JP2014107606A - Antenna coil, component-integrated substrate, and communication terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration in characteristics of an antenna coil.SOLUTION: An antenna coil 10 comprises: a laminated body 12 in which a plurality of first base material layers 121 having a first magnetic permeability are laminated in a predetermined lamination direction; a coil conductor 14 formed in the laminated body 12 and including a winding axis approximately parallel to the lamination direction, the entire outer peripheral part of the coil conductor 14 contacting one of the plurality of first base material layers in a planar view from the lamination direction; and at least one first magnetic layer 16 provided in the laminated body 12, formed inside the coil conductor in a planar view from the lamination direction, and having a second magnetic permeability greater than the first magnetic permeability.

Description

  The present invention relates to an antenna coil, a component-embedded substrate, and a communication terminal device, which are provided in a laminated body and include a spiral coil that rotates in a winding axis direction while turning around a winding axis.

  Conventionally, as this type of antenna coil, for example, there is one described in Patent Document 1 below. As shown in FIG. 12, the antenna coil 100 includes a core 101 having a rectangular plate shape and a laminated structure. The core 101 has first to third resin layers 102 to 104 made of a polymer resin. Magnetic powder (for example, soft ferrite) is mixed in the first resin layer 102. The second resin layer 103 and the third resin layer 104 made of only resin not mixed with the magnetic powder are formed so as to sandwich the first resin layer 102 from above and below.

  The core is provided with a coil conductor 105 that forms a spiral coil. The coil conductor 105 includes at least a plurality of first conductor patterns 106, a plurality of second conductor patterns 107, and a plurality of metal conductors 108.

  Each first conductor pattern 106 is formed on the upper surface of the core 101 and has a linear shape that is non-parallel to both the left and right sides of the core upper surface. Each second conductor pattern 107 is formed on the lower surface of the core and has a linear shape that is non-parallel to the left and right sides of the lower surface of the core.

  When the second conductor pattern 107 is seen through from the upper surface side of the core, one end of each second conductor pattern 107 is one end of the left first conductor pattern 106 among the two first conductor patterns 106 adjacent in the left-right direction. And the other end of the second conductor pattern 107 is overlapped with the other end of the right first conductor pattern 106. Through-holes filled with metal conductors 108 are formed at such overlapping positions in the plane.

  The antenna coil 100 is used as an antenna in RFID (Radio Frequency IDentification) or the like. On the transmission side, the antenna coil 100 generates a magnetic field radially around the coil conductor 105 when a high-frequency signal is applied from an IC (not shown) connected to the antenna coil 100. A magnetic field obtained by combining these magnetic fields (that is, a combined magnetic field) is radiated toward the surrounding communication partner. On the reception side, when the radiation magnetic field on the transmission side passes, the antenna coil 100 generates an electromotive force due to electromagnetic induction and gives a high-frequency signal to an IC connected to the antenna coil 100.

International Publication No. 2008/146932

  Hereinafter, the result of examination of Patent Document 1 by the inventor will be described. As shown in FIG. 13, in the antenna coil 100, for example, when the coil conductor 105 is seen through from above the upper surface of the core, many portions of the first resin layer 102 are coil conductors as shown by the portions surrounded by the alternate long and short dash line. It exists inside 109 (hereinafter referred to as an inner portion) 109 from the inner diameter of 105. Further, when a high frequency signal is given, a magnetic field is generated in a substantially concentric manner around the coil conductor 105. In FIG. 13, a substantially concentric magnetic field is illustrated by four arrows A1 to A4. Of this magnetic field, only the one that passes through the inner part (indicated by arrow A1) affects the radiation characteristics of the antenna. That is, the portion outside the inner diameter of the coil conductor (hereinafter simply referred to as the outer portion) is irrelevant to the antenna radiation characteristics. However, since the magnetic layer protrudes outside the inner diameter of the coil conductor 105, the radiated magnetic field of the antenna coil 100 passes through the outer portion having a high magnetic permeability. Due to the material loss that occurs as a result, the strength of the radiated magnetic field of the antenna coil 100 is deteriorated, which affects the antenna characteristics (for example, communication distance).

  Therefore, an object of the present invention is to provide an antenna coil, a component-embedded substrate, and a communication terminal device that can suppress deterioration of antenna characteristics.

