Maurice Dore * <[log in to unmask]> Wrote:
| 
| 
| What is the shelf life of Copper bare boards with OSP finish.
| What is the nominal RH at which the board may be stored at.
| If it's 45% RH, what's the effect  if environment RH is 
| increased to 60%
| ie what effect will an increase of RH have on the PWB during 
| storeage?
| Thanks in advance.
| 

Since Maurice brought up the shelf life issue of Cu bard boards with OSP 
finish, I'd like to add another similar topic to the discussion.  That is 
- What is the shelf life of electroless Ni / immersion Au surface finish? 
 And what is the appropriate storage environment?  Due to the advancement 
of PCB new surface finishes, a discussion like this will help to promote 
the understanding of their impact on solderability and reliability of 
end-product.  

To Maurice:  In August 1995 edition of Electronic Packaging & Production, 
there is a paper titled as Alternatives to HASL: A User's Guide For 
Surface Finish.  OSP is said to have 12 month shelf life with some process 
dependency.  It is a very good reference to have.


[log in to unmask]