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From: | |
Reply To: | TechNet E-Mail Forum. |
Date: | Tue, 5 Feb 2002 19:01:27 EST |
Content-Type: | multipart/alternative |
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Hi Kathy,
Did a little surfing to see if I could find some images similar to yours.
Didn't find any, but did find some interesting sites that >may< be relevent.
First one is a link about glass compression. This happens when the laminate
is compressed with fast heat-up rates. Said to possibly be a cause for
drilling problems including delamination. Go to:
http://www.arlonmed.com/applications/compres.htm
Next is a link from a manufacturer of entry and back up materials. They make
a backup material called "SlickBack" (pretty catchy name huh?). There's some
good SEM images there of hole wall quality using their material vs standard
materials...
http://www.lcoa.com/pages/slickback_mg.htm
The last link has standard guidelines for feed and speed rates used for
different laminates, hole sizes, stack heights, how many hits a tungsten
carbide bit should take before replacing, etc. Good reference page.
http://www.holders.co.uk/kennametal_overview.htm
As "murphy" always has it, you don't find out about these problems until
AFTER you build the assemblies huh? Same logic always goes for misloaded
components, it's NEVER the 1-per, it's always the 50-per...such is our life
(GRIN)
-Steve Gregory-
> I have a few assemblies that a customer had asked me to look at and I
> noticed an oddity around the vias. It looks like there is delamination
> around the vias. Steve was kind enough to post these photo's on his web
> page for all to view. I need to know if this is delamination or just
> haloing. I saw an issue like this a long time ago (15 years ago) and at
> that time we scrapped them because we didn't know what the issue was caused
> by. Some at that time thought the drill bit for that size was either
> pushed to fast through the material causing a slight delanmination or the
> drill bit was dull.
>
> I appreciate any assistance or thoughts on the issue. I have already
> suggested that a cross section may have to be completed.
>
> http://www.stevezeva.homestead.com
>
> Thanks in advance.
>
> Kathy
>
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