Coil component and circuit board having the same
By adding capacitance and adjustment structure between the winding and the conductive components, the problem of difficulty in increasing the self-resonant frequency in the prior art is solved, and efficient self-resonant frequency improvement and inductance protection in wide frequency bands are achieved.
Patent Information
- Application Number
- CN202110187676.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2020-02-18
- Filing Date
- 2021-02-18
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2041-02-18
AI Technical Summary
The prior art is difficult to increase the self-resonant frequency in a wide frequency band, especially in frequency bands above 1 GHz.
By adding capacitance components between the winding and the conductive parts, the capacitance between the winding and the conductive parts is reduced, the distance between the winding and the conductive parts is adjusted, and a multi-layer structure and insulation design are used to increase the self-resonant frequency while preventing the fall of the conductive parts from falling off. and inductance decreases.
The self-resonant frequency is significantly improved in the wide band, avoiding the reduction of inductance, and ensuring the stability and effect of high-frequency performance.
Smart Images
Figure CN113345700B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a coil component and a circuit board including the same, and more particularly to a coil component formed by winding a wire around a drum core and a circuit board including the same. Background Art
[0002] As a coil component formed by winding a winding wire around a drum core, there is known a coil component described in Patent Document 1. The coil component described in Patent Document 1 has a winding wire wound around a winding core portion to form a three-layer structure, and the self-resonant frequency is adjusted by the number of turns of the winding wire in each winding layer.
[0003] Prior art literature
[0004] Patent Literature
[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-82463 Summary of the invention
[0006] However, although the self-resonant frequency can be lowered in the method described in Patent Document 1, it is difficult to increase the self-resonant frequency. In addition, the method described in Patent Document 1 cannot obtain a sufficient effect in a frequency band exceeding 1 GHz.
[0007] Therefore, an object of the present invention is to provide a coil component capable of increasing the self-resonant frequency in a wide frequency band, and a circuit board including the same.
[0008] The coil component of the present invention is characterized in that it comprises: a core, which has a winding core portion, a first flange portion located at one end of the winding core portion in the axial direction, and a second flange portion located at the other end of the winding core portion in the axial direction; a winding, which is wound on the winding core portion; a first conductive component, which overlaps with the winding via a dielectric; a first terminal electrode, which is arranged on the first flange portion and connected to one end of the winding; a second terminal electrode, which is arranged on the second flange portion and connected to the other end of the winding; and a third terminal electrode, which is arranged on the first flange portion and connected to the first conductive component.
[0009] According to the present invention, since a capacitance component is added between the winding wire and the first conductive member, the capacitance component between turns of the winding wire (inter-wire capacitance) is reduced apparently, thereby increasing the self-resonant frequency in a wide frequency band.
[0010] In the present invention, the first conductive component may also be located between the winding core and the winding wire. Thus, the first conductive component can be prevented from falling off. Alternatively, the winding wire may also be located between the winding core and the first conductive component. Thus, the distance between the winding wire and the first conductive component can be easily adjusted.
[0011] The coil component of the present invention may also include: a second conductive component that overlaps with the winding via a dielectric; and a fourth terminal electrode that is disposed on the second flange portion and connected to the second conductive component, and the first conductive component and the second conductive component are insulated from each other. Thus, a capacitance component between the winding and the second conductive component is also added, so that the self-resonant frequency can be further increased. Moreover, since the first conductive component and the second conductive component are insulated from each other, a reduction in inductance caused by the first and second conductive components functioning as coils will not occur.
[0012] The circuit substrate of the present invention is characterized in that it comprises: a substrate having first, second and third pad patterns; and a coil component having the above-mentioned characteristics, wherein the coil component is mounted on the substrate in a manner in which the first, second and third terminal electrodes are respectively connected to the first, second and third pad patterns, and a ground potential is given to the third pad pattern.
[0013] According to the present invention, since the first conductive member adds a capacitance component between the winding wire and the ground, the inter-wire capacitance is apparently reduced, and the self-resonance frequency of the coil component can be increased.
