JP2012028799A - Component with built-in inductor and dc-dc converter using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inductor which can reduce leakage flux and can exhibit excellent performance even if the inductor is disposed closely to a semiconductor integrated circuit (IC), and to provide a DC-DC converter using it.SOLUTION: Coil conductors arranged on different magnetic body layers of a multilayer insulating substrate having an upper main surface and a lower main surface facing each other and a lateral face connecting the upper and lower main surfaces are stacked, connected through via holes and turned vertically to produce a stacked coil. The multilayer insulating substrate has a coil forming magnetic body layer, and an upper magnetic body layer and a lower magnetic body layer located above and below the coil forming magnetic body layer. The magnetic body layer located in the direction of magnetic flux generated by the stacked coil is made thicker than the other magnetic body layer thus reducing flux leakage from the main surface.

Description

  The present invention relates to a DC-DC converter control circuit, a semiconductor integrated circuit (IC) including a switching element, and an inductor used for a DC-DC converter including passive elements such as an inductor and a capacitor.

  Many portable electronic devices (such as mobile phones, personal digital assistants PDAs, notebook computers, DVDs, CDs, MD players, digital cameras, video cameras, etc.) use batteries as the power source, and operate the power supply voltage at a predetermined level. A DC-DC converter is provided as a power conversion device that converts voltage. In a DC-DC converter, a semiconductor integrated circuit (active element) including a switching element and a control circuit and passive elements such as an inductor and a capacitor are generally configured as a discrete circuit on a printed circuit board or the like on which a connection line is formed. Is.

FIG. 6 is a circuit diagram illustrating an example of a circuit configuration of the DC-DC converter. A dotted line portion in the figure is a circuit of a DC-DC converter, and this DC-DC converter is a semiconductor integrated circuit (IC) including an input capacitor Cin, an output capacitor Cout, an inductor Lout, and a DC-DC converter control circuit. The step-down DC-DC converter is configured. Hereinafter, the semiconductor integrated circuit may be referred to as a semiconductor integrated circuit component.
A DC input voltage Vin is input to switch a field effect transistor (hereinafter referred to as a switching element) in the semiconductor integrated circuit (IC). Assuming that the time when the switching element is on is Ton and the time when it is off is Toff, the output voltage Vout is expressed by Vout = Ton / (Ton + Toff) × Vin, and the output voltage Vout is stepped down from the input voltage Vin. . When the input voltage Vin fluctuates, the output voltage Vout maintained stably can be output by adjusting the ratio of Ton and Toff.
The input capacitor (Cin) is used for stabilizing the input voltage during transition and preventing voltage spikes. On the output side, a filter circuit (smoothing circuit) for outputting a DC voltage is provided. This filter circuit outputs an output inductor (Lout) for storing and discharging current energy, and an output for storing and discharging voltage energy. It is comprised by the combination of a capacitor | condenser (Cout).

Such DC-DC converters are strongly demanded to reduce the formation area on the circuit board as the various electronic devices become smaller and more multifunctional. In response to such demands, semiconductor integrated circuits (ICs) and inductors are integrated and miniaturized.
For example, in Patent Document 1, as shown in the external view of FIG. 8, a printed circuit board, a chip inductor, a semiconductor integrated circuit IC on which a control circuit and the like are formed, and a semiconductor integrated circuit IC mounted thereon. A DC-DC converter is disclosed in which a connection terminal is disposed on a substrate, and a chip inductor is disposed on the connection terminal so as to overlap the semiconductor integrated circuit.

JP2004-063676

  There is always a demand for reducing the size and weight of the various electronic devices, and there is a strong demand for a small-sized DC-DC converter built therein. The inductance value of the inductor needs to be at least about several μH. Since such an inductor has a very large volume compared to a semiconductor integrated circuit, it is actually the biggest restriction in reducing the size of a DC-DC converter. Therefore, downsizing is achieved by mounting an inductor so as to overlap the semiconductor integrated circuit.

  However, when the semiconductor integrated circuit IC and the inductor are arranged close to each other as in the cited document 1, the leakage magnetic flux from the inductor must be taken into consideration. For example, electrical insulating layers and coil patterns are alternately stacked, end portions of each coil pattern are sequentially connected to form a circular coil superimposed in the stacking direction in a multilayer insulating substrate, and the end portions are connected to external electrodes The leakage magnetic flux in the case of a multilayer inductor acts as follows.

