Antenna module

Abstract

The present invention provides an antenna module that ensures flatness. The antenna module (1) includes: a coil pattern (C) that is planarly wound around multiple turns; a first adhesive material layer (10) bonded to one surface of the coil pattern (C) in the direction of the coil axis; a second adhesive material layer (20) bonded to another surface of the coil pattern (C) in the direction of the coil axis; and a magnetic body (30) bonded to the first adhesive material layer (10) and disposed on the opposite side of the coil pattern (C) when viewed from the first adhesive material layer (10). The first and second adhesive material layers (10) and (20) bulge into the gaps between the patterns of the coil pattern (C). As a result, flatness can be ensured.

Description

Technical Field

[0001] This disclosure relates to antenna modules. Background Technology

[0002] Patent Document 1 discloses a method for manufacturing an antenna module by attaching an adhesive material layer to a coil pattern formed on the surface of a substrate, peeling off the substrate, and then attaching a magnet in place of the substrate. Therefore, since the final product does not contain a substrate, the antenna module can be made thinner.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-236267 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, the antenna module described in Patent Document 1 has large unevenness in the adhesive material layer, so if the antenna module is pasted on the object, there is a problem of losing flatness.

[0008] Therefore, the purpose of this disclosure is to provide an antenna module that can ensure flatness.

[0009] Technical solutions for solving the problem

[0010] An antenna module according to one embodiment of the present disclosure includes: a coil pattern that is planar and has multiple turns; a first adhesive material layer bonded to one surface of the coil pattern in the coil axis direction; a second adhesive material layer bonded to another surface of the coil pattern in the coil axis direction; and a magnetic body bonded to the first adhesive material layer and disposed on the opposite side of the coil pattern when viewed from the first adhesive material layer, with the first and second adhesive material layers bulging out toward the gap between the patterns of the coil pattern.

[0011] Invention Effects

[0012] According to this disclosure, an antenna module that can ensure flatness can be provided. Attached Figure Description

[0013] Figure 1 This is a schematic cross-sectional view used to illustrate the structure of the antenna module 1 according to the first embodiment of this disclosure.

[0014] Figure 2 This is a top view of coil pattern C.

[0015] Figure 3 It is Figure 1 The diagram shows an enlarged schematic cross-sectional view of region A.

[0016] Figure 4 This is a schematic diagram used to illustrate the manufacturing process of antenna module 1.

[0017] Figure 5 This is a schematic diagram used to illustrate the manufacturing process of antenna module 1.

[0018] Figure 6 This is a schematic cross-sectional view used to illustrate the structure of the antenna module 2 according to the second embodiment of this disclosure.

[0019] Figure 7 It is Figure 6 The diagram shows an enlarged schematic cross-sectional view of region B.

[0020] Figure 8 This is a schematic top view used to illustrate the structure of the antenna module 3 according to the third embodiment of this disclosure.

[0021] Figure 9 This is a schematic top view used to illustrate the structure of the antenna module 4 according to the fourth embodiment of this disclosure. Detailed Implementation

[0022] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0023] Figure 1 This is a schematic cross-sectional view used to illustrate the structure of the antenna module 1 according to the first embodiment of this disclosure.

[0024] like Figure 1 As shown, the antenna module 1 of the first embodiment includes a coil pattern C that is surrounded by multiple turns in a planar shape, a first adhesive material layer 10 bonded to one surface of the coil pattern C in the coil axis direction, a second adhesive material layer 20 bonded to another surface of the coil pattern C in the coil axis direction, a magnetic body 30 bonded to the first adhesive material layer 10 and disposed on the opposite side of the coil pattern C when viewed from the first adhesive material layer 10, a metal member 40 disposed on the opposite side of the first adhesive material layer 10 when viewed from the magnetic body 30, and a liner layer 50 bonded to the second adhesive material layer 20 and disposed on the opposite side of the coil pattern C when viewed from the second adhesive material layer 20.

