PCB Technical - Wave soldering and manual soldering in PCBA processing

In the electronics industry, there are wave soldering and manual soldering for software materials inPCBA processing. Then, what are the differences between these two soldering methods and what are the advantages and disadvantages?

1. The welding quality and efficiency are too low

1. Due to the application of high-quality intelligent electric soldering irons such as ERSA, OK, HAKKO and Quick, the welding quality has been improved, but there are still some factors that are difficult to control. For example, the control of the amount of solder in the solder joints and the wetting angle of the solder, the control of soldering consistency,

and the requirements for the tin-through rate of the metallized holes, etc. Especially when the component leads are gold-plated, it is necessary to remove gold and enamel tin before soldering on the parts that need to be soldered. This is a very troublesome thing.

2. Manual soldering also has human factors and other disadvantages, which make it difficult to meet high-quality requirements; for example, as the density of circuit boards and the thickness of circuit boards increase, the heat capacity of soldering increases, and soldering iron soldering can easily lead to insufficient heat. The climb height of solder or through-hole solder does not meet the requirements. If the soldering temperature is increased excessively or the soldering time is prolonged, it is easy to damage the printed circuit board and cause the pad to fall off.

3. The traditional manual soldering iron soldering requires a lot of people to use point-to-point soldering on the PCBA. Selective wave soldering uses the mode of applying flux first, then preheating the circuit board/flux, and then using a solder nozzle for soldering. It adopts an assembly line industrialized batch production mode. Welding nozzles of different sizes can be used for batch welding of drag welding, and the welding efficiency is usually dozens of times higher than that of manual welding.

Second, the high quality of wave soldering

1. When wave soldering is performed, the welding parameters of each solder joint can be "tailored", and there is enough process adjustment space to adjust the welding conditions of each solder joint, such as the amount of flux sprayed, soldering time, and soldering wave. The height and wave height are adjusted to the best, the defect rate can be greatly reduced, and it is even possible to achieve zero defect soldering of through-hole components. Compared with manual soldering, through-hole reflow soldering and traditional wave soldering, the defect rate of selective wave soldering ( DPM) is the lowest.

2. Wave soldering uses a programmable and movable small tin cylinder and a variety of flexible soldering nozzles, so it can be programmed to avoid certain fixing screws and stiffeners on the B side of the PCB during soldering. In order to avoid damage caused by contact with high temperature solder, there is no need to use custom soldering trays and other methods.

3. From the comparison of wave soldering and manual soldering, we can see that wave soldering has many advantages such as good soldering quality, high efficiency, strong flexibility, low defect rate, less pollution and diversity of soldering components.