JP5617614B2 - Coil built-in board - Google Patents

Description

  The present invention relates to a coil-embedded substrate that includes a coil inside and is applied to, for example, a DC-DC converter module.

  Patent Document 1 discloses a DC-DC converter module in which a coil is formed inside a substrate. FIG. 1 is a cross-sectional view of a multilayer ceramic electronic component (DC-DC converter module) 1 disclosed in Patent Document 1. As shown in FIG. A multilayer ceramic electronic component 1 is a ceramic multilayer having a multilayer structure including a base layer 2 made of ferrite ceramic and surface layers 3 and 4 respectively arranged on upper and lower main surfaces of the base layer 2 and made of ferrite ceramic. A body 5 is provided. The multilayer ceramic electronic component 1 includes a conductor pattern provided inside and outside the ceramic multilayer body 5. The conductor pattern is roughly classified into an in-plane wiring conductor 6, a surface conductor film 7, and an interlayer connection conductor 8. The in-plane wiring conductor 6 and the surface conductor film 7 are formed on the main surface of the ceramic green sheet that is laminated to form the base material layer 2 or the surface layers 3 and 4 in the process of manufacturing the multilayer ceramic electronic component 1. The interlayer connection conductor 8 is provided so as to penetrate the ceramic green sheet in the thickness direction. The in-plane wiring conductor 6 is formed inside the ceramic laminate 5.

  A coil conductor 9 is formed inside the base material layer 2 by a specific in-plane wiring conductor 6 and a specific interlayer connection conductor 8. The multilayer ceramic electronic component 1 constitutes, for example, a DC-DC converter, and surface-mounted electronic components 10 and 11 are mounted on the main surface facing outward of the surface layer 3. The electronic component 10 is, for example, an IC chip, and is electrically connected to the surface conductor film 7 formed on the main surface facing outward of the surface layer 3 via the solder bumps 12. The other electronic component 11 is, for example, a chip capacitor, and is electrically connected via a solder 13 to a surface conductor film 7 formed on the main surface facing outward of the surface layer 3. The surface conductor film 7 formed on the main surface facing outward of the lower surface layer 4 is used as a terminal electrode when the multilayer ceramic electronic component 1 is mounted on a mother substrate (not shown).

International Publication No. 2007/148556

  When there are various wirings, shield conductors, etc. around the coil conductor, if the distance between these various wirings, shield conductor, and coil conductor is non-uniform, the magnetic field due to the coil conductor is obstructed by the surrounding wiring and shield conductor. Thus, an ideal magnetic field distribution cannot be realized. As a result, the electrical characteristics of the inductor deteriorate. That is, when the obtained inductance value is reduced and the wire width of the coil conductor is reduced to increase the number of turns in order to obtain a required inductance value, the Q value and the DC resistance value deteriorate.

  In the conventional coil-embedded substrate used in the DC-DC converter module shown in FIG. 1, the coil conductor 9 is disposed at the center height position of the base material layer 2, so that the surface from the formation layer of the coil conductor 9 The thicknesses up to the layers 3 and 4 are equal, and the concentration (bias) of the magnetic flux density around the coil conductor 9 is small.

  However, if the base material layer 2 shown in FIG. 1 becomes thin with the downsizing of the module including the coil built-in substrate, the formation layer of the coil conductor 9 cannot always be arranged at the center height position of the base material layer 2. . For example, in consideration of the influence of the wiring conductor (such as the interlayer connection conductor 8) in the base material layer 2, it is also necessary to arrange the formation layer of the coil conductor 9 above or below the center height position.

  Accordingly, an object of the present invention is to provide a coil-embedded substrate in which the formation layer of the coil conductor 9 is disposed at a position deviated from the center height and the deterioration of the electrical characteristics of the coil conductor as an inductor is suppressed.

(1) The present invention provides a first magnetic layer in which a coil conductor and a magnetic body are laminated, a first surface layer formed on the first main surface side and including a surface conductor film, and a second main surface side. A coil-embedded substrate comprising: a second surface layer including a surface conductor film;
A second magnetic layer is provided between the coil conductor forming layer that is a layer including the coil conductor and the first surface layer,
The distance between the coil conductor forming layer and the first surface layer is A, the distance between the coil conductor forming layer and the second surface layer is B, the magnetic permeability of the first magnetic layer is μ1, and the second magnetic property is When the magnetic permeability of the body layer is expressed by μ2, the relationship is A <B and μ1 <μ2.

