JP2019016743A - Multilayer substrate - Google Patents

Abstract

To achieve a multilayer substrate having a constitution where a stepped part is formed at a boundary between a first region and a second region due to a difference in the number of lamination layers of insulating base material layers to inhibit variation in coil properties, which is caused by positional deviation of coil conductor patterns located near the stepped part.SOLUTION: A multilayer substrate 101 comprises a laminate 10 having a first region F1 and a second region F2, a stepped part SP and a coil 3 formed in the first region F1. The laminate 10 is formed by lamination of resin-based insulating base material layers in which the number of lamination layers is smaller in the second region F2 than in the first region F1. The stepped part SP is formed at a boundary between the first region F1 and the second region F2 due to a difference in the number of lamination layers of the insulating base material layers. The coil 3 is formed to include coil conductor patterns 31, 32, 33 and a first interlayer connection conductor (interlayer connection conductors V11, V12). The first interlayer connection conductor is arranged at a part ADP along and closer to the stepped part SP out of the coil conductor patterns 31, 32, 33 when viewed from a lamination direction (Z-axis direction) of the insulating base material layers.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a multilayer substrate, and more particularly to a multilayer substrate including a laminate in which a plurality of insulating base layers made mainly of a resin are laminated, and a coil formed in the laminate.

  2. Description of the Related Art Conventionally, various multilayer substrates including a laminate formed by laminating a plurality of insulating base layers mainly composed of a resin and a coil formed on the laminate are known.

  For example, Patent Document 1 discloses a multilayer substrate including a laminated body having a thick portion (hereinafter referred to as a first region) and a thin portion (hereinafter referred to as a second region), and a coil formed in the first region. It is disclosed. In the multilayer substrate, the coil includes a plurality of coil conductor patterns respectively formed on two or more insulating base layers and an interlayer connection conductor that connects the plurality of coil conductor patterns. The plurality of coil conductor patterns are arranged so as to overlap each other when viewed from the stacking direction of the plurality of insulating base layers.

  In the multilayer substrate, since the number of laminated insulating base material layers in the second region is smaller than the number of laminated insulating base material layers in the first region, the second region has flexibility, and the first region and the first region There are stepped portions having different numbers of layers near the boundary between the two regions.

International Publication No. 2015/083525

  Generally, a multilayer substrate (laminated body) as shown in Patent Document 1 is obtained by heating and pressing a plurality of laminated insulating base material layers using a mold corresponding to the shape of the stepped portion.

  FIG. 6 is a cross-sectional view showing a part of the manufacturing process of the multilayer substrate having a stepped portion. As shown in FIG. 6, the multilayer substrate (laminated body) includes a plurality of laminated insulating base material layers 11a, 12a, 13a, 14a, and 15a in the laminating direction (Z-axis direction) using molds 1a and 2a. Obtained by heating and pressing. On the surface of the mold 2a, a stepped portion SP2a corresponding to the shape of the stepped portion SP1a of the laminated body is formed. However, it is difficult to completely match the shape of the mold 2a with the stepped portion SP1a of the laminate, and the height H2 of the stepped portion SP2a of the mold 2a is set to be a stepped portion in order to suppress poor bonding during heating and pressing. In general, it is formed smaller than the height H1 of the portion SP1a.

  However, in the manufacturing method described above, the characteristics of the coil may vary due to the following reasons.

(A) A higher pressure is applied to the first region where the number of insulating base material layers is greater than that of the second region where the number of insulating base material layers is smaller during heating and pressurization. Therefore, at the time of heating and pressurizing, the insulating base material layer containing resin as a main material flows from the first region toward the second region. At this time, the flow of the insulating base material layer in the vicinity of the stepped portion SP1a is particularly large (see the arrow in FIG. 6), and the displacement of the coil conductor pattern located in the vicinity of the stepped portion SP1a occurs with the flow of the insulating base material layer. Cheap.

(B) Since the pressure is concentrated and applied to the portion where the plurality of coil conductor patterns are overlapped in the stacking direction of the plurality of insulating base layers, the positional deviation of the coil conductor pattern is large. Prone.

(C) Further, the vicinity of the stepped portion SP1a has a large area in contact with the mold 2a (for example, the right end surface of the insulating base layers 13a, 14a, and 15a in FIG. 6 and the bottom surface of the insulating base layer 15a). It is easily affected by heat from the press during heating and pressurization. Therefore, the insulating base material layer in the vicinity of the stepped portion SP1a tends to flow during heating and pressurization, and the coil conductor pattern located in the vicinity of the stepped portion SP1a is likely to be displaced.

