Laminate

Abstract

The purpose of one embodiment of the present invention is to provide a laminate having both good electrical conductivity and good adhesion (particularly, suppression of interlayer peeling and / or intra-layer cohesive failure in the laminate). Another object is to provide a method for producing a laminate for producing the laminate. In one embodiment, provided is a laminate comprising a metal layer, a metal-containing polymer layer, and a polymer layer arranged in this order, in which the metal layer and the metal-containing polymer layer contain the same metal, the metal layer has a thickness of 0.1 [mu] m to 1010 [mu] m, and the polymer layer has a thickness of 0.1 [mu] m to 1010 [mu] m. The metal-containing polymer layer has a thickness of 0.04 [mu] m or more and 10 [mu] m or less.

Description

Technical Field

[0001] This invention relates to laminates, and more particularly to laminates comprising a metal layer and a polymer layer. Background Technology

[0002] As circuit boards and other electronic components, laminates with conductive wiring applied to a substrate are used, such as laminates comprising a metal layer (wiring) and a polymer layer (substrate). Circuit boards are typically manufactured through the following processes: coating a photoresist onto a substrate having a metal foil; exposing and developing the photoresist to obtain the desired circuit pattern; and removing the metal foil not covered by the photoresist through chemical etching, and then forming the pattern.

[0003] Patent Document 1 discloses a method for forming a conductive film with a predetermined pattern on a substrate. In this method, a metal film containing metal particles is formed on the substrate in a pattern substantially identical to that of the conductive film by a droplet ejection method, followed by at least one electroless plating process, thereby forming a plating film covering the surface of the metal film to obtain a conductive film.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-128228 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, the method described in Patent Document 1 has room for improvement in balancing the conductivity and adhesion of the conductive film (especially the suppression of interlayer delamination and / or intralayer cohesive failure in the laminate).

[0009] Methods to improve the conductivity of conductive films include reducing the organic content in the conductive film and forming a coating film on the conductive film. However, these methods may reduce the adhesion. That is, in the past, the conductivity and adhesion of conductive films were inversely related.

[0010] Therefore, one objective of the present invention is to provide a laminate that combines good conductivity with good adhesion (particularly suppression of interlayer delamination and / or intralayer cohesive failure). Another objective of the present invention is to provide a method for manufacturing the laminate.

[0011] Methods for solving problems

[0012] This disclosure includes the following items. [1]

[0014] A laminate is a laminate comprising a metal layer, a polymer layer containing a metal, and a polymer layer arranged in the following order, wherein... The aforementioned metal layer and the aforementioned metal-containing polymer layer both contain the same metal. The thickness of the aforementioned metal layer is 0.1 μm or more and 10¹⁰ μm or less. The thickness of the aforementioned metal-containing polymer layer is 0.04 μm or more and 10 μm or less. [2]

[0016] A laminate is a laminate comprising a metal layer, a polymer layer containing a metal, and a polymer layer arranged in the following order, wherein... The aforementioned metal layer and the aforementioned metal-containing polymer layer both contain the same metal. The polymer constituting the aforementioned metal-containing polymer layer and the polymer constituting the aforementioned polymer layer are nitrogen-containing polymers. The aforementioned metal-containing polymer layer contains a metal chemically bonded to a nitrogen atom. [3]

[0018] According to the laminate of Project 1 or 2, wherein the aforementioned metal-containing polymer layer contains more than 1 atomic% and less than 20 atomic% of metal. [4]

[0020] The laminate according to any one of items 1 to 3, wherein the thickness of the polymer layer is more than 1 μm and less than 1000 μm. [5]

[0022] According to any one of items 1 to 4, the laminated body, wherein, The aforementioned metal layer includes a first metal layer and a second metal layer disposed between the first metal layer and the metal-containing polymer layer. The first metal layer, the second metal layer, and the polymer layer containing the metal all contain the same metal. The thickness of the first metal layer is 0.1 μm or more and 1000 μm or less. The thickness of the second metal layer is 0.01 μm or more and 10 μm or less. [6]

[0024] According to the laminate described in Project 5, the second metal layer is a layer formed by reducing a layer containing copper oxide. [7]

[0026] The laminate according to any one of items 1 to 6, wherein the metal layer comprises carbon. [8]

[0028] According to the laminate described in Project 7, the aforementioned metal layer contains 0.1 atomic% or more and 15 atomic% or less of carbon. [9]

[0030] The laminate according to any one of items 1 to 8, wherein the metal layer and the metal-containing polymer layer contain copper.

[10]

[0032] The laminate according to any one of items 1 to 9, wherein the pattern of the metal layer is formed on the polymer layer containing the metal.

[11]

[0034] The laminate according to any one of items 1 to 10, wherein the aforementioned metal-containing polymer layer contains sodium.

[12]

[0036] According to the laminate described in Item 11, the aforementioned metal-containing polymer layer contains 0.1 atomic% or more and 10 atomic% or less of sodium.

[13]

[0038] According to any one of items 1 to 12, the laminated body, wherein, The polymer constituting the aforementioned metal-containing polymer layer and the polymer constituting the aforementioned polymer layer are nitrogen-containing polymers. The aforementioned metal-containing polymer layer contains a metal chemically bonded to a nitrogen atom.

[14]

[0040] The laminate according to any one of items 1 to 13, wherein the aforementioned metal-containing polymer layer comprises a metal with zero valence and / or one valence.

[15]

[0042] According to the laminate described in Item 14, the aforementioned metal-containing polymer layer contains metals with zero and / or one valence, but does not contain metals with two valences.

[16]

[0044] According to the laminate described in item 14 or 15, the aforementioned metal-containing polymer layer comprises metals with 0 valence and 1 valence.

[17]

[0046] According to any one of items 1 to 16, in the laminate, the metal concentration is 1.0 atomic% or more and 5.0 atomic% or less at a position 20 nm from the boundary between the polymer layer containing the metal and the polymer layer toward the metal layer.

[18]

[0048] According to any one of items 1 to 17, in the X-ray photoelectron spectroscopy of the polymer layer containing the metal, there is a peak in the range of 571 eV to 574 eV.

[19]

[0050] According to any one of items 1 to 18, the laminate has a porosity of 0.1% to 30% by volume in a region at a depth of 1 nm or more and 500 nm or less from the side of the polymer layer containing the metal.

[20]

[0052] The laminate according to any one of items 1 to 19, wherein the metal layer comprises monovalent copper oxide. [twenty one]

[0054] According to any one of items 1 to 20, in a cross-sectional view in the thickness direction, the ratio (L2) / (L1) of the length of the boundary line between the metal layer and the polymer layer containing the metal to the in-plane length (L1) of the laminate is 1.0 or more and 2.2 or less. [twenty two]

[0056] The laminate according to any one of items 1 to 21, wherein the aforementioned metal-containing polymer layer is a metal-containing polyimide layer, and the aforementioned polymer layer is a polyimide layer. [twenty three]

[0058] According to any one of items 1 to 22, in the infrared absorption spectroscopy measurement, the minimum value of the ratio (IR1) / (IR2) of the peak intensity (IR1) of the first peak of the first structure of the polymer constituting the metal-containing polymer layer and the polymer of the polymer layer to the peak intensity (IR2) of the second peak of the second structure of the second structure of the polymer layer is 0.2 or more and 1.5 or less. [twenty four]

[0060] The laminates described in any one of items 1 to 23 are used as constituent elements of electronic circuit boards.

[25]

[0062] A method for manufacturing a laminate, which is a method for manufacturing a laminate according to any one of items 1 to 24, includes the following steps: The coating process involves coating a metal oxide onto a polymer substrate; and The reduction process involves reducing the aforementioned metal oxides.

[26]

[0064] According to the method described in Project 25, the above-mentioned reduction is performed by laser irradiation.

[27]

[0066] The method described according to item 25 or 26 further includes an electroless metal plating process.

[28]

[0068] According to the method described in Project 27, the electroless metal plating process is performed after the reduction process described above.

[29]

[0070] A method for manufacturing a laminate, comprising the following steps: a first metal layer, a second metal layer, a metal-containing polymer layer, and a polymer layer sequentially disposed thereon, wherein the first metal layer, the second metal layer, and the metal-containing polymer layer comprise the same metal. The process of forming the aforementioned first metal layer with a thickness of 0.1 μm or more and 1000 μm or less; The process of forming the aforementioned second metal layer with a thickness of 0.01 μm or more and 10 μm or less; The process of forming the aforementioned metal-containing polymer layer with a thickness of 0.04 μm or more and 10 μm or less; and The process of forming the above-mentioned polymer layer with a thickness of 1.0 μm or more and 1000 μm or less.

[30]

[0072] According to the method for manufacturing the laminate described in Item 29, the step of forming the second metal layer includes the following steps: The coating process involves coating a dispersion containing metal particles and / or metal oxide particles onto a substrate to form a dispersion layer. The drying process involves drying the aforementioned dispersion layer to form a dry coating film on the aforementioned substrate; and The process of forming the second metal layer by heating the dried coating film.

[31]

[0074] According to the method for manufacturing the laminate described in Item 29, the step of forming the second metal layer includes the following steps: The coating process involves coating a dispersion containing metal particles and / or metal oxide particles onto a substrate to form a dispersion layer. The drying process involves drying the aforementioned dispersion layer to form a dry coating film on the aforementioned substrate; and The process of forming the second metal layer by firing the dried coating film by irradiation with a laser.

[32]

[0076] According to the manufacturing method of the laminate described in item 30 or 31, the aforementioned metal particles and / or metal oxide particles are copper particles and / or copper oxide particles.

[33]

[0078] According to any one of items 29 to 32, the method for manufacturing a laminate includes the step of forming the first metal layer by immersing the second metal layer in a plating solution to form the first metal layer.

[34]

[0080] According to the method for manufacturing the laminate described in Project 33, the above-mentioned plating solution with a pH of 10 or higher and 14 or lower is used.

[0081] The effects of the invention

[0082] According to one aspect of the present invention, a laminate that balances good conductivity with good adhesion (particularly suppression of interlayer delamination and / or intralayer cohesive failure) can be provided. Furthermore, according to another aspect of the present invention, a method for manufacturing the laminate for producing such a laminate can be provided. Attached Figure Description

[0083] Figure 1 This is a schematic diagram illustrating the solution method for ratio (L2) / (L1).

[0084] Figure 2A This is a diagram showing an example of the structure of the laminate in this embodiment.

[0085] Figure 2B This is a diagram showing an example of the structure of the laminate in this embodiment.

[0086] Figure 3 This is a schematic diagram of a metal wiring manufacturing apparatus that can be used in this embodiment. Detailed Implementation

[0087] The following description, with reference to the accompanying drawings, illustrates exemplary embodiments of the present invention (hereinafter also referred to as these embodiments). The present invention is not limited to these embodiments and can be implemented in various ways within the scope of its essential points.

[0088] In this specification, various measurements are performed based on the methods described herein, particularly the methods described in the examples. In this specification, the upper or lower limit of a phased numerical range can be replaced with the upper or lower limit of another corresponding phased numerical range, particularly with the corresponding values ​​described in the examples. Furthermore, in this specification, "process" is not only an independent process, but can also be included in this terminology even when it cannot be clearly distinguished from other processes, as long as the function of the process can be achieved. Regarding the components shown in the accompanying drawings (scale, shape, length, etc.), they are sometimes exaggerated for further clarity.

[0089] laminated body

[0090] One aspect of the present invention provides a laminate sequentially comprising a metal layer, a polymer layer containing a metal, and a polymer layer. In a representative embodiment, the metal layer is bonded to the polymer layer containing a metal, and the polymer layer containing a metal is bonded to the polymer layer. In one embodiment, the laminate is used as a constituent element of an electronic circuit board. The laminate is suitable, for example, for use in circuit boards, such as printed wiring boards. Such circuit boards typically have a structure in which conductive wiring is applied to a substrate. That is, in one embodiment of the laminate, a pattern of a metal layer is disposed on the substrate (more specifically, on the polymer layer containing a metal in a substrate having a polymer layer and a polymer layer containing a metal). Multiple patterns of metal layers can be disposed on the substrate, and their shape and size can be selected as desired.

[0091] In one type of laminate, the metal layer and the polymer layer containing the metal contain the same metal.

[0092] In one type of laminate, the thickness of the metal layer is 0.1 μm or more and 1010 μm or less, or 0.1 μm or more and 1000 μm or less.

[0093] In one type of laminate, the thickness of the polymer layer containing metal is greater than 0.04 μm and less than 10 μm.

[0094] In one type of laminate, the thickness of the polymer layer is greater than 1 μm and less than 1000 μm.

[0095] In a thickness-direction cross-section view of a laminate in one manner, the ratio of the length (L2) of the boundary line between the metal layer and the metal-containing polymer layer to the in-plane length (L1) of the laminate (L2) / (L1) is greater than 1.0 and less than 2.2.

[0096] In one embodiment, the metal layer has a first metal layer and / or a second metal layer. In another embodiment, the metal layer has a first metal layer and a second metal layer disposed between the first metal layer and a metal-containing polymer layer. In yet another embodiment, the first metal layer is in contact with the second metal layer, and the second metal layer is in contact with the metal-containing polymer layer. Furthermore, in a representative embodiment, the metal-containing polymer layers are in contact with each other.

[0097] In one type of laminate, the first metal layer, the second metal layer, and the metal-containing polymer layer contain the same metal.

[0098] In one type of laminate, the thickness of the first metal layer is greater than 0.1 μm and less than 1000 μm.

[0099] In one type of laminate, the thickness of the second metal layer is greater than 0.01 μm and less than 10 μm.

[0100] In one type of laminate, the thickness of the polymer layer containing metal is greater than 0.04 μm and less than 10 μm.

[0101] In one type of laminate, the thickness of the polymer layer is greater than 1 μm and less than 1000 μm.

[0102] In one embodiment, the laminate has a first metal layer with a thickness of 0.1 μm or more and 1000 μm or less, which may cause a portion of the polymer to be modified during the formation process of the first metal layer. Even with such a first metal layer having a thickness of 0.1 μm or more and 1000 μm or less, according to this embodiment, it is possible to achieve both good conductivity and good adhesion (particularly suppression of interlayer delamination and / or suppression of intralayer cohesive failure of the laminate).

[0103] One aspect of the present invention provides a laminate comprising a metal layer, a polymer layer containing a metal, and a polymer layer arranged in the following order, wherein... The metal layer and the polymer layer containing the metal contain the same metal. The thickness of the metal layer is 0.1 μm or more and 1010 μm or less, or 0.1 μm or more and 1000 μm or less. The thickness of the polymer layer containing metal is greater than 0.04 μm and less than 10 μm.

[0104] One aspect of the present invention also provides a laminate comprising a metal layer, a polymer layer containing a metal, and a polymer layer arranged in the following order, wherein, The metal layer and the polymer layer containing the metal contain the same metal. Both the polymer constituting the metal-containing polymer layer and the polymer constituting the polymer layer are nitrogen-containing polymers. The polymer layer containing metal contains metal that is chemically bonded to nitrogen atoms.

[0105] The morphology, thickness, and constituent elements of each layer can be determined by observing and analyzing the thickness-direction cross-section of the laminate using a scanning transmission electron microscope (STEM). Details of the determination method are described in the examples.

[0106] Metal layers can be formed by methods such as coating a dispersion containing metal, metal plating, sputtering, etc. Metal-containing polymer layers can be formed by methods such as penetrating the metal into a portion of a polymer substrate (typically a portion from the surface of the polymer substrate to a certain depth). Therefore, the polymer substrate can have both a metal-containing polymer layer and a polymer layer. This penetration can occur, for example, when a metal layer is formed on the polymer substrate. In each layer, the metal can have a structure where metal particles are fused together. In this case, the particle shape may not exist, i.e., all metal particles may be fused together. Alternatively, a portion of the metal may have a particle shape, while the rest is fused. The weld may also extend across the metal layer and the metal-containing polymer layer.

[0107] The metal layer (in one embodiment, a first metal layer and a second metal layer) and the metal-containing polymer layer each contain one or more metals. In this disclosure, unless otherwise specified, "metal" refers to a metallic element belonging to Groups 3-16 of the periodic table (in other words, a metallic element other than alkali metals and alkaline earth metals). In one embodiment, the metal layer and the metal-containing polymer layer contain the same type (i.e., the same element) of metal. This same type of metal can be one type or two or more types. The metal contained in the metal layer and the metal contained in the metal-containing polymer layer must be common to at least one of these types. For example, the metal layer may contain metal species α and β, and the metal-containing polymer layer may contain metal species α and γ. In this case, metal species α is the "same type" of metal in this disclosure. Furthermore, for example, if the metal layer comprises a first metal layer and a second metal layer, the first metal layer, the second metal layer, and the metal-containing polymer layer may contain metal species α, while the second metal layer and the metal-containing polymer layer further contain metal species β. In this case, metal species α and β are the "same" metals disclosed herein. Alternatively, for example, if the metal layer comprises a first metal layer and a second metal layer, the first metal layer may contain metal species α and β, the second metal layer may contain metal species α and ω, and the polymer layer containing the metal may contain metal species α and γ. In this case, metal species α is the "same" metal disclosed herein. The "same" metal contained in the metal layer and the polymer layer containing the metal preferably includes copper, or is copper. The presence of the same metal contributes to good adhesion between the metal layer (especially the second metal layer in the presence of a first and second metal layer) and the polymer layer containing the metal, based on the anchoring effect. If all the metals in the metal layer and the metals in the polymer layer containing the metal are the same (in the presence of a first and second metal layer, if all the metals contained in the first metal layer, the second metal layer, and the polymer layer containing the metal are the same), it also provides the advantage of being less prone to adverse effects such as metal corrosion when dissimilar metals are present.