  In order to achieve the above object, a first aspect of the present invention is an antenna coil, in which a plurality of first base material layers having a first permeability are laminated in a predetermined lamination direction, and the lamination A coil conductor formed in the body and having a winding axis substantially parallel to the stacking direction, and a coil whose outer peripheral portion is in contact with any of the plurality of first base material layers in plan view from the stacking direction A conductor and at least one first magnetic layer that is formed inside the coil conductor in a plan view from the stacking direction and has a second permeability larger than the first permeability. And.

  A second aspect and a third aspect of the present invention are a component built-in substrate and a communication terminal device including the antenna coil.

  4th aspect of this invention is an antenna coil, Comprising: The laminated body by which the several 1st base material layer which has 1st magnetic permeability was laminated | stacked on the predetermined lamination direction, and it is formed in the said laminated body, The said lamination direction A coil conductor having a winding axis substantially parallel to the outer periphery of the coil conductor, the coil conductor being exposed to the air from the multilayer body, and the coil in the multilayer body in plan view from the stacking direction. And at least one first magnetic layer formed inside the conductor and having a permeability greater than the permeability of the air.

  According to each aspect described above, it is possible to provide an antenna coil, a component-embedded substrate, and a communication terminal device in which deterioration of antenna characteristics is suppressed.

It is a disassembled perspective view which shows the structure of the antenna coil which concerns on one Embodiment. FIG. 3 is a longitudinal sectional view of the antenna coil, as viewed from the direction of arrow B, along a section taken along line A-A ′ of FIG. 1. It is a schematic diagram which shows the effect | action and effect of the antenna coil of FIG. It is a figure which shows the communication terminal device provided with the coil antenna of FIG. FIG. 4 is an equivalent circuit diagram of a power feeding circuit and a booster antenna provided in the communication terminal device of FIG. 3. It is a figure which shows the detailed structure of the booster antenna of FIG. It is a longitudinal cross-sectional view which shows the structure of the antenna coil which concerns on a 1st modification. It is a longitudinal cross-sectional view which shows the structure of the antenna coil which concerns on a 2nd modification. It is a longitudinal cross-sectional view which shows the structure of the antenna coil which concerns on a 3rd modification. It is a longitudinal cross-sectional view which shows the structure of the antenna coil which concerns on a 4th modification. It is a longitudinal cross-sectional view which shows the structure of the antenna coil which concerns on a 5th modification. It is a longitudinal cross-sectional view which shows the structure of the antenna coil which concerns on a 6th modification. It is a longitudinal cross-sectional view which shows the 1st structural example of the antenna coil which concerns on a 7th modification. It is a longitudinal cross-sectional view which shows the 2nd structural example of the antenna coil which concerns on a 7th modification. It is a longitudinal cross-sectional view which shows the 3rd structural example of the antenna coil which concerns on a 7th modification. It is a longitudinal cross-sectional view which shows the structure of the component built-in board | substrate which concerns on an 8th modification. It is a perspective view which shows the conventional antenna coil. It is a top view which shows the conventional antenna coil.

(Embodiment)
Hereinafter, an antenna coil according to an embodiment of the present invention will be described in detail with reference to the drawings.

(Introduction)
First, the X axis, Y axis, and Z axis shown in several drawings will be described. The X axis, the Y axis, and the Z axis are orthogonal to each other. The Z-axis indicates the vertical direction of the antenna coil 10 or the stacking direction of the base material layer 121, and the positive direction of the Z-axis is upward for convenience. The X axis indicates the left-right direction of the antenna coil 10, and for convenience, the positive direction is the right direction of the antenna coil 10. The Y axis indicates the front-rear direction of the antenna coil 10, and for convenience, the positive direction is the depth direction of the antenna coil 10.

(Configuration of antenna coil 10)
In FIG. 1, the antenna coil 10 preferably includes a laminate 12, a coil conductor 14, and at least one first magnetic layer 16 as shown in FIGS. 1 and 2.

  The laminate 12 has a substantially rectangular parallelepiped shape of about 3.0 mm in the left-right direction and the front-rear direction and about 0.7 mm to 1.0 mm in the up-down direction, and the first main surface MS1 and the second main surface MS2, The peripheral surface Fs is substantially parallel to the Z axis.

