Wiring circuit board and method for manufacturing the same

Abstract

To provide a wiring circuit board containing a copper alloy that combines excellent mechanical strength and excellent conductivity, and a method for manufacturing the same. [Solution] The invention comprises a metal support substrate 2, a base insulating layer 3 disposed on one side of the metal support substrate 2 in the thickness direction, and a conductor layer 4 disposed on one side of the base insulating layer 3 in the thickness direction, wherein the metal support substrate 2 and / or the conductor layer 4 contain a copper alloy, the copper alloy contains a first metal made of 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 comprising a sea portion having a continuous shape and an island portion having a discontinuous shape.

Description

Technical Field

[0001] The present invention relates to a wiring circuit board and a method for manufacturing the same.

Background Art

[0002] Conventionally, in the field of wiring circuit boards, the use of an alloy containing copper (hereinafter, copper alloy) has been studied. More specifically, the following substrate for suspension has been proposed. That is, the substrate for suspension includes 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. And the metal support substrate is formed of a copper alloy-based spring material (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, the above metal support substrate may be required to have relatively excellent conductivity. For example, the metal support substrate may be used as a jumper wiring or as a ground layer. In such cases, the metal support substrate is required to have excellent conductivity. However, the conductivity of the above copper alloy-based spring material may not be sufficient. In addition, the use of a copper alloy instead of copper for the above wiring is also considered. In such cases, relatively excellent mechanical strength can be obtained. However, in such cases, from the viewpoint of the transmission characteristics of electrical signals, the conductivity of the wiring may not be sufficient. Therefore, when the wiring circuit board contains a copper alloy, an improvement in the conductivity of the copper alloy is required.

[0005] The present invention relates to a wiring circuit board containing a copper alloy, possessing excellent mechanical strength and excellent conductivity, and a method for manufacturing the same. [Means for solving the problem]

[0006] The present invention [1] includes a wiring circuit board comprising a metal support substrate, a base insulating layer disposed on one side of the metal support substrate in the thickness direction, and a conductor layer disposed on one side of the base insulating layer in the thickness direction, wherein the metal support substrate and / or the conductor layer contain a copper alloy, the copper alloy contains a first metal made of copper and a second metal that can be alloyed with copper, and in the metal support substrate and / or the conductor layer, the copper alloy has a sea-island structure comprising a continuous sea portion and a discontinuous island portion.

[0007] In the wiring circuit board described in [1] above, the metal support substrate and / or conductor layer contain a copper alloy, the copper alloy containing a first metal consisting of copper and a second metal that can be alloyed with copper. Therefore, the wiring circuit board has excellent mechanical strength.

[0008] Furthermore, the above copper alloy has a sea-island structure, which comprises a continuous sea portion and a discontinuous island portion. Therefore, the above wiring circuit board has excellent conductivity due to its sea-island structure.

[0009] As a result, the above-mentioned wiring circuit board possesses both excellent mechanical strength and excellent conductivity.

[0010] The present invention [2] includes the wiring circuit board described in [1] above, wherein the atomic ratio of the second metal in the sea portion is 0.9 times or less compared to the atomic ratio of the second metal in the island portion.

[0011] In the wiring circuit board described in [2] above, the atomic ratio of the second metal in the sea area is less than or equal to a predetermined value compared to the atomic ratio of the second metal in the island area. That is, the atomic ratio of copper is relatively high in the sea area which has a continuous shape. Therefore, the above wiring circuit board has superior conductivity.

[0012] The present invention [3] includes the wiring circuit board described in [1] or [2] above, wherein the second metal is titanium.

[0013] In the wiring circuit board described in [3] above, the second metal is titanium. That is, the copper alloy is a copper-titanium alloy. Therefore, the above wiring circuit board has superior mechanical strength.

[0014] The present invention [4] includes a wiring circuit board according to any one of the above [1] to [3], wherein, in an XRD chart obtained by measuring the X-ray diffraction (XRD) of the copper alloy, a peak having a peak top in the range of 2θ value 41.00° to 42.00° is confirmed.

[0015] In the wiring circuit board described in [4] above, when the X-ray diffraction (XRD) of the copper alloy is measured, a peak with a peak top in the range of 2θ values ​​between 41.00° and 42.00° is observed in the XRD chart. Such copper alloys have a particularly excellent sea-island structure. Therefore, the above wiring circuit board combines excellent mechanical strength and excellent conductivity in a good manner.

[0016] The present invention [5] includes a wiring circuit board according to any one of the above [1] to [4], wherein the number-average particle diameter of the island portion, as measured using a scanning electron microscope (SEM), is 50 nm or more.

[0017] In the wiring circuit board described in [5] above, the number-average particle size of the island portions is greater than or equal to a predetermined value. In other words, in the above wiring circuit board, the copper alloy has a particularly excellent sea-island structure. Therefore, the above wiring circuit board has a good combination of excellent mechanical strength and excellent conductivity.

[0018] The present invention [6] is a method for manufacturing a wiring circuit board according to any one of the above [1] to [5], comprising the steps of: preparing a metal support substrate; forming a base insulating layer on one side of the metal support substrate in the thickness direction; forming a conductor layer on one side of the base insulating layer in the thickness direction; and heating the metal support substrate and / or the conductor layer, wherein the metal support substrate and / or the conductor layer contain a copper alloy, the copper alloy contains a first metal made of copper and a second metal that can be alloyed with copper, and the heating temperature in the heating is 350°C or higher.

[0019] In the method for manufacturing a wiring circuit board described in [6] above, the metal support substrate and / or conductor layer contain a copper alloy, and the metal support substrate and / or conductor layer are heated to a predetermined heating temperature. Therefore, according to the above method for manufacturing a wiring circuit board, the above-mentioned sea-island structure can be formed well. As a result, according to the above method for manufacturing a wiring circuit board, a wiring circuit board with excellent mechanical strength and excellent conductivity can be efficiently obtained. [Effects of the Invention]

[0020] In the wiring circuit board of the present invention, the metal support substrate and / or conductor layer contain a copper alloy, the copper alloy containing a first metal consisting of copper and a second metal that can be alloyed with copper. Therefore, the above-mentioned wiring circuit board has excellent mechanical strength.

[0021] Furthermore, the above copper alloy has a sea-island structure, which comprises a continuous sea portion and a discontinuous island portion. Therefore, the above wiring circuit board has excellent conductivity due to its sea-island structure.

[0022] As a result, the above-mentioned wiring circuit board possesses both excellent mechanical strength and excellent conductivity.

[0023] In the method for manufacturing a wiring circuit board of the present invention, 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 predetermined heating temperature. Therefore, according to the above method for manufacturing a wiring circuit board, the above-described island structure can be formed well. As a result, according to the above method for manufacturing a wiring circuit board, a wiring circuit board having excellent mechanical strength and excellent conductivity can be efficiently obtained.

