A method and apparatus for evaluating the corrosion resistance of a three-proof coating material

Abstract

This invention discloses a method and apparatus for evaluating the corrosion resistance of a three-proof coating material, comprising: brushing a three-proof coating material onto the surface of a test plate; connecting the electrical contacts of the test plate to a DC power supply; placing a humidity reaction container at the bottom of a glass reaction vessel, setting a partition with vent holes above the humidity reaction container, placing a corrosive gas reaction vessel on the partition, placing the test plate on the partition, and covering the glass reaction vessel with a lid; applying a 10V DC voltage between the electrodes of the test plate, observing whether corrosion and electromigration phenomena occur on the test plate during the test, and evaluating the corrosion resistance of the three-proof coating material based on whether corrosion and electromigration phenomena occur on the test plate; the evaluation criteria are: if no corrosion or electromigration phenomena occur on the test plate, it indicates that the three-proof coating material has corrosion resistance; if corrosion and electromigration phenomena occur on the test plate, it indicates that the three-proof coating material does not have corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of testing and evaluation technology, and in particular to a method and apparatus for evaluating the corrosion resistance of a three-proof coating material. Background Technology

[0002] In modern process industrial production, distributed control systems, instrumentation, and computer systems, with electronic components at their core, are widely used in petroleum, chemical, and paper manufacturing enterprises. The trouble-free and normal operation of electronic equipment is crucial to ensuring the reliable and stable operation of the entire production process. However, in the on-site environments of petrochemical, metallurgical, and chemical industries, corrosive gases can severely threaten the reliable operation of electronic equipment and control systems. The damage caused by corrosion to control systems is generally characterized by its insidious, gradual, and sudden nature. Furthermore, due to the delayed and indirect nature of corrosion control benefits, many enterprises often do not pay enough attention to it and overlook it. Corrosive gases are unavoidable in chemical production processes, and although their concentration is very low, they still seriously threaten computer management and control systems.

[0003] Coating protection is used to protect circuit boards and related electronic components from environmental corrosion, thereby improving and extending their service life and ensuring reliability and safety. It is one of the most direct and effective means of protecting electronic products. However, due to the application and characteristics of control systems, the selection of materials for coating treatment must ensure the reliability, electrical characteristics, and maintainability of the control system. Simply put, coating protection technology involves directly applying anti-corrosion materials, i.e., conformal coatings, to electronic equipment, forming an anti-corrosion film on the surface of electronic components to prevent or slow down the corrosion process.

[0004] However, the three-proof coating materials produced by different components, different modification methods, and different processes vary greatly in terms of electromigration and corrosion resistance.

[0005] Therefore, it is necessary to evaluate the corrosion resistance of conformal coating materials to ensure the effectiveness of their application, reduce the application risks, and thus improve the reliability and safety of electronic products. Summary of the Invention

[0006] To overcome the aforementioned shortcomings of the prior art, this invention provides a method and apparatus for evaluating the corrosion resistance of conformal coating materials. The aim is to provide a method for evaluating the corrosion resistance of conformal coating materials, ensuring the effectiveness of their application, reducing application risks, and thereby improving the reliability and safety of electronic products.

[0007] The technical solution adopted by this invention to solve its technical problem is: a method for evaluating the corrosion resistance of a three-proof coating material, comprising the following steps:

[0008] Apply a three-proof coating material to the surface of the test plate;

[0009] Connect the electrical contacts of the test board to the DC power supply;

[0010] Place a humidity reaction container at the bottom of a glass reaction container, set a partition with vents above the humidity reaction container, place a corrosive gas reaction container on the partition, place the test plate on the partition, and cover the glass reaction container with a lid.

[0011] A 10V DC voltage was applied between the electrodes of the test plate for a test period of 48 hours. During the test, the presence of corrosion and electromigration phenomena was observed on the test plate. After the test, the corrosion resistance of the conformal coating material was evaluated based on whether corrosion and electromigration phenomena occurred on the test plate. The evaluation criteria were as follows: if no corrosion or electromigration phenomena occurred on the test plate, it indicated that the conformal coating material had corrosion resistance; if corrosion and electromigration phenomena occurred on the test plate, it indicated that the conformal coating material did not have corrosion resistance.

