CN114983032A - MEMS structure atomizing core and preparation method thereof - Google Patents

Abstract

The invention discloses an MEMS structure atomizing core and a preparation method thereof. The MEMS structure atomizing core comprises: the supporting structure is provided with a first surface and a second surface which are arranged back to back, the first surface is provided with an oil storage groove, the second surface is provided with an oil guide hole communicated with the oil storage groove, and the second surface and the first surface are arranged back to back; and the resistance heating structure is arranged on the second surface of the supporting structure, and after the resistance heating structure is connected with a power supply, the fluid medium conveyed from the oil guide hole can be contacted with the resistance heating structure and heated and atomized. The invention not only ensures that the atomizing core has higher reliability and better temperature consistency control, can accurately control the resistance range, but also can accurately control the oil seepage rate and quantity, can realize the manufacturing with batch and low cost by combining the semiconductor process, and avoids the pollution caused by the sintering of the ceramic process.

Description

MEMS structure atomizing core and preparation method thereof

Technical Field

The invention particularly relates to an MEMS structure atomizing core and a preparation method thereof, and belongs to the technical field of atomizers.

Background

Atomization is the process of turning a fluid medium into small droplets in some way. At present, the atomization mode mainly comprises high-pressure gas atomization, ultrasonic atomization, microwave heating atomization, resistance heating atomization and the like. As the "heart" of the atomization technique, the atomizing core determines the atomization effect.

The current common atomizing core structure is shown in fig. 1, which is formed on a porous ceramic by a printing process to form a heating resistor. The tiny micropores in the porous ceramic are the key for realizing the functions of stably guiding and locking the liquid by the ceramic atomizing core. Due to surface tension and capillary action, the fluid medium can uniformly penetrate into the atomizing core and be adsorbed on the surface of the atomizing core.

Compared with other atomization modes, the porous ceramic atomization core has the advantages that the temperature can rise faster and the temperature uniformity is better in the heating process. However, the resistance paste is prepared by a screen printing process and is subjected to high-temperature sintering and other processes subsequently, on one hand, the high-temperature sintering can cause the shrinkage of the resistance paste, so that the discreteness of the resistance is caused; on the other hand, since the porous ceramic support structure is a microporous structure, the resistance paste may permeate into pores during printing, thereby causing defects such as disconnection, open circuit, and the like. The alloy membrane is used as the atomizing core of the heating structure, and in the heating working state, the gap is generated between the alloy membrane and the porous ceramic due to the problem of the difference of the thermal expansion coefficients, so that the atomizing effect is influenced.

Disclosure of Invention

The invention mainly aims to provide an MEMS structure atomizing core and a preparation method thereof, thereby overcoming the defects in the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:

the embodiment of the invention provides an MEMS structure atomizing core, which comprises:

the supporting structure is provided with a first surface and a second surface which are arranged back to back, the first surface is provided with an oil storage groove, the second surface is provided with an oil guide hole communicated with the oil storage groove, and the second surface and the first surface are arranged back to back;

and the resistance heating structure is arranged on the second surface of the supporting structure, and when the resistance heating structure is connected with a power supply, the fluid medium conveyed from the oil guide hole can be contacted with the resistance heating structure and heated and atomized.

The embodiment of the invention also provides a preparation method of the MEMS structure atomizing core, which is characterized by comprising the following steps:

forming a patterned conductive material layer on the second surface of the support structure and serving as a resistance heating structure;

and forming an oil guide hole penetrating through the supporting structure at the bottom of the oil storage groove, and enabling the fluid medium conveyed from the oil guide hole to be in contact with the conductive material layer.

Compared with the prior art, the invention has the advantages that: the atomization core of the MEMS structure atomization core structure provided by the invention has higher reliability and better temperature consistency control, and can accurately control the resistance range; and the speed and the quantity of oil leakage can be accurately controlled, and the batch and low-cost manufacturing can be realized by combining a semiconductor process, so that the pollution caused by the sintering of a ceramic process is avoided.

Drawings

FIG. 1 is a sample of a porous ceramic atomizing core of the prior art;

FIG. 2 is a schematic structural diagram of an atomizing core of a MEMS structure provided in embodiment 1 of the present invention;

FIG. 3 is a schematic diagram of a heating resistor provided in an exemplary embodiment of the present invention;

FIG. 4 is a schematic flow chart of the preparation process of an atomizing core of an MEMS structure provided in embodiment 1 of the present invention;

FIG. 5 is a schematic structural diagram of a process for preparing an atomizing core of an MEMS structure provided in embodiment 1 of the present invention;

fig. 6 is a schematic structural diagram of an atomizing core of a MEMS structure provided in embodiment 2 of the present invention.

