Lyle,
     
     Obviously there are many different factors that can be contributing to 
     this problem, some of the more obvious are (back-up or entry material 
     problems, poor repointing of drills, etc...)
     
     One thing I would check if you haven't already, does your deburring
     machine have a high pressure spray? Is this working properly or do you
     have a number of clogged nozzles. Most debur machines that I'm 
     familiar with have high pressure and if that isn't working properly it
     will push the burr down into the hole but the water spray is not 
     enough to "blow" the burr out through the bottom of the hole/panel.
     
     Terry Pearo
     Marcel Electronics 
     


______________________________ Reply Separator _________________________________
Subject: Re: FAB: hole burrs
Author:  [log in to unmask] at Internet
Date:    12/12/96 11:56 AM


It started maybe 5 to 6 months ago.
     
     
     
>______________________________ Reply Separator 
_________________________________
>     Has this problem just started recently or has it been an ongoing 
>     problem for some length of time?
>     
>     
>     Terry Pearo
>     Marcel Electronics
>
>
>______________________________ Reply Separator 
_________________________________
>Subject: FAB: hole burrs
>Author:  [log in to unmask] at Internet 
>Date:    12/11/96 2:55 PM
>
>
>We are experiencing sporadic instances of copper burrs after deburring.  It 
>appears that the deburr brushes are "shaving" burrs and almost but not quite 
>removing them.  Describing the condition as a burr may be misleading because 
>most people think of a burr as protruded copper.  These burrs exist when the 
>surface is 100% smooth and free of surface burrs after drill . What is left 
>is a curl of copper protruding the hole. What we have observed and done so far:
>     
>-When it happens, it is on the whole job-maybe a 2 panel run, maybe a 100 
>panel run.
>     
>-it occurs on multilayer and double sided panels. 
>     
>-it happens on .5 ounce through 2 ounce foils. 
>     
>-we have tried every combination of brushes.  320 grit works as well as 
>anything else. (The deburr machine has 2 brushes top, 2 brushes bottom.  The 
>operators are performing brush footprint checks several times a day.
>     
>-it appears to be on the top side of the panel as it is drilled. We have had 
>our drill tool supplier in (inconclusive)and have emphasized the obvious to 
>the drill operators-clean between panel stacks, make sure depth is correct, 
etc.
>     
>Any ideas?
>     
>thanks,
>     
>Lyle Anderson
>[log in to unmask]
     
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