Resin multilayer board and circuit module

Abstract

A resin multilayer substrate 1 comprises: at least one resin insulation layer 10; a first conductor layer 20 that is layered on the resin insulation layer 10; a second conductor layer 30 that is layered on the resin insulation layer 10 on a side opposite the first conductor layer 20; and an interlayer connection conductor 40 that is provided so as to penetrate the resin insulation layer 10 in a layering direction of the first conductor layer 20 and the second conductor layer 30, and that connects the first conductor layer 20 and the second conductor layer 30. The interlayer connection conductor 40 includes a first portion 41 and a second portion 42 that is located closer to the second conductor layer 30 side than the first portion 41. The first portion 41 has a conductivity lower than that of the second portion 42. The first conductor layer 20 is not in contact with the second portion 42. The second conductor layer 30 is in contact with the second portion 42. When viewing a cross-section in a direction perpendicular to the layering direction, the distance D21 between two corners P21 where a distal end of the second portion 42 is farthest away in the direction perpendicular to the layering direction is longer than the distance D22 between two corners P22 where a base end of the second portion 42 contacts the second conductor layer 30, and a section of the first portion 41 is present more to the second conductor layer 30 side than a straight line connecting the corners P21 of the distal end part of the second portion 42.

Description

[Technical Field]

[0001] The present invention relates to a resin multilayer substrate and a circuit module. [Background technology]

[0002] Patent Document 1 discloses a printed circuit board including a first insulating layer, a plated via formed through the first insulating layer, a second insulating layer stacked on the first insulating layer, and a paste via formed through the second insulating layer so as to contact the plated via, wherein the contact interface between the plated via and the paste via is located within the first insulating layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-80034 Summary of the Invention [Problem to be solved by the invention]

[0004] In the printed circuit board described in Patent Document 1, the contact interface between the plated via and the paste via is provided within the first insulating layer, thereby improving the connectivity between the plated via and the paste via. Here, the plated via refers to a film grown by, for example, a liquid phase method or a vapor phase method, and the paste via refers to a film formed by solidifying a paste, for example.

[0005] However, in a configuration in which parts with different conductivities, such as paste vias and plated vias, are mixed within an insulating layer as interlayer connection conductors, there is a problem in that the connectivity at the interface between the two is weak and the strength of the interlayer connection conductor is insufficient.

[0006] The present invention has been made to solve the above problems, and aims to provide a resin multilayer substrate having interlayer connection conductors with high strength, and a circuit module including the resin multilayer substrate. [Means for solving the problem]

[0007] The resin multilayer substrate of the present invention comprises at least one resin insulating layer, a first conductor layer laminated on the resin insulating layer, a second conductor layer laminated on the resin insulating layer on the side opposite to the first conductor layer, and an interlayer connection conductor provided to penetrate the resin insulating layer in the lamination direction of the first conductor layer and the second conductor layer and connecting the first conductor layer and the second conductor layer. The interlayer connection conductor includes a first portion and a second portion located closer to the second conductor layer than the first portion. The first portion has a lower conductivity than the second portion. The first conductor layer is not in contact with the second portion. The second conductor layer is in contact with the second portion. When viewed in cross section in a direction perpendicular to the stacking direction, the distance between the two corners of the tip of the second part that are furthest apart in a direction perpendicular to the stacking direction is longer than the distance between the two corners where the base end of the second part is in contact with the second conductor layer, and a part of the first part is located on the second conductor layer side of the straight line connecting the corners of the tip of the second part.

[0008] A circuit module of the present invention includes the resin multilayer substrate of the present invention and an electronic component disposed on the resin multilayer substrate. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a resin multilayer substrate having interlayer connection conductors with high strength, and further, it is possible to provide a circuit module including the resin multilayer substrate. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a first embodiment of the present invention. [Figure 2] 2A to 2F are cross-sectional views that schematically show an example of a method for manufacturing the resin multilayer substrate 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a third embodiment of the present invention. [Figure 5] FIG. 5 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a fourth embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a fifth embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a sixth embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view that schematically shows an example of a circuit module that includes a resin multilayer substrate of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The resin multilayer substrate and circuit module of the present invention will be described below. However, the present invention is not limited to the following configurations, and can be appropriately modified and applied within the scope of the present invention. The present invention also includes a combination of two or more of the individual preferred configurations of the present invention described below.

[0012] The following embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. From the second embodiment onwards, descriptions of matters common to the first embodiment will be omitted, and only differences will be described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment.

[0013] In this specification, terms indicating the relationship between elements (e.g., "perpendicular," "parallel," "orthogonal," etc.) and terms indicating the shape of elements are not expressions that only express a strict meaning, but are expressions that also include a range of substantial equivalence, for example, a difference of a few percent.

[0014] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and other scales may differ from those of the actual product. In the drawings, the same or equivalent parts will be designated by the same reference numerals. In addition, the same elements will be designated by the same reference numerals in each drawing, and duplicate explanations will be omitted.

[0015] [First embodiment] In the resin multilayer board according to the first embodiment of the present invention, the interlayer connection conductor includes a first portion and a second portion, and the first conductor layer is in contact with the first portion.

[0016] FIG. 1 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a first embodiment of the present invention.

[0017] Although the overall configuration is not shown in Figure 1, the resin multilayer substrate 1 comprises at least one resin insulating layer 10, a first conductor layer 20 laminated on the resin insulating layer 10, a second conductor layer 30 laminated on the resin insulating layer 10 on the opposite side to the first conductor layer 20 (the lower side in Figure 1), and an interlayer connecting conductor 40 that penetrates the resin insulating layer 10 in the stacking direction of the first conductor layer 20 and the second conductor layer 30 (the up-down direction in Figure 1) and connects the first conductor layer 20 and the second conductor layer 30.

[0018] The resin constituting the resin insulation layer 10 may be a thermosetting resin or a thermoplastic resin, but is preferably a thermoplastic resin. When the resin insulation layer 10 is made of a thermoplastic resin, a plurality of resin sheets on which conductor layers are formed can be stacked and pressure-bonded together by heat treatment.

[0019] Examples of the thermosetting resin include epoxy resin, phenol resin, polyimide resin or modified resin thereof, and acrylic resin.

[0020] Examples of thermoplastic resins include liquid crystal polymers (LCP), fluororesins, thermoplastic polyimide resins, polyether ether ketone resins (PEEK), and polyphenylene sulfide resins (PPS).

[0021] The resin insulation layer 10 is preferably made of a liquid crystal polymer (LCP). Liquid crystal polymers have a lower water absorption rate than other thermoplastic resins. Therefore, when the resin insulation layer 10 is made of a liquid crystal polymer, the amount of moisture remaining in the resin insulation layer 10 can be reduced.

[0022] The resin insulating layer 10 may contain an inorganic material such as a ceramic filler.

[0023] Examples of ceramic fillers include boron nitride, talc, and fused silica.

[0024] The thickness of one resin insulating layer 10 (length in the lamination direction) is preferably 10 μm or more and 100 μm or less.

[0025] The first conductor layer 20 and the second conductor layer 30 may each have a patterned shape such as a wiring, or may have a planar shape that spreads over a surface. The shapes of the first conductor layer 20 and the second conductor layer 30 may be the same as or different from each other.

[0026] The first conductor layer 20 and the second conductor layer 30 are each a metal layer made of, for example, copper, silver, aluminum, stainless steel, nickel, gold, or an alloy containing at least one of these metals. The materials of the first conductor layer 20 and the second conductor layer 30 may be the same or different. The first conductor layer 20 and the second conductor layer 30 are each preferably made of a metal foil, more preferably made of copper (Cu) foil.

[0027] The first conductor layer 20 and the second conductor layer 30 may each have a matte surface on one main surface and a shiny surface on the other main surface.

[0028] The thickness (length in the stacking direction) of each of the first conductor layer 20 and the second conductor layer 30 is preferably 1 μm or more and 35 μm or less, and more preferably 6 μm or more and 18 μm or less. The thicknesses of the first conductor layer 20 and the second conductor layer 30 may be the same as or different from each other.

[0029] The first conductor layer 20 and the second conductor layer 30 may or may not be parallel to each other.

