No clean flux for no clean flux

No-clean flux is a new type of flux that does not contain halogen-activated agents and does not need to be cleaned after soldering. The use of this kind of flux can not only save the investment in cleaning equipment and cleaning solvents, but also reduce the pollution caused by the discharge of exhaust gas and waste water to the environment, so replacing traditional fluxes with no-clean fluxes has important economic and social benefits. To this end, many researchers at home and abroad have carried out the development of no-clean flux products.

In the early 90s of the 20th century, China's no-clean fluxes mainly relied on imports, such as Alpha Grillo RF-12A flux in the United States and NC316 flux in Japan.

In recent years, some no-clean flux products have also appeared in China.

No-clean fluxes should meet the following requirements.

1) Large wetting rate or spreading area;

2) No residue after welding;

3) After welding, the plate surface is dry and does not stick to the plate surface;

4) Have a sufficiently high surface insulation resistance;

5) Stable chemical properties at room temperature, no corrosion after welding;

6) Ion residue should meet the requirements of no-cleaning;

8) No solder balls, no bridging;

9) Non-toxic, no serious odor, no environmental pollution, safe operation;

lo) Good weldability, simple and easy to operate;

11) It can be evenly coated by foaming and spraying.

The use of solders containing solvent cleaning and water cleaning fluxes for soldering will bring environmental pollution to varying degrees, especially CFC-type solvents will emit ODS, which has a great impact on the ozone layer, so countries have formulated corresponding laws to prohibit their use. Non-CFC solvents are costly, present with VOC contamination and safety concerns. However, the investment in water cleaning equipment is large, and the operation cost increases due to the additional cleaning process, and the problem of wastewater discharge is also more serious.

Compared with solvent-cleaning and water-cleaning fluxes, solders containing no-clean fluxes have the advantages of no environmental pollution, low cost, short production cycle, and simple process. No-clean flux will be the trend of industry development.

The no-clean flux should be after soldering, there should be no residue on the surface of the electronic product, there should be no corrosion of the soldering product, and the smoke should be less during soldering.

The flux can be cleaned with a no-clean cleanable cleaner and a no-clean non-cleanable cleaner.

For the purtable flux Zheng Ze, there is no residue after cleaning, and the basic performance of the appliance can be achieved. The non-cleanable flux, after the soldering is completed, is covered on the board.

The residue on the board cannot be cleaned with cleaning agent, and it is easy to form a white residue, and at the same time, it will cause the insulation resistance of the board surface.

The value decreases, affecting the test pass rate.

Residues are difficult to avoid in welding, depending on the welding consumables and welding processes.

You can call the lack of shed to choose the corresponding flux. There are quite a wide range of fluxes on the market, and if the consumables allow, no-clean fluxes are preferred, and other types of fluxes are considered. If the residue damages the product, then choose a cost-effective cleaning method.

The material preparation of flux is different for each manufacturer, and the washing water for cleaning the board is also different, which is generally formulated by the manufacturer.

Rosin washable cleaner, rosin non-washable cleaner, no-wash washable and no-wash non-cleanable cleaner, etc. For the washable flux, there is no residue after cleaning, and the basic performance of the appliance can be achieved. However, after the welding of the non-cleanable flux, the residue on the board surface cannot be cleaned with cleaning agent, and it is easy to form a white residue, which will lead to the decrease of the insulation resistance value of the board surface and affect the test pass rate.

Rosin washable cleaner split segment ruler, rosin non-washable cleaner, no-wash washable and no-wash non-cleanable cleaner, etc. For the washable flux, there is no residue after cleaning, and the basic performance of the appliance can be achieved. However, after the welding of the non-cleanable flux, the residue on the board surface cannot be cleaned with a cleaning agent, and it is easy to form a white residue, which will lead to a decrease in the insulation resistance value of the board surface and affect the test pass rate.

Fluxes are chemicals that help and facilitate the soldering process while protecting and preventing oxidation. Fluxes can be classified as solids, liquids, and gases. There are mainly auxiliary heat conduction, removal of oxides, reducing the surface tension of the welded material, removing the surface oil stain of the welded material, increasing the welding area, preventing re-oxidation, etc., in which there are two key roles:

Oxide removal and reduction of surface tension of the welded material.

