Magnetic multi-turn sensor and method of manufacture
The present disclosure provides a magnetic multi-turn sensor comprising a continuous coil of magnetoresistive elements and a method of manufacturing said sensor. The continuous coil is formed on a substrate such as a silicon wafer that has been fabricated so as to form a trench and bridge arrangement that enables the inner and outer spiral to be connected without interfering with the magnetoresistive elements of the spiral winding in between. Once the substrate has been fabricated with the trench and bridge arrangement, a film of the magnetoresistive material can be deposited to form a continuous coil on the surface of the substrate, wherein a portion of the coil is formed in the trench and a portion of the coil is formed on the bridge.
1. A magnetic multi-turn sensor, comprising:
a plurality of magnetoresistive sensor elements connected in series and arranged in a continuous spiral configuration; and
a substrate on which the plurality of magnetoresistive sensor elements are formed, the substrate comprising:
a trench configured to receive at least one magnetoresistive element; and
at least one bridge formed over the trench, the at least one bridge being formed by a portion of substrate and being configured to support at least one magnetoresistive element.
2. A magnetic multi-turn sensor according to claim 1 , wherein the trench is configured to receive a plurality of magnetoresistive elements defining one side of the continuous spiral configuration, and wherein the substrate comprises one bridge configured to receive one magnetoresistive element connecting an inner and outer loop of the continuous spiral configuration.
3. A magnetic multi-turn sensor according to claim 1 , wherein the trench is configured to receive one magnetoresistive element connecting an inner and outer loop of the continuous spiral configuration, and wherein the substrate comprises the at least one bridge formed over the trench for receiving a plurality of magnetoresistive elements defining one side of the continuous spiral configuration.
4. A magnetic multi-turn sensor according to claim 1 , wherein the substrate comprises a plurality of bridges formed over the trench for receiving a plurality of magnetoresistive elements defining one side of the continuous spiral configuration, each bridge receiving one magnetoresistive element.
5. A magnetic multi-turn sensor according to claim 1 , wherein the plurality of magnetoresistive elements are one of: giant magnetoresistive (GMR) elements or tunnel magnetoresistive (TMR) elements.