Soldering iron soldering five-step basic soldering method
(1) Preparation for soldering
Prepare the soldering wire and soldering iron, and do the pre-soldering preparation.
(2) Heating the soldered parts
Soldering iron will contact the welding point, pay attention to the first to keep the soldering iron to heat the various parts of the solder (such as printed circuit board leads and pads) are heated, and then pay attention to let the flat part of the soldering iron head (the larger part of the soldering iron head) in contact with the larger thermal capacity of the soldering iron head of the side or the edge of the soldering iron head part of the soldering iron head in contact with the thermal capacity of the smaller to keep the soldering parts uniformly heated.
(3) Melt the solder
After the soldering piece is heated to a temperature that melts the solder, place the wire on the solder joint and the solder begins to melt and wet the joint.
(4) Removing the solder
After melting a certain amount of solder, remove the solder wire.
(5) Removing the soldering iron
Remove the soldering iron after the solder has completely wetted the solder joint, and note that the direction of removing the soldering iron should be roughly 45 ° direction.
For the welding of small heat capacity of the workpiece, can be simplified to two-step operation: ready to weld, at the same time to put on the soldering iron and soldering wire, while withdrawing the soldering wire and remove the soldering iron.
Soldering requirements
Soldering is one of the most important parts of the electronics assembly process. If there is no corresponding welding process quality assurance, it is difficult for any well-designed electronic device to meet the design specifications. Therefore, when welding, the following points must be done:
1. Soldering surface must be kept clean
Even if the weldability is good, due to long-term storage and pollution and other reasons, the surface of the weldment may produce harmful oxidized film, oil and so on. Therefore, in the implementation of welding must be clean before the surface, otherwise it is difficult to ensure quality.
2. Welding temperature, time should be appropriate, uniform heating
Welding, the solder and the welded metal heated to the welding temperature, so that the molten solder in the welded metal surface wetting diffusion and the formation of metal compounds. Therefore, to ensure a strong solder joint, there must be a proper soldering temperature.
At a high enough temperature, the solder can be fully wetted and fully diffused to form an alloy layer. Excessively high temperatures are detrimental to soldering. The soldering time has a great influence on the solder, the wetting of the soldered components, and the formation of the bonding layer. Accurate control of the welding time is the key to quality welding.
3. Welded joints to have sufficient mechanical strength
In order to ensure that the welded parts in the vibration or impact does not fall off, loose, therefore, the requirements of the solder joints to have sufficient mechanical strength. In order to make the welded joints have enough mechanical strength, generally can be used to be welded components of the lead terminals after bending and then welding method, but not with too much solder buildup, which is likely to cause false welding and soldering and welding between the short-circuit.
4. Welding must be reliable, to ensure that the conductive properties
In order to make the solder joints have good electrical conductivity, it is necessary to prevent false soldering. Virtual welding refers to the solder and the surface of the welded material does not form an alloy structure, but simply attached to the surface of the welded metal. In welding, if only part of the formation of alloy, while the rest of the alloy is not formed, this joint in the short term can also be through the current, measured by the meter is also difficult to find problems. But with the passage of time, the surface of the alloy is not formed to be oxidized, then there will be the phenomenon of on and off, which will inevitably lead to product quality problems.
