阅读说明：本技术 一种免清洗助焊剂及其制备方法 (No-clean 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％,戊二酸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；不含有松香树脂,不产生粘性残留物,不会因焊接后的助焊剂残留造成测试故障,焊接效果更好；不含有铅,具有优良的可焊性,可以耐受较高的预热温度、较长的焊接时间,并具有较高的工作温度,焊接效果好；完全不包含无卤素助焊剂,避免气味过大。(The invention discloses a cleaning-free soldering flux and a preparation method thereof, wherein the 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 glutaric 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 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, and no residue is left on the surface of the board; the soldering flux does not contain rosin resin, does not generate viscous residues, does not cause testing faults due to the residues of the soldering flux after soldering, and has better soldering effect; the lead-free soldering flux does not contain lead, has excellent solderability, can resist higher preheating temperature and longer soldering time, has higher working temperature and good soldering effect; no halogen-free flux is contained, and excessive odor is avoided.)

1. The cleaning-free soldering flux is characterized by comprising the following components:

60 to 75 percent of ethanol,

20 to 30 percent of isopropanol,

1 to 15 percent of n-butyl acetate,

1 to 10 percent of glutaric acid,

1 to 5 percent of dicarboxylic acid,

1-15% of ethylene glycol ethyl ether.

2. The no-clean flux according to claim 1, wherein said dicarboxylic acid is glutaconic acid.

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

s01; weighing the components according to the proportion;

s02: putting glutaric acid, dicarboxylic acid and a proper amount of isopropanol into a container, and heating until the solid is fully dissolved;

s03: cooling, adding ethanol and n-butyl acetate, and fully stirring to obtain an intermediate;

s04: and pumping the intermediate into a reaction kettle, adding ethanol, isopropanol and ethylene glycol ethyl ether, and uniformly stirring to obtain the cleaning-free soldering flux.

4. The method for preparing the no-clean soldering flux according to claim 3, wherein in the step S02, the heating temperature is 60-70 ℃.

5. The method for preparing the no-clean soldering flux according to claim 3, wherein in the step S02, the heating temperature is 65-70 ℃.

6. The method of claim 3, wherein in step S02, the heating temperature is 65 ℃.

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

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

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

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

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

Technical Field

The invention relates to a soldering flux, in particular to a cleaning-free soldering flux and a preparation method thereof.

Background

With the development of electronic products, the quantity of flux required in the assembly of circuit boards is increasing. The solvent of the traditional no-clean soldering flux contains rosin resin, and the defect that viscous residues are easily generated to cause test faults due to the residual soldering flux after soldering. The traditional cleaning-free soldering flux contains lead and halogen, and due to the environmental protection requirement and the requirement of electronic products, the lead-free halogen-free soldering flux is used for reducing the ionic pollution on the surface of the circuit board.

Disclosure of Invention

The invention aims to provide a cleaning-free 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 cleaning-free soldering flux which comprises the following components:

60 to 75 percent of ethanol,

20 to 30 percent of isopropanol,

1 to 15 percent of n-butyl acetate,

1 to 10 percent of glutaric acid,

1 to 5 percent of dicarboxylic acid,

1-15% of ethylene glycol ethyl ether.

Further, the dicarboxylic acid is preferably glutaconic acid.

The invention also provides a preparation method of the cleaning-free soldering flux, which comprises the following steps:

s01; weighing the components according to the proportion;

s02: putting glutaric acid, dicarboxylic acid and a proper amount of isopropanol into a container, and heating until the solid is fully dissolved;

s03: cooling, adding ethanol and n-butyl acetate, and fully stirring to obtain an intermediate;

s04: and pumping the intermediate into a reaction kettle, adding ethanol, isopropanol and ethylene glycol ethyl ether, and uniformly stirring to obtain the cleaning-free soldering flux.

Further, in step S02, the heating temperature is 60 to 70 degrees.

Further, in step S02, the heating temperature is 65 to 70 degrees.

Further, in step S02, the heating temperature is 65 degrees.