  The first main surface MS1 and the second main surface MS2 are each substantially parallel to the XY plane. These main surfaces MS1 and MS2 face each other in the Z-axis direction. In the present embodiment, the main surface MS1 is the bottom surface of the stacked body 12, and the main surface MS2 is the top surface of the stacked body 12.

  The peripheral surface Fs includes a front end surface ES1, a rear end surface ES2, a left side surface SS1, and a right side surface SS2.

  Both end surfaces ES1, ES2 are substantially parallel to the ZX plane. The end surfaces ES1 and ES2 face each other in the Y-axis direction. The end surface ES1 connects the sides of the front ends of the main surfaces MS1 and MS2. End surface ES2 connects the sides of the rear ends of main surfaces MS1 and MS2.

  Moreover, both side surfaces SS1, SS2 are substantially parallel to the YZ plane, and the side surfaces SS1, SS2 face each other in the X-axis direction. Side surface SS1 connects the left sides of main surfaces MS1 and MS2. Side SS2 connects the right sides of main surfaces MS1 and MS2.

  As shown in FIG. 1, the stacked body 12 is formed by stacking a plurality of first base material layers 121 in the Z-axis direction (that is, a predetermined stacking direction). In FIG. 1, as the plurality of base material layers 121, six base material layers 121 a to 121 f are illustrated. In this case, the front end surface ES <b> 1 is configured from the front end surface of each base material layer 121, and the rear end surface ES <b> 2 is configured from the rear end surface of each base material layer 121. Further, the left side surface SS1 and the right side surface SS2 are composed of the left side surface and the right side surface of each base material layer 121. Here, in FIG. 1, the reference symbol ES <b> 1 of the front end surface of the laminate 12 is attached only to the front end surface of the base material layer 121 a from the viewpoint of easy viewing. Similarly, reference numerals ES2, SS1, and SS2 are attached only to the rear end surface, left side surface, and right side surface of the base material layer 121a.

Each base material layer 121 is made of, for example, an insulating material, a dielectric material, or a magnetic material, and has a first magnetic permeability μa. The first magnetic permeability μa is smaller than the second magnetic permeability μb of the magnetic layer 16 (described later), and is, for example, a value close to the magnetic permeability μ ₀ in a vacuum or the atmosphere. Here, when each base material layer 121 is made of a magnetic material, each base material layer 121 is made of, for example, a material in which a predetermined additive is mixed with Ni—Zn—Cu ferrite in order to reduce the magnetic permeability. Produced. As a material of each base material layer 121, ceramic or resin can be used.

  The coil conductor 14 has a spiral structure that advances in the direction of the winding axis At while turning inside the multilayer body 12 counterclockwise around the winding axis At parallel to the Z axis. And a plurality of conductor patterns 141 and a plurality of interlayer connection conductors 143.

  In the present embodiment, as the plurality of conductor patterns 141, first conductor patterns 141a to 141f formed on the upper surfaces of the base material layers 121a to 121f are exemplified. Each conductor pattern 141 is made of a conductive material (for example, silver, copper, or aluminum) and has a substantially rectangular loop shape that turns counterclockwise (see an arrow α in a two-dot chain line) for one turn. Hereinafter, more specific shapes will be described.

  The outer edge of each conductor pattern 141 is included in or in contact with the outer edge of the corresponding base material layer 121 in plan view from the Z-axis direction. Further, the inner edge of each conductor pattern 141 includes the outer edge of the corresponding magnetic layer 16 (described later) or is in contact with the outer edge of the corresponding magnetic layer 16.

  Further, each conductor pattern 141 does not have a complete loop shape. That is, a cutout is formed in a part of each conductor pattern 141, whereby each conductor pattern 141 has a discontinuous substantially annular shape. In the conductor pattern 141a, a notch β1 is provided in the corner portion on the right back side. In plan view from the Z-axis direction, the notch β2 of the conductor pattern 141b is formed at a position shifted by a predetermined distance Δd in the clockwise direction with respect to the formation position of the notch β1. Here, Δd is, for example, the length of the cutout β1 of the conductor pattern 141a in the clockwise direction. Hereinafter, similarly, the notches β3 to β6 of the conductor patterns 141c to 141f are formed at positions shifted by a predetermined distance in the clockwise direction with respect to the formation positions of the notches β2 to β5.

