阅读说明：本技术 微通道板用硼硅酸盐基体玻璃材料及其制备方法 (Borosilicate matrix glass material for microchannel plate and preparation method thereof ) 是由 赵卫 苏海琴 朱香平 韦永林 于 2021-01-11 设计创作，主要内容包括：本发明公开了一种微通道板用硼硅酸盐基体玻璃材料及其制备方法,所述微通道板用硼硅酸盐基体玻璃材料包括芯玻璃和皮玻璃,所述皮玻璃的组分包括SiO-2、B-2O-36、Al-2O-3、Na-2O、K-2O和CaO；所述芯玻璃的组分包括SiO-2、B-2O-3、BaCO-3、La-2O-3、Al-2O-3和ZnO。本发明配方合理,替换掉铅等危化品,减少对环境的污染,芯料玻璃可以高速酸溶不留残渣,皮料玻璃耐腐蚀性能、机械性能好,具有使MCP不会变形、结构均匀性和孔径精度好的优点,并且本发明原料容易获得,成本不高,易于熔制,成形,生产制备效率高。(The invention discloses a borosilicate base glass material for a microchannel plate and a preparation method thereof, wherein the borosilicate base glass material for the microchannel plate comprises core glass and skin glass, and the skin glass comprises SiO 2 、B 2 O 3 6、Al 2 O 3 、Na 2 O、K 2 O and CaO; the coreThe glass comprises SiO 2 、B 2 O 3 、BaCO 3 、La 2 O 3 、Al 2 O 3 And ZnO. The invention has reasonable formula, replaces hazardous chemicals such as lead and the like, reduces the pollution to the environment, can dissolve core material glass at high speed without residue, has good corrosion resistance and mechanical property of skin material glass, has the advantages of no deformation of MCP, good structural uniformity and pore diameter precision, is easy to obtain raw materials, has low cost, is easy to melt and form, and has high production and preparation efficiency.)

1. A borosilicate base glass material for a microchannel plate, which comprises core glass and skin glass,

the skin glass comprises the following components in percentage by weight: SiO 2₂ 60～80mol％，B₂O₃ 6～20mol％，Al₂O₃ 0.5～8mol％，Na₂O 3～8mol％，K₂O 1～8mol％，CaO 1～6mol％；

The core glass comprises the following components in percentage by weight: SiO 2₂ 15～32mol％，B₂O₃ 12～40mol％，BaCO₃ 2～45mol％，La₂O₃ 10～32mol％，Al₂O₃ 0～8mol％，ZnO 1～8mol％。

2. The borosilicate base glass material for a microchannel plate according to claim 1, wherein: the skin glass comprises the following components in percentage by weight: SiO 2₂ 69～80mol％，B₂O₃ 7～15mol％，Al₂O₃ 1～5mol％，Na₂O 4～7mol％，K₂O 1～7mol％，CaO 1～5mol％。

3. The borosilicate base glass material for a microchannel plate according to claim 1, wherein: the core glass comprises the following components in percentage by weight: SiO 2₂ 15～32mol％，B₂O₃ 12～40mol％，BaCO₃ 2～45mol％，La₂O₃ 10～32mol％，Al₂O₃ 0～8mol％，ZnO 1～8mol％。

4. The borosilicate base glass material for a microchannel plate according to claim 1 or 2, wherein: the components of the skin glass also comprise0.05-0.5 wt% of clarifying agent Sb₂O₃。

5. The borosilicate base glass material for a microchannel plate according to claim 1 or 3, wherein: the core glass also comprises a clarifying agent Sb accounting for 0.05-0.5 wt% of the core glass₂O₃。

6. The borosilicate base glass material for a microchannel plate according to claim 1, wherein: the thermal expansion coefficient of the skin glass at 20-300 ℃ is 50-81.28.10^-7/℃。

7. The borosilicate base glass material for a microchannel plate according to claim 1, wherein: the core glass has a coefficient of thermal expansion of 27.79 to 65.73.10 at 20 ℃ to 300 ℃^-7/℃。

