JP6572791B2 - COIL COMPOSITE COMPONENT, MULTILAYER BOARD, AND METHOD FOR PRODUCING COIL COMPOSITE COMPONENT - Google Patents

Description

  The present invention relates to a coil composite component, a multilayer substrate used for the same, and a method for manufacturing the coil composite component, and more particularly to a technique for increasing the degree of freedom in designing a coil portion of the coil composite component.

  Conventionally, a DCDC converter module is known as a coil composite component (see, for example, Patent Document 1). The coil composite component includes a coil built-in substrate (multilayer substrate) and an electronic component mounted on the upper surface of the coil built-in substrate. A plurality of coil conductors stacked via the magnetic layer are connected in series to form a coil (coil portion).

JP, 2015-111734, A

  In such a conventional coil composite component, the coil portion is built in the magnetic multilayer board. For this reason, the design freedom of the coil part is restricted by the process, material, thickness, etc. of the magnetic multilayer substrate, and this restriction may be a factor that hinders improvement of the characteristics of the coil part. Therefore, the coil composite part having the coil part also has a problem that the improvement of the characteristics can be hindered by the restriction of the design freedom of the coil part.

  Then, an object of this invention is to provide the coil composite component etc. which can raise the design freedom of a coil part.

  In order to achieve the above object, a coil composite component according to an aspect of the present invention includes a block-shaped magnetic core portion and a plate-like shape that is bonded to the top surface of the magnetic core portion and has a lower magnetic permeability than the magnetic core portion. A wiring board; an electronic component mounted on the wiring part; a first substrate having a first surface electrode connected to the electronic part; a hole opening upward; and around the hole. A second substrate having a wound coil portion and a second surface electrode connected to the coil portion, the magnetic core portion being inserted into the hole portion, and the first substrate One surface electrode and the second surface electrode are connected.

  Thus, when the first substrate has the magnetic core portion and the second substrate has the coil portion, the coil portion can be realized by a process, material, thickness, or the like different from that of the first substrate. That is, it is possible to design the coil portion while suppressing restrictions imposed by the first substrate. Therefore, the degree of freedom in designing the coil portion of the coil composite component can be increased.

  In addition, the wiring portion has a protruding portion that protrudes laterally from the magnetic core portion, and the first surface electrode and the second surface electrode are formed in the insertion direction of the magnetic core portion and the protruding portion, It may be arranged at a position facing the second substrate and connected via a conductive bonding material.

  As described above, the first surface electrode and the second surface electrode are disposed at a position where the protruding portion in the insertion direction of the magnetic core portion and the second substrate face each other, so that the conductive bonding material is inserted by the insertion of the magnetic core portion. Is pressed by the first surface electrode and the second surface electrode. Therefore, the electrical connection between the first surface electrode and the second surface electrode can be easily achieved, and the strength of these mechanical connections can be increased.

  The coil portion may have an inner end surface exposed at the wall surface of the hole.

  Thus, by exposing the inner end face of the coil portion to the wall surface of the hole portion, it is possible to increase a loop-shaped magnetic flux (magnetic flux forming a so-called major loop) that circulates inside and outside the entire coil portion. Therefore, the inductance value of the coil portion can be increased.

  The electronic component may be a switching IC, and the coil unit may be a choke coil, constituting a DCDC converter circuit.

  By including the coil portion with increased design flexibility in this way, a DCDC converter circuit can be configured using a coil portion having desired characteristics. Accordingly, a DCDC converter circuit having desired characteristics can be realized.

  The second substrate may be a motherboard on which electronic components different from the switching IC are mounted.

  As described above, since the second substrate is the mother board, high-density mounting of the DCDC converter circuit and, for example, an electronic component to which power is supplied by the DCDC converter circuit can be achieved.

  The magnetic core portion includes a plurality of magnetic ceramic layers, and the wiring portion includes a plurality of low-permeability magnetic ceramic layers having lower magnetic permeability than the plurality of magnetic ceramic layers. The core part and the wiring part may be fired to form one ceramic multilayer substrate.

  Since the magnetic core portion and the wiring portion are thus baked to constitute one ceramic multilayer substrate, the first substrate can be manufactured by a general ceramic multilayer substrate manufacturing process, and an adhesive is used. The wiring part and the magnetic core part can be firmly joined without using the like. Therefore, the first substrate having excellent durability can be manufactured while simplifying the manufacturing process.

  Further, the present invention can be realized not only as the above-described coil composite part but also as a multilayer substrate used for the coil composite part. In other words, in order to achieve the above object, a multilayer substrate according to an aspect of the present invention is a multilayer substrate that is inserted into a hollow portion of a coil portion of a coil composite component, and includes a plurality of laminated magnetic ceramic layers. A plurality of stacked magnetic core portions that are inserted into the holes that form the hollow, and a plurality of laminated magnetic core portions that are bonded to the top surface of the magnetic core portions and have lower magnetic permeability than the plurality of magnetic ceramic layers. A plate-like wiring portion having a low permeability magnetic ceramic layer, an electronic component mounted on the wiring portion, a first electrode connected to the electronic component and connected to a second electrode connected to the coil portion. The magnetic core portion and the wiring portion are fired to form one ceramic multilayer substrate.

  According to such a multilayer substrate, the coil portion into which the multilayer substrate is inserted can be realized by a process, material, thickness, or the like different from that of the multilayer substrate. That is, it is possible to design the coil portion while suppressing the restrictions imposed by the multilayer substrate. Therefore, a coil composite part having a coil portion with a high degree of design freedom can be produced.

  Moreover, this invention is realizable also as a manufacturing method which manufactures the coil composite component mentioned above. That is, a method for manufacturing a coil composite component according to an aspect of the present invention includes a plurality of magnetic ceramic green sheets and a plurality of low permeability magnetic ceramic green sheets having a lower magnetic permeability than the plurality of magnetic ceramic green sheets. A firing process for fabricating a multilayer substrate by integrally firing, a hole opening upward, a coil wound around the hole, and a second surface electrode connected to the coil An insertion step of inserting the multilayer substrate into a second substrate, and in the firing step, the magnetic core portion is bonded to a top surface of the block-shaped magnetic core portion and the magnetic core portion. Of the first substrate having a plate-like wiring part having a lower magnetic permeability, an electronic component mounted on the wiring part, and a first surface electrode connected to the electronic part, at least the magnetic core part and The multilayer substrate having a wiring portion is manufactured, and in the insertion step, the multilayer substrate is inserted so that the magnetic core portion is inserted into the hole, and the first surface electrode and the second surface Connect the electrodes.

