Wiring forming components, a method for forming a wiring layer using wiring forming components, and wiring forming components.

Abstract

The wiring forming component (1) comprises: an adhesive layer (10) containing conductive particles (12); and a metal layer (20) disposed on the adhesive layer (10). The adhesive layer (10) includes: a first adhesive layer (15) containing conductive particles (12) and adhesive components; and a second adhesive layer (16) containing adhesive components.

Description

Technical Field

[0001] This disclosure relates to a wiring forming component, a method for forming a wiring layer using the wiring forming component, and the wiring forming component itself. Prior Technology

[0002] Patent document 1 discloses a method for manufacturing a printed wiring board that incorporates electronic components such as IC chips.

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2012-191204

[0004] In conventional manufacturing methods for in-system substrates, as shown in Figures 10(a) and (b), insulating resin layers 102 and 103 are formed on both sides of the stacking direction of the electronic component 101 on which electrodes 101a are provided. Subsequently, as shown in Figures 10(c) and (d), through-hole electrodes 104 and 105 reaching each electrode 101a of the electronic component 101 are formed on each insulating resin layer 102 and 103 by performing laser-based drilling, plating layer formation, and etching-based electrode formation or wiring formation. Furthermore, as shown in Figures 11(a) to (c), by repeatedly performing further forming of insulating resin layers 106 and 107, forming of through-hole electrodes 108 based on laser drilling and plating layer formation, and etching-based electrode formation or wiring formation, an in-system substrate 110 can be formed. In addition, as shown in Figure 11(c), the wiring formed on the insulating resin layer of the component-in-the-substrate not only has a portion 109 that is connected by a conductive layer, but also has a portion 109a that is not connected in the stacking direction, and is designed with various patterns according to the structure of the component-in-the-substrate.

[0005] In the manufacturing method of the substrate built into the above-mentioned component, a large number of processes are performed to form one conductive layer (through-hole electrode). In order to form multiple conductive layers, these processes need to be repeated, making the manufacturing process very complex. Summary of the Invention

[0006] Therefore, the purpose of this disclosure is to provide a wiring forming component that can fully ensure the design freedom of wiring patterns while simplifying the forming process of wiring layers connecting wirings, a method for forming wiring layers using the wiring forming component, and the wiring forming component.

[0007] In one aspect, this disclosure relates to a wiring forming component. A first wiring forming component comprises an adhesive layer containing conductive particles and a metal layer disposed on the adhesive layer, wherein the adhesive layer includes: a first adhesive layer containing conductive particles and an adhesive component; and a second adhesive layer containing an adhesive component. Furthermore, a second wiring forming component comprises an adhesive layer containing conductive particles and a metal layer disposed on the adhesive layer, wherein the adhesive layer includes, in its thickness direction, a first region containing conductive particles and the first adhesive component and a second region containing the second adhesive component.

[0008] Based on the aforementioned first and second wiring forming components, by including a first adhesive layer or a first region in the adhesive layer, electrical conductivity can be achieved between the metal layer that forms a wiring pattern or wiring after processing and other wiring patterns or wirings bonded via the adhesive layer. Compared to conventional procedures such as laser processing and filler plating, the formation process of the wiring layer connecting the wirings can be simplified. Furthermore, by including a second adhesive layer or a second region in the adhesive layer, even if the wiring layer formed by patterning the metal layer has portions that are not intended to be electrically connected in the lamination direction (or the thickness direction of the adhesive layer), the insulation reliability of those portions can be easily ensured. Moreover, when the substrate on which the wiring is to be formed by the wiring forming component has large irregularities (for example, when the electrode height is large), the second adhesive layer or the second region can ensure embedding and prevent the generation of bubbles or peeling. Therefore, based on the above-mentioned wiring forming components, the design freedom of the wiring pattern when forming the wiring layer can be fully ensured, and higher precision and more complex wiring can also be formed.

[0009] In the first wiring forming component described above, a metal layer, a second adhesive layer, and a first adhesive layer may be sequentially laminated. Furthermore, in the second wiring forming component described above, a metal layer, a second region, and a first region may be sequentially and adjacently arranged. In these cases, in wiring layers formed by patterning the metal layer or in separately formed rewiring, conductive particles are less likely to contact portions other than those with conductive connections, thus easily suppressing wiring transmission losses caused by contact of conductive particles.

[0010] In the first wiring forming component described above, the second adhesive layer may not contain conductive particles. Furthermore, in the second wiring forming component described above, the second region may not contain conductive particles.

[0011] In the first and second wiring forming components described above, the ratio of the surface roughness Rz of the adhesive layer side of the metal layer to the average particle size of the conductive particles can be 0.05 to 3. This allows for more reliable deformation of the conductive particles of the metal layer into a flat shape, and makes the electrical conductivity between the metal layer, which becomes a wiring pattern or wire after processing, and other wiring patterns or wires bonded via the adhesive layer more stable.

[0012] In the first and second wiring forming components described above, the surface roughness Rz of the adhesive layer side of the metal layer can be less than 20 μm. In this case, the conductive particles of the metal layer can be deformed into a flat shape more reliably, and the electrical conductivity between the metal layer that becomes a wiring pattern or wiring after processing and other wiring patterns or wirings bonded via the adhesive layer can be more stable.

[0013] The first wiring forming component and the second wiring forming component described above may further include a release film.

[0014] In another aspect, this disclosure relates to a wiring forming component, wherein an adhesive layer containing conductive particles and a metal layer are separately disposed, and the adhesive layer can bond to the metal layer during use. In the third wiring forming component, the adhesive layer includes: a first adhesive layer containing conductive particles and adhesive components; and a second adhesive layer containing adhesive components. Furthermore, in the fourth wiring forming component, the adhesive layer includes, in its thickness direction, a first region containing conductive particles and the first adhesive component and a second region containing the second adhesive component. In these cases, by including a first adhesive layer or a first region in the adhesive layer, electrical conductivity can be obtained between the metal layer that forms a wiring pattern or wire after processing and other wiring patterns or wires bonded via the adhesive layer. Compared with conventional procedures such as laser processing and filler plating, the formation process of the wiring layer connecting the wires can be simplified. Furthermore, based on the aforementioned wiring forming component, by including a second adhesive layer or a second region in the adhesive layer, even when the wiring layer formed by patterning the metal layer has portions where conductive connections are not desired in the lamination direction (or the thickness direction of the adhesive layer), the insulation reliability of those portions can be easily ensured. Also, when the substrate on which the wiring is to be formed by the wiring forming component has large irregularities (for example, when the electrode height is large), the second adhesive layer or the second region can ensure embedding and prevent the formation of bubbles. Therefore, based on the aforementioned wiring forming component, sufficient design freedom for the wiring pattern when forming the wiring layer can be ensured, and more intricate and complex wiring can be formed. Furthermore, since the adhesive layer and metal layer can be prepared separately (as a set of wiring forming components), wiring forming components with better material structures can be selected, increasing the operational freedom when using the wiring forming component to fabricate the wiring layer.

[0015] In the third wiring forming component described above, the second adhesive layer may not contain conductive particles. Furthermore, in the fourth wiring forming component described above, the second region may not contain conductive particles.

[0016] In another aspect, this disclosure relates to a method for forming a wiring layer using any of the aforementioned wiring forming components. The method includes: preparing any of the aforementioned wiring forming components; preparing a substrate on which wiring is formed; disposing the wiring forming component on the wiring-formed surface of the substrate with an adhesive layer facing the substrate to cover the wiring; heating and pressing the wiring forming component onto the substrate; and performing a patterning process on the metal layer. According to this method, the processing procedure can be significantly simplified compared to conventional methods. Furthermore, according to this method, as described above, the insulation reliability of the unconductive portions of the wiring layer can be ensured and / or the transmission loss of the wiring layer can be suppressed, or the generation of bubbles can be prevented when the substrate on which wiring is to be formed by the wiring forming component has large irregularities (e.g., when the electrode height is large), thus ensuring sufficient design freedom for the wiring pattern.

