Single magnetoresistor TMR magnetic field sensor chip and magnetic currency detector head

A single magnetoresistor TMR magnetic field sensor chip, installed above a magnetic excitation element, a sensing direction of the chip being parallel to a surface of the chip, and a direction of a magnetic excitation field generated on the chip by the magnetic excitation element being perpendicular to the surface of the chip, wherein the single magnetoresistor TMR magnetic field sensor chip comprises:

• a substrate,
• a magnetic biasing structure deposited on the substrate,
• a magnetoresistive element, and
• an input terminal and an output terminal;
• wherein the magnetoresistive element consists of at least one MTJ unit;
• wherein the MTJ unit consists of at least one MTJ string;
• wherein the MTJ string consists of at least one MTJ;
• wherein the sensing directions of the magnetoresistive element and the at least one MTJ are the same as the sensing direction of the chip;
• wherein the direction of a bias magnetic field generated on the chip by the magnetic excitation element is perpendicular to the sensing direction of the chip, and
• wherein the shape of the MTJ viewed from above is an ellipse, a ratio of lengths of its major axis and minor axis is greater than 3, and the minor axis of the MTJ is parallel to the sensing direction of the chip.

A single magnetoresistor TMR magnetic field sensor chip, installed above a magnetic excitation element, a sensing direction of the chip being parallel to a surface of the chip, and a direction of a magnetic excitation field generated on the chip by the magnetic excitation element being perpendicular to the surface of the chip, wherein the single magnetoresistor TMR magnetic field sensor chip comprises:

• a substrate,
• a magnetic biasing structure deposited on the substrate,
• a magnetoresistive element, and
• an input terminal and an output terminal;
• wherein the magnetoresistive element consists of at least one MTJ unit;
• wherein the MTJ unit consists of at least one MTJ string;
• wherein the MTJ string consists of at least one MTJ;
• wherein the sensing directions of the magnetoresistive element and the at least one MTJ are the same as the sensing direction of the chip;
• wherein the direction of a bias magnetic field generated on the chip by the magnetic excitation element is perpendicular to the sensing direction of the chip,
• wherein the magnetic biasing structure consists of a permanent magnet between two adjacent MTJ strings;
• wherein along a magnetization direction of the permanent magnet, two sides of the MTJ are both provided with the permanent magnet;
• and
• wherein a magnetic field generated at the permanent magnet by the magnetic excitation element is less than half of the coercive force of the permanent magnet, and is less than 0.1 T.

A single magnetoresistor TMR magnetic field sensor chip, installed above a magnetic excitation element, a sensing direction of the chip being parallel to a surface of the chip, and a direction of a magnetic excitation field generated on the chip by the magnetic excitation element being perpendicular to the surface of the chip, wherein the single magnetoresistor TMR magnetic field sensor chip comprises:

• a substrate,
• a magnetic biasing structure deposited on the substrate,
• a magnetoresistive element, and
• an input terminal and an output terminal;
• wherein the magnetoresistive element consists of at least one MTJ unit;
• wherein the MTJ unit consists of at least one MTJ string;
• wherein the MTJ string consists of at least one MTJ;
• wherein the sensing directions of the magnetoresistive element and the at least one MTJ are the same as the sensing direction of the chip;
• wherein the direction of a bias magnetic field generated on the chip by the magnetic excitation element is perpendicular to the sensing direction of the chip,
• wherein the magnetic biasing structure consists of a magnetic film deposited on the MTJ;
• and
• wherein a magnetic field generated at the magnetic film by the magnetic excitation element is less than half of the coercive force of the magnetic film, and is less than 0.1 T.

A single magnetoresistor TMR magnetic field sensor chip, installed above a magnetic excitation element, a sensing direction of the chip being parallel to a surface of the chip, and a direction of a magnetic excitation field generated on the chip by the magnetic excitation element being perpendicular to the surface of the chip, wherein the single magnetoresistor TMR magnetic field sensor chip comprises:

• a substrate,
• a magnetic biasing structure deposited on the substrate,
• a magnetoresistive element, and
• an input terminal and an output terminal;
• wherein the magnetoresistive element consists of at least one MTJ unit;
• wherein the MTJ unit consists of at least one MTJ string;
• wherein the MTJ string consists of at least one MTJ;
• wherein the sensing directions of the magnetoresistive element and the at least one MTJ are the same as the sensing direction of the chip;
• wherein the direction of a bias magnetic field generated on the chip by the magnetic excitation element is perpendicular to the sensing direction of the chip, and
• wherein both the input and output terminals at least comprise two wire bonding pads, and each wire bonding pad is located on two ends of the single magnetoresistor TMR magnetic field sensor chip.