Brief Description of the Drawings

[0024] [Figure 1] FIG. 1 is a cross-sectional view of an embodiment of a wiring circuit board of the present invention. [Figure 2] FIG. 2A shows the step of preparing a metal support substrate, FIG. 2B shows the step of heating the metal support substrate, FIG. 2C shows the step of forming a base insulating layer on one side in the thickness direction of the metal support substrate, FIG. 2D shows the step of forming a conductor layer on one side in the thickness direction of the base insulating layer, and FIG. 2E shows the step of forming a cover insulating layer on one side in the thickness direction of the base insulating layer and the conductor layer. [Figure 3] FIG. 3 shows SEM images of Reference Comparative Example 1 and Reference Example 1. [Figure 4] FIG. 4 shows EDX images of Reference Comparative Example 1 and Reference Example 1. [Figure 5] FIG. 5 shows XRD charts of Reference Comparative Example 1 and Reference Example 1.

Embodiments for Carrying Out the Invention

[0025] 1. Wiring Circuit Board (1) Overall Configuration Hereinafter, an embodiment of a wiring circuit board of the present invention will be described with reference to FIG. 1.

[0026] In Figure 1, the wiring circuit board 1 has thickness. The wiring circuit board 1 extends in the planar direction. The planar direction is perpendicular to the thickness direction. The wiring circuit board 1 has a plate shape. The thickness of the wiring circuit board 1 is, for example, 10 μm or more. Alternatively, the thickness of the wiring circuit board 1 is, for example, 500 μm or less, preferably 300 μm or less, and more preferably 200 μm or less.

[0027] In Figure 1, the wiring circuit board 1 comprises a metal support substrate 2, a base insulating layer 3 disposed on one side of the metal support substrate 2 in the thickness direction, a conductor layer 4 disposed on one side of the base insulating layer 3 in the thickness direction, and a cover insulating layer 5 disposed on one side of the base insulating layer 3 in the thickness direction so as to cover the conductor layer 4.

[0028] The wiring circuit board 1 includes a plurality of divided sections 11A and 11B. Each of the divided sections 11A and 11B is arranged on one side of the metal support substrate 2 in the thickness direction. The divided sections 11A and 11B are divided in the planar direction. In the planar direction, divided section 11B is spaced apart from divided section 11A. Divided section 11A comprises a base insulating layer 3A, a conductor layer 4A, and a cover insulating layer 5A. Divided section 11B comprises a base insulating layer 3B, a conductor layer 4B, and a cover insulating layer 5B.

[0029] (2) Metal support substrate The metal support substrate 2 is positioned at the other end of the wiring circuit board 1 in the thickness direction. The metal support substrate 2 forms the other end surface of the wiring circuit board 1 in the thickness direction. The metal support substrate 2 extends in the plane direction. Both the one surface and the other surface of the metal support substrate 2 in the thickness direction are flat surfaces. The metal support substrate 2 is in contact with the other surface of the divided parts 11A and 11B in the thickness direction.

[0030] The metal support substrate 2 is made of, for example, a metal, preferably a rolled metal (hereinafter referred to as rolled metal). Examples of metals include copper alloys. That is, the metal support substrate 2 contains a copper alloy, and preferably consists of a copper alloy. Details regarding copper alloys will be described later.

[0031] 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. Also, 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.

[0032] (3) Base insulating layer The base insulating layer 3 is arranged on one side of the metal support substrate 2 in the thickness direction. The base insulating layer 3 extends in the planar direction. One side of the base insulating layer 3 in the thickness direction is a flat surface. The base insulating layer 3 has a pattern shape. Specifically, the base insulating layer 3 includes a plurality of base insulating layers 3A, 3B. Each of the base insulating layers 3A, 3B is included in each of the divided parts 11A, 11B described above.

[0033] Examples of materials for the base insulating layer 3 include resin. Specifically, the base insulating layer 3 is preferably made of resin. Examples of resins include polyimide resin, polyamide-imide resin, acrylic resin, polyethernitrile resin, polyethersulfone resin, polyethylene terephthalate resin, polyethylene naphthalate resin, and polyvinyl chloride resin, with polyimide resin being preferred. Specifically, the above resin is preferably polyimide resin.

[0034] The base insulating layer 3 is formed, for example, by thermal curing the above-mentioned resin. Details of the thermal curing of the resin will be described later.

[0035] The thickness of the base insulating layer 3 is, for example, 1 μm or more, preferably 3 μm or more. Alternatively, the thickness of the base insulating layer 3 is, for example, 30 μm or less, preferably 20 μm or less.

[0036] (4) Conductor layer The conductor layer 4 is arranged on one side of the base insulating layer 3 in the thickness direction. The conductor layer 4 extends in the plane direction. In this embodiment, the conductor layer 4 has a substantially rectangular shape in cross-section. One side of the conductor layer 4 in the thickness direction is a flat surface.

[0037] The conductor layer 4 includes a plurality of wirings and terminals. The wiring may be clock wiring, differential wiring, or other types of wiring. In this embodiment, the wiring is differential wiring. Differential wiring is a pair of wirings comprising a pair (i.e., two) signal lines. Each signal wiring is arranged substantially parallel to each other, forming a single signal transmission line. Terminals are formed at both ends in the longitudinal direction of each wiring. The wiring and terminals are arranged on one side of the base insulating layers 3A and 3B in the thickness direction.

[0038] Examples of materials for the conductive layer 4 include conductive metals, specifically copper and copper alloys (described later), with copper being preferred. The terminal portion (not shown) may be plated by known methods as needed, and may also be heat-treated as needed. Details of the heat treatment will be described later.

[0039] (5) Cover insulating layer The cover insulating layer 5 is positioned on one side of the base insulating layer 3 in the thickness direction, covering the conductor layer 4. The cover insulating layer 5 forms one side of the wiring circuit board 1 in the thickness direction. The cover insulating layer 5 extends in the plane direction.

[0040] The cover insulating layer 5 has a pattern shape. Specifically, the cover insulating layer 5 includes a plurality of cover insulating layers 5A and 5B. Each of the cover insulating layers 5A and 5B is included in each of the divided parts 11A and 11B described above. Each of the cover insulating layers 5A and 5B is arranged on one side of each of the base insulating layers 3A and 3B so as to cover the wiring of the conductor layer 6. In this embodiment, the end faces of the cover insulating layers 5 (each of the cover insulating layers 5A and 5B) in the width direction are flush with the end faces of the base insulating layers 3 (each of the base insulating layers 3A and 3B) in the width direction.

