Hi Steve! Did any of the other 15 assemblies exhibit this "eaten"
appearance? Condensation (on its own/by itself)  in a thermal cycle chamber
will not cause the attack you have experienced. Condensation with flux
residue or fabrication residues can cause the condition on that assembly.
Could someone have done some hand soldering but forgot to clean?

Dave Hillman
Rockwell Collins
[log in to unmask]




"Stephen R. Gregory" <[log in to unmask]>@IPC.ORG> on 05/21/2001 10:22:32 AM

Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond
      to [log in to unmask]

Sent by:  TechNet <[log in to unmask]>


To:   [log in to unmask]
cc:

Subject:  [TN] Assembly "ate-up" after temp cycling...


Hi ya'll!

Well, I survived all the tornados we had yesterday...almost a dozen of them
all around my area!

Came in this morning and one of the supervisors showed me a board that came
out of a temp cycling oven after being in there for 32-hours...the temp
cycles are from 0-70 degrees C., 14 cycles over 32-hours. There were around
15 other boards in the oven,
but one came out looking like there was acid spilled on the backside, mask
was off all over the back, solder joints had been eaten away, as well as
pads!! It was the only board that had this...go to:
http://stevezeva.homestead.com/index.html

I've been asked what may have caused this...it looks to me like there may
have been some flux left on the board. Some say that it may have happened
from condensation that may have occured during the temp cycle, I say if
that
was the case, all the boards would like this. Something else had to be
involved for the copper and solder to be eaten away like this...what do you
guys think?

-Steve Gregory-

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------