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

Furthermore, the cleaning-free soldering flux is a foaming cleaning-free soldering flux.

Furthermore, the cleaning-free soldering flux is a spray type cleaning-free soldering flux.

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

Further, the cleaning-free soldering flux is used for maintenance and manual soldering.

The cleaning-free soldering flux provided by the technical scheme of the invention has the following physical characteristics:

the technical scheme of the invention provides a test of the cleaning-free soldering flux, which comprises the following steps:

1. density test

The density of the 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 no-clean soldering flux can be adjusted by a 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 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, and cleaning is not needed.

2. The soldering flux does not contain rosin resin, does not generate viscous residues, does not cause testing faults due to the residues of the soldering flux after soldering, and has better soldering effect.

3. The lead-free soldering flux does not contain lead, has excellent solderability, can resist higher preheating temperature and longer soldering time, has higher working temperature and has good soldering effect.

4. No halogen-free soldering flux is contained, the excessive smell is avoided, and the requirements of EN, Bellcore and IPC are met.

Drawings

FIG. 1 is a temperature profile of an exemplary embodiment of the present 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 no-clean flux is provided, which comprises the following components: 60-75% of ethanol, 20-30% of isopropanol, 1-15% of n-butyl acetate, 1-10% of glutaric acid, 1-5% of dicarboxylic acid and 1-15% of ethylene glycol ethyl ether.

In the technical scheme, repeated experiments show that ethanol, isopropanol and n-butyl acetate in a proper proportion are used as a carrier of the no-clean soldering flux, 1-10% of glutaric acid is used as a stabilizer, 1-5% of dicarboxylic acid and 1-15% of ethylene glycol ethyl ether are used as activators, the formula maturity of the technical scheme is high, the performance is stable, the effect after welding is better, the solid content is low, the ethanol, the isopropanol, the n-butyl acetate, the glutaric acid, the dicarboxylic acid and the ethylene glycol ethyl ether are completely evaporated in the welding process, no residue exists on the plate surface, and no cleaning is needed; rosin resin is not contained, viscous residues are not generated, and the welding effect is better; the lead-free soldering flux does not contain lead, can resist higher preheating temperature and longer soldering time, has higher working temperature and has good soldering effect; no halogen-free flux is contained, and excessive odor is avoided.

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 no-clean soldering flux, comprising the following steps:

s01; weighing the components according to the proportion;

s02: putting glutaric acid, dicarboxylic acid and a proper amount of isopropanol into a container, and heating until the solid is fully dissolved;

s03: cooling, adding ethanol and n-butyl acetate, and fully stirring to obtain an intermediate;

s04: and pumping the intermediate into a reaction kettle, adding ethanol, isopropanol and ethylene glycol ethyl ether, and uniformly stirring to obtain the cleaning-free soldering flux.

In a preferred embodiment, in step S02, the heating temperature is 60 to 70 degrees.

In a preferred embodiment, in step S02, the heating temperature is 65 to 70 degrees.

In a preferred embodiment, in step S02, the heating temperature is 65 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 no-clean flux is a foaming no-clean flux.

In a preferred embodiment, the no-clean flux is an aerosol no-clean flux.

In the above embodiment, the spray type cleaning-free soldering flux spraying preferably adopts a two-stroke spraying mode, and the lower pressure is ensured during the 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 sprayable no-clean flux per pass preferably overlaps the spray area of the previous pass by 50%, which is the most uniform spray pattern. The spraying type cleaning-free soldering flux can be sprayed by feeding a paper board to pass through a spraying type cleaning-free soldering flux spraying area, and then taking out the paper board before a preheating area to check the coverage area of the spraying type cleaning-free soldering flux. In addition, the spraying type cleaning-free soldering flux can be sprayed by feeding the glass plate or the empty circuit board for testing, and then the spraying amount of the spraying type cleaning-free soldering flux is checked by taking the glass plate or the empty circuit board out of the preheating area. The condition that the spray type cleaning-free soldering flux drips cannot occur, and if the dripping phenomenon occurs, the spray type cleaning-free soldering flux is too much. Excessive spray type cleaning-free soldering flux can not be completely volatilized through the preheating area, and the welding effect can be influenced. The spraying of the spray type 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 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 no-clean flux is used for maintenance and manual soldering.

