Andy is correct its a typo -
I do NOT allow removal of unused inner layer pads.
Paul
On Thu, 5 Aug 2010 17:24:11 +1000, Andy Kowalewski
<[log in to unmask]> wrote:
>That's a typo, right? If the holes without pads fail first, shouldn't you
>have said ".... - so I do NOT allow removal of redundant inner layer pads"?
>
>Cheers........
>
>Andy K.
>+61 2 9499 4853 begin_of_the_skype_highlighting +61 2 9499
4853 end_of_the_skype_highlighting
>
>-----Original Message-----
>From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of Paul O
>Connor
>Sent: Thursday, 5 August 2010 16:47
>To: [log in to unmask]
>Subject: Re: [DC] Fwd: non-functional pad removal
>
>I carried out thermal shock testing on 12 Layer 2oz cu daisy chain PTHs
>boards, Aspect ratios of 4:1 & 6:1 with 4 different hole wall thicknesses
>(from 22um up to 70um) approx 1300 Test hours
>the results shows the holes with pads removed fail first independent of hole
>wall thickness or aspect ratio - so I do allow removal of redundant inner
>layer pads.
>
>
>
>On Wed, 4 Aug 2010 09:26:03 -0500, Jack Olson <[log in to unmask]> wrote:
>
>> oops, I said it wrong. I went back to my notes, Brian Ellis said keep them
>>in:
>>
>>-=-=-=-
>> Subject: Re: non-functional pad removal
>>From: Brian Ellis <[log in to unmask]>
>>Date: Tue, 13 Jul 2010 08:45:21 +0300
>>If the inner layer copper thickness is >35 µm (and sometimes 35 µm),
>>e.g., power planes, then you should keep the copper there for fear of
>>resin starvation.
>>Brian
>>-=-=-=-
>>
>>
>>Also, I think I might have said some thing else wrong...
>>Werner said on July12
>>"To prevent the latter, remove NFPs from large diameter holes and leave
>them
>>in place for small diameters."
>>and I said that backwards in my sample note
>>
>>and just now on aug04 Werner said:
>> "Don't remove NFPs from layers 1,2,3,n-2,n-1,n—FOR LARGER DIAMETER HOLES"
>>Now I'm not sure what to remove and what to leave
>>
>>(and I'm just an instigator, no knowledge of this subject)
>>
>>Jack
>>
>>On Wed, Aug 4, 2010 at 8:56 AM, Dave Schaefer <[log in to unmask]>
>wrote:
>>
>>> Jack,
>>>
>>> Thanks for summarizing here, I do also monitor Technet but find it's
>>> difficult to locate topics of interest without plowing through a lot of
>>> unrelated and often NTC content there.
>>>
>>> There's a part of your summary that I can't seem to digest :
>>>
>>> "In additon, there was a direct conflict between two comments, one
>>> recommended removing NFPs for thick power planes (BEllis), the other said
>a
>>> DOE testing 24 layers of 2oz was more reliable with NFPs removed
>>> (GGagnon)."
>>>
>>> Both comments seem to indicate thick power planes should have NFPs
>removed
>>> -
>>> can you clarify?
>>>
>>> Thanks,
>>> Dave
>>>
>>>
>>
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