  In the present embodiment, examples of the plurality of interlayer connection conductors 143 include interlayer connection conductors 143b to 143e provided so as to penetrate the base material layers 121b to 121f in the Z-axis direction. Each interlayer connection conductor 143 is made of a conductive material. As the conductive material, a metal mainly composed of silver, copper or tin, or an alloy mainly composed of each of them is typical. Each interlayer connection conductor 143 is formed on the corresponding base material layer 121b so as to electrically connect the lower end and the upper end of the two conductor patterns 141 adjacent in the Z-axis direction. .

  The magnetic layer 16 is made of a magnetic material and has a second magnetic permeability μb. As the magnetic material, for example, Ni—Zn—Cu ferrite or hexagonal ferrite is typical. The second magnetic permeability μb is larger than the first magnetic permeability μa, for example, about 100.

  Each magnetic layer 16 has a rectangular shape in plan view from the Z-axis direction. In the present embodiment, one magnetic layer 16 is formed on the upper surface of each base material layer 121. Thereby, each magnetic layer 16 is formed on substantially the same plane as the conductor pattern 141. Here, the outer edge of the magnetic layer 16 is in contact with the inner edge of the conductor pattern 141 on the base material layer 121 (hereinafter also referred to as a corresponding base material layer) 121 formed on the same surface, or the conductor pattern 141 Do you enclose the outer edge?

(Manufacturing method of antenna coil 10)
Here, an example of the manufacturing method of the antenna coil 10 will be described. This manufacturing method includes the following steps (1) to (4). Here, the case where the base material layer 121 is made of a magnetic material having a relatively low first permeability μa and the magnetic layer 16 is made of a magnetic material having a relatively high second permeability μb will be described.

  (1) For example, the ferrite calcined powder and a predetermined additive are mixed with a binder, a plasticizer and the like by a ball mill so that the first permeability μa is obtained after sintering. The slurry obtained in this manner is molded by a doctor blade method or the like so as to have a predetermined size at the time of sintering, and a sheet material serving as a basis for the base material layer 121 is obtained.

  (2) Also, the ferrite calcined powder is mixed with a binder, a plasticizer, and the like by a ball mill so that a second magnetic permeability μb is obtained after sintering, whereby a magnetic paste serving as a basis for the magnetic layer 16 is generated. Is done.

  (3) In the sheet material obtained in (1) above, through holes for forming the interlayer connection conductor 143 are formed using a laser or a punching press, and for example, silver or the like is formed in these through holes. An electrode paste made of a metal as a main component is filled. On the surface of the sheet material, the magnetic paste obtained in the above (2) is screen-printed to form the magnetic layer 16. Further, an electrode paste made of copper or the like is screen-printed on the surface of the sheet material in order to form a conductor pattern 141, an external electrode, or the like. A desired number of such sheet materials are laminated.

  (4) The plurality of sheet materials laminated in the above (3) are pressure-bonded together, baked at, for example, 900 ° C. for 2 hours, and then diced. As a result, the antenna coil 10 is obtained.

(Application example of antenna coil 10)
The antenna coil 10 having the above-described configuration is mounted on a communication terminal device that supports non-contact communication using NFC (Near Field Communication) of 13.56 MHz band, for example. Here, FIG. 3 shows various components and various members housed in the casing 24 of the communication terminal device 20 when the casing cover 22 is opened. The communication terminal device 20 is typically a mobile phone or a smartphone, and includes a substrate 210 in which an IC 26 and a capacitor 28 are mounted in addition to the antenna coil 10 and a booster antenna 212 inside a housing 24. ing. In addition to the antenna coil 10, the IC 26, and the capacitor 28, a camera and various circuit elements are mounted and arranged on the substrate 210 at a high density. However, these are not the main parts of the present invention, so the explanation will be given. Omitted.

  On the substrate 210, the IC 26 is an integrated circuit used for non-contact communication by NFC or the like, for example. The antenna coil 10 and the capacitor 28 are connected in parallel to the IC 26. More specifically, both ends of the coil conductor 14 in the antenna coil 10 (the tip of the conductor pattern 141a, the rear end of the conductor pattern 141f) are connected to at least two terminals of the IC 26 via a pair of external electrodes (not shown). Connected. The IC 26, the antenna coil 10 and the capacitor 28 as described above constitute an NFC power supply circuit. A matching circuit may be connected between the antenna coil 10 and the IC 26.

