JP2019016742A - 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 a plurality of coil conductor patterns 31, 32, 33, 34. The coil conductor patterns 31, 32, 33, 34 have a wide part WP at a part close to and along the stepped part SP, which has a line width relatively larger than that of the other part when viewed from a lamination direction (Z-axis direction) of the insulating base material layer.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. The coil includes a plurality of coil conductor patterns respectively formed on two or more insulating base layers, and the plurality of coil conductor patterns overlap in a stacking direction of the plurality of insulating base layers. Are arranged.

  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 There are stepped portions having different numbers of layers near the boundary between the first region and the second region.

International Publication No. 2015/083525

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

  FIG. 10 is a cross-sectional view showing a part of the manufacturing process of the multilayer substrate having a stepped portion. As shown in FIG. 10, 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 the 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. 10), 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. 10 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 and including a plurality of coil conductor patterns formed in two or more insulating base layers among the plurality of insulating base layers;
With
The plurality of coil conductor patterns are arranged so that at least a part thereof overlaps each other when viewed from the stacking direction of the plurality of insulating base layers, and are close to the stepped portion when viewed from the stacking direction. The portion has a wide portion having a relatively wider line width than other portions.

  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 this configuration, a wide portion having a line width wider than other portions is arranged in the coil conductor pattern at a position close to the step portion. The flow is suppressed by the wide part. For this reason, with this configuration, it is possible to suppress the displacement and deformation of the coil conductor pattern located near the step portion during 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.

  Moreover, according to this structure, since a wide part is arrange | positioned substantially parallel along a level | step difference part, the flow of the insulating base material layer of the level | step-difference part vicinity at the time of heating and pressurization can be suppressed effectively.

(2) In the above (1), the wide portion is preferably linear. In this configuration, the wide portion disposed substantially in parallel along the stepped portion has a shape having a certain length, so that the flow of the insulating base material layer near the stepped portion at the time of heating and pressing is effectively performed. Can be suppressed.

(3) In the above (1) or (2), the number of the second regions may be plural.

(4) In any one of (1) to (3), 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. 1 is a cross-sectional view of a multilayer substrate 101 according to the first embodiment. FIG. 2 is an exploded plan view of the multilayer substrate 101. FIG. 3 is a cross-sectional view sequentially illustrating the manufacturing process of the multilayer substrate 101. FIG. 4 is a circuit diagram of the communication module 201 including the multilayer substrate 101. FIG. 5 is a cross-sectional view of the multilayer substrate 102 according to the second embodiment. FIG. 6 is an exploded plan view of the multilayer substrate 102. FIG. 7 is a plan view of the multilayer substrate 103 according to the third embodiment. FIG. 8A is a front view of the multilayer substrate 103, and FIG. 8B is a right side view of the multilayer substrate 103. FIG. 9 is an exploded plan view of the multilayer substrate 103. FIG. 10 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. 1 is a cross-sectional view of a multilayer substrate 101 according to the first embodiment. FIG. 2 is an exploded plan view of the multilayer substrate 101. In FIG. 2, the coil conductor patterns 31, 32, 33, and 34 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 15, 14, 13, 12, and 11 mainly composed of a resin (thermoplastic resin) in this order. The first region F1 of the laminate 10 is formed by laminating the insulating base material layers 15, 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. 1, 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, 14, 15 are resin sheets whose main material is, 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 (five 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 substantially parallel to the YZ plane.

  The insulating base layers 11, 12, 13, 14, and 15 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, 14 and 15 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, 14 and 15 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 linear conductor pattern extending 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.

  The insulating base material layer 12 is formed with interlayer connection conductors V1 and V2.

  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.

  In addition, an interlayer connection conductor V <b> 3 is formed on the insulating base material layer 13.

  A coil conductor pattern 34 is formed on the back surface of the insulating base material layer 14. The coil conductor pattern 34 is a rectangular loop-shaped conductor pattern of less than one turn that is wound along the outer shape of the insulating base layer 14. The coil conductor pattern 34 is a conductor pattern such as a Cu foil, for example.

  The insulating base material layer 14 is provided with an interlayer connection conductor V4.

  An external connection electrode P <b> 2 is formed on the back surface of the insulating base material layer 15. The external connection electrode P2 is a rectangular conductor pattern disposed at a position closer to the first side (the left side of the insulating base layer 15 in FIG. 2) than the center of the insulating base layer 15. The external connection electrode P2 is a conductor pattern such as a Cu foil, for example.