(2) The present invention provides a first magnetic layer in which a coil conductor and a magnetic body are laminated, a first surface layer formed on the first main surface side and including a surface conductor film, and a second main surface side. A coil-embedded substrate comprising: a second surface layer including a surface conductor film;
A third magnetic layer is provided between the coil conductor forming layer that is a layer including the coil conductor and the second surface layer,
The distance between the coil conductor forming layer and the first surface layer is A, the distance between the coil conductor forming layer and the second surface layer is B, the magnetic permeability of the first magnetic layer is μ1, and the third magnetic property is When the magnetic permeability of the body layer is expressed by μ3, the relationship is A <B and μ3 <μ1.

(3) The present invention provides a first magnetic layer in which a coil conductor and a magnetic body are laminated,
In the coil-embedded substrate provided with the first surface layer formed on the first main surface side and including the surface conductor film, and the second surface layer formed on the second main surface side and including the surface conductor film,
A second magnetic layer is provided between the coil conductor forming layer that is a layer including the coil conductor and the first surface layer,
A third magnetic layer is provided between the coil conductor forming layer that is a layer including the coil conductor and the second surface layer,
The distance between the coil conductor forming layer and the first surface layer is A, the distance between the coil conductor forming layer and the second surface layer is B, the magnetic permeability of the first magnetic layer is μ1, and the second magnetic property is When the magnetic permeability of the body layer is expressed by μ2 and the magnetic permeability of the third magnetic body layer is expressed by μ3, the relationship is A <B and μ3 <μ1 <μ2.

(4) In (1) or (3), a fourth magnetic body is provided between the coil conductor forming layer and the second magnetic layer, or between the first surface layer and the second magnetic layer. When the magnetic permeability of the fourth magnetic layer is expressed by μ4, it is preferable that μ1 <μ2 <μ4.

(5) In (2) or (3), a fifth magnetic body is provided between the coil conductor forming layer and the third magnetic layer, or between the second surface layer and the third magnetic layer. When the magnetic permeability of the fifth magnetic layer is expressed by μ5, it is preferable that μ5 <μ3 <μ1.

  According to the present invention, in accordance with the wiring conductor around the coil conductor by the wiring design in the substrate, the magnetic flux generated by the coil conductor can be controlled to form a coil that generates a more uniform magnetic field, the DC resistance is low, and the Q value is low. A high coil built-in substrate can be configured.

FIG. 1 is a cross-sectional view of a multilayer ceramic electronic component disclosed in Patent Document 1. In FIG. FIG. 2 is a cross-sectional view showing the configuration of the coil-embedded substrate of the first embodiment and a DC-DC converter module including the same. FIG. 3 is a cross-sectional view showing a configuration of a coil-embedded substrate and a DC-DC converter module including the same according to the second embodiment. 4A, FIG. 4B, and FIG. 4C show the three types of coil-embedded substrates 103A, 103B, and 103C of the third embodiment, and DC-DC converter modules 113A, 113B, and 113C including the same. It is sectional drawing which shows this structure. 5A, FIG. 5B, and FIG. 5C show three types of coil-embedded substrates 104A, 104B, and 104C of the fourth embodiment, and DC-DC converter modules 114A, 114B, and 114C including the same. It is sectional drawing which shows this structure. FIGS. 6A, 6B, and 6C show three types of coil-embedded substrates 105A, 105B, and 105C of the fifth embodiment, and DC-DC converter modules 115A, 115B, and 115C having the same. It is sectional drawing which shows this structure. FIGS. 7A and 7B are cross-sectional views showing configurations of the two types of coil-embedded substrates 106A and 106B of the sixth embodiment, and DC-DC converter modules 116A and 116B including them. FIGS. 8A and 8B are cross-sectional views showing the configurations of the two types of coil-embedded substrates 107A and 107B of the seventh embodiment and DC-DC converter modules 117A and 117B provided with them. FIG. 9 is a cross-sectional view showing the configuration of the coil-embedded substrate 108 of the eighth embodiment and the DC-DC converter module 118 having them.

