阅读说明：本技术 一种防止高温回流焊聚锡的保护剂及制备方法和使用方法 (Protective agent for preventing high-temperature reflow soldering from tin gathering, and preparation method and use method thereof ) 是由 陈春 张兵 向文胜 赵建龙 朱坤 陆兰 顾群艳 于 2020-06-05 设计创作，主要内容包括：本发明公开了一种防止高温回流焊聚锡的保护剂及制备方法和使用方法,其包括1-3wt％非离子表面活性剂、2-5wt％柠檬酸、1-2wt％硫脲以及余量的去离子水。本发明可以有效防止锡层在回流焊过程中防止堆锡、聚锡等现象；工艺简单,产品稳定,安全环保,使用方便。(The invention discloses a protective agent for preventing high-temperature reflow soldering tin gathering, a preparation method and a using method thereof, wherein the protective agent comprises 1-3 wt% of nonionic surfactant, 2-5 wt% of citric acid, 1-2 wt% of thiourea and the balance of deionized water. The invention can effectively prevent the tin layer from tin piling, tin gathering and the like in the reflow soldering process; simple process, stable product, safety, environmental protection and convenient use.)

1. The protective agent for preventing high-temperature reflow soldering from tin gathering is characterized in that: it comprises 1-3 wt% of nonionic surfactant, 2-5 wt% of citric acid, 1-2 wt% of thiourea and the balance of deionized water.

2. The protective agent for preventing high-temperature solder reflow poly-tin as claimed in claim 1, wherein: the nonionic surfactant is one or more of alkylphenol polyoxyethylene OP-10, fatty alcohol polyoxyethylene ether AEO-10 and alkyl glycoside APG.

3. A process for the preparation of the protective agent according to claim 1, characterized in that: which comprises the following steps:

1) adding two-thirds of water into a container;

2) under the condition of stirring, adding citric acid in proportion until the citric acid is completely dissolved;

3) under the condition of stirring, proportionally adding thiourea until the thiourea is completely dissolved;

4) under the condition of stirring, adding the nonionic surfactant in proportion until the nonionic surfactant is completely dissolved, and continuously stirring for 10-20 minutes;

5) adding water to required amount, and stirring.

4. A process for the preparation of the protective agent according to claim 1, characterized in that: the nonionic surfactant is one or more of alkylphenol polyoxyethylene OP-10, fatty alcohol polyoxyethylene ether AEO-10 and alkyl glycoside APG.

5. A method of using the protectant of claim 1, comprising the steps of: firstly, diluting the protective agent to 1-2 times, then putting the product into the protective agent, soaking the product for 30-120 seconds, taking the product out, cleaning the product, and drying the product.

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of electroplating, and particularly relates to a protective agent for preventing high-temperature reflow soldering from tin gathering, and a preparation method and a use method thereof.

[ background of the invention ]

Because tin has the advantages of corrosion resistance, discoloration resistance, no toxicity, easy soldering, softness, low melting point, good ductility and the like, tin is generally used as a plating material to be plated on the surface of electronic components. After the components of electronic products such as semiconductor packaging, PCB printing, passive components and the like are electroplated with tin, the tin layer is easy to discolor, pile tin and the like due to various factors in the reflow soldering process at a high temperature (265 ℃), so that the electrical property of the product is influenced, and the function failure of the product is caused.

At present, a protective agent for preventing high-temperature reflow soldering discoloration exists in the market, for example, the high-temperature reflow soldering tin layer provided by Jiangsu Aisen semiconductor materials GmbH in CN102776496A is used for preventing discoloration, namely, the preparation method and the use method thereof can effectively prevent the discoloration problem of the tin-plated layer in the high-temperature reflow soldering process. Other companies on the market have a plurality of similar products for preventing high-temperature reflow soldering discoloration, but the problems of tin accumulation and tin shrinkage of a tin layer after high-temperature reflow soldering cannot be solved in the using process, as shown in figure 1.

Therefore, it is necessary to provide a new protective agent for preventing high temperature reflow soldering poly-tin, and a preparation method and a use method thereof to solve the above problems.

[ summary of the invention ]

The invention mainly aims to provide a protective agent for preventing high-temperature reflow soldering from tin gathering, which can effectively prevent tin layer tin stacking and tin shrinking.

The invention realizes the purpose through the following technical scheme: the protective agent for preventing high-temperature reflow soldering of the poly-tin comprises 1-3 wt% of nonionic surfactant, 2-5 wt% of citric acid, 1-2 wt% of thiourea and the balance of deionized water.

Further, the nonionic surfactant is one or more of alkylphenol polyoxyethylene OP-10, fatty alcohol polyoxyethylene AEO-10 and alkyl glycoside APG.

The invention also aims to provide a preparation method of the protective agent for preventing high-temperature reflow soldering of the poly-tin, which comprises the following steps:

1) adding two-thirds of water into a container;

2) under the condition of stirring, adding citric acid in proportion until the citric acid is completely dissolved;

3) under the condition of stirring, proportionally adding thiourea until the thiourea is completely dissolved;

4) under the condition of stirring, adding the nonionic surfactant in proportion until the nonionic surfactant is completely dissolved, and continuously stirring for 10-20 minutes;

5) adding water to required amount, and stirring.

Further, the nonionic surfactant is one or more of alkylphenol polyoxyethylene OP-10, fatty alcohol polyoxyethylene AEO-10 and alkyl glycoside APG.

The invention also aims to provide a using method of the protective agent for preventing high-temperature reflow soldering tin gathering, which comprises the following steps: firstly, diluting the protective agent to 1-2 times, then putting the product into the protective agent, soaking the product for 30-120 seconds, taking the product out, cleaning the product, and drying the product.

Compared with the prior art, the protective agent for preventing high-temperature reflow soldering from tin gathering has the beneficial effects that: by adopting a unique complexing film forming principle, when the tin layer is soaked in the tin layer, a special chelating film layer can be formed on the surface of the tin layer, and when the tin layer is in a reflow soldering process at the high temperature of 265 ℃, the chelating film layer keeps the leveling of the molten tin layer by controlling the surface tension of the tin layer, so that the tin layer is ensured not to generate tin condensation phenomenon; the process is simple and effective, the product is stable, safe and environment-friendly, and the use is convenient.

[ description of the drawings ]

FIG. 1 is a diagram of a product after reflow soldering without using the protective agent of the present invention;

FIG. 2 is a diagram of a product after reflow soldering using the protecting agent of the present invention.

[ detailed description ] embodiments