Micro-grid gas detector and preparation method thereof

Abstract

The invention discloses a micro-grid gas detector, and relates to the technical field of micro-structure gas detectors, and the micro-grid gas detector comprises a micro-grid, a supporting medium and an anode plate which are sequentially arranged along the thickness direction; the supporting medium comprises edgings and a plurality of gaskets, the edgings are fixedly bonded to the circumferential edges of the micro-grid and the anode plate, the gaskets are distributed in an array mode and supported on the micro-grid and the anode plate, each gasket is provided with a hollow channel arranged in the thickness direction, and the hollow channels are used for being filled with adhesives; and the micro-grid, the gasket and the anode plate can be adhered and fixed through an adhesive. According to the micro-grid gas detector provided by the invention, the long-term use stability can be improved; the invention also provides a preparation method of the micro-grid gas detector.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microstructure gas detector, in particular to a micro-mesh gas detector and a preparation method thereof. BACKGROUND

[0002] Since the development of microstructure gas detector (MPGD) in the 1990s, various technical solutions have been formed. Among them, the micro-mesh gas detector (Micromegas detector) has significant technical competitiveness in the field of high-energy physics and particle detection due to its excellent energy resolution and position resolution (up to sub-millimeter level), high stability, low-cost manufacturing advantage, and feasibility of large-area preparation process. In large scientific research devices, Micromegas has achieved several key applications. The technical value of Micromegas detector in scientific research and industrial application is increasingly prominent. Optimization and performance improvement of its core manufacturing process have become a key research direction in the field. The basic principle of MPGD is to apply a very high electric field, usually 10 kV / cm-1000 kV / cm, in a narrow air gap of hundreds of microns. Under the action of the very high electric field, the incident electrons undergo avalanche, realizing signal amplification. Micromegas forms an avalanche region with a thickness of 50-500 microns by a metal micro-mesh and a PCB or glass anode plate. This is also the core step of the preparation process. When the area of the micro-mesh and the anode plate is large, some support pads need to be placed in the central region to ensure the uniformity and stability of the air gap thickness of each part of the avalanche region after preparation. The current preparation process of Micromegas detector mainly includes the following technical solutions: Etching forming method: based on semiconductor microfabrication technology, the micro-mesh electrode structure and support column are formed on the insulating substrate by selective etching of the material with chemical etching solution. However, due to the randomness of the chemical etching process, the micro-mesh aperture size deviation is large, and local blind hole defects are easily generated. At the same time, its long-term working stability is insufficient, and the effective area of a single module is limited, which restricts the integration of large-scale detection systems.

[0003] Hot pressing method: fixed between the metal micro-network and the anode plate through the insulating support medium to form an avalanche region (air gap size 50-500 μm); at the same time, the support medium is bonded with the upper metal micro-network and the lower anode plate by means of adhesive and three layers of hot melt adhesive film, a rigid laminated structure is constructed to maintain the constant air gap of the avalanche region. It can achieve good energy resolution and other performances, but the randomness of the hot melt adhesive melting process is strong, and because the amount of glue is large, it is easy to overflow, so that the avalanche region air gap thickness of the edge of the support medium is narrower than that of other areas. In this area, it often has a higher electric field strength, which makes it easier to discharge and thus reduces the long-term stability of the detector itself under high pressure and high gain. At the same time, due to the material properties of the hot melt adhesive film, the long-term stability is significantly reduced under high pressure working environment (> 5atm), and the hot melt adhesive in the sealed cavity continues to release gas, causing the working gas to be contaminated, resulting in a decrease of ≥20% in the gain of the detector within 48 hours.

