The more pads the more hole quality suffers from drilling.  Also the
thermal/mechanics of a PTH with pads on more layer than needed is
affected adversely.

Non-functional pads should be removed.

Jeffrey Bush
Director, Quality Assurance and Technical Support

VERMONT CIRCUITS INCORPORATED
  76 Technology Drive - POB 1890
    Brattleboro, Vermont 05302
      Voice: 802.257.4571.21 Fax: 802.257.0011
           http://www.vtcircuits.com
 

-----Original Message-----
From: Brian Ellis [mailto:[log in to unmask]] 
Sent: Wednesday, February 09, 2005 9:54 AM
To: [log in to unmask]
Subject: Re: [TN] Removal of Non-functional pads

I have always considered non-funct. pads as being desirable, because
they help compress the prepreg layes into a compact mass which would
reduce nasties like CAFs etc. At the same time, the extra copper keeps
the drill bit cooler by conducting more heat away.

Brian

Pete menuez wrote:
> Can someone explain the advantage of removing non-functional pads on
> innerlayers? We are contemplating adding non-functional pads to our
designs
> but want to understand the impact if we do.
>
> Thanks
>
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