[0017] In another aspect, this disclosure relates to a wiring forming member. The wiring forming member comprises: a substrate having wiring; and a cured form of any one of the aforementioned wiring forming members disposed on the substrate in a manner covering the wiring. In this wiring forming member, the wiring is electrically connected to a metal layer of the wiring forming member or another wiring formed from the metal layer. According to this configuration, as described above, it is possible to ensure the insulation reliability of the unconductive portions of the wiring layer and / or suppress transmission losses in the wiring layer, or to prevent bubble formation in cases where the substrate on which the wiring is to be formed by the wiring forming member has large irregularities (e.g., in cases where the electrode height is large), thus ensuring sufficient design freedom for the wiring pattern. [Invention Effects]

[0018] According to this disclosure, the design freedom of wiring patterns can be fully ensured while simplifying the formation process of wiring layers connecting wirings. Simple Explanation of the Diagram

[0019] Figure 1 is a cross-sectional view of a wiring component in one embodiment of the present disclosure. Figure 2 is a cross-sectional view showing another example of a wiring forming component in one embodiment of the present disclosure. Figures 3(a) to (d) are diagrams illustrating, in sequence, the method of forming a wiring layer using the wiring forming component shown in Figure 1. Figures 4(a) to (b) are cross-sectional views illustrating an example of forming a wiring layer using a wiring forming component of one embodiment of the present disclosure. Figures 5(a) to (b) are cross-sectional views illustrating an example of forming a wiring layer using the wiring forming component of the comparative example. Figures 6(a) to (b) are cross-sectional views illustrating another example of forming a wiring layer using a wiring forming component of one embodiment of the present disclosure. Figures 7(a) to (b) are cross-sectional views illustrating another example of forming a wiring layer using the wiring forming component of the comparative example. Figures 8(a) to (c) are cross-sectional views illustrating another example of forming a wiring layer using a wiring forming member of one embodiment of the present disclosure. Figures 9(a) to (b) are cross-sectional views illustrating an example of forming a wiring layer using the wiring forming component shown in Figure 2. Figures 10(a) to (d) are cross-sectional views used to sequentially illustrate conventional methods for manufacturing components with built-in substrates. Figures 11(a) to (c) are cross-sectional views used to sequentially illustrate the conventional method of manufacturing a component with a built-in substrate, and show the subsequent steps in Figure 10. Implementation

[0020] The following description, with reference to the accompanying drawings, explains a wiring forming component and a method for forming a wiring layer using the wiring forming component, according to one embodiment of this disclosure. Furthermore, in this disclosure, the wiring during the formation of the wiring and wiring layer also includes wiring patterns such as electrodes, vias, and grounding layers. In the following description, identical or equivalent parts are labeled with the same component symbols, and repeated descriptions are omitted. Moreover, regarding positional relationships such as top, bottom, left, and right, unless otherwise specified, the positional relationships shown in the drawings are used. Furthermore, the scale of the drawings is not limited to the scale shown.

[0021] In this specification, the numerical range indicated by "~" includes the values ​​before and after "~" as the minimum and maximum values, respectively. Furthermore, within the numerical range described in stages in this specification, the upper or lower limit value described in one numerical range can be replaced with the upper or lower limit value of other numerical ranges described in stages. Also, within the numerical range described in this specification, the upper or lower limit value of that numerical range can be replaced with the values ​​shown in the embodiments.

[0022] The wiring forming component of this embodiment includes: an adhesive layer containing conductive particles; and a metal layer disposed on the adhesive layer. The wiring forming component may have an adhesive layer comprising a first adhesive layer containing conductive particles and adhesive components and a second adhesive layer containing adhesive components, or the adhesive layer may have an adhesive layer comprising a first region containing conductive particles and the first adhesive component and a second region containing the second adhesive component in its thickness direction. For example, the first region may be formed by the first adhesive layer, and the second region may be formed by the second adhesive layer.

[0023] Figure 1 is a cross-sectional view of a wiring forming component according to one embodiment of the present disclosure. As shown in Figure 1, the wiring forming component 1 is composed of an adhesive layer 10 containing conductive particles 12 and a metal layer 20. The adhesive layer 10 includes: a first adhesive layer 15 containing conductive particles 12 and adhesive components; and a second adhesive layer 16 containing adhesive components. The wiring forming component 1 has a structure in which the metal layer 20, the second adhesive layer 16, and the first adhesive layer 15 are sequentially laminated.

[0024] Figure 2 is a cross-sectional view showing another example of a wiring forming component according to one embodiment of the present disclosure. The wiring forming component 3 shown in Figure 2 is composed of an adhesive layer 40 containing conductive particles 12 and a metal layer 20. The adhesive layer 40 includes a first adhesive layer 15 containing conductive particles 12 and adhesive components, and a second adhesive layer 16 containing adhesive components. The wiring forming component 3 has a structure in which the metal layer 20, the first adhesive layer 15, and the second adhesive layer 16 are sequentially laminated.

[0025] Wiring forming components 1 and 3 are not limited to these, but can be used, for example, in the fabrication of rewiring layers, multilayer wiring boards, and component-integrated substrates. Furthermore, wiring forming components 1 and 3 can be used in EMI shielding components, etc.

[0026] The first adhesive layer 15 is composed of conductive particles 12 and an adhesive layer 14 containing conductive particles 12 and insulating adhesive components. The adhesive layer 14 has a thickness of, for example, 1 μm to 50 μm. The adhesive components of the adhesive layer 14 are defined as solid components other than the conductive particles 12. Before the wiring layer is formed by the wiring forming member 1, the adhesive layer 14 can be in a B-stage state, i.e., a semi-cured state, where the surface has been dried.

[0027] The thickness d1 of the first adhesive layer 15 can be more than 0.1 times, more than 0.2 times, more than 0.3 times, more than 0.5 times, more than 0.8 times, or more than 1 times the average particle size Dp of the conductive particles 12. The thickness d1 of the first adhesive layer 15 can be less than 10 times, less than 7 times, less than 5 times, less than 3 times, less than 2 times, or less than 1 times the average particle size Dp of the conductive particles 12.

[0028] The second adhesive layer 16 is constituted by comprising an adhesive layer 17 containing an insulating adhesive component. The insulating adhesive component in the second adhesive layer 16 may be the same as or different from that in the first adhesive layer 14. The adhesive layer 17 has a thickness of, for example, 1 μm to 50 μm. The adhesive component of the adhesive layer 17 is defined as a solid component other than conductive particles. Before the wiring layer is formed by the wiring forming member 1, the adhesive layer 17 may be in a B-stage state, i.e., a semi-cured state, where the surface has been dried.

[0029] The thickness d2 of the second adhesive layer 16 can be more than 0.1 times, more than 0.5 times, more than 0.8 times, or more than 1 times the thickness d1 of the first adhesive layer 15. The thickness d2 of the second adhesive layer 16 can be less than 10 times, less than 7 times, less than 5 times, less than 3 times, or less than 1 times the thickness d1 of the first adhesive layer 15.

[0030] The wiring forming component of this embodiment can be constructed by sequentially stacking a metal layer, a second adhesive layer, and a first adhesive layer, as in wiring forming component 1, or by sequentially stacking a metal layer, a first adhesive layer, and a second adhesive layer, as in wiring forming component 3. Furthermore, the first adhesive component contained in the first region can be the same as the insulating adhesive component in adhesive layer 14, and the second adhesive component contained in the second region can be the same as the insulating adhesive component in adhesive layer 17.

[0031] [The composition of conductive particles] The conductive particles 12 are generally spherical particles with conductivity, composed of metal particles or conductive carbon particles, such as metal particles composed of metals like Au, Ag, Ni, Cu, and solder, and conductive carbon particles composed of conductive carbon. The conductive particles 12 can be coated conductive particles having a core containing non-conductive glass, ceramic, or plastic (polystyrene, etc.) and a coating layer containing the aforementioned metal or conductive carbon covering the core. Among these, the conductive particles 12 can be metal particles formed from molten metal or coated conductive particles having a plastic core and a coating layer containing a metal or conductive carbon covering the core.

[0032] In one embodiment, the conductive particle 12 comprises a core containing polymer particles (plastic particles) such as polystyrene and a metal layer covering the core. Regarding the polymer particles, their entire surface can be covered by the metal layer, while a portion of the polymer particle's surface may be exposed without being covered by the metal layer, to maintain its function as a connecting material. The polymer particles may, for example, be particles containing a polymer comprising at least one monomer selected from styrene and divinylbenzene as monomer units.

[0033] The metal layer can be formed from various metals such as Ni, Ni / Au, Ni / Pd, Cu, NiB, Ag, and Ru. The metal layer can be an alloy layer containing Ni and Au, or an alloy containing Ni and Pd. The metal layer can be a multilayer structure containing multiple metal layers. For example, the metal layer can contain Ni and Au layers. The metal layer can be fabricated by plating, evaporation, sputtering, soldering, etc. The metal layer can be a thin film (e.g., a thin film formed by plating, evaporation, sputtering, etc.).

[0034] The conductive particle 12 may have an insulating layer. Specifically, for example, an insulating layer further covering the coating layer may be provided outside the coating layer of the conductive particle in the above-described embodiment, which includes a core (e.g., a polymer particle) and a coating layer such as a metal layer covering the core. The insulating layer may be the outermost surface layer located on the outermost surface of the conductive particle. The insulating layer may be a layer formed of an insulating material such as silicon dioxide or acrylic resin.

[0035] From the viewpoint of excellent dispersibility and conductivity, the average particle size Dp of the conductive particles 12 can be 1 μm or more, 2 μm or more, or 5 μm or more. From the viewpoint of excellent dispersibility and conductivity, the average particle size Dp of the conductive particles can be 50 μm or less, 30 μm or less, or 20 μm or less. From the above viewpoints, the average particle size Dp of the conductive particles can be 1~50 μm, 5~30 μm, 5~20 μm, or 2~20 μm.

