JP5263434B1 - Antenna, antenna device, and communication device - Google Patents

Abstract

Provided are an antenna, an antenna device, and a communication device capable of adjusting inductance by an easy method while maintaining miniaturization even if the antenna has a coil wound around a core.
SOLUTION: A core, winding patterns 14a and 14b wound around the core, and an adjustment pattern 13 connected to one end of the winding patterns 14a and 14b are provided. At the end, a plurality of adjustment conductors 13b to 13d divided in the longitudinal direction of the adjustment pattern 13 are provided, and the adjustment conductors 13b to 13d are connected to each other at both ends.
[Selection] Figure 4

Description

  The present invention relates to an antenna, an antenna device, and a communication device that perform communication with a wireless communication medium such as an IC card or IC tag such as an RF-ID or NFC.

  Conventionally, when adjusting antenna characteristics in a contactless IC card or IC tag such as RF-ID or NFC, a capacitor pattern or an adjustment resistor is provided inside a planar loop antenna coil formed in a spiral shape on a substrate. A pattern is formed, and trimming and etching are performed to adjust the resonance frequency of the antenna and the Q value (see, for example, Patent Document 1). However, since it is difficult to reduce the size of the antenna in the technique described in (Patent Document 1), there is a small antenna having a shape in which an antenna coil is wound around a core formed of ferrite or the like. It has been proposed (see, for example, Patent Document 2).

Japanese Patent No. 4286777 Japanese Patent No. 4883208

  However, with the technique described in (Patent Document 2), it is difficult to adjust the inductance that contributes to determining the resonance frequency, and it is possible to reduce the size by securing a space including the inductance adjusting mechanism. There is sex. That is, in an antenna in which an antenna coil is wound in a planar loop shape, a space having an inductance adjustment mechanism can be secured inside the antenna coil, but in an antenna of the type in which a coil is wound around a core There is no such space. As a result, it is difficult to suppress variations in the resonance frequency of communication of the antenna by suppressing variations in inductance of the antenna alone.

  Therefore, the present invention provides an antenna, an antenna device, and a communication device that can adjust the inductance by an easy method while maintaining a reduction in size even when the antenna is wound around a core formed of ferrite or the like. An object is to provide an apparatus.

The present invention includes a magnetic core, a coil winding portion in which a conductive wire winds around the magnetic core, and an adjustment portion connected to one end of the coil winding portion, wherein at an end of the magnetic core, and a plurality of adjusting conductor divided into a plurality in the longitudinal direction of the wires connected to the coil winding part is the adjusting part, wherein the plurality of adjusting conductors at both ends in connecting to each other physician, first adjusting conductors located closest to the coil winding portion of the plurality of adjusting conductor is connected without passing through the end portion and the trimming point of the lead, the first The adjustment conductor other than the adjustment conductor is connected to the end portion of the conductor via a trimming point .

  According to the present invention, even in an antenna in which a coil is wound around a core formed of ferrite or the like, the inductance can be adjusted by an easy method while maintaining miniaturization.

The exploded perspective view of the portable terminal carrying the antenna of the present invention The perspective view of the antenna in embodiment of this invention The exploded perspective view of the antenna in an embodiment of the invention The figure which shows the conductor arrangement | positioning part and adjustment pattern of an antenna in embodiment of this invention 1 is a conceptual diagram showing an electronic circuit board mounted on the portable terminal shown in FIG. 1 and an antenna device formed by an antenna, and lines of magnetic force generated from the antenna device. The conceptual diagram which shows the antenna apparatus in a prior art example, and the magnetic force line which generate | occur | produces from the antenna apparatus The conceptual diagram which shows the antenna apparatus in other embodiment of this invention, and the magnetic force line which generate | occur | produces from the antenna apparatus 1 is an exploded perspective view of a portable terminal in which the antenna of the present invention is mounted at a position different from FIG. The figure which shows the inductance adjustment of the antenna in embodiment of this invention The figure which shows the adjustment result of the inductance value of the antenna in embodiment of this invention The figure which shows the adjustment result of the variation of the inductance value of the antenna in embodiment of this invention The figure which shows the example of the manufacturing process of the antenna in embodiment of this invention

The present invention includes a magnetic core, a coil winding portion in which a conductive wire winds around the magnetic core, and an adjustment portion connected to one end of the coil winding portion, The end of the magnetic core includes a plurality of adjustment conductors in which the conductor connected to the coil winding portion is divided into a plurality along the longitudinal direction of the adjustment portion, and the plurality of adjustment conductors are arranged at both ends. in connecting to each other physician, first adjusting conductors located closest to the coil winding portion of the plurality of adjusting conductor is connected without passing through the end portion and the trimming point of the lead, the first An adjustment lead other than the adjustment lead is connected to the end of the lead via a trimming point, and is an antenna in which a coil is wound around a core formed of ferrite or the like Even so, kept downsized Also it is possible to adjust the inductance in a simple manner.

(Embodiment)
FIG. 1 is an exploded perspective view of a portable terminal equipped with the antenna of the present invention. The mobile terminal 1 includes a display panel 2, a back cover 3, a battery 4 that is housed between the display panel 2 and the back cover 3, a camera 5, an electronic circuit board 6, and the like. As shown in FIG. 1, the display panel 2 may be a touch panel type and may not have an operation button. However, the display panel 2 may or may not be a touch panel type, and may have a separate operation button. good. The display panel 2 is a liquid crystal panel and includes a panel cover 2a. An antenna 8 according to an embodiment of the present invention is mounted on the back cover 3 by sticking with an adhesive tape or fixing with a screw. In this embodiment, the antenna 8 is disposed in the vicinity of the upper peripheral edge of the back cover 3 (peripheral edge close to the camera 5 away from the battery 4), and the upper peripheral edge of the camera 5 and the back cover 3. It is arranged between the parts. Although the antenna 8 may be disposed so as to overlap the battery 4, the entire mobile terminal 1 can be thinned by being disposed so as to overlap the thinner electronic circuit board 6. In the present embodiment, the back cover 3 is disposed on a flat portion. However, the back cover 3 may be disposed along the curved surface.

  External connection terminals 8 a and 8 b for forming an antenna device by connecting to the electronic circuit board 6 are provided on the surface of the antenna 8 facing the electronic circuit board 6. The connection between the electronic circuit board 6 and the antenna 8 may be contact with a pin, connector connection, or soldering of a conductive wire. In this embodiment, the electronic circuit board 6 is provided with antenna input / output pins 7a and 7b. As generally known, the antenna input / output pins 7a and 7b are connected to an antenna control unit 9 on an electronic circuit board 6 on which a matching circuit, a control IC, and the like are arranged. The antenna input / output pins 7a and 7b are connected to coil portions having both ends of the external connection terminals 8a and 8b provided on the antenna 8, thereby forming an antenna device. In the space formed between the back cover 3 and the display panel 2, components such as an antenna for other frequencies, a speaker, and an RF module are arranged in addition to the IC for RF-ID and the matching circuit.

