Options
2008
Conference Paper
Titel
Concept for packaging of a silicon based biochip
Abstract
We report on a concept for packaging of a silicon-based biochip for integration with a fluidic cartridge, thus forming a lab-on-chip (LOC). The biochip, which has dimensions of 2 mm x 2 mm, comprises a central membrane having a diameter of 200 ?m, and 20 bond pads with metal tracks leading to the membrane. The packaged biochip provides a fluidic interface to the cartridge as well as electrical interfaces to the biochip electronics being located in a readout instrument. The packaging method ensures the strict separation between the wet sensing area and the electrical contacts. The challenge is that the biochip has a freely moving membrane, additionally with a delicate biological coating, and this membrane is positioned on the same side of the silicon chip as the bond pads for the electrical interconnection. For packaging, the biochip is mounted into a recess of a rigid printed circuit board (PCB). The biochip is electrically connected with the PCB using a proprietary MicroFlex interconnection (MFI) technology, thus resulting in a flat surface towards the reaction chamber of the fluid cartridge. After the realization of the electrical contacts between the sensor chip and the PCB, the entire chip is encapsulated with an epoxy layer, leaving the membrane of the biochip uncovered. To protect the membrane against the fluidic epoxy, a specially shaped silicone casting-mould is used. In a last step, the biochip with the epoxy layer is glued on the bottom side of the cartridge.