In a modern home, there are many different electronic equipment: from ordinary gadgets to complex devices such as a home theater. A variety of electrical household appliances also usually contain electronic control units.
All of this technique demonstrates common features such as:
- very specific probability of failure;
- implementation using not only microcircuits, but also capacitors, resistors and other similar attachments.
If the owner of this technique is inclined to radio amateurism, then he is quite able to find the cause of the failure and restore the device to work. Even if this does not work out (for example, a microcircuit burned out), then some of the parts can be fully used in the future to assemble other circuits or simply as spare parts. To do this, you just need to solder them from the board. Let's consider what needs to be done for this.
Tools used
To implement the desoldering procedure, you will need the following tools:
- soldering iron (in principle, with a certain skill, it can be replaced with another heat source, but no one has come up with anything better than a soldering iron);
- medium medical tweezers (used as a holder, at the same time in some cases performs the function of a heat sink).
It is better to take a soldering iron with a temperature controller as part of a soldering station of the type shown in Figure 1.
When working, tweezers are sometimes replaced with a medical clip or an ordinary crocodile.
A typical PCB view from the solder side is shown in Figure 2. Therefore, it must be remembered that solder not only provides electrical contact between the terminals parts with live tracks of the printed circuit board, but also provides primary mechanical fastening details.
To remove excess solder, such devices are used as:
- hollow medical or specialized needles;
- suction;
- copper braid.
The braid is usually supplied on small spools, Figure 3, and purchased from specialized stores.
The greatest efficiency of solder removal is provided by suction, Figure 4, but it must be purchased separately.
Dismantling process
To solder elements with a small number of leads, the soldering points are heated with a soldering iron, after which the part is removed from the mounting holes with tweezers.
In situations where these elements have bent legs, they are first heated individually, straightened with tweezers, and then, after reheating all the leads, the part is pulled out.
Removing the part is facilitated by removing the solder as completely as possible. For this:
- the contact is warmed up and a hollow needle is inserted into the mounting hole so that the output goes inside the hole;
- the contact is heated together with the braid attached to it, as a result of which the solder passes to it;
- the heated contact is treated with suction.
The component is then easily pulled out of the holes.
When working with a braid, it is recommended to moisten its working part with liquid flux. This simple technique increases the surface tension so that the braid literally "sucks" the solder into itself.
Small-sized leadless elements for surface mounting are soldered by winding copper wire on a soldering iron tip. The details of this technique are clear from Figure 5.