JP6969533B2 - Multilayer boards and electronics - Google Patents

Description

The present invention relates to a multilayer substrate including a coil formed in a laminate formed by laminating a plurality of substrate layers, a mounting electrode formed on a mounting surface of the laminate, and an electronic device having the multilayer substrate. ..

Conventionally, a laminate formed by laminating a plurality of substrate layers, a coil formed in the laminate and having a winding axis in the lamination direction of the plurality of substrate layers, and a mounting formed on the mounting surface of the laminate. A multilayer board provided with an electrode (an electrode for mounting on another circuit board or the like) is known (Patent Document 1).

International Publication No. 2015/033744

However, in the configuration described in Patent Document 1, it is difficult to improve the mountability of the multilayer board while suppressing the decrease in the inductance of the coil due to the following problems.

(A) When a large-area mounting electrode is provided on the mounting surface in order to improve the mountability of the multilayer substrate, the magnetic flux from the coil may be hindered by the large-area mounting electrode, and the inductance of the coil may decrease. be. In addition, there is a risk that the loss due to the eddy current flowing through the mounting electrode will increase.

(B) Further, in relation to the land of another circuit board to which the multilayer board is mounted, a plurality of mounting electrodes having the same potential may be provided on the mounting surface. However, if the mounting electrodes having the same potential are arranged over a wide range of the mounting surface, a connecting conductor for connecting the mounting electrodes having the same potential is required, and this connecting conductor may hinder the magnetic flux from the coil. There is also.

An object of the present invention is to provide a multilayer substrate capable of suppressing a decrease in inductance of a coil formed in a laminated body and a loss due to an eddy current while increasing the degree of freedom in arranging mounting electrodes formed on the mounting surface. .. Another object of the present invention is to provide an electronic device including the multilayer board.

The multilayer board of the present invention is
A laminated body having a mounting surface and laminating a plurality of base material layers,
A coil formed in the laminated body and having a winding axis in the laminating direction of the plurality of base materials,
The mounting electrode formed on the mounting surface and
A connecting conductor formed in the laminated body and having a plurality of openings,
Equipped with
The plurality of openings have a long shape surrounded by conductors constituting the connecting conductor.
The mounting electrode is characterized by being a part of the connecting conductor exposed on the mounting surface.

Further, the multilayer board of the present invention is
A laminated body having a mounting surface and laminating a plurality of base material layers,
A coil formed in the laminated body and having a winding axis in the laminating direction of the plurality of base materials,
The mounting electrode formed on the mounting surface and
A connecting conductor formed in the laminated body and having a plurality of openings,
Equipped with
The plurality of openings have a long shape surrounded by conductors constituting the mounting electrode.
The mounting electrode is characterized in that it is connected to the connecting conductor.

According to this configuration, when the magnetic flux from the coil passes through both of the plurality of openings provided in the connecting conductor, an eddy current in a direction canceling the magnetic flux flows in the conductor portion sandwiched between the plurality of openings. hard. That is, by providing a plurality of openings in the connecting conductor, the same effect as in the case where a large opening is formed in the connecting conductor can be obtained, and the coil can be used without providing a large opening in the connecting conductor. It is possible to prevent the magnetic flux of the above from being obstructed by the connecting conductor. Therefore, with this configuration, while increasing the degree of freedom in arranging the mounting electrodes formed on the mounting surface (when the mounting electrode has an arbitrary shape, when the area of the mounting electrode is increased, or when the mounting surface has the same potential). Even when a plurality of mounting electrodes are arranged), it is possible to suppress a decrease in the inductance of the coil and a loss due to the eddy current flowing through the connecting conductor.

According to the present invention, a multilayer substrate having an increased degree of freedom in the arrangement of mounting electrodes formed on the mounting surface while suppressing a decrease in inductance of the coil formed in the laminate and a loss due to eddy current, and a multilayer substrate thereof. It is possible to realize an electronic device equipped with.

FIG. 1A is an external perspective view of the multilayer board 101 according to the first embodiment, and FIG. 1B is an external perspective view of the multilayer board 101 as viewed from another viewpoint. FIG. 2 is an exploded plan view of the multilayer board 101. 3A is a plan view of the multilayer board 101, and FIG. 3B is a cross-sectional view taken along the line AA in FIG. 1A. FIG. 4 is a cross-sectional view of a main part of the electronic device 301 according to the first embodiment. FIG. 5A is a plan view showing a layer in which the connecting conductors 41 and 42 are formed in the multilayer board 101, and FIG. 5B is a connecting conductor 41A in the multilayer board 100 which is a comparative example. , 42A is a plan view showing a layer formed. FIG. 6A is an external perspective view of the multilayer board 102 according to the second embodiment, and FIG. 6B is an external perspective view of the multilayer board 102 as viewed from another viewpoint. FIG. 7 is an exploded plan view of the multilayer board 102. FIG. 8 is a cross-sectional view taken along the line BB in FIG. 6 (A). 9 (A) is an external perspective view of the multilayer board 103 according to the third embodiment, and FIG. 9 (B) is an external perspective view of the multilayer board 103 as viewed from another viewpoint. FIG. 10 is an exploded plan view of the multilayer board 103. 11 is a cross-sectional view taken along the line CC in FIG. 9A.

