Hello  Rich,

by using Vacuum Drying method to dry-off the PCBs, compared to a classic
baking method this one provides plenty of benefits in terms of time
reduction for a cycle, vacuum helps moisture diffusion, also as we know
moisture boiling point temperature under vacuum is lower then in open
atmosphere that means thermal stress reduction on PCB/Laminates. 
Furthermore, by using Vacuum, other significant benefit is no oxidation of
PCB metal surfaces, plus heavy Power consume reduction

In the other hands, cost and serviceability of vacuum machine should be more
expensive then classic electrical oven. Also the cost should be higher.

Let's wait for someone  who experimented or are using VD.


Regards

Gabriele


-----Messaggio originale-----
Da: TechNet [mailto:[log in to unmask]] Per conto di Richard Kraszewski
Inviato: venerdì 1 giugno 2012 16.48
A: [log in to unmask]
Oggetto: [TN] Vacuum Drying of PCB's

I would appreciate anyone sharing their thoughts on vacuum drying of PCB's. 

What conditions do you use? (Time, temp and vacuum)

I realize it can be used to reduce required peak temperature but is there
potentially any time reduction benefit to using vacuum?

I saw a paper from the "Electronic Components and Systems Division within
German Electrical and Electronic Manufacturers´Association Working Group",
entitled 

 "Recommendation & Guideline Values for drying for bare PCBs" 

The offered a rather paltry reduction in drying time of 60 minutes from 8
hours if vacuum was used. Doesn't seem like much of a benefit. 


Rich Kraszewski/PLEXUS 


______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________


______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________