Film forming aid for water-based soldering ball surface treatment agent

Abstract

The application provides a film forming aid for water-based soldering ball surface treatment agent, and relates to the technical field of metal surface treatment.The film forming aid is composed of diethylene glycol methyl ether, diethylene glycol monoallyl ether and benzyl glycidyl ether, and a water-based soldering ball surface treatment agent prepared from the film forming aid and raw materials such as azole film forming agent, dispersant, complexing agent, non-ionic surfactant, penetrating agent and deionized water can form an oxidation-resistant film on the surface of the soldering ball, the oxidation-resistant film is not easy to fall off in the process of collision, the problem that the soldering ball surface is easy to turn yellow and black due to oxidation is solved, the film forming speed is fast, the efficiency is high, the oxidation resistance of the soldering ball surface can be effectively improved, and the storage and service life of the soldering ball are prolonged.The water-based soldering ball surface treatment agent has simple preparation process, is convenient to use, and has good physical stability after film forming.

Description

Technical Field

[0001] This invention relates to the field of metal surface treatment technology, and in particular to a film-forming aid for water-based solder ball surface treatment agents. Background Technology

[0002] As integrated circuits develop towards higher density, higher integration, miniaturization, and thinner profiles, solder balls, as key materials in advanced packaging processes such as Ball Grid Array (BGA) and Chip Scale Package (CSP), meet the packaging requirements of increasing I / O counts, wiring density, and substrate layer counts in integrated circuits. They are widely used in the packaging of high-end IC chips such as CPUs and GPUs. The role of solder balls is to achieve electrical and mechanical connections between chip components, and their quality directly affects the reliability of electronic product packaging. Therefore, high quality requirements are placed on solder balls in terms of brightness, roundness, conductivity, and mechanical connection performance.

[0003] However, in actual production and application, it has been found that the surface of solder balls is extremely prone to oxidation, leading to yellowing and blackening, which seriously affects the reliability of assembly. Therefore, it is necessary to protect the prepared solder balls to ensure the stability of high-quality solder balls during storage, transportation, and use.

[0004] Currently, there are three main methods for anti-oxidation treatment of solder ball surfaces. First, adding trace elements such as Ge and P increases the solder ball's anti-oxidation properties. However, this method leads to an increase in the liquidus temperature of the alloy, negatively impacting the solder ball's microstructure and welding performance. Second, using an inert gas protection method, the prepared solder balls are sealed by filling them with nitrogen gas. However, if the gas is not used promptly after unsealing, the solder ball surface will quickly oxidize, resulting in material waste. Third, using surface treatment agents, an organic surface treatment agent forms a heat-sensitive, volatile organic film on the solder ball surface, isolating it from the air and achieving anti-oxidation. However, organic solvents have high viscosity, causing solder balls to easily stick together. Furthermore, the formed organic film mainly relies on the physical adhesion of the surface treatment agent, making it easily detached during severe impacts and failing to provide effective anti-oxidation.

[0005] Therefore, overcoming the above problems and providing a solder ball surface treatment agent that has a faster film formation speed, higher efficiency, is more convenient to use, prevents solder ball surface adhesion after treatment, achieves the purpose of solder ball surface anti-oxidation, and improves the stability of solder ball storage, transportation and use is one of the important problems that need to be solved at present. Summary of the Invention

[0006] To overcome the above problems, this invention provides a film-forming aid. A water-based solder ball surface treatment agent prepared using this film-forming aid as a raw material can effectively improve the antioxidant properties of the solder ball surface, extend its storage and service life, simplify the preparation process, facilitate use, maintain a high film-forming speed, and exhibit good physical stability. The film-forming aid of this invention is composed of diethylene glycol methyl ether, diethylene glycol monoallyl ether, and benzyl glycidyl ether in a weight ratio of 1:(0.1-0.3):(0.5-2).