  Thereby, a coil part is realizable with a process, material, thickness, etc. different from a multilayer substrate. That is, it is possible to design the coil portion while restraining restrictions due to the multilayer substrate. Therefore, the degree of freedom in designing the coil portion of the coil composite component can be increased.

  The first surface electrode further includes a cutting step of cutting the bottom surface of the multilayer substrate after the baking step to produce a protruding portion in which the wiring portion projects laterally from the magnetic core portion. And the second surface electrode are disposed at a position where the protruding portion and the second substrate face each other in the insertion direction of the magnetic core portion, and the multilayer substrate after the cutting step is inserted in the insertion step. The first surface electrode and the second surface electrode may be connected via a conductive bonding material.

  By the cutting process for producing such a protruding portion, the first surface electrode and the second surface electrode can be disposed at positions facing each other in the insertion direction of the magnetic core portion. For this reason, an electroconductive joining material is pressed with the 1st surface electrode and the 2nd surface electrode in an insertion process. Therefore, the electrical connection between the first surface electrode and the second surface electrode can be easily achieved, and the strength of these mechanical connections can be increased.

  ADVANTAGE OF THE INVENTION According to this invention, the design freedom of the coil part which a coil composite component has can be raised.

1 is a perspective view showing an appearance of a coil composite component according to Embodiment 1. FIG. It is a perspective view which isolate | separates and shows the 1st board | substrate and 2nd board | substrate of the coil composite component which concerns on Embodiment 1. FIG. It is a figure which shows notionally the cross-section of the coil composite component which concerns on Embodiment 1. FIG. It is a figure which shows the circuit structure comprised by the coil composite component which concerns on Embodiment 1. FIG. 6 is a cross-sectional perspective view showing a manufacturing process of the first substrate in Embodiment 1. FIG. 6 is a cross-sectional perspective view showing a manufacturing process of the first substrate in Embodiment 1. FIG. 6 is a cross-sectional perspective view showing a manufacturing process of the first substrate in Embodiment 1. FIG. 6 is a cross-sectional perspective view showing a manufacturing process of the first substrate in Embodiment 1. FIG. FIG. 6 is a perspective view and a cross-sectional view showing a manufacturing process of the second substrate in the first embodiment. FIG. 6 is a perspective view and a cross-sectional view showing a manufacturing process of the second substrate in the first embodiment. FIG. 6 is a perspective view and a cross-sectional view showing a manufacturing process of the coil composite component according to the first embodiment. 5 is a cross-sectional view showing a manufacturing process of the coil composite component according to Embodiment 1. FIG. 5 is a cross-sectional view showing a manufacturing process of the coil composite component according to Embodiment 1. FIG. FIG. 8 is a perspective view showing a first substrate and a second substrate of the coil composite component according to Modification 1 of Embodiment 1 separately. FIG. 10 is a perspective view showing an appearance of a coil composite component according to Modification 2 of Embodiment 1. It is a figure which shows notionally the cross-section of the coil composite component which concerns on the modification 2 of Embodiment 1. FIG. It is a perspective view which isolate | separates and shows the 1st board | substrate of the coil composite component which concerns on Embodiment 2, a 2nd board | substrate, and a protection sheet. It is a figure which shows notionally the cross-section of the coil composite component which concerns on Embodiment 2. FIG. It is a top view which shows the external appearance of the portable terminal device by which the coil composite component which concerns on Embodiment 3 is mounted. It is a figure which shows notionally the cross-section of the coil composite component which concerns on Embodiment 3. FIG.

  Hereinafter, a coil composite component according to an embodiment of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, manufacturing steps, and order of the manufacturing steps shown in the following embodiments are merely examples, and are not intended to limit the present invention. . In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements. In addition, the size or size ratio of the components shown in the drawings is not necessarily strict. In the following embodiments, “connected” includes not only the case of direct connection but also the case of electrical connection via other elements.

(Embodiment 1)
In the coil composite component according to Embodiment 1, the degree of freedom in designing the coil portion is enhanced by providing the coil portion and the magnetic core portion housed in the hollow of the coil portion on different substrates.

  FIG. 1A is a perspective view showing an appearance of the coil composite component 1 according to Embodiment 1. FIG. FIG. 1B is a perspective view showing the first substrate 10 and the second substrate 20 of the coil composite component 1 according to Embodiment 1 separately.

  In the present embodiment, the thickness direction of the plate-like second substrate 20 is described as the Z-axis direction, and the directions perpendicular to and orthogonal to the Z-axis direction are respectively defined as the X-axis direction and the Y-direction. The description will be made on the top surface (upper surface) side of the coil composite component 1. However, in the actual usage mode, the thickness direction of the second substrate 20 may not be the vertical direction. For this reason, in an actual use mode, the top surface side of the coil composite component 1 is not limited to the upper surface side.

  A coil composite component 1 shown in these drawings is mounted on a small portable terminal device such as a mobile phone, for example, and converts a DC voltage supplied from a battery into a DC voltage suitable for various circuits and outputs the DCDC converter module. It is. Specifically, the coil composite component 1 includes a first substrate 10 having a magnetic core portion 11, a wiring portion 12, and an electronic component 13. In addition, the coil composite component 1 includes a hole portion 21 into which the magnetic core portion 11 is inserted, and a second substrate 20 having a coil portion L1 wound around the hole portion 21.

  Hereinafter, the detailed configuration of the coil composite component 1 will be further described with reference to FIG.

  FIG. 2 is a diagram conceptually showing a cross-sectional structure of the coil composite component 1 according to the first embodiment. Specifically, FIG. 2 is a cross-sectional view of the coil composite component 1 taken along the line II-II in FIG. 1B. In FIG. 2, for the sake of simplicity, strictly speaking, components in different cross sections may be shown and described in the same drawing. The electronic component 13 is shown in a side view. The same applies to the following cross-sectional views.

  As shown in FIG. 1B and FIG. 2, the first substrate 10 is connected to the block-shaped magnetic core portion 11 and the top surface of the magnetic core portion 11 and has a plate-like wiring portion having a lower permeability than the magnetic core portion 11. 12, an electronic component 13 mounted on the wiring part 12, and a first surface electrode 115 connected to the electronic component 13.