[0025] Antenna module 1 can function as an NFC antenna coil, for example, connected to a near-field communication (NFC) circuit (not shown) to perform near-field wireless communication with a target device. Alternatively, antenna module 1 can function as a wireless power transmission coil for wireless power supply using a near-field wireless communication frequency band (e.g., the 13.56MHz band), or as a coil for both near-field wireless communication and wireless power supply.

[0026] For example, as a top view Figure 2 As shown, coil pattern C is a planar spiral conductor pattern with multiple turns, made of a good conductor such as Cu. Coil pattern C is wound while maintaining gaps between adjacent turns. Figure 1 and Figure 2 In the example shown, the coil pattern C has 4 turns, but there is no particular limitation on the number of turns of the coil pattern C. In addition, the planar shape of the coil pattern C is not limited to a rectangle; it can also be circular or elliptical.

[0027] Figure 3 It is Figure 1 The diagram shows an enlarged schematic cross-sectional view of region A.

[0028] like Figure 3 As shown, the first adhesive layer 10 has an adhesive surface 11 for bonding with the coil pattern C and an adhesive surface 12 for bonding with the magnetic body 30. Thus, the coil pattern C and the magnetic body 30 are fixed together by the first adhesive layer 10. The first adhesive layer 10 can be a pressure-sensitive adhesive such as a heat-resistant acrylic adhesive, silicone adhesive, polyurethane adhesive, or rubber adhesive. The magnetic body 30 is a component that forms the magnetic circuit of the magnetic field generated by the coil pattern C. It can be a material formed by curing a paste-like component of magnetic particles and resin, or it can be a sheet component. In practical use, the antenna module 1 is configured on the communication device such that the coil pattern C is located between the communication device and the magnetic body 30. The metal component 40 mainly functions to reflect electromagnetic noise in the high-frequency region.

[0029] The second adhesive layer 20 has an adhesive surface 21 for bonding to the coil pattern C and an adhesive surface 22 for bonding to the liner layer 50. Thus, the coil pattern C and the liner layer 50 are fixed together by the second adhesive layer 20. As the second adhesive layer 20, pressure-sensitive adhesives such as heat-resistant acrylic adhesives, silicone adhesives, polyurethane adhesives, and rubber adhesives can be used. The liner layer 50 is peeled off when the antenna module 1 of this embodiment is mounted on a communication device. That is, before the antenna module 1 is mounted on the communication device, the liner layer 50 covers the adhesive surface 22 of the second adhesive layer 20. Furthermore, when the antenna module 1 of this embodiment is mounted on the communication device, the liner layer 50 is peeled off, and the adhesive surface 22 of the second adhesive layer 20 exposed therefrom is adhered to the communication device.

[0030] Thus, the antenna module 1 of this embodiment has a structure in which the coil pattern C is sandwiched between the first and second adhesive material layers 10 and 20 from both sides in the direction of the coil axis. Furthermore, as... Figure 3 As shown, the first adhesive layer 10 has a bulge 13 protruding into the gap between the patterns of the coil pattern C, and the second adhesive layer 20 has a bulge 23 protruding into the gap between the patterns of the coil pattern C. The bulges 13 and 23 are portions formed due to the deformation of the first and second adhesive layers 10 and 20, respectively, and their contact with a portion of the side surface of the coil pattern C improves the adhesion to the coil pattern C. Furthermore, because the bulges 13 and 23 penetrate the gap between the patterns of the coil pattern C from both sides in the coil axis direction, minute metal residues that may remain between the patterns due to manufacturing conditions do not move and are fixed by the bulges 13 and 23. This prevents progressive short-circuit defects caused by such metal residues. The bulges 13 and 23 can also be connected between the patterns of the coil pattern C.

