Hello,

How about deep dry etch (like BOSCH process) using thick photoresist AZ 4562. Of
course this
is assuming you have access to the facilty. I used to get 1 mm dia hole on 500
um thick silicon wafers.

Best regards,
Shimul

--- On Mon, 6/12/10, Xiaohui Lin  wrote:

From: Xiaohui Lin 
Subject: Re: [mems-talk] how to drill a hole in a silicon wafer
To: "General MEMS discussion" 
Date: Monday, 6 December, 2010, 4:25 AM

ultra sonic drilling can be use to drill 1mm hole on wafers