Purification system and purification method for electronic grade materials

Abstract

The invention relates to a purification system and a purification method for an electronic-grade material. The purification system comprises a rectification unit, a first storage unit, a gas supply unit and a gas-liquid separation unit. The rectification unit comprises a rectification tower body, a rotating part and a driving part, the rotating part is located in the rectification tower body, and the driving part is in transmission connection with the rotating part to drive the rotating part to rotate so as to separate a target product and metal impurities in the to-be-rectified object; the first storage unit is configured to store a to-be-rectified object and input the to-be-rectified object into the rectification unit; the gas supply unit is configured to store high-purity inert gas, input the stored high-purity inert gas into the rectification unit to replace air in the rectification unit, and input the stored high-purity inert gas into the first storage unit to bring a to-be-rectified object into the rectification unit; and the gas-liquid separation unit is configured to be communicated with the rectification unit. The purification system can improve the purification effect and simplify the purification process.

Description

Technical Field

[0001] The present application relates to the technical field of purification systems, and in particular to a purification system and a purification method for electronic grade materials. Background Art

[0002] Electronic-grade materials generally refer to various materials used to produce electronic components, assemblies and their systems. These materials are required to have the characteristics of high purity. The lower the metal impurity content, the better the performance of the products made with them, so as to meet the strict requirements of electronic equipment for stability, accuracy and functionality.

[0003] At present, the metal ion requirement for electronic materials is ppb level. However, the current purification system also requires adsorbents or multiple distillation devices to reduce the metal impurities in electronic grade materials, which not only makes the purification process complicated, but also has poor purification effect. Summary of the invention

[0004] The purpose of the present application is to provide a purification system and a purification method for electronic grade materials, wherein the purification system can improve the purification effect and simplify the purification process.

[0005] The first aspect of the embodiment of the present application provides a purification system for electronic-grade materials, including a distillation unit, a first storage unit, a gas supply unit and a gas-liquid separation unit. The distillation unit includes a distillation tower body, a rotating component and a driving component, the rotating component is located in the distillation tower body, and the driving component is connected to the rotating component to drive the rotating component to rotate to separate the target product and metal impurities in the distillate to be distilled; the first storage unit is configured to store the distillate to be distilled, and input the distillate to be distilled into the distillation unit; the gas supply unit is configured to store high-purity inert gas, and input the stored high-purity inert gas into the distillation unit to replace the air in the distillation unit, and input the stored high-purity inert gas into the first storage unit to bring the distillate to be distilled into the distillation unit; the gas-liquid separation unit is configured to connect the distillation unit to separate the electronic-grade material and gas in the target product flowing out of the distillation unit.

[0006] In the purification system provided in the embodiment of the present application, the first storage unit uses the high-purity inert gas provided by the gas supply unit as a carrier to transport the material to be distilled stored inside it to the distillation unit, which can reduce the introduction of foreign impurities. In addition, the distillation unit includes a distillation tower body, a rotating component and a driving component. The driving component can drive the rotating component to rotate in the distillation tower body, and the rotating rotating component can make the rising gas phase and the descending condensed liquid phase continuously act, so that the two phases are in close contact, and the fractionation effect can be improved without the need for fillers, so that the metal impurity content in the target product flowing out of the distillation tower body is reduced, and then the electronic grade material can be obtained after passing through the gas-liquid separation unit. It can be seen that the above purification system can improve the purification effect while simplifying the purification process.

[0007] In some embodiments of the present application, the distillation tower body includes a condensing section, a distillation section and a bottom section which are interconnected along the axial direction, wherein the distillation section is located between the condensing section and the bottom section, the bottom section is configured to connect to a first storage unit and an air supply unit, the rotating component is located in the distillation section, and the driving component is located at one end of the condensing section away from the distillation section.

[0008] In some embodiments of the present application, the distillation unit further includes a condensing component, a control component and a heating component. The condensing component is located in the condensing section body, the control component is connected to the distillation tower body to control the reflux ratio in the distillation tower body and the outflow of the target product, and the heating component is configured to heat the material to be distilled in the bottom section of the tower to vaporize the material to be distilled.