  The magnetic core portion 11 functions as a core of the coil portion L1 by being inserted into the hole portion 21 of the second substrate 20. The magnetic core portion 11 is a member having magnetism provided in a block shape, and is, for example, a prism having a rectangular shape when viewed from above. In addition, the shape of the magnetic core part 11 is not limited to this, A cylinder may be sufficient.

  In the present embodiment, the magnetic core portion 11 is formed by laminating a plurality of magnetic ceramic layers (for example, 10 magnetic ceramic layers). As this magnetic ceramic layer, for example, a magnetic ferrite ceramic is used, and specifically, a ferrite containing iron oxide as a main component and containing at least one of zinc, nickel, and copper is used.

  The wiring unit 12 is a wiring board on which wiring for realizing the circuit configuration of the coil composite component 1 is provided. This wiring includes, for example, an in-plane conductor 112 provided along the main surface of the wiring portion 12 and an interlayer connection conductor 113 provided in a direction perpendicular to the main surface (Z-axis direction). Moreover, the wiring part 12 has the mounting electrode 114 which is a surface electrode for mounting the electronic component 13, for example on the top | upper surface. As a material for the in-plane conductor 112, the interlayer connection conductor 113, the mounting electrode 114, and the first surface electrode 115, for example, a metal or alloy containing silver as a main component is used.

  In the present embodiment, the wiring portion 12 is formed by laminating a plurality of low-permeability magnetic ceramic layers (for example, four low-permeability magnetic ceramic layers) having lower magnetic permeability than the above-described plurality of magnetic ceramic layers. For example, a non-magnetic wiring portion in which a plurality of non-magnetic ceramic layers are stacked. For this low magnetic permeability magnetic ceramic layer, a material having a lower relative magnetic permeability than the above-mentioned magnetic ceramic layer material is used. For example, a nonmagnetic ferrite ceramic or an insulating glass ceramic mainly composed of alumina and glass is used. Used.

  Generally, the wiring formed in the magnetic ceramic layer tends to have a large inductance component compared to the wiring formed in the non-magnetic ceramic layer. For this reason, by forming the wiring of the coil composite component 1 in the non-magnetic wiring portion, it is possible to suppress the deterioration of the characteristics of the coil composite component 1 due to the wiring having an unnecessary inductance component. In general, the non-magnetic ceramic layer has higher mechanical strength than the magnetic ceramic layer. For this reason, the whole intensity | strength of the coil composite component 1 can be improved by comprising the wiring part 12 by a nonmagnetic ceramic layer.

  In addition, the wiring part 12 should just have a magnetic permeability lower than the magnetic core part 11, and does not need to be a nonmagnetic ceramic layer.

  Moreover, in this Embodiment, the wiring part 12 has the protrusion part 12a which protruded to the side from the magnetic core part 11, and the 1st surface electrode 115 is arrange | positioned at this protrusion part 12a. That is, in the first substrate 10, the area of the bottom surface (Z-axis direction minus side) of the wiring portion 12 is larger than the area of the top surface of the magnetic core portion 11, and the first surface electrode 115 is magnetic in the bottom surface of the wiring portion 12. It is formed in a region other than the region where the core part 11 is joined. For example, the wiring part 12 is a flat plate shape having a substantially rectangular shape when viewed from above, and a peripheral edge protruding laterally from the magnetic core part 11 is formed as a protruding part 12a.

  In this embodiment, the magnetic core portion 11 and the wiring portion 12 are fired to form one ceramic multilayer substrate. That is, the first substrate 10 is a substrate configured by integrally firing the material constituting the magnetic core portion 11 and the material constituting the wiring portion 12. For this reason, the first substrate 10 is bonded to a ceramic multilayer substrate configured by firing only the magnetic core portion 11 and a ceramic multilayer substrate configured by firing only the wiring portion 12 in a separate process. As a result, the substrate has a different structure. This is identified by the presence or absence of an adhesive such as resin between the material constituting the magnetic core portion 11 and the material constituting the wiring portion 12 when the cross section of the first substrate 10 is analyzed by, for example, SEM. Can do. That is, when there is no such adhesive, it can be identified that the first substrate 10 is constituted by one ceramic multilayer substrate.

  The electronic component 13 is a component for realizing the circuit configuration of the coil composite component 1. In this embodiment, the electronic component 13 includes a switching IC (Integrated Circuit) 131 and capacitors 132 and 133 that realize the circuit configuration of the DCDC converter module. included. The electronic component 13 is disposed on the top surface of the wiring unit 12, for example. Note that the arrangement location of the electronic component 13 is not limited to this, and may be the side surface of the wiring portion 12, for example.

  The second substrate 20 is a thermoplastic multilayer substrate in which a plurality of base layers 121 (for example, 10 layers) made of a resin such as polyimide, for example, are laminated. A coil portion L1 wound around and a second surface electrode 124 are provided. Moreover, the 2nd board | substrate 20 has the external connection terminal 125 which is a surface electrode for mounting the coil composite component 1 on a motherboard, for example in a bottom face.

  The hole 21 is a recess that is recessed slightly larger than the outer shape of the magnetic core 11 so that the magnetic core 11 can be inserted. In the present embodiment, the hole 21 penetrates the second substrate 20 in the thickness direction. It is. The hole 21 is preferably a through hole from the viewpoint of reducing the height of the coil composite component 1 and improving the heat dissipation of the electronic component 13, but may be a bottomed recess, for example.

  In the present embodiment, the coil portion L1 is a choke coil of a DCDC converter circuit, and is configured by various conductors provided on the second substrate 20. The various conductors include a coil conductor 122 that is an in-plane conductor provided along the main surface of the second substrate 20 and an interlayer connection conductor 123 provided in a direction (Z-axis direction) perpendicular to the main surface. included.

  The materials, thicknesses, widths, pitches between the conductors, members interposed between the conductors (that is, the base material layer 121), and the like of the various conductors constituting the coil portion L1 include inductance values and DC superposition characteristics required for the coil portion L1. It can be determined appropriately in consideration of the various electrical characteristics. Since these are provided on the second substrate 20, they are not limited by the process, material, thickness, or the like of the first substrate 10. Therefore, the coil part L1 which has a desired characteristic can be comprised, suppressing the restrictions by the 2nd board | substrate 20. FIG.

