Current crowding study of a micro spring contact for flip chip packaging

Author

Cheng, Bowen ; Chow, Eugene M. ; De Bruyker, Dirk ; Shubin, Ivan ; Cunningham, John ; Chow, Alex ; Shi, Jing ; Böhringer, Karl F.

Author_Institution

Palo Alto Res. Center, Inc., Palo Alto, CA, USA

fYear

2011

fDate

23-27 Jan. 2011

Firstpage

360

Lastpage

363

Abstract

Current crowding of a micro spring pressure contact under high current is studied. The spring conducts >; 250 mA electrical current between chips, has large mechanical compliance (>; 30 μm) compared to other packaging technologies, and fits in a 180 μm pitch 2d array. At 250 mA and 65°C, daisy chains of 134 spring contacts in a silicon package show stable resistances and hot spot temperature rises of less than a degree. At 1 A, failure near the spring tip or body is observed. Finite element modeling is performed to study the current density distribution and provide failure spot insight. A strategy is proposed to avoid current crowding.

Keywords

electronics packaging; elemental semiconductors; finite element analysis; flip-chip devices; micromachining; silicon; 2d array; Si; current 250 mA; current crowding; current density distribution; daisy chains; electrical current; finite element modeling; flip chip packaging; mechanical compliance; microspring pressure contact; silicon package; temperature 65 degC; Current density; Flip chip; Gold; Packaging; Proximity effect; Springs; Temperature measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Micro Electro Mechanical Systems (MEMS), 2011 IEEE 24th International Conference on

Conference_Location

Cancun

ISSN

1084-6999

Print_ISBN

978-1-4244-9632-7

Type

conf

DOI

10.1109/MEMSYS.2011.5734436

Filename

5734436