CN115153096A - Low-cost MEMS (micro-electromechanical system) atomizing core and preparation method thereof - Google Patents

Abstract

The invention relates to a low-cost MEMS (micro-electromechanical systems) atomizing core and a preparation method thereof, wherein the low-cost MEMS atomizing core comprises a substrate, a silicon dioxide film layer arranged on the back of the substrate, heating resistance wires respectively arranged at the bottoms of the silicon dioxide film layer, a protective layer silicon nitride for covering the heating resistance wires, a cavity arranged in the middle of the front of the substrate, and a smoke oil adsorption layer arranged on the front of the substrate and covering the surface of the cavity; the bottom of the protective layer silicon nitride is respectively provided with metal electrodes connected with two ends of the heating resistance wire; according to the invention, the substrate is arranged between the heating resistance wire and the tobacco tar adsorption layer, and the cavity is arranged on the front surface of the substrate, so that the surface area of the tobacco tar adsorption layer can be increased, the tobacco tar adsorption efficiency is improved, the low-cost MEMS atomization core is prepared by adopting a semiconductor process and an MEMS process, the low-cost MEMS atomization core has the characteristics of good batch and consistency, and structures such as a PCB (printed circuit board) are not required, so that the low-cost MEMS atomization core has the advantage of low cost.

Description

Low-cost MEMS (micro-electromechanical system) atomizing core and preparation method thereof

Technical Field

The invention relates to the field of atomization cores, in particular to a low-cost MEMS atomization core and a preparation method thereof.

Background

The atomizing core is used as a core component of a liquid atomizing product, liquid is heated to be changed into a foggy aerosol form to be emitted, and when the atomizing element heats the atomized liquid, the generation of harmful substances is rapidly, uniformly, consistently and finely reduced to the greatest extent.

The existing liquid heating atomization cores mainly comprise the following two types: a cotton-coated atomizing core and a porous ceramic atomizing core. Wherein, the metal heating wire in the cotton atomizing core is directly contacted with the cotton core, and at high temperature, the metal components in the heating wire and the scraps of the cotton core material can be carried by the aerosol formed by atomization and inhaled by a user, thereby causing potential health hazard. Meanwhile, the cotton core is in non-uniform contact with the metal heating wire, heating is not uniform, and high-temperature carbonization can also cause resistance change of the heating wire, so that temperature change of the heating wire is caused, and atomization uniformity, stability and consistency are poor. The porous ceramic atomizing core consists of two parts, namely porous ceramic and a heating electrode. Porous ceramic is made into a bowl-shaped structure through high-temperature sintering, the heating film is designed into a specific shape and is attached to the surface of the ceramic, and in the working process, the heating film uniformly heats liquid to form mist which is emitted by ceramic micropores. Due to the existence of the micron-sized honeycomb holes, the atomized aerosol is finer and smoother. And through adjusting micropore size, porosity, can control the lock liquid of ceramic core, stock solution ability, can also adjust the humidity of atomizing aerosol.

For example, wu-yun published in 2021, 6 months "research on manufacturing process of porous ceramic atomizing core for electronic cigarette" describes porous ceramic, printing a heat conducting layer on the bottom of the porous ceramic, printing two electrode positions on the heat conducting layer, printing a heating resistor between the two electrodes, and printing a protective layer on the two electrodes and the heating resistor; although the heat conduction layer is added between the porous ceramic and the heating component, the heat conduction efficiency can be improved; however, there are the following problems:

1. due to the existence of the porous structure, the liquid locking capacity of the ceramic core is reduced, and liquid leakage is easy to occur. At present, the liquid-locking capacity is improved by reducing the porosity and the number of multiple holes, but the liquid-absorbing capacity and the liquid-storing capacity are reduced at the same time;

2. the ceramic sintering process inevitably introduces harmful substances, which are harmful to the health of users;

3. the ceramic sintering process is complicated, and the production cost is greatly increased.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a low-cost MEMS atomizing core and a preparation method thereof.

In order to achieve the purpose, the invention adopts the technical scheme that: a low-cost MEMS atomizing core comprises a substrate, a silicon dioxide film layer arranged on the back of the substrate, a first metal electrode, a second metal electrode and a heating resistance wire which are respectively arranged at the bottom of the silicon dioxide film layer, a protective layer silicon nitride for covering the first metal electrode, the second metal electrode and the heating resistance wire, a cavity arranged in the middle of the front of the substrate, and a smoke oil adsorption layer arranged on the front of the substrate and covering the surface of the cavity;

the first metal electrode and the second metal electrode are respectively connected with two ends of the heating resistance wire;

and a third metal electrode and a fourth metal electrode which are connected with the first metal electrode and the second metal electrode are respectively arranged at the bottom of the silicon nitride of the protective layer.

