A deionized cleaning agent and its application in removing pollutants in the field of electronic circuit products

Abstract

The present invention discloses a deionized cleaning agent and its application in removing pollutants in the field of electronic circuit products, relating to the field of chemical antifouling. The cleaning agent includes the following components by mass fraction: organic base: 1wt%-10wt%; penetrant: 1wt%-5wt%; additive: 1wt%-8wt%; water: balance; the additive is at least one of 3-methylbutyric acid, dipropylene glycol methyl ether acetate, and ethylene glycol ethyl ether acetate. The water-based cleaning agent of the present application adopts an organic base with a penetrant having strong wettability and permeability, which can effectively remove the corrosive "acidic ions" remaining in the PCB manufacturing process during the cleaning process. At the same time, it has a strong penetration ability and can penetrate into the micropore area as fine as 3mil for thorough cleaning, effectively removing pollutants such as fingerprints, grease, and ions, and meeting the cleaning requirements of high-quality products.

Description

Technical Field

[0001] The present invention relates to the field of chemical antifouling, in particular to a deionizing cleaning agent and its application in removing pollutants in the field of electronic circuit products. Background Art

[0002] Currently, approximately 50%-70% of electronic circuit products suffer from quality defects throughout the manufacturing process, primarily due to contamination. With the advancement of semiconductor chip process technology nodes to 28nm, 14nm, and beyond, sensitivity to impurities and contaminants has increased. Pollutants primarily exist in the environment in ionic and non-ionic forms. Ionic contaminants primarily come from sources such as etching, plating, doping, oxidation, and solder mask contamination, as well as contact contamination from component packaging materials, flux, equipment oil, fingerprints, and ambient dust. These contaminants manifest as various organic and inorganic acids and salts. Contaminants composed of both cations and anions are considered polar pollutants. Excessive levels of metal ions in metal particles and cations can easily degrade the insulation of electronic components, cause capacitance drift, interfere with electrical signals, and even cause short circuits in electronic circuits. Furthermore, highly reactive metal particles and metal cations can displace less reactive precious metals from the conductive materials that make up electronic circuits, degrading their performance. In addition, the negative ions in ionic pollutants, such as chloride ions, will decompose with water in the moisture to form an ion electrode potential, causing leakage, corrosion and ionization of metal substances. Bromide ions have less impact than chlorine. Sulfate ions have the same effect as chlorine and bromide ions. Aminosulfonic acid is usually used in many electroplating processes, and its corrosive effect will be many times that of chlorine.

[0003] The biggest problem in the quality control of all electronic circuit product production processes is ionic contamination, which changes the product's electrical properties, reduces the yield rate of electronic products, changes the size of electronic products, changes the surface cleanliness, and causes dents on the surface, affecting the reliability of electronic products. In actual work, it is almost impossible to eradicate contamination. In the PCB and PCBA industry, according to the IPC-J-STD-001 standard, the third-level standard for flux residue is <40ug / cm2, the third-level standard for ionic contaminant content is ≤1.5(NaCl)ug / cm2, and the extraction resistivity is >2×10 6 Ω.cm. In addition, with the miniaturization of PCBA, it is almost certain that this content is still too high to meet the actual performance requirements of the product. The current commonly used ionic contaminant requirement is approximately ≤0.75 (NaCl) ug / cm 2 .

[0004] The primary approach to addressing contamination is to increase the number of cleaning steps and adopt more efficient water-based cleaning technologies. Currently, PCB manufacturers primarily employ the following cleaning methods: First, high-temperature boiling: boiling the boards in DI water at 80°C for 30 minutes to 1 hour. This long boiling time and high temperature consume significant energy and require frequent cleaning bath changes. Second, solvent-based deionized detergents are used for ultrasonic cleaning, with a 2-3 minute heating cycle. However, these solvents have drawbacks such as high evaporation rates, flammability, and explosiveness. The evaporation of organic solvents can cause atmospheric damage, harm the physical and mental health of workers, and pollute the environment. Third, conventional pickling, with ultrasonic cleaning for 2-3 minutes, may not be as effective as solvent-based deionized detergents and high-temperature boiling in DI water. This is particularly true for delicate circuits, line spacing, and hole sizes, as these cleaning processes can be difficult to clean. Furthermore, the system is more sensitive to impurities and contaminants, and can easily cause ionic contamination. Summary of the Invention

[0005] The present invention provides a deionizing cleaning agent and its application in removing pollutants in the field of electronic circuit products, so as to provide a water-based cleaning agent with safe raw material use, low energy consumption, good penetration ability and high cleaning efficiency for pollutants such as ions in electronic circuit products.

