If the drawing did not state that the hole size in the drill chart are
finished hole sizes then the board house has an out. Technically the board
meets print and there is nothing you can do but update your drawings. You
can not leave anything open to interpretation when it comes to the
manufacturing drawings, after all it is the only way to communicate what it
is you really want or need.
Ted T.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Lenny Carter
Sent: Tuesday, July 08, 2008 11:29 AM
To: [log in to unmask]
Subject: Re: [TN] Flex specifications - tolerance on hole size
I'm no expert by any means, but all pcb persons I have ever discussed this
with have always said the stated hole size is finished. Both pcb vendors
and pcb layout persons.
It is the pcb manufacturer's responsibility to know their process and over
drill hole diameter so the finished hole size is attained after plating.
Just my $.02
Lenny Carter
Design Engineer
ERG, Inc.
www.ergpower.com
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Graham Collins
Sent: Tuesday, July 08, 2008 11:45 AM
To: [log in to unmask]
Subject: Re: [TN] Flex specifications - tolerance on hole size
Hey guys.
Thanks for all the opinions and info. I'm stuck in the middle, on one side
is a designer saying that it means pre-finishing size, on the other I've got
a fabricator saying it means finished hole size. The drawing is ambiguous
on this point. I just want parts to build things with!!!
I do agree with Werner that it does not matter as they are only vias, but
once someone had inspected and measured something it became a debate.
regards,
- Graham
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ken Bloomquist
Sent: Monday, July 07, 2008 7:57 PM
To: [log in to unmask]
Subject: Re: [TN] Flex specifications - tolerance on hole size
Hi Werner,
I like your thinking but...
I'm not in the quality department, no offense to those of you who are, but I
wouldn't want to be ;-) But thinking like an inspector, how would you verify
that you got the right size holes if you don't call out a finished hole
size? I guess you could do a cross section but a pin gage is a lot simpler.
Just thinking out loud,
KennyB
-----Original Message-----
From: Werner Engelmaier /* [mailto:[log in to unmask]]
Sent: Monday, July 07, 2008 3:36 PM
To: [log in to unmask]
Subject: Re: [TN] Flex specifications - tolerance on hole size
Hi Graham,
Why do you care what the finished hole size is? Do you put component leads
into 0.028"/+- 0.003" holes, that is 25 mils minimum?
The finished hole size specifications are an anachronism harking back to the
THT-days-today they only should be specified for componet lead holes.
For vias the drilled hole diameter should be specified-it is much more
important.
Werner
Future workshops:
Pb-Free Soldering Processes-Survival, Quality, Reliability, July 17/18,
Thal, Switzerland Pb-Free Soldering Processes-Survival, Quality,
Reliability, July 21/22, Bad Segeberg, Germany Pb-Free Soldering
Processes-Survival, Quality, Reliability, August 18, Orlando Reliability
Issues with Lead-Free Soldering Processes, September 22, Schaumburg Failure
Mode and Root Cause Analyses Reliability (Fatigue, Brittle Fracture,
ENIG), September 22, Schaumburg
Solder Joint Reliability: Parts 1 & 4, Oct. 9, Moscow, Russia Solder Joint
Reliability: Parts 1 & 4, Oct. 17, Timisoara, Rumania Solder Joint
Reliability: Parts 1 & 4, Oct. 22, Tallinn, Estonia
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 15.0
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 15.0
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
-----------------------------------------------------
|