[0004] Screen printing method: metal micro-network printing as a derivative process of hot pressing method, discarding the three-layer hot melt adhesive film structure, and instead using a step-by-step printing and curing process - first, the first layer of adhesive is printed to the predetermined area of the anode plate through a patterned screen, then the insulating support medium is precisely placed on the adhesive coating, and the primary bonding is formed after heat curing; then, the second layer of adhesive is printed on the upper surface of the support medium through the second screen, and the metal micro-network is simultaneously pressed onto the surface of the wet adhesive, and after the second curing, the "metal micro-network-top layer adhesive-support medium-bottom layer adhesive-anode plate" laminated structure is integrated, and finally the detector with constant avalanche region air gap is formed. The printing of the adhesive still easily causes overflow of the support medium edge, resulting in a narrower or thicker avalanche region air gap thickness at the edge of the support medium than in other areas, reducing the long-term stability of the detector itself under high pressure and high gain. SUMMARY

[0005] The purpose of the present application is to provide a micro-grid gas detector and a preparation method thereof to solve the problems existing in the prior art and improve the long-term stability.

[0006] To achieve the above-mentioned purpose, the present application provides the following solutions: The present application provides a micro-grid gas detector, comprising a micro-network, a support medium and an anode plate arranged in sequence along the thickness direction; the support medium comprises a side strip and a plurality of spacers, the side strip is fixedly bonded to the circumferential edge of the micro-network and the anode plate, and a plurality of spacers are arrayed and supported on the micro-network and the anode plate, each spacer has a hollow channel arranged along the thickness direction, and the hollow channel is filled with adhesive to enable the micro-network, the spacer and the anode plate to be bonded and fixed by the adhesive.

[0007] Preferably, each of the gaskets has the same size, and the inner diameter size and the outer diameter size of each of the gaskets have a ratio of 1:1.5-2.0.

[0008] Preferably, the gaskets have an outer diameter of 0.5mm-2mm, and the edge strips have a width of 1.0mm-5.0mm, and the gaskets and the edge strips have the same size in the thickness direction and are each 30μm-500μm.

[0009] Preferably, the micro mesh is a metal micro mesh, has an opening ratio greater than 10%, and has a thickness of 10μm-50μm.

[0010] Preferably, the surface flatness of the anode plate is not more than 10μm.

[0011] Preferably, the gaskets have the same size in the thickness direction.

[0012] The present application also provides a preparation method of the micro mesh gas detector, comprising the following steps: distributing a plurality of gaskets on an anode plate; coating an adhesive in the hollow channels of each of the gaskets and on the circumferential edge of the anode plate; pressing an edge strip on the adhesive on the circumferential edge of the anode plate; coating the adhesive on the side of the edge strip away from the anode plate; and pressing a micro mesh on the edge strip and each of the gaskets and curing.

[0013] Preferably, the anode plate is subjected to a cleaning process before the gaskets are distributed on the anode plate, and / or is subjected to a cleaning process after the micro mesh is pressed on the edge strip and each of the gaskets and is cured.

[0014] Preferably, each of the coating processes of the adhesive is performed by a glue coating device.

[0015] Preferably, the micro mesh is pressed on the edge strip and each of the gaskets and is cured under constant pressure.

[0016] The present application has the following technical effects relative to the prior art: The micro mesh gas detector and the preparation method thereof provided by the present application have the following advantages: the adhesive between the micro mesh, the supporting medium and the anode plate only needs to be coated into the edge strip and the supporting edge of the micro mesh and the anode plate and the hollow channels of each of the gaskets, the inner wall of the hollow channel of the gasket radially restricts the adhesive to inhibit the risk of horizontal overflow, the volume of the adhesive matches the volume of the hollow channel, and the excessive overflow or insufficient filling is avoided, so that the uniformity of the adhesive distribution is improved, the gap deviation of the avalanche region caused by excessive / insufficient filling is avoided, the gain space fluctuation rate is reduced, the long-term working stability is enhanced, and the quality fluctuation of the detector caused by the randomness of the adhesive coating in the traditional process is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description only represent some of the embodiments of the present application, and all of the other drawings can be obtained by those of ordinary skill in the art without any creative effort based on these drawings.

