阅读说明：本技术 一种水基免清洗助焊剂及其制备方法 (Water-based cleaning-free soldering flux and preparation method thereof ) 是由 刘万华 于 2021-09-26 设计创作，主要内容包括：本发明公开一种水基免清洗助焊剂及其制备方法,包括下列组成成分：乙醇60-75％,异丙醇20-30％,乙酸正丁酯1-15％,已二酸1-10％,二羧酸1-5％,乙二醇乙醚1-15％。与现有技术相比,本发明具有成熟度高,性能稳定,焊接后效果更好的特点,其有益效果是：低固体含量的水基免清洗助焊剂,在焊接过程中助焊剂的所有成分在焊接过程中全部蒸发掉,板面无残留物,不需要清洗,更加安全可靠；与传统的含有无挥发性有机物的水基免清洗助焊剂不同,本发明的技术方案在焊接时不会在某些阻焊膜上有可能会产生较多的微型锡球,焊接效果好。(The invention discloses a water-based cleaning-free soldering flux and a preparation method thereof, wherein the water-based cleaning-free soldering flux comprises the following components: 60-75% of ethanol, 20-30% of isopropanol, 1-15% of n-butyl acetate, 1-10% of adipic acid, 1-5% of dicarboxylic acid and 1-15% of ethylene glycol ethyl ether. Compared with the prior art, the invention has the characteristics of high maturity, stable performance and better effect after welding, and has the beneficial effects that: the water-based cleaning-free soldering flux with low solid content has the advantages that all components of the soldering flux are completely evaporated in the welding process, no residue is left on the surface of the board, the soldering flux does not need to be cleaned, and the soldering flux is safer and more reliable; different from the traditional water-based cleaning-free soldering flux containing non-volatile organic compounds, the technical scheme of the invention can not generate more micro solder balls on some solder masks during soldering, and has good soldering effect.)

1. The water-based no-clean soldering flux is characterized by comprising the following components:

0.5 to 5 percent of benzotriazole,

1 to 10 percent of adipic acid,

1 to 10 percent of dicarboxylic acid,

the balance being deionized water.

2. The water-based no-clean flux according to claim 1, wherein the dicarboxylic acid is preferably glutaconic acid.

3. The method for preparing the water-based no-clean soldering flux according to claim 1 or 2, comprising the following steps:

s01; weighing the components according to the proportion;

s02: putting adipic acid and dicarboxylic acid into a container, and heating until the solid is fully dissolved;

s03: cooling to obtain an intermediate;

s04: and pouring the intermediate into a reaction kettle, adding deionized water and benzotriazole, and uniformly stirring to obtain the water-based no-clean soldering flux.

4. The method for preparing the water-based no-clean soldering flux according to claim 3, wherein the heating temperature is 90-100 ℃ in step S02.

5. The method for preparing the water-based no-clean soldering flux according to claim 3, wherein in step S02, the heating temperature is 95-100 ℃.

6. The method for preparing the water-based no-clean soldering flux according to claim 3, wherein the heating temperature is 95 ℃ in step S02.

7. The method of claim 3, wherein step S02 is performed in a stainless steel container.

8. The water-based no-clean flux according to any one of claims 1-7, wherein the water-based no-clean flux is a foaming water-based no-clean flux.

9. The water-based no-clean flux according to any one of claims 1-7, wherein the water-based no-clean flux is a spray-on water-based no-clean flux.

10. The water-based no-clean flux according to claim 8, wherein the foaming water-based no-clean flux requires the use of a porous sepiolite with a thickness of 2-3 cm or more and the use of an air knife.

11. The water-based no-clean flux according to any of claims 1-10, wherein the water-based no-clean flux is used for repair and manual soldering.

Technical Field

The invention relates to a soldering flux, in particular to a water-based no-clean soldering flux.

Background

With the development of electronic products, the quantity of flux required in the assembly of circuit boards is increasing. The flux using water as the main solvent can solve the fire problem possibly caused by the flux. Most of the traditional water-based cleaning-free soldering flux contains nonvolatile organic matters, and micro solder balls can be generated during soldering, so that the soldering effect is influenced. In addition, the traditional water-based soldering flux has the defects of complex formula, unstable performance, high solid content, difficult cleaning of plate surface residues and the like.

Therefore, research and development of a water-based cleaning-free soldering flux which has the advantages of simple formula, stable performance, low solid content and no residue on the board surface is a problem which needs to be solved urgently at present.