  An object of the present invention is due to a displacement of a coil conductor pattern located in the vicinity of a stepped portion in a configuration in which a stepped portion is formed at the boundary between the first region and the second region due to a difference in the number of laminated insulating base layers. An object of the present invention is to provide a multilayer substrate in which fluctuations in coil characteristics are suppressed.

(1) The multilayer substrate of the present invention is
A laminate having a plurality of insulating base material layers made of resin as a main material, and having a second region in which the number of the insulating base material layers is less than the first region, and the first region;
A step portion formed at a boundary between the first region and the second region due to a difference in the number of stacked layers of the plurality of insulating base layers;
A coil formed in the first region;
With
The coil is formed on the insulating base layer and a plurality of coil conductor patterns formed on two or more insulating base layers among the plurality of insulating base layers, and connects the plurality of coil conductor patterns to each other. A first interlayer connection conductor, and
The plurality of coil conductor patterns are arranged so that at least some of them overlap each other when viewed from the stacking direction of the plurality of insulating base material layers,
The first interlayer connection conductor is disposed in a portion of the plurality of coil conductor patterns that are close to each other along the step portion when viewed from the stacking direction.

  Generally, in the vicinity of the stepped portion, a high pressure is applied at the time of heating and pressurization, and it is easily affected by heat from the press, so that the flow of the insulating base material layer at the time of heating and pressurization is large. On the other hand, in the above configuration, the first interlayer connection conductor that is less likely to be displaced than the coil conductor pattern at the time of heating and pressurization is disposed in a portion adjacent to the stepped portion of the coil conductor pattern. The flow of the insulating base material layer in the vicinity of the step portion is suppressed by the first interlayer connection conductor. Therefore, with this configuration, it is possible to suppress misalignment or deformation of the coil conductor pattern located in the vicinity of the step portion during heating and pressurization, and it is possible to suppress changes in the coil characteristics due to misalignment or deformation of the coil conductor pattern.

(2) In the above (1), a dummy conductor pattern formed on the insulating base layer is provided, and the dummy conductor pattern is disposed at a position close to the stepped portion when viewed from the stacking direction. preferable. In this configuration, the dummy conductor pattern existing between the step portion and the coil further suppresses the flow of the insulating base material layer near the step portion during heating and pressurization.

(3) In said (2), it is preferable that the said dummy conductor pattern is arrange | positioned along the said level | step-difference part seeing from the said lamination direction. With this configuration, the flow of the insulating base material layer in the vicinity of the step portion during heating and pressurization is more effectively suppressed.

(4) In said (2) or (3), it is preferable that the said dummy conductor pattern is arrange | positioned so that it may straddle the said level | step-difference part seeing from the said lamination direction. With this configuration, the flow of the insulating base material layer in the vicinity of the step portion during heating and pressurization is further suppressed as compared with the case where the dummy conductor pattern is not disposed so as to straddle the step portion. Further, with this configuration, it is possible to increase the mechanical strength in the vicinity of the stepped portion after the stacked body is formed. Furthermore, with this configuration, it is possible to realize a multilayer substrate that can easily plastically deform (bend) the second region in the vicinity of the stepped portion.

(5) In any one of the above (2) to (4), the dummy conductor pattern is a plurality of dummy conductor patterns formed on two or more insulating base layers among the plurality of insulating base layers. A second interlayer connection conductor formed in the first region and connecting the plurality of dummy conductor patterns is provided, and the second interlayer connection conductor is disposed at a position close to the step portion when viewed from the stacking direction. It is preferred that In this configuration, the second interlayer connection conductor that is less likely to be displaced than the coil conductor pattern during heating and pressurization is disposed between the coil and the stepped portion. Therefore, the flow of the insulating base material layer in the vicinity of the step portion during heating and pressurization is further suppressed by the second interlayer connection conductor.

(6) In any one of the above (1) to (5), the plurality of insulating base layers are preferably made of a thermoplastic resin. According to this configuration, a laminated body can be easily formed by collectively pressing a plurality of laminated insulating base layers, so that the manufacturing process of the multilayer substrate can be reduced and the cost can be kept low.

  According to the present invention, in the configuration in which the stepped portion is formed at the boundary between the first region and the second region due to the difference in the number of laminated insulating base material layers, the coil conductor pattern located near the stepped portion is displaced. A multilayer substrate that suppresses fluctuations in coil characteristics can be realized.