[0018] Figure 1 A structural schematic diagram of the micro-grid gas detector provided for Embodiment One is shown in the figure. Figure 2 A structural schematic diagram of the gasket provided for Embodiment One is shown in the figure. Figure 3 A flowchart of the preparation method of the micro-grid gas detector provided for Embodiment Two is shown in the figure.

[0019] In the figure: 1-micro-grid; 2-supporting medium; 21-edge strip; 22-gasket; 23-hollow channel; 3-anode plate; 4-adhesive. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments only represent some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0021] The purpose of the present application is to provide a micro-grid gas detector and a preparation method thereof, so as to solve the problems in the prior art and improve the long-term use stability.

[0022] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Embodiment One The present embodiment provides a micro-grid gas detector, please refer to Figure 1 and Figure 2 , which comprises a micro-grid 1, a supporting medium 2 and an anode plate 3 arranged in sequence along the thickness direction; the supporting medium 2 comprises an edge strip 21 and a plurality of gaskets 22, the edge strip 21 is fixedly bonded to the circumferential edges of the micro-grid 1 and the anode plate 3, and the plurality of gaskets 22 are arrayed and supported on the micro-grid 1 and the anode plate 3, each gasket 22 has a hollow channel 23 arranged along the thickness direction, and the hollow channel 23 is filled with an adhesive 4, so as to be able to bond and fix the micro-grid 1, the gasket 22 and the anode plate 3 by means of the adhesive 4.

[0024] The adhesive 4 between the micro-grid 1, the supporting medium 2 and the anode plate 3 only needs to be coated into the edge strip 21 and the supporting edges of the micro-grid 1 and the anode plate 3 and the hollow channels 23 of each gasket 22. The inner wall of the hollow channel 23 of the gasket 22 forms a radial constraint on the adhesive 4, inhibits the risk of lateral overflow, matches the volume of the adhesive 4 with the volume of the hollow channel 23, avoids excessive overflow or underfilling, thus improving the uniformity of the distribution of the adhesive 4, avoiding avalanche gap deviation caused by excessive / insufficient, reducing the gain space fluctuation rate and enhancing the long-term working stability, and avoiding the quality fluctuation of the detector caused by the randomness of the coating of the adhesive 4 in the traditional process.

[0025] In an optional solution of the embodiment, preferably, the sizes of the gaskets 22 are the same, and the ratio of the inner diameter size to the outer diameter size of each gasket 22 is 1:1.5-2.0.

[0026] In order to ensure that the adhesive 4 in the gasket 22 has sufficient bonding area with the anode plate 3, the ratio of the inner diameter size to the outer diameter size of each gasket 22 is 1:1.5-2.0, and the specific size ratio is driven according to actual needs, such as 1:1.5 or 1:2.

[0027] In an optional solution of the embodiment, preferably, the outer diameter of the gasket 22 is 0.5mm-2mm, the width of the edge strip 21 is 1.0mm-5.0mm, and the sizes of the gasket 22 and the edge strip 21 in the thickness direction are the same and are 30μm-500μm.

[0028] The specific sizes of the gasket 22 and the edge strip 21 can be determined according to the required size of the actual micro-grid gas detector; the edge strip 21 is a strip-shaped body, which is bonded together with the anode plate 3 and the micro-grid 1 through the adhesive 4 at the edge of the sensitive area of the detector, and plays a role in fixing and maintaining the tension of the micro-grid 1; the gaskets 22 are uniformly distributed in the effective detection area, and function to support the micro-grid 1 in the central area of the detector, prevent mechanical vibration and electrostatic attraction force from affecting the air gap thickness between the micro-grid 1 and the anode plate 3, and ensure that the air gap thickness in each area is consistent.

[0029] Further, the gasket 22 and the edge strip 21 are both selected from insulating materials such as PET, polyimide or ceramic.

[0030] In an optional solution of the embodiment, preferably, the micro-grid 1 is a metal micro-grid, and the opening rate is greater than 10% and the thickness is 10μm-50μm.