[0009] In some embodiments of the present application, the condensation section and the rectification section are connected via a ground joint or a flange; and / or the rectification section and the bottom section are connected via a ground joint or a flange.

[0010] In some embodiments of the present application, the distillation section body includes a first tube body and a second tube body, the second tube body is located in the first tube body and connected to the bottom section body, and the rotating component is located in the second tube body.

[0011] In some embodiments of the present application, a thermal insulation layer is provided on the inner wall of the first tube body.

[0012] In some embodiments of the present application, the first tube has a buffer section.

[0013] In some embodiments of the present application, the rotating component is in a spiral shape.

[0014] In some embodiments of the present application, the length of the rotating component along the axial direction of the second tube is 45 cm to 90 cm.

[0015] In some embodiments of the present application, the material of the rotating component includes one or more of polytetrafluoroethylene, nickel alloy, and polyetherimide.

[0016] In some embodiments of the present application, the purification system further comprises:

[0017] a second storage unit, configured to be connected to the gas-liquid separation unit to receive and store the electronic-grade material flowing out of the gas-liquid separation unit;

[0018] The tail gas treatment unit is configured to communicate with the distillation unit, the gas-liquid separation unit and the second storage unit.

[0019] In some embodiments of the present application, the first storage unit is connected to the bottom section of the tower through a first PFA pipe;

[0020] And / or, the gas supply unit is connected to the tower kettle section through a second PFA pipe;

[0021] And / or, the gas-liquid separation unit is connected to the distillation tower body through a third PFA tube;

[0022] and / or, the second storage unit is connected to the gas-liquid separation unit via a fourth PFA pipe;

[0023] And / or, the tail gas treatment unit is connected to the condensation section, the gas-liquid separation unit and the second storage unit respectively through the fifth PFA pipe;

[0024] and / or, the gas supply unit is connected to the first storage unit via a sixth PFA pipe;

[0025] and / or, the gas supply unit is connected to the first PFA tube via a seventh PFA tube;

[0026] And / or, the gas supply unit is connected to the fifth PFA tube via an eighth PFA tube.

[0027] A second aspect of the present application provides a purification method, using the purification system of the first aspect of the present application, comprising:

[0028] A pretreatment process, in which high-purity inert gas is introduced into the purification system for pretreatment, so that the pressure change in the distillation unit reaches within a preset pressure range and the dew point temperature of the gas discharged from the distillation unit reaches a preset temperature;

[0029] a distillation step, under inert atmosphere conditions, bringing the material to be distilled in the first storage unit into the distillation unit through the gas supply unit for distillation treatment to obtain a first purified liquid, wherein the reflux ratio of the first purified liquid is greater than 2;

[0030] In the separation step, the first purified liquid is passed into a gas-liquid separation unit for gas-liquid separation to obtain electronic grade materials.

[0031] In some embodiments of the present application, the pretreatment step further includes:

[0032] The air tightness testing step is to introduce high-purity inert gas into the distillation unit so that the pressure in the distillation unit reaches a preset value, and after maintaining the pressure for 24 hours to 36 hours, the pressure change in the distillation unit is within 3% to 8%;

[0033] In the replacement step, the pressure in the distillation unit is increased and decreased multiple times to make the dew point temperature of the gas discharged from the distillation unit below -70°C.

[0034] In some embodiments of the present application, in the air tightness detection process, the preset value is 5psi to 6psi, and the high-purity inert gas includes high-purity nitrogen and / or high-purity argon.

[0035] In some embodiments of the present application, the high-purity inert gas includes high-purity nitrogen.

[0036] In some embodiments of the present application, in the high-purity nitrogen, the nitrogen content is greater than or equal to 99.999%, the water content is less than or equal to 1 ppm, and the oxygen content is less than or equal to 0.5 ppm.

[0037] In some embodiments of the present application, in the distillation process, after full reflux for 2h to 4h, the first purified liquid is extracted at a reflux ratio of (2 to 10): 1, the temperature of the bottom section of the tower is 144°C to 155°C, the temperature of the condensation section is 138°C to 144°C, the pressure of the bottom section of the tower is 0psi to 2psi, and the pressure of the top section of the tower is 0psi to 1psi.

