ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
We have investigated the relationship between contact forces and the fritting which should be utilized for making contact to integrated circuit pads in micromachined wafer probe cards. Micromachined probe cards are requisite to tests of higher pad-density and smaller pad-pitch chips with high-speed signals above 1 GHz. In addition, if a microactuator is integrated into each probe, we can realize a novel probe card in which contacts can directly be switched on and off. The critical problem of the micromachined probe cards, however, is that each micromachined probe cannot generate or endure the force required to break the oxide on an Al pad surface mechanically. To overcome the problem, we planned to reduce the required contact force by putting the fritting effect to good use. For that, in this article, we have measured forces required for making contact to Al pads and contact resistance when utilizing the fritting process for the break of the pad surface oxide. Furthermore, we have also measured the force necessary to disconnect the contact made by the fritting, since it is important to design the probe dimensions and integrated actuators. As a result, we have found that the fritting makes it possible to get low resistance contact to Al pads without applying external forces. Moreover, the contact resistance and the adhesion force, when using electroplated Au bumps as the contact probe, were found to be one-third of those when using electroplated Ni bumps, respectively. This indicates that the Au bump is more suitable for the probe of micromachined probe cards. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1150610
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