Printed circuit board and method for manufacturing same

Abstract

A printed circuit board is provided with: a metal support substrate (2); a base insulating layer (3) disposed on one surface of the metal support substrate (2) in the thickness direction; and a conductor layer (4) disposed on one surface of the base insulating layer (3) in the thickness direction, the metal support substrate (2) and / or the conductor layer (4) contains a copper alloy, the copper alloy contains a first metal comprising copper and a second metal that can be alloyed with copper, and in the metal support substrate (2) and / or the conductor layer (4), the copper alloy has a sea-island structure and a layered structure. The sea-island structure is provided with: a sea section having a continuous shape; and an island part having a discontinuous shape.

Description

TECHNICAL FIELD

[0001] The present application relates to a wiring circuit substrate and a manufacturing method thereof. BACKGROUND

[0002] In the past, in the field of wiring circuit substrates, an alloy containing copper (hereinafter, referred to as a copper alloy) has been studied. More specifically, a substrate for suspension has been proposed. That is, the substrate for suspension is provided with a metal support substrate, a base insulating layer formed on the metal support substrate, and a plurality of wirings formed on the base insulating layer. Further, the metal support substrate is formed of a copper alloy-based spring material (for example, refer to Patent Document 1).

[0003] PRIOR ART DOCUMENTS PATENT DOCUMENTS Patent Document 1: Japanese Patent Application Publication No. 2013-168206 SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION On the other hand, there are cases where the above-described metal support substrate is required to have a relatively excellent electric conductivity. For example, there are cases where the metal support substrate is used as a jumper wiring, and there are cases where the metal support substrate is used as a ground layer. In such cases, the metal support substrate is required to have an excellent electric conductivity.

[0004] However, there are cases where the electric conductivity of the above-described copper alloy-based spring material is insufficient. In addition, it has also been studied to use a copper alloy instead of copper as the above-described wiring. In such cases, a relatively excellent mechanical strength can be obtained. However, in such cases, from the viewpoint of transmission characteristics of electric signals, there are cases where the electric conductivity of the wiring is insufficient. Therefore, in the case where the wiring circuit substrate contains a copper alloy, it is required to improve the electric conductivity of the copper alloy.

[0005] The present application is a wiring circuit substrate containing a copper alloy, and having an excellent mechanical strength and an excellent electric conductivity, and a manufacturing method thereof.

[0006] TECHNICAL SOLUTION TO THE PROBLEM The present application [1] includes a wiring circuit substrate provided with: a metal support substrate; a base insulating layer disposed on one face in the thickness direction of the metal support substrate; and a conductor layer disposed on one face in the thickness direction of the base insulating layer, the metal support substrate and / or the conductor layer containing a copper alloy, the copper alloy containing a first metal composed of copper and a second metal that can be alloyed with the copper, the copper alloy having an island-in-sea structure and having a lamellar structure in the metal support substrate and / or the conductor layer, the island-in-sea structure being provided with: a sea portion having a continuous shape; and an island portion having a non-continuous shape.

[0007] In the wiring circuit substrate of the above [1], the metal support substrate and / or the conductor layer contain a copper alloy, and the copper alloy contains a first metal composed of copper and a second metal that can be alloyed with copper. Thus, the wiring circuit substrate has excellent mechanical strength.

[0008] Further, the copper alloy has an island-sea structure having a sea portion having a continuous shape and an island portion having a non-continuous shape. Further, the copper alloy has a layered structure. Thus, the wiring circuit substrate has excellent electrical conductivity.

[0009] As a result, the wiring circuit substrate has both excellent mechanical strength and excellent electrical conductivity.

[0010] The invention [2] includes the wiring circuit substrate of the above [1], wherein the second metal is titanium.

[0011] In the wiring circuit substrate of the above [2], the second metal is titanium. That is, the copper alloy is a copper-titanium alloy. Thus, the wiring circuit substrate has more excellent mechanical strength.

[0012] The invention [3] includes a manufacturing method of a wiring circuit substrate, which is a manufacturing method of the wiring circuit substrate of the above [1] or [2], and includes a step of preparing a metal support substrate; a step of forming a base insulating layer on one face in the thickness direction of the metal support substrate; a step of forming a conductor layer on one face in the thickness direction of the base insulating layer; and a step of heating the metal support substrate and / or the conductor layer, the metal support substrate and / or the conductor layer containing a copper alloy, the copper alloy containing a first metal composed of copper and a second metal that can be alloyed with copper, and the heating temperature in the heating being 400°C or lower.

[0013] In the manufacturing method of the wiring circuit substrate of the above [3], the metal support substrate and / or the conductor layer contain a copper alloy, and the metal support substrate and / or the conductor layer are heated at a given heating temperature. Thus, according to the manufacturing method of the wiring circuit substrate, a copper alloy having both the above island-sea structure and the above layered structure can be favorably formed. As a result, according to the manufacturing method of the wiring circuit substrate, a wiring circuit substrate having both excellent mechanical strength and excellent electrical conductivity can be efficiently obtained.

[0014] Effects of Invention In the wiring circuit substrate of the invention, the metal support substrate and / or the conductor layer contain a copper alloy, and the copper alloy contains a first metal composed of copper and a second metal that can be alloyed with copper. Thus, the wiring circuit substrate has excellent mechanical strength.

[0015] Further, the copper alloy has an island structure having a sea portion having a continuous shape and an island portion having a non-continuous shape. Further, the copper alloy has a layered structure. Therefore, the wiring circuit substrate has excellent electrical conductivity.

[0016] As a result, the wiring circuit substrate has both excellent mechanical strength and excellent electrical conductivity.

[0017] Further, in the manufacturing method of the wiring circuit substrate of the present application, the metal support substrate and / or the conductor layer contain a copper alloy, and the metal support substrate and / or the conductor layer are heated at a given heating temperature. Therefore, according to the manufacturing method of the wiring circuit substrate, the island structure and the layered structure can be formed well. As a result, according to the manufacturing method of the wiring circuit substrate, the wiring circuit substrate having both excellent mechanical strength and excellent electrical conductivity can be obtained efficiently. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a cross-sectional view of an embodiment of the wiring circuit substrate of the present application.

[0019] Figure 2A indicates a process of preparing a metal support substrate, Figure 2B indicates a process of heating the metal support substrate, Figure 2C indicates a process of forming a base insulating layer on one surface in the thickness direction of the metal support substrate, Figure 2D indicates a process of forming a conductor layer on one surface in the thickness direction of the base insulating layer, Figure 2E indicates a process of forming a cover insulating layer on one surface in the thickness direction of the base insulating layer and the conductor layer.

[0020] Figure 3 indicates SEM images of Reference Comparative Example 1 and Reference Example 1.

