Coil component and communication device with the same

Abstract

To allow a coil component which has a coil pattern embedded at least in part in a resin layer to have electric characteristics and physical characteristics made compatible.SOLUTION: A coil component 100 comprises a resin layer 130 which includes insulating inorganic fillers F1 to F3 and binder resin R, and a coil pattern 120 embedded at least in part in the resin layer 130 and having a plurality of turns. The resin layer 130 includes a region A1 overlapping with the coil pattern 120 when viewed from a lamination direction and a region A2 located between adjacent turns of the coil pattern 120, The inorganic fillers F1 to F3 of the resin layer 130 are larger in filling factor in the region A1 than in the region A2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a coil component and a communication device including the same. [Background technology]

[0002] Patent Document 1 discloses a coil module including a coil substrate, a coil pattern provided on the surface of the coil substrate, and an adhesive layer provided on the surface of the coil substrate so as to embed the coil pattern. The adhesive layer described in Patent Document 1 contains thermally conductive particles and an adhesive resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2016 / 199633 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, since the thermally conductive particles contained in the adhesive layer are uniformly dispersed, it is difficult to achieve both electrical properties and physical properties.

[0005] The present disclosure describes a technique for achieving both electrical and physical properties in a coil component having a coil conductor at least a portion of which is embedded in a resin layer. [Means for solving the problem]

[0006] A coil component according to one embodiment of the present disclosure comprises a resin layer containing an insulating inorganic filler and a binder resin, and a coil conductor at least partially embedded in the resin layer and wound around the coil conductor over multiple turns, wherein the resin layer includes a first region that overlaps with the coil conductor when viewed from the coil axis direction, and a second region located between adjacent turns of the coil conductor, and the filling rate of the inorganic filler in the resin layer is greater in the first region than in the second region. [Effects of the Invention]

[0007] According to the present disclosure, a technique is provided for achieving both electrical properties and physical properties in a coil component having a coil conductor at least a portion of which is embedded in a resin layer. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic plan view showing the appearance of a coil device 100 according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic partial cross-sectional view of the coil device 100. [Figure 3] FIG. 3 is a schematic diagram for explaining capacitors C1 and C2 formed by adjacent turns. [Figure 4] FIG. 4 is a schematic diagram illustrating the configuration of a communication device 10 including a coil device 100 and an antenna coil 200 for NFC. [Figure 5] FIG. 5 is a schematic diagram illustrating the configuration of a communication device 10 according to a modified example. [Figure 6] 6(a) to 6(c) are schematic diagrams illustrating the difference in size between the coil pattern 120 and the antenna coil 200 included in the coil device 100. FIG. [Figure 7] 7(a) and 7(b) are schematic diagrams for explaining the difference in shape between the coil pattern 120 and the antenna coil 200 included in the coil device 100. FIG. [Figure 8] FIG. 8 is a schematic diagram for explaining the difference between the coil axis of the coil pattern 120 included in the coil device 100 and the coil axis of the antenna coil 200. In FIG. [Figure 9] FIG. 9 is a schematic plan view showing the shape of the conductor pattern formed on one surface 31 of the substrate 30. As shown in FIG. [Figure 10] FIG. 10 is a schematic plan view showing the shape of the conductor pattern formed on the other surface 32 of the substrate 30. As shown in FIG. [Figure 11]FIG. 11 is a schematic plan view of the coil patterns CP1 and CP3 and the coil patterns CP2 and CP4 superimposed on each other, as viewed from one surface 31 of the substrate 30. In FIG. [Figure 12] FIG. 12 is a schematic diagram showing a state in which communication device 10 is housed in housing 500. As shown in FIG. [Figure 13] FIG. 13 is a schematic diagram showing a state in which the antenna coil 200 is housed in a housing 500 and the coil device 100 is disposed outside the housing 500. As shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0010] Fig. 1 is a schematic plan view showing the appearance of a coil device 100 according to an embodiment of the present disclosure, and Fig. 2 is a schematic partial cross-sectional view of the coil device 100.

[0011] 1 and 2, a coil device 100 according to this embodiment includes a substrate 110, a coil pattern 120 provided on the surface of the substrate 110, and a resin layer 130 provided on the surface of the substrate 110 so as to embed at least a portion of the coil pattern 120. An insulating film such as PET (polyethylene terephthalate) or PI (polyimide) can be used as the substrate 110. The substrate 110 has a thickness T1.

