JP2008275578A - Magnetic sensor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic sensor which can easily miniaturize, and to decrease a distortion produced in a magnetic core. <P>SOLUTION: On one surface of non-magnetic substrate 11, a first conductive layer 22, a first insulation plastic layer 12, SiO<SB>2</SB>layer 18, the magnetic core 14 and a second conductive layer 21 which is mounted on a second insulation plastic layer 13 are mounted in order. A solenoid coil 20 which is consisted of a conductor conducting electrically between the first conductive layer 22 and the second conductive layer 21 penetrating through the first conductive layer 22, the second conductive layer 21, the first insulation plastic layer 12 and the second insulation plastic layer 13 is formed. Further, the magnetic sensor 10 is constituted by disposing the magnetic core 14 which is mounted on SiO<SB>2</SB>layer 18, inside of the solenoid coil 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a magnetic sensor for detecting magnetism based on a change in permeability in the width direction with respect to application of a magnetic field in the longitudinal direction of a magnetic core by passing a high-frequency current or a pulse current through a magnetic core made of a soft magnetic material.

  In recent years, in mobile devices such as mobile phones and PDAs (personal digital assistants), there is an increasing demand for small and highly sensitive magnetic sensors. Flux gate sensors and magneto-impedance effect elements using amorphous wires are used as high-sensitivity magnetic sensors. However, flux gate sensors require a large number of turns of the coil and magnets to reduce the demagnetizing field of the magnetic core. It is necessary to increase the length of the core, and miniaturization is difficult. On the other hand, since the magneto-impedance effect element using an amorphous wire uses a wire, a special process is required for soldering the substrate and winding a bias coil (pickup coil), and there is a problem that the manufacturing cost is high. .

Patent Documents 1 to 3 propose a thin-film magnetoimpedance effect element using a soft magnetic film. Further, Patent Document 4 proposes an orthogonal fluxgate sensor that directly applies a high-frequency current or a pulse current to a magnetic core and reads a change in induced electromotive force induced in a pickup coil wound around the magnetic core. .
In contrast, studies have been made to form a bias coil (pickup coil) by a thin film process. In Patent Document 5 and Non-Patent Document 1, a magneto-impedance effect element and a solenoid-type bias coil, A sensor in which a negative feedback coil is integrated has been proposed. In Patent Documents 6 and 7, a bias coil (pickup coil) is formed of a planar spiral coil.
Japanese Patent No. 3210933 Japanese Patent No. 3650575 Japanese Patent No. 3656018 Japanese Patent No. 2617498 JP-A-11-109006 JP 2003-163391 A JP 2006-201123 A “Thin film MI sensor fabricated by micro-plating method”, The Institute of Electrical Engineers of Japan, Magnetics Society, Document No. MAG-00-24, 2000, p74-84 IEEE Transactions on Magnetics, 2003, Vol. 39, No. 1, p. 571

However, when a solenoid coil is formed by a thin film process, it is necessary to form a magnetic core on the lower layer wiring via an insulating layer. However, the lower layer wiring forms irregularities on the substrate, and the magnetic core is formed on this. In such a case, the magnetic characteristics may be deteriorated.
In Patent Document 5 and Non-Patent Document 1, as the insulating layer between the coil wiring and the magnetic core, a resin obtained by hard baking and curing a resist for relief of unevenness is used. When resin materials are used, the glass transition temperature and thermal decomposition temperature of the resin are limited, so the temperature at which the magnetic core is subjected to heat treatment in a magnetic field can be limited, and as a result, sufficient characteristics cannot be obtained. There is a problem. In particular, during heat treatment in a magnetic field, stress due to the difference in thermal expansion coefficient is applied, so that the strain generated in the magnetic core formed thereon increases, and the characteristics due to the inverse effect of magnetostriction may be greatly degraded.

  In order to avoid such a problem, in Patent Documents 6 and 7, a planar spiral coil is formed on a magnetic core to avoid the influence of the base. However, in such a structure, since the interlinkage area between the magnetic flux in the magnetic core and the magnetic flux generated by the coil is small, the conversion efficiency of the magnetic flux generated in the magnetic core and the current flowing in the coil is poor, and the area of the coil is Therefore, there is a problem that an extra area is required and it is difficult to reduce the size.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a magnetic sensor that can reduce distortion generated in a magnetic core and can be easily downsized, and a method for manufacturing the same.

In order to solve the above-described problem, a first aspect of the present invention provides a nonmagnetic substrate, a first conductor layer provided on one surface of the nonmagnetic substrate, the one surface, and the first surface. A first insulating resin layer made of polyimide provided on one conductor layer, an SiO ₂ layer formed on the first insulating resin layer, and a soft layer provided on the SiO ₂ layer. A magnetic core made of a magnetic film; an electrode for applying a high-frequency current or a pulse current to the magnetic core; a first insulating resin layer, a SiO ₂ layer, and a polyimide provided on the magnetic core; Two insulating resin layers and a second conductor layer provided on the second insulating resin layer, the first conductor layer and the second conductor layer, and the first and second conductor layers. Conducting the first conductor layer and the second conductor layer through the insulating resin layer Consists solenoid coil made of a conductor to be, in the interior of the solenoid coil, a magnetic sensor, characterized in that the magnetic core provided on the SiO ₂ layer on are disposed.

  According to a second aspect of the present invention, there is provided a nonmagnetic substrate, a first conductor layer provided on one surface of the nonmagnetic substrate, the one surface and the first conductor layer. A first insulating resin layer made of polyimide, a magnetic core made of a soft magnetic film provided on the first insulating resin layer, and a high frequency current or a pulse current applied to the magnetic core An electrode, a second insulating resin layer made of polyimide provided on the first insulating resin layer and the magnetic core, and a second conductor layer provided on the second insulating resin layer, A conductor that penetrates the first conductor layer and the second conductor layer, and that conducts the first conductor layer and the second conductor layer through the first and second insulating resin layers. The solenoid coil is configured, and inside the solenoid coil, the solenoid coil Is the magnetic core arrangement provided in first insulating resin layer, said first insulating resin layer, a magnetic sensor characterized by comprising the baked polyimide 400 ° C. or higher.

According to a third aspect of the present invention, there is provided a step of forming a first conductor layer having a plurality of linear conductor patterns on one surface of a nonmagnetic substrate, the one surface and the first surface. On the conductor layer, the first opening provided at a position aligned with one end of each conductor pattern of the first conductor layer and the other of the conductor patterns of the first conductor layer Forming a first insulating resin layer made of polyimide having a second opening provided at a position aligned with an end on the side, and on the first insulating resin layer, the first insulating resin layer An SiO ₂ layer is formed at a position including at least a region between the row of openings and the row of second openings and avoiding the top of the first opening and the second opening Engineering of forming a step of a magnetic core made of a soft magnetic material film on the SiO ₂ layer When a step of imparting a uniaxial anisotropy by rotating the magnetic field heat treatment and the in a static magnetic field heat treatment to said magnetic core, said first insulating resin layer, on the SiO ₂ layer and the magnetic core, the first opening A third opening provided at a position aligned with the second opening, a fourth opening provided at a position aligned with the second opening, and a position electrically connectable to an end of the magnetic core Forming a second insulating resin layer made of polyimide having a fifth opening provided in the first and third openings, and filling the first and third openings with the first and second insulating resin layers. A first penetrating conductor that penetrates, a second penetrating conductor that fills the second and fourth openings and penetrates the first and second insulating resin layers, and a filling that fills the fifth opening. Providing a third penetrating conductor penetrating the second insulating resin layer; On the second insulating resin layer, it is electrically connected to an end portion on one side of each conductor pattern of the first conductor layer through the first through conductor, and through the second through conductor. Forming a second conductor layer having a plurality of linear conductor patterns that are electrically connected to the other end of each conductor pattern of the first conductor layer, and on the second insulating resin layer. And a step of forming an electrode for applying a high-frequency current or a pulse current to the magnetic core via the third through conductor.