[0038] In some embodiments of the present application, the rotation speed of the rotating component is 2000 rpm / min to 5000 rpm / min.

[0039] In some embodiments of the present application, the material to be distilled includes hexachlorodisilane with a purity of 5N, and the electronic grade material includes hexachlorodisilane with a purity of 6N to 7N. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 This is a structural block diagram of some purification systems provided in this application.

[0042] Figure 2 Schematic diagram of the structure of some purification systems provided in this application.

[0043] Figure 3A schematic diagram of the partial structure of a distillation section provided in some embodiments of the present application.

[0044] Figure 4 A schematic diagram of the purification method provided in some embodiments of the present application.

[0045] Figure 5 Schematic diagram of the purification method provided in other embodiments of the present application.

[0046] Description of reference numerals:

[0047] 10-Purification system;

[0048] 100-distillation unit, 110-distillation tower body, 111-condensation section body, 112-distillation section body, 1121-first tube body, 1121a-insulation layer, 1121b-buffer section, 1122-second tube body, 113-bottom section body, 120-rotating component, 130-driving component, 140-condensation component, 150-control component, 160-heating component;

[0049] 200 - a first storage unit, 210 - a first PFA tube;

[0050] 300 - air supply unit, 310 - second PFA tube, 320 - sixth PFA tube, 330 - seventh PFA tube, 340 - eighth PFA tube;

[0051] 400 - gas-liquid separation unit, 410 - third PFA tube;

[0052] 500 - second storage unit, 510 - fourth PFA tube;

[0053] 600 - tail gas treatment unit, 610 - fifth PFA tube. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0055] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0056] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0057] In this application, unless otherwise stated, the directional words used, such as "upper" and "lower", refer specifically to the directions of the drawings in the accompanying drawings. In addition, in the description of this specification, the terms "include", "comprise", etc. mean "including but not limited to". In this article, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0058] In this article, "at least one" means one or more, and "plurality" means two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e. a and b), ac, bc, or abc, where a, b, c can be single or multiple.

[0059] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0060] As described in the above background technology, electronic grade materials are used as various materials for producing electronic components, assemblies and their systems, and they are required to have the characteristics of high purity. For example, electronic grade hexachlorodisilane (molecular formula is Cl6Si2, referred to as HCDS) is used as a silicon source precursor for high-quality silicon nitride and silicon oxide films in the manufacture of products such as NAND Flash memory logic chips below 28nm. The higher its purity, the better the performance of the products manufactured using it. However, the purification system in the related art requires adsorbents or multiple distillation devices to reduce the metal impurities in the electronic grade materials, which not only makes the purification process complicated, but also the purification effect is poor.

[0061] In this article, the purity of electronic-grade materials refers to the purity of the product after removing metal impurities. For example, a few N refers to the number of nines in purity. That is, it can be understood that 3N is 99.9%, 4N is 99.99%, 5N is 99.999%, 6N is 99.9999%, 7N is 99.99999%, etc.

[0062] In view of this, an embodiment of the present application provides a purification system and a purification method for electronic-grade materials, wherein the purification system can simplify the purification process and improve the purification effect.

[0063] The following is a detailed description of a purification system and purification method for electronic grade materials in an embodiment of the present application.

[0064] See also Figure 1 and Figure 2 As shown, a storage unit 200, a gas supply unit 300 and a gas-liquid separation unit 400. The distillation unit 100 includes a distillation tower body 110, a rotating component 120 and a driving component 130. The rotating component 120 is located in the distillation tower body 110. The driving component 130 is connected to the rotating component 120 in a transmission manner to drive the rotating component 120 to rotate to separate the target product and metal impurities in the distillate to be distilled; the first storage unit 200 is configured to store the product to be distilled and input the product to be distilled into the distillation unit 100; the gas supply unit 300 is configured to store high-purity inert gas, input the stored high-purity inert gas into the distillation unit 100 to replace the air in the distillation unit 100, and input the stored high-purity inert gas into the first storage unit 200 to bring the product to be distilled into the distillation unit 100; the gas-liquid separation unit 400 is configured to be connected to the distillation unit 100 to separate the electronic grade material and gas in the target product flowing out of the distillation unit 100.