[0012] The coil pattern 120 is a coil conductor that winds around the outer periphery of the substrate 110 for multiple turns. The number of turns of the coil pattern 120 is selected based on the desired inductance and capacitance. The outer peripheral end 121 and inner peripheral end 122 of the coil pattern 120 are both open and not connected to other conductive members. Therefore, the coil pattern 120 is electrically floating. The coil pattern 120 is formed, for example, by electrolytic plating on the surface of the substrate 110. In this case, the lower surface 123 of the coil pattern 120 is in contact with the surface of the substrate 110. The lower surface 123 of the coil pattern 120 may be formed of a seed layer containing resin. After forming the coil pattern 120, the substrate 110 may be peeled off; however, if the substrate 110 is left unpeeled, the lower surface 123 of the coil pattern 120 is protected. The thickness of the coil pattern 120 is T2. The thickness T2 of the coil pattern 120 is smaller than the pattern width L of the coil pattern 120, and therefore the coil pattern 120 has a flat shape.

[0013] The resin layer 130 contains insulating inorganic fillers F1 to F3 and a binder resin R. The resin layer 130 protects the coil pattern 120 and also adjusts the capacitance generated between adjacent turns of the coil pattern 120. The inorganic fillers F1 to F3 are all spherical but have different particle sizes. The inorganic filler F1 is a small-diameter filler having a first particle size distribution with an average particle size of a first particle. The inorganic filler F2 is a medium-diameter filler having a second particle size distribution with an average particle size of a second particle size larger than the first particle size. The inorganic filler F3 is a large-diameter filler having a third particle size distribution with an average particle size of a third particle size larger than the second particle size. By using three types of inorganic fillers F1 to F3 with different particle size distributions, the filling rate of the inorganic fillers in the resin layer 130 is increased.

[0014] The inorganic fillers F1 to F3 may be made of non-magnetic inorganic materials such as alumina, aluminum hydroxide, talc, magnesium hydroxide, silica, calcium carbonate, barium titanate, zirconium titanate, or zinc zirconate, or may be made of magnetic materials such as ferrite or Fe-based alloy magnetic materials. The inorganic fillers F1 to F3 may be made of the same materials or may be made of partially different materials. The dielectric constant of the inorganic fillers F1 to F3 may be higher than the dielectric constant of the binder resin R.

[0015] Examples of materials for the binder resin R include acrylic resin, polyester resin, polyethylene resin, polyvinyl chloride resin, polyvinyl butyral resin, polyurethane resin, polyester urethane resin, cellulose resin, ABS (acrylonitrile-butadiene-styrene) resin, nitrile-butadiene rubber, styrene-butadiene rubber, epoxy resin, phenolic resin, amide resin, polyester elastomer, and polyamide elastomer.

[0016] 2, the resin layer 130 includes an area A1 that overlaps with the coil pattern 120 when viewed from the stacking direction, which is the coil axis direction, an area A2 located between adjacent turns of the coil pattern 120, and an area A3 that overlaps with area A2 when viewed from the stacking direction. Area A2 does not overlap with the coil pattern 120 when viewed from the stacking direction and is within the height position range of the coil pattern 120. Area A3 does not overlap with the coil pattern 120 when viewed from the stacking direction and is located at a higher height position than the coil pattern 120.

[0017] The filling rate of the inorganic fillers F1 to F3 in the resin layer 130 may be higher in the region A1 than in the region A2. Accordingly, when a material with a higher dielectric constant than the binder resin R is used as the material for the inorganic fillers F1 to F3, the dielectric constant in the region A1 is increased. As a result, as shown in FIG. 3 , the capacitance of the capacitor C1 passing through the region A1 (and A3), which occurs between adjacent turns, is increased. In contrast, in the region A2, the filling rate of the inorganic fillers F1 to F3 is lower than that in the region A1, and therefore the proportion of the binder resin R is higher. This improves the embedding between adjacent turns, thereby reducing the occurrence of voids and improving adhesion to the coil pattern 120. This mechanism enables the coil component 100 to achieve both excellent electrical and physical properties. Furthermore, in this embodiment, the coil pattern 120 has a flat shape in which the thickness T2 is smaller than the pattern width L, and therefore the capacitance of the capacitor C2 passing through the region A2 is smaller than the capacitance of the capacitor C1 passing through the region A1. That is, the capacitance generated between adjacent turns is dominated by capacitor C1. In this embodiment, the dielectric constant in region A1 is increased, which effectively increases the capacitance generated between adjacent turns.

[0018] The resin layer 130 includes a surface layer 131 that contacts the base material 110 and on which the coil pattern 120 is located in the thickness direction, and a surface layer 132 that is located on the opposite side of the surface layer 131 and on which the coil pattern 120 is not located in the thickness direction. Here, the filling rate of the inorganic fillers F1 to F3 in the resin layer 130 may be higher in the surface layer 132 than in the surface layer 131. This further increases the capacitance of the capacitor C1 passing through the regions A1 and A3, and also improves the shape retention of the resin layer 130, thereby improving the flatness of the coil component 100.

