Planar coil and giant magnetoresistance isolator

Abstract

The utility model discloses a planar coil and a giant magnetoresistance isolator. The planar coil is of a rectangular runway type structure, one end of the planar coil is located inside the coil, and the other end of the planar coil is located on one side outside the coil and is formed by winding from inside to outside. The line width of the planar coil is 3 micrometers, the line spacing is 3 micrometers, and the line thickness is 0.5 micrometer. The planar coil adopts a rectangular runway type structure, so that the planar coil can generate a magnetic field which is large enough and uniform, the magnetic field can be detected by a giant magnetoresistance sensing layer of the giant magnetoresistance isolator, and the generated magnetic field intensity can meet the application requirement of the giant magnetoresistance isolator; the planar coil overcomes the defect that the magnetic field intensity generated by a circular runway type coil below the planar coil is not large enough and is not uniform, and has the advantages of small size, low power consumption and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of giant magnetoresistance isolators, in particular to a planar coil and a giant magnetoresistance isolator. Background Art

[0002] Giant magnetoresistance isolator is a magnetic device that uses the giant magnetoresistance effect to isolate signals or power in a circuit. The giant magnetoresistance effect refers to the significant change in the resistance of a magnetic material under a specific magnetic field. This effect is widely used in sensors, isolators and other fields.

[0003] The main function of the planar coil in the giant magnetoresistance isolator is to convert the input electrical signal into a magnetic field signal. After the magnetic field signal passes through the isolation barrier, it must be sensed by the giant magnetoresistance sensing layer (Wheatstone bridge GMR sensor). The shape and structure of the planar coil in the giant magnetoresistance isolator will affect the distribution and strength of the magnetic field generated by the planar coil, and ultimately directly affect the strength of the signal received by the giant magnetoresistance isolator. The structure of the planar coil currently used in the giant magnetoresistance isolator is mainly a circular runway-type coil. The magnetic field strength generated by this circular runway-type coil is not strong enough and the distribution is not uniform enough. It will affect the sensing effect of the giant magnetoresistance sensing layer in the giant magnetoresistance isolator, resulting in a reduction in the accuracy of the giant magnetoresistance isolator, which in turn affects the isolation effect. In addition, the size of the existing circular runway-type coil is relatively large and the power consumption is high. Utility Model Content

[0004] In view of this, the utility model provides a planar coil that solves at least some of the above-mentioned technical problems and a giant magnetoresistance isolator using the planar coil. The planar coil adopts a rectangular racetrack structure, which makes it easy for the planar coil to generate a sufficiently large and uniform magnetic field so that it can be detected by the giant magnetoresistance sensing layer, and the generated magnetic field strength can meet the application requirements of the giant magnetoresistance isolator; the planar coil overcomes the defect of the circular racetrack coil that the magnetic field strength generated thereunder is not large enough and is uneven, and the planar coil also has the advantages of small size and low power consumption.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] In the first aspect, this embodiment provides a planar coil for use in a giant magnetoresistance isolator. The planar coil is a rectangular runway structure wound from the inside to the outside, with one end of the planar coil located inside the coil and the other end located on one side outside the coil. The line width of the planar coil is 3 microns, the line spacing is 3 microns, and the line thickness is 0.5 microns.

[0007] In a preferred embodiment, the planar coil has 8 turns.

[0008] In a preferred embodiment, both ends of the wire of the planar coil are square sheet structures.

[0009] In a preferred embodiment, the planar coil is wound by copper wire, and the outer side of the copper wire is coated with insulating varnish.

[0010] In a preferred embodiment, the cross-section of the copper wire is one of circular, elliptical and polygonal.

[0011] In a second aspect, this embodiment further provides a giant magnetoresistance isolator, comprising: the above-mentioned planar coil, and also including a passivation insulating layer, an isolation gate layer, a Wheatstone bridge GMR sensor, and a silicon substrate, wherein:

[0012] The passivation insulating layer, the planar coil, the isolation gate layer, the Wheatstone bridge GMR sensor and the silicon substrate are sequentially arranged in layers from top to bottom.

[0013] Compared with the prior art, the beneficial effects of the present invention include at least:

[0014] The utility model provides a planar coil, which is applied to a giant magnetoresistance isolator. The planar coil adopts a rectangular racetrack structure, which makes it easy for the planar coil to generate a sufficiently large and uniform magnetic field, which can be detected by a giant magnetoresistance sensing layer, and the generated magnetic field strength can meet the application requirements of the giant magnetoresistance isolator; it overcomes the defect that the magnetic field strength generated by a circular racetrack coil is not large enough and is uneven, and the planar coil also has the advantages of small size and low power consumption.

[0015] Other features and advantages of the utility model will be described in the following description, and partly become apparent from the description, or understood by implementing the utility model. The purpose and other advantages of the utility model can be realized and obtained by the structures particularly pointed out in the written description and the drawings.

[0016] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 This is a schematic diagram of the planar coil structure provided by the utility model.

[0019] Figure 2 This is a schematic diagram of the magnetic field generated by the planar coil under a 10mA current provided by the utility model.

[0020] Figure 3This is a schematic structural diagram of the giant magnetoresistance isolator provided by the utility model. DETAILED DESCRIPTION

[0021] In order to make the technical means, creative features, objectives and effects achieved by the utility model easy to understand, the utility model is further explained below in conjunction with specific implementation methods.

