Electrodeposition of a Microconnector Bump

Model ID: 11682


This model demonstrates the impact of convection and diffusion on the transport-limited electrodeposition of a copper microconnector bump (metal post). Microconnector bumps are used in various types of electronic applications for interconnecting components, for instance liquid crystal displays (LCDs) and driver chips.

The location of the bumps on the electrode surface is controlled by the use of a photoresist mask. Control of the current distribution in terms of uniformity and shape is important for ensuring the shape and resulting reliability of the interconnector bumps.

The cell is running at a high overpotential so the deposition rate is governed by the transport rate of the depositing ion in the electrolyte. A result of this operating condition is that the electric potentials in the electrolyte and electrode need not be modeled to determine the current distribution on the bump. The model is based on a paper by Kondo and others.