Oh good grief.. Do I have to learn another new trick..? About 30 plus years ago both terms meant the same thing-- a bare board. If it had components on it, it was called an assembly. It all depended on where you came from, and who taught you. I sure dont remember seeing any books from IPC with definitions back then. How about "innerlayers", "cores", and "details". I hope they all still mean the same thing. Leonard Johnson [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. * ***************************************************************************