  Here, FIG. 4 shows an equivalent circuit of the power feeding circuit 30. As shown in FIG. 4, when the inductance value of the antenna coil 10 is L1 and the capacitance value of the capacitor 28 is C1, the resonance frequency of the power feeding circuit 30 is determined based on L1 and C1. FIG. 4 also shows the resistance component R1 of the antenna coil 10.

  Further, as shown in FIGS. 3 and 5, the booster antenna 212 is attached to the housing cover 22 so as to be disposed above the antenna coil 10 when the housing 24 is closed by the housing cover 22. The booster antenna 212 is a planar spiral coil or the like. The opening size (horizontal size × vertical size) of the booster antenna 212 is larger than the opening size (horizontal size × height) of the antenna coil 10, thereby extending the communication distance of the antenna coil 10.

  As shown on the right side of FIG. 5, the booster antenna 212 first includes an insulating sheet material 40, a first planar coil conductor 42, and a second planar coil conductor 44. On the front surface and the back surface of the insulating sheet material 40, planar coil conductors 42 and 44 wound in opposite directions are formed.

  In addition, a magnetic sheet material 46 is preferably attached to the lower surface of the insulating sheet material 40 in order to suppress the generation of eddy currents due to the magnetic fields radiated from the two planar coil conductors 42 and 44.

  Further, a line capacitance is generated between the planar coil conductors 42 and 44. Therefore, as shown in FIG. 4, the planar coil conductors 42 and 44 are equivalently connected via the capacitors 48 and 410. Here, the inductance value of the planar coil conductor 42 is L2, the inductance value of the planar coil conductor 44 is L3, the capacitance value of the capacitor 48 is C2, and the capacitance value of the capacitor 410 is C3. In this case, the resonance frequency of the booster antenna 212 is determined based on L2, L3, C2, and C3.

  The communication terminal device 20 operates as follows during non-contact communication by NFC. First, data transmission to a communication partner will be described. The IC 26 modulates a 13.56 MHz carrier wave with data to be transmitted (baseband signal) to generate a high frequency signal. The parallel resonant circuit including the antenna coil 10 and the capacitor 28 is designed to have a resonant frequency of 13.56 MHz. The IC 26 resonates by applying the generated high frequency signal (high frequency current) to the parallel resonance circuit. The antenna coil 10 induces a magnetic field in the vicinity of itself by a high-frequency current from the IC 26 during data transmission. The magnetic field from the antenna coil 10 is linked to the booster antenna 212 disposed in the vicinity. As a result, the antenna coil 10 and the booster antenna 212 are magnetically coupled, and as a result, an induced current flows through the coil constituting the booster antenna 212. Due to this induced current, the booster antenna 212 generates a magnetic field. Here, since the size of the booster antenna 212 is larger than that of the antenna coil 10, the strength of the magnetic field generated by the booster antenna 212 is large, thereby supplementing the communication distance of the antenna coil 10. The magnetic field of the booster antenna 212 is magnetically coupled to the booster antenna or the like on the communication partner side, and data transmission is performed.

  Next, data reception from a communication partner will be described. When a magnetic field generated on the communication partner side is linked to the booster antenna 212, an induced current flows through the booster antenna 212. Due to this induced current, the booster antenna 212 generates a magnetic field. The magnetic field of the booster antenna 212 is linked to the antenna coil 10, whereby the antenna coil 10 and the booster antenna 212 are magnetically coupled. As a result, an induced electromotive force is generated between external electrodes (not shown) of the antenna coil 10, and a high frequency current (high frequency signal) flows through the IC 26. The IC 26 demodulates the received high-frequency signal and receives data.

(Operation and effect of antenna coil 10)
As described in detail in “Problems to be Solved by the Invention” with reference to FIG. 13, the conventional antenna coil 100 deteriorates the intensity of the radiated magnetic field due to structural reasons, and the antenna characteristics are affected. There was a problem of coming out.

