That's a very good question. I would like to know also how flat a plated shut via can be if that's the correct term. Is there an IPC specification addressing this? The ~ 10 mil (.25mm) or greater finished hole vias in pad that I have filled and plated-over are always very flat. The ~ 4 mil (.1mm) finished hole micro vias in pad are mostly always flat. Sometimes I see a small dimple in them that looks less than 1 mil deep. Cheers Donald Kyle At 09:01 AM 10/25/2005, you wrote: >Hi TN, > > From an assembly perspective, what is the maximum surface roughness > tolerable for via in pad 0.5mm pitch BGA, particularly >larger parts with pin counts >=80? > >Same topic, but from a fabrication viewpoint:- What is achievable using >either 1 stage plated shut process or a 2 step process >using filled/levelled microvia which is then plated over? > >Best Regards > >David Greig >______________________________ >GigaDyne Ltd >http://www.gigadyne.co.uk ><http://www.gigadyne.co.uk/> <http://www.gigadyne.co.uk/> >______________________________ > > >--------------------------------------------------- >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 >847-615-7100 ext.2815 >----------------------------------------------------- --------------------------------------------------- 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 847-615-7100 ext.2815 -----------------------------------------------------