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

preheating:

according to the actual use condition of the cleaning-free soldering flux, the preheating temperature is preferably as follows: 80-130 ℃. The cleaning-free soldering flux in the embodiment of the invention can evaporate the solvent for soldering only by lower preheating temperature. The time of preheating temperature above 150 ℃ is reduced as much as possible, and the failure of the soldering flux is avoided. The preheating temperature of the hot air is avoided from being set above 150 ℃ as far as possible. Considering comprehensive factors such as flux physical property, PCB, components and welding effect, the optimal temperature rising slope of the typical embodiment of the invention is as follows: 1.5 ℃/s, minimum: 1.0 ℃/s, max: 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

The no-clean soldering flux comprises the following components: 60% of ethanol, 22% of isopropanol, 1% of n-butyl acetate, 2% of glutaric acid, 2% of dicarboxylic acid and 13% of ethylene glycol ethyl ether.

Example 2

The no-clean soldering flux comprises the following components: 74% of ethanol, 21% of isopropanol, 2% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 1% of ethylene glycol ethyl ether.

Embodiment 3

The no-clean soldering flux comprises the following components: 75% of ethanol, 20% of isopropanol, 2% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 1% of ethylene glycol ethyl ether.

Example 4

The no-clean soldering flux comprises the following components: 70% of ethanol, 20% of isopropanol, 5% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 3% of ethylene glycol ethyl ether.

Example 5

The no-clean soldering flux comprises the following components: 60% of ethanol, 20% of isopropanol, 3% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 15% of ethylene glycol ethyl ether.

Example 6

The no-clean soldering flux comprises the following components: 60% of ethanol, 20% of isopropanol, 15% of n-butyl acetate, 2% of glutaric acid, 1% of dicarboxylic acid and 2% of ethylene glycol ethyl ether.

Example 7

The no-clean soldering flux comprises the following components: 60% of ethanol, 20% of isopropanol, 14% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 14% of ethylene glycol ethyl ether.

Example 8

The no-clean soldering flux comprises the following components: 63% of ethanol, 30% of isopropanol, 4% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 1% of ethylene glycol ethyl ether.

Example 9

The no-clean soldering flux comprises the following components: 64% of ethanol, 23% of isopropanol, 3% of n-butyl acetate, 5% of glutaric acid, 3% of dicarboxylic acid and 2% of ethylene glycol ethyl ether.

Embodiment 10

The no-clean soldering flux comprises the following components: 61% of ethanol, 24% of isopropanol, 3% of n-butyl acetate, 4% of glutaric acid, 5% of dicarboxylic acid and 2% of ethylene glycol ethyl ether.

Example 11

The no-clean soldering flux comprises the following components: 64% of ethanol, 23% of isopropanol, 2% of n-butyl acetate, 5% of glutaric acid, 3% of dicarboxylic acid and 3% of ethylene glycol ethyl ether.

Example 12

The no-clean soldering flux comprises the following components: 65% of ethanol, 26% of isopropanol, 5% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 2% of ethylene glycol ethyl ether.

Example 13

The no-clean soldering flux comprises the following components: 66% of ethanol, 27% of isopropanol, 4% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 1% of ethylene glycol ethyl ether.

Embodiment 14

The no-clean soldering flux comprises the following components: 73% of ethanol, 20% of isopropanol, 1% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 4% of ethylene glycol ethyl ether.

Example 15

The no-clean soldering flux comprises the following components: 71% of ethanol, 20% of isopropanol, 1% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 6% of ethylene glycol ethyl ether.

Example 16

The no-clean soldering flux comprises the following components: 72% of ethanol, 20% of isopropanol, 1% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 5% of ethylene glycol ethyl ether.