[0041] Examples of materials for the cover insulating layer 5 include resins similar to those exemplified for the base insulating layer 3. In other words, the cover insulating layer 5 is preferably made of a resin. Examples of resins include polyimide resin, polyamide-imide resin, acrylic resin, polyethernitrile resin, polyethersulfone resin, polyethylene terephthalate resin, polyethylene naphthalate resin, and polyvinyl chloride resin, with polyimide resin being preferred. In other words, the above resin is preferably polyimide resin.

[0042] The cover insulating layer 5 is formed, for example, by heat curing the resin mentioned above. Details of the heat curing of the resin will be described later.

[0043] The thickness of the cover insulating layer 5 is, for example, 1 μm or more, preferably 3 μm or more. Alternatively, the thickness of the cover insulating layer 5 is, for example, 30 μm or less, preferably 20 μm or less.

[0044] The thickness of the cover insulating layer 5 is the length in the thickness direction between one side of the base insulating layer 3 in the thickness direction and one side of the cover insulating layer 5 in the thickness direction that faces the aforementioned side without the conductor layer 4 in between.

[0045] The sum of the thickness of the cover insulating layer 5 and the thickness of 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 sum of the thickness of the cover insulating layer 5 and the thickness of the base insulating layer 3 is, for example, 5 μm or more.

[0046] 2. Copper alloys (1) Overall structure In the above-described wiring circuit board 1, the metal support substrate 2 contains a copper alloy, and preferably is made of a copper alloy.

[0047] A copper alloy is an alloy containing copper. A copper alloy contains a primary metal consisting of copper and a secondary metal that can alloy with copper. "Alloyable" means that an alloy can be formed. The alloy may be a solid solution, a eutectic, an intermetallic compound, or a composite thereof.

[0048] In copper alloys, the second metal is an additive metal added to copper as the first metal. That is, the second metal is a metal other than copper. Examples of the second metal include titanium, nickel, silicon, and iron. These can be used alone or in combination of two or more. That is, the copper alloy may be a two-component alloy or an alloy of three or more components. The second metal is preferably titanium. When the second metal is titanium, the copper alloy is a copper-titanium alloy. When a copper-titanium alloy is used, the wiring circuit board 1 has superior mechanical strength.

[0049] In copper alloys, the content ratio of the first metal (i.e., copper (hereinafter the same)) and the content ratio of the second metal (preferably titanium (hereinafter the same)) are set appropriately according to the purpose and application.

[0050] More specifically, the atomic proportion of the first metal is, for example, 50 to 99 atomic percent, preferably 80 to 99 atomic percent, and more preferably 90 to 99 atomic percent, relative to the total amount (total number of atoms) of the copper alloy. That is the case.

[0051] Furthermore, the atomic proportion of the second metal is, for example, 1 to 50 atomic%, preferably 1 to 20 atomic%, and more preferably 1 to 10 atomic%, relative to the total amount (total number of atoms) of the copper alloy.

[0052] In copper alloys, the sum of the atomic proportions of the first metal and the second metal is, for example, 100 atomic percent.

[0053] Furthermore, on a mass basis, the mass percentage of the first metal is, for example, 50 to 99% by mass, preferably 80 to 99% by mass, and more preferably 90 to 99% by mass, relative to the total amount (total mass) of the copper alloy.

[0054] Furthermore, on a mass basis, the mass percentage of the second metal is, for example, 1 to 50% by mass, preferably 1 to 20% by mass, and more preferably 1 to 10% by mass, relative to the total amount (total mass) of the copper alloy.

[0055] In copper alloys, the sum of the mass percentages of the first metal and the second metal is, for example, 100% by mass.

[0056] (2) Phase separation structure In the metal support substrate 2, the copper alloy has a phase separation structure. Examples of phase separation structures include a sea-island structure and a lamellar structure (described later). In the metal support substrate 2, the copper alloy has at least a sea-island structure. In the metal support substrate 2, the copper alloy preferably does not have a lamellar structure (described later) and has a sea-island structure. Particularly preferably, in the metal support substrate 2, the entire copper alloy has a sea-island structure.

[0057] [Sea-island structure] A sea-island structure comprises a continuous sea area (i.e., a marine phase) and a discontinuous island area (i.e., an island phase).

[0058] More specifically, a copper alloy having a sea-island structure comprises a sea portion in which the content of the first metal is relatively high and the content of the second metal is relatively low, and an island portion in which the content of the first metal is relatively low and the content of the second metal is relatively high.

[0059] The ocean and island regions are in phase separation, and the island regions are arranged so that they are dispersed within a matrix consisting of the ocean regions.

[0060] The presence of a sea-island structure can be confirmed, for example, by the following methods. Specifically, the presence of a sea-island structure can be confirmed by, for example, energy-dispersive X-ray spectroscopy (EDX analysis) of a cross-section of a copper alloy and observing the distribution of the first metal and the second metal. Alternatively, the presence of a sea-island structure can be confirmed by, for example, imaging a cross-section of a copper alloy with a scanning electron microscope (SEM) and observing the sea and island areas in the image. Preferably, the presence of a sea-island structure is confirmed by energy-dispersive X-ray spectroscopy (EDX analysis).

[0061] The content of the first metal differs between the aquatic and island regions. More specifically, the content of the first metal is higher in the aquatic region than in the island region. Furthermore, the content of the second metal differs between the aquatic and island regions. More specifically, the content of the second metal is lower in the aquatic region than in the island region.

[0062] For example, on an atomic basis, the atomic proportion of the first metal in the copper alloy is, for example, 50 to 100 atomic percent, preferably 80 to 100 atomic percent, and more preferably 90 to 100 atomic percent, relative to the total amount (total number of atoms) of the copper alloy.

[0063] Furthermore, the atomic proportion of the second metal in the copper alloy is, for example, 0 to 50 atomic percent, preferably 0 to 20 atomic percent, and more preferably 0 to 10 atomic percent, relative to the total amount (total number of atoms) of the copper alloy.

[0064] Furthermore, the sum of the atomic proportions of the first metal and the atomic proportions of the second metal in the Kaifu region is, for example, 100 atomic percent.

[0065] On the other hand, the atomic proportion of the first metal in the island portion is, for example, 50 to 99 atomic percent, preferably 60 to 99 atomic percent, and more preferably 70 to 99 atomic percent, relative to the total amount (total number of atoms) of the copper alloy.

[0066] Furthermore, the atomic proportion of the second metal in the island portion is, for example, 1 to 50 atomic%, preferably 1 to 40 atomic%, and more preferably 1 to 30 atomic%, relative to the total amount (total number of atoms) of the copper alloy.

[0067] Furthermore, the sum of the atomic proportions of the first metal and the atomic proportions of the second metal in the island region is, for example, 100 atomic percent.