[0022] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", "front", "back", "interior" and "exterior" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Embodiment 1:

[0025] See also Figure 1-Figure 2 As shown, the embodiment of the utility model provides a planar coil, which is mainly used in giant magnetoresistance isolators. The planar coil is a rectangular runway structure, one end of the planar coil is located inside the coil, and the other end is located on one side outside the coil, and is wound from the inside to the outside; the line width of the planar coil is preferably 3 microns, the line spacing is 3 microns, and the line thickness is 0.5 microns, and the structure size is relatively small. Its working principle is: the two ends of the planar coil are connected to the power supply, and after a few milliamperes of current are passed through, a uniform and relatively large magnetic field strength can be generated below it, and the generated magnetic field strength can meet the sensing range of the giant magnetoresistance sensing layer.

[0026] In a specific embodiment, considering the magnetic field strength and the overall area generated by the planar coil, the number of turns of the planar coil is set to 8 turns, and the power consumption is relatively low.

[0027] In a specific embodiment, Figure 1 As shown, both ends of the wire of the planar coil are square sheet structures, which enlarges the wire end area and facilitates connection with the power supply.

[0028] In a specific embodiment, considering factors such as resistivity, thermal stability, weight and cost, the planar coil is wound by copper wire, and the outer side of the copper wire is coated with insulating paint, which is safe and durable; the cross-section of the copper wire can be one of circular, elliptical and polygonal.

[0029] Furthermore, in this embodiment, the planar coil structure is modeled using ANSYS Maxwell software to conduct a simulation experiment. The magnetic field generated by the planar coil under a current of 10 mA is shown in FIG. Figure 2 As shown in the figure, after a current of 10mA is passed, the horizontal component of the magnetic field intensity directly below the coil reaches more than 10Oe, which meets the detection range of the giant magnetoresistance sensing layer (Wheatstone bridge GMR sensor). For the conventional circular runway coil, under the same input current of 10mA, the horizontal component of the magnetic field intensity it generates is less than 5Oe, and the magnetic field on both sides of the coil is not uniform enough, which will reduce the detection effect of the giant magnetoresistance sensing layer. Under the input of 100MHZ, 1V alternating current, the impedance of the planar coil is 100 ohms, and the power consumption of the entire planar coil is only 10mW, which is relatively low. For the conventional circular runway coil, under the input of 100MHZ, 1V alternating current, due to the shape of the runways on both sides, its impedance is greater than 150 ohms. Under the same input conditions, the power consumption is greater than 15mW, which is relatively high.

[0030] From the description of the above embodiments, those skilled in the art can know that the utility model provides a planar coil used in a giant magnetoresistance isolator. The planar coil adopts a rectangular runway structure, which is convenient for the planar coil to generate a large and uniform magnetic field, which can be detected by the giant magnetoresistance sensing layer. The planar coil adopts a rectangular runway structure, and the magnetic field generated on both sides is symmetrical and uniform, which can overcome the defect that the magnetic field intensity generated by the circular runway coil below is not large enough and unevenly distributed. The line width of the planar coil is 3 microns, the line spacing is 3 microns, and the line thickness is 0.5 microns. The planar coil has a better line width and line spacing, which meets the manufacturing requirements of the giant magnetoresistance isolator. The planar coil designed by the utility model also has the advantages of small size, input current of only a few milliamperes, low power consumption, etc. The magnetic field intensity generated can fully meet the application requirements of the giant magnetoresistance isolator.

[0031] Embodiment 2:

[0032] See also Figure 3 As shown, the embodiment of the utility model further provides a giant magnetoresistance isolator, comprising: the planar coil in the above embodiment, and also including a passivation insulating layer, an isolation gate layer, a Wheatstone bridge GMR sensor, and a silicon substrate, wherein:

[0033] The passivation insulating layer, the planar coil, the isolation gate layer, the Wheatstone bridge GMR sensor and the silicon substrate are arranged in layers from top to bottom. In this embodiment, the isolation gate layer is preferably made of silicon dioxide material, which has a higher compressive strength than the more traditional polyimide material. The giant magnetoresistance isolator can be widely used in industrial control, communication, medical and other fields.

[0034] The above are only preferred embodiments of the present invention. It should be noted that a person skilled in the art can make several improvements and modifications without departing from the principles of the present invention.

[0035] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A planar coil, characterized in that: Used in giant magnetoresistance isolators, the planar coil is a rectangular runway structure wound from the inside to the outside, with one end of the planar coil located inside the coil and the other end located on one side outside the coil; the line width of the planar coil is 3 microns, the line spacing is 3 microns, and the line thickness is 0.5 microns.

2. A planar coil according to claim 1, characterized in that: The number of turns of the planar coil is 8.

3. A planar coil according to claim 1, characterized in that: Both ends of the wire of the planar coil are square sheet structures.

4. The planar coil according to claim 1, characterized in that: The planar coil is wound by copper wire, and the outer side of the copper wire is coated with insulating paint.

5. A planar coil according to claim 4, characterized in that: The cross section of the copper wire is one of a circle, an ellipse and a polygon.

6. A giant magnetoresistance isolator, characterized in that: include: A planar coil according to any one of claims 1 to 5, further comprising a passivation insulating layer, an isolation barrier layer, a Wheatstone bridge GMR sensor, and a silicon substrate, wherein: The passivation insulating layer, the planar coil, the isolation gate layer, the Wheatstone bridge GMR sensor and the silicon substrate are sequentially arranged in layers from top to bottom.

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