  As a material of the coil conductor 122, the interlayer connection conductor 123, the second surface electrode 124, and the external connection terminal 125, for example, a metal or alloy containing copper as a main component is used.

  In the present embodiment, the coil conductor 122 is shown as a spiral shape wound in triplicate. However, the present invention is not limited to this. For example, the coil conductor 122 is a part of a ring shape that is wound in a single layer. It may be C-shaped.

  In the first substrate 10 and the second substrate 20 configured as described above, the magnetic core portion 11 is inserted into the hole portion 21, and the first surface electrode 115 and the second surface electrode 124 are connected. ing. In the present embodiment, the first surface electrode 115 and the second surface electrode 124 are arranged at positions where the protruding portion 12a and the second substrate 20 face each other in the insertion direction (Z-axis direction) of the magnetic core portion 11, They are connected via a conductive bonding material 40.

  As the conductive bonding material 40, for example, a solder material, a conductive adhesive paste (SCP), a conductive adhesive film (SCF), or an anisotropic conductive film (ACF) can be used.

  By connecting the first surface electrode 115 and the second surface electrode 124, the coil portion L1 provided on the second substrate 20 and the electronic component 13 provided on the first substrate are electrically connected. Therefore, the circuit configuration of the coil composite component 1 (here, the DCDC converter circuit) is realized.

  FIG. 3 is a diagram illustrating a circuit configuration including the coil composite component 1 according to the first embodiment. In the figure, the correspondence between the circuit configuration and the first substrate 10 and the second substrate 20 is also conceptually shown.

  As shown in the figure, in the present embodiment, the coil composite component 1 constitutes a DCDC converter circuit. That is, by connecting the first surface electrode 115 of the first substrate 10 and the second surface electrode 124 of the second substrate 20, a DCDC converter circuit as shown in FIG. That is, the DCDC converter circuit includes a switching IC 131, a coil portion L1 that is a choke coil, a smoothing capacitor 132 on the input side, and a smoothing capacitor 133 on the output side. Among these, the switching IC 131 and the capacitors 132 and 133 are provided on the first substrate 10, and the coil portion L <b> 1 is provided on the second substrate 20.

Coil portion L1 has one end connected to the switching IC131 via a terminal _{P La,} is connected the other end via a terminal _{P Lb} switching IC131. The terminals P _La and P _Lb correspond to the first surface electrode 115 of the first substrate 10 and the second surface electrode 124 of the second substrate 20, respectively. In the present embodiment, the first surface electrode 115 and the second surface electrode The surface electrode 124 and the conductive bonding material 40 for bonding them are configured.

The switching IC 131 is connected to an enable terminal P _en , an input terminal P _in , a control terminal P _CON, and an output terminal P _out each configured by an external connection terminal 125, and a built-in switch element (not shown) This is a step-up / step-down switching IC that switches at a frequency.

Capacitor 132 has one end connected to the input voltage supply line connecting the input terminal _{P in} and the switching IC 131, the other end connected to the ground terminal _{P GND} composed of the external connection terminal 125. The capacitor 133 has one end connected to the output voltage power line connecting the switching IC 131 and the output terminal P _out, and the other end connected to the ground terminal P _GND configured by the external connection terminal 125.

For example, the ground line that connects each of the capacitors 132 and 133 and the ground terminal P _GND is configured by the interlayer connection conductor 113 that penetrates the wiring portion 12 and the interlayer connection conductor 123 that penetrates the second substrate 20. That is, the ground line is constituted by a conductor that does not penetrate the magnetic core portion 11. For this reason, the ground line of this Embodiment can suppress a floating inductor compared with the ground line comprised by the conductor which penetrates the magnetic core part 11. FIG. Therefore, the coil composite component 1 can constitute a DCDC converter circuit capable of suppressing noise due to the floating inductor on the ground line.

DCDC converter circuit configured in this way, by intermittently applying the input voltage to the switching IC131 is supplied to the input terminal P _in the coil portion L1, a desired output voltage or higher desired lower than the input voltage An output voltage is generated and output from the output terminal _Pout .

  In order to suppress floating inductors in the ground line, a configuration in which an interlayer connection conductor penetrating the magnetic core portion 11 is exposed from the side surface of the magnetic core portion 11 is also conceivable. However, this configuration requires a step of exposing the interlayer connection conductor in the manufacturing process, which may cause another problem of increasing the number of steps.

  Next, the manufacturing process (manufacturing method) of the coil composite component 1 will be described.

  In the manufacturing process of the coil composite component 1 according to the present embodiment, the magnetic core portion 11 and the wiring portion 12 of the first substrate 10 are integrally fired to produce a multilayer substrate (ceramic multilayer substrate), and the coil portion L1 is formed. The magnetic core part 11 of the produced multilayer substrate is inserted into the second substrate 20 having the same. Thereby, the coil composite component 1 which has the coil part L1 with a high design freedom is producible.

  First, a process for manufacturing a multilayer substrate (first substrate 10) will be described.

  4A to 4D are cross-sectional perspective views showing manufacturing steps of the first substrate 10 in the first embodiment. Here, a process of manufacturing the magnetic core portion 11 and the wiring portion 12 in the first substrate 10 is shown.

  First, ceramic green sheets for each layer forming the magnetic core portion 11 and the wiring portion 12 are prepared. Specifically, a plurality of magnetic ceramic green sheets for forming the magnetic core portion 11 are prepared by forming a slurry containing magnetic ceramic powder into a sheet. Moreover, the nonmagnetic ceramic green sheet for forming the wiring part 12 is prepared by carrying out sheet shaping | molding of the slurry containing nonmagnetic ceramic powder.

  Next, in a predetermined ceramic green sheet, a plurality of through holes are formed, and a conductive paste is filled in the through holes to form the interlayer connection conductor 113, and the conductive paste is printed on the main surface to provide an in-plane conductor. 112 is formed. The through hole is formed by, for example, laser processing. The in-plane conductor 112 is patterned, for example, by screen printing of a conductor paste containing Ag powder.

  Next, a plurality of magnetic ceramic green sheets and a plurality of low permeability magnetic ceramic green sheets (here, non-magnetic ceramic green sheets) having lower magnetic permeability than the plurality of magnetic ceramic green sheets are integrally fired (Co -Fire) to produce the multilayer substrate 10Ma shown in FIG. 4A (firing step). Specifically, a plurality of ceramic green sheets on which conductive paste is disposed are laminated and pressure-bonded, and then fired collectively.

