laminated substrate

Abstract

The laminated substrate (1) comprises: a resin laminate (10) having a laminated structure including a first laminate portion (11) including at least one first thermoplastic resin layer (11a) and a second laminate portion (12) adjacent to the first laminate portion (11) and including at least one second thermoplastic resin layer (12a), the laminate having a first main surface (10a) on the first laminate portion (11) side and a second main surface (10b) on the second laminate portion (12) side that are opposite to each other in the laminated direction; surface electrodes (20a, 20b) provided on the first main surface (10a) of the resin laminate (10); a first conductor pattern (30) for signal or power transmission provided between the first laminate portion (11) and the second laminate portion (12); and at least one first interlayer connection conductor (41a, 41b) provided to penetrate the first main surface (10a) in the laminated direction. A thermoplastic resin layer (11a) is provided, and the surface electrodes (20a, 20b) are electrically connected to a first conductor pattern (30); in the first conductor pattern (30), one surface on the side of the surface electrodes (20a, 20b) is connected to a first interlayer connection conductor (41a, 41b) in the stacking direction, and the other surface on the side opposite to the surface electrodes (20a, 20b) is not connected to the interlayer connection conductor; the first interlayer connection conductor (41a, 41b) includes a resin and at least one metal element; at a measurement temperature above the minimum melting point of the metal elements included in the first interlayer connection conductor (41a, 41b) and below the melting points of the first thermoplastic resin layer (11a) and the second thermoplastic resin layer (12a), the storage modulus of the first thermoplastic resin layer (11a) is lower than the storage modulus of the second thermoplastic resin layer (12a).

Description

Technical Field

[0001] The present invention relates to a laminated substrate. Background Art

[0002] As a laminated substrate for various electronic devices, for example, Patent Document 1 discloses a composite transmission line, which comprises a plurality of signal transmission lines and a power transmission line formed on a laminated insulator having a plurality of laminated insulator layers, wherein the plurality of signal transmission lines include at least a first signal transmission line and a second signal transmission line, the first signal transmission line including a first signal conductor pattern, the second signal transmission line including a second signal conductor pattern, the power transmission line comprising a power transmission conductor pattern formed along the plurality of layers of the laminated insulator, and an interlayer connection conductor for interlayer connection of these power transmission conductor patterns, the first signal conductor pattern, the second signal conductor pattern, and the power transmission conductor pattern being formed in parallel on different layers of the laminated insulator, the first signal conductor pattern and the second signal conductor pattern being arranged with a first ground conductor interposed therebetween in the stacking direction of the insulator layers, and the power transmission line being arranged on the side of the first signal conductor pattern.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6048633 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the composite transmission line described in Patent Document 1, the signal conductor pattern, power transmission conductor pattern, and ground conductor are each connected to an interlayer connection conductor. However, depending on the conditions used to form such a composite transmission line, particularly the conditions used to stack multiple insulating layers containing various conductors, the connectivity between the signal conductor pattern, power transmission conductor pattern, and ground conductor and the interlayer connection conductor may be reduced. This reduction in connectivity with the interlayer connection conductor has a greater impact on high-frequency characteristics and other characteristics of the signal conductor pattern or power transmission conductor pattern than on the ground conductor.

[0008] The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a multilayer substrate having excellent connectivity between a conductor pattern for signal or power transmission and an interlayer connection conductor.

[0009] Means used to solve problems

[0010] The laminate substrate of the present invention is characterized in that the laminate substrate comprises: a resin laminate having a laminate structure including a first laminate portion and a second laminate portion in a laminate direction, the first laminate portion including at least one first thermoplastic resin layer, the second laminate portion being adjacent to the first laminate portion and including at least one second thermoplastic resin layer, and the resin laminate having a first principal surface on the first laminate portion side and a second principal surface on the second laminate portion side that are opposed to each other in the laminate direction; a surface electrode provided on the first principal surface of the resin laminate; a first conductor pattern for signal or power transmission provided between the first laminate portion and the second laminate portion; and at least one first interlayer connecting conductor provided In order to penetrate the first thermoplastic resin layer in the stacking direction and electrically connect the surface electrode to the first conductor pattern, in the first conductor pattern, one surface on the surface electrode side in the stacking direction is connected to the first interlayer connecting conductor, and the other surface on the side opposite to the surface electrode is not connected to the interlayer connecting conductor, the first interlayer connecting conductor includes a resin and at least one metal element, and at a measurement temperature that is above the minimum melting point of the melting points of the metal elements contained in the first interlayer connecting conductor and below the melting points of the first thermoplastic resin layer and the second thermoplastic resin layer, the storage modulus of the first thermoplastic resin layer is lower than the storage modulus of the second thermoplastic resin layer.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to provide a multilayer substrate having excellent connectivity between a conductor pattern for signal or power transmission and an interlayer connection conductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is an exploded perspective schematic diagram showing the multilayer substrate according to the first embodiment of the present invention.

[0014] Figure 2 is shown with Figure 1 Schematic cross-sectional view of the portion corresponding to line segment A1-A2 in FIG.

[0015] Figure 3 is shown with Figure 1 Schematic cross-sectional view of the portion corresponding to line segment B1-B2 in FIG.

[0016] Figure 4 This is a schematic cross-sectional view showing an example of a conductor layer forming step of forming a conductor layer on one surface of a first thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0017] Figure 5This is a schematic cross-sectional view showing an example of a through-hole forming step of forming a through-hole in a first thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0018] Figure 6 This is a schematic cross-sectional view showing an example of a conductive paste filling step of filling the through-holes of the first thermoplastic resin sheet with a conductive paste in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0019] Figure 7 This is a schematic cross-sectional view showing an example of a conductor layer forming step of forming a conductor layer on the other surface of a first thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0020] Figure 8 This is a schematic cross-sectional view showing an example of a conductor layer forming step of forming a conductor layer on one surface of a second thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0021] Figure 9 This is a schematic cross-sectional view showing an example of a through-hole forming step of forming a through-hole in a second thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0022] Figure 10 This is a schematic cross-sectional view showing an example of a conductive paste filling step of filling the through-holes of the second thermoplastic resin sheet with a conductive paste in the method for manufacturing a laminated substrate according to the first embodiment of the present invention.

[0023] Figure 11 This is a schematic cross-sectional view showing an example of a lamination and thermocompression bonding process of a first thermoplastic resin sheet and a second thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0024] Figure 12 This is a schematic cross-sectional view showing an example of a lamination and thermocompression bonding process of a first thermoplastic resin sheet and a second thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0025] Figure 13 It is a schematic cross-sectional view of a multilayer substrate showing a modified example of the first embodiment of the present invention.

[0026] Figure 14 It is a schematic cross-sectional view showing a laminated substrate according to Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0027] Hereinafter, the laminated substrate of the present invention will be described. It should be noted that the present invention is not limited to the following structure, and may be appropriately changed without departing from the scope of the present invention. In addition, the structure obtained by combining multiple preferred structures described below also belongs to the present invention.

[0028] The embodiments shown below are illustrative only. Partial substitution or combination of the structures shown in different embodiments is of course possible. After Embodiment 2, the description of matters common to Embodiment 1 is omitted, and the main focus is on the differences. In particular, the same effects produced by the same structure are not mentioned in each embodiment. In the following description, when no particular distinction is made between the various embodiments, the term "laminated substrate of the present invention" is used.

[0029] [Implementation Method 1]

[0030] Figure 1 This is an exploded perspective schematic diagram showing the multilayer substrate according to the first embodiment of the present invention. Figure 2 is shown with Figure 1 Schematic cross-sectional view of the portion corresponding to line segment A1-A2 in FIG. Figure 3 is shown with Figure 1 Schematic cross-sectional view of the portion corresponding to line segment B1-B2 in FIG.

[0031] like Figure 1 、 Figure 2 and Figure 3 As shown, the laminated substrate 1 includes a resin laminate 10 , surface electrodes 20 a , 20 b , a first conductor pattern 30 for signal or power transmission, a first interlayer connecting conductor 41 a , and a first interlayer connecting conductor 41 b .

[0032] The resin laminate 10 has a Figure 1 、 Figure 2 and Figure 3 The stacked structure includes a first stacked portion 11 and a second stacked portion 12 adjacent to the first stacked portion 11 in the up-down direction (in the vertical direction).

[0033] The first laminate portion 11 includes a first thermoplastic resin layer 11 a .

[0034] The second laminate portion 12 includes a second thermoplastic resin layer 12 a .

[0035] Examples of the thermoplastic resin constituting the first thermoplastic resin layer 11 a and the second thermoplastic resin layer 12 a include liquid crystal polymer (LCP), fluororesin, thermoplastic polyimide resin, polyetheretherketone resin (PEEK), and polyphenylene sulfide resin (PPS).

[0036] The thermoplastic resins constituting the first thermoplastic resin layer 11 a and the second thermoplastic resin layer 12 a may be the same as or different from each other.

[0037] The first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a may each contain a liquid crystal polymer as a main component. Liquid crystal polymers have lower water absorption than other thermoplastic resins. Therefore, in the laminated substrate 1, when the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a each contain a liquid crystal polymer as a main component, changes in electrical properties due to water intrusion are less likely to occur.

[0038] When the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a each include a liquid crystal polymer as a main component, the molecular weight of the liquid crystal polymer constituting the first thermoplastic resin layer 11a and the molecular weight of the liquid crystal polymer constituting the second thermoplastic resin layer 12a are preferably different from each other. By varying the molecular weight of the liquid crystal polymer in the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a, as described below, the storage modulus of the first thermoplastic resin layer 11a can be lower than the storage modulus of the second thermoplastic resin layer 12a.

[0039] In the laminated substrate of the present invention, the first laminated portion includes at least one first thermoplastic resin layer. That is, the first laminated portion is composed only of the first thermoplastic resin layer and includes at least one first thermoplastic resin layer.

