JP6248688B2 - Resin multilayer board - Google Patents

Description

  The present invention relates to a resin multilayer substrate.

  Generally, a resin multilayer substrate can be manufactured by laminating a plurality of resin layers. Such a resin multilayer substrate may be mounted in a bent state or may be bent during use.

  The resin layer multilayer substrate may be short-circuited when the conductive patterns formed on the main surface of the resin layer come into contact with each other when folded. As a document in which such a resin multilayer substrate capable of suppressing a short circuit is disclosed, for example, International Publication No. 2012/147550 (Patent Document 1) is cited.

  The resin multilayer substrate disclosed in Patent Document 1 has an innermost surface that is an inner surface when folded and an outermost surface that is an outer surface, and is a plurality of laminated resin layers A first conductive pattern and a second conductive pattern arranged to be spaced apart from each other on the first surface which is the surface of any of the plurality of resin layers, and a position closer to the outermost surface than the first surface The third conductive pattern and the fourth conductive pattern are arranged so as to be separated from each other on the second surface existing as the surface of any of the plurality of resin layers. The interval between the third conductive pattern and the fourth conductive pattern is narrower than the interval between the first conductive pattern and the second conductive pattern.

  By adopting such a configuration, when the resin multilayer substrate is bent, the interval between the third conductive pattern and the fourth conductive pattern is less likely to extend than the interval between the first conductive pattern and the second conductive pattern. Sudden bending in a local section is suppressed. Thereby, it is suppressed that the some resin layer located inside is bent exceeding predetermined amount. As a result, it is possible to suppress a short circuit due to the close contact between the first conductive pattern and the second conductive pattern located on the first surface.

International Publication No. 2012/147550

  As an example of the resin multilayer substrate based on the prior art, there is a resin multilayer substrate 200 as shown in FIGS. 42 and 43, for example. 42 and 43 are a plan view of a resin layer on which a conductive pattern is formed and a cross-sectional view of a portion on which the conductive pattern is formed in a resin multilayer substrate based on the prior art. FIG. 42 is a plan view when viewed from above, and a broken line portion indicates a conductive pattern provided on the surface of the resin layer 2 located on the lower side. 43 is a cross-sectional view taken along line XLIII-XLIII shown in FIG.

  The resin multilayer substrate 200 includes a laminate 1 in which a plurality of resin layers 2 are laminated. For example, among the plurality of resin layers 2, the main surfaces 3, 13, 23 located on the lower side of the first resin layer 2c from the upper layer, the third resin layer 2b, and the fifth resin layer 2a, respectively. Are provided with conductive patterns 4, 14, 24. The conductive patterns 4, 14, 24 are provided so as to overlap in the stacking direction of the plurality of resin layers 2.

  FIG. 44 is a diagram showing a state in which the portion shown in FIG. 43 is deformed when the resin multilayer substrate is bent around the folding line. As shown in FIG. 44, when the resin multilayer substrate 200 is bent around a fold line F (see FIG. 42) perpendicular to the extending direction of the conductive patterns 4, 14, and 24, it is compared with the case where it is not bent. As a result, a load is applied to the conductive patterns 4, 14, and 24. Therefore, there is a concern that the conductive patterns 4, 14, and 24 are broken.

  In addition, for example, when the degree of bending is increased and bending is performed near 90 degrees, the conductive pattern 24 is greatly bent, particularly in the A region located on the inner side. For this reason, compressive stress is concentrated on a part of the conductive pattern 24. Thereby, the conductive pattern 24 is easily broken as compared with the conductive pattern 4.

  Furthermore, in the B region located outside, the conductive pattern 14 is more likely to break than the conductive pattern 4 due to excessive tensile stress acting on the conductive pattern 14. Moreover, since the layer thickness of the resin layer 2 located outside becomes thin due to the action of tensile stress, the distance between the conductive patterns 4 and 14 is narrowed, and there is a concern that the electrical characteristics fluctuate.

  Tensile stress is generated on the outer peripheral side of the resin multilayer substrate (laminate) in the thickness direction, and compressive stress is generated on the inner periphery side of the resin multilayer substrate (laminate) in the thickness direction. The closer you are, the bigger it will be. Therefore, the conductive pattern at a position closer to the outer peripheral side and the inner peripheral side is more likely to be affected by the above.

  In recent years, where the miniaturization of the conductive pattern is required, such a change in electrical characteristics and breakage of the conductive pattern tend to appear remarkably. For this reason, in order to prevent malfunctions due to fluctuations in electrical characteristics, breakage of the conductive pattern, etc., it is required to relieve the stress acting on the conductive pattern when the resin multilayer substrate is bent.

  However, in the resin multilayer substrate disclosed in Patent Document 1, it is possible to suppress a plurality of conductive patterns formed on the same surface from approaching in the horizontal direction, but the conductive pattern in the stacking direction of the resin layers. The variation in the distance between them and the breakage of the conductive pattern are not fully considered.

  This invention is made | formed in view of the above problems, and the objective of this invention provides the resin multilayer substrate which can relieve | moderate the stress which acts on a conductive pattern when it is used by bending. There is.

  A resin multilayer substrate according to the first aspect of the present invention is a foldable resin multilayer substrate including a plurality of resin layers, and is included in the plurality of resin layers and includes a first main surface. A layer, a first conductive pattern formed on the first main surface of the first resin layer, a first direction in which at least a part of the first conductive pattern extends, and the above A plurality of first dummy vias provided so as to penetrate in the thickness direction of the first resin layer. The first resin layer is located adjacent to both sides of the first region and the first region where the bending degree is increased in the first resin layer when bent around a fold line intersecting the first direction. A second region is formed that is less bent than the one region. In a state before bending, the first region extends along the folding line with a predetermined width in the width direction parallel to the first direction with the folding line as a center. In a state before folding, the second region extends along the folding line with a predetermined width in a width direction parallel to the first direction. The density of the first dummy vias provided in the first region is greater than the density of the first dummy vias provided in the second region.

  In the resin multilayer substrate according to the first aspect of the present invention, the plurality of first dummy vias are provided such that the distance between the centers of the adjacent first dummy vias gradually increases as the distance from the folding line increases. It is preferable that

  A resin multilayer substrate according to a second aspect of the present invention is a foldable resin multilayer substrate including a plurality of resin layers, and is included in the plurality of resin layers and includes a first main surface. A layer, a first conductive pattern formed on the first main surface of the first resin layer, a first direction in which at least a part of the first conductive pattern extends, and the above A plurality of first dummy vias provided so as to penetrate in the thickness direction of the first resin layer. The first resin layer is located adjacent to both sides of the first region and the first region where the bending degree is increased in the first resin layer when bent around a fold line intersecting the first direction. A second region is formed that is less bent than the one region. In a state before bending, the first region extends along the folding line with a predetermined width in the width direction parallel to the first direction with the folding line as a center. In a state before folding, the second region extends along the folding line with a predetermined width in a width direction parallel to the first direction. On the main surface of the first resin layer located on the opposite side of the first main surface, the via diameter of the first dummy via provided in the first region is the first diameter provided in the second region. It is larger than the via diameter of one dummy via.

  In the resin multilayer substrate according to the second aspect of the present invention, the plurality of first dummy vias are preferably provided such that the via diameter gradually decreases as the distance from the folding line increases.

  The resin multilayer substrate according to the first aspect and the second aspect of the present invention has the first main surface so as to sandwich the first conductive pattern and to be parallel to each other when viewed in a plan view. It is preferable to further include a pair of first dummy patterns provided along the first direction. In this case, the plurality of first dummy vias are preferably connected to the pair of first dummy patterns.

  The resin multilayer substrate based on the first aspect and the second aspect of the present invention is included in the plurality of resin layers, and is located on the inner side of the first resin layer when bent. A second resin layer including a second main surface not in contact with the main surface; a second conductive pattern formed on the second main surface of the second resin layer so as to correspond to the first conductive pattern; It is preferable to further include a plurality of second dummy vias provided along the first direction and provided so as to penetrate in the thickness direction of the second resin layer. In this case, it is preferable that the number of the second dummy vias provided in the second resin layer is smaller than the number of the first dummy vias provided in the first resin layer.