Detailed Description

In view of the deficiencies in the prior art, the inventors of the present invention have made extensive studies and extensive practices to provide technical solutions of the present invention. The technical solution, its implementation and principles, etc. will be further explained as follows.

An atomizing core which is simple in process, good in performance and high in precision is researched and developed, and is suitable for application fields such as electronic cigarettes, humidifiers, face steaming devices, mist making machines and medical atomizers.

In order to overcome the defects of the porous ceramic atomizing core prepared by thick film printing and alloy membrane at present, the invention provides a method for realizing the imaging of a metal film on the surface of a silicon substrate on a silicon substrate supporting structure by utilizing the deposition technology in the semiconductor process to form a stable heating resistor structure; on the other hand, an oil storage tank with higher precision is formed by dry etching and wet etching, an accurate oil guide hole can be formed, the permeation rate of fluid medium in the atomization process can be controlled, and a good atomization effect is kept.

The embodiment of the invention provides an MEMS structure atomizing core, which takes monocrystalline silicon as a main base material and is divided into two main structures, wherein a middle core is a heating structure and takes deposited metal materials as a heating part; the lower layer is a supporting structure, a frame structure formed by using monocrystalline silicon as a base material, and the middle part is provided with array micropores.

The embodiment of the invention provides an MEMS structure atomizing core, which comprises:

the supporting structure is provided with a first surface and a second surface which are arranged back to back, the first surface is provided with an oil storage tank, the second surface is provided with an oil guide hole communicated with the oil storage tank, and the second surface and the first surface are arranged back to back;

and the resistance heating structure is arranged on the second surface of the supporting structure, and after the resistance heating structure is connected with a power supply, the fluid medium conveyed from the oil guide hole can be contacted with the resistance heating structure and heated and atomized.

In some specific embodiments, the support structure includes a first support structure and a second support structure arranged in a stacked manner, wherein a thermal conductivity of the first support structure is greater than a thermal conductivity of the second support structure, the oil storage tank is at least arranged in the second support structure, the resistance heating structure is arranged on the first support structure, and the oil guide hole simultaneously penetrates through the first support structure and the second support structure.

In some specific embodiments, the first supporting structure is a silicon oxide supporting structure, the thickness of the first supporting structure is 100nm to 2000nm, the thickness of the second supporting structure is a monocrystalline silicon supporting structure, the thickness of the second supporting structure is 100 μm to 5000 μm, and the thickness of the second supporting structure at the bottom of the oil storage tank is 2 to 5 times the thickness of the first supporting structure.

In some more specific embodiments, the first support structure is formed by oxidation of a surface region of the second support structure.

In some specific embodiments, the second surface of the support structure is provided with a plurality of oil guiding holes, and the plurality of oil guiding holes are distributed in an array;

in some specific embodiments, the cross-sectional shape of the oil guide hole includes any one or a combination of two or more of a circle, an ellipse, a square, a triangle and a cross-section of a Chinese character 'mi'.

In some specific embodiments, the plurality of oil guiding holes are distributed in a square, S-shaped or opening shape as a whole.

In some more specific embodiments, the diameter of the oil guide hole is 1 μm to 500 μm, and the gap between adjacent oil guide holes is 1 μm to 500 μm.

In some more specific embodiments, the second surface of the support structure has a first region and a second region, the resistive heating structure includes a patterned conductive material layer at least overlying the first region, and the oil guide hole is at least disposed in the second region.

In some more specific embodiments, the second region of the second surface of the support structure is further provided with a plurality of guide grooves, each of the guide grooves is further communicated with the oil guide hole, and the depth of the guide groove is less than 1/2 of the thickness of the first support structure.

In some more specific embodiments, each of the guiding grooves is further filled with a guiding layer, the guiding layer is formed by combining metal particles and non-metal particles, wherein the metal particles are made of the same material as the resistance heating structure, the non-metal particles are made of the same material as the second supporting structure, and the resistance heating structure is further directly contacted with or connected to the guiding layer.

In some more specific embodiments, the layer of conductive material has a thickness of 100nm to 500 μm.

In some specific embodiments, the material of the conductive material layer includes one of the elements Ni, Cr, Au, Pt, Mo, and W, or an alloy formed by two or more of the elements.