[0108] The laminate according to this embodiment achieves both good conductivity and good adhesion. One of the mechanisms is speculated to be as follows. Typically, during manufacturing, weak mechanical portions (fragile areas) may form on the surface of a polymer substrate (e.g., a polymer film). Furthermore, depending on the laser, plating solution, or other methods used to form a metal layer on the polymer substrate (especially the first metal layer in the presence of a first metal layer and a second metal layer), a portion of the polymer may be denatured (e.g., thermal decomposition or hydrolysis), and this denatured portion may become a fragile area. In the fragile area, the polymer backbone typically decomposes. The ratio (IR1) / (IR2) of this disclosure is an indicator of the degree of polymer backbone decomposition. By allowing metal to penetrate such fragile areas in a controlled manner, a metal-containing polymer layer of this embodiment can be formed. In the presence of a metal-containing polymer layer, good adhesion is easily exhibited between the metal layer and the metal-containing polymer layer due to the anchoring effect between the metal in the metal layer (especially the second metal layer in the presence of a first metal layer and a second metal layer) and the metal in the metal-containing polymer layer. Especially when the metal layer and the metal-containing polymer layer contain the same metal, a good anchoring effect can be generated by utilizing the interaction of the same metal. The anchoring effect is even stronger when the metal-containing polymer layer is formed by penetrating the metal to a depth above the weak point. Furthermore, the metal in the metal-containing polymer layer acts as a filler, thereby helping to improve the mechanical strength of the weak point. Therefore, even if the polymer becomes brittle in the metal-containing polymer layer, it is less prone to cohesive failure. Through the anchoring effect and cohesive failure suppression effect described above, interlayer delamination and / or intralayer cohesive failure are less likely to occur at the locations spanning the metal layer (in one embodiment, a first metal layer and a second metal layer), the metal-containing polymer layer, and the polymer layer. Thus, the laminate of this embodiment exhibits good adhesion.

[0109] In a cross-sectional view of the laminate in this embodiment along its thickness, the ratio (L2) / (L1) of the length of the boundary line between the metal layer and the metal-containing polymer layer to the in-plane length (L1) of the laminate is, in one embodiment, 1.0 or more and 2.2 or less, or 1.0 or more and 2.0 or less. This ratio is an indicator of the unevenness of the boundary surface between the metal layer and the metal-containing polymer layer. From the perspective of the anchoring effect between these layers, a larger ratio is more advantageous. On the other hand, when the polymer in the metal-containing polymer layer is significantly weakened, this ratio tends to increase. Regarding the ratio (L2) / (L1), in one approach it is 1.0 or higher, considering the good adhesion between the metal layer and the metal-containing polymer layer due to the anchoring effect; in another approach it is greater than 1.0, or 1.05 or higher, considering the good mechanical strength of the metal-containing polymer layer which suppresses cohesive failure within the layer; in yet another approach it is 2.2 or lower, or 2.0 or lower, or 1.8 or lower, or 1.5 or lower, or 1.3 or lower. The ratio (L2) / (L1) is determined by observing the thickness-direction section of the laminate using STEM. Figure 1 This is a schematic diagram illustrating the method for solving the ratio (L2) / (L1). Additionally, in Figure 1 Note that the shape of the boundary surface is exaggerated and schematically illustrated. (Refer to...) Figure 1 In the cross-sectional image, the length of the boundary line drawn freehand between the metal layer ML and the metal-containing polymer layer MPL is taken as the length of the boundary line (L2). The length of the line segment P1-P2 connecting the intersection points P1 and P2 of this boundary line with the two ends of the STEM image is taken as the in-plane length (L1) of the laminate. The ratio (L2) / (L1) is calculated. The details of the measurement method are described in the examples. The ratio (L2) / (L1) can be controlled by the type of polymer in the metal-containing polymer layer, the formation conditions of the metal layer (laser irradiation conditions, plating conditions, etc.), etc. For example, by increasing the pulse output during laser irradiation, the polymer is appropriately weakened, thereby making it easier for the metal to enter the metal-containing polymer layer, and the ratio (L2) / (L1) increases.

[0110] The following provides a further explanation of each layer of the laminate.

[0111] <Metallic Layer>

[0112] The metal layer may consist of one or more layers. Each layer contains one or more metals. Preferred metals are copper (Cu), silver (Ag), nickel (Ni), chromium (Cr), tin (Sn), and zinc (Zn), as well as alloys containing them, with copper being more preferred. The metal layer is suitable as metal wiring in a substrate with metal wiring, such as a circuit board. The shape, i.e., pattern, of the metal wiring when viewed from above can be any shape, such as straight, curved, circular, quadrilateral, or bent. In a preferred embodiment, the metal wiring is copper wiring.

[0113] Metals can exist in the form of metal compounds, such as metal oxides. For example, copper can exist in the form of copper oxide (monovalent copper oxide, divalent copper oxide, and / or cuprous oxide). Suitable examples of metals constituting a metal layer are copper, particularly copper as a reduction product of copper oxide (also referred to as reduced copper in this disclosure). A layer formed by reducing a layer containing copper oxide is, for example, called a reduced copper layer. A reduced copper layer can be formed by reducing copper oxide using, for example, laser irradiation or heat. In one manner, the laser can be selectively applied (i.e., only to the areas where a reduced copper layer is desired). For example, in a coating containing metal oxide particles, the reduction of the metal oxide and the fusion (i.e., integration) resulting from the sintering of the particles occur only in the laser-irradiated portions of the coating, thereby forming a reduced copper layer. When a metal layer (in the presence of a first metal layer and a second metal layer, particularly the second metal layer) contains or is composed of a reduced copper layer, the adhesion between the metal layer and the polymer layer containing the metal tends to be excellent. It should be noted that in a reduced copper layer, a portion of the copper oxide may remain unreduced. The presence or absence of copper oxide (e.g., monovalent copper oxide) in the metal layer is determined using X-ray diffraction (XRD) by observing the presence or absence of peaks corresponding to copper oxide. Therefore, in one approach, the fact that the 0-valent (i.e., existing as an element) copper in the reduced copper layer is reduced copper (i.e., a reduction product of copper oxide) can be inferred from the presence of copper oxide remaining in the reduced copper layer.

[0114] In a preferred embodiment, the metal layer (particularly the second metal layer in the presence of a first metal layer and a second metal layer) comprises monovalent copper oxide. The monovalent copper oxide can improve the adhesion between the metal layer and the metal-containing polymer layer by contributing a high affinity for the polymer. In one embodiment, the upper surface side of the metal layer (the first metal layer side in the presence of a first metal layer and a second metal layer) has a structure in which particles comprising reduced copper are fused together, and the lower surface side (the second metal layer side in the presence of a first metal layer and a second metal layer) can have a structure containing more copper oxide than the upper surface side. In this case, on the upper surface side, copper particles readily bond strongly together through the copper oxide, while on the lower surface side, the adhesion between the metal layer and the metal-containing polymer layer is easily improved.

[0115] <Carbon>

[0116] The metal layer (especially the second metal layer in the presence of a first metal layer and a second metal layer) preferably contains carbon. This facilitates the improvement of the bending resistance of the metal layer, particularly the metal wiring. The presence of carbon contributes to good sinterability, especially in the case of sintering copper particles (e.g., by reducing copper oxide particles with laser irradiation or heat). Therefore, the metal layer particularly preferably contains copper (especially reduced copper) and carbon. In one embodiment, the carbon may be derived from organic matter contained in the dispersion containing metal particles, as described later. The carbon may be graphene, carbon nanotubes, or substances formed by carbonizing organic compounds, etc.

[0117] The carbon content in the metal layer (especially the second metal layer in the presence of a first metal layer and a second metal layer) is preferably 0.1 atomic% or more, or 1 atomic% or more, or 3 atomic% or more. The carbon content in the metal layer is preferably 15 atomic% or less, or 10 atomic% or less, or 7 atomic% or less, or 5 atomic% or less. By ensuring the carbon content in the metal layer falls within the above ranges, it is easier to improve the bending resistance of the metal layer, especially the metal wiring.

[0118] Here, "atomic%" refers to "atomic percentage," which is the ratio of the number of atoms of a specific element (such as carbon in the above example) to the total number of atoms of the object.

[0119] Furthermore, regarding the "carbon content in the metal layer," the measurement will be performed on a range of 50 nm to 300 nm from the interface between the metal layer and the polymer layer containing the metal in the thickness direction of the metal layer. It should be noted that if the thickness of the metal layer is less than 300 nm, the carbon content in the metal layer is understood to be the total carbon content contained in the entire metal layer. Additionally, in configurations where a first metal layer and a second metal layer are present, if the thickness of the second metal layer is less than 300 nm, even if the first metal layer contains carbon, the carbon content in the first metal layer is not included in the carbon content contained in the second metal layer.

[0120] Regarding the thickness of the metal layers (in the case of a first metal layer and a second metal layer, their combined thickness), from the perspective of easily ensuring sufficient conductivity, in one embodiment, it is 0.1 μm or more, or 0.5 μm or more. From the perspective of easily exhibiting excellent bending resistance, in one embodiment, it is 1010 μm or less, or 1000 μm or less, or 500 μm or less, or 10 μm or less, or 5 μm or less. From the perspective of lightweighting, space-saving, and flexibility when using the laminate as, for example, a circuit board, electronic device, etc., a thickness of 0 or less than the above-mentioned upper limit is also advantageous.

[0121] In configurations where a first metal layer and a second metal layer are present, the thickness of the first metal layer can be 0.1 μm or more and 1000 μm or less, and the thickness of the second metal layer can be 0.01 μm or more and 10 μm or less. The thickness of the metal layer is typically 0.11 μm or more. In one configuration, the metal layer may consist solely of a first metal layer and a second metal layer. When the metal layer consists solely of a first metal layer and a second metal layer, the thickness of the metal layer can be 1010 μm or less.

[0122] In one embodiment, the metal layer has a first metal layer and / or a second metal layer. In one embodiment, the laminate has a polymer layer, a metal-containing polymer layer, a second metal layer, and a first metal layer arranged in that order. In one embodiment, the first metal layer is a layer with a porosity of less than 0.5% by volume, and the second metal layer is a layer with a porosity greater than 0.5% by volume. Porosity refers to locations in the metal layer where the constituent material (mainly metal) is present in very small amounts or where the constituent material is absent; typically, it refers to voids surrounded by a continuous phase based on the constituent material. In one embodiment, the surface of the first metal layer on the upper surface side (i.e., the side opposite to the polymer layer side) is substantially devoid of voids, or if voids are present, they are present in extremely small amounts.

[0123] The method for determining porosity is described in detail in the examples.

[0124] (Example of a laminated structure with a first metal layer and a second metal layer)

[0125] Figure 2A , Figure 2B This is a diagram illustrating an example of the structure of a laminate where the metal layers include a first metal layer and a second metal layer, wherein... Figure 2A It is a top view, and Figure 2B It is a cross-sectional view. Figure 2B Equivalent to Figure 2A The cross-section of the dashed-dot section (part AA) in the diagram, therefore, in Figure 2A and Figure 2B In the diagram, the X, Y, and Z directions of the arrows correspond to each other.

[0126] The laminate 1 sequentially comprises a first metal layer ML1, a second metal layer ML2, a metal-containing polymer layer MPL, and a polymer layer PL. In the figure, the first metal layer ML1 and the second metal layer ML2 are collectively referred to as "metal layer ML". Voids exist within the second metal layer. These voids are areas where the constituent material (mainly metal) of the metal layer is minimal or absent; a representative example is a void V surrounded by a continuous phase based on the constituent material.

[0127] In the first metal layer, there are virtually no voids, or if voids exist, they are extremely small. Therefore, for convenience, voids are illustrated in the second metal layer in the accompanying drawings, but this is not intended to limit the presence of voids to the second metal layer within the metal layers.

[0128] In the figure, for convenience, the interface between the first metal layer ML1 and the second metal layer ML2, the boundary between the second metal layer ML2 and the metal-containing polymer layer MPL, and the interface between the metal-containing polymer layer MPL and the polymer layer PL are represented by imaginary lines (dashed lines).

[0129] In a laminate, when the first metal layer side is treated as the "top side" and the polymer layer side as the "bottom side", The upper surface of the first metal layer is open upwards. The lower surface of the first metal layer and the upper surface of the second metal layer are in contact with each other. The lower surface of the second metal layer and the upper surface of the polymer layer containing the metal are in contact with each other. The lower surface of the polymer layer containing metal and the upper surface of the polymer layer are in contact with each other. These surfaces can be flat, and can also be uneven, provided that they fall within the scope of the essential points of this invention.

[0130] The laminate 1 has a structure in which wiring patterns (a first metal layer and a second metal layer) are applied on a polymer substrate (a polymer layer containing metal and a polymer layer). In the figure, multiple metal layers are arranged along the X direction and in the Y direction, but the examples of wiring patterns are not limited to those shown.

[0131] In one configuration, the patterns of the second metal layer correspond to those of the first metal layer. In this case, when viewing the laminate 1 from above, the second metal layer becomes a shadow of the first metal layer and is not observed.

[0132] <First Metal Layer>

[0133] In one embodiment, a first metal layer may be disposed on a second metal layer. The first metal layer contributes to good conductivity. In another embodiment, the constituent material of the first metal layer may fill a portion of the voids in the second metal layer, and / or may be formed by intrusion into a polymer substrate to form a metal-containing polymer layer. From the perspective of achieving further improvement in conductivity (further reduction in resistance), a larger thickness of the first metal layer is generally advantageous. Therefore, it is conjectured that if a further improvement in conductivity (further reduction in resistance) can be achieved when the first metal layer has a predetermined film thickness, then even if the first metal layer is larger than that film thickness, the same further improvement in conductivity (further reduction in resistance) can be achieved.

[0134] Regarding the thickness of the first metal layer, it can be 0.1 μm or more, 0.5 μm or more, or 1.0 μm or more. This allows sufficient current to flow easily when the first metal layer is used for wiring. Preferably, the thickness of the first metal layer is 1000 μm or less, 999.99 μm or less, 500 μm or less, 100 μm or less, 50 μm or less, 10 μm or less, or 5 μm or less. This allows the first metal layer to exhibit excellent bending resistance.

[0135] The thickness of the first metal layer can be greater than the thickness of the second metal layer. This makes it easy to obtain a metal layer with excellent conductivity. Similarly, and from the perspective of easily thinning the laminate, the thickness of the first metal layer can be 1.5 times or more but less than 5.0 times the thickness of the second metal layer.

[0136] Regarding the porosity of the first metal layer, in one embodiment it is 0.5% or less by volume, or 0.3% or less by volume. Regarding this porosity, from the perspective of ease of formation of the first metal layer, in one embodiment it can be 0.01% or more by volume, or 0.1% or more by volume.

[0137] The porosity of the first metal layer can be controlled, for example, by adjusting the degreasing process before plating, and / or the plating temperature, and / or the plating time, and / or the composition of the plating solution, and / or the metal concentration (e.g., copper concentration) of the plating solution. It should be noted that the porosity of the already formed second metal layer can also be controlled (e.g., reduced) by adjusting the plating conditions, performing a degreasing process before plating, etc.

[0138] <Second Metal Layer>

[0139] The second metal layer can be disposed between the first metal layer and the metal-containing polymer layer (in one embodiment, a metal-containing polyimide layer). The thickness of the second metal layer is preferably 0.01 μm or more, or 0.05 μm or more, or 0.1 μm or more. Therefore, when the first metal layer is formed by plating, the plating growth of the first metal layer tends to exhibit excellent properties. The thickness of the second metal layer is preferably 10 μm or less, or 8 μm or less, or 5 μm or less, or 3 μm or less, or 1 μm or less. Therefore, the bending resistance of the metal layer tends to exhibit excellent properties.

[0140] The porosity of the second metal layer can be, for example, 30% by volume or less, or 28% by volume or less, or 20% by volume or less. This results in good adhesion (especially between the substrate and the metal layer), making delamination by chemical agents less likely. Furthermore, the metal layer tends to exhibit excellent oxidation resistance. In one embodiment, the porosity of the second metal layer is greater than 0.5% by volume. This easily mitigates stress caused by the expansion of the metal (e.g., copper), thus easily resisting thermal shock. The aforementioned porosity can be 1% by volume or more, or 4% by volume or more.

[0141] The porosity in the second metal layer can be controlled, for example, by adjusting the output and / or speed and / or wavelength of the irradiating laser used during the formation of the metal layer. For instance, a stronger laser output and a slower irradiation speed make it easier to reduce the porosity of the metal layer, while a weaker laser output and a faster irradiation speed make it easier to increase the porosity of the metal layer.

[0142] In one embodiment, the metal layer has a porosity of 0.1% to 30% by volume in a region extending from the metal-containing polymer layer to a depth of 1 nm or more and 500 nm or less, i.e., in the region adjacent to the metal-containing polymer layer. From the perspective of easily mitigating stress caused by the expansion of the metal (e.g., copper) and thus easily resisting thermal shock, this porosity is preferably 0.1% by volume or more, or 1% by volume or more, or 4% by volume or more. From the perspective of ensuring good adhesion (especially adhesion between the metal layer and the metal-containing polymer layer) to prevent peeling of the metal layer caused by chemical reagents and to easily exhibit excellent oxidation resistance of the metal layer, it is preferably 30% by volume or less, or 28% by volume or less, or 20% by volume or less.

[0143] <Polymer layers and metal-containing polymer layers>

[0144] Polymer layers and metal-containing polymer layers function as substrates (e.g., substrates for circuit boards as a type of laminate). The substrate forms a surface for configuring wiring patterns as a type of metal layer. The substrate is typically a plate or film, but can also be a three-dimensional object with a desired three-dimensional shape. Plates are, for example, supports used in circuit boards such as printed circuit boards. Films are, for example, base films used in flexible printed circuit boards. Three-dimensional objects are, for example, molded bodies used in various electronic components. When the substrate is a three-dimensional object, metal-containing polymer layers and polymer layers can be disposed on the surface of the substrate.

[0145] The polymer layer contains one or more polymers. The polymer layer containing metal contains one or more metals and one or more polymers. The polymers contained in the polymer layer containing metal and the polymers contained in the polymer layer can be the same or different, but are preferably the same. Here, "same" means that the polymers have the same constituent monomers. Examples of metals contained in the polymer layer containing metal are the same metals as those in the metal layer, preferably copper (Cu), silver (Ag), nickel (Ni), chromium (Cr), tin (Sn), and zinc (Zn), as well as alloys containing them, and more preferably copper. The metal can exist in the form of a metal compound.

[0146] In one approach, the metal-containing polymer layer refers to the region with a metal concentration of 1 atom% or higher, while the polymer layer refers to the region with a metal concentration of less than 1 atom%. The metal concentration of each layer can be determined by using STEM-based energy-dispersive X-ray X-ray analysis (EDX analysis) to identify the metal species present in the metal-containing polymer layer, the individual metal species present in the polymer layer, and the total metal content of the identified metal species. More specific methods for determining the metal concentration are described below.

