THIN-FILM DOUBLE-LAYER MAGNETORESISTIVE SENSORS

Multilayer magnetoresistive sensors have been developed which have characteristics surpassing those of sensors on one-layer MR structures, first of all, those of high sensitivity and of good reproductivity without introducing additional fields, i.e., without complicating the construction and manufacturing technology. The developed MR sensors have prospects for applying them as threshold and analogue transformers.

A sensor has been developed with the use of a structure consisting of two magnetoresistive films separated from each other with non-magnetic layer with a low magnitude of specific resistance which is designated to remove the exchange interaction between the magnetoresistive films.

The sensor contains 4-e meander switched on bridge.

• Sensor resistance - 10 kOhm,
• Differential sensitivity - 7 (mV\V)/(kA/m),
• Frequency range - 0-100 mHz,
• Temperature range - from - 40 to 125 Celsius degrees,
• Width of output signal linearity interval 0.8 kA/m,
• Maximum signal of reading with a feeding voltage of 10 V is 100mV,
• Crystal dimensions - 3x3 mm.

Similar products are manufactured abroad mainly by PHILLIPS and HONEYWELL firms. The PHILLIPS’ KMZ-10A,B,C, sensor has the following key specifications:

The technologies of manufacturing magnetoresistive transformers are used for creating devices with the use of magnetic microelectronics. In particular, the following modern devices can be created with its use:

• -one- (three-) coordinate electronic compass for navigation systems, robotics, and simulators;
• -for measuring positions of objects;
• -for measuring high-frequency magnetic fields;
• -for identification of an object (security devices);
• -for contactless measuring direct and alternating current;
• -for nondestructive inspection of materials (welds in tubes, etc.);
• -tachometers;
• -for contactless keyboards (including intellectual ones);
• -reading heads from disks, tapes, cards, etc.;
• -control system for contactless electric motors.

The work already done allows - within 1.5 - 2 years’ period - to develop a serial technology of MR films with a superhigh (gigantic) magnetoresistive effect (SHMR), a technology of magnetoinduction transformers; allows to develop devices on their basis, to make pilot samples, to organize serial production.

The author of the present publication and the developers are interested in organizing cooperation with a foreign firm working in this direction including supply of sensible elements or devices on the whole (in conformity with customer’s requirements). In this case, a foreign partner is required to provide either financial support in the form of an advance for the preparation of production or guarantees of payments for the products (development materials or sensible elements themselves) against which a bank loan could be obtained.

The work could be carried out within the framework of franchising, i.e., the development and products are made (on concluding the corresponding agreements in relation to the volume and quality of production) under the brand of a foreign firm which provides financial support in obtaining a modern equipment for the fulfillment of the order and participates in the marketing organization.

The author of the publications and the authors of the development are willing to consider also proposals of foreign partners if there are any.

In addition, there is a proposal connected with securing the authors’ rights protection of the original technological solutions developed. In particular, there is a question about taking out patents abroad for our technological innovations.

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