Briefly describe the key points for attention in the operation of solder bar wave soldering process

Date：2023-01-11 15:30:17 Views：685

Wave soldering can be divided into single wave soldering and double wave soldering. The soldering surface of the PCB circuit board is directly contacted with the high-temperature liquid tin, so as to achieve the purpose of welding technical requirements. The high-temperature liquid tin is kept in an inclined plane. The liquid tin is formed by a special device to form similar waves, which is mainly made of solder strips. Wave soldering process flow: fixture installation → spray flux system → preheating → primary wave peak → secondary wave peak → cooling, and then the core detection will come to communicate with you the key points of the wave soldering process operation of solder bar.

1、 Inclination of wave soldering track

The track inclination is obvious for the requirements of welding technology, especially when the welding technology requires high-density SMT devices. If the inclination is too small, bridging is very easy to occur, especially in the shielded area of SMT devices in the welding technical requirements; However, if the inclination is relatively large, although the probability of bridging will be reduced, the amount of tin eaten at the tin point will be reduced, which is prone to false soldering. Therefore, we must adjust the track inclination to 5~7 ℃.

2、 Wiping amount of flux

To further improve the welding technical requirements, we must apply a very thin flux on the bottom of the PCB circuit board, which needs to be wiped evenly, and cannot be too thick, especially for some products that need to be processed without cleaning.

3、 Preheat temperature of pcb circuit board for electronic products

Preheating the pcb circuit board in advance is to better make the solvent in the pre-rubbed flux fully evaporate during the tin feeding, and continuously improve the moisture content of the pcb circuit board and the composition efficiency of the solder joint; At the same time, preheating in advance will also make the temperature of the PCB rise slowly and gradually reach the required temperature to prevent the PCB from being warped and deformed due to direct thermal shock. Generally speaking, the preheating temperature is controlled at 180~200 ℃, and the preheating period is more than 1~3 minutes.

4、 Welding temperature in wave soldering furnace

Welding temperature is an important factor affecting the welding technical requirements. The lower welding temperature can greatly reduce the ductility and wetting function of the solder, and make the solder pad or electronic component solder end not completely wet, which is easy to cause welding problems such as faulty soldering, pinching, bridging, etc. However, too high welding temperature will accelerate the oxidation of solder pads, electronic components and solder bars, which is easy to cause poor welding technical requirements. Therefore, you can control the welding temperature according to the different solder and pcb circuit board.

5、 Wave crest angle of wave soldering

The height of the peak may be changed due to the passage of welding working time. We should make appropriate modifications during the welding process to ensure that the welding process is carried out at the appropriate peak angle. The peak angle is subject to the tin pressing depth being 1/2~1/3 of the PCB thickness.

The above is the relevant content of the wave soldering process of the solder bar sorted out by the core detection team. I hope it can help you. Our company has a team of professional engineers and industry elites, and has three standardized laboratories with an area of more than 1800 square meters, which can undertake various test projects such as electronic component testing and verification, IC authenticity identification, product design and material selection, failure analysis, functional testing, factory incoming material inspection and tape weaving.