[0014] According to the present invention, it is possible to provide a coil component capable of increasing the self-resonant frequency in a wide frequency band and a circuit board including the coil component. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic perspective view showing the appearance of a coil component 1 according to the first embodiment of the present invention.
[0016] Figure 2 It is a partial plan view of the substrate 5 on which the coil component 1 is mounted.
[0017] Figure 3 is an equivalent circuit diagram of the coil component 1.
[0018] Figure 4 It is a schematic perspective view showing the appearance of a coil component 1A according to a first modification.
[0019] Figure 5 It is a schematic perspective view showing the appearance of a coil component 1B according to a second modification.
[0020] Figure 6 It is a schematic cross-sectional view for explaining the structure of a coil component 1C according to a third modification.
[0021] Figure 7 It is a schematic perspective view showing the appearance of a coil component 1D according to a fourth modification.
[0022] Figure 8It is a schematic perspective view showing the appearance of a coil component 2 according to a second embodiment of the present invention.
[0023] Fig. 9 This is a schematic plan view of the coil component 2 as viewed from the z direction.
[0024] Fig.10 It is a schematic perspective view showing the appearance of a coil component 2A according to a fifth modification.
[0025] Fig.11 It is a schematic perspective view showing the appearance of a coil component 3 according to a third embodiment of the present invention.
[0026] Fig.12 It is a partial cross-sectional view of the coil component 3.
[0027] Fig.13 It is a partial cross-sectional view of a coil component according to a sixth modification.
[0028] Explanation of symbols
[0029] 1~3, 1A~1D, 2A Coil parts
[0030] 5 substrate
[0031] 6 Loading area
[0032] 10 Drum core
[0033] 11, 12 Flange
[0034] 13. Core
[0035] 13a, 13b xz plane
[0036] 13c, 13d xy plane
[0037] 14 plate core
[0038] 21, 22 conductive plate (conductive component)
[0039] 31, 32 dielectric plate (dielectric)
[0040] 40 Insulation sheet with foil
[0041] 41 Copper Foil
[0042] 42 Resin layer
[0043] 51 Conductive resin
[0044] 52 Insulating resin
[0045] E1~E4 terminal electrodes
[0046] L1~L4 wiring pattern
[0047] P1~P4 pad pattern
[0048] S Space
[0049] W winding. DETAILED DESCRIPTION
[0050] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0051] <First embodiment>
[0052] Figure 1 It is a schematic perspective view showing the appearance of a coil component 1 according to the first embodiment of the present invention.
[0053] like Figure 1 As shown, the coil component 1 of the first embodiment includes a drum core 10, terminal electrodes E1 to E4, windings W, conductive plates 21, 22, and dielectric plates 31, 32. The drum core 10 includes a winding core portion 13 with the x direction as the axial direction, a flange portion 11 provided at one end of the winding core portion 13 in the x direction, and a flange portion 12 provided at the other end of the winding core portion 13 in the x direction. As the material of the drum core 10, a high magnetic permeability material such as ferrite having a magnetic permeability μ of 10 to 4000 H / m is preferably used.
[0054] The terminal electrodes E1 and E3 are provided on the flange portion 11, and the terminal electrodes E2 and E4 are provided on the flange portion 12. The terminal electrodes E1 to E4 may be formed of terminal metal fittings or may be formed of a conductive paste applied to the surfaces of the flange portions 11 and 12. The winding W is wound on the winding core portion 13, and one end thereof is connected to the terminal electrode E1, and the other end is connected to the terminal electrode E2.