[0147] Regarding the thickness of the polymer layer, in one embodiment, it is 1 μm or more, preferably 5 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more. This results in excellent mechanical strength of the polymer layer. Regarding the thickness of the polymer layer, in one embodiment, it is 1000 μm or less, preferably 500 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less. This results in excellent flexibility of the polymer layer. Polymer layers with excellent flexibility are sometimes suitable for use as flexible printed circuit boards. From the perspective of weight reduction, space saving, and flexibility when using laminates as, for example, circuit boards, electronic devices, etc., thicknesses below the aforementioned upper limits are also advantageous.

[0148] Regarding the thickness of the polymer layer containing metal, in one embodiment it is 0.04 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, and even more preferably 0.2 μm or more. This results in excellent adhesion due to a good anchoring effect. Regarding the thickness of the polymer layer containing metal, in one embodiment it is 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less, even more preferably 1 μm or less, and particularly preferably 0.5 μm or less. This results in excellent mechanical strength of the polymer layer containing metal. From the perspective of lightweighting, space saving, and flexibility when using the laminate as, for example, circuit boards, electronic devices, etc., a thickness of the above-mentioned upper limit is also advantageous.

[0149] In one approach, the boundary between the metal-containing polymer layer and the polymer layer can be clearly distinguished. In another approach, the boundary can be identified as a difference in electron density in a cross-sectional image along the thickness direction of a scanning transmission electron microscope (STEM).

[0150] <Polymer>

[0151] The polymer layer and the metal-containing polymer layer are typically each a single layer, but can also consist of multiple layers. Examples of polymers included in the polymer layer and the metal-containing polymer layer include polypropylene (PP), polyesters {polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.}, polyethersulfone (PES), polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacetal (POM), polyarylate (PAR), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyphenylene sulfide (PPS), polyetherketone (PEK), polyetheretherketone (PEEK), polyimide (PI), polyphthalamide (PPA), polyether nitrile (PENt), polybenzimidazole (PBI), polycarbodiimide, polymethacrylamide, nitrile rubber, acrylic rubber, polyethylene tetrafluoride, and cyclic polyvinyl chloride. Oxygen resins, phenolic resins, melamine resins, urea resins, polymethyl methacrylate resin (PMMA), polybutene, polypentene, ethylene-propylene copolymer, ethylene-butene-diene copolymer, polybutadiene, polyisoprene, ethylene-propylene-diene copolymer, butyl rubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymer, polyethylene (PE), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), phenolic varnish, benzocyclobutene, polyvinylphenol, polychloropyrene, polyoxymethylene, polysulfone (PSF), polyphenylene sulfone resin (PPSU), cyclic olefin polymers (COP), acrylonitrile-butadiene-styrene resin (ABS), acrylonitrile-styrene resin (AS), polytetrafluoroethylene resin (PTFE), polychlorotrifluoroethylene (PCTFE), and organosilicon resins (polysiloxanes), etc.

[0152] Suitable examples of polymers are nitrogen-containing polymers and sulfur-containing polymers. Examples of nitrogen-containing polymers include polyimide (PI), polyphthalamide (PPA), polyether nitrile (PENt), polybenzimidazole (PBI), polycarbodiimide, polymethacrylamide, nitrile rubber, urea resin, acrylonitrile-butadiene-styrene resin (ABS), and acrylonitrile-styrene resin (AS). Examples of sulfur-containing polymers include polyphenylene sulfide (PPS), polysulfone (PSF), and polyphenylene sulfone resin (PPSU).

[0153] The polymer is preferably polyimide, or a combination of polyimide and other resins. Regarding the proportion of other resins in this case, it can be less than 50% by mass, less than 30% by mass, or less than 10% by mass in 100% of the total polymer. For example, the polymer layer can have a polyimide layer and layers other than polyimide.

[0154] (Polyimide)

[0155] A preferred embodiment of the polymer is a polyimide. In a preferred embodiment, the polymer layer containing the metal is a polyimide layer containing the metal, and the polymer layer is a polyimide layer. Since polyimides have excellent electrical insulation properties, they are useful as insulating regions in a laminate when the polymer layer is a polyimide layer. As a polyimide, thermoplastic polyimides are examples of those that readily exhibit excellent chemical stability. Polyimides refer to resins having imide groups in their molecular structure, for example having the following general formula (1): [Chemistry 1]

[0156] The structure represented by (where n is a positive integer, X is a tetravalent group, and Y is a divalent group). n is, for example, an integer from 1 to 200.

[0157] Polyimide is obtained, for example, by synthesizing polyamic acid (a polyimide precursor) from an acid anhydride and a diamine, followed by partial or complete imidization of the polyimide precursor. In this case, X is an organic group corresponding to the acid anhydride, and Y is an organic group corresponding to the diamine. In addition to the acid anhydride and diamine, the polyimide precursor may also contain other components (e.g., solvents, photopolymerization initiators, free radical polymerizable compounds, silane coupling agents, rust inhibitors, organotitanium compounds, plasticizers, thermal crosslinking agents, and thermal polymerization initiators, etc.). Various raw materials used to obtain the polyimide precursor can be used alone or in combination of two or more.

[0158] Commercially available polyimide films can also be used to form metal-containing polyimide layers and polyimide layers. Examples of commercially available polyimide films include Kapton H, Kapton V, Kapton EN (trade names, all manufactured by Toray & DuPont), Apical NPI, Pixeo FRS (trade name, manufactured by Kaneka), Upilex S, Upilex SGA, Upilex VT, and Upilex NVT (trade name, manufactured by UBE). Metal can be incorporated into a portion of such a polyimide film to form a metal-containing polyimide layer. From the perspective of easily and moderately performing hydrolysis or thermal decomposition during plating or reduction, thus facilitating the formation of a metal-containing polyimide layer, and thus exhibiting excellent adhesion, Kapton H is preferred as a commercially available polyimide film.

[0159] <Ratio (IR1) / (IR2)>

[0160] In one approach, at least a portion of the polymer in the metal-containing polymer layer may have a molecular structure resulting from the modification (e.g., thermal decomposition or hydrolysis) of the polymer in the polymer layer. For example, when a metal is deposited on a polymer substrate and subjected to laser irradiation or heating, if thermal decomposition occurs on the surface of the polymer substrate, the metal can easily penetrate into the polymer substrate, forming a metal-containing polymer layer. Alternatively, for example, if the polymer substrate is immersed in a plating solution (especially an alkaline plating solution), the plating solution penetrates into the polymer substrate, and the metal precipitates from the plating solution, thereby forming a metal-containing polymer layer. In this case, if only polymer modification occurs, substrate damage due to reduced substrate strength is likely to occur, but by forming a metal-containing polymer layer, the adhesion can be improved while maintaining substrate strength. Suitable examples of polymers capable of thermal decomposition and / or hydrolysis include polyimide, polyester, polycarbonate, etc., with polyimide being preferred. The interaction between the carbonyl group of polyamic acid, a hydrolysate of polyimide, and the metal can improve the adhesion between the metal layer and the metal-containing polymer layer.

[0161] Polymer denaturation can be confirmed by infrared (IR) absorption spectroscopy. In one approach, during the infrared absorption spectroscopy of a polymer layer containing a metal, the ratio (IR1) / (IR2) of the peak intensity (IR1) of a first peak from a first structure in the polymer backbone to the peak intensity (IR2) of a second peak from a second structure in the same backbone is controlled within a specified range. The ratio (IR1) / (IR2) reflects the degree of polymer denaturation (e.g., thermal decomposition or hydrolysis).

[0162] As an example, when the polymer is polyimide and the modified product is hydrolyzed (polyamic acid), we can focus on the C=O structure (first structure) of the imide ring in the polyimide main chain and the C=C structure (second structure) of the benzene ring in the polyimide main chain, and calculate the ratio (IR1) / (IR2) as follows. If the imide ring of polyimide is hydrolyzed, it will open to form polyamic acid. In infrared spectroscopy, at 1702 cm⁻¹... -1 ~1722cm 1 A peak (first peak) from C=O stretching was observed at 1494 cm⁻¹. -1 ~1514cm -1 A peak (second peak) from C=C stretching was observed within the range. The polyimide ratio (IR1) / (IR2) (also referred to as the degree of imide in this disclosure) can be determined based on the peak intensities of these peaks. A smaller degree of imide indicates a greater degree of hydrolysis.

[0163] As another example, when the polymer is polyester and the modified product is hydrolysate, at 1240cm -1 ~1260cm-1 The range observed shows a CO stretching peak (first peak) at 1495 cm⁻¹, exhibited by the CO structure (first structure) from the ester site in the polyester main chain. -1 ~1515cm -1 Within the range observed, the C=C stretching peak (second peak) exhibited by the C=C structure (second structure) of the benzene ring in the main chain was noted. The smaller the ratio (IR1) / (IR2) of the first peak to the second peak, the greater the degree of hydrolysis.

[0164] As another example, when the polymer is polycarbonate and the modified product is hydrolysate, at 1760cm -1 ~1780cm -1 The CO stretching peak (first peak) observed from the CO structure (first structure) of the carbonate site in the polycarbonate main chain at 1495 cm⁻¹ was observed. -1 ~1515cm -1 Within the range observed, the C=C stretching peak (second peak) exhibited by the C=C structure (second structure) of the benzene ring in the main chain was noted. The smaller the ratio (IR1) / (IR2) of the first peak to the second peak, the greater the degree of hydrolysis.

[0165] The minimum value of the ratio (IR1) / (IR2) of the polymer layer containing the metal can be an indicator of the degree of denaturation in the regions where the polymer denaturation is significant. Regarding this minimum value, from the perspective of easily ensuring the strength of the polymer layer containing the metal, it is preferably 0.2 or higher, or 0.3 or higher; from the perspective of good adhesion, it is preferably 1.5 or lower, or 1.1 or lower, or 1.0 or lower, or 0.9 or lower. It should be noted that the minimum value of the ratio (IR1) / (IR2) can represent the region in the polymer layer containing the metal that is closest to the metal layer, but such regions are excluded from the measurement area because they are difficult to measure using micro-IR. Therefore, the above minimum value sometimes becomes a value representing a certain region within the polymer layer. In this case, the magnitude of the above minimum value is also useful as an indicator of the degree of denaturation of the polymer in the polymer layer containing the metal.

[0166] The maximum value of the ratio (IR1) / (IR2) of the polymer layer containing metal can be an indicator of the degree of denaturation of the undenatured or slightly denatured parts of the polymer. In one embodiment, the maximum value can be greater than the minimum value and be greater than 0.5 and less than 2.0, provided that the minimum value of the ratio (IR1) / (IR2) is 0.2 or more and less than 1.5.

[0167] <Metals with a valence of 0 and / or 1, and metals chemically bonded to nitrogen atoms>

[0168] The metal-containing polymer layer preferably contains a metal with zero and / or one valence (in one embodiment, referred to as the "same" metal in this disclosure), more preferably containing both zero and one valence metals. One-valent metals readily achieve chemical bonding between the metal and nitrogen atoms. Furthermore, the metal-containing polymer layer preferably does not contain a divalent metal. The presence of a divalent metal can sometimes reduce the mechanical strength of the metal-containing polymer layer, and the absence of a divalent metal in the metal-containing polymer layer is advantageous in suppressing such a reduction in mechanical strength.

[0169] In a preferred embodiment, the laminate (in one embodiment, a metal-containing polymer layer) comprises nitrogen atoms (N) and a metal chemically bonded to the nitrogen atoms. In one embodiment, the metal chemically bonded to the nitrogen atoms is the "same" metal as disclosed herein. The nitrogen atoms may originate from nitrogen-containing polymers, for example, from polyimides (especially the imide bonds of polyimides). In one embodiment, both the polymer constituting the metal-containing polymer layer and the polymer constituting the polymer layer are nitrogen-containing polymers, and the metal-containing polymer layer comprises a metal chemically bonded to the nitrogen atoms. Preferred metals that can chemically bond to nitrogen atoms include, for example, copper (Cu), silver (Ag), nickel (Ni), chromium (Cr), tin (Sn), and zinc (Zn), and alloys thereof, with copper being more preferred. The metal chemically bonded to the nitrogen atoms contributes to improved adhesion between the metal layer and the metal-containing polymer layer through an anchoring effect. The presence or absence of a metal chemically bonded to nitrogen atoms can be confirmed by detecting peaks from the chemical bonding between nitrogen and the metal using X-ray photoelectron spectroscopy (XPS). More detailed confirmation methods are described in the examples.

[0170] In one approach, the chemical bonding of nitrogen atoms to metals can be formed when the metal is deposited on a polymer substrate under laser irradiation or heating, or when the polymer substrate is immersed in a plating solution (especially an alkaline plating solution).

[0171] For example, when the metal-containing polymer layer contains copper as a metal (in one embodiment, as the "same" metal of this disclosure) and contains a nitrogen-containing polymer as a polymer, a peak (also called a first peak) may be present in the range of 571 eV to 574 eV in the X-ray photoelectron spectroscopy (XPS) measurement of the metal-containing polymer layer. The first peak indicates the presence of a chemical bond between nitrogen and monovalent copper. Such a chemical bond is advantageous in terms of good adhesion between the metal layer and the metal-containing polymer layer, based on the anchoring effect exhibited by the metal within the metal-containing polymer layer. Furthermore, it is more preferable that, in addition to the aforementioned first peak, a second peak is present in the range of 563 eV to 566 eV. The second peak indicates the presence of 0-valent copper (i.e., present as an elemental metal). The 0-valent metal functions as a filler within the metal-containing polymer layer. Therefore, the presence of the 0-valent metal can help suppress the destruction of the metal-containing polymer layer by increasing its mechanical strength. Furthermore, it is more preferable that a third peak is absent in the range of 934 eV to 937 eV. The third peak indicates the presence of divalent copper. When divalent copper exists in the form of divalent copper oxide, the mechanical strength of the polymer layer containing the metal can be reduced.

[0172] <Metal content of the polymer layer containing metal>

[0173] From the perspective of achieving good adhesion based on the anchoring effect of metal and the effect of filler, the amount of metal contained in the metal-containing polymer layer is preferably 1 atomic% or more, or 1.2 atomic% or more. On the other hand, from the perspective of easily ensuring the strength of the metal-containing polymer layer by appropriately suppressing excessive diffusion of metal into the polymer, the amount of metal in the metal-containing polymer layer is preferably 20 atomic% or less, or 15 atomic% or less, or 14 atomic% or less, or 12 atomic% or less, or 10 atomic% or less, or 8 atomic% or less, or 5 atomic% or less. When all the metals in the metal-containing polymer layer are the "same kind" metals of this disclosure, the amount of metal in the metal-containing polymer layer is the amount of that "same kind" metal. The amount of metal in the metal-containing polymer layer can be determined by using STEM-based energy-dispersive X-ray analysis (EDX analysis) to determine the metal species present in the metal-containing polymer layer and to measure the total amount of the determined metal species. It should be noted that, in one embodiment, the amount of the metal species present in the polymer layer containing the metal, based on the atomic number, is within the range described above. Under more demanding manufacturing conditions for the laminate (e.g., higher energy laser irradiation, higher temperature heating, immersion in a more alkaline plating solution, etc.), the amount of metal in the polymer layer containing the metal tends to be larger.

[0174] Furthermore, from the perspective of obtaining the anchoring effect and filler effect based on the metal throughout the metal-containing polymer layer, the metal concentration at a position 20 nm from the boundary between the metal-containing polymer layers toward the metal layer side is preferably 1.0 atomic% or more, 1.3 atomic% or more, 1.4 atomic% or more, 1.8 atomic% or more, or 2.0 atomic% or more. On the other hand, from the perspective of easily ensuring a high strength of the metal-containing polymer layer, the above-mentioned metal concentration is preferably 5.0 atomic% or less, 4.5 atomic% or less, or 4.0 atomic% or less. The metal concentration at a position 20 nm from the boundary between the metal-containing polymer layers toward the metal layer side can be determined by STEM-based EDX analysis.

[0175] <Sodium content in the polymer layer containing metal>

[0176] The polymer layer containing metal preferably contains sodium in addition to the aforementioned metal. In a typical embodiment, the sodium comes from the plating bath. To control the amount of sodium in the polymer layer containing metal, when forming a metal layer (e.g., a first metal layer) by plating, the chemical composition of the plating bath (especially the sodium concentration), plating time, and / or plating temperature can be appropriately adjusted.

[0177] The amount of sodium contained in the metal-containing polymer layer is preferably 0.1 atomic% or more, more preferably 1 atomic% or more. This allows for excellent adhesion between the metal layer, the metal-containing polymer layer, and the polymer layer through a sodium-based anchoring effect. This anchoring effect is presumably generated through the interaction between the metal and sodium in the metal-containing polymer layer. The amount of sodium contained in the metal-containing polymer layer is preferably 10 atomic% or less, more preferably 8 atomic% or less, and even more preferably 6 atomic% or less. This appropriately suppresses excessive diffusion of sodium into the polymer, thus easily ensuring a high strength of the metal-containing polymer layer.

[0178] Method for manufacturing laminates

[0179] One aspect of the present invention provides a method for manufacturing the laminate of this disclosure. In one aspect, the method for manufacturing the laminate includes a step of coating a metal (which may be an element, alloy, or compound) onto a polymer substrate (coating step). In the case of coating a metal oxide, the method may further include a step of reducing the metal oxide (reduction step). Regarding reduction, in one aspect it can be performed by laser irradiation and / or heating, and in another aspect it can be performed by laser irradiation. The method for manufacturing the laminate including the coating step may further include a plating step, such as an electroless metal plating step. In one aspect, the plating step, such as an electroless metal plating step, may be performed after the reduction step.

[0180] In one method of manufacturing a laminate, the metal layer can be formed by a coating process of applying a metal oxide onto a polymer substrate and a reduction process of reducing the metal oxide.

[0181] In the manufacturing method of laminates, the metal layer can be formed through the following steps: The coating process involves coating a dispersion of metal particles (which can be elemental, alloy, or compound) onto a polymer substrate to form a coating film; and The firing process involves arbitrarily drying the coating film and then firing it by laser irradiation and / or heating. In one embodiment, the layer formed by these processes can be used as the metal layer of this disclosure (and therefore a single-layer metal layer). Alternatively, in another embodiment, a second metal layer can be formed by these processes.