A single magnetoresistor TMR magnetic field sensor chip, installed above a magnetic excitation element, a sensing direction of the chip being parallel to a surface of the chip, and a direction of a magnetic excitation field generated on the chip by the magnetic excitation element being perpendicular to the surface of the chip, wherein the single magnetoresistor TMR magnetic field sensor chip comprises:

• a substrate,
• a magnetic biasing structure deposited on the substrate,
• a magnetoresistive element, and
• an input terminal and an output terminal;
• wherein the magnetoresistive element consists of at least one MTJ unit;
• wherein the MTJ unit consists of at least one MTJ string;
• wherein the MTJ string consists of at least one MTJ;
• wherein the sensing directions of the magnetoresistive element and the at least one MTJ are the same as the sensing direction of the chip;
• wherein the direction of a bias magnetic field generated on the chip by the magnetic excitation element is perpendicular to the sensing direction of the chip, and
• wherein the substrate is provided thereon with an electrical connection conductor for achieving an electrical connection, and the width of the electrical connection conductor is not less than 10 μm.

A single magnetoresistor TMR magnetic field sensor chip, installed above a magnetic excitation element, a sensing direction of the chip being parallel to a surface of the chip, and a direction of a magnetic excitation field generated on the chip by the magnetic excitation element being perpendicular to the surface of the chip, wherein the single magnetoresistor TMR magnetic field sensor chip comprises:

• a substrate,
• a magnetic biasing structure deposited on the substrate,
• a magnetoresistive element, and
• an input terminal and an output terminal;
• wherein the magnetoresistive element consists of at least one MTJ unit;
• wherein the MTJ unit consists of at least one MTJ string;
• wherein the MTJ string consists of at least one MTJ;
• wherein the sensing directions of the magnetoresistive element and the at least one MTJ are the same as the sensing direction of the chip;
• wherein the direction of a bias magnetic field generated on the chip by the magnetic excitation element is perpendicular to the sensing direction of the chip, and
• wherein the single magnetoresistor TMR magnetic field sensor chip has a length of 500 μm to 3000 μm and a width of 20 μm to 1500 μm.

A magnetic currency detector head, the magnetic head comprising:

• a single magnetoresistor TMR magnetic field sensor chip,
• a substrate,
• a magnetic biasing structure deposited on the substrate,
• a magnetoresistive element, and
• an input terminal and an output terminal;
• wherein the magnetoresistive element consists of at least one MTJ unit;
• wherein the MTJ unit consists of at least one MTJ string;
• wherein the MTJ string consists of at least one MTJ;
• wherein the sensing directions of the magnetoresistive element and the at least one MTJ are the same as a sensing direction of the chip;
• wherein the direction of a bias magnetic field generated on the chip by the magnetic excitation element is perpendicular to the sensing direction of the chip
• a signal processing circuit,
• a magnetic excitation element, wherein the single magnetoresistor TMR magnetic field sensor chip is installed above the magnetic excitation element, the sensing direction of the chip is parallel to a surface of the chip, and a direction of a magnetic excitation field generated on the chip by the magnetic excitation element is perpendicular to the surface of the chip,
• an output pin and
• a circuit board;
• wherein the magnetic excitation element is installed below the single magnetoresistor TMR magnetic field sensor chip, used for providing a magnetic excitation field, to generate an external magnetic field in the sensing direction of the chip in a measured space;
• wherein the single magnetoresistor TMR magnetic field sensor chip is configured to sense the external magnetic field, and converts the external magnetic field to an electrical signal;
• and
• wherein the signal processing circuit is configured to convert the electrical signal, which is transferred to the output pin through the circuit board.