WO2018147398A1 - Inductor built into substrate - Google Patents

Inductor built into substrate Download PDF

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Publication number
WO2018147398A1
WO2018147398A1 PCT/JP2018/004507 JP2018004507W WO2018147398A1 WO 2018147398 A1 WO2018147398 A1 WO 2018147398A1 JP 2018004507 W JP2018004507 W JP 2018004507W WO 2018147398 A1 WO2018147398 A1 WO 2018147398A1
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Prior art keywords
gap
magnetic body
magnetic
substrate
multilayer substrate
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PCT/JP2018/004507
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French (fr)
Japanese (ja)
Inventor
武志 東
修平 安嶋
明石　裕樹
石井　卓也
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パナソニックＩｐマネジメント株式会社
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Publication of WO2018147398A1 publication Critical patent/WO2018147398A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F17/00—Fixed inductances of the signal type 
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F17/00—Fixed inductances of the signal type 
    • H01F17/04—Fixed inductances of the signal type  with magnetic core
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/24—Magnetic cores

Definitions

  • This disclosure relates to a substrate built-in type inductor such as a transformer and a coil incorporated in a multilayer substrate.
  • Inductors with built-in substrates such as transformers and coils built into a multilayer board have windings built into the multilayer board, so high frequency of several hundred kHz to several MHz, for example, to reduce the size and increase the efficiency of power supply modules It is used as a thin coil or thin transformer that operates in
  • FIG. 9 is a cross-sectional view of the substrate built-in type inductor described in Patent Document 1.
  • a multilayer substrate 901 includes a substrate 901a having winding patterns 905b and 905c printed on both sides surrounding the positions of the core insertion holes 902, 903, a substrate 901b having a winding pattern 905a printed on the lower surface, and an upper surface.
  • a substrate 901c printed with a winding pattern 905d is stacked and bonded.
  • the core 907 includes a U-shaped core 907a having magnetic legs to be inserted into the core insertion holes 902 and 903 and an I-shaped core 907b that connects the magnetic legs to each other, and is fixed by a core clamp 908.
  • the winding patterns of the respective layers are connected through vias.
  • inductors such as coils and transformers are provided with a gap in the core for preventing magnetic saturation and adjusting the inductance value.
  • the U-type core 907a and the I-type core 907b are not in close contact with each other, and a gap is provided at the junction.
  • an eddy current is generated in the winding pattern. This eddy current is larger as the operating frequency is higher and the distance between the gap and the winding pattern is shorter, which causes heat generation and efficiency deterioration of the winding.
  • the present disclosure is intended to provide a highly efficient substrate-embedded inductor that suppresses heat generation and efficiency deterioration of the winding due to eddy currents caused by leakage magnetic flux from the gap.
  • a substrate-embedded inductor has a plurality of core insertion holes, and is a multilayer substrate composed of a plurality of insulating layers in which a winding pattern is installed around at least one core insertion hole. And a core made of at least a first magnetic body and a second magnetic body, which constitutes a closed magnetic circuit with the multilayer substrate interposed therebetween via the core insertion hole, and the first magnetic body and the second magnetic body These magnetic bodies are opposed to each other with a gap having a predetermined length, and the shortest spatial distance between the gap and the winding pattern is not less than a predetermined value.
  • the leakage magnetic flux generated from the core gap and intermingled with the winding pattern is reduced, so that eddy current is reduced, and heat generation and efficiency deterioration can be suppressed.
  • FIG. 1 is a cross-sectional view illustrating a configuration example of a substrate-embedded inductor according to the first embodiment.
  • FIG. 2 is a diagram illustrating simulation results of the distance from the center of the multilayer substrate to the gap and eddy current loss.
  • FIG. 3 is an enlarged view of the vicinity of the gap in the broken line frame A1 of FIG.
  • FIG. 4 is a cross-sectional view of the substrate built-in inductor according to the second embodiment.
  • FIG. 5 is a cross-sectional view of the substrate-embedded inductor according to the third embodiment.
  • FIG. 6 is a cross-sectional view of another substrate-embedded inductor according to the third embodiment.
  • FIG. 7 is a cross-sectional view of the substrate built-in type inductor according to the fourth embodiment.
  • FIG. 8A is a cross-sectional view of a board built-in inductor according to a first modification of the fourth embodiment.
  • FIG. 8B is a cross-sectional view of the board built-in inductor according to the second modification of the fourth embodiment.
  • FIG. 8C is a cross-sectional view of the board built-in inductor according to the third modification of the fourth embodiment.
  • FIG. 8D is a cross-sectional view of the substrate built-in inductor according to the fourth modification example of the fourth embodiment.
  • FIG. 8E is a cross-sectional view of the substrate built-in inductor according to the fifth modification example of the fourth embodiment.
  • FIG. 9 is a cross-sectional view of the substrate built-in inductor described in Patent Document 1. In FIG.
  • FIG. 1 is a cross-sectional view showing a configuration example of a substrate built-in inductor according to the first embodiment.
  • 1 includes a multilayer substrate 1, core insertion holes 2 and 3 provided in the multilayer substrate 1, and a core 7.
  • the multilayer substrate 1 a plurality of substrate layers on which wiring conductors 5 are printed are stacked on an insulating plate 4.
  • One of the outermost layers (here, the lowermost layer) has wiring conductors 5 printed on both surfaces of the insulating plate 4.
  • the printed wiring conductor 5 layer is referred to as a wiring layer.
  • the multilayer substrate 1 basically has a laminated structure of wiring layer (layer of wiring conductor 5) -insulating plate 4-wiring layer --- insulating plate 4-wiring layer.
  • the multilayer substrate 1 has one or more insulating plates 4 and two or more wiring layers.
  • the core insertion holes 2 and 3 hold the core 7 inserted in the multilayer substrate 1.
  • the core 7 is made of a ferromagnetic material and includes at least a first magnetic material 7a and a second magnetic material 7b, and constitutes a closed magnetic circuit with the multilayer substrate 1 interposed therebetween.
  • the first magnetic body 7a is a U-shaped ferromagnetic body having two magnetic legs.
  • the second magnetic body 7b is an I-type ferromagnetic body.
  • Both magnetic legs of the first magnetic body 7a are inserted into the core insertion hole 2 and the core insertion hole 3 from the upper surface of the multilayer substrate 1 and held.
  • an I-type second magnetic body 7b is provided on the lower surface side of the multilayer substrate 1.
  • the first magnetic body 7a and the second magnetic body 7b are combined to constitute the core 7.
  • the I-type second magnetic body 7b can be replaced with a U-type magnetic body.
  • the wiring conductor 5 provided surrounding the positions of the core insertion holes 2 and 3 and generating a magnetic flux in the core 7 when current flows is distinguished from other wiring conductors for electrical connection and is referred to as a winding pattern. I will decide.
  • the winding pattern provided on a part or all of the layers of the multilayer substrate 1 is connected via the vias between the wiring layers, and constitutes the winding of the substrate built-in type inductor.
  • the first magnetic body 7a and the second magnetic body 7b are not in close contact with each other, and a gap 9a is provided at the junction.
  • the gap 9a is provided to prevent magnetic saturation and to adjust the inductance value.
  • insulating paper or the like is sandwiched between the gaps 9a.
  • the present inventors have analyzed the relationship between the distance between the gap 9a and the winding pattern and the loss due to eddy current for the substrate built-in type inductor designed under specific conditions by electromagnetic field simulation.
  • FIG. 2 is a diagram showing a simulation result of the distance from the center of the multilayer substrate 1 to the gap 9a and the eddy current loss.
  • the multilayer substrate 1 is provided with a winding pattern on all layers, a pair of U-shaped cores is used, the thickness of the gap 9a is fixed to 0.7 mm, and both magnetic legs are changed to change the position of the gap 9a. Changed.
  • the horizontal axis indicates the distance X from the center of the multilayer substrate 1 to the gap 9a.
  • the vertical axis shows the ratio of eddy current loss to the maximum value of eddy current loss.
  • FIG. 3 is an enlarged view of the vicinity of the gap 9a in the broken line frame A1 of FIG.
  • the winding pattern has a distance of 0.5 mm from the core insertion hole 3, and the spatial distance to the gap 9a is about 0.7 mm, which is the same as the length of the gap 9a.
  • the shortest spatial distance between the winding pattern and the gap 9a is set to be equal to or longer than the length of the gap 9a, whereby the winding is caused by the leakage magnetic flux from the gap 9a.
