How to identify cold solder joints in solar photovoltaic panel testing

How to identify cold solder joints?

Several methods are used to identify cold joints while doing soldering such as visual inspection, the use of a magnifying glass, and multimeter testing. This allows you to identify the cold joints or your mistakes and correct them. In the article, we’ll explore the various methods to identify cold solder joints and how to repair them.

What is a cold joint in a soldering iron?

One type of cold joint is a distributed joint. It occurs when the molten solder is applied to the joint and moves the soldering iron without letting the solder cool down. It is called a disturbed joint because it is disturbed by the tilted pin and has a convex and crystalline appearance.

Why do solder joints break when soldering?

The oxidation on the surface and at the tip of iron also results in a cold joint as the heat from the is not transferring properly to the components being soldering. Mostly the cold solder joints are dull and have cracks which means the connection can break anytime. There are different ways to identify soldering cold joints and repair them.

What should a solder joint look like?

Make sure the solder covers the joint smoothly. It should look shiny and form an excellent, even shape. Remove the iron slowly to let the solder cool without cracking. Don't blow on it; let it cool naturally. Once it's cool, inspect the joint. It should be solid and have a smooth, concave surface.

Can cold solder joints affect PCB performance?

Cold solder joints can shorten the lifespan of the entire device, leading to repeated failures and costly repairs. In the worst cases, the device might stop working altogether. Even if a cold solder joint seems like a small problem, it can significantly impact PCB performance.

Why do solder joints look rough?

It happens when the solder does not melt properly during the soldering process. A low temperature on the soldering iron or poor technique can cause this. The solder won't flow and bond properly when it is not hot enough. As a result, you get a joint that looks rough or dull instead of shiny and smooth.