  FIG. 2 is a perspective view of the antenna according to the embodiment of the present invention. FIG. 3 is an exploded perspective view of the antenna according to the embodiment of the present invention. Furthermore, FIG. 4 is a diagram showing a conductor arrangement portion and an adjustment pattern of the antenna according to the embodiment of the present invention.

  As shown in FIG. 2, the antenna 8 of the present embodiment is disposed so as to wrap around a core 11 formed of a magnetic material such as ferrite, amorphous, silicon steel, permalloy, or soft magnetic material. And a flexible substrate 12 having a coil pattern (conductive wire) and the like formed on a support made of resin. In the present embodiment, the core 11 is made of ferrite, and in this embodiment, the size is 13.7 × 33.5 × 0.3 mm, and 13.4 to 14 mm × 33.2 due to variation in the firing dimensions. It may be about 33.8 mm × 0.27 to 0.33 mm. The shape of the core 11 can be said to be a parallelepiped, particularly a rectangular parallelepiped plate. The coil pattern referred to here generates magnetic lines of force for communicating with a wireless communication medium such as an IC card or IC tag (not shown). 2 and 3, the specific shape of the coil pattern is not shown, but a coil pattern having a straight line S having an arrow as a coil axis is formed. The coil pattern and the adjustment pattern, which will be described later, are usually formed by, for example, a copper foil formed between two resin layers, such as a polyimide film and a coverlay or a resist, which the flexible substrate 12 has. The coil axis S is a coil pattern wound about the coil axis S and is substantially perpendicular to the coil pattern of the flexible substrate 12. The conductor pattern formed on the flexible substrate 12 including this coil pattern will be described in detail later with reference to FIG. The conductive wire is not limited to a conductor pattern, and a metal wire or the like may be wound around the core 11, or a conductor film may be formed on the core 11.

  Further, the core 11 is planar in the X and Y directions as shown in FIG. 2, and has a thin shape in the thickness direction perpendicular to the X and Y directions (the same direction as the coil axis S). The coil pattern is wound along the X direction. The core 11 may have the longest X direction parallel to the coil pattern, and the thickness in the thickness direction may be smaller than the X direction width and the Y direction width.

  Actually, as shown in FIG. 3, the flexible substrate 12 is divided into two parts with the core 11 interposed therebetween. In the present embodiment, for convenience, the side having the external connection terminals 8a and 8b in the flexible substrate 12 divided into two is defined as the lower flexible substrate 12a, and the other side as the upper flexible substrate 12b. As will be described in detail later, the lower flexible substrate 12a and the upper flexible substrate 12b are joined by solder. In the present embodiment, the flexible substrate 12 is joined at two sides substantially parallel to the coil axis S. Further, “lower side” and “upper side” are given for convenience in order to facilitate understanding in FIG. 3, and when the antenna 8 is mounted on a device, it may be upside down.

  In the present embodiment, the width of the upper flexible substrate 12b in the coil axis S direction is set so that the core 11 does not protrude. This is because, particularly when the core 11 is made of a ferrite that is easily broken, fragments and residues are scattered in the communication device (for example, the portable terminal 1 in FIG. 1) in which the antenna 8 is incorporated, and the communication device is not adversely affected. It is for doing so.

  In order to fix the core 11 between the lower flexible substrate 12a and the upper flexible substrate 12b, a double-sided adhesive tape as an adhesive layer is used in the present embodiment. That is, the double-sided adhesive tape is affixed between the core 11 and the lower flexible substrate 12a and between the core 11 and the upper flexible substrate 12b.

  In addition, although not shown in the drawing, at least one of the surfaces facing the lower flexible substrate 12a or the upper flexible substrate 12b of the core 11 of the present embodiment has slits with a pitch of 2 to 5 mm in advance. Yes. Since the core 11 is divided into small pieces using this slit, it has flexibility. Then, as described above, the double-sided adhesive tape is affixed to the surface facing the lower flexible substrate 12a or the upper flexible substrate 12b of the core 11 of the present embodiment. Furthermore, the lower flexible substrate 12a and the upper flexible substrate 12b have flexibility from the beginning.

  Therefore, the antenna 8 can be affixed and disposed along the curved surface even if the portion affixed to the back cover 3 of the portable terminal 1 shown in FIG. 1 has a curved surface. As a result, the core 11 may be in a state where at least a part thereof is divided by the slits described above and is configured by a plurality of small pieces. If the core 11 remains as a single unit, the core 11 falls apart at this point. What prevents this is a double-sided adhesive tape that is attached to the surface of the core 11 facing the lower flexible substrate 12a or the upper flexible substrate 12b. Alternatively, a protective tape may be provided separately. Accordingly, with the above configuration, in FIG. 2 and FIG. 3, a communication device (for example, the portable terminal 1 in FIG. 1) in which a part of each small piece of the core 11 divided by the slit described above is dropped and the antenna 8 is incorporated. It is possible to prevent the small pieces and residues that have fallen inside from being scattered. As a result, the communication device can be prevented from being adversely affected.

  As for the method for fixing the core 11 to the flexible substrate 12, as shown in the present embodiment, it is not always necessary to apply a double-sided adhesive tape to both surfaces of the core 11. For example, a fixing method using only one of the above double-sided adhesive tapes is conceivable. Moreover, instead of sticking a double-sided adhesive tape between the core 11 and each flexible substrate, the lower flexible substrate 12a and the upper flexible substrate are formed on two sides of the flexible substrate 12 that are substantially orthogonal to the coil axis S and are not joined by soldering. A method of bonding the substrate 12b is also conceivable. At this time, the lower flexible substrate 12 a and the upper flexible substrate 12 b need to extend outward in the coil axis S direction from the outer edge of the core 11. As for the adhesion of this portion, there is a method of directly applying an adhesive in addition to the method using the double-sided adhesive tape as described above.

  In the present embodiment, a double-sided adhesive tape is also applied to the surface of the lower flexible substrate 12a that does not face the core 11, but this is because the antenna 8 is connected to the portable terminal 1 in FIG. It is for attaching to the back cover 3 and fixing.

  The present embodiment will be described with reference to FIG. 3 again. As described above, the lower flexible substrate 12a and the upper flexible substrate 12b constituting the flexible substrate 12 are joined to each other by soldering at two sides of the flexible substrate 12 substantially parallel to the coil axis S. In FIG. 3, the lower flexible substrate 12a is provided with an adjustment pattern 13, which will be illustrated later in FIG. 4, and pattern exposed portions 17a and 17b are provided for enabling bonding by soldering. Similarly, both ends of the divided pattern in which the coil pattern is divided into a plurality of parts, which will be shown in FIG. 4 later, are exposed on the upper flexible board 12b, and soldering between the lower flexible board 12a and the upper flexible board 12b is performed. Pattern exposed portions 19a and 19b are provided for enabling adhesion by the above.