  Further, an interlayer connection conductor V5 is formed on the insulating base material layer 15.

  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 V2. 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 V3. The second end of the coil conductor pattern 33 is connected to the first end of the coil conductor pattern 34 via the interlayer connection conductor V4. The second end of the coil conductor pattern 34 is connected to the external connection electrode P2 through the interlayer connection conductor V5.

  As described above, the coil conductor patterns 31, 32, 33, and 34 and the interlayer connection conductors V2, V3, and V4 constitute the helical coil 3 of about 3.5 turns having the winding axis AX in the Z-axis direction. .

  As shown in FIG. 1 and the like, the coil conductor patterns 31, 32, 33, and 34 substantially overlap each other when viewed from the stacking direction (Z-axis direction) of the plurality of insulating base layers 11, 12, 13, 14, and 15. Are arranged as follows. Further, as shown in FIG. 1 and the like, the coil conductor patterns 31, 32, 33, and 34 are portions close to the step part SP (coil conductor patterns 31, 32, and 33 in FIG. 2) as viewed from the Z-axis direction. , 34 has a wide portion WP having a relatively wider line width than the other portions on the right side portion extending in the Y-axis direction).

  In the present embodiment, as shown in FIG. 2, the wide portion WP has a linear shape extending in the Y-axis direction 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 in the coil conductor patterns 31, 32, 33, and 34, and more than other parts. The part arrange | positioned adjacent to level | step-difference part SP is said. In the present embodiment, an example in which the wide portion WP and the stepped portion SP are substantially parallel has been described. However, the “part close to the stepped portion” and the stepped portion SP are strictly parallel to each other. It is not a thing. The “part along the stepped portion” in the present invention means, for example, a portion of the coil conductor pattern in which the angle formed between the extending direction of the coil conductor pattern and the stepped portion SP is within a range of −30 ° to + 30 °. say.

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

(A) In the present embodiment, among the coil conductor patterns 31, 32, 33, and 34, the wide portion WP having a wider line width than the other portions is disposed at a position close to the stepped portion SP. 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. Therefore, 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 flow of the insulating base material layer in the vicinity of the stepped portion SP at the time of heating and pressing is suppressed by the wide portion WP having a wider line width than the other portions. Therefore, according to 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 to suppress the change in coil characteristics due to the displacement and deformation of the coil conductor pattern. it can.

  In the present embodiment, the plurality of insulating base material layers 11, 12, 13, 14, and 15 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, Changes in coil characteristics are likely to 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.

(B) In this embodiment, the wide part WP is arrange | positioned substantially parallel along the level | step-difference part SP. With this configuration, it is possible to effectively suppress the flow of the insulating base material layer in the vicinity of the stepped portion SP during heating and pressing. In addition, it is preferable that the length of the wide portion WP arranged substantially parallel along the stepped portion SP is long.

(C) Moreover, in this embodiment, the wide part WP is linear form extended | stretched in the Y-axis direction along the level | step-difference part SP. In this configuration, since the wide portion WP arranged substantially in parallel along the stepped portion SP has a shape having a certain length, the flow of the insulating base layer near the stepped portion SP during heating and pressurization is prevented. It can be effectively suppressed.

(D) In this embodiment, the plurality of insulating base material layers 11, 12, 13, 14, and 15 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, 14, 15. The manufacturing process can be 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. FIG. 3 is a cross-sectional view sequentially illustrating the manufacturing process of the multilayer substrate 101. In FIG. 3, for the sake of explanation, description will be made with a manufacturing process in one piece (one chip), but an actual manufacturing process of a multilayer substrate is performed in a collective substrate state. The same applies to each of the sectional views showing the subsequent manufacturing steps.

  First, as shown in (1) in FIG. 3, a plurality of insulating base layers 11, 12, 13, 14, 15 are prepared, and a plurality of insulating base layers 11, 12, 13, 14, 15 are prepared. The coil conductor patterns 31, 32, 33, 34, the conductor 21 and the external connection electrodes P1, P2 are formed. Specifically, a metal foil (for example, Cu foil) is laminated on one side main surface (back surface) of the insulating base material layers 11, 12, 13, 14, and 15 in the aggregate substrate state, and the metal foil is patterned by photolithography. To do. Thereby, the coil conductor pattern 31 and the conductor 21 are formed on the back surface of the insulating base material layer 11, and the coil conductor pattern 32 and the external connection electrode P1 are formed on the back surface of the insulating base material layer 12. Further, the coil conductor pattern 33 is formed on the back surface of the insulating base material layer 13, the coil conductor pattern 34 is formed on the back surface of the insulating base material layer 14, and the external connection electrode P <b> 2 is formed on the back surface of the insulating base material layer 15.

