The soldering process begins with the selection of the tool. How to solder a soldering iron, if a person has never performed such work and did not hold this tool in his hands? There is only one way out: it is necessary to study the guidelines and get down to work.
Power tool indicates its scope: 3-19 W is designed to work with chips, 40 W are convenient for soldering household appliances and radio components.
Tool selection for joining materials by soldering
For successful work, you need to find the right soldering iron. Power tool indicates its scope:
- 3-19 W is designed to work with chips;
- 40 watts are convenient for soldering household appliances and radio components.
Scheme of a soldering iron.
More powerful tools are used to connect the surface elements of radiators, thick wires. The 25 W soldering iron does an excellent job with connecting resistors, thin wires and other radio components.
For the work of the master will need additional devices:
- tin, lead and cadmium alloy;
- degreasing composition.
The work will not be of high quality if you do not purchase such tools as:
The stand for the tool will help to avoid employee injury, because soldering iron when heated has a temperature of 300 ° C.
Electric circuit temperature controller soldering iron.
When choosing a solder should pay attention to low-melting to 65-70 ° C or refractory to 1000 ° C. For amateur radio works, POS-61 brand solder is required, which is used in a different form, but it is much more convenient to purchase it in the form of a thin piece of wire of small thickness. The radio amateur, getting ready for work, acquires a degreasing compound, rosin or its alcohol solution.
The flux is easy to prepare at home by mixing an alcohol solution and crushed rosin in containers. Active flux in the arsenal of amateur radio helps solder connectors and pins. To protect the surface of the desktop get a piece of plexiglass or hardboard.
There is an opinion that successful work with a soldering iron must be combined with the use of a digital tester. It allows you to measure voltage and overcome resistance.Back to table of contents
How to prepare a soldering iron for work: recommendations
Designation of radio components on the scheme.
First you need to perform two operations with the instrument:
- To stray.
The soldering iron is connected to the power supply. After 2-3 minutes, the surface lubricant burns out. Sometimes the soldering iron lasts 15-20 minutes, and after this time the working part is processed by a file. The sting is immersed in the rosin, followed by immersion in the solder.
Metal-ceramic stings are not treated with a file, but smeared with a wet sponge. If the copper core deforms too quickly, the procedure should be carried out repeatedly.Back to table of contents
Surface treatment before starting work
Soldering iron tip.
The initial stage of the technological process involves the cleaning of surfaces from old varnish or oxide film.
For work prepare the necessary tool:
Removal of impurities is carried out chemically or mechanically. The surface must be wiped with a soft cloth, and with emery cloth No. 180-240, clean the joints of the parts.
In chemical processing, acids are used, followed by drying parts in air. Machining can be done by grinding, abrasive cleaning, hydromechanical method.Back to table of contents
Connecting radio components with a soldering iron
Soldering iron tinning scheme: 1 - soldering iron, 2 - solder, 3 - gaseous flux, 4 - dissolved oxide, 5 - surface oxide layer, 6 - flux, 7 - solder fusion zone with base metal, 8 - base metal.
If you learn how to solder radio components, you can assemble radio elements into a general scheme that performs a specific function. It is necessary to stock up in advance with solder, which contains 39% of lead and 61% of tin (POS-61).
The prepared surfaces are soldered, having previously adjusted the temperature of the outer end of the soldering iron using a special device. To the hot end of the soldering iron, the solder does not fasten tightly enough, so you should cool the tool slightly. Using tweezers, you must hold the parts while soldering, otherwise they are easily damaged due to overheating.
The instrument is turned on and waited until the sting warms up to 240 ° C. If the rosin at the end of the soldering iron has boiled, then it is ready to go. A poorly heated instrument creates a loose contact that is subject to rapid destruction. The perfect brazed seam is glossy, with a smooth shiny surface.
From the printed circuit board, parts are soldered in such a way that it does not heat up more than 280 ° C. Otherwise, delamination of the printed tracks in the area of the highest heat occurs. Details are carefully fixed before connecting. With a small offset the quality of the soldering will be very low.
Testing of electronic components.
After heating the tool, clean the ends of the two wires, removing 1.5 cm of insulation. Two wires are connected to each other, dipping the end of the soldering iron into the rosin, then into the solder. Apply it to the place of connection of the drives. For soldering single-core wire, you must first clean its ends with sandpaper. Having fixed the wires, they attach the sting of the instrument to them, holding it for 5 seconds. Solder wire touches, and then give him time to cool completely.
To evaporate a resistor or diode, the soldering point is heated by a soldering iron. Then remove the wire using tweezers. The formed hole is sealed with solder, which is melted by a soldering iron.
A small element in the form of a toothpick is inserted into the hole, and it produces clockwise rotational movements, and after hardening, the solder is removed.
Pre-check the suitability of all wires for soldering. It is necessary to judge the findings, and then proceed directly to the soldering elements.Back to table of contents
Work related to the connection of LEDs and other elements
Modern radio-electronic devices are equipped with non-existent SMD components. Their scheme does not provide for the presence of wire leads. The connection occurs by soldering the contact surfaces. For work use a soldering iron of 10-12 W, connecting each contact consistently.
When watering the SMD element, the leads are heated. For a soldering iron, you need to do a few stings with branches on the end. When using a more powerful tool with a copper wire on the sting make a few turns, forming a convenient nozzle. It allows you to quickly unsolder SMD components. The nozzle is dismantled and used as an alternative to a low-power soldering iron for connecting thin conductors to the LEDs. When soldering such a tape (to protect the printed track), soldering should be carried out in a very short time.Back to table of contents
Joining parts on chips with a soldering iron
Often, before the master-amateur is a more difficult task: solder the chip using a soldering iron.
It is necessary to prepare for work a medical injection needle with a diameter of 0.6 mm. The findings in the microcircuit process flux, and the needle is worn on each output alternately. Solder is heated by a soldering iron, rotating the needle in different directions to avoid its connection with the output. After inserting the needle into the board, the soldering iron is removed and the needle is disconnected from the leg. It is necessary to free each leg from the solder. The whole process takes, for the release of the needle, no more than 2 seconds. Then the microcircuit is removed, and in case of obstacles, the leg is again treated with a needle and a soldering iron.
Radio amateur quickly and easily repair equipment, if you learn how to solder properly.
A reliable tool will not only cope with the work, but will help you to do it efficiently and on time.