Multi-cavity MEMS alkali metal air chamber

Abstract

A multi-cavity MEMS alkali metal gas chamber disclosed by the present invention comprises a base body, and an optical cavity, a reaction cavity and a micro-channel which are dug in the base body, the optical cavity is communicated with the reaction cavity through the micro-channel, the micro-channel comprises at least one bending unit, and the bending units are sequentially communicated and connected together end to end. The bending unit comprises at least one direction changing area on a transmission path, so that the transmission path is nonlinear, the direction changing area at least comprises a particulate matter collecting area, and the particulate matter collecting area is used for blocking particulate matters in alkali metal gas flowing through the direction changing area; and the conveying path is a path formed from one end of the bending unit to the other end of the bending unit in the extending direction of the bending unit. According to the invention, particulate matters can be prevented from entering the optical cavity to a great extent or completely, and the particulate matters are prevented from polluting the optical cavity, so that the cleanness and permeability in the optical cavity are ensured, and the cleaning is very convenient.

Description

Technical Field

[0001] The invention relates to the technical field of air chambers made by MEMS technology, in particular to a multi-cavity MEMS alkali metal air chamber. Background Art

[0002] The multi-cavity MEMS (micro-electromechanical system) alkali metal gas chamber includes a reaction chamber and an optical chamber. The reaction chamber produces alkali metal gas through some physical or chemical reactions, and the alkali metal gas is mixed with particles. During long-term use, fine particles will enter the optical cavity from the reaction chamber and remain in the optical cavity, resulting in the deterioration of the cleanliness and permeability of the optical cavity. Therefore, preventing particles from entering the optical cavity is one of the important conditions for improving the long-term stability of the alkali metal gas chamber, and it is also a problem that needs to be solved.

[0003] refer to Figure 1 In the existing alkali metal gas chamber, the microchannels connecting the reaction chamber and the optical chamber are generally straight, and the cross-sectional size of the microchannels is about 100μm (micrometer) * 100 micrometers. Particles can pass through the microchannels unimpeded. The microchannels designed in this way cannot effectively prevent the passage of particles, thereby causing pollution to the optical cavity. Summary of the invention

[0004] In view of the deficiencies in the prior art, an object of the present invention is to provide a multi-cavity MEMS alkali metal gas chamber, which can solve the problems described in the background technology.

[0005] The technical solution to achieve the purpose of the present invention is: a multi-cavity MEMS alkali metal gas chamber, comprising a substrate, and an optical cavity, a reaction cavity and a microchannel dug inside the substrate, wherein the optical cavity is connected to the reaction cavity through the microchannel,

[0006] The microchannel includes at least one bending unit, each bending unit is connected together end to end, the bending unit includes at least one direction-changing area on the transmission path, so that the transmission path is non-linear, and at least one particle collection area is included in the direction-changing area, and the particle collection area is used to block particles in the alkali metal gas flowing through the direction-changing area to leave the particles in the particle collection area.

[0007] The transmission path is a path formed from one end of the bending unit to the other end along the extending direction of the bending unit.

[0008] Furthermore, the microchannel has the following characteristics through the direction change area and the particle collection area of ​​the bending unit: gas can flow in both directions, particles can flow in one direction, and only flow from the optical cavity to the reaction cavity is allowed while flow from the reaction cavity to the optical cavity is prohibited.

[0009] Furthermore, it comprises at least two microchannels, and each microchannel is arranged in parallel and at intervals on the body.

[0010] Furthermore, the bending unit includes a first connecting portion and a second connecting portion, the first connecting portion and the second connecting portion are connected together, and an angle A is formed at the connection between the first connecting portion and the second connecting portion, and the angle A satisfies 0°<A<180°.

[0011] Furthermore, 0°<A<90°.

[0012] Furthermore, the two adjacent first connecting parts and the second connecting parts connected together form a particle collection area at the connection point, so that the two ends of the first connecting part in the middle position are respectively connected to the two second connecting parts to form a particle collection area respectively, and the two ends of the second connecting part in the middle position are respectively connected to the two first connecting parts to form a particle collection area respectively.

[0013] Further, the particle collection area is a concave area, the concave area is connected to the first connecting part and the second connecting part, and the concave area is located in the extension direction of the first connecting part or in the extension direction of the second connecting part.

[0014] Further, when the concave area is located in the extension direction of the first connecting portion, the concave area is located outside the second connecting portion; when the concave area is located in the extension direction of the second connecting portion, the concave area is located outside the first connecting portion.