  • the eddy current generated in the pattern can be suppressed, and the eddy current loss can be reduced to a level where there is no problem in actual use.
  • a gap 9a is provided at a position away from the lower surface of the multilayer substrate 1, and the vertical distance from the lower surface to the gap 9a is set to be equal to or greater than the thickness of the gap 9a. That's fine.
  • the length of both magnetic legs of the first magnetic body 7a may be equal to or greater than the sum of the thickness of the multilayer substrate 1 and the length of the gap 9a.
  • the substrate-embedded inductor according to the first embodiment has a plurality of core insertion holes 2 and 3, and a plurality of winding patterns installed around at least one core insertion hole 2 or 3.
  • the first magnetic body 7a and the second magnetic body 7b are opposed to each other with a gap 9a, and the shortest spatial distance between the gap 9a and the winding pattern is equal to or greater than a predetermined value.
  • the magnetic flux intermingled with the winding pattern is reduced, leading to a reduction in eddy currents generated on the winding pattern, and suppressing heat generation and efficiency deterioration.
  • each of the first magnetic body 7a and the second magnetic body 7b has a facing surface parallel to the multilayer substrate 1, and a gap is formed between the facing surfaces. It may be a length.
  • the loss due to eddy current can be reduced by 30% or more with respect to the maximum loss.
  • the first magnetic body 7a is a U-type having two magnetic legs inserted into the plurality of core insertion holes 2, 3, and the second magnetic body 7b is an I-type or two magnetic legs.
  • the length of the two magnetic legs of the first magnetic body 7a may be equal to or greater than the sum of the thickness of the multilayer substrate 1 and the length of the gap.
  • the shortest spatial distance between the winding pattern and the gap 9a can be easily ensured to be equal to or longer than the length of the gap 9a.
  • FIG. 4 is a cross-sectional view of the substrate built-in inductor according to the second embodiment.
  • the substrate-embedded inductor of the second embodiment differs from the configuration of the substrate-embedded inductor of FIG. 1 in that the length of both magnetic legs of the first magnetic body 7a is shorter than the thickness of the multilayer substrate 1, and the position of the gap 9a Are above the lower surface of the multilayer substrate 1, that is, inside the multilayer substrate 1, and a predetermined number of layers from the lower surface of the multilayer substrate 1 have a wiring layer without a winding pattern.
  • the eddy current loss can be suppressed by setting the shortest spatial distance between the winding pattern and the gap 9a to be equal to or greater than the thickness of the gap 9a.
  • the wiring layer in contact with the upper and lower surfaces of the lowermost insulating plate does not have a winding pattern. Note that the wiring layer in contact with the upper surface of the lowermost insulating plate and the wiring layer in contact with the lower surface may each have wiring other than the winding pattern.
  • the length of both magnetic legs of the U-shaped core is shorter than the thickness of the multilayer substrate 1 by the thickness of the gap 9 a, and the second magnetic body 7 b is set to be extremely close to the lower surface of the multilayer substrate 1. It has become.
  • the layer without the winding pattern is approximately twice as long as the thickness of the gap 9a from the lower surface.
  • the distance from the gap 9a may be provided in the horizontal direction with respect to the multilayer substrate 1.
  • the winding pattern is used as the core in the layer extending from the lower surface of the multilayer substrate 1 to twice the thickness of the gap 9a. You may arrange
  • the second magnetic body 7b is in close contact with the lower surface of the multilayer substrate 1, no winding pattern is provided on the lower surface, or a separate insulating film is provided between the lower surface and the second magnetic body 7b. It is necessary to provide insulation means such as applying.
  • the first magnetic body 7a is a U-type having two magnetic legs inserted into the plurality of core insertion holes 2 and 3
  • the second magnetic body 7b is I-type or U-shaped having two magnetic legs, and the length of the magnetic legs of the first magnetic body 7a is equal to or less than the thickness of the multilayer substrate 1, and the gap 9a and the winding pattern
  • the multilayer substrate 1 has a wiring layer without a winding pattern in order to secure the shortest spatial distance more than the gap length.
  • the wiring layer without the winding pattern is a wiring layer in contact with the upper surface of the lowermost insulating plate and a wiring layer in contact with the lower surface of the lowermost insulating plate.
  • the shortest spatial distance between the winding pattern and the gap 9a can be easily ensured to be equal to or longer than the length of the gap, and the first magnetic body 7a Insulating paper or the like sandwiched between the second magnetic bodies 7b becomes unnecessary.
  • the opposing surfaces of the first magnetic body 7a and the second magnetic body 7b forming the gap 9a are substantially parallel to the multilayer substrate 1, but in this case, the gap surface (opposing The leakage flux generated from the outer periphery (four sides if rectangular) is equidistant from the winding pattern.
  • the gap surface and the multilayer substrate 1 are provided with an angle, for example, perpendicular, so that most of the leakage magnetic flux generation portion is kept away from the winding pattern.
  • FIG. 5 is a cross-sectional view of the substrate built-in type inductor according to the third embodiment.
  • the substrate-embedded inductor of the third embodiment is different from the substrate-embedded inductor of FIG. 1 in that both magnetic legs of the first magnetic body 7a are longer than the substrate thickness and the second magnetic body 7b is shortened.
  • the gap 9b has a thickness between both the magnetic legs of the first magnetic body 7a.
  • the shortest distance from the winding pattern is only one side of the rectangular gap surface, and the shortest spatial distance between the winding pattern and the gap 9b is the same as in the first embodiment.
  • the leakage magnetic flux interlinking with the winding pattern can be almost halved as compared with the first embodiment. That is, since eddy currents generated on the winding pattern are also suppressed, eddy current loss is also reduced. If the eddy current loss corresponding to the first embodiment is used, the shortest spatial distance between the winding pattern and the gap 9b can be halved compared to the first embodiment in which the thickness is equal to or greater than the thickness of the gap 9b.
  • the structure used as the gap 9c which has an oblique angle like FIG. 6, for example may be sufficient. Strictly different from the vertical case, such as the appearance of leakage magnetic flux and the effect on eddy current loss, the same effect can be obtained.
  • the first magnetic body 7a is a U-type having two magnetic legs inserted into the plurality of core insertion holes 2 and 3
  • the second magnetic body 7b is I-type, the length of the two magnetic legs of the first magnetic body 7a is longer than the thickness of the multilayer substrate 1, and the second magnetic body 7b has a gap 9b between the two magnetic legs. Sandwiched between.
  • the end of the two magnetic legs of the first magnetic body 7a and the both ends of the second magnetic body 7b form a gap 9c by opposing surfaces having an angle of 90 degrees with respect to the longitudinal direction of the multilayer substrate. May be.
  • the end portions of the two magnetic legs of the first magnetic body 7a and the both end portions of the second magnetic body 7b may form a gap 9c by a surface obliquely opposed to the multilayer substrate.
  • the leakage magnetic flux intermingled with the winding pattern can be maintained at about one half, and an effect of suppressing heat generation and efficiency deterioration can be obtained.
  • the predetermined value may be (0.5 ⁇ gap length).
  • the shortest spatial distance between the winding pattern and the gap 9b or 9c can be minimized while maintaining efficiency, and the substrate-embedded inductor can be further miniaturized.
  • FIG. 7 is a cross-sectional view of the substrate built-in inductor according to the fourth embodiment.
  • the substrate-embedded inductor according to the fourth embodiment is different from the substrate-embedded inductor shown in FIG. 1 in that a gap is provided between the upper surface of the multilayer substrate 1 and the first magnetic body 7a.
  • the length of the gap that is, the distance d1 between the upper surface of the multilayer substrate 1 and the first magnetic body 7a is a predetermined spatial distance.
  • the predetermined spatial distance may be the same as the length of the gap 9a, for example.
  • Embodiments 1 and 3 have described the configuration in which a distance corresponding to the thickness of the gap 9a is provided between the lower surface of the multilayer substrate 1 and the second magnetic body 7b.
  • the purpose of this is to suppress the eddy current generated in the winding pattern by interlinking with the leakage magnetic flux and its influence by setting the distance between the gap 9a and the winding pattern to a predetermined value or more.
  • the substrate built-in type inductor according to the fourth embodiment has a configuration in which a gap is provided on both the upper and lower surfaces of the multilayer substrate 1 with a distance from the core 7 as shown in FIG.
  • FIGS. 8A to 8E structural examples in which a gap is provided between the multilayer substrate 1 and the first magnetic body 7a are shown in FIGS. 8A to 8E, which will be described below.