8. A preparation method of borosilicate matrix glass material for a microchannel plate is characterized by comprising the following steps: which comprises the following steps:

(1) preparation of a core glass rod: mixing the component raw materials of the core glass of any one of the claims 1-5, and then casting and molding a core glass rod after high-temperature melting and clarification;

(2) preparing a glass tube: mixing the raw materials of the skin glass of any one of claims 1-5, melting at high temperature, clarifying, casting to form a glass rod, and processing the glass rod into a skin glass tube;

(3) preparing a blank plate: nesting a core glass rod in a sheath glass tube, drawing monofilaments and multifilaments, regularly arranging the multifilaments, then melting and pressing the multifilaments into blank plate sections, and then slicing, rounding, grinding and polishing to obtain blank plates;

(4) processing: acid etching is carried out on the blank plate by adopting acid liquor to prepare a micro-channel plate with the aperture of 4-8 mu m, the thickness of 0.20-0.40 mm and the outer diameter of 15-30 mm;

the steps (1) and (2) are not in sequence.

9. The method of manufacturing a borosilicate base glass material for a microchannel plate according to claim 8, wherein: the high-temperature melting temperature in the step (1) is 1400-1500 ℃, and the casting temperature is 1350-1400 ℃.

10. The method of manufacturing a borosilicate base glass material for a microchannel plate according to claim 8, wherein: the high-temperature melting temperature in the step (1) is 1500-1600 ℃, and the casting temperature is 1400-1500 ℃.

Technical Field

The invention relates to the technical field of glass materials, in particular to a borosilicate base glass material for a microchannel plate and a preparation method thereof.

Background

In the field of photomultiplier technology, a single-channel electron multiplier can only be used to detect electrons, neutrons, etc., X-rays, r-rays, energetic particles, etc., while a two-dimensionally arranged electron multiplying display microchannel plate (MCP) is an element composed of thousands of hollow glass capillaries closely arranged in parallel to each other to multiply electrons distributed in two-dimensional space, each micropore, i.e., one channel, in the plate is a micro electron multiplier, which can be used to detect and amplify a photoelectric image, and the more channels in the plate (each channel is a pixel), the clearer the image. Due to the characteristics of high gain, low noise, high resolution, wide frequency band, low power consumption, long service life and self-saturation effect, the microchannel plate (MCP) is widely applied to micro-light image tubes, photomultiplier tubes, camera houses and ion detectors.

The traditional MCP is prepared by manufacturing a silicate leather material glass tube containing lead and bismuth and an acid-soluble core material glass rod, performing processes of wire drawing, screen arrangement, hot melt pressing, slicing, coarse grinding, polishing, corrosion, hydrogen reduction, film coating and the like twice, and forming a qualified product after inspection and testing. In the manufacturing process of the traditional MCP, the cladding glass is required to have good thermal stability and chemical stability, a functional layer with conductive capability and secondary electron emission capability can be formed on the surface layer of the inner wall of a channel after hydrogen burning treatment, and meanwhile, the matching with the core glass is also required to be considered in the aspects of softening temperature, viscosity and the like, so that the limited factors are more. By adjusting the component proportion of the glass and optimizing the preparation process, the improvement of the performance such as gain, service life and the like of the traditional MCP has a plurality of limitations, great difficulty and non-ideal effect.

In order to obtain MCPs with high performance parameters, such as high gain, low dark count, long lifetime, researchers have turned the eye to a new fabrication technique, the atomic layer deposition fabrication technique. By adopting an atomic energy lamination technology, functional layers such as a conductive layer, a secondary electron emission layer and the like are prepared in the hole of the borosilicate glass substrate, so that the microchannel plate with the conductive and electron multiplication capabilities is obtained. The novel atomic layer deposition microchannel plate (ALD-MCP) effectively avoids the restriction of a substrate glass material on the performance optimization, realizes the independent design of the substrate material and a functional material, can obviously improve the comprehensive performance of the microchannel plate, omits the step of high-temperature reduction hydrogen burning treatment of the microchannel plate, simplifies the preparation, and improves the performance.