[0007] Another object of the present invention is to provide a water-based solder ball surface treatment agent prepared using the aforementioned film-forming aid as the main raw material, wherein the surface treatment agent comprises the following raw materials: 1-5 wt% azole film-forming agent, 1-2 wt% film-forming aid, 0.1 wt%-3 wt% dispersant, 0.01 wt%-1 wt% complexing agent, 0-1 wt% nonionic surfactant, 0.01 wt%-0.5 wt% penetrant, and the balance being deionized water.

[0008] Further, the azole film-forming agent is one or more of benzotriazole, 1,2,4-triazole, pyrazole, 5-phenyl-1H-tetrazole, benzimidazole, benzothiazole, 2-mercaptobenzimidazole, 2-aminobenzimidazole, 2-mercaptobenzothiazole, 5-aminotetrazole, methylbenzotriazole, 3-amino-1,2,4-triazole, and 3,5-diamino-1,2,4-triazole.

[0009] Preferably, the azole film-forming agent is composed of 2-mercaptobenzothiazole and 5-phenyl-1H-tetrazole in a weight ratio of 1:2.

[0010] Further, the dispersant is one or more of polyacrylic acid, polyacrylamide, fatty acid polyethylene glycol ester, polyethylene glycol 8000, polyethylene glycol oleate, 4-methyl-2-pentanol, dimethyl silicone oil, oxidized polyethylene, and sodium dodecyl sulfate.

[0011] Preferably, the dispersant is polyacrylic acid.

[0012] Further, the complexing agent is one or more of the following: citric acid, azelaic acid, succinic acid, oxalic acid, aminotrimethylphosphonic acid, sodium ethylenediaminepentamethylphosphonate, diethylenetriaminepentamethylphosphonic acid, glutamic acid, arginine, glycine, triethanolamine, tetraethylammonium hydroxide, ethylenediamine, and sodium ethylenediaminetetramethylphosphonate.

[0013] Preferably, the complexing agent is triethanolamine.

[0014] Furthermore, the nonionic surfactant is one or more of the following: fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, sorbitan monooleate, alkylolamide, cocoyl diethanolamide, glyceryl stearate, lauric diethanolamide, and isomeric tridecyl alcohol polyoxyethylene ether.

[0015] Furthermore, the nonionic surfactant is composed of alkylphenol polyoxyethylene ether OP-10 and fatty alcohol polyoxyethylene ether AEO-9 in a weight ratio of 1:1.2.

[0016] Furthermore, the penetrant is one or more of the following: isooctyl alcohol polyoxyethylene ether phosphate (AEP), sodium isooctyl alcohol polyoxyethylene ether phosphate (OEP70), fatty alcohol polyoxyethylene ether (JFC), diisooctyl maleate sulfonate (T), and sodium dibutylnaphthalene sulfonate.

[0017] Preferably, the penetrant is polyoxyethylene ether JFC-2.

[0018] This invention also provides a method for preparing the water-based solder ball surface treatment agent, comprising the following steps:

[0019] S1. Mix diethylene glycol methyl ether, diethylene glycol monoallyl ether and benzyl glycidyl ether in a certain proportion to obtain mixture A;

[0020] S2. Dissolve the complexing agent and nonionic surfactant in an appropriate amount of deionized water to obtain mixture B;

[0021] S3. Add mixture B to mixture A and stir continuously. Heat the solution to 55°C, add azole film-forming agent, mix evenly, and let stand to room temperature to obtain mixture C.

[0022] S4. Add dispersant, penetrant and remaining deionized water to solution C in sequence, mix well to obtain water-based solder ball surface treatment agent.

[0023] In the water-based solder ball surface treatment agent of the present invention, 2-mercaptobenzothiazole can adsorb onto the metal atom vacancies on the solder ball surface through its S group, thereby protecting the solder ball surface. 5-phenyl-1H-tetrazazole can share electron pairs with the metal atom vacancies on the solder ball surface through its N group, achieving adsorption film formation on the solder ball surface. Simultaneously, diethylene glycol methyl ether and diethylene glycol monoallyl ether are synergistically miscible with water and organic matter, providing a solubilizing effect and solving the layering problem of the water-based solder ball surface treatment agent. Benzyl glycidyl ether exhibits good chemical stability and low volatility, improving the system stability of the water-based solder ball surface treatment agent.

