Memory chipmaker Micron Technology has launched its image-sensor business as a more independent division called Aptina Imaging, a move the company believes will improve its flexibility and business potential.
Aptina Imaging now can assemble image sensors, lenses, and other components into a camera phone package. The integration happens earlier in the manufacturing process, when the sensors are still part of their silicon wafer, than is typical today. (Credit: Micron)
The new subsidiary is based in San Jose, California, a Silicon Valley location that's a long way from Micron's Boise, Idaho, headquarters. It will employ several hundred of Micron's 19,000 employees, Micron said.
"We need the additional flexibility and identity to be able to grow the way the markets we see are growing," said Shane Thomas, director of product marketing for the imaging business.
For example, Aptina will have a dedicated sales force and get new options for finding manufacturing capacity to build its products, Thomas said. "We're able to respond more quickly to our customers' needs."
Thomas wouldn't comment on two interesting business possibilities, however: whether Micron might be packaging Aptina for sale or spin-off and whether Aptina might use other fabrication facilities besides Micron's.
"We're always open to exploring other options for our business, but we're not commenting beyond that," spokeswoman Kirstin Bordner said about the possibility of a spin-off.
Using other fabrication facilities could mean Aptina wouldn't have to compete with other Micron manufacturing priorities, and other companies have expertise. Taiwan Semiconductor Manufacturing, for example, builds sensors for Kodak and made a cutting-edge sensor prototype developed by Stanford researcher Keith Fife.
Aptina Imaging's new logo (Credit: Micron)
New products, but are smaller pixels better?
Aptina also has several new product developments for its image sensors.
Most significant in the near term is a refinement of the company's existing process for sensors whose pixels measure 1.75 microns (millionths of a metre) across. The new version improves quantum efficiency (the ability to detect small amounts of light), fill factor (the amount of the pixel that's devoted to capturing light rather than electronics), and dark current (electronic noise that occurs even when there's no actual light to generate a signal in the sensor).
And Aptina has a new chip using the process, a 9-megapixel model of the "1/2.3" format that's very common in compact cameras.
The company also said its first chips using 1.4-micron pixels will be in production later this year. And it's begun making engineering samples of chips with 1.2-micron pixels that will be on sale in 2009.
Making pixels smaller means more can be put on a single chip of a fixed size, or more smaller, cheaper chips can be used to reach a certain megapixel count. But there's a possible penalty: smaller pixels can produce more image noise. Bucking the trend, Nikon's new D3 SLR has comparatively gargantuan 8.45-micron pixels and works well in low-light conditions even at a sensitivity setting of ISO 6,400.
Aptina Imaging's camera module, shown in front, back, and side views to the upper left, measures 4x4x.2.5mm. A conventional phone camera module is at the lower right. (Credit: Micron)
Thomas said Micron is making sure image quality is level or better as it goes to smaller pixels, though.
"We're going to provide 1.4-micron pixels that are equal to if not greater (in quality) to 1.75 micron pixels. And 1.75 is better than 2.2," Thomas said. "Clearly, if you just shrink the pixel and you don't make enhancements to the other stuff around it, you're not going to get what you want. We're absolutely focusing on more than just shrinking the pixel."
Teensy mobile phone cameras -- now prepackaged
On the mobile-phone side of the business, Aptina announced a significant development, a much greater degree of integration that means the manufacturing fab will produce not just image sensors but full-fledged camera modules.
Lenses and other components are attached directly to the silicon wafer, and mobile-phone manufacturers can buy the whole module instead of just the sensor from one company and other components from another.
The approach is reminiscent of buying processed food rather than raw ingredients in grocery stories, a practice that can be convenient for buyers but that also boosts profit margins for suppliers. Thomas preferred to express the idea as "adding more value to the complete value chain."
The camera package measures just 4x4x2.5mm -- a significant notch smaller than conventional phone packages. Aptina hopes this means it will be adopted in the hundreds of millions of low-end phones sold today that still don't have cameras.
The sensor itself has VGA resolution -- 640x480 pixels -- and its dimensions are the teensy 1/11 format, Thomas said. The camera modules will be shipping in samples in the second quarter and will be in production "shortly thereafter," Thomas said.