[0021] Figure 4 indicates EDX images of Reference Comparative Example 1 and Reference Example 1. DETAILED DESCRIPTION

[0022] 1. Wiring circuit substrate (1) Overall structure Hereinafter, with reference to Figure 1 An embodiment of the wiring circuit substrate of the present application will be described.

[0023] In Figure 1In the present embodiment, the wiring circuit substrate 1 has a thickness. The wiring circuit substrate 1 extends in a surface direction. The surface direction is orthogonal to the thickness direction. The wiring circuit substrate 1 has a plate shape. The thickness of the wiring circuit substrate 1 is, for example, 10 μm or more. In addition, the thickness of the wiring circuit substrate 1 is, for example, 500 μm or less, preferably 300 μm or less, and more preferably 200 μm or less.

[0024] In Figure 1 In the present embodiment, the wiring circuit substrate 1 includes a metal support substrate 2, a base insulating layer 3 disposed on one surface of the metal support substrate 2 in the thickness direction, a conductor layer 4 disposed on one surface of the base insulating layer 3 in the thickness direction, and a cover insulating layer 5 disposed on one surface of the base insulating layer 3 in the thickness direction so as to cover the conductor layer 4.

[0025] The wiring circuit substrate 1 includes a plurality of divided bodies 11A and 11B. The divided bodies 11A and 11B are disposed on one side of the metal support substrate 2 in the thickness direction, respectively. The divided bodies 11A and 11B are divided in the surface direction. The divided body 11B is spaced apart from the divided body 11A in the surface direction. The divided body 11A includes a base insulating layer 3A, a conductor layer 4A, and a cover insulating layer 5A. The divided body 11B includes a base insulating layer 3B, a conductor layer 4B, and a cover insulating layer 5B.

[0026] (2) Metal support substrate The metal support substrate 2 is disposed on the other end of the wiring circuit substrate 1 in the thickness direction. The metal support substrate 2 forms the other end surface of the wiring circuit substrate 1 in the thickness direction. The metal support substrate 2 extends in the surface direction. One surface and the other surface of the metal support substrate 2 in the thickness direction are each a flat surface. The metal support substrate 2 is in contact with the other surface of the divided bodies 11A and 11B in the thickness direction.

[0027] The metal support substrate 2 is composed of, for example, a metal, preferably a metal obtained by rolling (hereinafter referred to as a rolled metal). As the metal, a copper alloy can be given. That is, the metal support substrate 2 contains a copper alloy, preferably is composed of a copper alloy. Details of the copper alloy are described later.

[0028] The metal support substrate 2 is relatively thin. The thickness of the metal support substrate 2 is, for example, 250 μm or less, preferably 225 μm or less, and more preferably 200 μm or less. In addition, the thickness of the metal support substrate 2 is usually 25 μm or more. That is, the thickness of the metal support substrate 2 is, for example, 25 μm or more and 250 μm or less, preferably 25 μm or more and 225 μm or less, and more preferably 25 μm or more and 200 μm or less.

[0029] (3) Base insulating layer A substrate insulating layer 3 is disposed on one surface of the metal support substrate 2 in the thickness direction. The substrate insulating layer 3 extends along the surface direction. One surface of the substrate insulating layer 3 in the thickness direction is a flat surface. The substrate insulating layer 3 has a patterned shape. Specifically, the substrate insulating layer 3 includes a plurality of substrate insulating layers 3A and 3B. Each of the substrate insulating layers 3A and 3B is contained within the aforementioned partitions 11A and 11B.

[0030] Resin can be cited as a material for the base insulating layer 3. That is, the base insulating layer 3 is preferably made of resin. Examples of resins include polyimide resin, polyamide-imide resin, acrylic resin, polyether nitrile resin, polyethersulfone resin, polyethylene terephthalate resin, polyethylene naphthalate resin, and polyvinyl chloride resin, with polyimide resin being the most preferred. That is, the above-mentioned resin is preferably a polyimide resin.

[0031] The base insulating layer 3 is formed, for example, by thermally curing the aforementioned resin. Details regarding the thermal curing of the resin will be described later.

[0032] The thickness of the substrate insulating layer 3 is, for example, 1 μm or more, preferably 3 μm or more. Alternatively, the thickness of the substrate insulating layer 3 is, for example, 30 μm or less, preferably 20 μm or less.

[0033] (4) Conductor layer Conductor layer 4 is disposed on one surface of the substrate insulating layer 3 in the thickness direction. Conductor layer 4 extends along the surface direction. In this embodiment, conductor layer 4 has a generally rectangular shape in cross-section. One surface of conductor layer 4 in the thickness direction is a flat surface.

[0034] Conductor layer 4 includes multiple wirings and terminals. The wirings can be clock wirings, differential wirings, or other types of wirings. In this embodiment, the wirings are differential wirings. Differential wirings are paired wirings having a pair (i.e., two) signal lines. The signal wirings are arranged substantially parallel to each other, forming a signal transmission line. Terminals are formed at both ends of each wiring along its length. The wirings and terminals are disposed on one surface of each of the substrate insulating layers 3A and 3B in the thickness direction.

[0035] The material for conductor layer 4 can be, for example, a conductive metal, specifically copper and copper alloys (described later), with copper being the preferred choice. Furthermore, the terminal portion (not shown) is plated using known methods as needed, and furthermore, heat-treated as needed. Details regarding the heat treatment will be described later.

[0036] (5) Cover with insulation layer The cover insulating layer 5 is disposed on one surface of the base insulating layer 3 in the thickness direction, such that it covers the conductor layer 4. The cover insulating layer 5 forms one surface of the wiring circuit board 1 in the thickness direction. The cover insulating layer 5 extends along the surface direction.

[0037] The covering insulating layer 5 has a patterned shape. Specifically, the covering insulating layer 5 includes multiple covering insulating layers 5A and 5B. Each of the covering insulating layers 5A and 5B is contained within the aforementioned dividers 11A and 11B. Each of the covering insulating layers 5A and 5B is arranged on one side of each of the base insulating layers 3A and 3B in a manner that covers the wiring of the conductor layer 4.

[0038] In this embodiment, the end face of the covering insulating layer 5 (each of the covering insulating layers 5A and 5B) in the width direction is flush with the end face of the base insulating layer 3 (each of the base insulating layers 3A and 3B) in the width direction.

[0039] As the material for the covering insulating layer 5, examples include the same resin exemplified as the material for the base insulating layer 3. That is, the covering insulating layer 5 is preferably composed of resin. Examples of resins include polyimide resin, polyamide-imide resin, acrylic resin, polyether nitrile resin, polyethersulfone resin, polyethylene terephthalate resin, polyethylene naphthalate resin, and polyvinyl chloride resin, with polyimide resin being the most preferred. In other words, the aforementioned resin is preferably a polyimide resin.

[0040] The insulating layer 5 is formed, for example, by heat curing the aforementioned resin. Details regarding the heat curing of the resin will be described later.

