Contact properties of Ni micro-springs for MEMS probe card

Author

Kataoka, Kenichi ; Itoh, Toshihiro ; Suga, Tadatomo ; Inoue, Kazuo

Author_Institution

Res. Center for Adv. Sci. & Technol., Tokyo Univ., Japan

fYear

2004

fDate

20-23 Sept. 2004

Firstpage

231

Lastpage

235

Abstract

We have developed MEMS probe cards consisting of micro-springs arranged in a 250-μm-pitch array. Three-dimensional spring structures were designed and Ni micro-springs were directly fabricated on a circuit board by a multi-layer electroplating process. ´S shaped´ springs consisting of seven electroplated layers and ´folded lever´ springs of five layers were designed and fabricated. Mechanical properties of the micro-springs were measured and no fracture or deformation were found after applying force of 10 mN for 10,000 times to 7-layer springs, while deformation of 1 μm were found in 5-layer springs. Low force electric contacts of smaller than 5 Ω for Al, and 3 Ω for Cu electrodes were obtained. Difference of the contact resistance in different types of spring structure was found.

Keywords

contact resistance; copper; electrical contacts; electroplating; micromechanical devices; nickel; plastic deformation; 1 micron; 250 micron; Cu; Cu electrodes; MEMS probe card; Ni; Ni microsprings; circuit board; contact resistance; electric contact properties; electroplated layers; folded lever springs; mechanical properties; multilayer electroplating process; pitch array; three dimensional spring structures; Contact resistance; Electrodes; Fabrication; Force measurement; Laboratories; Micromechanical devices; Precision engineering; Printed circuits; Probes; Springs;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Contacts, 2004. Proceedings of the 50th IEEE Holm Conference on Electrical Contacts and the 22nd International Conference on Electrical Contacts

Print_ISBN

0-7803-8460-1

Type

conf

DOI

10.1109/HOLM.2004.1353123

Filename

1353123