Hand soldering precautions
1.The method of holding the solder wire is suitable for the coil solder wire. When welding the small segment of the solder wire, the forefinger can continuously forward the solder wire forward and hold the solder wire with the thumb and index finger, and the solder wire can not be continuously sent forward at this time.
It is well known that ships are harmful heavy metals due to the fact that there is a certain proportion of lead in the tin-wire composition. Therefore, you should wear gloves or wash your hands after operation to avoid cannibalism.
2. The flux and solder should be moderate.
The flux should be applied according to the size and surface state of the soldered area. The welded joint should be volcanic on the side, and the profile of the pin can be vaguely distinguished from the tin on the solder joint. Too little flux content will affect the welding quality, too much will cause residue around the solder joint after welding, the insulation performance of printed circuit board will be decreased, and the corrosion of components and printed circuit board may also be caused at the same time. For the welding of switch elements, excessive flux flow easily to the switch contacts, thus causing contact bad.
Solder should also be used moderately, neither too much nor too little. Excessive use of solder not only wastes solder and increases welding time, but also reduces the working efficiency and affects the beauty of solder joints. When soldering on a high density circuit board, excessive soldering can lead to an undetectable short circuit. Conversely, if there is too little solder, the solder joint will fall off because it is not secure.
During welding, the solder should be prevented from flowing everywhere, and the solder can easily cause the short circuit between the solder joint and the solder joint.
3. The temperature and time of welding should be grasped well
In welding, electric soldering iron should not be too low temperature, welding time can not be too short. In this way, the solder can reach the appropriate temperature and the solder can melt and wetting quickly. If the welding temperature is too low, solder can not melt and wetting, fluidity is poor, the solder surface will be burr, and the surface is not smooth, even like bean curd, forming virtual, false welding. At this point, a little force can make the welded components fall off. Electric soldering iron temperature should not be too high: otherwise a little longer welding time will cause solder surface oxidation, solder flow, so that the solder joint does not eat tin, the connection of violent parts pin and smoke pot welding pot will be very small, according to the melting resistance is very large, resulting in virtual welding. In addition, the excessive temperature of the soldering iron will also cause the printed circuit board to be crimped with copper stripes device overheating.
When the lead wire is welded to the wiring village, we first place our heads on the end f and the lead wire. After the solder reaches a certain temperature, the solder saves a small amount of solder at the head position of the soldering iron, so that the heat of the soldering iron can be transmitted to the welding piece as soon as possible.
When all soldered parts reach I solder melting temperature, shall extend the coal from the cautery head to other parts to be welded to the farthest away from the heating part of the electric soldering iron, and wait until the solder is moistened and repaired with a solder joint. To avoid surfacing, remove solder wire immediately.
4.If the solder joint is small, it is best to use the couple wire.
First puts the soldering iron fire on the interface between the coal and the component pin, and at the same time heats the two. When the temperature is fixed, point the solder wire to the pad and pin: make the solder melt and wetting the pad and pin. When wetting the entire solder joint, timely withdrawal of solder wire and soldering iron, welding out of the smooth solder joint.
If there is no solder wire, and the solder joint is small, can be solder iron head sell appropriate amount of solder, and then dip rosin, directly placed in the solder joint, to be soldered tin and moistened after the electric soldering iron can be scattered away. When removing the electric soldering iron, pull it up from below to make the solder joint bright and full. Take care to grasp the time. If the time is a little longer, the flux will decompose and the solder will be oxidized, which will make the welding quality drops.
If the temperature of the electric soldering iron is high, the flux is easy to decompose and volatilize, which will cause the flux to be less than when the solder joint is welded. The solution is to place the printed circuit board face up on the table, clip a small piece of rosin flux (usually the size of sesame seeds) onto the pad with tweezers, and then weld it with solder with a soldering iron head. It is easier to weld high quality solder joints.
5. Take the right approach to remove the iron head
Reasonable use of soldering iron head and timely withdrawal of soldering iron head can help to control the amount of solder and take away excess solder. Moreover, the angle and direction of withdrawal are different, and the formation of solder joint is also related to the formation of solder joint. Solder after the formation of the iron to the back of the upper 45 "timely evacuation, so that the solder joint smooth soldering iron head away with a small amount of solder.
6. rewelding of solder joints
If the solder joint does not succeed in one welding or if the amount of tin is not enough, it should be rewelded. When rewelding, must wait for the last solder to melt and melt into a body before the electric iron can be removed.
This article is from ALLICDATA ELECTRONICS LIMITED.