[0041] The thickness of the covering insulating layer 5 is, for example, 1 μm or more, preferably 3 μm or more. Alternatively, the thickness of the covering insulating layer 5 is, for example, 30 μm or less, preferably 20 μm or less.

[0042] It should be noted that the thickness of the covering insulation layer 5 is the length in the thickness direction between one face of the base insulation layer 3 in the thickness direction and one face of the covering insulation layer 5 in the thickness direction that is opposite to the aforementioned face without being separated by the conductor layer 4.

[0043] The combined thickness of the covering insulating layer 5 and the base insulating layer 3 is, for example, 80 μm or less, preferably 50 μm or less, and more preferably 40 μm or less. Alternatively, the combined thickness of the covering insulating layer 5 and the base insulating layer 3 is, for example, 5 μm or more.

[0044] 2. Copper alloy (1) Overall structure In the above-mentioned wiring circuit board 1, the metal support board 2 contains a copper alloy, preferably made of a copper alloy.

[0045] Copper alloys are alloys containing copper. A copper alloy contains a primary metal consisting of copper and a secondary metal that can alloy with copper. The ability to alloy means that an alloy can be formed. Alloys can be solid solutions, eutectic crystals, intermetallic compounds, or complexes thereof.

[0046] In copper alloys, the second metal is an additive metal added to copper, which is the first metal. That is, the second metal refers to a metal other than copper. Examples of second metals include titanium, nickel, silicon, and iron. Two or more of these can be used alone or in combination. In other words, a copper alloy can be a two-component alloy or an alloy with three or more components.

[0047] The second metal is preferably titanium. When the second metal is titanium, the copper alloy is a copper-titanium alloy. When using a copper-titanium alloy, the wiring circuit board 1 has superior mechanical strength.

[0048] In the copper alloy, the proportions of the first metal (i.e., copper (hereinafter the same)) and the proportions of the second metal (preferably titanium (hereinafter the same)) are appropriately set according to the purpose and use.

[0049] More specifically, the atomic ratio of the first metal relative to the total amount (total number of atoms) of the copper alloy is, for example, 50 to 99 atoms, preferably 80 to 99 atoms, and more preferably 90 to 99 atoms.

[0050] In addition, the atomic percentage of the second metal relative to the total amount (total number of atoms) of the copper alloy is, for example, 1 to 50 atomic%, preferably 1 to 20 atomic%, more preferably 1 to 10 atomic.

[0051] It should be noted that in copper alloys, the total atomic ratio of the first metal and the second metal is, for example, 100 atoms.

[0052] In addition, based on mass, the mass ratio of the first metal relative to the total mass of the copper alloy (total mass) is, for example, 50 to 99 by mass, preferably 80 to 99 by mass, and more preferably 90 to 99 by mass.

[0053] In addition, based on mass, the mass ratio of the second metal relative to the total mass of the copper alloy (total mass) is, for example, 1 to 50% by mass, preferably 1 to 20% by mass, and more preferably 1 to 10% by mass.

[0054] It should be noted that in copper alloys, the total mass ratio of the first metal to the second metal is, for example, 100 by mass.

[0055] (2) Phase separation structure In the metal support substrate 2, the copper alloy has a phase-separated structure. Examples of phase-separated structures include island structures and layered structures. In the metal support substrate 2, the copper alloy has both an island structure and a layered structure. That is, the copper alloy possesses both an island structure and a layered structure.

[0056] [Island Structure] An island structure consists of a marine portion (i.e., marine phase), which has a continuous shape, and an island portion (i.e., island phase), which has a discontinuous shape.

[0057] More specifically, the copper alloy with an island structure has: a sea portion, in which the proportion of a first metal is relatively large and the proportion of a second metal is relatively small; and an island portion, in which the proportion of a first metal is relatively small and the proportion of a second metal is relatively large.

[0058] The marine and island parts are separated, with the island parts arranged in a dispersed manner within the matrix composed of the marine parts.

[0059] The existence of island structures can be confirmed, for example, by performing energy-dispersive X-ray spectroscopy (EDX analysis) on a cross-section of a copper alloy and observing the distribution of the first and second metals, thereby confirming the existence of island structures. Alternatively, for example, by using a scanning electron microscope (SEM) to photograph a cross-section of the copper alloy and observing the sea-like and island-like portions in the photograph, the existence of island structures can be confirmed. Energy-dispersive X-ray spectroscopy (EDX analysis) is preferred for confirming the existence of island structures.

[0060] The proportions of the first metal differ between the sea section and the island section. More specifically, the proportion of the first metal in the sea section is higher than that in the island section. Furthermore, the proportions of the second metal differ between the sea section and the island section. More specifically, the proportion of the second metal in the sea section is lower than that in the island section.

[0061] For example, in atomic reference, the atomic proportion of the first metal in the seabed relative to the total amount (total number of atoms) of the copper alloy is, for example, 50 to 100 atomic%, preferably 80 to 100 atomic%, more preferably 90 to 100 atomic.

[0062] In addition, the atomic percentage of the second metal in the seabed relative to the total amount (total number of atoms) of the copper alloy is, for example, 0 to 50 atomic%, preferably 0 to 20 atomic%, more preferably 0 to 10 atomic.

[0063] It should be noted that the total atomic ratio of the first metal in the sea and the atomic ratio of the second metal in the sea is, for example, 100 atoms.

[0064] On the other hand, the atomic ratio of the first metal in the island portion relative to the total amount (total number of atoms) of the copper alloy is, for example, 50 to 99 atoms, preferably 60 to 99 atoms, and more preferably 70 to 99 atoms.

[0065] In addition, the atomic ratio of the second metal in the island portion relative to the total amount (total number of atoms) of the copper alloy is, for example, 1 to 50 atomic%, preferably 1 to 40 atomic%, more preferably 1 to 30 atomic%.

[0066] It should be noted that the total atomic ratio of the first metal in the island and the atomic ratio of the second metal in the island is, for example, 100 atoms.

[0067] Furthermore, the atomic ratio of the first metal in the sea portion is, for example, 1.01 times or more, preferably 1.05 times or more, and more preferably 1.1 times or more, relative to the atomic ratio of the first metal in the island portion. Additionally, the atomic ratio of the first metal in the sea portion is, for example, 5 times or less, relative to the atomic ratio of the first metal in the island portion.

[0068] That is, relative to the atomic ratio of the first metal in the island portion, the atomic ratio of the first metal in the sea portion is, for example, 1.01 times or more and 5 times or less, preferably 1.05 times or more and 5 times or less, more preferably 1.1 times or more and 5 times or less.

[0069] Furthermore, the atomic ratio of the second metal in the island portion is, for example, 0 times or more, relative to the atomic ratio of the second metal in the sea portion. Additionally, the atomic ratio of the second metal in the sea portion is, for example, 1 times or less, preferably 0.8 times or less, and more preferably 0.5 times or less, relative to the atomic ratio of the second metal in the island portion.

