A contamination-free plasma sterilization apparatus and sterilization method and application

Abstract

The application provides a kind of anti-staining plasma sterilization device and sterilization method and application, belong to plasma sterilization technical field.The sterilization device includes: sterilization chamber, the inner wall of the sterilization chamber is equipped with heat-conducting graphite film;Heater is set to the outside of the sterilization chamber, and the heater is connected with the heat-conducting graphite film.By setting heat-conducting graphite film on the inner wall of the sterilization chamber, the high-speed moving particles in the plasma can be avoided to sputter out of the aluminum and other metals in the sterilization chamber during the sterilization process, and then adhere to the surface of the sterilized object to cause aluminum contamination, eliminating the hidden danger to human health and life safety.The application can realize various sterilization modes, and can select plasma formed by different gases for sterilization according to different sterilization specifications.

Description

Technical Field

[0001] This invention belongs to the field of plasma sterilization technology, specifically relating to an anti-contamination plasma sterilization device, sterilization method, and application. Background Technology

[0002] Commonly used sterilization techniques include autoclaving, ethylene oxide sterilization, irradiation sterilization, and plasma sterilization. For precision medical devices that are sensitive to moisture and heat, such as various endoscopes and medical optical fibers, plasma sterilization is mainly used.

[0003] Research on plasma sterilization began in the 1960s. In 1987, patent publication US4643876A first disclosed the use of hydrogen peroxide vapor to generate plasma for sterilizing items. Several years later, Johnson & Johnson developed the Starrad 100S commercial hydrogen peroxide plasma sterilizer, which was approved by the FDA in 1997. In 2004, hydrogen peroxide plasma sterilization technology entered China and is now widely used. Currently, most widely used plasma sterilizers are hydrogen peroxide plasma sterilizers, based on the principle of US4643876A and its related patents.

[0004] Typically, the sterilization chamber temperature needs to be maintained at 50-60℃ during a hydrogen peroxide plasma sterilization cycle to achieve better sterilization results and ensure sufficient evaporation and removal of moisture from the surface of the items to be sterilized. Therefore, most commercially available hydrogen peroxide plasma sterilizers have heaters installed in their sterilization chambers. The inner walls of these sterilization chambers are mostly made of aluminum alloy due to its good thermal conductivity, light weight, and low price. However, during sterilization, the heater heats the sterilization chamber, causing high-speed charged particles in the plasma to bombard the inner wall of the chamber, sputtering aluminum atoms from the surface. These free aluminum atoms can penetrate the sterilization packaging and adhere to the surface of the medical devices being sterilized, causing contamination. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art and provide a contamination-resistant plasma sterilization device, sterilization method and application, which solves the problem that existing plasma sterilization devices will cause aluminum contamination on the items to be sterilized, which poses a hidden danger to human health and life safety.

[0006] This invention is achieved through the following technical solution:

[0007] A first aspect of the present invention provides a contamination-resistant plasma sterilization device, comprising:

[0008] A sterilization chamber, wherein the inner wall of the sterilization chamber is provided with a heat-conducting graphite film;

[0009] A heater is located outside the sterilization chamber and is connected to the thermally conductive graphite membrane.

[0010] A further improvement of the present invention is that:

[0011] A through hole is provided on the lower part of the side wall of the sterilization chamber, and the thermally conductive graphite film extends from the inner wall of the sterilization chamber to the outside of the through hole and is then connected to the heater; preferably, the through hole has a sealing structure.

[0012] A further improvement of the present invention is that:

[0013] The thermally conductive graphite film is selected from natural thermally conductive graphite sheets, artificially synthesized graphite films, nanocomposite graphite films, graphene films or coatings, with natural thermally conductive graphite sheets being preferred.

[0014] The thickness of the thermally conductive graphite film is 0.03-3mm, preferably 0.1-1.5mm.

[0015] A further improvement of the present invention is that:

[0016] The sterilization chamber is equipped with a shelf;

[0017] The shelf includes a horizontal bracket, with connectors at both ends of the horizontal bracket. One end of the connector is connected to the end of the horizontal bracket, and the other end extends upward and outward along the end of the horizontal bracket.

[0018] The shelf is made of a polymer material, preferably at least one of polypropylene (PP), cyclic olefin copolymer (COC), and cyclic olefin polymer (COP). The shelf can be formed using conventional molding processes, such as injection molding, molding, and compression molding.

