A, the gas enters from the gas inlet frame port 61a of the cover 6, enters into the gas inlet groove 14 of the base 1 through the gas inlet 14a, and flows to the position of the particle sensor 5, as shown in fig. 8B, the piezoelectric actuator 2 continuously drives the gas sucking the gas path to facilitate rapid introduction and stable circulation of the external gas, and passes through the upper side of the particle sensor 5, at this time, the laser assembly 4 emits a projected light beam to enter into the gas inlet groove 14 through the light-transmitting window 14B, the gas irradiated into the gas inlet groove 14 passes through the aerosol contained in the gas above the particle sensor 5, the light beam scatters and generates a projected light spot when contacting the aerosol, the particle sensor 5 receives the projected light spot generated by scattering to perform calculation to obtain information related to the particle size and concentration of the aerosol contained in the gas, and the gas above the particle sensor 5 is also continuously driven and transmitted by the piezoelectric actuator 2 to be guided into the vent hole 15a of the gas guide component bearing area 15, and enters the first section 16b of the gas outlet groove 16, and finally as shown in fig. 8C, after the gas enters the first section 16b of the gas outlet groove 16, as the piezoelectric actuator 2 continuously conveys the gas into the first section 16b, the gas in the first section 16b is pushed to the second section 16C, and finally is discharged outwards through the gas outlet 16a and the gas outlet frame port 61 b.

As shown in fig. 9, the base 1 further includes a light trap region 17, the light trap region 17 is formed by hollowing from the first surface 11 to the second surface 12 and corresponds to the laser installation region 13, and the light trap region 17 passes through the light-transmitting window 14b so that the light beam emitted by the laser element 4 can be projected into the light trap region 17, the light trap region 17 is provided with a tapered light trap structure 17a, and the light trap structure 17a corresponds to the path of the light beam emitted by the laser element 4; in addition, the light trap structure 17a reflects the projected light beam emitted by the laser component 4 into the light trap region 17 in the oblique cone surface structure, so as to avoid the light beam from reflecting to the position of the particle sensor 5, and a light trap distance D is kept between the position of the projected light beam received by the light trap structure 17a and the light-transmitting window 14b, and the light trap distance D needs to be larger than 3mm, so that when the light trap distance D is smaller than 3mm, the projected light beam projected on the light trap structure 17a is reflected back to the position of the particle sensor 5 directly due to excessive stray light, and distortion of detection precision is caused.

Referring to fig. 9 and fig. 2C, the particle detecting module 100 of the present invention can detect not only particles in the gas, but also the characteristics of the introduced gas, so that the particle detecting module 100 further includes a first volatile organic compound sensor 7a, which is positioned on the driving circuit board 3, electrically connected to the driving circuit board, and accommodated in the gas outlet trench 16, for detecting the gas guided out of the gas outlet path, so as to detect the concentration of the volatile organic compound contained in the gas outlet path. Or the particle detection module 100 of the present disclosure further includes a second volatile organic compound sensor 7b, which is positioned on the driving circuit board 3 and electrically connected thereto, and the second volatile organic compound sensor 7b is accommodated in the optical trap region 17, and detects the concentration of the volatile organic compound of the gas that passes through the gas inlet path of the gas inlet trench 14 and is led into the optical trap region 17 through the light-transmitting window 14 b.

As can be seen from the above description, the particle detection module 100 of the present invention is configured by appropriately configuring the laser installation region 13, the air inlet groove 14, the air guide component bearing region 15 and the air outlet groove 16 on the substrate 1, and by matching with the cover sealing design of the cover 6 and the driving circuit board 3, so that the cover 6 covers the first surface 11 of the substrate 1, and the driving circuit board 3 covers the second surface 12, so that the air inlet groove 14 defines an air inlet path, and the air outlet groove 16 defines an air outlet path, forming a single-layer air guide channel path, so that the height of the overall structure of the particle detection module 100 of the present invention is reduced, so that the length L of the particle detection module 100 is between 2mm and 4mm, the width W is between 2mm and 4mm, and the thickness H is between 1mm and 3.5mm, which is beneficial for assembling and combining with the miniaturized portable electronic device 2A shown in fig. 12, or assembling and combining with the miniaturized mobile device 3A shown in fig. 13, is convenient for the user to carry to detect the concentration of the particles in the surroundings. In addition, another embodiment of the piezoelectric actuator 2 can be a mems pump 2a, referring to fig. 10A and 10B, the mems pump 2a includes a first substrate 21a, a first oxide layer 22a, a second substrate 23a and a piezoelectric element 24 a; it should be noted that the mems pump 2a of the present embodiment is formed by epitaxy, deposition, photolithography, etching, etc. in a semiconductor process, and should not be disassembled, so as to describe its internal structure, it is specifically described in an exploded view.