<< First Embodiment >>
FIG. 2 is a cross-sectional view showing the configuration of the coil-embedded substrate of the first embodiment and a DC-DC converter module including the same. The DC-DC converter module 111 includes a coil built-in substrate 101 and electronic components (11 and the like) mounted on the upper surface of the coil built-in substrate 101. Usually, a plurality of electronic components are mounted on the upper surface of the coil-embedded substrate 101, but FIG. 2 shows only one of these electronic components (electronic component 11).

  The coil built-in substrate 101 is formed on the first magnetic body layer 21 in which the coil conductor 9 and the magnetic body are laminated, on the electronic component mounting surface side (first main surface side), and includes the first surface conductor film 7. A surface layer 31 and a second surface layer 32 including a surface conductor film 7 are provided on the mounting surface side (second main surface side) with respect to the wiring board to be mounted.

The first magnetic layer 21, the first surface layer 31, and the second surface layer 32 are provided with in-plane wiring conductors 6 and interlayer connection conductors 8 as necessary.
A second magnetic layer 22 is provided between the coil conductor forming layer 21 </ b> C, which is a layer including the coil conductor 9, and the first surface layer 31.
Here, the interval between the coil conductor forming layer 21C and the first surface layer 31 is A, the interval between the coil conductor forming layer 21C and the second surface layer 32 is B, and the magnetic permeability of the first magnetic layer 21 is μ1, When the magnetic permeability of the second magnetic layer 22 is expressed by μ2, there are relationships of A <B and μ1 <μ2.

  As described above, when the coil conductor forming layer 21C is closer to the electronic component mounting surface side (first main surface side), the first magnetic body is interposed between the coil conductor forming layer 21C and the first surface layer 31. By disposing the second magnetic layer 22 having a higher magnetic permeability than the layer 21, nonuniformity of the magnetic field distribution due to the narrow interval between the coil conductor forming layer 21 </ b> C and the first surface layer 31 is suppressed. Specifically, the second magnetic layer 22 guides the magnetic flux generated by the coil conductor 9 in the layer direction, and the spread of the magnetic flux to the first surface layer 31 (in the vertical direction) is suppressed. Therefore, it is difficult for eddy currents to flow through the in-plane wiring conductor 6, the surface conductor film 7, the interlayer connection conductor 8, and the like formed on the first surface layer 31. That is, it is less affected by the in-plane wiring conductor 6, the surface conductor film 7, the interlayer connection conductor 8, and the like formed on the first surface layer 31, and the deterioration of the electrical characteristics of the coil conductor 9 as the inductor is suppressed. The

  As a result, a coil that generates a more uniform magnetic field can be formed, and a substrate with a built-in coil having a low DC resistance and a high Q value can be configured.

  The coil-embedded substrate 101 is manufactured by a green sheet process. The first magnetic layer 21 and the second magnetic layer 22 are, for example, magnetic ferrites composed mainly of Fe—Ni—Zn—Cu-based oxides. Before firing, it is a laminate of these ceramic green sheets. The first surface layer 31 and the second surface layer 32 are non-magnetic ferrites mainly composed of Fe-Zn-Cu oxide. Before firing, it is a laminate of this ceramic green sheet.

  The interlayer connection conductor 8 is a sintered body of conductive paste. Before firing, a conductive paste (unsintered interlayer connection conductor) filled in through holes formed in a predetermined ceramic green sheet. The coil conductor 9, the in-plane wiring conductor 6, the surface conductor film 7, and the interlayer connection conductor 8 are sintered bodies of conductive paste. Before firing, the conductive paste is printed on a predetermined ceramic green sheet. The conductive metal contained in these conductive pastes is preferably composed mainly of silver or silver / palladium.

<< Second Embodiment >>
FIG. 3 is a cross-sectional view showing a configuration of a coil-embedded substrate and a DC-DC converter module including the same according to the second embodiment. The DC-DC converter module 112 includes a coil built-in substrate 102 and electronic components (11 and the like) mounted on the upper surface of the coil built-in substrate 102.

The coil-embedded substrate 102 is formed on the first magnetic layer 21 in which the coil conductor 9 and the magnetic body are laminated, on the electronic component mounting surface side (first main surface side), and includes the surface conductor film 7. A surface layer 31 and a second surface layer 32 including a surface conductor film 7 are provided on the mounting surface side (second main surface side) with respect to the wiring board to be mounted.
A third magnetic layer 23 is provided between the coil conductor forming layer 21 </ b> C that is a layer including the coil conductor 9 and the second surface layer 32.

