阅读说明：本技术 一种中性镀锡稳定剂及其制备方法 (Neutral tin plating stabilizer and preparation method thereof ) 是由 朱志豪 谢浩威 邱红艳 于 2021-06-30 设计创作，主要内容包括：本发明公开了一种中性镀锡稳定剂及其制备方法,具体涉及电子电镀领域。所述中性镀锡稳定剂包括葡萄糖酸钠、氨基三乙酸、酒石酸钾钠、乙二胺四乙酸四钠、硼酸、氢氧化钠和纯水。所述方法包括纯水搅拌加入氢氧化钠得氢氧化钠溶液,再加入硼酸得硼酸溶液；向硼酸溶液中加入葡萄糖酸钠、氨基三乙酸、酒石酸钾钠和乙二胺四乙酸四钠,继续搅拌得中性镀锡稳定剂。由本发明方法制备的中性镀锡稳定剂,一方面可以稳定酸碱度；另一方面可以大大减少二价锡氧化,效果卓越。本发明的制备中性镀锡稳定剂的方法简单,易于工业化大生产。(The invention discloses a neutral tin plating stabilizer and a preparation method thereof, and particularly relates to the field of electronic electroplating. The neutral tin plating stabilizer comprises sodium gluconate, nitrilotriacetic acid, potassium sodium tartrate, ethylene diamine tetraacetic acid tetrasodium, boric acid, sodium hydroxide and pure water. The method comprises the steps of stirring pure water, adding sodium hydroxide to obtain a sodium hydroxide solution, and adding boric acid to obtain a boric acid solution; and adding sodium gluconate, nitrilotriacetic acid, potassium sodium tartrate and tetrasodium ethylene diamine tetraacetate into the boric acid solution, and continuously stirring to obtain the neutral tin plating stabilizer. The neutral tin plating stabilizer prepared by the method can stabilize the pH value on one hand; on the other hand, the oxidation of the divalent tin can be greatly reduced, and the effect is excellent. The method for preparing the neutral tin plating stabilizer is simple and is easy for industrial mass production.)

1. The neutral tin plating stabilizer is characterized by comprising sodium gluconate, nitrilotriacetic acid, potassium sodium tartrate, ethylenediaminetetraacetic acid tetrasodium salt, boric acid, sodium hydroxide and pure water.

2. The neutral tin plating stabilizer of claim 1, which is prepared from the following raw materials in parts by weight: 1-5 parts of sodium gluconate, 2-8 parts of nitrilotriacetic acid, 2-10 parts of potassium sodium tartrate, 1-10 parts of ethylene diamine tetraacetic acid tetrasodium salt, 2-8 parts of boric acid, 3-10 parts of sodium hydroxide and 49-89 parts of pure water.

3. A method of preparing a neutral tin plating stabilizer according to claim 1 or 2, characterized in that the method comprises the steps of:

step one, adding pure water into a stirring tank and starting stirring;

step two, adding sodium hydroxide into the pure water obtained in the step one while stirring, and stirring and dissolving to obtain a sodium hydroxide solution;

adding boric acid into the sodium hydroxide solution, and continuously stirring to obtain a boric acid solution;

and step four, sequentially adding sodium gluconate, nitrilotriacetic acid, potassium sodium tartrate and tetrasodium ethylene diamine tetraacetate into the boric acid solution, and continuously stirring to obtain the neutral tin plating stabilizer.

4. The method of claim 3, wherein the first step is performed at a stirring speed of 40-60 r/min.

5. The method of claim 3, wherein the stirring time in step three is 1 hour.

6. The method for preparing a neutral tin plating stabilizer according to claim 3, wherein the stirring speed in the third step is 40 to 60 r/min.

7. The method of claim 3, wherein the stirring time in step four is 6 hours.

8. The method of preparing a neutral tin plating stabilizer according to claim 3, wherein the stirring speed in the fourth step is 40 to 60 r/min.

Technical Field

The invention relates to the field of electronic electroplating, in particular to a neutral tin plating stabilizer and a preparation method thereof.