The first substrate 21a is a silicon wafer (Si wafer) with a thickness of 150 to 400 micrometers (μm), the first substrate 21a has a plurality of flow holes 211a, a first surface 212a and a second surface 213a, and in the present embodiment, the number of the flow holes 211a is 4, but not limited thereto, and each of the flow holes 211a penetrates from the second surface 213a to the first surface 212a, and the flow holes 211a form a tapered shape from the second surface 213a to the first surface 212a to enhance the flow effect.

The first oxide layer 22a is a silicon dioxide (SiO)₂) The first oxide layer 22a is stacked on the first surface 212a of the first substrate 21a, the first oxide layer 22a has a plurality of bus channels 221a and a bus chamber 222a, and the number and the positions of the bus channels 221a and the flow holes 211a of the first substrate 21a correspond to each other. In this embodiment, the number of the bus channels 221a is also 4, one end of each of the 4 bus channels 221a is connected to the 4 inflow holes 211a of the first substrate 21a, and the other end of each of the 4 bus channels 221a is connected to the bus chamber 222a, so that the gas enters from the inflow holes 211a, and then is collected into the bus chamber 222a through the corresponding bus channel 221 a.

The second substrate 23a is a silicon-on-insulator (SOI wafer) comprising: a silicon layer 231a, a second oxide layer 232a and a silicon layer 233 a; the silicon wafer layer 231a has a thickness of 10 to 20 micrometers (μm), and has an actuating portion 2311a, a peripheral portion 2312a, a plurality of connecting portions 2313a, and a plurality of fluid channels 2314a, wherein the actuating portion 2311a is circular; the outer peripheral portion 2312a is in a hollow ring shape and surrounds the periphery of the actuating portion 2311 a; the connecting portions 2313a are respectively located between the actuating portions 2311a and the outer peripheral portion 2312a and connect the two, providing a function of elastic support. The fluid passages 2314a are formed around the periphery of the actuating portion 2311a and are respectively located between the connecting portions 2313 a.

The second oxide layer 232a is a silicon oxide layer with a thickness of 0.5 to 2 micrometers (μm), is formed on the silicon wafer layer 231a, is in a hollow ring shape, and defines a vibration chamber 2321a with the silicon wafer layer 231 a. The silicon material layer 233a is circular, stacked on the second oxide layer 232a and bonded to the first oxide layer 22a, and the silicon material layer 233a is silicon dioxide (SiO)₂) A thin film with a thickness of 2-5 μm, having a through hole 2331a, a vibrating portion 2332a, a fixing portion 2333a, a third surface 2334a anda fourth surface 2335 a. The through hole 2331a is formed in the center of the silicon layer 233a, the vibrating portion 2332a is located in the peripheral region of the through hole 2331a and vertically corresponds to the vibrating chamber 2321a, the fixing portion 2333a is the peripheral region of the silicon layer 233a and is fixed to the second oxide layer 232a by the fixing portion 2333a, the third surface 2334a is joined to the second oxide layer 232a, and the fourth surface 2335a is joined to the first oxide layer 22 a; the piezoelectric element 24a is stacked on the actuation portion 2311a of the silicon wafer layer 231 a.

The piezoelectric element 24a includes a lower electrode layer 241a, a piezoelectric layer 242a, an insulating layer 243a and an upper electrode layer 244a, the lower electrode layer 241a is stacked on the actuating portion 2311a of the silicon layer 231a, the piezoelectric layer 242a is stacked on the lower electrode layer 241a, the two are electrically connected through the contact area, in addition, the width of the piezoelectric layer 242a is smaller than the width of the lower electrode layer 241a, so that the piezoelectric layer 242a cannot completely shield the lower electrode layer 241a, the insulating layer 243a is stacked on a partial area of the piezoelectric layer 242a and an area of the lower electrode layer 241a not shielded by the piezoelectric layer 242a, finally, the upper electrode layer 244a is stacked on the insulating layer 243a and the rest surface of the piezoelectric layer 242a not shielded by the insulating layer 243a, so that the upper electrode layer 244a can be in contact with the piezoelectric layer 242a for electrical connection, and the insulating layer 243a is used to block between the upper electrode layer 244, avoid the direct contact between the two to cause short circuit.

