Having a little trouble understanding your question. Kovar is copper clad. Are you using this stuff in CTE/core boards or what? Used to use in with Invar, a variation on the them, for LCCC boards. Talk to TI, as one example. They use it, as some other semi manufacturers, to etch lead frames. That's where I found out about it over 15 years ago when using CIC/CCI. MoonMan --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------