Magnetic detection device having bridge circuit provided with resistance adjustment portion and method of manufacturing the same

Abstract

In a magnetic detection device using a magnetic resistance element, the resistance of a layer having a multi-layer structure can be easily adjusted without causing damages to the layer. A magneto-resistance layer is connected in series to a reference resistance layer, and a magneto-resistance layer is connected in series to a reference resistance layer on a substrate. A voltage is applied between a power supply layer and a grounding layer. A first output conductive layer and the reference resistance layer extend in parallel to each other so that they are partially electrically connected to each other via a connection layer. A second output conductive layer and the reference resistance layer extend in parallel to each other so that they are partially electrically connected to each other via a connection layer. Accordingly, it is possible to adjust the resistance of the reference resistance layers by selecting the respective positions of the connection layers.

1 . A magnetic detection device comprising:
 a magneto-resistance layer having a variable electric resistance in accordance with an external magnetic field, the magneto-resistance layer having and end portion; and   the magneto-resistance layer being connected in series to a reference resistance layer, the reference resistance layer having and end portion and having a fixed electric resistance under the external magnetic field, a voltage is applied to the magneto-resistance layer and the reference resistance layer connected in series to each other, and   an output conductive layer that outputs a central potential between the magneto-resistance layer and the reference resistance layer,   wherein the output conductive layer extends along at least one of the magneto-resistance layer and the reference resistance layer with a gap therebetween,   wherein the output conductive layer is electrically connected at a connecting portion to at least one of the magneto-resistance layer and the reference resistance layer via a conductive connection layer, the connecting portion disposed apart from the end portion of the magneto-resistance layer and the end portion of the reference resistance layer, and   wherein the position of the connection layer is selectable.   
   
   
       2 . The magnetic detection device according to  claim 1 , wherein the output conductive layer and at least one of the magneto-resistance layer and the reference resistance layer are disposed with a gap therebetween in a width direction of the layers. 
   
   
       3 . The magnetic detection device according to  claim 1 , wherein the output conductive layer overlaps with at least one of the magneto-resistance layer and the reference resistance layer with a gap therebetween in a thickness direction of the layers. 
   
   
       4 . A magnetic detection device comprising:
 a first magneto-resistance layer having an end portion and having variable electric resistances in accordance with an external magnetic field,   a second magneto-resistance layer having an end portion and having the variable electric resistances in accordance with the external magnetic field being connected to the first magneto-resistance layer in series, a voltage is applied to the first magneto-resistance layer and the second magneto-resistance layer connected in series to each other, and   an output conductive layer that outputs a central potential between the first magneto-resistance layer and the second magneto-resistance layer,   wherein the output conductive layer extends along at least one of the first magneto-resistance layer and the second magneto-resistance layer and is parallel to at least one of the first magneto-resistance layer and the second magneto-resistance layer with a gap therebetween,   wherein the output conductive layer is electrically connected at a connecting portion to at least one of the first magneto-resistance layer and the second magneto-resistance layer via a conductive connection layer, the connecting portion disposed apart from the end portion of the first magneto-resistance layer and the end portion of the second magneto-resistance layer, and   wherein the position of the connection layer is selectable.   
   
   
       5 . The magnetic detection device according to  claim 4 , wherein the output conductive layer and at least one of the first magneto-resistance layer and the second magneto-resistance layer are disposed with a gap therebetween in a width direction of the layers. 
   
   
       6 . The magnetic detection device according to  claim 4 , wherein the output conductive layer overlaps with at least one of the first magneto-resistance layer and the second magneto-resistance layer with a gap therebetween in a thickness direction of the layers.