Gerald,

Punching is not a lost art, it's merely a technique that has limitations.  Many fabricators stopped using the technology years ago because of those limitations .  Bottom line: it is another process used to manufacture PCBs.  As with any other process, one must understand the limitations.  Punching (holes and/or outline) for single sided boards from paper based laminates or random glass laminates is a common practice for high volume.

Punching holes for a plated thru hole board falls into the class 1 or maybe (really a stretch) low end class 2 board for any laminate type.  Punching holes that are to be plated thru is a techinical challenge.  Using the techonolgy on a multilayer board is something I don't care to consider.

Drilling holes for 2 sided and multilayer boards and punching (blanking) the outline is something that can be economically justified.  Rough edges and fractured laminate are factors one must understand when specifying a punched board.

Don Vischulis

-----Original Message-----
>From: Gerald Gagnon <[log in to unmask]>
>Sent: Mar 18, 2006 9:57 AM
>To: [log in to unmask]
>Subject: Re: [TN] Die Punching PWBs as opposed to drilling and NC routing
>
>Joe,
>
>Thanks.
>
>I hope there will be more comments particularly from producers and users of
>punched PWBs. Coming from the mainstream, punching seems to be a lost art.
>
>I am concerned about punching multilayers particularly with the newer
>materials that we use today which might not have been evaluated or
>formulated for punching.
>
>Thanks,
>
>Gerry
>
>
>From: Joe Fjelstad <[log in to unmask]>
>Reply-To: TechNet E-Mail Forum <[log in to unmask]>, [log in to unmask]
>To: [log in to unmask]
>Subject: Re: [TN] Die Punching PWBs as opposed to drilling and NC routing
>Date: Fri, 17 Mar 2006 16:00:16 EST
>
>NC drills are highly versatile and stacking panels provides some economy
>and
>so it will be hard to displace them.
>
>Punching can be fast (all holes at once) but is one at a time and depending
>on approach, hole count and feature size the tooling might be costly and
>must
>be amortized over a number of panels to pay for the tool.
>
>Hole quality is not as good making plating more of a challenge if you plan
>on doing double sided PCBs. I have not heard of MLBs being punched  (except
>when the drills got too dull ;-)
>
>There should also be some concerned about punching small holes on fine
>pitch
>in glass fabric as there would be a higher risk of CAF, however  for polymer
>films it is not so much of an issue.
>
>I expect there will be other comments coming.
>
>Joe
>
>---------------------------------------------------
>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
>-----------------------------------------------------
>
>_________________________________________________________________
>Don&#146;t just search. Find. Check out the new MSN Search!
>http://search.msn.click-url.com/go/onm00200636ave/direct/01/
>
>---------------------------------------------------
>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
-----------------------------------------------------