  The insulating base layers 11, 12, 13, 14, 15 are resin (thermoplastic resin) sheets whose main material is, for example, polyimide (PI), liquid crystal polymer (LCP), or the like.

  Further, interlayer connection conductors (interlayer connection conductors V1, V2, V3, V4, V5 in FIG. 2) are formed on the plurality of insulating base material layers 12, 13, 14, and 15. The interlayer connection conductor is provided with a conductive paste containing one or more of Cu, Sn, or the like, or an alloy thereof after providing through holes in the insulating base layer with a laser or the like, and is cured by subsequent heating and pressing. Is provided. Therefore, the interlayer connection conductor is made of a material having a melting point (melting temperature) lower than the temperature of subsequent heating and pressurization.

  Next, as shown in (2) in FIG. 3, a plurality of insulating base material layers 11, 12, 13, 14 stacked in the Z-axis direction using the upper mold 1 and the lower mold 2 are used. 15 are heated and pressurized (see white arrows in (2) in FIG. 3). Specifically, a plurality of insulating base layers 15, 14, 13, 12, 11 are stacked in this order on the lower mold 2, and then stacked using the upper mold 1 and the lower mold 2. The insulating base material layers 11, 12, 13, 14, and 15 are heated and pressed to form a laminate.

  Thereafter, the multilayer substrate 101 is removed from the upper mold 1 and the lower mold 2, and the multilayer substrate 101 is divided to divide the multilayer substrate 101 as shown in FIG. obtain.

  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, 14, and 15. 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. 4 is a circuit diagram of the communication module 201 including the multilayer substrate 101. In FIG. 4, 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. 4, 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. 1) 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 of the IC 4 itself shown in FIG. The IC 4 is, for example, a packaged RFIC chip (bare chip). The capacitor C1 is, for example, a chip type capacitor.

  In the multilayer substrate 101, the coil conductor patterns 31, 32, 33, and 34 have a wide portion WP having a relatively wider line width than other portions. The inductance component of the antenna ANT is reduced. Therefore, the LC resonance circuit can be configured by setting the capacitance component of the capacitor C1 to be slightly larger than when the wide portion WP is not provided.

  Although FIG. 4 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, which are formed on a plurality of insulating base layers.

<< Second Embodiment >>
The second embodiment shows an example in which the shape of the coil conductor pattern is different from that of the first embodiment.

  FIG. 5 is a cross-sectional view of the multilayer substrate 102 according to the second embodiment. FIG. 6 is an exploded plan view of the multilayer substrate 102. In FIG. 6, the coil conductor patterns 31, 32, 33, and 34 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 the shapes of the coil conductor patterns 31A, 32A, 33A, 34A and the external connection electrodes P2A. The multilayer substrate 102 is different from the multilayer substrate 101 in that the protective layer 5 is formed on the second main surface VS2A of the multilayer body 10. 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 coil conductor pattern 31A is a rectangular spiral conductor pattern of about 1.5 turns arranged at a position closer to the first side (the left side of the insulating base layer 11 in FIG. 6) than the center of the insulating base layer 11. .

  The coil conductor pattern 32 is a rectangular spiral conductor pattern of about 1.5 turns arranged at a position closer to the first side (the left side of the insulating base layer 12 in FIG. 6) than the center of the insulating base layer 12. .

  The coil conductor pattern 33 is a rectangular spiral conductor pattern of about 1.5 turns that is wound along the outer shape of the insulating base layer 13.

  The coil conductor pattern 34 is a rectangular spiral conductor pattern of about 1.5 turns that is wound along the outer shape of the insulating base layer 14.

  The external connection electrode P <b> 2 </ b> A is an L-shaped conductor pattern formed on the back surface of the insulating base material layer 15.

  The protective layer 5 has substantially the same planar shape as the insulating base material layer 15 and is laminated on the back surface of the insulating base material layer 15. The protective layer 5 has a rectangular opening AP at a position corresponding to the position of the external connection electrode P2A. Therefore, when the protective layer 5 is formed (laminated) on the back surface of the insulating base material layer 15, the external connection electrode P2A is exposed to the second main surface VS2A of the multilayer body 10. The protective layer 5 is, for example, a coverlay film or a solder resist film.

