JPH09283335A - Multilayered board device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the number of turns per layer of a circuit board by forming either one of a first and second coils on one or both sides of a circuit board, combining such circuit boards, laminating these boards, and connecting coil patterns in series to form a multilayered board. SOLUTION: Two coil patterns 11, 12 expanding vortically and adjacent are formed on one or both sides of a circuit board and their outer terminals 11b, 12b are mutually connected through a connecting pattern 13. Terminals of the patterns 11, 12 at the vortical centers thereof have through-holes 14, 15 piercing the circuit board 20 and the patterns 11, 12 have through-holes 17, 18 identical in size and shape at the centers. Such circuits are laminated to form a multilayered board, the coil patterns formed on the upper and lower layers of the circuit boards are electrically interconnected through the through- holes to form a multilayered coil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer substrate device provided with a choke coil and a transformer used for a switching power supply or the like.

[0002]

2. Description of the Related Art Generally, in a switching power supply, when the switching frequency is as high as several hundred kilohertz or more, the inductance of the transformer coil or choke coil may be small. In other words, the number of turns of the coil may be small. Therefore, as shown in FIG. 12, a spiral coil pattern 2 is formed of a conductor foil on the surface of an insulating substrate 1, and a plurality of such insulating substrates are laminated to form a primary coil and a secondary coil of a transformer. The coil is configured as a single laminated coil or a laminated choke coil. In addition, 2a is a center side end of the coil pattern 2,
2b is an outer end portion, and 3 and 4 are through holes.

Such a laminated coil is disclosed in, for example, Japanese Patent Laid-Open No.
-283404, it is attached to the central leg of the E-shaped core.

[0004]

However, when increasing the inductance of the laminated coil, in other words,
When increasing the number of turns of the coil, increasing the number of turns of the coil pattern for each insulating substrate increases the shape of the laminated coil, and in particular, when using an E-type core, a large core is required. , Considering the E-type core, if the width of the coil pattern is narrowed and the number of turns of each insulating substrate is increased while maintaining the size of the laminated coil, the resistance value of the coil increases and the circuit constant of the connected circuit is changed. However, there is a drawback that the cost of the laminated coil increases when the number of insulating substrates having a coil pattern is increased.

The present invention has been made in view of the above-mentioned drawbacks, and an object thereof is to provide a multilayer substrate device in which a coil pattern is formed on a circuit substrate and the number of windings per layer of the circuit substrate is increased. It is a thing.

[0006]

The present invention is configured as follows in order to achieve the above object. That is, the first invention provides a pattern coil of the first type that includes one or two spiral coil patterns independently, and two coil patterns that spirally spread in the same winding direction. A second type of pattern coil in which outer ends of the pattern are coupled to each other by a connection pattern, and at least one of the first type of pattern coil and the second type of pattern coil is provided on one side of a circuit board. Alternatively, it is formed on both sides, these circuit boards are combined and laminated, and the coil patterns are connected in series to form a multilayer board, and a magnetic path of magnetic flux generated from the coil patterns is formed by using a magnetic member on the multilayer board. It was done.

In this structure, the first type pattern coil has one or two spirally formed coil patterns.
The second type of pattern coil has two spiral coil patterns in the same winding direction, and
The two coil patterns are connected by a connecting pattern so that they are wound in mutually opposite directions when viewed from the center of the coil pattern. Then, when forming a multilayer substrate, two types of pattern coils are arbitrarily combined and laminated as needed. For example, when using a 6-layer pattern coil,
It is also possible to combine and stack three first type pattern coils and two second type pattern coils,
Further, one pattern coil of the first type and five pattern coils of the second type may be laminated and configured, and further, five pattern coils of the first type and pattern coil of the second type. You may comprise from one.

Further, the coil pattern may be formed on both sides of the circuit board, and a plurality of such circuit boards may be laminated, or the coil pattern may be formed on only one side of the circuit board.

Furthermore, the coil patterns of these laminated circuit boards are connected in series, and it is as if two coils were arranged side by side in the multilayer board. When a current is applied to the coil patterns, the upper and lower coil patterns are connected. The magnetic fluxes generated in the same direction have the same direction, and magnetic fluxes in the opposite directions are generated in the central portions of adjacent coil patterns in the same pattern coil.