[0055] The conductive plates 21 and 22 are conductive parts made of metal or the like, and are arranged so as to cover the xz surface of the winding core 13. The dielectric plates 31 and 32 are made of a dielectric material such as resin or ceramic, and are arranged so as to cover the surfaces of the conductive plates 21 and 22, respectively. Thus, the winding W is wound around the winding core 13 via the dielectric plate 31 and the conductive plate 21 on one xz surface of the winding core 13, and is wound around the winding core 13 via the dielectric plate 32 and the conductive plate 22 on the other xz surface of the winding core 13. Thus, the conductive plate 21 is connected to the terminal electrode E3, and the conductive plate 22 is connected to the terminal electrode E4. The conductive plate 21 and the terminal electrode E3, and the conductive plate 22 and the terminal electrode E4 may be respectively integrated.
[0056] Figure 2 It is a partial plan view of the substrate 5 on which the coil component 1 according to the present embodiment is mounted.
[0057] like Figure 2As shown, a mounting area 6 for mounting the coil component 1 is defined on the substrate 5. Pad patterns P1 to P4 are provided in the mounting area 6, and when the coil component 1 is mounted on the mounting area 6, the terminal electrodes E1 to E4 are connected to the pad patterns P1 to P4, respectively. The pad patterns P1 to P4 are connected to the wiring patterns L1 to L4, respectively. Among them, the wiring patterns L1 and L2 constitute a pair of input and output wirings, which are connected via the winding W included in the coil component 1. On the other hand, the wiring patterns L3 and L4 are grounding patterns supplied with a ground potential GND. Therefore, if the coil component 1 is mounted on the substrate 5, the conductive plates 21 and 22 are given a ground potential GND. In addition, in Figure 2 In the illustrated plane, the wiring patterns L3 and L4 are separated from each other, but the two may be short-circuited in another region not shown.
[0058] Figure 3 : is an equivalent circuit diagram of the coil component 1 according to the present embodiment.
[0059] like Figure 3 As shown, the coil component 1 of the present embodiment is connected with a winding W that functions as a coil between the terminal electrode E1 and the terminal electrode E2, and a capacitance component is added between the winding W and the conductive plates 21 and 22. The amount of the additional capacitance component can be adjusted by the area of the conductive plates 21 and 22, the thickness of the dielectric plates 31 and 32, and the dielectric constant. If such a capacitance component is added, the capacitance component (inter-wire capacitance) generated between adjacent turns of the winding W has a smaller effect on the self-resonant frequency, and as a result, the self-resonant frequency becomes higher. This means that the inter-wire capacitance is reduced in appearance. Such an effect can also be obtained in a frequency band exceeding 1 GHz. However, if the thickness of the dielectric plates 31 and 32 is too thin, the distance between the winding W and the conductive plates 21 and 22 becomes too close, and depending on the frequency band used, the two may cause a high-frequency short circuit. Therefore, considering the frequency band used, the distance between the winding W and the conductive plates 21 and 22 is preferably designed to ensure that no high-frequency short circuit occurs.
[0060] In this way, the coil component 1 of the present embodiment has the conductive plates 21 and 22 overlapping with the winding W via the dielectric plates 31 and 32, so that a self-resonant frequency higher than the self-resonant frequency calculated based on the actual line capacitance can be obtained. In addition, the winding W is wound over the conductive plates 21 and 22 and the dielectric plates 31 and 32, so that the conductive plates 21 and 22 and the dielectric plates 31 and 32 can be prevented from falling off. Moreover, since the conductive plates 21 and 22 are insulated from each other in the coil component, when the terminal electrodes E3 and E4 are connected to the same ground pattern, the conductive plates 21 and 22 will not function as coils. Thus, the reduction of inductance caused by the conductive plates 21 and 22 functioning as coils can be prevented.
[0061] Figure 4 It is a schematic perspective view showing the appearance of a coil component 1A according to a first modification.