  On the other hand, according to the present antenna coil 10, as a preferable example, all the outer edge portions of each conductor pattern 141 are included in the outer edge of the base layer 121 having a low magnetic permeability μa in a plan view from the Z-axis direction. The Further, the outer edge of the magnetic layer 16 having a high magnetic permeability μb is in contact with or included in the inner edge of each conductor pattern 141. Therefore, as shown in FIG. 2B, when a high frequency signal is input to the antenna coil 10, a magnetic field component irrelevant to the antenna radiation characteristic does not pass through the magnetic layer 16 having a high magnetic permeability μb, so that the loss caused thereby can be reduced. it can. As a result, it is possible to suppress the strength deterioration of the radiated magnetic field and obtain better antenna characteristics (for example, communication distance) than conventional.

  Moreover, since the base material layers 121 (same kind of layers) adjacent to each other in the Z-axis direction can be bonded to each other outside the conductor patterns 141, it is difficult to peel off. Moreover, since each pattern conductor 141 is pinched | interposed by the base material layer 121, since it becomes difficult to oxidize etc., the reliability of the antenna coil 10 becomes high.

  Further, according to the present antenna coil 10, as shown in FIG. 2, the magnetic layer 16 having a large magnetic permeability μb and the base material layer 121 having a small magnetic permeability μa are arranged on the inner side of the coil conductor 14 in the Z axis. They are stacked alternately in the direction. According to this structure, compared to the case where the entire inner side of the coil conductor 14 is made of a magnetic material having a high magnetic permeability μb, magnetic saturation is less likely to occur, and the DC superposition characteristics are improved.

  Further, according to the present antenna coil 10, since the planar conductor pattern 141 and the magnetic layer 16 are only formed on each base material layer 121, the antenna coil 10 can be reduced in height. Is possible.

(Appendix)
Moreover, in the said embodiment, according to this antenna coil 10, it demonstrated that all the outer edges of each conductor pattern 141 were included in the outer edge of the base material layer 121 as above-mentioned. However, the present invention is not limited to this, and all the outer edges of each conductor pattern 141 may not be included in the outer edge of the base material layer 121. In particular, the outer edge of each conductor pattern 141 may be in contact with the outer edge of the base layer 121 having a low magnetic permeability μa in plan view from the Z-axis direction. In other words, the outer edge of each conductor pattern 141 may be exposed from the laminate 12 in air having a relatively low magnetic permeability. Also in this case, similarly to the above-described embodiment, it is possible to suppress the strength deterioration of the radiated magnetic field and obtain better antenna characteristics (for example, communication distance) than the conventional one.

  Moreover, when each conductor pattern 141 is exposed in the air, the effect that an opening area becomes large especially by planar view from a Z direction is acquired.

  In the application example of the antenna coil 10, the communication terminal device 20 includes the booster antenna 212. However, the present invention is not limited to this, and the booster antenna 212 may be omitted when good communication characteristics can be obtained with the antenna coil 10 alone.

(First modification)
In the antenna coil 10, as shown in FIG. 6, a second magnetic layer 50 is additionally formed on the first main surface MS <b> 1 and / or the second main surface MS <b> 2 of the multilayer body 12 substantially parallel to the XY plane. It doesn't matter. Here, the magnetic layer 50 has a third magnetic permeability μc larger than the first magnetic permeability μa. Here, the third magnetic permeability μc may be the same as the second magnetic permeability μb. Similar to the magnetic layer 16, the magnetic layer 50 is made of, for example, Ni—Zn—Cu based ferrite.

  By providing the magnetic layer 50, it is possible to collect a magnetic field inside the coil conductor 14, so that better antenna characteristics can be obtained. In this case, the number of magnetic layers 50 on the first main surface MS1 and the second main surface MS2 may be the same or different.

(Second modification)
Further, in the antenna coil 10, as shown in FIG. 7A, the second base material layer 52 on which the conductor pattern 141 and the magnetic layer 16 are not formed is inserted between two first base material layers 121 adjacent in the Z-axis direction. It doesn't matter. Here, the material of the base material layer 52 may be the same as that of the base material layer 121. By providing the base material layer 52, the distance between the two conductor patterns 141 adjacent in the Z-axis direction (hereinafter referred to as the inter-pattern distance) is increased, so that the line capacitance generated between them is reduced. . As a result, the decrease in the self-resonant frequency of the antenna coil 10 can be mitigated.