  The protective layer 5 is not an essential configuration. In the present embodiment, the example in which the protective layer 5 is formed on the second main surface VS2A side of the stacked body 10 has been described. However, the protective layer may be formed on the first main surface VS1 side. The structure formed in the 2 main surface VS2B side may be sufficient.

  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 31A. The second end of the coil conductor pattern 31A is connected to the first end of the coil conductor pattern 32A via the interlayer connection conductor V2. The second end of the coil conductor pattern 32A is connected to the first end of the coil conductor pattern 33A via the interlayer connection conductor V3. The second end of the coil conductor pattern 33A is connected to the first end of the coil conductor pattern 34A via the interlayer connection conductor V4. The second end of the coil conductor pattern 34A is connected to the external connection electrode P2A via the interlayer connection conductor V5.

  In the present embodiment, the coil conductor patterns 31A, 32A, 33A, and 34A and the interlayer connection conductors V2, V3, and V4 constitute a coil 3A having about 6 turns having a winding axis AX in the Z-axis direction.

  As shown in FIG. 5 and the like, the coil conductor patterns 31A, 32A, 33A, 33A, and 34A are portions close to the step portion SP as viewed from the Z-axis direction (the coil conductor patterns 31A, 32A, and 33A in FIG. 6). , 34A, a wide portion WP having a relatively wider line width than the other portions is provided on the right side portion extending in the Y-axis direction.

  Even in such a configuration, the basic configuration of the multilayer substrate 102 is the same as that of the multilayer substrate 101 according to the first embodiment, and the same operations and effects as the multilayer substrate 101 are achieved.

  Further, as shown in the present embodiment, the coil may be configured such that a rectangular spiral coil conductor pattern is connected by an interlayer connection conductor.

<< Third Embodiment >>
In the third embodiment, an example of a multilayer substrate having a plurality of second regions is shown.

  FIG. 7 is a plan view of the multilayer substrate 103 according to the third embodiment. FIG. 8A is a front view of the multilayer substrate 103, and FIG. 8B is a right side view of the multilayer substrate 103. FIG. 9 is an exploded plan view of the multilayer substrate 103. In FIG. 9, the coil conductor patterns 31B, 32B, 33B, and 34B are shown as dot patterns for easy understanding of the structure.

  The multilayer substrate 103 is different from the multilayer substrate 101 according to the first embodiment in the shape of the stacked body. The multilayer substrate 103 is different from the multilayer substrate 101 in that the multilayer substrate 103 includes conductors 22 and 23, an interlayer connection conductor V6, and the like. Other configurations of the multilayer substrate 103 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 multilayer substrate 103 includes a laminated body 10B, stepped portions SP1 and SP2, a coil 3B, external connection electrodes P1 and P2B, and the like.

  The stacked body 10B has a first region F1 and second regions F21 and F22, and the coil 3B is formed in the first region F1. The stacked body 10B includes a first main surface VS1 and second main surfaces VS2A, VS2B, and VS2C that face the first main surface VS1. The second main surface VS2A is a surface located in the first region F1, the second main surface VS2B is a surface located in the second region F21, and the second main surface VS2C is a surface located in the second region F22. . The external connection electrode P1 is formed on the second main surface VS2B of the second region F21, and the external connection electrode P2B is formed on the second main surface VS2C of the second region F22.

  The laminated body 10B is an L-shaped insulating flat plate whose longitudinal direction coincides with the X-axis direction. The laminated body 10B is formed by laminating a plurality of insulating base material layers 14b, 13b, 12b, and 11b made mainly of a resin (thermoplastic resin). The first region F1 of the laminate 10B is formed by laminating the insulating base layers 14b, 13b, 12b, and 11b in this order. The second regions F21 and F22 are formed by laminating the insulating base material layers 12b and 11b in this order. As shown in FIG. 9, the insulating base layers 11b and 12b are insulating base layers formed over the first region F1 and the second regions F21 and F22.

  The number of insulating base material layers (2 layers) in the second regions F21 and F22 is smaller than the number of insulating base material layers (four layers) in the first region F1. Therefore, a stepped portion SP1 is formed at the boundary between the first region F1 and the second region F21 due to the difference in the number of stacked insulating base material layers. Further, the stepped portion SP2 is formed at the boundary between the first region F1 and the second region F22 due to the difference in the number of stacked insulating base material layers.