A second aspect of the present invention has a first pattern coil, which is formed by arranging two coil patterns having the same spiral winding direction in parallel, on one surface thereof, and is wound in a direction opposite to the coil pattern. A circuit board of the first type having a second pattern coil formed by arranging two coil patterns in the winding direction on the other surface and two coil patterns in the same winding direction are provided side by side and A fourth pattern having, on one surface, a third pattern coil in which the outer end portions are connected by a connection pattern, and two independent coil patterns in the winding direction opposite to the coil pattern are juxtaposed. A second type circuit board having a coil on the other surface, at least one circuit board of the first type is laminated on the second type circuit board, and the coil patterns of the upper and lower layers are connected in series. And many Configure substrate, the multilayer substrate is obtained by installing the magnetic member for forming a magnetic path of the magnetic flux generated from the coil pattern.

The multi-layer board is composed of a combination of two types of circuit boards in which pattern coils are formed on both sides of the circuit board. Between them, through holes are connected in series so that the generated magnetic fluxes have the same direction. The upper and lower circuit boards are electrically insulated between the pattern coils and coupled between the circuit boards by using a prepreg when manufacturing the multilayer board. Further, the first type circuit board and the second type circuit board are sequentially stacked on the basis of the pattern coil in which the two coil patterns are connected by the connection pattern.

According to a third aspect of the present invention, a first pattern coil in which two coil patterns having the same winding direction are provided and the outer end portions of both coil patterns are connected by a connecting pattern, and a winding opposite to the coil pattern. A second pattern coil in which two coil patterns in the same direction are provided and the outer ends of both coil patterns are connected by a connection pattern,
A third pattern coil having one spiral coil pattern is provided, and the first pattern coil and the second pattern coil are combined and laminated, and each pattern coil is serially arranged with the third pattern coil as the outermost layer. The connection is made to form a multilayer substrate, and the multilayer substrate is provided with a magnetic member for forming a magnetic path of a magnetic flux generated from a coil pattern.

In the present invention, the third pattern coil in which the first pattern coil and the second pattern coil in which the two coil patterns are joined by the connection pattern are alternately laminated and one coil pattern is formed as the outermost layer Are stacked and the final end is provided outside the coil pattern. The upper and lower pattern coils are connected in series using through holes so that the magnetic fluxes generated in the upper and lower coil patterns have the same direction. In this case, in the pattern coil of each layer, the current flows in the direction of the adjacent coil pattern.

A fourth aspect of the invention comprises a primary circuit board on which a coil pattern serving as a primary coil of a transformer is formed and a secondary circuit board on which a coil pattern serving as a secondary coil is formed. A multilayer board is configured to include a circuit board and a plurality of secondary circuit boards, and at least the secondary circuit board has the same winding as the first type coil pattern in which one or two spiral coil patterns are formed. The second type pattern coil is provided with two coil patterns that spirally extend in the turning direction and the outer ends of both coil patterns are connected to each other by a connecting pattern. At least one of the two types of pattern coils is formed on one side or both sides of the circuit board, a plurality of these circuit boards are combined and laminated, and the coil patterns are connected in series. To form a multi-layered substrate, and the multi-layered substrate is formed by using a magnetic member so that the magnetic fluxes that generate the magnetic paths of the magnetic fluxes generated from the coil patterns of the upper and lower layers have the same direction. apparatus.

According to the present invention, a primary coil and a secondary coil are formed in a multilayer substrate, and at least the secondary coil has a laminated structure similar to that of the multilayer substrate of the first invention, and is supplied to the primary coil. The electric power or signal to be transmitted is transmitted to the secondary coil. If the number of turns of the coil pattern is reduced and the pattern width is widened by using the primary coil as one circuit board, the effect on the circuit as a circuit constant becomes extremely small, so that the secondary coil can be operated without affecting the circuit operation. A power output or a signal output can be obtained.

According to a fifth aspect of the present invention, a circuit board of the first type having one or two spiral coil patterns is formed, and two coil patterns that spirally extend in the same winding direction are formed and both coils are formed. A second type of circuit board in which the outer end portions of the pattern are connected to each other by a connection pattern,
A plurality of first-type circuit boards and second-type circuit boards are combined and laminated, and upper and lower coil patterns are connected in series to form a multilayer board, and a coil is formed by using a magnetic member for the multilayer board. The magnetic path of the magnetic flux generated from the pattern is formed.