[0019] A further improvement of the present invention is that:

[0020] The sterilization chamber has a plasma coupling window on its bottom surface, and a plasma generating unit is fixed at the plasma coupling window, with the plasma generating unit located below the plasma coupling window.

[0021] A further improvement of the present invention is that:

[0022] The bottom of the sterilization chamber is also provided with a vacuum system pipeline and a working gas pipeline, and the vacuum system pipeline and the working gas pipeline are respectively located on both sides of the plasma coupling window;

[0023] The vacuum system is connected to a vacuum pump.

[0024] A further improvement of the present invention is that:

[0025] The sterilization chamber is equipped with a hydrogen peroxide purification system and a hydrogen peroxide injection system connected to each other at the top, and the hydrogen peroxide purification system is connected to the interior of the sterilization chamber.

[0026] A further improvement of the present invention is that:

[0027] The sterilization chamber has an outer shell on its outer wall. The material of the outer shell is selected from ABS, ultra-high molecular weight polyethylene, polyoxymethylene, nylon, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polytetrafluoroethylene, polyphenylene ether, reinforced polypropylene, reinforced nylon, reinforced polybutylene terephthalate, and reinforced polyethylene terephthalate. Reinforced polypropylene, reinforced nylon, reinforced polybutylene terephthalate, reinforced polyethylene terephthalate, polyimide, polytetrafluoroethylene, and blends thereof are preferred. ABS and ultra-high molecular weight polyethylene are also preferred.

[0028] A second aspect of the present invention provides a plasma sterilization method, wherein the above-described anti-contamination plasma sterilization device is used to sterilize and disinfect the items to be sterilized; preferably,

[0029] The sterilization method includes:

[0030] The first sterilization method is as follows: Close the working gas pipeline, open the hydrogen peroxide injection system and hydrogen peroxide purification system to introduce hydrogen peroxide into the sterilization chamber, and use hydrogen peroxide plasma for sterilization; or...

[0031] The second sterilization method is as follows: shut down the hydrogen peroxide injection system and the hydrogen peroxide purification system, open the working gas pipeline, introduce working gas into the sterilization chamber, and use working gas plasma for sterilization.

[0032] A further improvement of the present invention is that:

[0033] The working gas is selected from oxygen, nitrogen, helium, argon, chlorine, hydrogen, and mixtures thereof, with oxygen being preferred.

[0034] A third aspect of the present invention provides an application of the above-described anti-contamination plasma sterilization device in sterilization and disinfection.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] This invention, by setting a thermally conductive graphite film on the inner wall of the sterilization chamber, can prevent metals such as aluminum in the sterilization chamber from being sputtered out by high-speed particles in the plasma during the sterilization process, and thus avoid aluminum contamination on the surface of the items to be sterilized, thereby eliminating potential hazards to human health and safety.

[0037] This invention connects the sterilization chamber to a hydrogen peroxide injection system, a purification system, and a working gas pipeline, enabling multiple sterilization modes. Depending on the sterilization specifications, different gases can be used to generate plasma for sterilization. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of an anti-contamination plasma sterilization device provided by the present invention.

[0039] The components include: 1. Hydrogen peroxide injection system, 2. Thermally conductive graphite film, 3. Outer shell, 4. Heater, 5. Vacuum system pipeline, 6. Vacuum pump, 7. Working gas pipeline, 8. Plasma generation unit, 9. Plasma coupling window, 10. Shelf, and 11. Hydrogen peroxide purification system. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings:

[0041] The first objective of this invention is to provide a contamination-resistant plasma sterilization device, such as... Figure 1 As shown, the device includes a sterilization chamber. The inner wall of the sterilization chamber is provided with a thermally conductive graphite film 2. A portion of the thermally conductive graphite film 2 extends out of the sterilization chamber through a small hole and is connected to a heater 4 outside the sterilization chamber. Specifically, a through hole is provided on the lower part of the side wall of the sterilization chamber. The thermally conductive graphite film 2 extends from the inner wall of the sterilization chamber to the outside of the through hole and is then connected to the heater 4. Preferably, the through hole has a sealing structure.