[0012] A method for evaluating the corrosion resistance of a three-proof coating material includes the following steps:

[0013] S1: Pre-clean the test board;

[0014] S2: Apply a three-proof coating material to the surface of the test plate;

[0015] S3: Connect the electrical contacts of the test board to the DC power supply;

[0016] S4: Place a humidity reaction container at the bottom of the glass reaction vessel, install a partition with vent holes above the humidity reaction container, place a corrosive gas reaction container on the partition, place the test plate on the partition, and cover the glass reaction vessel with a lid; a ring of silicone grease is applied to the joint between the lid and the glass reaction vessel; the humidity reaction container is used to provide 95% relative humidity to the glass reaction vessel; the corrosive gas reaction container is used to provide corrosive gas to the glass reaction vessel;

[0017] S5: Apply a 10V DC voltage between the electrodes of the test plate for a test period of 48 hours. During the test, observe whether there is any corrosion or electromigration on the test plate. After the test, evaluate the corrosion resistance of the conformal coating material based on whether corrosion or electromigration occurs on the test plate. The evaluation criteria are: if no corrosion or electromigration occurs on the test plate, it indicates that the conformal coating material has corrosion resistance; if corrosion or electromigration occurs on the test plate, it indicates that the conformal coating material does not have corrosion resistance.

[0018] As a further improvement of the present invention: In step S4, the humidity reaction vessel provides a relative humidity of 95% to the glass reaction vessel by holding a humidity reaction solution; the preparation method of the humidity reaction solution includes: dissolving 55g to 75g of K2SO4 in 500ml of deionized water.

[0019] As a further improvement of the present invention: in step S4, the corrosive gas reaction vessel includes an SO2 gas reaction vessel, an NH3 reaction vessel and / or an H2S gas reaction vessel; the SO2 gas reaction vessel is used to provide SO2 gas, the NH3 reaction vessel is used to provide NH3, and the H2S gas reaction vessel is used to provide H2S gas.

[0020] As a further improvement of the present invention: the SO2 gas reaction vessel is used to store the SO2 gas reaction solution, thereby providing 20ppm SO2 gas to the glass reaction vessel; the preparation method of the SO2 gas reaction solution includes: weighing 24.3g of anhydrous Na2SO3 (analytical grade), 10.15g of anhydrous K2HPO4 (analytical grade), and 22.2g of anhydrous KH2PO4 (analytical grade); pouring the weighed Na2SO3 powder into a beaker and adding 75ml of water, heating for about 20 minutes until the powder no longer dissolves; then mixing the anhydrous K2HPO4 and anhydrous KH2PO4 powders into the beaker and adding 62.5ml of water, heating for about 10 minutes until completely dissolved; then mixing the two together, and after complete dissolution, pouring the solution into a beaker, placing it in a desiccator, and placing it in a 180mm desiccator, and immediately covering it.

[0021] As a further improvement of the present invention: the NH3 reaction vessel is used to store an NH3 reaction solution, thereby providing 20 ppm NH to the glass reaction vessel. 3； The method for preparing the NH3 reaction solution includes: mixing 5 ml of a 25% ammonia solution with 20 ml of deionized water.

[0022] As a further improvement of the present invention: the H2S gas reaction vessel is used to store an H2S gas reaction solution, thereby providing 40ppm H2S gas to the glass reaction vessel; the preparation method of the H2S gas reaction solution includes: dissolving 2g(NH4)2S in 100ml of deionized water.

[0023] As a further improvement of the present invention: step S1 is replaced by: pre-cleaning the test board, selecting the IPC-B-24 test board, immersing it in the IPA aqueous solution, then rinsing it with deionized water, then rinsing it with anhydrous ethanol, then baking the test board at 50°C for 1 hour, taking it out, and cooling it to room temperature; step S2 is replaced by: manually brushing the conformal coating material onto the surface of the test board, the brushing method being: lightly dipping the brush into the conformal coating material, brushing the copper foil surface of the test board in the same direction, after brushing, turning 90 degrees and brushing again, so that all parts of each electrode of the test board are brushed; each dip and brush is done once, that is, brushing one board twice; repeating the above operation twice, that is, coating 3 times, and then curing according to the recommended curing parameters of the conformal coating material.

[0024] A device for evaluating the corrosion resistance of a three-proof coating material, applied to the aforementioned method for evaluating the corrosion resistance of a three-proof coating material, includes: a glass reaction vessel and a DC power supply. A humidity reaction vessel is placed at the bottom of the glass reaction vessel. A partition with vent holes is set above the humidity reaction vessel. A corrosive gas reaction vessel is placed on the partition. A test plate is placed on the partition. The electrical contacts of the test plate are connected to the DC power supply via welded insulated connecting wires. A lid is placed on top of the glass reaction vessel.