[0070] That is, relative to the atomic ratio of the second metal in the island portion, the atomic ratio of the second metal in the sea portion is, for example, 0 times or more and 1 times or less, preferably 0 times or more and 0.8 times or less, more preferably 0 times or more and 0.5 times or less.

[0071] Furthermore, based on mass, the mass ratio of the first metal in the sea to the total mass of the copper alloy (total mass) is, for example, 50 to 100% by mass, preferably 80 to 100% by mass, and more preferably 90 to 100% by mass.

[0072] In addition, the proportion of the second metal in the seabed relative to the total amount (total mass) of the copper alloy is, for example, 0 to 50% by mass, preferably 0 to 20% by mass, and more preferably 0 to 10% by mass.

[0073] It should be noted that the total mass ratio of the first metal in the sea and the mass ratio of the second metal in the sea is, for example, 100 mass.

[0074] In addition, the mass ratio of the first metal in the island section relative to the total mass of the copper alloy is, for example, 50 to 99% by mass, preferably 75 to 99% by mass, and more preferably 80 to 99% by mass.

[0075] In addition, the proportion of the second metal in the island portion relative to the total amount (total mass) of the copper alloy is, for example, 1 to 50% by mass, preferably 1 to 25% by mass, and more preferably 1 to 20% by mass.

[0076] It should be noted that the total mass ratio of the first metal in the island and the mass ratio of the second metal in the island is, for example, 100 mass.

[0077] Furthermore, the mass ratio of the first metal in the sea portion to the mass ratio of the first metal in the island portion is, for example, 1.01 times or more, preferably 1.05 times or more, and more preferably 1.1 times or more. Additionally, the mass ratio of the first metal in the sea portion to the mass ratio of the first metal in the island portion is, for example, 5 times or less.

[0078] That is, relative to the mass ratio of the first metal in the island portion, the mass ratio of the first metal in the sea portion is, for example, 1.01 times or more and 5 times or less, preferably 1.05 times or more and 5 times or less, more preferably 1.1 times or more and 5 times or less.

[0079] Furthermore, the mass ratio of the second metal in the sea portion to the mass ratio of the second metal in the island portion is, for example, 0 times or more. Also, the mass ratio of the second metal in the sea portion to the mass ratio of the second metal in the island portion is, for example, 1 times or less, preferably 0.8 times or less, and more preferably 0.5 times or less.

[0080] That is, relative to the mass ratio of the second metal in the island portion, the mass ratio of the second metal in the sea portion is, for example, 0 times or more and 1 times or less, preferably 0 times or more and 0.8 times or less, more preferably 0 times or more and 0.5 times or less.

[0081] The aforementioned atomic ratio and mass ratio are determined by known methods. Examples of such methods include energy-dispersive X-ray spectroscopy (EDX analysis), fluorescence X-ray analysis, inductively coupled plasma emission spectroscopy, and glow discharge emission analysis, with energy-dispersive X-ray spectroscopy (EDX analysis) being the preferred method.

[0082] Furthermore, it is possible to determine the atomic ratio and calculate the mass ratio based on the atomic ratio.

[0083] In the island structure, the number-average particle size of the island portion is, for example, 10 nm or more, preferably 20 nm or more, more preferably 30 nm or more, and even more preferably 50 nm or more. Furthermore, in the island structure, the number-average particle size of the island portion is, for example, 250 nm or less, preferably less than 200 nm, and even more preferably 150 nm or less. That is, the number-average particle size of the island portion is, for example, 10 nm or more and 250 nm or less, preferably 20 nm or more and 250 nm or less, more preferably 20 nm or more and less than 200 nm, even more preferably 30 nm or more and 150 nm or less, and particularly preferably 50 nm or more and 150 nm or less.

[0084] The number-average particle size of the islands was measured using a scanning electron microscope (SEM) according to the embodiments described later. More specifically, in the cross-sectional images of the copper alloy taken by the scanning electron microscope (SEM) (hereinafter referred to as SEM images), the particle size of more than 10 islands was measured, and their average value was calculated as the number-average particle size.

[0085] Such island structures can be formed, for example, by heating a copper alloy with a layered structure. Details regarding the heating process will be described later.

[0086] [Layered structure] The layered structure comprises: a first phase having a nanoscale thin-layer shape; and a second phase having a nanoscale thin-layer shape.

[0087] More specifically, the layered copper alloy comprises: a first phase having a relatively high proportion of a first metal and a relatively low proportion of a second metal; and a second phase having a relatively low proportion of the first metal and a relatively high proportion of the second metal.

[0088] The first and second phases are configured in a phase-separated and alternately stacked manner.

[0089] The presence of a layered structure can be confirmed, for example, by using a scanning electron microscope (SEM) to photograph a cross-section of the copper alloy and observing the first and second phases in the SEM image, thereby confirming the presence of the layered structure. Alternatively, for example, by performing energy-dispersive X-ray spectroscopy (EDX analysis) on the cross-section of the copper alloy and observing the distribution of the first and second metals, the presence of the layered structure can be confirmed. Preferably, the presence of the layered structure is confirmed by photographing with a scanning electron microscope.

[0090] In the first phase and the second phase, the proportion of the first metal differs from each other. More specifically, the proportion of the first metal in the first phase is higher than that in the second phase. Furthermore, in the first phase and the second phase, the proportion of the second metal differs from each other. More specifically, the proportion of the second metal in the first phase is lower than that in the second phase.

[0091] In the layered structure, the thickness of the first phase is, for example, 10 nm or more and 100 nm or less. Additionally, in the layered structure, the thickness of the second phase is, for example, 5 nm or more and 100 nm or less. The thicknesses of the first and second phases were determined by observing cross-sections of a copper alloy with a layered structure obtained using a scanning electron microscope (SEM).

[0092] Layered structures can be formed, for example, by rolling a copper alloy. The conditions for rolling the copper alloy are appropriately set within the range that allows the aforementioned layered structure to be obtained.

[0093] (3) Physical properties The aforementioned copper alloys possess relatively high mechanical strength. The tensile strength of the copper alloy is, for example, 800 MPa or more, preferably 900 MPa or more. The tensile strength of the aforementioned copper alloy is, for example, 2000 MPa or less, preferably 1700 MPa or less. That is, the tensile strength of the copper alloy is, for example, 800 MPa or more and 2000 MPa or less, preferably 900 MPa or more and 1700 MPa or less. It should be noted that the tensile strength of the copper alloys was measured according to JIS Z2241 (2011).