  According to a fourth aspect of the present invention, there is provided a step of forming a first conductor layer having a plurality of linear conductor patterns on one surface of a nonmagnetic substrate, the one surface and the first surface. On the conductor layer, the first opening provided at a position aligned with one end of each conductor pattern of the first conductor layer and the other of the conductor patterns of the first conductor layer Forming a first insulating resin layer made of polyimide having a second opening provided at a position aligned with the end of the side, and the polyimide constituting the first insulating resin layer at 400 ° C. or higher Between the row of the first openings and the row of the second openings on the first insulating resin layer baked at a temperature of 400 ° C. or higher. Forming a magnetic core made of a soft magnetic film in a region of A step of imparting uniaxial anisotropy to the core by a heat treatment in a rotating magnetic field and a heat treatment in a static magnetic field, and a position on the first insulating resin layer and the magnetic core that are aligned with the first opening. A third opening, a fourth opening provided at a position aligned with the second opening, and a fifth opening provided at a position electrically connectable to the end of the magnetic core. Forming a second insulating resin layer made of polyimide having a portion, and a first through conductor filled in the first and third openings and penetrating the first and second insulating resin layers, A second penetrating conductor filling the second and fourth openings and penetrating the first and second insulating resin layers; and a second insulating resin layer filling the fifth opening. A step of providing a third through conductor penetrating through the second insulating resin layer; In addition, each of the first conductor layers is electrically connected to one end of each conductor pattern of the first conductor layer through the first through conductor, and each of the first conductor layers through the second through conductor. A step of forming a second conductor layer having a plurality of linear conductor patterns electrically connected to the other end of the conductor pattern; and the third through conductor on the second insulating resin layer. A step of forming an electrode for applying a high frequency current or a pulse current to the magnetic core through the magnetic core.

According to a fifth aspect of the present invention, in the method for manufacturing a magnetic sensor according to the third aspect, the step of baking the polyimide constituting the first insulating resin layer at a temperature of 400 ° C. or higher is performed. The method of manufacturing a magnetic sensor according to claim 1, wherein the method is provided after the step of forming one insulating resin layer and before the step of forming a magnetic core on the SiO ₂ layer.
According to a sixth aspect of the present invention, in the method of manufacturing a magnetic sensor according to the fourth or fifth aspect, the step of imparting uniaxial anisotropy to the magnetic core by a heat treatment in a rotating magnetic field and a heat treatment in a static magnetic field. Is performed at a temperature of 400 ° C. or lower.

According to the present invention, a solenoid coil is configured by laminating a conductor layer and an insulating resin layer on a non-magnetic substrate, and a magnetic core disposed inside the solenoid coil has an SiO ₂ layer or a temperature of 400 ° C. or higher. Since it is provided on an insulating resin layer made of baked polyimide, the Young's modulus of the base of the magnetic core increases, making it less susceptible to strain, thus suppressing the deterioration of magnetic properties due to the inverse effect of magnetostriction. can do. In addition, since the Young's modulus is large and the coefficient of linear expansion (CTE) is small compared to the case where a normal insulating resin such as polyimide baked at a temperature of less than 400 ° C. is used as a base, the influence of magnetostriction can be suppressed. it can. In addition, the magnetic core is arranged inside the solenoid coil, so that the interlinkage area of the magnetic flux is larger than when a bias magnetic field is applied using a planar spiral coil, and the conversion efficiency of the magnetic flux and current is improved. can do.

The present invention will be described below with reference to the drawings based on the best mode.
FIG. 1 is a drawing showing an example of a magnetic sensor according to the present invention. FIG. 1 (a) is a perspective view seen through from above as if the insulating resin layer is transparent, and FIG. 1 (b) is a perspective view. It is sectional drawing which follows the II line | wire of Fig.1 (a). FIG. 2 is an exploded perspective view of the magnetic sensor shown in FIG. 1, and is formed on the non-magnetic substrate 11 and the first conductor layer 22 provided thereon, the first insulating resin layer 12 and the first conductor layer 22. The SiO ₂ layer 18 and the magnetic core 14, the second insulating resin layer 13, and the second conductor layer 21 provided thereon are grouped and illustrated as if they were separated. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

As shown in FIGS. 1 to 4, the magnetic sensor 10 of this embodiment includes a nonmagnetic substrate 11, a first conductor layer 22 provided on one surface 11 a of the nonmagnetic substrate 11, and a nonmagnetic substrate. A first insulating resin layer 12 made of polyimide provided on one surface 11a of the substrate 11 and the first conductor layer 22; an SiO ₂ layer 18 formed on the first insulating resin layer 12; , A magnetic core 14 made of a soft magnetic film provided on the SiO ₂ layer 18, an electrode 17 for applying a high frequency current or a pulse current to the magnetic core 14, a first insulating resin layer 12, SiO ₂ A second insulating resin layer 13 made of polyimide provided on the layer 18 and the magnetic core 14 and a second conductor layer 21 provided on the second insulating resin layer 13 are provided.

Further, as shown in FIGS. 2 and 3, conductors 23 a and 23 b that pass through the first and second insulating resin layers 12 and 13 and connect the first conductor layer 22 and the second conductor layer 21 are provided. The solenoid coil 20 is configured by the first conductor layer 22, the second conductor layer 21, and the conductors 23a and 23b. As shown in FIG. 3, the magnetic core 14 provided on the SiO ₂ layer 18 is arranged inside the solenoid coil 20.
The SiO ₂ layer 18 is formed by depositing SiO ₂ by sputtering or the like, and has a thickness of 0.2 to 5 μm, for example. SiO ₂ is electrically insulative and has a large Young's modulus, which can prevent the magnetic core 14 from being adversely affected by thermal contraction or distortion of the insulating resin layers 12 and 13. Moreover, the unevenness | corrugation of the 1st conductor layer 22 can be eased by application | coating of the polyimide on the 1st conductor layer 22. FIG.

