JP6737246B2 - Multilayer board - Google Patents

Description

The present invention relates to a multilayer substrate, and more particularly to a multilayer substrate including a laminated body in which a plurality of insulating base material layers containing a resin as a main material are laminated, and a coil formed in the laminated body.

2. Description of the Related Art Conventionally, various multilayer substrates including a laminated body formed by laminating a plurality of insulating base material layers containing a resin as a main material and a coil formed in the laminated body are known.

For example, Patent Document 1 discloses a multilayer substrate including a laminated body having a thick portion (hereinafter, first region) and a thin portion (hereinafter, second region), and a coil formed in the first region. It is disclosed. The coil is configured to include a plurality of coil conductor patterns respectively formed on two or more insulating base material layers, and the plurality of coil conductor patterns are arranged so as to overlap in a laminating direction of the plurality of insulating base material layers. It is located in.

In the multilayer substrate, the second region has flexibility because the number of laminated insulating base layers in the second region is smaller than the number of laminated insulating base layers in the first region. A step portion having a different number of stacked layers is present near the boundary between the second 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 material layers using a mold according to the shape of the step portion.

FIG. 10 is a cross-sectional view showing a part of the manufacturing process of the multilayer substrate having the step portion. As shown in FIG. 10, the multilayer substrate (laminated body) has a plurality of laminated insulating base material layers 11a, 12a, 13a, 14a, 15a in the laminating direction (Z-axis direction) using the dies 1a, 2a. Obtained by heating and pressing. A step portion SP2a corresponding to the shape of the step portion SP1a of the laminated body is formed on the surface of the mold 2a. However, it is difficult to completely match the shape of the die 2a with the stepped portion SP1a of the laminated body, and in order to suppress the joint failure during heating and pressurization, the height H2 of the stepped portion SP2a of the die 2a is stepped. Generally, it is formed to be smaller than the height H1 of the portion SP1a.

However, in the above-described manufacturing method, 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 laminated insulating base layers is larger than that of the second region where the number of laminated insulating base layers is smaller than that of the second region. Therefore, at the time of heating and pressing, 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 due to the flow of the insulating base material layer. Cheap.

(B) Since the pressure is concentrated during heating and pressurization at the portion where the plurality of coil conductor patterns are arranged to overlap each other in the stacking direction of the plurality of insulating base material layers, the positional displacement of the coil conductor patterns is large. Prone.

(C) Since the area in contact with the mold 2a is large in the vicinity of the step portion SP1a (for example, the right end surfaces of the insulating base material layers 13a, 14a, 15a and the lower surface of the insulating base material layer 15a in FIG. 10), When heated and pressed, it is easily affected by heat from the press. Therefore, the insulating base material layer near the stepped portion SP1a easily flows during heating and pressurization, and the position of the coil conductor pattern located near the stepped portion SP1a easily shifts.

An object of the present invention is to accompany displacement of a coil conductor pattern located in the vicinity of a step portion in a configuration in which a step 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 layers. An object of the present invention is to provide a multi-layer 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 mainly made of resin and having a first region and a second region in which the number of insulating base material layers is smaller than that of 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 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;
Equipped with
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, and are close to each other along the step portion when viewed from the stacking direction. It is characterized in that the portion has a wide portion having a relatively wider line width than the other portions.

Generally, in the vicinity of the step portion, a high pressure is applied during heating and pressurization and is easily affected by heat from the press machine, so that the flow of the insulating base material layer during heating and pressurization is large. On the other hand, in this configuration, in the coil conductor pattern, the wide portion having a line width wider than that of the other portion is arranged in the position close to the step portion, and therefore, the insulating base material layer near the step portion at the time of heating and pressing is formed. The flow is suppressed by the wide part. Therefore, with this configuration, it is possible to suppress the positional displacement and deformation of the coil conductor pattern located near the step portion during heating and pressurization, and to suppress the characteristic change of the coil due to the positional displacement and deformation of the coil conductor pattern.

Further, according to this configuration, since the wide portions are arranged substantially parallel to each other along the step portion, it is possible to effectively suppress the flow of the insulating base material layer near the step portion during heating and pressing.