[0062] Figure 4 The coil component 1A of the first variant shown is different from the coil component 1 of the first embodiment in that the conductive plate 22 and the dielectric plate 32 are omitted. The other basic structures are the same as the coil component 1 of the first embodiment, so the same symbols are marked on the same elements, and repeated descriptions are omitted. As illustrated in the first variant, the group consisting of the conductive plate and the dielectric plate can also be provided with only one group. In this case, compared with the coil component 1 of the first embodiment, the area where the winding W overlaps with the conductive plate becomes half, so the value of the additional capacitance component becomes half. In this way, by changing the number of conductive plates, the self-resonant frequency can be adjusted. In addition, in the coil component 1A of the first variant, the terminal electrode E4 can also be omitted, and the terminal electrode E4 can also be used as a dummy terminal for ensuring the mounting strength.
[0063] Figure 5 It is a schematic perspective view showing the appearance of a coil component 1B according to a second modification.
[0064] Figure 5 The coil component 1B of the second variant shown is different from the coil component 1A of the first variant in that the length in the x direction of the conductive plate 21 and the dielectric plate 31 is shortened to half. The other basic structures are the same as the coil component 1A of the first variant, so the same symbols are marked on the same elements and repeated descriptions are omitted. As illustrated in the second variant, the group consisting of the conductive plate and the dielectric plate does not need to overlap with all the turns of the winding W, and may only overlap with a part of the turns. In this case, compared with the coil component 1A of the first variant, the area where the winding W overlaps with the conductive plate is further halved, so the value of the additional capacitance component is further halved. In this way, by appropriately designing the area where the winding W overlaps with the conductive plate, the self-resonant frequency can be adjusted.
[0065] Figure 6 It is a schematic cross-sectional view for explaining the structure of a coil component 1C according to a third modification.
[0066] Figure 6 The coil component 1C of the third modification shown in the embodiment is different from the coil component 1A of the first modification in that the xz plane 13a, 13b and the xy plane 13c of the winding core 13 are covered by the conductive plate 21 and the dielectric plate 31. The other basic structures are the same as the coil component 1A of the first modification, so the same elements are marked with the same symbols and repeated descriptions are omitted. As shown in the third modification, the group consisting of the conductive plate 21 and the dielectric plate 31 can also cover multiple surfaces of the winding core 13.
[0067] exist Figure 6 In the example shown, the other xy plane 13d of the winding core 13 is not covered by the conductive plate 21 and the dielectric plate 31, but a portion of the xy plane 13d may be covered by the conductive plate 21 and the dielectric plate 31. However, if the conductive plate 21 is annular, the inductance is greatly reduced because the conductive plate 21 functions as a coil. Therefore, even when the conductive plate 21 covers all four surfaces of the winding core 13, it is necessary to design the conductive plate 21 so that it does not become annular.
[0068] Figure 7 It is a schematic perspective view showing the appearance of a coil component 1D according to a fourth modification.
[0069] Figure 7 The coil component 1D of the fourth modification shown is different from the coil component 1 of the first embodiment in that a planar core 14 is added. The other basic structures are the same as those of the coil component 1 of the first embodiment, so the same elements are denoted by the same reference numerals and repeated descriptions are omitted.
[0070] The plate-like core 14 is fixed to the flanges 11 and 12, and functions as a magnetic circuit connecting the flanges 11 and 12. As the material of the plate-like core 14, it is preferable to use a high magnetic permeability material similar to the drum core 10. In this way, if the plate-like core 14 is added, a closed magnetic circuit is formed by the drum core 10 and the plate-like core 14, so that the inductance can be increased.
[0071] <Second embodiment>
[0072] Figure 8 2 is a schematic perspective view showing the appearance of a coil component 2 according to a second embodiment of the present invention. Fig. 9 This is a schematic plan view of the coil component 2 as viewed from the z direction.
[0073] like Figure 8 as well as Fig. 9 As shown, the coil component 2 of the second embodiment is different from the coil component 1 of the first embodiment in that the conductive plates 21, 22 and the dielectric plates 31, 32 are arranged outside the winding W. In other words, the winding W is located between the winding core 13 and the conductive plates 21, 22 and the dielectric plates 31, 32. The other basic structures are the same as those of the coil component 1 of the first embodiment, so the same symbols are marked on the same elements, and repeated descriptions are omitted.
