You can make the holes yourself with a diamond drill bit. Triple Ripple
drill bits come in a number of sizes, down to ~0.75 mm. Look online for
vendors.
Put the bit in a Dremel and run the motor at the highest speed. You can get
a drill press arrangement for the Dremel to make to drill straight and not
wobble as much as holding by hand.
A high-speed mill will also work. 10,000 rpm is recommended as optimal, but
5,000 rpm will also work.

Putting a drop of water on the hole and drilling slowly will keep everything
from getting too hot.

One issue when the the bit exits the bottom of the wafer is that big chips
of glass can break out. To prevent this, use cyanacrylate adhesive
(Superglue) to bond another wafer underneath the waer you're drilling. Drill
all the way through the "product" wafer and into the underlying layer.

As with any drilled hole, it will tend to be a little bigger than the drill
bit, so size the bit accordingly.

For production type applications, you can have a company do it
ultrasonically. Bullen Ultrasonics is one such company.

    --Kirt Williams

----- Original Message -----
From: "???" 
To: 
Sent: Friday, May 01, 2009 1:31 PM
Subject: [mems-talk] Bearing holes in pyrex/glass wafers


> Hi all!
>
> I'm trying to think of a way to make a 2mm diameter through hole in a
> pyrex wafer.
>
> I thought of etching the hole with DRIE, but thought it was inefficient
> and time consuming.
>
> It also seems that I can't use conventional drilling machines to bear
> holes in the pyrex as the substrate is to brittle.
>
> Does anyone know how to drill holes in pyrex/glass wafers?
>
> The features don't have to be too accurate..
>
> Thanks!
>
> TJ