[0015] Further, the concave area is an arc-shaped area, and the arc-shaped area is a circular arc area or an elliptical arc area or an arc-shaped area formed by a curve other than a circular arc and an elliptical arc.

[0016] Furthermore, among all the bending units connected head to tail, the bending unit connected to the reaction chamber is recorded as the head bending unit, and among all the bending units connected head to tail, the bending unit connected to the optical cavity is recorded as the tail bending unit.

[0017] The first connecting portion of the first bending unit is connected to the reaction chamber, and the first connecting portion of the first bending unit is arranged to be inclined upward.

[0018] The second connecting portion of the tail bending unit is connected to the optical cavity, and the second connecting portion of the tail bending unit is arranged to be inclined downward.

[0019] Beneficial effects of the present invention: The microchannel provided by the present invention can greatly or completely block particles from entering the optical cavity, preventing particles from contaminating the optical cavity, thereby ensuring the cleanliness and permeability of the optical cavity. Through the bending unit and the particle collection area, the bidirectional flow of gas and the unidirectional flow of particles can be ensured, thereby facilitating the cleaning of the optical cavity and the microchannel, and the cleaning is very convenient. In addition, the microchannel structure is simple to set up, and the manufacturing process is simple. The microchannel can be made by processes such as photolithography, and the manufacturing cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a microchannel structure connecting the reaction chamber and the optical chamber in an existing alkali metal gas chamber as an example;

[0021] Figure 2 It is a structural schematic diagram of the present invention;

[0022] Figure 3 It is a schematic structural diagram of the microchannel of the present invention;

[0023] Figure 4 A schematic diagram of the alkali metal gas flow path and the particles left in each concave area;

[0024] In the figure, 1-reaction chamber, 2-microchannel, 21-first connecting part, 22-second connecting part, 23-concave area, 3-substrate, 4-optical cavity. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0026] like Figure 1-Figure 4 As shown, this embodiment provides a multi-cavity MEMS alkali metal gas chamber, including a substrate 3, and an optical cavity 4, a reaction cavity 1 and a microchannel 2 excavated inside the substrate 3. The optical cavity 4 is connected to the reaction cavity 1 through the microchannel 2, that is, the two ends of the microchannel 2 are respectively connected to the optical cavity 4 and the reaction cavity 1. The reaction cavity 1 is used as a region for generating alkali metal gas. The reactants generate alkali metal gas in the reaction cavity 1 by physical or chemical methods, and the alkali metal gas can flow into the reaction cavity 1 through the microchannel 2.

[0027] The alkali metal gas is one of the types of products generated in the reaction chamber 1 , and other substances may also be formed.

[0028] The microchannel 2 includes at least one bending unit, and each bending unit is connected together in sequence from end to end. The bending unit includes at least one direction-changing area in the transmission path, so that the transmission path is non-linear, and at least one particle collection area is included in the direction-changing area. The particle collection area is used to block particles in the alkali metal gas flowing through the direction-changing area to leave the particles in the particle collection area, so as to achieve the purpose of collecting particles and preventing particles from entering the optical cavity 4. The transmission path is a path formed from one end of the bending unit along the extension direction of the bending unit to the other end.

[0029] The microchannel 2 has the following characteristics through the direction change area and particle collection area of ​​the bending unit: for gas, the gas can flow in both directions, for particles, the particles flow in one direction, and only flow from the optical cavity 4 to the reaction cavity 1 is allowed, while flow from the reaction cavity 1 to the optical cavity 4 is prohibited.

[0030] That is, the gas can flow from the reaction chamber 1 to the optical chamber 4, and during the process of the particles flowing from the reaction chamber 1 to the optical chamber 4, due to the blocking effect of the particle collection area, the particles are blocked in the particle collection area, and thus cannot flow into the optical chamber 4. Conversely, if the particles flow from the optical chamber 4 to the reaction chamber 1, due to the positional relationship of the particle arrangement, the particles are difficult to be blocked by the particle collection area, so that most of the particles can flow with the gas and enter the reaction chamber 1, thereby realizing the unidirectional flow of the particles.

[0031] With such characteristics, even if a very small amount of particles enter the optical cavity 4, by blowing gas into the optical cavity 4 (for situations where gas can be introduced into the optical cavity, such as the optical cavity is not completely sealed), the gas can also carry the particles remaining in the optical cavity 4 into the microchannel 2 and finally flow into the reaction cavity 1, thereby achieving the cleaning of the optical cavity 4.