[0042] Heater 4 heats the thermally conductive graphite film 2 extending beyond the through-hole in the side wall of the sterilization chamber. Heat is transferred through the surface of the thermally conductive graphite film to the portion of the thermally conductive graphite film on the inner wall of the sterilization chamber. The thermally conductive graphite film on the inner wall of the sterilization chamber heats up and radiates heat into the sterilization chamber, thereby increasing the temperature inside the sterilization chamber and ultimately maintaining it within the range of 50-60°C. The heater is located outside the sterilization chamber and is capable of measuring and controlling the temperature inside the sterilization chamber.

[0043] The heater mainly consists of a resistance wire, circuitry, and a controller. When energized, the resistance wire generates heat, which is then transferred to the thermally conductive graphite membrane 2 via contact. The controller adjusts the current to regulate the amount of heat generated by the resistance wire, thereby controlling the temperature of the thermally conductive graphite membrane and ultimately the temperature within the sterilization chamber 4. The heater 4 has a power rating of 0.1-10 kW, preferably 0.5-5 kW. Existing technology can be used for the heater, and details will not be elaborated upon here.

[0044] Thermally conductive graphite films have high thermal conductivity and are easy to process. They can be used for heat dissipation management, heat dissipation of power devices in confined areas, or to provide auxiliary heat dissipation for power devices. They can also be used to prepare the inner wall lining material of plasma sterilizer chambers.

[0045] The thermally conductive graphite film, also known as high thermal conductivity graphite sheet (GTS) material, is a very thin, high thermal conductivity material in the prior art. The thermally conductive graphite film has good reprocessability and can be laminated or coated with other film materials such as PET, depending on the application. This material is elastic, can be cut and stamped into any shape, and can be bent multiple times; it is suitable for rapid heat conduction from a point heat source to a surface heat source, and has very high thermal conductivity. It is made of a highly oriented graphite polymer film. The thermally conductive graphite film of this invention can use various existing thermally conductive graphite films, preferably selected from at least one of natural thermally conductive graphite sheets, artificially synthesized graphite films, nanocomposite graphite films, graphene films, or coatings, with natural thermally conductive graphite sheets being preferred; the thickness is 0.03-3 mm, preferably 0.1-1.5 mm.

[0046] The device of this invention solves the aluminum contamination problem existing in the prior art by setting a thermally conductive graphite film 2 on the inner wall of the sterilization chamber, for the following reasons:

[0047] 1. Graphite has excellent thermal conductivity, with a thermal resistance 40% lower than aluminum and 20% lower than copper, and a thermal conductivity of 800-2500 W / mK. In contrast, the thermal conductivity of aluminum alloy 5052, which is commonly used to prepare the inner wall of the sterilization chamber of plasma sterilization equipment, is only 138 W / mK, and the thermal conductivity of other commonly used metals is below 500 W / mK. Therefore, the thermal conductivity of graphite film is better than that of metal, and it can maintain a constant temperature in the sterilization chamber very well.

[0048] 2. The metallic bond energy of aluminum is approximately 321.7 kJ / mol, while the metallic bond energies of other commonly used metals such as iron, chromium, nickel, and copper do not exceed 430 kJ / mol. The carbon-carbon double bond energy in graphite is approximately 611 kJ / mol. Therefore, compared to metals, carbon-carbon double bonds are less likely to be broken by high-speed charged particles, thus preventing the sputtering of carbon atoms. Of the sputtered carbon atoms, some combine with reactive oxygen species in the plasma phase to form carbon dioxide or carbon monoxide, which are then removed. The remaining carbon atoms reach the surface of the items to be sterilized and will not cause harm to the human body.

[0049] In a preferred embodiment of the present invention, a shelf 10 is provided inside the sterilization chamber. The shelf 10 has at least one layer, preferably two layers, inside the sterilization chamber. The shelf 10 includes a horizontal bracket, and a connector is connected to both ends of the horizontal bracket. One end of the connector is connected to the end of the horizontal bracket, and the other end extends upward and outward along the end of the horizontal bracket. The connector can be fixed to the side wall of the sterilization chamber by heat fusion or by snap-fit ​​to the side wall of the sterilization chamber. Specifically, slots are provided on two opposite side walls inside the sterilization chamber, and a buckle matching the slot is provided on the end of the connector away from the horizontal bracket. The buckle and the slot cooperate with each other to fix the shelf 10 inside the sterilization chamber.