[0024] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0025] (1) The present invention utilizes chemical adsorption to form a protective film on the surface of the solder ball, making it less likely to fall off during collision;

[0026] (2) The solder balls do not stick together after coating, which solves the problem of yellowing and blackening of the solder ball surface due to oxidation;

[0027] (3) The water-based solder ball surface treatment agent provided by the present invention has a fast film formation speed and high efficiency, which can effectively improve the anti-oxidation performance of the solder ball surface and extend its storage and service life;

[0028] (4) The water-based solder ball surface treatment agent of the present invention has a simple preparation process, is easy to use, and has good physical stability after film formation. Attached Figure Description

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] Figure 1 This is the SEM image of the control group in Test Example 2 of this invention;

[0031] Figure 2 The above are SEM images of the experimental group in Test Example 2 of this invention;

[0032] Figure 3 This is a SEM image of the control group after the high-temperature experiment in Test Example 2 of this invention;

[0033] Figure 4 This is a SEM image of the experimental group after the high-temperature experiment in Test Example 2 of this invention;

[0034] Figure 5 This is a SEM image of the control group after the collision test in Test Example 2 of this invention;

[0035] Figure 6 This is a SEM image of the experimental group after the collision test in Test Example 2 of this invention. Implementation

[0036] The technical solution provided by the present invention will be further described below with reference to the embodiments. Example

[0037] A water-based solder ball surface treatment agent is composed of the following raw materials in weight percentage: 3.5% azole film-forming agent, 2% film-forming aid, 0.5% triethanolamine complexing agent, 1.5% polyacrylic acid dispersant, 0.5% nonionic surfactant, 0.2% polyoxyethylene ether JFC-2 penetrant, and the remainder is deionized water;

[0038] The azole film-forming agent is composed of 2-mercaptobenzothiazole and 5-phenyl-1H-tetrazole in a weight ratio of 1:2.

[0039] The nonionic surfactant is composed of alkylphenol polyoxyethylene ether OP-10 and fatty alcohol polyoxyethylene ether AEO-9 in a weight ratio of 1:1.2.

[0040] The film-forming aid is composed of diethylene glycol methyl ether, diethylene glycol monoallyl ether, and benzyl glycidyl ether in a weight ratio of 1:0.2:0.5.

[0041] The preparation steps of this water-based solder ball surface treatment agent are as follows:

[0042] S1. Mix diethylene glycol methyl ether, diethylene glycol monoallyl ether and benzyl glycidyl ether in a certain proportion to obtain mixture A;

[0043] S2. Dissolve the complexing agent and nonionic surfactant in an appropriate amount of deionized water to obtain mixture B;

[0044] S3. Add mixture B to mixture A and stir continuously. Heat the solution to 55°C, add azole film-forming agent, mix evenly, and let stand to room temperature to obtain mixture C.

[0045] S4. Add dispersant, penetrant and remaining deionized water to solution C in sequence, mix well to obtain water-based solder ball surface treatment agent.

[0046] Comparative Example 1

[0047] Same as Example 1, except that the film-forming aid is diethylene glycol methyl ether.

[0048] Comparative Example 2

[0049] Same as Example 1, except that the film-forming aid is composed of diethylene glycol methyl ether and diethylene glycol monoallyl ether in a weight ratio of 1:0.1.

[0050] Comparative Example 3

[0051] Same as Example 1, except that the film-forming aid is composed of diethylene glycol methyl ether and diethylene glycol monoallyl ether in a weight ratio of 1:0.2.

[0052] Comparative Example 4

[0053] Same as Example 1, except that the film-forming aid is composed of diethylene glycol methyl ether and diethylene glycol monoallyl ether in a weight ratio of 1:1.

[0054] Comparative Example 5

[0055] Same as Example 1, except that the film-forming aid is composed of diethylene glycol methyl ether, diethylene glycol monoallyl ether and benzyl glycidyl ether in a weight ratio of 1:0.2:0.2.