  The stepped portion SP1 according to the present embodiment is substantially parallel to the YZ plane, and the stepped portion SP2 according to the present embodiment is substantially parallel to the XZ plane.

  The insulating base layers 11b and 12b are L-shaped flat plates whose longitudinal direction coincides with the X-axis direction. The insulating base layers 13b and 14b are rectangular flat plates whose longitudinal direction coincides with the X-axis direction. The lengths of the insulating base layers 11b and 12b in the X-axis direction are longer than the lengths of the insulating base layers 13b and 14b in the X-axis direction. Further, the length in the Y-axis direction of a part of the insulating base layers 11b and 12b (lower left portions of the insulating base layers 11b and 12b in FIG. 9) is larger than the length in the Y-axis direction of the insulating base layers 13b and 14b. Too long. The planar shapes of the insulating base layers 11b and 12b are substantially the same, and the planar shapes of the insulating base layers 13b and 14b are substantially the same.

  A coil conductor pattern 31B and a conductor 21 are formed on the back surface of the insulating base material layer 11b. The coil conductor pattern 31B is a rectangular loop-shaped conductor pattern of less than one turn disposed near the center of the insulating base layer 11B. The conductor 21 is a linear conductor pattern extending in the X-axis direction.

  A coil conductor pattern 32B and external connection electrodes P1, P2B are formed on the back surface of the insulating base material layer 12b. The coil conductor pattern 32B is a rectangular loop-shaped conductor pattern of less than one turn disposed near the center of the insulating base layer 12b. The external connection electrode P1 is a rectangular conductor pattern disposed near the center of the second side of the insulating base layer 12b (the right side of the insulating base layer 12b in FIG. 9). The external connection electrode P2B is an L-shaped conductor pattern disposed near the first corner of the insulating base layer 12b (the lower left corner of the insulating base layer 12b in FIG. 9).

  A coil conductor pattern 33B and a conductor 23 are formed on the back surface of the insulating base layer 13b. The coil conductor pattern 33B is a rectangular loop-shaped conductor pattern of less than one turn arranged at a position closer to the second side (the right side of the insulating base layer 13b in FIG. 9) than the center of the insulating base layer 13b. The conductor 23 is a rectangular conductor pattern disposed near the first corner of the insulating base layer 13b (the lower left corner of the insulating base layer 13b in FIG. 9).

  A coil conductor pattern 34B and a conductor 22 are formed on the back surface of the insulating base layer 14b. The coil conductor pattern 34B is a rectangular loop-shaped conductor pattern of less than one turn disposed at a position closer to the second side (the right side of the insulating base layer 14b in FIG. 9) than the center of the insulating base layer 14b. The conductor 22 is a linear conductor pattern extending in the X-axis direction.

  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 31B. The second end of the coil conductor pattern 31B is connected to the first end of the coil conductor pattern 32B via the interlayer connection conductor V2. The second end of the coil conductor pattern 32B is connected to the first end of the coil conductor pattern 33B via the interlayer connection conductor V3. The second end of the coil conductor pattern 33B is connected to the first end of the coil conductor pattern 34B via the interlayer connection conductor V4. The second end of the coil conductor pattern 34 </ b> B is connected to the first end of the conductor 22. The second end of the conductor 22 is connected to the first end of the conductor 23 via the interlayer connection conductor V5. The second end of the conductor 23 is connected to the external connection electrode P2B through the interlayer connection conductor V6.

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

  As shown in FIG. 8A and the like, the coil conductor patterns 31B, 32B, 33B, and 34B are adjacent to the step portion SP1 as viewed from the Z-axis direction (the coil conductor patterns 31B, 32B, and 33B, the right side portion extending in the Y-axis direction) has a wide portion WP1 having a relatively wider line width than the other portions.

  Further, as shown in FIG. 8B and the like, the coil conductor patterns 31B, 32B, 33B, and 34B are portions close to the step part SP2 as viewed from the Z-axis direction (the coil conductor patterns 31B and 31B in FIG. 9). Among the 32B, 33B, and 34B, the lower side portion extending in the X-axis direction) has a wide portion WP2 having a relatively wider line width than other portions.

  As shown in FIG. 9, the wide part WP1 according to the present embodiment has a linear shape extending in the Y-axis direction along the step part SP1. Moreover, as shown in FIG. 9, the wide part WP2 according to the present embodiment is a straight line extending in the X-axis direction along the step part SP2.

