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Date: | Thu, 12 Dec 1996 08:55:21 -0700 |
Content-Type: | text/plain |
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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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