Background

Currently, in miniaturized KOJI (Ko) products and before the products are held with reliable functionality, the products still need to be electrochemically plated with a tin layer to maintain solderability for the subsequent process to be soldered to the circuit board, however, miniaturized products such as chip-resistor, multi-layer capacitor and chip-inductor must be plated with a neutral tin plating system to prevent the products from sticking together during plating, and stabilizers are carried on the shoulders of the system to stabilize pH and reduce oxidation of divalent tin, while most stabilizers used in the market are sodium gluconate, although sodium gluconate can reduce oxidation of divalent tin, the pH value of the system cannot be stabilized, so that the pH value is frequently regulated and controlled to cause instability of the whole system.

Disclosure of Invention

Therefore, the invention provides a neutral tin plating stabilizer and a preparation method thereof, which aim to solve the problem that the prior art can only simply reduce the oxidation of divalent tin and can not stabilize the pH value of a system.

In order to achieve the above purpose, the invention provides the following technical scheme:

according to one aspect of the invention, a neutral tin plating stabilizer is provided, and comprises sodium gluconate, nitrilotriacetic acid, potassium sodium tartrate, ethylenediaminetetraacetic acid tetrasodium salt, boric acid, sodium hydroxide and pure water.

Further, the stabilizer is prepared from the following raw materials in parts by weight: 1-5 parts of sodium gluconate, 2-8 parts of nitrilotriacetic acid, 2-10 parts of potassium sodium tartrate, 1-10 parts of ethylene diamine tetraacetic acid tetrasodium salt, 2-8 parts of boric acid, 3-10 parts of sodium hydroxide and 49-89 parts of pure water.

According to another aspect of the invention, there is provided a method for preparing the neutral tin plating stabilizer, which comprises the following steps:

step one, adding pure water into a stirring tank and starting stirring;

step two, adding sodium hydroxide into the pure water obtained in the step one while stirring, and stirring and dissolving to obtain a sodium hydroxide solution;

adding boric acid into the sodium hydroxide solution, and continuously stirring to obtain a boric acid solution;

and step four, sequentially adding sodium gluconate, nitrilotriacetic acid, potassium sodium tartrate and tetrasodium ethylene diamine tetraacetate into the boric acid solution, and continuously stirring to obtain the neutral tin plating stabilizer.

Further, the stirring speed of the first step is 40-60 r/min.

Further, in the third step, the stirring time is 1 h.

Further, the stirring speed of the third step is 40-60 r/min.

Further, in the fourth step, the stirring time is 6 hours.

Further, the stirring speed of the fourth step is 40-60 r/min.

The invention has the following advantages:

the neutral tin plating stabilizer prepared by the method can stabilize the pH value on one hand; on the other hand, the oxidation of the divalent tin can be greatly reduced, and the effect is excellent. The method for preparing the neutral tin plating stabilizer is simple and is easy for industrial mass production.

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1 neutral tin plating stabilizer and preparation method thereof

The embodiment provides a preparation method of a neutral tin plating stabilizer, which comprises the following steps:

step 1), respectively weighing 2 parts of sodium gluconate, 3 parts of nitrilotriacetic acid, 5 parts of potassium sodium tartrate, 2 parts of tetrasodium ethylenediamine tetraacetate, 5 parts of sodium hydroxide, 4 parts of boric acid and 78 parts of pure water;

step 2), adding 78 parts of pure water into the stirring tank and starting stirring, wherein the stirring speed is 40-60 r/min;

step 3), slowly adding 5 parts of sodium hydroxide to obtain a sodium hydroxide solution;

step 4), slowly adding 4 parts of boric acid into the sodium hydroxide solution; slowly stirring for 1h at the stirring speed of 40-60r/min to obtain a boric acid solution;

step 5), sequentially adding 2 parts of sodium gluconate, 3 parts of nitrilotriacetic acid, 5 parts of potassium sodium tartrate and 2 parts of tetrasodium ethylene diamine tetraacetate into the boric acid solution; and continuously stirring for 6 hours after adding, wherein the stirring speed is 40-60r/min, and thus obtaining the neutral tin plating stabilizer.