In this configuration, the first type circuit board is
One or two coil patterns formed in a spiral shape are provided, and the second type circuit board has two spiral coil patterns in the same winding direction, and these two coil patterns are also provided. Are connected by a connecting pattern so that they are wound in mutually opposite directions when viewed from the center of the coil pattern. When forming a multilayer board, two types of circuit boards are arbitrarily combined and laminated as needed. or,
The coil patterns of the upper and lower circuit boards that are laminated are connected in series, and it is as if two coils were juxtaposed in the multilayer board. When a current is applied to a coil pattern, the coil patterns are placed in the center of adjacent coil patterns. Generates magnetic flux in the opposite direction.

According to a sixth aspect of the present invention, two coil patterns having the same winding direction are formed and a first circuit board in which the outer end portions of both coil patterns are connected by a connecting pattern, and a coil of the first circuit board. A second circuit board in which two coil patterns in the winding direction opposite to the pattern are formed and the outer end portions of both coil patterns are connected by a connecting pattern, and a third coil pattern in which one spiral coil pattern is formed A circuit board, wherein a plurality of first and second circuit boards are combined and stacked, a third circuit board is stacked as an outermost layer, and each pattern coil is connected in series to form a multilayer board. The multilayer substrate is provided with a magnetic member that forms a magnetic path of a magnetic flux generated from the coil pattern.

According to the present invention, a plurality of first circuit boards and second circuit boards in which two coil patterns are connected by a connection pattern are alternately laminated, and a third coil pattern is formed as the outermost layer. The circuit boards are stacked and the final end is provided outside the coil pattern. The direction of the magnetic flux generated in the coil pattern and the direction of the current flowing in the pattern coil are the same as in the case of the third invention.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) An embodiment of the present invention will be described in detail with reference to the drawings. This embodiment is a multilayer substrate device provided with a two-terminal coil device.

FIG. 1 shows a pattern coil provided on the back surface of the circuit board 20 as viewed from the front side of the circuit board 20.

On the back surface of the circuit board 20, two coil patterns 11 and 12 that spread in a clockwise spiral are formed adjacent to each other. Coil pattern 1 to simplify the drawing
Although 1 and 12 are shown as windings of about 3 turns,
Actually, it is formed by spirally winding 5 to 12 turns, if necessary. Coil pattern 11 and coil pattern 1
2 is the end of the outermost turn, namely the outer end 11
The connection pattern 13 connects between b and 12b. Here, when viewed from the center of one coil pattern,
The other coil pattern has the opposite winding direction. Further, through holes 14 and 15 penetrating the circuit board are formed at the end portions 11a and 12a of the coil patterns 11 and 12 on the spiral center side. The through hole is usually formed by copper plating.

The circuit board 20 has a thickness of 100 μm, for example.
Is a laminated board made of glass epoxy resin. The coil patterns 11 and 12 have a thickness of 35 μm or more on the back surface of the substrate.
The copper foil is 70 μm wide and has a width of 0.1 mm to 1.0 m. The coil patterns 11 and 12 are provided on the circuit board 20.
Through holes 17 and 18 having the same size and shape are formed in the center of the.

FIG. 2 shows a pattern coil having two independent coil patterns provided adjacent to the surface of the circuit board 20, and is a drawing of the surface of the circuit board viewed from above.

The coil patterns 21 and 22 are also shown as three turns as in FIG. 1, but the actual number is the same as the number of turns of the coil pattern in FIG. The winding direction viewed from the center of the coil patterns 21 and 22 is counterclockwise, unlike the case of FIG. The end portions 21a and 22a of the coil patterns 21 and 22 on the center side of the spiral are coil patterns 1 on the back surface through the through holes 14 and 15 penetrating the circuit board 20.
1 and 12 are electrically coupled. Further, through holes 25 and 26 penetrating the circuit board 20 are formed in the outer end portions 21b and 22b of the coil patterns 21 and 22, respectively.

At the centers of the spirals of the coil patterns 21 and 22, through holes 17 and 18 penetrating the circuit board 20 are formed.
Is located. The thickness and width of the copper foil forming the circuit board 20 and the coil patterns 21 and 22 are the same as in the case of FIG.

As in the above-mentioned configuration, the circuit board 20 has the coil pattern 1 forming the first layer pattern coil.
1 and 12 and coil patterns 21 and 22 forming the second layer pattern coil are provided.

FIG. 3 shows a pattern coil formed on the back surface of the circuit board 40 and comprising two independent coil patterns, as viewed from the front side of the circuit board 40.