[0094] Furthermore, the aforementioned copper alloy exhibits high electrical conductivity. For example, when the copper alloy has been rolled, the conductivity of the copper alloy at 20°C in the rolling direction (MD direction) is, for example, 30% IACS or less, preferably 20% IACS or less. Additionally, the conductivity of the copper alloy at 20°C in the rolling direction (MD direction) is, for example, 1% IACS or more, preferably 5% IACS or more. That is, the conductivity of the copper alloy at 20°C in the rolling direction (MD direction) is, for example, 1% IACS or more and 30% IACS or less, preferably 5% IACS or more and 20% IACS or less.

[0095] In addition, in the case where the copper alloy has been rolled, the conductivity of the copper alloy at 20°C in the direction orthogonal to the rolling direction (TD direction) is, for example, 30% IACS or less, preferably 20% IACS or less. In addition, the conductivity of the copper alloy at 20°C in the direction orthogonal to the rolling direction (TD direction) is, for example, 1% IACS or more, preferably 5% IACS or more. That is, the conductivity of the copper alloy at 20°C in the direction orthogonal to the rolling direction (TD direction) is, for example, 1% IACS or more and 30% IACS or less, preferably 5% IACS or more and 20% IACS or less.

[0096] It should be noted that IACS represents the International Annealed Copper Standard, and the conductivity is measured in accordance with JIS H0505 (1975).

[0097] 3. Manufacturing method of wiring circuit board Hereinafter, an embodiment of the manufacturing method of the wiring circuit board of the present invention will be described with reference to FIG. 2.

[0098] (1)Metal support substrate In the manufacturing of the wiring circuit board 1, first, as shown in Figures 2A-2B FIG., a metal support substrate 2 is prepared.

[0099] More specifically, in this step, as shown in Figures 2A-2B FIG., first, a metal support substrate 2 that has not been heated (described later) is prepared. Hereinafter, the metal support substrate 2 that has not been heated (described later) is referred to as a blank 20. The blank 20 is obtained, for example, as a commercially available product. The blank 20 is, for example, a rolled copper alloy. In addition, the blank 20 is, for example, composed of a copper alloy having a layered structure.

[0100] Next, in this method, as shown in Figures 2A-2B FIG., the blank 20 is heated (preheated) to obtain a heated metal support substrate 2. That is, in the present embodiment, the step of preparing the metal support substrate 2 includes the step of heating the blank 20. Hereinafter, the heated metal support substrate 2 is referred to as a heated substrate 21. It should be noted that the details of the heating will be described later.

[0101] (2)Base insulating layer Next, in this method, as shown in Figures 2A-2B FIG., a base insulating layer 3 is formed on one surface in the thickness direction of the metal support substrate 2 (preferably the heated substrate 21).

[0102] There are no particular limitations on the method for forming the substrate insulating layer 3. For example, firstly, a varnish is prepared. The varnish may contain, for example, a photosensitizer, a resin component, and a solvent. When the substrate insulating layer 3 is composed of a polyimide resin, the resin component preferably includes anhydride and a diamine.

[0103] Next, in this method, the aforementioned varnish is applied to one side of the metal support substrate 2 in the thickness direction, and dried by heating, thereby forming a photosensitive coating film. The coating film contains polyamic acid resin. Polyamic acid resin is a reaction product of acid dianhydride and diamine, and is a precursor of polyimide resin.

[0104] In the process of forming the substrate insulating layer 3, the drying temperature is, for example, 50°C or higher. Furthermore, in the process of forming the substrate insulating layer 3, the drying temperature is, for example, 200°C or lower. That is, the drying temperature is, for example, 50°C or higher and 200°C or lower.

[0105] In the process of forming the substrate insulating layer 3, the drying time is, for example, 1 minute or more. Furthermore, in the process of forming the substrate insulating layer 3, the drying time is, for example, 1 hour or less. That is, the drying time is, for example, 1 minute or more and 1 hour or less.

[0106] Next, in this method, the above coating is exposed and developed to form a given pattern. Then, in this method, the coating with the given pattern (i.e., the precursor of the resin) is thermally cured by heating to obtain the substrate insulating layer 3.

[0107] In the process of forming the substrate insulating layer 3, the thermosetting temperature is, for example, 100°C or higher, preferably 200°C or higher. Furthermore, in the process of forming the substrate insulating layer 3, the thermosetting temperature is, for example, 500°C or lower, preferably 450°C or lower. That is, the thermosetting temperature is, for example, 100°C or higher and 500°C or lower, preferably 200°C or higher and 450°C or lower.

[0108] In the process of forming the substrate insulating layer 3, the heat curing time is, for example, 1 hour or more. Alternatively, in the process of forming the substrate insulating layer 3, the heat curing time is, for example, 10 hours or less. That is, the heat curing time is, for example, 1 hour or more and 10 hours or less.

[0109] Through the above steps, the substrate insulating layer 3 is disposed on one side of the metal support substrate 2 in the thickness direction.

[0110] (3) Conductor layer Next, in this method, as referred to Figures 2A-2B In this way, a conductor layer 4 is formed on one side in the thickness direction of the substrate insulating layer 3.

[0111] There are no particular limitations on the method for forming conductor layer 4, and well-known conductor patterning methods can be used. Examples of conductor patterning methods include additive, semi-additive, and subtractive methods, with additive methods being preferred.

[0112] In addition, although not shown in the figure, the terminal portion of the conductor layer 4 can be plated as needed in this method, and the conductor layer 4 can also be heat-treated.

[0113] Through the above steps, the conductor layer 4 is disposed on one side of the substrate insulating layer 3 in the thickness direction.

[0114] (4) Cover with insulation layer Next, in this method, as referred to Figure 1 In this way, a covering insulating layer 5 is formed on one side of the substrate insulating layer 3 and the conductor layer 4 in the thickness direction.

[0115] There are no particular limitations on the method of forming the covering insulating layer 5. For example, the covering insulating layer 5 can be formed by the same method as the method of forming the base insulating layer 3 described above.

[0116] More specifically, for example, firstly, a varnish is prepared. The varnish, for example, contains a photosensitizer, a resin component, and a solvent. In the case where the insulating layer 5 is made of polyimide resin, the resin component preferably contains dianhydride and diamine.

[0117] Next, in this method, the varnish is applied to one side in the thickness direction of the substrate insulating layer 3 and the conductor layer 4, and dried by heating, thereby forming a photosensitive coating film. The coating film contains polyamic acid resin. Polyamic acid resin is a reaction product of acid dianhydride and diamine, and is a precursor of polyimide resin.

[0118] In the process of forming the covering insulating layer 5, the drying temperature is, for example, 50°C or higher. Furthermore, in the process of forming the covering insulating layer 5, the drying temperature is, for example, 200°C or lower. That is, the drying temperature is, for example, 50°C or higher and 200°C or lower.

[0119] In the process of forming the covering insulating layer 5, the drying time is, for example, 1 minute or more. Furthermore, in the process of forming the covering insulating layer 5, the drying time is, for example, 1 hour or less. That is, the drying time is, for example, 1 minute or more and 1 hour or less.