  Here, the interval between the coil conductor forming layer 21C and the first surface layer 31 is A, the interval between the coil conductor forming layer 21C and the second surface layer 32 is B, and the magnetic permeability of the first magnetic layer 21 is μ1, When the magnetic permeability of the third magnetic layer 23 is expressed by μ3, A <B and μ3 <μ1 are satisfied.

  As described above, when the coil conductor forming layer 21C is closer to the electronic component mounting surface side (first main surface side), the first magnetic body is interposed between the coil conductor forming layer 21C and the second surface layer 32. By disposing the third magnetic layer 23 having a lower magnetic permeability than the layer 21, nonuniformity of the magnetic field distribution due to the wide interval between the coil conductor forming layer 21C and the second surface layer 32 is suppressed. Specifically, in the third magnetic layer 23, the transmission of the magnetic flux by the coil conductor 9 is suppressed, and the magnetic field concentrates almost evenly above and below the coil conductor forming layer 21C. Therefore, it is difficult for eddy currents to flow through the in-plane wiring conductor 6, the surface conductor film 7, the interlayer connection conductor 8, and the like formed on the second surface layer 32. That is, it is less affected by the in-plane wiring conductor 6, the surface conductor film 7, the interlayer connection conductor 8, and the like formed on the second surface layer 32, and deterioration of the electrical characteristics of the coil conductor 9 as an inductor is suppressed. The

  In addition, since ferrite having a small magnetic permeability generally has a relatively small dielectric loss tangent (tan δ), disposing a third magnetic layer 23 having a small magnetic permeability reduces the dielectric loss, and also by this. The Q value can be increased.

  As a result, an inductor that generates a more uniform magnetic field can be formed, and a substrate with a built-in coil having a low DC resistance and a high Q value can be configured.

<< Third Embodiment >>
4A, FIG. 4B, and FIG. 4C show the three types of coil-embedded substrates 103A, 103B, and 103C of the third embodiment, and DC-DC converter modules 113A, 113B, and 113C including the same. It is sectional drawing which shows this structure. These DC-DC converter modules 113A, 113B, 113C are composed of coil-embedded substrates 103A, 103B, 103C and electronic components (11 etc.) mounted on the upper surfaces of these coil-embedded substrates 103A, 103B, 103C. ing.

  The arrangement of the second magnetic layer 22 is different from the coil-embedded substrates 103A, 103B, and 103C and the coil-embedded substrate 101 shown in FIG. In the first embodiment, the example in which the second magnetic layer 22 is simply disposed between the coil conductor forming layer 21C and the first surface layer 31 is shown. However, in the coil built-in substrate 103A in FIG. The second magnetic layer 22 is disposed at a position near the first surface layer 31 or a position in contact with the first surface layer 31. In the coil-embedded substrate 103B in FIG. 4B, the second magnetic layer 22 is disposed at a position near the coil conductor forming layer 21C or a position in contact with the coil conductor forming layer 21C. Furthermore, in the coil-embedded substrate 103C of FIG. 4C, the second magnetic layer 22 is disposed over the entire area between the coil conductor forming layer 21C and the first surface layer 31 in the second magnetic layer 22. Yes.

  Thus, the magnetic flux by the coil conductor 9 is controlled by appropriately determining the thickness and position of the second magnetic layer 22, and the uniformity of the magnetic field distribution can be further enhanced.

<< Fourth Embodiment >>
5A, FIG. 5B, and FIG. 5C show three types of coil-embedded substrates 104A, 104B, and 104C of the fourth embodiment, and DC-DC converter modules 114A, 114B, and 114C including the same. It is sectional drawing which shows this structure. These DC-DC converter modules 114A, 114B, and 114C are configured by coil-embedded substrates 104A, 104B, and 104C and electronic components (11 and the like) mounted on the upper surfaces of these coil-embedded substrates 104A, 104B, and 104C. ing.