FIG. 1A is a cross-sectional view of the multilayer substrate 101 according to the first embodiment, and FIG. 1B is a plan view of the multilayer substrate 101. FIG. 2 is an exploded plan view of the multilayer substrate 101. FIG. 3 is a circuit diagram of the communication module 201 including the multilayer substrate 101. 4A is a cross-sectional view of the multilayer substrate 102 according to the second embodiment, and FIG. 4B is a plan view of the multilayer substrate 102. FIG. 5 is an exploded plan view of the multilayer substrate 102. FIG. 6 is a cross-sectional view showing a part of the manufacturing process of the multilayer substrate having a stepped portion.

  Hereinafter, several specific examples will be given with reference to the drawings to show a plurality of modes for carrying out the present invention. In each figure, the same reference numerals are assigned to the same portions. In consideration of ease of explanation or understanding of the main points, the embodiments are shown separately for convenience, but the components shown in different embodiments can be partially replaced or combined. In the second and subsequent embodiments, description of matters common to the first embodiment is omitted, and only different points will be described. In particular, the same operation effect by the same configuration will not be sequentially described for each embodiment.

<< First Embodiment >>
FIG. 1A is a cross-sectional view of the multilayer substrate 101 according to the first embodiment, and FIG. 1B is a plan view of the multilayer substrate 101. FIG. 2 is an exploded plan view of the multilayer substrate 101. In FIG. 2, the coil conductor patterns 31, 32, and 33 are shown as dot patterns for easy understanding of the structure. In FIG. 1, the thickness of each part is exaggerated. The same applies to the cross-sectional views shown below.

  The multilayer substrate 101 includes a laminated body 10, a stepped portion SP, a coil 3, external connection electrodes P1, P2, and the like.

  The laminate 10 has a first region F1 and a second region F2, and the coil 3 is formed in the first region F1. The stacked body 10 includes a first main surface VS1 and second main surfaces VS2A and VS2B facing the first main surface VS1. The second main surface VS2A is a surface located in the first region F1, and the second main surface VS2B is a surface located in the second region F2. The external connection electrode P1 is formed on the second main surface VS2B of the second region F2, and the external connection electrode P2 is formed on the second main surface VS2A of the first region F1.

  The laminated body 10 is a rectangular insulating flat plate whose longitudinal direction coincides with the X-axis direction. The laminate 10 is formed by laminating a plurality of insulating base material layers 14, 13, 12, and 11 mainly made of a resin (thermoplastic resin) in this order. The first region F1 of the stacked body 10 is formed by stacking the insulating base material layers 14, 13, 12, and 11 in this order. The second region F2 is formed by laminating the insulating base material layers 12 and 11 in this order. As shown in FIG. 2 etc., the insulating base material layers 11 and 12 are insulating base material layers formed over the first region F1 and the second region F2. The insulating base layers 11, 12, 13, and 14 are resin sheets mainly composed of, for example, polyimide (PI), liquid crystal polymer (LCP), or the like.

  The number of laminated insulating base material layers in the second region F2 (two layers) is smaller than the number of laminated insulating base material layers in the first region F1 (four layers). Therefore, the second region F2 of the stacked body 10 is easier to bend than the first region F1, and has flexibility. The first region F1 is harder than the second region F2, and is less likely to bend than the second region F2. In addition, a stepped portion SP is formed at the boundary between the first region F1 and the second region F2 due to the difference in the number of stacked insulating base material layers. The step part SP according to the present embodiment is parallel to the YZ plane.

  The insulating base layers 11, 12, 13, and 14 are rectangular flat plates whose longitudinal directions coincide with the X-axis direction. The length of the insulating base material layers 11 and 12 in the X-axis direction is longer than the length of the insulating base material layers 13 and 14 in the X-axis direction. The planar shapes of the insulating base layers 11 and 12 are substantially the same, and the planar shapes of the insulating base layers 13 and 14 are substantially the same.

  A coil conductor pattern 31 and a conductor 21 are formed on the back surface of the insulating base material layer 11. The coil conductor pattern 31 is a rectangular loop-shaped conductor pattern of less than one turn disposed at a position closer to the first side (left side of the insulating base layer 11 in FIG. 2) than the center of the insulating base layer 11. The conductor 21 is a crank-shaped conductor pattern that extends substantially in the X-axis direction. The coil conductor pattern 31 and the conductor 21 are conductor patterns such as a Cu foil, for example.