[0120] Next, in this method, the coating is exposed and developed to form a given pattern. Then, in this method, the coating with the given pattern (i.e., the precursor of the resin) is thermally cured by heating to obtain the covering insulating layer 5.

[0121] In the process of forming the covering insulating layer 5, the thermosetting temperature is, for example, 100°C or higher, preferably 200°C or higher. Furthermore, in the process of forming the covering insulating layer 5, the thermosetting temperature is, for example, 500°C or lower, preferably 450°C or lower. That is, the thermosetting temperature is, for example, 100°C or higher and 500°C or lower, preferably 200°C or higher and 450°C or lower.

[0122] In the process of forming the covering insulating layer 5, the heat curing time is, for example, 1 hour or more. Alternatively, in the process of forming the covering insulating layer 5, the heat curing time is, for example, 10 hours or less. That is, the heat curing time is, for example, 1 hour or more and 10 hours or less.

[0123] Through the above steps, the covering insulating layer 5 is disposed on one side of the base insulating layer 3 and the conductor layer 4 in the thickness direction. More specifically, on one side of the base insulating layer 3 in the thickness direction, the covering insulating layer 5 covers the wiring of the conductor layer 4 and exposes the terminal portion (not shown).

[0124] In addition, in the above-mentioned processes, the metal support substrate 2, the base insulating layer 3, the conductor layer 4, and the covering insulating layer 5 are aligned with each other to manufacture the wiring circuit substrate 1 (refer to...). Figure 3 ).

[0125] 4. Heating (1) Heating method In the above-described method for manufacturing the wiring circuit board 1, the blank 20 is heated to obtain the heated substrate 21.

[0126] The billet 20, for example as described above, is a rolled copper alloy. Furthermore, the copper alloy in the billet 20 has the aforementioned layered structure. Additionally, the copper alloy in the billet 20 preferably does not have the aforementioned island structure. Particularly preferred is that the copper alloy in the billet 20 as a whole has the aforementioned layered structure.

[0127] That is, in the above-described method for manufacturing the wiring circuit board 1, the blank 20 having a layered structure is heated. There are no particular limitations on the heating method. For example, although not shown, the blank 20 can be heated by winding the blank 20 around a heat treatment core and placing the blank 20 wound around the heat treatment core in a heating furnace.

[0128] In the above heating process, the heating conditions are adjusted in a way that yields a copper alloy that combines the aforementioned island structure and layered structure.

[0129] More specifically, the heating temperature in the above-mentioned heating is 300°C or higher, preferably 310°C or higher. Additionally, the heating temperature in the heating process is, for example, 400°C or lower, preferably 390°C or lower. That is, the heating temperature in the heating process is, for example, 300°C or higher and 400°C or lower, preferably 310°C or higher and 390°C or lower.

[0130] The heating time described above is adjusted according to the heating temperature, for example, to be 3 minutes or more. Additionally, the heating time is, for example, 10 hours or less. That is, the heating time is, for example, 3 minutes or more and 10 hours or less.

[0131] The aforementioned heating process enables the inhomogenization of a second metal and grain growth within a portion of the copper alloy. Furthermore, during this heating, the layered structure is maintained in the remaining portion opposite to the portion of the copper alloy. As a result, a copper alloy exhibiting both island-like and layered structures is formed.

[0132] More specifically, if the billet 20 is heated under the given conditions, the second metal becomes non-uniform in a portion of the copper alloy. That is, through the heating process, islands are formed within the copper alloy, where the proportion of the first metal is relatively small and the proportion of the second metal is relatively large. Furthermore, through the heating process, seas are formed, where the proportion of the first metal is relatively large and the proportion of the second metal is relatively small. Additionally, the islands are dispersed within the seas within the copper alloy. In other words, through the heating process, the aforementioned island structure is formed.

[0133] On the other hand, when the blank 20 is heated under the given conditions described above, the second metal does not become inhomogeneous or grow grains in the remaining portion relative to a portion of the copper alloy, and the aforementioned layered structure is maintained.

[0134] As a result, a copper alloy with both the island structure and the layered structure described above is obtained as the heating substrate 21.

[0135] In other words, the heated substrate 21 contains a copper alloy that combines the aforementioned island structure and layered structure, and is preferably composed of a copper alloy that combines the aforementioned island structure and layered structure. As described above, such a heated substrate 21 is supplied as a metal support substrate 2 for manufacturing a wiring circuit substrate 1.

[0136] 5. Effects In the aforementioned wiring circuit board 1, the metal support substrate 2 contains a copper alloy, which contains a first metal made of copper and a second metal capable of alloying with copper. Therefore, the aforementioned wiring circuit board 1 has excellent mechanical strength.

[0137] Furthermore, the aforementioned copper alloy has an island structure, comprising: a continuous sea portion and a discontinuous island portion. Additionally, the copper alloy has a layered structure. Therefore, the aforementioned wiring circuit board exhibits excellent conductivity.

[0138] As a result, the aforementioned wiring circuit board 1 possesses both excellent mechanical strength and excellent conductivity.

[0139] In particular, copper alloys possessing both island-like and layered structures exhibit superior productivity compared to copper alloys with only island-like structures and no layered structure. More specifically, the heating temperature required to obtain copper alloys with both island-like and layered structures is relatively lower than the heating temperature required to obtain copper alloys with only island-like structures and no layered structure. Therefore, copper alloys with both island-like and layered structures offer relatively superior productivity and lower cost compared to copper alloys with only island-like structures and no layered structure.

[0140] Furthermore, in the aforementioned wiring circuit board 1, if the second metal is titanium and the copper alloy is a copper-titanium alloy, the aforementioned wiring circuit board has superior mechanical strength.

[0141] Furthermore, in the aforementioned wiring circuit board, the number-average particle size of the islands is above a given value. That is, in the aforementioned wiring circuit board 1, the copper alloy has a particularly excellent island structure. Therefore, the aforementioned wiring circuit board 1 effectively combines excellent mechanical strength and excellent electrical conductivity.

[0142] Furthermore, in the above-described method for manufacturing the wiring circuit board 1, the metal support substrate 2 contains a copper alloy, and this metal support substrate is heated at a given heating temperature. Therefore, according to the above-described method for manufacturing the wiring circuit board 1, a copper alloy possessing both the above-described island structure and the above-described layered structure can be well formed. As a result, according to the above-described method for manufacturing the wiring circuit board 1, a wiring circuit board 1 possessing both excellent mechanical strength and excellent conductivity can be efficiently obtained.

[0143] Furthermore, in the above-described method for manufacturing wiring circuit boards, the heating temperature is relatively low, thus the above-described method for manufacturing wiring circuit boards has excellent productivity and low cost.

[0144] 6. Variations In the variations, the same reference numerals are used to mark the same components and processes as in the first embodiment, and detailed descriptions are omitted. Furthermore, unless otherwise specified, the variations can achieve the same effects as the first embodiment. Moreover, the first embodiment and its variations can be appropriately combined.