  The resin multilayer substrate according to the first aspect and the second aspect of the present invention has the second main surface so that the second conductive pattern is sandwiched between and parallel to each other when viewed in a plan view. It is preferable to further include a pair of second dummy patterns provided along the first direction and extending along the first direction. In this case, the plurality of second dummy vias are preferably connected to the pair of second dummy patterns.

  In the resin multilayer substrate according to the first aspect and the second aspect of the present invention, each of the pair of first dummy patterns is independent from each other and is not divided along the first direction. It is preferable to extend continuously. In this case, when viewed in plan, the plurality of first dummy vias are continuously provided on both sides of the first conductive pattern in a direction intersecting the first direction. It is preferably connected to a dummy pattern.

  In the resin multilayer substrate according to the first aspect and the second aspect of the present invention, each of the pair of second dummy patterns is independent from each other and is not divided along the first direction. It is preferable to extend continuously. In this case, when viewed in plan, the plurality of second dummy vias are continuously provided on both sides of the second conductive pattern in a direction intersecting the first direction. It is preferably connected to a dummy pattern.

  ADVANTAGE OF THE INVENTION According to this invention, when using it by bending, the resin multilayer substrate which can relieve | moderate the stress which acts on a conductive pattern can be provided.

It is a top view which shows the resin layer which is a resin layer contained in the resin multilayer substrate which concerns on Embodiment 1 of this invention, and is located in the 1st layer from upper direction. It is a top view which shows the resin layer which is a resin layer contained in the resin multilayer substrate which concerns on Embodiment 1 of this invention, and is located in the 3rd layer from upper direction. It is a resin layer contained in the resin multilayer substrate which concerns on Embodiment 1 of this invention, Comprising: It is a top view which shows the resin layer located in the 5th layer from upper direction. It is sectional drawing of the part in which the dummy via is formed in the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing of the part in which the conductive pattern which will be located between dummy vias in planar view in the resin multilayer substrate concerning Embodiment 1 of this invention is provided. FIG. 5 is a diagram showing a state in which the portion shown in FIG. 4 is deformed when a resin multilayer substrate is bent around a fold line. FIG. 6 is a diagram showing a state in which a portion shown in FIG. 5 is deformed when a resin multilayer substrate is bent around a folding line. It is a top view which shows the resin layer which is a resin layer contained in the resin multilayer substrate which concerns on Embodiment 2 of this invention, and is located in the 1st layer from upper direction. It is a resin layer contained in the resin multilayer substrate which concerns on Embodiment 2 of this invention, Comprising: It is a top view which shows the resin layer located in the 3rd layer from upper direction. It is a top view which shows the resin layer which is a resin layer contained in the resin multilayer substrate which concerns on Embodiment 2 of this invention, and is located in the 5th layer from upper direction. It is sectional drawing of the part in which the dummy via | veer is formed in the resin multilayer substrate concerning Embodiment 2 of this invention. It is sectional drawing of the part in which the conductive pattern which will be located between dummy vias when planarly viewed in the resin multilayer substrate concerning Embodiment 2 of this invention is provided. FIG. 12 is a diagram illustrating a state in which the portion illustrated in FIG. 11 is deformed when the resin multilayer substrate is folded around the folding line. It is a figure which shows the state which the part shown in FIG. 12 deform | transformed when the resin multilayer substrate is bent centering on a bending line. It is sectional drawing of the part in which the dummy via is formed in the resin multilayer substrate concerning Embodiment 3 of this invention. FIG. 16 is a diagram showing a state in which the portion shown in FIG. 15 is deformed when the resin multilayer substrate is bent around a fold line. It is a resin layer contained in the resin multilayer substrate concerning Embodiment 4 of the present invention, and is a top view showing the 3rd resin layer from the upper part. It is sectional drawing of the part by which the dummy via is formed in the resin multilayer substrate concerning Embodiment 4 of this invention. It is a figure which shows the state which the part shown in FIG. 18 deform | transformed when the resin multilayer substrate is bent centering on a bending line. It is a resin layer contained in the resin multilayer substrate concerning Embodiment 5 of the present invention, and is a top view showing the 3rd layer from the upper part. It is sectional drawing of the part in which the dummy via is formed in the resin multilayer substrate concerning Embodiment 5 of this invention. It is a figure which shows the state which the part shown in FIG. 21 deform | transformed when the resin multilayer substrate is bent centering on a bending line. It is a resin layer contained in the resin multilayer substrate concerning Embodiment 6 of the present invention, and is a top view showing the 3rd layer from the upper part. It is a resin layer contained in the resin multilayer substrate concerning Embodiment 7 of the present invention, and is a top view showing the 3rd layer from the upper part. It is a resin layer contained in the resin multilayer substrate concerning Embodiment 7 of the present invention, and is a top view showing the 5th layer from the upper part. It is sectional drawing of the part in which the dummy via | veer is formed in the resin multilayer substrate concerning Embodiment 7 of this invention. FIG. 27 is a diagram showing a state in which the portion shown in FIG. 26 is deformed when a resin multilayer substrate is bent around a fold line. It is a resin layer contained in the resin multilayer substrate concerning Embodiment 8 of the present invention, and is a top view showing the 3rd layer from the upper part. It is a resin layer contained in the resin multilayer substrate concerning Embodiment 8 of the present invention, and is a top view showing the 5th layer from the upper part. It is sectional drawing of the part in which the dummy via | veer is formed in the resin multilayer substrate concerning Embodiment 8 of this invention. It is a figure which shows the state which the part shown in FIG. 30 deform | transformed when the resin multilayer substrate is bent centering on a bending line. It is sectional drawing of the part in which the dummy via is formed in the resin multilayer substrate concerning Embodiment 9 of this invention. It is a figure which shows the state which the part shown in FIG. 32 deform | transformed when the resin multilayer substrate is bent centering on a bending line. It is a resin layer contained in the resin multilayer substrate in modification 1, and is a top view showing the 3rd layer and the 5th layer from the upper part. It is a resin layer contained in the resin multilayer substrate in the modification 2, Comprising: It is a top view which shows the 3rd layer and 5th layer from upper direction. It is sectional drawing which shows the 1st process of the manufacturing method of the resin multilayer substrate concerning Embodiment 10 of this invention. It is sectional drawing which shows the 2nd process of the manufacturing method of the resin multilayer substrate which concerns on Embodiment 10 of this invention. It is sectional drawing which shows the 3rd process of the manufacturing method of the resin multilayer substrate concerning Embodiment 10 of this invention. It is sectional drawing which shows the 4th process of the manufacturing method of the resin multilayer substrate concerning Embodiment 10 of this invention. It is sectional drawing which shows the 5th process of the manufacturing method of the resin multilayer substrate concerning Embodiment 10 of this invention. It is sectional drawing which shows the 6th process of the manufacturing method of the resin multilayer substrate concerning Embodiment 10 of this invention. It is a top view of the resin layer in which the conductive pattern is formed in the resin multilayer substrate based on a prior art. It is sectional drawing of the part in which the conductive pattern is formed in the resin multilayer substrate based on a prior art. FIG. 44 is a diagram showing a state in which the portion shown in FIG. 43 is deformed when the resin multilayer substrate is bent around the bend line.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the same or common parts are denoted by the same reference numerals in the drawings, and description thereof will not be repeated.