[0050] The shelf 10 is made of a polymer material, characterized by: 1. containing only C, H, and O elements in its molecular structure; 2. having a heat distortion temperature higher than 100℃; 3. being resistant to chemical corrosion; 4. having low moisture absorption and good dimensional stability; and 5. having good mechanical properties. The material of the shelf 10 is selected from polypropylene (PP), cyclic olefin copolymer (COC), and cyclic olefin polymer (COP). The shelf is preferably a polymer material, more preferably at least one of polypropylene (PP), cyclic olefin copolymer (COC), and cyclic olefin polymer (COP). The shelf can be molded using conventional molding processes, such as injection molding, molding, and compression molding.

[0051] In a preferred embodiment of the present invention, a plasma coupling window 9 is provided on the bottom surface of the sterilization chamber, and a plasma generating unit 8 is fixed at the plasma coupling window 9, with the plasma generating unit 8 located below the plasma coupling window 9.

[0052] like Figure 1 As shown, a thermally conductive graphite film is also provided at the plasma coupling window 9. The plasma coupling window 9 does not need to be connected to the sterilization chamber. The plasma is generated by forming an alternating electromagnetic field in the sterilization chamber without contact.

[0053] The plasma generating unit 8 is fixed at the bottom of the sterilization chamber. The plasma generating unit 8 adopts existing technology products, which will not be described in detail here.

[0054] In a preferred embodiment of the present invention, a vacuum system pipeline 5 and a working gas pipeline 7 are respectively provided at the bottom of the sterilization chamber, and the vacuum system pipeline 5 and the working gas pipeline 7 are located on both sides of the plasma coupling window 9. The vacuum system pipeline 5 is connected to a vacuum pump 6. During the sterilization process, the vacuum pump 6 is used to evacuate the sterilization chamber, reducing the air concentration in the sterilization chamber and increasing the concentration of hydrogen peroxide or working gas; furthermore, the low vacuum environment is conducive to the diffusion of gaseous hydrogen peroxide or working gas and the formation of plasma.

[0055] If necessary, working gas can be introduced into the sterilization chamber through working gas pipeline 7 to generate plasma through glow discharge, which can replace hydrogen peroxide for sterilization.

[0056] Working gas is introduced through working gas pipeline 7. When the working gas undergoes glow discharge, plasma is generated, which sterilizes the items. The sterilization principle is as follows:

[0057] (1) High-speed charged particles in plasma can penetrate and etch the cell membranes of bacteria and viruses;

[0058] (2) Some working gases, such as oxygen, can generate active groups during the formation of plasma. These groups are very easy to oxidize and denature the proteins and nucleic acids in bacteria, molds, spores, and viruses, causing various microorganisms to die.

[0059] (3) During the formation of plasma, some ultraviolet light is generated. These high-energy ultraviolet photons are absorbed by proteins in microorganisms or viruses, causing their molecules to denature and become inactive.

[0060] The working gas is selected from oxygen, nitrogen, helium, argon, chlorine, hydrogen, and mixtures thereof, with oxygen being preferred.

[0061] In a preferred embodiment of the present invention, the top of the sterilization chamber is equipped with a hydrogen peroxide purification system 11 and a hydrogen peroxide injection system 1 connected to each other, and the hydrogen peroxide purification system 11 is connected to the interior of the sterilization chamber. Hydrogen peroxide enters the sterilization chamber sequentially through the hydrogen peroxide injection system 1 and the hydrogen peroxide purification system 11. Before the generation of plasma, gaseous hydrogen peroxide has already been injected into the sterilization chamber and diffused. This process also has a sterilization effect, but the effect is limited. After a period of time after the hydrogen peroxide is injected, plasma is generated by the plasma generation unit 8 for sterilization. This process is the main sterilization process.

[0062] Both the hydrogen peroxide purification system 11 and the hydrogen peroxide injection system 1 are fixed to the top of the sterilization chamber; the hydrogen peroxide injection system 1 includes a cartridge feeding mechanism and a cartridge puncture system; the hydrogen peroxide purification system 2 includes a purification cooling chamber and a diffusion heating chamber.

[0063] Both the hydrogen peroxide injection system 1 and the hydrogen peroxide purification system 11 are existing technology products, and will not be described in detail here.