[0030] One resin insulating layer 10 may be provided between the first conductor layer 20 and the second conductor layer 30, or two or more resin insulating layers 10 may be provided. When two or more resin insulating layers 10 are provided between the first conductor layer 20 and the second conductor layer 30, the configurations of the resin insulating layers 10 may be the same as or different from each other. Furthermore, when two or more resin insulating layers 10 are provided between the first conductor layer 20 and the second conductor layer 30, the thicknesses of the resin insulating layers 10 may be the same as or different from each other.

[0031] The interlayer connection conductor 40 is provided so as to penetrate the resin insulating layer 10 in the stacking direction but not through the first conductor layer 20 and the second conductor layer 30, thereby connecting the first conductor layer 20 and the second conductor layer 30. Therefore, the interlayer connection conductor 40 penetrates the resin insulating layer 10 in the stacking direction by the number of layers provided between the first conductor layer 20 and the second conductor layer 30.

[0032] In a cross section perpendicular to the lamination direction, the shape of the interlayer connection conductor 40 is preferably circular. In this case, not only a perfect circle but also an ellipse, an oval, etc. are included in the circle.

[0033] The interlayer connection conductor 40 includes a first portion 41 and a second portion 42 located closer to the second conductor layer 30 than the first portion 41.

[0034] The first portion 41 has a lower conductivity than the second portion 42 .

[0035] The first portion 41 may be a paste via or a plated via. As described above, a paste via refers to a solidified paste, and a plated via refers to a film grown by a liquid phase method or a vapor phase method.

[0036] When the first portion 41 is a plated via, it is preferable that the first portion 41 does not include a resin member. For example, when the first portion 41 is a plated via, it is preferable that the content of the conductive member in the first portion 41 is 90.0% by volume or more and 100% by volume or less.

[0037] The second portion 42 may be a paste via or a plated via, but is preferably a plated via.

[0038] When the second portion 42 is a plated via, it is preferable that the second portion 42 does not include a resin member. For example, when the second portion 42 is a plated via, it is preferable that the content of the conductive member in the second portion 42 is 90.0% by volume or more and 100% by volume or less.

[0039] In this specification, "not containing a resin member" means that the content of the resin member is 0.1% by volume or less.

[0040] When the second portion 42 is a plated via, the conductive member that constitutes the second portion 42 is preferably the same as the metal that constitutes the second conductor layer 30, for example, Cu.

[0041] For example, it is preferable that the first portion 41 is a paste via and the second portion 42 is a plated via. In this case, the content of the resin material in the first portion 41 is greater than the content of the resin material in the second portion 42. When the resin multilayer substrate 1 is produced by batch pressing, which will be described later, the first portion 41 functions as a bonding material, thereby enabling the second portion 42 and the first conductor layer 20 to be electrically connected.

[0042] The type and content of the resin material contained in the first portion 41 or the second portion 42 can be measured by methods such as Fourier transform infrared spectroscopy (FT-IR), gas chromatography mass spectrometry (GC-MS), etc. The same applies to the third portion 43 described later.

[0043] When the first portion 41 is a paste via, examples of the conductive material constituting the first portion 41 include Cu, Sn, Ag, Ni, Cr, Pt, Mo, Ga, Ge, Sb, In, Pb, and alloys containing at least one of these metals. The conductive material constituting the first portion 41 may be the same as or different from the conductive material constituting the second portion 42. The conductive material constituting the first portion 41 is, for example, an alloy containing Cu and Sn.

[0044] When the first portion 41 is a paste via, examples of the resin material constituting the first portion 41 include at least one thermosetting resin selected from the group consisting of epoxy resin, phenolic resin, polyimide resin or modified resin thereof, and acrylic resin, or at least one thermoplastic resin selected from the group consisting of polyamide resin, polystyrene resin, polymethacrylic resin, polycarbonate resin, and cellulose-based resin.

[0045] When the first portion 41 is a paste via, the content of the conductive material in the first portion 41 is preferably less than the content of the conductive material in the second portion 42. In addition, the content of the conductive material in the first portion 41 is preferably greater than the content of the resin material in the first portion 41.

[0046] There are no particular limitations on the combination of materials for the first portion 41 and the second portion 42. It is preferable that an alloy or resin-containing metal be used for the first portion 41 for bonding purposes, while it is preferable that a pure metal, resin, or a material with little alloy or no resin be used for the second portion 42 to increase conductivity.

[0047] When the first portion 41 is a plated via, for example, Sn can be used as the conductive material that forms the first portion 41. By using Sn, which has a low melting point, the first portion 41 can easily function as a bonding material.

[0048] In this way, when the first portion 41 and the second portion 42 are plated vias, the combination may be plated vias made of different metals, for example, the conductive material constituting the first portion 41 being Sn and the conductive material constituting the second portion 42 being Cu.

[0049] The first conductor layer 20 is not in contact with the second portion 42. In the example shown in FIG.

[0050] The second conductor layer 30 is in contact with the second portion 42. The second conductor layer 30 and the second portion 42 are preferably made of the same material and are joined together without a dissimilar material therebetween.

[0051] In the resin multilayer substrate 1 shown in FIG. 1, among the ends of the second portion 42 in the stacking direction (the up-down direction in FIG. 1), the end on the first conductor layer 20 side is defined as the tip end, and the end on the second conductor layer 30 side is defined as the base end. Meanwhile, among the ends of the first portion 41 in the stacking direction, the end on the second conductor layer 30 side is defined as the tip end, and the end on the first conductor layer 20 side is defined as the base end. In FIG. 1, the point of the tip end of the second portion 42 that is furthest apart in the direction perpendicular to the stacking direction (the left-right direction in FIG. 1) is shown as a corner P21. Furthermore, in FIG. 1, the point of the base end of the second portion 42 that is in contact with the second conductor layer 30 is shown as a corner P22. Furthermore, in FIG. 1, the point of the base end of the first portion 41 that is in contact with the first conductor layer 20 is shown as a corner P12.

[0052] As shown in Figure 1, when viewed in cross section in a direction perpendicular to the stacking direction, the distance between the two corners P21 at the tip of the second portion 42 that are furthest apart in a direction perpendicular to the stacking direction (the length indicated by the double arrow D21 in Figure 1) is longer than the distance between the two corners P22 at which the base end of the second portion 42 is in contact with the second conductor layer 30 (the length indicated by the double arrow D22 in Figure 1), and part of the first portion 41 is located on the second conductor layer 30 side of the straight line connecting the corners P21 at the tip of the second portion 42.

[0053] In the resin multilayer substrate 1 shown in Figure 1, the second portion 42 has a concave shape and is connected to the first portion 41 so as to enclose the first portion 41, thereby increasing the strength of the portion where the reaction product for joining the first portion 41 and the second portion 42 is formed, and therefore increasing the strength of the interlayer connecting conductor 40.

[0054] The first portion 41 that exists on the second conductor layer 30 side of the line connecting the corners P21 at the tips of the second portions 42 may be one location as shown in FIG. 1, or may be two or more locations.

[0055] When viewed in cross section in a direction perpendicular to the stacking direction, the distance D21 between the corners P21 at the tip ends of the second portions 42 is, for example, not less than 60 μm and not more than 80 μm.

[0056] When viewed in cross section in a direction perpendicular to the stacking direction, the distance D22 between the corners P22 at the base ends of the second portions 42 is, for example, not less than 40 μm and not more than 60 μm.

[0057] The ratio of D22 / D21 is, for example, not less than 0.67 and not more than 0.75.

[0058] When viewed in cross section in a direction perpendicular to the stacking direction, if the maximum thickness in the stacking direction between the straight line connecting the corners P21 at the tip ends of the second portion 42 and the first conductor layer 20 is T11, the maximum thickness T11 is, for example, 5 μm or more and 15 μm or less.

[0059] When viewed in cross section perpendicular to the stacking direction, the maximum thickness in the stacking direction between the second conductor layer 30 and a line connecting the corners P21 at the tips of the second portion 42 is T21, and the maximum thickness T21 is, for example, 20 μm or more and 30 μm or less. The maximum thickness T21 is preferably greater than the maximum thickness T11.

[0060] When viewed in cross section in a direction perpendicular to the stacking direction, the maximum thickness in the stacking direction between a line connecting the corners P21 at the tips of the second portion 42 and the end of the first portion 41 located on the second conductor layer 30 side is defined as T12, and the maximum thickness T12 is, for example, 1 μm or more and 10 μm or less. The maximum thickness T12 may be the same as the maximum thickness T11, or may be smaller than the maximum thickness T11, or may be larger than the maximum thickness T11.