(Embodiment 1)
FIGS. 1 to 3 are plan views showing resin layers included in the resin multilayer substrate according to the present embodiment, which are located in the first, third, and fifth layers from above. 1 to 3 are plan views when viewed from above, and a broken line portion indicates a conductive pattern or a dummy pattern provided on a main surface located on the lower side of the resin layer 2. 4 and 5 are cross-sectional views of a portion where a dummy via is formed in the resin multilayer substrate according to the present embodiment and a portion where a conductive pattern which is located between the dummy vias when viewed in plan is provided. They are IV-IV arrow directional cross-sectional view and VV line arrow directional cross-sectional view which are shown in FIG. With reference to FIGS. 1 to 5, the resin multilayer substrate according to the present embodiment will be described. In this specification, the “dummy” of the dummy pattern and the dummy via means that the dummy pattern and the dummy via do not function as a part of the circuit and are not substantially electrically connected to other circuit elements.

  As shown in FIGS. 1 to 5, a resin multilayer substrate 100 according to the present embodiment is a resin multilayer substrate including a laminate 1 in which a plurality of resin layers 2 are laminated. The plurality of resin layers 2 have flexibility, and the resin multilayer substrate 100 is configured to be bendable. In the present embodiment, the resin layer 2 located above in FIGS. 4 and 5 is arranged on the inner peripheral side by bending the one end side closer to the other end side with the fold line F shown in FIGS. 1 to 3 as the center. The resin layer 2 located at the lower side is located on the outer peripheral side. Thereby, the laminated body 1 has the inner surface 1a which becomes an inner surface when bent, and the outer surface 1b which becomes an outer surface when bent.

  As shown in FIGS. 1 and 3 to 5, the resin multilayer substrate 100 includes a ground electrode 7 and a ground electrode 8 that are planar conductors made of conductive foil. The ground electrode 7 is provided on the main surface (main surface located on the outer surface 1a side) of the first resin layer from above. The ground electrode 8 is provided on the main surface (main surface located on the outer surface 1b side) of the fifth resin layer from the top. The ground electrodes 7 and 8 are provided opposite to each other so as to sandwich a first conductive pattern 4, a first dummy pattern 5, and a plurality of first dummy vias 6 described later in the stacking direction of the resin layer 2, thereby forming a strip line. doing.

  As shown in FIGS. 2, 4 and 5, the resin multilayer substrate 100 includes a first resin layer 2 a, a first conductive pattern 4, a first dummy pattern 5, and a plurality of first dummy vias 6. The first resin layer 2a is included in the plurality of resin layers 2 and includes a first main surface 3a. The first resin layer 2a corresponds to, for example, the third resin layer 2 from above. The first major surface 3a is located on the outer surface 1b side.

  The first conductive pattern 4 is a planar conductor made of a conductive foil, and is formed on the first main surface 3a. The first conductive pattern 4 is provided, for example, so as to extend in the longitudinal direction (first direction: arrow A direction in FIG. 2). The first conductive pattern 4 is constituted by a wiring pattern such as a signal line or a power supply line.

  The first dummy patterns 5 are planar conductors made of conductive foil, and when viewed in a plane, a pair of first dummy patterns 5 are provided so as to sandwich the first conductive pattern 4 therebetween and be parallel to each other on the first main surface 3a. ing. The pair of first dummy patterns 5 extends in the first direction (arrow A direction), for example, along the first conductive pattern 4. The first direction coincides with the longitudinal direction of the first conductive pattern 4 and is orthogonal to the folding line F on the first main surface 3a.

  Each of the pair of dummy patterns 5 is divided into a plurality of partial patterns 5a so as to be separated from each other. Each of the plurality of partial patterns 5a is provided so as to correspond to the position where the first dummy via 6 is provided. That is, each of the plurality of partial patterns 5 a has a function like a receiving pad (receiving conductor) of the first dummy via 6. The pair of first dummy patterns 5 is electrically separated from the first conductive pattern 4.

  The plurality of first dummy vias 6 are connected to the pair of first dummy patterns 5 and are provided so as to penetrate in the thickness direction of the first resin layer 2a. Each of the plurality of first dummy vias 6 is connected to the partial pattern 5a. The plurality of first dummy vias 6 are provided so that via diameters on the main surface 3b located on the opposite side of the first main surface 3a in the first resin layer 2a are the same. The first dummy via 6 is formed by filling a hole provided in the resin layer 2 with a conductive paste and curing it.

  When folded around a folding line F that intersects the first direction, the first resin layer 2a is positioned adjacent to both sides of the first region R1 and the first region R1 where the degree of folding increases. A second region R2 that is less bent than the first region R1 is formed. In the first resin layer 2a, regions other than the first region R1 and the second region R2 are regions that are not substantially bent.

  The first region R1 extends along the folding line F with a predetermined width W1 in the width direction parallel to the first direction with the folding line F as the center in the state before folding. The second region R2 extends along the folding line F with a predetermined width W2 in the width direction parallel to the first direction in a state before folding.

  The plurality of first dummy vias 6 are provided such that the density of the first dummy vias 6a provided in the first region R1 is higher than the density of the first dummy vias 6b provided in the second region R2.

  6 and 7 are diagrams showing a state in which the portion shown in FIG. 4 is deformed and a state in which the portion shown in FIG. 5 is deformed when the resin multilayer substrate is bent around the folding line. A state where the resin multilayer substrate 100 is bent will be described with reference to FIGS.

  When one end of the resin multilayer substrate 100 is bent nearly 90 degrees upward with the folding line F as the center, the resin multilayer substrate 100 is compressed on the resin layer 2 side located on the upper side (the ground electrode 7 side) and below (ground) The resin layer 2 side located on the electrode 8 side) is in a tensile state.

  In the resin layer 2a, a plurality of first dummy vias 6 are provided on both sides of the first conductive pattern 4 in the folding line direction so as to sandwich the first conductive pattern 4 when viewed in plan. Since the first dummy via 6 is harder than the resin layer 2, when the first dummy via 6 is provided in the resin layer 2 as compared with the case where the first dummy via 6 is not provided, the resin layer in the bent portion. 2 expansion and contraction can be suppressed.

  In the first region R1 where the degree of bending becomes large, bending stress tends to concentrate. By making the density of the first dummy vias 6a provided in the first region R1 larger than the density of the first dummy vias 6b provided in the second region R2, the stress acting on the first conductive pattern 4 and the resin layer 2 is increased. Can be effectively mitigated. In addition, by changing the density according to the bending condition in this way, it is possible to prevent the first dummy vias 6 from being excessively concentrated in the bent portion, and the flexibility of the resin multilayer substrate 100 can be improved. Thereby, it is possible to ensure the ease of bending when a bending stress is applied to the resin multilayer substrate 100. As a result, the first conductive pattern 4 can be further miniaturized in addition to the disconnection of the first conductive pattern 4. Further, the resin layer 2 itself can be prevented from being damaged.

  By effectively relieving the bending stress acting on the first conductive pattern 4 and the resin layer 2, fluctuations in the thickness of the resin layer 2 can be suppressed. Thereby, the 1st conductive pattern 4 moves to the ground electrode 7 side, and it is suppressed that the capacity | capacitance between the 1st conductive pattern 4 and the ground electrode 7 fluctuates. As a result, fluctuations in electrical characteristics can be suppressed.

  The first dummy via 6 and the first dummy pattern 5 are both made of dummy conductors. Therefore, even if the relative positional relationship among the first dummy via 6, the first dummy pattern 5, and other conductors is changed by bending stress when the resin multilayer substrate is bent, the electrical characteristics of the resin multilayer substrate are affected. The effect is suppressed.

(Embodiment 2)
8 to 10 are plan views showing resin layers included in the resin multilayer substrate according to the present embodiment, which are located in the first, third, and fifth layers from above. 8 to 10 are plan views when viewed from above, and a broken line portion indicates a conductive pattern or a dummy pattern provided on the main surface located on the lower side of the resin layer 2. 11 and 12 are cross-sectional views of a portion where a dummy via is formed in the resin multilayer substrate according to the present embodiment and a portion where a conductive pattern which is located between the dummy vias in plan view is provided. FIG. 11 is a cross-sectional view taken along line XI-XI and a cross-sectional view taken along line XII-XII shown in FIGS. 9 and 10. A resin multilayer substrate 100A according to the present embodiment will be described with reference to FIGS.