[0025] As a further improvement of the present invention: the corrosive gas reaction vessel includes an SO2 gas reaction vessel, an NH3 reaction vessel, and / or an H2S gas reaction vessel; the SO2 gas reaction vessel is used to store an SO2 gas reaction solution, thereby providing 20 ppm SO2 gas to the glass reaction vessel; the NH3 reaction vessel is used to store an NH3 reaction solution, thereby providing 20 ppm NH3 to the glass reaction vessel; the H2S gas reaction vessel is used to store an H2S gas reaction solution, thereby providing 40 ppm H2S gas to the glass reaction vessel.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. This invention provides a method for evaluating the corrosion resistance of conformal coating materials, ensuring the effectiveness of conformal coating material applications, reducing the application risks of conformal coating materials, and thereby improving the reliability and safety of electronic products.

[0028] 2. This invention establishes a comprehensive evaluation scheme and acceptance criteria for the anti-corrosion performance of conformal coating materials, which can accurately and effectively evaluate the performance of materials and identify the corrosion risks of conformal coatings during production processes, material applications, and product life cycles; it also establishes a comprehensive control standard for the anti-corrosion performance of conformal coating materials under corrosive gases; and it provides analytical means for the introduction of anti-corrosion performance in the development of new materials.

[0029] 3. This invention uses a self-developed corrosive gas evaluation and verification device for three-proof coating materials to reproduce extreme corrosion conditions in real-world environments; it is powered on throughout the test process, enabling real-time and rapid monitoring of the quality of each sample. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the internal structure of the corrosion resistance evaluation device for the three-proof coating material of the present invention. Figure 1 .

[0031] Figure 2 This is a schematic diagram of the internal structure of the corrosion resistance evaluation device for the three-proof coating material of the present invention. Figure 2 .

[0032] Figure reference numerals: 1. Glass reaction vessel; 2. DC power supply; 3. Humidity reaction vessel; 4. Partition; 5. Corrosive gas reaction vessel; 6. Insulated connecting wire; 7. Cover; 8. Test plate; 9. SO2 gas reaction vessel; 10. NH3 reaction vessel; 11. H2S gas reaction vessel; 12. Vent. Detailed Implementation

[0033] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. The invention is now further described in conjunction with the accompanying drawings and embodiments:

[0034] Implementation Case 1:

[0035] A method for evaluating the corrosion resistance of a three-proof coating material includes the following steps:

[0036] S1: Pre-clean the test board;

[0037] S2: Apply a three-proof coating material to the surface of the test plate;

[0038] S3: Connect the electrical contacts of the test board to the DC power supply via insulated connecting wires;

[0039] S4: Place a humidity reaction container at the bottom of the glass reaction container, set a partition with vent holes above the humidity reaction container, place a corrosive gas reaction container on the partition, place the test plate on the partition, and cover the glass reaction container with a lid.

[0040] S5: Apply a 10V DC voltage between the electrodes of the test plate for a test period of 48 hours. During the test, observe whether there is any corrosion or electromigration on the test plate. After the test, evaluate the corrosion resistance of the conformal coating material based on whether corrosion or electromigration occurs on the test plate. The evaluation criteria are: if no corrosion or electromigration occurs on the test plate, it indicates that the conformal coating material has corrosion resistance; if corrosion or electromigration occurs on the test plate, it indicates that the conformal coating material does not have corrosion resistance.

[0041] Implementation Case 2:

[0042] A method for evaluating the corrosion resistance of a three-proof coating material includes the following steps:

[0043] S1: Pre-clean the test plate. Select the IPC-B-24 test plate, immerse it in the IPA aqueous solution, then rinse it with deionized water, then rinse it with anhydrous ethanol, and then bake the test plate at 50°C for 1 hour. Take it out and cool it to room temperature.

[0044] S2: Apply a conformal coating material to the surface of the test panel and then cure it according to the recommended curing parameters of the conformal coating material;

[0045] S3: Connect the electrical contacts of the test board directly to the corresponding pads by manually soldering test leads, and then use solder wire to solder the insulated connection wires to connect the test board to the DC power supply.