[0182] In one embodiment, the first metal layer may be formed on the second metal layer. In another embodiment, the first metal layer may be formed by immersing a composite having the second metal layer formed on a polymer substrate in a plating solution, such as an electroless metal plating solution.

[0183] One aspect of the present invention provides a method for manufacturing a laminate, which is used to manufacture a laminate having a first metal layer, a second metal layer, a metal-containing polymer layer and a polymer layer sequentially disposed thereon, wherein the first metal layer, the second metal layer and the metal-containing polymer layer comprise the same metal, wherein the manufacturing method comprises the following steps: The process of forming a first metal layer with a thickness of 0.1 μm or more and 1000 μm or less; The process of forming a second metal layer with a thickness of 0.01 μm or more and 10 μm or less; A process for forming a metal-containing polymer layer with a thickness of 0.04 μm or more and 10 μm or less; and The process of forming a polymer layer with a thickness of 1.0 μm or more and less than 1000 μm.

[0184] The process of forming the second metal layer preferably includes the following steps: The coating process involves coating a dispersion containing metal particles and / or metal oxide particles onto a substrate to form a dispersion layer. The drying process forms a dry coating film on a substrate by drying the dispersion layer; and The process of forming a second metal layer by heating a dried coating film.

[0185] Furthermore, the process of forming the second metal layer preferably includes the following steps: The coating process involves coating a dispersion containing metal particles and / or metal oxide particles onto a substrate to form a dispersion layer. The drying process forms a dry coating film on a substrate by drying the dispersion layer; and The process of forming a second metal layer by firing a dried coating film with a laser.

[0186] Furthermore, the process of forming the first metal layer preferably includes a step of forming the first metal layer by immersing the second metal layer in a plating solution. In this case, the aforementioned plating solution with a pH of 10 or higher and 14 or lower is preferably used.

[0187] In the method of manufacturing laminates, metal particles and / or metal oxide particles are preferably copper particles and / or copper oxide particles.

[0188] As specific examples of manufacturing methods for laminates in the case of forming a first metal layer and a second metal layer, the following first to third methods can be cited.

[0189] The first method includes the following steps: The process of preparing the polymer substrate; The process of coating a dispersion containing metal oxide particles onto the polymer substrate to form a coating film (coating process); The process of optionally reducing the coating to obtain a second metal layer (reduction process); and The process of forming a first metal layer on a second metal layer by plating a second metal layer, while making a portion of the second metal layer side of the polymer substrate a polymer layer containing metal and the remaining portion a polymer layer (plating process).

[0190] The second method includes the following steps: The process of preparing the polymer substrate; The process of coating a dispersion containing elemental metal particles onto the polymer substrate to form a second metal layer (coating process); and The process of forming a first metal layer on a second metal layer by plating a second metal layer, while making a portion of the second metal layer side of the polymer substrate a polymer layer containing metal and the remaining portion a polymer layer (plating process).

[0191] The third method includes the following steps: The process of forming the second metal layer; A polymer layer is formed on the second metal layer by casting, and then left to stand after casting, thereby forming a metal-containing polymer layer between the second metal layer and the polymer layer; and The process of forming a first metal layer on the second metal layer by coating a dispersion containing metal particles onto the second metal layer, plating the second metal layer, or sputtering metal onto the second metal layer (coating process, plating process, or sputtering process).

[0192] In the third method, the second metal layer can be, for example, a commercially available metal foil.

[0193] Each method may also include optional steps other than those mentioned above.

[0194] <Dispersion>

[0195] The dispersion may contain metal particles (which may be elemental, alloy, or compound). The dispersion may further contain a dispersion medium, a dispersant, and / or a reducing agent. The dispersion can be prepared by adding a dispersion medium and optional dispersant to the particles and then stirring and dispersing using known methods such as a homogenizer.

[0196] The following are examples of the components of the dispersion.

[0197] <particles>

[0198] The metal contained in the particles of the dispersion can be one or more metals selected from the group consisting of copper (Cu), silver (Ag), nickel (Ni), chromium (Cr), tin (Sn), and zinc (Zn), and alloys thereof, and can exist in the form of metal compounds, such as metal oxides. The particles can have a core / shell structure. For example, the core and / or shell can be metal, and the core and shell can contain different metals. Furthermore, the metal can form a complex. The dispersion preferably contains copper or copper oxide. Examples of copper oxide include monovalent copper oxide (Cu₂O) and divalent copper oxide (CuO). Monovalent copper oxide is preferred from the perspective of high affinity with polymer substrates (especially polyimide substrates) and easy acquisition of good adhesion between the metal layer and the metal-containing polymer layer. Monovalent copper oxide can be obtained, for example, by hydrazine reduction of copper salts.

[0199] The average particle size is preferably 1 nm or more, or 3 nm or more, or 5 nm or more, and more preferably 100 nm or less, or 50 nm or less, or 40 nm or less. Here, the average particle size refers to the particle size when dispersed in the dispersion, and is the value measured by a cumulative method (e.g., using an Otsuka Electronics FPAR-1000). That is, the average particle size is not limited to the primary particle size, and sometimes it is also the secondary particle size. When the average particle size is 100 nm or less, it is preferable to form a metal layer at low temperatures, considering the wide versatility of the substrate and the tendency to easily form fine patterns on the substrate. Furthermore, when the average particle size is 1 nm or more, it is preferable to have good dispersion stability of the particles in the dispersion, good long-term storage stability of the dispersion, and the ability to produce uniform thin films. In one embodiment, the particles in the dispersion are essentially only metal particles. In this case, the value of the average particle size measured on the dispersion can be regarded as the average particle size of the metal particles.

[0200] The proportion of particles in 100% by mass of the dispersion is preferably 5% by mass or more, or 10% by mass or more, or 15% by mass or more, and more preferably 60% by mass or less, or 55% by mass or less, or 50% by mass or less.

[0201] <Dispersion Medium>

[0202] As dispersion media, alcohols (monohydric alcohols and polyhydric alcohols (e.g., glycols)), ethers of alcohols (e.g., glycols), esters of alcohols (e.g., glycols), etc., can be used. They can be used alone or in combination, and the selection is based on factors such as evaporability, the equipment used in coating, and the solvent resistance of the substrate (i.e., the substrate to be coated). From the perspectives of slow drying and less dispersion aggregation when using continuous printing, and good intermittent stability and less abnormal spraying when using inkjet printing, the dispersion preferably contains one or more dispersion media selected from the group consisting of 1-hexanol, 1-heptanol, and 1-octanol, and more preferably contains one or more dispersion media selected from the group consisting of 1-heptanol and 1-octanol.

[0203] Regarding the boiling point of the dispersion medium, from the perspective of improving printing continuity, a high boiling point is preferred, for example, preferably 50°C or higher, more preferably 100°C or higher, and even more preferably 150°C or higher. On the other hand, from the perspective of effectively obtaining the function as a dispersion medium, the above-mentioned boiling point is preferably 400°C or lower, more preferably 300°C or lower, and even more preferably 250°C or lower.

[0204] The content of the dispersion medium in the dispersion is preferably 30% or more by mass, or 40% or more by mass, or 50% or more by mass, and preferably 95% or less by mass, or 90% or less by mass.

[0205] <Dispersant>

[0206] As a dispersant, a compound capable of dispersing particles in a dispersion medium can be used. The number-average molecular weight of the dispersant is preferably 300 or more, or 350 or more, or 400 or more, preferably 300,000 or less, or 200,000 or less, or 150,000 or less. Furthermore, the number-average molecular weight disclosed herein is a value calculated using gel permeation chromatography with standard polystyrene. If the number-average molecular weight is 300 or more, it tends to have excellent insulation properties and a greater contribution to the dispersion stability of the dispersion; if the number-average molecular weight is 300,000 or less, it is preferred from a processability perspective. The dispersant preferably has a group that has an affinity for metals, particularly metal oxides, in the particles. Examples of such groups include phosphate groups, hydroxyl groups, amino groups, and carboxyl groups. From the perspective of affinity for particles and inhibition of particle aggregation based on steric hindrance, the dispersant preferably contains or is a phosphorus-containing organic compound, or contains or is a phosphate ester, or contains or is a polymeric phosphate ester. The polymer chain can be a hydrocarbon chain. When a second metal layer is formed using a dispersion and a first metal layer is formed by methods such as plating, if the dispersion contains a phosphorus-containing organic compound, there is a tendency for better adhesion between the first and second metal layers.

[0207] Known dispersants can be used as dispersants. Examples include salts of long-chain polyaminoamides and polar acid esters, unsaturated polycarboxylic acid polyaminoamides, polycarboxylic acid salts of polyaminoamides, and salts of long-chain polyaminoamides and acid polymers, which contain basic groups. Alkyl ammonium salts, amine salts, and amide amine salts of polymers such as acrylic (co)polymers, modified polyester acids, polyether ester acids, polyether carboxylic acids, and polycarboxylic acids can also be used. Commercially available dispersants can also be used as such dispersants.

[0208] The acid value (mgKOH / g) of the dispersant is preferably 20 or higher, or 30 or higher, and more preferably 130 or lower, or 100 or lower. An acid value within the above range results in good dispersion stability of the dispersion, which is preferred. The above-mentioned acid value range is particularly effective when the average particle size of the copper oxide particles and / or copper-containing particles is small. Specifically, examples preferably include "DISPERBYK-102" (acid value 101), "DISPERBYK-140" (acid value 73), "DISPERBYK-142" (acid value 46), "DISPERBYK-145" (acid value 76), "DISPERBYK-118" (acid value 36), and "DISPERBYK-180" (acid value 94) manufactured by BYK Chemical Co., Ltd.

[0209] Furthermore, the difference between the amine value (mgKOH / g) and the acid value of the dispersant ([amine value] - [acid value]) is preferably -50 or higher and 0 or lower. The amine value represents the total amount of free base and its components, while the acid value represents the total amount of free fatty acids and their components. The amine value and acid value are determined using methods based on JIS K 7700 or ASTM D2074, respectively. A value of -50 or higher and 0 or lower for the [amine value] - [acid value] indicates good dispersion stability of the dispersion, which is preferred. A value of -40 or higher and 0 or lower is more preferably preferred, and even more preferably -20 or higher and 0 or lower.

[0210] The mass ratio of the dispersant (mass of dispersant / mass of metal) relative to the total mass of the metal in the dispersion is preferably 0.0050 or more, or 0.050 or more, or 0.10 or more, preferably 0.30 or less, or 0.25 or less, or 0.23 or less. The "total mass of metal" refers to the total mass of the metal as it exists in the dispersion (e.g., elemental metal, alloy, or metal compound). The amount of dispersant affects the dispersion stability of the dispersion; a small amount leads to particle aggregation, while a large amount tends to increase the dispersion stability. However, if the content of the dispersant in the dispersion is 35% by mass or less, the influence of residues from the dispersant in the metal layer can be suppressed, thereby improving conductivity. In one embodiment, the amount of dispersant in 100% by mass of the dispersion is preferably 0.5% by mass or more, or 0.8% by mass or more, or 1.0% by mass or more, preferably 35% by mass or less, or 30% by mass or less, or 25% by mass or less.

[0211] <Reducing agent>

[0212] When the dispersion contains metal oxide particles, the dispersion may contain a reducing agent. Examples of reducing agents include hydrazine, sodium, sodium borohydride, potassium iodide, sulfite, sodium thiosulfate, formic acid, oxalic acid, ascorbic acid, iron(II) sulfide, tin(II) chloride, diisobutylaluminum hydride, carbon, etc., with hydrazine being preferred. Hydrazine may also be in the form of hydrated hydrazine (i.e., the concept of hydrazine in this disclosure also includes hydrated hydrazine). By using a dispersion containing a reducing agent, the metal oxide can be reduced more effectively, and a metal layer with lower resistivity can be formed. In addition, hydrazine is also advantageous in maintaining the dispersion stability of the dispersion. The hydrazine in the dispersion may exist as a component of the particles and / or exist separately from the particles.

[0213] The content of the reducing agent in the dispersion (the amount of water removed in the case of hydrates) is proportional to the amount of metal oxide, and can be adjusted considering the desired reducing power. In one embodiment, the mass ratio of the reducing agent to the metal oxide in the dispersion (mass of reducing agent / mass of metal oxide) is preferably 0.0001 or more, preferably 0.1 or less, or 0.05 or less, or 0.03 or less. When the mass ratio of the reducing agent is 0.0001 or more, it is preferred from the perspective of good dispersion stability and low resistivity of the metal layer; when the mass ratio of the reducing agent is 0.1 or less, the long-term stability of the dispersion is good.

[0214] Two or more reducing agents can be used together. For example, when hydrazine and other reducing agents are used together, the total content of hydrazine and other reducing agents in the dispersion is proportional to the amount of metal oxide, and can be adjusted considering the required reducing power. In one embodiment, the ratio of the total mass of hydrazine and other reducing agents in the dispersion to the mass of metal oxide (total mass of reducing agent / mass of metal oxide) is preferably 0.0001 or more, preferably 0.1 or less, or 0.05 or less, or 0.03 or less. When the above-mentioned total mass ratio of reducing agents is 0.0001 or more, it is preferable from the perspective of good dispersion stability of the dispersion and low resistance of the metal layer; when the above-mentioned total mass ratio of reducing agents is 0.1 or less, the long-term stability of the dispersion is good.

[0215] A dispersion can be manufactured by mixing the ingredients and then dispersing them using methods such as mixers, ultrasonic methods, three-roll mills, two-roll mills, mills, homogenizers, Banbury mixers, paint mixers, kneaders, ball mills, sand mills, and self / revolutionary mixers. The viscosity of the dispersion can be designed according to the target coating method. For example, the viscosity of a dispersion for screen printing is preferably 50 mPa·s or more, more preferably 100 mPa·s or more, further preferably 200 mPa·s or more, preferably 50,000 mPa·s or less, more preferably 10,000 mPa·s or less, and further preferably 5,000 mPa·s or less. Furthermore, the viscosity of the dispersion is measured using a cone-plate rotational viscometer at 23°C.

[0216] Metal oxides tend to be more stable than elemental metals, and using dispersions containing metal oxide particles can be advantageous in terms of the preservation stability of the dispersion. Therefore, the first method described above is preferred.

[0217] The first method will be explained in more detail below.

[0218] <Examples of each step in the manufacturing process of laminates>

[0219] <Preparation of Polymer Substrates>

[0220] Polymer substrates can be prepared by using commercially available polymer films and forming polymer substrates as described above.

[0221] <Coating Process>

[0222] In the coating process, a dispersion containing metal oxide particles is coated to form a coating film containing metal oxides. Examples of coating methods for the dispersion include inkjet printing, screen printing, direct gravure printing, gravure offset printing, flexographic printing, and offset printing. Coating is performed using methods such as die coating, spin coating, slot coating, bar coating, doctor blade coating, spray coating, and dip coating.

[0223] From the perspective of easily forming a highly uniform wiring pattern, the coating thickness is preferably 1 nm or more, 10 nm or more, or 100 nm or more, and more preferably 10,000 nm or less, 8,000 nm or less, or 7,000 nm or less. However, the coating thickness can be controlled to a level similar to that of each layer (metal layer and / or metal-containing polymer layer) having a specified thickness as in this embodiment. The coating thickness can be controlled by factors such as the amount of metal oxide dispersion applied and the number of coating applications.

[0224] <Drying Process>

[0225] The manufacturing method of laminates can include a drying process.

[0226] In the drying process, the coating film is dried. For example, in the drying process, the coating film obtained through the above-described coating process is dried. The drying conditions are, for example, 60–120°C for 5 minutes to 5 hours. In the drying process, the coating film can be dried under reduced pressure below atmospheric pressure.

[0227] From the perspective of easily forming a highly uniform wiring pattern, the thickness of the dried coating is preferably 1 nm or more, 10 nm or more, or 100 nm or more, and more preferably 10,000 nm or less, 8,000 nm or less, or 7,000 nm or less. However, the thickness of the dried coating can be controlled to the extent that it produces each layer (metal layer and / or polymer layer containing metal) with a specified thickness as in this embodiment. The thickness of the dried coating can be controlled by the thickness of the coating before drying, the drying temperature, and the drying time.

[0228] <Restoration Process>

[0229] The manufacturing method of a laminate can include a reduction step that reduces a coating film. For example, in the reduction step, an oxide-containing film obtained through the coating step described above is reduced. The reduction step can be performed simultaneously with the drying step and / or the plating step, or it can be performed separately from these steps. In the reduction step, a metal-containing film is obtained by reducing the coating film (e.g., an oxide-containing film). In the reduction step, oxide-containing particles in the oxide-containing film can be reduced, thereby generating metal, which is then formed into a metal layer through welding and integration of the metal itself. However, if the oxide-containing film is used directly as a metal layer, this step can be omitted.

[0230] Examples of reduction methods include reduction at temperatures above 100°C and below 500°C under a nitrogen atmosphere; reduction at temperatures above 100°C and below 500°C in a hydrogen-nitrogen mixture (e.g., a mixture of hydrogen and nitrogen containing approximately 3% hydrogen by volume in a total of 100% by volume); reduction by laser irradiation; and reduction by immersing an oxide-containing film in a reducing solution. From the perspective of easily ensuring the thickness of the metal-containing polymer layer and easily achieving improved adhesion, reduction by laser irradiation is preferred. By appropriately setting the laser irradiation intensity, a portion of the polymer can be easily modified while ensuring the mechanical strength of both the metal layer and the polymer layer. By diffusing the metal into the modified portion of the polymer, the desired metal-containing polymer layer can be formed. In particular, if a <plating process> is performed after laser irradiation, the diffusion of the metal into the modified polymer is easily promoted. Furthermore, by adjusting the laser irradiation conditions, fine lines such as tens of nanometers can be patterned simultaneously with reduction. Therefore, it is easy to form fine metal wiring as a metal layer.

[0231] (Laser-based reduction)

[0232] As a laser-based reduction method, a known laser irradiation device with a laser irradiation section can be used. Lasers are preferred because they facilitate short-time exposure to high-intensity light, allow for rapid temperature rise of the dried coating formed on the substrate, and facilitate firing (e.g., easy reduction of monovalent copper oxide). Laser firing allows for short firing times, resulting in less damage to the substrate, making it suitable for polymer substrates with low heat resistance. Furthermore, laser firing offers greater freedom in wavelength selection, making it easier to select the wavelength considering the light absorption wavelength of the dried coating and / or the light absorption wavelength of the substrate. Moreover, laser firing allows for beam scanning-based exposure, facilitating adjustment of the exposure range; for example, it allows for selective irradiation (drawing) of only the target area of ​​the dried coating without the use of a mask.