[0056] Test Example 1

[0057] The appearance of the products obtained in the examples and comparative examples was observed, and the results are as follows:

[0058] The product in Example 1 did not separate into layers, and remained unchanged in color after 24 hours. The product in Comparative Example 5 did not separate into layers, but turned slightly yellow after 24 hours.

[0059] The product of Comparative Example 1 had a pale yellow insoluble substance at the bottom; the product of Comparative Example 2 was yellow and contained a small amount of insoluble substance; the product of Comparative Example 3 was basically dissolved and did not separate into layers, but turned yellow after 24 hours; the product of Comparative Example 4 did not separate into layers and turned yellow after 24 hours.

[0060] Therefore, the ratio of diethylene glycol methyl ether, diethylene glycol monoallyl ether, and benzyl glycidyl ether in the film-forming aid should be 1:0.2:0.5 to ensure the stability and solubility of the surface treatment agent.

[0061] Meanwhile, in some embodiments, when the weight ratio of diethylene glycol methyl ether, diethylene glycol monoallyl ether and benzyl glycidyl ether in the film-forming aid is between 1:(0.1-0.3):(0.5-2), the effect is the same as in Example 1.

[0062] Test Example 2

[0063] Take equal weights of newly opened solder balls and divide them into two groups. One group is left untreated as a control group, while the other group is immersed in the water-based surface treatment agent from Example 1 for 10 minutes, followed by cleaning and drying, serving as the experimental group. Surface color difference, high temperature, and impact tests were performed on both groups of solder balls. The results are as follows:

[0064] Changes in the appearance of the solder ball surface (after 24 hours) Color difference variation on the surface of solder balls (ΔE) Solder ball surface after high temperature test Color difference change on the surface of solder balls after high-temperature experiment (ΔE) solder ball surface after impact test Color difference change on the surface of solder balls after impact test (ΔE) control group darken -14.80 black -22.73 black -18.45 experimental group No significant changes -2.04 No significant changes -3.33 No significant changes -2.18

[0065] Meanwhile, combined with the SEM images of the control group and the experimental group, it can be seen that the brightness of the solder ball surface after being soaked in the water-based surface treatment agent of the present invention did not change significantly, the color difference range was small and could not be distinguished by the naked eye, and the color difference of the solder ball surface after high temperature and collision test was still very small. The SEM results show that after soaking in the surface treatment agent, an adsorption protective film can be formed on the surface of the solder ball, preventing the surface of the solder ball from oxidizing and turning black or yellow. Example

[0066] Same as Example 1, except that: the azole film-forming agent is composed of 2-mercaptobenzothiazole and 5-aminotetrazole in a weight ratio of 1:2.

[0067] Comparative Example 6

[0068] Same as Example 1, except that: the azole film-forming agent is composed of 2-mercaptobenzothiazole and 3-amino-1,2,4-triazole in a weight ratio of 1:2.

[0069] The product in Example 2 did not separate into layers, nor did it separate into layers or change color after being left for 24 hours. The product in Comparative Example 6 also did not separate into layers, nor did it separate into layers or change color after being left for 24 hours. Compared with newly opened solder balls, the color difference change on the surface of the solder balls after immersion in the coating solution of Example 2 and Comparative Example 6 for 10 minutes, as well as after high temperature and impact tests, was less than 2.5.

[0070] Therefore, it can be seen that the film-forming agent, which uses 2-mercaptobenzothiazole and nitrazole organic molecules in synergy, can achieve stable film formation on the surface of solder balls, and its effect is the same as that in Example 1. Example

[0071] Same as Example 1, except that the nonionic surfactant is composed of alkylphenol polyoxyethylene ether OP-10 and fatty alcohol polyoxyethylene ether AEO-7 in a weight ratio of 1:1.2.

[0072] Comparative Example 7

[0073] Same as Example 1, except that the nonionic surfactant is composed of nonylphenol polyoxyethylene ether NP-10 and fatty alcohol polyoxyethylene ether AEO-9 in a weight ratio of 1:1.2.