(Third modification)
Further, as shown in FIG. 7B, the third base material layer 56 in which only the third magnetic layer 54 having the fourth magnetic permeability μd is formed is interposed between the two first base material layers 121 adjacent in the Z-axis direction. You can insert it into Here, the magnetic permeability μd has a value larger than the first magnetic permeability μa, but may be the same as the magnetic permeability μb. The material of the base material layer 56 may be the same as that of the first base material layer 121. By providing the base material layer 56, the magnetic permeability of the magnetic core inside the coil conductor 14 can be increased as compared with the configuration of FIG. As a result, better antenna characteristics can be obtained.

(Fourth modification)
Further, in the antenna coil 10, as shown in FIG. 7C, a fourth base material layer 58 similar to the third base material layer 56 is formed on the first main surface MS1 and / or the second main surface MS2 of the laminate 12. It may be additionally formed. Only the fourth magnetic layer 510 having the fifth magnetic permeability μe is formed on the surface of the base material layer 58. Here, the magnetic permeability μe has a value larger than the magnetic permeability μa, but may be the same as the magnetic permeability μb. By providing the fourth base material layer 58 in this manner, it is possible to collect a magnetic field inside the coil conductor 14, and thus better antenna characteristics can be obtained.

(Fifth modification)
Further, as shown in FIG. 8, the directivity of the antenna coil 10 can be adjusted by changing the distance between patterns depending on the position in the Z-axis direction. For example, the antenna coil 10 having directivity biased upward or downward can be realized if the inter-pattern distance is reduced as it goes upward or downward along the Z-axis direction. Also in this case, the inter-pattern distance may be adjusted using the third base material layer 56 shown in FIG. 7B.

(Sixth modification)
Moreover, as shown in FIG. 9, the 5th base material layer 512 is additionally formed in 1st main surface MS1 of the laminated body 12, and the 6th base material layer 514 is additionally formed in 2nd main surface MS2. It doesn't matter. Here, the base material layers 512 and 514 are made of the same material as the base material layer 121. However, only the second conductor pattern 513 is formed on the surface of the base material layer 512. Further, only the fifth magnetic layer 516 having the sixth magnetic permeability μf is formed on the base material layer 514. Here, the magnetic permeability μf has a value larger than the magnetic permeability μa, but may be the same as the magnetic permeability μb. This also makes it possible to realize the antenna coil 10 having a directivity biased upward.

(Seventh modification)
As shown in FIGS. 10A to 10C, a plurality of interlayer connectors 518 made of the same magnetic material as the magnetic layer 16 may be formed in the antenna coil 10. Such an interlayer connector 518 is formed so as to penetrate the corresponding magnetic layer 16 in the vertical direction so as to magnetically connect two magnetic layers 16 adjacent in the Z-axis direction. Here, in the example of FIG. 10A, each interlayer connection body 518 is provided in a central portion in the X-axis direction so as to be arranged in parallel in the Z-axis direction. In the example of FIG. 10B, each interlayer connection body 518 is provided in the vicinity of the left end in the X-axis direction so as to be arranged in parallel in the Z-axis direction. In the example of FIG. 10C, each interlayer connection body 518 is provided so as to be arranged in an oblique direction with respect to the Z axis in a plan view from the Y axis direction.

(Eighth modification)
As shown in FIG. 11, the antenna coil 10 is formed on a component-embedded substrate 520 that incorporates an electronic circuit (an equivalent circuit is equivalent to the power feeding circuit 30 side in FIG. 4) composed of an IC 26 and / or a chip-type capacitor 28. It may be modularized. Here, the capacitor 28 is not limited to a chip component, and may be formed as a conductor pattern in the component-embedded substrate 520. Such modularization makes it possible to shorten the distance of the wiring used for connecting the antenna coil 10, the IC 26 and the capacitor 28, thereby reducing the loss due to the wiring and the influence of external noise. 11 shows an example in which the IC 26 and the capacitor 28 are built in the component built-in substrate 520. However, the present invention is not limited to this, and the IC 26 and / or the chip-type capacitor 28 is formed on the surface of the component built-in substrate 520. May be implemented. In this case, the component-embedded substrate 520 typically includes other chips.