  FIG. 7 is a diagram for explaining the leakage magnetic flux of the inductor. In the above-described multilayer inductor, the magnetic flux generated in the inductor section passes through an insulating layer (dummy insulating layer) made of a magnetic material that does not have a coil pattern formed above and below the coil, and passes around the coil. However, some of them may leak outside. The leakage magnetic flux acts as noise on an electronic component arranged around the inductor, for example, the semiconductor integrated circuit.

  Therefore, the present invention reduces leakage magnetic flux in an inductor used in a DC-DC converter in which a semiconductor integrated circuit (IC) and an inductor are combined and integrated, and is excellent even if the inductor is disposed close to the semiconductor integrated circuit (IC). An object of the present invention is to provide an inductor capable of exhibiting performance and a DC-DC converter using the inductor.

  According to a first aspect of the present invention, a multilayer insulating substrate formed by laminating a plurality of magnetic layers is provided with a first magnetic layer portion and a second magnetic layer portion above and below the coil-forming magnetic layer portion, Inductor built-in component in which a plurality of mounting conductors for mounting semiconductor integrated circuit components are formed on the upper main surface of the multilayer insulating substrate, and a plurality of terminal conductors for connection to external circuits are formed on the lower main surface In the coil-forming magnetic layer portion, coil conductors arranged in different magnetic layers are laminated to form a laminated coil that is connected through a via hole and circulates in the vertical direction, and is an input terminal conductor Is connected to the mounting conductor for input through a first connection conductor constituted by via holes extending in the thickness direction of the multilayer insulating substrate and extending to the upper and lower main surfaces, and the output terminal conductor is connected to one end of the laminated coil and the via hole. Connected through the other end of the laminated coil Is connected to the mounting electrodes for output, an inductor built-in component, characterized in that the thickness of the first magnetic layer portion thicker than the thickness of the second magnetic layer portion of the other.

In the present invention, the output terminal conductor is preferably connected to a conductor pattern for mounting an output capacitor formed on the upper main surface of the multilayer insulating substrate via another first connection conductor.
The input terminal conductor is preferably connected to an input capacitor mounting conductor pattern formed on the upper main surface of the multilayer insulating substrate via the first connection conductor.

  It is preferable that the other end of the laminated coil is further connected to another mounting conductor via the other first connection conductor.

  Preferably, a grounding conductor is widely formed on the lower main surface of the multilayer insulating substrate, and the grounding conductor is connected to the grounding mounting conductor via another first connection conductor.

  A second invention is a DC-DC converter including the inductor built-in component of the first invention and a semiconductor integrated circuit component, wherein the semiconductor integrated circuit component is mounted on a mounting conductor of the inductor built-in component. DC-DC converter.

  Also, a DC-DC converter including an inductor built-in component, a semiconductor integrated circuit component, and a capacitor according to the first invention, wherein the semiconductor integrated circuit component is mounted on a mounting conductor of the inductor built-in component, and the inductor built-in component It is also a DC-DC converter characterized in that an output capacitor is mounted on the conductor pattern for mounting the output capacitor. Further, it is preferable that an input capacitor is mounted on the conductor pattern for mounting the inductor built-in component input capacitor.

  According to the present invention, a leakage magnetic flux from a component with a built-in inductor can be reduced, and a DC-DC converter in which a semiconductor integrated circuit (IC) and an inductor are combined and integrated has a high performance and a small and low profile DC-DC converter. Can be provided.

1 is a perspective view of a component with a built-in inductor according to an embodiment of the present invention. It is sectional drawing of the component with a built-in inductor which concerns on one Example of this invention. It is a perspective view of the component with a built-in inductor according to another embodiment of the present invention. It is a disassembled perspective view of the components with a built-in inductor according to another embodiment of the present invention. It is a disassembled perspective view of the DC-DC converter comprised using the inductor built-in component which concerns on the other Example of this invention. It is a circuit diagram which shows an example of the circuit structure of a DC-DC converter. It is sectional drawing for demonstrating the leakage magnetic flux of an inductor. It is a perspective view of the conventional DC-DC converter.