Hereinafter, a plurality of embodiments for carrying out the present invention will be shown with reference to the drawings with reference to some specific examples. The same reference numerals are given to the same parts in each figure. Although the embodiments are shown separately for convenience in consideration of the explanation of the main points or the ease of understanding, partial replacement or combination of the configurations shown in different embodiments is possible. In the second and subsequent embodiments, the description of matters common to the first embodiment will be omitted, and only the differences will be described. In particular, the same action and effect due to the same configuration will not be mentioned sequentially for each embodiment.

<< First Embodiment >>
FIG. 1A is an external perspective view of the multilayer board 101 according to the first embodiment, and FIG. 1B is an external perspective view of the multilayer board 101 as viewed from another viewpoint. FIG. 2 is an exploded plan view of the multilayer board 101. 3A is a plan view of the multilayer board 101, and FIG. 3B is a cross-sectional view taken along the line AA in FIG. 1A. In FIG. 2, the coil conductor patterns 31, 32, 33, and 34 are shown as dot patterns in order to make the structure easy to understand. Further, in FIG. 3A, the coil conductor patterns 31, 32, 33, 34 are shown by dot patterns, and the openings SL11, SL12, SL21, and SL22 are shown by hatching.

The multilayer substrate 101 includes a laminate 10, a coil 3 (described in detail later), a plurality of mounting electrodes P1 and P2, connecting conductors 41 and 42, and the like.

The laminated body 10 is a rectangular parallelepiped whose longitudinal direction coincides with the X-axis direction, and has a first main surface VS1 and a second main surface VS2 facing each other. The coil 3 is formed inside the laminated body 10, and the plurality of mounting electrodes P1 and P2 are formed (exposed) on the first main surface VS1 of the laminated body 10. In the present embodiment, the first main surface VS1 corresponds to the "mounting surface" of the present invention.

The laminated body 10 is formed by laminating the protective layer 1 and a plurality of base material layers 15, 14, 13, 12, 11 in this order. The plurality of base material layers 11, 12, 13, 14, and 15 are rectangular flat plates made of a resin material (thermoplastic resin) whose longitudinal directions coincide with the X-axis direction. The plurality of substrate layers 11, 12, 13, 14, 15 are sheets mainly made of, for example, a liquid crystal polymer (LCP) or a polyetheretherketone (PEEK).

A coil conductor pattern 31 is formed on the back surface of the base material layer 11. The coil conductor pattern 31 is a rectangular spiral conductor pattern having about 3 turns arranged near the center of the base material layer 11. The coil conductor pattern 31 is a conductor pattern such as a Cu foil.

A coil conductor pattern 32 is formed on the back surface of the base material layer 12. The coil conductor pattern 32 is a rectangular spiral conductor pattern having about 3 turns arranged near the center of the base material layer 12. The coil conductor pattern 32 is a conductor pattern such as a Cu foil.

A coil conductor pattern 33 is formed on the back surface of the base material layer 13. The coil conductor pattern 33 is a rectangular spiral conductor pattern having about 3 turns arranged near the center of the base material layer 13. The coil conductor pattern 33 is a conductor pattern such as a Cu foil.

A coil conductor pattern 34 is formed on the back surface of the base material layer 14. The coil conductor pattern 34 is a rectangular spiral conductor pattern having about 3 turns arranged near the center of the base material layer 14. The coil conductor pattern 34 is a conductor pattern such as a Cu foil.

Connection conductors 41 and 42 are formed on the back surface of the base material layer 15. The connecting conductor 41 is a rectangular conductor pattern arranged near the first side of the base material layer 15 (the left side of the base material layer 15 in FIG. 2). The connecting conductor 42 is a rectangular conductor pattern arranged near the second side of the base material layer 15 (the right side of the base material layer 15 in FIG. 2). The connecting conductors 41 and 42 are large-area conductor patterns that occupy most of the surface of the base material layer 15 (for example, 1/2 or more). The connecting conductors 41 and 42 are conductor patterns such as Cu foil.

The connecting conductor 41 has elongated openings SL11 and SL12 surrounded by conductors constituting the connecting conductor 41. The openings SL11 and SL12 are both rectangular conductor non-forming portions having a longitudinal direction in the Y-axis direction, and are arranged in the X-axis direction. The connecting conductor 42 has elongated openings SL21 and SL22 surrounded by conductors constituting the connecting conductor 42. The openings SL21 and SL22 are both rectangular through holes having a longitudinal direction in the Y-axis direction, and are arranged in the X-axis direction.

The term "long opening" in the present specification means a second direction (for example, the X-axis direction) in which the length in an arbitrary first direction (for example, the Y-axis direction) is orthogonal to the first direction. An opening with a shape longer than the length of.

The protective layer 1 has a planar shape substantially the same as that of the base material layer 15, and is a protective film laminated on the back surface of the base material layer 15. The protective layer 1 is, for example, a coverlay film, a solder resist film, an epoxy resin film, or the like.