  As shown in the present embodiment, the number of second regions may be plural. That is, the number of step portions may be plural. In addition, the shape, the number, the position, and the like of the first region and the second region can be appropriately changed within a range where the effects of the present invention are exhibited, and the number of the first regions may be two or more.

  In addition, as shown in the present embodiment, when there are a plurality of stepped portions, a configuration in which wide portions are formed in portions adjacent to each stepped portion of the coil conductor pattern, respectively. preferable. In addition, if the wide part is formed in the part which adjoins along at least 1 level | step-difference part among coil conductor patterns, there exists an effect of this invention. However, from the viewpoint of the effects of the present invention, a configuration in which wide portions are formed in portions of the coil conductor pattern that are close to each other along the stepped portions is preferable.

<< Other Embodiments >>
In each embodiment shown above, although the laminated body showed the example which is a rectangular flat plate or a L-shaped flat plate, it is not limited to this structure. The planar shape of the laminated body can be changed as appropriate within the scope of the effects of the present invention, and may be, for example, a polygon, a circle, an ellipse, a crank 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 4 or 5 insulating base material layers 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 may be six or more. Furthermore, the number of insulating base material layers in the first region and the number of insulating base material layers in the second region 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. .

  Moreover, in each embodiment shown above, the example in which the rectangular helical coils 3 and 3B of about 3.5 turns having the winding axis in the Z-axis direction and the coil 3A of about 6 turns were configured was shown. However, the shape of the coil, the number of turns, etc. are not limited to these. 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. 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 of the coil need not be along the Z-axis direction, and may be along the X-axis direction or the Y-axis direction, for example.

  In each of the embodiments described above, an example in which all the coil conductor patterns are arranged so as to substantially overlap each other when viewed from the Z-axis direction is shown, but the present invention is not limited to this configuration. 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 the four coil conductor patterns each formed in four 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 embodiment shown above, although the example which all the coil conductor patterns have a wide part was shown, it is not limited to this structure. If the wide portion is formed in at least one coil conductor pattern among the plurality of coil conductor patterns, the effects of the present invention are exhibited. However, from the viewpoint of the effect of the present invention, the wide portion is preferably formed in all coil conductor patterns.

  Moreover, in each embodiment shown above, although the wide part showed the example which is linear form, it is not limited to this structure. The wide part should just be formed in the part which adjoins along a level | step-difference part among coil conductor patterns, for example, circular arc shape, curvilinear shape, crank shape, L shape etc. may be sufficient.

  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 laminated body can be appropriately changed within the range where the functions and effects of the present invention are exhibited. For example, a capacitor formed of a conductor pattern, various transmission lines (strip line, microstrip line, meander, coplanar, etc.), 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, second, and third 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 or an L shape, and may be a square, a polygon, a circle, an ellipse, a T 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 AP ... Opening AX ... Coil winding axis F1 ... First region F2, F21, F22 ... Second region P1, P2, P2A, P2B ... External connection electrodes SP, SP1, SP1a, SP2 , SP2a... Step portions V1, V2, V3, V4, V5, V6... Interlayer connection conductor VS1... DESCRIPTION OF SYMBOLS 1 ... Upper metal mold 2 ... Lower metal mold 1a, 2a ... Metal mold 3, 3A, 3B ... Coil 4 ... IC
5 ... Protective layer 10, 10B ... Laminate 11, 11a, 11b, 12, 12a, 12b, 13, 13a, 13b, 14, 14a, 14b, 15, 15a ... Insulating substrate layers 21, 22, 23 ... Conductor 31 , 31A, 31B, 32, 32A, 32B, 33, 33A, 33B, 34, 34A, 34B ... coil conductor patterns 101, 102, 103 ... multilayer substrate 201 ... communication module

Claims (4)

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 and including a plurality of coil conductor patterns formed in two or more insulating base layers among the plurality of insulating base layers;
With
The plurality of coil conductor patterns are arranged so that at least a part thereof is overlapped with each other when viewed from the stacking direction of the plurality of insulating base layers, and close to the step portion when viewed from the stacking direction. A multilayer substrate having a wide portion having a relatively wider line width than other portions in the portion.   The multilayer substrate according to claim 1, wherein the wide portion is linear.   The multilayer substrate according to claim 1, wherein the number of the second regions is plural.   The multilayer substrate according to claim 1, wherein the plurality of insulating base layers are made of a thermoplastic resin.

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