[0233] Examples of laser sources include YAG (yttrium aluminum garnet), YVO (yttrium vanadate), Yb (ytterbium), semiconductor lasers (GaAs, GaAlAs, GaInAs), and carbon dioxide. As lasers, they can pick up not only the fundamental wave but also harmonics when necessary.

[0234] The center wavelength of the laser is preferably 350 nm or higher and 600 nm or lower. Particularly when using monovalent copper oxide as the copper oxide, monovalent copper oxide can effectively absorb lasers with center wavelengths within the aforementioned range, thus being uniformly reduced and forming low-resistance metal wiring. A more preferred center wavelength when using monovalent copper oxide is 350 nm or higher and 400 nm or lower.

[0235] The laser is preferably irradiated onto the dried coating using a galvanometer scanner. By using a galvanometer scanner to scan the dried coating with the laser, metal wiring of any shape can be obtained.

[0236] Regarding the laser irradiation output, from the perspective of effectively performing the desired sintering (e.g., the reduction of monovalent copper oxide), 1mW or more, 10mW or more, or 20mW or more are preferred. From the perspective of easily suppressing the damage to the metal wiring caused by ablation due to excessive laser output, and thus easily obtaining low-resistance metal wiring, less than 200mW, less than 100mW, or less than 50mW are preferred. Generally, laser sintering with a high output of 200mW or more promotes the sintering of metal particles together, thereby burning away the dispersant and organic matter from the reducing agent in the coating and reducing the resistance value. In addition, by performing laser sintering with a high output of 200mW or more, the reduction of metal oxides (e.g., monovalent copper oxide) is promoted, so it is easy to perform plating growth on the reduced metal. On the other hand, in this embodiment, by making the laser output less than 200mW and intentionally leaving a portion of the metal oxides and organic matter, a physical bond can be formed between the metal oxides and organic matter and the substrate, thereby improving the adhesion between the substrate and the metal layer. At this point, due to the presence of residual metal oxides and organic matter, the plating is not easily grown. Therefore, by shaking the sample during plating, as described later, plating growth can be promoted. In addition, by performing an electroless plating process after laser sintering with further suppressed output, it is easier to control the thickness of the metal-containing polymer layer and the amount of metal contained in the metal-containing polymer layer within a more favorable range.

[0237] Especially when using monovalent copper oxide as the copper oxide, it is preferable to have a laser center wavelength of 350 nm or more and 400 nm or less, and to have an irradiation output within the aforementioned range. Using this center wavelength, the laser is almost entirely absorbed by the monovalent copper oxide, thus suppressing excessive polymer denaturation caused by laser absorption by the polymer substrate. Furthermore, using the aforementioned irradiation output prevents the generation of excessive heat by reducing the irradiation output to the point where the metal oxide is reduced. In this way, it is possible to achieve both the formation of a metal-containing polymer layer through laser irradiation and the suppression of strength reduction in the polymer substrate due to polymer denaturation.

[0238] <Degreasing process>

[0239] In one aspect of the method disclosed herein, a degreasing step of the coating film may be performed prior to the plating step.

[0240] In one approach, directly degreasing the metal oxides without reduction easily improves productivity. In another approach, degreasing can be performed after reducing the metal oxides (e.g., using the reduction process described above). Examples of degreasing methods include UV degreasing and wet degreasing. The degreasing process tends to accelerate the growth rate of subsequent plating, thus increasing productivity. Furthermore, this process may improve the porosity of the plated metal layers (in one approach, a first metal layer and a second metal layer). It should be noted that degreasing can also be performed simultaneously with electroless plating; in this case, the degreasing process can be omitted.

[0241] From the perspective of easily exhibiting excellent interlayer adhesion in laminates, the degreasing process is preferably carried out by immersing the coating film in a degreasing solution containing an amino compound. Examples of compounds containing amino groups include amino acids such as alanine, arginine, asparagine, cysteine, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine; alkylamines such as methylamine, dimethylamine, ethylamine, trimethylamine, diethylamine, triethylamine, propylamine, isopropylamine, and diisopropylamine; alkanolamines such as 2-aminoethanol, diethanolamine, triethanolamine, N-methylethanolamine, and N,N-dimethylethanolamine; polyamines such as ethylenediamine, diethylenetriamine, tetraethylenepentamine, tris(hydroxymethyl)aminomethane, m-phenylenediamine, p-phenylenediamine, and 1,3-bis(aminomethyl)cyclohexane; aminosulfonic acids such as taurine; aminothiols such as 2-aminoethanethiol; and nitrogen-containing heterocyclic compounds such as 3-pyridinemethylamine and 3-pyridinemethanol. From the perspective of promoting the growth rate of the coating, 2-aminoethanol is particularly preferred.

[0242] Degreasing solutions can be commercially available products. Specifically, examples include ALC-009 (containing 2-aminoethanol as an amino compound), which is available from Uemura Kogyo Co., Ltd., and CleanerSecuriganth 902 (containing 2-aminoethanol as an amino compound), which is available from Atotech Japan Co., Ltd.

[0243] The concentration of amino-containing compounds in the degreasing solution is preferably 5 mmol / L or more, more preferably 10 mmol / L or more, and even more preferably 20 mmol / L or more, from the perspective of removing substances that hinder the plating reaction. Furthermore, from the perspective of promoting the plating reaction, it is preferably 100 mmol / L or less, more preferably 90 mmol / L or less, and even more preferably 80 mmol / L or less.

[0244] Regarding the immersion time of the coating in the degreasing solution, from the perspective of promoting the growth rate of the coating, it is preferably 1 minute or more, more preferably 2 minutes or more. Furthermore, from the perspective of reducing damage to the substrate, it is preferably 15 minutes or less, more preferably 10 minutes or less. From the perspective of uniform degreasing, immersion under stirring is preferred.

[0245] To enhance the growth rate of the plating, the immersion temperature is preferably 15°C or higher, more preferably 30°C or higher, and even more preferably 40°C or higher. Furthermore, to minimize damage to the substrate, the temperature is preferably 70°C or lower, more preferably 60°C or lower.

[0246] <Plating Process>

[0247] In the plating process, electroless plating, electroplating, or both can be performed. For example, the second metal layer obtained through the reduction process is treated as a seed layer, followed by electroless plating and / or electroplating to obtain the first metal layer. After the plating process, in order to remove moisture contained in the metal layer, it can be dried at 100°C for about 1 hour.

[0248] By appropriately setting the conditions of the plating and reduction processes described above, the desired metal-containing polymer layer can be easily formed. For example, in the reduction process, when a second metal layer is formed by reduction using laser irradiation, by appropriately setting the laser irradiation intensity, a portion of the polymer can be denatured while ensuring the mechanical strength of both the second metal layer and the polymer layer. In particular, according to the method of performing the plating process after laser irradiation, the metal contained in the first and / or second metal layers readily diffuses into the denatured portion of the polymer substrate, resulting in the easy formation of the desired metal-containing polymer layer.

[0249] In one approach, a coating can be deposited after a drying process, with or without a reduction and / or degreasing process. In another approach, the deposition is electroless. In one approach, productivity is easily improved by directly depositing the oxide-containing film without reduction. Electroless deposition can reduce some or all of the metal oxides in the oxide-containing film, or it can leave the oxides unreduced. Alternatively, in another approach, conductivity is easily improved by electroless depositing a metal-containing film obtained by reducing the oxide-containing film (e.g., wet reduction). Electroless deposition allows the formation of a metal layer consisting of a layer of metal oxides and / or metal, and a deposited layer. Electroless deposition can easily form thick metal layers, making it particularly advantageous when manufacturing laminates for applications requiring high current. Electroless deposition is also advantageous in terms of the breadth of applicability to patterns. Common electroless deposition methods can be applied as depositing methods. For example, electroless deposition can be performed simultaneously with a reduction process, a degreasing process, or a cleaning process.

[0250] Electroless plating utilizes plating solutions. Since the coating after the drying process is susceptible to peeling due to external stress, uneven plating deposition can occur. In such cases, stress tends to concentrate in one area, potentially leading to peeling of that coating during the plating process. In one embodiment, the plating solution contains EDTA (ethylenediaminetetraacetic acid). EDTA is believed to function as a complexing agent, forming highly stable complexes with metal ions (e.g., copper ions), thus suppressing side reactions in the plating bath, stabilizing the bath, and promoting uniform plating deposition, thereby helping to prevent coating peeling. Furthermore, since EDTA is stable in high-temperature liquids, using a plating solution containing EDTA under heating (e.g., above 30°C) can also help accelerate the plating speed. Additionally, using a plating solution containing EDTA (ethylenediaminetetraacetic acid) after wet reduction can easily improve productivity by promoting metal plating growth. Regarding the amount of EDTA in the plating solution, from the perspective of maximizing the advantages brought by EDTA, it is preferably 7 g / L or more, or 10 g / L or more, or 15 g / L or more. From the perspective of reducing impurities in the plating precipitates and easily reducing resistivity, it is preferably 50 g / L or less, or 45 g / L or less, or 40 g / L or less. In another embodiment, the plating solution contains Rochelle salt. Rochelle salt functions as a complexing agent. Plating solutions containing Rochelle salt typically react at low temperatures and have a lower pH compared to plating solutions containing EDTA. Therefore, they are less likely to cause substrate brittleness, prevent substrate cohesive failure, and easily improve adhesion. On the other hand, plating reactivity is generally low; however, by shaking the sample as described later, plating reactivity can be improved. Regarding the amount of Rochelle salt in the plating solution, from the perspective of maximizing the advantages brought by Rochelle salt, it is preferably 30 g / L or more, or 40 g / L or more; from the perspective of reducing impurities in the plating precipitates and easily reducing resistivity, it is preferably 100 g / L or less, or 85 g / L or less. Furthermore, especially when reduction is performed under a nitrogen atmosphere or in a hydrogen-nitrogen mixture using firing at 100°C to 500°C, the use of Rochelle salt tends to prevent the inclusion of divalent metals in the metal-containing polymer layer.

[0251] In a typical approach, the plating bath contains a metal ion source (e.g., a copper ion source) and a reducing agent. For example, the coating film can be immersed in the plating bath while air bubbling is performed. The metal ions in the plating bath are reduced by electroless plating, thereby depositing metal on the surface of the coating film and forming a plated metal layer. In the case where the coating film contains metal oxides, in electroless plating, some or all of the oxides may be reduced by the plating bath or may not be reduced, thus forming a plated metal layer on the layer containing metal oxides and / or metal.

[0252] Metal ion sources can exist in liquids in ionic form. Examples of copper ion sources include CuSO4, CuCl2, CuCl, CuNO3, and Cu3(PO4)2. From the perspective of forming a coating layer with excellent adhesion, CuCl2 and CuSO4 are preferred.

[0253] Regarding the metal concentration (e.g., copper concentration) of the plating solution, from the perspective of improving the plating speed, it is preferably 1.5 g / L or more, or 1.8 g / L or more, or 2.0 g / L or more; from the perspective of the uniformity of the plating film, it is preferably 5.0 g / L or less, or 4.0 g / L or less, or 3.5 g / L or less, or 3.0 g / L or less. Especially when wet reduction and plating are combined, the metal concentration of the plating solution is preferably 1.8 g / L or more and 3.5 g / L or less.

[0254] As a reducing agent, one or more can be selected from the group consisting of potassium tetrahydrogenate, dimethylamine borane, glyoxylic acid, and phosphonic acid. The amount of reducing agent in the plating solution is preferably 0.1 g / L or more, or 0.5 g / L or more, or 1.0 g / L or more, preferably 15.0 g / L or less, or 12.0 g / L or less, or 9.0 g / L or less.

[0255] In addition to EDTA (ethylenediaminetetraacetic acid) and Rochelle salt, the plating solution may further contain additional complexing agents. Examples of additional complexing agents include triethanolamine, ammonium sulfate, citric acid, and glycine. The amount of additional complexing agent in the plating solution is preferably 5 g / L or more, or 7 g / L or more, or 10 g / L or more, preferably 50 g / L or less, or 45 g / L or less, or 40 g / L or less.

[0256] The plating solution may be further enriched with surfactants as needed.

[0257] From the perspective of good plating growth, the electroless plating solution preferably contains formaldehyde. The reducing power of formaldehyde increases with increasing pH; therefore, in a typical manner, the plating solution contains a pH adjuster. Sodium hydroxide, potassium hydroxide, lithium hydroxide, etc., are used as pH adjusters. Regarding the pH of the electroless plating solution, it is preferably 10 or higher for good plating growth, and preferably 14 or lower, or 13.5 or lower, or 13 or lower for suppressing excessive embrittlement of the polymer substrate. The concentration of the pH adjuster in the electroless plating solution can be an amount useful for controlling the pH within the above-mentioned range; in one embodiment, it can be 0.01 mol / L or higher and 0.5 mol / L or lower, or 0.01 mol / L or higher and 0.3 mol / L or lower, or 0.01 mol / L or higher and 0.2 mol / L or lower.

[0258] The plating solution can be a commercially available product. Commercially available products include Thru-cupELC-SP (available from Uemura Kogyo Co., Ltd.), MelplateCU-390 and MelplateCU-5100P (available from Meltex Co., Ltd.), OPC Copper NCA and OPC Copper HFS (available from Okuno Pharmaceutical Co., Ltd.), C4500 (available from Rohm and Haas Co., Ltd.), Printganth UPlus (available from Atotech Co., Ltd.), and Cu-510 (available from MacDermid Co., Ltd., Japan).

[0259] From the perspective of achieving faster plating growth, the temperature of the electroless plating bath based on the plating solution is preferably above 25°C, or above 30°C, or above 35°C, and preferably below 80°C, or below 70°C, or below 65°C. The plating time is preferably above 5 minutes, or above 10 minutes, and preferably below 120 minutes, or below 60 minutes, or below 50 minutes, or below 40 minutes.

[0260] Samples can be shaken during electroless plating. The sample can be shaken manually or using a shaking device. The sample can be shaken up and down multiple times at intervals ranging from 30 seconds to 10 minutes. This can facilitate the removal of air bubbles from the sample surface, resulting in uniform plating growth, and can also promote uniform plating growth by stirring the plating bath.

[0261] In one approach, electroplating can be performed after electroless plating. Electroplating can utilize common electroplating methods. For example, electrodes and a conductive substrate to be plated are immersed in a solution (plating bath) containing metal ions (e.g., copper ions). Then, a direct current is applied between the electrodes and the conductive substrate from an external direct current power source. In another approach, current can be applied to the metal layer by connecting a clamp (e.g., a clip) connected to one electrode of an electrode pair with an external direct current power source to a metal layer (e.g., a reduced copper layer) on the polymer substrate. As a result, metal is deposited on the surface of the metal layer on the polymer substrate through the reduction of metal ions, forming a plated metal layer.

[0262] For electroplating baths, copper sulfate baths, copper fluoroborate baths, copper cyanide baths, and copper pyrophosphate baths can be used. From the perspectives of safety and productivity, copper sulfate baths and copper pyrophosphate baths are preferred.

[0263] For example, a sulfuric acid copper sulfate plating bath containing copper sulfate pentahydrate, sulfuric acid, and chlorine is suitable as the copper sulfate plating bath. The concentration of copper sulfate pentahydrate in the copper sulfate plating bath is preferably 50 g / L or more, or 100 g / L or more, preferably 300 g / L or less, or 200 g / L or less. The concentration of sulfuric acid is preferably 40 g / L or more, or 80 g / L or more, preferably 160 g / L or less, or 120 g / L or less. The solvent in the plating bath is usually water. The temperature of the plating bath is preferably 20°C or more, or 30°C or more, preferably 60°C or less, or 50°C or less. The current density during electrolytic treatment is preferably 1 A / dm³. 2 Above, or 2A / dm 2 The above is preferably 15A / dm. 2 Below, or 10A / dm 2 the following.

[0264] The copper pyrophosphate plating bath is preferably a plating bath containing copper pyrophosphate and potassium pyrophosphate. The concentration of copper pyrophosphate in the copper pyrophosphate plating bath is preferably 60 g / L or more, or 70 g / L or more, preferably 110 g / L or less, or 90 g / L or less. The concentration of potassium pyrophosphate is preferably 240 g / L or more, or 300 g / L or more, preferably 470 g / L or less, or 400 g / L or less. The solvent in the plating bath is usually water. The pH of the plating bath is preferably 8.0 or more, or 8.2 or more, preferably 9.0 or less, or 8.8 or less. Ammonia or the like can be added to adjust the pH. The temperature of the plating bath is preferably 20°C or more, or 30°C or more, preferably 60°C or less, or 50°C or less. The current density during electrolytic treatment is preferably 0.5 A / dm³. 2 Above, or 1A / dm 2 The above is preferably 10A / dm. 2 Below, or 7A / dm 2 the following.

[0265] The plating bath used for electroplating may further contain surfactants.

[0266] From the perspective of obtaining good conductivity, the thickness of the coating layer is preferably 0.1 μm or more, or 0.5 μm or more, or 1.0 μm or more, preferably 1000 μm or less, or 500 μm or less, or 100 μm or less, or 50 μm or less, or 10 μm or less, or 5 μm or less.

[0267] It should be noted that the metal layer can be formed by sputtering. The sputtering conditions, namely the sputtering pressure, the power input during film formation, the distance or angle from the substrate, and the sputtering temperature, can be adjusted appropriately.

[0268] <Metal wiring manufacturing apparatus>

[0269] The laminate of this embodiment can be manufactured using, for example, an apparatus as described below.

[0270] Figure 3 This is a schematic diagram of a metal wiring manufacturing apparatus used in one embodiment of the present invention. The metal wiring manufacturing apparatus 10 includes a structure holding part 101 and a light oscillator 102. The metal wiring manufacturing apparatus 10 may include an inactive gas generator 103, a light scanning part 104, a speed control part 105, and / or a computer 106.