[0036] The maximum particle size of the conductive particles 12 can be smaller than the minimum spacing (shortest distance between adjacent electrodes) of the electrodes in the wiring pattern. From the viewpoint of excellent dispersibility and conductivity, the maximum particle size of the conductive particles 12 can be 1 μm or more, or 2 μm or more, or 5 μm or more. From the viewpoint of excellent dispersibility and conductivity, the maximum particle size of the conductive particles can be 50 μm or less, or 30 μm or less, or 20 μm or less. From the above viewpoints, the maximum particle size of the conductive particles can be 1 to 50 μm, or 2 to 30 μm, or 5 to 20 μm.

[0037] In this specification, for any 300 particles, the particle size was determined by observation using a scanning electron microscope (SEM). The average particle size obtained was taken as the average particle size Dp, and the maximum value obtained was taken as the maximum particle size. In addition, in cases where the particle has protrusions or the particle shape is not spherical, the particle size was taken as the diameter of the circle tangent to the particle in the SEM image.

[0038] The content of conductive particles 12 is determined based on factors such as the fineness of the connected electrodes. For example, the amount of conductive particles 12 is not particularly limited, but based on the total volume of the adhesive components (components in the adhesive composition other than conductive particles), it can be 0.1% by volume or more, or 0.2% by volume or more. If the above-mentioned amount is 0.1% by volume or more, there is a tendency to suppress the decrease in conductivity. Based on the total volume of the adhesive components (components in the adhesive composition other than conductive particles 12), the amount of conductive particles 12 can be 30% by volume or less, or 10% by volume or less. If the above-mentioned amount is 30% by volume or less, there is a tendency to prevent short circuits. In addition, "volume%" is determined based on the volume of each component before curing at 23°C, and the volume of each component can be converted from weight to volume using specific gravity. Furthermore, the volume of a component can be determined by adding it into a suitable solvent (water, alcohol, etc.) that sufficiently wets the component, without dissolving or swelling it in a graduated cylinder or similar container.

[0039] [Adhesive layer / Composition of adhesive components] The adhesive components constituting adhesive layers 14 and 17 contain a curing agent and monomers. When using epoxy resin monomers, imidazole-based, acehydrazine-based, boron trifluoride-amine complexes, sulfonium salts, amineimides, polyamine salts, dicyandiamine, etc., can be used as curing agents. Using polyurethane-based, polyester-based polymers as coating curing agents and microencapsulating them can extend the usable time, which is preferable. On the other hand, when using acrylic monomers, peroxide compounds, azo compounds, etc., that generate free radicals through decomposition by heating can be used as curing agents.

[0040] Regarding the curing agent used with epoxy monomers, it should be appropriately selected based on the target bonding temperature, bonding time, and storage stability. From the viewpoint of high reactivity, the curing agent should have a gel time with the epoxy resin composition of less than 10 seconds at a specified temperature; from the viewpoint of storage stability, it should be one whose gel time with the epoxy resin composition remains unchanged after storage in a constant temperature bath at 40°C for 10 days. From this perspective, a sulfonate salt can be used as the curing agent.

[0041] Regarding the curing agent used with acrylic monomers, it should be appropriately selected based on the target bonding temperature, bonding time, and storage stability. From the viewpoint of high reactivity and storage stability, it can be an organic peroxide or azo compound with a half-life of 10 hours at a temperature above 40°C and a half-life of 1 minute at a temperature below 180°C, or an organic peroxide or azo compound with a half-life of 10 hours at a temperature above 60°C and a half-life of 1 minute at a temperature below 170°C. These curing agents can be used alone or in combination, and can also be mixed with decomposition accelerators, inhibitors, etc.

[0042] Regardless of whether epoxy monomers or acrylic monomers are used, when the bonding time is set to 10 seconds or less, to obtain a sufficient reaction rate, the amount of curing agent can be set to 0.1 to 40 parts by mass, or 1 to 35 parts by mass, relative to 100 parts by mass of the total monomers and film-forming materials described later. When the amount of curing agent is less than 0.1 parts by mass, a sufficient reaction rate cannot be obtained, and there is a tendency to obtain poor adhesion strength and low bonding resistance. On the other hand, if the amount of curing agent exceeds 40 parts by mass, there is a tendency for the adhesive to have decreased fluidity, increased bonding resistance, or decreased storage stability.

[0043] Furthermore, when epoxy resin monomers are used as monomers, various epoxy compounds with two or more glycidyl groups in one molecule, such as epichlorohydrin and bisphenol A, bisphenol F, bisphenol AD, etc., can be used. These include bisphenol-type epoxy resins derived from epichlorohydrin and phenolic varnishes, cresol varnishes, glycidylamine, glycidyl ether, biphenyl, and alicyclic compounds.

[0044] When using acrylic acid monomers, the free radical polymerizable compound can be a substance having functional groups that can polymerize by free radicals. Examples of such free radical polymerizable compounds include (meth)acrylates, maleic anhydride compounds, and styrene derivatives. Furthermore, the free radical polymerizable compound can be used in either the monomer or oligomer state, and monomers and oligomers can be used in combination. One monomer can be used alone, or two or more monomers can be used in combination.

[0045] Furthermore, the adhesive layers forming adhesive layers 14 and 17 may further contain film-forming materials, fillers, softeners, accelerators, antioxidants, colorants, flame retardants, thixotropic agents, coupling agents, and phenolic resins, melamine resins, isocyanates, etc.

[0046] When the adhesive layer contains a film-forming material, improved film-forming properties can be expected. The film-forming material is a polymer that facilitates the processing of low-viscosity compositions containing the aforementioned curing agent and monomer. By using a film-forming material, the tendency of the film to break, crack, or become sticky is suppressed, resulting in easy-to-use adhesive layers 14 and 17.

[0047] Thermoplastic resins are preferably used as film-forming materials, including phenoxy resins, polyvinyl formal resins, polystyrene resins, polyvinyl butyral resins, polyester resins, polyamide resins, xylene resins, polyurethane resins, polyacrylic acid resins, and polyester aminoformate resins. Furthermore, these polymers may contain siloxane bonds or fluorine substituents. Two or more of these resins can be used alone or in combination. Among the above-mentioned resins, phenoxy resins are preferred from the viewpoints of adhesive strength, compatibility, heat resistance, and mechanical strength.

[0048] The larger the molecular weight of a thermoplastic resin, the easier it is to achieve film-forming properties, and the melt viscosity affecting film flowability can be set over a wide range. The molecular weight of thermoplastic resins, by weight average, can range from 5,000 to 150,000, or from 10,000 to 80,000. Setting the weight average molecular weight above 5,000 facilitates good film-forming properties, while setting it below 150,000 facilitates good compatibility with other components.

[0049] In addition, in this disclosure, the weight-average molecular weight refers to the value determined by gel permeation chromatography (GPC) using a standard polystyrene-based metric line under the following conditions. (Measurement conditions) Device: Manufactured by TOSOH CORPORATION, GPC-8020 Detector: Manufactured by TOSOH CORPORATION, RI-8020 Column: Manufactured by Hitachi Chemical Company, Ltd., Gelpack GLA160S+GLA150S Sample concentration: 120 mg / 3 mL Solvent: Tetrahydrofuran Injection volume: 60μL Pressure: 2.94 × 10⁶ Pa (30 kgf / cm²) Flow rate: 1.00 mL / min

[0050] When the adhesive layer contains film-forming material, the content of the film-forming material can be 5% to 80% by mass, or 15% to 70% by mass, based on the total amount of curing agent, monomer, and film-forming material. By setting it to 5% or more by mass, good film-forming properties are easily obtained, and by setting it to 80% or less by mass, the curable components tend to exhibit good flowability.

[0051] With the presence of filler, further improvements in connection reliability can be expected. The maximum diameter of the filler can be smaller than the particle size of the conductive particles 12, and the filler content can be 5 to 60 parts by volume relative to 100 parts by volume of the adhesive layer. If the filler content is 5 to 60 parts by volume, there is a tendency to obtain good connection reliability.

[0052] [Composition of the metal layer] The surface roughness Rz of one surface of the metal layer 20 and the surface roughness Rz of its opposite surface can be the same or different. The metal layer 20 has a thickness of, for example, 5 μm to 200 μm. The thickness of the metal layer referred to herein includes the surface roughness Rz. The metal layer 20 can be, for example, copper foil, aluminum foil, nickel foil, stainless steel, titanium, or platinum. The metal layer 20 can be a layer of metal foil.

[0053] An adhesive layer 10 is disposed on the first surface 20a of the metal layer 20. From the viewpoint of adhesion between the metal layer 20 and the adhesive layer 10 or the adhesive layer 40, the surface roughness Rz of the first surface 20a of the metal layer 20 (the surface adhering to the adhesive layer 10 or the adhesive layer 40) can be 0.3 μm or more, 0.5 μm or more, or 1.0 μm or more. Furthermore, from the viewpoint of achieving good electrical conductivity, the surface roughness Rz of the first surface 20a of the metal layer 20 can be 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, less than 20 μm, 17 μm or less, 10 μm or less, 8.0 μm or less, 5.0 μm or less, or 3.0 μm or less. The surface roughness Rz of the first surface 20a of the metal layer 20 can be, for example, 0.3 μm or more and 20 μm or less, or more specifically, 0.5 μm or more and 10 μm or less. Furthermore, the surface roughness Rz of the second surface 20b of the metal layer 20 can be, for example, 20 μm or more, or it can be rougher than the surface roughness Rz of the first surface 20a, or it can have the same surface roughness as the first surface 20a, or it can be no rougher than the surface roughness Rz of the first surface 20a.

