Wafer-Level Cameras

LEFT: This picture was taken with an Aptina WLC. RIGHT: To demonstrate the viability of our WLC's image quality, we shot the same scene with a conventional VGA module from a production high-end smart phone.

What, exactly, is a wafer-level camera?

WLC modules provide functionality similar to that of today’s camera modules, but as the name implies, they’re manufactured at the wafer level. The entire camera system—lens elements, filter, sensor, and sometimes even the processor—are included in a miniscule, integrated package. View the video in the frame above for a simplified illustration of this process.

Presently, the efficiencies and resolution of WLCs are best suited to capture and expand the market for lower-resolution camera phones. Aptina’s demonstrated WLC uses a 1/11-inch VGA sensor. The finished product will be a popular choice as a secondary handset camera for video conferencing or as a primary camera on emerging market handsets, which couldn’t otherwise support the cost of a camera.

The images above show a photographic example from our prototype WLC module and compare the prototype’s performance to a production, reflowable module used in a high-end smart phone. Note the WLC prototype’s comparative image quality.

The logical next step

Many companies are currently pursuing WLC technology because it’s universally understood to be the logical future for lower-resolution handset cameras. WLC modules will be the technology of choice in these spaces because they provide cost and handset manufacturing efficiencies that were previously unachievable.

We’re uniquely suited to deliver WLCs because we’re able to leverage our competencies in design and manufacturing. We’re the leader in CMOS imagers for camera phones because we have the best image quality and image sensor/processor combinations. Our market dominance in handset image sensors is founded on the fact that we’re able to offer the complete solution. With WLCs, we’re able to further expand the value of that solution, while leveraging our skills in packaging and integration. WLC is simply the next logical step in our effort to provide the most complete imaging solutions possible.

Integrated optical systems from the image quality leader

WLC modules represent a strategic convergence of several of our key competencies and patented technology advantages. We have a legacy of expertise in building some of the best sensors and pixels in the world. We’ve also demonstrated leadership in our innovative through-wafer-interconnect technology, which enables smaller, sleeker packages. With WLC, we make excellent use of these technologies to integrate the entire optical system and leverage our key competencies in lens integration and sensor tuning.

In order to make excellent pixel-scale optics, we’ve engineered precise techniques for optimizing the optical path near the pixel. WLC modules extend our expertise into the integration of the wafer-scale optics. Because we design both the sensor and lens, we can tailor sensors to specifically match the lens they’re paired with (or vice versa), eliminating the costly time delays typically involved with lens/sensor integration.

And we don’t compromise the die layout. Our chipscale package works with our existing die layouts, which allows us to continue to use the same testing processes and fab monitoring.

Ultimate freedom in industrial design

We’ve long been a technology leader in pixel shrinks and ultra-small die sizes. But small die are only part of the form factor of finished camera modules. Module height has limited camera placement to the thickest parts of the phone or forced compromises in industrial design. Moreover, today’s smallest die pose new obstacles for current manufacturing methods; the associated module optics are simply too small to be handled manually. With a Z-height of just 2.5mm, our WLCs significantly reduce the size of the finished camera, opening up new possibilities for phone design and camera placement.