Every radio amateur or master who repairs himself, sooner or later will have to pick up a soldering iron and try it. The quality of the work performed and even the performance of the product will depend directly on the many factors that must be known about before starting work.
Correct work with a soldering iron
Despite the seeming simplicity of the soldering iron work, it is very desirable to have the initial skills of qualitative work and be able to correctly use solder with rosin.
Soldering is performed using a variety of solders. The so-called solder in the coil with rosin is perhaps the most popular. When performing work related to soldering, solder is used. The amount of tin and lead contained in it is 60 and 40%, respectively. This alloy melts at 180 g.
What is necessary for working with soldering iron:
- The soldering iron itself;
The heated solder creates a sufficient internal connection with metals such as copper, brass, silver, etc., if the following conditions are met:
- Surfaces of parts must be stripped of oxides.
- The part in the place of soldering is warmer than the melting point of the solder itself.
- During operation, the place of soldering is required to be protected from the effects of oxygen, various fluxes are used for this. They create a protective film directly above the place of soldering.
A book on how to solder can be read and understood, but soldering skills can only be obtained in practice.
Tricks and the secrets of working with a soldering iron
After the solder began to melt, they can already be soldered. To do this, cover the tip of the soldering iron with a thin layer of solder, and then wipe it thoroughly against a damp sponge. So remove the remaining solder from work with rosin. It will not be superfluous to take the habit of wiping the sting of a wet sponge every time after soldering.
Before you start to solder the radio parts, it must be prepared. It is necessary to bend its terminals in such a way that the piece freely enters the holes intended for it.
Beginners without work experience often touch the soldering point with the tip of the soldering iron tip. And you need to keep the soldering iron so that the contact area between it and the place of soldering is as much as possible, otherwise the place where you need to make a soldering is not heated enough to fasten the parts.
How to clean a soldering iron tip
When soldering, a deposit often appears on the soldering iron. It can be removed with plain water. If you hold the soldering iron over a damp cloth, the scale will remain on it, and the sting will again become clean. Periodically you need to do this while working with a soldering iron. If the fabric does not help, you can use a hard sponge.
Soldering tips classes
- The stings are removable with a coating of nickel.
- Copper stings.
Soldering tips of the first class are usually used in complex soldering irons, in which it is possible to regulate the temperature.
The stings of the second are the most common.
Types of soldering tips nickel plated
- Sting in the form of a needle - they are soldered very small radio components, such as SMD. When repairing phones, this sting is irreplaceable. It is used on boards with high density of mounted parts.
- Sting-shovel - is used to carry out the evaporation and in cases of installation of large radio components. They work with multi-output microcircuits.
- Sting in the form of a drop - it is convenient for them to transfer solder with rosin to the soldering site, which leads to an improvement in the quality of work.
- Sting with a curved shape - most often they solder the radio components, which are in a copper shell, so that no extra solder remains on the board. It can also be used for conventional soldering. The soldering iron is heated to a temperature of 290-300 ° C.
When working with a soldering iron, it must always be kept in perfect cleanliness. New soldering tips are usually treated with a hammer so that small jags form on its surface. Subsequently they are neatly trimmed with a file to give the most correct form to the jam.
Then the stinger should be stained using solder with rosin. That is, cover with a thin layer of solder, dipping it into rosin.
How to cool the soldering station
Tweezers made of metal, which hold the radio parts, also works as a heat sink during soldering. You can use for this purpose a special clip "crocodile".
Soldering Soldering Tips
To obtain a good result when soldering, it is necessary to correctly apply solder with rosin and flux. It is a low-melting alloy of a special metal, which solder the terminals of parts and wires.
- The best solder is tin in its pure form. But such a metal is too expensive to use when soldering. Therefore, when working with radio components, so-called lead-tin solders are used.
- Lead with tin. On the strength of soldering these solders are not worse than pure tin. They melt at a temperature of 170-190 degrees. It is customary to designate such solders with the abbreviation "POS" - tin-lead solder. The figure that stands after these letters in the designation means the fraction of tin expressed in percent. It is better to use the solder "POS-6O".
- Fluxes are substances that have antioxidant properties. They are used to prevent oxidation of the place of soldering. If you do not use the flux, the solder simply does not stick to the surface of the metal.
Types of fluxes
When working with radio components, fluxes are used in which acid is not contained. For example, rosin. In the shops, we sell also a bowl of rosin for the lubrication of musical instruments. It can also be used for soldering. But metal dishes are brazed using solder without rosin. To repair it you will need "soldering acid". It is dissolved in hydrochloric acid zinc. Radio components can not be soldered with such solder, since in time it will destroy the soldering.
If soldering is required in hard-to-reach places, then it is necessary to have a liquid flux. You can make it yourself. Rosin is ground into powder, poured into acetone or ethyl alcohol. Stirring the solution, you need to pour more rosin to get a thick paste-like mass. At the place of soldering, such a liquid rosin should be applied with a brush or a stick. In this case there is a nuance - to work with printed circuit boards the flux should be more liquid. For hard-to-reach places, solder wire with rosin can also be used, which is much more convenient.
When working with various fluxes, it is necessary to take into account that those that have acetone in their composition are very toxic. Therefore, working with them, it is necessary to avoid falling into the respiratory tract. Solder better near the window, if the summer, and in winter often ventilate the room in which work is being done. At the end of the work, you should wash your hands with soap and warm water.
How to braze solder with rosin
An important condition for successful soldering is the observance of the cleanliness of the surfaces that are required to be welded together. Be sure to clean the solder points to a shine. Then the details should be put on a piece of rosin and warmed. The molten rosin will help the solder spread evenly over the conductor or the part that you need to solder. You can gently turn the part, leading at the same time with a soldering tip, so that the solder spreads evenly over the surface.
If you need to tin a conductor that is soldered into the board, then after cleaning the soldering site with a grinding paper or knife, you need to bring a piece of rosin, and then smoothly distribute the solder as evenly as possible by conducting a soldering iron.
The quality of soldering is influenced by how well the wires or the contacts of the parts are properly connected during soldering. They should be pressed tightly between themselves and after that bring the soldering iron to the prepared conductors, touching it. After the heated solder spreads over the surface, filling even small spaces between them, the soldering iron should be removed.
Continuous soldering time should not be more than five seconds. After this period of time the solder will harden and the parts will be firmly fastened. However, in order for the soldering not to break down, the parts can not be shifted within 10-15 seconds after the end of the soldering. Otherwise, the connection will be unstable.
If the work is done with transistors, then their conclusions must be protected so as not to overheat. It is better to keep them either with pliers or with tweezers, thus performing heat removal.
When performing soldering of radio components, you should never twist the ends of the parts. If you want to solder parts or replace conductors, you need to think about this beforehand, before starting the installation. The ends of the details are best soldered at a short distance from each other, and not in one place.