The acid-soluble glass system of the microchannel plate reported in the literature at present is also borosilicate glass, and the acid-soluble glass system is single, but silicon in the glass is easily attached to the surface of the microchannel plate after being washed by acid and is not easy to remove. With the improvement of the requirements of the imaging definition and the resolution of the application device of the microchannel plate, the diameter of the microchannel plate is reduced all the time, and the diameter is developed from 12 micrometers of the first generation to 6-8 micrometers at present, and the 2 and 4-micrometer microchannel plates are reported. The refining of the channel causes the speed of discharging the residue to be reduced when the core glass is acid-etched, and the acid dissolution time of the core glass is increased. Meanwhile, the thickness of the microchannel plate is continuously reduced along with the reduction of the diameter of the microchannel, and the thickness of the microchannel plate is from 0.30mm to 0.40mm of 8 mu m aperture to 0.20mm to 0.24mm of 4 mu m aperture, so that the problem that the plate is easy to deform or even break after the microchannel plate is reduced is prominent, and the micro-pore refinement of the microchannel plate is limited. One important influence on the deformation of the thin microchannel plate is that the mechanical strength of the skin glass and the edge-covering framework glass is reduced while the core glass is removed by acid etching, so that the performance of the core glass plays an important role in the practical application of the microchannel plate.

The key to the preparation of MCP is that the glass fiber is formed by drawing an acid-soluble core glass rod and a cladding glass tube together, then adding foreign edge-covering glass fiber, regularly arranging the two glass fibers into bundles, fusing at high temperature, cutting into thin glass sheets, and removing the core glass by acid etching to form a porous structure. The MCP structure manufactured by the solid acid-soluble method is uniform in geometric dimension, the channel aperture is easy to control, small aperture preparation can be achieved, the input end face and the output end face are simple in grinding and polishing process and good in polishing quality, the channel is easy to manufacture into a bent shape, however, the solid acid-soluble method has the problem of matching of core glass and cladding glass, the core glass is easy to etch by acid in preparation, the cladding glass needs to have good acid etching resistance, and in the heat treatment process, mutual permeation between the core glass and the cladding glass is reduced as much as possible, and good thermochemical compatibility is achieved. Because the sheath glass and the core glass must be matched with each other in the process and compatible with each other in physical and chemical properties, the two glasses usually form a group, are developed in a matching way and cannot be separated. In general, the preparation of MCP requires solving the following problems.

1. MCP distortion problem: a series of hot working and cold working operations such as high-temperature hydrogen burning require that MCP is not broken and is very difficult to deform, particularly, after the aperture is reduced, the plate becomes thinner and thinner, as long as residual stress in glass in the plate is not thoroughly removed in any cold working or hot working process, and when the stress exceeds the mechanical strength of the plate, the plate is broken or deformed, so that MCP is scrapped, particularly, after high-temperature hydrogen burning, metal Pb and Bi are separated out by reducing skin glass, the performance of the glass is changed sharply, the aperture is smaller, the change is larger, and the MCP is deformed more seriously.

2. MCP core frit glass solubility problem: the speed of discharging residues is reduced when the core glass is subjected to acid etching due to the thinning of the channel, the acid dissolving time of the core glass is prolonged, the corrosion to the skin glass is increased, the interior of the micro channel is uneven, the smoothness of the inner wall of the micro hole is reduced, and the adsorption of residual gas and impurities is reduced, so that the normal use is influenced.

3. The toxic problem of the traditional MCP matrix glass component: a large amount of compounds composed of elements such as Pb, Bi and the like are introduced into the traditional glass components, so that more toxic and harmful gas and dust are generated in the glass preparation process, great harm is caused to human bodies and the environment, and the traditional glass components contain a large amount of alkali metal ions which can cause poisoning of tubes due to migration of the alkali metal ions.

