Jeffrey John Holmes
Accountancy at Redfield Rd, Scottsdale, AZ
License number
Colorado 23134
Issued Date
Jun 18, 2004
Renew Date
Dec 1, 2013
Expiration Date
Nov 30, 2015
Type
Certified Public Accountant
Address
Address
8208 E Redfield Rd, Scottsdale, AZ
Professional information
Apparatus And Method Of Elastically Bowing A Base Plate
US Patent:
5461774, Oct 31, 1995
Filed:
Mar 25, 1994
Appl. No.:
8/217831
Inventors:
Jeffrey G. Holmes - Scottsdale AZ
Andrew C. McNeil - Scottsdale AZ
Andrew C. McNeil - Scottsdale AZ
Assignee:
Motorola, Inc. - Schaumburg IL
International Classification:
H01R 4316, H01B 734
US Classification:
29840
Abstract:
An electronic module assembly (10) is constructed by attaching semiconductor die (20, 22) to corresponding ceramic substrates (16, 18). A solder preform (14) is placed between the ceramic substrates and a base plate (12) which in turn is placed on a mounting fixture (26). Steel shims (28-42) are placed around the perimeter between the base plate and the mounting fixture surface. A restraining mechanism (24) passes through the center of the base plate and fastens to the mounting fixture to create a force on the base plate causing it to bow in an elastic manner. The assembly is reflow soldered and cooled with the module assembly restrained in the pre-bow apparatus. The elastic bow compensates for differences in thermal expansion and contraction characteristics between the ceramic substrates and base plate encountered during the reflow and later processes to prevent stresses from developing on the solder bond between materials.