Rudy, Your description is very accurate. If the boards are more than 2 minutes old, you need to use a preclean solution of 50% cheap orange juice mixed with 50% battery acid. I would also recommend a nitrogen atmosphere for the board designer. Seriously though, we have a Duroid board here that has the same finish requirement. I've been told because of dimensional instability concerns it should not be HASL'd. The concern included possible fracturing of the plated through holes. We are presently considering converting this board to Ni/Au. Norm Dill ---------- From: [log in to unmask] To: [log in to unmask] Subject: Unfused Solder and/or Tin Date: Thursday, October 17, 1996 12:18PM Recently had occaision to have some problems associated with recovering scrapped PCB's that have as final finish UNFUSED plated Tin or Solder (wasn't sure which). Is there anyone who can enlighten me as to why an assembler/user would want such a finish. The finish oxidizes heavily, and quickly, and I suspect likely needs to be cleaned immediately before soldering, or alternately requires a flux so active that it will etch the substrate if not washed off in a few minutes.... Other than that, it is likely wonderful?? Can anyone help me understand this strange (to me) finish? Rudy Sedlak *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************