Disclosure of Invention

In view of the above disadvantages, the present invention provides a borosilicate base glass material for a microchannel plate and a preparation method thereof, which can reduce the problem that the borosilicate base glass material for a microchannel plate has high viscosity and can not be prepared when the glass is prepared, replace hazardous chemical products such as lead, and reduce environmental pollution, and can dissolve a core glass at a high speed without leaving residues, and has good corrosion resistance and mechanical properties of a cladding glass.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a borosilicate base glass material for a microchannel plate, comprising a core glass and a sheath glass, wherein the sheath glass has a composition of:

SiO₂ 60～80mol％，B₂O₃ 6～20mol％，Al₂O₃ 0.5～8mol％，Na₂O 3～8mol％，K₂O 1～8mol％，CaO 1～6mol％；

the core glass comprises the following components in percentage by weight: SiO 2₂ 15～32mol％，B₂O₃ 12～40mol％，BaCO₃ 2～45mol％，La₂O₃ 10～32mol％，Al₂O₃ 0～8mol％，ZnO 1～8mol％。

As a preferable scheme of the invention, the skin glass comprises the following components in percentage by weight: SiO 2₂ 69～80mol％，B₂O₃7～15mol％，Al₂O₃ 1～5mol％，Na₂O 4～7mol％，K₂O 1～7mol％，CaO 1～5mol％。

As a preferable scheme of the present invention, the core glass comprises the following components: SiO 2₂ 15～32mol％，B₂O₃12～40mol％，BaCO₃ 2～45mol％，La₂O₃ 10～32mol％，Al₂O₃ 0～8mol％，ZnO 1～8mol％。

SiO₂The softening point and the high-temperature viscosity of the glass are improved, and SiO is properly increased₂In an amount that enables the softening point, high temperature viscosity and chemical stability of the glass to be in an appropriate state.

B₂O₃Is a glass former oxide, is a basic skeleton of a glass structure, is a main component of acid-soluble glass, and when the content is excessive, the glass contains a large amount of [ BO₃]The planar structure is not favorable for the chemical stability of the glass, the viscosity and the thermal expansion coefficient of the glass are also reduced, the incompatibility with the skin glass of the microchannel plate is worsened, and therefore, the control B₂O₃The content of (A) is favorable for improving the chemical stability of the glass;

BaCO₃the glass is a network external oxide of glass, is a main oxide component for improving the acid dissolution rate of the glass, is a fluxing agent of the glass, and is unstable in performance and easy to generate a phase separation phenomenon after the content of the oxide is excessive; according to the invention, a proper amount of BaO is added into the glass, so that the material property of glass forming can be improved, and the thermal processing performance of the glass is improved.

La₂O₃The glass is a glass structure adjusting oxide and is also a main oxide component for improving the acid dissolution rate of the glass, and in a high boron dam glass system, when the total content is too high, the chemical stability of the glass can be reduced, and the processing and forming difficulty of the glass is increased; the invention adjusts La properly₂O₃The content of (A) is effective in increasing the softening temperature of the glass and improving the material properties.

Na₂CO₃And K₂CO₃The glass is a network exooxide of the glass, alkali metal ions are easy to move and diffuse in a glass body, the viscosity of the glass which is melted at high temperature can be reduced, the glass is easy to melt, the glass is a good fluxing agent, the thermal expansion coefficient of the glass can be increased, the chemical stability and the mechanical strength of the glass are reduced, and the introduction amount cannot be too much: the invention can be based on Na in the micro-channel plate cladding glass matched with the Na₂CO₃、K₂CO₃The content is adjusted, and one or more of the content is introduced, so that the diffusion degree of the core skin in the fiber drawing and hot fusion processes is effectively reduced.

ZnO、MgO、CaCO₃Is a network exo-oxide of the glass, but too much addition can significantly reduce the acid dissolution rate of the glass. The invention utilizes ZnO, MgO and CaCO₃Are also alkaline earth metal oxides and further replace glassMedium BaCO₃The method is beneficial to improving the anti-crystallization capacity of the glass, adjusting the material property of the glass and improving the chemical stability of the glass.