[0065] In the purification system 10 provided in the embodiment of the present application, the first storage unit 200 uses the high-purity inert gas provided by the gas supply unit 300 as a carrier to transport the material to be distilled stored therein to the distillation unit 100, which can reduce the introduction of foreign impurities. In addition, the distillation unit 100 includes a distillation tower body 110, a rotating component 120 and a driving component 130. The driving component 130 can drive the rotating component 120 to rotate in the distillation tower body 110, and the rotating rotating component 120 can make the rising gas phase and the descending condensed liquid phase closely contact each other, thereby helping to improve the fractionation effect, so that the metal impurity content in the target product flowing out of the distillation tower body 110 is reduced, and then the electronic grade material can be obtained after passing through the gas-liquid separation unit 400. It can be seen that the above-mentioned purification system 10 can improve the purification effect while simplifying the purification process.

[0066] In some embodiments, the distillation tower body 110 includes a condensing section 111, a distillation section 112 and a bottom section 113 which are interconnected along the axial direction, wherein the distillation section 112 is located between the condensing section 111 and the bottom section 113, the bottom section 113 is configured to connect to the first storage unit 200 and the gas supply unit 300, the rotating component 120 is located in the distillation section 112, and the driving component 130 is located at one end of the condensing section 111 away from the distillation section 112.

[0067] In this article, the axial direction refers to the axial direction of the distillation tower body 110, that is, Figure 2 In the Y-axis direction, Figure 2 The X-axis direction is represented as the horizontal direction.

[0068] In the above embodiment, the distillation tower body 110 includes a condensation section, a distillation section and a bottom section which are interconnected along the axial direction. This can not only shorten the purge path, but also reduce the occurrence of purge dead corners, so that the air content and moisture content in the distillation tower body 110 after being purged with high-purity inert gas are reduced, thereby reducing the amount of acid generated by the side reactions between the distillate and the air and water. The reduction in the amount of acid can help reduce the amount of impurities brought by the contact parts, thereby improving the purification effect.

[0069] In the embodiment of the present application, the shapes of each section of the distillation tower body 110 can be shapes well known in the art. For example, the shapes of the condensation section 111 and the distillation section 112 can be cylindrical, and the shape of the tower bottom section 113 can be circular.

[0070] In some embodiments, the distillation tower body 110 may be made of an anti-corrosion material, such as high borosilicate glass, which can further reduce the occurrence of tower body corrosion and the introduction of foreign impurities.

[0071] In addition, the structure of the distillation tower body 110 may be improved to enhance the air tightness of the distillation tower body 110 and reduce the inflow of external air and water, thereby helping to further improve the purification effect.

[0072] In other embodiments, the condensing section 111 and the rectifying section 112 may be connected via a ground joint or a flange. The rectifying section 112 and the tower bottom section 113 may be connected via a ground joint or a flange.

[0073] In some embodiments, the distillation unit 100 further includes a condensing component 140, a control component 150 and a heating component 160. The condensing component 140 is located in the condensing section 111. The control component 150 is connected to the distillation tower body 110 to control the reflux ratio in the distillation tower body 110 and the outflow of the target product. The heating component 160 is configured to heat the material to be distilled in the bottom section 113 to vaporize the material to be distilled.

[0074] In the embodiment of the present application, the condensing component 140, the control component 150 and the heating component 160 can all be components for distillation devices well known in the art, for example, the condensing component 140 can be a spiral condenser, the control component 150 can be a reflux valve, and the heating component 160 can be a heater with a heating function. The embodiment of the present application does not specifically limit the condensing component 140, the control component 150 and the heating component 160.

[0075] In the above embodiment, the volume of each section of the distillation tower body 110 can be designed according to actual needs. For example, when conducting a small-scale experiment in a laboratory, the volume of the bottom section of the tower can be 100 mL to 2000 mL.

[0076] See also Figure 3 As shown, in some embodiments, the distillation section 112 includes a first tube body 1121 and a second tube body 1122 , the second tube body 1122 is located in the first tube body 1121 and communicates with the bottom section 113 , and the rotating component 120 is located in the second tube body 1122 .