[0068] Furthermore, from the viewpoint of conductivity, the atomic ratio of the first metal in the sea area is, for example, 1.01 times or more, preferably 1.05 times or more, and more preferably 1.1 times or more, compared to the atomic ratio of the first metal in the island area. Also, the atomic ratio of the first metal in the sea area is, for example, 5 times or less compared to the atomic ratio of the first metal in the island area.

[0069] In other words, the atomic ratio of the first metal in the sea area is, for example, 1.01 times or more and 5 times or less, preferably 1.05 times or more and 5 times or less, compared to the atomic ratio of the first metal in the island area.

[0070] Furthermore, from the viewpoint of conductivity, the atomic ratio of the second metal in the sea area is, for example, 0 times or more compared to the atomic ratio of the second metal in the island area. Also, the atomic ratio of the second metal in the sea area is, for example, 0.9 times or less, preferably 0.8 times or less, and more preferably 0.5 times or less compared to the atomic ratio of the second metal in the island area.

[0071] In other words, the atomic ratio of the second metal in the sea area is, for example, 0 to 0.9 times, preferably 0 to 0.8 times, and more preferably 0 to 0.5 times, relative to the atomic ratio of the second metal in the island area.

[0072] Furthermore, on a mass basis, the mass ratio of the first metal in the sea portion is, for example, 50 to 100% by mass, preferably 80 to 100% by mass, and more preferably 90 to 100% by mass, relative to the total amount (total mass) of the copper alloy.

[0073] Furthermore, the content of the second metal in the sea portion is, for example, 0 to 50% by mass, preferably 0 to 20% by mass, and more preferably 0 to 10% by mass, relative to the total amount (total mass) of the copper alloy.

[0074] Furthermore, the sum of the mass percentage of the first metal and the mass percentage of the second metal in the sea region is, for example, 100 atomic percent.

[0075] Furthermore, the mass percentage of the first metal in the island portion is, for example, 50 to 99% by mass, preferably 75 to 99% by mass, and more preferably 80 to 99% by mass, relative to the total amount (total mass) of the copper alloy.

[0076] Furthermore, the content of the second metal in the island portion is, for example, 1 to 50% by mass, preferably 1 to 25% by mass, and more preferably 1 to 20% by mass, relative to the total amount (total mass) of the copper alloy.

[0077] Furthermore, the sum of the mass percentage of the first metal and the mass percentage of the second metal in the island region is, for example, 100% by mass.

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

[0079] In other words, the mass ratio of the first metal in the sea area is, for example, 1.01 times or more and 5 times or less, preferably 1.05 times or more and 5 times or less, compared to the mass ratio of the first metal in the island area.

[0080] Furthermore, the mass ratio of the second metal in the sea area to the mass ratio of the second metal in the island area is, for example, 0 times or more. Also, the mass ratio of the second metal in the sea area to the mass ratio of the second metal in the island area is, for example, 0.9 times or less, preferably 0.8 times or less, and more preferably 0.5 times or less.

[0081] In other words, the mass ratio of the second metal in the sea area to the mass ratio of the second metal in the island area is, for example, 0 to 0.9 times, preferably 0 to 0.8 times, and more preferably 0 to 0.5 times.

[0082] The above atomic ratio and mass ratio are measured by known methods. Examples of measurement methods include energy-dispersive X-ray spectroscopy (EDX analysis), X-ray fluorescence analysis, inductively coupled plasma emission spectroscopy, and glow discharge emission spectroscopy, with energy-dispersive X-ray spectroscopy (EDX analysis) being preferred.

[0083] Furthermore, the atomic ratio can be measured, and the mass ratio can be calculated based on the atomic ratio.

[0084] In a sea-island structure, the number-average particle diameter of the island portion is, for example, 50 nm or more, preferably 100 nm or more, more preferably 200 nm or more, and even more preferably 220 nm or more. Also, in a sea-island structure, the number-average particle diameter of the island portion is, for example, 5000 nm or less, preferably 2000 nm or less, and even more preferably 1000 nm or less. That is, the number-average particle diameter of the island portion is, for example, 50 nm or more and 5000 nm or less, preferably 100 nm or more and 2000 nm, more preferably 200 nm or more and 1000 nm or less, and even more preferably 220 nm or more and 1000 nm or less.

[0085] The number-average particle diameter of the island regions is measured using a scanning electron microscope (SEM) in accordance with the examples described later. More specifically, the particle diameters of 10 or more island regions are measured in the cross-sectional image of the copper alloy taken by the scanning electron microscope (SEM image), and the average value is calculated as the number-average particle diameter.

[0086] Copper alloys having a sea-island structure preferably have Cu3Ti and / or Cu4Ti. In such cases, in the XRD chart obtained by measuring the X-ray diffraction (XRD) of the copper alloy, a peak originating from Cu3Ti and / or Cu4Ti is observed, with its peak top in the range of 2θ value (i.e., diffraction angle) 41.00° to 42.00°. Copper alloys in which such peaks are observed have a particularly excellent sea-island structure. Therefore, the above-described wiring circuit board 1 combines excellent mechanical strength and excellent conductivity in a good manner.

[0087] The X-ray diffraction of the copper alloy is measured in accordance with the examples described later.

[0088] Such sea-island structures are formed, for example, by heating a copper alloy having a lamellar structure. Details regarding the heating process will be described later.

[0089] (3) Physical properties Copper alloys have relatively high mechanical strength. The tensile strength of the above copper alloys is, for example, 500 MPa or more, preferably 800 MPa or more. The tensile strength of the above copper alloys is, for example, 2000 MPa or less, preferably 1500 MPa or less. That is, the tensile strength of copper alloys is, for example, 500 MPa or more and 2000 MPa or less, preferably 800 MPa or more and 1500 MPa or less. The tensile strength of copper alloys is measured in accordance with JIS Z2241 (2011).

[0090] Furthermore, the above copper alloy has relatively high conductivity. For example, when a copper alloy is rolled, the conductivity of the copper alloy at 20°C is, for example, 50% IACS or less, preferably 40% IACS or less, in the rolling direction (MD direction). Also, the conductivity of the copper alloy at 20°C is, for example, 1% IACS or more, preferably 5% IACS or more, in the rolling direction (MD direction). That is, the conductivity of the copper alloy at 20°C is, for example, 1% IACS or more and 50% IACS or less, preferably 5% IACS or more and 40% IACS or less, in the rolling direction (MD direction).