According to the magnetic sensor 10 of the present embodiment, the SiO ₂ layer 18 is interposed between the first conductor layer 22 and the magnetic core 14, so that the first conductor layer 22 serving as the lower layer wiring of the solenoid coil 20 is used. It is possible to prevent the influence of the volume change due to the temperature of the polyimide layer 12 that relieves the unevenness from reaching the magnetic core 14, and to suppress the characteristic deterioration of the magnetic core 14. Moreover, the characteristic deterioration of the magnetic core 14 due to the strain due to the stress of the insulating resin layer can be suppressed. By arranging the magnetic core 14 inside the solenoid coil 20, the interlinkage area of the magnetic flux is larger than when a bias magnetic field is applied using a planar spiral coil, and the conversion efficiency between the magnetic flux and the current is improved. can do.

Examples of the nonmagnetic substrate 11 include a semiconductor substrate such as a thermally oxidized silicon substrate, a glass substrate, a ceramic substrate, and the like.
The magnetic core 14 is obtained by imparting uniaxial anisotropy to a thin film made of a soft magnetic material. The soft magnetic material can be composed of a Co-based soft magnetic material such as CoNbZr. An example is Co ₈₅ Nb ₁₂ Zr ₃ . It can also be composed of CoTaZr, CoFeSiB, NiFe, FeSiAl, or the like, which has a zero magnetostriction composition.

In the case of this embodiment, as shown in FIG. 1A, a plurality of magnetic cores 14 are formed in parallel, and a conductor made of a conductor such as Cu so that each is electrically connected in series. Layer 15 is provided. In addition, it is preferable that the plurality of magnetic cores 14 be arranged in a zigzag shape (meander shape) so that the lengths of the magnetic cores 14 in the longitudinal direction are aligned, because the area required for the arrangement of the magnetic cores 14 can be reduced. The conductor layer 15 is preferably provided on the end of the magnetic core 14 and the SiO ₂ layer 18. In the present embodiment, since the electrode pads 17 and 17 are provided on the second insulating resin layer 13, the magnetic core 14 is not affected by the unevenness of the electrode pads 17 and 17.

  The number of the magnetic cores 14 may be one or plural, and is not particularly limited. When even numbers are connected in a meander shape as in this embodiment, a pair of electrodes 17 and 17 for applying a high-frequency current or a pulse current to the magnetic core 14 are arranged on the same side in the longitudinal direction of the magnetic core 14. Therefore, the area required for arranging the electrodes 17 and 17 can be further reduced.

  The solenoid coil 20 in this embodiment will be described in more detail. In a plan view with respect to one surface 11a of the nonmagnetic substrate 11 (see FIG. 1A), the first conductor layer 22 and the second conductor layer 21 are in the longitudinal direction of the magnetic core 14 (see FIG. 1A). A plurality of linear conductor patterns substantially orthogonal to the left-right direction).

  As shown in FIG. 3, the first insulating resin layer 12 includes a first opening 12a provided at a position aligned with one end 22a of each conductor pattern of the first conductor layer 22, It has the 2nd opening part 12b provided in the position aligned with the edge part 22b of the other side of each conductor pattern of the 1st conductor layer 22. As shown in FIG. The second insulating resin layer 13 includes a third opening 13 a provided at a position aligned with the first opening 12 a of the first insulating resin layer 12, and the second insulating resin layer 12 of the first insulating resin layer 12. And a fourth opening 13b provided at a position aligned with the second opening 12b.

  The first opening 12a and the third opening 13a are filled with a conductor (first through conductor) 23a that penetrates the first insulating resin layer 12 and the second insulating resin layer 13, The end portion 21a on one side of each conductor pattern of the second conductor layer 21 is electrically connected to the end portion 22a on one side of each conductor pattern of the first conductor layer 22 through the first through conductor 23a. Yes. Similarly, the second opening 12b and the fourth opening 13b are filled with a conductor (second through conductor) 23b penetrating the first insulating resin layer 12 and the second insulating resin layer 13, The other end portion 21b of each conductor pattern of the second conductor layer 21 is electrically connected to the other end portion 22b of each conductor pattern of the first conductor layer 22 through the second through conductor 23b. ing. Thus, the first conductor layer 22, the first through conductor 23a, the second conductor layer 21, and the second through conductor 23b form a circuit substantially orthogonal to the longitudinal direction of the magnetic core 14, whereby the solenoid coil 20 is configured. As shown in FIG. 1A, a pair of electrode pads 24 and 24 for allowing a current to flow through the coil 20 are provided at both ends of the solenoid coil 20. In the present embodiment, since these electrode pads 24 and 24 are provided on the second insulating resin layer 13, the magnetic core 14 is not affected by the unevenness of the electrode pads 24 and 24.

  In addition, the magnetic core 14 can be directly connected to the electrode 17, but in order to facilitate electrical connection with the electrode 17, as shown in FIGS. 1 and 4, at both ends of the magnetic core 14, In order to provide a conductor layer 16 made of a conductor such as Al and to conduct the conductor layer 16 on the first insulating resin layer 12 and the electrode 17 on the second insulating resin layer 13, the second insulating resin layer 13 is provided. A penetrating conductor (third penetrating conductor) 19 is preferably provided. For this reason, the second insulating resin layer 13 is provided with a fifth opening 13c filled with the third through conductor 19.

  In the present embodiment, the electrode 17 for flowing current to the solenoid coil 20 and the electrode 24 for applying high-frequency current or pulse current to the magnetic core 14 are provided on the second insulating resin layer 13. A protective layer (not shown) is optionally formed at a desired position on the second insulating resin layer 13 and the second conductor layer 21 except that an opening for ensuring conduction to the electrodes 17 and 24 is left. Can be formed. By protecting the second conductor layer 21 serving as the upper wiring of the solenoid coil 20, adverse effects on the solenoid coil 20 from the outside can be suppressed. The protective layer can be formed of a resin such as polyimide, polybenzoxazole, or silicone.

Next, an example of a method for manufacturing the magnetic sensor 10 according to the first embodiment of the present invention will be described.
First, the first conductor layer 22 having a plurality of linear conductor patterns is formed on the one surface 11 a of the nonmagnetic substrate 11. The first conductor layer 22 is composed of a conductor such as copper (Cu), aluminum (Al), gold (Au), chromium (Cr), or the like by a single method or two or more layers by a technique such as sputtering or plating. It can be formed as a laminate.

  Next, on the one surface 11a of the nonmagnetic substrate 11 and the first conductor layer 22, the first conductor layer 22 is provided in a position aligned with the end portion 22a on one side of each conductor pattern. A first insulating resin layer 12 having a first opening 12a and a second opening 12b provided at a position aligned with the other end 22b of each conductor pattern of the first conductor layer 22. It is formed using polyimide. In the magnetic sensor 10 of the first embodiment, the temperature when baking the polyimide constituting the first insulating resin layer 12 can be set to a temperature of less than 400 ° C. or a temperature of 400 ° C. or more. Can do.

Next, on the first insulating resin layer 12, at least a region between the row of the first openings 12a and the row of the second openings 12b is included, and the first opening 12a and The SiO ₂ layer 18 is formed at a position avoiding the second opening 12b. The SiO ₂ layer 18 can be formed by, for example, CVD or sputtering. In the present embodiment, in the width direction of the magnetic core 14 (vertical direction in FIG. 1A), the SiO ₂ layer 18 is divided into a row composed of the first openings 12a and a row composed of the second openings 12b. However, it may be spread outside this region. In that case, an opening (not shown) is provided in the SiO ₂ layer 18 so as to avoid the top of the first opening 12a and the second opening 12b, and the first through-conductor 23a and the second through-hole are provided. The conductor 23b can be formed.