(2) In the above (1), the wide portion is preferably linear. With this configuration, the wide portions arranged substantially parallel to each other along the stepped portion have a shape having a constant length, so that the flow of the insulating base material layer in the vicinity of the stepped portion during heating and pressing can be 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) above, it is preferable that the plurality of insulating base material layers are made of a thermoplastic resin. According to this configuration, the laminated body can be easily formed by pressing the plurality of laminated insulating base material layers at one time, 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 step 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 step portion is misaligned. It is possible to realize a multi-layer substrate in which fluctuations in coil characteristics are suppressed.

FIG. 1 is a cross-sectional view of the multilayer substrate 101 according to the first embodiment. FIG. 2 is an exploded plan view of the multilayer substrate 101. 3A to 3C are cross-sectional views sequentially showing 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 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 the step portion.

Hereinafter, some 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 parts are designated by the same reference numerals. Although the embodiments are shown separately for the sake of convenience in explaining the points or easiness of understanding, partial replacement or combination of the configurations shown in the different embodiments is possible. In the second and subsequent embodiments, description of matters common to the first embodiment will be omitted, and only different points will be described. In particular, similar effects obtained by the same configuration will not be sequentially described for each embodiment.

<<First Embodiment>>
FIG. 1 is a cross-sectional view of the multilayer substrate 101 according to the first embodiment. FIG. 2 is an exploded plan view of the multilayer substrate 101. Note that in FIG. 2, the coil conductor patterns 31, 32, 33, and 34 are shown as dot patterns in order to make the structure easy to understand. Further, in FIG. 1, the thickness of each part is exaggerated in the drawing. This also applies to each cross-sectional view shown below.

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

The laminated body 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 also has 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 area F1, and the second main surface VS2B is a surface located in the second area 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 laminated body 10 is formed by laminating a plurality of insulating base material layers 15, 14, 13, 12, 11 having a resin (thermoplastic resin) as a main material in this order. The first region F1 of the laminated body 10 is formed by laminating the insulating base material layers 15, 14, 13, 12, 11 in this order. The second region F2 is formed by stacking 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 material layers 11, 12, 13, 14, and 15 are resin sheets whose main material is, for example, polyimide (PI) or liquid crystal polymer (LCP).

The number of laminated insulating base layers in the second region F2 (2 layers) is smaller than the number of laminated insulating base layers in the first region F1 (5 layers). Therefore, the second region F2 of the stacked body 10 is more flexible than the first region F1 and has flexibility. The first region F1 is harder than the second region F2 and is harder to bend than the second region F2. Further, 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 laminated insulating base layers. The step portion SP according to this embodiment is substantially parallel to the YZ plane.

The insulating base material 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, 12 in the X-axis direction is longer than the length of the insulating base material layers 13, 14, 15 in the X-axis direction. The insulating base material layers 11 and 12 have substantially the same planar shape, and the insulating base material layers 13, 14 and 15 have substantially the same planar shape.

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 conductor pattern in the shape of a rectangular loop of less than one turn, which is arranged at a position closer to the first side (the left side of the insulating base material layer 11 in FIG. 2) than the center of the insulating base material layer 11. The conductor 21 is a linear conductor pattern that extends in the X-axis direction. The coil conductor pattern 31 and the conductor 21 are conductor patterns such as Cu foil.

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

In addition, interlayer connection conductors V1 and V2 are formed on the insulating base material layer 12.

A coil conductor pattern 33 is formed on the back surface of the insulating base material layer 13. The coil conductor pattern 33 is a conductor pattern in the shape of a rectangular loop that is wound around the outer shape of the insulating base material layer 13 and has a little less than one turn. The coil conductor pattern 33 is a conductor pattern such as Cu foil.

Further, the insulating base material layer 13 is provided with an interlayer connection conductor V3.

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 having a little less than one turn wound along the outer shape of the insulating base material layer 14. The coil conductor pattern 34 is a conductor pattern such as Cu foil.

Further, the insulating base material layer 14 is provided with an interlayer connection conductor V4.

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

Further, the insulating base material layer 15 is provided with an interlayer connection conductor V5.