  As shown in FIGS. 8 to 12, the resin multilayer substrate 100 </ b> A according to the present embodiment is different in the configuration of the laminate 1 from the resin multilayer substrate 100 according to the first embodiment.

  In the resin layer 2a according to the present embodiment, the plurality of first dummy vias 6 are provided such that the intervals gradually increase as the first dummy vias 6 are separated from the fold line F along the first direction (arrow A direction). . Correspondingly, the plurality of partial patterns 5a are also provided such that the intervals gradually increase as they move away from the folding line F along the first direction (arrow A direction) (see FIG. 10). Other configurations are substantially the same as the configuration of the first resin layer 2a according to the first embodiment. The resin layer 2a is located at the fifth layer from the top, for example.

  As shown in FIGS. 8, 11 and 12, the resin multilayer substrate 100A includes a resin layer 2c in which a conductive pattern 24 is provided on the main surface 23a. The resin layer 2c is located, for example, in the first layer from above, and includes a main surface 23a located on the outer surface 1b side and a main surface 23b located on the inner surface side 1a. When the resin layer 2c is bent, the resin layer 2c is positioned inside a second resin layer 2b described later.

  The conductive pattern 24 is provided, for example, so as to extend in the longitudinal direction. The conductive pattern 24 is constituted by a wiring pattern such as a signal line or a power supply line. The conductive pattern 24 is provided so as to overlap the first conductive pattern 4 and a second conductive pattern 14 described later in the stacking direction of the resin layer 2.

  As shown in FIGS. 9, 11 and 12, the resin multilayer substrate 100A further includes a second resin layer 2b, a second conductive pattern 14, a second dummy pattern 15, and a plurality of second dummy vias 16. . The second resin layer 2b is included in the plurality of resin layers 2, and includes a second main surface 13a that is located on the inner side of the first resin layer 2a when bent and does not contact the first main surface 3a. . The second resin layer 2b is located at the third layer from the top, for example, and includes a main surface 13a located on the outer surface 1b side and a main surface 13b located on the inner surface side 1a.

  The second conductive pattern 14 is a planar conductor made of a conductive foil, and is formed on the second main surface 13 a of the second resin layer 2 b so as to correspond to the first conductive pattern 4. The second conductive pattern 14 is provided, for example, so as to extend in the longitudinal direction. The second conductive pattern 14 is provided so as to overlap the first conductive pattern 4 in the stacking direction of the resin layer 2. The second conductive pattern 14 is a wiring pattern such as a signal line or a power supply line.

  The second dummy patterns 15 are planar conductors made of conductive foil, and when viewed in plan, a pair of second dummy patterns 15 are provided so as to sandwich the second conductive pattern 14 therebetween and be parallel to each other on the second main surface 13a. ing. The pair of second dummy patterns 15 extends in the first direction (arrow A direction), for example, along the second conductive pattern 14. The pair of second dummy patterns 15 are provided so as to correspond to the first dummy patterns 5 so as to be positioned above the stacking direction when viewed from the first dummy patterns 5.

  Each of the pair of second dummy patterns 15 is divided into a plurality of partial patterns 15a so as to be separated from each other. Each of the plurality of partial patterns 15a is provided so as to correspond to the position where the second dummy via 16 is provided. The pair of dummy patterns 15 is electrically separated from the second conductive pattern 14.

  The plurality of second dummy vias 16 are connected to the pair of second dummy patterns 15 and are provided so as to penetrate in the thickness direction of the second resin layer 2b. Each of the plurality of second dummy vias 16 is connected to the partial pattern 15a. The plurality of second dummy vias 16 are provided such that the distance between the centers of adjacent second dummy vias gradually increases as the distance from the folding line F in the first direction in which the second conductive pattern 14 extends is increased. . The plurality of second dummy vias 16 may be provided so that the distance between the centers is substantially constant.

  The plurality of second dummy vias 16 are provided such that via diameters on the main surface 13b located on the opposite side of the second main surface 13a in the second resin layer 2b are the same. Similar to the first dummy via 6, the second dummy via 16 is formed by filling a hole provided in the resin layer with a conductive paste and curing.

  The plurality of second dummy vias 16 are arranged symmetrically with respect to the folding line F. The density of the second dummy vias 16 provided in the second resin layer 2b is lower than the density of the first dummy vias 6a provided in the first region R1. Further, the number of second dummy vias 16 is smaller than the number of first dummy vias 6.

  FIG. 13 and FIG. 14 are diagrams showing a state in which the portion shown in FIG. 11 and the portion shown in FIG. 12 are deformed when the resin multilayer substrate is bent around the folding line. A state where the resin multilayer substrate 100 is bent will be described with reference to FIGS. 13 and 14.

  Also in the present embodiment, when one end side of the resin multilayer substrate 100A is bent nearly 90 degrees upward with the fold line F as the center, the resin multilayer substrate 100 located on the upper side is in a compressed state and is The resin layer 2 side that is positioned is in a tensile state.

  In this case, the first conductive pattern 4, the second conductive pattern 14, the conductive pattern 24, and the resin layer 2 are provided by the first dummy via 6 provided in the first resin layer 2a located on the outer peripheral side as in the first embodiment. It is possible to alleviate the concentration of bending stress acting on the.

  In the present embodiment, the distance between the centers of the adjacent first dummy vias 6 gradually increases as the plurality of first dummy vias 6 move away from the folding line F in the first direction in which the first dummy pattern 5 extends. It is provided to be wide. Accordingly, the first dummy vias 6 can be prevented from being excessively crowded, and the resin multilayer substrate 100A can be bent more gently.

  In addition, by providing a plurality of second dummy vias 16 at the bent portion of the second resin layer 2b located on the inner peripheral side of the first resin layer 2a, the first conductive pattern 4, the second conductive pattern 14, and the conductive pattern 24 and the concentration of bending stress acting on the resin layer 2 can be reduced.

  Here, when the same number of dummy vias as the outer peripheral side are arranged on the inner peripheral side, the dummy vias positioned on the inner peripheral side when bent are closer to each other than the dummy vias positioned on the outer peripheral side. When dummy vias contact each other, it may be difficult to ensure bending deformation.

  In the present embodiment, the number of the second dummy vias 16 is made smaller than the number of the plurality of first dummy vias 6 so that the second dummy vias 16 come into contact with each other while alleviating the bending stress concentrated on the bent portion. Can be prevented. Furthermore, by providing the plurality of second dummy vias 16 so that the distance between the centers of the adjacent second dummy vias gradually increases as the distance from the folding line F increases, the resin multilayer substrate 100A can be bent more gently. As a result, the flexibility of the resin multilayer substrate 100A can be sufficiently secured.

  As a result, in addition to the disconnection of the first conductive pattern 4, the second conductive pattern 14, and the conductive pattern 24, the first conductive pattern 4, the second conductive pattern 14, and the conductive pattern 24 can be further miniaturized. Become. Furthermore, it is possible to prevent the resin layer 2 itself from being damaged.

  Moreover, the fluctuation | variation of the thickness of the resin layer 2 can also be suppressed by relieving the bending stress which acts on the 1st conductive pattern 4, the 2nd conductive pattern 14, the conductive pattern 24, and the resin layer 2. FIG. Accordingly, it is possible to prevent the second conductive pattern 14 from approaching the conductive pattern 4 in the bent portion and to prevent the first conductive pattern 4 from approaching the second conductive pattern 14. As a result, it is possible to prevent the capacitance between the second conductive pattern 14 and the conductive pattern 4 from fluctuating and the capacitance between the first conductive pattern 4 and the second conductive pattern 14 from being changed. Variations can be suppressed.

