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
>
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> ------------------------------------------------------------------------
> Name: viaset9.jpg
> viaset9.jpg Type: JPEG Image (image/jpeg)
> Encoding: base64
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