The protective layer 1 has a plurality of openings AP1 and AP2. The plurality of openings AP1 are rectangular through holes arranged at positions near the first side of the protective layer 1 (the left side of the protective layer 1 in FIG. 2). The plurality of openings AP2 are rectangular through holes arranged at positions near the second side of the protective layer 1 (the right side of the protective layer 1 in FIG. 2). Therefore, even when the protective layer 1 is formed on the back surface of the base material layer 15, a part of the connecting conductor 41 is exposed to the outside from the plurality of openings AP1, and a part of the connecting conductor 42 is exposed from the plurality of openings AP2. Exposed to the outside. The mounting electrode P1 according to the present embodiment is a part of the connecting conductor 41 exposed from the plurality of openings AP1 to the first main surface VS1. Further, the mounting electrode P2 according to the present embodiment is a part of the connecting conductor 42 exposed from the plurality of openings AP2 to the first main surface VS1. Therefore, the plurality of mounting electrodes P1 are all at the same potential, and the plurality of mounting electrodes P2 are all at the same potential.

As shown in FIG. 2 and the like, the plurality of mounting electrodes P1 (connecting conductors 41) are attached to one end of the coil conductor pattern 31 via the interlayer connecting conductors V1 formed in the base material layers 12, 13, 14, and 15. Be connected. The other end of the coil conductor pattern 31 is connected to one end of the coil conductor pattern 32 via the interlayer connecting conductor V2 formed on the base material layer 12. The other end of the coil conductor pattern 32 is formed at one end of the coil conductor pattern 33 via the interlayer connecting conductor V3 formed on the base material layer 13. The other end of the coil conductor pattern 33 is connected to one end of the coil conductor pattern 34 via the interlayer connecting conductor V4 formed on the base material layer 14. The other end of the coil conductor pattern 34 is connected to a plurality of mounting electrodes P2 (connecting conductors 42) via an interlayer connecting conductor V5 formed on the base material layer 15. For these interlayer connection conductors, for example, a conductive paste containing a metal powder of one or more metals of Cu and Sn or an alloy thereof and a resin component is disposed in a through hole provided in a base material layer, and then in a laminating process. It is a via conductor provided by solidifying by heat pressing treatment.

In this way, the coil conductor patterns 31, 32, 33, 34 and the interlayer connecting conductors V2, V3, V4 are used to provide the winding shaft in the stacking direction (Z-axis direction) of the base material layers 11, 12, 13, 14, and 15. A coil 3 having about 12 turns is configured. Further, one end of the coil 3 is connected to a connecting conductor 41 (a plurality of mounting electrodes P1), and the other end of the coil 3 is connected to a connecting conductor 42 (a plurality of mounting electrodes P2).

As described above, the mounting electrode P1 is a part of the connecting conductor 41 exposed to the first main surface VS1, and the mounting electrode P2 is a part of the connecting conductor 42 exposed to the first main surface VS1. .. Therefore, if the connecting conductors 41 and 42 have a large area, it is easy to form mounting electrodes P1 and P2 having an arbitrary shape, and it is also easy to form mounting electrodes P1 and P2 having a large area. It is easy to arrange a plurality of mounting electrodes P1 and P2 having the same potential at various positions. That is, by increasing the area of the connecting conductors 41 and 42, the degree of freedom in arranging the mounting electrodes P1 and P2 formed on the first main surface VS1 is increased.

Further, as shown in FIG. 3B, the connecting conductors 41 and 42 overlap the coil 3 when viewed from the Z-axis direction. Further, in the present embodiment, as shown in FIG. 3B, a part of the mounting electrodes P1 and P2 (connecting conductors 41 and 42) has a plurality of base material layers 11, 12, 13, 14 and 15. Of these, it is buried in the base material layer 15 located on the VS1 side of the first main surface.

Further, in the present embodiment, as shown in FIGS. 3A and 3B, the plurality of openings SL11, SL12, SL21, SL22 do not overlap the coil conductor patterns 31, 32, 33, 34. , Are arranged along the coil conductor patterns 31, 32, 33, 34.

Here, "arranged along the coil conductor pattern" in the present invention means, for example, that the angle between the stretching direction of the opening of the connecting conductor and the stretching direction of the coil conductor pattern is -30 ° to + 30 °. Say if it is within the range of.

The multilayer board 101 according to this embodiment is manufactured by, for example, the following manufacturing method. Here, for convenience of explanation, the manufacturing process with one chip (individual piece) will be described, but the actual manufacturing process of the multilayer board 101 is performed in the state of an assembled board. The "aggregate substrate" is a mother substrate including a plurality of multilayer boards 101.

(1) First, a plurality of base material layers 11, 12, 13, 14, and 15 are prepared. The base material layers 11, 12, 13, 14, and 15 are sheets mainly made of a thermoplastic resin such as a liquid crystal polymer (LCP) or a polyetheretherketone (PEEK).

After that, the coil conductor patterns 31, 32, 33, 34 and the connecting conductors 41, 42 are formed on the plurality of base material layers 11, 12, 13, 14, and 15, respectively. Specifically, a metal foil (for example, Cu foil) is laminated on one side main surface (back surface) of the substrate layers 11, 12, 13, 14, and 15 in the assembled substrate state, and the metal foil is patterned by photolithography. .. As a result, the coil conductor pattern 31 is formed on the back surface of the base material layer 11, the coil conductor pattern 32 is formed on the back surface of the base material layer 12, and the coil conductor pattern 33 is formed on the back surface of the base material layer 13. The coil conductor pattern 34 is formed on the back surface of the layer 14, and the connecting conductors 41 and 42 are formed on the back surface of the base material layer 15.