[0031] Here, the coil pattern C has a cross-sectional shape in which the pattern width increases as it gets closer to the first adhesive material layer 10. However, for the coil pattern C, the pattern width does not need to change uniformly across the cross-section; it can also include a portion where the pattern width does not change. This is due to the manufacturing process. That is, in the fabrication of the antenna module 1 in this embodiment, firstly, as... Figure 4 As shown, a coil pattern C is formed on the surface of an insulating substrate 70 made of materials such as PET (polyethylene terephthalate). At this time, the width of the coil pattern C slightly narrows as it moves away from the substrate 70. Next, as... Figure 5As shown, a laminate of the second adhesive layer 20 and the liner layer 50 is prepared, and the two are bonded by pressing the adhesive surface 21 of the second adhesive layer 20 towards the coil pattern C. At this time, the second adhesive layer 20 deforms, creating bulges 23 between the patterns of the coil pattern C. Afterwards, after peeling off the substrate 70, a laminate of the first adhesive layer 10, the magnetic body 30, and the metal component 40 is prepared, and the two are bonded by pressing the adhesive surface 11 of the first adhesive layer 10 towards the coil pattern C. At this time, the first adhesive layer 10 deforms, creating bulges 13 between the patterns of the coil pattern C.

[0032] Furthermore, when the first adhesive layer 10 is bonded to one surface of the coil pattern C, since a second adhesive layer 20 exists on the other surface of the coil pattern C, the deformation of the first adhesive layer 10 and the second adhesive layer 20 are dispersed, which can ensure the high flatness of the antenna module 1.

[0033] Here, because the pattern width of the coil pattern C becomes narrower closer to the second adhesive layer 20, even when the first adhesive layer 10 and the second adhesive layer are made of the same material, the bulge of the second adhesive layer 20 increases, resulting in a decrease in the flatness of the adhesive surface 22 of the second adhesive layer 20. To suppress this decrease, it is preferable that the thickness of the first adhesive layer 10 is thinner than the thickness of the second adhesive layer 20. Accordingly, even when the bulge of the second adhesive layer 20 is large, the flatness of the adhesive surface 22 can be sufficiently ensured. On the other hand, for the first adhesive layer 10, the bulge is small, so even when its thickness is thinner than the second adhesive layer 20, the flatness of the adhesive surface 12 is ensured, thereby suppressing the deviation in distance between the coil pattern C and the magnetic body 30. The bulge of the first adhesive layer 10 is the amount by which it protrudes from the interface between the adhesive surface 11 of the first adhesive layer 10 and the coil pattern C toward the second adhesive layer 20. The bulge of the second adhesive layer 20 is the amount by which it protrudes from the portion of the second adhesive layer 20 closest to the lining layer 50 at the interface between the adhesive surface 21 of the second adhesive layer 20 and the coil pattern C toward the first adhesive layer 10.

[0034] Thus, the antenna module 1 of this embodiment can be made thin because it does not contain a substrate as an antenna module. In addition, because the coil pattern C of the antenna module 1 of this embodiment is held between the first and second adhesive material layers 10 and 20 from both sides in the coil axis direction, high flatness can be ensured and progressive short-circuit defects caused by metal residue can be prevented.

[0035] Here, in order to further improve flatness, such as Figure 1As shown, a non-conductive member 60 can also be disposed within the opening of the coil pattern C. The non-conductive member 60 is made of a heat-resistant resin material or the like and is fixed within the opening of the coil pattern C by bonding it to at least one of the first and second adhesive material layers 10 and 20. By bonding the non-conductive member 60 to both the first and second adhesive material layers 10 and 20, the coil pattern C and the first and second adhesive material layers 10 and 20 can be more firmly fixed. Furthermore, if the thickness of the non-conductive member 60 is approximately the same as the thickness of the coil pattern C, no depressions will form on the first and second adhesive material layers 10 and 20 at the portion overlapping the opening of the coil pattern C, thus achieving higher flatness. Here, when sufficient flexibility is required for the antenna module 1, it is preferable to use a material with a smaller Young's modulus than the metal material constituting the coil pattern C as the material for the non-conductive member 60. Accordingly, the reduction in flexibility caused by using the non-conductive member 60 can be suppressed.