[0061] The ratio of T12 / (T11+T21) is, for example, 0.03 or more and 0.29 or less. The ratio of T12 / (T11+T12) is, for example, 0.17 or more and 0.40 or less. The ratio of T12 / T11 is, for example, 0.2 or more and 0.6 or less. The ratio of T12 / T21 is, for example, 0.03 or more and 0.50 or less.

[0062] 1 , when a cross section of the interlayer connection conductor 40 passing through a straight line connecting the corners P21 of the tip ends of the second portions 42 is viewed from the stacking direction, the area of ​​the first portions 41 located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip ends of the second portions 42 is preferably 10% or more, more preferably 20% or more, and even more preferably 50% or more of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the straight line connecting the corners P21 of the tip ends of the second portions 42. The area of ​​the first portions 41 located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip ends of the second portions 42 may be 100%, 90% or less, or 80% or less of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the straight line connecting the corners P21 of the tip ends of the second portions 42.

[0063] When viewed in cross section in a direction perpendicular to the stacking direction, the shape of the corner P21 at the tip of the second portion 42 is not particularly limited, and may be, for example, flat as shown in Fig. 1 or pointed as shown in Fig. 3 described below. When the corner P21 at the tip of the second portion 42 is flat, the corner P21 at the tip of the second portion 42 may or may not be parallel to the first conductor layer 20 or the second conductor layer 30.

[0064] When viewed in a cross section perpendicular to the stacking direction, the second portion 42 may not be present on the first conductor layer 20 side of the line connecting the corners P21 at the tips of the second portion 42.

[0065] When viewed in cross section in a direction perpendicular to the stacking direction, a straight line connecting the corners P21 at the tips of the second portions 42 may be parallel to the second conductor layer 30.

[0066] When viewed in cross section in a direction perpendicular to the stacking direction, the outer angle (the angle indicated by θ2 in Figure 1) formed between the interlayer connection conductor 40 and the second conductor layer 30 at the corner P22 at the base end of the second portion 42 may be an acute angle.

[0067] In the example shown in Figure 1, when viewed in cross section in a direction perpendicular to the stacking direction, the distance between the corners P21 at the tip end of the second portion 42 (the length indicated by the double arrow D21 in Figure 1) is shorter than the distance between the corners P12 at the base end of the first portion 41 (the length indicated by the double arrow D12 in Figure 1), but may be the same as the distance D12 between the corners P12 at the base end of the first portion 41.

[0068] When viewed in cross section in a direction perpendicular to the stacking direction, the distance D12 between the corners P12 at the base ends of the first portions 41 is, for example, not less than 80 μm and not more than 100 μm.

[0069] The ratio of D12 / D21 is, for example, 1.25 or more and 1.33 or less, and the ratio of D12 / D22 is, for example, 1.67 or more and 2 or less.

[0070] When viewed in cross section in a direction perpendicular to the stacking direction, the straight line connecting the corners P21 at the tip ends of the second portions 42 may be parallel to the first conductor layer 20.

[0071] When viewed in cross section in a direction perpendicular to the stacking direction, the outer angle (the angle indicated by θ1 in Figure 1) formed between the interlayer connection conductor 40 and the first conductor layer 20 at the corner P12 at the base end of the first portion 41 may be an obtuse angle, an acute angle, or a right angle.

[0072] When the resin multilayer substrate 1 shown in FIG. 1 includes a plurality of interlayer connection conductors 40, at least one of the interlayer connection conductors 40 needs to have the structure shown in FIG.

[0073] The resin multilayer substrate 1 shown in FIG. 1 is manufactured, for example, by the following method.

[0074] 2A to 2F are cross-sectional views schematically showing an example of a method for manufacturing a resin multilayer substrate 1. The resin multilayer substrate 1 may be manufactured in the form of a single chip (individual piece), or may be manufactured by producing an aggregate substrate and then separating it into individual pieces. The aggregate substrate here refers to a substrate that includes multiple resin multilayer substrates 1.

[0075] First, as shown in FIG. 2A, a first base material 61 is prepared, in which a second conductor layer 30 is formed on one surface of a resin insulating layer 10.

[0076] For example, a metal foil such as Cu foil is laminated on one main surface of the resin insulating layer 10, and the metal foil is patterned by photolithography to form the second conductor layer 30. The resin insulating layer 10 is, for example, a resin sheet whose main component is a thermoplastic resin such as a liquid crystal polymer.

[0077] 2B, a via hole 70 is formed in the first base material 61 so as to penetrate the resin insulating layer 10 and expose a portion of the upper surface of the second conductor layer 30. The via hole 70 preferably has a tapered shape in which the hole diameter decreases toward the second conductor layer 30.

[0078] For example, via holes 70 are formed in the resin insulating layer 10 using a laser or the like so that the upper surface of the second conductor layer 30 is exposed.

[0079] 2C, the via hole 70 is filled with the second material 72. The second material 72 is filled partway into the via hole 70. The height of the second material 72 is not particularly limited as long as it does not exceed the thickness of the resin insulating layer 10.

[0080] For example, by plating such as electrolytic plating, the via hole 70 is filled with a plating metal such as Cu as the second material 72. The second material 72 forms the second portion 42 (see FIG. 2F).

[0081] 2D, the first material 71 is filled into the via hole 70 after it has been filled with the second material 72. The space within the via hole 70 is filled with the first material 71 and the second material 72.

[0082] For example, after the via hole 70 is filled with the second material 72, a conductive paste containing a metal material such as Cu or Sn and a resin material is filled as the first material 71. The first material 71 is solidified by a heat press described later, thereby forming the first portion 41 (see FIG. 2F).

[0083] 2E, a plurality of substrates are laminated, including a first substrate 61 filled with a first material 71 and a second material 72. While Fig. 2E shows an example in which a first substrate 61 filled with a first material 71 and a second material 72 and a second substrate 62 filled with a first material 71 and a second material 72 are laminated, there is no particular limitation as long as the first substrate 61 filled with a first material 71 and a second material 72 is included.

[0084] 2F, heat and pressure are applied to perform a collective pressing, which solidifies the conductive paste to form the first portion 41, bonds the first portion 41 to the first conductor layer 20, and bonds the first portion 41 to the second portion 42.

[0085] At this time, by adjusting the plating conditions, the via hole formation conditions, etc., it is possible to form the interlayer connection conductor 40 having the structure shown in FIG.

[0086] An example of the composition of the plating solution used in the plating process and the electrolysis conditions is shown below. (plating solution) Cu 50g / L H2SO4 150g / L Cl - 130 ppm SPS (bis(3-sulfopropyl)disulfide) 1 ppm PEG (polyethylene glycol, average molecular weight 4000) 300 ppm JGB (Janus Green B) 10 ppm (Electrolysis conditions) 30A / dm 2

[0087] Through the above steps, the resin multilayer substrate 1 is manufactured.

[0088] According to this manufacturing method, the circuit board 1A can be easily manufactured by batch pressing the resin insulating layer 10. Therefore, the number of manufacturing steps for the circuit board 1A can be reduced, and the manufacturing cost can be kept low.

[0089] [Second embodiment] In the resin multilayer substrate according to the second embodiment of the present invention, when viewed in cross section perpendicular to the stacking direction, a portion of the second portion is located closer to the first conductor layer than the straight line connecting the corners of the tip ends of the second portion.

[0090] FIG. 3 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a second embodiment of the present invention.

[0091] Although the overall configuration is not shown in Figure 3, the resin multilayer substrate 2 comprises at least one resin insulating layer 10, a first conductor layer 20 laminated on the resin insulating layer 10, a second conductor layer 30 laminated on the resin insulating layer 10 on the opposite side to the first conductor layer 20 (the lower side in Figure 3), and an interlayer connecting conductor 40 that penetrates the resin insulating layer 10 in the stacking direction of the first conductor layer 20 and the second conductor layer 30 (the up-down direction in Figure 3) and connects the first conductor layer 20 and the second conductor layer 30.

[0092] In the resin multilayer substrate 2 shown in Figure 3, when viewed in cross section in a direction perpendicular to the stacking direction, the distance between the two corners P21 at the tip of the second portion 42 that are furthest apart in a direction perpendicular to the stacking direction (the length indicated by the double arrow D21 in Figure 3) is longer than the distance between the two corners P22 at which the base end of the second portion 42 is in contact with the second conductor layer 30 (the length indicated by the double arrow D22 in Figure 3), and part of the first portion 41 is located on the second conductor layer 30 side of the straight line connecting the corners P21 at the tip of the second portion 42.

