Sherman, I posted a similar question several months ago concerning heat sealing and other solderability storage issues. Of the responses I rec'd, no one provided a reason or information source that stated why heat sealing should not be used today. I know it has been avoided in the past. Some of that came from older military requirements based on the theory that the trapped gases created during the sealing process promoted tin oxidation. Since the plastic bag chemistry has changed in recent years, this may no longer be a concern. Some component manufacturers are now shipping solderable components in heat sealed bags. Norm Dill [log in to unmask] ---------- From: TechNet-request To: technet Cc: xxx{REMOTE/REMOTESUN/BGERPHE}%MSMAIL.Trimble Subject: ASSY: Packaging Date: Thursday, July 18, 1996 7:04AM Our shipping folks insist on packaging board level assemblies in static shielding bags and HEAT SEALING them. As I recall several years ago I heard that heat sealing plastic bags for PCBs at the board level was bad. Seems as if some vapors were deposited on the fab decreasing the solderability. Does anyone know of a reason to require that these bags be taped shut and not heat sealed??? Thanks in advance Sherman Banks [log in to unmask] *************************************************************************** * 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. * ***************************************************************************