In a message dated 1/25/01 5:30:19 PM Eastern Standard Time, [log in to unmask] writes: << After drilling, these boards go through Blackhole graphitic carbon / Cu flash / image / Cu pattern plate with Sn as etch resist / strip dry film, etch Cu and strip the Sn/ LPI and HAL. >> Sandy, How are you getting the graphite into the holes? Are you using something like IBM's Fluidhead Technology, or simple immersion? Are the circumferential voids only in the vias? Are they truly circumferential (and not just on the glass bundle terminations)? Do you perform a conditioning bake before drill? What desmear process are you using? How "clean" are your holes out of drill? I'll e-mail you directly.......... Bob Lazzara Circuit Connect -- Atlanta (800) 560-9457 --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------