The independent coil patterns 31 and 32 are wound clockwise when viewed from the center of the coil pattern. The through holes 37 and 38 penetrating the circuit board 40 are shown in FIG.
The outer end portions 31b and 32b of the coil patterns 31 and 32 are formed at positions overlapping the outer end portions 21b and 22b of FIG. Through holes 35, 36 are formed in the outer end portions 31b, 32b.
Is provided. In addition, the center end portions 31a and 32a of the coil patterns 31 and 32 are the end portions 21a and 2 of FIG.
The through holes 33 and 34 are formed at positions not overlapping with 2a, respectively. Other configurations are the same as those in FIG.

FIG. 4 shows a pattern coil composed of two independent coil patterns provided adjacent to the surface of the circuit board, as viewed from above the surface of the circuit board.

The coil patterns 41 and 42 are shown as three turns of winding as in FIG. 2, but the actual number is the same as the number of turns of the coil pattern of FIG. The winding direction viewed from the center of the coil patterns 41, 42 is counterclockwise as in the case of FIG. The end portions 41a, 42a of the coil patterns 41, 42 on the center side of the spiral are electrically connected to the coil patterns 31, 32 on the back surface of the circuit board 40 via through holes 33, 34 penetrating the circuit board 40. Has been done. In addition, the outer end portions 41b, 4 of the coil patterns 41, 42,
2b includes through holes 45 and 46 penetrating the circuit board.
Are respectively formed.

Further, the circuit board 40 of FIG. 2 is penetrated through the circuit board 40 at the center of the spiral of each coil pattern 41, 42.
Through holes 3 having the same size and shape as the through holes 17 and 18 of 0
7, 38 are formed. The thickness and width of the copper foil forming the circuit board 40 and the coil patterns 41, 42 are also the same as in FIG.

The difference between the coil patterns 21 and 22 in FIG. 2 and the coil patterns 41 and 42 in FIG. 4 is that they are formed so that the positions of the center-side end portions 21a, 22a and 41a, 42a of the coil patterns do not overlap. And the outer end portions 21b, 22b of FIG. 2 and the outer end portion 41 of FIG.
b and 42b are also formed so as not to overlap with each other, and the coil pattern 41 has an outer end portion 42b of the coil pattern 42.
That is, the outer end portion 41b is provided so as to extend to the vicinity of.

As described above, the circuit board 40 has the coil patterns 31, 3 forming the third layer pattern coil.
2 and coil patterns 41 and 42 that form the fourth layer pattern coil.

FIG. 5 shows a cross section of the main part of the multilayer substrate device.
Coil patterns 11 and 12 and coil patterns 21 and 22
On the circuit board 20 on which the coil patterns are formed, the coil patterns 31 and 32 and the coil pattern 41 are provided through the prepreg 80.
The circuit boards 40 on which 42 is formed are stacked. The prepreg 80 used here has a sheet-like shape in which a glass cloth base material is impregnated with an epoxy resin to be in a semi-cured state, as in the case of being usually used in manufacturing a multilayer substrate. When the circuit boards 20, 40 and the prepreg 80 are entirely heated while being pressed in the stacking direction, the epoxy resin is once melted and then re-cured. In this process, the adhesion between the circuit boards and the electrical connection between the pattern coils are performed. Insulation is performed to form a multilayer substrate.

In the drawing, the circuit boards are laminated, and the pattern coil has a total of four layers.
The circuit boards are laminated to form a multilayer board. The surface of the uppermost circuit board 40 and the coil patterns 41, 42
And the lowermost circuit board 20 and coil patterns 11 and 12
Are covered with an electrically insulating material 16, for example a resist material. The actual thickness of the multilayer substrate is 1.5 mm ~
It is about 2.0 mm.

In the above-mentioned multilayer board, the pattern coils provided on the upper and lower circuit boards are electrically connected to each other through through holes.

The connection between the circuit board 20 and the circuit board 40 is made by connecting the outer end portions 2 of the coil patterns 21 and 31 in the upper and lower layers.
1b and 31b are connected through a through hole connecting the through holes 25 and 35, and the coil pattern 22
And 32 have outer ends 22b and 32b through holes 26.
And 36 are connected to each other through a through hole. The connection through hole is formed after the circuit boards are laminated.