  The arrangement of the third magnetic layer 23 is different from the coil-embedded substrates 104A, 104B, 104C and the coil-embedded substrate 102 shown in FIG. 3 in the second embodiment. In the second embodiment, an example in which the third magnetic layer 23 is simply disposed between the coil conductor forming layer 21C and the second surface layer 32 is shown. However, in the coil built-in substrate 104A in FIG. The third magnetic layer 23 is disposed at a position near the second surface layer 32 or a position in contact with the second surface layer 32. In the coil-embedded substrate 104B of FIG. 5B, the third magnetic layer 23 is disposed at a position near the coil conductor forming layer 21C or a position in contact with the coil conductor forming layer 21C. Further, in the coil-embedded substrate 104C of FIG. 5C, the third magnetic layer 23 is disposed over the entire area between the coil conductor forming layer 21C and the second surface layer 32. Yes.

  Thus, the magnetic flux by the coil conductor 9 is controlled by appropriately determining the thickness and position of the third magnetic layer 23, and the uniformity of the magnetic field distribution can be further enhanced.

<< Fifth Embodiment >>
FIGS. 6A, 6B, and 6C show three types of coil-embedded substrates 105A, 105B, and 105C of the fifth embodiment, and DC-DC converter modules 115A, 115B, and 115C having the same. It is sectional drawing which shows this structure. These DC-DC converter modules 115A, 115B, and 115C are configured by coil-embedded substrates 105A, 105B, and 105C and electronic components (11 and the like) mounted on the upper surfaces of these coil-embedded substrates 105A, 105B, and 105C. ing.

  In the coil-embedded substrates 105A, 105B, and 105C of the fifth embodiment, the second magnetic body layer 22 is disposed between the coil conductor forming layer 21C and the first surface layer 31, and the coil conductor forming layer 21C and A third magnetic layer 23 is disposed between the second surface layer 32 and the second surface layer 32.

  In the coil built-in substrate 105 </ b> A of FIG. 6A, the second magnetic layer 22 is disposed at a position near the first surface layer 31 or a position in contact with the first surface layer 31. The third magnetic layer 23 is disposed at a position near the second surface layer 32 or a position in contact with the second surface layer 32.

  In the coil-embedded substrate 105B of FIG. 6B, the second magnetic layer 22 is disposed at a position near the coil conductor forming layer 21C or a position in contact with the coil conductor forming layer 21C. Further, the third magnetic layer 23 is disposed at a position near the coil conductor forming layer 21C or a position in contact with the coil conductor forming layer 21C.

  In the coil built-in substrate 105 </ b> C in FIG. 6C, the second magnetic layer 22 is disposed over the entirety between the coil conductor forming layer 21 </ b> C and the first surface layer 31. The third magnetic layer 23 is disposed over the entirety between the coil conductor forming layer 21 </ b> C and the second surface layer 32.

  Here, the interval between the coil conductor forming layer 21C and the first surface layer 31 is A, the interval between the coil conductor forming layer 21C and the second surface layer 32 is B, and the magnetic permeability of the first magnetic layer 21 is μ1, When the magnetic permeability of the second magnetic layer 22 is expressed by μ2 and the magnetic permeability of the third magnetic layer 23 is expressed by μ3, A <B and μ3 <μ1 <μ2 are satisfied.

  As described above, the second magnetic layer 22 is provided between the coil conductor forming layer 21C and the first surface layer 31, and the third magnetic layer 23 is provided between the coil conductor forming layer 21C and the second surface layer 32. By providing each of them, a conductor close to the coil conductor forming layer 21C (the in-plane wiring conductor 6, the surface conductor film 7 and the interlayer connection conductor 8 formed on the first surface layer 31) and a distant conductor (the second surface layer 32). The in-plane wiring conductor 6, the surface conductor film 7, the interlayer connection conductor 8 and the like formed in the above can be more effectively suppressed from adverse effects due to eddy current loss.

  Further, by appropriately determining the thickness and position of the second magnetic layer 22 and the third magnetic layer 23, the magnetic flux by the coil conductor 9 is controlled, and the uniformity of the magnetic field distribution can be further improved.

<< Sixth Embodiment >>
FIGS. 7A and 7B are cross-sectional views showing configurations of the two types of coil-embedded substrates 106A and 106B of the sixth embodiment, and DC-DC converter modules 116A and 116B including them. These DC-DC converter modules 116A and 116B are configured by coil-embedded substrates 106A and 106B and electronic components (11 and the like) mounted on the upper surfaces of these coil-embedded substrates 106A and 106B.