Preferably, the heating resistance wire is S-shaped, U-shaped or circular and is positioned right below the silicon dioxide film layer.

Preferably, the material of the heating resistance wire is one of PT, AL and CU.

Preferably, the third metal electrode and the fourth metal electrode are respectively arranged on two sides of the bottom of the silicon nitride of the protective layer.

Preferably, the substrate is made of a silicon wafer material.

Preferably, the tobacco tar adsorbing material is coated, sprayed or deposited on the front surface of the substrate and the surface of the cavity.

Preferably, the tobacco tar adsorbing material is graphene, PDMS and Fe ₂ O ₃ /one kind of EPDM oil absorbing material.

The invention also discloses a preparation method of the low-cost MEMS atomization core, which comprises the following preparation steps:

step A: generating a silicon dioxide film layer on the back of the substrate, and finishing the manufacture of a heating resistance wire, a protective layer silicon nitride, a first metal electrode, a second metal electrode, a third metal electrode and a fourth metal electrode on the surface of the silicon dioxide film layer;

and B: and manufacturing a cavity structure and a tobacco tar adsorption layer on the front surface of the substrate to obtain the low-cost MEMS atomizing core.

Preferably, step a further comprises the following preparation steps:

step A1: selecting a silicon wafer;

step A2: generating a silicon dioxide film layer on the smooth surface of the silicon wafer;

step A3: finishing the manufacture of a heating resistance wire, a first metal electrode and a second metal electrode on the surface of the silicon dioxide film layer;

step A4: depositing a protective layer of silicon nitride on the surfaces of the heating resistance wire, the first metal electrode and the second metal electrode;

step A5: etching two through holes on two sides of the protective layer silicon nitride, wherein the through holes are required to be opposite to the first metal electrode and the second metal electrode;

step A6: and finishing metal filling in the through hole, and leading out a third metal electrode and a fourth metal electrode on the surface of the protective layer silicon nitride.

Preferably, step B further comprises the following preparation steps:

step B1: etching a cavity structure on the rough surface of the substrate;

and step B2: and finishing the manufacture of the tobacco tar adsorption layer on the surface of the cavity.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. according to the invention, the substrate is arranged between the heating resistance wire and the tobacco tar adsorption layer, and the cavity is arranged on the front surface of the substrate, so that the surface area of the tobacco tar adsorption layer can be increased, the tobacco tar adsorption efficiency is improved, and the power consumption of the MEMS atomization core is reduced under the same tobacco tar atomization temperature target;

2. according to the invention, as the tobacco tar adsorbing material has a high oil absorption characteristic, tobacco tar permeates from two ends of the tobacco tar adsorbing material to the middle of the tobacco tar adsorbing material, so that the whole tobacco tar adsorbing material adsorbs a certain amount of electronic cigarette tobacco tar;

3. according to the invention, the tobacco tar adsorption layer is prepared by using novel tobacco tar adsorption materials such as graphene, PDMS (polydimethylsiloxane) or Fe2O3/EPDM (ethylene-propylene-diene monomer), so that a mixture of tobacco tar atomized smoke with harmful metal powder particles can not be generated in the process of atomizing the tobacco tar adsorbed by the tobacco tar adsorption layer when the tobacco tar adsorption layer is heated;

4. the low-cost MEMS atomization core is prepared by adopting a semiconductor process and an MEMS process, and has the characteristics of high batch and high consistency; in addition, the adopted process does not comprise a bonding process and a TSV process, and structures such as a PCB (printed Circuit Board) and the like are not needed, so that the method has the advantage of low cost.

Drawings

The technical scheme of the invention is further explained by combining the accompanying drawings as follows:

FIG. 1 is a top view of the soot removal absorbent layer of the present invention;

FIG. 2 isbase:Sub>A cross-sectional view taken at A-A of FIG. 1;

FIG. 3 is a corresponding structural diagram in step 2 of the present invention;

FIG. 4 is a structural diagram corresponding to step 3 of the present invention;

FIG. 5 is a corresponding block diagram in step 4 of the present invention;

FIG. 6 is a corresponding block diagram in step 5 of the present invention;

FIG. 7 is a corresponding block diagram of step 7 of the present invention;

fig. 8 is a corresponding structural diagram in step 8 of the present invention.

