A microwave assembly chip cleaning agent for double solvent vapor phase cleaning and a preparation method thereof

Abstract

The application discloses a kind of microwave assembly chip cleaning agent for double solvent gas phase cleaning and preparation method thereof, belong to microelectronic cleaning technical field, the cleaning agent includes the following mass percentage components: alcohol ether solvent 10-50%, ester solvent 1-10%, nitrogen-containing and sulfur-containing solvent 1-10%, antioxidant T501 0-1%, the balance is hydrocarbon solvent.The application is synergized by alcohol ether solvent, ester solvent, nitrogen-containing and sulfur-containing solvent and hydrocarbon solvent, enhances the removal capacity to weld mark, oil stain, dust and other dirt;Preparation method is simple, suitable for large-scale industrial production;At the same time has specific density and boiling point, can cooperate with fluorine system solvent and carry out microwave assembly chip double solvent gas phase cleaning, solve the problem that fluorine system solvent is safe and environmental protection, but cleaning power is weak, difficult to meet the cleaning cleanliness requirement, other cleaning methods can also solve the problem that bare chip is easily damaged, affects product reliability.

Description

Technical Field

[0001] This invention belongs to the field of microelectronic cleaning technology, and in particular relates to a microwave component chip cleaning agent for dual-solvent vapor phase cleaning and its preparation method. Background Technology

[0002] In recent years, with the increasing demand for microelectronic products in both military and civilian fields, microelectronic assembly technology has been continuously developing towards multi-chip, high-density, miniaturization, three-dimensional stacking, and high integration. Microwave component chips, as a crucial component of this technology, have a significant impact on product performance and reliability due to their cleanliness. During the soldering process of microwave component chips to product pads using flux (commonly RMA type flux), the chips inevitably become contaminated with flux residues. If not cleaned, the halogens, acids, and other chemical components contained in the flux residues can corrode the chip surface in humid environments, creating hidden dangers or causing chip failure, and can easily lead to short circuits and bridging.

[0003] Common methods for cleaning flux residues include manual soaking and brushing, ultrasonic cleaning, spray cleaning, and vapor phase cleaning. However, due to the inherent characteristics of microwave component chips, it is crucial to avoid damaging the bare chips during the cleaning process to prevent any potential problems, while simultaneously considering cleanliness and stability. Vapor phase cleaning is currently one of the suitable methods. However, with increasingly stringent environmental protection requirements and greater emphasis on human health and safety worldwide, cleaning agents used for vapor phase cleaning, such as early chlorofluorocarbons (e.g., CFC113) and now chlorinated hydrocarbons and bromopropane, have been phased out or are on the verge of being replaced. Therefore, for microwave component chips, fluorinated solvents with extremely low physiological toxicity and environmental friendliness can be selected for vapor phase cleaning. However, fluorinated solvents have relatively weak cleaning capabilities, making it difficult to meet the cleanliness requirements for cleaning flux residues. Therefore, a dual-solvent vapor phase cleaning method combining a cleaning agent with a fluorinated solvent is needed to address the many limitations in the microwave component chip cleaning process, thereby ensuring product performance and reliability. Summary of the Invention

[0004] This invention provides a microwave component chip cleaning agent for dual-solvent vapor phase cleaning and its preparation method, which solves the problem that although the existing technology uses fluorine-based solvents to clean microwave component chips with extremely low human physiological toxicity and environmental friendliness, the cleaning ability is weak, and it is difficult to meet the cleaning cleanliness requirements when using them to clean flux residues.

[0005] To address the aforementioned technical problems, the first aspect of this invention provides a microwave component chip cleaning agent for dual-solvent vapor phase cleaning, the cleaning agent comprising the following components by mass percentage:

[0006] Alcohol ether solvents 10-50%;

[0007] Ester solvents 1-10%;

[0008] Nitrogen and sulfur-containing solvents: 1-10%;

[0009] Antioxidant T501 0-1%;

[0010] The remainder is a hydrocarbon solvent.

[0011] Furthermore, the alcohol ether solvent includes one or a mixture of two or more of propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, dipropylene glycol butyl ether, 2,4-dimethyl-2,4-pentanediol or 3-methyl-3methoxy-1-butanol.

[0012] Furthermore, the ester solvent includes one or a mixture of two or more of diesters (DBE), ethylene glycol diacetate, or 3-methoxy-3-methyl-1-acetate.

[0013] Furthermore, the nitrogen- and sulfur-containing solvents include one or a mixture of two of N,N-diethylformamide or dimethyl sulfoxide.