  In the present embodiment, the copper foils at both ends of the divided pattern exposed by the pattern exposed portions 19a and 19b of the upper flexible substrate 12b are further subjected to solder plating in advance before the flexible substrate 12 is assembled. Is given. The copper foils at both ends of the divided pattern exposed by the pattern exposed portions 17a and 17b provided on the lower flexible substrate 12a and the copper foils of the external connection terminals 8a and 8b are preliminarily subjected to gold plating. . This gold plating process is essential for ensuring reliability and preventing corrosion when the external connection terminals 8a and 8b are in contact with the antenna input / output pins 7a and 7b provided on the electronic circuit board 6. As described above, even in a state where the gold plating process or the solder plating process is performed, in this embodiment, the copper foil of the part is expressed as “exposed”. As a result, one coil pattern is formed. More specifically, the coil pattern and other conductor patterns formed on the flexible substrate 12 are formed as shown in FIG.

  FIG. 4A is the same view as the perspective view of the antenna in the embodiment of the present invention shown in FIG. 2, and shows the configuration of the upper flexible substrate. FIG. 4B is a perspective view of the lower flexible substrate of the antenna according to the embodiment of the present invention. Further, the lower flexible substrate 12a includes external connection terminals 8a and 8b and an adjustment pattern 13 in addition to the winding pattern 14a.

  The antenna 8 includes a core 11 that is a magnetic body, winding patterns 14 a and 14 b that are coil winding portions around which the conducting wire is wound around the core 11, and an adjustment unit that is connected to one end of the winding patterns 14 a and 14 b. And an adjustment pattern 13. Since the adjustment pattern 13 is formed at the end of the core 11, for example, it is not inserted between the winding patterns 14a, but the external connection terminals 8a are connected to the adjustment pattern 13 and the external connection terminals 8b are winding patterns. 14a and 14b. The adjustment pattern 13 includes an adjustment pattern (13b to 13d in FIG. 9) that is a plurality of adjustment conductors divided into a plurality in the longitudinal direction. The plurality of adjustment conductors are connected to each other at both ends, and in FIG. 4B, are connected to the adjustment pattern end 13a and the external connection terminal 8a.

  That is, on the lower flexible substrate 12a, a plurality of winding patterns 14a, which are part of a coil pattern for communicating with a wireless communication medium such as an IC card or an IC tag, are parallel to each other and the coil axis S. It is formed to intersect. A plurality of winding patterns 14b, which are part of the coil pattern, are formed on the upper flexible substrate 12b so as to be parallel to each other and intersect the coil axis S. At both ends of the plurality of winding patterns 14a and 14b, the copper foil is “exposed” by the pattern exposed portions 17a and 17b and the pattern exposed portions 19a and 19b, respectively. 4A and 4B, winding patterns 14 a and 14 b are formed in the region B. And it is the adjustment pattern 13 which is formed in the area | region A of the lower side flexible substrate 12a which is a part of coil pattern. In the present embodiment, it is formed only on the lower flexible substrate 12a and not on the upper flexible substrate 12b. At this time, the lower flexible board 12a faces away from the electronic circuit board 6 (metal body) in the portable terminal 1, and the upper flexible board 12b faces the electronic circuit board 6 (metal body) in the portable terminal 1. Placed in. However, it may be formed only on the upper flexible substrate 12b or on both. The adjustment pattern 13 is such that one of the conductive wires of the winding pattern 14a of the lower flexible substrate 12a is divided into three in parallel. Therefore, the three divided patterns are connected by the adjustment pattern end 13a and the external connection terminal 8a.

  FIG. 5 is a conceptual diagram showing an antenna device formed by the electronic circuit board 6 and the antenna 8 mounted on the portable terminal 1 shown in FIG. 1, and magnetic lines generated from the antenna device. FIG. 6 is a conceptual diagram showing the antenna device in the conventional example and the lines of magnetic force generated from the antenna device, and is shown for comparison with the antenna device in the present embodiment of FIG. Although not shown, the antenna 101 of FIG. 6 includes an antenna coil formed in a spiral shape on the surface opposite to the surface facing the electronic circuit board 6 as shown in the above-mentioned Patent Document 1. .

  As shown in FIG. 5, the antenna device according to the present embodiment includes an antenna 8 including a coil portion, and an electronic circuit board 6 disposed in the vicinity of the antenna 8. As is generally known, a wiring pattern is provided on the surface or inside of the electronic circuit board 6 to connect the terminals of each circuit component mounted thereon. With the miniaturization due to the integration of today's circuits, the electronic circuit board 6 almost has a plurality of wiring layers. Therefore, the power supply line and the GND (ground) line supplied to each circuit component are often provided as a wiring layer different from the wiring pattern described above. As a matter of course, these wiring patterns, power supply lines, and GND lines are conductors such as copper. That is, the electronic circuit board 6 can be regarded as a metal body. As described above, when the power supply line and the GND line are provided as separate wiring layers, these are formed over almost the entire surface of the assigned wiring layer, so that a particularly high-quality metal body is obtained. Further, as the metal body, when at least a part of the back cover 3 is a metal body, a metal film applied to the back cover 3, a part of the metal body of the panel when the display panel 2 is a liquid crystal, a shield plate Any metal body that achieves the object of the present application, such as a metal layer of the battery 4 or a metal part of the camera 5, may be used.

  As described above, in the antenna device including the antenna 8 and the electronic circuit board 6 that can be regarded as a metal body, the opening of the coil portion of the antenna 8 is perpendicular to the electronic circuit board 6. Is arranged at the end of the electronic circuit board 6. Note that the end of the electronic circuit board 6 refers to the case where the end of the antenna 8 protrudes from the outermost end of the electronic circuit board 6 and the end of the antenna 8 from the outermost end of the electronic circuit board 6. Includes both cases of being located inside.

  On the other hand, the conventional antenna device shown in FIG. 6 includes an antenna coil formed in a spiral shape on the surface opposite to the surface facing the electronic circuit board 6, so that the opening of the antenna 101 is provided. The part is parallel to the electronic circuit board 6. When a signal is input to the antenna 101 and a current flows, in a region P at a certain time, the magnetic force lines generated from the antenna 101 are all away from the antenna 101, and the magnetic force lines M pass only in one direction. As a result, a current flows through, for example, a non-contact type IC card located in the region P, so that the non-contact type IC card communicates with a portable terminal equipped with a conventional antenna device including the electronic circuit board 6 and the antenna 101. It can be carried out. However, in the region Q, the magnetic lines of force M extend in two opposite directions, a direction away from the antenna 101 and a direction toward the antenna 101. Accordingly, when the non-contact type IC card is positioned in the region Q, that is, almost right next to the antenna and substantially perpendicular to the electronic circuit board 6, the magnetic field lines M in both directions act on the non-contact type IC card and cancel each other. meet. As a result, no current flows through the non-contact type IC card, and communication between the portable terminal equipped with the conventional antenna device including the electronic circuit board 6 and the antenna 101 and the non-contact type IC card is not performed.