  A coil conductor pattern 32 and an external connection electrode P1 are formed on the back surface of the insulating base layer 12. The coil conductor pattern 32 is a rectangular loop-shaped conductor pattern of less than one turn disposed at a position closer to the first side (the left side of the insulating base layer 12 in FIG. 2) than the center of the insulating base layer 12. The external connection electrode P1 is a rectangular conductor pattern arranged near the center of the second side of the insulating base layer 12 (the right side of the insulating base layer 12 in FIG. 2). The coil conductor pattern 32 and the external connection electrode P1 are conductor patterns such as a Cu foil, for example.

  In addition, interlayer connection conductors V <b> 1 and V <b> 11 are formed on the insulating base material layer 12. The interlayer connection conductor V11 according to the present embodiment corresponds to the “first interlayer connection conductor” in the present invention.

  A coil conductor pattern 33 is formed on the back surface of the insulating base layer 13. The coil conductor pattern 33 is a rectangular loop-shaped conductor pattern of less than one turn that is wound along the outer shape of the insulating base layer 13. The coil conductor pattern 33 is a conductor pattern such as a Cu foil, for example.

  Further, an interlayer connection conductor V12 is formed on the insulating base material layer 13. The interlayer connection conductor V12 according to the present embodiment corresponds to the “first interlayer connection conductor” in the present invention.

  An external connection electrode P <b> 2 is formed on the back surface of the insulating base material layer 14. The external connection electrode P2 is a rectangular conductor pattern disposed at a position closer to the third side (lower side of the insulating base layer 14 in FIG. 2) than the center of the insulating base layer 14. The external connection electrode P2 is a conductor pattern such as a Cu foil, for example.

  In addition, an interlayer connection conductor V <b> 2 is formed on the insulating base material layer 14.

  The external connection electrode P1 is connected to the first end of the conductor 21 via the interlayer connection conductor V1. The second end of the conductor 21 is connected to the first end of the coil conductor pattern 31. The second end of the coil conductor pattern 31 is connected to the first end of the coil conductor pattern 32 via the interlayer connection conductor V11. The second end of the coil conductor pattern 32 is connected to the first end of the coil conductor pattern 33 via the interlayer connection conductor V12. The second end of the coil conductor pattern 33 is connected to the external connection electrode P2 via the interlayer connection conductor V2.

  In this way, the coil conductor patterns 31, 32, 33 and the interlayer connection conductors V11, V12 constitute a rectangular helical coil 3 of less than 3 turns having the winding axis AX in the Z-axis direction.

  As shown in FIGS. 1A and 1B, the coil conductor patterns 31, 32, and 33 are substantially overlapped with each other when viewed from the stacking direction (Z-axis direction) of the plurality of insulating base layers. Has been placed. Further, as shown in FIGS. 1A and 1B, the interlayer connection conductors V11 and V12 (first interlayer connection conductor) have coil conductor patterns 31, 32, and 33 as viewed from the Z-axis direction. Among these, it is arranged in a portion ADP (the right side portion extending in the Y-axis direction among the coil conductor patterns 31, 32, and 33 in FIG. 2) that is close along the stepped portion SP.

  Here, the “part close to the step part” in the present invention is a part extending along the step part SP of the coil conductor patterns 31, 32, 33, and the step part more than the other parts. The part arrange | positioned close to SP is said. In addition, the “part along the stepped portion” in the present invention means, for example, that the angle formed between the extending direction of the coil conductor pattern and the stepped portion SP in the coil conductor pattern is within a range of −30 ° to + 30 °. Say the part.

  The multilayer substrate 101 according to this embodiment has the following effects.

(A) Generally, in the vicinity of the stepped portion SP, a high pressure is applied at the time of heating and pressurization, and it is easily affected by heat from the press machine, so that the flow of the insulating base layer at the time of heating and pressurization is large. On the other hand, in the present embodiment, an interlayer connection conductor (first interlayer connection conductor) that is less likely to be displaced than the coil conductor pattern at the time of heating and pressurization is disposed in the portion ADP adjacent along the stepped portion SP. The flow of the insulating base material layer in the vicinity of the stepped portion SP at the time of pressurization is suppressed by the first interlayer connection conductor. Therefore, with this configuration, it is possible to suppress the displacement and deformation of the coil conductor pattern located in the vicinity of the stepped portion SP at the time of heating and pressurization, and it is possible to suppress changes in the coil characteristics caused by the displacement and deformation of the coil conductor pattern.