[0054] Surface roughness Rz refers to the ten-point average roughness Rzjis measured according to the method specified in JIS standard (JIS B 0601-2001), and refers to the value measured using a commercially available surface roughness shape measuring instrument. For example, it can be measured using a Nano Search Microscope (manufactured by SHIMADZU CORPORATION, "SFT-3500").

[0055] Here, the relationship between the surface roughness Rz of the first surface 20a of the metal layer 20 and the average particle size Dp of the conductive particles 12 will be explained below. In this embodiment, the ratio of the surface roughness Rz of the first surface 20a of the metal layer 20 to the average particle size Dp of the conductive particles 12, i.e., "surface roughness / average particle size", can be 0.03 or more, 0.04 or more, 0.05 or more, 0.06 or more, 0.1 or more, 0.2 or more, 0.3 or more, 0.5 or more, or 1 or more. Furthermore, the ratio of the surface roughness Rz of the first surface 20a of the metal layer 20 to the average particle size Dp of the conductive particles 12, i.e., "surface roughness / average particle size", can be 3 or less, 2 or less, 1.7 or less, or 1.5 or less. The ratio of the surface roughness Rz of the first surface 20a of the metal layer 20 to the average particle size Dp of the conductive particles 12, i.e., “surface roughness / average particle size”, can be, for example, greater than 0.05 and less than 3, or more specifically, greater than 0.06 and less than 2.

[0056] In the wiring forming component 3, from the viewpoint of preventing bubble formation in cases where the substrate to which the wiring is to be formed has large irregularities (e.g., in cases where the electrode height is large), the flowability of the second adhesive layer 16 (or the second region) can be higher than that of the first adhesive layer 15 (or the first region). The flowability of the adhesive layer can be, for example, expressed as a flow rate.

[0057] In the wiring forming component 3, the ratio of the flow rate of the second adhesive layer 16 to the flow rate of the first adhesive layer 15 (hereinafter referred to as the "flow ratio") may exceed 1.0, or may exceed 1.0 and be less than 3.0, or may exceed 1.0 and be less than 2.0. Furthermore, when the adhesive layer includes a first region containing conductive particles and a first adhesive component and a second region containing a second adhesive component, and a metal layer, the first region, and the second region are sequentially and adjacently disposed therein, the ratio of the flow rate of the second region to the flow rate of the first region (hereinafter referred to as the "flow ratio") may exceed 1.0, or may exceed 1.0 and be less than 3.0, or may exceed 1.0 and be less than 2.0.

[0058] The flow rate of each adhesive layer (the first adhesive layer and the second adhesive layer) is as follows: that is, the flow rate when the adhesive layer is placed on the glass plate from the side of the first adhesive layer, and temporary pressing is performed under the conditions of pressing temperature of 70°C, pressing pressure of 0.1MPa and pressing time of 1.0s, and then the glass plate is placed on the second adhesive layer, and this pressing is performed under the conditions of pressing temperature of 180°C, pressing pressure of 2MPa and pressing time of 10 minutes, and is defined by the following formula (1). Flow rate [%] = SB / SA × 100……(1) In formula (1), SA represents the surface area of ​​the adhesive layer before temporary pressing, and SB represents the area of ​​the adhesive layer after temporary pressing.

[0059] Specifically, the flow rate of each of the above adhesive layers can be determined according to the steps (I) to (IV) below. (I) A wire forming component is punched along the thickness direction while having a metal layer, thereby obtaining a circular plate-shaped adhesive film for evaluation with radius r. (II) The evaluation adhesive film is placed on the first glass plate from the second adhesive layer side, and hot-pressed from the metal layer side under the conditions of a pressing temperature of 70°C, a pressing pressure of 0.1 MPa, and a pressing time of 1.0 s to obtain a temporary fixture. (III) Place the second glass plate on the metal layer of the temporary fixation body, and perform hot pressing from the metal layer side under the conditions of pressing temperature of 180℃, pressing pressure of 2MPa and pressing time of 10 minutes to obtain the pressed body. (IV) Determine the contact area SB1 (unit: mm 2) between the metal layer and the first adhesive layer exposed from the metal layer and the first glass plate, and the contact area SB2 (unit: mm 2) between the surface of the second adhesive layer and the second glass plate, and calculate the flow rate of the first adhesive layer and the flow rate of the second adhesive layer according to the following formulas (1-1) and (1-2). The flow rate of the first adhesive layer [%] = S B1 / (r 2π)×100……(1-1) The flow rate of the second adhesive layer [%] = S B2 / (r 2π)×100……(1-2)

[0060] One way to improve the fluidity of the adhesive layer is to adjust the composition of the adhesive and the content of fillers.

[0061] On the other hand, this disclosure relates to a method for forming a wiring layer using a wiring forming component. Referring to FIG2, the method for forming a wiring layer using the above-described wiring forming component 1 will be described. FIG3(a) to (d) are diagrams illustrating the method for forming a wiring layer using the wiring forming component shown in FIG1.

[0062] First, as shown in FIG3(a), a wiring forming member 1 is prepared. Next, a substrate 30 on which wiring 32 is formed is prepared. Then, the wiring forming member 1 is arranged such that the adhesive layer 10 side of the wiring forming member 1 faces the substrate 30. Subsequently, as shown in FIG3(b), the wiring forming member 1 is laminated onto the substrate 30 to cover the wiring 32.

[0063] Next, as shown in Figure 3(c), the wiring forming member 1 is subjected to prescribed heating and pressure to press the substrate 30. At this time, if the first surface 20a of the metal layer 20 of the wiring forming member 1 is flat, the conductive particles 12, which require ensuring conductivity, can be more reliably deformed into flat conductive particles 12a. Furthermore, in the pressed wiring forming member 1a, flat conductive particles 12a (whereby the insulation layer is broken and the conductive portion is exposed) are arranged on the wiring 32, achieving good electrical conductivity between the metal layer 20 and the wiring 32. At this time, the adhesive layer 10 is also flattened, becoming a thinner adhesive layer 18a. Furthermore, the adhesive layer 10 includes a first adhesive layer 15 and a second adhesive layer 16 containing conductive particles in the adhesive composition, thus achieving good insulation reliability in the thickness direction of areas where conductive connection is not desired.

[0064] Next, as shown in Figure 3(d), a predetermined pattern forming process (e.g., etching) is performed on the metal layer 20 to form a predetermined wiring pattern 20c (another wiring). Additionally, at this time, the second surface 20b of the metal layer 20 can be processed to become a smooth surface. The processes described in Figures 3(a) to (d) can be repeated a predetermined number of times to form the wiring layer.

[0065] That is, the method for forming a wiring layer using a wiring forming component includes: a step of preparing a wiring forming component; a step of preparing a substrate on which wiring is formed; a step of disposing the aforementioned wiring forming component on the wiring-formed surface of the aforementioned substrate with the adhesive layer side facing the substrate to cover the aforementioned wiring; a step of heating and pressing the aforementioned wiring forming component onto the aforementioned substrate; and a step of patterning the aforementioned metal layer.

[0066] As described above, a wiring forming member 1b is formed. This wiring forming member 1b includes: a substrate 30 having wiring 32; and a cured form (a wiring forming member heat-pressed) of the wiring forming member 1 disposed on the substrate 30 to cover the wiring 32. In this wiring forming member 1b, the wiring 32 and the metal layer 20 of the wiring forming member 1, or a wiring pattern 20c formed from the metal layer 20 (e.g., etched), are electrically connected by conductive particles 12a. Furthermore, if the processes in Figures 3(a) to (d) are repeated a predetermined number of times, the wiring forming member 1b can be a structure having a plurality of wiring layers (layers connecting the aforementioned wirings).

[0067] As described above, the method for forming a wiring layer using the wiring forming member 1 of this embodiment simplifies the wiring layer formation process compared to conventional procedures such as laser processing and filler plating. Furthermore, the formed wiring layer can be easily made thinner. Even when using the wiring forming member 3, the same effect can be obtained by performing the same steps as described above.

[0068] Furthermore, based on the wiring layer forming method using the wiring forming component 1 of this embodiment, the following effects can fully ensure the design freedom of the wiring pattern when forming the wiring layer. (i) By including the second adhesive layer 16 in the adhesive layer 10, even if the wiring layer formed by patterning the metal layer 20 has a portion that is not intended to be connected in the lamination direction (or the thickness direction of the adhesive layer), the insulation reliability of that portion can be easily ensured. (ii) In wiring layers formed by patterning the metal layer 20 or in separately formed rewiring, the conductive particles 12 are less likely to come into contact with parts other than the conductive connection parts, and the transmission loss of wiring caused by the contact of conductive particles is easily suppressed.

[0069] Refer to the diagram for an explanation of the above effects.

[0070] Figures 4(a) to (b) are cross-sectional views illustrating an example of forming a wiring layer using the wiring forming member 1 of this embodiment.