  By this firing, the magnetic ceramic powder and the non-magnetic ceramic powder in each green sheet are sintered, and the Ag powder in the conductor paste is sintered. That is, by this firing, as shown in FIG. 4A, the plate-like assembly 11M of the magnetic core portion 11 and the plate-like assembly 12M of the wiring portion 12 are sintered to form one multilayer substrate 10Ma. Is done. That is, in the firing step, among the first substrate 10 having the magnetic core portion 11, the wiring portion 12, the electronic component 13, and the first surface electrode 115, a multilayer substrate (ceramic multilayer) having at least the magnetic core portion 11 and the wiring portion 12. Substrate).

  Next, by cutting the bottom surface of the multilayer substrate 10Ma, a protruding portion 12a (see FIG. 2) projecting laterally from the magnetic core portion 11 is produced in the wiring portion 12 (cutting step). Specifically, a portion corresponding to the end of the first substrate 10 in the bottom surface of the multilayer substrate 10Ma is cut with the dicer DS, so that the protruding portion 12a is produced.

  Here, in the present embodiment, the interlayer connection conductor 113 is formed up to the lowermost ceramic green sheet in the state before firing the multilayer substrate 10Ma. Therefore, the end 113a of the interlayer connection conductor 113 is exposed on the bottom surface of the fired multilayer substrate 10Ma. Therefore, since the position of the dicer DS can be adjusted with the exposed end portion 113a as a reference, the cutting process can be simplified.

  For example, the position of the dicer DS in the Y-axis direction is adjusted with reference to the plurality of end portions 113a arranged in the X-axis direction, and the dicer DS is moved along the plurality of end portions 113a. Thereby, the protrusion part 12a which protrudes in the Y-axis direction from the magnetic core part 11 is produced. Further, the position of the dicer DS in the X-axis direction is adjusted with reference to the plurality of end portions 113a arranged in the Y-axis direction, and the dicer DS is moved along the plurality of end portions 113a. Thereby, the protrusion part 12a which protrudes in the X-axis direction from the magnetic core part 11 is produced.

  By such a cutting process, as shown in FIG. 4B, a multilayer substrate in which a plurality of magnetic core portions 11 are joined to the assembly 12 </ b> M of the wiring portions 12 is produced.

  Next, as shown in FIG. 4C, break grooves 12VC are formed in the aggregate 12M.

  Next, as illustrated in FIG. 4D, the aggregate 12 </ b> M is cut along the break groove 12 </ b> VC, and the multilayer substrate 10 </ b> Mb separated into pieces for each first substrate 10 is manufactured. That is, the multilayer substrate 10Mb corresponds to the magnetic core part 11 and the wiring part 12 of one coil composite component 1. Thereafter, in the present embodiment, the first surface electrode 115 is formed on the bottom surface of the protruding portion 12 a of the wiring portion 12.

  Through such a manufacturing process, the magnetic core portion 11 and the wiring portion 12 of the first substrate 10 are integrally fired to form one multilayer substrate 10Mb.

  Subsequently, a process of manufacturing the second substrate 20 will be described.

  5A and 5B are a perspective view and a cross-sectional view showing a manufacturing process of the second substrate 20 in the first embodiment.

  First, sheets (for example, resin sheets) of a plurality of base material layers 121 that form the second substrate 20 are prepared. Next, in a predetermined sheet, a plurality of through holes are formed, and a conductor paste is filled in the through holes to form the interlayer connection conductor 123, and the conductor paste is printed on the main surface to form the coil conductor 122. To do. Thereafter, a plurality of sheets are laminated and cured.

  Thereby, as shown in FIG. 5A, an aggregate substrate 20Ma in which the base material layer 121M is formed in the entire region is manufactured.

  Next, as shown in FIG. 5B, holes 21 of each second substrate 20 are formed by drilling with a drill or the like. Specifically, the hole portion 21 is formed so as to form a hollow in the winding center portion of the coil portion L1. Thereby, an aggregate substrate 20Mb that is an aggregate of the plurality of second substrates 20 is produced.

  Subsequently, the multilayer substrate 10Mb manufactured in the firing step is inserted into the collective substrate 20Mb and then separated.

  FIG. 6A is a perspective view and a cross-sectional view showing the manufacturing process of the coil composite component 1. 6B and 6C are cross-sectional views illustrating the manufacturing process of the coil composite component 1.

  First, as shown in FIG. 6A, a first electrode having a hole portion 21 opened upward, a coil portion L1 wound around the hole portion 21, and a second surface electrode 124 connected to the coil portion L1. The multilayer substrate 10Mb is inserted into the two substrates 20 (insertion step). In the present embodiment, the multilayer substrate 10Mb is inserted into the collective substrate 20Mb of the second substrate 20.

  Specifically, in this insertion step, the multilayer substrate 10Mb is inserted so that the magnetic core portion 11 is inserted into the hole portion 21, and the first surface electrode 115 and the second surface electrode 124 are connected. Here, in the present embodiment, the first surface electrode 115 and the second surface electrode 124 are located at positions where the protruding portion 12a and the second substrate 20 face each other in the insertion direction (Z-axis direction) of the magnetic core portion 11. Has been placed. Therefore, the multilayer substrate 10Mb after the cutting process is inserted, and the first surface electrode 115 and the second surface electrode 124 are connected via the conductive bonding material 40.

  Next, as shown in FIG. 6B, after mounting the electronic component 13 by, for example, reflow, a break groove 20VC is formed in the collective substrate 20Mb.

  Finally, as shown in FIG. 6C, the collective substrate 20Mb is cut along the break groove 20VC, and is separated into pieces for each second substrate 20 in which the first substrate 10 is inserted. Thereby, the coil composite component 1 is manufactured.

  As described above, in the coil composite component 1 according to the present embodiment, the first substrate 10 has the magnetic core portion 11 and the second substrate 20 has the coil portion L1, so that the coil portion L1 is the first substrate. It can be realized by a process, material or thickness different from 10. That is, it is possible to design the coil portion L <b> 1 while suppressing the restriction due to the first substrate 10. Therefore, the design freedom of the coil part L1 which the coil composite component 1 has can be raised.