Detailed Description

The invention is described in further detail below with reference to the figures and the embodiments.

The attached drawings 1-2 show that the low-cost MEMS atomizing core comprises a substrate (1), a silicon dioxide film layer (2), a heating resistance wire (3), a first metal electrode (4-1), a second metal electrode (4-2), a third metal electrode (4-3), a fourth metal electrode (4-4), a protective layer silicon nitride (5) and a smoke oil adsorption layer (6).

The substrate (1) is positioned on the upper half part of the MEMS atomizing core, and a silicon dioxide film layer (2) grows on the smooth lower surface of the substrate (1); meanwhile, a cavity (100) is etched on the rough surface of the substrate (1), and the surface of the cavity (100) is covered with the tobacco tar adsorption layer (6);

the silicon dioxide film layer (2) is positioned below the substrate (1), and a heating resistance wire (3), a first metal electrode (4-1) and a second metal electrode (4-2) are arranged on the lower surface of the silicon dioxide film layer;

the heating resistance wire (3) is positioned under the silicon dioxide film layer (2) and is in an S shape, a U shape or a circular shape, and the like, and two ends of the heating resistance wire (3) are respectively electrically interconnected with the first metal electrode (4-1) and the second metal electrode (4-2) and are used for converting electric energy into heat energy; the material of the heating resistor can be Pt, al, cu and other metals;

the first metal electrode (4-1) and the second metal electrode (4-2) are positioned on two sides of the MEMS atomization core and are electrically connected with the third metal electrode (4-3) and the fourth metal electrode (4-4) on the lower surface of the protective layer silicon nitride (5) through metal filled in the through holes;

the protective layer silicon nitride (5) covers the heating resistance wire (3), the first metal electrode (4-1) and the second metal electrode (4-2), and two through holes are formed in the two ends of the protective layer silicon nitride; a third metal electrode (4-3) and a fourth metal electrode (4-4) are led out from the lower surface of the through hole;

the smoke oil adsorption layer (6) covers the cavity (100) in a spraying, coating or depositing mode and the like, and the smoke oil adsorption layer can be made of graphene, PDMS (polydimethylsiloxane), a novel Fe2O3/EPDM oil absorption material and the like; the tobacco tar in the electronic cigarette is contacted with two ends of the tobacco tar adsorbing material, and the tobacco tar is permeated from the two ends of the tobacco tar adsorbing material to the middle of the tobacco tar adsorbing material due to the high oil absorption characteristic of the tobacco tar adsorbing material, so that a certain amount of electronic cigarette tobacco tar is adsorbed by the whole tobacco tar adsorbing material;

the working principle is as follows: after direct current voltage is applied to the third metal electrode (4-3) and the fourth metal electrode (4-4) below the protective layer silicon nitride (5), electric signals with opposite polarities are transmitted to the first metal electrode (4-1) and the second metal electrode (4-2) above the protective layer silicon nitride (5) through the metal through holes, and then are transmitted to the heating resistance wire (3) through the first metal electrode (4-1) and the second metal electrode (4-2), so that potential differences are formed at two ends of the heating resistance wire, the heating resistance wire (3) is heated, the voltage-heat conversion process is realized, the heating resistance wire (3) generates heat, and the temperature of the heating resistance wire is improved; because substrate (1) and silica layer thin layer (2) of cavity (100) below are very thin, the tobacco tar adsorbed layer (6) above the cavity is transmitted to through substrate (1) and silica layer thin layer (2) to the vast majority of produced heat, and then makes the tobacco tar adsorbed in tobacco tar adsorbed layer (6) heat to realize the atomizing of electron cigarette tobacco tar.