A magnetic core 14 made of a soft magnetic film is formed on the SiO ₂ layer 18, and uniaxial anisotropy is imparted to the magnetic core 14 by heat treatment in a rotating magnetic field and heat treatment in a static magnetic field. When uniaxial anisotropy is imparted to the magnetic core, the temperature of the heat treatment in the rotating magnetic field and the heat treatment in the static magnetic field is preferably 400 ° C. or lower.

  Here, when a plurality of magnetic cores 14 are formed in parallel, a conductor layer 15 for electrically connecting the magnetic cores 14 is formed. In addition, a conductor layer 16 for facilitating conduction with the electrode 17 can be provided at both ends of the magnetic core 14. These conductor layers 15 and 16 are made of a single layer or two or more layers of conductors such as copper (Cu), aluminum (Al), gold (Au), and chromium (Cr) by a technique such as sputtering or plating. It can be formed as a laminate. The conductor layers 15 and 16 may be formed before or after the step of imparting uniaxial anisotropy to the magnetic core 14.

Next, on the first insulating resin layer 12, the SiO ₂ layer 18, and the magnetic core 14, a third opening 13a provided at a position aligned with the first opening 12a, and a second opening 2nd insulating resin layer 13 which has the 4th opening part 13b provided in the position aligned with 12b, and the 5th opening part 13c provided in the position which can be electrically connected with the end of magnetic core 14 Is formed using polyimide. When the conductor layer 16 is provided, the fifth opening 13c may be provided at a position that matches the conductor layer 16, and when the conductor layer 16 is not provided, the fifth opening 13c is aligned with the end of the magnetic core 14. Provide at the position to be.

Next, a first through conductor 23a that fills the first opening 12a and the third opening 13a with a conductor and penetrates the first insulating resin layer 12 and the second insulating resin layer 13, and a second The second through conductor 23b penetrating the first insulating resin layer 12 and the second insulating resin layer 13 by filling the opening 12b and the fourth opening 13b with a conductor, and the fifth opening 13c A third through conductor 19 that fills the conductor and penetrates the second insulating resin layer 13 is provided. Further, on the second insulating resin layer 13, the first through conductor 23 a is electrically connected to the end 22 a on one side of each conductor pattern of the first conductor layer 22, and the second through conductor is provided. A second conductor layer 21 having a plurality of linear conductor patterns that are electrically connected to the other end 22b of each conductor pattern of the first conductor layer 22 through 23b is formed. Further, together with the second conductor layer 21, an electrode 17 for passing a current through the solenoid coil 20 and an electrode 24 for applying a high frequency current or a pulse current to the magnetic core 14 are formed.
As described above, the magnetic sensor 10 of the first embodiment is obtained. Furthermore, a step of forming a protective layer may be added.

Next, a modified example of the magnetic sensor of the present invention will be described.
FIG. 5 is a view showing a modified example of the magnetic sensor of the present invention. FIG. 5 (a) is a perspective view showing the insulating resin layer as seen through from above as if it is transparent, and FIG. 5 (b). These are sectional drawings which follow the VV line of Fig.5 (a). FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. FIG. 7 is a sectional view taken along line VII-VII in FIG.

  As shown in FIGS. 5 to 7, the magnetic sensor 30 of this embodiment includes a nonmagnetic substrate 31, a first conductor layer 22 provided on one surface 31 a of the nonmagnetic substrate 31, and a nonmagnetic substrate. A first insulating resin layer 32 made of polyimide provided on one surface 31a of the substrate 31 and the first conductor layer 22, and a soft magnetic film provided on the first insulating resin layer 32; A magnetic core 34, an electrode 37 for applying a high frequency current or a pulse current to the magnetic core 34, and a second insulating resin layer made of polyimide provided on the first insulating resin layer 32 and the magnetic core 34. 33 and a second conductor layer 21 provided on the second insulating resin layer 33.

  Furthermore, conductors 23a and 23b that pass through the first and second insulating resin layers 32 and 33 and connect the first conductor layer 22 and the second conductor layer 21 are provided, and the first conductor layer is provided. The solenoid coil 20 is constituted by the second conductor layer 21, the second conductor layer 21, and the conductors 23a and 23b. As shown in FIG. 6, the magnetic core 34 is disposed inside the solenoid coil 20, and the first insulating resin layer 32 is made of polyimide baked at a temperature of 400 ° C. or higher.

  According to the magnetic sensor 30 of this embodiment, the first insulating resin layer 32 provided between the first conductor layer 22 and the magnetic core 34 is formed of polyimide that is hard-baked at a temperature of 400 ° C. or higher. As a result, the volume change due to heat becomes smaller than when baking at a temperature of less than 400 ° C., the shrinkage of polyimide during heat treatment in a magnetic field can be suppressed, and the deterioration of characteristics due to magnetostriction can be suppressed. it can. By arranging the magnetic core 34 inside the solenoid coil 20, the interlinkage area of the magnetic flux is larger than when a bias magnetic field is applied using a planar spiral coil, and the conversion efficiency between the magnetic flux and current is improved. can do.

Examples of the nonmagnetic substrate 31 include a semiconductor substrate such as a thermally oxidized silicon substrate, a glass substrate, and a ceramic substrate.
The configuration of the magnetic core 34 can be selected in the same manner as the magnetic core 14 in the first embodiment described above. In the magnetic sensor 30 of this embodiment, the number of the magnetic cores 34 may be one or more. There is no particular limitation. The configuration of the solenoid coil 20 can be configured similarly to the first embodiment.

  In the present embodiment, the electrode 37 for supplying current to the solenoid coil 20 and the electrode 24 for applying high-frequency current or pulse current to the magnetic core 34 are provided on the second insulating resin layer 33. A protective layer (not shown) is optionally provided at a desired location on the second insulating resin layer 33 and the second conductor layer 21 except that an opening for ensuring conduction to the electrodes 37 and 24 is left. Can be formed. By protecting the second conductor layer 21 serving as the upper wiring of the solenoid coil 20, adverse effects on the solenoid coil 20 from the outside can be suppressed. The protective layer can be formed of a resin such as polyimide, polybenzoxazole, or silicone.

Next, an example of a method for manufacturing the magnetic sensor 30 according to the second embodiment of the present invention will be described.
First, the first conductor layer 22 having a plurality of linear conductor patterns is formed on one surface 31 a of the nonmagnetic substrate 31. The first conductor layer 22 is composed of a conductor such as copper (Cu), aluminum (Al), gold (Au), chromium (Cr), or the like by a single method or two or more layers by a technique such as sputtering or plating. It can be formed as a laminate.

Next, on the one surface 31a of the nonmagnetic substrate 31 and the first conductor layer 22, the first conductor layer 22 is provided in a position aligned with the end portion 22a on one side of each conductor pattern. A first insulating resin layer 32 having a first opening 32a and a second opening 32b provided at a position aligned with the other end 22b of each conductor pattern of the first conductor layer 22. It is formed using polyimide. In the second embodiment, the temperature at which the polyimide constituting the first insulating resin layer 32 is baked is 400 ° C. or higher. As a result, problems such as deterioration of the characteristics of the magnetic core 34 can be solved without providing an SiO ₂ layer.

