It is today that the ISSCC officially starts, but yesterday the tutorials, two forums and two evening sessions were organized. For the imaging community, the “Silicon 3D-Integration, Technology and Systems” forum was of interest. And especially the talk by Jean-Luc Jaffard of ST Microelectronics, entitled : “Chip Scale Camera Module Using Through Silicon Via Technology”. The agenda of his presentation looked as follows : imager market outlines, camera module physical size contributing factors, optical technologies, through silicon via process, camera module assembly and reliability, future evolutions and conclusions.
In general this talk could be seen as a great overview of the state-of-the-art of TSV for imagers. For the non-imaging experts in the room the talk contained a lot of new information (and basically the forum was addressing a broad spectrum of interested people, not just imaging experts). For the imaging engineers, the most interesting part was situated in the second half of the talk.
Jean-Luc showed a nice comparison of pros and cons of an injected plastic lens, a molded glass lens and wafer level optics. Basically wafer level optics go hand-in-hand with TSV technology. A series of cartoons illustrated the process of the TSVs, as well as the future integration of camera modules : wafer lens, TSV sensor, image processing, memory all stacked on top of each other as a real 3D masterpiece. Discussing about the wafer level camera roadmap, Jean Luc mentioned that today the modules already make use of wafer level optics, but that the modules are still individually assembled. Next step will be the combination of wafer level optics and TSV sensors bonded before dicing, while in a couple of years from now we will see wafer level optics, including auto-focus means, bonded to a TSV sensor before dicing.
If someone thinks that the development of camera modules soon will come to an end, the answer is simply NO !
Albert, 08-02-2010