[0040] In the laminated substrate of the present invention, the second laminated portion includes at least one second thermoplastic resin layer. That is, the second laminated portion is composed only of the second thermoplastic resin layer and includes at least one second thermoplastic resin layer.

[0041] In the laminate substrate of the present invention, the first thermoplastic resin layer constituting the first laminate portion and the second thermoplastic resin layer constituting the second laminate portion may be composed of the same thermoplastic resin. For example, the first thermoplastic resin layer and the second thermoplastic resin layer may each contain a liquid crystal polymer as a main component. In this case, the molecular weight of the liquid crystal polymer constituting the first thermoplastic resin layer and the molecular weight of the liquid crystal polymer constituting the second thermoplastic resin layer are preferably different.

[0042] The resin laminate 10 has a first principal surface 10a on the first laminated portion 11 side and a second principal surface 10b on the second laminated portion 12 side, which are opposed in the lamination direction. More specifically, the first principal surface 10a of the resin laminate 10 corresponds to the surface of the first thermoplastic resin layer 11a opposite to the second thermoplastic resin layer 12a. Furthermore, the second principal surface 10b of the resin laminate 10 corresponds to the surface of the second thermoplastic resin layer 12a opposite to the first thermoplastic resin layer 11a.

[0043] The surface electrode 20 a is provided on the first main surface 10 a of the resin laminate 10 .

[0044] The surface electrode 20 b is provided on the first main surface 10 a of the resin laminate 10 at a position separated from the surface electrode 20 a .

[0045] Examples of the constituent material of the surface electrodes 20 a and 20 b include copper, silver, aluminum, stainless steel, nickel, gold, and alloys containing at least one of these metals.

[0046] It is preferable that each of the surface electrode 20a and the surface electrode 20b is made of copper.

[0047] It is preferable that each of the surface electrode 20a and the surface electrode 20b is made of a conductor foil, and among the conductor foils, it is particularly preferable that they are made of copper foil.

[0048] The constituent materials of the surface electrode 20 a and the surface electrode 20 b are preferably the same, but may be different from each other.

[0049] The first conductor pattern 30 is provided between the first laminate section 11 and the second laminate section 12. The first conductor pattern 30 is preferably provided so as to straddle the boundary between the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a. As a result, the interface between the first conductor pattern 30 and the first thermoplastic resin layer 11a and the interface between the first conductor pattern 30 and the second thermoplastic resin layer 12a are offset from the interface between the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a in the lamination direction. This suppresses delamination at the interface between the first conductor pattern 30 and the first thermoplastic resin layer 11a and the interface between the first conductor pattern 30 and the second thermoplastic resin layer 12a.

[0050] The boundary between the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a can be determined by infrared spectroscopy. Figure 2 and Figure 3 The determination can be made by observing the cross section along the stacking direction shown or by observing the position of the end portion of each interlayer connection conductor.

[0051] In the first conductor pattern 30, one surface on the side of the surface electrodes 20a and 20b in the stacking direction is connected to the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b. In contrast, in the first conductor pattern 30, the other surface on the side opposite to the surface electrodes 20a and 20b in the stacking direction is not connected to the interlayer connecting conductor.

[0052] Examples of the constituent material of the first conductive pattern 30 include copper, silver, aluminum, stainless steel, nickel, gold, and alloys containing at least one of these metals.

[0053] The first conductor pattern 30 preferably includes copper.

[0054] The first conductor pattern 30 preferably includes a conductor foil, and particularly preferably includes a copper foil among the conductor foils.

[0055] The first interlayer connection conductor 41 a is provided so as to penetrate the first thermoplastic resin layer 11 a in the stacking direction. Thus, the first interlayer connection conductor 41 a electrically connects the surface electrode 20 a and the first conductor pattern 30 .

[0056] The first interlayer connecting conductor 41b is provided at a position separated from the first interlayer connecting conductor 41a so as to penetrate the first thermoplastic resin layer 11a in the stacking direction.

[0057] In the transmission direction orthogonal to the stacking direction, more specifically, in the direction in which the first interlayer connecting conductor 41 a and the first interlayer connecting conductor 41 b face each other, the lengths of the first interlayer connecting conductor 41 a and the first interlayer connecting conductor 41 b are each shorter than the length of the first conductor pattern 30 .

[0058] The first interlayer connecting conductors 41a and 41b each include a resin and at least one metal element. Each of the first interlayer connecting conductors 41a and 41b is formed into a sintered body of the conductive paste by, for example, filling a through-hole formed through the first thermoplastic resin layer 11a with a conductive paste and then performing a heat treatment.

[0059] The resin contained in the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b preferably includes at least one thermosetting resin selected from the group consisting of epoxy resin, phenolic resin, polyimide resin, silicone resin or its modified resin, 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 resin.

[0060] Examples of the metal element contained in the first interlayer connection conductor 41 a and the first interlayer connection conductor 41 b include copper, tin, and silver.

[0061] Each of the first interlayer connecting conductor 41 a and the first interlayer connecting conductor 41 b preferably includes copper as a metal element, and more preferably includes copper and tin as metal elements.

[0062] The first interlayer connection conductor 41 a preferably includes tin as a metal element having the smallest melting point among the metal elements included in the first interlayer connection conductor 41 a .

[0063] The first interlayer connection conductor 41 b preferably includes tin as a metal element having the smallest melting point among the metal elements included in the first interlayer connection conductor 41 b .

[0064] The first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b preferably contain the same resin, but they may be different. Furthermore, the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b preferably contain the same metal element, but they may be different. That is, the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b preferably contain the same resin and the same metal element.

[0065] like Figure 1 、 Figure 2 and Figure 3 As shown, the multilayer substrate 1 may further include a second conductor pattern 50 for grounding.

[0066] The second conductor pattern 50 is provided on the second principal surface 10b side of the resin laminate 10 relative to the first conductor pattern 30. More specifically, the second conductor pattern 50 is provided on the second principal surface 10b of the resin laminate 10. The second conductor pattern 50 may be provided inside the resin laminate 10 instead of on the second principal surface 10b of the resin laminate 10.

[0067] The second conductor pattern 50 overlaps with the first conductor pattern 30 when viewed in the stacking direction.

[0068] Examples of the constituent material of the second conductive pattern 50 include copper, silver, aluminum, stainless steel, nickel, gold, and alloys containing at least one of these metals.

[0069] The second conductor pattern 50 preferably includes copper.

[0070] The second conductor pattern 50 preferably includes a conductor foil, and among the conductor foils, it is particularly preferred that the second conductor pattern 50 includes a copper foil.

[0071] like Figure 1 and Figure 2 As shown, the multilayer substrate 1 may further include a second interlayer connecting conductor 42a, a second interlayer connecting conductor 42b, a second interlayer connecting conductor 42c, and a second interlayer connecting conductor 42d.

[0072] The second interlayer connecting conductors 42a and 42b are provided across the first interlayer connecting conductor 41a when viewed in the stacking direction, penetrating the second thermoplastic resin layer 12a in the stacking direction.

[0073] The second interlayer connecting conductors 42c and 42d are provided across the first interlayer connecting conductor 41b when viewed in the stacking direction, penetrating the second thermoplastic resin layer 12a in the stacking direction.

[0074] The second interlayer connecting conductors 42a, 42b, 42c, and 42d each preferably include a resin and at least one metal element. In this case, the second interlayer connecting conductors 42a, 42b, 42c, and 42d are each formed into a sintered body of the conductive paste by, for example, filling a through-hole formed through the second thermoplastic resin layer 12a with a conductive paste and then performing a heat treatment.

[0075] The resin contained in the second interlayer connecting conductor 42a, the second interlayer connecting conductor 42b, the second interlayer connecting conductor 42c and the second interlayer connecting conductor 42d preferably includes at least one thermosetting resin selected from the group consisting of epoxy resin, phenolic resin, polyimide resin, silicone resin or its modified resin, 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 resin.

[0076] Examples of the metal element contained in the second interlayer connecting conductor 42 a , the second interlayer connecting conductor 42 b , the second interlayer connecting conductor 42 c , and the second interlayer connecting conductor 42 d include copper, tin, and silver.

[0077] Each of the second interlayer connecting conductor 42 a , the second interlayer connecting conductor 42 b , the second interlayer connecting conductor 42 c , and the second interlayer connecting conductor 42 d preferably includes copper as a metal element, and more preferably includes copper and tin as metal elements.

[0078] The resin contained in the second interlayer connecting conductors 42a, 42b, 42c, and 42d is preferably the same, but may be different. Furthermore, the metal element contained in the second interlayer connecting conductors 42a, 42b, 42c, and 42d is preferably the same, but may be different. That is, the second interlayer connecting conductors 42a, 42b, 42c, and 42d preferably contain the same resin and the same metal element.

[0079] like Figure 1 、 Figure 2 and Figure 3 As shown, the multilayer substrate 1 may further include a ground electrode 60 .

[0080] The ground electrode 60 is provided on the first principal surface 10 a of the resin laminate 10 at a position separated from the surface electrode 20 a and the surface electrode 20 b .

[0081] Examples of the constituent material of the ground electrode 60 include copper, silver, aluminum, stainless steel, nickel, gold, and alloys containing at least one of these metals.

[0082] The ground electrode 60 preferably comprises copper.

[0083] The ground electrode 60 preferably includes a conductor foil, and particularly preferably includes a copper foil among the conductor foils.

[0084] like Figure 1 and Figure 2 As shown, the multilayer substrate 1 may further include a third interlayer connecting conductor 43 a , a third interlayer connecting conductor 43 b , a third interlayer connecting conductor 43 c , and a third interlayer connecting conductor 43 d .

[0085] The third interlayer connecting conductors 43a and 43b are provided across the first interlayer connecting conductor 41a when viewed in the stacking direction, penetrating the first thermoplastic resin layer 11a in the stacking direction.