The connecting conductor 41 is provided with a plurality of openings SL11 and SL12. The openings SL11 and SL12 are long (rectangular) through holes surrounded by conductors constituting the connecting conductor 41. Further, the connecting conductor 42 is provided with a plurality of openings SL21 and SL22. The openings SL21 and SL22 are long (rectangular) through holes surrounded by conductors constituting the connecting conductor 42.

Further, the interlayer connection conductors V1, V2, V3, V4, V5 are formed on the plurality of base material layers 12, 13, 14, and 15. For the interlayer connection conductor, after forming through holes in the base material layers 12, 13, 14, and 15 with a laser or the like, a conductive paste containing one or more of Cu, Sn, etc. or an alloy thereof is arranged, and later. It is provided by curing with a heating press.

(2) Next, a plurality of base material layers 15, 14, 13, 12, 11 are laminated in this order, and the plurality of base material layers 11, 12, 13, which are laminated in the stacking direction (Z-axis direction). 14 and 15 are heat-pressed to form a laminated body in an aggregate substrate state.

After that, the protective layer 1 is laminated on the back surface of the laminated body (the back surface of the base material layer 15) to form the laminated body 10 in the assembled substrate state. The protective layer 1 has a plurality of openings. Therefore, even when the protective layer 1 is formed on the back surface of the laminated body, a part of the connecting conductors 41 and 42 is exposed to the outside. A part of the connecting conductor 41 exposed from the opening of the protective layer 1 is the mounting electrode P1, and a part of the connecting conductor 42 exposed from the opening of the protective layer 1 is the mounting electrode P2.

(3) Finally, the laminated body 10 in the assembled substrate state is separated into individual pieces to obtain individual multilayer substrates 101.

According to the above manufacturing method, the multilayer substrate 101 can be easily formed by laminating a plurality of substrate layers 11, 12, 13, 14, and 15 and heat-pressing (batch pressing), so that the multilayer substrate 101 can be manufactured. The number of processes can be reduced and the cost can be kept low.

Further, according to the above manufacturing method, the conductive paste can be arranged in the holes provided in the base material layer, and the conductive paste can be solidified by a heating press (collective press), so that a step of forming an interlayer connection conductor can be formed. Can be reduced.

The multilayer board of the present invention is used, for example, as shown below. FIG. 4 is a cross-sectional view of a main part of the electronic device 301 according to the first embodiment.

The electronic device 301 includes a multilayer board 101, a circuit board 201, and the like. The circuit board 201 is, for example, a glass / epoxy board. The electronic device 301 also has a configuration other than the above, but is not shown in FIG.

The multilayer board 101 is mounted on the circuit board 201. Specifically, the mounting electrode P1 of the multilayer board 101 is bonded to the external electrode EP1 formed on the first surface S1 of the circuit board 201 via a conductive bonding material 5 such as solder. Further, the mounting electrode P2 of the multilayer board 101 is bonded to the external electrode EP2 formed on the first surface S1 of the circuit board 201 via the conductive bonding material 5.

Next, the advantages of having a plurality of openings in the connecting conductor will be described with reference to comparative examples. FIG. 5A is a plan view showing a layer in which the connecting conductors 41 and 42 are formed in the multilayer board 101, and FIG. 5B is a connecting conductor 41A in the multilayer board 100 which is a comparative example. , 42A is a plan view showing a layer formed.

The multilayer board 100, which is a comparative example, is different from the multilayer board 101 in that the connecting conductors 41A and 42A have one opening. Specifically, the opening SL10 is formed in the connecting conductor 41A, and the opening SL20 is formed in the connecting conductor 42A. Other configurations of the multilayer board 100 are the same as those of the multilayer board 101.

When the multilayer board includes a large-area connecting conductor, the magnetic flux generated from the coil is obstructed by the connecting conductor, and the inductance of the coil is lowered. However, when the large openings SL10 and SL20 are formed in the connecting conductor as in the multilayer board 100 of the comparative example shown in FIG. 5B, a part of the magnetic flux generated from the coil (magnetic flux φ0) is generated. It passes through the openings SL10 and SL20 without being hindered by the connecting conductors 41A and 42A. When the magnetic flux φ0 passes through the openings SL10 and SL20, an eddy current i0 is generated in a direction that cancels the magnetic flux φ0, but the magnetic flux φ0 is not completely canceled because the areas of the openings SL10 and SL20 are large. Passes through the openings SL10 and SL20. Further, according to this configuration, the eddy current generated in the connecting conductors 41A and 42A can be reduced and the loss can be reduced as compared with the case where the connecting conductor is not provided with a large opening.

On the other hand, the multilayer substrate 101 according to the present embodiment includes a connecting conductor 41 having a plurality of openings SL11 and SL12, and a connecting conductor 42 having a plurality of openings SL21 and SL22. For example, when a part of the magnetic flux generated from the coil (magnetic flux φ1 in FIG. 5A) passes through both of the plurality of openings SL11 and SL12 of the connecting conductor 41, the eddy current cancels out the magnetic flux φ1. (Currents i11, i12 in FIG. 5A). At this time, since an eddy current in the opposite direction is induced in the conductor portion sandwiched between the plurality of openings SL11 and SL12, it is difficult for the eddy current to flow. Therefore, when a plurality of openings SL11 and SL12 are formed in the connecting conductor 41, the same effect as in the case where a large opening is formed in the connecting conductor as in the multilayer board 100 of the comparative example is obtained. .. This also applies to the connecting conductor 42. That is, by providing a plurality of openings in the connecting conductor, it is possible to prevent the magnetic flux from the coil from being obstructed by the connecting conductor without providing a large opening in the connecting conductor.

