As the circuitry width become finer (3/3 mil, 2.5/2.5mil), I would like to know whether the line width tolerance got new specification or not. For PCB, the general IPC standard is 20% of circuitry width. Let's say circuitry width 6mil got +30um tolerance. If circuitry width 3mil, do we still use 20% of circuitry width as the specification. Does IPC have the new specification for fine lines? Or from the PCB design point of view, what should be the general tolerance for 3/3mil and 2.5/2.5mil? Wish your helpful information! Best regards! Li Juan --------------------------------------------------------------------------------- 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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest 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 ---------------------------------------------------------------------------------