[0074] In the present embodiment, a space S may be present between the wound winding W and the dielectric plates 31 and 32. In this case, the self-resonance frequency can be adjusted according to the size of the space S.
[0075] As exemplified in the present embodiment, the conductive plates 21 and 22 and the dielectric plates 31 and 32 may be arranged outside the wound wire W.
[0076] Fig.10 It is a schematic perspective view showing the appearance of a coil component 2A according to a fifth modification.
[0077] Fig.10 The coil component 2A of the fifth modification shown is different from the coil component 2 of the second embodiment in that the conductive plate 22 and the dielectric plate 32 are omitted. The other basic structures are the same as the coil component 2 of the second embodiment, so the same elements are marked with the same symbols and repeated descriptions are omitted. As illustrated in the fifth modification, the group consisting of the conductive plate and the dielectric plate can also be provided with only one group.
[0078] <Third Embodiment>
[0079] Fig.11 It is a schematic perspective view showing the appearance of a coil component 3 according to a third embodiment of the present invention.
[0080] like Fig.11 As shown, the coil component 3 of the third embodiment is different from the coil component 2 of the second embodiment in that the wound winding W is covered with an insulating sheet (RCC) 40 with copper foil. Fig.12 As shown, the insulating sheet 40 with copper foil has a structure in which a copper foil 41 and a resin layer 42 are stacked, and the resin layer 42 is arranged in a manner that the copper foil 41 is located between the copper foil 41 and the winding W. The copper foil 41 is connected to the terminal electrode E3. The other basic structures are the same as those of the coil component 2A of the fifth modification, so the same symbols are marked on the same elements, and repeated descriptions are omitted.
[0081] In the present embodiment, the copper foil 41 constituting the insulating sheet 40 with copper foil functions as a conductive component, and the resin layer 42 constituting the insulating sheet 40 with copper foil functions as a dielectric. Thus, in the present embodiment, since the insulating sheet 40 with copper foil is arranged on the wound winding W, the coil component can be manufactured at a lower cost.
[0082] Or, as used to illustrate the sixth variation Fig.13 As shown, an insulating resin 52 may be applied to the surface of the winding core 13 in such a manner as to embed the winding W, and a conductive resin 51 may be applied on the insulating resin 52 to electrically connect the conductive resin 51 to the terminal electrode E3. In this case, the coil component can be manufactured at a further low cost.
[0083] As mentioned above, although the preferred embodiment of the present invention has been described, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the gist of the present invention, and these modifications are naturally included in the scope of the present invention.
Claims
1. A coil component, characterized in that: have: a core having a winding core portion, a first flange portion located at one end of the winding core portion in the axial direction, and a second flange portion located at the other end of the winding core portion in the axial direction; A winding wire, which is wound around the winding core; a first conductive member and a second conductive member overlapping the winding via a dielectric; a first terminal electrode, which is provided on the first flange portion and connected to one end of the winding wire; a second terminal electrode, which is provided on the second flange portion and connected to the other end of the winding; a third terminal electrode provided on the first flange portion and connected to the first conductive member; and a fourth terminal electrode provided on the second flange portion and connected to the second conductive member, The first conductive component and the second conductive component are insulated from each other, The first conductive member and the second conductive member are located between the winding core and the winding wire. Each turn of the winding wire is wound around the winding core via the first conductive member on the first surface of the winding core, and is wound around the winding core via the second conductive member on the second surface of the winding core.
2. A circuit substrate, characterized in that: have: a substrate having a first pad pattern, a second pad pattern, a third pad pattern, and a fourth pad pattern; as well as The coil component according to claim 1, The coil component is mounted on the substrate in a manner such that the first terminal electrode, the second terminal electrode, the third terminal electrode, and the fourth terminal electrode are connected to the first land pattern, the second land pattern, the third land pattern, and the fourth land pattern, respectively. A ground potential is applied to the third land pattern and the fourth land pattern.