Therefore, by adopting the configuration according to the present embodiment, the degree of freedom in the arrangement of the mounting electrodes P1 and P2 formed on the first main surface VS1 is increased, the inductance of the coil 3 is reduced, and the eddy current flowing through the connecting conductor is increased. It is possible to realize a multilayer board that suppresses loss due to current. Further, according to the above configuration, the area of the conductor portion of the connecting conductor can be increased as compared with the case where a large opening is provided in the connecting conductor, so that the potential of the connecting conductor is stabilized and the potential difference in the connecting conductor is increased. Can be less likely to occur.

Further, in the present embodiment, the laminated body 10 is formed by laminating a plurality of base material layers 11, 12, 13, 14, and 15 made of a thermoplastic resin. According to this configuration, the laminated body 10 can be easily formed by heat-pressing (collectively pressing) a plurality of laminated base material layers 11, 12, 13, 14, and 15, so that the manufacturing process of the multilayer substrate 101 can be performed. It can be reduced and the cost can be kept low. Further, with this configuration, it is possible to realize a multilayer substrate that can be easily plastically deformed and can maintain (retain) a desired shape.

When a plurality of base material layers constituting the laminate are made of a resin material as in the present embodiment, when heat of a predetermined temperature or higher is received, a part of the base layer is thermally decomposed to release gas such as _{CO 2 and water.} Occurs. When the multilayer board is heated while such gas and water are left in the multilayer board, the gas (gas or steam) expands and delamination is likely to occur. Therefore, usually, at the time of manufacturing a multilayer substrate, a heating press is performed under reduced pressure, and a predetermined preheating step is provided to discharge gas to the outside of the laminate during the heating press.

If the multilayer substrate has a metal pattern having a large area (for example, a conductor pattern such as connecting conductors 41 and 42), the gas cannot pass through this metal pattern. Therefore, depending on the location where the gas is generated, the gas discharge path to the outside of the multilayer board may be longer than that in the case where the conductor pattern is not provided, and the gas may remain in the multilayer board. On the other hand, in the present embodiment, since the connecting conductors 41 and 42 are provided with a plurality of openings (SL11, SL12, SL21, SL22), the gas generated inside when the multilayer board is heated is discharged shortly through these openings. It is discharged through the route. That is, according to this configuration, the amount of gas remaining in the multilayer board is reduced, delamination of the multilayer board during heating (during heating at the manufacturing stage and use stage of the multilayer board) is reduced, and the characteristics of the coil and the like are reduced. Uniformity is maintained. In addition, the occurrence of unevenness and bending on the surface of the multilayer board due to residual gas is suppressed, and the flatness of the multilayer board is improved, so that the mountability of the multilayer board on a circuit board or the like is improved.

Further, in the present embodiment, the interlayer connecting conductors V1, V2, V3, V4, V5 formed in the laminated body are via conductors formed by solidifying a conductive paste containing a resin material. Since these via conductors are simultaneously formed by heat pressing the plurality of base material layers 11, 12, 13, and 14, they are easy to form. Further, since the conductive paste contains a resin material, high bondability between the base material layer containing the resin as the main material and the interlayer connecting conductor can be obtained. The resin material contained in the conductive paste is preferably the same as the resin material of the base material layer.

However, the via conductor containing the resin material has a large amount of gas generated during heating, and the multilayer substrate provided with such a via conductor is delaminated during heating (during heating in the manufacturing stage and the stage of use) and is a multilayer substrate. Surface irregularities, curves, etc. are likely to occur. Therefore, when the interlayer connecting conductors V1, V2, V3, V4, and V5 are via conductors containing a resin material, it is preferable to provide openings of the connecting conductors 41 and 42 in the vicinity of these interlayer connecting conductors. As a result, the gas generated from the via conductor when the multilayer board is heated can be efficiently discharged, delamination of the multilayer board can be suppressed, and the flatness of the multilayer board can be improved.

Further, in the present embodiment, as shown in FIG. 3B, a part of the mounting electrodes P1 and P2 (connecting conductors 41 and 42) is embedded in the base material layer 15. According to this configuration, the flatness of the first main surface VS1 can be improved even in a structure in which the connecting conductors 41 and 42 are provided with a plurality of openings SL11, SL12, SL21, SL22. Therefore, the mountability of the multilayer board on a circuit board or the like can be improved. When a plurality of substrate layers 11, 12, 13, 14 made of a thermoplastic resin are heat-pressed to form a laminated body as in the present embodiment, a part of the mounting electrodes P1 and P2 is used as a base. A multilayer substrate with a structure embedded in a material layer can be easily realized.

