Hi Pradeep,
We have done studies on PWB reliability in the end use environment and
there is a slow wear out of the copper interconnections over time due to
the thermal cycling (ex day/night, startup/shut down). Mike Freda and
Jason Furlong published a couple of papers on acceleration testing to
estimate the field life of PWB. Those studies are very useful to
establish warrantee expectations.
Intermittent failure in the PWB are observed particularly with microvias
and buried vias. If you ever get the board back and you determine it is
the PWB that is failing, we can tell you how to find the failing
interconnect using beeper for opens and thermal camera for high
resistance and intermittent opens.
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: TechNet [mailto:[log in to unmask]] On Behalf Of mp3
Sent: Tuesday, April 07, 2009 11:29 AM
To: [log in to unmask]
Subject: Re: [TN] PCB Failure analysis
Thanks a lot Pankaj for the inputs. We do agree with you that a
permanent failure is easier to address than an intermittent one. But in
this case the failure has happened after 3 years and that too after it
was functioning satisfactorily. Our boards are electroless copper plated
and we ensure a minimum copper thickness of 25 microns in the PTH.
We do not hv the PCB in hand and we being a PCB fabricator do not hv too
much details on the circuits design and components. But generally we
feel unless there is some malfunctioning resultiing in a high current,
the PCB may not fail. Can u give ur comments on this
Rgds
Pradeep
Karnwal, Pankaj wrote at Tue Apr 07 13:18:23 IST 2009:
>Hi Dwight Mattix
>
>I am agree with you, :-)
>
>But first thing comes in my mind that, have the board is not repaired
>yet to identify the reason of failure ??
>
>We usually do the step analysis :
>1. Simulate the reported problem on our test Jig / end product.
>2. Reason detection of failure with out disturbing the board by
>physically ( Resoldering, tightening of connection ) and electronically
>( Reloading the firmware, upgrading ) 3. Once reason is
>detected/suspected, like failure of component, soldering issue, we do
>the repair activity, with preservation of data, like photo graph of
>affected area , X-ray images, copy the firmware.
>4. If repair activity is done successful, then confirmation of fault is
>important by the revert back the situation.
>5. One the reason or fault location is confirmed then root cause
>analysis of failure is starts...
>
>If component is defective then it can be send to the component Mfg. to
>FA ( Failure analysis ).
>
>You are seems to be lucky you found a permanent nature of fault, it can
>be easily addressed, in case of intermittent failure it becomes 10
>times difficult :-)
>
>BR
>Pankaj Karnwal
>Engineer QA
>
>Barco Electronics System Ltd.
>India
>
>Save Environment for future
>
>
>
>
>-----Original Message-----
>From: Dwight Mattix [mailto:[log in to unmask]]
>Sent: Monday, April 06, 2009 7:12 PM
>Subject: Re: PCB Failure analysis
>
>There's always two conversations going on in these matters. Be careful
>not to mix them too soon.
>
>One is technical/scientific. The other is about business/financial
>responsibility. Don't start the second conversation prematurely.
>
>First things first. Answer first question while keeping your technical
>hat firmly in place -- before going on to discuss second matter.
>
>Have you (or the customer) done a failure analysis yet? Have you been
>able to isolate on the failure and categorize the failure mode(s)?
>
>The second matter is more difficult.
>
>Been there. Done that. Got the tee-shirt. Weekly. :-)
>
>Good luck.
>
>At 10:05 PM 4/5/2009, mp3 wrote:
>>Hello,
>>
>>One of our customers have comeback after 3 years asking for a failure
>>analysis report on a 10 layer industrial grade PCB. The PCB was
>>supplied 3 years back and has been functioning satisfactorilly for the
>>last 3 years. Now the customer has 3 PCBs which have failed and is
>>insisting it is a PCB related failure. The failure in all the
>>3 circuit boards are in the same area around a quadpack IC. We
>>verified
>
>>the traveller card of the boards processed and found all aspects to be
>>compliant. The PCBs were being used in a jig for high reliability
>>harness checking. We feel it should be a component related issue
>>rather
>
>>than a PCB related issue.
>>
>>Can you give us some inputs on the above which will help us in
>>arriving
>
>>at the right conclusion.
>>
>>Rgds
>>
>>Pradeep
>>
>>-------------------------------
>>Micropack Ltd, Bangalore, India
>>
>>---------------------------------------------------
>>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
>-----------------------------------------------------
>
>
>DISCLAIMER:
>Unless indicated otherwise, the information contained in this message
is privileged and confidential, and is intended only for the use of the
addressee(s) named above and others who have been specifically
authorized to receive it. If you are not the intended recipient, you are
hereby notified that any dissemination, distribution or copying of this
message and/or attachments is strictly prohibited. The company accepts
no liability for any damage caused by any virus transmitted by this
email. Furthermore, the company does not warrant a proper and complete
transmission of this information, nor does it accept liability for any
delays. If you have received this message in error, please contact the
sender and delete the message. Thank you.
>
>---------------------------------------------------
>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
>-----------------------------------------------------
>
>
>
-------------------------------
Micropack Ltd, Bangalore, India
---------------------------------------------------
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
-----------------------------------------------------
|