[0036] Furthermore, if the planar dimensions of the non-conductive component 60 are set to be approximately the same as the dimensions of the opening area of ​​the coil pattern C, the flatness can be further improved.

[0037] Or, it can be like Figure 6 As shown in the second embodiment of the antenna module 2, a recess 42 is provided on the inner surface 41 of the metal member 40 on the magnetic body 30 side, following the pattern shape of the coil pattern C. Accordingly, if... Figure 6 The diagram shows an enlarged schematic cross-sectional view of region B, i.e. Figure 7 As shown, because the first adhesive layer 10 and the magnetic body 30 deform toward the metal member 40 in the part where the coil pattern C is provided, the unevenness caused by the thickness of the coil pattern C can be absorbed by the recess 42.

[0038] Furthermore, because the first adhesive material layer 10 and the magnetic body 30 are deformed in a mountain shape toward the metal member 40, the recess 42 is wider than the winding width from the inner edge of the innermost circumference of the coil pattern C to the outer edge of the outermost circumference, thus absorbing the entire deformed portion of the first adhesive material layer 10 and the magnetic body 30.

[0039] Figure 8 This is a schematic top view used to illustrate the structure of the antenna module 3 according to the third embodiment of this disclosure, showing the state as viewed from the metal member 40 side.

[0040] Figure 8The antenna module 3 of the third embodiment shown differs from the antenna module 2 of the second embodiment in that it has a slit SL1 on the metal member 40. Since the other basic structures are the same as those of the antenna module 2 of the second embodiment, the same symbols are used for the same elements, and repeated descriptions are omitted. The slit SL1 is provided in such a way that it divides the metal member 40 into two parts. By providing such a slit SL1, the eddy current in that part is interrupted. Therefore, since the counter-magnetic field is suppressed, the degradation of communication characteristics can be suppressed.

[0041] Figure 9 This is a schematic top view used to explain the structure of the antenna module 4 according to the fourth embodiment of this disclosure, showing the state as viewed from the metal member 40 side.

[0042] Figure 9 The antenna module 4 of the fourth embodiment shown differs from the antenna module 2 of the second embodiment in that the metal member 40 is provided with a slit SL2. Since the other basic structures are the same as those of the antenna module 2 of the second embodiment, the same symbols are used for the same elements, and repeated descriptions are omitted. The slit SL2 is provided in such a way that it does not completely sever the metal member 40, but only severs one side of the metal member 40. By providing such a slit SL2, the direction of the eddy current is locally reversed. Therefore, by suppressing the reverse magnetic field, the degradation of communication characteristics can be suppressed.

[0043] The preferred embodiments of this disclosure have been described above, but this disclosure is not limited to the above embodiments. Various changes can be made without departing from the spirit of this disclosure, and of course, they are also included within the scope of this disclosure.

[0044] The technology disclosed herein includes, but is not limited to, the following structural examples.

[0045] The antenna module disclosed herein comprises: a coil pattern that is planar and wound multiple turns; a first adhesive layer bonded to one surface of the coil pattern in the coil axis direction; a second adhesive layer bonded to another surface of the coil pattern in the coil axis direction; and a magnetic material bonded to the first adhesive layer and disposed on the opposite side of the coil pattern when viewed from the first adhesive layer, with the first and second adhesive layers bulging out into the gap between the patterns of the coil pattern. This ensures high flatness and prevents progressive short-circuit defects.