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 connecting 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 connecting 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 connecting conductor V4. The second end of the coil conductor pattern 34 is connected to the external connection electrode P2 via the interlayer connection conductor V5.

In this way, the coil conductor patterns 31, 32, 33, 34 and the interlayer-connector conductors V2, V3, V4 constitute a helical coil 3 having about 3.5 turns and 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, 34 substantially overlap each other when viewed from the stacking direction (Z-axis direction) of the plurality of insulating base material layers 11, 12, 13, 14, 15. Are arranged as follows. Further, as shown in FIG. 1 and the like, the coil conductor patterns 31, 32, 33, 34 are close to each other along the step portion SP when viewed from the Z-axis direction (the coil conductor patterns 31, 32, 33 in FIG. 2). , 34 on the right side portion extending in the Y-axis direction) has a wide portion WP having a relatively wider line width than other portions.

In the present embodiment, as shown in FIG. 2, the wide width portion WP has a linear shape extending in the Y-axis direction along the step portion SP.

Here, in the present invention, "a portion which is close to the step portion" means a portion of the coil conductor patterns 31, 32, 33, 34 which extends along the step portion SP and which is more than other portions. It refers to a portion arranged close to the step portion SP. Further, in the present embodiment, the example in which the wide portion WP and the step portion SP are substantially parallel has been shown, but it is limited to the one in which the “portion adjacent along the step portion” and the step portion SP are strictly parallel. Not a thing. The “portion along the step portion” in the present invention means, for example, a portion of the coil conductor pattern in which the angle between the extending direction of the coil conductor pattern and the step portion SP is within the range of −30° to +30°. To tell.

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

(A) In the present embodiment, a wide portion WP having a wider line width than other portions is arranged at a position of the coil conductor patterns 31, 32, 33, 34 near the step portion SP. Generally, in the vicinity of the stepped portion SP, a high pressure is applied during heating and pressurization and is easily affected by heat from the press machine, so that the flow of the insulating base material layer during 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 step portion SP during 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 positional displacement and deformation of the coil conductor pattern located in the vicinity of the step portion SP during heating and pressurization, and suppress the characteristic change of the coil due to the positional displacement and deformation of the coil conductor pattern. it can.

In this embodiment, the plurality of insulating base material layers 11, 12, 13, 14, 15 are made of thermoplastic resin. Therefore, compared with the case where a laminated body is formed by using a bonding layer (for example, a semi-cured prepreg resin sheet), the flow of the insulating base material layer during heating and pressurization tends to be large, and the positional deviation of the coil conductor pattern and The characteristics of the coil are likely to change due to deformation or the like. Therefore, the above configuration is particularly effective when forming a laminated body without using a bonding layer.

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

(C) In addition, in the present embodiment, the wide portion WP has a linear shape extending in the Y-axis direction along the step portion SP. In this configuration, the wide portion WP arranged substantially parallel to the step portion SP has a shape having a constant length, so that the flow of the insulating base material layer near the step portion SP at the time of heating and pressing is prevented. Can be effectively suppressed.

(D) In this embodiment, the plurality of insulating base material layers 11, 12, 13, 14, and 15 are made of thermoplastic resin. According to this structure, 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, and 15, and thus, the multilayer substrate 101. The manufacturing process can be reduced and the cost can be kept low.

The multilayer substrate 101 according to this embodiment is manufactured, for example, by the manufacturing method described below. 3A to 3C are cross-sectional views sequentially showing the manufacturing process of the multilayer substrate 101. Note that, in FIG. 3, for convenience of description, a manufacturing process of individual pieces (one chip) will be described, but the actual manufacturing process of the multilayer substrate is performed in a collective substrate state. This also applies to each cross-sectional view showing the subsequent manufacturing process.

First, as shown in (1) of FIG. 3, a plurality of insulating base material layers 11, 12, 13, 14, and 15 are prepared to form a plurality of insulating base material layers 11, 12, 13, 14, and 15. , 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 main surface (back surface) of the insulating substrate layers 11, 12, 13, 14, 15 in the state of a collective substrate, and the metal foil is patterned by photolithography. To do. Thus, 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 P2 is formed on the back surface of the insulating base material layer 15.

