OmniBSI technology involves turning the image sensor upside down and applying the color filters and micro lenses to the backside of the pixels so that the sensor can collect light through the backside. OmniBSI effectively reverses the arrangement of layers so that metal and dielectric layers reside below the sensor array, providing the most direct path for light to travel into the pixel.

This approach differs from conventional front side illumination (FSI) pixel architectures, where light travels to the photo-sensitive area (the silicon substrate) through the front side of the pixel. This requires the light to first pass through transistors, dielectric layers and metal circuitry required to enable the sensor to convert photons into electrons. These layers of metal and dielectric material can block light or deflect it into neighboring pixels, preventing it from reaching the photo-sensitive area, causing a reduced fill factor and additional problems such as cross talk between pixels.

OmniBSI offers the most direct path for light to reach the sensor, optimizing the fill factor to deliver best-in-class low-light sensitivity. Other performance improvements over FSI include increased sensitivity per unit area, better quantum efficiency, reduced cross talk and improved photo response non-uniformity, all resulting in significant improvements in image quality. OmniVision's current 1.4 µm OmniBSI pixel surpasses all the performance metrics of 1.4 µm, and even most 1.75 µm, FSI pixels.

Finally, BSI technology accommodates a much larger aperture size for lower f-stops, facilitating the development of superior performing camera modules. A larger aperture also means better imaging in low light situations. An additional benefit of BSI is the capability to create more aggressive chief ray angles which enables shorter lens heights. This allows for thinner camera modules and easier zoom tolerances, a critical factor in enabling the next generation of advanced, ultra-thin camera phones.

OmniBSI further extends OmniVision's competitive edge in digital imaging technology while continuing the use of a production-proven 0.11 µm process technology. This provides major cost and performance advantages for OmniVision and our customers.