  Further, in the coil composite component 1 according to the present embodiment, the first surface electrode 115 and the second surface electrode 124 are arranged at positions where the protruding portion 12a and the second substrate 20 face each other in the insertion direction of the magnetic core portion 11. Thus, the conductive bonding material 40 is pressed by the first surface electrode 115 and the second surface electrode 124 by the insertion of the magnetic core portion 11. Therefore, the electrical connection between the first surface electrode 115 and the second surface electrode 124 can be easily achieved, and the strength of these mechanical connections can be increased.

  Moreover, in the coil composite component 1 which concerns on this Embodiment, a DCDC converter circuit can be comprised using the coil part L1 which has a desired characteristic by having the coil part L1 with which the design freedom was raised. Accordingly, a DCDC converter circuit having desired characteristics can be realized.

  Further, in the coil composite component 1 according to the present embodiment, the magnetic core portion 11 and the wiring portion 12 are baked to form one ceramic multilayer substrate, whereby the first substrate 10 is made a general ceramic multilayer. While being able to produce by the manufacturing process of a board | substrate, the wiring part 12 and the magnetic core part 11 can be joined firmly, without using an adhesive agent etc. Therefore, it is possible to manufacture the first substrate 10 having excellent durability while simplifying the manufacturing process.

  Moreover, in the manufacturing process of the coil composite component 1 according to the present embodiment, the multilayer substrate 10Mb manufactured by the firing process is replaced with the second substrate 20 having the coil portion L1 (in this embodiment, the collective substrate of the second substrate 20). 20Mb). Thus, the coil portion L1 can be realized by a process, material, thickness, or the like different from that of the multilayer substrate 10Mb. That is, it is possible to design the coil portion L1 while suppressing the restrictions imposed by the multilayer substrate 10Mb. Therefore, the coil composite component 1 having the coil portion L1 having a high degree of design freedom can be manufactured.

  Further, in the manufacturing process of the coil composite component 1 according to the present embodiment, the first surface electrode 115 and the second surface electrode 124 are opposed to each other in the insertion direction of the magnetic core portion 11 by the cutting process for producing the protruding portion 12a. Can be placed in position. For this reason, in the insertion step, the conductive bonding material 40 is pressed by the first surface electrode 115 and the second surface electrode 124. Therefore, the electrical connection between the first surface electrode 115 and the second surface electrode 124 can be easily achieved, and the strength of these mechanical connections can be increased.

  In the present embodiment, in the manufacturing process of the coil composite component 1, the electronic component 13 is mounted and then separated for each second substrate 20. However, the electronic component 13 may be mounted after cutting the collective substrate 20Mb.

(Modification 1 of Embodiment 1)
In the above embodiment, the entire peripheral edge portion of the wiring portion 12 protrudes laterally from the magnetic core portion 11. However, the portion of the wiring portion that protrudes from the magnetic core portion 11 is not limited to this.

  FIG. 7 is a perspective view showing the first substrate 110 and the second substrate 20 of the coil composite component 101 according to the first modification of the first embodiment separately. As shown in the figure, in this modification, only a part of the peripheral edge portion of the wiring portion 12 (the end portion on the minus side in the X-axis direction) protrudes laterally from the magnetic core portion 11.

  Even in the coil composite component 101 configured as described above, the coil portion can be realized by a process, material, thickness, or the like different from that of the first substrate 110. Therefore, as in the first embodiment, the degree of freedom in designing the coil portion of the coil composite component 101 can be increased.

(Modification 2 of Embodiment 1)
In the first embodiment and the modification example 1 described above, the wiring portion extends beyond the magnetic core portion 11 in the first substrate. However, the wiring part does not have to protrude from the magnetic core part.

  FIG. 8 is a perspective view showing an appearance of the coil composite component 201 according to the second modification of the first embodiment. FIG. 9 is a diagram conceptually showing a cross-sectional structure of a coil composite component 201 according to the second modification of the first embodiment. Specifically, FIG. 9 is a cross-sectional view of the coil composite component 201 taken along line IX-IX in FIG.

  In the coil composite component 201 shown in these drawings, the outer shape of the first substrate 210 is mainly different from the coil composite component 1 shown in the first embodiment.

  The first substrate 210 includes the magnetic core part 211 and the wiring part 12 whose side surfaces are flush with each other as compared with the first substrate 10 of the first embodiment. That is, the first substrate 210 is produced without going through a cutting process, for example. In the first substrate 210, in addition to the magnetic core portion 211, the wiring portion 12 provided with the first surface electrode 215 on the top surface is also accommodated in the hole portion 221.

  The second substrate 220 has a larger opening than the second substrate 20 of the first embodiment, and is provided with a hole portion 221 that accommodates both the magnetic core portion 211 and the wiring portion 12. For this reason, in the 2nd board | substrate 220, the area | region which provides a coil conductor in top view (viewing from the Z-axis direction plus side) decreases. Therefore, the coil conductor is wound twice in the coil portion L2 as compared with the coil portion L1 in which the coil conductor is wound in triplicate.

  In the present modification, the first surface electrode 215 and the second surface electrode 224 are arranged side by side in a direction different from the insertion direction of the magnetic core part 211 and the wiring part 12, for example, in the X-axis direction. Has been placed. The first surface electrode 215 and the second surface electrode 224 are connected by wire bonding with a wire 240.

  Even in the coil composite component 201 configured as described above, the coil portion L2 can be realized by a process, material, thickness, or the like different from that of the first substrate 210. Therefore, as in the first embodiment, the degree of freedom in designing the coil portion L2 included in the coil composite component 201 can be increased.

  The first surface electrode 215 is provided on the side surface of the first substrate 210, and the second surface electrode 224 is provided at a position facing the first surface electrode 215 on the wall surface of the hole 221. The two-surface electrode 224 may be connected by a conductive bonding material.

(Embodiment 2)
In the first embodiment and the first and second modifications thereof, the external connection terminals are provided on the bottom surface of the coil composite component (that is, the bottom surface of the second substrate). However, the coil composite component may have a so-called cavity down structure in which external connection terminals are provided on the top surface.

  FIG. 10 is a perspective view showing the first substrate 10, the second substrate 320, and the protective sheet 330 of the coil composite component 301 according to the second embodiment separately. FIG. 11 is a diagram conceptually showing a cross-sectional structure of the coil composite component 301 according to the second embodiment.

  As shown in these drawings, the coil composite component 301 according to the present embodiment includes the structure of the second substrate 320 and the protective sheet 330 as compared with the coil composite component 1 according to the first embodiment. Is different. Note that the protective sheet 330 may not be provided.