[0271] <Structural Retention Section>

[0272] In one embodiment, the structure holding part 101 is a sample chamber. In another embodiment, the structure has a substrate and a coating disposed on the substrate. One embodiment of the structure is a laminate of a polymer substrate and an oxide-containing film disposed on the polymer substrate. The sample chamber may have a window. The sample chamber may have an inert gas inlet, for example, it may be configured such that an inert gas generated by the inert gas generator 103 is introduced into the sample chamber via the inert gas inlet.

[0273] <Light Oscillator>

[0274] The light oscillator 102 is configured to emit light at a desired wavelength. In a typical configuration, the light source is a laser. When using a laser as the light source, laser sources such as YAG (yttrium aluminum garnet), YVO (yttrium vanadate), Yb (ytterbium), semiconductors (GaAs, GaAlAs, GaInAs), and carbon dioxide can be used. Regarding lasers, not only the fundamental wave but also harmonics can be picked up when necessary. Alternatively, LED light can also be used. The light oscillator 102 may include a cooling device, etc.

[0275] <Light Scanning Department>

[0276] The light scanning unit 104 scans the light L emitted from the light oscillator 102. Figure 3 The diagram shows an example where the light scanning unit 104 is a galvanometer scanner. The galvanometer scanner, which is the light scanning unit 104, includes an X-axis galvanometer 104a, an X-axis galvanometer motor 104b, a Y-axis galvanometer 104c, and a Y-axis galvanometer motor 104d. The galvanometer scanner may include an fθ lens (not shown), a Z-axis adjustment drive lens (not shown), etc. The X-axis galvanometer motor 104b and the Y-axis galvanometer motor 104d are electrically connected to a speed control unit 105 (e.g., a scanner control unit).

[0277] The galvanometer scanner is configured to control the rotation angle and rotation speed of the X-axis galvanometer motor 104b and the Y-axis galvanometer motor 104d based on control signals from the speed control unit 105. The speed control unit 105 is controlled by a computer 106.

[0278] The light beam L is scanned by the light scanning unit 104 and irradiates the surface of the coating film 12 formed on the substrate 11.

[0279] In the above description, a galvanometer scanner is shown as the light scanning unit 104, but other light scanning units besides galvanometer scanners can also be used. For example, in the light scanning unit 104, instead of a galvanometer scanner, an XY stage capable of moving the substrate 11 on which the coating 12 is formed can be used as a stage, and the substrate 11 can be moved instead of the irradiation point P of the laser L.

[0280] Figure 3 In the light scanning unit 104 (galvanometer scanner) shown, X-axis galvanometer 104a and Y-axis galvanometer 104c are used for movement in the X-axis direction and Y-axis direction respectively. However, galvanometers can also be used for either the X-axis or the Y-axis. For example, galvanometers can be used only for movement in the X-axis direction, and a motor with a stage (not shown) on which the substrate 11 is placed can be used for movement in the Y-axis direction.

[0281] The scanning speed control in the metal wiring manufacturing apparatus 10 can be performed as follows: First, scanning data (coordinate data) representing the desired shape, position, and size of the metal wiring pattern is input into the speed control unit 105. Based on the scanning data, the scanner control unit of the speed control unit 105 calculates the length (L) (unit: mm) of the scanning line according to the length of the pattern along the X-axis. Next, based on the calculated length (L) of the scanning line, the scanner control unit calculates the laser scanning speed (hereinafter referred to as the scanning speed) (V) (unit: mm / second) at a predetermined scanning cycle (F) (unit: Hz) (e.g., 15 Hz) using the following formula.

[0282] Scan speed (V) = Scan cycle (F) × Scan line length (L)

[0283] Next, the scanner control unit moves the irradiation point P of the laser L along the X-axis in the galvanometer scanner, which is the light scanning unit 104, according to the scanning speed calculated in this way, and performs one scan.

[0284] Subsequently, the scanner control unit moves the irradiation point P of laser L along the Y-axis in the galvanometer scanner.

[0285] As described above, the scanning speed (V) of the laser L can be set based on the length (L) of the scanning line so that the scanning period (F) is the same at any position within the coating film 12.

[0286] substrate with metal wiring

[0287] One aspect of the present invention provides a laminate comprising a polymer substrate and metal wiring on the polymer substrate. In one aspect, the polymer substrate has a polymer layer and a polymer layer containing metal. In a representative aspect, the metal wiring is bonded to the polymer layer containing metal, and the polymer layer containing metal is bonded to the polymer layer. The substrate with metal wiring is suitable, for example, for use in circuit boards, such as printed wiring boards. Such circuit boards typically have a structure in which conductive wiring is applied to a substrate. That is, in one aspect of the substrate with metal wiring, a pattern of metal layers is disposed on the polymer substrate (more specifically, on the polymer layer containing metal of the polymer substrate having a polymer layer and a polymer layer containing metal) as metal wiring. Multiple patterns of metal layers can be disposed on the substrate, and their shape and size can be selected as desired.

[0288] In one embodiment, in the infrared absorption spectroscopy determination of the polymer substrate, the minimum value of the ratio (IR1) / (IR2) of the peak intensity (IR1) of the first peak of the first structure in the main chain of the polymer constituting the polymer substrate to the peak intensity (IR2) of the second peak of the second structure in the main chain is within the aforementioned range of the ratio (IR1) / (IR2) of the polymer layer containing the metal and the polymer layer.

[0289] Other implementation methods

[0290] This invention is not limited to the embodiments described above, and can be implemented with various modifications within the scope of its key features. For example, in addition to having a metal layer, a polymer layer containing a metal, and a polymer layer, the laminate may further have other layers. Furthermore, the polymer layer may be a molded body with a thickness greater than 1000 μm. This molded body may be a plate-like body, a three-dimensional object of various shapes, etc.

[0291] This disclosure also includes the following items.

[0292] Method 1

[0293] [Project 1]

[0294] A laminate is a laminate comprising a metal layer, a polymer layer containing a metal, and a polymer layer arranged in the following order, wherein... The aforementioned metal layer includes a first metal layer and a second metal layer disposed between the first metal layer and the metal-containing polymer layer. The first metal layer, the second metal layer, and the polymer layer containing the metal all contain the same metal. The thickness of the first metal layer is 0.1 μm or more and 1000 μm or less. The thickness of the second metal layer is 0.01 μm or more and 10 μm or less. The thickness of the aforementioned metal-containing polymer layer is 0.04 μm or more and 10 μm or less, and The thickness of the polymer layer is 1.0 μm or more and 1000 μm or less.

[0295] [Project 2]

[0296] According to the laminate described in Project 1, the second metal layer comprises carbon.

[0297] [Project 3]

[0298] According to the laminate of Project 1 or 2, the second metal layer contains more than 0.1 atomic% and less than 15 atomic% carbon.

[0299] [Project 4]

[0300] The laminate according to any one of items 1 to 3, wherein the aforementioned homogeneous metal is copper.

[0301] [Project 5]

[0302] The laminate according to any one of items 1 to 4, wherein the pattern of the metal layer is formed on the polymer layer containing the metal.

[0303] [Project 6]

[0304] The laminate according to any one of items 1 to 5, wherein the aforementioned metal-containing polymer layer comprises sodium.

[0305] [Project 7]

[0306] The laminate according to any one of items 1 to 6, wherein the aforementioned metal-containing polymer layer comprises: Sodium of 0.1 atomic percent or more and 10 atomic percent or less; and Metals with a percentage of 1 atom or more but less than 10 atom.

[0307] [Project 8]

[0308] The laminate according to any one of items 1 to 7, wherein... The polymer constituting the aforementioned metal-containing polymer layer, and the polymer constituting the aforementioned polymer layer, are nitrogen-containing polymers. The aforementioned laminate contains a metal chemically bonded to a nitrogen atom.

[0309] [Project 9]

[0310] The laminate according to any one of items 1 to 8, wherein the aforementioned metal-containing polymer layer comprises a metal with zero or one valence.

[0311] [Project 10]

[0312] The laminate according to any one of items 1 to 9, wherein the second metal layer is a layer formed by reducing a layer containing copper oxide.

[0313] [Project 11]

[0314] The laminate according to any one of items 1 to 10, wherein the aforementioned metal-containing polymer layer is the aforementioned metal-containing polyimide layer, and the aforementioned polymer layer is a polyimide layer.

[0315] [Project 12]

[0316] According to any one of items 1 to 11, in the infrared absorption spectroscopy measurement, the minimum value of the ratio (IR1) / (IR2) of the peak intensity (IR1) of the first peak of the first structure of the polymer constituting the metal-containing polymer layer and the polymer of the polymer layer to the peak intensity (IR2) of the second peak of the second structure of the second structure of the polymer layer is 0.2 or more and 1.5 or less.

[0317] [Project 13]

[0318] The laminate according to any one of items 1 to 12 is used as a constituent element of an electronic circuit board.

[0319] [Project 14]

[0320] A method for manufacturing a laminate, which is the method for manufacturing a laminate as described in any one of items 1 to 12, includes the following steps: The coating process involves coating a metal oxide onto a polymer substrate; and The reduction process involves reducing the aforementioned metal oxides.

[0321] [Project 15]

[0322] According to the method described in Project 14, the above-mentioned reduction is performed by laser irradiation.

[0323] [Project 16]

[0324] The method described according to item 14 or 15 further includes an electroless metal plating process.

[0325] [Project 17]

[0326] According to the method described in Project 16, the electroless metal plating process is performed after the reduction process.

[0327] [Project 18]

[0328] A method for manufacturing a laminate, comprising the following steps: a first metal layer, a second metal layer, a metal-containing polymer layer, and a polymer layer sequentially disposed thereon, wherein the first metal layer, the second metal layer, and the metal-containing polymer layer comprise the same metal. The process of forming the aforementioned first metal layer with a thickness of 0.1 μm or more and 1000 μm or less; The process of forming the aforementioned second metal layer with a thickness of 0.01 μm or more and 10 μm or less; The process of forming the aforementioned metal-containing polymer layer with a thickness of 0.04 μm or more and 10 μm or less; and The process of forming the above-mentioned polymer layer with a thickness of 1.0 μm or more and 1000 μm or less.

[0329] [Project 19]

[0330] According to the method for manufacturing a laminate as described in Item 18, the step of forming the second metal layer includes the following steps: The coating process involves coating a dispersion containing metal particles and / or metal oxide particles onto a substrate to form a dispersion layer. The drying process involves drying the aforementioned dispersion layer to form a dry coating film on the aforementioned substrate; and The process of forming the second metal layer by heating the dried coating film.

[0331] [Project 20]

[0332] According to the method for manufacturing a laminate as described in item 18 or 19, the step of forming the second metal layer includes the following steps: The coating process involves coating a dispersion containing metal particles and / or metal oxide particles onto a substrate to form a dispersion layer. The drying process involves drying the aforementioned dispersion layer to form a dry coating film on the aforementioned substrate; and The process of forming the second metal layer by firing the dried coating film by irradiation with a laser.

[0333] [Project 21]

[0334] According to the manufacturing method of the laminate described in Project 20, the step of forming the first metal layer includes the following step: forming the first metal layer by immersing the second metal layer in a plating solution.

[0335] [Project 22]

[0336] According to the method for manufacturing the laminate as described in Project 21, the above-mentioned plating solution with a pH of 10 or higher and 14 or lower is used.

[0337] [Project 23]

[0338] The method for manufacturing a laminate according to any one of items 19 to 22, wherein the metal particles and / or metal oxide particles are copper particles and / or copper oxide particles.

[0339] Method 2

[0340] [Project 1]

[0341] A substrate with metal wiring is a substrate comprising a polymer substrate and metal wiring on the polymer substrate, wherein... In the infrared absorption spectroscopy measurement of the polymer substrate described above, the minimum value of the ratio (IR1) / (IR2) of the peak intensity (IR1) of the first peak of the first structure in the main chain of the polymer constituting the polymer substrate to the peak intensity (IR2) of the second peak of the second structure in the main chain is 0.2 or more and 1.5 or less.

[0342] [Project 2]

[0343] According to the substrate with metal wiring described in Project 1, wherein, The polymer mentioned above is polyimide. The first structure described above is an imide ring, and the first peak is located at 1702 cm⁻¹. -1 ~1722cm -1 Scope The second structure described above is a benzene ring, and the second peak is located at 1494 cm⁻¹. -1 ~1514cm -1 The range.

[0344] [Project 3]

[0345] The substrate with metal wiring according to item 1 or 2, wherein the metal wiring is copper wiring.

[0346] [Project 4]

[0347] A substrate with metal wiring according to any one of items 1 to 3, wherein the metal wiring comprises carbon.

[0348] [Project 5]

[0349] A substrate with metal wiring according to any one of items 1 to 4, wherein the metal wiring comprises monovalent copper oxide.

[0350] [Project 6]

[0351] The substrate with metal wiring according to any one of items 1 to 5, wherein, The polymer substrate and the metal wiring described above both contain the same metal. The polymer substrate described above contains the same metal with 0 valence and / or 1 valence.

[0352] [Project 7]

[0353] According to any one of items 1 to 6, the substrate with metal wiring has a porosity of 0.1% to 30% in a region with a depth of 1 nm or more and 500 nm or less from the polymer substrate side.

[0354] [Project 8]

[0355] A method for manufacturing a substrate with metal wiring, which is the method for manufacturing a substrate with metal wiring as described in any one of items 1 to 7, wherein the manufacturing method includes the following steps: The coating process involves coating a metal oxide onto a polymer substrate; and The reduction process involves reducing the aforementioned metal oxides.

[0356] [Project 9]

[0357] According to the method described in Project 8, the above-mentioned reduction is performed by laser irradiation.

[0358] [Project 10]

[0359] The method described in Project 8 or 9 further includes an electroless metal plating process.

[0360] [Project 11]

[0361] According to the method described in Project 10, the electroless metal plating process is performed after the reduction process.

[0362] Method 3

[0363] [Project 1]

[0364] A laminate is a laminate comprising a metal layer, a polymer layer containing a metal, and a polymer layer arranged in the following order, wherein, The aforementioned metal layer and the aforementioned metal-containing polymer layer both contain the same metal. The polymer constituting the aforementioned metal-containing polymer layer and the polymer constituting the aforementioned polymer layer are nitrogen-containing polymers. The aforementioned metal-containing polymer layer contains a metal chemically bonded to a nitrogen atom.

[0365] [Project 2]

[0366] According to the laminate described in Project 1, the aforementioned metal-containing polymer layer comprises a metal with 0 valence and / or 1 valence.

[0367] [Project 3]

[0368] According to the laminate of Project 1 or 2, wherein the aforementioned metal-containing polymer layer comprises metals with 0 valence and 1 valence.

[0369] [Project 4]

[0370] The laminate according to any one of items 1 to 3, wherein... The aforementioned metal includes copper. The metals chemically bonded to nitrogen atoms mentioned above include copper with a monovalent oxidation state.

[0371] [Project 5]

[0372] The laminate according to any one of items 1 to 4, wherein... The nitrogen-containing polymer mentioned above is polyimide. In the infrared absorption spectroscopy measurements of the aforementioned metal-containing polymer layer and the aforementioned polymer layer, the value at 1702 cm⁻¹... -1 ~1722cm -1 The peak intensity (IRI) of the first peak in the range is at 1494 cm⁻¹ -1 ~1514cm -1 The ratio of the peak intensity (IR2) of the second peak in the range (IR1) / (IR2) is greater than 0.2 and less than 1.5.

[0373] [Project 6]

[0374] The laminate according to any one of items 1 to 5, wherein the pattern of the metal layer is disposed on the polymer layer containing the metal.

[0375] [Project 7]

[0376] A method for manufacturing a laminate, which is a method for manufacturing a laminate according to any one of items 1 to 6, wherein the manufacturing method includes the following steps: The coating process involves coating a metal oxide onto a polymer substrate; and The reduction process involves reducing the aforementioned metal oxides.

[0377] [Project 8]

[0378] According to the method described in Project 7, the above-mentioned reduction is performed by laser irradiation.

[0379] [Project 9]

[0380] The method described in Project 7 or 8 further includes an electroless metal plating process.

[0381] [Project 10]

[0382] According to the method described in Project 9, the electroless metal plating process is performed after the reduction process.

[0383] Method 4

[0384] [Project 1]

[0385] A laminate is a laminate comprising a metal layer, a polymer layer containing a metal, and a polymer layer arranged in the following order, wherein, The aforementioned metal layer and the aforementioned metal-containing polymer layer both contain the same metal. The thickness of the aforementioned metal layer is 0.1 μm or more and 1000 μm or less. The thickness of the aforementioned metal-containing polymer layer is 0.04 μm or more and 10 μm or less. The thickness of the aforementioned polymer layer is 1 μm or more and 1000 μm or less. In a cross-sectional view along the thickness direction of the aforementioned laminate, the ratio (L2) / (L1) of the length of the boundary line between the metal layer and the polymer layer containing the metal to the in-plane length (L1) of the laminate is 1.0 or more and 2.0 or less.

[0386] [Project 2]

[0387] According to the laminate described in Project 1, the aforementioned same metal is copper.

[0388] [Project 3]

[0389] According to item 1 or 2, the laminate is wherein the pattern of the metal layer is disposed on the polymer layer containing the metal.

[0390] [Project 4]

[0391] The laminate according to any one of items 1 to 3, wherein the aforementioned metal-containing polymer layer comprises: Sodium of 0.1 atomic percent or more and 10 atomic percent or less; and Metals with a percentage of 1 atom or more but less than 10 atom.

[0392] [Project 5]

[0393] The laminate according to any one of items 1 to 4, wherein... The polymer constituting the aforementioned metal-containing polymer layer and the polymer constituting the aforementioned polymer layer are nitrogen-containing polymers. The aforementioned laminate contains a metal chemically bonded to a nitrogen atom.

[0394] [Project 6]

[0395] A method for manufacturing a laminate, which is a method for manufacturing a laminate according to any one of items 1 to 5, wherein the manufacturing method includes the following steps: The coating process involves coating a metal oxide onto a polymer substrate; and The reduction process involves reducing the aforementioned metal oxides.

[0396] [Project 7]

[0397] According to the method described in Project 6, the above-mentioned reduction is performed by laser irradiation.

[0398] [Project 8]

[0399] The method described in Project 6 or 7 further includes an electroless metal plating process.

[0400] [Project 9]

[0401] According to the method described in Project 8, the electroless metal plating process is performed after the reduction process.