  • FIG. 8A shows the first magnetic body from the upper surface of the multilayer substrate 1 by attaching a fixture 11 having a thickness corresponding to a predetermined spatial distance and a shape surrounding the magnetic legs of the first magnetic body 7a to both magnetic legs.
  • gap distance to 7a is shown.
  • the material of the fixture 11 is preferably an insulator.
  • 8B to 8D show configuration examples in which a part of the shape of the U-shaped core is changed.
  • FIG. 8B has a step 12 corresponding to the thickness of the gap 9a inside the base of both magnetic legs.
  • FIG. 8C has a step 13 outside as opposed to FIG. 8B.
  • FIG. 8D shows a configuration example having a protrusion 15 corresponding to the thickness of the gap 9a on the multilayer substrate 1 side above the first magnetic body 7a.
  • one protrusion 15 is provided at the center, but a plurality of protrusions 16 may be arranged in a balanced manner on the multilayer substrate 1 side above the first magnetic body 7a as shown in FIG. 8E.
  • the substrate-embedded inductor according to the fourth embodiment has a predetermined spatial distance d1 between the magnetic body portion excluding the two magnetic legs of the first magnetic body 7a and the multilayer substrate 1. .
  • the present disclosure is useful for a substrate-embedded inductor provided on a multilayer substrate used for miniaturization of various electronic devices.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Coils Or Transformers For Communication (AREA)
  • Parts Printed On Printed Circuit Boards (AREA)

Abstract

This inductor built into a substrate is provided with: a multilayer substrate (1) that has a plurality of core insertion holes (2 and 3) and comprises a laminate of a plurality of insulating layers (4), with coil patterns (5) being disposed around at least one core insertion hole (2 or 3); and a core (7) that consists of at least a first magnetic body (7a) and a second magnetic body (7b) and forms a closed magnetic path that sandwiches the multilayer substrate (1) via a core insertion hole (2 or 3). The first magnetic body (7a) and the second magnetic body (7b) face each other with a predetermined gap (9a) therebetween, and the shortest spatial distance between the gap (9a) and the coil patterns (5) is equal to or greater than a predetermined value.

Description

基板組込み型インダクタSubstrate embedded inductor
　本開示は多層基板に組み込まれるトランスやコイルなどの基板組込み型インダクタに関する。 This disclosure relates to a substrate built-in type inductor such as a transformer and a coil incorporated in a multilayer substrate.
　多層基板に組み込まれるトランスやコイルなどの基板組込み型インダクタは、巻線部が多層基板に内蔵されるので、電源モジュールの小型化および高効率化のため、例えば数百ｋＨｚ～数ＭＨｚの高周波数で動作する薄型コイルや薄型トランスとして用いられる。 Inductors with built-in substrates such as transformers and coils built into a multilayer board have windings built into the multilayer board, so high frequency of several hundred kHz to several MHz, for example, to reduce the size and increase the efficiency of power supply modules It is used as a thin coil or thin transformer that operates in
　図９は特許文献１に記載されている基板組込み型インダクタの断面図である。同図において、多層基板９０１は、巻線パターン９０５ｂと９０５ｃをコア挿通孔９０２，９０３の位置を囲んで両面に印刷した基板９０１ａと、下面に巻線パターン９０５ａを印刷した基板９０１ｂと、上面に巻線パターン９０５ｄを印刷した基板９０１ｃを重ねて接着して構成される。コア９０７は、コア挿通孔９０２，９０３に挿入する磁脚をもったＵ型コア９０７ａと磁脚相互を連結するＩ型コア９０７ｂよりなり、コアクランプ９０８で固定される。図示していないが各層の巻線パターンはビアを介して連結される。 FIG. 9 is a cross-sectional view of the substrate built-in type inductor described in Patent Document 1. In the figure, a multilayer substrate 901 includes a substrate 901a having winding patterns 905b and 905c printed on both sides surrounding the positions of the core insertion holes 902, 903, a substrate 901b having a winding pattern 905a printed on the lower surface, and an upper surface. A substrate 901c printed with a winding pattern 905d is stacked and bonded. The core 907 includes a U-shaped core 907a having magnetic legs to be inserted into the core insertion holes 902 and 903 and an I-shaped core 907b that connects the magnetic legs to each other, and is fixed by a core clamp 908. Although not shown, the winding patterns of the respective layers are connected through vias.
実開平０３－０４８２１４号公報Japanese Utility Model Publication No. 03-048214
　一般にコイルやトランスといったインダクタは、磁気飽和を防止するとともにインダクタンス値の調整のためコアにギャップが設けられる。上記従来のような基板組込み型インダクタも同様で、Ｕ型コア９０７ａとＩ型コア９０７ｂは密着せずに、その接合部にギャップが設けられる。ところがこのギャップ近傍において、コア９０７から漏れた高周波磁束が巻線パターンに鎖交すると、巻線パターンに渦電流が発生する。この渦電流は動作周波数が高いほど、またギャップと巻線パターンとの距離が短いほど大きく、巻線の発熱や効率劣化の原因となる。 Generally, inductors such as coils and transformers are provided with a gap in the core for preventing magnetic saturation and adjusting the inductance value. The same is true for the above-described conventional substrate-embedded inductor, and the U-type core 907a and the I-type core 907b are not in close contact with each other, and a gap is provided at the junction. However, in the vicinity of the gap, when the high-frequency magnetic flux leaking from the core 907 is linked to the winding pattern, an eddy current is generated in the winding pattern. This eddy current is larger as the operating frequency is higher and the distance between the gap and the winding pattern is shorter, which causes heat generation and efficiency deterioration of the winding.
　上記課題に鑑み本開示は、ギャップからの漏洩磁束による渦電流による、巻線の発熱および効率劣化を抑制した高効率な基板組込み型インダクタの提供を目的とする。 In view of the above problems, the present disclosure is intended to provide a highly efficient substrate-embedded inductor that suppresses heat generation and efficiency deterioration of the winding due to eddy currents caused by leakage magnetic flux from the gap.
　上記課題を解決するために基板組込み型インダクタは、複数のコア挿通孔を有し、少なくとも一つのコア挿通孔を中心に巻線パターンが設置された複数の絶縁層の積層で構成された多層基板と、前記コア挿通孔を介して前記多層基板を挟んで閉磁路を構成する、少なくとも第１の磁性体と第２の磁性体より成るコアとを備え、前記第１の磁性体と前記第２の磁性体は所定の長さのギャップを有して対向し、前記ギャップと前記巻線パターンの最短空間距離が所定値以上である。 In order to solve the above problems, a substrate-embedded inductor has a plurality of core insertion holes, and is a multilayer substrate composed of a plurality of insulating layers in which a winding pattern is installed around at least one core insertion hole. And a core made of at least a first magnetic body and a second magnetic body, which constitutes a closed magnetic circuit with the multilayer substrate interposed therebetween via the core insertion hole, and the first magnetic body and the second magnetic body These magnetic bodies are opposed to each other with a gap having a predetermined length, and the shortest spatial distance between the gap and the winding pattern is not less than a predetermined value.
　本開示に係る基板組込み型インダクタによると、コアのギャップから発生して巻線パターンに錯交する漏洩磁束が減少するので渦電流が低減し、発熱及び効率劣化を抑制することができる。 According to the substrate-embedded inductor according to the present disclosure, the leakage magnetic flux generated from the core gap and intermingled with the winding pattern is reduced, so that eddy current is reduced, and heat generation and efficiency deterioration can be suppressed.
