Hi Paul,
Years ago [Once upon a time....!?!] there was an IBM paper [from a MN location, I think—don't ask me for a reference], that showed that you had to have a 90% physical separation crack to result in a 10% resistance increase. This has been confirmed less rigorously many times—that is why you had so many people wondering about your statement.
Werner
-----Original Message-----
From: Paul Reid <[log in to unmask]>
To: [log in to unmask]
Sent: Wed, Aug 18, 2010 9:28 am
Subject: Re: [IPC-600-6012] opinion poll
Hi Werner,
A number of defects like that still caused a 10% change in resistance.
Crack or separation not withstanding, objective measurement of
resistance change trumps the more subjective microsection evaluation.
Maybe we are on the wrong angle to see the full extent of the damage.
I do know that small corner cracks have produced large changes in
resistance. Failing corner cracks may or may not extend across the full
thickness of the copper.
Sincerely,
Paul Reid
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Werner
Engelmaier
Sent: August 17, 2010 8:22 PM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] opinion poll
Denise/Paul,
I am with Denise on this one-twice.
First, this separation would never cause a 10% resistance increase even
if it goes around all 360 degrees.
Second, this is not a crack, but a separation.
Werner
-----Original Message-----
From: Denise Chevalier <[log in to unmask]>
To: [log in to unmask]
Sent: Tue, Aug 17, 2010 2:25 pm
Subject: Re: [IPC-600-6012] opinion poll
Again I am not sure I would call this a crack. The initial deposit is
not connected to the foil (rounded) but does not appear to have
"cracked". I am also surprised you lost 10% resistance due to this
defect. It appears you have plenty of connection from the surface into
the hole wall. Are you sure this was the cause for the loss of
resistance?
Denise
Denise J Chevalier
Amphenol Printed Circuits
Quality Engineer
Phone - 603-324-4530
Fax - 603-386-6442
CONFIDENTIALITY NOTICE: This email message, including any attachments,
is for the sole use of the
intended recipient(s) and contains confidential and privileged
information. Any unauthorized review, use,
disclosure or distribution is prohibited. If you are not the intended
recipient, please reply to the sender by
email and destroy all copies of the original message.
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Paul Reid
Sent: Tuesday, August 17, 2010 2:04 PM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] opinion poll
Here is a corner crack that produced a 10% increase in resistance.
I don't know if the attachment will make it to the forum.
I am CC Chris with this incase it does not get posted.
We are having problems with our email.
Sincerely,
Paul Reid
Program Coordinator
PWB Interconnect Solutions Inc.
235 Stafford Rd., West, Unit 103
Nepean, Ontario
Canada, K2H 9C1
613 596 4244 ext. 229
Skype paul_reid_pwb
[log in to unmask] <mailto:[log in to unmask]>
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Francis
Byle
Sent: August 17, 2010 1:30 PM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] opinion poll
Careful, you'll give Chris a big head...
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Brown,
Elaine
Sent: Tuesday, August 17, 2010 12:25
To: [log in to unmask]
Subject: Re: [IPC-600-6012] opinion poll
Indeed I am confident enough in Chris's knowledge of 6012 that we would
not be having the
discussion if it were not visible before microetch, then the
microetching must be done to
assess whether the separation extends beyond the plane of the foil,
which it does.
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Monarchio,
James
Sent: Tuesday, August 17, 2010 12:12 PM
To: [log in to unmask]
Subject: EXTERNAL: Re: [IPC-600-6012] opinion poll
I agree with Matt, you need to determine if there is indeed separation
first and inspection without etching is a good way to do it.
Jim
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Byrne,
Matthew J (US SSA)
Sent: Tuesday, August 17, 2010 8:54 AM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] opinion poll
The possibility of a separation at the knee between plating layers needs
to be evaluated without microetching the cross section mount. If no
separation is found then no defect should be called out. Microetching
helps in failure analysis.
Matt Byrne
Manufacturing Engineer, PWB Technology
BAE Systems, Room 795
600 Main St, Johnson City, NY 13790
607-770-2267
[log in to unmask]
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Brown,
Elaine
Sent: August 17, 2010 6:27 AM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] opinion poll
It is non-conforming for both the crack and the plating separation.
The second picture is not so clear cut. If indeed the area at the knee
is separation it is rejectable.
If it is differential microetching, it is not. Hard to tell from the
photo.
I do not think we have any criteria for burning.
Elaine
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Chris
Mahanna
Sent: Monday, August 16, 2010 1:19 PM
To: [log in to unmask]
Subject: EXTERNAL: [IPC-600-6012] opinion poll
Hi Everyone,
Attached is a picture of a thru-hole corner after thermal stress. The
plating is pulse. I believe the corner was 'burnt' because of the
geometry of the (conformant) negative etchback. All the corners show
burn; some show blisters; only this one cracked.
In your opinion, what are the non-conformance(s) if any?
Thanks
Chris
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
NOTICE: This email message is for the sole use of the intended
recipient(s) and may contain confidential and privileged information.
Any unauthorized review, use, disclosure or distribution is prohibited.
If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
---------------------------------------------------
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
-----------------------------------------------------
|