[0402] Example

[0403] The following examples and reference examples illustrate this embodiment in more detail. However, this embodiment is not limited to the examples described below. Unless otherwise stated, the processes, treatments, and operations described below are performed at room temperature. Room temperature is, for example, 25°C.

[0404] Manufacturing of laminates

[0405] [Example 1]

[0406] Laminations were prepared using the following method, and various evaluations were performed.

[0407] <Dispersion>

[0408] A solvent consisting of 800g of ion-exchanged water and 400g of 1,2-propanediol (manufactured by Wako Pure Chemical Industries, Ltd.), 80g of copper(II) acetate monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.), and 20g of hydrazine hydrate (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed and stirred under a nitrogen atmosphere. The mixture was then separated into a supernatant and a precipitate by centrifugation.

[0409] 2.8 g of the obtained precipitate, 0.4 g of DISPERBYK-145 (trade name, manufactured by BYK Chemical Company), a phosphorus-containing organic compound, and 6.6 g of ethanol (manufactured by Wako Pure Chemicals Co., Ltd.) as the dispersion medium were mixed, and the precipitate was then dispersed using a homogenizer under a nitrogen atmosphere. The supernatant and precipitate were then separated by centrifugation, and the precipitate was recovered. The precipitate was diluted with ethanol and dispersed again using a homogenizer under a nitrogen atmosphere.

[0410] A dispersion containing monovalent copper oxide particles was obtained by repeatedly performing the above-described centrifugation (concentration) and dispersion (dilution) operations. These monovalent copper oxide particles contain monovalent copper oxide (copper oxide (I)). The average particle size is 15 nm. It should be noted that the average particle size was determined using an Otsuka Electronics FPAR-1000 by the accumulation method (the same applies below).

[0411] The final composition of the dispersion is as follows: 2.8 g of precipitate, 0.4 g of DISPERBYK-145, 6.6 g of ethanol, and 0.01 g of hydrazine hydrate.

[0412] <Polymer substrate>

[0413] As a polyimide substrate (polyimide film), a Kapton 100H (manufactured by Toray DuPont) substrate with a width × depth × thickness of 70 mm × 70 mm × 0.025 mm was prepared. After subjecting the surface of the substrate to UV ozone treatment for 3 minutes, 1 ml of dispersion was dropped onto the surface. The added dispersion was spin-coated onto the substrate (1400 rpm × 300 seconds), and then dried at room temperature for 10 minutes. Subsequently, it was further dried at 90°C for 2 hours. This yielded a sample with a coating film formed on the substrate.

[0414] <Metallic layer (second metal layer)>

[0415] use Figure 3The metal wiring manufacturing apparatus 10 with the structure shown is as follows: First, the sample is placed in the structure holding part 101 (sample chamber). The sample chamber is kept open (atmospheric). Then, using a galvanometer scanner (as a light scanning part 104), a laser (center wavelength 355nm, frequency 300kHz, pulse output 17mW, and spot diameter 18μm) is irradiated onto the coating in the sample chamber while moving the focal point at a maximum speed of 10mm / s. At this time, the laser is moved 20mm in the scanning direction (first irradiation), then moved 10μm in a direction perpendicular to the scanning direction, and then moved again in the scanning direction at a maximum speed of 10mm / s (second irradiation). This operation is repeated, and then laser scanning is performed while moving 10μm each time in a direction perpendicular to the scanning direction. As a result, a copper-containing film (second metal layer) with dimensions of 20mm in length and 10mm in width is formed on the polyimide substrate.

[0416] <Metallic Layer (First Metallic Layer)>

[0417] Next, an electroless plating solution (manufactured by Okuno Pharmaceutical Co., Ltd., trade name: OPC Copper NCA) containing formaldehyde and sodium hydroxide (containing 2.2 g / L of formaldehyde) was heated to 60°C. The sample was then immersed in the heated plating solution for 30 minutes. The pH of the plating solution was adjusted to 12.8, and the sodium hydroxide concentration was adjusted to 0.17 mol / L. During immersion, the sample was agitated up and down every 3 minutes (agitation operation). After the 30-minute immersion treatment, the sample was removed and washed with water. This formed a plating layer (first metal layer) on the copper-containing film (second metal layer).

[0418] The laminate of Example 1 is obtained through the above steps.

[0419] [Example 2]

[0420] <Dispersion>

[0421] A solvent consisting of 30240 g of water and 13976 g of 1,2-propanediol (manufactured by Asahi Glass Co., Ltd.), 3224 g of copper(II) acetate monohydrate (manufactured by Nippon Chemical Industry Co., Ltd.), and 940 g of hydrazine hydrate (manufactured by Finechem Co., Ltd., Japan) was mixed and stirred under a nitrogen atmosphere. The mixture was then separated into a supernatant and a precipitate by centrifugation.

[0422] In addition, 72 g of DISPERBYK-145 (trade name, manufactured by BYK Chemical Co., Ltd.) (BYK-118), a phosphorus-containing organic compound, and 764 g of 1-heptanol (manufactured by Toyosei Kogyo Co., Ltd.), a dispersion medium, were mixed to obtain a mixed solution. 345 g of the precipitate obtained above was mixed with 794 g of the mixed solution, and then the precipitate was dispersed using a homogenizer under a nitrogen atmosphere. This yielded a dispersion containing monovalent copper oxide particles. These monovalent copper oxide particles comprise monovalent copper oxide (copper(I)). Furthermore, 1063 g of the above dispersion, 5 g of DISPERBYK-145, and 82 g of 1-heptanol were further mixed, and then the precipitate was dispersed using a homogenizer under a nitrogen atmosphere to obtain the target dispersion.

[0423] In the final composition of the dispersion, the amount of hydrazine was 0.2% by mass. Additionally, the solid residue (monovalent copper oxide particles) after heating the dispersion at atmospheric pressure and 60°C for 4.5 hours was 26.1% by mass. The average particle size of the monovalent copper oxide particles was 30 nm.

[0424] <Polymer substrate>

[0425] As a polyimide substrate (polyimide film), a Kapton (trademark) 100H (manufactured by Toray / DuPont) film with a width × depth × thickness of 70 mm × 70 mm × 0.025 mm was prepared. After subjecting the surface of the substrate to UV ozone treatment for 3 minutes, the dispersion was used as ink, and printing was performed on the surface using an inkjet printer (manufactured by Fuji Film Co., Ltd., Dimatix DMP-2835). The printhead was a Samba cartridge (2.4 pl ejection), the voltage was 40 V, and the frequency was 25 kHz. A pattern of 50 mm × 50 mm was depicted here. After printing, it was dried at 60 °C for 30 minutes. This yielded a sample with a coating film formed on the substrate.

[0426] <Metallic layer (second metal layer)>

[0427] The above sample was fired at 300°C for 1 hour under a nitrogen atmosphere to form a copper-containing film (second metal layer) on the polyimide substrate.

[0428] <Metallic Layer (First Metallic Layer)>

[0429] Next, an electroless plating solution (manufactured by Okuno Pharmaceutical Co., Ltd., trade name: OPC Copper HFS) containing formaldehyde and sodium hydroxide (containing 2.5 g / L of formaldehyde) was heated to 60°C. The sample was then immersed in the heated plating solution for 120 minutes. The pH of the plating solution was adjusted to 12.6, and the sodium hydroxide concentration was adjusted to 0.05 mol / L. During immersion, the sample was agitated longitudinally every 3 minutes (agitation operation). After 120 minutes of immersion, the sample was removed and washed with water. This formed a plating layer (first metal layer) on the copper-containing film (second metal layer).

[0430] The laminate of Example 2 is obtained through the above steps.

[0431] [Reference Example 1]

[0432] After obtaining the laminate by the same steps as in Example 1, it was heated at 150°C for 240 hours to obtain the laminate of Reference Example 1.

[0433] [Example 3]

[0434] For the <dispersion>, <polymer substrate>, and <metal (second metal layer)>, the same steps as in Example 2 were followed. For the <metal layer (first metal layer)>, the same steps as in Example 1 were followed to obtain the laminate of Example 3.

[0435] [Example 4]

[0436] <Dispersion>

[0437] A solvent consisting of 800g of ion-exchanged water and 400g of 1,2-propanediol (manufactured by Wako Pure Chemical Industries, Ltd.), 80g of copper(II) acetate monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.), and 20g of hydrazine hydrate (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed and stirred under a nitrogen atmosphere. The mixture was then separated into a supernatant and a precipitate by centrifugation.

[0438] 4.4 g of the obtained precipitate, 0.4 g of DISPERBYK-145 (trade name, manufactured by BYK Chemical Company) as a phosphorus-containing organic compound, and 5.0 g of ethanol (manufactured by Wako Pure Chemicals Co., Ltd.) as a dispersion medium were mixed, and the precipitate was then dispersed using a homogenizer under a nitrogen atmosphere. The supernatant and precipitate were then separated by centrifugation, and the precipitate was recovered. The precipitate was diluted with ethanol, and then dispersed again using a homogenizer under a nitrogen atmosphere.

[0439] A dispersion containing monovalent copper oxide particles was obtained by repeatedly performing the above-described centrifugation (concentration) and dispersion (dilution) operations. These monovalent copper oxide particles comprise monovalent copper oxide (copper oxide (I)). The average particle size is 15 nm.

[0440] The final composition of the dispersion is as follows: 4.4 g of precipitate, 0.4 g of DISPERBYK-145, 6.6 g of ethanol, and 0.01 g of hydrazine hydrate.

[0441] <Polymer substrate>

[0442] As a polyimide substrate (polyimide film), a Kapton 500H (manufactured by Toray DuPont) substrate with a width × depth × thickness of 70 mm × 70 mm × 0.125 mm was prepared. After subjecting the surface of the substrate to UV ozone treatment for 3 minutes, 1 ml of dispersion was dropped onto the surface. The added dispersion was spin-coated onto the substrate (500 rpm × 300 seconds), and then dried at room temperature for 10 minutes. Subsequently, it was further dried at 90°C for 2 hours. This yielded a sample with a coating film formed on the substrate.

[0443] <Metallic layer (second metal layer)>

[0444] use Figure 3 The metal wiring manufacturing apparatus 10 with the structure shown is described above. First, the sample is placed in the structure holding part 101 (sample chamber). Nitrogen gas is introduced into the sample chamber at a rate of 1.0 L / min. Then, using a galvanometer scanner (as the light scanning part 104), a laser (center wavelength 355 nm, frequency 300 kHz, pulse output 110 mW, and spot diameter 18 μm) is irradiated onto the coating in the sample chamber while moving the focal point at a maximum speed of 5 mm / s. At this time, the laser is moved 20 mm in the scanning direction (first irradiation), then moved 30 μm in a direction perpendicular to the scanning direction, and then moved again in the scanning direction at a maximum speed of 5 mm / s (second irradiation). This operation is repeated, and then laser scanning is performed while moving 30 μm each time in a direction perpendicular to the scanning direction. As a result, a copper-containing film (second metal layer) with dimensions of 20 mm in length and 10 mm in width is formed on the polyimide substrate.

[0445] <Metallic Layer (First Metallic Layer)>

[0446] The same steps as in Example 1 are used.

[0447] [Example 5]

[0448] Except for omitting the step of <metal layer (first metal layer)> (i.e., not forming the first metal layer), the laminate of Example 5 was obtained using the same method as in Example 2.

[0449] [Example 6]

[0450] Except for omitting the step of <metal layer (first metal layer)> (i.e., not forming the first metal layer), the laminate of Example 6 was obtained using the same method as in Example 1.

[0451] [Comparative Example 1]

[0452] <Dispersion>

[0453] A dispersion containing monovalent copper oxide particles was obtained using the same steps as in Example 1. These monovalent copper oxide particles comprise monovalent copper oxide (copper oxide (I)). Further addition of 8.4 g of copper powder 1400YP (manufactured by Mitsui Metals Industry Co., Ltd.) and stirring with a stirrer yielded the target dispersion.

[0454] <Polymer substrate>

[0455] As a polyimide substrate (polyimide film), an Upilex (trademark) S (manufactured by UBE Corporation) substrate with a width × depth × thickness of 70 mm × 70 mm × 0.025 mm was prepared. After subjecting the surface of the substrate to UV ozone treatment for 3 minutes, 1 ml of dispersion was dropped onto the surface. The added dispersion was spin-coated onto the substrate (1400 rpm × 30 seconds), and then dried at room temperature for 10 minutes. It was then further dried at 90°C for 2 hours. Therefore, no reduction process was performed. A sample with a coating film formed on the substrate was thus obtained.

[0456] <First Metal Layer>

[0457] Next, an electroless plating solution containing formaldehyde and sodium hydroxide (manufactured by Okuno Pharmaceutical Co., Ltd., trade name: OPC Copper NCA) (containing 2.2 g / L of formaldehyde) was heated to 60°C. The sample was then immersed in the heated plating solution for 30 minutes. The pH of the plating solution was adjusted to 12.8, and the sodium hydroxide concentration was adjusted to 0.17 mol / L. During the immersion process, the sample was not shaken up and down every 3 minutes. After the 30-minute immersion treatment, the sample was removed and then rinsed with water.

[0458] The above steps are used to obtain the laminate of Comparative Example 1.

[0459] evaluate

[0460] The laminates of the embodiments, comparative examples, and reference examples were evaluated using the following methods.

[0461] <Evaluation of Resistance Value>

[0462] The resistivity of the laminate was measured using a 4-terminal, 4-probe method. The pattern dimensions of the metal layers (first and second metal layers) and the film thickness of the metal layers in the laminate were input into a low resistivity meter GP MCP-T600 (manufactured by Nitto Seiko Analytech), and then the volume resistivity was measured. Regarding the evaluation criteria, a volume resistivity value less than 10 μΩcm was rated as "A," and a volume resistivity value greater than 10 μΩcm was rated as "B." It should be noted that Reference Example 1 is an example used to evaluate the effect of metal concentration in a polymer layer containing metal; since an oxide coating was formed on the first metal layer, the resistivity could not be evaluated, and therefore no evaluation was performed. The evaluation results are shown in the table below.

[0463] <Evaluation of Fit>

[0464] Adhesion was evaluated using a tape peel test. A tape with an adhesion strength of 0.4 N / mm (Mickey & Co., trade name: Cellotte (registered trademark) CT-18) was applied to the surface of the laminate, and then immediately peeled off at a 60-degree angle between the surface and the tape. Without peeling, a tape with an adhesion strength of 1.5 N / mm (3M Japan, trade name: Scotch Strong Single-Sided Tape #879) was applied to the surface of the laminate, and then immediately peeled off at a 60-degree angle between the surface and the tape. Regarding the evaluation criteria, "A" was given for cases where the metal layer was not peeled off using the 1.5 N / mm tape, "B" was given for cases where the metal layer was peeled off using the 1.5 N / mm tape but not using the 0.4 N / mm tape, and "C" was given for cases where the metal layer was peeled off using the 0.4 N / mm tape. The evaluation results are shown in the table below.

[0465] It should be noted that the presence or absence of "peeling" is confirmed by visually observing the surface of the laminate after the tape has been peeled off, as well as the adhesive surface of the peeled tape. Furthermore, for metal layers, if at least a portion of the peeling is observed, it is evaluated as "present" peeling.

[0466] <Evaluation of Fit Reproducibility>

[0467] The above-described <Seamlessness Evaluation> was performed at four different locations within the laminate. Specifically, for Examples 2, 3, 5, and Comparative Example 1, four 20mm × 20mm test pieces were cut from the laminate at 5mm intervals. For Examples 1, 4, 6, and Reference Example 1, since the size of the laminate was smaller than the test pieces, four 20mm × 10mm laminates were prepared, and the same evaluation was performed on all four laminates. Regarding the evaluation criteria, an "A" evaluation was given when all four locations yielded the same result as the "Seamlessness Evaluation" column, and a "B" evaluation was given when three or fewer locations yielded the same result as the "Seamlessness Evaluation" column. The evaluation results are shown in the table below. Excellent fit reproducibility means that the laminate can reliably exhibit good fit, which also means that it is easy to achieve improved reliability of electronic devices obtained using this laminate.

[0468] <Thickness, porosity, element concentration, interface roughness>

[0469] The following samples were evaluated using scanning transmission electron microscopy (STEM). It should be noted that for each measurement, the measurement site was changed five times, and the average of the five measurements was used.

[0470] (Sample preparation)

[0471] By using focused ion beam (FIB) microsampling, the thickness-direction cross-section of the laminate is exposed and processed. To protect this cross-section, a naphthalene film with a thickness of approximately 200 nm is formed using plasma CVD. Then, to impart conductivity, a platinum (Pt) film is formed by sputtering. Subsequently, a portion of the sample is cut using FIB to obtain a thin-film sample.

[0472] (Thickness of the metal layer)

[0473] The above-mentioned thin-section samples were subjected to STEM observation. The observation conditions are as follows.

[0474] Measuring apparatus: HD-2300A (manufactured by Hitachi)

[0475] Measurement conditions: accelerating voltage 200kV

[0476] Measurement magnification: The magnification of the overall thickness of the metal layer falling into the field of view (50,000x as an example).

[0477] Observation mode: Secondary electron imaging mode

[0478] The two surfaces of the laminate and the boundary between the metal layer and the metal-containing polymer layer were identifiable in the observed image. Therefore, the image was analyzed using ImageJ, the image processing software from the National Institutes of Health (NIH). ImageJ was used to 8-bit convert the image, followed by smoothing using the Smooth function and filtering based on a MedianFilter (Radius; 2 pixels). The entire metal layer was then selected for threshold-based binarization. The threshold for binarization was determined by the "Default" decision method inserted into the software. Porous areas were identified as black regions. The area percentage (in area %) of these black regions was calculated using "Analyze Particle," and this value was used to simulate porosity (in volume %).

[0479] In the binarized image, the portion corresponding to the upper surface of the metal layer (the exposed surface of the laminate) is observed to be approximately straight. A line segment is drawn along this approximately straight line, and this line segment is designated as the upper rectangle. The left and right sides of the rectangle are designated according to the way they extend from the exposed surface to the polyimide substrate side in the laminate to a specified depth. The area ratio of the black portion within this rectangle is calculated as the porosity. With the upper side fixed, the left and right sides are increased, and the porosity calculation is repeated. The lower side of the rectangle when the porosity value is 0.5% by volume is recorded. The length of the left side of the rectangle at this point is taken as the thickness of the first metal layer. The porosity calculation is further repeated, and the length of the left side of the rectangle when the lower side reaches the boundary between the metal layer and the metal-containing polymer layer is taken as the total thickness of the metal layer. It should be noted that since the boundary between the metal layer and the metal-containing polymer layer has an uneven shape, the line segment connecting the two ends of the binarized image to the intersection of the above boundary, i.e., the imaginary boundary line, is regarded as the boundary between the metal layer and the metal-containing polymer layer. The thickness of the second metal layer is obtained by subtracting the thickness of the first metal layer from the total thickness of the metal layers.