Al₂O₃In order to adjust the structure of the glass, the content of the oxide affects the thermal expansion coefficient and the chemical and thermal stability of the glass, the invention uses Al₂O₃Replacing part of B₂O₃And the dosage is reasonably controlled, so that the problem of obviously reducing the acid dissolution rate of the glass is avoided.

As a preferable scheme of the invention, the components of the sheath glass and the core glass further comprise a clarifying agent Sb accounting for 0.05-0.5 wt% of the mass percent of the core glass₂O₃And the transparency can be further improved.

In a preferred embodiment of the present invention, the skin glass has a softening point of 484 to 626 ℃ and a coefficient of thermal expansion of 50 to 81.28.10 at 20 to 300 ℃^-7/° C, the acid dissolution rate of the coated glass is less than 1mg/mm²H, hardly corroding.

In a preferred embodiment of the present invention, the core glass has a softening point of 533 to 622 ℃ and a coefficient of thermal expansion of 27.79 to 65.73.10 at 20 to 300 ℃^-7/° C, the acid dissolution rate of the salt-core glass is greater than or equal to 50mg/mm²·h。

The core glass and the sheath glass have no crystallization at 500-1000 ℃, and have good crystallization resistance.

A preparation method of borosilicate matrix glass material for a microchannel plate comprises the following steps:

(1) preparation of a core glass rod: preparing the core glass, mixing the raw materials, melting and clarifying at the high temperature of 1400-1500 ℃, preferably 1450 ℃, and then casting and molding a core glass rod at the temperature of 1350-1400 ℃, preferably 1380 ℃;

(2) preparing a glass tube: preparing the raw materials of the skin glass, mixing, melting and clarifying at the high temperature of 1500-1600 ℃, preferably 1550 ℃, casting and molding a glass rod at the temperature of 1400-1500 ℃, preferably 1450 ℃, and processing the glass rod into a skin glass tube;

(3) preparing a blank plate: nesting a core glass rod in a sheath glass tube, drawing monofilaments and multifilaments, regularly arranging the multifilaments, then melting and pressing the multifilaments into blank plate sections, and then slicing, rounding, grinding and polishing to obtain blank plates;

(4) processing: acid etching is carried out on the blank plate by adopting acid liquor to prepare a micro-channel plate with the aperture of 4-8 mu m, the thickness of 0.20-0.40 mm and the outer diameter of 15-30 mm;

the steps (1) and (2) are not in sequence.

The invention has the beneficial effects that: the borosilicate matrix glass material for the microchannel plate has a reasonable formula, can reduce viscosity during glass preparation, is suitable for an ALD coating technology, does not need to introduce Pb and Bi elements to form a functional layer, only needs to mainly consider thermal property and chemical stability of glass and compatibility of skin glass and core glass, provides more selection space for component optimization of the glass, reduces preparation difficulty of the glass, replaces hazardous chemicals such as lead and the like, reduces pollution to the environment, can dissolve the core glass at high speed without residues, shortens the time of an acid etching process, reduces corrosion of acid solution to skin glass and edge glass of the microchannel plate, and solves the problems of deformation and damage of the small-aperture microchannel plate; the corrosion resistance and the mechanical property of the skin glass are good, so that the skin glass is not easy to damage and deform in the processing process; in addition, the invention has the advantages of easy acquisition of raw materials, low cost, easy melting and forming, and is beneficial to wide popularization and application.

The present invention will be further described with reference to the following examples.

Detailed Description

Example (b): the core glass rod preparation process of the invention takes boric acid, silicon dioxide, nitric acid dam or carbonic acid dam, lanthanum oxide, aluminum oxide, zinc oxide, magnesium oxide and calcium carbonate as raw materials to be mixed, and a clarifying agent Sb accounting for 0.2 percent of the weight of the batch mixture is added₂O₃Melting and clarifying the batch at 1450 ℃, and casting and molding a core glass rod at 1380 ℃; the specific components of the core glass rod and the test results are shown in Table 1.