[0019] Furthermore, the proportion of inorganic filler F3 in the resin layer 130 may be greater in region A2 than in region A3. This increases the capacitance of capacitor C2 passing through region A2. The proportion of inorganic filler F2 in the resin layer 130 may also be greater in region A2 than in region A3. As shown in FIG. 2, the thickness T2 of the coil pattern may be thinner than the thickness T1 of the base material 110. This allows the overall thickness of the coil device 100 to be reduced, and the capacitance of capacitor C1 passing through region A1 becomes more dominant.

[0020] The coil device 100 according to this embodiment functions as a booster coil that extends the communication distance, for example, by being arranged so as to overlap an antenna coil for near field communication (NFC).

[0021] FIG. 4 is a schematic diagram illustrating the configuration of a communication device 10 including a coil device 100 and an antenna coil 200 for NFC.

[0022] The antenna coil 200 shown in FIG. 4 has a coil axis direction in the Z direction, and is placed in the Z direction relative to a wireless device 400 with which it communicates. The wireless device 400 also includes an antenna coil for NFC, and by placing the antenna coil 200 and the wireless device 400 in the Z direction, communication is established between them. When the coil component 100 according to this embodiment is placed between the antenna coil 200 and the wireless device 400, the coil component 100 functions as a booster coil, thereby extending the communication distance. In the example shown in FIG. 4, the coil component 100 and the antenna coil 200 may be fixed to each other via an adhesive sheet, or the coil component 100 and the antenna coil 200 may be placed spaced apart from each other.

[0023] 4, a power transmitting coil 300 for wireless power transmission is arranged on the opposite side of the coil component 100 as viewed from the antenna coil 200. A power receiving coil for wireless power transmission is included in the wireless device 400, and when the power transmitting coil 300 and the wireless device 400 are overlapped in the Z direction, power is transmitted wirelessly from the power transmitting coil 300 to the wireless device 400.

[0024] FIG. 5 is a schematic diagram illustrating the configuration of a communication device 10 according to a modified example.

[0025] 5, the antenna coil 200 and the power transmitting coil 300 are positioned at the same position in the Z direction, and the antenna coil 200 is disposed so as to surround the power transmitting coil 300. In this manner, the antenna coil 200 and the power transmitting coil 300 may be disposed coaxially. In the example shown in Fig. 5, the coil component 100, the antenna coil 200, and the power transmitting coil 300 may be fixed to one another via an adhesive sheet, or the coil component 100, the antenna coil 200, and the power transmitting coil 300 may be disposed separated from one another by a space.

[0026] 4 and 5, the planar size of the coil pattern 120 included in the coil device 100 is larger than the planar size of the antenna coil 200. In this way, by using the coil pattern 120 that is larger than the antenna coil 200, the planar area in which communication is possible is expanded.

[0027] 6(a) to 6(c) are schematic diagrams illustrating the difference in size between the coil pattern 120 and the antenna coil 200 included in the coil device 100. FIG.

[0028] In the example shown in Fig. 6(a), in a plan view seen from the Z direction, the antenna coil 200 is disposed at a position overlapping the opening region of the coil pattern 120. The inner shape size of the coil pattern 120 is defined by the region surrounded by the innermost turn 102 of the coil pattern 120. Also, the planar size of the coil pattern 120 is defined by the region surrounded by the outermost turn 101 of the coil pattern 120. Similarly, the inner shape size of the antenna coil 200 is defined by the region surrounded by the innermost turn 202 of the antenna coil 200. Also, the planar size of the antenna coil 200 is defined by the region surrounded by the outermost turn 201 of the antenna coil 200. In the example shown in Fig. 6(a), the outermost turn 201 of the antenna coil 200 is located inside the innermost turn 102 of the coil pattern 120.

[0029] In the example shown in Fig. 6(a), both the coil pattern 120 and the antenna coil 200 have a planar shape with the X direction as the longitudinal direction and the Y direction orthogonal to the X direction as the short side direction. The inner shape size of the coil pattern 120 in the X direction is Wx1, and the inner shape size of the antenna coil 200 in the X direction is Wx2 (<Wx1). The inner shape size of the coil pattern 120 in the Y direction is Wy1, and the inner shape size of the antenna coil 200 in the Y direction is Wy2 (<Wy1). And the difference in the inner shape size in the X direction between the coil pattern 120 and the antenna coil 200 (=Wx1 - Wx2) is larger than the difference in the inner shape size in the Y direction between the coil pattern 120 and the antenna coil 200 (=Wy1 - Wy2). Thereby, the communicable planar area expands in the X direction and the Y direction, and the communicable area in the X direction expands more greatly. For example, in a mobile terminal such as a smartphone, since the wireless device 400 may be disposed at the center of the mobile terminal or at the end in the X direction of the mobile terminal, by expanding the communicable planar area in the X direction more greatly using the coil component 100, good communication can be performed for any type of mobile terminal.