図１は、実施の形態１に係る基板組込み型インダクタの構成例を示す断面図である。FIG. 1 is a cross-sectional view illustrating a configuration example of a substrate-embedded inductor according to the first embodiment. 図２は、多層基板の中心からギャップまでの距離と渦電流損失のシミュレーション結果を示す図である。FIG. 2 is a diagram illustrating simulation results of the distance from the center of the multilayer substrate to the gap and eddy current loss. 図３は、図１の破線枠Ａ１におけるギャップ近傍の拡大図である。FIG. 3 is an enlarged view of the vicinity of the gap in the broken line frame A1 of FIG. 図４は、実施の形態２に係る基板組込み型インダクタの断面図である。FIG. 4 is a cross-sectional view of the substrate built-in inductor according to the second embodiment. 図５は、実施の形態３に係る基板組込み型インダクタの断面図である。FIG. 5 is a cross-sectional view of the substrate-embedded inductor according to the third embodiment. 図６は、実施の形態３に係る他の基板組込み型インダクタの断面図である。FIG. 6 is a cross-sectional view of another substrate-embedded inductor according to the third embodiment. 図７は、実施の形態４に係る基板組込み型インダクタの断面図である。FIG. 7 is a cross-sectional view of the substrate built-in type inductor according to the fourth embodiment. 図８Ａは、実施の形態４の第１変形例に係る基板組込み型インダクタの断面図である。FIG. 8A is a cross-sectional view of a board built-in inductor according to a first modification of the fourth embodiment. 図８Ｂは、実施の形態４の第２変形例に係る基板組込み型インダクタの断面図である。FIG. 8B is a cross-sectional view of the board built-in inductor according to the second modification of the fourth embodiment. 図８Ｃは、実施の形態４の第３変形例に係る基板組込み型インダクタの断面図である。FIG. 8C is a cross-sectional view of the board built-in inductor according to the third modification of the fourth embodiment. 図８Ｄは、実施の形態４の第４変形例に係る基板組込み型インダクタの断面図である。FIG. 8D is a cross-sectional view of the substrate built-in inductor according to the fourth modification example of the fourth embodiment. 図８Ｅは、実施の形態４の第５変形例に係る基板組込み型インダクタの断面図である。FIG. 8E is a cross-sectional view of the substrate built-in inductor according to the fifth modification example of the fourth embodiment. 図９は、特許文献１に記載されている基板組込み型インダクタの断面図である。FIG. 9 is a cross-sectional view of the substrate built-in inductor described in Patent Document 1. In FIG.
　以下、実施の形態について、図面を参照しながら具体的に説明する。 Hereinafter, embodiments will be specifically described with reference to the drawings.
　なお、以下で説明する実施の形態は、いずれも包括的または具体的な例を示すものである。以下の実施の形態で示される数値、形状、材料、構成要素、構成要素の配置位置及び接続形態、などは、一例であり、本発明を限定する主旨ではない。また、以下の実施の形態における構成要素のうち、最上位概念を示す独立請求項に記載されていない構成要素については、任意の構成要素として説明される。 It should be noted that each of the embodiments described below shows a comprehensive or specific example. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of the constituent elements, and the like 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.
　（実施の形態１）
　以下、実施の形態１に係る基板組込み型インダクタについて、図面を参照しながら説明する。図１は実施の形態１に係る基板組込み型インダクタの構成例を示す断面図である。 (Embodiment 1)
Hereinafter, the substrate built-in inductor according to the first embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration example of a substrate built-in inductor according to the first embodiment.
　図１に示す基板組込み型インダクタは、多層基板１、多層基板１に設けられたコア挿通孔２、３、コア７を備える。 1 includes a multilayer substrate 1, core insertion holes 2 and 3 provided in the multilayer substrate 1, and a core 7.
　多層基板１は、絶縁板４の上に配線導体５を印刷した基板層が複数積み重ねられる。最外層の片方（ここでは最下層）は絶縁板４の両面に配線導体５が印刷される。印刷された配線導体５の層を配線層と呼ぶものとする。多層基板１は、配線層（配線導体５の層）－絶縁板４－配線層－・・・－絶縁板４－配線層といった積層構成を基本とする。多層基板１は、１以上の絶縁板４と２以上の配線層を有する。 In the multilayer substrate 1, a plurality of substrate layers on which wiring conductors 5 are printed are stacked on an insulating plate 4. One of the outermost layers (here, the lowermost layer) has wiring conductors 5 printed on both surfaces of the insulating plate 4. The printed wiring conductor 5 layer is referred to as a wiring layer. The multilayer substrate 1 basically has a laminated structure of wiring layer (layer of wiring conductor 5) -insulating plate 4-wiring layer --- insulating plate 4-wiring layer. The multilayer substrate 1 has one or more insulating plates 4 and two or more wiring layers.
　コア挿通孔２及び３は、多層基板１に設けられた孔挿通されたコア７を保持する。 The core insertion holes 2 and 3 hold the core 7 inserted in the multilayer substrate 1.
　コア７は、強磁性体により形成され、少なくとも第１の磁性体７ａと第２の磁性体７ｂを備え、多層基板１を挟んで閉磁路を構成する。図１では、第１の磁性体７ａは、２本の磁脚をもつＵ型の強磁性体である。第２の磁性体７ｂはＩ型の強磁性体である。 The core 7 is made of a ferromagnetic material and includes at least a first magnetic material 7a and a second magnetic material 7b, and constitutes a closed magnetic circuit with the multilayer substrate 1 interposed therebetween. In FIG. 1, the first magnetic body 7a is a U-shaped ferromagnetic body having two magnetic legs. The second magnetic body 7b is an I-type ferromagnetic body.
　第１の磁性体７ａの両磁脚が多層基板１の上面からコア挿通孔２およびコア挿通孔３に挿入され、保持されている。多層基板１の下面側ではＩ型の第２の磁性体７ｂが設けられている。第１の磁性体７ａと第２の磁性体７ｂとが組み合わさってコア７を構成する。Ｉ型の第２の磁性体７ｂは、Ｕ型の磁性体で代用することも可能とする。 Both magnetic legs of the first magnetic body 7a are inserted into the core insertion hole 2 and the core insertion hole 3 from the upper surface of the multilayer substrate 1 and held. On the lower surface side of the multilayer substrate 1, an I-type second magnetic body 7b is provided. The first magnetic body 7a and the second magnetic body 7b are combined to constitute the core 7. The I-type second magnetic body 7b can be replaced with a U-type magnetic body.
　尚、コア挿通孔２、３の位置を囲んで設けられ、電流が流れることによってコア７に磁束を発生させる配線導体５を、他の電気的接続用の配線導体と区別して巻線パターンと称することにする。多層基板１の一部もしくは全ての層に設けられた巻線パターンは、配線層間でビアを介して接続され、基板組込み型インダクタの巻線を構成する。 The wiring conductor 5 provided surrounding the positions of the core insertion holes 2 and 3 and generating a magnetic flux in the core 7 when current flows is distinguished from other wiring conductors for electrical connection and is referred to as a winding pattern. I will decide. The winding pattern provided on a part or all of the layers of the multilayer substrate 1 is connected via the vias between the wiring layers, and constitutes the winding of the substrate built-in type inductor.
　第１の磁性体７ａと第２の磁性体７ｂとは密着せずに、その接合部にギャップ９ａが設けられる。ギャップ９ａを設けるのは、磁気飽和を防止するとともにインダクタンス値の調整のためであり、通常は絶縁紙などが挟み込まれる。 The first magnetic body 7a and the second magnetic body 7b are not in close contact with each other, and a gap 9a is provided at the junction. The gap 9a is provided to prevent magnetic saturation and to adjust the inductance value. Usually, insulating paper or the like is sandwiched between the gaps 9a.
　このギャップ９ａ近傍において、コア７から漏れた高周波の漏洩磁束が巻線パターンに鎖交すると、巻線パターンに渦電流が発生する。この渦電流は動作周波数が高いほど、またギャップ９ａと巻線パターンとの距離が短いほど大きく、巻線の発熱や効率劣化の原因となる。そこで、本発明者らは特定の条件下で設計した基板組込み型インダクタについて、ギャップ９ａと巻線パターンとの距離と渦電流による損失との関係を電磁界シミュレーションによって解析した。 In the vicinity of the gap 9a, when high-frequency leakage magnetic flux leaking from the core 7 is linked to the winding pattern, an eddy current is generated in the winding pattern. The eddy current is larger as the operating frequency is higher and the distance between the gap 9a and the winding pattern is shorter, which causes heat generation of the winding and deterioration of efficiency. Therefore, the present inventors have analyzed the relationship between the distance between the gap 9a and the winding pattern and the loss due to eddy current for the substrate built-in type inductor designed under specific conditions by electromagnetic field simulation.