  The component with a built-in inductor according to the present invention includes an upper main surface and a lower main surface that face each other, and a side surface that connects the upper and lower main surfaces, and the inductor is disposed on different magnetic layers in the component with a built-in inductor. A laminated coil in which coil conductors are laminated, connected via via holes, and circulate in the vertical direction. The built-in inductor component includes a coil-forming magnetic layer portion, an upper magnetic layer portion located above and below, and a lower magnetic layer portion. A magnetic layer portion is provided, and the thickness of the magnetic layer portion located in the direction of the magnetic flux generated by the laminated coil is made thicker than the thickness of the other magnetic layer portion, thereby reducing the leakage magnetic flux from the main surface. Yes.

FIG. 1 is an external perspective view of a component with a built-in inductor, and FIG. 2 is a cross-sectional view showing the internal structure of the component with a built-in inductor.
The inductor built-in component 10 is formed by laminating a coil conductor 15 and an insulating layer, and includes an upper main surface and a lower main surface that face each other, and a side surface that connects between the main surfaces. A mark is formed, and terminal electrodes 5a and 5b are provided on opposite side surfaces in the longitudinal direction.
The insulating layer has magnetism and is made of soft ferrite, a magnetic resin material obtained by dispersing a magnetic material in a resin, or the like. When soft ferrite is used as the insulating layer, it is preferable to select NiCu-based, NiZn-based, NiCuZn-based spinel ferrite having a specific resistivity of 1 × 10 ³ Ω · cm or more, and hexagonal ferrite excellent in high-frequency characteristics. Soft ferrite is converted into a green sheet by a well-known sheeting method such as a doctor blade method or a calender roll method, and a conductor pattern is printed or coated on the green sheet with a conductor paste containing Ag, Cu or an alloy containing them. A so-called LTCC (Low-Temperature Co-fired Ceramics) method is applied in which a plurality of layers are laminated to form a laminated body and sintered at a temperature of 1100 ° C. or lower according to the conductor paste used. I can do it.

  When using a magnetic resin material, the magnetic resin material is formed into a sheet shape by a known method, a via hole is formed at a predetermined position, and a thin metal foil such as Cu is formed on the sheet surface by plating or the like. . After applying a photosensitive resist film thereon, patterning exposure is performed in a predetermined shape to remove the resist film in portions other than the portions where the coil conductor pattern is formed and via holes, and the conductive member is removed by chemical etching. Thus, a coil conductor pattern is formed. A method of laminating a plurality of these and applying pressure and thermocompression bonding is used.

The coil conductors are connected via via holes (not shown) to form a laminated coil (inductor) that circulates in the laminating direction. The inductor built-in component 10 includes a plurality of insulating layers, and a coil conductor is formed in some of the insulating layers. And it laminates | stacks with the insulating layer distribute | arranged to the upper and lower sides, and the edge part of each coil conductor is sequentially connected through a via hole. Ends not connected to other coil conductors extend to opposite side surfaces in the longitudinal direction and are connected to the terminal electrodes 5a and 5b.
In addition, the coil formation magnetic body part prescribed | regulated by this invention is the area | region C in which the coil conductor shown in FIG. 2 was formed. The upper magnetic layer portion is a region A located above the region C, and the lower magnetic layer portion is a region B located above the region C.

  The upper magnetic layer portion (region A) is located in the direction of the magnetic flux generated by the laminated coil, and the thickness t1 is formed thicker than the thickness t2 in the lower magnetic layer portion (region B). With such a configuration, the magnetic flux is positively confined and leaked to the outside, in particular, the leakage magnetic flux leaking to the main surface side is reduced.

FIG. 3 is an external perspective view showing another example of a component with a built-in inductor, and FIG. 4 is an exploded perspective view showing an internal structure thereof. FIG. 5 is an external perspective view of a DC-DC converter using a component with a built-in inductor. The DC-DC converter of the present embodiment is configured by the same equivalent circuit as the step-down DC-DC converter shown in FIG.
The inductor built-in component 10 according to the present embodiment is formed by laminating a coil conductor and an insulating layer, and includes an upper main surface and a lower main surface that face each other, and a side surface that connects between the main surfaces, on the upper main surface. Includes mounting conductor patterns 50a to 50h for mounting semiconductor integrated circuit components including a DC-DC converter control circuit, grounding conductor patterns 70a and 70b, and second connection conductor patterns 60a, 60b, 60c, 60e, 60f, 60 g, conductor patterns 65 a to 65 d for mounting capacitors are formed, and the lower main surface is provided with terminal conductor patterns 90 (Vcon, Ven, Vdd, Vin, Vout, GND) for connection to an external circuit. In this embodiment, an LGA (Land Grid Array) type terminal structure is employed.