[0093] In the resin multilayer substrate 2 shown in Figure 3, similar to the resin multilayer substrate 1 shown in Figure 1, the second portion 42 has a concave shape and is connected to the first portion 41 so as to enclose the first portion 41, thereby increasing the strength of the portion where the reaction product for joining the first portion 41 and the second portion 42 is formed, and therefore increasing the strength of the interlayer connecting conductor 40.

[0094] Furthermore, in the resin multilayer substrate 2 shown in Figure 3, when viewed in cross section in a direction perpendicular to the stacking direction, a part of the second portion 42 is located closer to the first conductor layer 20 than the straight line connecting the corners P21 at the tip ends of the second portion 42.

[0095] In the resin multilayer substrate 2 shown in Figure 3, the surface area of ​​the boundary surface between the second portion 42 and the first portion 41 is larger than in the resin multilayer substrate 1 shown in Figure 1, thereby further increasing the strength of the interlayer connection conductor 40.

[0096] The first portion 41 existing on the second conductor layer 30 side of the line connecting the corners P21 at the tips of the second portions 42 may be at two or more locations as shown in FIG. 3, or may be at one location.

[0097] The second portion 42 that exists closer to the first conductor layer 20 than the line connecting the corners P21 at the tips of the second portion 42 may be located in one place as shown in FIG. 3, or in two or more places.

[0098] When viewed in cross section in a direction perpendicular to the stacking direction, if the maximum thickness in the stacking direction between the straight line connecting the corners P21 at the tip ends of the second portion 42 and the end of the second portion 42 located on the first conductor layer 20 side is T22, the maximum thickness T22 is, for example, 1 μm or more and 10 μm or less.

[0099] The maximum thickness T22 may be the same as the maximum thickness T12, may be greater than the maximum thickness T12, or may be smaller than the maximum thickness T12.

[0100] The ratio of T22 / (T11+T21) is, for example, 0.03 or more and 0.29 or less. The ratio of T22 / (T21+T22) is, for example, 0.03 or more and 0.33 or less. The ratio of T22 / T11 is, for example, 0.20 or more and 0.67 or less. The ratio of T22 / T21 is, for example, 0.2 or more and 0.6 or less.

[0101] 3 , when a cross section of the interlayer connection conductor 40 passing through a straight line connecting the corners P21 of the tip ends of the second portions 42 is viewed from the stacking direction, the area of ​​the first portions 41 located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip ends of the second portions 42 is preferably 10% or more, and more preferably 20% or more, of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the straight line connecting the corners P21 of the tip ends of the second portions 42. The area of ​​the first portions 41 located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip ends of the second portions 42 may be 50% or less of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the straight line connecting the corners P21 of the tip ends of the second portions 42.

[0102] Similarly, when a cross section of the interlayer connection conductor 40 passing through a straight line connecting the corners P21 of the tip ends of the second portions 42 is viewed from the stacking direction, the area of ​​the second portions 42 located closer to the first conductor layer 20 than the straight line connecting the corners P21 of the tip ends of the second portions 42 is preferably 10% or more, and more preferably 20% or more, of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the straight line connecting the corners P21 of the tip ends of the second portions 42. The area of ​​the second portions 42 located closer to the first conductor layer 20 than the straight line connecting the corners P21 of the tip ends of the second portions 42 may be 50% or less of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the straight line connecting the corners P21 of the tip ends of the second portions 42.

[0103] In addition, the area ratio of the second portion 42 that is located on the first conductor layer 20 side of the straight line connecting the corners P21 of the tip portions of the second portion 42 may be the same as the area ratio of the first portion 41 that is located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip portions of the second portion 42, or may be larger than the area ratio of the first portion 41 that is located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip portions of the second portion 42, or may be smaller than the area ratio of the first portion 41 that is located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip portions of the second portion 42.

[0104] When viewed in cross section in a direction perpendicular to the stacking direction, the shape of the corner P21 at the tip of the second portion 42 is not particularly limited, and may be, for example, pointed as shown in Fig. 3 or flat as shown in the above-mentioned Fig. 1. When the corner P21 at the tip of the second portion 42 is flat, the corner P21 at the tip of the second portion 42 may or may not be parallel to the first conductor layer 20 or the second conductor layer 30.

[0105] When the resin multilayer substrate 2 shown in FIG. 3 includes a plurality of interlayer connection conductors 40, at least one of the interlayer connection conductors 40 needs to have the structure shown in FIG.

[0106] The other configurations are the same as those in the first embodiment.

[0107] [Third embodiment] In the resin multilayer substrate according to the third embodiment of the present invention, when viewed in cross section perpendicular to the stacking direction, the first portion covers the corners of the tip of the second portion, extending around to part of the side surface of the second portion.

[0108] FIG. 4 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a third embodiment of the present invention.

[0109] Although the overall configuration is not shown in Figure 4, the resin multilayer substrate 3 comprises at least one resin insulating layer 10, a first conductor layer 20 laminated on the resin insulating layer 10, a second conductor layer 30 laminated on the resin insulating layer 10 on the opposite side to the first conductor layer 20 (the lower side in Figure 4), and an interlayer connecting conductor 40 that penetrates the resin insulating layer 10 in the stacking direction of the first conductor layer 20 and the second conductor layer 30 (the up-down direction in Figure 4) and connects the first conductor layer 20 and the second conductor layer 30.

[0110] In the resin multilayer substrate 3 shown in Figure 4, when viewed in cross section in a direction perpendicular to the stacking direction, the distance between the two corners P21 at the tip of the second portion 42 that are furthest apart in a direction perpendicular to the stacking direction (the length indicated by the double arrow D21 in Figure 4) is longer than the distance between the two corners P22 at which the base end of the second portion 42 is in contact with the second conductor layer 30 (the length indicated by the double arrow D22 in Figure 4), and part of the first portion 41 is located on the second conductor layer 30 side of the straight line connecting the corners P21 at the tip of the second portion 42.

[0111] In the resin multilayer substrate 3 shown in Figure 4, similar to the resin multilayer substrate 1 shown in Figure 1, the second portion 42 has a concave shape and is connected to the first portion 41 so as to enclose the first portion 41, thereby increasing the strength of the portion where the reaction product for joining the first portion 41 and the second portion 42 is formed, and therefore increasing the strength of the interlayer connecting conductor 40.

[0112] 4, when viewed in cross section in a direction perpendicular to the stacking direction, the first portion 41 covers a corner P21 at the tip of the second portion 42 so as to wrap around to a part of the side surface of the second portion 42. Note that the first portion 41 may cover at least a part of the corner P21 at the tip of the second portion 42.

[0113] In the resin multilayer substrate 3 shown in Figure 4, the first portion 41 covers the corner P21 at the tip of the second portion 42, which makes the strength of the interlayer connection conductor 40 even higher than in the resin multilayer substrate 1 shown in Figure 1.

[0114] When the resin multilayer substrate 3 shown in FIG. 4 includes a plurality of interlayer connection conductors 40, at least one of the interlayer connection conductors 40 needs to have the structure shown in FIG.

[0115] The other configurations are common to the first and second embodiments.

[0116] [Fourth embodiment] In the resin multilayer substrate according to the fourth embodiment of the present invention, when viewed in cross section perpendicular to the stacking direction, the outer angle formed between the interlayer connection conductor and the second conductor layer at the corner of the base end of the second portion is an obtuse angle.

[0117] FIG. 5 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a fourth embodiment of the present invention.

[0118] Although the overall configuration is not shown in Figure 5, the resin multilayer substrate 4 comprises at least one resin insulating layer 10, a first conductor layer 20 laminated on the resin insulating layer 10, a second conductor layer 30 laminated on the resin insulating layer 10 on the opposite side to the first conductor layer 20 (the lower side in Figure 5), and an interlayer connecting conductor 40 that penetrates the resin insulating layer 10 in the stacking direction of the first conductor layer 20 and the second conductor layer 30 (the up-down direction in Figure 5) and connects the first conductor layer 20 and the second conductor layer 30.