Referring to fig. 11A to 11C, fig. 11A to 11C are schematic operation diagrams of the mems pump 2 a. Referring to fig. 11A, after receiving the driving voltage and the driving signal (not shown) transmitted by the driving circuit board 3, the lower electrode layer 241A and the upper electrode layer 244a of the piezoelectric element 24a transmit the driving voltage and the driving signal to the piezoelectric layer 242a, and the piezoelectric layer 242a starts to deform due to the inverse piezoelectric effect after receiving the driving voltage and the driving signal, which drives the actuating portion 2311A of the silicon wafer layer 231A to start to move, and when the piezoelectric element 24a drives the actuating portion 2311A to move upward and pull away the distance from the second oxide layer 232a, at this time, the volume of the vibration chamber 2321A of the second oxide layer 232a is increased, so that a negative pressure is formed in the vibration chamber 2321A, and the gas in the collecting chamber 222a of the first oxide layer 22a is sucked into the through hole 2331A. Referring to fig. 11B, when the actuator 2311a is pulled by the piezoelectric element 24a to displace upward, the vibrating portion 2332a of the silicon layer 233a displaces upward due to the resonance principle, when the vibrating portion 2332a displaces upward, the space of the vibration chamber 2321a is compressed and the gas in the vibration chamber 2321a is pushed to move toward the fluid channel 2314a of the silicon layer 231a, so that the gas can be discharged upward through the fluid channel 2314a, while the vibrating portion 2332a displaces upward to compress the vibration chamber 2321a, the volume of the vibration chamber 222a is raised due to the displacement of the vibrating portion 2332a, a negative pressure is formed inside the vibration chamber to suck the gas outside the micro-pump 2a from the inflow hole 211a into the vibration chamber, and finally, as shown in fig. 11C, when the piezoelectric element 24a drives the actuator 2311a of the silicon layer 231a to displace downward, the gas in the vibration chamber 2321a is pushed toward the fluid channel 2314a, the gas is exhausted, the vibrating portion 2332a of the silicon material layer 233a is also driven by the actuating portion 2311a to move downward, the gas synchronously compressing the confluence chamber 222a moves toward the vibration chamber 2321a through the through hole 2331a, and then the piezoelectric element 24a drives the actuating portion 2311a to move upward, the volume of the vibration chamber 2321a is greatly increased, so that the gas is sucked into the vibration chamber 2321a with high suction force, and the above operations are repeated, so that the piezoelectric element 24a continuously drives the actuating portion 2311a to move up and down to drive the vibrating portion 2332a to move up and down, and the internal pressure of the micro-electromechanical pump 2a is changed to continuously suck and exhaust the gas, thereby completing the operation of the micro-electromechanical pump 2 a.

Certainly, in order to embed the particle detection module 100 in the mobile device 3A, the piezoelectric actuator 2 of the present invention can be replaced by a micro electromechanical pump 2a, so that the overall size of the particle detection module 100 of the present invention is further reduced, so that the length L and the width W of the particle detection module 100 are reduced to 2mm to 3mm, and the thickness H is between 1mm to 2.5mm, and the particle detection module is implemented in the mobile device 3A such as a conventional thin smart phone with a thickness of 5mm, and the detection module is directly embedded in the smart phone, so that a user can detect the quality of the surrounding air in real time.

In summary, in the particle detection module provided by the present disclosure, the laser element is directly disposed on the driving circuit board, the driving circuit board is attached to the second surface of the base, the first surface of the base is attached to the outer cover, the air inlet groove defines an air inlet path, and the air outlet groove defines an air outlet path, so that the thickness of the particle detection module can be greatly reduced, in addition, the piezoelectric actuator and the laser element are separately disposed, and the design of the air channel is supplemented, so that the piezoelectric actuator can be prevented from interfering with the operation of the laser element and the particle sensor when actuated, the volume of the particle detection module can be reduced, the length of the particle detection module can be reduced to 2mm to 4mm, the width can be reduced to 2mm to 4mm, the thickness can be reduced to 1mm to 3.5mm, the particle detection module can be conveniently carried, and the optical trap structure of the light trap region is utilized, scattered light generated after the laser component contacts the base body through the light beam of the particle sensor can be reduced from entering the particle sensor again, the detection efficiency of the particle sensor 5 can be improved, and the particle sensor has industrial applicability and advancement.

