Dear Frank,
Wow!! This is a tremendously broad question. An overview of wafer bonding
techniques, along with which materials can be bonded?
Actually, the second question is easier. Technically, anything can be
bonded to anything (or nearly so). However, as you mentioned, the method is
important.
First and foremost, your biggest issue with wafer bonding is the Thermal
Coefficient of Expansion (TCE) for each material. Once two differing
materials are bonded together, any change of temperature can cause a stress
gradient, as one of the materials expands more rapidly than the other.
That said, there are three basic bonding processes:
1) Anodic Bonding - this is the use of electricity in combination with
elevated temperatures to perform a bond between an ion bearing glass and an
oxidizable metal.
2) Thermocompression Bonding - Bonding using an intermediate layer, along
with a combination of heat and pressure, to create a bond between two
substrates.
3) Direct bonding - bonding of two extremely smooth surfaces directly,
without use of intermediate layer or electricity. This will typicaly
require a high temperature anneal after bonding.
A good overview paper would be A.R. Mirza and A. A. Ayon. "Silicon Wafer
Bonding: Key to MEMS High-Volume Manufacturing", Sensors, Vol. 15, no. 12
1998.
As to manufacturers for bonding equipment, EV Group has been manufacturing
bonding equipment for over ten years, and has extensive experience in the
field. Please visit our web site at www.evgroup.com.
Best Regards,
Chad Brubaker
EV Group-Technology, Tel: (602) 437 9492 x 119, Fax: (602) 437 9435
E-mail: [email protected], Web: www.EVGroup.com, 03/07/02
-----Original Message-----
From: BERAUER,FRANK (HP-Singapore,ex7) [mailto:[email protected]]
Sent: Thursday, March 07, 2002 2:53 AM
To: '[email protected]'
Subject: [mems-talk] Wafer Bonding Information?
Dear fellow MEMS researchers,
I would like to get an overview of wafer bonding techniques.
I am especially interested to know which materials can be bonded
together by which bonding techniques and what advantages and dis-
advantages there are. Also, which equipment manufacturers there
are. I would be grateful if somebody can point me to good sources
of information or literature.
Thanks and have a nice day,
Frank Berauer
Senior R&D Engineer
Hewlett-Packard Singapore
_______________________________________________
[email protected] mailing list: to unsubscribe or change your list
options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk
Hosted by the MEMS Exchange, providers of MEMS processing services.
Visit us at http://www.mems-exchange.org/
