Humidity Control in PCB Assemblies
A printed circuit board is an insulated board on which wire is laid to create a circuit. They are a critical and very necessary part of all electronic products. They are in everything from complex computers to basic smartphones. Since they are the base for the circuits that transfer electricity, if they were not included in an average electric machine that machine would not work as designed. Always, things like dust, heat, and humidity will have an effect on PCB boards.
Just like dust can interfere with and even interrupt circuits, and heat can cause some metal within the circuits to melt, humidity can allow current to run through unwanted areas of the circuit board, causing extreme damage to the board and the circuits on it. Too much moisture in the board can cause numerous problems from delamination to solderability issues. As we all know, moisture is not good for any electronic component and this is especially true when it comes to PCBs. Reality is that PCBs are extremely absorbent so both the builder and the end user must use extreme caution when avoiding moisture.
If you are an end user, you’re highly recommended to pre-bake the boards before you solder them. Though fabricators always pack PCB boards with desiccant packs to keep the moisture down, even the short time that the boards are exposed to humidity before they are put into the assembly process can be enough for that board to absorb too much moisture.
The most recommended way of keeping your boards safe is to keep a humidity level at around %50, or between %40-%60, which will let the PCBs stay dry while not drying out completely or causing static discharge, which can occur below this level of humidity: a normal amount of moisture in the air only will not affect them.
Remember moisture is our enemy. But baking the moisture out the boards prior to the assembly process is the simplest and most cost-effective way to keep your boards safe and dry.