TECHNET Archives

October 2009

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Bob Willis <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Bob Willis <[log in to unmask]>
Date:
Tue, 20 Oct 2009 13:52:23 +0100
Content-Type:
text/plain
Parts/Attachments:
text/plain (84 lines)
Nice one I will have to search through my library for all the other things we use to leave inside boards. Guess you can do a CSI with the finger print and run it through Codus and find the person responsible.

Bob Willis
2 Fourth Ave, Chelmsford, Essex, CM1 4HA England
Tel: (44) 1245 351502
Fax: (44) 1245 496123
Mobile: 07860 775858
www.ASKbobwillis.com
www.SolderingStandards.com 
New Package on Package Workshops 24th November www.ASKbobwillis.com/PoPWorkshops.pdf 
PCB Inspection & Quality Control Workshop 3rd November www.ASKbobwillis.com/faworkshops.pdf
Book Bob's "Step by Step Failure Analysis Workshop"4th November  www.ASKbobwillis.com/faworkshops.pdf
Package on Package Assembly & Inspection Workshops 21th January ITRI www.ASKbobwillis.com/PoPWorkshops.pdf


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Reuven Rokah
Sent: 20 October 2009 10:03
To: [log in to unmask]
Subject: Re: [TN] delamination signatures

There is also delamination caused by finger print stain on inner layers.
It usually round and have its finger print size.


Best Regards

Reuven ROKAH 
e mail: [log in to unmask]
Think green before printing this mail... Thanks

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Chris Mahanna
Sent: Tuesday, October 20, 2009 3:24 AM
To: [log in to unmask]
Subject: [TN] delamination signatures

Hello TN,

I'm wondering how certain one can be about the root cause of delam. simply by reading its signature.  Our experience is similar to Paul Reid's (post attached below).  One obvious question: what about when it is both co and adhesive failure?
Are there other features to the signature that are important in determining primary root cause?

Chris

------------------------------------------------------------------------------------------

My sense is that moisture induced delamination presents as adhesive
delamination that is horizontal cracks that resemble blisters and are
located at a laminated interface (b-stage to c-stage or copper, or along
bundles of glass). It may be that the vapor pressure exerted by trapped
moisture induces a mechanical failure at laminated interfaces.

Material degradation induced delamination more often presents as
cohesive failure that may exhibit cracks with vertical sections, often
bifurcating and spanning across b-stage and c-stage material, even
through glass bundles, and tend to propagate with sharper angles. This
failure mode appears to be more a chemical degradation of the epoxy
system.

Sincerely,

Paul Reid


---------------------------------------------------
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
-----------------------------------------------------

ATOM RSS1 RSS2