  In the present embodiment, the plurality of insulating base material layers 11, 12, 13, and 14 are made of a thermoplastic resin. Therefore, compared to the case where a laminate is formed using a bonding layer (for example, a semi-cured prepreg resin sheet), the flow of the insulating base material layer during heating and pressurization is likely to increase, Coil characteristic changes easily occur due to deformation and the like. Therefore, the above configuration is particularly effective when a laminated body is formed without using a bonding layer.

  As shown in the present embodiment, the number of first interlayer connection conductors is preferably plural. By disposing the plurality of first interlayer connection conductors in the portion ADP adjacent along the stepped portion SP, the flow of the insulating base layer near the stepped portion SP at the time of heating and pressing can be effectively suppressed.

(B) In this embodiment, the plurality of insulating base material layers 11, 12, 13, and 14 are made of a thermoplastic resin. According to this configuration, as will be described in detail later, the laminated body 10 can be easily formed by collectively pressing the plurality of laminated insulating base material layers 11, 12, 13, and 14. The number of processes is reduced, and the cost can be kept low.

  The multilayer substrate 101 according to the present embodiment is manufactured by, for example, the following manufacturing method.

(1) First, a plurality of insulating base material layers 11, 12, 13, and 14 are prepared. Thereafter, the coil conductor patterns 31, 32, 33, the conductor 21 and the external connection electrodes P1, P2 are formed on the plurality of insulating base material layers 11, 12, 13, 14. Specifically, a metal foil (for example, Cu foil) is laminated on one main surface (back surface) of the insulating base material layers 11, 12, 13, and 14 in the aggregate substrate state, and the metal foil is patterned by photolithography. Thereby, the coil conductor pattern 31 and the conductor 21 are formed on the back surface of the insulating base material layer 11, the coil conductor pattern 32 and the external connection electrode P1 are formed on the back surface of the insulating base material layer 12, and the back surface of the insulating base material layer 13 is formed. The coil conductor pattern 33 is formed on the insulating substrate layer 14, and the external connection electrode P 2 is formed on the back surface of the insulating base layer 14.

  The insulating base layers 11, 12, 13, and 14 are resin (thermoplastic resin) sheets whose main material is, for example, polyimide (PI), liquid crystal polymer (LCP), or the like.

  In addition, interlayer connection conductors V1, V2, V11, and V12 are formed on the plurality of insulating base material layers 12, 13, and 14, respectively. The interlayer connection conductors V1, V2, V11, and V12 are made of conductive paste containing one or more of Cu, Sn, or the like, or an alloy thereof after providing through holes in the insulating base layers 12, 13, and 14 with a laser or the like. It is provided by disposing and curing by subsequent heating and pressing. Therefore, the interlayer connection conductors V1, V2, V11, and V12 are made of materials having a melting point (melting temperature) lower than the temperature of subsequent heating and pressurization.

(2) Next, using the upper mold and the lower mold (see molds 1a and 2a in FIG. 5), a plurality of insulating base material layers 11 stacked in the stacking direction (Z-axis direction), 12, 13, and 14 are heated and pressurized. Specifically, a plurality of insulating base material layers 14, 13, 12, 11 are stacked in this order on the lower mold, and then the plurality of insulating base material layers stacked using the upper mold and the lower mold. 11, 12, 13, and 14 are heated and pressed to form a laminate.

(3) Thereafter, the multilayer substrate 101 is removed from the upper mold and the lower mold, and the multilayer substrate 101 is separated by dividing the multilayer substrate in the aggregate substrate state.

  According to this manufacturing method, the laminated body 10 can be easily formed by collectively pressing the plurality of laminated insulating base material layers 11, 12, 13, and 14. Therefore, the manufacturing process of the multilayer substrate 101 is reduced, and the cost can be kept low.

  The multilayer substrate 101 according to the present embodiment is used as follows, for example. FIG. 3 is a circuit diagram of the communication module 201 including the multilayer substrate 101. In FIG. 3, the coil 3 included in the multilayer substrate 101 is represented by a coil antenna ANT.

  The communication module 201 includes a coil antenna ANT (multilayer substrate 101), a capacitor C1, and an IC4. As shown in FIG. 3, a coil antenna ANT is connected to the IC 4 and a capacitor C1 is connected in parallel to the coil antenna ANT. IC4, capacitor C1, and multilayer substrate 101 are mounted on a circuit board (not shown) and are electrically connected by a conductor pattern formed on the circuit board. The multilayer substrate 101 is connected to the circuit board by bonding external connection electrodes (external connection electrodes P1 and P2 in FIG. 1A) to the circuit board via a conductive bonding material such as solder.