A plurality of such circuit boards 20 and 40 are laminated to form a multilayer board. Conventional multilayer substrate forming techniques are used to manufacture the multilayer substrate. In this case, as shown in FIG. 5, the through holes 17 and 37 are aligned to form the core insertion hole 19
Similarly, the core insertion hole 29 is provided from the through holes 18 and 38. In addition, the coil patterns 11, 21,
31 and 41 are laminated, and the coil patterns 12 and 2 are similarly formed.
2, 32 and 42 are also arranged in an overlapping manner. A core 39 is mounted on the multilayer substrate using the core insertion holes 19 and 29.
The cores 39 are, for example, U-shaped cores made of ferrite having a high magnetic permeability, and are paired together. That is, the leg portions of the core are inserted into the core through holes 19 and 29 from both sides of the multilayer substrate, and the tip end faces of the leg portions are bonded with an adhesive. U is the core
The type and the I type may be combined.

External end 4 of the two-terminal coil system described above.
When a current is applied between 1b and 42b, the core insertion holes 19, 2
The directions of the magnetic fluxes passing through the leg portions of the core 39 inserted in 9 are opposite to each other, and the magnetic flux generated from the coil pattern almost passes through the core.

In the above description, the through hole is formed in each circuit board, but the core insertion holes 19 and 29 may be formed in the center of the coil pattern after forming the multilayer board.

(Embodiment 2) Another embodiment of the multilayer substrate will be described. This example is an example in which a plurality of circuit boards similar to those described in FIG. 1 are laminated to form a multilayer board.

In FIG. 6, 2 is provided on the circuit board 50.
Two spiral coil patterns 51 and 52 are formed.
Unlike the coil patterns 11 and 12 shown in FIG. 1, the winding directions of the coil patterns 51 and 52 are spirally spread counterclockwise. Coil pattern 51 and coil pattern 5
The two outer end portions 51b and 52b are connected to each other by a connecting pattern 53, and the winding directions viewed from the center of one coil pattern are opposite to each other. Further, through holes 54 and 55 penetrating the circuit board are formed at the end portions 51a and 52a of the coil patterns 51 and 52 on the spiral center side. Each coil pattern 5
A through hole 5 penetrating the circuit board 50 is provided at the center of the first and second holes 52.
7, 58 are formed. Other configurations are the same as those in FIG.

When the pattern coil shown in FIG. 1 and the pattern coil shown in FIG. 6 are used to form a four-layer pattern coil, the pattern coil shown in FIG. 6 and the pattern coil shown in FIG. To do. In this case, the center side end portion 52a of the coil pattern 52 of the circuit board 50
Is connected to a circuit pattern (not shown) provided on the back surface of the circuit board 50 through the through hole 55, and this serves as a lead terminal of the coil. A pattern coil similar to that shown in FIG. 1 is formed on the back surface of the circuit board (not shown). The shape of the pattern coil is as viewed from the front side of the circuit board, as in FIG. The end portion 51a of the coil pattern 51 and the end portion 11a of the coil pattern 11 are electrically connected to each other through a through hole (not shown).

Next, a pattern coil of the third layer is formed on the front surface of a circuit board (not shown) so as to overlap the pattern coil on the back surface side. This pattern coil is the circuit board 5 of FIG.
A pattern coil similar to 0. The difference is that the position of the center side end of the coil pattern on the right side of the drawing is shifted to the left side so as to overlap with the end 12a of the coil pattern 12. The end portions are connected to each other by through holes.

FIG. 7 shows a fourth layer pattern coil. The coil pattern 61 is provided on the back surface of the circuit board 60, and has a coil pattern shape when the back surface direction is viewed from the front side, as in FIG. 1 on the circuit board 60
Only the individual coil pattern 61 is formed. This coil pattern has the same structure as the coil pattern 31 of FIG. The coil pattern 61 has a shape that spirally expands in the clockwise direction, and the center-side end portion 61 a is connected to the center-side end portion of the lower layer coil pattern through a through hole extending the through hole 63. Coil pattern 6
The outer end portion 61b of No. 1 is connected to a circuit pattern (not shown) as a lead terminal via a through hole 65 or via an electronic component. A through hole 67 is provided at the center of the coil pattern 61. In addition, the circuit board 60,
A through hole 68 is provided at a position corresponding to the through hole 58 in FIG.

