- Solder Bridging Bad solder joints
The top problem that smaller and more compact components cause when it comes to PCB board soldering is solder bridging. The problem happens due to the inadvertent connection between two or more joints. This connection is typically the result of excessive solder between bones.
Identifying a solder bridge is often challenging and given their microscopic size. It can be a massive problem as solder bridges can cause short circuits and lead to a component’s burning up.
So how do you fix this problem? Once you identify the bridge, hold a soldering iron in its middle to melt the solder. Draw through the deck to break it. In case the bridge is too large, remove the excess solder using a solder sucker.
2. Excessive Solder
This problem occurs when you apply more solder onto a pin than you should, leading to excess buildup. The issue is common among beginners who assume that the more solder they ask, the better. However, the main problem is that it is difficult to know what is happening underneath after doing so much welding.
Excessive solder on the pin may deter proper wetting of both the pin and the pad. Moreover, too much solder could cause solder bridging, as we mentioned earlier. The best way to avoid this problem is always to apply enough solder to wet the pin and the pads correctly.
3. Solder Balling
Another common PCB board soldering defect is solder balling. Typically, this issue occurs with reflow soldering. The problem has the appearance of small spheres of solder adhering to a laminate or conductor surface.
Several factors can cause solder balls, including:
·Poor solder paste printing
·Rough PCB design
·Poor reflow temperature
·Using oxidized components
·Adopting proper PCB soldering techniques is the best way to avoid this problem.
4. Cold Joint
You have probably noticed the surface of PCB joints looking dull and lumpy before. This problem results from too low PCB soldering temperature reaching the bones; hence the joint does not melt.
So why does insufficient heat reach the joint? Well, there is a variety of potential reasons. It could be that you have not allowed the soldering iron or the collective to heat up adequately to melt the solder. Sometimes, the defect is the result of the improper design of the traces and pads.
Cold joints need immediate rectification; otherwise, cracks may form and lead to the entire component’s eventual failure.
5. Overheated Joint
This issue is the opposite of cold joints. The problem may be the result of your setting PCB soldering temperature too high on the soldering iron. Sometimes, the problem is that the solder may not flow, which may be due to the pad surface’s nature. The weld may also fail to flow when lead already has an oxide surface that prevents enough heat transfer.
As a result of the issues above, you end up heating a joint for too long, sometimes causing severe damage. Even when the cost is not critical, it may still cause pads to lift and lead to expensive repairs. The solution here is to set the right solder iron temperature. Also, always clean dirty pads and joints using flux.
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