  The LC resonance circuit is configured by the coil antenna ANT, the capacitor C1, and the capacitance component possessed by the IC4 itself shown in FIG. The IC 4 is, for example, a packaged RFIC chip (bare chip). The capacitor C1 is, for example, a chip capacitor.

  Although FIG. 3 shows an example in which the capacitor C1 is a chip capacitor mounted on a circuit board, the present invention is not limited to this. The capacitor C1 may be mounted on the multilayer substrate 101, for example. The capacitor C1 is not limited to a chip component. The capacitor C1 may be, for example, an interlayer capacitance formed between conductive patterns facing each other formed on a plurality of insulating base material layers.

<< Second Embodiment >>
In the second embodiment, an example of a multilayer substrate having a dummy conductor pattern is shown.

  4A is a cross-sectional view of the multilayer substrate 102 according to the second embodiment, and FIG. 4B is a plan view of the multilayer substrate 102. FIG. 5 is an exploded plan view of the multilayer substrate 102. In FIG. 5, the coil conductor patterns 31, 32, and 33 are shown as dot patterns for easy understanding of the structure.

  The multilayer substrate 102 is different from the multilayer substrate 101 according to the first embodiment in that the multilayer substrate 102 includes dummy conductor patterns 41 and 42 and interlayer connection conductors V21 and V22. Other configurations of the multilayer substrate 102 are substantially the same as those of the multilayer substrate 101.

  Hereinafter, parts different from the multilayer substrate 101 according to the first embodiment will be described.

  The dummy conductor pattern 41 is a rectangular conductor pattern disposed near the center of the insulating base material layer 12. The dummy conductor pattern 42 is a rectangular conductor pattern disposed near the second side of the insulating base layer 13 (the right side of the insulating base layer 13 in FIG. 4).

  The interlayer connection conductors V21 and V22 are formed on the insulating base material layer 13. Further, as shown in FIGS. 4A and 4B, the interlayer connection conductors V21 and V22 are formed in the first region F1 of the multilayer body 10. The dummy conductor patterns 41 and 42 are connected via interlayer connection conductors V21 and V22.

  The interlayer connection conductors V21 and V22 according to the present embodiment correspond to the “second interlayer connection conductor” in the present invention.

  In the present embodiment, as shown in FIGS. 4A and 4B, the dummy conductor patterns 41 and 42 are arranged at positions close to each other along the stepped portion SP as viewed from the Z-axis direction. Yes. In the present embodiment, the dummy conductor pattern 41 is disposed so as to straddle the stepped portion SP as viewed from the Z-axis direction. As shown in FIG. 4B, the dummy conductor patterns 41 and 42 do not overlap the coil opening OP when viewed from the winding axis AX direction (Z-axis direction) of the coil 3.

  Here, “the dummy conductor pattern is disposed at a position close to the step portion” means that at least a part of the dummy conductor pattern is disposed between the portion ADP and the step portion SP. Further, “the dummy conductor pattern is arranged along the stepped portion” means that the portion along the stepped portion SP of the outer edge of the dummy conductor pattern is ½ or more of the entire length of the stepped portion SP. A dummy conductor pattern is arranged.

  In the present embodiment, the interlayer connection conductors V21 and V22 (second interlayer connection conductors) are disposed at positions close to the stepped portion SP when viewed from the Z-axis direction.

  Here, “the second interlayer connection conductor is disposed at a position close to the step portion” means that the second interlayer connection conductor is disposed between the portion ADP and the step portion SP.

  The multilayer substrate 102 according to the present embodiment has the following effects in addition to the effects described in the first embodiment.

(C) In the present embodiment, the dummy conductor patterns 41 and 42 are disposed close to the stepped portion SP when viewed from the Z-axis direction. In this configuration, the dummy conductor patterns 41 and 42 existing between the stepped portion SP and the coil 3 further suppress the flow of the insulating base material layer near the stepped portion SP during heating and pressurization. Therefore, this configuration further suppresses displacement and deformation of the coil conductor pattern located in the vicinity of the stepped portion SP during heating and pressurization, and further suppresses changes in coil characteristics due to displacement and deformation of the coil conductor pattern. The

(D) Further, as shown in the present embodiment, the dummy conductor patterns 41 and 42 are preferably arranged at positions close to each other along the stepped portion SP as viewed from the Z-axis direction. With this configuration, the flow of the insulating base material layer in the vicinity of the stepped portion SP during heating and pressurization is more effectively suppressed.