[0145] In the above embodiment, the billet 20 is heated by winding it around a heat treatment core and then placing the billet 20 in this wound state in a heating furnace. However, the heating method is not limited to the method described above. For example, the billet 20 can be heat-treated by passing it through a heating furnace using a roll-to-roll conveying method. The heating conditions are the same as described above.

[0146] In addition, in the above embodiment, before forming the substrate insulating layer 3, the blank 20 (i.e., a copper alloy with a layered structure) is heated to form a heated substrate 21 (i.e., a copper alloy with both island structure and layered structure), but the timing of heating is not limited to the above.

[0147] For example, in the manufacturing of the wiring circuit board 1, the varnish is heated during the process of forming the base insulating layer 3. At the same time, the metal support substrate 2 is heated together with the varnish. Therefore, for example, it is possible to heat the blank 20 during the process of forming the base insulating layer 3 instead of heating it beforehand. More specifically, the blank 20 is coated with a varnish that serves as the material for the base insulating layer 3, and then the varnish is heated to form the base insulating layer 3. In this case, the blank 20 can also be heated together with the varnish under the above conditions to form the heated substrate 21 (i.e., a copper alloy possessing both the island structure and the layered structure described above).

[0148] Furthermore, for example, in the manufacturing of the wiring circuit board 1, during the process of forming the conductor layer 4, there may be a situation where the conductor layer 4 is heated as a heat treatment as needed. In such a case, the blank 20 and the conductor layer 4 can also be heated together under the above conditions to form the heated substrate 21 (i.e., a copper alloy that has both the above-mentioned island structure and layered structure).

[0149] Furthermore, for example, in the manufacturing of the wiring circuit board 1, the varnish is heated during the process of forming the covering insulating layer 5. For this purpose, for example, the blank 20 can also be heated during the process of forming the covering insulating layer 5 to form a copper alloy that combines the above-mentioned island structure and layered structure.

[0150] More specifically, a base insulating layer 3 is layered onto the blank 20, and then a conductor layer 4 is layered onto the base insulating layer 3. Next, a varnish, which serves as the material for the covering insulating layer 5, is applied to the base insulating layer 3 and the conductor layer 4. Then, the varnish is heated to form the covering insulating layer 5. At this time, the blank 20 and the varnish can also be heated together under the above conditions to form a heated substrate 21 (i.e., a copper alloy that combines the above-mentioned island structure and layered structure).

[0151] That is, the heating of the blank 20 can be performed before the process of forming the base insulating layer 3, or during the process of forming the base insulating layer 3, or during the process of forming the conductor layer 4, or during the process of forming the covering insulating layer 5. Furthermore, these processes can also be combined. The heating of the blank 20 is performed before the process of forming the base insulating layer 3.

[0152] In addition, in the above embodiment, the conductor layer 4 contains copper (i.e., unalloyed copper), but for example, the conductor layer 4 may also contain a copper alloy that combines the above-mentioned island structure and layered structure.

[0153] In this case, for example, a conductor layer 4 containing a copper alloy with a layered structure is formed, and then the conductor layer 4 is heated, thereby forming a conductor layer 4 containing a copper alloy that has both the above-mentioned island structure and layered structure.

[0154] For example, a base insulating layer 3 is stacked on a metal support substrate 2, and then a conductor layer 4 is stacked on the base insulating layer 3. At this time, for example, the conductor layer 4 is formed using a copper alloy with a layered structure by a subtractive forming method. Next, the conductor layer 4 is heat-treated.

[0155] At this point, the conductor layer 4 is heated under the above conditions, thereby forming a copper alloy containing an island structure. That is, in the process of forming the conductor layer 4, the conductor layer 4 is heated, thereby forming a conductor layer 4 containing a copper alloy that has both the island structure and the layered structure described above.

[0156] Alternatively, for example, the conductor layer 4 can be heated during the process of forming the covering insulating layer 5 to form a copper alloy that combines the above-mentioned island structure and layered structure.

[0157] For example, a base insulating layer 3 is laminated onto a metal support substrate 2, and then a conductor layer 4 is laminated onto the base insulating layer 3. At this time, for example, a copper alloy with a layered structure is used to form the conductor layer 4 by a subtractive process. Next, a varnish, which serves as the material for a covering insulating layer 5, is applied to the base insulating layer 3 and the conductor layer 4. Then, the varnish is heated to form the covering insulating layer 5. At this time, the conductor layer 4 is heated together with the varnish under the aforementioned conditions, thereby forming a copper alloy containing an island-like structure. That is, by heating the conductor layer 4 during the process of forming the covering insulating layer 5, a conductor layer 4 containing a copper alloy possessing both the aforementioned island-like structure and layered structure can be formed.

[0158] Under such circumstances, the wiring circuit board 1 also possesses both excellent mechanical strength and excellent conductivity.

[0159] That is, the conductor layer 4 contains a copper alloy, which contains a first metal made of copper and a second metal that can be alloyed with copper. Therefore, the above-mentioned wiring circuit board 1 has excellent mechanical strength.

[0160] Furthermore, in the aforementioned conductor layer 4, the copper alloy has a sea-island structure, comprising: a sea portion having a continuous shape; and island portions having a discontinuous shape. Moreover, the atomic proportion of the second metal in the sea portion is less than a given value relative to the atomic proportion of the second metal in the island portion. That is, the atomic proportion of copper is relatively high in the sea portion having a continuous shape. Therefore, the aforementioned wiring circuit board 1 exhibits excellent conductivity due to the copper in the sea portion.

[0161] Alternatively, if the conductor layer 4 contains a copper alloy that combines the aforementioned island structure and layered structure, the metal support substrate 2 may not contain a copper alloy that combines the aforementioned island structure and layered structure. Alternatively, both the metal support substrate 2 and the conductor layer 4 may contain a copper alloy that combines the aforementioned island structure and layered structure.

[0162] In other words, in the manufacturing method of the above-described wiring circuit board 1, the metal support substrate 2 and / or conductor layer 4 are heated to form a copper alloy that combines the above-described island structure and layered structure. Furthermore, the metal support substrate 2 and / or conductor layer 4 contain a copper alloy that combines the above-described island structure and layered structure.

[0163] Preferably, in the above-described method for manufacturing the wiring circuit board 1, the metal support substrate 2 (specifically, the blank 20) ​​is heated. Furthermore, the metal support substrate 2 contains a copper alloy that combines the aforementioned island structure and layered structure.

[0164] It should be noted that the material of the metal support substrate 2 is not particularly limited if it does not contain a copper alloy that combines the aforementioned island structure and layered structure. More specifically, the material of the metal support substrate 2 can be, for example, a copper alloy without an island structure, or a metal other than a copper alloy. Examples of metals other than copper alloys include copper and stainless steel.