[0046] S4: Place a humidity reaction container at the bottom of the glass reaction vessel, install a partition with vent holes above the humidity reaction container, place a corrosive gas reaction container on the partition, place the test plate on the partition, and cover the glass reaction vessel with a lid; apply a ring of silicone grease to the joint between the lid and the glass reaction vessel to prevent gas leakage; the humidity reaction container provides 95% relative humidity to the glass reaction vessel by holding a humidity reaction solution; the corrosive gas reaction container is used to provide corrosive gas to the glass reaction vessel; the corrosive gas includes SO2 gas, NH3 and / or H2S gas;

[0047] S5: Apply a 10V DC voltage between the electrodes of the test plate for a test period of 48 hours. During the test, observe whether there is any corrosion or electromigration on the test plate. After the test, evaluate the corrosion resistance of the conformal coating material based on whether corrosion or electromigration occurs on the test plate. The evaluation criteria are: if no corrosion or electromigration occurs on the test plate, it indicates that the conformal coating material has corrosion resistance; if corrosion or electromigration occurs on the test plate, it indicates that the conformal coating material does not have corrosion resistance.

[0048] The method for preparing the humidity reaction solution includes dissolving 55g to 75g of K2SO4 in 500ml of deionized water.

[0049] The corrosive gas reaction vessel includes an SO2 gas reaction vessel, an NH3 reaction vessel, and / or an H2S gas reaction vessel.

[0050] The SO2 gas reaction vessel is used to store the SO2 gas reaction solution, thereby providing 20 ppm SO2 gas to the glass reaction vessel.

[0051] The preparation method of the SO2 gas reaction solution includes: weighing 24.3g of anhydrous Na2SO3 (analytical grade), 10.15g of anhydrous K2HPO4 (analytical grade), and 22.2g of anhydrous KH2PO4 (analytical grade); pouring the weighed Na2SO3 powder into a beaker and adding 75ml of water, heating for about 20 minutes until the powder no longer dissolves; then mixing the anhydrous K2HPO4 and anhydrous KH2PO4 powders into the beaker and adding 62.5ml of water, heating for about 10 minutes until completely dissolved; then mixing the two together, and after complete dissolution, pouring the solution into a beaker, placing it in a desiccator, and immediately sealing the lid.

[0052] The NH3 reaction vessel is used to store the NH3 reaction solution, thereby providing 20 ppm NH3 to the glass reaction vessel.

[0053] The method for preparing the NH3 reaction solution includes: mixing 5 ml of a 25% ammonia solution with 20 ml of deionized water.

[0054] The H2S gas reaction vessel is used to store an H2S gas reaction solution, thereby providing 40ppm H2S gas to the glass reaction vessel.

[0055] The preparation method of the H2S gas reaction solution includes: dissolving 2g of (NH4)2S in 100ml of deionized water and weighing 1g of the mixture.

[0056] In step S1, the IPA aqueous solution is an aqueous solution with an IPA content of 75% (w / w); the test board is an IPC-B-24 comb-type circuit board; the IPC-B-24 comb-type circuit board is FR-4 with bare copper pads.

[0057] In step S2, the specific steps for applying the conformal coating material to the surface of the test board include: manually applying the conformal coating material to the surface of the test board by brushing the material in the following manner: lightly dip a brush into the conformal coating material and brush the copper foil surface of the test board in the same direction. After brushing, turn the brush 90 degrees and brush it again to ensure that all parts of each electrode of the test board are brushed. Each time the brush is dipped, it is brushed once, that is, brushing one board twice. Repeat the above operation twice, that is, coating three times.

[0058] Implementation Case 3:

[0059] A device for evaluating the corrosion resistance of a three-proof coating material includes: a glass reaction vessel 1 and a DC power supply 2. A humidity reaction vessel 3 is placed at the bottom of the glass reaction vessel. A partition 4 with vent holes 12 is set above the humidity reaction vessel. A corrosive gas reaction vessel 5 is placed on the partition. A test plate 8 is placed on the partition. The electrical contacts of the test plate are connected to the DC power supply through an insulated connecting wire 6. A lid 7 is closed on top of the glass reaction vessel.

[0060] The DC power supply is used to provide a 10VDC voltage.

[0061] The glass reaction vessel has a volume of 5L.

[0062] A ring of silicone grease is applied to the joint between the lid and the glass reaction vessel to prevent gas leakage.

[0063] The corrosive gas reaction vessel is provided with at least one.

[0064] The corrosive gas reaction vessels include SO2 gas reaction vessel 9, NH3 reaction vessel 10 and / or H2S gas reaction vessel 11.