  However, in the antenna device according to the present embodiment shown in FIG. 5, the opening of the coil portion of the antenna 8 is substantially perpendicular to the electronic circuit board 6, and the longitudinal direction of the coil portion of the antenna 8 is the outermost portion of the electronic circuit board 6. The antenna 8 is disposed so as to be substantially parallel to the end portion. The coil axis of the antenna 8 is substantially parallel to the electronic circuit board 6. For this reason, for example, even if the non-contact type IC card is positioned not only in the area P but also in the area Q, good communication can be performed. Note that “substantially parallel” and “substantially perpendicular” mean that it is not necessary to be strictly parallel or perpendicular, and that the effect of the present invention can be satisfactorily obtained without any problem as long as it is about plus or minus 15 degrees. If it is about plus or minus 30 degrees, the effect of the present invention can be obtained.

  That is, since the opening of the antenna 8 is perpendicular to the electronic circuit board 6, when a signal is input to the antenna 8 and a current flows, all the magnetic lines M generated from the antenna 8 in the region Q at a certain time are all from the antenna 8. The magnetic field lines M pass only in one direction. As a result, a current flows through, for example, the non-contact type IC card located in the region Q, and the portable terminal equipped with the antenna device of the present embodiment including the electronic circuit board 6 and the antenna 8 is different from the non-contact type IC card. Communication can be performed.

  Also in the region P, when a signal is input to the antenna 8 and a current flows, in the region P at a certain time, the magnetic force line M is either one of the direction away from the antenna 8 or the direction toward the antenna 8. This is because the magnetic force lines M generated from the antenna 8 are attenuated near the electronic circuit board 6 so that the axis X of the magnetic force lines M is not perpendicular to the electronic circuit board 6 and is inclined. As a result, a current flows through, for example, a non-contact type IC card located in the region P, and the portable terminal equipped with the antenna device of the present embodiment including the electronic circuit board 6 and the antenna 8 and the non-contact type IC card are Communication can be performed.

  In addition, the magnetic force line M shown in FIG. 5 has an axis X connecting the boundary between the magnetic force line in the direction away from the antenna 8 and the magnetic force line in the direction toward the antenna 8. When, for example, a non-contact type IC card is located near the axis X of the magnetic force line M, both the magnetic lines in the direction away from the antenna 8 and the direction toward the antenna are non-contact type as in the conventional region Q in FIG. Work on IC cards and cancel each other out. As a result, no current flows through the non-contact type IC card, and communication between the portable terminal equipped with the antenna device of this embodiment and the non-contact type IC card is not performed.

  Next, the reason why the axis X of the magnetic force line M is inclined with respect to the electronic circuit board 6 will be described. Eddy currents induced on the surface of the electronic circuit board 6 facing the antenna 8 due to the magnetic field lines generated by the antenna 8 generate magnetic field lines in a direction perpendicular to the surface of the electronic circuit board 6 facing the antenna 8. Therefore, the magnetic lines of force M generated from the antenna 8 and the magnetic lines of force generated from the eddy current induced on the surface of the electronic circuit board 6 facing the antenna 8 are combined, and the magnetic lines of force M generated from the antenna 8 are near the electronic circuit board 6. In the vertical direction. As a result, the axis X of the magnetic force line M is inclined to the side away from the electronic circuit board 6. That is, in the axial direction of the antenna 8, the electronic circuit board 6 is arranged on one side of the antenna 8 and the electronic circuit board 6 is not arranged on the other side, so that the magnetic flux is weakened by eddy current only on one side, thereby causing the lines of magnetic force M. Can be tilted.

  Further, since the antenna 8 is disposed at the end of the electronic circuit board 6, the magnetic field lines M on the electronic circuit board 6 side (right side in FIG. 5) of the antenna 8 are attenuated and the antenna 8 is away from the electronic circuit board 6 ( The magnetic field lines M on the left side in FIG. 5 are relatively strengthened. As a result, the axis X of the magnetic force line M is inclined with respect to the electronic circuit board 6. In the configuration of the present embodiment, the angle α of the axis X of the magnetic lines of force M is inclined with respect to the electronic circuit board 6 at about 40 ° to 85 °. If the antenna 8 is not disposed at the end of the electronic circuit board 6, the magnetic field lines in the direction perpendicular to the surface of the electronic circuit board 6 due to the eddy current on the surface of the electronic circuit board 6 are reduced, and the axis X of the magnetic field lines M is It remains substantially perpendicular to the circuit board 6. In that case, it is difficult to communicate in the region P (directly above) even if communication is possible in the region Q (diagonal direction and lateral direction).

  The end portion of the antenna 8 and the electronic circuit board 6 may be arranged with the end portions thereof aligned, or the end portion of the antenna 8 may protrude from the end portion of the electronic circuit board 6. Further, the end portion of the antenna 8 may be located inside the end portion of the electronic circuit board 6.

  From the above, by positioning the antenna 8 at the end of the electronic circuit board 6, the current flowing through the electronic circuit board 6 can be utilized to the maximum extent. If the angle α is about 85 °, the effect of the present invention can be obtained at a minimum, and preferably 80 ° or less.

  Note that although the antenna device and the electronic circuit board 6 shown in FIG. 5 are arranged with a certain gap, there is a case where the gap cannot be secured when arranged in a portable terminal or the like. In that case, the antenna device and the electronic circuit board 6 are arranged in contact with each other as shown in FIG.

  FIG. 7 is a conceptual diagram showing an antenna device according to another embodiment of the present invention and lines of magnetic force generated from the antenna device. As shown in FIG. 7, even if the electronic circuit board 6 and the antenna 8 are arranged in contact with each other, the magnetic field lines are inclined by the same mechanism as that of the antenna device shown in FIG.

  As described above, even if there is a gap between the electronic circuit board 6 and the antenna 8, the core is within the range of the width in the coil axial direction A in the coil portion of the core from one end of the electronic circuit board 6. If at least a part of the antenna 8 is arranged close to or in contact with one end of the electronic circuit board 6 and the surface including the one end, the one end of the electronic circuit board 6 is arranged inside and outside the one end of the electronic circuit board 6. The effects of the present invention can be sufficiently obtained. In addition, if the width of the core is at least 4 mm to 15 mm, it is confirmed that the angle α ≦ 85 ° at which the effect of the present invention is obtained is established in the relationship between the antenna 8 and the electronic circuit board 6 described above. Yes. Needless to say, this relationship is based on the premise that the width of the electronic circuit board 6 that the core has in the same direction is larger than the width that the core has in the coil axial direction A.

  As described above, when the antenna 8 according to the embodiment of the present invention is provided at the end of the electronic circuit board 6 of the mobile terminal 1, the magnetic field lines are inclined, and the range in which transmission and reception can be performed is expanded. However, the position where the antenna 8 according to the embodiment of the present invention is to be mounted is not limited to this.

