Description

<style>.e_editor{font:14px/24px Roboto,Helvetica,Tahoma,Arial,'Microsoft YaHei','b8bf53';}.e_editor div,e_editor p,e_editor td,e_editor th,e_editor li{font-weight:inherit;font-size:inherit;font-style:inherit;font-family:inherit;}.e_editor ul{margin:-10px 0 20px;}.e_editor li{padding:5px 0;}.e_table{width:96%;border-collapse:collapse;empty-cells:show;}.e_table th,.e_table td{padding:5px;border:2px solid #eee;}.e_img{padding:10px 0;text-align:center;}.e_p{line-height:20px;padding:0 0 20px;text-indent:0em;}</style> <div class="e_editor"> <div class="e_p"> Hi All, </div> <div class="e_p"> I have been looking in to some failures of PCB's in Assembly. After SMT the boards are stored for different periods of time in high humility environment (72% RH and 21.4 degrees Celsius) before being sent to Assembly to be handsoldered/put through a wave machine. </div> <div class="e_p"> Is there anyway to work out how long say a FR4 board can sit in 72% RH at 21.4 degrees Celsius absorbing moisture without blistering by handsoldering/going through the wave machine? </div> <div class="e_p"> I have seen a few articles on moisture absorption but no linear/non-linear data that correlates moisture absorbed over time and blistering from handsoldering/using a wave machine. </div> </div>