[0030] In the example shown in FIG. 6(b), the outer size Wy3 of the antenna coil 200 in the Y direction is larger than the inner size Wy1 of the coil pattern 120 in the Y direction, resulting in a portion of the coil pattern 120 and a portion of the antenna coil 200 overlapping in a planar view. Also in the example shown in FIG. 6(b), the inner size Wx1 of the coil pattern 120 in the X direction is larger than the inner size Wx2 of the antenna coil 200 in the X direction, and the inner size Wy1 of the coil pattern 120 in the Y direction is larger than the inner size Wy2 of the antenna coil 200 in the Y direction. Furthermore, the difference in the inner sizes of the coil pattern 120 and the antenna coil 200 in the X direction (= Wx1 - Wx2) is larger than the difference in the inner sizes of the coil pattern 120 and the antenna coil 200 in the Y direction (= Wy1 - Wy2). In this way, a portion of the coil pattern 120 and a portion of the antenna coil 200 may overlap.

[0031] 6(c), the outer size Wy3 of the antenna coil 200 in the Y direction is larger than the outer size Wy4 of the coil pattern 120 in the Y direction, so that not only do parts of the coil pattern 120 and the antenna coil 200 overlap in a plan view, but also part of the antenna coil 200 protrudes in the Y direction from the coil pattern 120 in a plan view. In the example shown in FIG. 6(c), the inner size Wx1 of the coil pattern 120 in the X direction is larger than the inner size Wx2 of the antenna coil 200 in the X direction, but the inner size Wy1 of the coil pattern 120 in the Y direction is approximately the same as the inner size Wy2 of the antenna coil 200 in the Y direction. Furthermore, the difference in the inner sizes of the coil pattern 120 and the antenna coil 200 in the X direction (=Wx1-Wx2) is larger than the difference in the inner sizes of the coil pattern 120 and the antenna coil 200 in the Y direction (=Wy1-Wy2). In this way, a part of the antenna coil 200 may protrude from the coil pattern 120 in a plan view.

[0032] In the example shown in FIG. 7(a), the inner size Wy2 of the antenna coil 200 in the Y direction is larger than the outer size Wy4 of the coil pattern 120 in the Y direction, and as a result, a part of the opening region of the antenna coil 200 is located outside the coil pattern 120 in a planar view. The outer size Wx3 of the antenna coil 200 in the X direction is smaller than the inner size Wx1 of the coil pattern 120 in the X direction. In this case, the absolute value of the difference in the inner sizes of the coil pattern 120 and the antenna coil 200 in the X direction (=|Wx1-Wx2|) may be larger than the absolute value of the difference in the inner sizes of the coil pattern 120 and the antenna coil 200 in the Y direction (=|Wy1-Wy2|). In this way, a part of the opening region of the antenna coil 200 may be located outside the coil pattern 120. Even in this case, the planar size of the coil pattern 120 may be larger than the planar size of the antenna coil 200.

[0033] 7(b), the inner size Wy2a in the Y direction at the center of the antenna coil 200 in the X direction is larger than the inner size Wy2b in the Y direction at both ends of the antenna coil 200 in the X direction. The inner size Wy2a in the Y direction at the center of the antenna coil 200 in the X direction is larger than the outer size Wy4 in the Y direction of the coil pattern 120, so that a part of the opening region of the antenna coil 200 is located outside the coil pattern 120 in a plan view. The outer size Wx3 in the X direction of the antenna coil 200 is smaller than the inner size Wx1 in the X direction of the coil pattern 120. In this way, the size of the antenna coil 200 in the Y direction may vary depending on the position in the X direction.

[0034] 8, the center of the coil axis of the antenna coil 200 is offset in the X direction from the center of the coil axis of the coil pattern 120, causing a part of the antenna coil 200 to protrude in the X direction from the coil pattern 120. By offsetting the centers of the coil axes of the antenna coil 200 and the coil pattern 120 in this way, it is possible to adjust the coupling coefficient between the antenna coil 200 and the coil pattern 120.

[0035] 9 to 11 are schematic plan views illustrating a more specific configuration of the communication device 10 according to the modified example shown in Fig. 5. In the example shown in Fig. 9 to 11, the antenna coil 200 and the power transmitting coil 300 are provided on the surface of the same substrate 30. In Fig. 9 to 11, the planar position of the coil pattern 120 is also indicated by a dashed line.