[0064] In a preferred embodiment of the present invention, the outer wall of the sterilization chamber is provided with an outer shell 3. The material of the outer shell 3 is selected from ABS (acrylonitrile-butadiene-styrene copolymer), ultra-high molecular weight polyethylene, polyoxymethylene, nylon, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polytetrafluoroethylene, polyphenylene ether, reinforced polypropylene, reinforced nylon, reinforced polybutylene terephthalate, and reinforced polyethylene terephthalate. Reinforced polypropylene, reinforced nylon, reinforced polybutylene terephthalate, reinforced polyethylene terephthalate, polyimide, polytetrafluoroethylene, and blends thereof are preferred. ABS and ultra-high molecular weight polyethylene are also preferred. The outer shell 3 is formed using conventional polymer molding processes, such as injection molding and molding, including conventional molding methods and equipment.

[0065] Typical settings for sterilization conditions and parameters using the apparatus of the present invention are: the pressure inside the sterilization chamber reaches 10. -6When the pressure is within a specified value in the range of -100Pa, 4-6 mL of hydrogen peroxide with a concentration of 58% ± 2% or 1-100 sccm of working gas is introduced into the sterilization chamber. The pressure in the sterilization chamber is controlled within a specified value in the range of 0.01-200Pa. The power of the plasma generation unit is usually set between 10-2000W. During the sterilization process, the temperature in the sterilization chamber is controlled within a set value between 25-60℃. The plasma treatment time is between 1-60 minutes.

[0066] The second objective of this invention is to provide a plasma sterilization method, which uses the aforementioned anti-contamination plasma sterilization device to sterilize and disinfect items to be sterilized.

[0067] The specific sterilization method is as follows:

[0068] When sterilization requirements are high, such as for surgical instruments and medical devices, the working gas pipeline is closed, and the hydrogen peroxide injection system and hydrogen peroxide purification system are turned on to introduce hydrogen peroxide into the sterilization chamber, and hydrogen peroxide plasma is used for sterilization.

[0069] When sterilization requirements are not high, such as for the sterilization of ordinary items, the hydrogen peroxide injection system and hydrogen peroxide purification system are turned off, the working gas pipeline is opened, and the working gas is introduced into the sterilization chamber for sterilization using working gas plasma.

[0070] Throughout the sterilization process, the vacuum pump 6 and heater 4 are always on, while the plasma generation unit 8 is only turned on during the plasma generation phase.

[0071] The principle of using working gas plasma to sterilize items is as follows:

[0072] (1) High-speed charged particles in plasma can penetrate and etch the cell membranes of bacteria and viruses;

[0073] (2) Some working gases, such as oxygen, can generate active groups during the formation of plasma. These groups are very easy to oxidize and denature the proteins and nucleic acids in bacteria, molds, spores, and viruses, causing various microorganisms to die.

[0074] (3) During the formation of plasma, some ultraviolet light is generated. These high-energy ultraviolet photons are absorbed by proteins in microorganisms or viruses, causing their molecules to denature and become inactive.

[0075] The working gas is selected from oxygen, nitrogen, helium, argon, chlorine, hydrogen, and mixtures thereof, with oxygen being preferred.

[0076] A third objective of this invention is to provide an application of the above-mentioned anti-contamination plasma sterilization device in sterilization and disinfection.

[0077] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0078] The thermally conductive graphite film, shelf material, and shell material used in the embodiments of this invention are all commercially available products.

[0079] Example 1

[0080] In this embodiment, the plasma sterilization device of the present invention is used to sterilize and disinfect silicon wafers. The thermally conductive graphite film is made of natural thermally conductive graphite sheet (sold by Meixing Company) with a thickness of 0.5mm. The sterilization chamber is made of aluminum alloy 5052. The shelf is made of polypropylene (the polypropylene raw material is sold by Sinopec Zhenhai Refining & Chemical Company, model H30S). The outer shell of the sterilization chamber is made of ultra-high molecular weight polyethylene.

[0081] Shut down the working gas pipeline, turn on the hydrogen peroxide injection system and hydrogen peroxide purification system, and introduce hydrogen peroxide into the sterilization chamber. Use hydrogen peroxide plasma to sterilize the silicon wafers, specifically:

[0082] When the pressure in the sterilization chamber reaches 0.01 Pa, 6 mL of 58% hydrogen peroxide is introduced into the sterilization chamber to control the pressure in the sterilization chamber to 80 Pa. The power of the plasma generation unit is 500 W. During the sterilization process, the temperature in the sterilization chamber is controlled at 50-55℃, and the plasma treatment time is 8 min.