[0077] In the above embodiments, in order to improve the heat preservation effect of the rectification section body 112, in some embodiments, a heat preservation layer 1121a is provided on the inner wall of the first tube body 1121. The heat preservation layer 1121a may be a silver-plated layer.

[0078] In other embodiments, a vacuum is formed between the first tube 1121 and the second tube 1122, which can reduce heat transfer and further improve the thermal insulation effect.

[0079] In addition, when the driving component 130 drives the rotating component 120 to rotate and the temperature in the rectifying section 112 changes, the rectifying section 112 will generate additional stress, which is not conducive to its stable rectification. Figure 3 As shown, in some embodiments, the first tube body 1121 has a buffer section 1121b, which can buffer part of the stress and is beneficial to the stable distillation of the distillation section body 112. Specifically, the buffer section 1121b can be in a corrugated shape.

[0080] In an embodiment of the present application, compared with a packing type distillation structure, a distillation unit including a rotating component can help reduce the pressure difference between the top and bottom of the distillation tower body, and can also make the residual amount in the tower smaller (less than 0.5 ml) after the distillation is completed, thereby facilitating the purging of the distillation tower body. The rotating component 120 can be any shape known in the art that is conducive to improving the contact between the gas phase and the liquid phase. In some embodiments, the shape of the rotating component 120 is spiral. Specifically, the rotating component 120 can be a spiral rotating belt.

[0081] In some embodiments, the length of the rotating component 120 along the axial direction of the second tube 1122 is 45 cm to 90 cm.

[0082] In the above embodiment, the length of the rotating component 120 is within the above range, which can increase the contact probability between the gas phase and the liquid phase during the rotation of the rotating component 120, thereby improving the fractionation effect.

[0083] In some embodiments, the inner diameter of the second tube is 7 mm to 9 mm. For example, the inner diameter of the second tube can be 7 mm, 8 mm or 9 mm.

[0084] In addition, the driving component 130 can also drive the rotating component 120 to rotate at a rate of 2000 rpm / min to 5000 rpm / min, so that the gas phase and the liquid phase can contact more fully, which helps to improve the separation efficiency and further improve the fractionation effect.

[0085] In some embodiments, the material of the rotating component 120 includes one or more of polytetrafluoroethylene, nickel alloy, and polyetherimide.

[0086] In some optional embodiments, the material of the rotating component 120 includes polytetrafluoroethylene, which has high corrosion resistance, thereby reducing the occurrence of pollution caused by the corrosion of the rotating belt by the acid generated during the purification process.

[0087] In the embodiment of the present application, the driving component 130 may be any component known in the art that can provide power, such as a motor.

[0088] In some embodiments, the purification system 10 further includes a second storage unit 500 and a tail gas treatment unit 600, wherein the second storage unit 500 is configured to be connected to the gas-liquid separation unit 400 to receive and store the electronic grade material flowing out of the gas-liquid separation unit 400. The tail gas treatment unit 600 is configured to communicate with the distillation unit 100, the gas-liquid separation unit 400 and the second storage unit 500.

[0089] In the above embodiment, the exhaust gas treatment unit 600 is used to exhaust the connected units, which can reduce pollution to the environment and reduce the occurrence of pipeline blockage caused by products produced by side reactions.

[0090] In some embodiments, the first storage unit 200 and the second storage unit 500 may both be made of quartz glass, which can reduce corrosion caused by the stored raw materials.

[0091] In some embodiments, the first storage unit 200 is connected to the bottom section 113 through the first PFA pipe 210; and / or the gas supply unit 300 is connected to the bottom section 113 through the second PFA pipe 310; and / or the gas-liquid separation unit 400 is connected to the distillation tower body 110 through the third PFA pipe 410; and / or the second storage unit 500 is connected to the gas-liquid separation unit 400 through the fourth PFA pipe 510; and / or the tail gas treatment unit 600 is respectively connected to the condensation section 111, the gas-liquid separation unit 400 and the second storage unit 500 through the fifth PFA pipe 610.

[0092] In some embodiments, the gas supply unit 300 is connected to the first storage unit 200 through a sixth PFA pipe 320 .