  In the above description, the example in which the IC 26 is an integrated circuit for non-contact communication using NFC has been described. However, the IC 26 may be an integrated circuit for non-contact communication of 13.56 MHz band such as FeliCa, or may be an integrated circuit for non-contact communication of other frequency band.

  The antenna device and the communication terminal device according to the present invention can suppress the deterioration of the characteristics of the antenna coil, and are suitable for communication terminal devices such as mobile phones and smartphones.

DESCRIPTION OF SYMBOLS 10 Antenna coil 12 Laminated body 121 1st base material layer 14 Coil conductor 141 Conductor pattern 143 Interlayer connection conductor 20 Communication terminal device 26 IC
28 capacitor 210 substrate 212 booster antenna 50, 54, 510, 516 second magnetic layer to fifth magnetic layer 52, 56, 58, 512, 514, second base material layer to sixth base material layer 518 interlayer connector 520 parts Built-in board

Claims (14)

A laminate in which a plurality of first base material layers having a first permeability are laminated in a predetermined lamination direction;
A coil conductor formed in the laminated body and having a winding axis substantially parallel to the laminating direction, the outer peripheral portion being in contact with any one of the plurality of first base material layers in a plan view from the laminating direction Coil conductors,
At least one first magnetic layer in the laminated body, which is formed inside the coil conductor in a plan view from the laminating direction and has a second magnetic permeability greater than the first magnetic permeability. Provided antenna coil.   2. The antenna coil according to claim 1, wherein an outer peripheral portion of the coil conductor is in contact with one of the plurality of first base material layers. The coil conductor includes a plurality of conductor patterns formed on each of the plurality of first base material layers, and a plurality of interlayer connection conductors connecting two conductor patterns adjacent in the stacking direction,
The antenna according to claim 1, wherein a plurality of the first magnetic layers are provided, and each first magnetic layer is provided inside the corresponding conductor pattern formed on the corresponding first base material layer. coil.   The said laminated body is further provided with the at least 1 2nd magnetic layer which is provided in the surface substantially orthogonal to the said lamination direction, and has a magnetic permeability larger than said 1st magnetic permeability. Antenna coil. A second base material layer provided between two first base material layers adjacent to each other in the stacking direction,
The antenna coil according to claim 3, wherein the conductor pattern is not formed on the second base material layer. A third base material layer provided between two first base material layers adjacent to each other in the stacking direction,
The antenna coil according to claim 3, wherein a third magnetic layer having a magnetic permeability larger than the first magnetic permeability is formed on the surface of the third base material layer. A fourth base material layer provided on a surface substantially orthogonal to the laminating direction in the laminate, further comprising:
The antenna coil according to claim 3, wherein a fourth magnetic layer having a magnetic permeability larger than the first magnetic permeability is formed on a surface of the fourth base material layer.   The antenna coil according to claim 3, wherein each distance between two conductor patterns adjacent to each other in the stacking direction differs depending on a position along the stacking direction. A fifth base layer in which at least one fifth magnetic layer having a magnetic permeability greater than the first magnetic permeability is provided on one surface substantially orthogonal to the stacking direction in the stacked body;
A sixth base material layer provided on the other surface substantially orthogonal to the laminating direction in the laminate, further comprising:
The antenna coil according to claim 3, wherein the conductor pattern is not formed on the fifth base layer and the sixth base layer.   The antenna coil according to claim 3, further comprising a plurality of interlayer connectors that are formed on the first base material layer and magnetically connect two first magnetic layers adjacent to each other in the stacking direction.   A component-embedded substrate comprising the antenna coil according to claim 1.   A communication terminal device comprising the antenna coil according to claim 1 or the component built-in substrate according to claim 11.   The communication terminal device according to claim 12, further comprising a booster antenna provided in the vicinity of the antenna coil. A laminate in which a plurality of first base material layers having a first permeability are laminated in a predetermined lamination direction;
A coil conductor formed in the laminated body and having a winding axis substantially parallel to the laminating direction, the coil conductor having an outer peripheral portion exposed to the air from the laminated body;
At least one first magnetic layer in the laminated body, formed inside the coil conductor in plan view from the laminating direction, and having a magnetic permeability larger than the magnetic permeability of the air. , Antenna coil.

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