Hello,
I have got 2 questions for you today !
My electronic board is varnished to protect it against humidity. The varnish cover all the component too, except the connectors. Is it already taken into account in the FIDES guide, or is there a way to model it ?
I would like to know the raisons of PIRH = 0 while the component is up (operating). I don′t clearly understand this point.
Thank for your support.
Dear,
The varnish coating of electronic board is not taken into account in the FIDES Guide. Indeed, the coating will have a protective effect, especialy against humidity, but it will not stop the contribution. If you want to modelize the effect of coating on your board (for example to give some reliability engineering judgment to do coating or not), you can play on the RH factor to take into account the RH realy undergone by component.
For most components, the physical contribution modelized in the FIDES Guide for humidity is only active in non operating phases. If you want a deeper understanding of the reason why, you will have to look for explanations about the physics of failures involved. The subject is a bit too complex for this forum (and for me...).
Regards,
Lambda