Example 2 neutral tin plating stabilizer and preparation method thereof

The embodiment provides a preparation method of a neutral tin plating stabilizer, which comprises the following steps:

step 1), respectively weighing 3 parts of sodium gluconate, 3 parts of nitrilotriacetic acid, 4 parts of potassium sodium tartrate, 3 parts of tetrasodium ethylenediamine tetraacetate, 5 parts of sodium hydroxide, 4 parts of boric acid and 78 parts of pure water;

step 2), adding 78 parts of pure water into the stirring tank and starting stirring, wherein the stirring speed is 40-60 r/min;

step 3), slowly adding 5 parts of sodium hydroxide to obtain a sodium hydroxide solution;

step 4), slowly adding 4 parts of boric acid into the sodium hydroxide solution; slowly stirring for 1h at the stirring speed of 40-60r/min to obtain a boric acid solution;

step 5), adding 3 parts of sodium gluconate, 3 parts of nitrilotriacetic acid, 4 parts of potassium sodium tartrate and 3 parts of tetrasodium ethylene diamine tetraacetate into the boric acid solution in sequence; and continuously stirring for 6 hours after adding, wherein the stirring speed is 40-60r/min, and thus obtaining the neutral tin plating stabilizer.

Example 3 neutral tin plating stabilizer and preparation method thereof

The embodiment provides a preparation method of a neutral tin plating stabilizer, which comprises the following steps:

step 1), respectively weighing 3 parts of sodium gluconate, 4 parts of nitrilotriacetic acid, 4 parts of potassium sodium tartrate, 4 parts of tetrasodium ethylenediamine tetraacetate, 5 parts of sodium hydroxide, 2 parts of boric acid and 78 parts of pure water;

step 2), adding 78 parts of pure water into the stirring tank and starting stirring, wherein the stirring speed is 40-60 r/min;

step 3), slowly adding 5 parts of sodium hydroxide to obtain a sodium hydroxide solution;

step 4), slowly adding 2 parts of boric acid into the sodium hydroxide solution; slowly stirring for 1h at the stirring speed of 40-60r/min to obtain a boric acid solution;

step 5), adding 3 parts of sodium gluconate, 4 parts of nitrilotriacetic acid, 4 parts of potassium sodium tartrate and 4 parts of tetrasodium ethylene diamine tetraacetate into the boric acid solution in sequence; and continuously stirring for 6 hours after adding, wherein the stirring speed is 40-60r/min, and thus obtaining the neutral tin plating stabilizer.

Example 4 neutral tin plating stabilizer and preparation method thereof

The embodiment provides a preparation method of a neutral tin plating stabilizer, which comprises the following steps:

step 1), respectively weighing 1 part of sodium gluconate, 2 parts of nitrilotriacetic acid, 5 parts of potassium sodium tartrate, 4 parts of tetrasodium ethylenediamine tetraacetate, 5 parts of sodium hydroxide, 5 parts of boric acid and 78 parts of pure water;

step 2), adding 78 parts of pure water into the stirring tank and starting stirring, wherein the stirring speed is 40-60 r/min;

step 3), slowly adding 5 parts of sodium hydroxide to obtain a sodium hydroxide solution;

step 4), slowly adding 5 parts of boric acid into the sodium hydroxide solution; slowly stirring for 1h at the stirring speed of 40-60r/min to obtain a boric acid solution;

step 5), sequentially adding 1 part of sodium gluconate, 2 parts of nitrilotriacetic acid, 5 parts of potassium sodium tartrate and 4 parts of tetrasodium ethylene diamine tetraacetate into the boric acid solution; and continuously stirring for 6 hours after adding, wherein the stirring speed is 40-60r/min, and thus obtaining the neutral tin plating stabilizer.

