Risk Factors for PCB Boards (Part 2)
It is every designers target to ensure their PCB boards are robust and can function effectively and smoothly. However, there are two factors that can lead to damaged PCBs. These are environmental factors, and problems that can develop during the design and production stages of flexible PCB manufacture. In this article, we outline several environmental factors that damage PCB boards.
Moisture and Humidity
Either moisture or humidity can make PCB boards non-functional. While an entire final product (e.g. mobile phone or television) may be able to survive a little amount of moisture, the individual PCB within these units will short out in the presence of moisture if the water crosses two channels on the PCB. While the active presence of moisture will cause this problem, similar issues may arise if the PCB is operating in damp conditions. In such circumstances, mold may form and lead to circuit failure.
Small charges from static electricity can reach the boards in a variety of situations. If a static charge affects the board while it is in use, the risk is increased. PCBs need to be positioned in a location that is free from any source of static charge such as fabric or carpet.
Both cold and heat can have negative effects on PCBs. At higher temperatures the air can hold more moisture than it can at cold temperatures, so PCB boards will be shorted. If the environment where the PCB is operating cools to the point that the air can’t hold the moisture, condensation will occur and as a result, shorting may also occur. Heat is as much of an issue as cold. Heat can lead to the board warping, which may break the linkages and cause the PCB to malfunction.