[0006] In order to solve the above technical problems, one of the purposes of the present invention is to provide a water-based deionized cleaning agent, comprising the following components by mass fraction:

[0007] Organic base: 1wt%-10wt%;

[0008] Penetrant: 1wt%-5wt%;

[0009] Additives: 1wt%-8wt%;

[0010] Water: balance;

[0011] Wherein, the additive is at least one of 3-methylbutyric acid, dipropylene glycol methyl ether acetate, and ethylene glycol ethyl ether acetate, and the penetrant is alkyl glycoside.

[0012] As a preferred embodiment, the organic base is at least one of triethanolamine, isopropanolamine, ethylenediamine, and N-methylpyrrolidone.

[0013] As a preferred embodiment, the additive includes 3-methylbutyric acid and dipropylene glycol methyl ether acetate in a mass ratio of 1:2.

[0014] As a preferred embodiment, the organic base comprises ethylenediamine and isopropanolamine in a ratio of 5:4.

[0015] As a preferred solution, the water is deionized water.

[0016] In order to solve the above technical problems, a second purpose of the present invention is to provide an application of a water-based deionized cleaning agent in removing pollutants in the field of electronic circuit products.

[0017] As a preferred solution, the deionized detergent is heated to 45° C.-50° C., the electronic circuit product is mixed with the deionized detergent, and then cleaned by ultrasonic stirring for 30 seconds-300 seconds.

[0018] As a preferred solution, the electronic circuit product is a PCB or PCBA, which is generally used for tinning of PCB and cleaning of finished products of tin-spraying boards. PCB tin-spraying boards are often used in control panels of automobiles and airplanes, and have high requirements for pollution levels.

[0019] As a preferred solution, the deionized detergent needs to be replaced when its pH is less than 10.

[0020] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0021] 1. Compared with DI water high-temperature boiling, the water-based cleaning agent in this application requires lower temperature and shorter time, which simplifies the cleaning process and facilitates on-site operation. Compared with solvent-based deionized cleaning agents, the raw materials used are safer, non-flammable and non-explosive, and will not volatilize to produce harmful substances. There is no pollution during use and it can be directly discharged without polluting the environment. Compared with pickling treatment, it does not damage the workpiece, the deionized cleaning efficiency is higher, and there are no pollution, corrosion and copper surface oxidation problems.

[0022] 2. The water-based cleaning agent of this application uses an organic base in combination with a reagent with strong wettability and permeability. It can effectively remove the corrosive "acidic ions" remaining in the PCB production process during the cleaning process, such as chloride ions, bromide ions, weak organic acid ions, sulfate ions and other acidic positive and negative ion residues. At the same time, it has strong penetration ability and can penetrate into micropore areas as fine as 3 mils for thorough cleaning, effectively removing fingerprints, grease, ions and other pollutants, especially cleaning the most difficult to remove flux residues on tin-sprayed boards, meeting the cleaning requirements of high-quality products. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 : This is a schematic diagram of the process flow of a water-based deionized cleaning agent used for PCB cleaning in the present invention. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] Example 1

[0026] A water-based deionized cleaning agent comprises 5wt% N-methylpyrrolidone, 4wt% isopropanolamine, 3wt% penetrant, 2wt% 3-methylbutyric acid, 4wt% dipropylene glycol methyl ether acetate and the balance deionized water, wherein the penetrant is an alkyl glycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0027] Example 2

[0028] A water-based deionized cleaning agent comprises 5wt% ethylenediamine, 4wt% isopropanolamine, 3wt% penetrant, 2wt% 3-methylbutyric acid, 4wt% dipropylene glycol methyl ether acetate and the balance deionized water, wherein the penetrant is an alkyl polyglycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0029] Example 3

[0030] A water-based deionized cleaning agent comprises 5wt% triethanolamine, 4wt% isopropanolamine, 3wt% penetrant, 2wt% 3-methylbutyric acid, 4wt% dipropylene glycol methyl ether acetate and the balance deionized water, wherein the penetrant is an alkyl polyglycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0031] Example 4