[0086] The third interlayer connecting conductors 43c and 43d are provided across the first interlayer connecting conductor 41b when viewed in the stacking direction, penetrating the first thermoplastic resin layer 11a in the stacking direction.

[0087] The third interlayer connecting conductors 43a, 43b, 43c, and 43d each preferably include a resin and at least one metal element. In this case, the third interlayer connecting conductors 43a, 43b, 43c, and 43d are each formed into a sintered body of the conductive paste by, for example, filling a through-hole formed through the first thermoplastic resin layer 11a with a conductive paste and then performing a heat treatment.

[0088] The resin contained in the third interlayer connecting conductor 43a, the third interlayer connecting conductor 43b, the third interlayer connecting conductor 43c and the third interlayer connecting conductor 43d preferably includes at least one thermosetting resin selected from the group consisting of epoxy resin, phenolic resin, polyimide resin, silicone resin or its modified resin, 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 resin.

[0089] Examples of the metal element contained in the third interlayer connecting conductor 43 a , the third interlayer connecting conductor 43 b , the third interlayer connecting conductor 43 c , and the third interlayer connecting conductor 43 d include copper, tin, and silver.

[0090] Each of the third interlayer connecting conductor 43 a , the third interlayer connecting conductor 43 b , the third interlayer connecting conductor 43 c and the third interlayer connecting conductor 43 d preferably includes copper as a metal element, and more preferably includes copper and tin as metal elements.

[0091] The resin contained in the third interlayer connecting conductor 43a, the third interlayer connecting conductor 43b, the third interlayer connecting conductor 43c, and the third interlayer connecting conductor 43d is preferably the same, but may be different. Furthermore, the metal element contained in the third interlayer connecting conductor 43a, the third interlayer connecting conductor 43b, the third interlayer connecting conductor 43c, and the third interlayer connecting conductor 43d is preferably the same, but may be different. That is, the third interlayer connecting conductor 43a, the third interlayer connecting conductor 43b, the third interlayer connecting conductor 43c, and the third interlayer connecting conductor 43d preferably contain the same resin and the same metal element.

[0092] like Figure 1 and Figure 2 As shown, the multilayer substrate 1 may further include a connection conductor layer 70 a , a connection conductor layer 70 b , a connection conductor layer 70 c , and a connection conductor layer 70 d .

[0093] The connecting conductor layers 70a, 70b, 70c, and 70d are each provided at mutually separated positions between the first laminate portion 11 and the second laminate portion 12. The connecting conductor layers 70a, 70b, 70c, and 70d are preferably provided at mutually separated positions, straddling the boundary between the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a. As a result, the interface between each connecting conductor layer and the first thermoplastic resin layer 11a and the interface between each connecting conductor layer and the second thermoplastic resin layer 12a are offset from the interface between the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a in the stacking direction, thereby suppressing delamination at the interface between each connecting conductor layer and the first thermoplastic resin layer 11a and at the interface between each connecting conductor layer and the second thermoplastic resin layer 12a.

[0094] The connecting conductor layer 70 a electrically connects the second interlayer connecting conductor 42 a and the third interlayer connecting conductor 43 a .

[0095] The connecting conductor layer 70 b electrically connects the second interlayer connecting conductor 42 b and the third interlayer connecting conductor 43 b .

[0096] The connecting conductor layer 70c electrically connects the second interlayer connecting conductor 42c and the third interlayer connecting conductor 43c.

[0097] The connecting conductor layer 70d electrically connects the second interlayer connecting conductor 42d and the third interlayer connecting conductor 43d.

[0098] In the transmission direction orthogonal to the stacking direction, the lengths of the connection conductor layer 70 a , the connection conductor layer 70 b , the connection conductor layer 70 c , and the connection conductor layer 70 d are each shorter than the length of the first conductor pattern 30 .

[0099] Examples of materials constituting the connection conductor layers 70 a , 70 b , 70 c , and 70 d include copper, silver, aluminum, stainless steel, nickel, gold, and alloys containing at least one of these metals.

[0100] Each of the connection conductor layer 70 a , the connection conductor layer 70 b , the connection conductor layer 70 c , and the connection conductor layer 70 d preferably includes copper.

[0101] Each of the connection conductor layer 70 a , the connection conductor layer 70 b , the connection conductor layer 70 c , and the connection conductor layer 70 d preferably includes a conductor foil, and among the conductor foils, it is particularly preferable to include copper foil.

[0102] The constituent materials of the connection conductor layer 70 a , the connection conductor layer 70 b , the connection conductor layer 70 c , and the connection conductor layer 70 d are preferably the same, but may be different from each other.

[0103] In the laminate substrate of the present invention, at a measurement temperature (hereinafter simply referred to as the measurement temperature) that is higher than the minimum melting point of the metal elements contained in the first interlayer connecting conductor and lower than the melting points of the first thermoplastic resin layer and the second thermoplastic resin layer, the storage modulus of the first thermoplastic resin layer is lower than the storage modulus of the second thermoplastic resin layer.

[0104] Regarding the measurement temperature, the temperature below the melting point of the first thermoplastic resin layer and the second thermoplastic resin layer refers to a temperature below the lower melting point of the first thermoplastic resin layer and the second thermoplastic resin layer. The melting point of the first thermoplastic resin layer and the melting point of the second thermoplastic resin layer may be the same or different.

[0105] The temperature dependence of the storage modulus of the thermoplastic resin layer was measured by dynamic viscoelasticity measurement (DMA).

[0106] In the multilayer substrate 1, at a measurement temperature that is at least the minimum melting point of the metal elements contained in the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b and not more than the melting points of the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a, the storage modulus of the first thermoplastic resin layer 11a is lower than the storage modulus of the second thermoplastic resin layer 12a.

[0107] In the laminated substrate 1, the effect of the storage modulus of the first thermoplastic resin layer 11a being lower than the storage modulus of the second thermoplastic resin layer 12a at the above-mentioned measurement temperature will be described below by showing an example of a method for manufacturing the laminated substrate 1. Figure 1 The manufacturing method of the laminated substrate 1 shown in FIG. Figure 2 The process of forming the cross section shown is described, but other cross sections such as Figure 3 The process is the same for the cross section shown.

[0108] <Conductor Layer Forming Step of Forming a Conductor Layer on One Surface of the First Thermoplastic Resin Sheet>

[0109] Figure 4 This is a schematic cross-sectional view showing an example of a conductor layer forming step of forming a conductor layer on one surface of a first thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0110] like Figure 4 As shown, a conductor layer 130, a conductor layer 170a, and a conductor layer 170b are formed on one surface of a first thermoplastic resin sheet 111a. The first thermoplastic resin sheet 111a becomes the first thermoplastic resin layer 11a. The conductor layers 130, 170a, and 170b become the first conductor pattern 30, and the connecting conductor layer 70a and 70b, respectively.

[0111] In this step, a conductor layer to be the connection conductor layer 70c and a conductor layer to be the connection conductor layer 70d are formed on one surface of the first thermoplastic resin sheet 111a. Figure 4 Not shown.

[0112] Examples of methods for forming each conductor layer on one surface of the first thermoplastic resin sheet 111a include a method of etching a conductor foil attached to one surface of the first thermoplastic resin sheet 111a and a method of transferring a conductor foil having a pattern of each conductor layer formed therein to one surface of the first thermoplastic resin sheet 111a.

[0113] As the first thermoplastic resin sheet 111a, a thermoplastic resin sheet having a storage modulus lower than that of the second thermoplastic resin sheet 112a is used at a temperature that is at least the minimum melting point of the metal elements contained in the conductive paste 190 (described later) and not more than the melting points of the first thermoplastic resin sheet 111a and the second thermoplastic resin sheet 112a (described later). As a result, in the laminated substrate 1 obtained later, the storage modulus of the first thermoplastic resin layer 11a is lower than that of the second thermoplastic resin layer 12a at the measurement temperature.

[0114] Examples of the thermoplastic resin constituting the first thermoplastic resin sheet 111 a include liquid crystal polymers, fluororesins, thermoplastic polyimide resins, polyetheretherketone resins, and polyphenylene sulfide resins.

[0115] The first thermoplastic resin sheet 111a may also include a liquid crystal polymer as a main component. In this case, the storage modulus of the first thermoplastic resin sheet 111a can be adjusted by varying the molecular weight of the liquid crystal polymer. As described later, the storage modulus of the first thermoplastic resin sheet 111a can be made lower than the storage modulus of the second thermoplastic resin sheet 112a.

[0116] The thickness of the first thermoplastic resin sheet 111 a is, for example, not less than 10 μm and not more than 2000 μm.

[0117] Examples of the constituent material of the conductor foil include copper, silver, aluminum, stainless steel, nickel, gold, and alloys containing at least one of these metals.

[0118] The conductor foil preferably includes copper. That is, each conductor layer is preferably formed using copper foil.

[0119] The thickness of the conductor foil is, for example, 3 μm or more and 40 μm or less. The thicknesses of the conductor foils used to form the conductor layers are preferably the same, but may be different from each other.

[0120] <Through-Hole Forming Step of Forming Through-Hole in First Thermoplastic Resin Sheet>

[0121] Figure 5 This is a schematic cross-sectional view showing an example of a through-hole forming step of forming a through-hole in a first thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0122] like Figure 5 As shown in FIG. 1 , through-holes 181a, 183a, and 183b are formed penetrating through first thermoplastic resin sheet 111a, thereby partially exposing conductive layer 130, conductive layer 170a, and conductive layer 170b.

[0123] In this step, through holes are formed penetrating the first thermoplastic resin sheet 111a to expose another portion of the conductor layer 130, a through hole to expose a portion of the conductor layer to become the connection conductor layer 70c, and a through hole to expose a portion of the conductor layer to become the connection conductor layer 70d. Figure 5 Not shown.