When a part of the coil conductor pattern overlaps the opening provided in the connecting conductor, the flow of the resin becomes irregular during the heating press, and the coil conductor pattern is misaligned (or deformed) or the surface of the laminated body is formed. There is a risk of unevenness. On the other hand, in the present embodiment, the coil conductor pattern 34 closest to the connecting conductors 41 and 42 does not overlap the plurality of openings SL11, SL12, SL21 and SL22 when viewed from the Z-axis direction, and a plurality of openings SL11, SL12, SL21 and SL22 are not overlapped with each other. It is arranged along the openings SL11, SL12, SL21, and SL22. According to this configuration, the regularity of the flow of the resin during the heating press is maintained, and the misalignment of the coil conductor pattern during the heating press is suppressed. When a plurality of coil conductor patterns 31, 32, 33, 34 are provided as in the present embodiment, all of the plurality of coil conductor patterns 31, 32, 33, 34 are a plurality when viewed from the Z-axis direction. It is preferable that the openings SL11, SL12, SL21, and SL22 do not overlap with each other and are arranged along a plurality of openings SL11, SL12, SL21, and SL22.

<< Second Embodiment >>
The second embodiment shows a multilayer substrate having a coil shape different from that of the first embodiment.

FIG. 6A is an external perspective view of the multilayer board 102 according to the second embodiment, and FIG. 6B is an external perspective view of the multilayer board 102 as viewed from another viewpoint. FIG. 7 is an exploded plan view of the multilayer board 102. FIG. 8 is a cross-sectional view taken along the line BB in FIG. 6 (A).

The multilayer board 102 is different from the multilayer board 101 according to the first embodiment in that the coil 3A is provided. The coil 3A differs from the coil 3 included in the multilayer substrate 101 in that it has loop-shaped coil conductor patterns 31a, 32a, 33a, 34a. Other configurations of the multilayer board 102 are substantially the same as those of the multilayer board 101.

Hereinafter, a portion different from the multilayer board 101 according to the first embodiment will be described.

The coil conductor pattern 31a is a loop-shaped conductor pattern formed on the back surface of the base material layer 11, and is arranged near the center of the base material layer 11. The coil conductor pattern 32a is a loop-shaped conductor pattern formed on the back surface of the base material layer 12, and is arranged near the center of the base material layer 12. The coil conductor pattern 33a is a loop-shaped conductor pattern formed on the back surface of the base material layer 13, and is arranged near the center of the base material layer 13. The coil conductor pattern 34a is a loop-shaped conductor pattern arranged on the back surface of the base material layer 14, and is arranged near the center of the base material layer 14. The coil conductor patterns 31a, 32a, 33a, 34a are conductor patterns such as Cu foil.

As shown in FIG. 7 and the like, the plurality of mounting electrodes P1 (connecting conductors 41) are connected to one end of the coil conductor pattern 31a via the interlayer connecting conductor V1. The other end of the coil conductor pattern 31a is connected to one end of the coil conductor pattern 32a via the interlayer connection conductor V2. The other end of the coil conductor pattern 32a is connected to one end of the coil conductor pattern 33a via the interlayer connection conductor V3. The other end of the coil conductor pattern 33a is connected to one end of the coil conductor pattern 34a via the interlayer connection conductor V4. The other end of the coil conductor pattern 34a is connected to a plurality of mounting electrodes P2 (connecting conductor 42) via the interlayer connection conductor V5.

As described above, the coil conductor patterns 31a, 32a, 33a, 34a and the interlayer connecting conductors V2, V3, V4 form a rectangular helical coil 3A having about 3.5 turns having a winding axis in the Z-axis direction. ..

Even with such a configuration, the basic configuration of the multilayer board 102 is the same as that of the multilayer board 101 according to the first embodiment, and has the same effect as that of the multilayer board 101.

<< Third Embodiment >>
In the third embodiment, a multilayer substrate having a structure in which the mounting electrodes are connected to the connecting conductor via the interlayer connecting conductor is shown.

9 (A) is an external perspective view of the multilayer board 103 according to the third embodiment, and FIG. 9 (B) is an external perspective view of the multilayer board 103 as viewed from another viewpoint. FIG. 10 is an exploded plan view of the multilayer board 103. 11 is a cross-sectional view taken along the line CC in FIG. 9A. In FIG. 10, the coil conductor pattern 31b is shown as a dot pattern in order to make the structure easy to understand.

The multilayer board 103 includes a laminated body 10B, a coil 3B, a plurality of mounting electrodes P1B and P2B, connecting conductors 41B and 42B, and the like.

The coil 3B is different from the coil 3 included in the multilayer substrate 101 according to the first embodiment in that the coil 3B is composed of the coil conductor pattern 31b. Further, the mounting electrodes P1B and P2B are different from the mounting electrodes P1 and P2 included in the multilayer board 101 in that they are not a part of the connecting conductor. Other configurations of the multilayer board 103 are substantially the same as those of the multilayer board 101.

Hereinafter, a portion different from the multilayer board 101 according to the first embodiment will be described.

The laminated body 10B is formed by laminating a plurality of base material layers 14b, 13b, 12b, 11b in this order. The base material layers 11b, 12b, 13b, 14b are substantially the same as the base material layers 11, 12, 13, 14 described in the first embodiment.

A coil conductor pattern 31b is formed on the back surface of the base material layer 11. The coil conductor pattern 31b is a rectangular spiral conductor pattern having about 2.5 turns arranged near the center of the base material layer 11b. The coil conductor pattern 31b is a conductor pattern such as a Cu foil.