In this multilayer board, the number of windings of the coil pattern is smaller than that in the multilayer boards of the above-described embodiments. Therefore, in order to obtain the same number of turns, the number of turns of the coil pattern formed on each circuit board is increased by several turns, or
The coil pattern 92 is formed as the lowermost layer on the back surface of the circuit board 50 in the same manner as in FIG. 7.

On the back surface of the circuit board 50, only one coil pattern 92 is formed. This coil pattern 92 has the same structure as the coil pattern 32 of FIG. 3, and has a shape that expands in a spiral shape in the clockwise direction. The center-side end portion 92a of the coil pattern 92 is formed in the coil pattern 52, which is an upper layer, through the through hole 55.
Is connected to the center side end portion 52a. Coil pattern 9
The outer end portion 92b of No. 2 is connected to a circuit pattern (not shown) as a lead terminal. The direction of the magnetic flux when a current is passed between the lead terminals of the coil is the same as in the above-described embodiment.

(Embodiment 3) Next, an embodiment of a multi-layer substrate device constituting a current detection transformer will be described below.

FIG. 9 is a circuit board 70 having a pattern coil formed of a coil pattern 71 as a primary coil.
Is shown. The coil pattern 71 is a winding that is less than one turn. That is, this is a configuration in which a part of the circuit pattern 72 is deformed into a U shape. This coil pattern 71 is, for example,
It is configured as a part of the power circuit on the primary side of the switching power supply, and has a pattern width wider than the coil pattern of the secondary coil in order to reduce electric resistance. A through hole 73 is provided in the terminal portion 71a of the coil pattern 71 and is connected to a circuit pattern (not shown). Further, the circuit board 70 includes the through hole 1 of the circuit board 20 of FIG.
Two through holes 74 and 75 are provided corresponding to the positions of 7 and 18.

As shown in FIG. 10, the circuit board 70 is laminated on the circuit board 40 via the prepreg 80. That is, a circuit board having a pattern coil as shown in FIGS. 1 to 6 as a secondary coil and a circuit board 70 having a pattern coil serving as a primary coil are laminated to form a multilayer board. ing. An electric insulating layer 76 such as a resist is provided on the circuit board 70 and the coil pattern 71. A pair of U-shaped cores 79 are combined and mounted in a ring shape in the core mounting holes 76 and 77 formed by the through holes of each circuit board. The circuit board 70 is, for example, a laminated board made of glass epoxy resin having a thickness of 100 μm, like the circuit board of FIG. Also, the coil pattern
The substrate 71 has a thickness of 35 μm to 70 μm and a width of 1 m on the substrate surface.
It is formed of copper foil of m to 2 mm.

In the switch power source, for example, the above-mentioned secondary coil functions as a detection coil for detecting a change in current flowing in the primary side power circuit to which the primary coil of the transformer and the switching element are connected, and its output is supplied to the control circuit. Given, which affects the switching period of the switching element of the primary side power circuit.

In the above description, the coil pattern of the circuit board 70 is shown to have about one turn, but in the case of a switching transformer, for example, the coil on the primary side also uses the method described in FIGS. 1 to 8. And a coil having the required number of turns, and a multilayer substrate integrated with the circuit pattern on the secondary side. In this case, the pattern coil of the primary coil may be laminated on the upper layer of the pattern coil of the secondary coil, or the coil pattern of the primary coil and the coil pattern of the secondary coil may be alternately laminated to enhance magnetic coupling. Also good.

In the above-mentioned embodiment, the example using the U-shaped core has been described, but magnetic pieces may be bonded to the front and back surfaces of the multilayer substrate corresponding to the position of the pattern coil instead of the U-shaped core. In this case, the through hole provided in each circuit board can be omitted.

(Embodiment 4) In each of the above-described embodiments, an example in which the coil patterns are formed on the front and back surfaces of the circuit board has been described. However, the coil patterns for each layer are formed only on one surface of the circuit board, and these circuits are formed. The substrates can be laminated using well known multilayer substrate manufacturing techniques. In this case, FIG. 1, FIG. 3, FIG. 7, and FIG. 8 have a pattern coil shape formed on the surface of the circuit board.