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

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, 15. The interlayer connecting conductor is provided with a through hole in the insulating base material layer by a laser or the like, and then a conductive paste containing one or more of Cu, Sn and the like or an alloy thereof is arranged and cured by subsequent heating and pressurization. It is provided by Therefore, the interlayer connection conductor is made of a material having a melting point (melting temperature) lower than the temperature of the subsequent heating and pressurization.

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

After that, the laminated body in the state of the collective substrate is removed from the upper mold 1 and the lower die 2, and the laminated body in the state of the collective substrate is divided to obtain an individual multilayer substrate 101 as shown in (3) 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 can be reduced, and the cost can be kept low.

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

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

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

Although FIG. 4 shows an example in which the capacitor C1 is a chip type capacitor mounted on a circuit board, the capacitor C1 is not limited to this. The capacitor C1 may be mounted on the multilayer substrate 101, for example. Moreover, the capacitor C1 is not limited to a chip component. The capacitor C1 may be, for example, an interlayer capacitance formed between a plurality of insulating base material layers that are opposed to each other.

<<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 sectional view of the multilayer substrate 102 according to the second embodiment. FIG. 6 is an exploded plan view of the multilayer substrate 102. Note that in FIG. 6, the coil conductor patterns 31, 32, 33, and 34 are shown as dot patterns in order to make the structure easy to understand.

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. Further, 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 laminated 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 material layer 11 in FIG. 6) than the center of the insulating base material 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 material layer 12 in FIG. 6) from the center of the insulating base material layer 12. ..

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

The coil conductor pattern 34 is a conductor pattern in the shape of a rectangular spiral wound around the outer shape of the insulating base material layer 14 and having about 1.5 turns.

The external connection electrode P2A 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, by forming (stacking) the protective layer 5 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 stacked 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 component. Further, 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 shown, but the protective layer may be formed on the first main surface VS1 side. The structure may be formed on the second main surface VS2B side.

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 connecting 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 connecting 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 connecting 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 this embodiment, the coil conductor patterns 31A, 32A, 33A, 34A and the interlayer connecting conductors V2, V3, V4 form 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, 34A are close to each other along the step portion SP when viewed from the Z-axis direction (the coil conductor patterns 31A, 32A, 33A in FIG. 6). , 34A, a wide portion WP having a relatively wider line width than the other portions is provided in the right side portion extending in the Y-axis direction).

Even with 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 operation/effect as the multilayer substrate 101 is achieved.

Further, as shown in the present embodiment, the coil may have a structure in which rectangular spiral coil conductor patterns are connected by interlayer connection conductors.

<<Third Embodiment>>
The third embodiment shows an example of a multilayer substrate having a plurality of second regions.

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. Note that in FIG. 9, the coil conductor patterns 31B, 32B, 33B, and 34B are shown as dot patterns in order to make the structure easy to understand.

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

The laminated 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 has a first main surface VS1 and second main surfaces VS2A, VS2B, VS2C that face the first main surface VS1. The second main surface VS2A is a surface located in the first area F1, the second main surface VS2B is a surface located in the second area F21, and the second main surface VS2C is a surface located in the second area 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 insulator 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, 11b whose main material is resin (thermoplastic resin). The first region F1 of the laminated body 10B is formed by laminating the insulating base material layers 14b, 13b, 12b, 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 material layers 11b and 12b are insulating base material layers formed over the first region F1 and the second regions F21 and F22.

The number of laminated insulating base layers in the second regions F21 and F22 (two layers) is smaller than the number of laminated insulating base layers in the first region F1 (four layers). Therefore, the step 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 laminated insulating base layers. Further, a step 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 laminated insulating base layers.

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

The insulating base material layers 11b and 12b are L-shaped flat plates whose longitudinal direction coincides with the X-axis direction. The insulating base material layers 13b and 14b are rectangular flat plates whose longitudinal direction coincides with the X-axis direction. The length of the insulating base material layers 11b and 12b in the X-axis direction is longer than the length of the insulating base material layers 13b and 14b in the X-axis direction. Further, the length in the Y-axis direction of a part of the insulating base material layers 11b and 12b (the lower left portion of the insulating base material layers 11b and 12b in FIG. 9) is greater than the length of the insulating base material layers 13b and 14b in the Y-axis direction. Is also long. The insulating base material layers 11b and 12b have substantially the same planar shape, and the insulating base material layers 13b and 14b have substantially the same planar shape.