[0032] A water-based deionized cleaning agent comprises 9wt% triethanolamine, 3wt% penetrant, 2wt% 3-methylbutyric acid, 4wt% dipropylene glycol methyl ether acetate and the balance deionized water, wherein the penetrant is an alkyl glycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0033] Example 5

[0034] A water-based deionized cleaning agent comprises 9wt% isopropanolamine, 3wt% penetrant, 2wt% 3-methylbutyric acid, 4wt% dipropylene glycol methyl ether acetate and the balance deionized water, wherein the penetrant is an alkyl polyglycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0035] Example 6

[0036] A water-based deionized cleaning agent comprises 9wt% ethylenediamine, 3wt% penetrant, 2wt% 3-methylbutyric acid, 4wt% dipropylene glycol methyl ether acetate and the balance deionized water, wherein the penetrant is an alkyl polyglycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0037] Example 7

[0038] A water-based deionized cleaning agent comprises 9wt% N-methylpyrrolidone, 3wt% penetrant, 2wt% 3-methylbutyric acid, 4wt% dipropylene glycol methyl ether acetate and the balance deionized water, wherein the penetrant is an alkyl glycoside, and the cleaning process steps are as follows: Figure 1As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0039] Example 8

[0040] A water-based deionized cleaning agent comprises 5wt% ethylenediamine, 4wt% isopropanolamine, 3wt% penetrant, 2wt% ethylene glycol ethyl ether acetate and the balance deionized water, wherein the penetrant is an alkyl polyglycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with deionized detergent, and then 200 mL of deionized cleaning solution is added, the pH is controlled above 10, heated to 50°C, the product to be cleaned is added, ultrasonically stirred for 3 minutes, and the product is taken out and washed with DI water 2-3 times, and then dried and tested.

[0041] Embodiment 9

[0042] A water-based deionized cleaning agent comprises 3 wt% ethylenediamine, 6 wt% isopropanolamine, 1 wt% penetrant, 2 wt% 3-methylbutyric acid, 4 wt% dipropylene glycol methyl ether acetate, and the balance deionized water, wherein the penetrant is an alkyl polyglycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0043] Example 10

[0044] A water-based deionized cleaning agent comprises 5wt% ethylenediamine, 4wt% isopropanolamine, 1wt% penetrant, 3wt% 3-methylbutyric acid, 3wt% dipropylene glycol methyl ether acetate, and the balance deionized water, wherein the penetrant is an alkyl polyglycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0045] Comparative Example 1

[0046] A water-based deionized cleaning agent comprises 5wt% N-methylpyrrolidone, 4wt% isopropanolamine, 3wt% penetrant and the balance deionized water, wherein the penetrant is an alkyl polyglycoside, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0047] Comparative Example 2

[0048] A water-based deionized cleaning agent comprises 5wt% N-methylpyrrolidone, 4wt% isopropanolamine, 2wt% 3-methylbutyric acid, 4wt% dipropylene glycol methyl ether acetate and the balance deionized water, wherein the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0049] Comparative Example 3

[0050] A water-based deionized cleaning agent comprises 5wt% N-methylpyrrolidone, 4wt% isopropanolamine, 3wt% penetrant, 2wt% 3-methylbutyric acid, 4wt% dipropylene glycol methyl ether acetate and the balance deionized water, wherein the penetrant is fatty alcohol polyoxyethylene ether, and the cleaning process steps are as follows: Figure 1 As shown, in the chemical washing step, the cleaning tank is cleaned with a deionized detergent, and then 200 mL of deionized detergent is added, the pH is controlled to be above 10, and the tank is heated to 50°C. The product to be cleaned is added and ultrasonically stirred for 3 minutes. After the product is taken out, it is washed with DI water 2-3 times and tested after drying. During the process, the pH of the deionized detergent is controlled to be above 10, otherwise the deionized detergent needs to be replaced.

[0051] Performance testing

[0052] 1. Detection of ionic contaminant content: Clean the samples according to the cleaning steps in the examples or comparative examples, and use IPC-TM-650 2.3.25 and IPC-TM-650 2.3.28.2 ion chromatography to detect the ionic contaminant content of the samples before and after cleaning. Take the average value of 5 samples in each group. The detection standard is <0.75μgNaCl / cm 2 The test results are shown in Table 1 below.