A conductor 21 is formed on the back surface of the base material layer 12b. The conductor 21 is a linear conductor pattern extending in the X-axis direction from the vicinity of the center of the base material layer 12b toward the second side (the left side of the base material layer 12b in FIG. 10). The conductor 21 is a conductor pattern such as a Cu foil.

Connection conductors 41B and 42B are formed on the back surface of the base material layer 13b. The connecting conductor 41B is a rectangular conductor pattern arranged near the first side of the base material layer 13b (the left side of the base material layer 13b in FIG. 10). The connecting conductor 42B is a rectangular conductor pattern arranged near the second side of the base material layer 13b (the right side of the base material layer 13b in FIG. 10).

The connecting conductor 41B has elongated openings SL11 and SL12B surrounded by conductors constituting the connecting conductor 41B. The connecting conductor 42B has long openings SL21 and SL22B surrounded by conductors constituting the connecting conductor 42B. The openings SL11 and SL21 are the same as those described in the first embodiment. The opening SL12B is an L-shaped through hole that has a bent portion and extends in two directions (+ Y direction and + X direction). The opening SL22B is an L-shaped through hole that has a bent portion and extends in two directions (+ Y direction and −X direction).

A plurality of mounting electrodes P1B and P2B are formed on the back surface of the base material layer 14b. The mounting electrode P1B is a rectangular conductor pattern arranged near the first side (left side of the base material layer 14b in FIG. 10) of the base material layer 14b. The mounting electrode P2B is a rectangular conductor pattern arranged near the second side (the right side of the base material layer 14b in FIG. 10) of the base material layer 14b. The mounting electrodes P1B and P2B are conductor patterns such as Cu foil.

As shown in FIGS. 10 and 11 and the like, the plurality of mounting electrodes P1B are each connected to the connecting conductor 41B via the interlayer connecting conductor V11 formed on the base material layer 14b. The connecting conductor 41B is connected to one end of the coil conductor pattern 31b via the interlayer connecting conductor V1 formed on the base material layers 12b and 13b. The other end of the coil conductor pattern 31b is connected to one end of the conductor 21 via the interlayer connecting conductor V2 formed on the base material layer 12b. The other end of the conductor 21 is connected to the connecting conductor 42B via the interlayer connecting conductor V3 formed on the base material layer 13b. The connecting conductor 42B is connected to a plurality of mounting electrodes P2B via the interlayer connecting conductor V12 formed on the base material layer 14b.

In this embodiment, the coil conductor pattern 31b constitutes the coil 3B. One end of the coil 3B is connected to a plurality of mounting electrodes P1B, and the other end of the coil 3B is connected to a plurality of mounting electrodes P2B.

Further, in the present embodiment, the plurality of mounting electrodes P1B are connected to the connecting conductor 41B, and the plurality of mounting electrodes P2B are connected to the connecting conductor 42B. That is, the mounting electrodes P1B and P2B according to the present embodiment are not a part of the connecting conductors (41B and 42B), but are separate bodies.

Even with such a configuration, the basic configuration of the multilayer board 103 is the same as that of the multilayer board 101 according to the first embodiment, and has the same effect as that of the multilayer board 101.

As shown in the present embodiment, the opening provided in the connecting conductor may have a bent portion and may have a shape extending in at least two directions. The number, shape, and arrangement of the openings provided in the connecting conductor can be appropriately changed within the range in which the action and effect of the present invention are exhibited. The planar shape of the opening may be, for example, U-shaped, arc-shaped, crank-shaped, or the like as long as it is long.

Further, as shown in the present embodiment, in the multilayer substrate of the present invention, the protective layer formed on the first main surface VS1 of the laminated body is not essential.

<< Other Embodiments >>
In each of the embodiments shown above, an example is shown in which the multilayer board is an electronic component mounted on another circuit board or the like, but the multilayer board of the present invention is not limited thereto. The multilayer board of the present invention may be a cable connecting two members, a cable connecting another circuit board and a component, or the like. Further, the laminated body of the multilayer board may have a structure having a bent portion only in a part thereof.

In each of the above embodiments, an example in which the laminated bodies 10 and 10B are rectangular flat plates is shown, but the present invention is not limited to this configuration. The shape of the laminated body can be appropriately changed as long as the action / effect of the present invention is exhibited. The planar shape of the laminated body may be, for example, polygonal, L-shaped, crank-shaped, T-shaped, Y-shaped, or the like.

Further, in each of the above-described embodiments, an example of a laminated body in which 4 or 5 base material layers are laminated is shown, but the laminated body of the present invention is not limited to this. The number of layers of the base material layer forming the laminate can be appropriately changed within the range in which the action and effect of the present invention are exhibited.

In each of the above embodiments, the laminated body is an example of a flat plate made of a thermoplastic resin, but the present invention is not limited to this configuration. The laminate may be, for example, a flat plate made of a thermosetting resin, or a dielectric ceramic of low-temperature co-fired ceramics (LTCC). Further, the laminate may be a composite laminate of a plurality of resins, or may be formed by laminating a thermosetting resin sheet such as a glass / epoxy substrate and a thermoplastic resin sheet. Further, the laminate is not limited to one in which a plurality of base material layers are heat-pressed (collectively pressed) to fuse the surfaces thereof, and may have a structure in which an adhesive layer is provided between the layers of each base material.

