The application of a solder bump technique for contacting a three-dimensional multi electrode array is presented. Solder bumping (or C4: Controlled Collapse Chip Connections, also called Flip Chip contacting) is the most suitable contacting technique available for small dimensions and large numbers of connections. Techniques adapted from the literature could successfully be scaled down to be used for 55x55 μm pads at 120 μm heart-to-heart spacing, yielding well-conducting, reasonably strong bonds.
Frieswijk, T. A., Bielen, J. A., Rutten, W. L. C., & Bergveld, P. (1997). Development of a solder bump technique for contacting a three-dimensional multi electrode array. Microsystem technologies, 3(2), 48-52. https://doi.org/10.1007/s005420050054