Problem- glass drilling

[vpmachine]

I'm trying to drill .75mm. (.0295) holes in a silicon glass mirror. I'm able to drill the hole with a carbide circuit board drill, the problem is the hole will have tiny chips around the hole.These chips are barely visible to the "naked eye", but they are still a problem. The hole only needs to be about .04" deep as the back side of the hole doesn't matter. Thanks for any help

[trevis1st]

Just to make sure this is Silcon Dioxide. Why such a small whole? I would look into the lapidary supply for ball end diamond burr with a fine mesh. You can also look for a slurry compound and take a stiff rod to spin it on the glass. How thick is the glass? If it's thin enough you could also sandblast your way through. Micro sandblasters are great. =o)

[mackeym]

Diamond drills are also an option. These should produce some nice clean holes. http://www.ukam.com/micro_core_drills.htm

[ImanCarrot]

Yep, diamond sintered drills are the way to go... nice and slow though. If you want to get totaly rid of the chips then wax a sacrificial plate on top of the mirror (can even be a microscope slide) and drill through. Be careful of scratching the mirror. WD40 for coolant is ok.