[0014] Furthermore, the hydrocarbon solvent includes C 11 n-Alkanes or C 10 -C 13 A mixture of one or two isoalkanes.

[0015] Furthermore, the boiling range of the hydrocarbon solvent is 180℃-220℃.

[0016] Secondly, a method for preparing a microwave component chip cleaning agent based on a dual-solvent method is provided, the method comprising the following steps:

[0017] S1. Pump the hydrocarbon solvent into a storage tank with a conical bottom and let it stand for more than 24 hours to remove impurities and moisture from the bottom. Then pump it into the reaction vessel according to the specified ratio.

[0018] S2. Add alcohol ether solvents, ester solvents, nitrogen-containing and sulfur-containing solvents, and antioxidant T501 to the reaction vessel in sequence;

[0019] S3. Stir the material in the reactor evenly for 30 minutes, and after passing it through a dryer and filter, it becomes the finished product of microwave component chip cleaning agent based on dual solvents.

[0020] The advantages and beneficial effects of this invention are:

[0021] 1. This invention not only possesses strong cleaning capabilities for weld beads, oil stains, dust, and other contaminants, but also exhibits specific density and boiling point. Its dual-solvent vapor-phase cleaning mechanism, when combined with fluorinated solvents, is rigorously defined. The cleaning agent of this invention can be mixed with a fluorinated solvent in a certain proportion to form a cleaning solution. The two are not completely miscible; the cleaning agent's density is lower than that of the fluorinated solvent, placing it in the upper layer of the cleaning solution. It primarily dissolves flux residues on the workpiece. Its boiling point ensures a relatively low temperature for azeotropic mixing with the fluorinated solvent, guaranteeing that the boiling temperature of the mixture will not adversely affect the workpiece. Furthermore, the boiling state of the mixture effectively washes away flux residues, thereby accelerating their removal and dissolution.

[0022] 2. This invention does not contain trichlorotrifluoroethane (F-113), 1,1,1-trichloroethane, trichloroethylene, carbon tetrachloride, or other ODS substances, nor does it contain heavy metals, benzene compounds, halogens, or other components. It has a low odor, is safe and environmentally friendly, meets RoHS regulations, and complies with the national standard GB38508 requirements for the limit of volatile organic compound content in cleaning agents.

[0023] 3. This invention is safe to use. With a closed-cup flash point greater than 60°C, it is a high flash point, low flammability solvent product, which can reduce the risk of fire during storage or use. At the same time, it has stable chemical properties, excellent material compatibility, no corrosion to circuit boards, metal materials, etc., and can be distilled and recycled to reduce usage costs, thus having good economic benefits.

[0024] 4. The preparation method involved in this invention is simple, the raw materials used are widely available and easy to obtain, and it is very suitable for large-scale industrial production. Attached Figure Description

[0025] Appendix Figure 1 The image shows the sample cleaned using Example 1 in the cleaning performance test of this invention.

[0026] Appendix Figure 2 The image shows the sample cleaned using Comparative Example 1 in the cleaning performance test of this invention.

[0027] Appendix Figure 3 The image shows the sample cleaned using Comparative Example 2 in the cleaning performance test of this invention.

[0028] Appendix Figure 4 The image shows the sample cleaned using Comparative Example 3 in the cleaning performance test of this invention.

[0029] Appendix Figure 5 This is a comparison diagram of the sample before and after cleaning in application example 1 of the present invention;

[0030] Appendix Figure 6 This is a microscopic comparison of a sample before and after cleaning, representing an application example of the present invention. Detailed Implementation

[0031] The specific implementation schemes of the present invention will be described in detail and clearly below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are mostly within the scope of protection of the present invention.

[0032] Example 1

[0033] A microwave component chip cleaning agent for dual-solvent vapor phase cleaning, comprising the following components and weights (taking 1000g of product as an example):

[0034] Propylene glycol butyl ether (concentration 99.5%) 240g;

[0035] 3-Methyl-3-methoxy-1-butanol (99% concentration) 140g;

[0036] Ethylene glycol diacetate (concentration 99.5%) 50g;

[0037] N,N-Diethylformamide (99% concentration) 50g;

[0038] Antioxidant T501 (99% concentration) 0.5g;

[0039] C 10 -C 13 Isoalkanes (concentration 99.5%) 519.5g.

