Flip-chip assembly of an integrated optical sensor

For enabling low cost mass production for photonic circuits, the application of flipchip technology creates huge expectations. We report on the results of a project, having the goal to demonstrate standard packaging technology in combination with integrated optics, entailing demands and limitations different from IC technology. Mainly fiber attachment, but also special features as sensor window accessibility at the top-side of the chip are prohibiting the positioning of the optical layer stack and solder pads at the same side of the silicon wafer. Therefore, feed through technology had to be included. Compatibility issues in combining feed through technology with integrated optics processing have been solved and the feasibility of feed-through metallization and flip-chip assembly in combination with an integrated optical sensor has been demonstrated