Hello Dave,
Thank you for your info.
I'm however very surprised with your statement that the problem in
wavesoldering can be solved by selecting another type of flux, looking
at the nature of the problem.
Can you tell me which flux type(s) would solve the problem?
We are using a Soltec SIGMA nitrogen wavesoldering machine, with a
no-clean flux COBAR 398. 

Eddie Van Horen
Alcatel Telecom Belgium







>     Hi Eddie - the problems you have brought up on the use of
Palladium 
>     finishes have been recognized by industry. We (Rockwell) have 
>     experienced both great success and tremendous problems with
Palladium 
>     finished SOICs for both wave and reflow soldering operations. Our
key 
>     ingredient, along with other companies, is the TYPE of flux you
are 
>     using. Not all low residue or water soluble or rosin based fluxes
are 
>     the same! We tested several low residues fluxes and found that 
>     specific fluxes did or did not perform adequately. The use of an
inert 
>     atmosphere (either nitrogen or a vapor phase environment) can give
the 
>     soldering process an extra boost too. We are reflow soldering 
>     Palladium SOICs on military product with very low defect numbers.
The 
>     IPC 002 (component solderability), 003 (PWB solderability), and 
>     Solderable finishes specification committees are all working on
the 
>     issue of non-tin/lead finishes. I would contact Bob Hall,
Solderable 
>     finishes task group chairman, through the IPC and see if he has
any 
>     information the committee can pass on.
>     
>     Dave Hillman
>     Rockwell Collins
>     855 35th St NE
>     Cedar Rapids IA 52498
>     [log in to unmask]
>
>
>______________________________ Reply Separator
_________________________________
>Subject: ASSY: SOIC'S IN WAVESOLDERING (fwd)
>Author:  [log in to unmask] at ccmgw1
>Date:    4/9/96 11:42 AM
>
>
>     
>Forwarded to TechNet for Assistance
>Thanks
>Dave Bergman, IPC
>     
>     
>---------- Forwarded message ---------- 
>Date: Tue, 09 Apr 1996 13:36:48 +0100 (MET)
>From: EDDIE VAN HOREN 014 57 20 08 <[log in to unmask]> 
>To: [log in to unmask]
>Subject: SOIC'S IN WAVESOLDERING
>     
>David,
>I'm looking for help somewhere in the industry on a serious soldering 
>problem.
>Is there something like a bulletin board where items can be posted for 
>discussion?
>Today's problem in a nutshell :
>     
>Subject : wavesoldering of SO-components (mainly SOIC).
>     
>Since a few years, Texas Instruments has changed the lead finish of the

>SOIC's to a layer of nickel with a palladium flash (simplified).
>This can result in 1000 ppm open solder joints when wave soldering.
>In the very near future, starting next june, Motorola is also switching

>to a simular leadfinish. All others are expected to follow soon.
>In the farther future, useing other PCB finishes than SnPb ( NiAu, 
>preservated Cu etc.) will undoubtedly increase the problem.
>I see this as a tremendous problem for those people who are 
>wavesoldering this kind of components.
>Is there a way to find out whether this problem is recognized by users,

>and if somebody sees a solution to the problem ?
>And again, is there a way to put questions to the IPC community?
>     
>Best regards.
>Eddie
>     
>Eddie Van Horen
>Industrial Engineer
>Alcatel Telecom Belgium
>Bell Telephonelaan 2
>2440 Geel
>Belgium
>Tel (32) 14 57 20 08
>Fax (32) 3 240 48 02
>E-mail : [log in to unmask]
>     
>     
>