[0065] The SO2 gas reaction vessel is used to store the SO2 gas reaction solution, thereby providing 20 ppm SO2 gas to the glass reaction vessel.

[0066] The NH3 reaction vessel is used to store the NH3 reaction solution, thereby providing 20 ppm NH3 to the glass reaction vessel.

[0067] The H2S gas reaction vessel is used to store an H2S gas reaction solution, thereby providing 40ppm H2S gas to the glass reaction vessel.

[0068] Working principle of the invention:

[0069] The test board (with the coating material fully cured and wired according to its electrical contacts), the corrosive gas reaction vessel, and the humidity reaction vessel are placed together in a glass reaction vessel. To prevent gas leakage, a ring of silicone grease is applied to the joint between the lid and the glass reaction vessel. Next, a 10V DC voltage is applied between the electrodes of the test board for a test period of 48 hours. During the test, the comb-shaped electrodes are observed for corrosion and conductivity, and the results are recorded. After the test, the results are judged and photographed. If no corrosion or electromigration is observed on the test board, it indicates that the conformal coating material has corrosion resistance; if corrosion and electromigration are observed on the test board, it indicates that the conformal coating material does not have corrosion resistance.

[0070] The main functions of this invention are:

[0071] This invention provides a method for evaluating the corrosion resistance of conformal coating materials, ensuring the effectiveness of their application, reducing application risks, and thus improving the reliability and safety of electronic products. This invention establishes a comprehensive evaluation scheme and acceptance criteria for the corrosion resistance of conformal coating materials, which can accurately and effectively assess material performance and identify corrosion risks associated with production processes, material applications, and product lifecycles. It also establishes comprehensive control standards for the corrosion resistance of conformal coating materials under corrosive gases and provides analytical tools for the development of new materials to improve corrosion resistance. This invention utilizes a self-developed corrosive gas evaluation and verification device for conformal coating materials to recreate extreme corrosion conditions in real-world environments. The device is powered throughout the testing process, enabling real-time and rapid monitoring of the performance of each sample.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for evaluating the corrosion resistance of a three-proof coating material, characterized in that: Includes the following steps: Apply a three-proof coating material to the surface of the test plate; Connect the electrical contacts of the test board to the DC power supply; Place a humidity reaction container at the bottom of a glass reaction container, set a partition with vents above the humidity reaction container, place a corrosive gas reaction container on the partition, place the test plate on the partition, and cover the glass reaction container with a lid. A 10V DC voltage was applied between the electrodes of the test plate for a test period of 48 hours. During the test, the presence of corrosion and electromigration phenomena was observed on the test plate. After the test, the corrosion resistance of the conformal coating material was evaluated based on whether corrosion and electromigration phenomena occurred on the test plate. The evaluation criteria were as follows: if no corrosion or electromigration phenomena occurred on the test plate, it indicated that the conformal coating material had corrosion resistance; if corrosion and electromigration phenomena occurred on the test plate, it indicated that the conformal coating material did not have corrosion resistance.

2. The method for evaluating the corrosion resistance of a three-proof coating material according to claim 1, characterized in that: Includes the following steps: S1: Pre-clean the test board; S2: Apply a three-proof coating material to the surface of the test plate; S3: Connect the electrical contacts of the test board to the DC power supply; S4: Place a humidity reaction container at the bottom of the glass reaction vessel, install a partition with vent holes above the humidity reaction container, place a corrosive gas reaction container on the partition, place the test plate on the partition, and cover the glass reaction vessel with a lid; a ring of silicone grease is applied to the joint between the lid and the glass reaction vessel; the humidity reaction container is used to provide 95% relative humidity to the glass reaction vessel; the corrosive gas reaction container is used to provide corrosive gas to the glass reaction vessel; S5: Apply a 10V DC voltage between the electrodes of the test plate for a test period of 48 hours. During the test, observe whether there is any corrosion or electromigration on the test plate. After the test, evaluate the corrosion resistance of the conformal coating material based on whether corrosion or electromigration occurs on the test plate. The evaluation criteria are: if no corrosion or electromigration occurs on the test plate, it indicates that the conformal coating material has corrosion resistance; if corrosion or electromigration occurs on the test plate, it indicates that the conformal coating material does not have corrosion resistance.

3. The method for evaluating the corrosion resistance of a three-proof coating material according to claim 2, characterized in that: In step S4, the humidity reaction vessel provides a relative humidity of 95% to the glass reaction vessel by holding a humidity reaction solution; the preparation method of the humidity reaction solution includes dissolving 55g to 75g of K2SO4 in 500ml of deionized water.