  The first dummy via 6, the first dummy pattern 5, the second dummy via 16, and the second dummy pattern 15 are all made of dummy conductors. For this reason, even if the relative positional relationship among the first dummy via 6, the first dummy pattern 5, and other conductors changes due to bending stress when the resin multilayer substrate is bent, the electrical characteristics of the resin multilayer substrate are affected. Is suppressed. Similarly, even if the relative positional relationship among the second dummy via 16, the second dummy pattern 15, and the other conductors is changed, the influence on the electrical characteristics of the resin multilayer substrate is suppressed.

(Embodiment 3)
FIG. 15 is a cross-sectional view of a portion where a dummy via is formed in the resin multilayer substrate according to the present embodiment. With reference to FIG. 15, the resin multilayer substrate 100B according to the present embodiment will be described.

  As shown in FIG. 15, the resin multilayer substrate 100 </ b> B according to the present embodiment has one first dummy pattern (partial pattern 5 a) or second one for each first dummy via 6 or second dummy via 16. When compared with the resin multilayer substrate 100A according to the second embodiment in which the dummy pattern (partial pattern 15a) is formed, the first dummy pattern 5 and the second dummy pattern 15 are respectively provided continuously (connected). The other configurations are substantially the same.

  Specifically, each of the pair of first dummy patterns 5 extends continuously without being divided along the first direction in an independent state. Further, when viewed in a plan view, the plurality of first dummy vias 6 are formed on the first dummy pattern 5 provided continuously on both sides of the first conductive pattern 4 in the direction intersecting the first direction. It is connected.

  Each of the pair of second dummy patterns 15 extends continuously without being divided along the first direction in an independent state. When viewed in a plan view, the plurality of second dummy vias 16 are connected to the second dummy pattern 15 provided continuously on each side of the second conductive pattern 14 in a direction intersecting the first direction. Has been.

  FIG. 16 is a diagram showing a state in which the portion shown in FIG. 15 is deformed when the resin multilayer substrate is bent around the folding line. A state where the resin multilayer substrate 100B is bent will be described with reference to FIG.

  Also in the present embodiment, when one end side of the resin multilayer substrate 100B is bent nearly 90 degrees upward with the fold line F as the center, the resin multilayer substrate 100B is in a compressed state on the upper side and the downward direction. The resin layer 2 side that is positioned is in a tensile state.

  In the present embodiment, as compared with the second embodiment, the first dummy pattern 5 is provided to be continuous, and the second dummy pattern is provided to be continuous, whereby the first conductive pattern is provided. Further relax the bending stress acting on the pattern 4, the second conductive pattern 14, the conductive pattern 24 provided on the main surface 23a of the resin layer 2c, the first resin layer 2a, the second resin layer 2b, and the resin layer 2c. Can do. As a result, an effect equal to or greater than that of the second embodiment can be obtained.

(Embodiment 4)
FIG. 17 is a plan view showing a third resin layer from above, which is a resin layer included in the resin multilayer substrate according to the present embodiment. FIG. 17 is a plan view when viewed from above, and a broken line portion shows a conductive pattern and a dummy pattern provided on the main surface located on the lower side of the resin layer 2. 18 is a cross-sectional view of a portion where a dummy via is formed in the resin multilayer substrate according to the present embodiment, and is a cross-sectional view taken along line XVIII-XVIII shown in FIG. A resin multilayer substrate 100C according to the present embodiment will be described with reference to FIGS.

  As shown in FIGS. 17 and 18, the resin multilayer substrate 100C according to the present embodiment is electrically conductive with the resin layer 2c that is on the inner side when bent when compared with the resin multilayer substrate 100A according to the second embodiment. The point that the pattern is not formed, the point that the dummy via is formed is only one layer, the number of laminated resin layers 2 is different, and the other configurations are almost the same.

  In the resin multilayer substrate 100C, the first resin layer 2a in which the conductive pattern, the dummy pattern, and the dummy via are formed is located in the third layer from above.

  FIG. 19 is a diagram showing a state in which the portion shown in FIG. 18 is deformed when the resin multilayer substrate is bent around the folding line. With reference to FIG. 19, a state where the resin multilayer substrate 100C is bent will be described.

  Also in the present embodiment, when one end side of the resin multilayer substrate 100C is bent nearly 90 degrees upward with the folding line F as the center, the resin multilayer substrate 100 located above is in a compressed state and is The resin layer 2 side that is positioned is in a tensile state.

  In this case, the concentration of bending stress acting on the first conductive pattern 4 and the resin layer 2 is concentrated by the plurality of first dummy vias 6 provided in the first resin layer 2a located on the outer peripheral side as in the second embodiment. Can be relaxed.

  The plurality of first dummy vias 6 are provided so that the intervals gradually increase as the distance from the folding line F in the first direction in which the first dummy pattern 5 extends is increased. Thereby, since the first dummy vias 6 can be prevented from being excessively crowded, the resin multilayer substrate 100C can be bent more gently.

  As a result, also in the present embodiment, it is possible to prevent the first conductive pattern 14 from being broken and the resin layer 2 from being damaged. Even if the relative positional relationship between the first dummy via 6, the first dummy pattern 5, and the other conductors is changed by bending stress when the resin multilayer substrate is bent, the first dummy via 6 and the first dummy pattern 5 are changed. Since both are made of dummy conductors, the influence on the electrical characteristics of the resin multilayer substrate is suppressed.

(Embodiment 5)
FIG. 20 is a plan view showing a third layer from the top, which is a resin layer included in the resin multilayer substrate according to the present embodiment. FIG. 20 is a plan view when viewed from above, and a broken line portion shows a conductive pattern and a dummy pattern provided on the main surface located on the lower side of the resin layer 2. FIG. 21 is a cross-sectional view of the portion where the dummy via is formed in the resin multilayer substrate according to the present embodiment, and is a cross-sectional view taken along line XXI-XXI shown in FIG. With reference to FIG. 20 and FIG. 21, the resin multilayer substrate 100D will be described.

  As shown in FIGS. 20 and 21, the resin multilayer substrate 100D according to the present embodiment is arranged with the first dummy via 6 and the first dummy pattern 5 when compared with the resin multilayer substrate 100C according to the fourth embodiment. However, the other configurations are almost the same. Further, the resin multilayer substrate 100D according to the present embodiment is different in that it is configured to be bent at a plurality of folding lines F1 and F2.

  When viewed in a plan view, regions where the density of the plurality of first dummy vias 6 is high and regions where the density is low are alternately formed. Specifically, the plurality of first dummy vias 6 are respectively formed in two first regions R1, two second regions R2, and one third region R3.

  The first region R1 extends along the folding lines F1 and F2 with a predetermined width W1 in the width direction parallel to the first direction with the folding lines F1 and F2 as the center before the first region R1. The fold line F1 and the fold line F2 are parallel to each other.

  Each of the two second regions R2 is located adjacent to the outside of each first region R1, has a predetermined width W2 in the width direction parallel to the first direction, and extends along the folding lines F1 and F2. Extend. When the resin multilayer substrate 100D is bent, the degree of bending of the second region R2 is smaller than that of the first region R1.

  The third region R3 is located adjacent to the inside of each first region R1 so as to be sandwiched between the first regions R1, and has a predetermined width W3 in the width direction parallel to the first direction, and is a folding line. It extends along F. The number of dummy vias 6b provided in the third region R3 is larger than the number of dummy vias 6b provided in each second region R2, and the width W3 of the third region R3 is larger than the width W2 of each second region R2. Although it is large, it is not limited to this, It can change suitably. For example, the number of dummy vias 6b provided in the third region R3 may be the same as the number of dummy vias 6b provided in each second region R2, and the width W3 of the third region R3 is set to each second region R2. It may be the same as the width W2 of R2.

  In this case, the densities of the first dummy vias 6a provided in the first region R1 are at least the densities of the first dummy vias 6b provided in the second region R2 and the first dummy vias 6d provided in the third region R3. Higher than the density.

  The density of the first dummy vias 6b provided in the second region R2 may be the same as the density of the dummy vias 6b provided in the third region R3, or may be higher or lower. Good.