Claims (9)

1. A particle detection module, comprising:

a base having:

a first surface;

a second surface opposite to the first surface;

a laser setting area formed by hollowing from the first surface to the second surface;

an air inlet groove which is formed by sinking from the second surface, is adjacent to the laser setting area, is provided with an air inlet, is communicated with the outside of the base and is provided with a light-transmitting window at the adjacent position of the laser setting area;

the air guide assembly bearing area is formed by sinking from the second surface, communicated with the air inlet groove and communicated with a vent hole on the bottom surface; and

an air outlet groove, which is recessed from the first surface to the bottom surface of the air guide assembly bearing area, is formed by hollowing the area of the first surface, which is not corresponding to the air guide assembly bearing area, from the first surface to the second surface, is communicated with the air vent hole, is provided with an air outlet and is communicated with the outside of the base;

the piezoelectric actuator is accommodated in the air guide assembly bearing area;

the driving circuit board is attached to the second surface of the base by the sealing cover;

the laser assembly is positioned on the driving circuit board, is electrically connected with the driving circuit board, is correspondingly accommodated in the laser arrangement area, and emits a light beam path which penetrates through the light-transmitting window and forms an orthogonal direction with the air inlet groove;

a particle sensor, which is positioned on the driving circuit board and electrically connected with the driving circuit board, and is correspondingly accommodated at the orthogonal direction position of the light beam path projected by the air inlet groove and the laser component, so as to detect the particles which pass through the air inlet groove and are irradiated by the light beam projected by the laser component; and

the outer cover covers the first surface of the base and is provided with a side plate, and the side plate is provided with an air inlet frame opening and an air outlet frame opening respectively corresponding to the air inlet and the air outlet of the base;

the outer cover covers the first surface of the base, the driving circuit board covers the second surface of the base, so that the air inlet groove defines an air inlet path, the air outlet groove defines an air outlet path, the particle detection module has a length of 2 mm-4 mm, a width of 2 mm-4 mm and a thickness of 1 mm-3.5 mm, so that the piezoelectric actuator accelerates external gas to enter the air inlet path defined by the air inlet groove from the air inlet frame port, the particle concentration in the gas is detected through the particle sensor, the gas is guided through the piezoelectric actuator, is discharged into the air outlet path defined by the air outlet groove from the vent hole and is finally discharged through the air outlet frame port.

2. The particle detection module of claim 1, wherein the air guide unit carrying region has a positioning notch at each of four corners for the piezoelectric actuator to be inserted and positioned.

3. The particle detection module of claim 1, wherein the base further comprises an optical trap region hollowed out from the first surface toward the second surface and corresponding to the laser installation region, the optical trap region having an optical trap structure with a tapered surface installed corresponding to the beam path.

4. The particle detection module of claim 3, wherein the projection light source received by the optical trap structure is positioned at an optical trap distance from the optically transparent window.

5. The particulate detection module of claim 1, wherein the particulate sensor is a PM2.5 sensor.

6. The particle detection module of claim 1, wherein the particle detection module has a length of 2mm to 3mm, a width of 2mm to 3mm, and a thickness of 1mm to 2.5mm, and the piezoelectric actuator is a micro-electromechanical pump comprising:

a first substrate having a plurality of inflow holes, the plurality of inflow holes being tapered;

the first oxide layer is stacked on the first substrate and provided with a plurality of confluence passages and a confluence chamber, and the confluence passages are communicated between the confluence chamber and the plurality of inflow holes;

a second substrate bonded to the first substrate, comprising:

a silicon wafer layer having:

an actuating portion, which is circular;

an outer peripheral portion, which is in a hollow ring shape and surrounds the periphery of the actuating portion;

a plurality of connecting portions respectively connected between the actuating portion and the outer circumferential portion; and

a plurality of fluid channels surrounding the periphery of the actuating part and respectively positioned among the connecting parts; a second oxide layer formed on the silicon chip layer and having a hollow ring shape, and defining a vibration chamber with the silicon chip layer; and

a circular silicon layer on the second oxide layer and bonded to the first oxide layer, comprising:

a through hole formed in the center of the silicon material layer;

a vibrating part located in the peripheral area of the through hole; and

a fixing part located at the peripheral region of the silicon material layer; and

and the piezoelectric component is circular and is stacked on the actuating part of the silicon wafer layer.

7. The particle detection module of claim 6, wherein the piezoelectric element comprises:

a lower electrode layer;

a piezoelectric layer stacked on the lower electrode layer;

an insulating layer, which is laid on partial surface of the piezoelectric layer and partial surface of the lower electrode layer; and

and the upper electrode layer is superposed on the insulating layer and the rest surface of the piezoelectric layer, which is not provided with the insulating layer, and is electrically connected with the piezoelectric layer.

8. The particle detection module of claim 1, further comprising a first volatile organic compound sensor positioned on the driving circuit board and electrically connected to the air outlet trench for detecting air discharged from the air outlet path.

9. The particle detection module of claim 3, further comprising a second VOC sensor positioned on the driving circuit board and electrically connected to the light trapping region for detecting gas introduced into the light trapping region through the light-transmissive window and the gas inlet path of the gas inlet trench.

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