[0124] Examples of methods for forming the through-holes in the first thermoplastic resin sheet 111a include laser irradiation from the opposite surface of the first thermoplastic resin sheet 111a. Such laser irradiation can be performed, for example, using a pulsed carbon dioxide gas laser irradiation device. After laser irradiation, a debonding treatment using, for example, oxygen plasma discharge treatment or corona discharge treatment is preferably performed to remove resin residue. Resin residue can also be removed by, for example, potassium permanganate treatment.

[0125] like Figure 5 As shown, each through hole preferably has a tapered shape in which the diameter becomes smaller toward each conductor layer formed on one surface of the first thermoplastic resin sheet 111 a .

[0126] <Conductive Paste Filling Step of Filling Through-Hole of First Thermoplastic Resin Sheet with Conductive Paste>

[0127] Figure 6 This is a schematic cross-sectional view showing an example of a conductive paste filling step of filling the through-holes of the first thermoplastic resin sheet with a conductive paste in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0128] like Figure 6 As shown, conductive paste 190 is filled in each of through-hole 181 a , through-hole 183 a , and through-hole 183 b .

[0129] In this step, the conductive paste 190 is also filled into the through hole that exposes another portion of the conductive layer 130, the through hole that exposes a portion of the conductive layer that will become the connecting conductive layer 70c, and the through hole that exposes a portion of the conductive layer that will become the connecting conductive layer 70d. Figure 6 Not shown.

[0130] The conductive paste 190 filled in the first thermoplastic resin sheet 111 a becomes first interlayer connecting conductors such as the first interlayer connecting conductor 41 a and third interlayer connecting conductors such as the third interlayer connecting conductor 43 a .

[0131] Examples of a method for filling conductive paste 190 into each through-hole formed in first thermoplastic resin sheet 111 a include screen printing and vacuum filling.

[0132] Conductive paste 190 includes resin and at least one metal element.

[0133] The resin contained in the conductive paste 190 preferably includes at least one thermosetting resin selected from the group consisting of epoxy resin, phenolic resin, polyimide resin, silicone 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 resin.

[0134] Examples of the metal element contained in conductive paste 190 include copper, tin, and silver.

[0135] Conductive paste 190 preferably contains copper as the metal element, and more preferably contains copper and tin as the metal elements.

[0136] Conductive paste 190 preferably includes tin as a metal element having the smallest melting point among the metal elements included in conductive paste 190 .

[0137] Conductive paste 190 may further include an excipient, a solvent, a thixotropic agent, an activator, and the like.

[0138] Examples of the excipient include rosin-based resins including rosin and its modified derivatives such as modified rosin, synthetic resins including rosin and its modified derivatives such as modified rosin, and mixtures of these resins.

[0139] Examples of rosin-based resins including rosin and its modified derivatives such as modified rosin include gum rosin, tall rosin, wood rosin, polymerized rosin, hydrogenated rosin, formylated rosin, rosin esters, rosin-modified maleic acid resins, rosin-modified phenolic resins, rosin-modified alkyd resins, and various other rosin derivatives.

[0140] Examples of the synthetic resin including rosin and its modified derivatives such as modified rosin include polyester resins, polyamide resins, phenoxy resins, and terpene resins.

[0141] Examples of the solvent include alcohols, ketones, esters, ethers, aromatic hydrocarbons, and hydrocarbons. Specific examples thereof include benzyl alcohol, ethanol, isopropyl alcohol, butanol, diethylene glycol, ethylene glycol, glycerol, ethyl cellosolve, butyl cellosolve, ethyl acetate, butyl acetate, butyl benzoate, diethyl adipate, dodecane, tetradecene, α-terpineol, terpineol, 2-methyl-2,4-pentanediol, 2-ethylhexanediol, toluene, xylene, propylene glycol monophenyl ether, diethylene glycol monohexyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diisobutyl adipate, hexylene glycol, cyclohexanedimethanol, 2-terpineoxyethanol, 2-dihydroterpineoxyethanol, and mixtures thereof. Among these, terpineol, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, or diethylene glycol monoethyl ether is preferred.

[0142] Examples of thixotropic agents include hydrogenated castor oil, carnauba wax, amides, hydroxy fatty acids, dibenzylidene sorbitol, bis(p-methylbenzylidene)sorbitol, beeswax, stearic acid amide, hydroxystearic acid ethylenebisamide, etc. Furthermore, as needed, fatty acids such as caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid, hydroxy fatty acids such as 1,2-hydroxystearic acid, antioxidants, surfactants, amines, etc. may be added to these thixotropic agents.

[0143] Examples of the activator include amine hydrohalides, organic halogen compounds, organic acids, organic amines, and polyols.

[0144] Examples of the amine hydrohalide salt include diphenylguanidine hydrobromide, diphenylguanidine hydrochloride, cyclohexylamine hydrobromide, ethylamine hydrochloride, ethylamine hydrobromide, diethylaniline hydrobromide, diethylaniline hydrochloride, triethanolamine hydrobromide, and monoethanolamine hydrobromide.

[0145] Examples of the organic halogen compound include chlorinated paraffin, tetrabromoethane, dibromopropanol, 2,3-dibromo-1,4-butanediol, 2,3-dibromo-2-butene-1,4-diol, and tris(2,3-dibromopropyl)isocyanurate.

[0146] Examples of the organic acid include malonic acid, fumaric acid, glycolic acid, citric acid, malic acid, succinic acid, phenylsuccinic acid, maleic acid, salicylic acid, anthranilic acid, glutaric acid, suberic acid, adipic acid, sebacic acid, stearic acid, abietic acid, benzoic acid, trimellitic acid, pyromellitic acid, and dodecanoic acid.

[0147] Examples of the organic amine include monoethanolamine, diethanolamine, triethanolamine, tributylamine, aniline, and diethylaniline.

[0148] Examples of the polyol include erythritol, pyrogallol, and ribitol.

[0149] <Conductor Layer Forming Step of Forming a Conductor Layer on the Other Surface of the First Thermoplastic Resin Sheet>

[0150] Figure 7 This is a schematic cross-sectional view showing an example of a conductor layer forming step of forming a conductor layer on the other surface of a first thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0151] like Figure 7 As shown, a conductor layer 120a and a conductor layer 160 are formed on the other surface of the first thermoplastic resin sheet 111a. The conductor layer 120a and the conductor layer 160 serve as the surface electrode 20a and the ground electrode 60, respectively.

[0152] In this step, a conductor layer serving as the surface electrode 20b is formed on the other side of the first thermoplastic resin sheet 111a. Figure 7 Not shown.

[0153] Examples of methods for forming each conductor layer on the other side of the first thermoplastic resin sheet 111a include etching a conductor foil attached to the other side of the first thermoplastic resin sheet 111a, and transferring a conductor foil having a pattern of each conductor layer formed thereon to the other side of the first thermoplastic resin sheet 111a. It is preferable to use the same conductor foil as that described in the conductor layer forming step for forming a conductor layer on one side of the first thermoplastic resin sheet.

[0154] Through the above, first thermoplastic resin sheet 111 a is prepared, which is filled with conductive paste 190 and has respective conductor layers formed on one surface and the other surface.

[0155] <Conductor Layer Forming Step of Forming a Conductor Layer on One Surface of the Second Thermoplastic Resin Sheet>

[0156] Figure 8 This is a schematic cross-sectional view showing an example of a conductor layer forming step of forming a conductor layer on one surface of a second thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0157] like Figure 8 As shown, a conductor layer 150 is formed on one surface of the second thermoplastic resin sheet 112a. The second thermoplastic resin sheet 112a becomes the second thermoplastic resin layer 12a. The conductor layer 150 becomes the second conductor pattern 50.

[0158] Examples of methods for forming the conductive layer 150 on one surface of the second thermoplastic resin sheet 112a include etching a conductive foil attached to one surface of the second thermoplastic resin sheet 112a and transferring a conductive foil having a pattern of the conductive layer 150 formed thereon to one surface of the second thermoplastic resin sheet 112a. It is preferable to use the same conductive foil as that described in the conductive layer forming step of forming the conductive layer on one surface of the first thermoplastic resin sheet.

[0159] As the second thermoplastic resin sheet 112a, a thermoplastic resin sheet having a storage modulus higher than that of the first thermoplastic resin sheet 111a at a temperature not lower than the minimum melting point of the metal elements contained in the conductive paste 190 and not higher than the melting points of the first thermoplastic resin sheet 111a and the second thermoplastic resin sheet 112a is used. As a result, in the laminated substrate 1 obtained later, the storage modulus of the first thermoplastic resin layer 11a is lower than the storage modulus of the second thermoplastic resin layer 12a at the aforementioned measurement temperature.

[0160] Examples of the thermoplastic resin constituting the second thermoplastic resin sheet 112 a include liquid crystal polymers, fluororesins, thermoplastic polyimide resins, polyetheretherketone resins, and polyphenylene sulfide resins.

[0161] The second thermoplastic resin sheet 112a may also include a liquid crystal polymer as a main component. In this case, the storage modulus of the second thermoplastic resin sheet 112a can be adjusted by changing the molecular weight of the liquid crystal polymer. As described above, the storage modulus of the second thermoplastic resin sheet 112a can be made higher than the storage modulus of the first thermoplastic resin sheet 111a.

[0162] The thickness of the second thermoplastic resin sheet 112 a is, for example, not less than 10 μm and not more than 2000 μm.

[0163] <Through-Hole Forming Step of Forming Through-Hole in Second Thermoplastic Resin Sheet>

[0164] Figure 9 This is a schematic cross-sectional view showing an example of a through-hole forming step of forming a through-hole in a second thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0165] like Figure 9 As shown in FIG. 1 , through-holes 182a and 182b are formed respectively penetrating the second thermoplastic resin sheet 112a, thereby exposing a portion and another portion of the conductive layer 150.

[0166] In this step, through holes are formed through the second thermoplastic resin sheet 112a to expose another portion of the conductor layer 150, and through holes are formed to expose another portion of the conductor layer 150. Figure 9 Not shown.