[0093] In the above embodiment, the material of the PFA tube is mainly copolymerized with polytetrafluoroethylene (PTFE) and perfluoropropyl vinyl ether. The PFA tube is used to connect the various units, which can reduce the occurrence of acid corrosion, thus helping to reduce the introduction of foreign impurities and further improve the purification effect.

[0094] In addition, a check valve is provided on the second PFA tube 310, and the material of the check valve is the same as that of the second PFA tube 310, so as to reduce the occurrence of corrosion. An angle valve is provided on the fourth PFA tube, and the material of the angle valve is the same as that of the fourth PFA tube 510, and the sealing of the second storage unit 500 can be ensured by the angle valve, which is convenient for sampling and analysis.

[0095] In some embodiments, the air supply unit 300 is connected to the first PFA tube 210 via the seventh PFA tube 330 ; and / or, the air supply unit 300 is connected to the fifth PFA tube 610 via the eighth PFA tube 340 .

[0096] In the above embodiment, the air supply unit 300 can purge the inside of its pipeline through the above connection to reduce the residual air and liquid in the pipeline, thereby helping to reduce the loss caused by the side reactions between the raw materials and the air and water.

[0097] Second, see Figure 4 As shown, an embodiment of the present application provides a purification method, using the purification system of the first aspect of the present application, comprising:

[0098] S100, a pretreatment step, introducing high-purity inert gas into the purification system for pretreatment, so that the pressure change in the distillation unit reaches within a preset pressure range and the dew point temperature of the gas discharged from the distillation unit reaches a preset temperature;

[0099] S200, a distillation process, under inert atmosphere conditions, bringing the material to be distilled in the first storage unit into the distillation unit through the gas supply unit for distillation treatment to obtain a first purified liquid, wherein the reflux ratio of the first purified liquid is greater than 2, the pressure of the tower bottom section is 0psi to 2psi, and the pressure of the tower top section is 0psi to 1psi;

[0100] S300, a separation step, passing the first purified liquid into a gas-liquid separation unit for gas-liquid separation treatment to obtain an electronic grade material.

[0101] In this article, the reflux ratio refers to the ratio of the reflux liquid flow rate L returned from the condensing section of the distillation tower to the top product flow rate D.

[0102] See also Figure 5 As shown, in some embodiments, the pre-processing step of S100 further includes:

[0103] S110, air tightness testing step, introducing high-purity inert gas into the distillation unit, so that the pressure in the distillation unit reaches a preset value, and after maintaining the pressure for 24h to 36h, the pressure change in the distillation unit is within 3% to 8%;

[0104] S120, a replacement step, performing multiple pressure-increasing and pressure-reducing operations on the pressure in the distillation unit to make the dew point temperature of the gas discharged from the distillation unit below -70°C.

[0105] In this article, dew point temperature refers to the temperature at which the air reaches saturation through cooling while the amount of water vapor (humidity content) in the air remains unchanged. The lower the dew point temperature, the less water the air contains.

[0106] In some embodiments, during the air tightness detection process, the preset value is 5psi to 6psi.

[0107] In some embodiments, the high purity inert gas includes high purity nitrogen and / or high purity argon.

[0108] In some embodiments, the high purity inert gas includes high purity nitrogen.

[0109] In some embodiments, in the high-purity nitrogen, the nitrogen content is greater than or equal to 99.999%, the water content is less than or equal to 1 ppm, and the oxygen content is less than or equal to 0.5 ppm.

[0110] In some embodiments, in the distillation process, after full reflux for 2h to 4h, the first purified liquid is extracted at a reflux ratio of (2 to 10):1, the temperature of the bottom section of the tower is 144°C to 155°C, and the temperature of the condensation section is 138°C to 144°C.

[0111] In some embodiments, the material to be distilled includes hexachlorodisilane with a purity of 5N, and the electronic grade material includes hexachlorodisilane with a purity of 6N-7N.

[0112] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0113] Example 1

[0114] This embodiment provides a method for purifying 5N hexachlorodisilane, comprising:

[0115] After high-purity nitrogen with a purity of 5N is introduced into the purification system until the pressure at the top and bottom of the distillation tower reaches about 5psi, the closed system is maintained for 36 hours, wherein the moisture in the nitrogen is ≤10ppb and the oxygen is ≤10ppb.

