VTT replaces quartz with silicon in timing circuit

Miniaturised and wireless electronics step in new age

Technical Research Centre of Finland VTT, in co-operation with VTI technologies Oy, has developed a new timer circuit that is one hundred times smaller than the traditional quartz crystal. The substitution of quartz for silicon opens up totally new possibilities for reducing the size of electronic devices and for improving their performance. The device is especially helpful in the realization of wireless electronics. For example, it is possible to install buttons, biometric detectors and sharp clocks into smart cards that are thinner than anything seen before.

A reference of time – a clock – is an integral part of our life, for example, in helping us to synchronize our lives with the surrounding society.

Quite similarly, a reference of time or frequency is needed practically in all electronic devices to allow coherent communication within the device and with the outside world.

For example, in radios and cell phones, the frequency reference enables the reception of exactly the right signal from the fizzling chaos of radio waves.

The central problem of quartz resonators is their large size in comparison with the highly miniaturised integrated circuits. The situation is like having 100 kilometres tall giants serving a single purpose, time, for a city of some million inhabitants.

With size less than one square millimeter the silicon microresonator demonstrated by VTT and VTI enables combining it with integrated circuits in a way not possible with quartz crystals.

Wide applications

The new microresonator foreruns in the way to intelligent sub-millimetre electronics and responds to today’s challenge for further miniaturising and increasing functionality of consumer electronics where radios will replace cables. This cannot be done just by shrinking integrated circuits alone but miniaturisation of supporting components is also required.

Furthermore, the microresonator opens up e.g. entire new ways to develop and implement devices for wireless local area networks like miniature radio receivers. These will find their ways to everyday objects like clothes, shoes, earphones and eye glasses.

Microresonators are also needed in other devices used for wireless communication and data processing. Smart cards, for instance, will become thinner and more intelligent and they do not need any reader. The card may also have a display and biometric identification sensor.

Intelligent electronics will be everywhere; in homes, public spaces, roads, portable equipment, health care, identification and payment.

Manufactured in Finland

Quartz crystal resonators are perhaps the second most important component, right after integrated circuit, in any electrical equipment. The annual world-wide sales of quartz resonators is over a 4 billion units, worth of USD 3 billion (EUR 2.5 billion).

There are already three small start-up companies that have launched their first silicon oscillators. Stability-wise VTT and VTI are the technology leaders.

At first stage, silicon resonators will replace quartz resonators in products where size really matters. But in the long run evolution of quartz technology can’t compete with silicon technology.

VTI Technologies, a leading silicon accelerometer and pressure sensor manufacturer, is reviewing the business potential of silicon resonators. VTI’s sensors are widely applied in automotive, medical and sports applications.

If business partners are found VTI is planning to start manufacturing of silicon resonators in Finland. In this, the company can utilise existing know-how and manufacturing lines. VTI is ready for large volume. Currently the annual sensor production is 23 million units and can be expanded to more than 100 millions.