  As shown in FIG. 2, when the width of the core 11 of the antenna 8 in the direction of the coil axis S is L, the distance from the end 6a of the electronic circuit board 6 to the antenna 8 that is substantially perpendicular to the coil axis S is , -L to + L. Thereby, as explained above, the axis X of the lines of magnetic force M can be tilted. -L means that the antenna 8 protrudes outward from the edge 6a of the electronic circuit board 6, and that it protrudes by -L means that only the entire core 11 portion of the antenna 8 extends from the electronic circuit board 6. Indicates that it is popping out. + L is opposite to −L, and indicates that the antenna 8 is positioned inward by L from the end side 6 a of the electronic circuit board 6.

  FIG. 8 is an exploded perspective view of a mobile terminal in which the antenna of the present invention is mounted at a position different from that in FIG. In FIG. 8, the antenna 8 is mounted almost at the center of the back cover 3 of the mobile terminal 1. In such a state, for example, as shown in FIG. 6, the magnetic field lines generated from the antenna 8 are not inclined. At this time, even if a wireless communication medium (not shown) such as an IC card or an IC tag is arranged in a direction substantially orthogonal to the position where the antenna 8 of the back cover 3 shown in FIG. 8 is arranged, communication is not possible. Instead, communication is possible if the wireless communication medium is slightly separated from the longitudinal direction of the mobile terminal 1 (that is, in the direction of the coil axis S of the antenna 8 shown in FIG. 2). For example, the wireless communication medium may be brought close to a position facing the battery 4. Further, even if the antenna 8 is placed at the center, the direction of the antenna 8 is rotated by 90 degrees and the direction of the coil axis S of the antenna 8 is made perpendicular to the electronic circuit board 6 as shown in FIG. The same effect can be obtained.

  Such an adjustment pattern for adjusting the inductance of the antenna 8 in the embodiment of the present invention will be described in detail.

  FIG. 9 is a diagram illustrating adjustment of the inductance of the antenna according to the embodiment of the present invention. FIG. 9A is a diagram showing a state without trimming the adjustment pattern, FIG. 9B is a diagram showing a state where trimming is performed at the first trimming point of the adjustment pattern, and FIG. 9C is a diagram showing the adjustment pattern. FIG. 9D is a diagram showing a state trimmed at the second trimming point, and FIG. 9D is an enlarged view of the adjustment pattern.

  The inductance of the antenna 8 becomes a factor in determining the resonance frequency of the antenna device when the antenna 8 is connected to the electronic circuit board 6 on which the matching circuit and other antenna control unit 9 are mounted in FIG. Is. The inductance of the antenna 8 having the structure of the present embodiment is greatly affected by the size variation of the core 11 shown in FIGS. This is due to the influence of the ferrite shape corresponding to the length and cross-sectional area as shown in the self-inductance formula of the solenoid (self-inductance = permeability x square of the number of turns per unit length x solenoid length x cross-sectional area) Can be easily understood from the fact that is substantially proportional.

  As described above, since the inductance of the antenna 8 varies, the resonance frequency of the antenna device equipped with the antenna 8 also varies. By adjusting the resonance frequency within a predetermined range from the center frequency (for example, 13.56 MHz for RF-ID) defined in the communication standard, wireless communication can be performed with high probability and quality. At this time, if the variation in inductance of the antenna 8 alone is reduced (for example, within ± 2%), the adjustment range necessary for adjusting the resonance frequency of the antenna device on which the antenna 8 is mounted is reduced. Can do. Therefore, the present invention suppresses the variation in the inductance of the antenna 8 caused by the variation in the size of the core 11 of the antenna 8 by the adjustment pattern 13.

  As shown in FIG. 4A, the antenna 8 of the present invention has an adjustment pattern 13 in the region A and winding patterns 14a and 14b in the region B. In the adjustment pattern 13, along the longitudinal direction of the adjustment pattern 13, one pattern (conductor) is divided into three adjustment conductors 13b, an adjustment conductor 13c, and an adjustment conductor 13d. The wire widths of the winding patterns 14a and 14b in the region B are 0.4 to 0.5 mm, and the interval between the adjacent wires is 0.4 to 0.5 mm, and is wound for 10 turns. The lead wire width of the adjustment pattern 13 in the region A is 0.4 to 0.5 mm, with the innermost lead wire 13b being substantially the same as the lead wire width of the winding patterns 14a and 14b. The other adjustment conducting wires 13c and 13d are 0.3 mm, and the interval between adjacent conducting wires is 0.4 to 0.5 mm. In the adjustment pattern 13, the conducting wire is divided into three in parallel, and the adjusting conducting wires 13b to 13d are connected by the adjustment pattern end 13a and the external connection terminal 8a. Of course, the conducting wire may be divided into two or may be divided into four or more, and the number may be adjusted according to the size of the antenna 8 and the degree of variation. Moreover, it is preferable that the innermost adjustment lead wire 13b of the adjustment pattern 13 is almost the same as the lead wire width of the winding patterns 14a and 14b. May be made thinner than the adjustment lead wire 13b. By making it thinner, it is possible to achieve miniaturization. The innermost adjustment lead wire 13b of the adjustment pattern 13 is made substantially the same as the lead wire width of the winding patterns 14a and 14b because the adjustment pattern 13 is adjusted as shown in FIG. This is because only the adjustment lead 13b may remain due to trimming.

  The adjustment conductors 13b to 13d extend in parallel to each other in the direction perpendicular to the coil axis of the antenna 8, the adjustment conductor 13b is the longest, and the adjustment conductor 13d is the shortest. Thereby, the location of the first trimming point 15a and the second trimming point 15b can be shifted so as to be easily trimmed. Moreover, the adjustment conducting wires 13b to 13d extend in parallel with the winding patterns 14a and 14b. Thus, it is not always necessary to form all the patterns in parallel. The trimming referred to here means that the pattern is disconnected (insulated) by punching or laser processing the first trimming point 15a, the second trimming point 15b, or the like. Note that the winding patterns 14 a and 14 b and the adjustment lead wires 13 b to 13 d are basically arranged so that most of the winding patterns 14 a and 14 b face the core 11 (overlap). This is natural for obtaining the antenna performance efficiently because the core 11 has a function of collecting the magnetic flux.

  The winding pattern 14b formed on the upper flexible substrate 12b substantially overlaps the winding pattern 14a formed on the lower flexible substrate 12a with the core 11 in between. Therefore, in the upper flexible substrate 12b, nothing is formed in most of the region where the adjustment pattern 13 formed on the lower flexible substrate 12a overlaps. Of course, you may form the winding pattern 14b in the part.

  Next, a method for adjusting the inductance value will be described. In the present embodiment, since the adjustment pattern 13 is divided into three adjustment wires 13b to 13d, there are two trimming points, a first trimming point 15a and a second trimming point 15b. . That is, when the adjustment pattern 13 is divided into n pieces, (n-1) trimming points are formed, and the inductance value is adjusted by trimming or not trimming any one of the trimming points.

  In FIG. 9A to FIG. 9C, the adjustment lead wires 13 b to 13 d that can be handled as one lead wire by being connected by the adjustment pattern end 13 a and the external connection terminal 8 a to the end portion 11 a of the core 11. Each distance is different. Further, the adjustment conducting wires 13b to 13d and the end portion 11a of the core 11 are substantially parallel and may be arranged in a tilted relationship up to about plus or minus 45 degrees, but is not at least a vertical relationship.

