On Apr 1, 2019, at 11:38 AM, [log in to unmask] wrote:

> Hello fellow designers,
>
> One of our products uses 3 PCBA's made on our internal surface  
> mount line. After the PCBA's are created, they are hand soldered  
> together with through hole components and then put into a housing  
> which is then filled with an Epoxy resin (Stycast 2075).
>
> We are wondering about moisture update on the PCBA's between the  
> surface mount process and our hand soldering process. There is some  
> concern that any moisture absorbed would be trapped by the resin  
> and therefore lead to premature electrical failure in harsh  
> applications. Our factory is located in Ontario and is air  
> conditioned in the warm months.
>
> Option 1 (best case)
> We would like to avoid any special drying or baking process on the  
> PCBA's.
> *       Does anyone think there would be a risk in doing this?
>
> Option 2
> We could put them in a dry cabinet. The one we have is a Dr.  
> Storage T40W-600. It runs at 40C and <=5%RH.
> *       Is this temperature of 40C enough to dry out the PCBA's?
> *       How long should they be stored in there before use?
>
> Option 3
> We could buy a baking oven similar to what is used for components  
> prior to re-flow.
> *       What temperature and duration would be suitable?
>
> I have some IPC standards (J-STD-033D, 1601A) but I'm not sure how  
> to relate our PCBA's to the tables of drying/baking conditions.
>
> With Best Regards,
> Mike Messenger, P.Eng, PMP
>
> Siemens Canada Limited
> Manufacturing Engineer
> PD PA PI LWT IE
> 1954 Technology Drive
> Peterborough, ON K9J 7B1
> 705-740-7025
> [log in to unmask]<mailto:[log in to unmask]>
> www.siemens.ca<http://www.siemens.ca>