4. The method for evaluating the corrosion resistance of a three-proof coating material according to claim 3, characterized in that: In step S4, the corrosive gas reaction vessel includes an SO2 gas reaction vessel, an NH3 gas reaction vessel, and / or an H2S gas reaction vessel; the SO2 gas reaction vessel is used to provide SO2 gas, the NH3 gas reaction vessel is used to provide NH3, and the H2S gas reaction vessel is used to provide H2S gas.

5. The method for evaluating the corrosion resistance of a three-proof coating material according to claim 4, characterized in that: The SO2 gas reaction vessel is used to store the SO2 gas reaction solution, thereby providing 20 ppm SO2 gas to the glass reaction vessel. The preparation method of the SO2 gas reaction solution includes: weighing 24.3 g of anhydrous Na2SO3 (analytical grade), 10.15 g of anhydrous K2HPO4 (analytical grade), and 22.2 g of anhydrous KH2PO4 (analytical grade); pouring the weighed Na2SO3 powder into a beaker and adding 75 ml of water, heating for about 20 minutes until the powder no longer dissolves; then mixing the anhydrous K2HPO4 and anhydrous KH2PO4 powders into the beaker and adding 62.5 ml of water, heating for about 10 minutes until completely dissolved; then mixing the two together, and after complete dissolution, pouring the solution into a beaker, placing it in a desiccator, and placing it in a 180 mm desiccator, and immediately sealing the lid.

6. The method for evaluating the corrosion resistance of a three-proof coating material according to claim 4, characterized in that: The NH3 reaction vessel is used to store the NH3 reaction solution, thereby providing 20 ppm NH to the glass reaction vessel. 3； The method for preparing the NH3 reaction solution includes: mixing 5 ml of 25% ammonia solution with 20 ml of deionized water.

7. The method for evaluating the corrosion resistance of a three-proof coating material according to claim 4, characterized in that: The H2S gas reaction vessel is used to store the H2S gas reaction solution, thereby providing 40ppm H2S gas to the glass reaction vessel; the preparation method of the H2S gas reaction solution includes: dissolving 2g of (NH4)2S in 100ml of deionized water.

8. The method for evaluating the corrosion resistance of a three-proof coating material according to claim 2, characterized in that: The step S1 is replaced by: pre-cleaning the test plate, selecting the IPC-B-24 test plate, immersing it in the IPA aqueous solution, rinsing it with deionized water, rinsing it with anhydrous ethanol, baking the test plate at 50°C for 1 hour, taking it out, and cooling it to room temperature. Step S2 is replaced by: manually brushing the conformal coating material onto the surface of the test board. The brushing method is as follows: lightly dip a brush into the conformal coating material and brush the copper foil surface of the test board in the same direction. After brushing, turn the brush 90 degrees and brush again to ensure that all parts of each electrode of the test board are brushed. Brush once for each dip, that is, brush one board twice. Repeat the above operation twice, that is, apply three coats. Then cure according to the recommended curing parameters of the conformal coating material.

9. A device for evaluating the corrosion resistance of a three-proof coating material, applied to the method for evaluating the corrosion resistance of a three-proof coating material as described in any one of claims 1-8, characterized in that: include: The system includes a glass reaction vessel and a DC power supply. A humidity reaction vessel is placed at the bottom of the glass reaction vessel. A partition with vents is installed above the humidity reaction vessel. A corrosive gas reaction vessel is placed on the partition. A test plate is placed on the partition. The electrical contacts of the test plate are connected to the DC power supply via insulated connecting wires. A lid is placed on top of the glass reaction vessel. A ring of silicone grease is applied to the joint between the lid and the glass reaction vessel. The corrosive gas reaction vessel includes an SO2 gas reaction vessel, an NH3 gas reaction vessel, and / or an H2S gas reaction vessel.

10. The device for evaluating the corrosion resistance of anti-coating materials according to claim 9, characterized in that: The SO2 gas reaction vessel is used to store an SO2 gas reaction solution, thereby providing 20 ppm SO2 gas to the glass reaction vessel; the NH3 reaction vessel is used to store an NH3 reaction solution, thereby providing 20 ppm NH3 to the glass reaction vessel; the H2S gas reaction vessel is used to store an H2S gas reaction solution, thereby providing 40 ppm H2S gas to the glass reaction vessel.

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