[0071] Figure 4(a) shows a substrate 30 having wiring patterns 32a and 32b, with the wiring forming member 1 placed on the surface of the substrate 30 where the wiring patterns are formed, so as to cover the wiring patterns 32a and 32b, with the adhesive layer 10 side facing the substrate 30. Subsequently, by heating and pressing the wiring forming member 1 onto the substrate 30 and performing a pattern forming process on the metal layer 20, a wiring forming member having a wiring pattern 20d that is electrically connected to the wiring pattern 32a and a wiring pattern 20e that is not electrically connected to the wiring pattern 32b, as shown in Figure 4(b), can be obtained.

[0072] Here, by means of the adhesive layer 10 of the wiring forming member 1, which includes a first adhesive layer 15 containing conductive particles 12 and adhesive component 14, and a second adhesive layer 16 containing adhesive component 17 but without conductive particles, the adhesive layer 18a can be provided with the following thickness: during crimping, good conductivity can be ensured between the wiring patterns 20d and 32a via the conductive particles 12, while ensuring that no conductive distance occurs between the wiring patterns 20e and 32b, which are not intended to be connected, via the conductive particles 12. Thus, the wiring patterns 20e and 32b are not connected, and the insulation reliability in the thickness direction of the adhesive layer can be ensured.

[0073] On the other hand, Figures 5(a) to (b) are cross-sectional views illustrating an example of forming a wiring layer using the wiring forming member 2 as a comparative example. The wiring forming member 2 is a single layer consisting of an adhesive layer 11 containing conductive particles 12 and adhesive component 14. In this case, if the wiring forming member 2 is configured in the same way as described above for heat pressing and pattern forming, good conductivity can be ensured between the wiring patterns 20d and 32a via the conductive particles 12. On the other hand, the wiring patterns 20e and 32b, which are not intended to be connected, are also connected via the conductive particles 12b. That is, it is difficult to provide an adhesive layer 18b with a thickness that ensures good conductivity between the wiring patterns 20d and 32a via the conductive particles 12, while ensuring that no conductivity occurs between the wiring patterns 20e and 32b, which are not intended to be connected, via the conductive particles 12. Therefore, the design freedom of wiring patterns when forming wiring layers is limited.

[0074] Figures 6(a) to (b) are cross-sectional views illustrating another example of forming a wiring layer using the wiring forming member 1 of this embodiment.

[0075] Figure 6(a) shows a substrate 30 having a wiring pattern 32a, with the wiring forming member 1 placed on the surface of the substrate 30 where the wiring pattern is formed, with the adhesive layer 10 facing the substrate 30 to cover the wiring pattern 32a. Subsequently, by heating and pressing the wiring forming member 1 onto the substrate 30 and performing a pattern forming process on the metal layer 20, a wiring forming member having a wiring pattern 20d that is electrically connected to the wiring pattern 32a and a wiring pattern 20f (or the non-electrically connected portion of the wiring pattern) as shown in Figure 5(b) can be obtained.

[0076] Here, by including a first adhesive layer 15 containing conductive particles 12 and adhesive component 14 and a second adhesive layer 16 containing adhesive component 17 but without conductive particles in the adhesive layer 10 of the wiring forming member 1, an adhesive layer 18a can be provided such that, during crimping, while ensuring good conductivity between the wiring patterns 20d and 32a via the conductive particles 12, the wiring pattern 20f does not contact the conductive particles 12. This suppresses transmission loss in the wiring pattern 20f caused by contact of conductive particles. In particular, by sequentially stacking the metal layer 20, the second adhesive layer 16, and the first adhesive layer 15 in the wiring forming member 1, contact between the wiring pattern 20f and the conductive particles 12 is easily prevented.

[0077] On the other hand, Figures 7(a) to (b) are cross-sectional views illustrating an example of forming a wiring layer using the wiring forming member 2 as a comparative example. The wiring forming member 2 is a single layer consisting of an adhesive layer 11 containing conductive particles 12 and adhesive component 14. In this case, if the wiring forming member 2 is used for heat pressing and pattern forming in the same manner as described above, good conductivity can be ensured between the wiring pattern 20d and the wiring pattern 32a via the conductive particles 12, while the conductive particles 12c contact the wiring pattern f (or the non-conductive connection portion of the wiring pattern). If the number of conductive particles 12c increases, the transmission loss of the wiring also increases. Therefore, the design freedom of the wiring pattern when forming the wiring layer is limited.

[0078] Figures 8(a) to (c) are cross-sectional views illustrating another example of forming a wiring layer using the wiring forming member 1 of this embodiment.

[0079] Figure 8(a) shows a substrate 30 having a wiring pattern 32a, with the wiring forming member 1 placed on the surface of the substrate 30 where the wiring pattern is formed, with the adhesive layer 10 facing the substrate 30 to cover the wiring pattern 32a. Subsequently, by heating and pressing the wiring forming member 1 onto the substrate 30 and performing a patterning process on the metal layer 20, a wiring pattern 20d, as shown in Figure 8(b), that is electrically connected to the wiring pattern 32a can be formed. Furthermore, by forming a rewiring step, a wiring forming member having a non-conductive rewiring pattern 20g (or a non-conductive portion of the rewiring pattern), as shown in Figure 8(c), can be obtained.

[0080] At this time, similar to the wiring forming member shown in Figure 6(b), the transmission loss of the wiring caused by the contact of conductive particles can be suppressed in the rewiring pattern 20g.

[0081] Furthermore, based on the wiring layer forming method using the wiring forming component 3 of this embodiment, the following effects can fully ensure the design freedom of the wiring pattern when forming the wiring layer. (i) By including the second adhesive layer 16 in the adhesive layer 40, even when the substrate for which wiring is to be formed by wiring forming components has large irregularities (e.g., when the electrode height is large), embedding can be ensured by the second adhesive layer or the second region, and bubbles or peeling are not easily generated.

[0082] Figures 9(a) to (b) are cross-sectional views illustrating an example of forming a wiring layer using the wiring forming member 3 of this embodiment.

[0083] Figure 9(a) shows the state in which a wiring forming member 3 is placed on the surface of the substrate 30 where the wiring pattern is formed, covering the electrode 32c, with the adhesive layer 40 facing the substrate 30. Subsequently, by heating and pressing the wiring forming member 3 onto the substrate 30 and performing a pattern forming process on the metal layer 20, a wiring pattern 20h that is electrically connected to the electrode 32c, as shown in Figure 9(b), can be formed.

[0084] Here, the adhesive layer 40 of the wiring forming member 3 includes a first adhesive layer 15 containing conductive particles 12 and adhesive component 14, and a second adhesive layer 16 containing adhesive component 17 but without conductive particles. During crimping, good conductivity can be ensured between the wiring pattern 20h and the electrode 32c via the conductive particles 12. Furthermore, as described above, by setting the flowability of the second adhesive layer to be higher than that of the first adhesive layer and setting the height of the electrode 32c to be larger, even in cases where the surface of the substrate 30 has large unevenness, bubbles and peeling are less likely to occur around the electrode 32c.

[0085] The above describes in detail the embodiments of this disclosure. However, this disclosure is not limited to the above embodiments and can be applied to various embodiments.

[0086] For example, as shown in FIG1, conductive particles 12 are locally disposed in the first adhesive layer 15 of the wiring forming member 1, but the conductive particles 12 can also be randomly or evenly dispersed in the adhesive layer 14.

[0087] Furthermore, in the first adhesive layer 15 of the wiring forming member 1, conductive particles 12 are partially disposed on the side of the second adhesive layer 16, but conductive particles 12 may also be partially disposed on the side opposite to the side of the second adhesive layer 16 (the side of the second surface 10b of the adhesive layer 10).

[0088] Furthermore, as with the wiring forming component 3, in the case where a structure has a metal layer 20, a first adhesive layer 15 and a second adhesive layer 16 stacked in sequence, the conductive particles 12 can be partially disposed on the side of the metal layer 20, or the conductive particles 12 can be partially disposed on the side of the second adhesive layer 16.

[0089] Furthermore, the second adhesive layer 16 of the wiring forming components 1 and 3 does not contain conductive particles, but the second adhesive layer 16 may also contain a portion of the particle body of the conductive particles 12 (in other words, it may not contain the entire particle body of the conductive particles 12).

[0090] Furthermore, the adhesive layer 10 of the wiring forming member 1 or the adhesive layer 40 of the wiring forming member 3 may be composed of two layers, a first adhesive layer 15 and a second adhesive layer 16, or may be composed of three or more layers having layers other than the first adhesive layer 15 and the second adhesive layer 16 (e.g., a third adhesive layer). The third adhesive layer may be a layer having the same composition as described above for the first adhesive layer 15 or the second adhesive layer 16, or may be a layer having the same thickness as described above for the first adhesive layer 15 or the second adhesive layer 16. For example, the wiring forming member 3 may be constructed by sequentially stacking a metal layer, a third adhesive layer, a first adhesive layer, and a second adhesive layer, and the wiring forming member 1 may also be constructed by sequentially stacking a metal layer, a second adhesive layer, a first adhesive layer, and a third adhesive layer, but is not limited to these.

