Soldering is one of the most important parts of the electronics assembly process for pcb manufacturers. If there is no corresponding quality assurance of soldering process, any well-designed electronic equipment will be difficult to achieve the design goals. Therefore, during the welding process, the following operations must be performed:
1. Even if the weldability is good, the welding surface must be kept clean.
Due to long-term storage and pollution, harmful oxide films, oil stains, etc. may be produced on the surface of the solder pads. Therefore, the surface must be cleaned before welding, otherwise it is difficult to guarantee the quality.
2. The temperature and time of welding should be appropriate.
When the solder is uniform, the solder and solder metal are heated to soldering temperature so that the molten solder soaks and diffuses onto the surface of the solder metal and forms a metal compound. Therefore, in order to ensure a strong solder joint, it is necessary to have an appropriate soldering temperature. At sufficiently high temperatures, the solder can be wetted and diffused to form an alloy layer. The temperature is too high for soldering. Soldering time has a great influence on the solder, the wettability of the soldered components and the formation of the bond layer. Correctly mastering the welding time is the key to high-quality welding.
3. Solder joints must have sufficient mechanical strength.
In order to ensure that the welded parts will not fall off and loosen under vibration or impact, it is necessary to have sufficient mechanical strength of the solder joints. In order to make the solder joints have sufficient mechanical strength, the method of bending the lead terminals of the soldered components can generally be used, but excessive solder should not be accumulated, which is likely to cause short circuits between virtual soldering and short circuits. Solder joints and solder joints.
4. Welding must be reliable and ensure electrical conductivity.
In order to make the solder joints have good conductivity, it is necessary to prevent false soldering. Welding means that there is no alloy structure between the solder and the solder surface, but simply adheres to the soldered metal surface. In welding, if only a part of the alloy is formed and the rest is not formed, the solder joint can also pass current in a short time, and it is difficult to find problems with the instrument. However, as time goes by, the surface that does not form an alloy will be oxidized, which will lead to the phenomenon of time opening and fracture, which will inevitably cause quality problems of the product.
In short, a good quality solder joint should be: the solder joint is bright and smooth; the solder layer is uniform, thin, suitable for the size of the pad, and the outline of the joint is blurred; the solder is sufficient and spread into the shape of a skirt; no cracks, pinholes, No flux residue.
Post time: Mar-21-2023