Example 17

The no-clean soldering flux comprises the following components: 69% of ethanol, 20% of isopropanol, 6% of n-butyl acetate, 1% of glutaric acid, 3% of dicarboxylic acid and 1% of ethylene glycol ethyl ether.

Example 18

The no-clean soldering flux comprises the following components: 62% of ethanol, 20% of isopropanol, 6% of n-butyl acetate, 10% of glutaric acid, 1% of dicarboxylic acid and 1% of ethylene glycol ethyl ether.

Example 19

The no-clean soldering flux comprises the following components: 62% of ethanol, 22% of isopropanol, 1% of n-butyl acetate, 9% of glutaric acid, 4% of dicarboxylic acid and 2% of ethylene glycol ethyl ether.

Embodiment 20

The no-clean soldering flux comprises the following components: 66% of ethanol, 20% of isopropanol, 7% of n-butyl acetate, 2% of glutaric acid, 1% of dicarboxylic acid and 4% of ethylene glycol ethyl ether.

Example 21

The no-clean soldering flux comprises the following components: 61% of ethanol, 25% of isopropanol, 10% of n-butyl acetate, 2% of glutaric acid, 1% of dicarboxylic acid and 1% of ethylene glycol ethyl ether.

Embodiment 22

The no-clean soldering flux comprises the following components: 60% of ethanol, 26% of isopropanol, 1% of n-butyl acetate, 2% of glutaric acid, 1% of dicarboxylic acid and 10% of ethylene glycol ethyl ether.

Example 23

The no-clean soldering flux comprises the following components: 60% of ethanol, 28% of isopropanol, 1% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 7% of ethylene glycol ethyl ether.

Embodiment 24

The no-clean soldering flux comprises the following components: 60% of ethanol, 25% of isopropanol, 12% of n-butyl acetate, 1% of glutaric acid, 1% of dicarboxylic acid and 1% of ethylene glycol ethyl ether.

Example 25

The method for preparing the no-clean flux as in example 1, comprising the steps of:

s01: weighing the components according to the proportion;

s02: putting glutaric acid, dicarboxylic acid and a proper amount of isopropanol into a container, heating to 60 ℃, and fully dissolving solids;

s03: cooling, adding ethanol and n-butyl acetate, and fully stirring to obtain an intermediate;

s04: and pumping the intermediate into a reaction kettle, adding ethanol, isopropanol and ethylene glycol ethyl ether, and uniformly stirring to obtain the cleaning-free soldering flux.

Example 26

The method for preparing the no-clean flux of example 4 comprises the following steps:

s01: weighing the components according to the proportion;

s02: putting glutaric acid, dicarboxylic acid and a proper amount of isopropanol into a container, heating to 65 ℃, and fully dissolving solids;

s03: cooling, adding ethanol and n-butyl acetate, and fully stirring to obtain an intermediate;

s04: and pumping the intermediate into a reaction kettle, adding ethanol, isopropanol and ethylene glycol ethyl ether, and uniformly stirring to obtain the cleaning-free soldering flux.

Example 27

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

s01, calculating each component according to the production quantity to produce 2000 liters of no-clean soldering flux, and configuring as follows: a. 20 kg of glutaric acid is weighed, b, 20 kg of dicarboxylic acid is weighed, c, 34 liters of isopropanol are weighed;

s02: putting glutaric acid, dicarboxylic acid and a proper amount of isopropanol into a stainless steel container barrel, heating by using an electric furnace, controlling the temperature to be 60-70 ℃, gradually melting solid powder to form a uniform solution, and then cutting off a power supply;

s03: after cooling, 166 liters of ethanol and 100 liters of n-butyl acetate are poured in, and the mixture is fully and uniformly stirred again to obtain 340 liters of intermediate;

s04: pumping 340 liters of the intermediate into a reaction kettle, adding 1234 liters of ethanol, adding 366 liters of isopropanol, adding 60 kilograms of ethylene glycol ethyl ether, and uniformly stirring; and standing for one hour to obtain the cleaning-free 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.