  Next, a magnetic core 34 made of a soft magnetic film is formed on the first insulating resin layer 32, and uniaxial anisotropy is imparted to the magnetic core 34 by heat treatment in a rotating magnetic field and heat treatment in a static magnetic field. . When uniaxial anisotropy is imparted to the magnetic core, the temperature of the heat treatment in the rotating magnetic field and the heat treatment in the static magnetic field is preferably 400 ° C. or lower.

  Here, in the case where a plurality of magnetic cores 34 are formed in parallel, a conductor layer 35 for electrically connecting the magnetic cores 34 is formed. In addition, a conductor layer 36 for facilitating conduction with the electrode 37 can be provided at both ends of the magnetic core 34. These conductor layers 35, 36 are made of a conductor such as copper (Cu), aluminum (Al), gold (Au), chromium (Cr), by a method such as sputtering, plating, etc., alone or in two or more layers. It can be formed as a laminate. The conductor layers 35 and 36 may be formed before or after the step of imparting uniaxial anisotropy to the magnetic core 34.

  Next, the third opening 33a provided on the first insulating resin layer 32 and the magnetic core 34 at a position aligned with the first opening 32a, and the position aligned with the second opening 32b. The polyimide resin is used for the second insulating resin layer 33 having the fourth opening 33b provided in the first and the fifth opening 33c provided at a position where it can be electrically connected to the end of the magnetic core 34. Form. When the conductor layer 36 is provided, the fifth opening 33c may be provided at a position that matches the conductor layer 36. When the conductor layer 36 is not provided, the fifth opening 33c is aligned with the end of the magnetic core 34. It is provided at the position where

Next, the first through conductor 23a that fills the first opening 32a and the third opening 33a with a conductor and penetrates the first insulating resin layer 32 and the second insulating resin layer 33, and the second The second through conductor 23b penetrating the first insulating resin layer 32 and the second insulating resin layer 33 by filling the opening 32b and the fourth opening 33b with the conductor, and the fifth opening 33c A third through conductor 39 (see FIG. 7) that fills the conductor and penetrates the second insulating resin layer 33 is provided. Further, on the second insulating resin layer 33, the first through conductor 23a is electrically connected to the end 22a on one side of each conductor pattern of the first conductor layer 22, and the second through conductor is provided. A second conductor layer 21 having a plurality of linear conductor patterns that are electrically connected to the other end 22b of each conductor pattern of the first conductor layer 22 through 23b is formed. Further, together with the second conductor layer 21, an electrode 37 for passing a current through the solenoid coil 20 and an electrode 24 for applying a high frequency current or a pulse current to the magnetic core 34 are formed.
Thus, the magnetic sensor 30 of the second embodiment is obtained. Furthermore, a step of forming a protective layer may be added.

As described above, the present invention has the following effects.
(1) By providing a resin layer (first insulating resin layers 12 and 32) made of polyimide as an insulating layer between the first conductor layer 22 serving as the lower wiring of the solenoid coil 20 and the magnetic cores 14 and 34 Unevenness due to the pattern of the first conductor layer 22 can be alleviated, and the characteristic deterioration of the soft magnetic film serving as the magnetic cores 14 and 34 can be suppressed.

(2) The thermal history was added by providing the SiO ₂ layer 18 having excellent mechanical strength at the lower part of the magnetic core 14 provided in the wiring of the solenoid coil 20 using a resin material such as polyimide as an insulating layer. The strain entering the magnetic core 14 can be reduced by the volume change of the resin at the time, and the deterioration of the magnetic characteristics due to the inverse effect of magnetostriction can be prevented.

  (3) In forming the solenoid coil 20 using a resin material such as polyimide as an insulating layer, polyimide which is the upper insulating layer (second insulating resin layers 13 and 33) after the magnetic cores 14 and 34 are formed. During the imidization baking, there is a possibility that the uniaxial anisotropy of the magnetic cores 14 and 34 may be deteriorated due to thermal disturbance. However, by performing this in a static magnetic field, the deterioration can be prevented.

(4) By setting the polyimide imidization baking temperature of the first insulating resin layers 12 and 32 to 400 ° C. or higher, shrinkage due to the thermal history of the resin can be suppressed, and the influence of magnetostriction on the magnetic cores 14 and 34 , Peeling of the SiO ₂ layer 18 can be suppressed. The photosensitive polyimide precursor is imidized by heat treatment after pattern formation by photolithography to become polyimide. Although it is the influence of the heat processing temperature in this case, generally imidation advances at the temperature of 200-250 degreeC or more, and it becomes a polyimide. However, when imidization proceeds at a low temperature, imidization is not sufficient, and a solvent or a portion from which a reaction product of imidization is missing exists as a gap between molecules, resulting in low density, mechanical, chemical It will be weak. When heat treatment is applied in this state, the molecular backbone of the polyimide flows during the heat treatment, and volume shrinkage occurs to fill the gaps in the molecular backbone. Due to the volume shrinkage, the magnetic cores 14 and 34 made of the soft magnetic film are distorted, and the characteristics are deteriorated due to the inverse effect of magnetostriction or the SiO ₂ is peeled off. On the other hand, when imidization proceeds at a high temperature of 400 ° C. or higher, imidization proceeds sufficiently, the molecular main chain of the imidized polyimide flows, and the solvent and imidation reaction products are lost. Since the portion is filled, it becomes high density, mechanically and chemically strong, and the volume change is small even if heat treatment is applied later. As a result, the shrinkage of the polyimide during heat treatment in a magnetic field can be suppressed, and the deterioration of characteristics due to magnetostriction can be suppressed.

The following is a detailed example of a method for manufacturing the magnetic sensor according to the first embodiment of the present invention.
On the thermally oxidized silicon substrate, copper (Cu) is deposited by sputtering through an adhesion layer such as chromium (Cr) or titanium-tungsten (TiW) to a thickness of about 1 μm. A photoresist is applied, a desired pattern is formed by photolithography, wet etching is performed, and the resist is removed to obtain a coil lower layer wiring. At this time, instead, a coil lower layer wiring may be obtained by forming a resist frame after forming a Cu film with a thickness of about 100 nm on a thermally oxidized silicon substrate, and forming a Cu film with a thickness of about 1 μm by plating.

On this coil lower layer wiring, a photosensitive polyimide precursor is applied so that the film thickness after imidization becomes 5 to 30 μm, and an opening (first portion) is formed in the conductive portion between the coil lower layer wiring and the upper layer wiring by photolithography. 1 and a second opening), and heat treatment is performed in a nitrogen atmosphere at 400 ° C. for 4 hours to cure. Thereafter, a SiO ₂ film having a thickness of 1 μm is formed by plasma CVD, a resist is applied, a desired pattern is formed by photolithography, etching is performed, and the resist is removed to obtain a SiO ₂ layer. At this time, the shape of the SiO ₂ layer is formed so as to surround the region where the magnetic core is formed and not to remain in the conductive portion of the upper layer wiring and the lower layer wiring of the solenoid coil. Moreover, it forms so that it may have an opening part wider than the polyimide opening part of a vertical conduction part.