The embodiment of the invention also provides a preparation method of the MEMS structure atomizing core, which is characterized by comprising the following steps:

forming a patterned conductive material layer on the second surface of the support structure and serving as a resistance heating structure;

and forming an oil guide hole penetrating through the supporting structure at the bottom of the oil storage groove, and enabling the fluid medium conveyed from the oil guide hole to be in contact with the conductive material layer.

In some more specific embodiments, the preparation method specifically comprises:

oxidizing a part of monocrystalline silicon of the support structure close to the second surface to form silicon oxide, taking the silicon oxide formed by oxidation as a first support structure, and taking the unoxidized residual part as a second support structure;

processing and forming an oil storage tank on the first surface of the supporting structure, arranging all the oil storage tank in the second supporting structure, manufacturing and forming the oil guide hole at the bottom of the oil storage tank, and enabling the oil guide hole to continuously penetrate through the second supporting structure and the first supporting structure;

and forming a resistance heating structure on the surface of the first support structure.

In some more specific embodiments, the preparation method specifically comprises:

processing and forming a plurality of guide grooves on the surface layer of the first support structure, so that the guide grooves are communicated with the oil guide holes, and then forming a guide layer containing metal particles and non-metal particles in the guide grooves, wherein the metal particles are made of the same material as the resistance heating structure, and the non-metal particles are made of the same material as the second support structure;

and forming the resistance heating structure on the surface of the first support structure, and enabling the resistance heating structure to be directly contacted with or connected with the guide layer.

The technical solution, implementation procedures, principles and the like of the embodiments of the present invention will be further explained with reference to the drawings and specific embodiments, unless otherwise specified, all processes such as oxidation, deposition, etching and the like used in the embodiments of the present invention may be known to those skilled in the art, and the specific process conditions are not limited herein.

The invention provides an MEMS structure atomizing core structure which is mainly divided into two parts, wherein one part is a structure deposited with a heating film, and the other part is an oil-permeable structure comprising guide holes distributed in an array manner. The invention not only ensures that the reliability of the atomizing core is higher, the temperature consistency is better controlled, and the resistance range can be accurately controlled; and the speed and the quantity of oil leakage can be accurately controlled, and the batch and low-cost manufacturing can be realized by combining a semiconductor process, so that the pollution caused by the sintering of a ceramic process is avoided.

Example 1

Referring to fig. 2 and 3, an MEMS atomizing core structure includes a second supporting structure 200, a first supporting structure 100, and a resistance heating structure 300, which are sequentially stacked, the second supporting structure 200 has a first surface facing away from the first supporting structure 100, the first supporting structure 100 has a second surface facing away from the second supporting structure 200, the first surface of the second supporting structure 200 is provided with an oil storage tank 210, the second surface of the second supporting structure 200 is provided with a plurality of oil guiding holes 220, the oil guiding holes 220 continuously penetrate through the first supporting structure 100 and the second supporting structure 200 and are communicated with the oil storage tank 210, the resistance heating structure 200 is disposed on the second surface of the first supporting structure 100, and when the resistance heating structure 300 is powered, a fluid medium delivered from the oil guiding holes 220 can contact with the resistance heating structure 300 and be heated and atomized, the fluid medium includes tobacco tar and the like.

In this embodiment, the thermal conductivity of the first support structure 100 is greater than the thermal conductivity of the second support structure 200, the entire reservoir 210 is disposed in the second support structure 200, the reservoir 210 has a variable diameter structure that gradually changes in a direction toward the first support structure 100, and a radial or transverse dimension of the reservoir 210 gradually decreases in a direction toward the first support structure 100.

In this embodiment, the first supporting structure 100 is a silicon oxide supporting structure, the thickness of the first supporting structure 100 is 100nm to 2000nm, the second supporting structure 200 is a monocrystalline silicon supporting structure, the thickness of the second supporting structure 200 is 100 μm to 5000 μm, and the thickness of the second supporting structure 200 remaining at the bottom of the oil storage tank 210 is 2 to 5 times the thickness of the first supporting structure 100.

In the present embodiment, the first support structure 100 is formed by oxidizing a surface layer region of the second support structure 200.

In this embodiment, the second surface of the support structure is provided with a plurality of oil guiding holes 220, the plurality of oil guiding holes 220 are distributed in an array, the cross-sectional shape of the oil guiding holes 220 includes any one or a combination of two or more of circular, oval, square, triangular and square, the plurality of oil guiding holes 220 are distributed in a square, S-shaped or square shape as a whole, the aperture of each oil guiding hole 220 is 1 μm to 500 μm, and the gap between adjacent oil guiding holes 220 is 1 μm to 500 μm.