  In FIG. 9A, none of the three adjusting conductors 13b to 13d is trimmed. Therefore, the adjustment pattern 13 functions as one thick conductive wire disposed near the end 11a of the core 11, and the adjustment conductive wire 13d is the outermost part of the coil pattern. And the distance from the outermost adjustment conducting wire 13d to the end 11a of the core 11 is short.

  In FIG. 9B, the adjustment pattern 13 is trimmed (insulated) at the first trimming point 15a. Therefore, only the adjustment lead wires 13b and 13c are actually functioning in the adjustment pattern 13. As a result, the adjustment lead 13c becomes the outermost part of the coil pattern, and the distance from the outermost adjustment lead 13c to the end 11a of the core 11 is longer than that in FIG. 9A.

  In FIG. 9C, the adjustment pattern 13 is trimmed at the second trimming point 15b. Therefore, only the adjustment lead 13b is actually functioning in the adjustment pattern 13. As a result, the adjustment lead wire 13b becomes the outermost part of the coil pattern, and the distance from the outermost adjustment lead wire 13b to the end portion 11a of the core 11 is longer than those in FIGS. 9 (a) and 9 (b).

  In an antenna coil having a structure as in the present invention configured by winding a coil around a core, both end portions of the core where the coil is not wound serve as an entrance / exit for the magnetic flux of the antenna. The inductance value tends to increase as the magnetic flux entrance / exit increases. FIG. 9A shows the state where the magnetic flux entrance / exit is the smallest, and FIG. 9C shows the largest state.

  As a result, the distances from the adjustment conductors 13b to 13d to the end portion 11a of the core 11 are different, so that the size of the magnetic flux entrance / exit changes, and as a result, the inductance value of the antenna 8 can be adjusted.

  Moreover, what is necessary is just to trim one place in either case of FIG.9 (b) and FIG.9 (c). That is, regardless of how many adjustment patterns 13 are divided, both ends of the plurality of adjustment conductors 13b, 13c, 13d... Are connected on the adjustment pattern end 13a side and the external connection terminal 8a side, and are arranged in parallel. Therefore, the length of the coil pattern and the number of adjustment conductors (from the inside of the core 11) to be left as the adjustment pattern 13 are disconnected so that the distance between the end portion 11a of the core 11 and the adjustment pattern 13 becomes a desired distance. It is only necessary to set the number of adjusting conductors (from the outside of the core 11) and trim only one portion between them. As described above, the adjustment lead to be left as the adjustment pattern 13 is always arranged inside the core 11, and the adjustment lead to be disconnected is always arranged outside the core 11, so that one trimming point can be provided and the antenna can be easily arranged. The inductance value of 8 can be adjusted. Of course, for example, an adjustment lead to be disconnected may be arranged between the adjustment leads left as the adjustment pattern 13, but in that case, a plurality of trimming points are required.

  In FIG. 2, when the antenna 8 is arranged around the end portion of the electronic circuit board 6, the adjustment pattern 13 is arranged so as to be located inside the electronic circuit board 6 with respect to the winding pattern 14 a. However, you may arrange | position so that the adjustment pattern 13 may be located in the outer side of the electronic circuit board 6 rather than the winding pattern 14a. However, since it is easier to reduce the size of the trimming points 15a and 15b located near the external connection terminals 8a and 8b, the external connection terminal 8a is arranged by placing the adjustment pattern 13 inside the electronic circuit board 6 than the winding pattern 14a. 8b can be easily connected to other parts. The trimming points 15 a and 15 b and the external connection terminals 8 a and 8 b do not need to be arranged so as to overlap the core 11, and are thus arranged outside the core 11. Since the trimming points 15a and 15b are trimmed by punching or laser processing, it is difficult to perform trimming if they overlap with the core 11. Further, since the external connection terminals 8a and 8b are not directly related to the inductance value, they do not need to be overlapped with the core 11 and increase the area of the coil portion (winding pattern) on the core 11 correspondingly. Better. That is, by arranging the trimming points 15 a and 15 b and the external connection terminals 8 a and 8 b so as not to overlap with the core 11, it is possible to achieve both reduction in size of the core 11 and improvement in the inductance value of the antenna 8.

  Further, if the number of divisions of the adjustment pattern 13 is increased and the area A of the adjustment pattern 13 that is one pattern becomes too large, the antenna 8 becomes large. Therefore, although it depends on a desired adjustment range of the inductance value, as a guide, the width of the region A: the width of the region B = 80% (about 70 to 90%): 20% (about 10 to 30%) should be set. Thus, downsizing and a sufficient inductance value adjustment range can be obtained.

  When the inductance was adjusted as shown in FIG. 9 using the antenna 8 shown in FIG. 2 and the like, the following results were obtained.

  The following (Table 1) is the result of studying with a model slightly different from FIG. 2, etc., and the ferrite core size is 40 x 12 x 0.3 mm, the number of turns is 8, and only the outermost pattern is adjusted. The pattern is divided into three parts in parallel. Inductance value adjustment results in three ways: free space (where the metal body is not close), the adjustment pattern 13 is in close contact with the metal body (for example, the electronic circuit board 6), and the adjustment pattern 13 is not in contact with the metal body. It is. In each situation, when the trimming is not performed, the trimming is performed at the trimming point 15a, the inductance value L when the trimming is performed at the trimming point 15b, and the change amount and the change rate of the inductance value L due to the trimming are shown. At this time, the amount of change and the rate of change are based on the case where trimming is not performed.

  As can be seen from (Table 1), when the antenna 8 is arranged in free space and the metal body is not arranged near the antenna 8 (the metal body has no influence on the antenna 8), the inductance value is maximum. Fluctuates by a little less than 4%, and that level of adjustment is possible.

  Next, the lower flexible substrate 12a including the adjustment pattern 13 was disposed so as to be in close contact with the metal body. The gap between the metal body and the pattern at this time was set to 30 μm. At this time, the size of the entrance / exit of the magnetic flux is greatly influenced by the adjacent metal body, the influence of the adjustment pattern 13 is almost invisible, and the inductance value fluctuates by a little less than 0.2%. That is, it is useful when only a small inductance value adjustment is required.

  Finally, the lower flexible substrate 12a provided with the adjustment pattern 13 was disposed so as not to face the metal body. That is, the arrangement relationship shown in FIG. 2 is obtained. The gap between the metal body at this time and the coil pattern of the antenna was set to 30 μm, the same as before. At this time, the size of the entrance / exit of the magnetic flux was influenced by both the influence of the adjacent metal body and the adjustment pattern 13, and the inductance value varied by 7.5% at the maximum. That is, the variation of the inductance value of the antenna 8 due to the variation of the size of the core 11 can be adjusted in a wide range, and the allowable range of the inductance adjustment is increased.