　図２は、多層基板１の中心からギャップ９ａまでの距離と渦電流損失のシミュレーション結果を示す図である。図２では、多層基板１には全層に巻線パターンを施し、一対のＵ型コアを用い、ギャップ９ａの厚みは０．７ｍｍに固定して両磁脚を変化することによってギャップ９ａの位置を変更した。横軸は、多層基板１の中心からギャップ９ａまでの距離Ｘを示す。縦軸は、渦電流損失の最大値に対する渦電流損失の比を示す。多層基板１の厚みが２．１ｍｍであり、ギャップ９ａの位置が多層基板１の下面（Ｘ＝１．０５ｍｍ）から離れるに従い渦電流損失は低下を始め、Ｘ＝１．５５ｍｍ、即ち多層基板１の下面から０．５ｍｍ離れると、渦電流損失の最大レベルとなる初期値の７０％まで低減されることが確認できた。多層基板１の下面からコア７までの距離が長いほど、渦電流損失は低減されることは明らかであるが、基板組込み型インダクタの大きさを勘案すると、この距離を無制限には取れない。そこで、この渦電流損失を最大値の７０％に低減することを、実用上の損失低減目標値とし、さらに条件やパラメータを変えてシミュレーションを行った。その結果、ギャップ９ａと巻線パターンとの空間距離を、およそギャップ９ａの長さ以上に離すことにより、渦電流損失が最大と成る初期値に対して７０％以下になった。図３は、図１の破線枠Ａ１におけるギャップ９ａ近傍の拡大図である。巻線パターンはコア挿通孔３から０．５ｍｍの距離を取っており、ギャップ９ａとの空間距離はギャップ９ａの長さと同じ約０．７ｍｍとなっている。 FIG. 2 is a diagram showing a simulation result of the distance from the center of the multilayer substrate 1 to the gap 9a and the eddy current loss. In FIG. 2, the multilayer substrate 1 is provided with a winding pattern on all layers, a pair of U-shaped cores is used, the thickness of the gap 9a is fixed to 0.7 mm, and both magnetic legs are changed to change the position of the gap 9a. Changed. The horizontal axis indicates the distance X from the center of the multilayer substrate 1 to the gap 9a. The vertical axis shows the ratio of eddy current loss to the maximum value of eddy current loss. The thickness of the multilayer substrate 1 is 2.1 mm, and the eddy current loss starts to decrease as the gap 9a moves away from the lower surface (X = 1.05 mm) of the multilayer substrate 1, and X = 1.55 mm, that is, the multilayer substrate 1 It was confirmed that when it was 0.5 mm away from the lower surface of the plate, it was reduced to 70% of the initial value, which is the maximum level of eddy current loss. Obviously, the longer the distance from the lower surface of the multilayer substrate 1 to the core 7, the more the eddy current loss is reduced. However, in consideration of the size of the substrate-embedded inductor, this distance cannot be made unlimited. Therefore, the simulation was performed by reducing the eddy current loss to 70% of the maximum value as a practical loss reduction target value and further changing the conditions and parameters. As a result, the spatial distance between the gap 9a and the winding pattern was set to about 70% or less of the initial value at which the eddy current loss was maximized by separating the gap 9a from the gap 9a. FIG. 3 is an enlarged view of the vicinity of the gap 9a in the broken line frame A1 of FIG. The winding pattern has a distance of 0.5 mm from the core insertion hole 3, and the spatial distance to the gap 9a is about 0.7 mm, which is the same as the length of the gap 9a.
　以上のように、実施の形態１の基板組込み型インダクタにおいては、巻線パターンとギャップ９ａとの最短空間距離をギャップ９ａの長さ以上に設定することにより、ギャップ９ａからの漏洩磁束によって巻線パターンに発生する渦電流を抑制し、渦電流損失を実使用上問題無いレベルに低減することができる。 As described above, in the substrate built-in type inductor according to the first embodiment, the shortest spatial distance between the winding pattern and the gap 9a is set to be equal to or longer than the length of the gap 9a, whereby the winding is caused by the leakage magnetic flux from the gap 9a. The eddy current generated in the pattern can be suppressed, and the eddy current loss can be reduced to a level where there is no problem in actual use.
　尚、実際の設計においては、巻線パターンとギャップ９ａとの最短空間距離をギャップ９ａの厚みに設定することは寸法公差上困難な場合がある。例えば、多層基板１の下面に巻線パターンがある場合には、多層基板１の下面から離れた位置にギャップ９ａを設け、下面からギャップ９ａまでの垂直方向距離をギャップ９ａの厚み以上に設定すればよい。換言すれば、第１の磁性体７ａの両磁脚の長さを多層基板１の厚みとギャップ９ａの長さの和以上としてもよい。 In actual design, setting the shortest spatial distance between the winding pattern and the gap 9a to the thickness of the gap 9a may be difficult due to dimensional tolerances. For example, when there is a winding pattern on the lower surface of the multilayer substrate 1, a gap 9a is provided at a position away from the lower surface of the multilayer substrate 1, and the vertical distance from the lower surface to the gap 9a is set to be equal to or greater than the thickness of the gap 9a. That's fine. In other words, the length of both magnetic legs of the first magnetic body 7a may be equal to or greater than the sum of the thickness of the multilayer substrate 1 and the length of the gap 9a.
　以上説明してきたように実施の形態１に係る基板組込み型インダクタは、複数のコア挿通孔２、３を有し、少なくとも一つのコア挿通孔２または３を中心に巻線パターンが設置された複数の絶縁層４の積層で構成された多層基板１と、複数のコア挿通孔２、３を介して多層基板１を挟んで閉磁路を構成する、少なくとも第１の磁性体７ａと第２の磁性体７ｂより成るコア７とを備え、第１の磁性体７ａと第２の磁性体７ｂはギャップ９ａを有して対向し、ギャップ９ａと巻線パターンとの最短空間距離が所定値以上である。 As described above, the substrate-embedded inductor according to the first embodiment has a plurality of core insertion holes 2 and 3, and a plurality of winding patterns installed around at least one core insertion hole 2 or 3. At least a first magnetic body 7a and a second magnetism that constitute a closed magnetic path with the multilayer substrate 1 sandwiched between the multilayer substrate 1 composed of a stack of insulating layers 4 and a plurality of core insertion holes 2, 3. And the first magnetic body 7a and the second magnetic body 7b are opposed to each other with a gap 9a, and the shortest spatial distance between the gap 9a and the winding pattern is equal to or greater than a predetermined value. .
　この構成によれば、ギャップ９ａから発生する漏洩磁束のうち、巻線パターンに錯交する磁束が減少するので、巻線パターン上に発生する渦電流の低減につながり、発熱及び効率劣化を抑制できる。 According to this configuration, of the leakage magnetic flux generated from the gap 9a, the magnetic flux intermingled with the winding pattern is reduced, leading to a reduction in eddy currents generated on the winding pattern, and suppressing heat generation and efficiency deterioration. .
　ここで、第１の磁性体７ａと第２の磁性体７ｂとはそれぞれ多層基板１に対して平行な対向面を有し、ギャップは対向面の間に形成され、上記の所定値はギャップの長さとしてもよい。 Here, each of the first magnetic body 7a and the second magnetic body 7b has a facing surface parallel to the multilayer substrate 1, and a gap is formed between the facing surfaces. It may be a length.
　この構成によれば、渦電流による損失を最大損失に対して３０%以上低減することができる。 According to this configuration, the loss due to eddy current can be reduced by 30% or more with respect to the maximum loss.
　ここで、第１の磁性体７ａは複数のコア挿通孔２、３に挿入される２本の磁脚を有するＵ型であり、第２の磁性体７ｂはＩ型もしくは２本の磁脚を有するＵ型であり、第１の磁性体７ａの２本の磁脚の長さは多層基板１の厚さとギャップの長さとの和以上であってもよい。 Here, the first magnetic body 7a is a U-type having two magnetic legs inserted into the plurality of core insertion holes 2, 3, and the second magnetic body 7b is an I-type or two magnetic legs. The length of the two magnetic legs of the first magnetic body 7a may be equal to or greater than the sum of the thickness of the multilayer substrate 1 and the length of the gap.
　この構成によれば、巻線パターンとギャップ９ａとの最短空間距離を容易にギャップ９ａの長さ以上に確保することができる。 According to this configuration, the shortest spatial distance between the winding pattern and the gap 9a can be easily ensured to be equal to or longer than the length of the gap 9a.
　（実施の形態２）
　図４は実施の形態２に係る基板組込み型インダクタの断面図である。図４において、図１に示した実施の形態１に係る基板組込み型インダクタと同じ構成要素のものについては同じ番号を付与し、その説明を省略する。実施の形態２の基板組込み型インダクタが図１の基板組込み型インダクタの構成と異なるのは、第１の磁性体７ａの両磁脚の長さが多層基板１の厚みより短く、ギャップ９ａの位置が多層基板１の下面より上方、即ち多層基板１の内部に有る点と、多層基板１の下面から所定数の層は巻線パターンのない配線層を有する点である。 (Embodiment 2)
FIG. 4 is a cross-sectional view of the substrate built-in inductor according to the second embodiment. In FIG. 4, the same components as those of the substrate built-in type inductor according to the first embodiment shown in FIG. The substrate-embedded inductor of the second embodiment differs from the configuration of the substrate-embedded inductor of FIG. 1 in that the length of both magnetic legs of the first magnetic body 7a is shorter than the thickness of the multilayer substrate 1, and the position of the gap 9a Are above the lower surface of the multilayer substrate 1, that is, inside the multilayer substrate 1, and a predetermined number of layers from the lower surface of the multilayer substrate 1 have a wiring layer without a winding pattern.