FIG. 11 shows a cross section of the main part of the multilayer substrate device. The end portion 11a of the coil pattern 11 of the circuit board 10a on the spiral center side is electrically connected to the center side end portion 21a of the coil pattern 21 of the upper circuit board 10b through a through hole. Similarly, the coil pattern 12
And the center end portions 12a, 22a of the coil pattern 22
Are also connected to each other through through holes. Next, the connection between the second-layer circuit board 10b and the third-layer circuit board 10c is performed by connecting the outer end portions 21b and 31b of the upper and lower coil patterns 21 and 31 through through holes. 22 and 32 outer ends 22b and 3
2b are connected to each other through through holes. The connection between the third-layer circuit board 10c and the fourth-layer circuit board 10d is similarly made. That is, the coil patterns 31 and 41
Center end portions 31a and 41a of the coil patterns 32 and 42 are connected to each other through the through holes, and the outer end portions 32 of the coil patterns 32 and 42 are
b and 42b are connected through a through hole. A pair of U-shaped cores are mounted in the core insertion holes 19 and 29 provided at the center of the coil pattern.

When the pattern coil shown in FIGS. 1 and 6 is used, the circuit board having the coil pattern shown in FIG. 1 is placed on the circuit board having the pattern coil shown in FIG. In this case, the coil pattern 52
The center-side end portion 52a is connected to a circuit pattern (not shown) provided on the back surface of the circuit board through the through hole 55. Further, the end portion 51a of the coil pattern 51 and the end portion 11a of the coil pattern 11 are electrically connected to each other via a through hole extending the through hole 14. Next, a third-layer circuit board having a coil pattern similar to that of FIG. 6 is overlaid, and the center side end of the right coil pattern and the end 12a of the coil pattern 12 are connected by a through hole. The fourth layer is a circuit board on which the coil pattern of FIG. 7 is formed. The center end 61a of the coil pattern 61 extends through the through hole 63 and is connected to the center end of the lower coil pattern. The outer end portion 61b of the coil pattern 61 is connected to a circuit pattern on the surface (not shown) as a lead terminal.

As described above, when the pattern coil is provided only on one surface of the circuit board, unlike the case where the pattern coil is provided on both surfaces of the circuit board, an adhesive material such as epoxy resin is used between the circuit boards to form a multilayer board. You can

[0059]

Since the present invention is constructed as described above, it has the following effects. (1) Since two coil patterns are provided on the circuit board,
The coil pattern per one can be made small, and a coil pattern having a larger number of turns can be provided on the multilayer substrate having the same number of layers as the circuit board, without narrowing the width of the coil pattern. As a result, a coil with a high inductance value and a transformer with a high winding ratio can be configured. Further, when the inductance is set to the same value as the conventional one, the number of layers of the circuit board can be reduced as compared with the conventional one, so that the cost can be easily reduced.

(2) Since a choke coil, a transformer coil, and a detection coil are provided on the multilayer substrate on which electronic circuit parts are mounted, a coil device separately made is mounted on the multilayer substrate as in the conventional case. Compared with the case, the thickness of the entire multilayer substrate device can be remarkably reduced.

[Brief description of drawings]

FIG. 1 shows a circuit board having connected coil patterns according to the present invention.

FIG. 2 shows a circuit board with independent coil patterns according to the present invention.

FIG. 3 shows a circuit board having a coil pattern of windings in the opposite direction to that of FIG. 2 according to the present invention.

FIG. 4 shows a circuit board with independent coil patterns in the same winding direction as in FIG. 2 according to the present invention.

FIG. 5 shows a cross-sectional view of a main part of a multilayer substrate device according to the present invention.

FIG. 6 shows another example of a circuit board having a connected coil pattern according to the present invention.

FIG. 7 shows a circuit board having one coil pattern according to the present invention.

FIG. 8 shows another example of a circuit board having one coil pattern according to the present invention.

FIG. 9 shows a circuit board provided with a coil pattern serving as a primary coil of a current detection coil according to the present invention.

FIG. 10 is a cross-sectional view of a main part of a multi-layer substrate device that constitutes a transformer according to the present invention.

FIG. 11 is a cross-sectional view of an essential part of another embodiment of the multilayer substrate device of the present invention.

FIG. 12 shows an insulating substrate on which a conventional coil pattern is formed.