  FIG. 22 is a diagram showing a state in which the portion shown in FIG. 21 is deformed when the resin multilayer substrate is bent around the folding line. With reference to FIG. 22, a state where the resin multilayer substrate 100D is bent will be described.

  In the present embodiment, the resin multilayer substrate 100D is bent nearly 90 degrees with one end side facing upward. In this case, bending is performed in two stages along the folding lines F1 and F2. The resin layer 2 located on the upper side is in a compressed state, and the resin layer 2 located on the lower side is in a tensile state.

  In this case, when the first dummy vias 6 are alternately arranged with the high density portions and the low density portions and bent in a stepwise manner with the high density portions, compared with the fourth embodiment, Further, the resin multilayer substrate 100D can be bent gently. In the present embodiment, an effect equal to or greater than that of the fourth embodiment is obtained.

  In the present embodiment, the case of bending in two stages has been described as an example. However, the present invention is not limited to this, and a high-density area and a low-density area may be arranged alternately and bend in three or more stages. Good.

(Embodiment 6)
FIG. 23 is a plan view showing the third layer from above, which is a resin layer included in the resin multilayer substrate according to the present embodiment. FIG. 23 is a plan view when viewed from above, and a broken line portion shows a conductive pattern and a dummy pattern provided on the main surface located on the lower side of the resin layer 2. The resin multilayer substrate 100E will be described with reference to FIG.

  As shown in FIG. 23, the resin multilayer substrate 100E is different from the resin multilayer substrate 100D according to the fifth embodiment in that the folding line F intersects the first direction at a predetermined angle. The configuration is almost the same.

  Even in this case, the first region R1, the second region R2, and the third region R3 have predetermined widths W1, W2, and W3 in the width direction parallel to the first direction, and extend along the folding line F. Exists.

  Also in the present embodiment, the resin multilayer substrate 100E is more gently bent by alternately arranging the high density portions and the low density portions of the first dummy vias 6 and stepwise bending the high density portions. Can do. Thereby, substantially the same effect as in the fifth embodiment can be obtained.

(Embodiment 7)
24 and 25 are plan views showing the third and fifth layers from the top, which are resin layers included in the resin multilayer substrate according to the present embodiment. 24 and 25 are plan views when viewed from above, and the broken line portion shows a conductive pattern and a dummy pattern provided on the main surface located on the lower side of the resin layer 2. FIG. 26 is a cross-sectional view of a portion where the dummy via is formed in the resin multilayer substrate according to the present embodiment, and is a cross-sectional view taken along the line XXVI-XXVI shown in FIGS. 24 and 25. A resin multilayer substrate 100F according to the present embodiment will be described with reference to FIGS.

  As shown in FIGS. 24 to 26, the resin multilayer substrate 100F according to the present embodiment is electrically conductive with the resin layer 2c that is inside when bent when compared with the resin multilayer substrate 100A according to the second embodiment. The pattern is not provided, the via diameter of the first dummy via 6 and the via diameter of the second dummy via 16 are different, and the other configurations are substantially the same. The via diameter refers to the diameter of the dummy via on the main surfaces 3b and 13b located on the opposite side of the main surfaces 3a and 13a of the resin layers 2a and 2b on which the dummy patterns 5 and 15 are provided.

  As shown in FIG. 25, in the first resin layer 2a, the via diameter of the first dummy via 6a provided in the first region R1 is larger than the via diameter of the first dummy via 6a provided in the second region R2. A plurality of first dummy vias 6 are provided so as to be larger.

  The plurality of first dummy vias 6 are provided such that the via diameter gradually decreases as the distance from the folding line F in the first direction is increased. As in the second embodiment, the density of the dummy vias 6a provided in the first region R1 is higher than the density of the first dummy vias 6b provided in the second region R2.

  As shown in FIG. 26, in the second resin layer 2b, the plurality of second dummy vias 16 are arranged such that the distance between the centers is constant. The plurality of second dummy vias 16 are arranged symmetrically with respect to the folding line F. Further, the number of second dummy vias 16 is smaller than the number of first dummy vias 6. The via diameter of the second dummy via 16a located on the side closer to the fold line F is larger than the via diameter of the second dummy via 16b located on the side far from the fold line F.

  FIG. 27 is a diagram showing a state where the portion shown in FIG. 26 is deformed when the resin multilayer substrate is bent around the folding line. With reference to FIG. 27, a state where the resin multilayer substrate 100F is bent will be described.

  Also in the present embodiment, when one end side of the resin multilayer substrate 100F is bent nearly 90 degrees upward with the fold line F as the center, the resin multilayer substrate 100F is in a compressed state on the upper side and the downward direction The resin layer 2 side that is positioned is in a tensile state.

  In this case, the bending stress tends to concentrate in the first region R1 where the degree of bending becomes large. By making the via diameter of the first dummy via 6 provided in the first region R1 larger than the via diameter of the first dummy via 6 provided in the second region R2, it acts on the first conductive pattern 4 and the resin layer 2. It is possible to effectively relieve bending stress.

  Further, by changing the via diameter of the first dummy via 6 in accordance with the bending condition in this way, it is possible to suppress the first dummy vias 6 having large via diameters from contacting each other, and the resin multilayer substrate 100F has sufficient flexibility. Can be secured.

  By providing a plurality of second dummy vias 16 at the bent portion of the second resin layer 2b located on the inner peripheral side of the first resin layer 2a, the first conductive pattern 4, the second conductive pattern 14, and the resin layer 2 are provided. It is possible to alleviate the concentration of bending stress acting on the.

  Furthermore, by reducing the number of the plurality of second dummy vias 16 than the number of the plurality of first dummy vias, it is possible to prevent the second dummy vias 16 from coming into contact with each other while alleviating the stress concentrated on the bent portion. it can. Thereby, the softness | flexibility of the resin multilayer substrate 100F can fully be ensured.

  As a result, in addition to the disconnection of the first conductive pattern 4 and the second conductive pattern 14, the first conductive pattern 4 and the second conductive pattern 14 can be further miniaturized, and the resin layer 2 itself It can be prevented from being damaged.

  Moreover, the fluctuation | variation of the thickness of the resin layer 2 can also be suppressed by relieving the bending stress which acts on the 1 conductive pattern 4, the 2nd conductive pattern 14, and the resin layer 2. FIG. Thereby, it can prevent that the 1st conductive pattern 4 approaches the 2nd conductive pattern 14 in a bending part. As a result, it is possible to suppress a change in capacitance between the first conductive pattern 4 and the second conductive pattern 14, and it is possible to suppress a change in electrical characteristics.

  The first dummy via 6, the first dummy pattern 5, the second dummy via 16, and the second dummy pattern 15 are all made of dummy conductors. For this reason, even if the relative positional relationship among the first dummy via 6, the first dummy pattern 5, and other conductors changes due to bending stress when the resin multilayer substrate is bent, the electrical characteristics of the resin multilayer substrate are affected. Is suppressed. Similarly, even if the relative positional relationship among the second dummy via 16, the second dummy pattern 15, and the other conductors is changed, the influence on the electrical characteristics of the resin multilayer substrate is suppressed.

(Embodiment 8)
28 and 29 are plan views showing the third and fifth layers from the top, which are resin layers included in the resin multilayer substrate according to the present embodiment. FIG. 28 and FIG. 29 are plan views when viewed from above, and the broken line portion shows a conductive pattern and a dummy pattern provided on the main surface located on the lower side of the resin layer 2. FIG. 30 is a cross-sectional view of the portion where the dummy via is formed in the resin multilayer substrate according to the present embodiment, and is a cross-sectional view taken along the line XXX-XXX shown in FIGS. 28 and 29. The resin multilayer substrate 100G according to the present embodiment will be described with reference to FIGS.

  As shown in FIGS. 28 to 30, the resin multilayer substrate 100G according to the present embodiment is different from the resin multilayer substrate 100F according to the seventh embodiment in that the first dummy via 6 and the first dummy pattern 5 are different. However, other configurations are almost the same.