[0091] Furthermore, when a copper alloy is rolled, the conductivity of the copper alloy at 20°C is, for example, 50% IACS or less, preferably 40% IACS or less, in the direction perpendicular to the rolling direction (TD direction). Also, the conductivity of the copper alloy at 20°C is, for example, 1% IACS or more, preferably 5% IACS or more, in the direction perpendicular to the rolling direction (TD direction). That is, the conductivity of the copper alloy at 20°C is, for example, 1% IACS or more and 50% IACS or less, preferably 5% IACS or more and 40% IACS or less, in the direction perpendicular to the rolling direction (TD direction).

[0092] IACS stands for International Annealed Copper Standard, and conductivity is measured in accordance with JIS H0505 (1975).

[0093] 3. Manufacturing method of a wiring circuit board In the following, an embodiment of the method for manufacturing a wiring circuit board according to the present invention will be described with reference to Figure 2.

[0094] (1) Metal support substrate In the manufacturing of the wiring circuit board 1, first, the metal support substrate 2 is prepared as shown in Figures 2A and 2B.

[0095] More specifically, in this process, as shown in Figure 2A, first, an unheated (described later) metal support substrate 2 is prepared. Hereinafter, the unheated (described later) metal support substrate 2 will be referred to as the raw material 20. The raw material 20 is, for example, available as a commercially available product. The raw material 20 is, for example, a rolled copper alloy. The raw material 20 is, for example, a copper alloy having a lamellar structure.

[0096] Next, in this method, as shown in Figure 2B, the raw material 20 is heated (preheated) to obtain a heated metal support substrate 2. In other words, in this embodiment, the step of preparing the metal support substrate 2 includes the step of heating the raw material 20. Hereinafter, the heated metal support substrate 2 will be referred to as the heated substrate 21. Further details regarding heating will be described later.

[0097] (2) Base insulating layer Next, in this method, as shown in Figure 2C, a base insulating layer 3 is formed on one side in the thickness direction of the metal support substrate 2 (preferably the substrate to be heated 21).

[0098] The method for forming the base insulating layer 3 is not particularly limited, but for example, first, a varnish is prepared. The varnish contains, for example, a photosensitive agent, a resin component, and a solvent. If the base insulating layer 3 is made of a polyimide resin, the resin component preferably includes an acidic dianhydride and a diamine.

[0099] Next, in this method, the above-mentioned varnish is applied to one side of the metal support substrate 2 in the thickness direction and dried by heating to form a photosensitive coating film. The coating film contains polyamic acid resin. Polyamic acid resin is a reaction product of an acid dianhydride and a diamine, and is a precursor of polyimide resin.

[0100] In the process of forming the base insulating layer 3, the drying temperature is, for example, 50°C or higher. Alternatively, in the process of forming the base 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.

[0101] In the process of forming the base insulating layer 3, the drying time is, for example, 1 minute or more. Alternatively, in the process of forming the base 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.

[0102] Next, in this method, the above-mentioned coating film is exposed to light and developed to form the coating film into a predetermined pattern. Then, in this method, the coating film of the predetermined pattern (i.e., the resin precursor) is heat-cured to obtain the base insulating layer 3.

[0103] In the step of forming the base insulating layer 3, the thermosetting temperature is, for example, 100°C or higher, preferably 200°C or higher. Alternatively, in the step of forming the base 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.

[0104] In the process of forming the base insulating layer 3, the heat curing time is, for example, 1 hour or more. Alternatively, in the process of forming the base insulating layer 3, the heat curing time is, for example, 10 hours or less. In other words, the heat curing time is, for example, 1 hour or more and 10 hours or less.

[0105] As a result, the base insulating layer 3 is positioned on one side in the thickness direction of the metal support substrate 2.

[0106] (3) Conductor layer Next, in this method, as shown in Figure 2D, a conductor layer 4 is formed on one side in the thickness direction of the base insulating layer 3.

[0107] The method for forming the conductor layer 4 is not particularly limited, and known conductor pattern formation methods can be employed. Examples of conductor pattern formation methods include additive methods, semi-additive methods, and subtractive methods, with additive methods being preferred.

[0108] Furthermore, although not shown in the diagram, the terminal portion of the conductor layer 4 may be plated, or the conductor layer 4 may be heat-treated, as needed.

[0109] As a result, the conductor layer 4 is positioned on one side in the thickness direction of the base insulating layer 3.

[0110] (4) Cover insulating layer Next, in this method, as shown in Figure 2E, a cover insulating layer 5 is formed on one side in the thickness direction of the base insulating layer 3 and the conductor layer 4.

[0111] The method for forming the cover insulating layer 5 is not particularly limited, but for example, the cover insulating layer 5 may be formed in the same manner as the method for forming the base insulating layer 3 described above.

[0112] More specifically, for example, first prepare a varnish. The varnish contains, for example, a photosensitive agent, a resin component, and a solvent. If the cover insulating layer 5 is made of polyimide resin, the resin component preferably includes an acidic dianhydride and a diamine.

[0113] Next, in this method, the above-mentioned varnish is applied to one side in the thickness direction of the base insulating layer 3 and the conductive layer 4, and a photosensitive coating film is formed by drying it by heating. The coating film contains polyamic acid resin. Polyamic acid resin is a reaction product of an acid dianhydride and a diamine, and is a precursor of polyimide resin.

[0114] In the process of forming the cover insulating layer 5, the drying temperature is, for example, 50°C or higher. Alternatively, in the process of forming the cover 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.

[0115] In the process of forming the cover insulating layer 5, the drying time is, for example, 1 minute or more. Alternatively, in the process of forming the cover 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.

[0116] Next, in this method, the above-mentioned coating film is exposed to light and developed to form the coating film into a predetermined pattern. Then, in this method, the coating film of the predetermined pattern (i.e., the resin precursor) is heat-cured to obtain the cover insulating layer 5.

[0117] In the step of forming the cover insulating layer 5, the thermosetting temperature is, for example, 100°C or higher, preferably 200°C or higher. Alternatively, in the step of forming the cover 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.

[0118] In the process of forming the cover insulating layer 5, the heat curing time is, for example, 1 hour or more. Alternatively, in the process of forming the cover 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.

[0119] As described above, the cover insulating layer 5 is positioned on one side in the thickness direction of the base insulating layer 3 and the conductor layer 4. More specifically, on one side in the thickness direction of the base insulating layer 3, the cover insulating layer 5 covers the wiring of the conductor layer 4 and exposes the terminal portion (not shown).

[0120] Furthermore, in each of the above processes, the metal support substrate 2, the base insulating layer 3, the conductor layer 4, and the cover insulating layer 5 are aligned with each other to manufacture the wiring circuit board 1 (see Figure 1).

[0121] 4.Heating In the manufacturing method of the wiring circuit board 1 described above, the raw material 20 is heated to obtain the heated substrate 21.