The invention also discloses a preparation method of the low-cost MEMS atomization core, which comprises the following preparation steps:

step 1, preparing a silicon wafer;

step 2, depositing silicon dioxide: as shown in fig. 3, a thermal oxidation process is applied to the smooth surface of the silicon wafer to form a silicon dioxide thin film layer;

step 3, sputtering Pt: as shown in fig. 4, a heating resistance wire, a first metal electrode and a second metal electrode are obtained by patterning;

step 4, depositing silicon nitride: as shown in fig. 5, a plasma enhanced chemical vapor deposition process is used to grow a protective layer of silicon nitride;

step 5, photoetching and etching silicon nitride: as shown in fig. 6, two metal vias are formed over the first metal electrode and the second metal electrode;

step 6, removing the redundant photoresist;

step 7, sputtering Pt: as shown in fig. 7, a third metal electrode and a fourth metal electrode are obtained through patterning, and the metal via holes are required to be filled with Pt;

step 8, etching the cavity: as shown in fig. 8, the silicon rough surface is etched by DRIE process to form a cavity structure;

step 9, depositing a graphene layer: depositing a layer of heat-conducting graphene oxide by using a heating auxiliary spraying method;

step 10, immersing graphene oxide into a hydriodic acid solution for reduction reaction;

step 11, washing with ethanol for a plurality of times;

and step 12, obtaining a reduced graphene oxide layer as shown in fig. 2.

The above is only a specific application example of the present invention, and the protection scope of the present invention is not limited in any way. All the technical solutions formed by equivalent transformation or equivalent replacement fall within the protection scope of the present invention.

Claims (10)

1. A low-cost MEMS atomizing core is characterized in that: the device comprises a substrate, a silicon dioxide film layer arranged on the back of the substrate, a first metal electrode, a second metal electrode and a heating resistance wire which are respectively arranged at the bottom of the silicon dioxide film layer, a protective layer silicon nitride for covering the first metal electrode, the second metal electrode and the heating resistance wire, a cavity arranged in the middle of the front of the substrate, and a smoke oil adsorption layer arranged on the front of the substrate and covering the surface of the cavity;

the first metal electrode and the second metal electrode are respectively connected with two ends of the heating resistance wire;

and a third metal electrode and a fourth metal electrode which are connected with the first metal electrode and the second metal electrode are respectively arranged at the bottom of the silicon nitride of the protective layer.

2. The low cost MEMS atomizing core of claim 1, wherein: the heating resistance wire is S-shaped, U-shaped or round and is positioned right below the silicon dioxide film layer.

3. The low cost MEMS atomizing core of claim 2, wherein: the heating resistance wire is made of one metal of PT, AL and CU.

4. The low cost MEMS atomizing core of claim 3, wherein: and the third metal electrode and the fourth metal electrode are respectively arranged on two sides of the bottom of the silicon nitride of the protective layer.

5. The low cost MEMS atomizing core of claim 4, wherein: the substrate is made of a silicon wafer material.

6. A low cost MEMS atomizing core according to any one of claims 1 to 5, wherein: the tobacco tar adsorbing material is coated on the front surface of the substrate and the surface of the cavity in a spraying, coating or depositing mode.

7. The low cost MEMS atomizing core of claim 6, wherein: the tobacco tar adsorbing material is graphene, PDMS and Fe ₂ O ₃ /one kind of EPDM oil absorbing material.

8. A preparation method of a low-cost MEMS atomizing core is characterized by comprising the following steps: comprises the following preparation steps:

step A: generating a silicon dioxide film layer on the back of the substrate, and finishing the manufacture of a heating resistance wire, a protective layer of silicon nitride, a first metal electrode, a second metal electrode, a third metal electrode and a fourth metal electrode on the surface of the silicon dioxide film layer;

and B: and manufacturing a cavity structure and a tobacco tar adsorption layer on the front surface of the substrate to obtain the low-cost MEMS atomizing core.

9. The method of making a low cost MEMS atomizing core of claim 8, wherein: the step A also comprises the following preparation steps:

step A1: selecting a silicon wafer;

step A2: generating a silicon dioxide film layer on the back of the silicon wafer;

step A3: manufacturing a heating resistance wire, a first metal electrode and a second metal electrode on the surface of the silicon dioxide film layer;

step A4: depositing a protective layer of silicon nitride on the surfaces of the heating resistance wire, the first metal electrode and the second metal electrode;

step A5: etching two through holes on two sides of the protective layer silicon nitride, wherein the through holes are required to be opposite to the first metal electrode and the second metal electrode;

step A6: and finishing metal filling in the through hole, and leading out a third metal electrode and a fourth metal electrode on the surface of the protective layer silicon nitride.

10. The method of making a low cost MEMS atomizing core of claim 9, wherein: the step B also comprises the following preparation steps:

step B1: etching a cavity structure on the front surface of the substrate;

and step B2: and finishing the manufacture of the tobacco tar adsorption layer on the surface of the cavity.

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