I am not sure of the temperature (probably just above the Tg of quartz
which I think is around 1200) but you may want to look at some low
temperature techniques. There are methods using dilute HF which allow
bonding at much lower (even room temperature).
I believe there was a similar discussion here not that long ago so try
searching the archives.

Gareth


rajiv bharadwaj wrote:

>All,
>
>What is the optimum bonding temperature for quartz bonds? I have tried 1100
>degree C for making microfluidic channels. However, I observe leakage of
>current between two closely lying channels over time. I suspect the bonding
>between the substrates in failing.
>
>Has anyone had a similar experience? Any suggestions on this matter would be
>appreciated.
>
>