Basic operation steps of manual welding

To get a good solder joint, save temperature and welding of electric soldering iron and master the correct contact point of the solder joint.

Outside, the welding process is also important.

 Pick up the time, select the right brand iron head to

The two hands should coordinate and coordinate with each other when joining the suburbs consistent, usually with the right.The hand looks at the electric iron, and the left hand goes in line operation.

1. Preparation

First of all, the soldering elements and solder wires are prepared to be soldering iron ahead of 3~5min to turn on the power supply, so that the temperature of the soldering iron will rise to the appropriate welding temperature.

At this time, the following methods can be used to detect whether the electric iron can be welded: after the electric iron is connected to the power supply, the electric iron is slightly equal to the plate carve, then let the iron head contact with rosin, such as rosin melting, indicating that the iron head has been heated, but may not melt solder:

If the iron head touches the rosin, the sound of "magnetic rag" can be heard, and the white smoke from the rosin can be seen, indicating that the electric soldering iron has reached melting solder temperature, can be welded.

Note: never use the hand to touch or make the iron head close to the skin to check whether the electric iron is hot!

When heated, the iron head is usually lightly wiped on a sponge (or rosin) that should have water, to remove the iron head the oxide residue on it. Here wipe sponge add water, with the hand grip sponge can not squeeze water is appropriate.

The desktop should also be cleaned up before welding, and components that are not related to welding should not be placed on the desktop.

2. Heated welds

Tip the slanting section of the iron head up to a predetermined temperature from the right side at the base of the device pin and at the base of the device on the pad, the plane of the electric iron and the circuit board is 45 °9 angle, and the heating welding is performed on the pin of the components.

It is important to note that the soldering iron head must be in contact with the pins and pads of the components at the same time, so that both are heated and heated at the same time.

The time depends on the size of the welding area.

Such as according to the time, palm good heating time is very long, that is the time to ensure solder joint four smooth. When welding one foot of a body tube on a printed circuit board, the point should be heated 2-3s. Do not exceed 5S. the welding time should not be too long or too long. When heating time is too low, the temperature of the boundary point is low, and the water of the welding pot fully melts the rosin and so on, which is not completely vaporized and volatilized, leaving a layer of rosin between the solder and the welding piece, which will result in virtual welding. If the heating time is too long, it may not burn the welded components or cause the copper pin boundary disc to fall off. Therefore, we must master the addition according to the welded components hot time.

3. Solder wire

When the heating surface of the welded piece is heated to a fixed temperature, immediately transfer the solder wire from the left side (opposite the slanted section of the iron head) to the welded pin to melt the appropriate amount of solder with the left hand. Note that the solder wire cannot be sent directly to the soldering iron head. After the solder wire melts, the solder joint forms quickly. The melting time of solder wire determines the size of wide solder joint. The amount of solder wire should be controlled according to the size of solder joint to make the size of solder joint uniform.

It is important to note that during welding, the amount of solder should be determined by the size of the solder joint, and the amount of solder should be moderate, not too much or too little. Generally speaking, solder can be fully submerged pad is appropriate. If there is too much solder, the solder in the solder joint will not be fully melted, and the welding will not be strong. Once the solder is fully melted, too much solder will flow again, which may lead to a short circuit in some parts. It's not beautiful, and it's a waste of solder. If the solder is too little, it will cause the mechanical strength of the solder joint is not enough, and the welding is not strong enough, which will easily cause the components or wires to fall off. In order to ensure the welding quality, the amount of solder on the solder joint should be just immersed in the lead after melting or when the weld is filled in the larger part of the welding.

4. Remove solder wire

When the solder wire melts and covers the pad and device pins, the resulting solder joint is of moderate size, and the solder wire pinched in the left hand will be removed rapidly along the left, and the heating state of the soldering iron will remain the same.

5. Remove soldering iron

After removing the solder wire, the heating state is maintained for about 1 s to ensure the sufficient thermal contact between the solder and the welded components, thus improving the reliability of welding.