In this embodiment, an example is shown in which the interlayer connecting conductors V1, V2, V3, V4, V5, V11, and V12 are via conductors formed by solidifying a conductive paste, but the present invention is not limited to this configuration. No. The interlayer connecting conductor formed in the laminated body may be, for example, through-hole plating (through-hole in which a plating film such as Cu is formed on the inner wall). In this case, the amount of gas generated can be reduced as compared with the case where the interlayer connecting conductor is a via conductor containing a resin component.

Further, the circuit configuration formed on the multilayer board is not limited to the configuration of each embodiment shown above, and can be appropriately changed as long as the operation and effect of the present invention are exhibited. The circuit formed on the multilayer substrate may be formed with a frequency filter such as a capacitor formed by a conductor pattern and various filters (low-pass filter, high-pass filter, band-pass filter, band-elimination filter). Further, for example, other various transmission lines (microstrip line, mianda, coplanar, etc.) may be formed on the multilayer board. Further, various electronic components such as chip components may be mounted or embedded in the multilayer board.

Further, in each of the above-described embodiments, an example of a multilayer substrate including two connecting conductors having a rectangular planar shape is shown, but the present invention is not limited to this configuration. The number, shape, arrangement, etc. of the connecting conductors can be appropriately changed within the range in which the action and effect of the present invention are exhibited. The planar shape of the connecting conductor may be, for example, polygonal, L-shaped, crank-shaped, T-shaped, Y-shaped, circular, elliptical, or the like.

Further, in each of the above-described embodiments, an example of a multilayer substrate including three mounting electrodes P1 having a rectangular planar shape and three mounting electrodes P2 having a rectangular planar shape is shown. Not limited. The number, shape, arrangement, etc. of the mounting electrodes can be appropriately changed within the range in which the action and effect of the present invention are exhibited. The planar shape of the mounting electrode may be, for example, polygonal, L-shaped, L-shaped, crank-shaped, T-shaped, Y-shaped, circular, elliptical, or the like. Further, the mounting electrodes may be provided on, for example, the first main surface VS1 and the second main surface VS2, respectively.

Finally, the description of the embodiments described above is exemplary in all respects and not restrictive. Modifications and changes can be made as appropriate for those skilled in the art. The scope of the invention is indicated by the claims, not by the embodiments described above. Further, the scope of the present invention includes modifications from the embodiments within the scope of the claims and within the scope of the claims.

AP1, AP2 ... Opening EP1 ... External electrodes P1, P1B, P2, P2B of the circuit board ... Mounting electrodes S1 ... First surface of the circuit board SL10, SL11, SL12, SL12B, SL20, SL21, SL22, SL22B ... Openings V1, V2 , V3, V4, V5, V11, V12 ... Interlayer connection conductor VS1 ... First main surface of laminated body VS2 ... Second main surface of laminated body 1 ... Protective layer 3, 3A, 3B ... Coil 5 ... Conductive bonding material 10 , 10B ... Laminated 11 ... Base material layer 11, 12, 13, 14 ... Base material layer 11, 11b, 12, 12b, 13, 13b, 14, 14b, 15 ... Base material layer 21 ... Conductor 31, 31a, 31b , 32, 32a, 33, 33a, 34, 34a ... Coil conductor pattern 41, 41A, 41B, 42, 42A, 42B ... Connection conductor 100, 101, 102, 103 ... Multilayer board 201 ... Circuit board 301 ... Electronic equipment

Claims (8)

A laminate having a mounting surface and containing a plurality of base material layers,
A coil formed in the laminated body and having a winding axis in the laminating direction of the plurality of base materials,
The mounting electrode formed on the mounting surface and
A connecting conductor formed in the laminated body and having a plurality of openings,
Equipped with
The plurality of openings have a long shape surrounded by conductors constituting the connecting conductor.
The connecting conductor overlaps the coil when viewed from the stacking direction.
The mounting electrode is a multilayer substrate that is a part of the connecting conductor exposed on the mounting surface. A laminate having a mounting surface and containing a plurality of base material layers,
A coil formed in the laminated body and having a winding axis in the laminating direction of the plurality of base materials,
The mounting electrode formed on the mounting surface and
A connecting conductor formed in the laminated body and having a plurality of openings,
Equipped with
The plurality of openings have a long shape surrounded by conductors constituting the mounting electrode.
The mounting electrode is a multilayer substrate connected to the connecting conductor. The multilayer substrate according to claim 1 or 2, wherein the plurality of openings have a bent portion and extend in at least two directions. The multilayer substrate according to any one of claims 1 to 3, wherein the plurality of substrate layers are made of a resin material. The multilayer substrate according to claim 4, wherein the resin material is a thermoplastic resin. The multilayer substrate according to claim 4 or 5, wherein a part of the mounting electrodes is embedded in a base material layer located closest to the mounting surface side among the plurality of base material layers. The coil has a coil conductor pattern formed on at least one of the plurality of substrate layers.
The multilayer substrate according to any one of claims 4 to 6, wherein the plurality of openings do not overlap with the coil conductor pattern when viewed from the stacking direction, and are arranged along the coil conductor pattern. The multilayer board according to any one of claims 1 to 7.
With the circuit board
Equipped with
The mounting electrode is an electronic device that is bonded to the circuit board via a conductive bonding material.

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