[0116] After the pressure change at the top and bottom of the tower is less than 6%, introduce 5N high-purity nitrogen into the system through the gas supply unit until the pressure at the top and bottom of the tower is about 6psi, close the valve of the gas supply unit, open the exhaust valve of the distillation tower body until the pressure at the top and bottom of the tower is about 1psi, then close the exhaust valve of the distillation tower body, and repeat the above operation until the dew point temperature of the exhaust gas from the distillation tower body is below -70℃.

[0117] In a 5N high-purity nitrogen gas atmosphere, 500mL of 5N pure hexachlorodisilane raw material in the first storage unit is transported to the bottom section of the tower by nitrogen gas, and then the residual liquid in the pipeline is purged to the bottom section of the tower by the above-mentioned nitrogen gas, and distillation is started. The heating power is 120W, and the bottom temperature is heated to 144°C. The pressure of the bottom section is 1psi, and the pressure of the top section is 0.5psi. After the top of the tower is fully refluxed for 3 hours, it is extracted into the second storage unit at a reflux ratio of 3. The heating is turned off after 3 hours of extraction.

[0118] Example 2

[0119] The difference from Example 1 is that the reflux ratio is 5.

[0120] Example 3

[0121] The difference from Example 1 is that the reflux ratio is 7.

[0122] Comparative Example 1

[0123] The difference from Example 1 is that the reflux ratio is 1.

[0124] Test Section

[0125] (1) Metal impurity measurement

[0126] Sampling was carried out in a glove box, and the sample was treated according to the method of GB / T 42720-2023 to obtain an ICP-MS test sample, and finally the metal ion content in the sample was detected by ICP-MS.

[0127] Analysis of test results of various embodiments

[0128] The products of each example were prepared according to the above method, and the metal impurities in the products were measured. The results are shown in Table 1 below.

[0129]

[0130] Note: Purity in Table 1 = 1-the sum of all metal impurities.

[0131] According to Table 1, from the test results of Examples 1 to 3 and Comparative Example 1, when the reflux ratio is in the range of 2 to 10, the content of each metal ion decreases significantly after the single-tower distillation purification of each embodiment, and meets the requirements of electronic grade materials. Among them, although the total purity prepared in Comparative Example 1 meets the requirements, the Al metal content does not meet the requirements of electronic grade materials. It can be seen that the purification method of the embodiment of the present application can produce electronic grade hexachlorodisilane. Moreover, compared with the existing purification methods such as distillation combined with adsorption and electrolysis, the process is simple, no foreign impurity components are introduced, and the purification effect is good.

[0132] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

Claims

1. A purification system for electronic grade materials, characterized in that: include: A distillation unit, comprising a distillation tower body, a rotating component and a driving component, wherein the rotating component is located in the distillation tower body, and the driving component is in transmission connection with the rotating component to drive the rotating component to rotate to separate the target product and metal impurities in the distillate to be distilled; A first storage unit is configured to store the material to be rectified and input the material to be rectified into the distillation unit; A gas supply unit is configured to store high-purity inert gas, input the stored high-purity inert gas into the distillation unit to replace the air in the distillation unit, and input the stored high-purity inert gas into the first storage unit to bring the product to be distilled into the distillation unit; The gas-liquid separation unit is configured to be connected to the distillation unit to separate the electronic grade material and gas in the target product flowing out of the distillation unit.

2. The purification system according to claim 1, characterized in that The distillation tower body comprises a condensing section body, a distillation section body and a tower bottom section body which are interconnected along the axial direction, wherein the distillation section body is located between the condensing section body and the tower bottom section body, the tower bottom section body is configured to connect the first storage unit and the gas supply unit, the rotating component is located in the distillation section body, and the driving component is located at one end of the condensing section body away from the distillation section body; Optionally, the distillation unit further includes a condensing component, a control component and a heating component, the condensing component is located in the condensing section body, the control component is connected to the distillation tower body to control the reflux ratio in the distillation tower body and the outflow of the target product, and the heating component is configured to heat the material to be distilled in the bottom section of the tower to vaporize the material to be distilled.