  In the first resin layer 2a, the plurality of first dummy vias 6 are arranged so that the distance between the centers is constant. Correspondingly, the plurality of partial patterns 5a are also arranged so that the distance between the centers is constant.

  FIG. 31 is a diagram showing a state in which the portion shown in FIG. 30 is deformed when the resin multilayer substrate is bent around the folding line. With reference to FIG. 31, the state where the resin multilayer substrate 100G is bent will be described.

  Also in the present embodiment, when one end side of the resin multilayer substrate 100G is bent nearly 90 degrees upward with the fold line F as the center, the resin multilayer substrate 100G is in a compressed state on the upper side, and downward The resin layer 2 side that is positioned is in a tensile state.

  In this case, as in the seventh embodiment, a plurality of first dummy vias 6 provided on the first resin layer 2a located on the outer peripheral side and a plurality provided on the second resin layer 2b located on the inner peripheral side. This second dummy via 16 can alleviate the concentration of bending stress acting on the first conductive pattern 4, the second conductive pattern 14, and the resin layer 2 while sufficiently ensuring the flexibility of the resin multilayer substrate 100G. As a result, the present embodiment can provide substantially the same effect as that of the seventh embodiment.

(Embodiment 9)
FIG. 32 is a cross-sectional view of a portion where a dummy via is formed in the resin multilayer substrate according to the present embodiment. With reference to FIG. 32, resin multilayer substrate 100H according to the present embodiment will be described.

  As shown in FIG. 32, the resin multilayer substrate 100H according to the present embodiment is different from the resin multilayer substrate 100F according to the seventh embodiment in that only one layer is provided with a dummy via. The other configurations are almost the same.

In the resin multilayer substrate 100H, the first resin layer 2a is located in the third layer from above.
FIG. 33 is a diagram showing a state in which the portion shown in FIG. 32 is deformed when the resin multilayer substrate is bent around the folding line. With reference to FIG. 33, the state where the resin multilayer substrate 100H is bent will be described.

  Also in the present embodiment, when one end side of the resin multilayer substrate 100G is bent nearly 90 degrees upward with the fold line F as the center, the resin multilayer substrate 100G is in a compressed state on the upper side, and downward The resin layer 2 side that is positioned is in a tensile state.

  In this case, the bending stress acting on the first conductive pattern 4 and the resin layer 2 by the plurality of first dummy vias 6 provided in the first resin layer 2a located on the outer peripheral side as in the seventh embodiment. Can be relaxed.

  Further, by changing the via diameter of the first dummy via 6 according to the bending condition, it is possible to prevent the first dummy via 6 having an excessively large via diameter from being arranged, and sufficiently ensure the flexibility of the resin multilayer substrate 100H. can do.

  As a result, also in the present embodiment, breakage of the first conductive pattern 14 and breakage of the resin layer 2 can be prevented, and fluctuations in electrical characteristics can be suppressed.

(Modification 1)
34A and 34B are plan views showing the third and fifth layers from the top, which are resin layers included in the resin multilayer substrate in Modification 1. FIG. With reference to FIG. 34A and FIG. 34B, the resin multilayer substrate 100I in the present modification will be described.

  In this modified example, the conductive pattern is configured to include not only the linear conductive pattern but also the first capacitive electrode 41 or the second capacitive electrode 42 as compared with the above-described embodiment. The point is different. The first dummy via 6 is provided along the first direction (the direction of arrow A in FIG. 34) in which at least a part of the first conductive pattern extends.

  Even in such a case, by providing the first dummy via 6 and the second dummy via 16 according to the above-described embodiment, it acts on the first capacitor electrode 41, the second capacitor electrode 42, and the resin layer 2. The concentration of bending stress can be reduced. Thereby, the breakage of the first capacitor electrode 41 and the second capacitor electrode 42 and the breakage of the resin layer 2 can be prevented, and fluctuations in electrical characteristics can be suppressed.

(Modification 2)
FIG. 35A and FIG. 35B are plan views showing the third and fifth layers from the top, which are resin layers included in the resin multilayer substrate in Modification 2. With reference to FIG. 35A and FIG. 35B, the resin multilayer substrate 100J in the present modification will be described.

  In this modification, when compared with the above-described embodiment, the conductive pattern is not only a linear conductive pattern, but also a spiral first inductor pattern 43 and a second inductor pattern for forming a coil. 44 in that it is configured to include 44. The first dummy via 6 is provided along the first direction (the direction of arrow A in FIG. 35) in which at least a part of the first conductive pattern extends.

  Even in such a case, by providing the first dummy via 6 and the second dummy via 16 in accordance with the above-described embodiment, the first inductor pattern 43, the second inductor pattern 44, and the resin layer 2 are acted on. The concentration of bending stress can be reduced. Thereby, the breakage of the first inductor pattern 43 and the second inductor pattern 44 and the breakage of the resin layer 2 can be prevented, and fluctuations in electrical characteristics can be suppressed.

(Embodiment 10)
With reference to FIGS. 36 to 41, a method for manufacturing a resin multilayer substrate according to the tenth embodiment will be described.

  First, a resin sheet 30 with conductor foil as shown in FIG. 36 is prepared. The resin sheet with conductor foil 30 is a sheet having a structure in which the conductor foil 31 is attached to one surface of the resin layer 2. The resin layer 2 is made of, for example, LCP (liquid crystal polymer) that is a thermoplastic resin. The material of the resin layer 2 may be PEEK (polyetheretherketone), PEI (polyetherimide), PPS (poniphenylene sulfide), PI (polyimide), etc. in addition to LCP.

  The conductor foil 31 is a foil having a thickness of 18 μm made of Cu, for example. The material of the conductor foil 31 may be Ag, Al, SUS, Ni, Au other than Cu, or an alloy of two or more different metals selected from these metals. In the present embodiment, the conductor foil 31 has a thickness of 18 μm, but the conductor foil 31 may have a thickness of about 3 to 40 μm. The conductor foil 31 may be any thickness that allows circuit formation.

  Next, as shown in FIG. 37, via holes 32 are formed so as to penetrate the resin layer 2 by irradiating the surface on the resin layer 2 side of the resin sheet 30 with conductor foil with a carbon dioxide laser beam. The via hole 32 penetrates the resin layer 2 but does not penetrate the conductor foil 31. Thereafter, the smear (not shown) of the via hole 32 is removed. Although carbon dioxide laser light is used here to form the via hole 32, other types of laser light may be used. Further, in order to form the via hole 32, a method other than laser beam irradiation may be employed.

  Next, as shown in FIG. 38, a resist pattern 33 corresponding to a desired circuit pattern is printed on the surface of the conductor foil 31 of the resin sheet with conductor foil 30 by a method such as screen printing.

  Next, etching is performed using the resist pattern 33 as a mask, and as shown in FIG. 39, the portion of the conductor foil 31 that is not covered with the resist pattern 33 is removed. Thereafter, as shown in FIG. 40, the resist pattern 33 is removed. In this way, a desired conductive pattern and dummy pattern are obtained on one surface of the resin layer 2.

  Next, as shown in FIG. 41, the via holes 32 are filled with a conductive paste by screen printing or the like. Screen printing is performed from the lower surface in FIGS. In FIG. 40, for convenience of explanation, the via hole 32 is displayed in a posture facing downward, but in practice, screen printing may be performed by changing the posture as appropriate. Further, the filling of the conductive paste may be performed by vacuum printing. Alternatively, the filling of the conductive paste may be hole filling by a paste filling machine. The conductive paste to be filled may be mainly composed of silver as described above, but may instead be composed mainly of copper, for example.