Disclosure of Invention

The invention aims to provide a water-based no-clean soldering flux to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: the invention provides a water-based cleaning-free soldering flux, which comprises the following components:

the water-based no-clean soldering flux is characterized by comprising the following components:

0.5 to 5 percent of benzotriazole,

1 to 10 percent of adipic acid,

1 to 10 percent of dicarboxylic acid,

the balance being deionized water.

Further, the dicarboxylic acid is preferably glutaconic acid.

The invention also provides a preparation method of the water-based no-clean soldering flux, which comprises the following steps:

s01; weighing the components according to the proportion;

s02: putting adipic acid and dicarboxylic acid into a container, and heating until the solid is fully dissolved;

s03: cooling to obtain an intermediate;

s04: and pouring the intermediate into a reaction kettle, adding deionized water and benzotriazole, and uniformly stirring to obtain the water-based no-clean soldering flux.

Further, in step S02, the heating temperature is 90-100 degrees.

Further, in step S02, the heating temperature is 95-100 degrees.

Further, in step S02, the heating temperature is 95 degrees.

Further, in step S02, the container is a stainless steel container.

Further, the water-based no-clean soldering flux is a foaming water-based no-clean soldering flux.

Further, the water-based no-clean soldering flux is a spray-type water-based no-clean soldering flux.

Further, the foaming type water-based no-clean soldering flux needs to use porous sepiolite with the thickness of more than 2-3 cm and an air knife.

Further, the water-based no-clean flux is used for maintenance and manual welding.

The physical characteristics of the water-based no-clean soldering flux provided by the technical scheme of the invention are as follows:

the technical scheme of the invention provides a test of the water-based no-clean soldering flux:

1. density test

The density of the water-based no-clean soldering flux is tested by using a densimeter, the density and the soldering flux temperature are measured, and a diluent can be properly added for adjustment.

2. Titration assay

The solid content value of the water-based no-clean soldering flux can be adjusted by the thinner.

3. The test results are shown in table 1:

according to EN61190-1 (2002) and IPC J-STD-004A standards

TABLE 1

Compared with the prior art, the invention has the beneficial effects that:

1. the water-based cleaning-free soldering flux with low solid content has the advantages that all components of the soldering flux are completely evaporated in the welding process, no residue is left on the surface of the board, the cleaning is not needed, and the water-based cleaning-free soldering flux is safer and more reliable.

2. According to the technical scheme, more micro solder balls can not be generated on some solder masks during soldering, and the soldering effect is good.

3. The water-based no-clean soldering flux has the advantages of simple formula, stable performance and low solid content.

4. Different from the traditional water-based no-clean soldering flux containing non-volatile organic compounds, the soldering flux has no fire risk caused by the volatilization of the soldering flux, no emission of volatile organic compounds during the volatilization of the soldering flux, no pungent smell generated by the evaporation of the soldering flux in the production process, no diluent, no need of safety inspection before use, and can reduce the transportation, storage and insurance costs of the water-based no-clean soldering flux and reduce the consumption of the soldering flux by 30 percent.

5. The invention does not contain halogen and accords with Bellcore and IPC standards.

Drawings

FIG. 1 is a temperature profile of an exemplary embodiment of the present invention;

FIG. 2 is a solder ball display diagram of a conventional water-washed flux;

fig. 3 is a tin ball-free display diagram according to an exemplary embodiment of the invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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.

According to an exemplary embodiment of the present invention, a water-based no-clean soldering flux is provided, which comprises the following components: 0.5-5% of benzotriazole, 1-10% of adipic acid, 1-10% of dicarboxylic acid and the balance of deionized water.

In the technical scheme, repeated experiments show that deionized water is used as a carrier, 0.5-5% of benzotriazole is used as a stabilizer, 1-10% of adipic acid and 1-10% of dicarboxylic acid are used as activators, the formula of the technical scheme has high maturity, stable performance, better effect after welding and low solid content, and in the welding process, the benzotriazole, the adipic acid, the dicarboxylic acid and the deionized water are all evaporated, no residue exists on the plate surface, the cleaning is not needed, the welding effect is better, and the welding is safer and more reliable; the soldering flux is free from generating more micro solder balls during soldering by using the volatile organic compound, has good soldering effect, avoids fire risk caused by volatilization of the soldering flux, does not discharge volatile organic compounds during volatilization of the soldering flux, does not generate pungent smell caused by evaporation of the soldering flux during production, does not need diluent, does not need safety inspection before use, can reduce transportation, storage and insurance costs, and can reduce 30% of consumption of the soldering flux.