[Explanation of symbols]

11,12,21,22,31,32,41,42,
51, 52, 61, 71, 92 Coil patterns 11a, 12a, 21a, 22a, 31a, 32a, 4
1a, 42a, 51a, 52a, 61a, 92a Central end portion 11b, 12b, 21b, 22b, 31b, 32b, 4
1b, 42b, 51b, 52b, 61b, 92b Outer end portion 13,52 Connection pattern 14,15,25,26,33,34,45,46,5
4,55,63,65 through hole 17,18,37,38,57,58,67,68
Through hole 19,29 Core insertion hole 20, 40, 50, 60, 70, 10a, 10b, 10
c, 10d circuit board 39 core 80 prepreg

Claims (6)

[Claims] 1. A first type pattern coil that independently includes one or two spiral coil patterns, and two coil patterns that spirally spread in the same winding direction are provided outside both coil patterns. A pattern coil of a second type in which end portions of the pattern coil are mutually connected by a connection pattern, and at least one of the pattern coil of the first type and the pattern coil of the second type is provided on one side or both sides of the circuit board. A multilayer board is formed by stacking and stacking these circuit boards and connecting the coil patterns in series, and a magnetic path of magnetic flux generated from the coil pattern is formed on the multilayer board by using a magnetic member. Characteristic multi-layer substrate device. 2. A first pattern coil formed by arranging two coil patterns having the same spiral winding direction in parallel is provided on one surface, and the first pattern coil has two winding directions opposite to the coil pattern. A first type circuit board having a second pattern coil formed by arranging two coil patterns on the other surface, and two coil patterns in the same winding direction are provided side by side, and outer end portions of both coil patterns are provided. Has a third pattern coil coupled to each other in a connection pattern on one surface thereof, and a fourth pattern coil formed by arranging two independent coil patterns in the winding direction opposite to the coil pattern side by side on the other side. A second type circuit board having a surface,
At least one first-type circuit board is laminated on the first-type circuit board, and upper and lower coil patterns are connected in series to form a multilayer board. A multi-layer substrate device having a magnetic member for forming a magnetic path. 3. A first pattern coil in which two coil patterns of the same winding direction are provided and the outer end portions of both coil patterns are connected by a connecting pattern, and two coil patterns in the winding direction opposite to the coil pattern are provided. A first pattern coil, which is provided with a coil pattern and a second pattern coil in which the outer end portions of both coil patterns are connected by a connection pattern; and a third pattern coil formed of one spiral coil pattern. The second pattern coil is combined and laminated, and each pattern coil is connected in series with the third pattern coil as the outermost layer to form a multi-layer substrate, and a magnetic path of magnetic flux generated from the coil pattern is formed on the multi-layer substrate. A multi-layer substrate device comprising a magnetic member to be formed. 4. A primary circuit board having a coil pattern serving as a primary coil of a transformer and a secondary circuit board having a coil pattern serving as a secondary coil, and a single or a plurality of primary circuit boards and a plurality of primary circuit boards. A multilayer board is configured to include a plurality of secondary circuit boards, and at least the secondary circuit board spirals in the same winding direction as the coil pattern of the first type in which one or two spiral coil patterns are formed. Spread 2
A second type of pattern coil in which one coil pattern is provided and the outer end portions of both coil patterns are connected to each other by a connecting pattern, and the first type pattern coil and the second type pattern coil are At least one of the above is formed on one side or both sides of the circuit board, a plurality of these circuit boards are combined and laminated, and are connected in series so that the magnetic fluxes that generate the coil patterns of the upper and lower layers are in the same direction to form a multilayer board. Then, a magnetic path of a magnetic flux generated from a coil pattern is formed on the multi-layer substrate by using a magnetic member. 5. A circuit board of the first type having one or two spiral coil patterns and two coil patterns spirally spreading in the same winding direction and at the outside of both coil patterns. A circuit board of a second type having end portions connected to each other by a connection pattern is provided, and a plurality of circuit boards of the first type and a circuit board of the second type are combined and laminated, and upper and lower coil patterns are connected in series. And a magnetic path of magnetic flux generated from a coil pattern is formed on the multilayer board by using a magnetic member. 6. A first circuit board in which two coil patterns having the same winding direction are formed and the outer end portions of both coil patterns are connected by a connection pattern, and a coil pattern of the first circuit board is opposite to that of the first circuit board. A second circuit board in which two coil patterns in the winding direction are formed and the outer ends of both coil patterns are joined by a connection pattern, and a third circuit board in which one spiral coil pattern is formed are provided. A plurality of first and second circuit boards are combined and laminated, a third circuit board is laminated as an outermost layer, and each pattern coil is connected in series to form a multilayer board. A multi-layer substrate device comprising a magnetic member for forming a magnetic path of a magnetic flux generated from a coil pattern.