[0036] FIG. 9 is a schematic plan view showing the shape of the conductor pattern formed on one surface 31 of the substrate 30. As shown in FIG.

[0037] As shown in FIG. 9, one surface 31 of the substrate 30 is provided with a coil pattern CP1 that forms part of the antenna coil 200, a coil pattern CP3 that forms part of the power transmission coil 300, and terminal electrodes E1 to E4.

[0038] The coil pattern CP3 is a six-turn configuration consisting of turns 610, 620, 630, 640, 650, and 660, with turn 610 located on the outermost periphery and turn 660 located on the innermost periphery. Of these, turns 610, 620, 630, 640, and 650 are radially divided into four by three spiral slits. Meanwhile, turn 660 is radially divided into two by one spiral slit. As a result, turn 610 is divided into four lines 611-614, turn 620 is divided into four lines 621-624, turn 630 is divided into four lines 631-634, turn 640 is divided into four lines 641-644, turn 650 is divided into four lines 651-654, and turn 660 is divided into two lines 661 and 662.

[0039] Lines 611, 621, 631, 641, 651, and 661 are continuous lines wound in a spiral for six turns, and are located on the outermost periphery of each turn. Lines 612, 622, 632, 642, 652, and 662 are continuous lines wound in a spiral for six turns, and are located on the second outermost periphery of each turn. Lines 613, 623, 633, 643, and 653 are continuous lines wound in a spiral for five turns, and are located on the second innermost periphery of each turn. Lines 614, 624, 634, 644, and 654 are continuous lines wound in a spiral for five turns, and are located on the innermost periphery of each turn.

[0040] The outer peripheral ends of the lines 611 to 614 are commonly connected to the terminal electrode E1, while the inner peripheral ends of the lines 661, 662, 653, and 654 are connected to through-hole conductors 801 to 804 that penetrate the substrate 30, respectively.

[0041] Coil pattern CP1 includes a conductor pattern 41 that is arranged outside coil pattern CP3 so as to surround coil pattern CP3, and a conductor pattern 42 that is arranged outside coil pattern CP3 separately from conductor pattern 41. Of these, conductor pattern 41 is a continuous line wound approximately one turn, and coil pattern CP3 is arranged in its opening region (inner diameter region). One end of conductor pattern 41 is connected to terminal electrode E3, and the other end of conductor pattern 41 is connected to through-hole conductor 43 that penetrates substrate 30. Furthermore, one end of conductor pattern 42 is connected to terminal electrode E4, and the other end of conductor pattern 42 is connected to through-hole conductor 44 that penetrates substrate 30.

[0042] Figure 10 is a schematic plan view showing the shape of the conductive pattern formed on the other surface 32 of the substrate 30, and shows the state as seen from the one surface 31 side of the substrate 30, that is, the state as seen through the substrate 30.

[0043] As shown in FIG. 10, on the other surface 32 of the substrate 30, a coil pattern CP2 that forms the remaining portion of the antenna coil 200 and a coil pattern CP4 that forms the remaining portion of the power transmission coil 300 are formed.

[0044] The pattern shape of coil pattern CP4 is the same as that of coil pattern CP3. Coil pattern CP4 is a six-turn configuration consisting of turns 710, 720, 730, 740, 750, and 760, with turn 710 located on the outermost periphery and turn 760 located on the innermost periphery. Of these, turns 710, 720, 730, 740, and 750 are divided radially into four by three spiral slits. Meanwhile, turn 760 is divided radially into two by one spiral slit. As a result, turn 710 is divided into four parts into lines 711-714, turn 720 is divided into four parts into lines 721-724, turn 730 is divided into four parts into lines 731-734, turn 740 is divided into four parts into lines 741-744, turn 750 is divided into four parts into lines 751-754, and turn 760 is divided into two parts into lines 761 and 762.

[0045] Lines 711, 721, 731, 741, 751, and 761 are continuous lines wound in a spiral for six turns, and are located on the outermost periphery of each turn. Lines 712, 722, 732, 742, 752, and 762 are continuous lines wound in a spiral for six turns, and are located on the second outermost periphery of each turn. Lines 713, 723, 733, 743, and 753 are continuous lines wound in a spiral for five turns, and are located on the second innermost periphery of each turn. Lines 714, 724, 734, 744, and 754 are continuous lines wound in a spiral for five turns, and are located on the innermost periphery of each turn.