　このような構成で、巻線パターンとギャップ９ａとの最短空間距離をギャップ９ａの厚み以上にすることで渦電流損失を抑制できる。図４では、最下層の絶縁板の上面と下面に接する配線層は巻線パターンを有しない。なお、最下層の絶縁板の上面に接する配線層、および、下面に接する配線層はそれぞれ巻線パターン以外の配線を有していてもよい。 With such a configuration, the eddy current loss can be suppressed by setting the shortest spatial distance between the winding pattern and the gap 9a to be equal to or greater than the thickness of the gap 9a. In FIG. 4, the wiring layer in contact with the upper and lower surfaces of the lowermost insulating plate does not have a winding pattern. Note that the wiring layer in contact with the upper surface of the lowermost insulating plate and the wiring layer in contact with the lower surface may each have wiring other than the winding pattern.
　図４では、例えば、Ｕ型コアの両磁脚の長さは多層基板１の厚みよりもギャップ９ａの厚みだけ短く、第２の磁性体７ｂが多層基板１の下面に密着する極端な設定になっている。この場合巻線パターンの無い層は下面からギャップ９ａの厚みの約２倍の長さとなる。 In FIG. 4, for example, the length of both magnetic legs of the U-shaped core is shorter than the thickness of the multilayer substrate 1 by the thickness of the gap 9 a, and the second magnetic body 7 b is set to be extremely close to the lower surface of the multilayer substrate 1. It has become. In this case, the layer without the winding pattern is approximately twice as long as the thickness of the gap 9a from the lower surface.
　尚、ギャップ９ａからの距離は多層基板１と水平方向に設けてもよく、実施の形態２の場合、多層基板１の下面からギャップ９ａの厚みの２倍までに入る層では巻線パターンをコア挿通孔２、３からギャップ９ａの厚みだけ離して配置してもよい。但し、この場合においても第２の磁性体７ｂは多層基板１の下面に密着するので、下面には巻線パターンを設けないか、下面と第２の磁性体７ｂとの間に別途絶縁膜を施す等の絶縁手段を設ける必要がある。 The distance from the gap 9a may be provided in the horizontal direction with respect to the multilayer substrate 1. In the case of the second embodiment, the winding pattern is used as the core in the layer extending from the lower surface of the multilayer substrate 1 to twice the thickness of the gap 9a. You may arrange | position apart from the penetration holes 2 and 3 only by the thickness of the gap 9a. However, even in this case, since the second magnetic body 7b is in close contact with the lower surface of the multilayer substrate 1, no winding pattern is provided on the lower surface, or a separate insulating film is provided between the lower surface and the second magnetic body 7b. It is necessary to provide insulation means such as applying.
　以上説明してきたように実施の形態２に係る基板組込み型インダクタは、第１の磁性体７ａは複数のコア挿通孔２，３に挿入される２本の磁脚を有するＵ型であり、第２の磁性体７ｂはＩ型もしくは２本の磁脚を有するＵ型であり、第１の磁性体７ａの磁脚の長さは多層基板１の厚さ以下であり、ギャップ９ａと巻線パターンの最短空間距離をギャップの長さ以上確保する為に多層基板１は巻線パターンのない配線層を有する。巻線パターンのない配線層は、例えば図４では、最下層の絶縁板の上面に接する配線層、および、最下層の絶縁板の下面に接する配線層である。 As described above, in the substrate built-in type inductor according to the second embodiment, the first magnetic body 7a is a U-type having two magnetic legs inserted into the plurality of core insertion holes 2 and 3, The second magnetic body 7b is I-type or U-shaped having two magnetic legs, and the length of the magnetic legs of the first magnetic body 7a is equal to or less than the thickness of the multilayer substrate 1, and the gap 9a and the winding pattern The multilayer substrate 1 has a wiring layer without a winding pattern in order to secure the shortest spatial distance more than the gap length. In FIG. 4, for example, the wiring layer without the winding pattern is a wiring layer in contact with the upper surface of the lowermost insulating plate and a wiring layer in contact with the lower surface of the lowermost insulating plate.
　この構成によれば、巻線パターンとギャップ９ａの最短空間距離を容易にギャップの長さ以上確保ができることに加え、所定値以上の上記の最短空間距離を得るために第１の磁性体７ａと第２の磁性体７ｂの間に挟む絶縁紙等が不要となる。 According to this configuration, the shortest spatial distance between the winding pattern and the gap 9a can be easily ensured to be equal to or longer than the length of the gap, and the first magnetic body 7a Insulating paper or the like sandwiched between the second magnetic bodies 7b becomes unnecessary.
　（実施の形態３）
　実施の形態１と実施の形態２ではギャップ９ａを形成する第１の磁性体７ａと第２の磁性体７ｂの対向する面は多層基板１とほぼ平行であったが、この場合ギャップ面（対向する面）の外周（長方形であれば４辺）から発生した漏洩磁束はいずれも巻線パターンと等距離にある。これに対して実施の形態３では、ギャップ面と多層基板１とに角度を設ける、例えば垂直とすることによって、漏洩磁束の発生部の大半を巻線パターンから遠ざける。 (Embodiment 3)
In the first and second embodiments, the opposing surfaces of the first magnetic body 7a and the second magnetic body 7b forming the gap 9a are substantially parallel to the multilayer substrate 1, but in this case, the gap surface (opposing The leakage flux generated from the outer periphery (four sides if rectangular) is equidistant from the winding pattern. On the other hand, in the third embodiment, the gap surface and the multilayer substrate 1 are provided with an angle, for example, perpendicular, so that most of the leakage magnetic flux generation portion is kept away from the winding pattern.
　図５は実施の形態３に係る基板組込み型インダクタの断面図である。図５において、図１に示した実施の形態１に係る基板組込み型インダクタと同じ構成要素のものについては同じ番号を付与し、その説明を省略する。実施の形態３の基板組込み型インダクタが図１の基板組込み型インダクタの構成と異なるのは、第１の磁性体７ａの両磁脚を基板厚みより長くし、第２の磁性体７ｂを短くして第１の磁性体７ａの両磁脚の間にギャップ９ｂの厚みを有して挟み込まれる構成とした点である。 FIG. 5 is a cross-sectional view of the substrate built-in type inductor according to the third embodiment. In FIG. 5, the same components as those in the substrate built-in type inductor according to the first embodiment shown in FIG. The substrate-embedded inductor of the third embodiment is different from the substrate-embedded inductor of FIG. 1 in that both magnetic legs of the first magnetic body 7a are longer than the substrate thickness and the second magnetic body 7b is shortened. Thus, the gap 9b has a thickness between both the magnetic legs of the first magnetic body 7a.
　このようなコア７の構成とすることにより、巻線パターンとの最短距離にあるのは長方形のギャップ面の一辺のみとなり、実施の形態１と同様に巻線パターンとギャップ９ｂとの最短空間距離をギャップ９ｂの厚み以上とした場合は、実施の形態１に比べて巻線パターンに鎖交する漏洩磁束をほぼ半減することができる。即ち、巻線パターン上に発生する渦電流も抑制されるので、渦電流損失も低減される。また、実施の形態１相当の渦電流損失とするなら、巻線パターンとギャップ９ｂとの最短空間距離は、ギャップ９ｂの厚み以上とした実施の形態１に比べて半減することができる。 With such a configuration of the core 7, the shortest distance from the winding pattern is only one side of the rectangular gap surface, and the shortest spatial distance between the winding pattern and the gap 9b is the same as in the first embodiment. Is set to be equal to or greater than the thickness of the gap 9b, the leakage magnetic flux interlinking with the winding pattern can be almost halved as compared with the first embodiment. That is, since eddy currents generated on the winding pattern are also suppressed, eddy current loss is also reduced. If the eddy current loss corresponding to the first embodiment is used, the shortest spatial distance between the winding pattern and the gap 9b can be halved compared to the first embodiment in which the thickness is equal to or greater than the thickness of the gap 9b.