[0091] Furthermore, the wiring forming components 1 and 3 may further include a release film. The release film may be attached to the side of the adhesive layer 10 or adhesive layer 40 opposite to the side where the metal layer 20 is attached (the second surface 10b side of the adhesive layer 10 or the second surface 40b side of the adhesive layer 40), or it may be attached to the side of the metal layer 20 opposite to the side where the adhesive layer 10 or adhesive layer 40 is attached (the first surface 20a of the metal layer) (the second surface 20b side of the metal layer 20). This facilitates the processing of the wiring forming components and improves the work efficiency when forming wiring layers using the wiring forming components.

[0092] Furthermore, the above description uses the case where the wiring forming component is formed by bonding the adhesive layer 10 or adhesive layer 40 to the metal layer 20 as an example. However, in this embodiment, the wiring forming component can be composed of a kit where the adhesive layer 10 or adhesive layer 40 and the metal layer 20 are separate components, and the adhesive layer 10 can be bonded to the first surface 20a of the metal layer 20 during use. In this case, since the adhesive layer 10 or adhesive layer 40 and the metal layer 20 can be prepared separately (as a kit of wiring forming components), it is possible to select wiring forming components with better material structures, thereby increasing the degree of operational freedom when using wiring forming components to manufacture wiring layers.

[0093] This disclosure provides an invention as described below [1] to

[18] . [1] A wiring forming component comprising: an adhesive layer containing conductive particles; and a metal layer disposed on the adhesive layer, wherein the adhesive layer comprises: a first adhesive layer containing the aforementioned conductive particles and adhesive components; and a second adhesive layer containing adhesive components. [2] The wiring forming component as described in [1] above, wherein The aforementioned metal layer, the aforementioned second adhesive layer, and the aforementioned first adhesive layer are sequentially stacked. [3] The wiring forming component as described in [1] or [2] above, wherein The aforementioned second adhesive layer does not contain conductive particles. [4] A wiring forming component as described in any of [1] to [3] above, wherein The surface roughness Rz of the aforementioned adhesive layer side of the aforementioned metal layer is 0.05 to 3 relative to the average particle size of the aforementioned conductive particles. [5] A wiring forming component as described in any of [1] to [4] above, wherein The surface roughness Rz of the adhesive layer side of the aforementioned metal layer is less than 20 μm. [6] The wiring forming member as described in any of [1] to [5] above further comprises a release film. [7] A wiring forming component comprising: an adhesive layer containing conductive particles; and a metal layer disposed on the adhesive layer, wherein the adhesive layer includes, in its thickness direction, a first region containing the aforementioned conductive particles and a first adhesive component and a second region containing a second adhesive component. [8] The wiring forming component as described in [7] above, wherein The aforementioned metal layer, the aforementioned second region, and the aforementioned first region are sequentially and adjacently arranged. [9] A wiring forming component as described in [7] or [8] above, wherein The aforementioned second region does not contain conductive particles.

[10] A wiring forming component as described in any of [7] to [9] above, wherein The surface roughness Rz of the aforementioned adhesive layer side of the aforementioned metal layer is 0.05 to 3 relative to the average particle size of the aforementioned conductive particles.

[11] A wiring forming component as described in any of [7] to

[10] above, wherein The surface roughness Rz of the adhesive layer side of the aforementioned metal layer is less than 20 μm.

[12] The wiring forming member as described in any of [7] to

[11] above further comprises a release film.

[13] A wiring forming component comprising an adhesive layer containing conductive particles and a metal layer separately disposed thereof, wherein the adhesive layer can bond with the metal layer during use. The aforementioned adhesive layer includes: a first adhesive layer containing the aforementioned conductive particles and adhesive components; and a second adhesive layer containing adhesive components.

[14] The wiring forming component as described in

[13] above, wherein The aforementioned second adhesive layer does not contain conductive particles.

[15] A wiring forming component comprising an adhesive layer containing conductive particles and a metal layer separately disposed thereof, wherein the adhesive layer can bond with the metal layer during use. The aforementioned adhesive layer includes: a first region containing the aforementioned conductive particles and a first adhesive component; and a second region containing a second adhesive component.

[16] The wiring forming component as described in

[15] above, wherein The aforementioned second region does not contain conductive particles.

[17] A method for forming a wiring layer includes: a step of preparing a wiring forming component as described in any one of [1] to

[12] above; a step of preparing a substrate on which wiring is formed; a step of disposing the wiring forming component on the surface of the substrate on which the wiring is formed, such that the adhesive layer and the substrate are opposite each other, to cover the wiring; a step of heating and pressing the wiring forming component onto the substrate; and a step of patterning the metal layer.

[18] A wiring forming member comprising: a substrate having wiring; and a cured form of the wiring forming member described in any one of [1] to

[12] above disposed on the substrate in such a manner as to cover the wiring, wherein the wiring is electrically connected to the aforementioned metal layer of the wiring forming member or another wiring formed from the aforementioned metal layer. [Example]

[0094] The present disclosure will now be described in more detail with reference to embodiments, but the present disclosure is not limited to the embodiments.

[0095] <Materials Preparation> The following thermosetting components and fillers were prepared as adhesive components. (Thermosetting components) Epoxy Resin A: NC-3000H (Biphenyl phenolic varnish type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., trade name, epoxy equivalent: 289g / eq) Phenolic resin A: KA-1165 (cresol phenolic varnish type phenolic resin, manufactured by DIC CORPORATION, trade name, hydroxyl equivalent: 119 g / eq) In addition, the hydroxyl equivalent of phenolic resin is determined by the following determination method. Curing Accelerator A: G-8009L (Isocyanate Masking Imidazole, manufactured by DKS Co. Ltd., trade name) (filler) Silica Particles A: SC-2050(KC) (Melted spherical silica, average particle size 0.5μm, manufactured by Admatechs Company Limited, trade name)

[0096] [Method for determining hydroxyl equivalent] 1 g of the sample was accurately weighed into a round-bottom flask, followed by 5 mL of acetic anhydride and pyridine reagent. The flask was then fitted with an air cooler and heated at 100 °C for 1 hour. After cooling, 1 mL of water was added, and the flask was heated again at 100 °C for 10 minutes. After recooling, the air cooler and the neck of the flask were rinsed with 5 mL of neutralized methanol, and 1 mL of phenolphthalein reagent was added. The solution obtained in this manner was titrated with a 0.1 mol / L potassium hydroxide-ethanol solution to determine the hydroxyl value. Based on the obtained hydroxyl value, the hydroxyl equivalent (g / eq) was calculated, equivalent to the mass of 1 mol (1 eq) of hydroxyl groups.

[0097] The following were prepared as conductive particles. (Conductive particle 1) As conductive particle 1, gold-plated resin particles (resin material: styrene-divinylbenzene copolymer) with an average particle size of 20 μm and a specific gravity of 1.7 were prepared.

[0098] (Conductive particle 2) As conductive particle 2, gold-plated resin particles (resin material: styrene-divinylbenzene copolymer) with an average particle size of 10 μm and a specific gravity of 1.8 were prepared.

[0099] <Preparation of Adhesive Layer> (PET film with adhesive layer R-1) Epoxy resin A2 3.12g, phenolic resin A9.52g, and curing accelerator A0.065g were dissolved in methyl ethyl ketone (MEK) 13.05g. Silicon dioxide particles A1 12.56g and conductive particles 1 17.03g were then added to prepare a coating solution for forming an adhesive layer. Using a coating apparatus (manufactured by Yasui Seiki Inc., product name: Precision Coating Machine), the coating solution was coated onto a 50μm thick PET film and dried with hot air at 160°C for 10 minutes, thereby creating a 20μm thick adhesive layer R-1 containing conductive particles in the adhesive composition on the PET film.

[0100] (PET film with adhesive layer R-2) The thickness of the adhesive layer was changed to 25 μm. Otherwise, adhesive layer R-2 was fabricated on the PET film in the same manner as the PET film with adhesive layer R-1.

[0101] (PET film with adhesive layer R-3) The thickness of the adhesive layer was changed to 30 μm. Otherwise, adhesive layer R-3 was fabricated on the PET film in the same manner as the PET film with adhesive layer R-1.

[0102] (PET film with R-4 adhesive layer) Conductive particles 2 were used instead of conductive particles 1, and the thickness of the adhesive layer was changed to 14 μm. Otherwise, adhesive layer R-4 was fabricated on the PET film in the same manner as the PET film with adhesive layer R-1.

[0103] (PET film with R-5 adhesive layer) Conductive particles 2 were used instead of conductive particles 1, and the thickness of the adhesive layer was changed to 10 μm. Otherwise, adhesive layer R-5 was fabricated on the PET film in the same manner as the PET film with adhesive layer R-1.

[0104] (Copper foil with adhesive layer S-1 attached) Epoxy resin A23.12g, phenolic resin A9.52g and curing accelerator A0.065g were dissolved in methyl ethyl ketone (MEK) 13.05g, and then silicon dioxide particles A12.56g were added to prepare a coating solution for adhesive layer formation.