[0046] The outer peripheral ends of the lines 711 to 714 are commonly connected to the terminal electrode E2 via through-hole conductors. Meanwhile, the inner peripheral ends of the lines 761, 762, 753, and 754 are respectively connected to the through-hole conductors 804, 803, 802, and 801. This results in the power transmitting coil 300 having a configuration in which four 11-turn lines are connected in parallel between the terminal electrodes E1 and E2.

[0047] The conductor pattern 45 constituting the coil pattern CP2 is a continuous line wound with approximately one turn and is arranged outside the coil pattern CP4 so as to surround the coil pattern CP4. In other words, the coil pattern CP4 is arranged in the opening region (inner diameter region) of the conductor pattern 45 constituting the coil pattern CP2. One end and the other end of the conductor pattern 45 are connected to the through-hole conductors 43 and 44, respectively. As a result, the antenna coil 200 consisting of the coil patterns CP1 and CP2 has a total of approximately two turns.

[0048] FIG. 11 is a schematic plan view of the coil patterns CP1 and CP3 and the coil patterns CP2 and CP4 superimposed on each other, as viewed from one surface 31 of the substrate 30. In FIG.

[0049] As shown in FIG. 11, when the substrate 30 on which the antenna coil 200 and the power transmission coil 300 are formed is overlapped with the coil pattern 120, as in the example shown in FIG. 7(b), the inner size in the Y direction of the antenna coil 200 (CP1, CP2) has portions larger and smaller than the outer size in the Y direction of the coil pattern 120, and as a result, of the conductor patterns 41, 42, 45 constituting the antenna coil 200 (CP1, CP2), the sections extending in the X direction have portions located outside and inside the coil pattern 120, and the outer size in the X direction of the antenna coil 200 (CP1, CP2) is smaller than the inner size in the X direction of the coil pattern 120, and as a result, of the conductor patterns 41, 42, 45 constituting the antenna coil 200 (CP1, CP2), the sections extending in the Y direction are located inside the coil pattern 120.

[0050] FIG. 12 is a schematic diagram showing a state in which communication device 10 is housed in housing 500. As shown in FIG.

[0051] In the example shown in FIG. 12 , a housing 500 has inner surfaces 501 and 502 facing each other. The coil component 100 is attached to the inner surface 501 via an adhesive layer 140, and a circuit board 510, on which the antenna coil 200 and the power transmission coil 300 are formed, is placed on the inner surface 502. The adhesive layer 140 may bond the resin layer 130 of the coil component 100 to the inner surface 501 of the housing 500. In the example shown in FIG. 12 , the antenna coil 200 and the power transmission coil 300 are pattern coils made of conductor patterns formed on the circuit board 510 and are integrated with the circuit board 510. Here, the thickness T3 of the coil component 100 may be thinner than the thickness T4 of the circuit board 510. This allows the coil component 100 to be accommodated in the internal space of the housing 500 even when the height of the internal space of the housing 500 is low.

[0052] The housing 500 has an outer surface 503 located opposite the inner surface 501. The outer surface 503 is covered with a rubber mat 520, and the smartphone 20 or the like can be placed on the rubber mat 520. The rubber mat 520 prevents scratches on the smartphone 20 and prevents the smartphone 20 from slipping. When the smartphone 20 is placed on the rubber mat 520, communication can be performed between the wireless device 400 and the antenna coil 200 included in the smartphone 20, and power can be transmitted from the power transmitting coil 300 to the wireless device 400. Here, the coil component 100 according to this embodiment is disposed between the wireless device 400 and the antenna coil 200, thereby enabling more efficient communication between the wireless device 400 and the antenna coil 200. In particular, as explained using Figures 6(a) to (c), Figures 7(a), (b), and Figure 8, if the planar size of the coil pattern 120 included in the coil component 100 is made larger than the planar size of the antenna coil 200, the planar area in which communication is possible is expanded, and therefore communication can be established even if the planar position of the smartphone 20 placed on the rubber mat 520 is shifted from the center position of the antenna coil 200.

[0053] 12, both the coil component 100 and the antenna coil 200 are housed in the housing 500, but as in a modified example shown in Fig. 13, a circuit board 510 on which the antenna coil 200 and the power transmission coil 300 are formed may be housed in the housing 500, and the coil component 100 may be disposed on the outer surface 503 of the housing 500. In this case, the coil component 100 is disposed between the outer surface 503 of the housing 500 and the rubber mat 520 via an adhesive layer 530.

[0054] The above describes preferred embodiments of the present disclosure, but the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the present disclosure, and it goes without saying that these modifications are also included within the scope of the present disclosure.

