For quality work, we need to have:
- Tweezers or pliers
- Soldering iron
- A small sponge.
- Side cutters
First you need to turn on the soldering iron in the socket. Then moisten the sponge with water. When the soldering iron is heated enough to melt the solder, it is necessary to cover the socket (solder). Then wipe it with a damp sponge. In this case, too long contact should be avoided as it is fraught with hypothermia.
To remove old solder residue, you can wipe it clean without sticking the sponge. Preparations are made for the radio components. Everything is done with tweezers or pliers. To do this, bend the ends of the radio components so that they can easily enter the holes in the board. Now let’s talk about how to install SMD components.
Getting to the Details
First you need to insert the components into the holes in the board designed for them. While doing this, make sure that the polarities are respected. This is particularly important for elements such as electrolytic capacitors and diodes.
Then dilute the results a small amount so that the piece does not fall outside the established place (but do not overdo it). Just remember to rub the sponge back with the sponge just before you start soldering. Let’s now look at how the SMD setup happens at home in the soldering step.
It is necessary to place the soldering iron tip between the board and the printout to heat the place where the soldering will be performed. This time should not exceed 1-2 seconds in order not to disable the track. Then you can solder the solder.
Flux can spread to a person at this stage, so be careful. After this moment, when the required amount of solder has time to melt, it is necessary to pull the wire away from where the piece was soldered.
The soldering iron tip must be held for one second to ensure even distribution. Then it is necessary to remove the device without moving the part. It will take a few minutes and the soldering place will cool down. It is necessary to ensure that the part does not move during all this time. It can be cut using the extreme side cutters. But be careful not to damage the soldering point.
Quality Control Studies
Look at the resulting SMD surface mount:
- Ideally, the contact area and the output of the part should be connected. At the same time, the soldering itself must have a smooth and shiny surface.
- To obtain a spherical shape or to obtain a connection with adjacent pads, it is necessary to heat the solder and remove its excess. Remember that there is always a certain amount on the soldering iron tip after working with it.
- If there is a matte finish and scratches, melt the solder again and let it cool without moving the parts. If necessary, you can add a small amount.
You can use a suitable solvent to remove flux residue from the wood. However, this process is not necessary because its presence does not interfere and does not affect the operation of the circuit. And now let’s pay attention to the solder theory. We will examine the features of each option later.
Understand the connection of certain metals under soldering, using other metals more meltable. In electronics, solder is used for this, of which 40% is lead and 60% is tin.
This alloy already becomes liquid at 180 degrees. Modern solders are produced as thin tubes filled with a special resin that already performs the function of a flux. Heated solder can create an internal connection when the following conditions are met:
- The surfaces of the parts to be soldered must be cleaned. To do this, it is important to remove all oxide films formed over time.
- The part should be heated at the soldering point to a temperature sufficient to melt the solder. Some difficulties arise when there is a large area with good thermal conductivity. After all, the power of the soldering iron may not be enough to heat it.
- Care should be taken to protect against oxygen. This task can be done with colophones that form a protective film.
The Most Common Mistakes
Now consider the three most common errors and how to fix them:
- Solder points touch the tip of the soldering iron tip. Very little heat is provided. It is necessary to apply the insertion in such a way that the largest contact area between the insertion and the soldering point is formed. Then the SMD installation will be of high quality.
- Very little solder is used and significant time intervals are maintained. When the process begins, some of the flux has already evaporated. Solder does not receive a protective layer as a result – an oxide film. And how to set up SMD at home? For this, soldering point professionals shake both with soldering and soldering at the same time.
- Do not remove the tip too early from the soldering point. The heat should be intense and fast.
For SMD installation, you can take a capacitor and fill it hand.
We’re going to practice now. Suppose there is an LED and a resistor. They need to solder the wire. It does not use circuit boards, pins and other auxiliary elements. To achieve this goal, you must take the following actions:
- Remove insulation from cable ends. They must be clean because they are protected from moisture and oxygen.
- Turn individual wiring cores. .
- Tighten the ends of the wires. During this process, it is necessary to bring the heated tip together with the solder wire (which should be evenly distributed over the surface).
- We shorten the ends of the resistor and LED. Then you need to repair them (regardless of whether old or new parts are used).
- We keep the results parallel and apply a small amount of solder. Before the gaps are filled evenly, it is necessary to remove the soldering iron quickly. The part does not need to be touched until the solder has hardened completely. If this happens, micro-cracks occur that adversely affect the mechanical and electrical properties of the joint.
In this case, it is necessary to make less effort than before, because here the holes in the wood are a holder for the parts. However, experience is important here. Often the result of a beginner’s work is that the plan starts to look like a large solid conductor. But this is a simple matter, so after a little work the result will be at a good level.
Now let’s see how SMD editing is done in this case. Initially, the solder tip and solder are simultaneously soldered. In addition, both the processed outputs and the sheet must be heated. It is necessary to hold the sting until the solder evenly covers the entire contact area. Then it can be circled in a semicircle around the treated area.
In this case, the solder should move in the opposite direction. We observe that it is evenly distributed throughout the contact area. After that, remove the solder. And the last step is to quickly remove the tip from the soldering point. We expect the solder to take its final shape and harden. So in this case SMD installation, the printed circuit board in the first trials won’t look too hot, but over time you can learn to make it at a level you can’t tell from the factory version.