Development of Bi-Directional Module using Wafer-Bonded Chips

Double-sided module exhibits electrical and thermal characteristics that are superior to wire-bonded counterpart. Such structure, however, induces more than twice the thermo-mechanical stress in a single-layer structure. Compressive posts have been developed and integrated into the double-sided module to reduce the stress to a level acceptable by silicon dice. For a 14 mm x 21 mm module carrying 6.6 mm x 6.6 mm die, finite-element simulation suggested an optimal design having four posts located 1 mm from the die; the z-direction stress at the chip was reduced from 17 MPa to 0.6 MPa.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Electrical Engineering

Department dc:contributor.department

Electrical and Computer Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2015

Author dc:creator

• Kim, Woochan

Chair dc:contributor.committeechair

• Ngo, Khai D. T.

Committee members dc:contributor.committeemember

• Agah, Masoud
• Guido, Louis J.
• Ekkad, Srinath
• Lu, Guo Quan

• Double-sided die
• wafer-bonded chip
• hourglass joint
• compressive post
• module fabrication
• module characterization
• high density integration
• thermal management
• thermo-mechanical stress
• reliability test

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

vt_gsexam:3944

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/51170