[0055] For example, while the coil device 100 according to the above embodiment uses the coil pattern 120 in which a conductor pattern is wound around the surface of the substrate 110, the use of a pattern coil is not essential, and a coil conductor in which a coated conductor wire is wound in a planar spiral shape may also be used. Furthermore, the antenna coil 200 and the power transmission coil 300 are not limited to pattern coils, and may also use a coil conductor in which an insulating coated conductor wire is wound in a planar spiral shape.

[0056] The technology according to the present disclosure includes, but is not limited to, the following configuration examples.

[0057] A coil component according to an embodiment of the present disclosure includes a resin layer containing an insulating inorganic filler and a binder resin, and a coil conductor at least partially embedded in the resin layer and wound around the coil conductor over multiple turns, the resin layer including a first region overlapping the coil conductor as viewed in the coil axial direction and a second region positioned between adjacent turns of the coil conductor, the inorganic filler filling rate in the resin layer being higher in the first region than in the second region, thereby achieving both electrical and physical properties.

[0058] In the coil component, the resin layer includes a first surface layer in the thickness direction where the coil conductor is located and a second surface layer located on the opposite side of the first surface layer where the coil conductor is not present, and the filling rate of the inorganic filler in the resin layer may be higher in the second surface layer than in the first surface layer, thereby increasing the strength of the second surface layer.

[0059] In the coil component, the inorganic filler includes a first inorganic filler having a first particle size distribution with an average particle size of a first particle size and a second inorganic filler having a second particle size distribution with an average particle size of a second particle size larger than the first particle size, the resin layer further includes a third region overlapping the second region as viewed in the coil axis direction, and the proportion of the second inorganic filler in the resin layer may be higher in the second region than in the third region, thereby enabling an increase in capacitance of the coil pattern.

[0060] The coil component further includes a substrate having a coil conductor formed on its surface, the coil conductor being configured as a coil pattern having a circumferential conductor pattern, and the thickness of the coil pattern may be thinner than the thickness of the substrate, thereby reducing the overall thickness.

[0061] In the above coil component, both ends of the coil conductor may be open, which makes it easier to manufacture the coil component.

[0062] In the coil component, the dielectric constant of the inorganic filler may be higher than the dielectric constant of the binder resin, which makes it possible to obtain a larger capacitance.

[0063] A communication device according to an embodiment of the present disclosure includes an antenna coil and the above-described coil component arranged to overlap the antenna coil, whereby the coil component functions as a booster coil for the antenna coil.

[0064] In the above communication device, the planar size of the coil conductor included in the coil component may be larger than the planar size of the antenna coil, thereby making it possible to expand the planar area in which communication is possible.

[0065] In the above communication device, the coil conductor and the antenna coil have a planar shape with a first direction as the longitudinal direction and a second direction perpendicular to the first direction as the lateral direction, and the difference between the inner size of the coil conductor in the first direction and the inner size of the antenna coil in the first direction may be larger than the difference between the inner size of the coil conductor in the second direction and the inner size of the antenna coil in the second direction, thereby making it possible to further expand the planar area available for communication in the first direction.

[0066] In the above communication device, the coil conductor and the antenna coil have a planar shape with a first direction as the longitudinal direction and a second direction perpendicular to the first direction as the lateral direction, and the outer size of the coil conductor in the first direction may be larger than the outer size of the antenna coil in the first direction, and the inner size of the antenna coil in the second direction may be larger than the outer size of the coil conductor in the second direction. This makes it possible to further expand the planar area available for communication in the first direction.

[0067] In the above communication device, the coil conductor and the antenna coil may have a planar shape with a first direction as the longitudinal direction and a second direction perpendicular to the first direction as the transverse direction, the outer size of the coil conductor in the first direction may be larger than the outer size of the antenna coil in the first direction, and the outermost turn of the antenna coil in the second direction may have a portion located outside the outermost turn of the coil conductor in the second direction and a portion located inside the innermost turn of the coil conductor in the second direction, thereby making it possible to greatly expand the planar area in which communication is possible in the first direction.

[0068] In the above communication device, the antenna coil is formed on a circuit board, and the thickness of the coil component may be thinner than the thickness of the circuit board, which allows the coil component to be placed in a smaller space.