The special active system of no-clean flux is no-clean after soldering, with stronger activity and perfect wave soldering effect. Product advantages: remove the oxide on the surface of the PCB board, due to the excellent cleaning and lubrication effect, strong soldering ability, full solder joints, and good gloss.

Environmentally friendly, non-toxic, non-corrosive, no need to clean. It is non-destructive to all electronic components. There is less residue after welding, high cleanliness of the board surface, low viscosity, fast drying, and easy post-welding operation.

It has fast drying, matte and full structure of solder joints, can remove oxides, can wet the metal welding surface and form a protective layer, prevent metal re-oxidation, and keep the metal welding surface clean.

No-clean flux 398A requires that the smoke is less when the product is welded, and there should be no residue on the surface of the product after soldering the electronic product, which is less than the general flux.

1.No-clean flux.

That is, the surface of the flux after soldering.

Relatively clean, in the requirements are not high or usually do not need to wash, the board surface is also relatively clean. However, in case of special circumstances, it is still necessary to clean the board surface.

2.Cleaning flux is also called resin flux, that is, rosin.

Flux. The surface of the plate is usually dirty after welding, but it also has an advantage that as long as the plate is not required to be particularly clean, the rosin flux can also be used without washing the board, and the rosin flux can be formed into a protective layer immediately after welding, which plays an insulating role.

1.No-clean flux means that the plate surface of the flux is relatively clean after soldering, and the board surface is relatively clean when the requirements are not high or there is usually no need to wash the board.

However, in case of special circumstances, it is still necessary to clean the board surface.

2.Cleaning flux is also called resin flux, that is, rosin flux.

The plate surface is usually dirty after welding, but it also has the advantage that as long as the board surface is not particularly clean, the rosin flux can also be used without washing, and the rosin flux can be formed into a protective layer immediately after welding, which plays an insulating role.

After soldering flux DXT-398A, choose the best manufacturer's supporting materials to clean.

Here are four examples of common problems:

Problem 1: The PCB surface turns white after cleaning.

The reasons for this could be the following:

1.Non-cleanable type of flux for soldering;

2.The cleaning agent has been used dirty;

The flux of the pre-coating of the board is insoluble with the flux of the current flux.

Problem 2: There is residue on the IC feet of the patch after cleaning.

Possible causes of this kind of problem:

1.The solder paste used in the patch is not washable.

2.Ultrasonic cleaning time is insufficient.

3.The cleaning agent has been used dirty;

Problem 3: The IC feet are black after cleaning.

The reasons for this could be:

1.The detinning flux contains excess halogens.

2.Solder paste corrodes, causing oxidation of the pins.

Problem 4: After cleaning, the PCB board surface speaks, and there are water ripples remaining.

The reasons for this could be:

1.The cleaning agent has been used for too long.

2.The detergent contains an excess of water.

3.After cleaning, there is air moisture in the drying process, and condensation causes pollution solutions:

Question 1:1Transposition-cleaning flux.

2.Replace the cleaner with a new one, and pay attention to frequent replacement to maintain the activity of the cleaner3Adjust the cleanability of the cleaning agent.

Question 2:1Switch to a washable solder paste.

2.Increase the cleaning time of ultrasonic waves appropriately.

3.Switch to a new cleaner to maintain the cleaning power of the detergent.

Solution: Problem 3:

1.Use halogen-free or special flux to de-IC tin.

2.Smoother, less corrosive solder paste.

Solution: Problem 4:

1.Pay attention to how often you change the cleaning agent.

2.Check the ** of the water, colleagues check the ultrasonic, the water separator of the cleaning machine 3Try to avoid the effects of moisture in the air.

Components Dosage (g l) isopropanol 50 100 ethylene glycol 50 100 oxidized polyethylene wax 1 5 glutaric acid 1 5 tetraethylene glycol dimethyl ether 1 5 hydrogenated rosin 50 100 ethyl palmitate 20 50 benzotriazole 1 5 lauryl ethoxylates 1 5 calcium chloride 1 5 methanol 50 100 ethylenediamine 1 5 water Balance.