In a preferred embodiment, the dicarboxylic acid is glutaconic acid.

Through the technical scheme, the inventor finds that better welding effect can be achieved by taking glutaconic acid as an activator.

According to another exemplary embodiment of the present invention, there is also provided a method for preparing the water-based no-clean soldering flux, comprising the following steps:

s01; weighing the components according to the proportion;

s02: putting adipic acid and dicarboxylic acid into a container, and heating until the solid is fully dissolved;

s03: cooling to obtain an intermediate;

s04: and pouring the intermediate into a reaction kettle, adding deionized water and benzotriazole, and uniformly stirring to obtain the water-based no-clean soldering flux.

In a preferred embodiment, in step S02, the heating temperature is 90 to 100 degrees.

In a preferred embodiment, in step S02, the heating temperature is 95 to 100 degrees.

In a preferred embodiment, in step S02, the heating temperature is 95 degrees.

In a preferred embodiment, step S02 is performed in a stainless steel container.

In a preferred embodiment, step S02 is performed in a stainless steel container.

In a preferred embodiment, the water-based no-clean flux is a foamed water-based no-clean flux.

In a preferred embodiment, the water-based no-clean flux is a spray-on water-based no-clean flux.

In the above embodiment, the spray type water-based cleaning-free soldering flux is preferably sprayed in a two-stroke spraying mode, and the lower pressure is ensured during spraying. The transverse moving speed of the nozzle is set so as to ensure that each welding point can be sprayed twice, and the spraying is carried out from two different side surfaces each time. The spray of the water-based no-clean flux on each pass preferably overlaps the spray area on the previous pass by 50%, which is the most uniform spray pattern. The spraying of the spray type water-based no-clean soldering flux can be realized by feeding a paper board to pass through a spraying area of the spray type water-based no-clean soldering flux and then taking out the paper board before a preheating area to check the coverage area of the spray type water-based no-clean soldering flux. In addition, the spraying type water-based cleaning-free soldering flux can be sprayed by feeding the glass plate or the hollow circuit board for testing, and then the spraying amount of the spraying type water-based cleaning-free soldering flux is checked by taking the glass plate or the hollow circuit board out of the preheating area. The condition that the spray type water-based cleaning-free soldering flux drips cannot occur, and if the dripping phenomenon occurs, the spray type water-based cleaning-free soldering flux is too much. Excessive spray type water-based cleaning-free soldering flux can not be completely volatilized through a preheating area, and the soldering effect can be influenced. The spraying of the spray type water-based cleaning-free soldering flux is based on the fact that the soldering flux can uniformly cover the area needing to be welded on the circuit board and does not drip, and therefore the best welding effect is achieved.

In a preferred embodiment, the foaming water-based no-clean soldering flux needs to use porous sepiolite with the thickness of more than 2-3 cm and an air knife to ensure the foaming effect.

In a preferred embodiment, the water-based no-clean flux is used for maintenance and hand soldering.

The application method of the water-based no-clean soldering flux provided by the technical scheme of the invention comprises the following steps:

preheating:

all water must evaporate completely before the PCB enters the wave crest. The preheating temperature surface is preferably 85 ℃ to 160 ℃. The preheating temperature of the hot air is not higher than 150 ℃.

Temperature rise slope: in general: 1.5 ℃/S

Minimum: 1.0 ℃/S

Maximum: 2.5 ℃/S

Referring to FIG. 1, in an exemplary embodiment of the invention, a typical peak contact or dwell time is 3-4 seconds for a single peak weld. The twin-peak weld is one wave for 1-2 seconds and two waves for 2-4 seconds. The minimum total welding time is not less than 2 seconds. It should be noted that the wettability of the solder material affects the time required for the contact of the wave and the via filling rate.

Examples

Example 1

A water-based no-clean soldering flux comprises the following components: 0.5 percent of benzotriazole, 1 percent of adipic acid, 10 percent of dicarboxylic acid and the balance of 88.5 percent of deionized water.

Example 2

A water-based no-clean soldering flux comprises the following components: 5% of benzotriazole, 1.3% of adipic acid, 1.7% of dicarboxylic acid and the balance of deionized water.

Embodiment 3

A water-based no-clean soldering flux comprises the following components: 1% of benzotriazole, 3.5% of adipic acid, 2.5% of dicarboxylic acid and the balance of 93% of deionized water.

