Why flux when soldering

There are many different categories, types, and compositions of flux out there for soldering, just as there are many different types of solders and soldering processes.

To be assured that your PCB design is going to be manufactured correctly with the best combination of materials and processes, you need to work with a CM that has a complete understanding of all of it. Your CM should have years of experience working with these different materials and have the equipment and resources to facilitate these processes. At Tempo Automation , we do have the experience, skills, and facilities needed to manufacture your PCB.

We have been assembling and soldering circuit boards for a long time, and we will make sure that your design is built to the highest levels of quality. And to help you get started on the best path, we furnish information for your DFM checks and enable you to easily view and download DRC files.

If you want more information on how to use flux when soldering electronics, contact us. Tempo Automation Inc. Learn More. Download Now. Defining and Explaining How to Use Flux When Soldering Electronics Flux is a chemical cleaning agent used before and during the soldering process of electronic components onto circuit boards. Depending on the automated soldering process being used by your contract manufacturer, the flux will be applied in these methods: Wave Soldering: The flux used for wave soldering is usually made up of more solvents than flux used for other applications, and will be sprayed on the board prior to it going through the solder wave.

Once in place, the flux will clean the components that are to be soldered to remove any oxide layers that have formed. If the board is using a less corrosive type of flux, then the board will have to go through a pre-cleaning before the flux is applied. Solder Reflow: For boards that are going through the solder reflow process, a paste composed of a sticky flux and small spheres of metal solder is used.

This solder paste holds the parts in place until the heat of the oven causes the solder particles to reflow. Not only are the metal surfaces cleaned by the flux, but the pasty nature of the flux seals out the air preventing further oxidation. The solder paste flux also contains additives to improve the flow characteristics of the solder as it melts.

Selective Soldering: The flux used for selective soldering processes is applied either by spraying it, or by using a more precise drop jet process. Accurate quote in less than 1 day. By proceeding on our website you consent to the use of cookies. In short: flux is a chemical agent which can be roughly likened to paint primer for your solder connection. Applying flux accomplishes three things: reduces oxidation, improves electrical contact, and helps even solder flow.

Solder attaches more easily to non-oxidized metal, which will cause the solder to flow evenly on the electrical lead. Since the solder is even in the electrical lead its electrical conductivity is also improved. There are three main types of fluxes in use today: rosin flux, organic acid flux, and inorganic acid flux.

Rosin flux is the oldest and still one of the most common fluxes used for electrical components. It is only active when heated, and generally safe for unheated electrical circuits.

Rosin flux can be cleaned using an isopropyl alcohol solution. The best additional material for adhesion is pure tin. And, that is what you seek, right?

Bonding electronics with or without flux agents — what is your choice? Most consumers have no idea what flux is and what it is for. The flux is used in soldering. Workpieces that are mechanically and electrically connected to one another are referred to as soldering.

These can be various activities, such as wires that are connected on a stranded wire or components that are soldered on a circuit board. The actual function of soldering is to fill in the gaps between the workpieces so that a mechanical, electrical, and thermal connection is created in this way.

The problem with practicing this activity is that the workpieces are exposed to air for a long time and thus oxidize. When the surface is heated, this property becomes even more apparent. The oxide layer prevents the desired connection between the workpieces.

Only now does the flux come into play. This auxiliary substance is a chemical compound. With the help of this connection, no new oxide layer is created and the existing layer is removed.

A flux is a substance added during soldering, which causes better wetting of the workpiece by the solder. It removes the oxides on the surface through a chemical reaction.

The same applies to oxides that are created during the soldering process by the oxygen in the air. For work on oxidized joining partners, acidic fluxes are used soldering fluid based on hydrochloric acid, salicylic acid, acetylsalicylic acid, adipic acid, soldering grease. Residues of acidic flux must be removed as they lead to corrosion of the solder joint in the long term. The flux not only removes the oxidation but also is there to reduce the interfacial tension in order to create better and more durable solder joints.

This auxiliary material ensures that the parts to be joined are held together before they are finally soldered. The flux guarantees a good solder connection. Inside the solder wire there is at least one core that is filled with flux.

If the solder wire comes into contact with the components during soldering, the solder melts, and the flux is released, i. Of course, if the flux is burned it will no longer work. For this reason, additional flux is used. As a rule, this must also be used in order to get an optimal soldering result. It is advisable to treat the soldering surfaces beforehand with the appropriate flux, which creates a protective surface that prevents oxidation.

With conventional hand soldering, there is enough flux in the soldering wire. The choice of flux depends on whether aluminum or stainless steel is to be processed or whether electronic work is to be carried out.

In this case, high-quality flux must be used to avoid any residue or rust. Dirty parts to be joined require an acidic flux. As a result, there are differences in the dosage, so that flux is offered in tubes or even in canisters. The differences between the products are briefly explained here:. Flux is required so that the workpieces are optimally wetted by the solder during soldering. A chemical reaction removes the oxides present on the workpiece surfaces or prevents the formation of new oxides during the soldering process.

Besides, the surface tension of the liquid solder is reduced so that the solder can lie cleanly on the workpieces. Conveniently, the flux is fed to the solder joint together with the solder. For this purpose, the tin solder is built up in the shape of a tube and the flux is embedded inside. Flux is a filler metal that people use brazing, soldering, and welding processes. It helps to prevent oxidation of the surfaces of metals that you work with and need to join.

During the oxidation process, metal becomes weaker what makes it easier to be joined during soldering.