[0167] Examples of methods for forming the through-holes in the second thermoplastic resin sheet 112a include laser irradiation from the opposite side of one surface of the second thermoplastic resin sheet 112a. Such laser irradiation can be performed, for example, using a pulsed carbon dioxide gas laser irradiation device. After laser irradiation, a debonding treatment using, for example, oxygen plasma discharge treatment or corona discharge treatment is preferably performed to remove resin residue. Resin residue can also be removed by, for example, potassium permanganate treatment.

[0168] like Figure 9 As shown, each through hole preferably has a tapered shape in which the diameter becomes smaller toward the conductive layer 150 formed on one surface of the second thermoplastic resin sheet 112a.

[0169] <Conductive Paste Filling Step of Filling Through-Hole of Second Thermoplastic Resin Sheet with Conductive Paste>

[0170] Figure 10 This is a schematic cross-sectional view showing an example of a conductive paste filling step of filling the through-holes of the second thermoplastic resin sheet with a conductive paste in the method for manufacturing a laminated substrate according to the first embodiment of the present invention.

[0171] like Figure 10 As shown, conductive paste 190 is filled into each of through-hole 182 a and through-hole 182 b .

[0172] In this step, the conductive paste 190 is filled into the through hole for exposing another part of the conductive layer 150 and the through hole for exposing another part of the conductive layer 150. Figure 10 Not shown.

[0173] The conductive paste 190 filled in the second thermoplastic resin sheet 112 a becomes a second interlayer connecting conductor such as the second interlayer connecting conductor 42 a .

[0174] Examples of a method for filling conductive paste 190 into each through-hole formed in second thermoplastic resin sheet 112 a include screen printing and vacuum filling.

[0175] Through the above, the second thermoplastic resin sheet 112 a filled with the conductive paste 190 and having the conductor layer 150 formed on one surface is produced.

[0176] The production of the first thermoplastic resin sheet 111a filled with conductive paste 190 and having conductor layers formed on one surface and the other surface and the production of the second thermoplastic resin sheet 112a filled with conductive paste 190 and having conductor layer 150 formed on one surface may be performed at the same time or at different times.

[0177] <Lamination and Thermocompression Bonding of First and Second Thermoplastic Resin Sheets>

[0178] Figure 11 and Figure 12 This is a schematic cross-sectional view showing an example of a lamination and thermocompression bonding process of a first thermoplastic resin sheet and a second thermoplastic resin sheet in the method for producing a laminated substrate according to the first embodiment of the present invention.

[0179] First, if Figure 11 As shown, a first thermoplastic resin sheet 111a filled with conductive paste 190 and having conductor layers formed on one surface and the other surface and a second thermoplastic resin sheet 112a filled with conductive paste 190 and having conductor layer 150 formed on one surface are stacked in a stacking direction so that one surface of the first thermoplastic resin sheet 111a contacts the other surface of the second thermoplastic resin sheet 112a.

[0180] In the laminate of the first thermoplastic resin sheet 111a and the second thermoplastic resin sheet 112a, the conductor layer 130 is in contact with both the first thermoplastic resin sheet 111a and the second thermoplastic resin sheet 112a. However, the contact area between the conductor layer 130 and the second thermoplastic resin sheet 112a is larger than the contact area between the conductor layer 130 and the first thermoplastic resin sheet 111a by the amount by which one surface of the conductor layer 130 is exposed from the through-hole formed in the first thermoplastic resin sheet 111a.

[0181] Next, the laminate of first thermoplastic resin sheet 111a and second thermoplastic resin sheet 112a is brought to a temperature equal to or higher than the minimum melting point of the metal elements contained in conductive paste 190 and equal to or lower than the melting points of first thermoplastic resin sheet 111a and second thermoplastic resin sheet 112a.

[0182] Next, in this state, pressure is applied to the stack of the first thermoplastic resin sheet 111a and the second thermoplastic resin sheet 112a in the stacking direction, thereby thermocompression bonding the first thermoplastic resin sheet 111a and the second thermoplastic resin sheet 112a. This results in the first thermoplastic resin sheet 111a and the second thermoplastic resin sheet 112a forming the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a, respectively. Since the first thermoplastic resin sheet 111a and the second thermoplastic resin sheet 112a are made of thermoplastic resin, thermocompression bonding bonds the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a to each other.

[0183] In the first thermoplastic resin sheet 111a, the storage modulus at the above temperature is lower than that of the second thermoplastic resin sheet 112a. Therefore, the pressure applied in the lamination direction during thermocompression bonding is easily converted into Figure 12As shown by the arrow, the pressure in the direction perpendicular to the stacking direction is applied. Figure 12 As shown, the conductive paste 190 filled in the first thermoplastic resin sheet 111a is deformed and densified by pressure in a direction perpendicular to the stacking direction. The conductive paste 190 filled in the first thermoplastic resin sheet 111a is sintered in this state to form the first interlayer connecting conductor 41a, the first interlayer connecting conductor 41b, the third interlayer connecting conductor 43a, the third interlayer connecting conductor 43b, the third interlayer connecting conductor 43c, and the third interlayer connecting conductor 43d, each having high density.

[0184] On the other hand, the second thermoplastic resin sheet 112a has a higher storage modulus at the above temperature than the first thermoplastic resin sheet 111a, and therefore, the pressure applied in the stacking direction is less likely to be converted into pressure in a direction perpendicular to the stacking direction than in the first thermoplastic resin sheet 111a. Figure 12 As shown, the conductive paste 190 filled in the second thermoplastic resin sheet 112a is less likely to deform than the conductive paste 190 filled in the first thermoplastic resin sheet 111a. The conductive paste 190 filled in the second thermoplastic resin sheet 112a is sintered in this state to form the second interlayer connecting conductors 42a, 42b, 42c, and 42d.

[0185] Through this process, the various conductive layers, including the conductive layer 130 formed on one surface of the first thermoplastic resin sheet 111a, become the first conductive pattern 30, the connecting conductive layer 70a, the connecting conductive layer 70b, the connecting conductive layer 70c, and the connecting conductive layer 70d. At this stage, the conductive layer 130 contacts the second thermoplastic resin sheet 112a, which has a higher storage elastic modulus at the aforementioned temperature than the first thermoplastic resin sheet 111a, with a large contact area. Therefore, the conductive layer 130 remains in a state where it is less likely to deform and shift position during thermocompression bonding, thus becoming the first conductive pattern 30. This suppresses deformation and positional shifts in the first conductive pattern 30, while also being connected to the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b, each having high density. Consequently, the connectivity between the first conductive pattern 30 and the first interlayer connecting conductor 41a, and between the first conductive pattern 30 and the first interlayer connecting conductor 41b, is excellent.

[0186] Each conductive layer, such as the conductive layer 120 a formed on the other surface of the first thermoplastic resin sheet 111 a , becomes the surface electrode 20 a , the surface electrode 20 b , and the ground electrode 60 through this step.

[0187] The conductive layer 150 formed on one surface of the second thermoplastic resin sheet 112 a becomes the second conductive pattern 50 through this process.

[0188] Through the above content, we can create Figure 1 、 Figure 2 and Figure 3 The laminated substrate 1 is shown.

[0189] During the manufacturing process of the laminate substrate 1, the conductive paste 190 is deformed and densified by the pressure in the direction perpendicular to the lamination direction, and is sintered to obtain the first interlayer connection conductor 41a. Figure 1 、 Figure 2 and Figure 3 The first interlayer connecting conductor 41a has a constricted shape as shown. More specifically, the first interlayer connecting conductor 41a tends to have a cross-sectional area, in a cross section perpendicular to the stacking direction, that is smaller than both the cross-sectional area of the end portion on the first conductor pattern 30 side and the cross-sectional area of the end portion on the side opposite to the first conductor pattern 30. This reduces stress applied to the first interlayer connecting conductor 41a, thereby further improving connectivity between the first conductor pattern 30 and the first interlayer connecting conductor 41a. Furthermore, the constricted shape of the first interlayer connecting conductor 41a tends to increase the cross-sectional area of the end portion on the first conductor pattern 30 side. More specifically, the contact area between the first interlayer connecting conductor 41a and the first conductor pattern 30 tends to increase, further improving connectivity between the first conductor pattern 30 and the first interlayer connecting conductor 41a.

[0190] Similarly, during the manufacturing process of the laminate substrate 1, the conductive paste 190 is deformed and densified by the pressure in the direction perpendicular to the lamination direction, and is sintered to obtain the first interlayer connection conductor 41b. Figure 1 and Figure 3 The first interlayer connecting conductor 41b has a constricted shape as shown. More specifically, the first interlayer connecting conductor 41b tends to have a cross-sectional area, in a cross section perpendicular to the stacking direction, that is smaller than both the cross-sectional area of the end portion on the first conductor pattern 30 side and the cross-sectional area of the end portion on the side opposite to the first conductor pattern 30. This reduces stress applied to the first interlayer connecting conductor 41b, thereby further improving connectivity between the first conductor pattern 30 and the first interlayer connecting conductor 41b. Furthermore, the constricted shape of the first interlayer connecting conductor 41b tends to increase the cross-sectional area of the end portion on the first conductor pattern 30 side. More specifically, the contact area between the first interlayer connecting conductor 41b and the first conductor pattern 30 tends to increase, further improving connectivity between the first conductor pattern 30 and the first interlayer connecting conductor 41b.

[0191] The third interlayer-connector conductors 43a, 43b, 43c, and 43d are also likely to have a constricted shape similarly to the first interlayer-connector conductors 41a and 41b.