[0053] 2. Surface tension measurement: Measured using a surface tension meter using the platinum plate method. This method uses a 24mm x 10mm x 0.1mm platinum plate with a sandblasted surface to improve wetting with the liquid being tested. During the test, the platinum plate is gently brought into contact with the liquid surface (or interface). The surface tension of the liquid pulls the plate downward. When the surface tension of the liquid and other related forces balance the opposing force measured by the instrument, the test value stabilizes. When the sensor is immersed in the liquid being tested, the surface tension around the platinum plate acts, pulling it downward as far as possible. When the surface tension of the liquid and other related forces reach equilibrium with the balance force, the sensing platinum plate ceases immersion in the liquid. At this point, the instrument's balance sensor measures the immersion depth and converts it into the liquid's surface tension value.

[0054] Table 1 - Performance test results of the examples and comparative examples of the present application

[0055]

[0056]

[0057] Combining the performance test results of Example 1 and Comparative Examples 1 and 3 in Table 1, it can be seen that the penetrant of the present application uses alkyl glycoside, which can reduce the surface tension or interfacial tension of the liquid, and easily form a spreading effect when in contact with the surface of other objects, thereby promoting the solution to spread or penetrate into the solid material. For materials with large pores and cracks, the invasion of the external liquid causes the molecules originally in the adsorption state to be replaced at the competitive adsorption sites, thereby desorbing and desorbing; for materials with mesopores and micropores, the invasion of the external liquid produces a natural capillary phenomenon at the end of the pore. Under the action of capillary static force, the molecules in the pore move to the other end and are discharged, thereby promoting the flow of the substance, so that the cleaning agent has strong penetration, wetting, and dispersion effects, thereby improving the cleaning effect of ionic pollutants.

[0058] Combining the performance test results of Example 1 and Comparative Example 2 in Table 1, it can be seen that the present application uses 3-methylbutyric acid and dipropylene glycol methyl ether acetate as additives, whose main function is to assist the penetrant to further reduce the surface tension of the liquid, reduce the surface tension to allow the cleaning liquid to enter the micropores, and improve the cleaning effect of ionic pollutants.

[0059] Combined with the performance test results of Examples 1-7 and 9 in Table 1, it can be seen that the water-based cleaning agent of the present application uses an organic base in combination with a penetrant and additive with strong wettability and permeability, which can effectively remove the corrosive "acidic ions" remaining in the PCB production process during the cleaning process. When the organic base is compounded with ethylenediamine and isopropanolamine in a mass ratio of 5:4, the ion decontamination effect of the cleaning agent is optimized, and the surface tension is small, which can meet the cleaning requirements of high-quality products.

[0060] The specific embodiments described above further illustrate the objectives, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A water-based deionized cleaning agent, characterized in that: The following components are included in the mass fraction: Organic base: 1wt%-10wt%; Penetrant: 1wt%-5wt%; Additives: 1wt%-8wt%; Water: balance; The organic base is ethylenediamine and isopropanolamine in a mass ratio of 5:4; the additive is 3-methylbutyric acid and dipropylene glycol methyl ether acetate in a mass ratio of 1:2; and the penetrant is alkyl glycoside.

2. A water-based deionized cleaning agent according to claim 1, characterized in that: The water is deionized water.

3. Use of the water-based deionizing cleaning agent according to any one of claims 1 to 2 for removing pollutants in the field of electronic circuit products.

4. The use of a water-based deionized cleaning agent as claimed in claim 3 for removing pollutants in the field of electronic circuit products, characterized in that: The water-based deionized cleaning agent is heated to 45° C.-50° C., the electronic circuit product is mixed with the deionized cleaning agent, and then the product is cleaned by ultrasonic stirring for 30 seconds-300 seconds.

5. The use of a water-based deionized cleaning agent as claimed in claim 3 for removing pollutants in the field of electronic circuit products, characterized in that: The electronic circuit product is a PCB or a PCBA.

6. The use of a water-based deionized cleaning agent as claimed in claim 3 for removing pollutants in the field of electronic circuit products, characterized in that: The water-based deionized cleaning agent needs to be replaced when the pH value is less than 10.

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