[0031] The metal micro-grid provides strength and conductivity, and the opening rate can ensure high gain, high efficiency, high resolution and stability. The specific opening rate and thickness of the micro-grid 1 are determined according to the actual use scenario.

[0032] In an optional solution of the embodiment, preferably, the surface flatness of the anode plate 3 is not more than 10 μm.

[0033] In this way, by controlling the surface flatness of the anode plate 3, the gap height between the micro-grid 1 and the anode plate 3 can be ensured to be uniform within the whole detection area, thereby ensuring uniform gain and good energy resolution.

[0034] In an optional solution of the embodiment, preferably, the filling amount of the adhesive 4 in each hollow channel 23 is the same.

[0035] In this way, by injecting the adhesive 4 into the hollow channel 23 in a fixed amount, the volume of the adhesive 4 can be ensured to fill the hollow channel 23 accurately and to cover the upper surface of the gasket 22 partially so as to connect with the micro-grid 1, thereby forming a sealing layer in the vertical direction; and by controlling the filling amount in each hollow channel 23 to be the same, the quality fluctuation of the detector caused by the randomness of the adhesive 4 coating in the traditional process can be avoided.

[0036] Embodiment Two The embodiment provides a preparation method of a micro-grid gas detector, which comprises the following steps: arraying a plurality of gaskets 22 on the anode plate 3; coating the adhesive 4 in the hollow channel 23 of each gasket 22 and on the circumferential edge of the anode plate 3; pressing the edge strip 21 to the adhesive 4 on the circumferential edge of the anode plate 3; coating the adhesive 4 on the side of the edge strip 21 away from the anode plate 3; pressing the micro-grid 1 to the edge strip 21 and each gasket 22 and curing.

[0037] Further preferably, before arraying the gaskets 22 on the anode plate 3, the anode plate 3 is subjected to a cleaning treatment; and / or after pressing the micro-grid 1 to the edge strip 21 and each gasket 22 and curing, a cleaning treatment is performed so that the cleanliness meets the requirements.

[0038] Further preferably, each coating process of the adhesive 4 is performed by a glue coating device, and the glue coating device can realize fast and quantitative coating.

[0039] Further preferably, the micro-grid 1 is pressed to the edge strip 21 and each gasket 22 and is subjected to constant-pressure curing.

[0040] In detail, the preparation method of the micro-grid gas detector provided in the embodiment is as follows: Pre-treatment: Select anode plate 3 with surface flatness <10 pm, which can be a PCB or glass or other materials that meet the requirements. The material of the PCB is generally FR4 epoxy glass fiber composite (suitable for rigid structure) or polyimide film (suitable for flexible application). The substrate is cleaned in three ways: ultrasonic cleaning to remove particulate contaminants, soaking and rinsing in anhydrous ethanol, and blowing the surface with dry air to achieve the required cleanliness of the substrate.

[0041] Support medium 2 production: Process insulating material to form two types of key structures: edge strips 21 with a width of 1.0 mm-5.0 mm, and gasket 22 arrays with an outer diameter of 0.5 mm-2 mm and an inner / outer diameter ratio of 1:1.5-2.0. The height of the support medium 2 is set to 30 pm-500 pm according to the application scenario of the detector, and the material can be selected from PET, polyimide, or ceramic insulating materials.

[0042] Positioning assembly: Precisely position and place the gaskets 22 on the anode plate 3 to form an assembly body uniformly through an automatic positioning system or manually by an operator according to the preset geometric topology. The arrangement needs to meet the uniformity constraint condition of the electric field in the avalanche region. The use of conventional automation systems is also beneficial to improve production efficiency.

[0043] First glue injection: The glue injection equipment quantitatively injects adhesive 4 into each hollow channel 23, ensuring that the adhesive 4 accurately fills the hollow channel 23 and partially covers the upper surface of the gasket 22, while continuously spraying a closed adhesive ring with the same width as the edge strip 21 along the outer edge of the sensitive region.

