What should I do if there are solder beads on the PCB surface after SMT solder paste soldering?

inPCBADuring the manufacturing process, due toSMTSome reasons during the process will bePCBIt is very common for some undesirable phenomena to be left on it, such as tin beads. Tin beads refer to inSMTSmall spherical or punctate solder that appears on the solder pads or the metal layer on the back after the circuit board is assembled. If these tin beads are not dealt with, it will lead to equipment failure and shorten the service life of the circuit board. Next up is Shenzhen JJYSolder paste manufacturerIt will be discussed.SMTAfter solder paste solderingPCBWhat should be done when there are tin beads on the board surface?

The formation of tin beads is due toSMTIt is caused by some reasons in the production process. The common reasons are as follows:

1Induction cladding

When induction heating is used on a circuit board, tin balls may form inPCBUp. This is caused by the instability of the molten pool and the temperature inconsistency of the circuit board. When the induction heating in the circuit board is too high, it will cause the melting point of the solder pads or the metal layer on the back to decrease, thereby leading to the formation of solder beads.

2Get involved

During the assembly of circuit boards, sometimesPCBThe board may deform or misalign, causing the solder to enter the wrong position. This will lead to the formation of tin beads.

3Welding repair

The circuit board isSMTWelding rework is often required during the processing. If the repair is not done properly, it will cause solder beads to appear on the solder pads.

Treatment method

whenSMTAfter the solder beads appear in the surface mount technology (SMT) production process, we should take timely measures to deal with them to ensure the service life of the circuit board and the normal operation of the equipment. Here are several methods for your reference:

1Mechanical treatment

Mechanical treatment is the most common method for handling solder beads, which can be carried out using a solder absorber and solder silver wire. Using a tin absorber to remove the tin beads can solve the problem very well. When using solder silver wire and heating it on the solder pad, it will melt and adsorb the tin balls.

2Optical examination and infrared microscope examination

For someSMTFor equipment, mechanical processing is insufficient to solve the problem. At this point, we can inspect the position and shape of the solder balls through optical inspection or infrared microscopy. This method can better identify the position of the tin balls and carry out effective processing.

3Strengthen control and inspection

Strengthening control and inspection is preventionSMTThe best way to form solder balls in production can prevent situations such as solder pad zeroing or curling.

Summary

When the tin balls form, we need to take action to deal with them in a timely manner. Mechanical processing, optical inspection, infrared microscopy examination, as well as enhanced control and inspection are all very effective methods. It is hoped that these methods can help you better handle the issue of solder beads to ensure the service life of the circuit board and the normal 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.