I think the question would be better asked internally first...how much
clearance do "you" need...any worthy PCB CAM department will have 1) the
software/design capability to output clearance that 2) the production
processes can achieve...to reach the desired results...

If you need 2 mil clearance...then state upon the fab drawing what you
need...and a worthy shop can do that for you...

Some shops adjust clearances to meet the edge of the pads...this forces
closer registration...others increase clearances to maximum allowed by their
processes (and allowed on the fab drawing, if addressed) to provide for
greater flexibility in processins...i.e. registration issues...

So...what clearance does your company, or product need?

Franklin

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------