[0083] The concentration distribution of aluminum on the surface of silicon wafers after hydrogen peroxide plasma sterilization and before sterilization was measured using secondary ion mass spectrometry. The results are shown in Table 1. Table 1 shows that the aluminum distribution on the surfaces of sterilized and unsterilized silicon wafers is not significantly different, indicating that there was no aluminum contamination during the sterilization process in this embodiment. The sterilization indicator card indicates that the sterilization was successful.

[0084] Table 1

[0085]

[0086]

[0087] Example 2

[0088] In this embodiment, the plasma sterilization device of the present invention is used to sterilize and disinfect silicon wafers. The thermally conductive graphite film is made of natural thermally conductive graphite sheet (sold by Amstar Corporation) with a thickness of 0.5 mm. The sterilization chamber is made of aluminum alloy 5052. The shelf is made of cyclic olefin copolymer (sold by Polyplastics Corporation of Japan, model Topas 6017). The outer shell of the sterilization chamber is made of ultra-high molecular weight polyethylene.

[0089] Shut down the hydrogen peroxide injection system and hydrogen peroxide purification system, open the working gas pipeline, and introduce oxygen into the sterilization chamber. Use oxygen plasma to sterilize the silicon wafers, specifically:

[0090] When the pressure in the sterilization chamber reaches 0.01 Pa, 10 sccm of working gas (oxygen) is introduced into the sterilization chamber to control the pressure in the sterilization chamber to 0.1 Pa. The power of the plasma generation unit is 500 W. During the sterilization process, the temperature in the sterilization chamber is controlled at 50-55℃, and the plasma treatment time is 8 min.

[0091] The concentration distribution of aluminum on the surface of silicon wafers after oxygen plasma sterilization and before sterilization was measured using secondary ion mass spectrometry. The results are shown in Table 2. Table 2 shows that the aluminum distribution on the surfaces of sterilized and unsterilized silicon wafers almost overlaps, indicating that there was no aluminum contamination during the sterilization process in this embodiment. The sterilization indicator card shows that the sterilization was successful.

[0092] Table 2

[0093]

[0094]

[0095] Example 3

[0096] In this embodiment, the plasma sterilization device of the present invention is used to sterilize and disinfect silicon wafers. The thermally conductive graphite film is a synthetic graphite film (sold by Meixing Company) with a thickness of 0.2mm. The sterilization chamber is made of aluminum alloy 5052. The shelf is made of polypropylene (the polypropylene raw material is sold by Sinopec Zhenhai Refining & Chemical Company, model H30S). The outer shell of the sterilization chamber is made of ultra-high molecular weight polyethylene.

[0097] Shut down the working gas pipeline, turn on the hydrogen peroxide injection system and hydrogen peroxide purification system, and introduce hydrogen peroxide into the sterilization chamber. Use hydrogen peroxide plasma to sterilize the silicon wafers, specifically:

[0098] When the pressure in the sterilization chamber reaches 0.01 Pa, 6 mL of 58% hydrogen peroxide is introduced into the sterilization chamber to control the pressure in the sterilization chamber to 80 Pa. The power of the plasma generation unit is 500 W. During the sterilization process, the temperature in the sterilization chamber is controlled at 50-55℃, and the plasma treatment time is 8 min.

[0099] The concentration distribution of aluminum on the surface of silicon wafers after hydrogen peroxide plasma sterilization and before sterilization was measured using secondary ion mass spectrometry. The results are shown in Table 3. Table 3 shows that the aluminum distribution on the surfaces of sterilized and unsterilized silicon wafers is not significantly different, indicating that there was no aluminum contamination during the sterilization process in this embodiment. The sterilization indicator card indicates that the sterilization was successful.

[0100] Table 3

[0101]

[0102] Example 4

[0103] In this embodiment, the plasma sterilization device of the present invention is used to sterilize and disinfect silicon wafers. The thermally conductive graphite film is a nano-composite graphite film (sold by Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.) with a thickness of 0.1 mm. The sterilization chamber is made of aluminum alloy 5052. The shelf is made of cyclic olefin copolymer (sold by Polyplastics Inc. of Japan, model Topas 6017). The outer shell of the sterilization chamber is made of ultra-high molecular weight polyethylene.

