PCB manufacturing process follows a specific progression of steps that have to be executed perfectly in order to create reliable and electrically viable joints using solder paste. However, certain process flaws and inadvertent errors may lead towards creation of random small spherical particle-like shapes in or away from the main solder pool after the reflow process is complete. These spheres are known as solder balls. While some manufacturers may choose to ignore such an occurrence, the IPC A 610 standard deems a PCB with more than 5 solder balls (<=0.13mm) within 600mm^2 as defective. This is because solder balls that have a diameter of 0.13mm or within 0.13mm of traces can adversely impact the reliability of a PCB since they violate the minimum electrical clearance principle. So, the answer to the question of whether solder balls on a PCB are good or bad is clear – they are definitely bad.
Formation of solder balls in reflow or wave soldering operations is generally the result of uneven solder particle melt which may happen because of the presence of an oxide layer or improperly wetted surfaces. The creation of these balls can be random, non-random or may be to the result of a solder splash back. Trapped air or water vapor inside or below the surface of solder paste may try to escape when the circuit board is heated to get the paste to flow. When this happens, the air ends up creating a bubble like structure while taking some amount of solder paste from the surrounding surfaces. This spherical shape usually has a void inside where the solder paste hasn’t been able to reach. This occurrence can have an adverse effect on the reliability and functioning of the circuit board.
Considering these factors, it is important to analyze your PCB assembly process and find out the root cause behind the creation of solder balls. This analysis will help you determine the actual problem that needs to be corrected to prevent solder balls from forming. Consulting an expert organization like Alpha Assembly Solutions can help you in determining defect causes, from conveyor speed to surface contamination, and find cost effective ways to correct the same.
So don’t let solder balls hamper the quality of your PCB product. Go ahead and seek expert assistance to combat this issue today!
Formation of solder balls in reflow or wave soldering operations is generally the result of uneven solder particle melt which may happen because of the presence of an oxide layer or improperly wetted surfaces. The creation of these balls can be random, non-random or may be to the result of a solder splash back. Trapped air or water vapor inside or below the surface of solder paste may try to escape when the circuit board is heated to get the paste to flow. When this happens, the air ends up creating a bubble like structure while taking some amount of solder paste from the surrounding surfaces. This spherical shape usually has a void inside where the solder paste hasn’t been able to reach. This occurrence can have an adverse effect on the reliability and functioning of the circuit board.
Considering these factors, it is important to analyze your PCB assembly process and find out the root cause behind the creation of solder balls. This analysis will help you determine the actual problem that needs to be corrected to prevent solder balls from forming. Consulting an expert organization like Alpha Assembly Solutions can help you in determining defect causes, from conveyor speed to surface contamination, and find cost effective ways to correct the same.
So don’t let solder balls hamper the quality of your PCB product. Go ahead and seek expert assistance to combat this issue today!
No comments:
Post a Comment