  This conductive paste forms an alloy layer between the conductive pattern and the metal that is the material of the dummy pattern at the temperature (hereinafter referred to as “thermocompression temperature”) when the laminated resin layer is thermocompression bonded later. It is preferable that the metal powder contains an appropriate amount. Since this conductive paste contains copper, that is, Cu as a main component for exerting conductivity, this conductive paste includes at least one of Ag, Cu, and Ni in addition to the main component, and Sn, Bi, Zn. It is preferable that at least one of them is included. In FIG. 41, via conductors such as dummy vias are formed by filling with conductive paste. Since the resin layer 2 is to be stacked and assembled later, via conductors are arranged in the plurality of resin layers 2 according to the design.

  A plurality of resin layers 2 processed as described above are laminated to form a laminate. When laminating, the distance between the conductive patterns is set according to the design. Alternatively, the distance between via conductors is set.

  At the time when the plurality of resin layers 2 are laminated halfway, temporary compression bonding may be performed at a temperature lower than the thermocompression bonding temperature. The temperature of the temporary pressure bonding is, for example, 150 ° C. or higher and 200 ° C. or lower. By temporarily press-bonding, the resin layers 2 laminated up to this point are joined. When the temporary pressure bonding is performed, the remaining resin layer 2 is further stacked.

  Next, this laminate is subjected to main pressure bonding. In the final press-bonding process, the laminated body that has already been temporarily press-bonded and the entire resin layer 2 that has been stacked after the temporary press-bonding are collectively thermocompression bonded. The temperature of the main press bonding is, for example, 250 ° C. or more and 300 ° C. or less. The above-mentioned “thermocompression bonding temperature” means the temperature of the main compression bonding. By performing this pressure bonding, the resin layers 2 adjacent in the thickness direction are bonded to each other to form an integral resin multilayer substrate. When there are conductive patterns arranged so as to be exposed on the upper surface or the lower surface of the resin multilayer substrate, these become external electrodes. After the main pressure bonding, the surface of the external electrode is preferably plated with Ni, Au or the like.

  When external electrodes using conductive patterns are to be formed on both the top and bottom surfaces of a resin multilayer board, the front and back are reversed in any layer in the middle of the stack, and the same orientation as the front and back of the layer immediately below except for the reversed portion It is preferable to stack with.

  Instead of pre-bonding, all the resin layers 2 may be stacked and then collectively bonded.

  In any case, when the main pressure bonding is finished, the resin multilayer substrate as shown in each of the above embodiments is obtained.

  According to the method for producing a resin multilayer substrate in the present embodiment, the resin multilayer substrate as described in each of the above embodiments can be obtained.

  In Embodiments 1 to 9 and Modifications 1 and 2 described above, the case where the bending angle is approximately 90 degrees has been described as an example. However, the present invention is not limited to this, and the bending angle is 90 degrees. You may bend so that it may become below, and you may bend so that it may become 90 degree | times or more. In particular, when the bending angle is increased, the effect of the present invention is more remarkably exhibited.

  In Embodiments 1 to 9 and Modifications 1 and 2 described above, the case where the laminate 1 is configured by laminating six or four resin layers 2 is illustrated, but the present invention is not limited thereto. The number of the resin layers 2 can be changed as appropriate without departing from the spirit of the present invention.

  In Embodiments 1 to 9 and Modifications 1 and 2 described above, the case where the main surface of the resin layer 2 provided with the conductive pattern is on the outer surface 1b side is described as an example. It is not limited, The inner surface 1a side may be sufficient and can be changed suitably.

  Although the embodiments of the present invention have been described above, the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, and includes meanings equivalent to the terms of the claims and all modifications within the scope.

  DESCRIPTION OF SYMBOLS 1 Laminated body, 1a Inner surface, 1b Outer surface, 2 Resin layer, 2a 1st resin layer, 2b 2nd resin layer, 4 1st conductive pattern, 5 1st dummy pattern, 5a Partial pattern, 6 1st dummy via, 7 , 8 Ground electrode, 14 Second conductive pattern, 15 Second dummy pattern, 15a Partial pattern, 16 Second dummy via, 24 Conductive pattern, 30 Resin sheet, 31 Conductive foil, 32 Via hole, 33 Resist pattern, 41 First Capacitance electrode, 42 2nd capacitance electrode, 43 1st inductor pattern, 44 2nd inductor pattern, 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H, 100I, 100J, 200 Resin multilayer substrate .

Claims (9)

A foldable resin multilayer substrate having a plurality of resin layers,
A first resin layer included in the plurality of resin layers and including a first main surface;
A first conductive pattern formed on the first main surface of the first resin layer,
A plurality of first dummy vias provided along a first direction in which at least a part of the first conductive pattern extends, and provided so as to penetrate in a thickness direction of the first resin layer;
In the first resin layer, when folded around a fold line that intersects the first direction, the first region where the degree of bending increases, and is positioned adjacent to both sides of the first region,
A second region that is less bent than the first region is formed;
In a state before bending, the first region has a predetermined width in a width direction parallel to the first direction around the bending line, and extends along the bending line.
In a state before folding, the second region extends along the folding line with a predetermined width in a width direction parallel to the first direction,
The resin multilayer substrate, wherein a density of the first dummy via provided in the first region is higher than a density of the first dummy via provided in the second region.   2. The resin multilayer substrate according to claim 1, wherein the plurality of first dummy vias are provided such that a distance between centers of the adjacent first dummy vias gradually increases as the distance from the bending line increases. A foldable resin multilayer substrate having a plurality of resin layers,
A first resin layer included in the plurality of resin layers and including a first main surface;
A first conductive pattern formed on the first main surface of the first resin layer;
A plurality of first dummy vias provided along a first direction in which at least a part of the first conductive pattern extends, and provided so as to penetrate in a thickness direction of the first resin layer;
The first resin layer is located adjacent to both sides of the first region and the first region where the degree of bending increases when folded around a fold line intersecting the first direction. A second region that is less bent than one region is formed,
In a state before bending, the first region has a predetermined width in a width direction parallel to the first direction around the bending line, and extends along the bending line.
In a state before folding, the second region extends along the folding line with a predetermined width in a width direction parallel to the first direction,
On the main surface of the first resin layer located on the side opposite to the first main surface, the via diameter of the first dummy via provided in the first region is the first diameter provided in the second region. A resin multilayer substrate that is larger than the via diameter of one dummy via. A plurality of the first dummy via, said via diameter As the distance from the fold lines are provided so as to gradually become smaller, the resin multilayer substrate according to claim 3. A pair of first dummy patterns provided on the first main surface so as to sandwich the first conductive pattern and to be parallel to each other when viewed in a plan view, and extend along the first direction Further comprising
The resin multilayer substrate according to claim 1, wherein the plurality of first dummy vias are connected to the pair of first dummy patterns. A second resin layer that is included in the plurality of resin layers and includes a second main surface that is located on the inner side of the first resin layer when bent and is not in contact with the first main surface;
A second conductive pattern formed on the second main surface of the second resin layer so as to correspond to the first conductive pattern;
A plurality of second dummy vias provided along the first direction and provided so as to penetrate in the thickness direction of the second resin layer;
6. The number of the second dummy vias provided in the second resin layer is smaller than the number of the first dummy vias provided in the first resin layer. 6. Resin multilayer board. A pair of second dummy patterns provided on the second main surface so as to be sandwiched between the second conductive patterns and parallel to each other when viewed in a plan view, and extend along the first direction. Further comprising
The resin multilayer substrate according to claim 6, wherein the plurality of second dummy vias are connected to the pair of second dummy patterns. Each of the pair of first dummy patterns extends continuously without being divided along the first direction in a state independent from each other,
When viewed in a plan view, a plurality of the first dummy vias are connected to the first dummy pattern provided continuously on each side of the first conductive pattern in a direction intersecting the first direction. The resin multilayer substrate according to claim 5 . Each of the pair of second dummy patterns extends continuously without being divided along the first direction in an independent state from each other,
When viewed in a plan view, a plurality of the second dummy vias are connected to the second dummy patterns provided continuously on both sides of the second conductive pattern in a direction intersecting the first direction. The resin multilayer substrate according to claim 7.

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