US 2016/0109535 A1 · SINGLE-CHIP BRIDGE-TYPE MAGNETIC FIELD SENSOR

Abstract

A single-chip magnetic field sensor bridge, comprising a substrate, a reference arm, a sensing arm, shielding structures, and wire bond pads is disclosed. The reference arm and the sense arm respectively comprise at least two rows/columns of reference element strings and sense element strings formed by electrically connecting one or more identical magnetoresistive sensing elements. The reference element strings and the sense element strings are alternately arranged. The magnetoresistive sensing elements are AMR, GMR or TMR sensing elements. The reference element strings are provided with shielding structures thereon, and the sensing element strings are located in gaps between two adjacent shielding structures. The shielding structures are arrays of elongated strips composed of permalloy or another soft ferromagnetic material. The sensors can be implemented as one of three different bridge structures, called a quasi-bridge, a half-bridge, or a full-bridge. This single-chip magnetic field sensor bridge has the advantages of small size, low cost, high sensitivity, small offset, good linearity, and good temperature stability.

Claims22

Dependent claims

A single-chip magnetic field sensor bridge, comprising:

a substrate;
a Wheatstone half-bridge or a Wheatstone quasi-bridge on the substrate, the Wheatstone half-bridge or quasi-bridge including:
a reference arm R1, which includes at least two row/column reference element strings, each reference element string includes one or more identical sensing magnetoresistive sensor elements electrically interconnected;
further including a sensing arm S1, which includes at least two row/column sense element strings, each sense element string includes one or more identical magnetoresistive sensor elements electrically interconnected;
the reference and the sensing arms have the same number of rows/columns, along the horizontal/vertical spacing directions, the spacing between the adjacent reference element strings and the adjacent sensing element strings is the same;
at least three shielding structures, with a well defined gap between the shielding structures, each reference element string has a corresponding shielding structure, each sensing element string is located in the corresponding gap, and
further including multiple input and output wire bond pads,
wherein the magnetoresistive sensor elements include AMR, GRM or TRM sensor elements.

5 more elements

A single-chip magnetic field sensor bridge, comprising:

a substrate;
a Wheatstone full-bridge on the substrate, the Wheatstone full-bridge includes mutual interconnection between a first bridge arm and a second bridge arm, the first bridge arm includes a first reference arm R1, which includes at least two rows/columns of the first reference element strings, each first reference element string consists of one or more electrically interconnected magnetoresistive sensor elements;
as well as a first sense arm S1, which includes at least two rows/columns of the first sense element strings, each first sense element string consists of one or more electrically interconnected magnetoresistive sensor elements;
the reference element strings and the sense element strings have the same number of rows/columns, and the spacing along the longitudinal/vertical direction, describing the adjacent first reference element strings and first sense element strings is defined by length L;
the second bridge arm includes a second reference arm R2, which includes at least two rows/columns of the first reference element strings, each reference element string consists of one or more electrically interconnected magnetoresistive sensor elements;
as well as a second sense arm S1, which includes at least two rows/columns of the second sense element strings, each sense element string consists of one or more electrically interconnected magnetoresistive sensor elements;
the second reference element string and the second sense element string have the same number of rows/columns, and the spacing along the longitudinal/vertical direction, describing the adjacent second reference element strings and second sense element strings is defined by length L;
in the area between the first bridge arm and the second bridge arm the first reference element string and the second reference element string or the first sense element string and the second reference element string are located adjacent to each other;
the adjacent the first reference element string and the second reference element string or the first sense element string and the second reference element string are separated by a distance 2L;
at least three shielding structures, wherein the shielding structures have a nearest neighbor spacing, and each of the first reference element strings and each of the second reference element strings are under a corresponding shielding structure, and each of the first sense element stings and each of the second elements strings is located in the gaps between the shielding structures;
and a multiplicity of input and output wire bond pads,
wherein the magnetoresistive sensor elements are AMR, GMR, or TMR sensor elements.

9 more elements

Dependencies are inferred from the claim text.

Single-chip bridge-type magnetic field sensor

Life of this patent

Single-chip bridge-type magnetic field sensor

Life of this patent

Abstract

Claims22