[0122] The raw material 20 is, for example, a rolled copper alloy as described above. In the raw material 20, the copper alloy has a lamellar structure. In the raw material 20, the copper alloy preferably does not have the sea-island structure described above. Particularly preferably, in the raw material 20, the entire copper alloy has a lamellar structure.

[0123] The lamellar structure comprises a first phase having a nano-order thin layer shape and a second phase having a nano-order thin layer shape.

[0124] More specifically, a copper alloy having a lamellar structure comprises a first phase in which the content of the first metal is relatively large and the content of the second metal is relatively small, and a second phase in which the content of the first metal is relatively small and the content of the second metal is relatively large.

[0125] The first and second phases are phase-separated and arranged to be stacked alternately.

[0126] The presence of a lamellar structure can be confirmed, for example, by the following methods. Specifically, the presence of a lamellar structure can be confirmed by photographing a cross-section of a copper alloy with a scanning electron microscope (SEM) and observing the first and second phases in the resulting image (SEM image). Alternatively, the presence of a lamellar structure can be confirmed 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. Preferably, the presence of a lamellar structure is confirmed by imaging with a scanning electron microscope.

[0127] In phase 1 and phase 2, the proportion of metal 1 differs from that of metal 1. More specifically, the proportion of metal 1 in phase 1 is higher than that in phase 2. Also, in phase 1 and phase 2, the proportion of metal 2 differs from that of metal 2. More specifically, the proportion of metal 2 in phase 1 is lower than that in phase 2.

[0128] In a lamellar structure, the thickness of the first phase is, for example, between 10 nm and 100 nm. Similarly, the thickness of the second phase is, for example, between 5 nm and 100 nm. The thicknesses of the first and second phases are measured by photographing a cross-section of a copper alloy with a lamellar structure using a scanning electron microscope (SEM) and observing the resulting image.

[0129] Copper alloys having a lamellar structure are formed, for example, by rolling a copper alloy. The conditions for rolling the copper alloy are set appropriately within the range in which the lamellar structure described above can be obtained.

[0130] In the manufacturing method of the wiring circuit board 1 described above, the raw material 20 having a lamellar structure is heated. The heating method is not particularly limited. For example, although not shown, the raw material 20 can be heated by winding it onto a heat treatment core and then placing the raw material 20 wound onto the heat treatment core in a heating furnace.

[0131] In the heating process described above, the heating conditions are adjusted so that a copper alloy having the aforementioned sea-island structure is obtained.

[0132] More specifically, the heating temperature in the above heating is 350°C or higher, preferably 360°C or higher. Alternatively, the heating temperature in heating is, for example, 500°C or lower, preferably 450°C or lower. That is, the heating temperature in heating is, for example, 350°C or higher and 500°C or lower, preferably 360°C or higher and 450°C or lower.

[0133] The heating time in the above heating process is adjusted according to the heating temperature, but is, for example, 3 minutes or more. Also, the heating time in the heating process is, for example, 10 hours or less. In other words, the heating time in the heating process is, for example, 3 minutes or more and 10 hours or less.

[0134] The above heating process allows for the uneven distribution and grain growth of the secondary metal throughout the copper alloy, resulting in the formation of a copper alloy with a sea-island structure.

[0135] More specifically, when the raw material 20 is heated under the above-described conditions, the second metal becomes unevenly distributed throughout the copper alloy. In other words, the above heating creates island regions 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, the above heating creates sea regions where the proportion of the first metal is relatively large and the proportion of the second metal is relatively small. In addition, within the copper alloy, the island regions are arranged to be dispersed within the sea regions. That is to say, the above-described sea-island structure is formed by the above heating.

[0136] As a result, a copper alloy having the above-described sea-island structure is obtained as the substrate to be heated 21.

[0137] In other words, the heated substrate 21 contains a copper alloy having a sea-island structure, and preferably consists of a copper alloy having a sea-island structure. As described above, such a heated substrate 21 is used as a metal support substrate 2 in the manufacture of the wiring circuit board 1.

[0138] 5. Effects In the above-described wiring circuit board 1, the metal support substrate 2 contains a copper alloy, and the copper alloy contains a first metal consisting of copper and a second metal that can be alloyed with copper. Therefore, the above-described wiring circuit board 1 has excellent mechanical strength.

[0139] Furthermore, the above copper alloy has a sea-island structure, which comprises a continuous sea portion and a discontinuous island portion. Therefore, the above wiring circuit board 1 has excellent conductivity due to its sea-island structure.

[0140] As a result, the above-described wiring circuit board 1 possesses both excellent mechanical strength and excellent conductivity.

[0141] Furthermore, in the above-described wiring circuit board 1, if the atomic ratio of the second metal in the sea portion is less than or equal to the predetermined value compared to the atomic ratio of the second metal in the island portion, the above-described wiring circuit board has superior conductivity. In other words, if the atomic ratio of copper is relatively high in the continuous sea portion, the above-described wiring circuit board has superior conductivity.

[0142] Furthermore, in the above-described wiring circuit board 1, if the second metal is titanium and the copper alloy is a copper-titanium alloy, the above-described wiring circuit board will have superior mechanical strength.

[0143] Furthermore, in the above-described wiring circuit board, the number-average particle size of the island portions is greater than or equal to a predetermined value. In other words, in the above-described wiring circuit board 1, the copper alloy has a particularly excellent sea-island structure. Therefore, the above-described wiring circuit board 1 combines excellent mechanical strength and excellent conductivity in a good manner.

[0144] Furthermore, when the X-ray diffraction (XRD) of the copper alloy in the above-described wiring circuit board 1 is measured, a peak with its peak top in the range of 2θ values ​​between 41.00° and 42.00° is observed in the XRD chart. Such copper alloys have a particularly excellent sea-island structure. Therefore, the above-described wiring circuit board 1 combines excellent mechanical strength and excellent conductivity in a good manner.

[0145] Furthermore, in the above-described method for manufacturing a wiring circuit board, the metal support substrate 2 contains a copper alloy, and the metal support substrate is heated to a predetermined heating temperature. Therefore, according to the above-described method for manufacturing a wiring circuit board 1, the above-described sea-island structure can be formed well. As a result, according to the above-described method for manufacturing a wiring circuit board 1, a wiring circuit board 1 that combines excellent mechanical strength and excellent conductivity can be efficiently obtained.

[0146] 6. Variations In the modified examples, components and processes similar to those in the first embodiment are given the same reference numerals, and their detailed descriptions are omitted. Furthermore, the modified examples can achieve the same effects and advantages as the first embodiment, unless otherwise specified. Moreover, the first embodiment and its modified examples can be combined as appropriate.