[0119] In the resin multilayer substrate 4 shown in Figure 5, when viewed in cross section in a direction perpendicular to the stacking direction, the distance between the two corners P21 at the tip of the second portion 42 that are furthest apart in a direction perpendicular to the stacking direction (the length indicated by the double arrow D21 in Figure 5) is longer than the distance between the two corners P22 at which the base end of the second portion 42 is in contact with the second conductor layer 30 (the length indicated by the double arrow D22 in Figure 5), and part of the first portion 41 is located on the second conductor layer 30 side of the straight line connecting the corners P21 at the tip of the second portion 42.

[0120] In the resin multilayer substrate 4 shown in Figure 5, similar to the resin multilayer substrate 1 shown in Figure 1, the second portion 42 has a concave shape and is connected to the first portion 41 so as to enclose the first portion 41, thereby increasing the strength of the portion where the reaction product for joining the first portion 41 and the second portion 42 is formed, and therefore increasing the strength of the interlayer connecting conductor 40.

[0121] Furthermore, in the resin multilayer substrate 4 shown in Fig. 5, when viewed in cross section in a direction perpendicular to the stacking direction, the outer angle (the angle indicated by θ2 in Fig. 5) formed between the interlayer connection conductor 40 and the second conductor layer 30 at a corner P22 at the base end of the second portion 42 is an obtuse angle. As shown in Fig. 5, the second portion 42 has a constricted portion between the tip end and the base end. Note that at least a portion of the outer angle θ2 formed between the interlayer connection conductor 40 and the second conductor layer 30 may be an obtuse angle.

[0122] In the resin multilayer substrate 4 shown in Figure 5, the outer angle θ2 formed between the interlayer connection conductor 40 and the second conductor layer 30 is an obtuse angle, which makes it possible to increase the area of ​​the joint between the second portion 42 and the second conductor layer 30, thereby making the strength of the interlayer connection conductor 40 even higher than that of the resin multilayer substrate 1 shown in Figure 1.

[0123] When the resin multilayer substrate 4 shown in FIG. 5 includes a plurality of interlayer connection conductors 40, at least one of the interlayer connection conductors 40 needs to have the structure shown in FIG.

[0124] The other configurations are common to any of the first to third embodiments.

[0125] [Fifth embodiment] In the resin multilayer substrate according to the fifth embodiment of the present invention, the interlayer connection conductor further includes a third portion, and the first conductor layer contacts the third portion, thereby enabling an increase in wiring density.

[0126] FIG. 6 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a fifth embodiment of the present invention.

[0127] Although the overall configuration is not shown in Figure 6, the resin multilayer substrate 5 comprises at least two resin insulating layers 10, a first conductor layer 20 laminated on the resin insulating layer 10, a second conductor layer 30 laminated on the resin insulating layer 10 on the opposite side to the first conductor layer 20 (the lower side in Figure 6), and an interlayer connecting conductor 40 that penetrates the resin insulating layer 10 in the stacking direction of the first conductor layer 20 and the second conductor layer 30 (the up-down direction in Figure 6) and connects the first conductor layer 20 and the second conductor layer 30.

[0128] Two resin insulating layers 10 may be provided between the first conductor layer 20 and the second conductor layer 30, or three or more resin insulating layers 10 may be provided. The resin insulating layers 10 may have the same configuration or different configurations. Furthermore, the resin insulating layers 10 may have the same thickness or different thicknesses.

[0129] In the example shown in Fig. 6, one resin insulating layer 10 is provided on the first conductor layer 20 side, and one resin insulating layer 10 is provided on the second conductor layer 30 side. In Fig. 6, the boundary between the resin insulating layers 10 is indicated by a dashed line. It is sufficient that at least one resin insulating layer 10 is provided on the first conductor layer 20 side, and at least one resin insulating layer 10 is provided on the second conductor layer 30 side. The number of resin insulating layers 10 provided on the first conductor layer 20 side may be the same as or different from the number of resin insulating layers 10 provided on the second conductor layer 30 side.

[0130] The interlayer connection conductor 40 includes a first portion 41 and a second portion 42 located closer to the second conductor layer 30 than the first portion 41.

[0131] The first portion 41 and the second portion 42 are the same as those in the first embodiment.

[0132] The interlayer connection conductor 40 further includes a third portion 43 located closer to the first conductor layer 20 than the first portion 41 .

[0133] The first portion 41 has a lower conductivity than the third portion 43 .

[0134] The third portion 43 may be a paste via or a plated via, but is preferably a plated via.

[0135] When the third portion 43 is a plated via, it is preferable that the third portion 43 does not include a resin member. For example, when the third portion 43 is a plated via, it is preferable that the content of the conductive member in the third portion 43 is 90.0% by volume or more and 100% by volume or less.

[0136] When the third portion 43 is a plated via, the conductive material constituting the third portion 43 is preferably the same as the metal constituting the first conductor layer 20, for example, Cu. The conductive material constituting the third portion 43 may be the same as the conductive material constituting the second portion 42, or may be different.

[0137] For example, it is preferable that the first portion 41 is a paste via, and the second portion 42 and the third portion 43 are plated vias. In this case, the content of the resin material in the first portion 41 is greater than the content of the resin material in the second portion 42 and the third portion 43. When the resin multilayer substrate 5 is produced by batch pressing, the first portion 41 functions as a bonding material, thereby electrically connecting the second portion 42 and the third portion 43.

[0138] When the first portion 41 is a paste via, the conductive material constituting the first portion 41 may be the same as or different from the conductive materials constituting the second portion 42 and the third portion 43. The conductive material constituting the first portion 41 is, for example, an alloy containing Cu and Sn.

[0139] There are no particular limitations on the combination of materials for the first portion 41, the second portion 42, and the third portion 43. It is preferable to use an alloy or a resin-containing metal for the first portion 41 for bonding purposes, while it is preferable to use a pure metal, resin, or a material with little alloy or no resin for the second portion 42 and the third portion 43 in order to increase conductivity.

[0140] When the first portion 41, the second portion 42, and the third portion 43 are plated vias, the combination may be plated vias made of different metals, for example, the conductive material constituting the first portion 41 being Sn and the conductive material constituting the second portion 42 and the third portion 43 being Cu.

[0141] The first conductor layer 20 is not in contact with the second portion 42. In the example shown in Fig. 6, the first conductor layer 20 is in contact with the third portion 43. It is desirable that the first conductor layer 20 and the third portion 43 are made of the same material and are joined together without a dissimilar material therebetween.

[0142] The second conductor layer 30 is in contact with the second portion 42. The second conductor layer 30 and the second portion 42 are preferably made of the same material and are joined together without a dissimilar material therebetween.

[0143] In the resin multilayer substrate 5 shown in Figure 6, when viewed in cross section in a direction perpendicular to the stacking direction, the distance between the two corners P21 at the tip of the second portion 42 that are furthest apart in a direction perpendicular to the stacking direction (the length indicated by the double arrow D21 in Figure 6) is longer than the distance between the two corners P22 at which the base end of the second portion 42 is in contact with the second conductor layer 30 (the length indicated by the double arrow D22 in Figure 6), and part of the first portion 41 is located on the second conductor layer 30 side of the straight line connecting the corners P21 at the tip of the second portion 42.

[0144] In the resin multilayer substrate 5 shown in Figure 6, similar to the resin multilayer substrate 1 shown in Figure 1, the second portion 42 has a concave shape and is connected to the first portion 41 so as to enclose the first portion 41, thereby increasing the strength of the portion where the reaction product for joining the first portion 41 and the second portion 42 is formed, and therefore increasing the strength of the interlayer connecting conductor 40.

[0145] In the resin multilayer substrate 5 shown in Fig. 6, among the ends of the third portion 43 in the stacking direction (the up-down direction in Fig. 6), the end on the second conductor layer 30 side is defined as the tip end, and the end on the first conductor layer 20 side is defined as the base end. In Fig. 6, the point of the tip end of the third portion 43 that is furthest away in the direction perpendicular to the stacking direction (the left-right direction in Fig. 6) is shown as a corner P31. Furthermore, in Fig. 6, the point of the base end of the third portion 43 that is in contact with the first conductor layer 20 is shown as a corner P32.

[0146] As shown in Figure 6, when viewed in cross section in a direction perpendicular to the stacking direction, the distance between the two corners P31 at the tip of the third portion 43 that are furthest apart in a direction perpendicular to the stacking direction (the length indicated by the double arrow D31 in Figure 6) is longer than the distance between the two corners P32 at which the base end of the third portion 43 contacts the first conductor layer 20 (the length indicated by the double arrow D32 in Figure 6), and part of the first portion 41 may be located closer to the first conductor layer 20 than the straight line connecting the corners P31 at the tip of the third portion 43.