  Compared to the second substrate 20 of the first embodiment, the second substrate 320 has an external connection terminal 325 provided on the top surface and has a hole 321 in which the entire first substrate 10 is accommodated.

  The external connection terminal 325 is provided on the top surface of the second substrate 320, that is, the top surface of the coil composite component 301. For this reason, the coil composite component 301 according to the present embodiment has a cavity down structure in which the top surface side is mounted on the motherboard.

  The hole portion 321 has a deep bottom portion 321a and a shallow bottom portion 321b. The deep bottom portion 321a is a hole portion into which the magnetic core portion 11 is inserted, and is a through hole that penetrates to the bottom surface of the second substrate 320 in the present embodiment. The shallow bottom portion 321 b is a recess that accommodates the wiring portion 12 and the electronic component 13.

  A coil portion L3 is wound around the hole portion 321. The inner end surface of the coil portion L3 is exposed on the wall surface of the hole portion 321. Specifically, the innermost end surface of the coil conductor 322 is exposed on the side surface of the hole portion 321. In the present embodiment, the coil conductor 322 is wound twice in the deep bottom portion 321a and is wound in a single manner in the shallow bottom portion 321b. And the end surface of the innermost circumference of the coil conductor 322 wound twice is exposed on the side surface of the deep bottom portion 321a.

  The protective sheet 330 is a sheet provided on the bottom surface of the second substrate 320, that is, the bottom surface of the coil composite component 301. That is, in the present embodiment, the protective sheet 330 covers the surface opposite to the mounting surface of the coil composite component 301 in a state where the coil composite component 301 is mounted. Although the material of a protective sheet is not specifically limited, For example, it is preferable that it is a magnetic sheet which consists of resin containing a magnetic material.

  Even in the coil composite component 301 configured as described above, the coil portion L3 can be realized by a process, a material, a thickness, or the like different from that of the first substrate 10. Therefore, as in the first embodiment, the degree of freedom in designing the coil portion L3 included in the coil composite component 301 can be increased.

  Further, in the coil composite component 301 according to the present embodiment, the inner end face of the coil portion L3 is exposed on the wall surface of the hole portion 321, so that a loop-shaped magnetic flux (so-called “circular” inside and outside the coil portion L3) The magnetic flux that forms the major loop) can be increased. That is, it is possible to suppress a loop-shaped magnetic flux (magnetic flux forming a so-called minor loop) that individually circulates inside and outside the coil conductor 322 of the coil portion L3. Therefore, the inductance value of the coil portion L3 can be increased.

  Further, in the coil composite component 301 according to the present embodiment, the protective sheet 330 is provided, so that when the cavity down structure is adopted, the surface opposite to the mounting surface can be protected. This is particularly useful when the hole 321 passes through the second substrate 320. In this case, if the protective sheet 330 is a magnetic sheet, the magnetic flux generated by the coil portion L3 passes through the protective sheet 330, so that it is difficult to leak outside. For this reason, the radiation noise of the coil composite component 301 can be reduced.

  The hole 321 is preferably filled with a sealing resin such as a liquid curable resin such as a composite resin mainly composed of an epoxy resin.

(Embodiment 3)
The coil composite component described above is used as a DCDC converter module mounted on a small portable terminal device such as a mobile phone. Since such a portable terminal device requires high-density mounting of electronic components, the coil composite component may be provided with a coil portion on a motherboard on which the electronic components are mounted.

  FIG. 12 is a top view showing an external appearance of the mobile terminal device 4 on which the coil composite component 401 according to Embodiment 3 is mounted. As shown in the figure, the mobile terminal device 4 is, for example, a mobile phone that houses a coil composite component 401 inside a housing.

  FIG. 13 is a diagram conceptually showing a cross-sectional structure of the coil composite component 401 according to the third embodiment.

  As shown in the figure, the coil composite component 401 according to the present embodiment is different from the coil composite component 1 according to the first embodiment in that the second substrate 420 having the coil portion L1 is a motherboard.

  The second substrate 420 is a motherboard on which electronic components 413 different from the switching IC 131 are mounted. The electronic component 413 is an electronic component that constitutes, for example, a liquid crystal driving circuit, an RF (Radio Frequency) front-end circuit, or a power supply circuit. The electronic component 413 is supplied with power (power supply voltage) by, for example, a DCDC converter circuit configured by the coil portion L1 and the electronic component 13.

  Even in the coil composite component 401 configured as described above, the coil portion L1 can be realized by a process, a material, a thickness, or the like different from that of the first substrate 10. Therefore, as in the first embodiment, the degree of freedom in designing the coil portion L3 included in the coil composite component 401 can be increased.

  Further, in the coil composite component 401 according to the present embodiment, since the second substrate 420 is a mother board, high-density mounting of a DCDC converter circuit and, for example, an electronic component to which power is supplied by the DCDC converter circuit can be achieved. Figured.

  Furthermore, since the second substrate 420 is a motherboard, the combined height of the motherboard and the coil composite component 401 (that is, the height of the coil composite component 401 in this modification) can be reduced. For this reason, the coil composite component 401 which concerns on this Embodiment is especially useful as a coil composite component mounted in the small portable terminal device by which the low profile is calculated | required.

(Other embodiments)
As described above, the coil composite component and the manufacturing method thereof according to the embodiment and the modification of the present invention have been described. However, the present invention is not limited to the individual embodiment and the modification. Unless it deviates from the gist of the present invention, various modifications conceived by those skilled in the art have been made in this embodiment and its modifications, and forms constructed by combining different embodiments and components in those modifications, It may be included within the scope of one or more embodiments of the invention.

  The present invention can be realized not only as the above-described coil composite component but also as a multilayer substrate (first substrate in the above description) used for the coil composite component. That is, the multilayer board is a multilayer board that is inserted into the hollow of the coil portion of the coil composite component, and has a plurality of laminated magnetic ceramic layers, and is a block that is inserted into the hole that forms the hollow. And a plate-like wiring portion having a plurality of laminated low magnetic permeability magnetic ceramic layers bonded to the top surface of the magnetic core portion and having lower magnetic permeability than the plurality of magnetic ceramic layers, and wiring And the first surface electrode connected to the second electrode connected to the coil part, and the magnetic core part and the wiring part are fired to 1 Two ceramic multilayer substrates are constructed.