[0147] In the embodiment described above, the raw material 20 is heated by winding it onto a heat treatment core and then placing the wound raw material 20 in a heating furnace. However, the heating method is not limited to the above. For example, the raw material 20 can also be heat-treated by passing it through the heating furnace while being transported by a roll-to-roll method. The heating conditions are the same as described above.

[0148] Furthermore, in the above embodiment, the raw material 20 (i.e., a copper alloy having a lamellar structure) is heated before forming the base insulating layer 3 to form the heated substrate 21 (i.e., a copper alloy having a sea-island structure), but the timing of heating is not limited to the above.

[0149] 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 this time, the metal support substrate 2 is also heated together with the varnish. Therefore, for example, the raw material 20 can be heated during the process of forming the base insulating layer 3, without heating the raw material 20 before forming the base insulating layer 3. More specifically, varnish as the material for the base insulating layer 3 is applied to the raw material 20, and then the varnish is heated to form the base insulating layer 3. At this time, the raw material 20 can also be heated together with the varnish under the above conditions to form the heated substrate 21 (i.e., the copper alloy having the above-mentioned sea-island structure).

[0150] Furthermore, for example, in the manufacturing of the wiring circuit board 1, the conductor layer 4 may be heated as a heat treatment during the process of forming the conductor layer 4, if necessary. In such cases as well, the raw material 20 can be heated together with the conductor layer 4 under the above conditions to form the heated substrate 21 (i.e., the copper alloy having the above-described sea-island structure).

[0151] Furthermore, for example, in the manufacturing of the wiring circuit board 1, the varnish is heated in the process of forming the cover insulating layer 5. Therefore, for example, in the process of forming the cover insulating layer 5, the base material 20 can also be heated to form the copper alloy having the sea-island structure described above. More specifically, a base insulating layer 3 is laminated onto the base material 20, and then a conductor layer 4 is laminated onto the base insulating layer 3. Next, varnish as the material for the cover insulating layer 5 is applied to the base insulating layer 3 and the conductor layer 4, and then the varnish is heated to form the cover insulating layer 5. At this time, the base material 20 can also be heated together with the varnish under the above conditions to form the heated substrate 21 (i.e., the copper alloy having the sea-island structure described above).

[0152] In other words, heating of the raw material 20 may be performed before the process of forming the base insulating layer 3, during the process of forming the base insulating layer 3, during the process of forming the conductor layer 4, or during the process of forming the cover insulating layer 5. Furthermore, these may be combined. Heating of the raw material 20 is performed before the process of forming the base insulating layer 3.

[0153] Furthermore, in the above-described embodiment, the conductive layer 4 contains copper (i.e., unalloyed copper), but for example, the conductive layer 4 may contain a copper alloy having the sea-island structure described above.

[0154] In such cases, for example, a conductive layer 4 containing a copper alloy having a lamellar structure can be formed, and then the conductive layer 4 can be heated to form the conductive layer 4 containing the copper alloy having the sea-island structure described above.

[0155] For example, a base insulating layer 3 is laminated onto a metal support substrate 2, and then a conductive layer 4 is laminated onto the base insulating layer 3. At this time, the conductive layer 4 is formed using a copper alloy having a lamellar structure, for example, by a subtractive method. Next, the conductive layer 4 is heat-treated. At this time, by heating the conductive layer 4 under the above conditions, a copper alloy containing a sea-island structure is formed. In other words, by heating the conductive layer 4 in the process of forming the conductive layer 4, a conductive layer 4 containing the copper alloy having the above-mentioned sea-island structure can be formed.

[0156] Furthermore, for example, in the process of forming the cover insulating layer 5, the conductive layer 4 can be heated to form a copper alloy having a sea-island 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, the conductor layer 4 is formed using a copper alloy having a lamellar structure, for example, by a subtractive method. Next, varnish is applied to the base insulating layer 3 and the conductor layer 4 as the material for the cover insulating layer 5, and then the varnish is heated to form the cover insulating layer 5. At this time, by heating the conductor layer 4 together with the varnish under the above conditions, a copper alloy containing a sea-island structure is formed. In other words, by heating the conductor layer 4 in the process of forming the cover insulating layer 5, a conductor layer 4 containing a copper alloy having a sea-island structure can be formed.

[0158] Even in such cases, the wiring circuit board 1 possesses both excellent mechanical strength and excellent conductivity.

[0159] In other words, the conductive layer 4 contains a copper alloy, and the copper alloy contains a first metal consisting of copper and a second metal that can be alloyed with copper. Therefore, the above-described wiring circuit board 1 has excellent mechanical strength.

[0160] Furthermore, in the conductive layer 4 described above, the copper alloy has a sea-island structure, and the sea-island structure comprises a continuous sea portion and a discontinuous island portion. Therefore, the wiring circuit board 1 has excellent conductivity derived from the copper in the sea portion.

[0161] Furthermore, if the conductive layer 4 contains a copper alloy having a sea-island structure, the metal support substrate 2 does not need to contain the same copper alloy having a sea-island structure. Alternatively, both the metal support substrate 2 and the conductive layer 4 may contain the same copper alloy having a sea-island structure.

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

[0163] Preferably, in the manufacturing method of the wiring circuit board 1 described above, the metal support substrate 2 (specifically, the raw material 20) is heated. Furthermore, the metal support substrate 2 contains a copper alloy having a sea-island structure.

[0164] Furthermore, if the metal support substrate 2 does not contain a copper alloy having a sea-island structure, the material of the metal support substrate 2 is not particularly limited. More specifically, the material of the metal support substrate 2 may be, for example, a copper alloy without a sea-island structure, or a metal other than a copper alloy. Examples of metals other than copper alloys include copper and stainless steel.

[0165] Although not described in detail here, in the above-mentioned wiring circuit board 1, the cover insulating layer 5 is an arbitrary layer, and may be omitted if necessary. [Examples]

[0166] The present invention will be further described below with reference to examples and comparative examples. However, the present invention is not limited in any way to the examples and comparative examples. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical properties, and parameters used in the following description may be replaced with the corresponding upper limits (numerical values ​​defined as "less than or equal to" or "less than") or lower limits (numerical values ​​defined as "greater than or equal to" or "greater than or equal to") of the blending ratios (content ratios), physical properties, and parameters described in the "Modes for Carrying Out the Invention" above.

[0167] 1. Sample manufacturing Reference Example 1 A commercially available rolled copper alloy (30 μm thick) was prepared as the raw material. The copper alloy was a copper-titanium alloy containing copper as the primary metal and titanium as the secondary metal. In the copper alloy, the copper content was 96.3% by mass, and the titanium content was 3.7% by mass.