[0105] Using a coating apparatus (manufactured by Yasui Seiki Inc., product name: Precision Coating Machine), the coating liquid was applied to one side of a copper foil (manufactured by MITSUI MINING & SMELTING CO.,LTD., trade name "3EC-M3-VLP", thickness: 12μm) with a surface roughness Rz: 3.0μm, and then dried with hot air at 160°C for 10 minutes, thereby creating an adhesive layer S-1 with a thickness of 5μm on the copper foil.

[0106] (Copper foil with adhesive layer S-2) The thickness of the adhesive layer was changed to 10 μm. Otherwise, an adhesive layer S-2 was made on the copper foil in the same way as the copper foil with adhesive layer S-1.

[0107] (Copper foil with adhesive layer S-3) The thickness of the adhesive layer was changed to 6 μm. Otherwise, an adhesive layer S-2 was made on the copper foil in the same way as the copper foil with adhesive layer S-1.

[0108] (Copper foil with adhesive layer R-1) Epoxy resin A2 3.12g, phenolic resin A9.52g, and curing accelerator A0.065g were dissolved in methyl ethyl ketone (MEK) 13.05g. Silicon dioxide particles A1 12.56g and conductive particles 1 17.03g were then added to prepare a coating solution for forming the adhesive layer. Using a coating apparatus (manufactured by Yasui Seiki Inc., product name: Precision Coating Machine), the coating solution was applied to one side (surface roughness Rz: 3.0μm) of a copper foil (manufactured by MITSUI MINING & SMELTING CO.,LTD., trade name "3EC-M3-VLP", thickness: 12μm). The foil was then hot-air dried at 160°C for 10 minutes, thereby creating a 20μm thick adhesive layer R-1 containing conductive particles in the adhesive composition on the copper foil.

[0109] (Copper foil with adhesive layer R-2) The thickness of the adhesive layer was changed to 25 μm. Otherwise, an adhesive layer R-2 was made on the copper foil in the same way as the copper foil with adhesive layer R-1.

[0110] (Copper foil with adhesive layer R-3) The thickness of the adhesive layer was changed to 30 μm. Otherwise, an adhesive layer R-3 was made on the copper foil in the same way as the copper foil with adhesive layer R-1.

[0111] (Copper foil with R-4 adhesive layer) Conductive particles 2 were used instead of conductive particles 1, and the thickness of the adhesive layer was changed to 14 μm. Otherwise, adhesive layer R-4 was fabricated on the copper foil in the same manner as the copper foil with adhesive layer R-1.

[0112] (Copper foil with R-6 adhesive layer) Conductive particles 2 were used instead of conductive particles 1, and the thickness of the adhesive layer was changed to 20 μm. Otherwise, adhesive layer R-6 was fabricated on the copper foil in the same manner as the copper foil with adhesive layer R-1.

[0113] (PET film with adhesive layer S-1) Epoxy resin A23.12g, phenolic resin A9.52g and curing accelerator A0.065g were dissolved in methyl ethyl ketone (MEK) 13.05g, and then silicon dioxide particles A12.56g were added to prepare a coating solution for adhesive layer formation.

[0114] Using a coating apparatus (manufactured by Yasui Seiki Inc., product name: Precision Coating Machine), the coating liquid was applied to a 50 μm thick PET film and dried with hot air at 160°C for 10 minutes, thereby creating a 5 μm thick adhesive layer S-1 on the PET film.

[0115] (PET film with adhesive layer S-3) The thickness of the adhesive layer was changed to 6 μm. Otherwise, an adhesive layer S-3 was fabricated on the PET film in the same manner as the PET film with adhesive layer S-1.

[0116] <Fabrication of Wiring Formation Components - 1> (Example A-1) A PET film with adhesive layer R-1 and a copper foil with adhesive layer S-1 were bonded together using a hot-roll laminator (Leon13DX) at 70°C and 1.0 m / min, with their respective adhesive layers in contact. This produced a wiring component with a structure consisting of a copper foil, a second adhesive layer (second region) composed of adhesive layer S-1, a first adhesive layer (first region) composed of adhesive layer R-1, and a PET film, sequentially laminated.

[0117] (Example A-2) The PET film with adhesive layer R-1 was laminated with the copper foil with adhesive layer S-2. Otherwise, in the same manner as in Example A-1, a wiring forming component was fabricated having a structure in which copper foil, a second adhesive layer (second region) composed of adhesive layer S-2, a first adhesive layer (first region) composed of adhesive layer R-1, and PET film are sequentially laminated.

[0118] (Example A-3) The PET film with adhesive layer R-4 was bonded to the copper foil with adhesive layer S-3. Otherwise, in the same manner as in Example A-1, a wiring forming component was fabricated having a structure in which copper foil, a second adhesive layer (second region) composed of adhesive layer S-3, a first adhesive layer (first region) composed of adhesive layer R-4 and PET film are sequentially stacked.

[0119] (Example A-4) The PET film with adhesive layer R-5 was laminated with the copper foil with adhesive layer S-2. Otherwise, in the same manner as in Example A-1, a wiring forming component was fabricated having a structure in which copper foil, a second adhesive layer (second region) composed of adhesive layer S-2, a first adhesive layer (first region) composed of adhesive layer R-5 and PET film are sequentially laminated.

[0120] (Comparative Example A-1) A wiring forming component is configured such that the copper foil with adhesive layer R-1 is provided with a structure having copper foil and a first adhesive layer (first region) composed of adhesive layer R-1 stacked sequentially.

[0121] (Comparative Example A-2) A wiring forming component is configured such that the copper foil with adhesive layer R-2 is provided with a structure having copper foil and a first adhesive layer (first region) composed of adhesive layer R-2 stacked sequentially.

[0122] (Comparative Example A-3) A wiring forming component is configured with a copper foil having an adhesive layer R-3 attached, having a structure in which copper foil and a first adhesive layer (first region) composed of adhesive layer R-3 are sequentially stacked.

[0123] (Comparative Example A-4) A wiring forming component is configured such that the copper foil with adhesive layer R-4 is provided with a structure having copper foil and a first adhesive layer (first region) composed of adhesive layer R-4 stacked sequentially.

[0124] (Comparative Example A-5) A wiring forming component is configured such that the copper foil with adhesive layer R-6 is provided with a structure having copper foil and a first adhesive layer (first region) composed of adhesive layer R-6 stacked sequentially.

[0125] <Determination of Connection Resistance and Evaluation of Cross-sectional Structure> (Evaluation sample preparation) The wiring forming component was attached from the first adhesive layer (first region) side (after peeling off the PET film if it is present) to a circuit board (PWB) having three copper circuits with a line width of 1000 μm, a spacing of 10000 μm, and a thickness of 15 μm on an epoxy board containing glass cloth. The connector was then formed by heating and pressing at 180°C and 2 MPa for 60 minutes using a thermoforming device (heating method: constant temperature type, manufactured by TORAY ENGINEERING Co., Ltd.) over a width of 2 mm.

[0126] A resist was formed on the fabricated connector, which was then immersed in an etching solution and subjected to oscillation. The etching solution was adjusted to a concentration of 100 g / L copper chloride and 100 ml / L hydrochloric acid. Once the specified copper foil portion disappeared, the connector was rinsed with pure water. Subsequently, the resist was removed, yielding an evaluation sample with a specified wiring pattern.

[0127] [Measurement of connection resistance] Immediately afterwards, a digital multimeter was used to measure the resistance between the formed wiring pattern and the copper circuitry on the substrate. The resistance value was represented by the average of 37 points of resistance between the wiring pattern and the copper circuitry on the substrate.

[0128] [Evaluation of Cross-Sectional Structure] For the evaluation samples made, the cross section was observed by the following method, and the distance A between the wiring pattern and the substrate (e.g., the distance between 20f and 30 in Figure 6(b)) and the shortest distance B between the wiring pattern and the conductive particles (e.g., the shortest distance between 20f and 12 in Figure 6(b)) were measured. (Methods for observing cross-sections) First, the evaluation samples were molded using a resin composition containing 100g of bisphenol A type epoxy resin (trade name: JER811, manufactured by Mitsubishi Chemical Corporation) and 10g of curing agent (trade name: Epomount curing agent, manufactured by Refine Tec Ltd.). Subsequently, the cross-section was ground using a grinder, and observed using a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-Tech Science Corporation).

[0129] If the shortest distance B is large, or the ratio of the shortest distance B to the distance A is large, it is easier to ensure that there is no distance between the wiring pattern that is not intended to be connected and the copper circuit, thus ensuring the insulation reliability in the thickness direction of the adhesive layer. Furthermore, a large shortest distance B, or a shortest distance B relative to the distance A, can further reduce the number of conductive particles that do not contribute to the conduction between the conductive particles and the wiring pattern (or the non-conductive parts of the wiring pattern), which is advantageous in suppressing the transmission loss of the wiring.