[0480] In addition, the thickness of the polymer layer containing metal and the total thickness of the polymer layer were measured on a secondary electron image.

[0481] (Thickness of the polymer layer containing metal)

[0482] The above-mentioned thin-section sample was subjected to STEM-based energy-dispersive X-ray diffraction (EDX) analysis to obtain spectral image data. The measurement conditions are as follows.

[0483] Measuring apparatus: HD-2300A (manufactured by Hitachi)

[0484] Measurement conditions: accelerating voltage 200kV

[0485] Magnification ratio: 50,000x

[0486] STEM-EDX: Octane T plus (EDAX)

[0487] EDX detector: Apollo XLT2 SUTW

[0488] Target elements: copper, carbon, nitrogen, oxygen, sodium

[0489] Linear analysis was performed along the thickness direction of the laminate from the metal layer side towards the polymer layer side. Regarding copper concentration, a spectral image was obtained showing the transition from a high concentration region (corresponding to the metal layer) through a medium concentration region (corresponding to the metal-containing polymer layer) to a low concentration region (corresponding to the polymer layer). In each embodiment, the aforementioned medium concentration region was present. This confirmed the presence of the metal-containing polymer layer. The transition from the high concentration region to the medium concentration region was steep; this point was taken as the boundary between the metal layer and the metal-containing polymer layer. On the other hand, regarding the boundary between the medium concentration region and the low concentration region, the point where the copper concentration was 1 atom% was taken as the boundary of these regions (and therefore the boundary between the metal-containing polymer layer and the polymer layer). The thickness from the boundary between the metal layer and the metal-containing polymer layer to the boundary between the metal-containing polymer layer and the polymer layer was determined as the thickness of the metal-containing polymer layer.

[0490] (Thickness of the polymer layer)

[0491] The thickness of the polymer layer is determined by subtracting the thickness of the polymer layer containing metal obtained from the EDX from the total thickness of the polymer layer containing metal obtained from the secondary electron image.

[0492] (Porosity of the metal layer with a depth of 1nm to 500nm)

[0493] Specify a rectangle in (thickness of metal layer) (which has the left and right sides of the rectangle described above, with the bottom side at a depth of 1 nm from the boundary between the metal layer and the polymer layer containing the metal towards the metal layer, and the top side at a depth of 500 nm), and obtain the area ratio (area %) of the black part within the rectangle in the form of a simulated value of porosity (volume %).

[0494] (Interface bump ratio: (L2) / (L1))

[0495] Except for observation using transmission electron microscopy (TEM) at a magnification of 100,000x without secondary electron microscopy, a binarized image is obtained through the same steps as for the (metal layer thickness). In this binarized image, the metal layer, except for voids, is observed as a black area, and the polymer layer containing the metal is observed as a white area. The boundary between the metal layer and the polymer layer containing the metal corresponds to the boundary between the black and white areas. The length of the boundary line drawn freehand in the entire binarized image is taken as the length of the boundary line (L2). The boundary between the black and white areas intersects with the two ends of the binarized image, and the length of the line segment connecting the intersection points is taken as the in-plane length (L1) of the laminate. The ratio (L2) / (L1) is calculated.

[0496] (Metal and sodium concentrations in the polymer layer containing the metal)

[0497] The elements to be measured are copper, carbon, nitrogen, oxygen, and sodium. The measurement range is selected from a position 30 nm from the boundary between the metal layer and the metal-containing polymer layer towards the polymer layer to the boundary between the metal-containing polymer layers. Otherwise, EDX analysis is performed using the same procedure as for the thickness of the metal-containing polymer layer. It should be noted that when the thickness of the metal-containing polymer layer is less than 30 nm, the range is selected from a position 10 nm from the boundary between the metal layer and the metal-containing polymer layer towards the polymer layer to the boundary between the metal-containing polymer layers. The copper concentration (as metal concentration) and sodium concentration are obtained as averages within this range.

[0498] (Carbon concentration in the metal layer)

[0499] The elements to be measured are copper, carbon, nitrogen, oxygen, and sodium. The measurement range is selected from a position 50 nm to 300 nm from the boundary between the metal layer and the polymer layer containing the metal towards the metal layer. Otherwise, EDX analysis is performed using the same procedure as for the thickness of the polymer layer containing the metal. The average value within this range is taken as the carbon concentration.

[0500] (Metal concentration at a position 20 nm from the boundary between the metal-containing polymer layers towards the metal layer)

[0501] The element to be measured is copper. The measurement range is selected from a position 20 nm from the boundary between the polymer layer containing the metal and the polymer layer towards the metal layer. Otherwise, EDX analysis is performed using the same procedure as for the thickness of the polymer layer containing the metal.

[0502] (Whether or not monovalent copper oxide is present in the metal layer)

[0503] A 1 cm square section was cut from the laminate to obtain the test sample. The test sample was placed in an X-ray diffraction apparatus in the manner of irradiating the metal layer with X-rays, and X-ray diffraction (XRD) measurements were performed under the following conditions.

[0504] (XRD measurement conditions)

[0505] Measuring apparatus: Rigaku Ultima-4

[0506] Measurement method: θ-2θ method

[0507] X-ray output: 40kV, 40mA

[0508] Scanning speed: 10° / min

[0509] Measurement range: 20~65°

[0510] If a peak is observed in the range of 2θ = 35.5° to 37.5°, and / or 2θ = 41.5° to 43.5°, and / or 2θ = 60.5° to 62.5°, then monovalent copper oxide is considered to be present in the metal layer.

[0511] <Imidin strength: ratio of (IR1) / (IR2)>

[0512] The imide degree is derived through the following process: (i) The process of obtaining the test sample that becomes the object of infrared absorption spectroscopy measurement; and (ii) The process of performing infrared absorption spectroscopy on the test sample and calculating the intensity of the first peak and the intensity of the second peak based on the spectrum obtained by the measurement.

[0513] The above (i) process is carried out based on the following method.

[0514] The specimen cut from the laminate is embedded in resin and then cut along an inclined direction using a room-temperature microtome. The cutting is performed at an angle of approximately 1.8° relative to the in-plane direction of the laminate (i.e., the direction perpendicular to the thickness direction). This results in a test specimen with a cross-sectional area (i.e., the measurement surface) that is approximately 30 times larger than when cutting along the thickness direction of the laminate.

[0515] The above (ii) process is carried out based on the following method.

[0516] First, for the test sample obtained in step (i) above, infrared spectroscopic measurements were performed using the polymer substrate as the object based on total internal reflection infrared spectroscopy (ATR-IR). The measurement conditions are as follows.

[0517] (IR measurement conditions)

[0518] Measurement apparatus: Micro-FT-IR (Bruker Hyperion)

[0519] Measurement method: Reflection (ATR)-IR imaging measurement

[0520] ATR crystals: germanium (30°)

[0521] ATR crystallization contact mode: "REF"

[0522] Detector: Focal Plane Array (FPA) detector (32×32 elements)

[0523] Wavenumber resolution: 4cm -1

[0524] Total number of times: 32

[0525] While shifting the infrared irradiation area from the metal layer side to the polymer layer side, an image of approximately 300 μm square was acquired, and the spectrum was extracted at arbitrary locations. The region at 1702 cm⁻¹ was then selected from the obtained spectrum. -1 ~1722cm -1 The range of peaks from the C=O stretching of the imide ring (first peak), and the peak at 1494 cm⁻¹ -1 ~1514cm -1 The range of peaks derived from the C=C stretching of the benzene ring (the second peak) is determined. After baseline correction, the ratio (IR1) / (IR2) of the peak intensity of the first peak (IR1) to the peak intensity of the second peak (IR2) is calculated as the imide degree. Spectral extraction and imide degree calculations are performed repeatedly while offsetting the infrared irradiation sites to evaluate the imide degree distribution along the thickness direction of the laminate. The minimum and maximum imide degrees are determined from the position 100 nm (as the size before enlargement based on tilt cutting, i.e., in the actual laminate) from the interface between the metal layer and the metal-containing polymer layer to the lower surface of the polymer layer.

[0526] <The presence or absence of a metal (copper) chemically bonded to nitrogen atoms in the polymer layer containing the metal, and the valence of the metal>

[0527] The test sample is obtained through the same steps as described in (i). Next, the test sample is covered with copper tape for antistatic purposes. Then, with only about 2 mm square around the test section exposed, X-ray photoelectron spectroscopy (XPS) is used for measurement. The secondary electron image obtained from the X-ray scan is observed and aligned. The measurement point is set at a position 100 nm (as the size before enlargement based on tilt cutting, i.e., in the actual laminate) from the interface between the metal layer and the metal-containing polymer layer towards the metal-containing polymer layer. This yields a narrow scan spectrum.

[0528] (XPS measurement conditions)

[0529] Measuring apparatus: ULVAC·PHI VersaProbeII

[0530] Excitation source: Monochromatic Al Kα 15kV × 0.17mA

[0531] Analysis size: 15μmΦ

[0532] Photoelectron extraction angle: 45°

[0533] Voltage ratings: 187.85 eV (full scan), 46.95 eV (narrow scan)

[0534] Charge correction: Cu 2p3 / 2 = 932.6 eV

[0535] For the obtained narrow scan spectrum, If peaks are observed in the range of 569 eV to 571 eV and 930 eV to 935 eV, then monovalent Cu is considered to be present. If a peak is observed in the range above 934 eV and below 937 eV, it is considered that divalent Cu is present. If peaks are observed in the range above 563 eV and below 566 eV (the second peak), and in the range above 566 eV and below 569 eV, then zero-valent Cu is considered to be present; and If a peak is observed in the range of 571 eV above and 574 eV below (the first peak), it is considered that the nitrogen atom (N) is bonded to monovalent Cu.

[0536] The results for the above are shown in the table below.

[0537] [Table 1]

[0538] As can be seen from the results of the embodiments, comparative examples and reference examples, a laminate with both good conductivity and good adhesion was obtained using the embodiments.

[0539] Industrial applicability

[0540] The laminates and other materials obtained by the present invention are suitable for use in wiring materials such as electronic circuit boards (printed circuit boards, RFID, and alternatives to wiring harnesses in automobiles), antennas formed on the housings of portable information devices (smartphones, etc.) (antennas for portable information device housings), mesh electrodes (electrode films for electrostatic capacitive touch panels), electromagnetic wave shielding materials, and heat dissipation materials.

[0541] Explanation of symbols

[0542] 1 layered body

[0543] 10 Metal wiring manufacturing equipment

[0544] 11 Substrate

[0545] 12 Coating

[0546] 101 Structural Retention Section

[0547] 102 Light Oscillator

[0548] 103 Inactive Gas Generator

[0549] 104 Light Scanning Unit

[0550] 104a X-axis galvanometer

[0551] 104b X-axis galvanometer motor

[0552] 104c Y-axis galvanometer

[0553] 104d Y-axis galvanometer motor

[0554] 105 Speed ​​Control Unit

[0555] 106 Computer

[0556] ML metal layer

[0557] ML1 First Metal Layer

[0558] ML2 Second Metal Layer

[0559] MPL contains a metal polymer layer

[0560] L laser

[0561] L1 In-plane length

[0562] Length of L2 boundary line

[0563] Intersection of P1 and P2

[0564] PL polymer layer

[0565] V. Void (cavity)

Claims

1. A laminate comprising a metal layer, a polymer layer containing a metal, and a polymer layer arranged in the following order, wherein, The metal layer and the polymer layer containing the metal contain the same metal. The thickness of the metal layer is greater than 0.1 μm and less than 10¹⁰ μm. The thickness of the polymer layer containing metal is 0.04 μm or more and 10 μm or less.

2. A laminate comprising a metal layer, a polymer layer containing a metal, and a polymer layer arranged in the following order, wherein, The metal layer and the polymer layer containing the metal contain the same metal. The polymer constituting the metal-containing polymer layer and the polymer constituting the polymer layer are nitrogen-containing polymers. The metal-containing polymer layer comprises a metal chemically bonded to nitrogen atoms.

3. The laminate according to claim 1 or 2, wherein, The polymer layer containing metal comprises more than 1 atomic% and less than 20 atomic% metal.

4. The laminate according to claim 1 or 2, wherein, The thickness of the polymer layer is greater than 1 μm and less than 1000 μm.

5. The laminate according to claim 1 or 2, wherein, The metal layer includes a first metal layer and a second metal layer disposed between the first metal layer and the metal-containing polymer layer. The first metal layer, the second metal layer, and the metal-containing polymer layer all contain the same metal. The thickness of the first metal layer is 0.1 μm or more and 1000 μm or less. The thickness of the second metal layer is greater than 0.01 μm and less than 10 μm.

6. The laminate according to claim 5, wherein, The second metal layer is formed by reducing a layer containing copper oxide.

7. The laminate according to claim 1 or 2, wherein, The metal layer contains carbon.

8. The laminate according to claim 7, wherein, The metal layer contains more than 0.1 atomic% and less than 15 atomic% carbon.

9. The laminate according to claim 1 or 2, wherein, The metal layer and the polymer layer containing the metal contain copper.

10. The laminate according to claim 1 or 2, wherein, The metal layer pattern is formed on the polymer layer containing the metal.

11. The laminate according to claim 1 or 2, wherein, The metal-containing polymer layer contains sodium.

12. The laminate according to claim 11, wherein, The metal-containing polymer layer contains more than 0.1 atomic% and less than 10 atomic% sodium.

13. The laminate according to claim 1, wherein, The polymer constituting the metal-containing polymer layer and the polymer constituting the polymer layer are nitrogen-containing polymers. The metal-containing polymer layer comprises a metal chemically bonded to nitrogen atoms.

14. The laminate according to claim 1 or 2, wherein, The metal-containing polymer layer comprises metals with zero and / or one valence.

15. The laminate according to claim 14, wherein, The metal-containing polymer layer contains metals with zero and / or one valence, but not metals with two valences.

16. The laminate according to claim 14, wherein, The metal-containing polymer layer comprises metals with 0 and 1 valences.

17. The laminate according to claim 1 or 2, wherein, At a position 20 nm from the boundary between the polymer layer containing the metal and the polymer layer toward the metal layer, the metal concentration is 1.0 atomic% or more and 5.0 atomic% or less.

18. The laminate according to claim 1 or 2, wherein, In X-ray photoelectron spectroscopy measurements of the metal-containing polymer layer, a peak was observed in the range of 571 eV to 574 eV.

19. The laminate according to claim 1 or 2, wherein, The metal layer has a porosity of 0.1% to 30% by volume in a region with a depth of 1 nm or more and 500 nm or less from the side of the polymer layer containing the metal.

20. The laminate according to claim 1 or 2, wherein, The metal layer comprises monovalent copper oxide.

21. The laminate according to claim 1 or 2, wherein, In a cross-sectional view along the thickness direction, the ratio of the length L2 of the boundary line between the metal layer and the metal-containing polymer layer to the in-plane length L1 of the laminate, i.e., L2 / L1, is greater than 1.0 and less than 2.

2.

22. The laminate according to claim 1 or 2, wherein, The polymer layer containing metal is a polyimide layer containing metal, and the polymer layer is a polyimide layer.

23. The laminate according to claim 1 or 2, wherein, In infrared absorption spectroscopy, the minimum value of the ratio of the peak intensity IR1 of the first peak of the first structure from the first structure in the main chain of the polymer layer containing the metal and the polymer of the polymer layer to the peak intensity IR2 of the second peak from the second structure in the main chain, i.e., IR1 / IR2, is 0.2 or more and 1.5 or less.

24. The laminate according to claim 1 or 2, which is used as a constituent element of an electronic circuit board.

25. A method for manufacturing a laminate, which is the method for manufacturing a laminate according to claim 1 or 2, comprising the following steps: The coating process involves coating a metal oxide onto a polymer substrate; and The reduction process involves reducing the metal oxide.

26. The method of claim 25, wherein, The reduction is performed by laser irradiation.

27. The method of claim 25, further comprising an electroless metal plating process.

28. The method according to claim 27, wherein, The electroless metal plating process is performed after the reduction process.

29. A method for manufacturing a laminate, comprising a first metal layer, a second metal layer, a metal-containing polymer layer, and a polymer layer sequentially disposed thereon, wherein the first metal layer, the second metal layer, and the metal-containing polymer layer comprise the same metal, wherein... The manufacturing method comprises the following steps: The process of forming the first metal layer with a thickness of 0.1 μm or more and 1000 μm or less; The process of forming a second metal layer with a thickness of 0.01 μm or more and 10 μm or less; The process of forming the metal-containing polymer layer with a thickness of 0.04 μm or more and 10 μm or less; and The process of forming the polymer layer with a thickness of 1.0 μm or more and 1000 μm or less.

30. The method for manufacturing a laminate according to claim 29, wherein, The process of forming the second metal layer includes the following steps: The coating process involves coating a dispersion containing metal particles and / or metal oxide particles onto a substrate to form a dispersion layer. The drying process involves forming a dry coating film on the substrate by drying the dispersion layer; and The process of forming the second metal layer by heating the dried coating film.

31. The method for manufacturing a laminate according to claim 29, wherein, The process of forming the second metal layer includes the following steps: The coating process involves coating a dispersion containing metal particles and / or metal oxide particles onto a substrate to form a dispersion layer. The drying process involves forming a dry coating film on the substrate by drying the dispersion layer; and The process of forming the second metal layer by firing the dried coating film with a laser.

32. The method for manufacturing a laminate according to claim 30 or 31, wherein, The metal particles and / or metal oxide particles are copper particles and / or copper oxide particles.

33. The method for manufacturing a laminate according to claim 29, wherein, The process of forming the first metal layer includes the following steps: forming the first metal layer by immersing the second metal layer in a plating solution.

34. The method for manufacturing a laminate according to claim 33, wherein, The plating solution used has a pH of 10 or higher and 14 or lower.

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