What is the difference between PCBA machining selective wave soldering and manual welding?

In PCBA processing, there are two processing methods, selective wave soldering and manual welding, for plug-in materials. What are the differences between these two welding methods, and what are their advantages and disadvantages? Next, introduce the difference between PCBA processing selective wave soldering and manual welding.

1.welding quality
Selective wave soldering is definitely superior to manual welding from the point of view of welding quality. Although because of the application of high quality intelligent electric soldering iron, manual welding quality has been improved, but there are still some difficult to control factors. For example, the solder quantity and welding wetting Angle control, welding consistency control, metallization hole passing rate requirements. Especially when the component lead is gold-plated, it is necessary to remove gold and tin for the parts that need to be welded with tin and lead before welding, which is a very troublesome thing.

Manual welding also has human factors and other drawbacks, it is difficult to meet the requirements of high quality; For example, with the increase of circuit board density and the increase of circuit plate thickness, the welding heat capacity increases, and the welding of soldering iron is easy to lead to insufficient heat, forming virtual welding or through hole solder climbing height does not meet the requirements. If the welding temperature is excessively increased or the welding time is prolonged, the printed circuit board will be easily damaged and the welding plate will fall off.

2.Welding efficiency
Traditional manual soldering iron welding requires a lot of people to use point-to-point welding of PCB. Selective wave soldering adopts pipeline-type industrial batch production mode. The welding nozzles of different sizes can be welded in batch by drag welding. The welding efficiency is usually dozens of times higher than that of manual welding.

3.welding flexibility
Selective wave soldering because of the use of programmable and mobile small tin cylinder and a variety of flexible welding nozzles, so in welding can be programmed to avoid the B-side of PCB some fixed screws and reinforcement parts, so as to avoid the contact with high temperature solder and cause damage, there is no need to use custom welding tray and other ways; Therefore, it is very suitable for multi-variety and small-batch production mode, especially in aerospace and military industry and other industries with a very broad application prospect!

4.selective wave soldering of high quality
When using selective wave soldering for welding, the welding parameters of each spot can be "tailored", there is enough process adjustment space to adjust the welding conditions of each spot, such as flux spraying amount, welding time, welding crest height and peak height to the best, the defect rate can be greatly reduced or even possible to achieve zero defect welding of through-hole components. Selective wave soldering has the lowest defect rate (DPM) compared to manual welding, through-hole reflow welding and conventional wave soldering.

From the comparison between selective wave soldering and manual welding, we can see that selective wave welding has many advantages such as good welding quality, high efficiency, strong flexibility, low defect rate, less pollution and diversity of welding components. It is the only choice to replace manual welding in PCBA welding of highly reliable electronic products.