[0192] The second interlayer connecting conductors 42a, 42b, 42c, and 42d are each formed by sintering the conductive paste 190 during the manufacturing process of the multilayer substrate 1, while maintaining a non-deformable state. Specifically, the second interlayer connecting conductors 42a, 42b, 42c, and 42d tend to have the same shape as the respective through-holes filled with the conductive paste 190, in this case, a tapered shape. Therefore, in a cross-section perpendicular to the stacking direction, the cross-sectional area of the ends of the second interlayer connecting conductors 42a, 42b, 42c, and 42d on the second conductor pattern 50 side tends to be smaller than the cross-sectional area of the ends of the first interlayer connecting conductors 41a and 41b on the first conductor pattern 30 side.

[0193] Furthermore, since the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b each have high density, the porosity tends to be low. More specifically, the porosity of the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b tends to be lower than the porosity of the second interlayer connecting conductor 42a, the second interlayer connecting conductor 42b, the second interlayer connecting conductor 42c, and the second interlayer connecting conductor 42d.

[0194] By using scanning electron microscopy (SEM) Figure 2 and Figure 3 The porosity of each interlayer connection conductor was compared by observing the cross section along the stacking direction shown.

[0195] The dielectric loss tangent of the second thermoplastic resin layer 12a is preferably smaller than the dielectric loss tangent of the first thermoplastic resin layer 11a. Here, the length of the first conductor pattern 30 in the transmission direction perpendicular to the stacking direction is large, and therefore easily affects power loss (for example, the generation of leakage current). In addition, because the area where the first conductor pattern 30 and the second conductor pattern 50 face each other via the second thermoplastic resin layer 12a is larger than the area where the first conductor pattern 30 and the ground electrode 60 face each other via the first thermoplastic resin layer 11a, power loss between the first conductor pattern 30 and the second conductor pattern 50 is likely to increase. In contrast, by making the dielectric loss tangent of the second thermoplastic resin layer 12a smaller than that of the first thermoplastic resin layer 11a, the aforementioned power loss can be reduced.

[0196] [Variation of Embodiment 1]

[0197] In the laminated substrate according to the first embodiment of the present invention, the first thermoplastic resin layer may include a plurality of first thermoplastic secondary resin layers. An example of such a laminated substrate according to the present invention will be described below as a laminated substrate according to a modified embodiment of the first embodiment of the present invention. The laminated substrate according to the modified embodiment of the first embodiment of the present invention is identical to the laminated substrate according to the first embodiment of the present invention, except for the structure of the first thermoplastic resin layer.

[0198] Figure 13 It is a schematic cross-sectional view of a multilayer substrate showing a modified example of the first embodiment of the present invention. Figure 13 Shown with Figure 2 Corresponding cross section.

[0199] like Figure 13 As shown, in the laminated substrate 1a, the first thermoplastic resin layer 11a includes a first thermoplastic secondary resin layer 11aa and a first thermoplastic secondary resin layer 11ab. More specifically, in the first thermoplastic resin layer 11a, the first thermoplastic secondary resin layer 11ab and the first thermoplastic secondary resin layer 11aa adjacent to the first thermoplastic secondary resin layer 11ab are provided in this order from the second laminate portion 12 side.

[0200] In the multilayer substrate 1a, at a measurement temperature that is at least the minimum melting point of the metal elements contained in the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b and not more than the melting points of the first thermoplastic resin layer 11a and the second thermoplastic resin layer 12a, the storage modulus of the first thermoplastic resin layer 11a is lower than the storage modulus of the second thermoplastic resin layer 12a.

[0201] In the laminated substrate 1a, if the storage modulus of the first thermoplastic resin layer 11a as a whole is lower than the storage modulus of the second thermoplastic resin layer 12a at the above-mentioned measurement temperature, the storage modulus of the first thermoplastic secondary resin layer 11aa and the first thermoplastic secondary resin layer 11ab may be lower than the storage modulus of the second thermoplastic resin layer 12a, or the storage modulus of one of the first thermoplastic secondary resin layer 11aa and the first thermoplastic secondary resin layer 11ab may be the same as the storage modulus of the second thermoplastic resin layer 12a.

[0202] At the above-mentioned measurement temperature, when the storage modulus of the first thermoplastic secondary resin layer 11aa and the first thermoplastic secondary resin layer 11ab is lower than the storage modulus of the second thermoplastic resin layer 12a, the storage moduli of the first thermoplastic secondary resin layer 11aa and the first thermoplastic secondary resin layer 11ab may be the same as or different from each other.

[0203] If the storage moduli of the first thermoplastic secondary resin layer 11aa and the first thermoplastic secondary resin layer 11ab at the measurement temperature differ, for example, the first thermoplastic secondary resin layer 11aa may include a liquid crystal polymer as a main component, while the first thermoplastic secondary resin layer 11ab may include a fluororesin as a main component. Alternatively, the first thermoplastic secondary resin layer 11aa may include a fluororesin as a main component, while the first thermoplastic secondary resin layer 11ab may include a liquid crystal polymer as a main component. Fluororesin, among the examples of thermoplastic resins described above, also has a relatively low storage modulus. Therefore, if the first thermoplastic secondary resin layer 11aa or the first thermoplastic secondary resin layer 11ab includes a fluororesin as a main component, the storage modulus of the entire first thermoplastic resin layer 11a at the measurement temperature is likely to be low.

[0204] As described above, the first conductor pattern 30 is long in the transmission direction perpendicular to the stacking direction, and therefore tends to affect power loss. Therefore, the dielectric loss tangent of the first thermoplastic secondary resin layer 11ab, disposed in contact with the first conductor pattern 30, is preferably lower than that of the first thermoplastic secondary resin layer 11aa. In other words, the first thermoplastic secondary resin layer with the lowest dielectric loss tangent of the two first thermoplastic secondary resin layers is preferably disposed in contact with the first conductor pattern 30. This reduces power loss in the first conductor pattern 30.

[0205] In the laminated substrate 1 a , the first thermoplastic resin layer 11 a includes two first thermoplastic secondary resin layers, but may include three or more first thermoplastic secondary resin layers.

[0206] If the first thermoplastic resin layer 11a includes three or more first thermoplastic secondary resin layers, at the aforementioned measurement temperature, if the storage modulus of the first thermoplastic resin layer 11a as a whole is lower than that of the second thermoplastic resin layer 12a, the storage modulus of these first thermoplastic secondary resin layers may be lower than that of the second thermoplastic resin layer 12a, or the storage modulus of a portion of these first thermoplastic secondary resin layers may be the same as that of the second thermoplastic resin layer 12a. If the storage modulus of these first thermoplastic secondary resin layers is lower than that of the second thermoplastic resin layer 12a at the aforementioned measurement temperature, the storage moduli of these first thermoplastic secondary resin layers may be the same as or different from each other. Furthermore, from the perspective of reducing electrical energy loss in the first conductor pattern 30, the first thermoplastic secondary resin layer with the smallest dielectric loss tangent among these first thermoplastic secondary resin layers is preferably provided in contact with the first conductor pattern 30.

[0207] In the laminated substrate 1 a , the second thermoplastic resin layer 12 a includes one layer, but may include a plurality of second thermoplastic resin layers.

[0208] When the first thermoplastic resin layer 11a includes a plurality of first thermoplastic secondary resin layers and the second thermoplastic resin layer 12a includes a plurality of second thermoplastic secondary resin layers, the maximum storage modulus of the plurality of first thermoplastic secondary resin layers at the measurement temperature may be lower than the minimum storage modulus of the plurality of second thermoplastic secondary resin layers. The storage moduli of the plurality of second thermoplastic secondary resin layers may be the same as or different from the maximum storage modulus of the plurality of first thermoplastic secondary resin layers, as long as the storage modulus of the plurality of second thermoplastic secondary resin layers is higher than the maximum storage modulus of the plurality of first thermoplastic secondary resin layers.

[0209] When the thermoplastic resin layer includes multiple layers, such as when the first thermoplastic resin layer 11a includes multiple layers of first thermoplastic secondary resin layers or when the second thermoplastic resin layer 12a includes multiple layers of second thermoplastic secondary resin layers, the temperature dependence of the storage modulus of the entire thermoplastic resin layer can be measured by dynamic viscoelasticity measurement using the multiple layers of thermoplastic resin layer as a measurement sample.

[0210] [Implementation Method 2]

[0211] In the laminated substrate of the present invention, the first laminate portion may include multiple first thermoplastic resin layers, and at least one first interlayer connecting conductor may be provided in each of the multiple first thermoplastic resin layers. An example of such a laminated substrate of the present invention will be described below as a laminated substrate according to Embodiment 2 of the present invention. The laminated substrate of Embodiment 2 of the present invention is identical to the laminated substrate of Embodiment 1 of the present invention, except for the structure of the resin laminate.

[0212] Figure 14 It is a schematic cross-sectional view showing a laminated substrate according to Embodiment 2 of the present invention. Figure 14 Shown with Figure 3 Corresponding cross section.

[0213] like Figure 14 As shown, in the laminated substrate 2, the first laminate section 11 includes a first thermoplastic resin layer 11a, a first thermoplastic resin layer 11b, and a first thermoplastic resin layer 11c. In the first laminate section 11, the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b adjacent to the first thermoplastic resin layer 11a, and the first thermoplastic resin layer 11c adjacent to the first thermoplastic resin layer 11b are arranged in this order from the second laminate section 12 side. Thus, in the first laminate section 11, the first thermoplastic resin layers 11a, 11b, and 11c, which are the same type of first thermoplastic resin layers, are stacked in the stacking direction, resulting in high adhesion between the first thermoplastic resin layers.

[0214] The first interlayer connection conductor 41 a and the first interlayer connection conductor 41 b are provided at separate positions in the first thermoplastic resin layer 11 a so as to penetrate the first thermoplastic resin layer 11 a in the stacking direction.

[0215] In the first thermoplastic resin layer 11 b , a first interlayer connecting conductor 41 c and a first interlayer connecting conductor 41 d are provided at separate positions so as to penetrate in the stacking direction.

