Pyrex can be bonded to both sides of a wafer by anodic pulse bonding.
The technique is in the literature, but I do not have the reference handy.
Depending on your channel width anodic bonding can result in the thinning
of the channel height due to
the pyrex moving into the channel during bonding. This is also described in
the literature.
Depending on what materials you are putting into the flow channels, and the
pressures involved other techniques for bonding are available.  The
literature has also  used HF, sodium silicate, and polymers to bond pyrex
to silicon.

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At 09:45 AM 3/14/02 -0600, you wrote:
>I need to bond Pyrex to both sides of a silicon wafer.  One of the pieces
>of Pyrex is a full 4 inch diameter wafer (same as Si wafer)  with a
>thickness of 0.5 inches.  This is used as the base for a flow cell etched
>into the wafer.  The other piece of Pyrex is a cover slip for microscopy
>work so it is only 0.13 mm in thickness and a 50mm square.
>
>Has anyone ever anodically bonded pyrex to both sides?  All the literature
>I read only describes the process for one side.
>
>Thank you,
>Connie Smith
>Department of Chemical Engineering
>Rice University
>6100 Main MS 362
>Houston, TX 77005
>Phone 713-348-3507
>Fax 713-348-5478
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