　尚、上記ではギャップ面を多層基板１と垂直になる例を示したが、例えば図６のように斜めの角度を有するギャップ９ｃとなる構成でもよい。漏洩磁束の発生の様子や渦電流損失への影響など、垂直の場合と厳密には異なるが、ほぼ同様の効果が得られる。 In addition, although the example which made the gap surface perpendicular | vertical with the multilayer substrate 1 was shown above, the structure used as the gap 9c which has an oblique angle like FIG. 6, for example may be sufficient. Strictly different from the vertical case, such as the appearance of leakage magnetic flux and the effect on eddy current loss, the same effect can be obtained.
　以上説明してきたように実施の形態３に係る基板組込み型インダクタは、第１の磁性体７ａは複数のコア挿通孔２、３に挿入される２本の磁脚を有するＵ型であり、第２の磁性体７ｂはＩ型であり、第１の磁性体７ａの２本の磁脚の長さは多層基板１の厚さより長く、第２の磁性体７ｂは２本の磁脚にギャップ９ｂを介して挟まれる。 As described above, in the substrate built-in type inductor according to the third embodiment, the first magnetic body 7a is a U-type having two magnetic legs inserted into the plurality of core insertion holes 2 and 3, The second magnetic body 7b is I-type, the length of the two magnetic legs of the first magnetic body 7a is longer than the thickness of the multilayer substrate 1, and the second magnetic body 7b has a gap 9b between the two magnetic legs. Sandwiched between.
　この構成によれば、ギャップ９ｂの一端が巻線パターンに対して遠ざかることで、巻線パターンに錯交する漏洩磁束が約２分の１に低減され、発熱及び効率劣化をさらに抑制できる。 According to this configuration, since one end of the gap 9b moves away from the winding pattern, the leakage magnetic flux intermingled with the winding pattern is reduced to about one half, and heat generation and efficiency deterioration can be further suppressed.
　ここで、第１の磁性体７ａの２本の磁脚の端部と第２の磁性体７ｂの両端部は多層基板の長手方向に対して９０度の角度をもつ対向面によりギャップ９ｃを形成してもよい。 Here, the end of the two magnetic legs of the first magnetic body 7a and the both ends of the second magnetic body 7b form a gap 9c by opposing surfaces having an angle of 90 degrees with respect to the longitudinal direction of the multilayer substrate. May be.
　ここで、第１の磁性体７ａの２本の磁脚の端部と第２の磁性体７ｂの両端部は多層基板に対して斜めに対向する面によりギャップ９ｃを形成してもよい。 Here, the end portions of the two magnetic legs of the first magnetic body 7a and the both end portions of the second magnetic body 7b may form a gap 9c by a surface obliquely opposed to the multilayer substrate.
　この構成によれば、巻線パターンに錯交する漏洩磁束を約２分の１に維持でき、発熱及び効率劣化の抑制効果が得られる。 According to this configuration, the leakage magnetic flux intermingled with the winding pattern can be maintained at about one half, and an effect of suppressing heat generation and efficiency deterioration can be obtained.
　ここで、所定値は、（０．５×ギャップの長さ）としてもよい。 Here, the predetermined value may be (0.5 × gap length).
　この構成によれば、効率を維持しながら巻線パターンとギャップ９ｂまたは９ｃの最短空間距離を最小限に抑えることができ、基板組込み型インダクタをさらに小型化できる。 According to this configuration, the shortest spatial distance between the winding pattern and the gap 9b or 9c can be minimized while maintaining efficiency, and the substrate-embedded inductor can be further miniaturized.
　（実施の形態４）
　図７は実施の形態４に係る基板組込み型インダクタの断面図である。図７において、図１に示した実施の形態１に係る基板組込み型インダクタと同じ構成要素のものについては同じ番号を付与し、その説明を省略する。実施の形態４の基板組込み型インダクタが図１の基板組込み型インダクタの構成と異なるのは、多層基板１の上面と第１の磁性体７ａとの間に隙間を設けた点である。隙間の長さ、すなわち、多層基板１の上面と第１の磁性体７ａとの間の距離ｄ１は、所定の空間距離である。所定の空間距離は、例えばギャップ９ａの長さと同じでよい。 (Embodiment 4)
FIG. 7 is a cross-sectional view of the substrate built-in inductor according to the fourth embodiment. In FIG. 7, the same components as those of the substrate built-in type inductor according to the first embodiment shown in FIG. The substrate-embedded inductor according to the fourth embodiment is different from the substrate-embedded inductor shown in FIG. 1 in that a gap is provided between the upper surface of the multilayer substrate 1 and the first magnetic body 7a. The length of the gap, that is, the distance d1 between the upper surface of the multilayer substrate 1 and the first magnetic body 7a is a predetermined spatial distance. The predetermined spatial distance may be the same as the length of the gap 9a, for example.
　実施の形態１及び３では、多層基板１の下面と第２の磁性体７ｂとの間にギャップ９ａの厚み相当の距離を取る構成を説明してきた。これはギャップ９ａと巻線パターンとの距離を所定値以上とすることによって、漏洩磁束と鎖交することによって巻線パターンに発生する渦電流とその影響を抑制することが目的であった。 Embodiments 1 and 3 have described the configuration in which a distance corresponding to the thickness of the gap 9a is provided between the lower surface of the multilayer substrate 1 and the second magnetic body 7b. The purpose of this is to suppress the eddy current generated in the winding pattern by interlinking with the leakage magnetic flux and its influence by setting the distance between the gap 9a and the winding pattern to a predetermined value or more.
　しかしながら、多層基板１と第２の磁性体７ｂとの間にギャップ９ａ相当の隙間を設けることには、放熱面積を増やして多層基板１と第２の磁性体７ｂの間での温度相互干渉を低減し、発熱を抑制するという効果もある。そのため実施の形態４に係る基板組込み型インダクタは、図７に示すように、多層基板１の上下面両方にコア７との距離を取って空隙を設ける構成を有する。 However, in order to provide a gap corresponding to the gap 9a between the multilayer substrate 1 and the second magnetic body 7b, the heat radiation area is increased so that the temperature mutual interference between the multilayer substrate 1 and the second magnetic body 7b is prevented. This also has the effect of reducing heat generation and suppressing heat generation. Therefore, the substrate built-in type inductor according to the fourth embodiment has a configuration in which a gap is provided on both the upper and lower surfaces of the multilayer substrate 1 with a distance from the core 7 as shown in FIG.
　さて、多層基板１－第１の磁性体７ａの間に隙間を設ける構成例を図８Ａ～８Ｅに示し、それぞれ以下に説明する。 Now, structural examples in which a gap is provided between the multilayer substrate 1 and the first magnetic body 7a are shown in FIGS. 8A to 8E, which will be described below.
　図８Ａは、所定の空間距離相当の厚みと第１の磁性体７ａの磁脚を囲う形状を有する固定具１１を、両磁脚に装着することによって多層基板１の上面から第１の磁性体７ａまでの空隙距離を確保する構成例を示す。固定具１１の材質は絶縁物が好ましい。 FIG. 8A shows the first magnetic body from the upper surface of the multilayer substrate 1 by attaching a fixture 11 having a thickness corresponding to a predetermined spatial distance and a shape surrounding the magnetic legs of the first magnetic body 7a to both magnetic legs. The structural example which ensures the space | gap distance to 7a is shown. The material of the fixture 11 is preferably an insulator.
　図８Ｂ～図８Ｄは、Ｕ型コアの形状の一部を変更した構成例を示す。 8B to 8D show configuration examples in which a part of the shape of the U-shaped core is changed.
　図８Ｂは両磁脚の付け根内側にギャップ９ａの厚み相当分の段差１２を有する。 FIG. 8B has a step 12 corresponding to the thickness of the gap 9a inside the base of both magnetic legs.
　図８Ｃは図８Ｂとは逆に外側に段差１３を有する。 FIG. 8C has a step 13 outside as opposed to FIG. 8B.
　図８Ｄは第１の磁性体７ａ上部の多層基板１側にギャップ９ａの厚み相当の突起１５を有する構成例を示す。図８Ｄでは中央部に一つの突起１５としたが、図８Ｅのように第１の磁性体７ａ上部の多層基板１側に複数個の突起１６をバランスよく配置しても構わない。 FIG. 8D shows a configuration example having a protrusion 15 corresponding to the thickness of the gap 9a on the multilayer substrate 1 side above the first magnetic body 7a. In FIG. 8D, one protrusion 15 is provided at the center, but a plurality of protrusions 16 may be arranged in a balanced manner on the multilayer substrate 1 side above the first magnetic body 7a as shown in FIG. 8E.
