What should be done about the solder beads that appear on the PCB board after SMT solder paste soldering?

Face up toSMTSolder pasteAfter weldingPCBThe problem of solder beads on the board is a relatively common challenge. We need to take effective measures to deal with it to ensure product quality and equipment reliability. The following is a brief introduction by JJY Solder Paste Manufacturer to the common causes of solder beads and their solutions:

I. Analysis of the Formation of Tin Beads

SMTDuring the (surface mount technology) process, the generation of solder beads often stems from multiple links, mainly including:

1Uneven induction heating: When using induction heating, if the temperature is not properly controlled or the stability of the molten pool is poor, it is easy to cause solder to be damagedPCBIt condenses into beads at an unexpected position. This is particularly common when the local temperature is too high, lowering the melting point limit of the pad or the metal layer on the back.

2Assembly deviation:PCBDuring the assembly process of the board, deformation or positioning errors may occur, causing the solder to flow wrongly to the non-pad area and thus forming solder beads.

3Improper repair process: The circuit board isSMTDuring the surface mount technology (SMT) processing, multiple soldering adjustments may be required. If the rework operation is not meticulous, it is easy to leave or generate new solder beads on the solder pads.

Ii. Response Strategies and Solutions

In response to the above problems, we can adopt the following strategies to reduce or eliminate the restrictions:

1Mechanical removal method: As a direct and efficient approach, it involves using a tin-absorbing tool (such as a tin absorber) or solder wire to locally heat the solder beads to melt them and remove them. This is a common method for dealing with already formed solder beads.

2High-precision detection technology: For tiny tin beads that are difficult to detect with the naked eye, high-precision equipment such as optical inspection or infrared microscopes can be used for positioning and analysis to ensure precise removal and reduce omissions.

3Process optimization and enhanced monitoring: Preventing the formation of tin beads from the source is even more crucial. Strengthen temperature control during the production process, ensure accurate equipment calibration, optimize welding parameters and increase the number of pairsPCBThe monitoring of the assembly accuracy of the board is an effective preventive measure. In addition, regular maintenance and upkeep of the equipment to reduce assembly errors caused by mechanical failures are also indispensable aspects.

Iii. Conclusion

Face up toSMTAfter solder paste solderingPCBTo deal with the problem of solder beads on the board, we need to comprehensively apply various means such as mechanical removal, high-precision detection and process optimization to form a complete set of countermeasures. Through the implementation of these measures, not only can the problem of tin beads be effectively solved, but also it can be significantly improvedPCBAThe overall quality and reliability of the product lay a solid foundation for the long-term stable operation of the equipment.

Shenzhen JJY Industrial Technology Co., Ltd. is located in Longhua, Shenzhen. It mainly produces and operates lead-free solder paste, lead-free high-temperature solder paste, lead-free medium-temperature solder paste, lead-free low-temperature solder paste, etc. If you have any needs, please feel free to contact us.