Specifying the drill size will not prevent fractured barrels or
innerlayer separation. People are designing on the edge of drill tool
capability now. Very small vias are hard to plate and get adequate
copper to survive thermal shock. Just ask for a thermally shocked
cross section of the smallest via on the panel if you need the peace
of mind. JMO
At 03:11 PM 01/17/2006, you wrote:
>I do not have a problem with through-holes for component leads and press-fit
>pins be specified that way (lots of mechanical redundancy), but I sure have
>seen a lot of plated-through vias with fractured barrel walls and
>innerlayer-separation that were not properly spec'ed.
>
>
>
>Werner
>
>---------------------------------------------------
>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
-----------------------------------------------------