[0165] It should be noted that, although not described in detail, in the above-mentioned wiring circuit board 1, the covering insulating layer 5 is an arbitrary layer, and the covering insulating layer 5 can be omitted as needed.

[0166] [Example] The following examples and comparative examples further illustrate the present invention. It should be noted that the present invention is not limited to any particular example or comparative example. Furthermore, the specific numerical values ​​of proportions (including proportions), physical property values, parameters, etc., used in the following description can replace the corresponding upper limit values ​​(defined as "below" or "less than") or lower limit values ​​(defined as "above" or "exceeding") of the proportions (including proportions), physical property values, parameters, etc., described in the "Specific Embodiments" above.

[0167] 1. Sample manufacturing See Comparative Example 1 A commercially available copper alloy (30 μm thick) was prepared as a blank and rolled. The copper alloy is a copper-titanium alloy containing copper as the first metal and titanium as the second metal. In the copper alloy, the proportion of copper is 96.3% by mass and the proportion of titanium is 3.7% by mass.

[0168] Refer to Example 1 The billet of Comparative Example 1 was heated at 350°C for 4 hours to obtain a heated substrate (thickness 30 μm). That is, the heated substrate was the aforementioned copper-titanium alloy obtained by rolling and heating.

[0169] 2. Evaluation (1) SEM photography Using a scanning electron microscope (SEM), cross-sections of the billet of Reference Comparative Example 1 along the rolling direction and cross-sections of the heated substrate of Reference Example 1 along the rolling direction were photographed and observed.

[0170] The following shows the filming equipment and conditions.

[0171] Device: S-4800, manufactured by Hitachi Condition: Accelerating voltage 3kV The above observations confirm that the blank of Comparative Example 1 has a layered structure. Furthermore, it is confirmed that the heated substrate of Reference Example 1 has an island structure. SEM images of Comparative Example 1 and Reference Example 1 are shown below. Figure 4 .

[0172] Furthermore, in the SEM image of the heated substrate of Reference Example 1, the number-average particle size of the islands was determined by the SEM method. More specifically, in the cross-sectional image (i.e., SEM image) of the heated substrate (copper alloy) of Reference Example 1 taken by scanning electron microscopy (SEM), the particle size of 10 islands was measured, and their average value was calculated as the number-average particle size.

[0173] As a result, the number-average particle size of the islands was 75 nm.

[0174] (2) EDX analysis Using an energy-dispersive X-ray diffraction (EDX) apparatus, elemental mapping was performed on cross-sections along the rolling direction of the billet of Comparative Example 1 and the heated substrate of Comparative Example 1. The distribution of titanium atoms was then observed.

[0175] The analysis apparatus and conditions are shown below.

[0176] [Mapping] Device: XFlash FlatQUAD, manufactured by Bruker Conditions: Accelerating voltage: 5kV [Point Analysis] Device: X-MAX150, manufactured by Horiba Corporation Conditions: Accelerating voltage: 5kVm, 15kV The above analysis confirmed that the blank of Comparative Example 1 did not have a sea-island structure. Furthermore, it was confirmed that the heated substrate of Reference Example 1 had a sea-island structure. EDX images (distribution of titanium atoms) of Comparative Example 1 and Reference Example 1 are shown below. Figure 4 It should be noted that, in ​ In the diagram, a bright color is used to represent the distribution of titanium atoms.

[0177] In addition, through the above elemental mapping, the atomic distribution of the sea part and the atomic distribution of the island part in the island structure are calculated respectively, and the mass ratio and atomic ratio of copper, as well as the mass ratio and atomic ratio of titanium, are calculated respectively.

[0178] As a result, in the sea, the mass percentage of copper is 100% and the atomic percentage of copper is 100 atoms. Additionally, in the sea, the mass percentage of titanium is 0% and the atomic percentage of titanium is 0 atoms.

[0179] On the other hand, in the island section, copper accounts for 88.55% by mass and 85.36% by atomic mass. Additionally, in the island section, titanium accounts for 11.45% by mass and 14.64% by atomic mass.

[0180] (3) Conductivity The conductivity of the blank of Reference Comparative Example 1 at 20°C and the conductivity of the heated substrate of Reference Example 1 at 20°C were measured according to JIS H0505 (1975).

[0181] It should be noted that, as conductivity, the conductivity in the rolling direction (MD direction) (hereinafter referred to as MD conductivity) and the conductivity in the direction orthogonal to the rolling direction (TD direction) (hereinafter referred to as TD conductivity) were measured separately.

[0182] The blank of Comparative Example 1 has an MD conductivity of 8% IACS and a TD conductivity of 8% IACS. The heated substrate of Example 1 has an MD conductivity of 14% IACS and a TD conductivity of 12% IACS.

[0183] That is, it was confirmed that the conductivity of the heated substrate of the reference embodiment is higher than that of the blank of the comparative reference example.

[0184] It should be noted that the above-described invention is provided as an illustrative embodiment of the present invention, but this is merely illustrative and should not be interpreted as limiting. Modifications of the invention that are obvious to those skilled in the art are included within the scope of protection of the technical solutions described below.

[0185] Industrial availability The wiring circuit board and its manufacturing method of the present invention are suitable for use in the fields of wiring circuit boards for electronic devices (wiring circuit boards for electronic components) and wiring circuit boards for electrical equipment (wiring circuit boards for electrical components).

[0186] Symbol Explanation 1: Wiring circuit board 2: Metal support substrate 3: Substrate insulation layer 4: Conductor layer 5: Cover with insulation layer 11: Segmentation 20: Billet 21: The substrate being heated.

Claims

1. A wiring circuit substrate, comprising: a metal support substrate; a base insulating layer disposed on one face in a thickness direction of the metal support substrate; and a conductor layer disposed on one face in a thickness direction of the base insulating layer, the metal support substrate and / or the conductor layer containing a copper alloy, the copper alloy containing a first metal composed of copper and a second metal capable of alloying with the copper, in the metal support substrate and / or the conductor layer, the copper alloy having an island structure and having a layered structure, the island structure comprising: a sea portion having a continuous shape; and an island portion having a non-continuous shape. the second metal being titanium.

3. A manufacturing method of a wiring circuit substrate, the manufacturing method of a wiring circuit substrate according to claim 1 or 2, comprising: a step of preparing a metal support substrate; a step of forming a base insulating layer on one face in a thickness direction of the metal support substrate; a step of forming a conductor layer on one face in a thickness direction of the base insulating layer; and a step of heating the metal support substrate and / or the conductor layer, the metal support substrate and / or the conductor layer containing a copper alloy, the copper alloy containing a first metal composed of copper and a second metal capable of alloying with the copper, the heating temperature in the heating step being 400°C or lower. ​ ​ ​ ​ ​ 2. The wiring circuit substrate according to claim 1, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​

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