SparkFun Forums

[sameh]

Hello
As part of my PFE to get an engineering degree, i'm dealing with PCB's in order to evaluate risks of moisture in printed circuits leading to delamination. I want to find a method to determine the MACA (maximum acceptable moisture content) in the PCB (Printed Circuit Board) as shown in the 1601 IPC standard (MACA is an estimate of the maximum amount of absorbed moisture that printed board can tolerate without damage when exposed to soldering heat and is expressed as a percentage of the dry weight of the printed board). In fact, by measuring the mass of PCBs before and after drying in the oven, when the PCB is saturated with moisture ( when it can no more gain weight), we can consider this percentage of moisture absorption the maximum one but how could we judge if that percentage is acceptable or not ? there's no standard that required a certain threshold or precise from which level we can say that the PCB isn't damaged and we should accept it !!
The moisture absorbed by the resin of the PCB is the main cause of delamination! How to know at what level of humidity, this delamination is observed?
Thank you for helping me to solve this problem

[Ross Robotics]

Well, you're going to have to experiment with it. Set up some projects with different size boards, maybe even different copper weight, then run them with high moisture until delamination occurs.