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 conductor pattern of a rectangular loop having a little less than one turn arranged near the center of the insulating base material layer 11B. The conductor 21 is a linear conductor pattern that extends in the X-axis direction.

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

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

A coil conductor pattern 34B and a conductor 22 are formed on the back surface of the insulating base material layer 14b. The coil conductor pattern 34B is a conductor pattern in the shape of a rectangular loop of less than one turn, which is arranged at a position closer to the second side (the right side of the insulating base material layer 14b in FIG. 9) from the center of the insulating base material 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 connecting 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 connecting 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 connecting conductor V4. The second end of the coil conductor pattern 34B 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 connecting conductor V5. The second end of the conductor 23 is connected to the external connection electrode P2B via the interlayer connection conductor V6.

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

As shown in FIG. 8A and the like, the coil conductor patterns 31B, 32B, 33B, 34B are close to each other along the step portion SP1 when viewed from the Z-axis direction (the coil conductor patterns 31B, 32B in FIG. 9, A wide portion WP1 having a relatively wider line width than the other portions is provided on the right side portion of 33B and 34B that extends in the Y-axis direction).

Further, as shown in FIG. 8B and the like, the coil conductor patterns 31B, 32B, 33B, 34B are close to each other along the step portion SP2 when viewed from the Z-axis direction (the coil conductor pattern 31B in FIG. 9, Of the portions 32B, 33B, 34B, the lower 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 width portion WP1 according to the present embodiment has a linear shape extending in the Y-axis direction along the step portion SP1. Further, as shown in FIG. 9, the wide width portion WP2 according to the present embodiment has a linear shape extending in the X-axis direction along the step portion SP2.

As shown in this embodiment, the number of the second regions may be plural. That is, the number of stepped portions may be plural. The shapes, numbers, positions, etc. of the first regions and the second regions can be changed as appropriate within the range where the effects of the present invention can be obtained, and the number of the first regions may be two or more.

Further, as shown in the present embodiment, when the number of step portions is plural, there is a configuration in which a wide portion is formed in a portion of the coil conductor pattern that is close to each step portion. preferable. In addition, if the wide portion is formed in a portion of the coil conductor pattern that is close to the step portion, the action and effect of the present invention can be obtained. However, from the viewpoint of the operation and effect of the present invention, it is preferable that a wide portion is formed in each portion of the coil conductor pattern that is adjacent along each step portion.

<<Other Embodiments>>
In each of the above-described embodiments, an example in which the laminated body is a rectangular flat plate or an L-shaped flat plate is shown, but the present invention is not limited to this configuration. The planar shape of the laminated body 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, a T shape, a Y shape, or the like.

Further, in each of the embodiments described above, an example of a laminated body formed by laminating four or five insulating base material layers is shown, but the present invention is not limited to this configuration. The number of insulating base material layers forming the laminated body 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, for example, two or three, or may be six or more. Further, the number of insulating base material layers stacked in the first region and the number of insulating base material layers stacked in the second region can be appropriately changed within a range in which the advantageous effects of the present invention are exhibited.

In each of the embodiments described above, an example is shown in which a plurality of insulating base material layers made of a thermoplastic resin are laminated and heated and pressed to form a laminate, but the present invention is not limited to this configuration. .. For example, a laminate may be formed by heating and pressing a laminate obtained by sandwiching a bonding layer (for example, a semi-cured prepreg resin) between a plurality of insulating base material layers made of a thermosetting resin. ..

Further, in each of the embodiments described above, an example in which the coils 3 and 3B having a rectangular helical shape having a winding axis in the Z-axis direction and having about 3.5 turns and the coil 3A having about 6 turns have been shown. However, the shape of the coil, the number of turns, etc. are not limited to these. The outer shape, the configuration, and the number of turns of the coil can be appropriately changed within the range where the effects of the present invention can be obtained. 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, an ellipse, or the like. The winding axis of the coil does not have to be along the Z-axis direction, but may be along the X-axis direction or the Y-axis direction, for example.

