Thomas J Dunlap

US Patent:

55781675, Nov 26, 1996

Filed:

Jan 31, 1996

Appl. No.:

8/594537

Inventors:

Steven A. Switzer - Tempe AZ
Kenneth E. Stegall - Gilbert AZ
Thomas J. Dunlap - Scottsdale AZ
Colleen M. Albrecht - Phoenix AZ

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

B23Q 300

US Classification:

1566541

Abstract:

The etching of a thin substrate (23) is performed using a holder (10). The holder (10) has a base (11) that has a cavity (20). The cavity (20) is pressurized to compensate for the pressure and stress that is applied to the substrate (23) by an etchant solution. The holder (10) also has a sequence of o-rings (22,24,26) that are used to hold the substrate (23) in place and to prevent etchant from leaking into the cavity (20) and attacking a bottom surface (32) of the substrate (23). The pressure necessary to hold the substrate (23) in place is applied by a cover ring (28) that is screwed onto the base (11).