[0040] The preparation of a dual-solvent-based microwave component chip cleaning agent using the above components is as follows:

[0041] S1. Place C 10 -C 13 Isomerized alkanes are pumped into a storage tank with a conical bottom and left to stand for more than 24 hours. After ensuring that impurities and moisture are removed from the bottom, they are pumped into the reaction vessel.

[0042] S2. Propylene glycol butyl ether, 3-methyl-3-methoxy-1-butanol, ethylene glycol diacetate, N,N-diethylformamide, and antioxidant T501 are added sequentially to the reaction vessel;

[0043] S3. Stir the material in the reactor evenly for 30 minutes, and after passing it through a dryer and filter, it becomes the finished product of microwave component chip cleaning agent based on dual solvents.

[0044] The performance indicators of the dual-solvent microwave component chip cleaning agent prepared in this embodiment are as follows:

[0045] Appearance: Colorless and transparent liquid

[0046] Odor: Slight solvent smell

[0047] Density (20℃): 0.822g / ml

[0048] Initial boiling point: 165℃

[0049] Flash point (closed cup): ≥61℃

[0050] Example 2

[0051] Unlike Example 1, its composition and weight are as follows (taking 1000g of product as an example):

[0052] 3-Methyl-3-methoxy-1-butanol (99% concentration) 350g;

[0053] Diester (concentration 99%) 40g;

[0054] N,N-Diethylformamide (99% concentration) 60g;

[0055] Antioxidant T501 (concentration 99%) 0.5g;

[0056] C 11 n-Alkanes (concentration 99.5%) 549.5g;

[0057] This embodiment is based on the performance indicators of a dual-solvent microwave component chip cleaning agent:

[0058] Appearance: Colorless and transparent liquid

[0059] Odor: Slight solvent smell

[0060] Density (20℃): 0.810 g / ml

[0061] Initial boiling point: 166℃

[0062] Flash point (closed cup): ≥61℃

[0063] The cleaning agent of this invention improves its solubility by combining alcohol ether solvents, ester solvents, nitrogen-containing and sulfur-containing solvents, and hydrocarbon solvents. It can remove flux residues, fingerprints, dust and other contaminants, and has good safety, excellent material compatibility, and no corrosion to circuit boards and metal materials.

[0064] Fluorine-based solvent dual-solvent vapor phase cleaning utilizes a strong cleaning solvent in conjunction with a fluorine-based solvent to clean contaminants from workpieces, achieving both the desired cleaning efficiency and specific cleaning process requirements. In this invention, the cleaning agent is mixed with a fluorine-based solvent in a specific ratio to form the cleaning solution. The two solvents are not completely miscible. The cleaning agent, positioned on top of the cleaning solution, primarily dissolves flux residues on the workpiece. Simultaneously, the azeotropic temperature of the cleaning agent and the fluorine-based solvent meets the cleaning requirements of microwave component chips. Without damaging the chip, the azeotropic effect continuously washes the chip, effectively accelerating the removal and dissolution of contaminants. Furthermore, the azeotropic process generates fluorine-based solvent vapor, providing steam for the vapor cleaning process in the vapor zone.

[0065] Cleaning performance test:

[0066] The cleaning performance of the cleaning agent prepared in Example 1 was tested.

[0067] Comparative Example 1 did not add alcohol ether solvents, and unlike Example 1, it did not add propylene glycol butyl ether and 3-methyl-3-methoxy-1-butanol. 10 -C 13 Isoalkanes are added to make up the balance.

[0068] Comparative Example 2 did not add ester solvents; unlike Example 1, it did not add ethylene glycol diacetate. C 10 -C 13 Isoalkanes are added to make up the balance.

[0069] Comparative Example 3 did not contain nitrogen- or sulfur-containing solvents. Unlike Example 1, it did not contain N,N-diethylformamide. 11 Add n-alkanes to make up the balance.

[0070] The cleaning performance test process is as follows: dual solvent immersion cleaning (temperature 85℃, time 8 min) → fluorinated solvent immersion rinsing (room temperature) → fluorinated solvent immersion rinsing (room temperature) → hot air drying.

[0071] Examples 1 and Comparative Examples 1, 2, and 3 were prepared with AE 3000 fluorinated solvent in a 7:3 ratio. Cleaning performance tests were conducted according to the established process flow. The cleaning results of Example 1 after cleaning are shown in the attached figure. Figure 1 As shown, the sample surface is clean and free of any residue, while Comparative Example 1, after cleaning, appears as shown in the image. Figure 2 As shown, flux residue on the sample surface is quite obvious. Comparative examples 2 and 3, after cleaning, show the following: Figure 3 and attached Figure 4As shown, slight marks remain on the surface of the sample. This indicates that the cleaning effect of Comparative Examples 1, 2, and 3 is worse than that of Example 1. They cannot meet the requirement of thoroughly cleaning flux residues without leaving any marks. This shows that each component of Example 1 is indispensable. The excellent cleaning performance of the cleaning agent requires the joint compounding of these components to ensure it.