[0168] Reference Example 1 The raw material of Reference Comparative Example 1 was heated at 400°C for 4 hours to obtain a heated substrate (thickness 30 μm). In other words, the heated substrate was the above-mentioned copper-titanium alloy that had been rolled and heated.

[0169] 2. Evaluation (1) SEM imaging Using a scanning electron microscope (SEM), cross-sections of the raw material 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 the images were observed.

[0170] The imaging equipment and conditions are as follows. Equipment: S-4800, manufactured by Hitachi Corporation Condition: Acceleration voltage 3kV

[0171] Based on the above observations, it was confirmed that the raw material of Reference Comparative Example 1 has a lamellar structure. Furthermore, it was confirmed that the heated substrate of Reference Example 1 does not have a lamellar structure, but rather a sea-island structure. SEM images of Reference Comparative Example 1 and Reference Example 1 are shown in Figure 3.

[0172] Furthermore, the number-average particle diameter of the island areas in the SEM image of the heated substrate of Reference Example 1 was determined by the SEM method. More specifically, the particle diameters of 10 island areas were measured in the image (i.e., SEM image) of the cross-section of the heated substrate (copper alloy) of Reference Example 1, which was captured by a scanning electron microscope (SEM), and the average value was calculated as the number-average particle diameter.

[0173] As a result, the number-average particle size of the island region was 250 nm.

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

[0175] The analytical equipment and conditions are as follows. [mapping] Device: XFlash FlatQUAD, manufactured by Bruker. Condition: Acceleration voltage: 5kV [Point analysis] Equipment: X-MAX150, manufactured by Horiba Corporation Conditions: Acceleration voltage: 5kVm, 15kV

[0176] The above analysis confirmed that the raw material of Reference Comparative Example 1 does not have a sea-island structure. Furthermore, it was confirmed that the heated substrate of Reference Example 1 has a sea-island structure. Figure 4 shows the EDX images (distribution of titanium atoms) of Reference Comparative Example 1 and Reference Example 1. In Figure 4, the distribution of titanium atoms is shown in lighter colors.

[0177] Furthermore, using the elemental mapping described above, the atomic distribution of the oceanic region and the island region in the sea-island structure were calculated, and the mass percentage and atomic percentage of copper, and the mass percentage and atomic percentage of titanium were determined, respectively.

[0178] As a result, in Kaifu, the mass percentage of copper was 100% by mass, and the atomic percentage of copper was 100% by atomic percentage. In addition, in Kaifu, the mass percentage of titanium was 0% by mass, and the atomic percentage of titanium was 0% by atomic percentage.

[0179] On the other hand, in the island areas, the mass percentage of copper was 88.55% by mass, and the atomic percentage of copper was 85.36% by atomic percentage. Also in the island areas, the mass percentage of titanium was 11.45% by mass, and the atomic percentage of titanium was 14.64% by atomic percentage.

[0180] In other words, the atomic ratio of titanium in the open sea area (0 atoms) was zero compared to the atomic ratio of titanium in the island area (14.64 atoms).

[0181] (3) XRD Using an X-ray diffraction (XRD) apparatus, the raw material of Reference Comparative Example 1 and the heated substrate of Reference Example 1 were subjected to X-ray diffraction analysis, and XRD charts were obtained. The obtained XRD charts are shown in Figure 5.

[0182] The analytical equipment and conditions are as follows. Equipment: D8 Discover with GADDS, manufactured by Bruker. Conditions: X-ray source CuKα, voltage 50kV, current 100mA, detector VANTEC-500

[0183] A peak with its peak top in the range of 2θ values ​​between 41.00° and 42.00° was observed in the XRD chart of the heated substrate of Reference Example 1. The peak with its peak top in the range of 2θ values ​​between 41.00° and 42.00° was derived from Cu3Ti and / or Cu4Ti.

[0184] On the other hand, no peaks with peak tops in the range of 2θ values ​​between 41.00° and 42.00° were observed in the XRD chart of the raw material of Reference Comparison Example 1.

[0185] (4) Conductivity The conductivity of the raw material of Reference Comparative Example 1 at 20°C, and the conductivity of the heated substrate of Reference Example 1 at 20°C were measured in accordance with JIS H0505 (1975).

[0186] Furthermore, the conductivity in the rolling direction (MD direction) (hereinafter referred to as MD conductivity) and the conductivity in the direction perpendicular to the rolling direction (TD direction) (hereinafter referred to as TD conductivity) were measured separately.

[0187] The MD conductivity of the raw material in Reference Comparative Example 1 was 8% IACS, and the TD conductivity was also 8% IACS. The MD conductivity of the heated substrate in Reference Example 1 was 22% IACS, and the TD conductivity was 18% IACS.

[0188] In other words, it was confirmed that the conductivity of the heated substrate in the reference example was higher than that of the raw material in the reference comparative example. [Explanation of symbols]

[0189] 1 Wiring circuit board 2. Metal support substrate 3. Base insulating layer 4 Conductor layer 5. Cover insulation layer 11 Split body 20 Original fabric 21 Heated substrate

Claims

1. Metal support substrate and A base insulating layer is disposed on one side in the thickness direction of the metal support substrate, A conductive layer disposed on one side in the thickness direction of the base insulating layer and Equipped with, The metal support substrate and / or the conductor layer contains a copper alloy, The aforementioned copper alloy is The first metal is made of copper, The copper and a second metal that can be alloyed It contains, In the metal support substrate and / or the conductive layer, the copper alloy is A wiring circuit board having a sea-island structure comprising a continuous sea section and a discontinuous island section.

2. With respect to the atomic ratio of the second metal in the island portion, The wiring circuit board according to claim 1, wherein the atomic ratio of the second metal in the aforementioned sea portion is 0.9 times or less.

3. The wiring circuit board according to claim 1, wherein the second metal is titanium.

4. The wiring circuit board according to claim 1, wherein in the XRD chart obtained by measuring the X-ray diffraction (XRD) of the copper alloy, a peak having a peak top in the range of 2θ value 41.00° to 42.00° is confirmed.

5. The wiring circuit board according to claim 1, wherein the number-average particle diameter of the island portion, as measured using a scanning electron microscope (SEM), is 50 nm or more.

6. A method for manufacturing a wiring circuit board according to any one of claims 1 to 5, The process of preparing the metal support substrate, The process of forming a base insulating layer on one side in the thickness direction of the metal support substrate, A step of forming a conductive layer on one side in the thickness direction of the base insulating layer, A step of heating the metal support substrate and / or the conductive layer. Equipped with, The metal support substrate and / or the conductor layer contains a copper alloy, The aforementioned copper alloy is The first metal is made of copper, The copper and a second metal that can be alloyed It contains, A method for manufacturing a wiring circuit board, wherein the heating temperature in the aforementioned heating is 350°C or higher.

Images