[0032] If the optical cavity 4 is sealed but gas cannot be blown into it, the multi-cavity MEMS alkali metal gas chamber can be shaken and the tilt position of the multi-cavity MEMS alkali metal gas chamber can be adjusted. For example, the optical cavity 4 can be tilted at the top and the reaction cavity 1 can be tilted at the bottom. The particles remaining in the optical cavity 4 can be brought into the microchannel 2 by shaking, and finally flow into the reaction cavity 1, thereby also achieving the cleaning of the optical cavity 4.

[0033] At the same time, after the gas flows from the reaction chamber 1 to the optical chamber 4, the particles remaining in each particle collection area in the microchannel 2 can also be carried out by the airflow from the optical chamber 4 and finally flow into the reaction chamber 1, thereby achieving the cleaning of the microchannel 2.

[0034] Exemplarily, at least two microchannels 2 are included, and each microchannel 2 is arranged in parallel and spaced apart on the body.

[0035] Exemplarily, the extending direction of the bending units is substantially horizontal, and is distributed along the connecting direction of the reaction chamber 1 and the optical chamber 4 .

[0036] Exemplarily, the bending unit includes a first connecting portion 21 and a second connecting portion 22, the first connecting portion 21 and the second connecting portion 22 are connected together, and an angle A is formed at the connection between the first connecting portion 21 and the second connecting portion 22, and the angle A satisfies 0°<A<180°, preferably, 0°<A<90°. Since the first connecting portion 21 and the second connecting portion 22 form an angle A, and the angle A is not 0° or 180°, the first connecting portion 21 and the second connecting portion 22 will not be a straight line, so that the bending unit forms a direction change area, so that the alkali metal gas flowing from the first connecting portion 21 to the second connecting portion 22 needs to change the flow direction at least once.

[0037] Exemplarily, two adjacent first connecting parts 21 and second connecting parts 22 connected together form a particle collection area at the connection. Therefore, the two ends of the first connecting part 21 in the middle position are respectively connected to the two second connecting parts 22 to form a particle collection area respectively, and the two ends of the first connecting part 21 in the middle position are each provided with a particle collection area. Similarly, the two ends of the second connecting part 22 in the middle position are respectively connected to the two first connecting parts 21 to form a particle collection area respectively, and the two ends of the second connecting part 22 in the middle position are each provided with a particle collection area.

[0038] The particle collection area is a concave area 23, which is connected to the first connecting portion 21 and the second connecting portion 22, and is located in the extension direction of the first connecting portion 21 or in the extension direction of the second connecting portion 22. When the concave area 23 is located in the extension direction of the first connecting portion 21, the concave area 23 is located outside the second connecting portion 22; when the concave area 23 is located in the extension direction of the second connecting portion 22, the concave area 23 is located outside the first connecting portion 21.

[0039] It should be noted that the concave area 23 is located in the extension direction of the first connecting portion 21 or in the extension direction of the second connecting portion 22, which does not exclude that the concave area 23 cannot exist in the extension direction of the first connecting portion 21 and the extension direction of the second connecting portion 22 at the same time, but means that the same concave area 23 cannot be located in the extension direction of the first connecting portion 21 and the extension direction of the second connecting portion 22 at the same time.

[0040] refer to Figure 3From left to right, a concave area 23 is provided in the extension direction of the first connecting portion 21 of the first bending unit, and the concave area 23 is located on the outside of the second connecting portion 22; a concave area 23 is also provided in the extension direction of the second connecting portion 22 of the first bending unit, and the concave area 23 is located on the outside of the first connecting portion 21 of the second bending unit.

[0041] Exemplarily, the concave area 23 is an arc-shaped area, which may be a circular arc-shaped area, an elliptical arc-shaped area, or an arc-shaped area formed by other curves.

[0042] Exemplarily, the bending unit connected to the reaction chamber 1 among all the bending units connected end to end is recorded as the first bending unit, and the bending unit connected to the optical cavity 4 among all the bending units connected end to end is recorded as the tail bending unit, the first connecting portion 21 of the first bending unit is connected to the reaction chamber 1, the first connecting portion 21 of the first bending unit is inclined upward, the second connecting portion 22 of the tail bending unit is connected to the optical cavity 4, and the second connecting portion 22 of the tail bending unit is inclined downward. Under such a setting, the concave area 23 of the first bending unit is located in the upward extension direction of the first connecting part 21 of the first bending unit, so that the alkali metal gas first flows into the microchannel 2 in an inclined upward direction, so that under the joint action of gravity and flow rate, the particulate matter carried by the alkali metal gas can better enter the concave area 23 on the first connecting part 21 of the first bending unit, and more particulate matter can be blocked there, so that along the extension direction of the microchannel 2, the particulate matter can be continuously blocked, and the particulate matter carried in the alkali metal gas gradually decreases, and finally no or very few particulate matter flows into the optical cavity 4.