[0072] Application Example 1

[0073] The product from Example 1 was used in combination with AE 3000 fluorosolvent (HFE-347pc-f) to form a dual solvent ratio of 7:3. The microwave component chips were cleaned using a GUYSON dual solvent vapor phase cleaning system from the UK. Figure 5 As shown, the cleaned chip showed no discoloration, no corrosion, and no residue on its surface. Figure 6 As shown, under a 25x microscope, no flux residue was observed on or around the solder of the sample. The surface was clean and smooth, and the solder in the soldering area had a complete shape and clear outline. Furthermore, after ionic contaminant testing, the cleanliness of the chip after cleaning met the requirements of GJB5807 for Level 3 electronic product assemblies, with a cleanliness level not exceeding 1.56 ug (NaCl) / cm³. 2 Requirements.

[0074] Application Example 2

[0075] The product from Example 2 was used in combination with 71IPA (a mixture of fluorinated solvent and isopropanol) at a 6:4 ratio to form a dual solvent system. The microwave component chips were cleaned using a GUYSON dual-solvent vapor phase cleaning system from the UK. The cleaned chips, after visual and microscopic inspection, showed no abnormalities compared to the original components. Figure 5 and attached Figure 6 The results shown are similar and meet the cleaning requirements, so they are not listed again. Furthermore, the cleaned chip also meets the requirement of a cleanliness level of no more than 1.56 ug (NaCl) / cm³ for Class III electronic product assemblies as specified in GJB5807. 2 Requirements.

[0076] In summary, this invention provides a dual-solvent microwave component chip cleaning agent, its preparation method, and its application method. The cleaning agent is formulated from human- and environmentally friendly raw materials. Specific components and proportions can be combined with different fluorinated solvents to perform dual-solvent vapor-phase cleaning of microwave component chips, all meeting stringent cleaning requirements. This achieves highly efficient chip cleaning while ensuring product non-destruction, safe and environmentally friendly use, and low cost. Furthermore, considering the performance characteristics of this cleaning agent, in practical applications, besides being used in dual-solvent vapor-phase cleaning processes, it can also be used to clean flux residues and other polar and non-polar contaminants on workpieces through manual brushing, ultrasonic cleaning, spraying, and other cleaning methods.

[0077] This invention has many other embodiments, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of this invention.

Claims

1. A microwave component chip cleaning agent for dual-solvent vapor phase cleaning, characterized in that, The cleaning agent is used in combination with fluorine-based solvents to clean microwave component chips using a dual-solvent vapor phase cleaning device. The cleaning agent comprises the following components by weight percentage: The solvent consists of 10-50% alcohol ether solvents, 1-10% ester solvents, 1-10% nitrogen- and sulfur-containing solvents, 0-1% antioxidant T501, and the balance is a hydrocarbon solvent, wherein the boiling range of the hydrocarbon solvent is 180℃-220℃. The alcohol ether solvents include one or a mixture of two or more of propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, dipropylene glycol butyl ether, 2,4-dimethyl-2,4-pentanediol or 3-methyl-3-methoxy-1-butanol; The nitrogen- and sulfur-containing solvents include one or a mixture of two of N,N-diethylformamide or dimethyl sulfoxide; The hydrocarbon solvent includes C 11 n-Alkanes or C 10 -C 13 A mixture of one or two isoalkanes.

2. The cleaning agent according to claim 1, characterized in that, The ester solvent includes one or a mixture of two or more of the following: diester, ethylene glycol diacetate, or 3-methoxy-3-methyl-1-acetate.

3. The cleaning agent according to claim 1 or 2, characterized in that, The alcohol ether solvent includes one or a mixture of two of propylene glycol butyl ether or 3-methyl-3-methoxy-1-butanol, the ester solvent includes ethylene glycol diacetate or a diester, and the nitrogen-containing and sulfur-containing solvent is N,N-diethylformamide.

4. A method for dual-solvent vapor phase cleaning of microwave component chips, characterized in that, The cleaning agent according to any one of claims 1-3 is mixed with a fluorinated solvent and the microwave component chip is cleaned by the azeotropic effect.

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