[0147] In the resin multilayer substrate 5 shown in Figure 6, when the third portion 43 is concave and connected to the first portion 41 so as to encase the first portion 41, the strength of the portion where the reaction product for joining the second portion 42 and the third portion 43 is formed can be increased, thereby further increasing the strength of the interlayer connecting conductor 40.

[0148] The first portion 41 that exists on the second conductor layer 30 side of the line connecting the corners P21 at the tips of the second portions 42 may be one location as shown in FIG. 6, or may be two or more locations.

[0149] The first portion 41 that exists on the first conductor layer 20 side of the line connecting the corners P31 at the tips of the third portion 43 may be one location as shown in FIG. 6, or may be two or more locations.

[0150] When viewed in cross section in a direction perpendicular to the stacking direction, the distance D21 between the corners P21 at the tip ends of the second portions 42 is, for example, not less than 60 μm and not more than 80 μm.

[0151] When viewed in cross section in a direction perpendicular to the stacking direction, the distance D22 between the corners P22 at the base ends of the second portions 42 is, for example, not less than 40 μm and not more than 60 μm.

[0152] The ratio of D22 / D21 is, for example, not less than 0.67 and not more than 0.75.

[0153] When viewed in cross section in a direction perpendicular to the stacking direction, the distance D31 between the corners P31 at the tips of the third portions 43 is, for example, not less than 60 μm and not more than 80 μm. The value of D31 may be the same as or different from the value of D21.

[0154] When viewed in cross section in a direction perpendicular to the stacking direction, the distance D32 between the corners P32 at the base ends of the third portion 43 is, for example, 40 μm or more and 60 μm or less. The value of D32 may be the same as or different from the value of D22.

[0155] The ratio of D32 / D31 is, for example, 0.67 or more and 0.75 or less. The value of D32 / D31 may be the same as or different from the value of D22 / D21.

[0156] When viewed in cross section in a direction perpendicular to the stacking direction, if the maximum thickness in the stacking direction between the straight line connecting the corners P21 at the tip of the second portion 42 and the straight line connecting the corners P31 at the tip of the third portion 43 is t11, the maximum thickness t11 is, for example, 10 μm or more and 30 μm or less.

[0157] When viewed in cross section perpendicular to the stacking direction, the maximum thickness in the stacking direction between the second conductor layer 30 and a line connecting the corners P21 at the tips of the second portion 42 is T21, and the maximum thickness T21 is, for example, 20 μm or more and 30 μm or less. The maximum thickness T21 is preferably greater than half of the maximum thickness t11 (i.e., t11 / 2).

[0158] When viewed in cross section in a direction perpendicular to the stacking direction, the maximum thickness in the stacking direction between a line connecting the corners P21 at the tips of the second portion 42 and the end of the first portion 41 located on the second conductor layer 30 side is defined as T12, and the maximum thickness T12 is, for example, 1 μm or more and 10 μm or less. The maximum thickness T12 may be equal to half the maximum thickness t11, may be less than half the maximum thickness t11, or may be greater than half the maximum thickness t11.

[0159] The ratio of T12 / ((t11 / 2)+T21) is, for example, 0.03 or more and 0.29 or less. The ratio of T12 / ((t11 / 2)+T12) is, for example, 0.17 or more and 0.40 or less. The ratio of T12 / (t11 / 2) is, for example, 0.2 or more and 0.6 or less. The ratio of T12 / T21 is, for example, 0.03 or more and 0.50 or less.

[0160] When viewed in cross section perpendicular to the stacking direction, the maximum thickness in the stacking direction between the first conductor layer 20 and a line connecting the corners P31 at the tips of the third portion 43 is defined as T31. The maximum thickness T31 is preferably greater than half the maximum thickness t11. The value of T31 may be the same as or different from the value of T21.

[0161] When viewed in cross section perpendicular to the stacking direction, the maximum thickness in the stacking direction between a line connecting the corners P31 at the tips of the third portion 43 and the end of the first portion 41 located on the first conductor layer 20 side is defined as T13. The maximum thickness T13 may be, for example, 1 μm or more and 10 μm or less. The maximum thickness T13 may be equal to half the maximum thickness t11, may be less than half the maximum thickness t11, or may be greater than half the maximum thickness t11. The value of T13 may be the same as or different from the value of T12.

[0162] The ratio of T13 / ((t11 / 2)+T31) is, for example, 0.03 or more and 0.29 or less. The value of T13 / ((t11 / 2)+T31) may be the same as or different from the value of T12 / ((t11 / 2)+T21). The ratio of T13 / ((t11 / 2)+T13) is, for example, 0.17 or more and 0.40 or less. The value of T13 / ((t11 / 2)+T13) may be the same as or different from the value of T12 / ((t11 / 2)+T12). The ratio of T13 / (t11 / 2) is, for example, 0.2 or more and 0.6 or less. The value of T13 / (t11 / 2) may be the same as or different from the value of T12 / (t11 / 2). The ratio of T13 / T31 is, for example, 0.03 or more and 0.50 or less. The value of T13 / T31 may be the same as or different from the value of T12 / T21.

[0163] 6, when a cross section of the interlayer connection conductor 40 passing through a straight line connecting the corners P21 of the tip ends of the second portions 42 is viewed from the stacking direction, the area of ​​the first portions 41 located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip ends of the second portions 42 is preferably 10% or more, more preferably 20% or more, and even more preferably 50% or more of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the straight line connecting the corners P21 of the tip ends of the second portions 42. The area of ​​the first portions 41 located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip ends of the second portions 42 may be 100%, 90% or less, or 80% or less of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the straight line connecting the corners P21 of the tip ends of the second portions 42.

[0164] Furthermore, when a cross section of the interlayer connection conductor 40 passing through a line connecting the corners P31 of the tips of the third portions 43 is viewed from the stacking direction, the area of ​​the first portions 41 located closer to the first conductor layer 20 than the line connecting the corners P31 of the tips of the third portions 43 is preferably 10% or more, more preferably 20% or more, and even more preferably 50% or more of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the line connecting the corners P31 of the tips of the third portions 43. The area of ​​the first portions 41 located closer to the first conductor layer 20 than the line connecting the corners P31 of the tips of the third portions 43 may be 100%, 90% or less, or 80% or less of the area of ​​the entire cross section of the interlayer connection conductor 40 passing through the line connecting the corners P31 of the tips of the third portions 43.

[0165] In addition, the area ratio of the first portion 41 located on the first conductor layer 20 side of the straight line connecting the corners P31 of the tip portions of the third portion 43 may be the same as the area ratio of the first portion 41 located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip portions of the second portion 42, or may be larger than the area ratio of the first portion 41 located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip portions of the second portion 42, or may be smaller than the area ratio of the first portion 41 located on the second conductor layer 30 side of the straight line connecting the corners P21 of the tip portions of the second portion 42.

[0166] When viewed in cross section in a direction perpendicular to the stacking direction, the shape of the corner P21 at the tip of the second portion 42 is not particularly limited, and may be, for example, flat as shown in Fig. 6 or pointed as shown in the above-mentioned Fig. 3. When the corner P21 at the tip of the second portion 42 is flat, the corner P21 at the tip of the second portion 42 may or may not be parallel to the first conductor layer 20 or the second conductor layer 30.

[0167] When viewed in cross section in a direction perpendicular to the stacking direction, the second portion 42 may not be present on the first conductor layer 20 side of the straight line connecting the corners P21 at the tip ends of the second portion 42, or a part of the second portion 42 may be present.

[0168] When viewed in cross section in a direction perpendicular to the stacking direction, a straight line connecting the corners P21 at the tips of the second portions 42 may be parallel to the second conductor layer 30.

[0169] When viewed in cross section in a direction perpendicular to the stacking direction, the outer angle (the angle indicated by θ2 in Figure 6) formed between the interlayer connection conductor 40 and the second conductor layer 30 at the corner P22 at the base end of the second portion 42 may be an acute angle, an obtuse angle, or a right angle.

[0170] When viewed in cross section in a direction perpendicular to the stacking direction, the shape of the corner P31 at the tip of the third portion 43 is not particularly limited, and may be, for example, flat as shown in Fig. 6 or pointed as shown in the above-mentioned Fig. 3. When the corner P31 at the tip of the third portion 43 is flat, the corner P31 at the tip of the third portion 43 may or may not be parallel to the first conductor layer 20 or the second conductor layer 30.