[0104] Shut down the hydrogen peroxide injection system and hydrogen peroxide purification system, open the working gas pipeline, and introduce nitrogen gas into the sterilization chamber. Use nitrogen plasma to sterilize the silicon wafers, specifically:

[0105] When the pressure in the sterilization chamber reaches 0.01 Pa, 20 sccm of working gas (nitrogen) is introduced into the sterilization chamber to control the pressure in the sterilization chamber to 0.1 Pa. The power of the plasma generation unit is 700 W. During the sterilization process, the temperature in the sterilization chamber is controlled at 50-55℃, and the plasma treatment time is 6 min.

[0106] The concentration distribution of aluminum on the surface of silicon wafers after nitrogen plasma sterilization and before sterilization was measured using secondary ion mass spectrometry. The results are shown in Table 4. Table 4 shows that the aluminum distribution on the surfaces of sterilized and unsterilized silicon wafers almost overlaps, indicating that there was no aluminum contamination during the sterilization process in this embodiment. The sterilization indicator card indicates that the sterilization was successful.

[0107] Table 4

[0108]

[0109] Example 5

[0110] In this embodiment, the plasma sterilization device of the present invention is used to sterilize and disinfect silicon wafers. The thermally conductive graphite film is a graphene film (sold by Shenzhen Xidao Technology Co., Ltd.) with a thickness of 0.05mm. The sterilization chamber is made of aluminum alloy 5052. The shelf is made of polypropylene (the polypropylene raw material is sold by Sinopec Zhenhai Refining & Chemical Co., Ltd., model H30S). The outer shell of the sterilization chamber is made of ultra-high molecular weight polyethylene.

[0111] Shut down the working gas pipeline, turn on the hydrogen peroxide injection system and hydrogen peroxide purification system, and introduce hydrogen peroxide into the sterilization chamber. Use hydrogen peroxide plasma to sterilize the silicon wafers, specifically:

[0112] When the pressure in the sterilization chamber reaches 0.01 Pa, 6 mL of 58% hydrogen peroxide is introduced into the sterilization chamber to control the pressure at 0.1 Pa. The power of the plasma generation unit is 700 W. During the sterilization process, the temperature in the sterilization chamber is controlled at 50-55℃, and the plasma treatment time is 6 min.

[0113] The concentration distribution of aluminum on the surface of silicon wafers after hydrogen peroxide plasma sterilization and before sterilization was measured using secondary ion mass spectrometry. The results are shown in Table 5. Table 5 shows that the aluminum distribution on the surfaces of sterilized and unsterilized silicon wafers is not significantly different, indicating that there was no aluminum contamination during the sterilization process in this embodiment. The sterilization indicator card shows that the sterilization was successful.

[0114] Table 5

[0115]

[0116] Comparative Example

[0117] The commercially available Laoken brand LK / KS150-A1 hydrogen peroxide plasma sterilizer (with the inner wall of the sterilization chamber made of 5052 aluminum alloy) was used to sterilize the silicon wafers. Specifically:

[0118] When the pressure in the sterilization chamber reaches 0.01 Pa, hydrogen peroxide of the same dosage as in Example 1 is introduced into the sterilization chamber to control the pressure in the sterilization chamber to 80 Pa, the power of the plasma generating unit to 500 W, the temperature in the sterilization chamber to be controlled at 50-55 °C during the sterilization process, and the plasma treatment time to 8 min.

[0119] The concentration distribution of aluminum on the surface of sterilized and unsterilized silicon wafers was measured by secondary ion mass spectrometry, and the results are shown in Table 6. Compared with unsterilized silicon wafers, the aluminum concentration on the surface of sterilized silicon wafers increased significantly, reaching a maximum of 8.46 × 10⁻⁶. 19 / cm 3By plotting the two aluminum concentration distributions in Table 6, integrating them with respect to depth, and then subtracting the results, the amount of aluminum contamination introduced during the sterilization process in this comparative example can be calculated to be 7.9 × 10⁻⁶. 12 / cm 2 The sterilization indicator card shows that the sterilization is successful.

[0120] Table 6

[0121]

[0122] Comparing Examples 1 to 5 and the comparative examples, it can be seen that the anti-contamination plasma sterilization device provided by the present invention introduces almost no aluminum impurities during the sterilization process, thus solving the aluminum contamination problem in the prior art.

[0123] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0124] In the description of this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0125] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the technical solutions described in the specific embodiments of the present invention. Therefore, the foregoing description is only a preferred option and is not restrictive.