[0044] Installation of edge strip 21: Precisely press the edge strip 21 onto the adhesive coating on the outer edge of the sensitive region, with a position deviation of <1 mm.

[0045] Second glue injection: Continuously spray a closed adhesive ring with the same width as the edge strip 21 above the edge strip 21.

[0046] Micromesh 1 lamination: Lay the metal micromesh 1 on the support medium 2 and apply a pre-pressure of 0.05 MP-0.10 MPa to ensure preliminary adhesion. Constant pressure curing: Use a press under uniform pressure conditions of 0.5 MPa-1.0 MPa, raise the temperature to 60℃-120℃, and control the pressure holding time to 2-10 hours to completely cure the adhesive. Then cool the temperature to room temperature.

[0047] Quality inspection and treatment: Check if there are surface contaminants on the Micromegas; if so, use ultrasonic cleaning, anhydrous ethanol rinsing, and finally dry air blowing to clean the surface.

[0048] The principles and implementation manners of the present application are described by using specific examples in the present application, and the above examples are only used for helping to understand the method of the present application and its core idea; meanwhile, for the general technical personnel in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed. In conclusion, the content of the present specification should not be understood as the limitation of the present application.

Claims

1. A micro-grid gas detector, characterized by: The micro mesh (1), the supporting medium (2) and the anode plate (3) are arranged in sequence along the thickness direction; the supporting medium (2) comprises a side bar (21) and a plurality of spacers (22), the side bar (21) is fixedly bonded to the circumferential edge of the micro mesh (1) and the anode plate (3), and a plurality of spacers (22) are arrayed and supported on the micro mesh (1) and the anode plate (3); each spacer (22) has a hollow channel (23) arranged along the thickness direction, and the hollow channel (23) is filled with an adhesive (4) to enable the micro mesh (1), the spacer (22) and the anode plate (3) to be fixedly bonded by the adhesive (4).

2. The microgrid gas detector of claim 1, wherein: The size of each spacer (22) is the same, and the ratio of the inner diameter size to the outer diameter size of each spacer (22) is 1:1.5-2.

0.

3. The microgrid gas detector of claim 2, wherein: The outer diameter of the spacer (22) is 0.5mm-2mm, the width of the side bar (21) is 1.0mm-5.0mm, and the size of the spacer (22) and the side bar (21) in the thickness direction is the same and is 30μm-500μm.

4. The microgrid gas detector of claim 1, wherein: The micro mesh (1) is a metal micro mesh, and the aperture ratio is greater than 10%, and the thickness is 10μm-50μm.

5. The microgrid gas detector of claim 1, wherein: The surface flatness of the anode plate (3) is not more than 10μm.

6. The microgrid gas detector of claim 1, wherein: The filling amount of the adhesive (4) in each hollow channel (23) is the same.

7. A method of manufacturing a microgrid gas detector as claimed in any one of claims 1 to 6, characterised by: The steps include: Arraying a plurality of spacers (22) on the anode plate (3); Coating adhesive (4) in the hollow channel (23) of each spacer (22) and on the circumferential edge of the anode plate (3); Pressing the side bar (21) on the adhesive (4) on the circumferential edge of the anode plate (3); Coating the adhesive (4) on the side of the side bar (21) away from the anode plate (3); Pressing the micro mesh (1) on the side bar (21) and each spacer (22) and curing.

8. The method of claim 7, wherein: Before the spacers (22) are distributed on the anode plate (3), the anode plate (3) is subjected to cleaning treatment; and / or, after the micro mesh (1) is pressed on the side bar (21) and each spacer (22) and cured, cleaning treatment is performed.

9. The method of claim 7, wherein: Each coating process of the adhesive (4) is performed by a glue coating device.

10. The method of claim 7, wherein: The micro mesh (1) is pressed on the side bar (21) and each spacer (22) and subjected to constant pressure curing.

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