[0046] The antenna module disclosed herein may further include a non-conductive member disposed within the opening of the coil pattern and bonded to at least one of the first and second adhesive material layers. This suppresses depressions that occur at the portion overlapping the opening of the coil pattern. Furthermore, the non-conductive member may also be bonded to both the first and second adhesive material layers. This securely fixes the coil pattern and the first and second adhesive material layers. Additionally, the thickness of the non-conductive member may be the same as the thickness of the coil pattern. This achieves higher flatness. Furthermore, the Young's modulus of the non-conductive member may be less than the Young's modulus of the member constituting the coil pattern. This ensures the overall flexibility of the antenna module.

[0047] Alternatively, the coil pattern can have a cross-sectional shape where the pattern width increases as it gets closer to the first adhesive layer, and the thickness of the first adhesive layer is thinner than the thickness of the second adhesive layer. This suppresses the reduction in flatness caused by the bulge. In this case, the bulge of the second adhesive layer into the pattern can also be greater than the bulge of the first adhesive layer into the pattern. This suppresses the deviation in distance between the coil pattern and the magnet.

[0048] The antenna module disclosed herein may also include a metal member disposed on the opposite side of the first adhesive material layer, as viewed from the magnetic body. This allows for the primary reflection of electromagnetic noise in the high-frequency region. In this case, the inner surface of the metal member on the magnetic body side may also have a recess along the pattern shape of the coil pattern. This suppresses recesses that occur at portions overlapping with the openings of the coil pattern. Additionally, a slit may be provided in the metal member. This suppresses the reverse magnetic field, thereby suppressing degradation of communication characteristics.

[0049] Explanation of reference numerals in the attached figures

[0050] 1-4 antenna modules

[0051] 10 First adhesive layer

[0052] 11, 12 Adhesive surfaces of the first adhesive material layer

[0053] 13. The bulge of the first adhesive layer

[0054] 20 Second adhesive layer

[0055] 21, 22 Adhesive surfaces of the second adhesive material layer

[0056] 23. The bulge of the second adhesive layer

[0057] 30 Magnetic bodies

[0058] 40 Metal components

[0059] 41. Inner surface of metal components

[0060] 42 Depression

[0061] 50 lining layers

[0062] 60 Non-conductive components

[0063] 70 Substrate

[0064] C coil pattern

[0065] SL1 and SL2 slits

Claims

1. An antenna module, wherein provided with: a coil pattern that surrounds a plurality of turns in a planar shape; a first adhesive material layer that is bonded to one surface in a coil axis direction of the coil pattern; a second adhesive material layer that is bonded to the other surface in the coil axis direction of the coil pattern; and a magnetic body that is bonded to the first adhesive material layer and is disposed on the opposite side of the coil pattern from the first adhesive material layer, the first and second adhesive material layers bulge toward a gap between patterns of the coil pattern, the coil pattern has a cross-sectional shape in which the pattern width is wider closer to the first adhesive material layer, the thickness of the first adhesive material layer is thinner than the thickness of the second adhesive material layer.

2. The antenna module according to claim 1, wherein further provided with: a non-conductive member that is disposed in an opening of the coil pattern and is bonded to at least one of the first and second adhesive material layers.

3. The antenna module according to claim 2, wherein the non-conductive member is bonded to both of the first and second adhesive material layers.

4. The antenna module according to claim 2, wherein the thickness of the non-conductive member is the same as the thickness of the coil pattern.

5. The antenna module according to claim 2, wherein the Young's modulus of the non-conductive member is smaller than the Young's modulus of a member that constitutes the coil pattern.

6. The antenna module according to claim 1, wherein the bulging amount of the second adhesive material layer toward the gap between patterns is greater than the bulging amount of the first adhesive material layer toward the gap between patterns.

7. The antenna module according to any one of claims 1 to 6, wherein further provided with: a metal member that is disposed on the opposite side of the first adhesive material layer from the magnetic body, as viewed from the magnetic body.

8. The antenna module according to claim 7, wherein an inner surface of the metal member on the magnetic body side has a recess along the pattern shape of the coil pattern.

9. The antenna module according to claim 7, wherein a slit is provided in the metal member. ​

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