[0171] When viewed in cross section in a direction perpendicular to the stacking direction, the third portion 43 may not be present on the second conductor layer 30 side of the straight line connecting the corners P31 at the tip ends of the third portion 43, or a part of the third portion 43 may be present.

[0172] When viewed in cross section in a direction perpendicular to the stacking direction, a straight line connecting the corners P31 at the tips of the third portion 43 may be parallel to the first conductor layer 20.

[0173] When viewed in cross section in a direction perpendicular to the stacking direction, at the corner P32 at the base end of the third portion 43, the outer angle (the angle indicated by θ1 in Figure 6) formed between the interlayer connection conductor 40 and the first conductor layer 20 may be an acute angle, an obtuse angle, or a right angle.

[0174] When the resin multilayer substrate 5 shown in FIG. 6 includes a plurality of interlayer connection conductors 40, at least one of the interlayer connection conductors 40 needs to have the structure shown in FIG.

[0175] The other configurations are common to any of the first to fourth embodiments.

[0176] The resin multilayer substrate 5 shown in Fig. 6 is manufactured by, for example, the same method as in Fig. 2A to Fig. 2F. In this case, the first base material 61 and the second base material 62 are stacked so that the first materials 71 face each other, thereby forming the interlayer connection conductor 40 having the structure shown in Fig. 6.

[0177] [Sixth embodiment] In the resin multilayer substrate according to the sixth embodiment of the present invention, when viewed in cross section perpendicular to the lamination direction, the line connecting the corners of the tip ends of the second portion is not parallel to the second conductor layer.

[0178] FIG. 7 is a cross-sectional view schematically showing an example of a resin multilayer substrate according to a sixth embodiment of the present invention.

[0179] 7, when viewed in cross section in a direction perpendicular to the stacking direction, the line connecting the corners P21 at the tips of the second portions 42 does not have to be parallel to the second conductor layer 30. The resin multilayer substrate 6 shown in FIG. 7 also provides the same effects as the resin multilayer substrate 1 shown in FIG.

[0180] When the resin multilayer substrate 6 shown in FIG. 7 includes a plurality of interlayer connection conductors 40, at least one of the interlayer connection conductors 40 needs to have the structure shown in FIG.

[0181] The other configurations are common to any of the first to fifth embodiments.

[0182] 6 described in the fifth embodiment, when the interlayer connection conductor 40 includes the third portion 43, when viewed in cross section in a direction perpendicular to the stacking direction, the line connecting the corners P21 at the tips of the second portions 42 may not be parallel to the second conductor layer 30, and the line connecting the corners P31 at the tips of the third portions 43 may be parallel to the first conductor layer 20, or may not be parallel to the first conductor layer 20. Alternatively, the line connecting the corners P31 at the tips of the third portions 43 may not be parallel to the first conductor layer 20, and the line connecting the corners P21 at the tips of the second portions 42 may be parallel to the second conductor layer 30, or may not be parallel to the second conductor layer 30.

[0183] [Other embodiments] The resin multilayer substrate of the present invention is not limited to the above-described embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the configuration, manufacturing conditions, etc. of the resin multilayer substrate.

[0184] For example, an alloy layer having a composition different from that of both the first and second portions may be formed on at least a portion of the interface between the first and second portions of the interlayer connection conductor. When an alloy layer is formed on the interface between the first and second portions, the connectivity between the first and second portions is improved. The alloy layer may be one layer or two or more layers.

[0185] The alloy layer formed at the interface between the first and second portions of the interlayer connection conductor can be confirmed, for example, by observing a cross section of the resin insulating layer cut in a direction parallel to the thickness direction using a scanning electron microscope (SEM). Since the alloy layer has a different composition from both the first and second portions, it appears in a different color tone from the first and second portions in the SEM photograph.

[0186] Note that even if the types of metal elements contained are the same, if the content ratios of the respective metal elements are different, they are also considered to have "different compositions." For example, compositions such as Cu5Sn, Cu3Sn, and Cu6Sn5 all contain Cu and Sn as metal species, but because the content ratios of the metal species are different, they can be said to have different compositions.

[0187] Similarly, when the interlayer connection conductor further includes a third portion, an alloy layer having a composition different from both the first portion and the third portion may be formed on at least a part of the interface between the first portion and the third portion of the interlayer connection conductor. When an alloy layer is formed on the interface between the first portion and the third portion, the connectivity between the first portion and the third portion is improved. The alloy layer may be one layer or two or more layers.

[0188] Furthermore, when the first portion of the interlayer connection conductor is in contact with the first conductor layer, an alloy layer having a composition different from that of both the first portion and the first conductor layer may be formed on at least a portion of the interface between the first portion of the interlayer connection conductor and the first conductor layer. When an alloy layer is formed on the interface between the first portion and the first conductor layer, the connectivity between the first portion and the first conductor layer is improved. The alloy layer may be one layer or two or more layers.

[0189] When the resin multilayer substrate of the present invention includes a plurality of interlayer connection conductors, it is sufficient that at least one of the interlayer connection conductors has the structure of the present invention. Also, the resin multilayer substrate of the present invention may include two or more types of interlayer connection conductors, that is, an interlayer connection conductor having the structure described in one embodiment and an interlayer connection conductor having the structure described in another embodiment.

[0190] When the resin multilayer substrate of the present invention includes a plurality of interlayer connection conductors, the interlayer connection conductors may include, for example, interlayer connection conductors consisting only of plated vias and interlayer connection conductors consisting only of paste vias.

[0191] The resin multilayer substrate of the present invention may include an insulating layer different from the resin insulating layer provided between the first conductor layer and the second conductor layer. For example, the resin multilayer substrate of the present invention may include a resin insulating layer or ceramic insulating layer having a dielectric constant different from that of the resin insulating layer provided between the first conductor layer and the second conductor layer. In this case, it is preferable that the dielectric constant of the resin insulating layer be higher than that of the resin insulating layer provided between the first conductor layer and the second conductor layer.

[0192] The resin multilayer substrate of the present invention may be a rigid substrate or a flexible substrate. When the resin multilayer substrate of the present invention is a flexible substrate, the flexible substrate may have a curved portion.

[0193] The resin multilayer substrate of the present invention can be used, for example, as a substrate for a circuit module, and such a circuit module also constitutes the present invention.

[0194] FIG. 8 is a cross-sectional view that schematically shows an example of a circuit module that includes a resin multilayer substrate of the present invention.

[0195] The circuit module 100 shown in FIG. 8 includes a resin multilayer substrate 110 and an electronic component 120 disposed on the resin multilayer substrate 110.

[0196] The resin multilayer substrate 110 is the resin multilayer substrate of the present invention. The resin multilayer substrate 110 may be a rigid substrate or a flexible substrate. The resin multilayer substrate 110 may have a bent portion.

[0197] The electronic component 120 is not particularly limited and may be, for example, an integrated circuit (IC), a connector, etc. One or more electronic components 120 may be arranged on either one of the main surfaces of the resin multilayer substrate 110, or one or more electronic components 120 may be arranged on each of the main surfaces of the resin multilayer substrate 110.

[0198] 8, it is preferable that an interlayer connection conductor 40 including the first and second portions (neither of which is shown) described in the first embodiment, etc., is provided inside a resin insulating layer 10 located on the surface layer of a resin multilayer substrate 110 on the side where an electronic component 120 is arranged (the lower side in FIG. 8). This ensures the connectivity of the interlayer connection conductor even in a fine wiring portion located on the surface layer.

[0199] As described above, when electronic components 120 are arranged on both main surfaces of the resin multilayer substrate 110, it is preferable that an interlayer connecting conductor 40 including a first portion and a second portion is provided inside the resin insulating layer 10 located on both surface layers of the resin multilayer substrate 110.

[0200] When multiple interlayer connection conductors 40 are provided inside the resin insulating layer 10 located on the surface layer of the resin multilayer substrate 110 on the side where the electronic component 120 is arranged, it is sufficient that at least one interlayer connection conductor 40 includes a first part and a second part, and all of the interlayer connection conductors 40 may include a first part and a second part.

[0201] The interlayer connection conductor 40 provided inside the resin insulating layer 10 located on the surface of the resin multilayer substrate 110 on the side where the electronic component 120 is not arranged may be composed of a first part and a second part, may be composed only of plated vias, may be composed only of paste vias, or may be a mixture of these.