  Further, for example, in the above description, the first substrate is configured by one ceramic multilayer substrate, but the present invention is not limited to this. For example, the first substrate may be configured such that each of the magnetic core portion and the wiring portion is constituted by one ceramic multilayer substrate, and these two ceramic multilayer substrates are joined. In addition, the first substrate may be configured such that one of the magnetic core portion and the wiring portion is formed of one ceramic multilayer substrate. Alternatively, the first substrate may be configured by bonding a magnetic core portion and a wiring portion, both of which are configured differently from the ceramic multilayer substrate.

  Further, the hole portion of the second substrate may have a tapered shape in which the cross-section becomes smaller toward the bottom surface side of the second substrate (minus side in the Z-axis direction), for example. By adopting such a shape, the magnetic core portion of the first substrate can be easily inserted into the hole portion of the second substrate in the manufacturing process of the coil composite component.

  Further, in the first embodiment, the modification thereof, and the third embodiment, the first substrate may be sealed with a sealing resin that covers the top surface of the second substrate.

  Further, the mother board described above or the protective sheet 330 in the second embodiment may be a flexible substrate.

  In the present invention, various dimensional values such as the thickness and shape of each layer of the multilayer substrate and the position and size of the conductor are not particularly limited. In addition, the components of ceramic materials constituting each layer of the multilayer substrate and the physical property values such as component permeability, magnetic permeability, the material component values used for conductors in the multilayer substrate, the physical property values such as conductivity, etc. There is no particular limitation. These numerical values are appropriately determined in consideration of various electrical characteristics such as inductance values and DC superimposition characteristics required for the coil composite component.

  INDUSTRIAL APPLICABILITY The present invention can provide a coil composite part having a coil portion with a high degree of design freedom, and thus can be applied to a DCDC converter module or the like that requires various electrical characteristics such as an inductance value and a direct current superposition characteristic. It can be widely used for electronic devices.

DESCRIPTION OF SYMBOLS 1, 101, 201, 301, 401 Coil composite part 4 Mobile terminal device 10, 110, 210 1st board | substrate 10Ma, 10Mb multilayer board | substrate 11, 211 Magnetic core part 11M, 12M Aggregation 12 Wiring part 12a Protrusion part 12VC, 20VC break Groove 13, 413 Electronic component 20, 220, 320, 420 Second substrate 20Ma, 20Mb Collected substrate 21, 221, 321 Hole 40 Conductive bonding material 112 In-plane conductor 113 Interlayer connection conductor 113a End portion 114 Mounting electrode 115, 215 First surface electrode 121, 121M Base material layer 122, 322 Coil conductor 123 Interlayer connection conductor 124, 224 Second surface electrode 125, 325 External connection terminal 131 Switching IC
132, 133 Capacitor 240 Wire 321a Deep bottom part 321b Shallow bottom part 330 Protection sheet L1, L2, L3 Coil part

Claims (9)

A block-shaped magnetic core part, a plate-like wiring part bonded to the top surface of the magnetic core part and having a lower magnetic permeability than the magnetic core part, an electronic component mounted on the wiring part, and the electronic component A first substrate having a connected first surface electrode;
A second substrate having a hole portion opened upward, a coil portion wound around the hole portion, and a second surface electrode connected to the coil portion;
Have
The magnetic core is inserted into the hole, and the first surface electrode and the second surface electrode are connected;
Coil composite parts. The wiring portion has a protruding portion projecting laterally from the magnetic core portion,
The first surface electrode and the second surface electrode are disposed at a position where the protruding portion and the second substrate face each other in the insertion direction of the magnetic core portion, and are connected via a conductive bonding material. ,
The coil composite component according to claim 1. The coil portion has an inner end surface exposed at the wall surface of the hole portion,
The coil composite component according to claim 1 or 2. The electronic component is a switching IC, the coil unit is a choke coil, and constitutes a DCDC converter circuit.
The coil composite component according to any one of claims 1 to 3. The second substrate is a motherboard on which electronic components different from the switching IC are mounted.
The coil composite component according to claim 4. In the magnetic core portion, a plurality of magnetic ceramic layers are laminated,
In the wiring portion, a plurality of low permeability magnetic ceramic layers having a lower permeability than the plurality of magnetic ceramic layers are laminated,
The magnetic core part and the wiring part are fired to constitute one ceramic multilayer substrate,
The coil composite component according to any one of claims 1 to 5. A multilayer substrate inserted into the hollow of the coil portion of the coil composite component,
A plurality of magnetic ceramic layers stacked, and a block-shaped magnetic core portion inserted into the hole forming the hollow;
A plate-like wiring portion having a plurality of laminated low magnetic permeability magnetic ceramic layers bonded to the top surface of the magnetic core portion and having a lower magnetic permeability than the plurality of magnetic ceramic layers;
An electronic component mounted on the wiring part;
A first surface electrode connected to the electronic component and connected to a second electrode connected to the coil portion;
The magnetic core part and the wiring part are fired to constitute one ceramic multilayer substrate,
Multilayer board. A method of manufacturing a coil composite part,
A firing step of integrally firing a plurality of magnetic ceramic green sheets and a plurality of low permeability magnetic ceramic green sheets having a lower magnetic permeability than the plurality of magnetic ceramic green sheets,
Inserting step of inserting the multilayer substrate into a second substrate having a hole portion opened upward, a coil portion wound around the hole portion, and a second surface electrode connected to the coil portion And including
In the firing step, a block-shaped magnetic core part, a plate-like wiring part bonded to the top surface of the magnetic core part and having a lower magnetic permeability than the magnetic core part, and an electronic component mounted on the wiring part, A first substrate having a first surface electrode connected to the electronic component, and producing the multilayer substrate having at least the magnetic core portion and the wiring portion,
In the inserting step, the multilayer substrate is inserted so that the magnetic core portion is inserted into the hole, and the first surface electrode and the second surface electrode are connected.
Manufacturing method of coil composite parts. Furthermore, after the firing step, by cutting the bottom surface of the multilayer substrate, including a cutting step of producing a protruding portion where the wiring portion projects laterally from the magnetic core portion,
The first surface electrode and the second surface electrode are arranged at a position where the protruding portion and the second substrate face each other in the insertion direction of the magnetic core portion,
In the insertion step, the multilayer substrate after the cutting step is inserted, and the first surface electrode and the second surface electrode are connected via a conductive bonding material.
The manufacturing method of the coil composite component of Claim 8.

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