After a resist frame is formed thereon, a cobalt-niobium-zirconium (CoNbZr) film having a thickness of 1 to 5 μm is formed by sputtering and patterned by lift-off to obtain a magnetic core formed in parallel. Then, Cu is sputtered through an adhesion layer such as Cr, TiW, etc., and then a resist frame is formed by photolithography, and a plurality of magnetic cores formed in parallel are directly formed by plating the openings. Pads to be connected (conductor layer) and pads at the end of the magnetic core are formed. Thereafter, heat treatment in a rotating magnetic field is performed for 2 hours in a vacuum of 300 to 400 ° C. and 3 kG, and then heat treatment in a static magnetic field is performed for 1 hour to impart uniaxial anisotropy in the width direction of the magnetic core.
Even when CoTaZr, CoFeSiB, NiFe, FeSiAl or the like is used as the material of the magnetic core, the film can be similarly formed by sputtering. When NiFe is used, the film may be formed by plating.

  A photosensitive polyimide precursor is applied thereon, and openings (third to fifth openings) for making electrical contact with the Cu wiring serving as the lower layer wiring and the Cu pad provided at the end of the magnetic core ) By photolithography. Subsequently, in order to imidize the photosensitive polyimide precursor, heat treatment is performed in a vacuum or in a nitrogen atmosphere at a temperature of about 250 to 380 ° C. for 1 hour. At this time, it is desirable to perform the heat treatment in a static magnetic field of several hundred Oe to several kOe in order to prevent the uniaxial anisotropy imparted by the heat treatment in the magnetic field in the previous step during the heat treatment from being disturbed.

Subsequently, Cu is deposited to a thickness of about 100 nm by sputtering, a resist frame is formed, and Cu is deposited to a thickness of about 1 to 10 μm to obtain a coil upper layer wiring. A resin such as polyimide, polybenzoxazole, or silicone is applied thereon, and an opening for making electrical contact with an external circuit is formed by photolithography. Subsequently, baking for curing these resins is performed to form a protective layer. Also in this case, it is desirable to perform heat treatment in a static magnetic field of several hundred Oe to several kOe.
As described above, the magnetic sensor according to the first embodiment of the present invention is obtained.

The following is a detailed example of a method for manufacturing a magnetic sensor according to the second embodiment of the present invention.
On the thermally oxidized silicon substrate, copper (Cu) is deposited by sputtering through an adhesion layer such as chromium (Cr) or titanium-tungsten (TiW) to a thickness of about 1 μm. A photoresist is applied, a desired pattern is formed by photolithography, wet etching is performed, and the resist is removed to obtain a coil lower layer wiring. At this time, instead, a coil lower layer wiring may be obtained by forming a resist frame after forming a Cu film with a thickness of about 100 nm on a thermally oxidized silicon substrate, and forming a Cu film with a thickness of about 1 μm by plating.

  On this coil lower layer wiring, a photosensitive polyimide precursor is applied so that the film thickness after imidization becomes 5 to 30 μm, and an opening (first portion) is formed in the conductive portion between the coil lower layer wiring and the upper layer wiring by photolithography. 1 and a second opening), and heat treatment is performed in a nitrogen atmosphere at 400 ° C. for 4 hours to cure.

  After a resist frame is formed thereon, a cobalt-niobium-zirconium (CoNbZr) film having a thickness of 1 to 5 μm is formed by sputtering and patterned by lift-off to obtain a magnetic core formed in parallel. Then, Cu is sputtered through an adhesion layer such as Cr, TiW, etc., and then a resist frame is formed by photolithography, and a plurality of magnetic cores formed in parallel are directly formed by plating the openings. Pads to be connected (conductor layer) and pads at the end of the magnetic core are formed. Thereafter, heat treatment in a rotating magnetic field is performed for 2 hours in a vacuum of 300 to 400 ° C. and 3 kG, and then heat treatment in a static magnetic field is performed for 1 hour to impart uniaxial anisotropy in the width direction of the magnetic core.

  A photosensitive polyimide precursor is applied thereon, and openings (third to fifth openings) for making electrical contact with the Cu wiring serving as the lower layer wiring and the Cu pad provided at the end of the magnetic core ) By photolithography. Subsequently, in order to imidize the photosensitive polyimide precursor, heat treatment is performed in a vacuum or in a nitrogen atmosphere at a temperature of about 250 to 380 ° C. for 1 hour. At this time, it is desirable to perform the heat treatment in a static magnetic field of several hundred Oe to several kOe in order to prevent the uniaxial anisotropy imparted by the heat treatment in the magnetic field in the previous step during the heat treatment from being disturbed.

Subsequently, a Cr adhesion layer and a Cu seed layer are formed to a thickness of about 250 nm by sputtering, a resist frame is formed, and Cu of about 1 to 10 μm is formed by plating to obtain a coil upper layer wiring.
As described above, the magnetic sensor according to the second embodiment of the present invention is obtained.

FIG. 8 shows, as a comparative example, a magneto-impedance effect element formed by applying polyimide and performing imidization baking at 375 ° C. for 1 hour (in the structure shown in FIGS. 5 to 7, the first insulating resin layer is 375 ° C.). It is the graph which described the relationship between the applied magnetic field in 300 MHz, and an impedance of the thing which consists of the polyimide baked in (3). Further, FIG. 9 shows a magneto-impedance effect in which polyimide is applied as Example 1 and imidization baking is performed at 375 ° C. for 1 hour, and a SiO ₂ layer is formed to 1 μm, and the SiO ₂ layer is formed on the SiO ₂ layer. 5 is a graph showing a relationship between an applied magnetic field at 300 MHz and impedance of an element (in the structure shown in FIGS. 1 to 4, a first insulating resin layer made of polyimide baked at 375 ° C.). Production conditions of two magneto-impedance effect elements (MI elements) (film thickness 1 μm, length 0.5 mm, width direction line / space: 30 μm / 20 μm, meander turn number: 1 turn, heat treatment in rotating magnetic field 360 ° C .; 2 hours, heat treatment in static magnetic field 360 ° C .; 1 hour) is the same. 8 and 9, the vertical axis represents the ratio (Z / Z ₀ ) to the impedance (Z ₀ ) when the applied magnetic field is zero.

In FIG. 8, the soft magnetic film is distorted by the contraction of the polyimide during the heat treatment in the magnetic field, and the anisotropy in the longitudinal direction due to the magnetostriction becomes larger than the anisotropy in the width direction given by the heat treatment in the magnetic field. The characteristics of the MI element were given uniaxial anisotropy in the longitudinal direction. On the other hand, in the case where SiO ₂ is formed on polyimide, as shown in FIG. 9, the strain due to polyimide contraction is relaxed by SiO ₂ having a large Young's modulus, the strain with respect to the magnetic core itself is small, and the anisotropy due to magnetostriction. It was found that the influence of was small. From this, in a magnetic sensor having a magnetic core inside the solenoid coil, when polyimide is used for the insulating layer under the magnetic core (MI element), SiO ₂ is deposited on the polyimide. It was found that the deterioration of characteristics can be suppressed.