  From the above results, the adjustment pattern 13 has different advantages regardless of whether it is arranged so as to face the metal or not so as to face the metal. Therefore, it may be provided on both surfaces of the lower flexible substrate 12a and the upper flexible substrate 12b, or only one of them may be provided. However, when it is provided on both sides, it is better to form them on the left and right sides of the coil pattern, for example, so that the trimming points do not overlap.

  FIG. 10 is a diagram showing the adjustment result of the inductance value of the antenna in the embodiment of the present invention, and FIG. 11 is a diagram showing the adjustment result of the variation in the inductance value of the antenna in the embodiment of the present invention. At this time, the adjustment pattern 13 is installed so as not to face the metal body (electronic circuit board 6). 10 and 11 used the antenna model having the size and shape shown in FIGS.

  10A shows the size of the core 11 when the trimming is not performed as shown in FIG. 9A, the width of the core 11 is 33.2 to 33.8 mm (width in the X direction in FIG. 2), and the height of 13. The relationship between the thickness of the core 11 and the inductance value when the thickness is changed in the range of 4 to 14 mm (width in the Y direction in FIG. 2) and thickness of 0.27 to 0.33 mm is shown. FIG. 10B shows a case in which trimming (adjustment) is appropriately performed so that the distribution range of the entire inductance value shown in FIG. 10A is minimized under the same situation as FIG. Indicates the inductance value. 10A shows the result before adjusting the inductance value by trimming, and FIG. 10B shows the result after adjusting the inductance value by trimming.

  FIG. 11 (a) shows the degree of variation of each inductance value shown in FIG. 10 (a) with respect to the average inductance value of the entire inductance value shown in FIG. 10 (a). That is, the relationship between the thickness of the core 11 and the variation of the inductance value before the adjustment of the inductance value by trimming is shown.

  FIG.11 (b) shows the degree of variation of each inductance value shown by FIG.10 (b) with respect to the average inductance value of the whole inductance value shown by FIG.10 (b). That is, the relationship between the thickness of the core 11 and the variation of the inductance value after adjusting the inductance value by trimming is shown.

  As can be seen from FIGS. 10A and 11A, if the inductance value is not adjusted, the X-direction width and the Y-direction width of the core 11 are only about plus or minus 1-2%, and the inductance value is positive. It can be seen that the variation is about 5%. In order to produce a practical antenna 8, for example, even if the X-direction width and the Y-direction width of the core 11 vary about ± 1 to 2%, the variation in inductance value is within about 2%. Need to fit in.

  And the said subject can be solved by forming the adjustment pattern 13 like this invention.

  Since FIG. 10A shows the inductance value of the antenna 8 of FIG. 9A, the inductance value is relatively low as described above. That is, the inductance value adjustment of the present invention is adjusted in the direction in which the inductance value increases with reference to no trimming in FIG. 9A. As shown in FIG. 10A, the inductance value increases as the thickness of the core 11 increases. On the other hand, in FIG. 10B, by adjusting the inductance value by trimming, almost the same inductance value can be obtained regardless of the thickness of the core 11.

  Also, as is apparent from FIGS. 11A and 11B, it can be seen that the degree of variation in inductance value due to trimming is small.

  FIG. 12 is a diagram showing an example of the manufacturing process of the antenna in the embodiment of the present invention. This manufacturing process will be described with reference to the exploded perspective view shown in FIG.

  As already described, at least one of the surfaces facing the lower flexible substrate 12a or the upper flexible substrate 12b of the core 11 shown in FIG. ing. This slit is inserted before the firing step when the core 11 is formed. In the pre-stage of this firing step, the slit is made with a size and depth so that the core 11 does not easily break at the slit portion even after firing.

  A double-sided adhesive tape is affixed to the surface that faces the lower flexible substrate 12a or the upper flexible substrate 12b to the core 11 that has been subjected to the firing step and thus has slits (step of FIG. 12). S1). In this embodiment, a double-sided adhesive tape is affixed to both sides of the core 11.

  As is well known, double-sided adhesive tapes are in a state where their one side is supported by a support film in order to facilitate handling. Naturally, in step S1 of FIG. 12, in the state where the double-sided adhesive tape is pasted on both surfaces of the core 11 shown in FIG. 3, all of these supporting films are left. In this state, one of the surfaces of the core 11 on which the double-sided adhesive tape is applied is pressed by, for example, a roller (step S2 in FIG. 12).

  Then, at least a part of the core 11 is divided by the slits, and the core 11 is configured by a plurality of small pieces. Still, since the double-sided adhesive tape is stuck on both surfaces of the core 11, the core 11 does not fall apart. And the core 11 which became such a state is affixed along the curved surface in the back cover 3 of the portable terminal 1 shown in FIG. 1, even if the location where the antenna 8 is affixed has a curved surface. Allows to be placed.

  In addition, stress that is not intended by the operator may be applied to the core 11 when the antenna 8 is assembled or mounted on the mobile terminal 1 (see FIG. 1). Also at this time, a part of each small piece of the core 11 divided by the slit is dropped, and the small piece or residue dropped in the communication device (for example, the portable terminal 1 in FIG. 1) in which the antenna 8 is incorporated is scattered. Can be prevented. And it can prevent a bad influence on a communication apparatus.

  Furthermore, the support film of the double-sided adhesive tape shown in FIG. 3 described above prevents the double-sided adhesive tape from sticking to the roller or the work table facing it when the roller is pressed.

  Note that the double-sided adhesive tape to be applied to the side of the lower flexible substrate 12a where the core 11 is not disposed is after the placement and alignment of the upper flexible substrate 12b and the solder bonding with the lower flexible substrate 12a to be described later are completed. Do. This is because it is a device for using an inexpensive double-sided adhesive tape material that cannot withstand the heat applied at the time of soldering, thereby eliminating the need for an expensive heat-resistant tape.

  As described above, the core 11 that can be bent to some extent is disposed on the lower flexible substrate 12a (step S3 in FIG. 12). In that case, after peeling off the support film of the double-sided adhesive tape affixed on the surface facing the lower flexible substrate 12a of the core 11, it arrange | positions to the lower flexible substrate 12a. The place where the core 11 is disposed is inside the portion indicated by the dotted line in FIG.

  After the core 11 shown in FIG. 3 is thus arranged on the lower flexible substrate 12 a, the upper flexible substrate 12 b is now arranged from the upper side of the core 11. Also at this time, the upper flexible substrate 12b is placed after the support film of the double-sided adhesive tape affixed to the surface of the core 11 facing the upper flexible substrate 12b is peeled off. The upper flexible substrate 12b is aligned so that the core 11 is disposed inside the dotted line shown in FIG. 4B (step S4 in FIG. 12).