In this embodiment, the second surface of the first support structure 100 has a first region and a second region, the resistance heating structure 300 includes a patterned conductive material layer covering the first region, and the oil guiding hole 220 is disposed in the second region, wherein the conductive material layer is disposed in a pattern, and the pattern of the conductive material layer may be a circular ring shape, a wave shape, a planar spiral shape, or the like, as shown in fig. 3.

In this embodiment, the thickness of the conductive material layer is 100nm-500 μm, and the material of the conductive material layer includes one of Ni, Cr, Au, Pt, Mo, and W or an alloy formed by two or more of these.

In this embodiment, the first surface of the first supporting structure 100 is further provided with a bonding pad 400, the bonding pad 400 is electrically connected to the resistance heating structure 300, the bonding pad 400 may be a metal bonding pad, and the parameters such as the size of the bonding pad are not specifically limited and described herein.

Referring to fig. 4 and 5, a method for preparing an atomizing core of an MEMS structure includes:

1) taking monocrystalline silicon as a raw material for manufacturing a supporting structure, and cleaning the monocrystalline silicon;

2) oxidizing partial area of the monocrystalline silicon surface layer by adopting an oxidation process to form silicon oxide, taking the silicon oxide part formed after oxidation as a first support structure, and taking the remaining part of the monocrystalline silicon as a second support structure;

3) photoetching and forming the shape of a resistance heating structure on the surface of the first support structure;

4) depositing a metal material on the photoetching area on the surface of the first support structure to form a conductive material layer, and taking the patterned conductive material layer as a resistance heating structure;

5) processing the surface of the second supporting structure back to the first supporting structure by adopting etching and other modes to form an oil storage tank, enabling the oil storage tank and the resistance heating structure to be arranged back to back, and controlling the thickness of the second supporting structure remained at the bottom of the oil storage tank to be 2-5 times of the thickness of the first supporting structure;

6) processing and forming a plurality of oil guide holes in the area, which is not covered by the resistance heating structure, on the surface of the first supporting structure by adopting etching and other modes, and enabling the oil guide holes to continuously penetrate through the first supporting structure and the second supporting structure along the thickness direction and to be communicated with the oil storage tank;

7) and manufacturing a bonding pad on the surface of the first support structure, and electrically connecting the bonding pad with the resistance heating structure.

Example 2

Referring to fig. 6, the structure of an atomizing core of an MEMS structure in this embodiment is substantially the same as that in embodiment 1, except that: in this embodiment, a plurality of guide grooves are further disposed on a second surface of the first support structure 100, facing away from the second support structure 200, each of the guide grooves is further communicated with at least one oil guide hole 220, the depth of each of the guide grooves is less than 1/2 of the thickness of the first support structure 100, a guide layer 500 is further filled in each of the guide grooves, the guide layer 500 is formed by combining metal particles and non-metal particles, the metal particles are made of the same material as the resistance heating structure 300, the non-metal particles are made of the same material as the second support structure 200, the volume ratio of the metal particles in the guide layer 500 is 50-75%, and the resistance heating structure 300 is further directly contacted or connected with the guide layer, wherein the particle diameters of the metal particles and the non-metal particles are both in a micro-nano level, and the metal particles and the non-metal particles can be sintered, The bonding and laminating layers are formed by bonding and are not specifically limited herein.

In this embodiment, the characteristic that the guiding layer itself has good compatibility with the resistance heating structure and the silicon oxide supporting structure can be utilized, the bonding force between the resistance heating structure and the silicon oxide supporting structure can be enhanced from the material science perspective, on the other hand, the guiding layer is also used as an anchor point, the bonding between the resistance heating structure and the silicon oxide supporting structure is enhanced from the mechanical perspective, and the problems of warping, separation and the like possibly caused by the difference of thermal expansion coefficients between the resistance heating structure and the silicon oxide supporting structure are solved. In addition, due to the existence of the guide grooves and the guide layers, a three-dimensional heating path (the resistance heating structure is in surface contact with the silicon oxide support structure, so that surface heating is realized, and the guide layers are deep into the silicon oxide support structure, so that one heating dimension is increased), and the heating efficiency and the heating uniformity are further improved.