[0216] The first interlayer connection conductor 41 e and the first interlayer connection conductor 41 f are provided at separate positions in the first thermoplastic resin layer 11 c so as to penetrate the first layer in the stacking direction.

[0217] In the transmission direction orthogonal to the stacking direction, the lengths of the first interlayer connecting conductor 41c, the first interlayer connecting conductor 41d, the first interlayer connecting conductor 41e and the first interlayer connecting conductor 41f are respectively smaller than the length of the first conductor pattern 30, similarly to the lengths of the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b.

[0218] The first interlayer connecting conductor 41c, the first interlayer connecting conductor 41d, the first interlayer connecting conductor 41e, and the first interlayer connecting conductor 41f each include resin and at least one metal element, similarly to the first interlayer connecting conductor 41a and the first interlayer connecting conductor 41b.

[0219] The resin contained in the first interlayer-connector conductors 41a, 41b, 41c, 41d, 41e, and 41f is preferably the same, but may be different. Furthermore, the metal elements contained in the first interlayer-connector conductors 41a, 41b, 41c, 41d, 41e, and 41f are preferably the same, but may be different. That is, the first interlayer-connector conductors 41a, 41b, 41c, 41d, 41e, and 41f preferably contain the same resin and the same metal element.

[0220] like Figure 14 As shown, the multilayer substrate 2 may further include a connection conductor layer 71 a , a connection conductor layer 71 b , a connection conductor layer 71 c , and a connection conductor layer 71 d .

[0221] The connecting conductor layer 71a is provided between the first thermoplastic resin layer 11a and the first thermoplastic resin layer 11b. The connecting conductor layer 71a is preferably provided across the boundary between the first thermoplastic resin layer 11a and the first thermoplastic resin layer 11b. As a result, the interface between the connecting conductor layer 71a and the first thermoplastic resin layer 11a and the interface between the connecting conductor layer 71a and the first thermoplastic resin layer 11b are offset from the interface between the first thermoplastic resin layer 11a and the first thermoplastic resin layer 11b in the stacking direction. This prevents delamination at the interface between the connecting conductor layer 71a and the first thermoplastic resin layer 11a and the interface between the connecting conductor layer 71a and the first thermoplastic resin layer 11b.

[0222] The connecting conductor layer 71 a electrically connects the first interlayer connecting conductor 41 a and the first interlayer connecting conductor 41 c .

[0223] The connecting conductor layer 71b is provided between the first thermoplastic resin layer 11a and the first thermoplastic resin layer 11b at a position separated from the connecting conductor layer 71a. The connecting conductor layer 71b is preferably provided at a position separated from the connecting conductor layer 71a, straddling the boundary between the first thermoplastic resin layer 11a and the first thermoplastic resin layer 11b. As a result, the interface between the connecting conductor layer 71b and the first thermoplastic resin layer 11a, and the interface between the connecting conductor layer 71b and the first thermoplastic resin layer 11b, are offset from the interface between the first thermoplastic resin layer 11a and the first thermoplastic resin layer 11b in the lamination direction. This prevents delamination at the interface between the connecting conductor layer 71b and the first thermoplastic resin layer 11a, and at the interface between the connecting conductor layer 71b and the first thermoplastic resin layer 11b.

[0224] The connecting conductor layer 71 b electrically connects the first interlayer connecting conductor 41 b and the first interlayer connecting conductor 41 d .

[0225] The connecting conductor layer 71c is provided between the first thermoplastic resin layer 11b and the first thermoplastic resin layer 11c. The connecting conductor layer 71c is preferably provided across the boundary between the first thermoplastic resin layer 11b and the first thermoplastic resin layer 11c. As a result, the interface between the connecting conductor layer 71c and the first thermoplastic resin layer 11b and the interface between the connecting conductor layer 71c and the first thermoplastic resin layer 11c are offset from the interface between the first thermoplastic resin layer 11b and the first thermoplastic resin layer 11c in the stacking direction. This suppresses delamination at the interface between the connecting conductor layer 71c and the first thermoplastic resin layer 11b and the interface between the connecting conductor layer 71c and the first thermoplastic resin layer 11c.

[0226] The connecting conductor layer 71c electrically connects the first interlayer connecting conductor 41c and the first interlayer connecting conductor 41e.

[0227] The connecting conductor layer 71d is provided between the first thermoplastic resin layer 11b and the first thermoplastic resin layer 11c, at a position separated from the connecting conductor layer 71c. The connecting conductor layer 71d is preferably provided astride the boundary between the first thermoplastic resin layer 11b and the first thermoplastic resin layer 11c and at a position separated from the connecting conductor layer 71c. As a result, the interface between the connecting conductor layer 71d and the first thermoplastic resin layer 11b, and the interface between the connecting conductor layer 71d and the first thermoplastic resin layer 11c, are offset from the interface between the first thermoplastic resin layer 11b and the first thermoplastic resin layer 11c in the stacking direction. This prevents delamination at the interface between the connecting conductor layer 71d and the first thermoplastic resin layer 11b, and at the interface between the connecting conductor layer 71d and the first thermoplastic resin layer 11c.

[0228] The connecting conductor layer 71d electrically connects the first interlayer connecting conductor 41d and the first interlayer connecting conductor 41f.

[0229] In the transmission direction orthogonal to the stacking direction, the lengths of the connecting conductor layer 71a, the connecting conductor layer 71b, the connecting conductor layer 71c and the connecting conductor layer 71d are respectively smaller than the length of the first conductor pattern 30, similarly to the lengths of the connecting conductor layer 70a, the connecting conductor layer 70b, the connecting conductor layer 70c and the connecting conductor layer 70d.

[0230] Examples of materials constituting the connection conductor layers 71a, 71b, 71c, and 71d include the same materials as those constituting the connection conductor layers 70a, 70b, 70c, and 70d.

[0231] The constituent materials of the connection conductor layer 71 a , the connection conductor layer 71 b , the connection conductor layer 71 c , and the connection conductor layer 71 d are preferably the same, but may be different from each other.

[0232] In the laminated substrate 2 , the first laminate portion 11 includes three first thermoplastic resin layers, but may include two first thermoplastic resin layers, or may include four or more first thermoplastic resin layers.

[0233] The second laminated portion 12 may also include multiple layers of second thermoplastic resin layers. Figure 14As shown, the second laminated section 12 may also include a second thermoplastic resin layer 12a and a second thermoplastic resin layer 12b. In the second laminated section 12, the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b adjacent to the second thermoplastic resin layer 12a are provided in this order from the first laminated section 11. Thus, in the second laminated section 12, the second thermoplastic resin layers 12a and 12b, which are the same type of second thermoplastic resin layers, are stacked in the stacking direction, resulting in high adhesion between the second thermoplastic resin layers.

[0234] In the laminated substrate 2, there are boundaries between first thermoplastic resin layers of the same type, such as the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c, and boundaries between second thermoplastic resin layers of the same type, such as the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b. However, even such boundaries can be detected by infrared spectroscopy as described above. Figure 14 The determination can be made by observing the cross section along the stacking direction shown or by observing the position of the end portion of each interlayer connection conductor.

[0235] In the laminate substrate of the present invention, when the first laminate portion includes a plurality of first thermoplastic resin layers and the second laminate portion includes a plurality of second thermoplastic resin layers, at a measurement temperature that is at least the minimum melting point of the metal elements contained in the first interlayer connecting conductor and not more than the melting points of the plurality of first thermoplastic resin layers and the plurality of second thermoplastic resin layers, the storage modulus of all the first thermoplastic resin layers constituting the first laminate portion is lower than the storage modulus of all the second thermoplastic resin layers constituting the second laminate portion.

[0236] In the laminate substrate 2, at a measurement temperature that is higher than the minimum melting point of the metal elements contained in the first interlayer connecting conductor 41a, the first interlayer connecting conductor 41b, the first interlayer connecting conductor 41c, the first interlayer connecting conductor 41d, the first interlayer connecting conductor 41e, and the first interlayer connecting conductor 41f and lower than the melting point of the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, the first thermoplastic resin layer 11c, and the second thermoplastic resin layer 12a, 12b. Thus, each of the first interlayer connecting conductor 41a, the first interlayer connecting conductor 41b, the first interlayer connecting conductor 41c, the first interlayer connecting conductor 41d, the first interlayer connecting conductor 41e, and the first interlayer connecting conductor 41f has high density.

[0237] In the multilayer substrate 2, the surface electrode 20a and the first conductor pattern 30 are electrically connected via the first interlayer-connector conductor 41a, the connecting conductor layer 71a, the first interlayer-connector conductor 41c, the connecting conductor layer 71c, and the first interlayer-connector conductor 41e. Thus, in the multilayer substrate 2, the first interlayer-connector conductors electrically connecting the surface electrode 20a and the first conductor pattern 30 are the first interlayer-connector conductor 41a, the first interlayer-connector conductor 41c, and the first interlayer-connector conductor 41e, each having high density. Therefore, connectivity between the surface electrode 20a and the first conductor pattern 30 is likely to be improved.

[0238] In the laminate substrate 2, the first interlayer connecting conductors 41a, 41c, and 41e are arranged so as not to overlap each other when viewed in the stacking direction, but may alternatively be arranged to overlap each other. Alternatively, the first interlayer connecting conductors that electrically connect the surface electrode 20a to the first conductor pattern 30 may be arranged to penetrate two or more first thermoplastic resin layers.

[0239] In the multilayer substrate 2, the surface electrode 20b and the first conductor pattern 30 are electrically connected via the first interlayer-connector conductor 41b, the connecting conductor layer 71b, the first interlayer-connector conductor 41d, the connecting conductor layer 71d, and the first interlayer-connector conductor 41f. Thus, in the multilayer substrate 2, the first interlayer-connector conductors electrically connecting the surface electrode 20b and the first conductor pattern 30 are the first interlayer-connector conductor 41b, the first interlayer-connector conductor 41d, and the first interlayer-connector conductor 41f, each having high density. Therefore, connectivity between the surface electrode 20b and the first conductor pattern 30 is likely to be improved.