Table 1:

Σ() in table 1 indicates the total content parts of each compound represented by a chemical formula in parentheses, and each compound is not necessarily all.

The process for preparing the skin glass rod takes silicon dioxide, boric acid, aluminum oxide, potassium oxide, sodium oxide, carbonate dam and calcium carbonate as raw materials to be mixed, and a clarifying agent Sb accounting for 0.2 percent of the weight of the batch mixture is added₂O₃The batch is melted and clarified at 1550 ℃ and cast into a core glass rod at 1450 ℃, and then the core glass rod is processed into a skin glass tube matched with the core glass rod. The specific components of the sheath glass tube and the test results are shown in Table 2.

Σ() in table 2 indicates the total content parts of each compound represented by the chemical formula in parentheses, and each compound is not necessarily all.

Nesting a core glass rod in a sheath glass tube, drawing monofilaments and multifilaments, regularly arranging the multifilaments, then melting and pressing the multifilaments into blank plate sections, and then slicing, rounding, grinding and polishing to obtain blank plates; and (4) carrying out acid etching on the blank plate by adopting acid liquor to prepare the microchannel plate. In this embodiment, a solid-edged microchannel plate having a pore diameter of 4 to 8 μm, a thickness of 0.20 to 0.40mm, and an outer diameter of 15 to 30mm, preferably an outer diameter of 25mm (effective diameter of 18.8mm) is obtained as an example. In other embodiments, the size of the aperture, thickness, outer diameter, etc. may be adjusted as desired for production.

The core glass of the invention is prepared by reasonably adding SiO₂、Al₂O₃And La₂O₃And (4) increasing the softening temperature of the glass. The skin glass of the invention has no calculus and bubble, uniform and transparent stripe, and has good process performance: easy melting, molding and accurate size.

The core glass and the sheath glass have similar temperature, viscosity and expansion coefficient, and the core glass has higher softening temperature than the sheath glass, so that single fibers and compound fibers with precise sizes can be drawn when the core glass and the sheath glass are drawn, the fibers at the boundaries of the multifilament basically do not deform, and devitrification do not occur after melt pressing, thereby ensuring the regular shape of the channel. The core glass rod made of the core glass is round, has excellent acid solubility, can be quickly dissolved by acid during acid treatment, and does not leave residues which damage the electrical performance of the MCP in the channel. And the core glass and the skin glass have good chemical compatibility, and the mutual permeability is reduced when the core glass and the skin glass are drawn and pressed.

The borosilicate substrate glass material for the microchannel plate can be used for manufacturing ALD-MCP substrate glass, the aperture is 4-6 mu m, the electrical property requirement of the ALD-MCP substrate glass can be met, the thickness of the plate is 0.23 +/-0.02 mm-0.35 +/-0.02 mm, the plate is not deformed, the mechanical strength and the hardness are good, the comprehensive performance of the product is good, the electric conduction and electron multiplication capacity of the microchannel plate are effectively enhanced, the stability of the microchannel plate is improved, the service life is prolonged, the pollution of hazardous chemicals to the environment can be reduced, and the borosilicate substrate glass material can be widely applied to the field of photomultiplier devices.

The above examples are only preferred embodiments of the present invention, and the present invention is not limited to all embodiments, and any technical solution using one of the above examples or equivalent changes made according to the above examples is within the scope of the present invention. The borosilicate base glass material for the microchannel plate adopts lead-free and bismuth-free borosilicate glass as base glass, so that the problem that the solid acid dissolution method for manufacturing the microchannel plate requires high-speed acid dissolution of core glass is solved, and the skin glass has better chemical stability and mechanical property, is not easy to damage and deform in the processing process, has good structural stability and high aperture processing precision, is easy to prepare, has high repeatability and has small harm to the environment and human health.

Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. In addition, although specific terms are used herein, they are used for convenience of description and do not limit the present invention in any way, and other compositions obtained by the same or similar methods and methods for preparing the same are within the scope of the present invention.