The insulating layer composing the inductor built-in component 10 is made of a ferrite magnetic material having a Curie temperature of 100 ° C. or higher. The composition of the insulating layer includes magnetic characteristics (initial permeability, loss, quality factor, etc.) required for the inductor. ) Can be selected as appropriate.
As such a magnetic material, for example, Fe ₂ O ₃ is 40.0 to 49.8 mol%, NiO is 20.0 to 39.5 mol%, CuO is 10.0 to 20.0 mol%, ZnO and 2.0 to 20.0 mol%, wherein the CoO .3 to 6.5 mol%, with respect to these oxides to 100 weight%, the _Bi 2 _{O 3} and contains less than 4.0 wt%, Among these, the content ratios of NiO, CuO, and ZnO are all 1.0 ≦ NiO / CuO ≦ 3.95, 0.5 ≦ CuO / ZnO ≦ 10.0, 1.0 ≦ NiO / ZnO ≦ 19 in molar ratios. There is a ferrite magnetic material that is .8. This ferrite magnetic material can be sintered at 950 ° C. or lower, its Curie temperature Tc is 120 ° C. or higher, and the initial permeability (frequency 100 kHz) is at least 10 or higher. In addition, the real term of the complex permeability in the frequency range of 1 MHz to 200 MHz is 10 or more and the imaginary term is less than 5.

  A binder, a plasticizer, a solvent, and the like were added to such a ferrite magnetic material to form a slurry, which was formed on a green sheet by a doctor blade method. After this sheet is appropriately drilled with a laser or the like, a conductor paste of Ag 100% is used, and screen printing is performed to form a coil conductor, a mounting conductor pattern, a terminal conductor pattern, a via hole that becomes the first connection conductor pattern, the second A connection conductor pattern or the like was formed.

  After a predetermined conductor pattern was formed on each sheet, it was laminated and pressure-bonded and sintered to obtain a mother multilayer substrate having a plurality of laminated coils having an inductance value of 3.3 μH.

Sintering was performed following degreasing in an electric furnace in an air atmosphere, the temperature was raised to 150 ° C./hr, held at 900 ° C. for 1 hour, and then lowered to about 300 ° C./hr.
The obtained mother multilayer substrate was electroplated, and Ni—P and Au plating were applied to the mounting conductor pattern, terminal conductor pattern, second connection conductor pattern, and the like formed on the outer surface. After plating, the semiconductor integrated circuit component IC and the capacitors Cin (10 μF) and Cout (4.7 μF) were mounted on the mounting conductor pattern and connected by solder. After soldering, the component mounting surface side is sealed with epoxy resin, divided into individual pieces along the division grooves formed in advance on the multilayer substrate, and DC-DC of 4.5 mm × 3.2 mm × 1.4 mm A converter was used.

The coil conductors are connected via via holes (indicated by black circles in the figure) to constitute a laminated coil (inductor) that circulates in the laminating direction. The inductor built-in component 10 includes a plurality of insulating layers S1 to S14, and coil conductors are formed in the insulating layers S4 to S13. And it laminates | stacks with the insulating layers S1-S3, S14 distribute | arranged to the upper and lower sides, and the edge part of each coil conductor is sequentially connected via the via holes Lg3-Lg12.
In the present embodiment, the coil-forming magnetic body layer defined in the present invention is an insulating layer (S4) between the coil conductor formed in the insulating layer S4 and the coil conductor formed in the insulating layer S13. To S12). The upper magnetic layer portions are magnetic layers S1 to S3, and the lower magnetic layer portions are magnetic layers S13 and S14.
One end of the laminated coil extends to the upper main surface via the via holes Lg1 to Lg3 and is connected to the terminal conductor pattern 50h. The other end extends via the via holes V13o and V14o to the lower main surface and is connected to the terminal conductor pattern Vout, and the mounting conductor pattern 50e via the via holes V1o to V12o and the second connection conductor pattern 60e, and the capacitor It is connected to the conductor pattern 65a for mounting.