3. The purification system according to claim 2, characterized in that: The condensing section body and the rectifying section body are connected via a ground joint or a flange; And / or, the distillation section body and the tower bottom section body are connected through a ground joint or a flange.

4. The purification system according to claim 2, characterized in that: The rectification section body comprises a first tube body and a second tube body, the second tube body is located in the first tube body and is connected to the tower bottom section body, and the rotating component is located in the second tube body; Optionally, the inner wall of the first tube body is provided with a heat-insulating layer; Optionally, the first tube body has a buffer section.

5. The purification system according to claim 4, characterized in that: The rotating component is in a spiral shape; Optionally, the length of the rotating component along the axial direction of the second tube is 45 cm to 90 cm; Optionally, the material of the rotating component includes one or more of polytetrafluoroethylene, nickel alloy, and polyetherimide.

6. The purification system according to claim 2, characterized in that: The purification system also includes: a second storage unit, configured to be connected to the gas-liquid separation unit to receive and store the electronic-grade material flowing out of the gas-liquid separation unit; The tail gas treatment unit is configured to communicate with the distillation unit, the gas-liquid separation unit and the second storage unit.

7. The purification system according to claim 6, characterized in that The first storage unit is connected to the tower bottom section through a first PFA pipe; And / or, the gas supply unit is connected to the tower bottom section through a second PFA pipe; And / or, the gas-liquid separation unit is connected to the distillation tower body through a third PFA tube; And / or, the second storage unit is connected to the gas-liquid separation unit via a fourth PFA pipe; And / or, the tail gas treatment unit is connected to the condensation section, the gas-liquid separation unit and the second storage unit respectively through a fifth PFA pipe; and / or, the gas supply unit is connected to the first storage unit via a sixth PFA pipe; and / or, the gas supply unit is connected to the first PFA tube via a seventh PFA tube; And / or, the gas supply unit is connected to the fifth PFA tube via an eighth PFA tube.

8. A purification method, characterized in that: A purification system according to any one of claims 1 to 7, comprising: A pretreatment step, introducing high-purity inert gas into the purification system for pretreatment, so that the pressure change in the distillation unit reaches within a preset pressure range and the dew point temperature of the gas discharged from the distillation unit reaches a preset temperature; a distillation step, under inert atmosphere conditions, bringing the material to be distilled in the first storage unit into the distillation unit through the gas supply unit for distillation treatment to obtain a first purified liquid, wherein the reflux ratio of the first purified liquid is greater than 2; In the separation step, the first purified liquid is passed into the gas-liquid separation unit for gas-liquid separation to obtain electronic grade material.

9. The purification method according to claim 8, characterized in that The pretreatment process also includes: An air tightness detection step is to introduce high-purity inert gas into the distillation unit so that the pressure in the distillation unit reaches a preset value, and after maintaining the pressure for 24 hours to 36 hours, the pressure change in the distillation unit is within 3% to 8%; a displacement step, performing multiple pressure-increasing and pressure-reducing operations on the pressure in the distillation unit so that the dew point temperature of the gas discharged from the distillation unit is below -70°C; Optionally, in the air tightness detection process, the preset value is 5psi to 6psi; Optionally, the high-purity inert gas includes high-purity nitrogen and / or high-purity argon; Optionally, the high-purity inert gas includes high-purity nitrogen; Optionally, in the high-purity nitrogen, the nitrogen content is greater than or equal to 99.999%, the water content is less than or equal to 1 ppm, and the oxygen content is less than or equal to 0.5 ppm.

10. The purification method according to claim 8, characterized in that In the distillation process, after full reflux for 2h to 4h, the first purified liquid is extracted at a reflux ratio of (2 to 10):1, the temperature of the tower bottom section is 144°C to 155°C, the temperature of the condensation section is 138°C to 144°C, the pressure of the tower bottom section is 0psi to 2psi, and the pressure of the tower top section is 0psi to 1psi; optionally, the rotation speed of the rotating component is 2000rpm / min to 5000rpm / min; And / or, the product to be distilled includes hexachlorodisilane with a purity of 5N, and the electronic grade material includes hexachlorodisilane with a purity of 6N-7N.

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