It should be understood that the above-mentioned embodiments are merely illustrative of the technical concepts and features of the present invention, which are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and therefore, the protection scope of the present invention is not limited thereby. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims (10)

1. An atomizing core of a MEMS structure, comprising:

the supporting structure is provided with a first surface and a second surface which are arranged back to back, the first surface is provided with an oil storage groove, the second surface is provided with an oil guide hole communicated with the oil storage groove, and the second surface and the first surface are arranged back to back;

and the resistance heating structure is arranged on the second surface of the supporting structure, and after the resistance heating structure is connected with a power supply, the fluid medium conveyed from the oil guide hole can be contacted with the resistance heating structure and heated and atomized.

2. The MEMS structural atomizing core of claim 1, wherein: the supporting structure comprises a first supporting structure and a second supporting structure which are arranged in a stacking mode, wherein the heat conductivity coefficient of the first supporting structure is larger than that of the second supporting structure, the oil storage tank is at least arranged in the second supporting structure, the resistance heating structure is arranged on the first supporting structure, and the oil guide hole penetrates through the first supporting structure and the second supporting structure simultaneously.

3. The MEMS structural atomizing core of claim 1, wherein: the first supporting structure is a silicon oxide supporting structure, the thickness of the first supporting structure is 100nm-2000nm, the second supporting structure is a monocrystalline silicon supporting structure, and the thickness of the second supporting structure is 100 mu m-5000 mu m.

4. The MEMS structural atomizing core of claim 3, wherein: the first support structure is formed by oxidation of a surface region of the second support structure.

5. The MEMS structural atomizing core of claim 3, wherein: the second surface of the supporting structure is provided with a plurality of oil guide holes which are distributed in an array;

preferably, the cross section of the oil guide hole is in a shape of any one or a combination of more than two of a circle, an ellipse, a square, a triangle and a Chinese character 'mi';

preferably, the plurality of oil guide holes are distributed in a square, S-shaped or opening shape on the whole;

preferably, the hole diameter of the oil guide hole is 1-500 μm, and the gap between adjacent oil guide holes is 1-500 μm.

6. The MEMS structural atomizing core of claim 2, wherein: the second surface of the support structure is provided with a first area and a second area, the resistance heating structure comprises a patterned conductive material layer at least covering the first area, and the oil guide hole is at least arranged in the second area;

preferably, the second region of the second surface of the support structure is further provided with a plurality of guide grooves, each of the guide grooves is further communicated with the oil guide hole, and the depth of each guide groove is less than 1/2 of the thickness of the first support structure;

preferably, each guide groove is further filled with a guide layer, the guide layer is formed by combining metal particles and non-metal particles, the metal particles and the resistance heating structure are made of the same material, the non-metal particles and the second support structure are made of the same material, and the resistance heating structure is further directly contacted with or connected with the guide layer.

7. The MEMS structural atomizing core of claim 6, wherein: the thickness of the conductive material layer is 100nm-500 mu m; preferably, the material of the conductive material layer includes one of the simple substances of Ni, Cr, Au, Pt, Mo, and W or an alloy formed by two or more of them.

8. A method of making an atomizing core of MEMS structure as in any of claims 1 to 7, comprising:

forming a patterned conductive material layer on the second surface of the support structure and serving as a resistance heating structure;

the method comprises the steps of processing and forming an oil storage tank on a first surface of a supporting structure, forming an oil guide hole penetrating through the supporting structure at the bottom of the oil storage tank, and enabling a fluid medium conveyed from the oil guide hole to be in contact with a conductive material layer.

9. The preparation method according to claim 8, which specifically comprises:

oxidizing a part of monocrystalline silicon of the support structure close to the second surface to form silicon oxide, taking the silicon oxide formed by oxidation as a first support structure, and taking the unoxidized residual part as a second support structure;

processing and forming an oil storage tank on the first surface of the supporting structure, arranging all the oil storage tank in the second supporting structure, manufacturing and forming the oil guide hole at the bottom of the oil storage tank, and enabling the oil guide hole to continuously penetrate through the second supporting structure and the first supporting structure;

and forming a resistance heating structure on the surface of the first support structure.

10. The preparation method according to claim 8 or 9, comprising in particular:

processing and forming a plurality of guide grooves on the surface layer of the first support structure, so that the guide grooves are communicated with the oil guide holes, and then forming a guide layer containing metal particles and non-metal particles in the guide grooves, wherein the metal particles are made of the same material as the resistance heating structure, and the non-metal particles are made of the same material as the second support structure;

and forming the resistance heating structure on the surface of the first support structure, and enabling the resistance heating structure to be directly contacted with or connected with the guide layer.

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