[0130] [Table 1] Total thickness of adhesive layer (μm) First adhesive layer Second adhesive layer Connection resistance value (mΩ) Section mechanism No. thickness (μm) Average particle size of conductive particles (μm) No. thickness (μm) Wiring pattern and Distance between substrates (μm) Wiring pattern and Conductive particles Shortest distance (μm) Example A-1 25 R-1 20 20 S-1 5 2.2 twenty two 2 Example A-2 30 R-1 20 20 S-2 10 3.0 twenty four 4 Example A-3 20 R-4 14 10 S-3 6 1.8 twenty two 3 Example A-4 20 R-5 10 10 S-2 10 2.3 twenty three 5 Comparative Example A-1 20 R-1 20 20 - - 1.9 20 0 Comparative Example A-2 25 R-2 25 20 - - 5.2 twenty three 0 Comparative Example A-3 30 R-3 30 20 - - 10.2 26 0 Comparative Example A-4 14 R-4 14 10 - - 1.8 16 0 Comparative Example A-5 20 R-6 20 10 - - 9.8 20 0

[0131] <Fabrication of Wiring Formation Components - 2> (Example B-1) A copper foil with adhesive layer R-1 and a PET film with adhesive layer S-1 were bonded together using a hot-roll laminator (Leon13DX) at 70°C and 1.0 m / min, with their respective adhesive layers in contact. This produced a wiring component with a structure consisting of a copper foil, a first adhesive layer (first region) composed of adhesive layer R-1, a second adhesive layer (second region) composed of adhesive layer S-1, and a PET film, sequentially laminated.

[0132] (Example B-2) The copper foil with adhesive layer R-4 was laminated with the PET film with adhesive layer S-3. Otherwise, in the same manner as in Example B-1, a wiring forming component was fabricated having a structure in which copper foil, a first adhesive layer (first region) composed of adhesive layer R-4, a second adhesive layer (second region) composed of adhesive layer S-3 and PET film are sequentially laminated.

[0133] (Examples A-1 to Example A-4) Wiring forming components of Examples A-1 to A-4 were manufactured in the same manner as described above.

[0134] <Determination of Connection Resistance> Evaluation samples were prepared in the same manner as described above, and the connection resistance values ​​were measured. Furthermore, for the wiring components of Examples B-1 and B-2, after peeling off the PET film, they were attached to the epoxy board from the side of the second adhesive layer (second region).

[0135] <Embedded Evaluation> (Evaluation sample preparation) A wiring forming component with dimensions of 250mm × 250mm was attached from the second adhesive layer (second region) side (after peeling off the PET film if a PET film is present) to a circuit board (PWB) having copper circuits with a diameter of 1.0mm, a spacing of 1.5mm, and a thickness of 12μm on an epoxy board containing glass cloth. The component was then heated and pressurized at 180°C and 2MPa for 60 minutes using a thermoforming device to create a connector. Furthermore, for the wiring forming components of Examples A-1 to A-4, after peeling off the PET film, they were attached to the epoxy board from the first adhesive layer (first region) side.

[0136] The sample with resist formed on the fabricated connector was immersed in an etching solution and subjected to oscillation. The etching solution was prepared using copper chloride: 100 g / L and hydrochloric acid: 100 ml / L. After the specified copper foil portion disappeared, it was rinsed with pure water. Subsequently, the resist was removed, yielding an evaluation sample with a specified wiring pattern.

[0137] [Embedded] The evaluation samples were visually inspected for the presence of bubbles or peeling, and the embedding performance was evaluated according to the following evaluation criteria. (Evaluation Criteria) A: No bubbles or peeling were observed in more than 90% of the area of ​​the evaluated sample. B: No bubbles or peeling were observed in more than 70% but less than 90% of the area of ​​the evaluated sample. C: Bubbles or peeling are observed in more than 30% of the area or the entire region of the sample being evaluated.

[0138] [Table 2] Adhesive layer Total thickness (μm) First adhesive layer Second adhesive layer Connection resistance value (mΩ) Embedded No. thickness (μm) Average particle size of conductive particles (μm) No. thickness (μm) Example B-1 25 R-1 20 20 S-1 5 2.5 A Example B-2 20 R-4 14 10 S-3 6 1.8 A Example A-1 25 R-1 20 20 S-1 5 2.2 B Example A-2 30 R-1 20 20 S-2 10 3.0 B Example A-3 20 R-4 14 10 S-3 6 1.8 B Example A-4 20 R-5 10 10 S-2 10 2.3 B

[0139] As shown in Table 2, the wiring forming components according to Embodiments B-1 and B-2 can also ensure sufficient conductivity between wirings while suppressing the generation of bubbles and the like.

[0140] 1: Wiring forming components 1a: Wiring layer 1b: Wiring forming components 3: Wiring forming components 10: Adhesive layer 10a: Page 1 10b: Page 2 15: First adhesive layer 16: Second adhesive layer 12, 12a, 12b, 12c: Conductive particles 14: Adhesive layer 17: Adhesive layer 18a, 18b: Adhesive layer 20: Metal layer 20a:Side 1 20b: Page 2 40: Adhesive layer 40a:Side 1 40b: Page 2

Claims

1. A wiring forming component comprising: an adhesive layer containing conductive particles; and a metal layer disposed on the adhesive layer, wherein the adhesive layer includes: The first adhesive layer contains the aforementioned conductive particles and adhesive components; and the second adhesive layer contains adhesive components. The wiring forming component is sequentially laminated with the aforementioned metal layer, the aforementioned second adhesive layer and the aforementioned first adhesive layer. The aforementioned second adhesive layer does not contain conductive particles, and the aforementioned first adhesive layer is the outermost layer of the aforementioned adhesive layers.

2. The wiring forming component as claimed in claim 1, wherein the surface roughness Rz of the adhesive layer side of the aforementioned metal layer is 0.05 to 3 in ratio to the average particle size of the aforementioned conductive particles.

3. The wiring forming component as described in claim 1, wherein the surface roughness Rz of the surface of the aforementioned adhesive layer side of the aforementioned metal layer is less than 20 μm.

4. The wiring forming member as described in claim 1, further comprising a release film.

5. The wiring forming component as claimed in claim 1, wherein the aforementioned second adhesive layer comprises epoxy resin and phenolic resin.

6. A wiring forming member comprising: an adhesive layer containing conductive particles; and a metal layer disposed on the adhesive layer, wherein the adhesive layer includes, in its thickness direction, a first region containing the conductive particles and a first adhesive component and a second region containing a second adhesive component, the wiring forming member having the metal layer, the second region and the first region disposed sequentially adjacent to each other, the second region not containing conductive particles, and the first region located on the outermost side of the adhesive layer.

7. The wiring forming component as claimed in claim 6, wherein the surface roughness Rz of the surface of the aforementioned adhesive layer side of the aforementioned metal layer is in the ratio of the average particle size of the aforementioned conductive particles to 0.05 to 3.

8. The wiring forming component as described in claim 6, wherein the surface roughness Rz of the surface of the aforementioned adhesive layer side of the aforementioned metal layer is less than 20 μm.

9. The wiring forming member as described in claim 6, further comprising a release film.

10. The wiring forming component as claimed in claim 6, wherein the aforementioned second region comprises epoxy resin and phenolic resin.

11. A wiring forming component comprising an adhesive layer containing conductive particles and a metal layer separately disposed thereof, wherein the adhesive layer is capable of bonding with the metal layer during use, wherein the adhesive layer comprises: The first adhesive layer contains the aforementioned conductive particles and adhesive components; and the second adhesive layer contains adhesive components. The second adhesive layer does not contain conductive particles. The first adhesive layer is the outermost layer of the aforementioned adhesive layers. When the wiring forming component is used, the aforementioned metal layer, the aforementioned second adhesive layer and the aforementioned first adhesive layer are sequentially stacked.

12. The wiring forming component as claimed in claim 11, wherein the aforementioned second adhesive layer comprises epoxy resin and phenolic resin.

13. A wiring forming component comprising an adhesive layer containing conductive particles and a metal layer separately disposed thereof, wherein the adhesive layer is capable of bonding with the metal layer during use, wherein the adhesive layer comprises: The first region contains the aforementioned conductive particles and the first adhesive component; and the second region contains the second adhesive component. The second region does not contain conductive particles. The first region is located on the outermost side of the aforementioned adhesive layer. When the wiring forming component is used, the aforementioned metal layer, the aforementioned second region, and the aforementioned first region are sequentially and adjacently disposed.

14. The wiring forming component as described in claim 13, wherein the aforementioned second region comprises epoxy resin and phenolic resin.

15. A method for forming a wiring layer, comprising: The steps for preparing the wiring forming components described in any one of Request 1 to Request 14; The steps to prepare a substrate with wiring; The steps include: disposing the aforementioned wiring forming component on the surface of the aforementioned substrate where the aforementioned wiring is formed, with the aforementioned adhesive layer facing the aforementioned substrate, to cover the aforementioned wiring; heating and pressing the aforementioned wiring forming component onto the aforementioned substrate; and performing a pattern forming process on the aforementioned metal layer.

16. A wiring forming member comprising: a substrate having wiring; and a cured form of the wiring forming member of any one of claims 1 to 14 disposed on the substrate in a manner covering the wiring, wherein the wiring is electrically connected to the aforementioned metal layer of the wiring forming member or another wiring formed from the aforementioned metal layer.

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