FIG. 10 shows a magneto-impedance effect element formed by applying polyimide and performing imidization baking at 400 ° C. for 4 hours as Example 2 (first insulating resin layer in the structure shown in FIGS. 5 to 7). Is a graph showing the relationship between the applied magnetic field and impedance at 300 MHz. Further, FIG. 11 shows a magneto-impedance effect in which, as Example 3, polyimide was applied, imidization baking was performed at 400 ° C. for 4 hours, a SiO ₂ layer was formed to 1 μm, and the SiO ₂ layer was formed on the SiO ₂ layer. 5 is a graph showing a relationship between an applied magnetic field at 300 MHz and impedance of an element (in which the first insulating resin layer is made of polyimide baked at 400 ° C. in the structure shown in FIGS. 1 to 4). Production conditions of two magneto-impedance effect elements (MI elements) (film thickness 1 μm, length 0.5 mm, width direction line / space: 30 μm / 20 μm, meander turn number: 1 turn, heat treatment in rotating magnetic field 360 ° C .; 2 hours, heat treatment in static magnetic field 360 ° C .; 1 hour) is the same. 10 and 11, the vertical axis is indicated by the ratio (Z / Z ₀ ) to the impedance (Z ₀ ) when the applied magnetic field is zero.

  As shown in FIGS. 10 and 11, in the magnetic sensor having a magnetic core inside the solenoid coil, the use of polyimide baked at 400 ° C. for the insulating layer under the magnetic core (MI element) deteriorates the characteristics. And the characteristics were improved as compared with those shown in FIGS. From this, by making the temperature of imidization baking 400 ° C. or higher, the volume change due to heat becomes smaller than when baking at lower temperature, and the shrinkage during heat treatment in the magnetic field of polyimide can be suppressed. It has been found that it is possible to suppress deterioration of characteristics due to magnetostriction.

FIG. 12 is a graph showing the relationship between the applied magnetic field and impedance at 300 MHz at four different points on the same wafer in the magnetic sensor of Example 3 described above.
The same relationship between applied magnetic field and impedance was observed at any point on the same wafer, and high reliability was observed.

  FIG. 13 shows a magneto-impedance effect element (shown in FIGS. 5 to 7), in which a DC current is applied to a solenoid coil of a magnetic sensor formed by applying polyimide and performing imidization baking at 400 ° C. for 4 hours as Example 4. 6 is a graph showing an impedance-magnetic field curve in a magnetic sensor when a high frequency current of 300 MHz is passed through a structure in which a first insulating resin layer is made of polyimide baked at 400 ° C.). Regarding the coil, the number of turns is 16.5 times, and the line / space in the width direction is 15 μm / 10 μm. The production conditions of the magneto-impedance effect element (MI element) were as follows: film thickness: 1 μm, length: 0.5 mm, width line / space: 30 μm / 20 μm, meander turn number: 1 turn, heat treatment in rotating magnetic field : 400 ° C; 2 hours, heat treatment in a static magnetic field: 400 ° C; 1 hour. In FIG. 13, the horizontal axis represents the strength of the magnetic field, and the vertical axis represents the impedance.

  As shown in FIG. 13, it was found that a bias magnetic field of 3.3 Oe was applied by energizing the coil with 10 mA. The magnetic field generation efficiency at this time was 0.33 Oe / mA. From this, it was found that the characteristic of the magneto-impedance effect element which draws a symmetric curve and has no sensitivity near 0 magnetic field has sensitivity near 0 magnetic field due to the bias current flowing to the solenoid coil. . This makes it possible to realize a sensor having sensitivity in the vicinity of zero magnetic field when driven by the magnetic impedance effect method.

  FIG. 14 shows the relationship between the number of turns of the solenoid coil and the bias generation efficiency (Oe / mA) in the magnetic sensor manufactured in the same manner as in Example 4 with the number of turns of the coil being 12.5 times or 8.5 times. FIG. In FIG. 14, the horizontal axis represents the number of turns of the solenoid coil, and the vertical axis represents the magnetic field generation efficiency (Oe / mA).

  As shown in FIG. 14, it was found that the bias magnetic field generation efficiency is proportional to the number of turns of the solenoid coil. From this, it was found that the higher the number of turns of the solenoid coil, the better the bias magnetic field generation efficiency.

FIG. 15 is a diagram illustrating an inductive output generated in the solenoid coil when a pulsed excitation current is applied in the fourth embodiment. In FIG. 15, the upper waveform shows the excitation pulse voltage, and the lower waveform shows the output voltage of the solenoid coil.
It was found that an induction output can be obtained in the solenoid coil at the rising edge and falling edge of the excitation pulse voltage. Note that the height (magnitude) of this induction output varies depending on the external magnetic field.

  FIG. 16 is a graph showing changes in induction output due to an external magnetic field when a pulsed excitation current as shown in FIG. 15 is applied in Example 4 in which the number of coil turns is 16. Regarding measurement conditions, a pulse having a voltage of 3.0 V, a current of 124 mA, a rise time of 3 ns, a pulse width of 30 ns, and a period of 1 ms is input. The horizontal axis represents the magnetic field strength (Oe), and the vertical axis represents the induction output (mV).

  As shown in FIG. 16, in the magnetic sensor of the present invention, it was found that the characteristics of the orthogonal flux gate element showing linear characteristics in the vicinity of the zero magnetic field were obtained when a pulse was input.

  The magnetic sensor of the present invention can be used for mobile devices such as mobile phones and PDAs (personal digital assistants) and other various devices.

BRIEF DESCRIPTION OF THE DRAWINGS It is drawing which shows the one example of the magnetic sensor of this invention, (a) is the perspective view which looked through and illustrated from above, as if the insulating resin layer was transparent, (b) is I- of (a). It is sectional drawing which follows an I line. It is a disassembled perspective view of the magnetic sensor shown in FIG. It is sectional drawing which follows the III-III line of Fig.1 (a). It is sectional drawing which follows the IV-IV line of Fig.1 (a). It is drawing which shows the example of a modification of the magnetic sensor of this invention, (a) is the see-through | perspective figure which transparently illustrated from the upper part as if the insulating resin layer was transparent, (b) is VV of (a). It is sectional drawing which follows a line. It is sectional drawing which follows the VI-VI line of Fig.5 (a). It is sectional drawing which follows the VII-VII line of Fig.5 (a). It is a graph which shows the result of having measured the characteristic of the magnetic sensor of a comparative example. It is a graph which shows the result of having measured the characteristic of the magnetic sensor of Example 1. FIG. It is a graph which shows the result of having measured the characteristic of the magnetic sensor of Example 2. FIG. It is a graph which shows the result of having measured the characteristic of the magnetic sensor of Example 3. FIG. It is a graph which shows the result of having measured the characteristic in four different points on the same wafer of Example 3. FIG. It is a graph which shows the result of having measured the magnetic impedance characteristic at the time of driving the magnetic sensor of Example 4 as a magneto-impedance effect element. It is a graph which shows the result of having measured the bias magnetic field generation efficiency at the time of driving the magnetic sensor of Example 4 as a magneto-impedance effect element. It is the figure which showed the output from the excitation pulse and coil in the magnetic sensor of Example 4. It is a graph which shows the result of having measured the characteristic at the time of driving as an orthogonal fluxgate element of the magnetic sensor of Example 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Magnetic sensor, 11 ... Nonmagnetic board | substrate, 12 ... 1st insulating resin layer, 12a ... 1st opening part, 12b ... 2nd opening part, 13 ... 2nd insulating resin layer, 13a ... 3rd opening 13b ... fourth opening 13c ... fifth opening, 14 ... magnetic core, 17 ... electrode (the electrode pads for the magnetic core), 18 ... SiO ₂ layer, 20 ... solenoid coil, 21 ... second 2 conductor layers, 22... First conductor layer, 23 a, 23 b... Conductor that makes the first conductor layer and the second conductor layer conductive. 24... Electrode (electrode pad for coil), 30. 31 ... Non-magnetic substrate, 32 ... First insulating resin layer, 32a ... First opening, 32b ... Second opening, 33 ... Second insulating resin layer, 33a ... Third opening, 33b ... 4th opening part, 33c ... 5th opening part, 34 ... Magnetic core.

