Crystal unit miniaturizes, maintains electrical characteristics

Kyocera Crystal Device Corp. (KCD), a specialist in the development and manufacturing of crystal devices, claims that its new crystal unit for smartphones, wearables, and other portable devices is the smallest in the world.

The CX1008 quartz crystal measures just 1.0 x 0.8 mm, yet it delivers the same electrical characteristics as Kyocera’s conventional CX1210 model. And that allows the new crystal unit to be adopted without circuit board revision.

Crystal units — used to generate highly stable reference signals in digital circuits — are based on the unique material characteristics of quartz to oscillate at a precise frequency when a specific voltage is applied.

Now the trend toward smaller, more functional smartphones and wearable devices requires smaller and better-performing crystal units. However, miniaturizing crystal units beyond a certain point could compromise their performance because electrical characteristics such as equivalent series resistance are degraded as the device becomes smaller.

But Kyocera has succeeded in downsizing the crystal unit while maintaining its electrical characteristics, first in its current CX1210 device measuring 1.2 x 1.0 mm and then commercializing the ultra-small CX1008 crystal unit that measures 1.0 x 0.8 mm.

Kyocera has accomplished this by developing a crystal element design technology in collaboration with Kazuya Yamamura, an associate professor at Osaka University. Kyocera has avoided the conventional processes and technologies by applying the ultra-high-precision plasma CVM technology that it developed alongside professor Yamamura.

The new method uses plasma-generated neutral radicals and a chemical reaction at the surface of an object. That enables the control of the quartz crystal with highly precise surface conditions and thickness.

With this technology, Kyocera is also aiming to accelerate the development of low-frequency, high-frequency, and high-precision oscillators for applications such as advanced driver assistance system (ADAS), Internet of Things (IoT), and 5G mobile communications.

Kyocera Crystal Device Corp.: global.kyocera.com/prdct/electro/product/crystal-device/