Alex,

Having looked in detail at your device application, I believe your device
could be bonded on an Electronic Visions wafer bonding system with near
micron alignment accuracy. One of the unique features of our bonding systems
is the ability to bond substrates of different sizes (for instance a 3"
wafer to a 4" wafer), which is the case in your situation.

I will send you some information on our precision aligned substrate bonding
systems.

Regards,
Dr. Andy Mirza
Technology Manager
Electronic Visions, Inc.
3701 E. University Drive
Ste. 300
Phoenix, AZ 85034
Tel: (602) 437-9492
Fax: (602) 437-9435
E-mail: a.mirza@elvisions.com
Web: http://www.elvisions.com

==========================================

> -----Original Message-----
> From: Alexander Shenderov [SMTP:ashend@bellsouth.net]
> Sent: Wednesday, March 03, 1999 10:28 AM
> To:   MEMS@ISI.EDU
> Subject:      ALIGNMENT OF FAR-APART WAFERS
>
> Dear all:
>
> I have a problem aligning two glass substrates with a pattern of
> transparent electrodes on each.  The wafers need to be  arranged
> face-to-face through a gasket 25 to 100 microns thick (obviously, with
> holes in it).  The electrode arrays on the opposing sides of the
> resultant chamber need to oppose each other to within few microns
> (optimally, a micron).
>
> Trouble is, you can not see the electrodes on both sides at the same
> time - they are waaay too far apart.
>
> Any suggestions will be highly appreciated.  In particular, does anybody
> know a manufacturer who could do such alignment?  I am in RTP, NC - if
> you know several locations.
>
> Thank you all.
>
> Alex
>