A Magneto Resistive Sensor for Shaft Encoder Applications
A microfabricated magneto resistive sensor for encoder applications reduces cost by 50% and increases life
Technologies used

Microfabricated sensors on Silicon
Mixed Signal ASIC

Industrial sector (PRODCOM code)
    332 Instruments for measuring
FRITZ KUEBLER GMBH - ZAEHL- UND SENSORTECHNIK was founded in 1960. It now has 120 employees and designs, manufactures and sells worldwide electromechanical and electronic counters, message displays and encoders. Encoders are sensors used in motion sensing applications where angular displacements and distances are measured (e.g. robotics).

The objective of the AE was to improve the encoder product line in both performance and cost by using a microfabricated sensor and higher integrated electronic technologies. In addition Kuebler wished to acquire the necessary expertise to repeat the development process on future products.

The existing encoder products are based on opto-electronic components, including photodiodes, LEDs, SMT and glass scales encapsulated in a mechanical housing, together with surface mount electronics. These encoders are costly to manufacture and assemble, and are sensitive to EMC, high temperatures, shocks and vibrations, dust and water.

The new sensor system developed under this AE consists of a magneto resistive bridge array which is sensitive to magnetic fields, a mixed signal ASIC for signal processing and a magnetic scale. This can work up to 125&Mac176;C and is not sensitive to EMC, dust and water. Further it costs around 50% of the existing product, and is suitable for mass production. A mixed signal ASIC was chosen in preference to a DSP because it would meet the performance criteria at a lower unit test, and the development cost using MPW were compared.

The new product has none of the technical disadvantages of its predecessor, and is more cost-effective and suitable for mass production. The cost of the new product will be around half that of the existing product.

The main lesson that Kuebler learnt from this AE was that for development projects such as this it is essential that the sub contractor is fully supportive. They also learnt that using the low cost method of developing a mixed signal ASIC using MPW from a foundry increases timescales.

In the AE the overall cost was 94 K ECU, and included the development of both the sensor and the mixed signal ASIC. The project took 15 months as proposed to the 12 months planned. The FU will spend an additional 100K ECU and a further 9 months to productionise the product and expects a payback period of 6 months for the AE investment alone. The ROI will be at least 30 times the AE investment assuming a 4 year life of the product.
Schubertstr. 47
D-78054 VS.Schwenningen

Detailed information

You can also benefit from microelectronics

Mixed Signal ASIC technology provided FRITZ KUEBLER GMBH with the means of improving its products and enhancing its market position. You can also achieve significant benefits by acquiring the right microelectronics technology and utilising it in your product or manufacturing process. You can get help from FUSE to realise this.

FUSE is a technology transfer programme, funded by the European Commission to stimulate the wider use of microelectronics technologies by European enterprises to increase their competitiveness and enhance their economic growth. The demonstrator described here is one of many examples in the public FUSE portfolio covering the whole spectrum of microelectronics technologies and spanning a wide range of applications and industry sectors.

FUSE provides you with:

  • Best practice in acquiring specific microelectronics technologies and conducting full development projects through the FUSE portfolio of real life demonstrator documents.
  • Local training and expert support to plan your innovation realistically and help you conduct your project successfully.

Further information and support relating to this and other demonstrators can be obtained from the addresses below.

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