(E) In the present embodiment, the interlayer connection conductors V21 and V22 (second interlayer connection conductors) are arranged at positions close to each other along the stepped portion SP when viewed from the Z-axis direction. In this configuration, an interlayer connection conductor (second interlayer connection conductor) that is less likely to be displaced than the coil conductor pattern during heating and pressurization is disposed between the coil 3 and the stepped portion SP. Therefore, the interlayer connection conductors V21 and V22 further suppress the flow of the insulating base layer in the vicinity of the stepped portion SP at the time of heating and pressing.

  The number of second interlayer connection conductors is preferably plural. By disposing the plurality of second interlayer connection conductors at positions close to each other along the stepped portion SP, the flow of the insulating base material layer near the stepped portion SP at the time of heating and pressing can be effectively suppressed.

(F) Moreover, in this embodiment, the dummy conductor pattern 41 is arrange | positioned so that it may straddle the level | step-difference part SP seeing from a Z-axis direction. With this configuration, compared to the case where the dummy conductor pattern is not arranged so as to straddle the stepped portion SP, the flow of the insulating base layer near the stepped portion SP at the time of heating and pressing (for example, the first region at the time of heating and pressing). The flow of the insulating base material layer moving from F1 toward the second region F2 is further suppressed. Further, with this configuration, the mechanical strength in the vicinity of the stepped portion SP after the stacked body 10 is formed can be increased. Furthermore, with this configuration, it is possible to realize a multilayer substrate that can easily plastically deform (bend) the second region F2 in the vicinity of the stepped portion SP.

  As shown in the present embodiment, it is preferable that the dummy conductor patterns 41 and 42 do not overlap the coil opening OP of the coil 3 when viewed from the Z-axis direction. With this configuration, it is possible to suppress the dummy conductor pattern from preventing the coil 3 from forming a magnetic field.

<< Other Embodiments >>
In each embodiment shown above, although the laminated body 10 showed the example which is a rectangular flat plate, it is not limited to this structure. The planar shape of the laminate can be appropriately changed within the range where the effects of the present invention are exhibited, and may be, for example, a polygon, a circle, an ellipse, a crank shape, an L shape, a T shape, a Y shape, or the like.

  Moreover, in each embodiment shown above, although the example of the laminated body formed by laminating | stacking the four insulating base material layers 11, 12, 13, and 14 was shown, it is not limited to this structure. The number of laminated insulating base layers forming the laminate can be appropriately changed within the range where the effects of the present invention are exhibited. The number of insulating base material layers forming the laminate may be two or three, for example, or five or more. Furthermore, the number of insulating base material layers in the first region F1 and the number of insulating base material layers in the second region F2 can also be changed as appropriate within the scope of the effects of the present invention.

  In each embodiment shown above, although the example which forms a laminated body by laminating | stacking and heat-pressing the several insulating base material layer which consists of thermoplastic resins was shown, it is not limited to this structure. . For example, a laminate may be formed by heating and pressing a laminate in which a bonding layer (for example, a semi-cured prepreg resin) is sandwiched between a plurality of insulating base material layers made of a thermosetting resin. .

  In each of the embodiments described above, an example in which a rectangular helical coil 3 having a winding axis AX in the Z-axis direction and having a winding axis AX of less than 3 turns is shown. It is not limited to. The outer shape, configuration, and number of turns of the coil can be changed as appropriate within the scope of the effects of the present invention. For example, the coil may be configured to connect a plurality of spiral coil conductor patterns with interlayer connection conductors. The outer shape of the coil (the outer shape of the coil viewed from the winding axis AX direction (Z-axis direction)) is not limited to a rectangle, and may be, for example, a circle or an ellipse. Further, the winding axis AX of the coil does not have to be completely coincident with the Z-axis direction.

  In each of the embodiments described above, an example in which all the coil conductor patterns 31, 32, and 33 are arranged so as to substantially overlap each other when viewed from the Z-axis direction has been described. However, the present invention is limited to this configuration. is not. The plurality of coil conductor patterns may be arranged so that at least a part thereof overlaps each other when viewed from the Z-axis direction.

  Furthermore, in each embodiment shown above, although the coil showed the example comprised including three coil conductor patterns each formed in three insulating base material layers, it is not limited to this structure. Absent. The coil should just be comprised including the 2 or more coil conductor pattern formed in 2 or more insulation base material layers, respectively. That is, the number of coil conductor patterns constituting the coil may be two or more.