  In the terminal conductor pattern 90, Vcon, Ven, Vdd, Vin, Vout, and GND indicate the functions of the terminals of the semiconductor integrated circuit component IC to be connected. The terminal conductor pattern Vcon is connected to the terminal Vcon for variably controlling the output voltage of the semiconductor integrated circuit component IC. The terminal conductor pattern Ven is connected to the terminal Ven for ON / OFF control of the output of the semiconductor integrated circuit component IC. The terminal conductor pattern Vdd is connected to a terminal Vdd for ON / OFF control of the switching element of the semiconductor integrated circuit component IC. The terminal conductor pattern Vin is connected to the input terminal Vin of the semiconductor integrated circuit component IC. The terminal conductor pattern Vout is connected to the output terminal Vout of the semiconductor integrated circuit component IC. The terminal conductor pattern GND is grounded on the circuit and is connected to the terminal GND of the semiconductor integrated circuit component IC.

A plurality of via holes V1a to V14p are formed in the outer region of the coil conductor of each layer. Via holes in each insulating layer are continuous in the thickness direction of the multilayer insulating substrate (the magnetic field direction generated by the laminated coil), and the mounting conductor patterns 50a, 50b, 50c, 50d, 50e, 50f, 50g, 50h and the terminal conductors. A first connection conductor pattern that connects the pattern 90 is formed.
In the present embodiment, a plurality of first connection conductor patterns are formed on all four sides of the inductor built-in component 10. For this reason, a laminated coil will be in the state enclosed by the 1st connection conductor pattern formed in the outer peripheral side (coil outer side area | region). Each side surface also includes a first connection conductor pattern connected to the terminal conductor pattern GND. With this configuration, leakage of magnetic flux from the side surface side of the inductor built-in component 10 is prevented by the magnetic shielding effect by the first connection conductor pattern.

  The mounting conductor patterns 50a to 50h are formed in an inner region of the multilayer coil as viewed from the upper main surface side of the inductor built-in component 10. The second connection conductor patterns 60a, 60b, 60c, 60e, 60f, and 60g are formed radially from the mounting conductor patterns 50a to 50g toward the side surface, and are connected to the via holes V1d to V1g and V1m to V1o. According to such a configuration, even when the magnetic flux from the laminated coil leaks to the upper main surface, the linkage between the second connection conductor pattern and the leakage magnetic flux can be reduced, and the generation of noise can be reduced. .

  On the lower main surface of the inductor built-in component 10, a terminal conductor pattern GND having a large area including the central portion is formed. Leakage magnetic flux to the lower main surface side is reduced by the shielding effect including other terminal conductor patterns.

Further, in this embodiment, the upper magnetic layer portion above the coil-forming insulating layer portion where the laminated coil is formed is formed thicker than the lower magnetic layer portion.
Usually, due to the magnetic field generated by the laminated coil, a part of the magnetic flux φ flowing through the inner region of the coil tends to penetrate the insulating layer and flow to the outside as the leakage magnetic flux φ ′. However, by configuring as in the present invention, leakage magnetic flux that passes through the magnetic layer and exits to the outside is reduced. In this way, the generation of leakage magnetic flux is suppressed, and the magnetic flux φ flows from the coil inner region to the coil outer region, so that the leakage magnetic flux is remarkably reduced.
The relationship between the thickness of the upper magnetic layer portion and the thickness of the lower magnetic layer portion depends on the magnetic properties such as magnetic permeability, but if the initial permeability of the magnetic layer is 50 or less, the upper magnetic layer The thickness of the portion is preferably 1.2 to 2.0 times the thickness of the lower magnetic layer portion. In order to reduce the leakage magnetic flux, it is preferable that the upper magnetic layer portion is formed thick. However, even if the thickness is increased more than necessary, the thickness of the component with a built-in inductor is merely increased, which is not preferable in terms of reduction in height, and the upper limit is practically about 2.0 times.
In the present embodiment, the planar area of the coil inner region is 4.2 mm ^2, the planar area of the coil outer region was 4.3 mm ^2. Moreover, the thickness of the coil-forming insulating layer portion is 0.3 mm, and the thicknesses of the upper insulating layer portion and the lower insulating layer portion positioned above and below it are 0.3 mm and 0.2 mm, respectively.

