Hi,
I agree with Tom that a micro-section will better confirm if this is a
delamination or otherwise.
However, if it is indeed a delamination, how could I confirm if it is
moisture related or contamination or a PCB supplier related process?
What sort of failure analysis could be performed on the affected board? I am
tempted to peel the surface layer to analyse indepth.
Any inputs is much appreciated. Thanks.
Best regards,
David.
----- Original Message -----
From: "Tom Parkinson - Quality System Manager - WinTronics, Inc."
<[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, May 20, 2003 11:48 PM
Subject: Re: [TN] What is this defect?
> Lum Wee Mei,
>
> I looked at the pictures of your PCBs on Steve's site and it was the
> same thing I ran in to a month ago. I was convinced it was a
> delamination, the board vendor said no way - it was pink ring. I sent a
> board to a third party test house and they did a microsection - sure
> enough it was a delamination. So be careful in judging pink ring -vs-
> delam unless you have a microsection to make a better determination.
>
> Tom
>
>
>
> Lum Wee Mei wrote:
> >
> > Glenn,
> >
> > Thanks for your input. The information has been very useful and I am
digging up
> > more information on "pink ring" and looking into the IPC-6015 for
details.
> >
> > Steve,
> > I am most grateful to you for the fast service despite almost 8:45pm
your time.
> >
> > Regards,
> > Wee Mei
> >
> > [log in to unmask] wrote:
> >
> > > Scary world, I just went through something very similar to this. It
turned
> > > out to be "Pink Ring". Maybe somebody has a better explanation, but
it was
> > > loss of black oxide around certain vias, mainly power and ground
planes, due
> > > to full metal (no spokes). My pictures look a lot like yours! We
decided
> > > it wasn't a defect since, according to IPC-6015, it didn't affect
> > > functionality. And, that was after accelerated life testing.
> > >
> > > Glenn
> > >
> > > -----Original Message-----
> > > From: Lum Wee Mei [mailto:[log in to unmask]]
> > > Sent: Monday, May 19, 2003 4:56 PM
> > > To: [log in to unmask]
> > > Subject: [TN] What is this defect?
> > >
> > > Hello,
> > >
> > > I have a defect that looks like delamination. One important
observation
> > > noted is that this defect is found only around PTH vias NOT component
> > > holes. In addition, this "suspected delamination" surfaces are very
flat
> > > to touch - no bulging. I do not think it is delamination because I
have
> > > never seen delamination occurs around PTH. However, I am be wrong.
This
> > > defect appear in several areas on the board but funny observation is
> > > that 3 out of 5 pcs of the fabricated boards have the same defect at
the
> > >
> > > same locations, around P3 and P4. The only difference is the intensity
> > > of the defect.
> > >
> > > This is a 8-layer design with L4 as power and L5 as ground. As such,
> > > clearances are expected for pads not to be shorted to these
> > > layers.However, instead of solid round clearance around the pads,
> > > irregular shapes are found. In one of them, the clearance actually
> > > overlap each other. The layer stackup is as follows :
> > >
> > > ---------------------------18um
> > > prepreg 1080+7628
> > > -----------------------core 0.21mm(35um/35um)
> > > prepreg 1080*2
> > > -----------------------core 0.21mm(35um/35um)
> > > prepreg 1080*2
> > > -----------------------core 0.21mm(35um/35um)
> > > prepreg 1080*2
> > > ---------------------------18um
> > >
> > > I have seek Steve's kind assistance to download 4 pictures of the
> > > defects. Kindly look at them. I would appreciate your opinions on :
> > > 1. If this is not delamination, what defect is it?
> > > 2. What is or are the likely cause(s)?
> > > 3. Does it has impact to reliability?
> > >
> > > Thanking you all in advance.
> > >
> > > Regards,
> > > Wee Mei
>
> ---------------------------------------------------
> Technet Mail List provided as a free 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/html/forum.htm for additional
> information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
> -----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------
|