[0043] The microchannel 2 provided in the present invention can greatly or completely block particles from entering the optical cavity 4, preventing particles from contaminating the optical cavity 4, thereby ensuring the cleanliness and permeability of the optical cavity 4. Through the bending unit and the particle collection area, the bidirectional flow of gas and the unidirectional flow of particles can be ensured, thereby facilitating the cleaning of the optical cavity 4 and the microchannel 2, and the cleaning is very convenient. In addition, the microchannel 2 has a simple structure and a simple manufacturing process. The microchannel 2 can be made by processes such as photolithography, and the manufacturing cost is low.

[0044] The multi-cavity MEMS alkali metal gas chamber of the present invention can be applied to devices or equipment requiring alkali metal inspiration, for example, it can be applied to devices such as chip-level atomic clocks or chip-level atomic magnetometers.

[0045] The embodiment disclosed in this specification is only an example of a unilateral feature of the present invention, and the protection scope of the present invention is not limited to this embodiment, and any other functionally equivalent embodiments fall within the protection scope of the present invention. For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims

1. A multi-cavity MEMS alkali metal gas chamber, characterized in that: The invention comprises a substrate, and an optical cavity, a reaction cavity and a microchannel excavated inside the substrate. The optical cavity is connected with the reaction cavity through the microchannel. The microchannel includes at least one bending unit, each bending unit is connected together end to end, the bending unit includes at least one direction-changing area on the transmission path, so that the transmission path is non-linear, and at least one particle collection area is included in the direction-changing area, and the particle collection area is used to block particles in the alkali metal gas flowing through the direction-changing area to leave the particles in the particle collection area. The transmission path is a path formed from one end of the bending unit to the other end along the extending direction of the bending unit.

2. The multi-cavity MEMS alkali metal gas chamber according to claim 1, characterized in that: The direction-changing area and particle collection area of ​​the microchannel through the bending unit have the following characteristics: gas can flow in both directions, particles can flow in one direction, and only flow from the optical cavity to the reaction cavity is allowed, while flow from the reaction cavity to the optical cavity is prohibited.

3. The multi-cavity MEMS alkali metal gas chamber according to claim 1, characterized in that: The machine comprises at least two microchannels, and each microchannel is arranged in parallel and at intervals on the machine body.

4. The multi-cavity MEMS alkali metal gas chamber according to claim 1, characterized in that: The bending unit includes a first connecting portion and a second connecting portion, the first connecting portion and the second connecting portion are connected together, and an angle A is formed at the connection between the first connecting portion and the second connecting portion, and the angle A satisfies 0°<A<180°.

5. The multi-cavity MEMS alkali metal gas chamber according to claim 4, characterized in that: 0°＜A＜90°。 6. The multi-cavity MEMS alkali metal gas chamber according to claim 4, characterized in that: The two adjacent first connecting parts and the second connecting parts connected together form a particle collection area at the connection point, so that the two ends of the first connecting part in the middle position are respectively connected to the two second connecting parts to form a particle collection area respectively, and the two ends of the second connecting part in the middle position are respectively connected to the two first connecting parts to form a particle collection area respectively.

7. The multi-cavity MEMS alkali metal gas cell according to claim 6, characterized in that: The particle collection area is a concave area, which is connected to the first connecting portion and the second connecting portion, and is located in the extension direction of the first connecting portion or in the extension direction of the second connecting portion.

8. The multi-cavity MEMS alkali metal gas chamber according to claim 7, characterized in that: When the concave area is located in the extension direction of the first connecting portion, the concave area is located outside the second connecting portion; when the concave area is located in the extension direction of the second connecting portion, the concave area is located outside the first connecting portion.

9. The multi-cavity MEMS alkali metal gas cell according to claim 7, characterized in that: The concave area is an arc-shaped area, and the arc-shaped area is a circular arc area or an elliptical arc area or an arc-shaped area formed by a curve other than a circular arc and an elliptical arc.

10. The multi-cavity MEMS alkali metal gas cell according to any one of claims 4 to 9, characterized in that: Among all the bending units connected head to tail, the bending unit connected to the reaction chamber is recorded as the first bending unit, and among all the bending units connected head to tail, the bending unit connected to the optical cavity is recorded as the last bending unit. The first connecting portion of the first bending unit is connected to the reaction chamber, and the first connecting portion of the first bending unit is arranged to be inclined upward. The second connecting portion of the tail bending unit is connected to the optical cavity, and the second connecting portion of the tail bending unit is arranged to be inclined downward.

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