  In the example of FIG. 7A, the fourth magnetic layer 24 is provided between the coil conductor forming layer 21 </ b> C and the second magnetic layer 22. In the example of FIG. 7B, a fourth magnetic layer 24 is provided between the first surface layer 31 and the second magnetic layer 22. 7A and 7B, the distance between the coil conductor forming layer 21C and the first surface layer 31 is A, the distance between the coil conductor forming layer 21C and the second surface layer 32 is B, When the magnetic permeability of the first magnetic layer 21 is μ1, the magnetic permeability of the second magnetic layer 22 is μ2, and the magnetic permeability of the fourth magnetic layer 24 is μ4, A <B, μ1 <μ2 < There is a relationship of μ4.

  As described above, the two conductor layers having different magnetic permeability are arranged between the coil conductor forming layer 21C and the first surface layer 31, and the thickness, the magnetic permeability, and the positional relationship thereof are determined to thereby determine the coil conductor. The magnetic flux by 9 can be controlled, and the uniformity of the magnetic field distribution can be further improved.

<< Seventh Embodiment >>
FIGS. 8A and 8B are cross-sectional views showing the configurations of the two types of coil-embedded substrates 107A and 107B of the seventh embodiment and DC-DC converter modules 117A and 117B provided with them. These DC-DC converter modules 117A and 117B are configured by coil-embedded substrates 107A and 107B and electronic components (11 and the like) mounted on the upper surfaces of these coil-embedded substrates 107A and 107B.

  In the example of FIG. 8A, a fifth magnetic layer 25 is provided between the coil conductor forming layer 21C and the third magnetic layer 23. In the example of FIG. 8B, a fifth magnetic layer 25 is provided between the second surface layer 32 and the third magnetic layer 23. 8A and 8B, the distance between the coil conductor forming layer 21C and the first surface layer 31 is A, the distance between the coil conductor forming layer 21C and the second surface layer 32 is B, When the magnetic permeability of the first magnetic layer 21 is μ1, the magnetic permeability of the third magnetic layer 23 is μ3, and the magnetic permeability of the fifth magnetic layer 25 is μ5, A <B, μ5 <μ3 < The relationship is μ1.

  As described above, the two conductor layers having different magnetic permeability are arranged between the coil conductor forming layer 21C and the second surface layer 32, and the thickness, magnetic permeability, and positional relationship thereof are determined to thereby determine the coil conductor. The magnetic flux by 9 can be controlled, and the uniformity of the magnetic field distribution can be further improved.

<< Eighth Embodiment >>
FIG. 9 is a cross-sectional view showing the configuration of the coil-embedded substrate 108 of the eighth embodiment and the DC-DC converter module 118 having them. The DC-DC converter module 118 includes a coil built-in substrate 108 and electronic components (11 and the like) mounted on the upper surface of the coil built-in substrate 108.

  In the example of FIG. 9, the second magnetic layer 22 is provided between the coil conductor forming layer 21 </ b> C and the first surface layer 31, and between the second magnetic layer 22 and the first surface layer 31. A fourth magnetic layer 24 is provided. In addition, a third magnetic layer 23 is provided between the coil conductor forming layer 21 </ b> C and the second surface layer 32, and a fifth magnetic layer is provided between the third magnetic layer 23 and the second surface layer 32. A body layer 25 is provided.

Here, the interval between the coil conductor forming layer 21C and the first surface layer 31 is A, the interval between the coil conductor forming layer 21C and the second surface layer 32 is B, and the magnetic permeability of the first magnetic layer 21 is μ1, The magnetic permeability of the second magnetic layer 22 is μ2, the magnetic permeability of the third magnetic layer 23 is μ3, the magnetic permeability of the fourth magnetic layer 24 is μ4, and the magnetic permeability of the fifth magnetic layer 25 is In terms of μ5, A <B,
μ5 <μ3 <μ1 <μ2 <μ4 or
μ3 <μ5 <μ1 <μ2 <μ4 or
μ5 <μ3 <μ1 <μ4 <μ2 or
μ3 <μ5 <μ1 <μ4 <μ2
Are in a relationship.

  In this way, two magnetic layers having different magnetic permeability are arranged between the coil conductor forming layer 21C and the first surface layer 31 and between the second surface layer 32, respectively, and their thickness, permeability By determining the magnetic susceptibility and the positional relationship, the magnetic flux by the coil conductor 9 is controlled, and the uniformity of the magnetic field distribution can be further improved.