[0202] Similarly, the interlayer connection conductor 40 provided inside the resin insulating layer 10 located in the inner layer of the resin multilayer substrate 110 may be composed of a first part and a second part, may be composed only of plated vias, may be composed only of paste vias, or may be a mixture of these.

[0203] A protective layer 50 may be provided on the surface layer of the resin multilayer substrate 110. The protective layer 50 may be, for example, a coverlay, a resist layer, or the like. The protective layer 50 may be provided on both main surfaces of the resin multilayer substrate 110, or on one of the main surfaces.

[0204] The circuit module of the present invention is not limited to the above-described embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the configurations of the resin multilayer substrate and electronic components, manufacturing conditions, etc.

[0205] The present specification discloses the following:

[0206] <1> At least one resin insulating layer; a first conductor layer laminated on the resin insulating layer; a second conductor layer laminated on the resin insulating layer on the side opposite to the first conductor layer; an interlayer connection conductor provided to penetrate the resin insulating layer in a stacking direction of the first conductor layer and the second conductor layer, and to connect the first conductor layer and the second conductor layer; the interlayer connection conductor includes a first portion and a second portion located closer to the second conductor layer than the first portion; the first portion has a lower electrical conductivity than the second portion; the first conductor layer is not in contact with the second portion; the second conductor layer is in contact with the second portion; When viewed cross-sectionally in a direction perpendicular to the stacking direction, the distance between the two corners at which the tip end of the second portion is furthest apart in a direction perpendicular to the stacking direction is longer than the distance between the two corners at which the base end of the second portion is in contact with the second conductor layer, and a resin multilayer substrate, wherein a part of the first portion is present on the second conductor layer side of a straight line connecting the corners of the tip ends of the second portion;

[0207] <2> When viewed cross-sectionally in a direction perpendicular to the stacking direction, a part of the second portion is located closer to the first conductor layer than a straight line connecting corners of the tip ends of the second portion; <1> The resin multilayer substrate according to claim 1.

[0208] <3> When viewed cross-sectionally in a direction perpendicular to the stacking direction, The first part covers a corner of the tip of the second part so as to wrap around to a part of a side surface of the second part. <1> or <2> The resin multilayer substrate according to claim 1.

[0209] <4> When viewed cross-sectionally in a direction perpendicular to the stacking direction, an outer angle formed between the interlayer connection conductor and the second conductor layer at a corner of the base end of the second portion is an obtuse angle; <1> ~ <3> 10. The resin multilayer substrate according to claim 9, wherein the first and second substrates are made of a resin material.

[0210] <5> the first conductor layer is in contact with the first portion; <1> ~ <4> 10. The resin multilayer substrate according to claim 9, wherein the first and second substrates are made of a resin material.

[0211] <6> the interlayer connection conductor further includes a third portion located closer to the first conductor layer than the first portion; the first portion has a lower electrical conductivity than the third portion; the first conductor layer is in contact with the third portion; <1> ~ <4> 10. The resin multilayer substrate according to claim 9, wherein the first and second substrates are made of a resin material.

[0212] <7> When viewed cross-sectionally in a direction perpendicular to the stacking direction, a distance between two corners where the tip end of the third portion is furthest apart in a direction perpendicular to the stacking direction is longer than a distance between two corners where the base end of the third portion is in contact with the first conductor layer; and a part of the first portion is present on the first conductor layer side of a straight line connecting corners of the tip end of the third portion; <6> The resin multilayer substrate according to claim 1.

[0213] <8> <1> ~ <7> a resin multilayer substrate according to any one of the above items; and an electronic component disposed on the resin multilayer substrate.

[0214] <9> the interlayer connection conductor including the first portion and the second portion is provided inside the resin insulating layer located on the surface layer of the resin multilayer substrate on the side where the electronic component is arranged. <8> The circuit module according to claim 1. [Explanation of symbols]

[0215] 1, 2, 3, 4, 5, 6, 110 Resin multilayer board 10 Resin insulation layer 20 First conductor layer 30 Second conductor layer 40 Interlayer connecting conductor 41 First part of interlayer connecting conductor 42 Second part of interlayer connecting conductor 43 Third part of interlayer connecting conductor 50 protective layer 61 1st base material 62 Second base material 70 Beer Hall 71 First material 72 Second material 100 Circuit Module 120 Electronic Board D12 Distance between corners of base end of first part D21 Distance between the corners of the tip of the second part D22 Distance between the corners of the base of the second part D31 Distance between the corners of the tip of the third section D32 Distance between the corners of the base of the third section T11: The maximum thickness in the lamination direction between the line connecting the corners of the tip of the second part and the first conductor layer t11 Maximum thickness in the lamination direction between the line connecting the corners of the tip of the second part and the line connecting the corners of the tip of the third part T12: The maximum thickness in the lamination direction between the straight line connecting the corners of the tip of the second part and the end of the first part located on the second conductor layer side T13: The maximum thickness in the lamination direction between the straight line connecting the corners of the tip of the third part and the end of the first part located on the first conductor layer side T21: The maximum thickness in the lamination direction between the straight line connecting the corners of the tip of the second part and the second conductor layer T22: The maximum thickness in the lamination direction between the straight line connecting the corners of the tip of the second part and the end of the second part located on the first conductor layer side T31: The maximum thickness in the lamination direction between the straight line connecting the corners of the tip of the third section and the first conductor layer P12 Corner of base end of first part P21 Corner of tip of second part P22 Corner of base end of second part P31 Corner of the tip of the third part P32 Corner of the base end of the third section θ1: Outer angle between the interlayer connection conductor and the first conductor layer θ2: The outer angle between the interlayer connection conductor and the second conductor layer

Claims

1. At least one resin insulating layer; a first conductor layer laminated on the resin insulating layer; a second conductor layer laminated on the resin insulating layer on the side opposite to the first conductor layer; an interlayer connection conductor provided to penetrate the resin insulating layer in a stacking direction of the first conductor layer and the second conductor layer, and to connect the first conductor layer and the second conductor layer; the interlayer connection conductor includes a first portion and a second portion located closer to the second conductor layer than the first portion; the first portion has a lower electrical conductivity than the second portion; the first conductor layer is not in contact with the second portion; the second conductor layer is in contact with the second portion; When viewed cross-sectionally in a direction perpendicular to the stacking direction, a distance between two corners where the tip end of the second portion is furthest apart in a direction perpendicular to the stacking direction is longer than a distance between two corners where the base end of the second portion is in contact with the second conductor layer, and a resin multilayer substrate, wherein a part of the first portion is located on the second conductor layer side of a straight line connecting the corners of the tip ends of the second portion;

2. When viewed cross-sectionally in a direction perpendicular to the stacking direction, The resin multilayer board according to claim 1 , wherein a part of the second portion is located closer to the first conductor layer than a straight line connecting the corners of the tip ends of the second portion.

3. When viewed cross-sectionally in a direction perpendicular to the stacking direction, The resin multilayer board according to claim 1 , wherein the first portion covers a corner of the tip end of the second portion so as to wrap around to a part of a side surface of the second portion.

4. When viewed cross-sectionally in a direction perpendicular to the stacking direction, 2. The resin multilayer board according to claim 1, wherein an outer angle formed between the interlayer connection conductor and the second conductor layer at a corner of the base end of the second portion is an obtuse angle.

5. 5. The resin multilayer board according to claim 1, wherein the first conductor layer is in contact with the first portion.

6. the interlayer connection conductor further includes a third portion located closer to the first conductor layer than the first portion; the first portion has a lower electrical conductivity than the third portion; 5. The resin multilayer board according to claim 1, wherein the first conductor layer is in contact with the third portion.

7. When viewed cross-sectionally in a direction perpendicular to the stacking direction, a distance between two corners where the tip end of the third portion is furthest apart in a direction perpendicular to the stacking direction is longer than a distance between two corners where the base end of the third portion is in contact with the first conductor layer; and The resin multilayer board according to claim 6 , wherein a part of the first portion is located closer to the first conductor layer than a straight line connecting the corners of the tip end of the third portion.

8. A resin multilayer substrate according to any one of claims 1 to 4, and an electronic component disposed on the resin multilayer substrate.

9. 9. The circuit module according to claim 8, wherein the interlayer connection conductor including the first portion and the second portion is provided inside the resin insulating layer located on the surface layer of the resin multilayer substrate on the side where the electronic component is arranged.

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