Seems to me there is no IPC standard regards the shelf life time. But 
the issue you should concern is the moisture absorption of the PCB. Most 
likely your SMT area shall a/c control, in this case I don't think it is 
a big deal.

But I doubt your PTH area....as you may know PCB without a/c or vacuum 
seal packing may have delimination during reflow/wave due to moisture 
absorption. And I believe this is the reason why your customer concern.

Just my 2 cents..

On 20 Apr 2009 16:24, James lee wrote:
>
> Dear Friends,
>
>  
>
> One of our customer question our PCBA WIP management procedure since 
> he saw some of SMT / PTH subassemblies boards were keeping in 
> production area longer than 3 days,
>
> Some of the boards are longer than one weeks and even a few pcs longer 
> than 1 month, so we had a big discussion about the shelf life of the 
> assembly boards but end of our discussion
>
> It seems he was not convinced, hereby I need your help to let know is 
> there any IPC standards to describe this rule?  
>
>  
>
> Thanks & Regards
>
>  
>
> James Lee
>
>  
>
>  
>