  There are several methods for aligning the lower flexible board 12a and the upper flexible board 12b on which the core 11 is disposed. For example, although not shown in the drawings of this embodiment, holes and markers for alignment pins are provided in advance on the outer edges of the lower flexible substrate 12a and the upper flexible substrate 12b, and the holes and markers are used. Perform alignment. Then, after the soldering of the lower flexible board 12a and the upper flexible board 12b, which will be described later, is performed, unnecessary hole portions and marker portions may be excised. This facilitates the alignment of the pattern exposed portions 17a and 19a and the pattern exposed portions 17b and 19b, and the flexible substrate 12 on which the coil pattern for communicating with a wireless communication medium such as an IC card or an IC tag is formed. It can be assembled more reliably. When a hole or marker portion cannot be formed, there is a method of aligning the upper flexible substrate 12b and the lower flexible substrate 12a using an image recognition device and a robot.

  After the alignment as described above, the lower flexible board 12a and the upper flexible board 12b are soldered together (step S5 in FIG. 12). Here, the copper foils at both ends of the divided pattern exposed by the pattern exposed portions 19a and 19b of the upper flexible substrate 12b and the ends of each of the divided patterns exposed by the pattern exposed portions 17a and 17b of the lower flexible substrate 12a. The position with the copper foil coincides. That is, in FIG. 3, the positions of the copper foils 16a and 18a, and the copper foils 16b and 18b coincide with each other, and the lower flexible board 12a and the upper flexible board 12b are soldered together. A single coil pattern is formed.

  Solder bonding is performed by heating the portion where the pattern exposed portions 17a and 19a overlap and the portion where the pattern exposed portions 17b and 19b overlap. As described above, the copper foils 18a and 18b at both ends of the divided pattern exposed by the pattern exposed portions 19a and 19b of the upper flexible substrate 12b are subjected to solder plating in advance. Further, the copper foils 16a and 16b at both ends of the divided pattern exposed by the pattern exposed portions 17a and 17b provided on the lower flexible substrate 12a are subjected to gold plating in advance. Therefore, when the portion is heated, the solder plated on the copper foils 18a and 18b of the upper flexible substrate 12b is melted, and the copper foils 16a and 16b of the lower flexible substrate 12a are joined.

  Since the double-sided adhesive tape is vulnerable to heat, only the portion where the pattern exposed portions 17a and 19a overlap and the portion where the pattern exposed portions 17b and 19b overlap are heated so that heat is not applied to them. In the heating device for solder joining, the solder is melted, the copper foils 18a and 18b of the upper flexible board 12b are joined to the copper foils 16a and 16b of the lower flexible board 12a, and the solder is cooled. After solidification, the flexible substrate 12 may be pulled up. As described above, as a heating method that requires local, quick, and fine temperature control, for example, bonding using pulse heat is preferable.

  However, the solder by the solder plating process applied to the pattern exposed portions 19a and 19b of the upper flexible substrate 12b may be insufficient for joining the lower flexible substrate 12a and the upper flexible substrate 12b. In that case, a solder cream layer is formed on either of both ends of the divided pattern 21a of the pattern exposed portions 17a and 17b of the lower flexible substrate 12a or on both ends of the divided pattern 21b of the upper flexible substrate 12b. May be.

  In place of the solder joint described above, ACF (anisotropic conductive film) may be used. That is, before step S4 in FIG. 12, the ACF is applied to either the pattern exposed portions 17a and 17b of the lower flexible substrate 12a or the pattern exposed portions 19a and 19b of the upper flexible substrate 12b shown in FIG. deep. In this case, the step S5 of FIG. 12, that is, the soldering step is not necessary.

  Finally, a double-sided adhesive tape is applied to the side of the lower flexible substrate 12a where the core 11 is not disposed (step S6 in FIG. 12). This is because the double-sided adhesive tape cannot withstand the heat applied during solder bonding, as described above. As is well known, double-sided adhesive tapes are in a state where their one side is supported by a support film in order to facilitate handling. Naturally, in step S6 of FIG. 12, the support film is left in a state where the double-sided adhesive tape is stuck on the lower flexible substrate 12a of the antenna 8 shown in FIG. For example, as shown in FIG. 1, the support film is peeled off before the antenna 8 completed through the above steps is mounted on the portable terminal 1.

  By using the processes as described above, the antenna 8 shown in FIG. 2 can be assembled extremely simply and with high accuracy. As shown in FIG. 3 and FIG. 12, the double-sided adhesive tape is previously applied to both surfaces of the core 11, and the soldering is performed after alignment with the flexible substrate 12. Even if the alignment of the core fails, it is possible to redo the alignment before soldering. Thereby, the assembly failure rate of the antenna 8 shown in FIG. 2 can be reduced.

  According to the present invention, the antenna is small and has a stable inductance value, and the communication characteristics of the antenna can be maintained. Therefore, the antenna is useful as an antenna, an antenna device, and a communication device of various electronic devices such as a mobile phone. In addition, the present invention can also be applied to uses such as storage shelves that enable automatic product management and book management, medicine management other than display shelves, dangerous goods management, and valuables management systems.

DESCRIPTION OF SYMBOLS 1 Mobile terminal 2 Display panel 3 Back cover 4 Battery 5 Camera 6 Electronic circuit board 7a, 7b Antenna input / output pin 8,101 Antenna 8a, 8b External connection terminal 9 Antenna control part 11 Core 12 Flexible board 12a Lower flexible board 12b Upper flexible substrate 13 Adjustment pattern 13a, Adjustment pattern end 13b, 13c, 13d Adjustment lead wire 14a, 14b Winding pattern 17a, 17b, 19a, 19b Pattern exposure part

Claims (10)

A magnetic core;
A coil winding part in which a conducting wire is wound around the magnetic core;
An adjustment unit connected to one end of the coil winding unit,
The adjustment unit, at the end of the magnetic core comprises a plurality of adjustment conductor divided into a plurality in the longitudinal direction of said conductors said adjustment portion which is connected to the coil winding part, the plurality of adjustment leads connected to each other physician at both ends,
The first adjustment lead located closest to the coil winding portion among the plurality of adjustment leads is connected to the end of the lead without passing through a trimming point,
Adjustment antennas other than the first adjustment conductor are connected to an end of the conductor via a trimming point . The antenna according to claim 1, wherein the inductance is adjusted by trimming only one of the trimming points . The antenna according to claim 1 , wherein the trimming point is disposed so as not to overlap the magnetic core . The antenna according to any one of claims 1 to 3 , wherein a longitudinal direction of the adjustment portion is substantially perpendicular to a winding axis of the coil winding portion. The antenna according to any one of claims 1 to 4 , wherein the plurality of adjustment conducting wires and the conducting wires of the coil winding portion are substantially parallel to each other. In the adjustment portion, said plurality of adjusting conductors, most adjusting conductor of the coil winding portion side, an antenna according to any one of claims 1-5, characterized in that thicker than other adjustments conductors. The antenna according to claim 6 , wherein a width of the adjustment lead wire closest to the coil winding portion is the same as a width of the lead wire of the coil winding portion. The spacing between conductors in the coil winding portion, the antenna according to any one of claims 1-7, characterized in that greater than the spacing between conductors in the adjusting unit. A metal body and the antenna according to any one of claims 1 to 8 ,
The antenna device according to claim 1, wherein the adjustment unit does not face a metal. A communication apparatus comprising the antenna apparatus according to claim 9 .