  In each of the embodiments described above, an example of a stacked body having one first region F1 and one second region has been described, but the present invention is not limited to this configuration. The shape, the number, the position, and the like of the first region F1 and the second region F2 can be appropriately changed within the range where the effects of the present invention are exhibited. For example, the number of first regions F1 may be plural, and the number of second regions F2 may be plural. That is, the number of stepped portions SP may be plural.

  In addition, when the number of the step portions SP is plural, it is preferable that the first interlayer connection conductor is disposed in a portion of the coil conductor pattern that is close along each step portion.

  In each embodiment shown above, the example of the multilayer board | substrate provided only with a coil was shown, However, The circuit structure formed in a multilayer board | substrate (laminated body) is not limited to this. The circuit formed in the laminate can be appropriately changed within the range where the effects of the present invention are exhibited. For example, a capacitor formed with a conductor pattern and various transmission lines (strip line, microstrip line, meander, coplanar, etc.) may be formed in the laminate. Further, for example, chip components such as a chip inductor and a chip capacitor may be mounted on the multilayer body.

  Further, the number, arrangement, shape, and the like of the external connection electrodes are not limited to the configurations shown in the first and second embodiments. The number and arrangement of the external connection electrodes can be changed as appropriate according to the circuit formed in the laminate. The planar shape of the external connection electrode is not limited to a rectangle, and may be, for example, a square, a polygon, a circle, an ellipse, a T shape, an L shape, or the like.

  In the first embodiment, the example in which the external connection electrode of the multilayer board is connected to the circuit board or the like via a conductive bonding material such as solder has been described. However, the present invention is not limited to this configuration. The multilayer board may be connected to a circuit board or the like using a connector, for example.

  Finally, the description of the above embodiment is illustrative in all respects and not restrictive. Modifications and changes can be made as appropriate by those skilled in the art. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope equivalent to the claims.

ANT ... coil antenna C1 ... capacitor AX ... coil winding axis F1 ... first region F2 ... second region OP ... coil openings P1, P2 ... external connection electrodes SP, SP1a, SP2a ... stepped portion ADP ... coil conductor pattern , Portions V1, V2 ... interlayer connection conductors V11, V12 ... interlayer connection conductors (first interlayer connection conductors) adjacent to each other along the stepped portion
V21, V22 ... interlayer connection conductor (second interlayer connection conductor)
VS1 ... 1st main surface VS2A of a laminated body, VS2B ... 2nd main surface 1a, 2a of a laminated body ... Mold 3 ... Coil 4 ... IC
DESCRIPTION OF SYMBOLS 10 ... Laminated body 11, 11a, 12, 12a, 13, 13a, 14, 14a, 15a ... Insulating base material layer 21 ... Conductor 31, 32, 33 ... Coil conductor pattern 41, 42 ... Dummy conductor pattern 101, 102 ... Multilayer Substrate 201 ... communication module

Claims (6)

A laminate having a plurality of insulating base material layers made of resin as a main material, and having a second region in which the number of the insulating base material layers is less than the first region, and the first region;
A step portion formed at a boundary between the first region and the second region due to a difference in the number of stacked layers of the plurality of insulating base layers;
A coil formed in the first region;
With
The coil is formed on the insulating base layer and a plurality of coil conductor patterns formed on two or more insulating base layers among the plurality of insulating base layers, and connects the plurality of coil conductor patterns to each other. A first interlayer connection conductor, and
The plurality of coil conductor patterns are arranged so that at least some of them overlap each other when viewed from the stacking direction of the plurality of insulating base material layers,
The first interlayer connection conductor is a multilayer substrate that is disposed in a portion of the plurality of coil conductor patterns that are close to each other along the step portion when viewed from the stacking direction. Comprising a dummy conductor pattern formed on the insulating base layer;
The multilayer substrate according to claim 1, wherein the dummy conductor pattern is disposed at a position close to the step portion when viewed from the stacking direction.   The multilayer substrate according to claim 2, wherein the dummy conductor pattern is disposed along the step portion when viewed from the stacking direction.   The multilayer substrate according to claim 2, wherein the dummy conductor pattern is disposed so as to straddle the stepped portion when viewed from the stacking direction. The dummy conductor pattern is a plurality of dummy conductor patterns formed on two or more insulating base layers among the plurality of insulating base layers.
A second interlayer connection conductor formed in the first region and connecting the plurality of dummy conductor patterns;
5. The multilayer substrate according to claim 2, wherein the second interlayer connection conductor is disposed at a position close to the step portion when viewed from the stacking direction.   The multilayer substrate according to claim 1, wherein the plurality of insulating base layers are made of a thermoplastic resin.

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