[0074] The product in Example 3 did not separate into layers, nor did it separate into layers or change color after being left for 24 hours. The product in Comparative Example 7 also did not separate into layers, nor did it separate into layers or change color after being left for 24 hours. Compared with newly opened solder balls, the color difference change on the surface of the solder balls after immersion in the coating solution of Example 3 and Comparative Example 7 for 10 minutes, as well as after high temperature and impact tests, was less than 2.5.

[0075] Therefore, it can be seen that using two nonionic surfactants in combination can ensure the stability of the coating effect on the solder ball surface, and the effect is the same as in Example 1.

[0076] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A film-forming aid, characterized in that, It is composed of diethylene glycol methyl ether, diethylene glycol monoallyl ether and benzyl glycidyl ether in a weight ratio of 1:(0.1-0.3):(0.5-2).

2. A water-based solder ball surface treatment agent composed of the film-forming aid described in claim 1, characterized in that, It includes the following raw materials: 1-5 wt% azole film-forming agent, 1-2 wt% film-forming aid, 0.1 wt%-3 wt% dispersant, 0.01 wt%-1 wt% complexing agent, 0-1 wt% nonionic surfactant, 0.01 wt%-0.5 wt% penetrant, and the balance being deionized water.

3. The water-based solder ball surface treatment agent according to claim 2, characterized in that, The azole film-forming agent is one or more of benzotriazole, 1,2,4-triazole, pyrazole, 5-phenyl-1H-tetrazole, benzimidazole, benzothiazole, 2-mercaptobenzimidazole, 2-aminobenzimidazole, 2-mercaptobenzothiazole, 5-aminotetrazole, methylbenzotriazole, 3-amino-1,2,4-triazole, and 3,5-diamino-1,2,4-triazole.

4. The water-based solder ball surface treatment agent according to claim 2, characterized in that, The dispersant is one or more of the following: polyacrylic acid, polyacrylamide, fatty acid polyethylene glycol ester, polyethylene glycol 8000, polyethylene glycol oleate, 4-methyl-2-pentanol, dimethyl silicone oil, oxidized polyethylene, and sodium dodecyl sulfate.

5. The water-based solder ball surface treatment agent according to claim 2, characterized in that, The complexing agent is one or more of the following: citric acid, azelaic acid, succinic acid, oxalic acid, aminotrimethylphosphonic acid, sodium ethylenediaminepentamethylphosphonate, diethylenetriaminepentamethylphosphonic acid, glutamic acid, arginine, glycine, triethanolamine, tetraethylammonium hydroxide, ethylenediamine, and sodium ethylenediaminetetramethylphosphonate.

6. The water-based solder ball surface treatment agent according to claim 2, characterized in that, The nonionic surfactant is one or more of the following: fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, sorbitan monooleate, alkylolamide, cocoyl diethanolamide, glyceryl stearate, lauric diethanolamide, and isomeric tridecyl alcohol polyoxyethylene ether.

7. The water-based solder ball surface treatment agent according to claim 2, characterized in that, The penetrant is one or more of the following: isooctyl alcohol polyoxyethylene ether phosphate (AEP), sodium isooctyl alcohol polyoxyethylene ether phosphate (OEP70), fatty alcohol polyoxyethylene ether (JFC), diisooctyl maleate sulfonate (T), and sodium dibutylnaphthalene sulfonate.

8. The method for preparing the water-based solder ball surface treatment agent according to any one of claims 2-7, characterized in that, Includes the following steps: S1. Mix diethylene glycol methyl ether, diethylene glycol monoallyl ether and benzyl glycidyl ether in a certain proportion to obtain mixture A; S2. Dissolve the complexing agent and nonionic surfactant in an appropriate amount of deionized water to obtain mixture B; S3. Add mixture B to mixture A and stir continuously. Heat the solution to 55°C, add azole film-forming agent, mix evenly, and let stand to room temperature to obtain mixture C. S4. Add dispersant, penetrant and remaining deionized water to solution C in sequence, mix well to obtain water-based solder ball surface treatment agent.

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