We use large quantities of pin and screw terminals from multiple suppliers and a
burn-off flux. 

Periodically, we returned terminals to a specific supplier for solderability 
issues (which OA flux did not totally resolve). We haven't needed to do this for
a couple of years.

We almost never have problems with terminals within a connector.

Work with your suppliers on improving incoming materials and solderability 
problems will be resolved.

______________________________ Reply Separator _________________________________
Subject: Re: Terminal Solderability
Author:  [log in to unmask] at internet
Date:    10/17/96 8:18 PM


     Hi Ed-
     
     There are not any major changes in store for terminal solderability 
     testing in the ANSIJ-STD-002 (components) specification (unless the 
     committee gets a suggestion to change something). However, there will 
     be some serious discussions in the 002/003 solderability committees on 
     the use of"R" flux versus some activated flux (an RMA) or a low 
     residue type flux for solderability testing. More info should be 
     available after the Naples IPC meeting. My experience with low residue 
     or no clean type fluxes (there is a difference) is that the amount and 
     type of activators used are much less aggressive, quicker to "burn" 
     off, and more soldering technique sensitive. After a short learning 
     curve period we have had very good success with using low residue 
     fluxes in manufacturing. Your terminal finish alloy is a high Sn 
     finish - tin preferentially oxidizes and thus the higher the tin 
     content the faster solderability will be impacted. Also bright acid 
     tin finishes tend to have more solderability problems because of 
     codeposition of the plating bath brighteners if not controled closely. 
     A 320 microinch thick finish should be enough to maintain 
     solderability unless the storage conditions are really bad.  You might 
     try switching to a lower tin content alloy if your design permits it 
     or maybe some pretinning. Good luck.
     
     
     Dave Hillman
     Rockwell Collins
     [log in to unmask]
     
     
     
______________________________ Reply Separator _________________________________
Subject: Terminal Solderability
Author:  [log in to unmask] at ccmgw1
Date:    10/17/96 1:49 PM
     
     
In our switch to a low solids no-clean, we are having problems with 
terminal solderability.  I know from my reading that this is a problem 
thoughout industry.  ASTM spec. #B545-92 gives excellent criteria for 
different classes.  Ours being class three, we spedify the base material, a 
barrier layer; 50microinches of nickle and final plating; 320 microinches 
of tin or tin/lead(12%max lead).  Terminals thus far with this 
specification have performed great.  However, previous designed terminals 
have only required the terminal to be solderable.  We are having a 
difficult time finding suppliers who will sign-up to the solderablity 
specification(dip test).  We were lucky for many years because we used a 
strong OA flux, and were able to solder terminals that were substandard.
We are an automotive supplier and the terminals in question are individual 
terminals autoinserted into boards or terminals that are part of a 
connector.
     
My questions:
--Is anyone else having this problem and how are you handling it?
--I have heard that there are some changes being made to the J-standards 
specific to terminal solderablity
--Does anyone have any suggestions?
     
Thanks for your assistance
     
Ed Holton
Sr. Manufacturing Engineer
[log in to unmask]
     
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