Example 5 neutral tin plating stabilizer and preparation method thereof

The embodiment provides a preparation method of a neutral tin plating stabilizer, which comprises the following steps:

step 1), respectively weighing 1 part of sodium gluconate, 2 parts of nitrilotriacetic acid, 10 parts of potassium sodium tartrate, 10 parts of tetrasodium ethylenediamine tetraacetate, 3 parts of sodium hydroxide, 2 parts of boric acid and 72 parts of pure water;

step 2), adding 72 parts of pure water into a stirring tank and starting stirring, wherein the stirring speed is 40-60 r/min;

step 3), slowly adding 3 parts of sodium hydroxide to obtain a sodium hydroxide solution;

step 4), slowly adding 2 parts of boric acid into the sodium hydroxide solution; slowly stirring for 1h at the stirring speed of 40-60r/min to obtain a boric acid solution;

step 5), sequentially adding 1 part of sodium gluconate, 2 parts of nitrilotriacetic acid, 10 parts of potassium sodium tartrate and 10 parts of tetrasodium ethylene diamine tetraacetate into the boric acid solution; and continuously stirring for 6 hours after adding, wherein the stirring speed is 40-60r/min, and thus obtaining the neutral tin plating stabilizer.

Example 6 neutral tin plating stabilizer and preparation method thereof

The embodiment provides a preparation method of a neutral tin plating stabilizer, which comprises the following steps:

step 1), respectively taking 5 parts of sodium gluconate, 8 parts of nitrilotriacetic acid, 2 parts of potassium sodium tartrate, 1 part of tetrasodium ethylenediamine tetraacetate, 10 parts of sodium hydroxide, 8 parts of boric acid and 66 parts of pure water;

step 2), adding 66 parts of pure water into the stirring tank and starting stirring, wherein the stirring speed is 40-60 r/min;

step 3), slowly adding 10 parts of sodium hydroxide to obtain a sodium hydroxide solution;

step 4), slowly adding 8 parts of boric acid into the sodium hydroxide solution; slowly stirring for 1h at the stirring speed of 40-60r/min to obtain a boric acid solution;

step 5), adding 5 parts of sodium gluconate, 8 parts of nitrilotriacetic acid, 2 parts of potassium sodium tartrate and 1 part of tetrasodium ethylene diamine tetraacetate into the boric acid solution in sequence; and continuously stirring for 6 hours after adding, wherein the stirring speed is 40-60r/min, and thus obtaining the neutral tin plating stabilizer.

Examples of the experiments

The test method is as follows: preparing tin methane sulfonate (Sn) with the same concentration²⁺12g/L) and a tin plating additive, wherein a plating solution is prepared by mixing 4% by volume of tin methanesulfonate and 5% by volume of the tin plating additive with 10% of the novel stabilizer for neutral tin plating obtained in examples 1 to 4 of the present invention, and a commercially available common conductive solution is used as a comparative example, the pH is adjusted to 3.5(pH 3.5), and a certain amount of three main-flow miniaturized passive components are prepared: respectively barrel-plating 0402 chip resistor, 0402 chip capacitor and 0402 chip inductor in prepared electroplating solution at 0.5ASD for 200 hr, andchecking for pH change, divalent tin (Sn)²⁺) Change and tetravalent tin (Sn)^{4 +}) And (4) changing. The results are shown in Table 1.

TABLE 1 variation of pH, stannous and stannic in examples 1-4 and comparative examples

Test example	Change in pH value (pH)	Divalent tin (Sn)2+)g/L	Tetravalent tin (Sn)4+)g/L
				Example 1	+0.1	-0.1	+0.1
Example 2	+0.1	-0.1	+0.1
				Example 3	+0.2	-0.0	+0.1
Example 4	+0.1	-0.1	+0.1
				Example 5	+0.1	-0.05	+0.05
Example 6	+0.05	-0.1	+0.1
				Comparative example	+0.7	-0.8	+1.0

As shown in Table 1, the novel stabilizer composition for neutral tin plating provided by the invention can stabilize the pH value and greatly reduce the oxidation of divalent tin, and has excellent effect.

Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.