[0069] The communication device may further include a housing that houses the coil component and the antenna coil, and the coil component may be fixed to the inner surface of the housing. Since both the coil component and the antenna coil are housed in the housing, the appearance of the housing is not impaired. Alternatively, the communication device may further include a housing that houses the antenna coil and a rubber mat that covers the outer surface of the housing, and the coil component may be disposed between the outer surface of the housing and the rubber mat. Since the coil component is hidden by the rubber mat, the appearance is not impaired. [Explanation of symbols]

[0070] 10. Communication Devices 20. Smartphone 30 Base material 31,32 Substrate surface 41, 42, 45 Conductor pattern 43,44 Through-hole conductor 100 Coil parts 101,201 Outermost turn 102,202 Innermost turn 110 Base material 120 coil pattern 121 Outer edge 122 Inner edge 123 Bottom surface 130 Resin layer 131 Surface (First Surface) 132 Surface (Second Surface) 140 Adhesive layer 200 Antenna Coil 300 Transmission coil 400 Wireless Devices 500 units 501 Inner surface (first inner surface) 502 Inner surface (second inner surface) 503 Outer surface 510 Circuit Board 520 Rubber Mat 530 Adhesive layer 610,620,630,640,650,660,710,720,730,740,750,760 turns 611~614, 621~624, 631~634, 641~644, 651~654, 661, 662, 711~714, 721~724, 731~734, 741~744, 751~754, 761, 762 Lines 801~804 Through-hole conductors A1 Area (First Area) A2 Area (Second Area) A3 Area (Third Area) C1, C2 capacitors CP1~CP4 coil pattern E1~E4 terminal electrode F1 Inorganic filler (first inorganic filler) F2, F3 Inorganic filler (second inorganic filler) R Binder resin

Claims

1. a resin layer containing an insulating inorganic filler and a binder resin; a coil conductor at least partly embedded in the resin layer and wound around the core over a plurality of turns; Equipped with the resin layer includes a first region overlapping the coil conductor when viewed in the coil axis direction and a second region positioned between adjacent turns of the coil conductor, a filling rate of the inorganic filler in the resin layer is higher in the first region than in the second region; Coil parts.

2. the resin layer includes, in a thickness direction, a first surface layer on which the coil conductor is located and a second surface layer on the opposite side of the first surface layer on which the coil conductor is not present, a filling rate of the inorganic filler in the resin layer is higher in the second surface layer than in the first surface layer; The coil component according to claim 1 .

3. the inorganic filler includes a first inorganic filler having a first particle size distribution with an average particle size of a first particle size, and a second inorganic filler having a second particle size distribution with an average particle size of a second particle size larger than the first particle size; the resin layer further includes a third region overlapping the second region when viewed from the coil axis direction, a ratio of the second inorganic filler in the resin layer is higher in the second region than in the third region; The coil component according to claim 1 .

4. Further, the coil conductor is formed on a substrate. the coil conductor is formed of a coil pattern in which a conductor pattern is wound around the coil, The thickness of the coil pattern is smaller than the thickness of the base material. The coil component according to claim 1 .

5. Both ends of the coil conductor are open. The coil component according to claim 1 .

6. The dielectric constant of the inorganic filler is higher than the dielectric constant of the binder resin. The coil component according to claim 1 .

7. An antenna coil; the coil component according to any one of claims 1 to 6, which is arranged so as to overlap the antenna coil; A communication device comprising:

8. a planar size of the coil conductor included in the coil component is larger than a planar size of the antenna coil; 8. The communication device of claim 7.

9. the coil conductor and the antenna coil have a planar shape with a first direction as a longitudinal direction and a second direction orthogonal to the first direction as a lateral direction, a difference between an inner size of the coil conductor in the first direction and an inner size of the antenna coil in the first direction is larger than a difference between an inner size of the coil conductor in the second direction and an inner size of the antenna coil in the second direction; 9. The communication device of claim 8.

10. the coil conductor and the antenna coil have a planar shape with a first direction as a longitudinal direction and a second direction orthogonal to the first direction as a lateral direction, an outer size of the coil conductor in the first direction is larger than an outer size of the antenna coil in the first direction; an inner size of the antenna coil in the second direction is larger than an outer size of the coil conductor in the second direction; 9. The communication device of claim 8.

11. the coil conductor and the antenna coil have a planar shape with a first direction as a longitudinal direction and a second direction orthogonal to the first direction as a lateral direction, an outer size of the coil conductor in the first direction is larger than an outer size of the antenna coil in the first direction; the outermost turn of the antenna coil positioned in the second direction has a portion positioned outside the outermost turn of the coil conductor positioned in the second direction, and a portion positioned inside the innermost turn of the coil conductor positioned in the second direction, 9. The communication device of claim 8.

12. The antenna coil is formed on a circuit board, The thickness of the coil component is thinner than the thickness of the circuit board.

8. The communication device of claim 7.

13. a housing that houses the coil component and the antenna coil; The coil component is fixed to the inner surface of the housing.

8. The communication device of claim 7.

14. a housing that houses the antenna coil; a rubber mat covering the outer surface of the housing; the coil component is disposed between the outer surface of the housing and the rubber mat; 8. The communication device of claim 7.

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