Magnetic sensor and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9417296-B2
Application number	US-201213403051-A
Country	US
Kind code	B2
Filing date	Feb 23, 2012
Priority date	Feb 23, 2011
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

For each of electric current path units each including series-connected resistor elements, one end is electrically connected with power supply terminal Vcc, the other end is electrically connected with ground terminal GND, and connection portion between the resistor elements is electrically connected with output terminals Vo 1 -Vo 4 . Resistor element constituting each of the electric current path units is a magnetoresistance effect element formed of magnetoresistance effect film, the power supply terminal and ground terminal are each shared among all the electric current path units. All the electric current path units are formed to contact one surface of insulating film; and with use of conductive film disposed to contact the other surface of the insulating film, power supply connection wiring for sharing the power supply terminal and ground connection wiring for sharing the ground terminal are formed.

First claim

The invention claimed is:

1. A magnetic sensor, comprising:
a power supply terminal and a ground terminal;
a conductive pattern including power supply connection wiring connected to the power supply terminal and ground connection wiring connected to the ground terminal;
an insulating film located on top of the conductive pattern;
four electric current path units located on top of the insulating film such that the conductive pattern is in contact with a first side of the insulating film and the electric current path units are in contact with a second side of the insulating film, two of the electric current path units being part of a first group and two of the electric current path units being part of a second group;
each electric current path unit including a respective pair of first and second elongated magneto resistive elements extending parallel to each other, a first end of the first and second elongated magneto resistive elements being connected to each other via a connection portion which is connected to an output terminal for the respective electric current path unit, a second end of the first magneto resistive element being connected to the power supply, a second end of the second magneto resistive element being connected to the ground terminal;
all of the elongated magneto resistive elements extending in the same direction such that they are all parallel to one another, the elongated magneto resistive elements of the first group of electric current path units being interdigitated with the elongated resistive elements of the second group of current path units;
the magneto resistive elements being bounded by an area having first and second opposite sides;
the output terminals of the electric current path units of the first group being disposed on the first side of the area the output terminals of each of the electric current path units of the second group being disposed on the second side of the area;
the power supply terminal being disposed on the first side of the area; and
the ground terminal being disposed on the second side of the area.

2. The magnetic sensor according to claim 1 , wherein at least one of the magneto resistive elements is formed in a U-shape including two elongated parts extending parallel to one another and being connected by a connecting part.

3. The magnetic sensor according to claim 1 , wherein at least one of the electric current path units includes a resistor element that is not a magneto resistive element.

4. The magnetic sensor according to claim 1 , wherein the only resistance elements in each of the electric current path units are magneto resistive resistance elements.

5. The magnetic sensor according to claim 1 , wherein each respective electric current path unit includes first and second end conductive connecting parts for connecting opposite ends of the respective electric current path unit to other electric current path units.

6. The magnetic sensor according to claim 1 , wherein at least some of the second ends of the first magneto resistive elements are connected to the power supply via a respective opening in the insulating film and the power supply connection wiring.

7. The magnetic sensor according to claim 1 , wherein at least some of the second ends of the second magneto resistive elements are connected to the ground terminal via a respective opening in the insulating film and the ground connection wiring.

8. The magnetic sensor according to claim 1 , wherein the conductive pattern is located on and in contact with an insulating surface part of a substrate.

9. The magnetic sensor according to claim 8 , further including a lead frame including a pad part, an external connection power supply terminal, an external connection ground terminal and a plurality of external connection output terminals; the substrate being bonded to the pad part;
the external connection power supply terminal part being wire-bonded to the power supply terminal;
an external connection ground terminal part being wire-bonded to the ground terminal; and
the plurality of external connection output terminals being wire-bonded to the respective ones of output terminals.

10. The magnetic sensor according to claim 1 , wherein an insulating protective film is located on top of the electric current path units.

11. The magnetic sensor according to claim 10 , wherein respective apertures are formed in the insulating protective film so as to expose the power supply terminal, ground terminal, and output terminals, respectively.

12. A manufacturing method of the magnetic sensor as claimed in claim 5 , the method comprising:
forming a conductive film on an insulating surface part of a substrate and applying patterning to the conductive film to form the power supply connection wiring and the ground connection wiring;
forming the insulating film on the insulating surface part of the substrate so as to cover the power supply connection wiring and ground connection wiring;
forming through-holes in the insulating film;
forming the electric current path units on the insulating film;
connecting at least some of the end conductive connecting parts to the power supply connection wiring through respective ones of the through-holes;
connecting at least some of the end conductive connecting parts to the ground connection wiring through respective ones of the through-holes;
forming the power supply terminal so as to be connected to at least one of the end conductive connecting parts;
forming the ground terminal to be connected to at least one of the end conductive connecting parts, and
forming each of the output terminals to be connected to a respective one of the connection portions of the electric current path units.

13. The manufacturing method according to claim 12 , wherein
in forming the electric current path units, a magneto resistance effect film and a conductor layer are formed in this order on the insulating film, the magneto resistance effect film and conductor layer are patterned into a shape corresponding to required electric current path units, and then, out of the remaining conductor layer, only portions corresponding to the magneto resistive elements are removed to thereby form the magneto resistive elements, the end conductive connecting parts and the connection portions each having a laminated structure of the magneto resistance effect film and conductor layer.

14. The manufacturing method according to claim 13 , wherein
in patterning the magneto resistance effect film and conductor layer, portions corresponding to the power supply terminal, ground terminal, and output terminal are made to remain, an insulating protective film is formed on the insulating film so as to cover the remaining magneto resistance effect film and conductor layer, and apertures are formed in required positions of the insulating protective film, whereby the power supply terminal, ground terminal, and output terminal are formed by some portions of the laminated structure of the magneto resistance effect film and conductor layer that are exposed through the apertures.

Assignees

• Akiyama Osamu
• Murata Manufacturing Co

Inventors

• Akiyama Osamu

Classifications

• Y10T29/49139

  by inserting component lead or terminal into base aperture · CPC title

• G01R33/093 Primary

  using multilayer structures, e.g. giant magnetoresistance sensors (thin magnetic films H01F10/00) · CPC title

• B82Y25/00

  Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance · CPC title