Example 4

A water-based no-clean soldering flux comprises the following components: 0.5 percent of benzotriazole, 8 percent of adipic acid, 1.5 percent of dicarboxylic acid and the balance of 90 percent of deionized water.

Example 5

A water-based no-clean soldering flux comprises the following components: 3% of benzotriazole, 1.5% of adipic acid, 4.5% of dicarboxylic acid and 91% of the balance of deionized water.

Example 6

A water-based no-clean soldering flux comprises the following components: 2.2 percent of benzotriazole, 5 percent of adipic acid, 3.8 percent of dicarboxylic acid and the balance of 89 percent of deionized water.

Example 7

A water-based no-clean soldering flux comprises the following components: 1% of benzotriazole, 6% of adipic acid, 5% of dicarboxylic acid and the balance 88% of deionized water.

Example 8

A water-based no-clean soldering flux comprises the following components: 3.5 percent of benzotriazole, 4 percent of adipic acid, 4 percent of dicarboxylic acid and the balance of 88.5 percent of deionized water.

Example 9

A water-based no-clean soldering flux comprises the following components: 2.5 percent of benzotriazole, 3 percent of adipic acid, 3 percent of dicarboxylic acid and the balance of 91.5 percent of deionized water.

Embodiment 10

A water-based no-clean soldering flux comprises the following components: 1.5 percent of benzotriazole, 2 percent of adipic acid, 2 percent of dicarboxylic acid and the balance of 94.5 percent of deionized water.

Example 11

A water-based no-clean soldering flux comprises the following components: 0.6 percent of benzotriazole, 2 percent of adipic acid, 1 percent of dicarboxylic acid and the balance of 96.4 percent of deionized water.

Example 12

A water-based no-clean soldering flux comprises the following components: 0.8 percent of benzotriazole, 2.2 percent of adipic acid, 1.5 percent of dicarboxylic acid and the balance of 95.5 percent of deionized water.

Example 13

A water-based no-clean soldering flux comprises the following components: 0.5 percent of benzotriazole, 1 percent of adipic acid, 1 percent of dicarboxylic acid and the balance of 97.5 percent of deionized water.

Embodiment 14

A water-based no-clean soldering flux comprises the following components: 0.8 percent of benzotriazole, 1.2 percent of adipic acid, 8 percent of dicarboxylic acid and the balance of 90 percent of deionized water.

Example 15

The method of making the water-based no-clean flux of example 1, comprising the steps of:

s01; weighing the components according to the proportion;

s02: putting adipic acid and dicarboxylic acid into a container, and heating to 90 ℃ until the solid is fully dissolved;

s03: cooling to obtain an intermediate;

s04: and pouring the intermediate into a reaction kettle, adding deionized water and benzotriazole, and uniformly stirring to obtain the water-based no-clean soldering flux.

Example 16

The method of making the water-based no-clean flux of example 11, comprising the steps of:

s01; weighing the components according to the proportion;

s02: putting adipic acid and dicarboxylic acid into a container, and heating to 95 ℃ until the solid is fully dissolved;

s03: cooling to obtain an intermediate;

s04: and pouring the intermediate into a reaction kettle, adding deionized water and benzotriazole, and uniformly stirring to obtain the water-based no-clean soldering flux.

Example 17

A preparation method of water-based no-clean soldering flux comprises the following steps:

weighing 40 kg of adipic acid and 20 kg of dicarboxylic acid, respectively pouring into a stainless steel barrel, adding 300 kg of deionized water, controlling the temperature by an electric furnace to be within the range of 90-100 ℃, uniformly stirring, turning off a power supply after solid substances are completely dissolved, and cooling to obtain an intermediate of NCFW 2020.

2. Pouring the intermediate into a reaction kettle, adding 1628 kg of deionized water and 12 kg of benzotriazole, and stirring uniformly. Standing for one hour, and performing quality inspection

S01, weighing 40 kg of adipic acid and 20 kg of dicarboxylic acid according to the production amount;

s02: putting adipic acid and dicarboxylic acid into a stainless steel container barrel, heating by using an electric furnace, controlling the temperature to be 90-100 ℃, gradually melting solid powder to form uniform solution, and then cutting off a power supply;

s03: cooling to obtain an intermediate;

s04: pouring the intermediate into a reaction kettle, adding 1628 kg of deionized water and 12 kg of benzotriazole, and uniformly stirring to obtain the water-based no-clean soldering flux.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.