Hi Louis - I'll steal a response from Doug - " it depends"!  If you are 
going to procure and assembly the ENIG finished circuit boards within 6 
months and the boards are going to have good storage, then no, meeting the 
Cat 3 level is not necessary. However, if you are going to hold the boards 
for a year in poor storage conditions, then a Cat 3 level may be required 
to produce high process yields. You need to inquire "why" someone has 
placed the Cat 3 level requirement and what was their rationale. There may 
be a good reason or it may be a case of someone thought it might be a good 
idea with no concrete value added reason.

Dave Hillman
Rockwell Collins
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From:   Louis Hart <[log in to unmask]>
To:     <[log in to unmask]>
Date:   03/23/2013 03:58 PM
Subject:        [TN] Non-HASL finishes and J-STD-003B durability 
conditioning
Sent by:        TechNet <[log in to unmask]>



Technetters, I am looking at some printed circuit boards with ENIG finish, 
which have a requirement that they pass J-STD-003B, class 3, solderability 
testing, with durability 3 conditioning (72% humidity at 85 C for 8 
hours).

IPC-4552, Appendix 3, 'Qualification of ENIG process' says 'Solderability 
shall meeting requirements of J-STD-003 Category 3...'

Looking at the draft J-STD-003C, Table 1-3, lists ENIG among numerous 
surface finishes requires solderability acceptable after exposure to 
default conditioning parameters corresponding to durability 3.

Is conformance by ENIG to such a requirement achievable in reality?

Louis Hart
Compunetics
Monroeville, PA
USA
[log in to unmask]<mailto:[log in to unmask]>
412-858-1232


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