The voltage conversion efficiency was measured using the obtained DC-DC converter. For comparison, a winding type inductor (inductance value is 3.3 μH) in which a wire is wound around a drum type ferrite magnetic core, a semiconductor integrated circuit component IC, and capacitors Cin and Cout used in the embodiment are mounted on a printed circuit board. Similarly, the efficiency was measured.
When the input voltage Vi is set to 3.6 V and the output voltage Vo is driven to 3.2 V, a conversion efficiency exceeding 95% can be obtained at an output current Io of 150 mA, and the DC-DC converter of the embodiment is a comparative example. The efficiency was comparable.

  In the DC-DC converter of the comparative example, the total mounting area of each circuit element exceeds five times that of the present invention. The DC-DC converter module using the component with a built-in inductor according to the present invention obtains conversion efficiency comparable to that of the conventional one, is small, and significantly reduces the mounting area. With such a configuration, it is possible to provide a small-sized and high-performance DC-DC converter by reducing the influence of noise on the semiconductor integrated circuit component due to the magnetic flux leakage from the component with a built-in inductor. By using a terminal structure such as an LGA, the circuit elements arranged together with the DC-DC converter can be arranged close to each other on the circuit board, and high-density mounting is possible.

  A semiconductor integrated circuit IC is mounted on a printed circuit board, and a connection terminal is disposed on the printed circuit board on which the semiconductor integrated circuit IC is mounted, and the inductor built-in component according to the present invention is connected to the semiconductor integrated circuit with the connection terminal. And a DC-DC converter having the same configuration as that of FIG. 8 was formed. In the component with a built-in inductor, the magnetic layer portion on the side facing the semiconductor integrated circuit is formed thicker than the other magnetic layer portion, and the influence of the leakage magnetic flux from the component with a built-in inductor on the semiconductor integrated circuit IC is reduced. The DC-DC converter which exhibits the outstanding efficiency was obtained by reducing.

1 DC-DC converter 10 Inductor built-in components 50a, 50b, 50c, 50d, 50e, 50f, 50g, 50h Mounting conductor patterns 60a, 60b, 60c, 60e, 60f, 60g Second connection conductor pattern
90 terminal conductor pattern

Claims (8)

A multilayer insulating substrate formed by laminating a plurality of magnetic layers is provided with a first magnetic layer portion and a second magnetic layer portion above and below the coil-forming magnetic layer portion. A plurality of mounting conductors for mounting semiconductor integrated circuit components are formed on the surface, and a lower main surface is a component with a built-in inductor in which a plurality of terminal conductors for connection to an external circuit are formed,
Coil conductors arranged in different magnetic layers are laminated on the coil-forming magnetic layer portion, and a laminated coil that is connected via a via hole and circulates in the vertical direction is formed.
The input terminal conductor is connected to the input mounting conductor via a first connection conductor constituted by via holes extending in the thickness direction of the multilayer insulating substrate and reaching the upper and lower main surfaces, and the output terminal conductor is the laminated layer One end of the coil is connected via a via hole, the other end of the laminated coil is connected to an output mounting electrode,
1. A component with a built-in inductor, wherein the thickness of the first magnetic layer portion is greater than the thickness of the other second magnetic layer portion.   The output terminal conductor is connected to a conductor pattern for mounting an output capacitor formed on the upper main surface of the multilayer insulating substrate via another first connection conductor. Inductor built-in components.   3. The input terminal conductor is connected to a conductor pattern for mounting an input capacitor formed on the upper main surface of the multilayer insulating substrate via the first connection conductor. 4. Inductor built-in parts.   4. The inductor built-in component according to claim 3, wherein the other end of the multilayer coil is further connected to another mounting conductor via the other first connection conductor.   The grounding conductor is widely formed on a lower main surface of the multilayer insulating substrate, and the grounding conductor is connected to a grounding mounting conductor via another first connection conductor. The inductor built-in component according to any one of 1 to 4.   A DC-DC converter comprising the inductor built-in component according to claim 1 and a semiconductor integrated circuit component, wherein the semiconductor integrated circuit component is mounted on a mounting conductor of the inductor built-in component. DC-DC converter. A DC-DC converter comprising the inductor built-in component according to claim 2, a semiconductor integrated circuit component, and a capacitor,
The semiconductor integrated circuit component is mounted on a mounting conductor of the inductor built-in component,
A DC-DC converter characterized in that an output capacitor is mounted on a conductor pattern for mounting an output capacitor of the inductor built-in component. 8. The DC-DC converter according to claim 7, wherein an input capacitor is mounted on the conductor pattern for mounting the inductor built-in component input capacitor.

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