In each of the embodiments described above, an example is shown in which all the coil conductor patterns are arranged so as to substantially overlap each other when viewed from the Z-axis direction, but the present invention is not limited to this configuration. The plurality of coil conductor patterns may be arranged so that at least some of them overlap with each other when viewed from the Z-axis direction.

Furthermore, in each of the above-described embodiments, an example in which the coil is configured to include four coil conductor patterns formed on the four insulating base material layers has been shown, but the present invention is not limited to this configuration. Absent. The coil may be configured to include two or more coil conductor patterns respectively formed on two or more insulating base material layers. That is, the number of coil conductor patterns forming the coil may be two or more.

In each of the above-described embodiments, an example in which all the coil conductor patterns have wide portions has been shown, but the present invention is not limited to this configuration. If the wide portion is formed in at least one coil conductor pattern among the plurality of coil conductor patterns, the action and effect of the present invention can be obtained. However, from the viewpoint of the effect of the present invention, it is preferable that the wide portion is formed in all the coil conductor patterns.

Further, in each of the embodiments described above, an example in which the wide portion is linear is shown, but the present invention is not limited to this configuration. The wide portion may be formed in a portion of the coil conductor pattern that is close to the step portion, and may have, for example, an arc shape, a curved shape, a crank shape, an L shape, or the like.

In each of the embodiments described above, the example of the multilayer substrate including only the coil is shown, but the circuit configuration formed on the multilayer substrate (laminate) is not limited to this. The circuit formed in the laminated body can be appropriately changed within the range where the action and effect of the present invention can be obtained. For example, a capacitor formed of a conductor pattern, various transmission lines (stripline, microstripline, meander, coplanar, etc.) and the like may be formed in a laminated body. Further, for example, chip components such as a chip inductor and a chip capacitor may be mounted on the laminated body.

Further, the number, arrangement, shape, etc. 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 appropriately changed according to the circuit formed in the laminated body. The planar shape of the external connection electrode is not limited to a rectangle or an L shape, and may be, for example, a square, a polygon, a circle, an ellipse, or a T shape.

In the first embodiment, an example is shown in which the external connection electrodes of the multilayer substrate are connected to the circuit board or the like via a conductive bonding material such as solder, but the configuration is not limited to this. The multilayer board may be connected to a circuit board or the like using, for example, a connector.

Finally, the above description of the embodiments is illustrative in all respects and not restrictive. Those skilled in the art can appropriately make modifications and changes. The scope of the invention is indicated by the claims rather than by the embodiments described above. Further, 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 area F2, F21, F22... Second area P1, P2, P2A, P2B... External connection electrodes SP, SP1, SP1a, SP2. , SP2a... Step portions V1, V2, V3, V4, V5, V6... Interlayer connection conductor VS1... First main surface VS2A, VS2B, VS2C of laminated body... Second main surface WP, WP1, WP2... Wide portion of laminated body 1... Upper mold 2... Lower mold 1a, 2a... Mold 3, 3A, 3B... Coil 4... IC
5... Protective layer 10, 10B... Laminated body 11, 11a, 11b, 12, 12a, 12b, 13, 13a, 13b, 14, 14a, 14b, 15, 15a... Insulating base material layer 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 (3)

A laminate having a plurality of insulating base material layers mainly made of resin and having a first region and a second region in which the number of insulating base material layers is smaller than that of 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 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;
Equipped with
Wherein the plurality of coil conductor patterns are viewed from the stacking direction of the plurality of insulating base layers are disposed so that they at least partially overlap each other, have a wide wide portion a relatively linewidth than other portions ,
The wide portion is linear and is arranged along the linear step portion,
No other conductor is arranged between the wide portion and the step portion,
Multi-layer board. The multilayer substrate according to claim 1, wherein the number of the second regions is plural. The multilayer substrate according to claim 1 or 2 , wherein the plurality of insulating base material layers are made of a thermoplastic resin.

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