Claims

1. A contamination-resistant plasma sterilization device, characterized in that, The sterilization device includes: A sterilization chamber, wherein the inner wall of the sterilization chamber is provided with a heat-conducting graphite film; A heater is disposed outside the sterilization chamber, and the heater is connected to the thermally conductive graphite membrane; A through hole is provided on the lower part of the side wall of the sterilization chamber, and the thermally conductive graphite film extends from the inner wall of the sterilization chamber to the outside of the through hole and is then connected to the heater; the through hole has a sealing structure.

2. The anti-contamination plasma sterilization device according to claim 1, characterized in that, The thermally conductive graphite film is selected from natural thermally conductive graphite sheets, artificially synthesized graphite films, nanocomposite graphite films, graphene films, or coatings. The thickness of the thermally conductive graphite film is 0.03-3 mm.

3. The anti-contamination plasma sterilization device according to claim 2, characterized in that, The thermally conductive graphite film is selected from natural thermally conductive graphite sheets.

4. The anti-contamination plasma sterilization device according to claim 3, characterized in that, The thickness of the thermally conductive graphite film is 0.1-1.5 mm.

5. The anti-contamination plasma sterilization device according to claim 1, characterized in that, The sterilization chamber is equipped with a shelf; the shelf includes a horizontal bracket, and each end of the horizontal bracket is connected to a connector, one end of the connector is connected to the end of the horizontal bracket, and the other end extends upward and outward along the end of the horizontal bracket; and / or; The shelf is made of polymer material.

6. The anti-contamination plasma sterilization device according to claim 5, characterized in that, The shelf is made of at least one of polypropylene, cyclic olefin copolymer, and cyclic olefin polymer.

7. The anti-contamination plasma sterilization device according to claim 1, characterized in that, The sterilization chamber has a plasma coupling window on its bottom surface, and a plasma generating unit is fixed at the plasma coupling window, with the plasma generating unit located below the plasma coupling window.

8. The anti-contamination plasma sterilization device according to claim 7, characterized in that, The bottom of the sterilization chamber is also provided with a vacuum system pipeline and a working gas pipeline, and the vacuum system pipeline and the working gas pipeline are respectively located on both sides of the plasma coupling window; The vacuum system is connected to a vacuum pump.

9. The anti-contamination plasma sterilization device according to claim 1, characterized in that, The sterilization chamber is equipped with a hydrogen peroxide purification system and a hydrogen peroxide injection system connected to each other at the top, and the hydrogen peroxide purification system is connected to the interior of the sterilization chamber.

10. The anti-contamination plasma sterilization device according to claim 1, characterized in that, The sterilization chamber has an outer shell on its outer wall. The material of the outer shell is selected from ABS, ultra-high molecular weight polyethylene, polyoxymethylene, nylon, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polytetrafluoroethylene, polyphenylene ether, reinforced polypropylene, reinforced nylon, reinforced polybutylene terephthalate, reinforced polyethylene terephthalate, preferably reinforced polypropylene, reinforced nylon, reinforced polybutylene terephthalate, reinforced polyethylene terephthalate, polyimide, polytetrafluoroethylene, and blends thereof.

11. The anti-contamination plasma sterilization device according to claim 10, characterized in that, The outer shell is made of ABS and ultra-high molecular weight polyethylene.

12. A plasma sterilization method, characterized in that, The anti-contamination plasma sterilization device according to any one of claims 1-11 is used to sterilize and disinfect the items to be sterilized. The sterilization method includes: The first sterilization method is as follows: Close the working gas pipeline, open the hydrogen peroxide injection system and hydrogen peroxide purification system to introduce hydrogen peroxide into the sterilization chamber, and use hydrogen peroxide plasma for sterilization; or... The second sterilization method is as follows: shut down the hydrogen peroxide injection system and the hydrogen peroxide purification system, open the working gas pipeline, introduce working gas into the sterilization chamber, and use working gas plasma for sterilization.

13. The plasma sterilization method according to claim 12, characterized in that, The working gas is selected from oxygen, nitrogen, helium, argon, chlorine, hydrogen, and mixtures thereof.

14. The plasma sterilization method according to claim 13, characterized in that, The working gas is selected from oxygen.

15. The application of the anti-contamination plasma sterilization device according to any one of claims 1-11 in sterilization and disinfection.

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