[0240] In the laminate substrate 2, the first interlayer connecting conductors 41b, 41d, and 41f are arranged so as not to overlap each other when viewed in the stacking direction, but may alternatively be arranged to overlap each other. Alternatively, the first interlayer connecting conductors that electrically connect the surface electrode 20b to the first conductor pattern 30 may be arranged to penetrate two or more first thermoplastic resin layers.

[0241] At the aforementioned measurement temperature, the storage elastic modulus of the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c are preferably the same. This facilitates improved adhesion between the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c in the first laminated portion 11. In this case, the thermoplastic resins constituting the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c are preferably the same, but may be different.

[0242] At the above-mentioned measurement temperature, the storage elastic moduli of the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c may be different from each other. In this case, the thermoplastic resin constituting the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c may be the same or different from each other.

[0243] At the above-mentioned measurement temperature, the storage elastic modulus of the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b may be the same or different. In either case, the thermoplastic resin constituting the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b may be the same or different. Furthermore, the thermoplastic resin constituting the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b may be the same as or different from the thermoplastic resin constituting the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c.

[0244] The first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, the first thermoplastic resin layer 11c, and the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b may each contain a liquid crystal polymer as a main component. In this case, the molecular weight of the liquid crystal polymer constituting the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c is preferably different from the molecular weight of the liquid crystal polymer constituting the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b. This allows the storage modulus of the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c to be lower than the storage modulus of the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b.

[0245] In the laminated substrate 2, the resin laminate 10 may further include at least one first thermoplastic resin layer on the side opposite to the first laminate 11 relative to the second laminate 12. For example, Figure 14 As shown, the resin laminate 10 may further include a first thermoplastic resin layer 11d on the side opposite to the first laminate portion 11 relative to the second laminate portion 12. By providing at least one first thermoplastic resin layer, here the first thermoplastic resin layer 11d, the impedance of the laminate substrate 2 can be appropriately adjusted.

[0246] In the laminated substrate 2, when the resin laminate 10 has a first thermoplastic resin layer 11d, the storage modulus of the first thermoplastic resin layer 11d is lower than the storage modulus of the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b at a measurement temperature that is above the minimum melting point of the melting points of the metal elements contained in the first interlayer connecting conductor 41a, the first interlayer connecting conductor 41b, the first interlayer connecting conductor 41c, the first interlayer connecting conductor 41d, the first interlayer connecting conductor 41e, and the first interlayer connecting conductor 41f and below the melting points of the first thermoplastic resin layer 11d, the second thermoplastic resin layer 12a, and the second thermoplastic resin layer 12b.

[0247] In addition, in the laminated substrate 2, when the resin laminate 10 has a first thermoplastic resin layer 11d, the storage modulus of the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, the first thermoplastic resin layer 11c, and the first thermoplastic resin layer 11d is preferably lower than the storage modulus of the second thermoplastic resin layer 12a and the second thermoplastic resin layer 12b at a measurement temperature that is higher than the minimum melting point of the melting points of the metal elements contained in the first interlayer connecting conductor 41a, the first interlayer connecting conductor 41b, the first interlayer connecting conductor 41c, the first interlayer connecting conductor 41d, the first interlayer connecting conductor 41e, and the first interlayer connecting conductor 41f and lower than the melting point of the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, the first thermoplastic resin layer 11c, the first thermoplastic resin layer 11d, and the second thermoplastic resin layer 12a, and the second thermoplastic resin layer 12b.

[0248] In the laminated substrate 2, at any of the aforementioned measurement temperatures, the storage elastic modulus of the first thermoplastic resin layer 11d may be the same as or different from the storage elastic moduli of the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c. In either case, the thermoplastic resin constituting the first thermoplastic resin layer 11d may be the same as or different from the thermoplastic resin constituting the first thermoplastic resin layer 11a, the first thermoplastic resin layer 11b, and the first thermoplastic resin layer 11c.

[0249] In the laminate substrate 2, when a plurality of first conductor patterns 30 are present and all of the first conductor patterns 30 are electrically connected to the surface electrodes provided on the first principal surface 10a of the resin laminate 10 via the first interlayer connecting conductor, it is preferable that all of the first conductor patterns 30 be provided so as to be in contact with the first thermoplastic resin layer of the first laminate section 11. In this case, the length of the first conductor pattern 30 in the lowest layer among all of the first conductor patterns 30, that is, the first conductor pattern 30 provided between the first laminate section 11 and the second laminate section 12, is preferably the greatest in the transmission direction orthogonal to the lamination direction.

[0250] Description of Reference Numerals

[0251] 1, 1a, 2-layered substrate;

[0252] 10. Resin laminate;

[0253] 10a first main surface;

[0254] 10b second main surface;

[0255] 11 first laminated portion;

[0256] 11a, 11b, 11c, 11d: a first thermoplastic resin layer;

[0257] 11aa, 11ab: first thermoplastic secondary resin layer;

[0258] 12 second laminated portion;

[0259] 12a, 12b second thermoplastic resin layer;

[0260] 20a, 20b surface electrodes;

[0261] 30 a first conductor pattern for signal or power transmission;

[0262] 41a, 41b, 41c, 41d, 41e, 41f first interlayer connection conductors;

[0263] 42a, 42b, 42c, 42d second interlayer connection conductors;

[0264] 43a, 43b, 43c, 43d third interlayer connection conductors;

[0265] 50 a second conductor pattern for grounding;

[0266] 60 ground electrode;

[0267] 70a, 70b, 70c, 70d, 71a, 71b, 71c, 71d are connecting conductor layers;

[0268] 111a a first thermoplastic resin sheet;

[0269] 112a a second thermoplastic resin sheet;

[0270] 120a, 130, 150, 160, 170a, 170b conductor layers;

[0271] 181a, 182a, 182b, 183a, 183b through holes;

[0272] 190 Conductive paste.

Claims

1. A laminate substrate, characterized in that: The laminated substrate comprises: A resin laminate having a laminate structure including, in a lamination direction, a first laminate portion and a second laminate portion, the first laminate portion including at least one first thermoplastic resin layer, the second laminate portion being adjacent to the first laminate portion and including at least one second thermoplastic resin layer, and having a first principal surface on the first laminate portion side and a second principal surface on the second laminate portion side that are opposed to each other in the lamination direction; a surface electrode provided on the first main surface of the resin laminate; a first conductor pattern for signal or power transmission, provided between the first laminate portion and the second laminate portion; and at least one first interlayer connecting conductor provided to penetrate the first thermoplastic resin layer in the stacking direction and electrically connect the surface electrode and the first conductor pattern, In the first conductor pattern, one surface on the surface electrode side in the stacking direction is connected to the first interlayer connection conductor, and the other surface on the side opposite to the surface electrode is not connected to the interlayer connection conductor. The first interlayer connection conductor includes resin and at least one metal element, At a measurement temperature that is equal to or higher than the minimum melting point of the metal element contained in the first interlayer connecting conductor and equal to or lower than the melting points of the first thermoplastic resin layer and the second thermoplastic resin layer, the storage modulus of the first thermoplastic resin layer is lower than the storage modulus of the second thermoplastic resin layer.

2. The laminated substrate according to claim 1, wherein The first interlayer connection conductor includes tin as the metal element having the minimum melting point.

3. The laminated substrate according to claim 1 or 2, wherein The first interlayer connection conductor includes copper as the metal element.

4. The laminated substrate according to claim 1 or 2, wherein The first interlayer connecting conductor has a cross-sectional area perpendicular to the stacking direction that is smaller than both a cross-sectional area of an end portion on the first conductor pattern side and a cross-sectional area of an end portion on the side opposite to the first conductor pattern.

5. The laminated substrate according to claim 1 or 2, wherein The laminate substrate further includes a second conductor pattern for grounding, the second conductor pattern being provided on the second main surface side of the resin laminate relative to the first conductor pattern and overlapping with the first conductor pattern when viewed in the lamination direction. The laminated substrate according to claim 5 , wherein: The laminate substrate further includes a plurality of second interlayer connecting conductors provided so as to penetrate the second thermoplastic resin layer in the laminating direction at positions sandwiching the first interlayer connecting conductor when viewed in the laminating direction and electrically connected to the second conductor pattern.

7. The laminated substrate according to claim 6, wherein In a cross section perpendicular to the stacking direction, a cross-sectional area of an end portion of the second interlayer connecting conductor on the second conductor pattern side is smaller than a cross-sectional area of an end portion of the first interlayer connecting conductor on the first conductor pattern side.

8. The laminated substrate according to claim 6 or 7, wherein The porosity of the first interlayer connecting conductor is lower than the porosity of the second interlayer connecting conductor.

9. The laminated substrate according to claim 5, wherein The dielectric loss tangent of the second thermoplastic resin layer is smaller than the dielectric loss tangent of the first thermoplastic resin layer.

10. The laminated substrate according to claim 1 or 2, wherein The first thermoplastic resin layer and the second thermoplastic resin layer each include a liquid crystal polymer as a main component.

11. The laminated substrate according to claim 1 or 2, wherein The first laminated portion includes a plurality of first thermoplastic resin layers, At least one first interlayer connecting conductor is provided in each of the plurality of first thermoplastic resin layers.

12. The laminated substrate according to claim 11, wherein At least one connecting conductor layer is provided between two adjacent first thermoplastic resin layers in the stacking direction, and the at least one connecting conductor layer electrically connects the first interlayer connecting conductors provided in the respective first thermoplastic resin layers. In a transmission direction orthogonal to the stacking direction, the length of the connecting conductor layer is smaller than the length of the first conductor pattern.

13. The laminated substrate according to claim 11, wherein At the measurement temperature, the plurality of first thermoplastic resin layers have the same storage modulus.

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