<< Other embodiments >>
In each of the embodiments described above, the electronic component mounting surface is the first surface layer 31 and the mounting surface is the second surface layer 32 side. Conversely, the mounting surface is the first surface layer 31 and the electronic component mounting surface. May be the second surface layer 32. Even in such a case, when the distance between the coil conductor forming layer 21C and the first surface layer is represented by A and the distance between the coil conductor forming layer 21C and the second surface layer is represented by B, The description shown in the embodiment is applied as it is.

6 ... In-plane wiring conductor 7 ... Surface conductor film 8 ... Interlayer connection conductor 9 ... Coil conductor 11 ... Electronic component 21 ... First magnetic layer 21C ... Coil conductor forming layer 22 ... Second magnetic layer 23 ... Third Magnetic layer 24 ... Fourth magnetic layer 25 ... Fifth magnetic layer 31 ... First surface layer 32 ... Second surface layers 101, 102, 108 ... Coil built-in substrates 103A, 103B, 103C ... Coil built-in substrates 104A, 104B, 104C ... Coil built-in substrates 105A, 105B, 105C ... Coil built-in substrates 106A, 106B ... Coil built-in substrates 107A, 107B ... Coil built-in substrates 111, 112, 118 ... DC-DC converter modules 113A, 113B, 113C ... DC DC converter modules 114A, 114B, 114C ... DC-DC converter modules 115A, 115B, 11 C ... DC-DC converter module 116A, 116B ... DC-DC converter module 117A, 117B ... DC-DC converter module

Claims (5)

A first magnetic layer in which a coil conductor and a magnetic body are laminated;
A first surface layer formed on the first main surface side and including a surface conductor film;
A second surface layer formed on the second main surface side and including a surface conductor film;
In the coil-embedded substrate with
A second magnetic layer made of a magnetic material between a coil conductor forming layer that is a layer containing the coil conductor and the first surface layer;
The distance between the coil conductor forming layer and the first surface layer is A, the distance between the coil conductor forming layer and the second surface layer is B, the magnetic permeability of the first magnetic layer is μ1, and the second magnetic property is A substrate with a built-in coil, wherein the magnetic permeability of the body layer is expressed by μ2, and A <B and μ1 <μ2. A first magnetic layer in which a coil conductor and a magnetic body are laminated;
A first surface layer formed on the first main surface side and including a surface conductor film;
A second surface layer formed on the second main surface side and including a surface conductor film;
In the coil-embedded substrate with
A third magnetic layer is provided between the coil conductor forming layer that is a layer including the coil conductor and the second surface layer,
The distance between the coil conductor forming layer and the first surface layer is A, the distance between the coil conductor forming layer and the second surface layer is B, the magnetic permeability of the first magnetic layer is μ1, and the third magnetic property is A substrate with a built-in coil, wherein the magnetic permeability of the body layer is expressed by μ3, wherein A <B and μ3 <μ1. A first magnetic layer in which a coil conductor and a magnetic body are laminated;
A first surface layer formed on the first main surface side and including a surface conductor film;
A second surface layer formed on the second main surface side and including a surface conductor film;
In the coil-embedded substrate with
A second magnetic layer is provided between the coil conductor forming layer that is a layer including the coil conductor and the first surface layer,
A third magnetic layer is provided between the coil conductor forming layer that is a layer including the coil conductor and the second surface layer,
The distance between the coil conductor forming layer and the first surface layer is A, the distance between the coil conductor forming layer and the second surface layer is B, the magnetic permeability of the first magnetic layer is μ1, and the second magnetic property is A coil-embedded substrate characterized in that A <B and μ3 <μ1 <μ2 when the magnetic permeability of the body layer is expressed by μ2 and the magnetic permeability of the third magnetic layer is expressed by μ3. A fourth magnetic layer is provided between the coil conductor forming layer and the second magnetic layer, or between the first surface layer and the second magnetic layer;
4. The coil-embedded substrate according to claim 1, wherein when the magnetic permeability of the fourth magnetic layer is expressed by μ4, a relationship of μ1 <μ2 <μ4 is satisfied. A fifth magnetic layer is provided between the coil conductor forming layer and the third magnetic layer, or between the second surface layer and the third magnetic layer,
4. The coil-embedded substrate according to claim 2, wherein the magnetic permeability of the fifth magnetic layer is expressed by μ5, and a relationship of μ5 <μ3 <μ1 is satisfied.

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