Claims (6)

A non-magnetic substrate;
A first conductor layer provided on one surface of the nonmagnetic substrate;
A first insulating resin layer made of polyimide provided on the one surface and the first conductor layer;
A SiO ₂ layer formed on the first insulating resin layer;
A magnetic core made of a soft magnetic film provided on the SiO ₂ layer;
An electrode for applying a high frequency current or a pulse current to the magnetic core;
A _second insulating resin layer made of polyimide provided on the first insulating resin layer, the SiO ₂ layer and the magnetic core;
A second conductor layer provided on the second insulating resin layer,
Solenoid coil comprising the first conductor layer and the second conductor layer, and a conductor that passes through the first and second insulating resin layers and conducts the first conductor layer and the second conductor layer. Is configured,
The magnetic sensor, wherein the magnetic core provided on the SiO ₂ layer is disposed inside the solenoid coil. A non-magnetic substrate;
A first conductor layer provided on one surface of the nonmagnetic substrate;
A first insulating resin layer made of polyimide provided on the one surface and the first conductor layer;
A magnetic core made of a soft magnetic film provided on the first insulating resin layer;
An electrode for applying a high frequency current or a pulse current to the magnetic core;
A second insulating resin layer made of polyimide provided on the first insulating resin layer and the magnetic core;
A second conductor layer provided on the second insulating resin layer,
Solenoid coil comprising the first conductor layer and the second conductor layer, and a conductor that passes through the first and second insulating resin layers and conducts the first conductor layer and the second conductor layer. Is configured,
The magnetic core provided on the first insulating resin layer is disposed inside the solenoid coil,
The magnetic sensor, wherein the first insulating resin layer is made of polyimide baked at a temperature of 400 ° C. or higher. Forming a first conductor layer having a plurality of linear conductor patterns on one surface of the nonmagnetic substrate;
A first opening provided on the one surface and the first conductor layer at a position aligned with one end of each conductor pattern of the first conductor layer and the first conductor layer Forming a first insulating resin layer made of polyimide having a second opening provided at a position aligned with the end portion on the other side of each conductor pattern of the conductor layer;
On the first insulating resin layer, at least a region between the row of the first openings and the row of the second openings is included, and the first opening and the second Forming a SiO ₂ layer at a position avoiding the top of the opening;
Forming a magnetic core made of a soft magnetic film on the SiO ₂ layer;
Providing the magnetic core with uniaxial anisotropy by heat treatment in a rotating magnetic field and heat treatment in a static magnetic field;
A third opening provided on the first insulating resin layer, the SiO ₂ layer, and the magnetic core at a position aligned with the first opening, and a position aligned with the second opening. Forming a second insulating resin layer made of polyimide having a fourth opening and a fifth opening provided at a position electrically connectable to an end of the magnetic core;
A first through conductor filling the first and third openings and penetrating the first and second insulating resin layers; and the first and second openings filling the second and fourth openings. Providing a second penetrating conductor that penetrates the two insulating resin layers, and a third penetrating conductor that fills the fifth opening and penetrates the second insulating resin layer;
On the second insulating resin layer, it is electrically connected to an end portion on one side of each conductor pattern of the first conductor layer through the first through conductor, and through the second through conductor. Forming a second conductor layer having a plurality of linear conductor patterns electrically connected to the other end of each conductor pattern of the first conductor layer;
And a step of forming an electrode for applying a high frequency current or a pulse current to the magnetic core via the third through conductor on the second insulating resin layer. Manufacturing method. Forming a first conductor layer having a plurality of linear conductor patterns on one surface of the nonmagnetic substrate;
A first opening provided on the one surface and the first conductor layer at a position aligned with one end of each conductor pattern of the first conductor layer and the first conductor layer Forming a first insulating resin layer made of polyimide having a second opening provided at a position aligned with the end portion on the other side of each conductor pattern of the conductor layer;
Baking the polyimide constituting the first insulating resin layer at a temperature of 400 ° C. or higher;
On the first insulating resin layer baked at a temperature of 400 ° C. or higher, a soft magnetic film is formed in a region between the row of the first openings and the row of the second openings. Forming a magnetic core comprising:
Providing the magnetic core with uniaxial anisotropy by heat treatment in a rotating magnetic field and heat treatment in a static magnetic field;
On the first insulating resin layer and the magnetic core, a third opening provided at a position aligned with the first opening, and a fourth provided at a position aligned with the second opening. Forming a second insulating resin layer made of polyimide and having a fifth opening provided at a position electrically connectable to the opening of the magnetic core and an end of the magnetic core;
A first through conductor filling the first and third openings and penetrating the first and second insulating resin layers; and the first and second openings filling the second and fourth openings. Providing a second penetrating conductor that penetrates the two insulating resin layers, and a third penetrating conductor that fills the fifth opening and penetrates the second insulating resin layer;
On the second insulating resin layer, it is electrically connected to an end portion on one side of each conductor pattern of the first conductor layer through the first through conductor, and through the second through conductor. Forming a second conductor layer having a plurality of linear conductor patterns electrically connected to the other end of each conductor pattern of the first conductor layer;
And a step of forming an electrode for applying a high frequency current or a pulse current to the magnetic core via the third through conductor on the second insulating resin layer. Manufacturing method. In the manufacturing method of the magnetic sensor according to claim 3,
The step of baking the polyimide constituting the first insulating resin layer at a temperature of 400 ° C. or higher is after the step of forming the first insulating resin layer and on the SiO ₂ layer. A method of manufacturing a magnetic sensor, comprising: before the step of forming. In the manufacturing method of the magnetic sensor according to claim 4 or 5,
A method for producing a magnetic sensor, wherein the step of imparting uniaxial anisotropy to the magnetic core by heat treatment in a rotating magnetic field and heat treatment in a static magnetic field is performed at a temperature of 400 ° C. or lower.

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