　以上説明してきたように実施の形態４に係る基板組込み型インダクタは、第１の磁性体７ａの２本の磁脚を除く磁性体部分と多層基板１との間に所定の空間距離ｄ１を有する。 As described above, the substrate-embedded inductor according to the fourth embodiment has a predetermined spatial distance d1 between the magnetic body portion excluding the two magnetic legs of the first magnetic body 7a and the multilayer substrate 1. .
　この構成によれば、多層基板１と第１の磁性体７ａの温度相互干渉が低減され、発熱及び効率劣化をさらに抑制できる。 According to this configuration, temperature mutual interference between the multilayer substrate 1 and the first magnetic body 7a is reduced, and heat generation and efficiency deterioration can be further suppressed.
　以上説明したように、本開示は、各種電子機器の小型化のために使用される多層基板に設けられる基板組込み型インダクタに有用である。 As described above, the present disclosure is useful for a substrate-embedded inductor provided on a multilayer substrate used for miniaturization of various electronic devices.
　　　１　多層基板
　　　２　コア挿通孔
　　　３　コア挿通孔
　　　４　絶縁板（絶縁層）
　　　５　配線導体（巻線パターン）
　　　７　コア
　　７ａ　第１の磁性体
　　７ｂ　第２の磁性体
　　９ａ、９ｂ、９ｃ　ギャップ
　　１１　固定具
　　１２、１３　段差
　　１５、１６　突起 DESCRIPTION OF SYMBOLS 1 Multilayer substrate 2 Core insertion hole 3 Core insertion hole 4 Insulation board (insulation layer)
5 Wiring conductor (winding pattern)
7 Core 7a 1st magnetic body 7b 2nd magnetic body 9a, 9b, 9c Gap 11 Fixing tool 12, 13 Step 15, 15 Protrusion

Claims (8)

  1. 　複数のコア挿通孔を有し、少なくとも一つのコア挿通孔を中心に巻線パターンが設置された複数の絶縁層の積層で構成された多層基板と、
    　前記複数のコア挿通孔を介して前記多層基板を挟んで閉磁路を構成する、少なくとも第１の磁性体と第２の磁性体より成るコアとを備え、
    　前記第１の磁性体と前記第２の磁性体はギャップを有して対向し、前記ギャップと前記巻線パターンとの最短空間距離が所定値以上である
    基板組込み型インダクタ。     A multi-layer substrate having a plurality of core insertion holes, and composed of a stack of a plurality of insulating layers in which a winding pattern is installed around at least one core insertion hole;
    Comprising a core made of at least a first magnetic body and a second magnetic body, which constitutes a closed magnetic path across the multilayer substrate via the plurality of core insertion holes,
    The substrate built-in type inductor, wherein the first magnetic body and the second magnetic body face each other with a gap, and a shortest spatial distance between the gap and the winding pattern is a predetermined value or more.
  2. 　前記第１の磁性体と前記第２の磁性体とはそれぞれ前記多層基板に対して平行な対向面を有し、
    　前記ギャップは前記対向面の間に形成され、
    　前記所定値は、前記ギャップの長さである
    請求項１に記載の基板組込み型インダクタ。     Each of the first magnetic body and the second magnetic body has opposing surfaces parallel to the multilayer substrate,
    The gap is formed between the opposing surfaces;
    The substrate built-in type inductor according to claim 1, wherein the predetermined value is a length of the gap.
  3. 　前記第１の磁性体は前記複数のコア挿通孔に挿入される２本の磁脚を有するＵ型であり、
    　前記第２の磁性体はＩ型もしくは２本の磁脚を有するＵ型であり、
    　前記第１の磁性体の２本の磁脚の長さは前記多層基板の厚さと前記ギャップの長さとの和以上である
    請求項２記載の基板組込み型インダクタ。     The first magnetic body is U-shaped having two magnetic legs inserted into the plurality of core insertion holes,
    The second magnetic body is I-type or U-type having two magnetic legs,
    3. The substrate built-in inductor according to claim 2, wherein the length of the two magnetic legs of the first magnetic body is equal to or greater than the sum of the thickness of the multilayer substrate and the length of the gap.
  4. 　前記第１の磁性体は前記複数のコア挿通孔に挿入される２本の磁脚を有するＵ型であり、
    　前記第２の磁性体はＩ型もしくは２本の磁脚を有するＵ型であり、
    　前記第１の磁性体の磁脚の長さは前記多層基板の厚さ以下であり、
    　前記ギャップと前記巻線パターンの最短空間距離を前記ギャップの長さ以上確保する為に前記多層基板は巻線パターンの無い配線層を有する
    請求項２記載の基板組込み型インダクタ。     The first magnetic body is U-shaped having two magnetic legs inserted into the plurality of core insertion holes,
    The second magnetic body is I-type or U-type having two magnetic legs,
    The length of the magnetic leg of the first magnetic body is not more than the thickness of the multilayer substrate,
    3. The substrate built-in type inductor according to claim 2, wherein the multilayer substrate has a wiring layer having no winding pattern in order to ensure the shortest spatial distance between the gap and the winding pattern equal to or longer than the length of the gap.
  5. 　前記第１の磁性体は前記複数のコア挿通孔に挿入される２本の磁脚を有するＵ型であり、
    　前記第２の磁性体はＩ型であり、
    　前記第１の磁性体の２本の磁脚の長さは前記多層基板の厚さより長く、前記第２の磁性体は前記２本の磁脚に前記ギャップを介して挟まれる
    請求項１記載の基板組込み型インダクタ。     The first magnetic body is U-shaped having two magnetic legs inserted into the plurality of core insertion holes,
    The second magnetic body is I-type,
    The length of the two magnetic legs of the first magnetic body is longer than the thickness of the multilayer substrate, and the second magnetic body is sandwiched between the two magnetic legs through the gap. Board built-in type inductor.
  6. 　前記第１の磁性体の２本の磁脚の端部と前記第２の磁性体の両端部は前記多層基板に対して斜めに対向する面により前記ギャップを形成する
    請求項５記載の基板組込み型インダクタ。     6. The substrate built-in according to claim 5, wherein the end of the two magnetic legs of the first magnetic body and the both ends of the second magnetic body form the gap by a surface obliquely opposed to the multilayer substrate. Type inductor.
  7. 　前記所定値は、（０．５×前記ギャップの長さ）である
    請求項５または請求項６に記載の基板組込み型インダクタ。     The board built-in inductor according to claim 5 or 6, wherein the predetermined value is (0.5 x length of the gap).
  8. 　前記第１の磁性体の２本の磁脚を除く磁性体部分と前記多層基板との間に所定の空間距離を有する
    請求項２記載の基板組込み型インダクタ。     The substrate built-in type inductor according to claim 2, wherein a predetermined spatial distance is provided between the magnetic material portion excluding two magnetic legs of the first magnetic material and the multilayer substrate.
PCT/JP2018/004507 2017-02-10 2018-02-09 Inductor built into substrate WO2018147398A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0520310U (en) * 1991-08-26 1993-03-12 松下電工株式会社 Electromagnetic device
JPH0855723A (en) * 1994-08-10 1996-02-27 Taiyo Yuden Co Ltd Laminated electronic parts
JP2005228758A (en) * 2004-02-10 2005-08-25 Yokogawa Electric Corp Printed coil transformer and printed circuit board
JP2013175657A (en) * 2012-02-27 2013-09-05 Shindengen Electric Mfg Co Ltd Low-profile core coil and low-profile transformer
JP2013175654A (en) * 2012-02-27 2013-09-05 Shindengen Electric Mfg Co Ltd Thin transformer

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0520310U (en) * 1991-08-26 1993-03-12 松下電工株式会社 Electromagnetic device
JPH0855723A (en) * 1994-08-10 1996-02-27 Taiyo Yuden Co Ltd Laminated electronic parts
JP2005228758A (en) * 2004-02-10 2005-08-25 Yokogawa Electric Corp Printed coil transformer and printed circuit board
JP2013175657A (en) * 2012-02-27 2013-09-05 Shindengen Electric Mfg Co Ltd Low-profile core coil and low-profile transformer
JP2013175654A (en) * 2012-02-27 2013-09-05 Shindengen Electric Mfg Co Ltd Thin transformer

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