First laminate structure, second laminate structure, and method for manufacturing printed wiring board

Abstract

This second laminate structure includes: a support; at least one resin layer disposed on the support; and a metal layer disposed on the resin layer. A peeling force of the metal layer and / or resin layer is reduced by peeling force reduction processing.

Description

First laminated structure, second laminated structure, and method for manufacturing printed wiring board

[0001] The present disclosure relates to a first laminate structure, a second laminate structure, and a method for manufacturing a printed wiring board.

[0002] Printed wiring boards have patterned circuits that contain metal. In recent years, with the demand for smaller and lighter electronic products, there has been a demand for thinner printed wiring boards and finer circuit wiring. Known methods for forming patterned circuits include the subtractive method, in which a metal layer is etched, and the semi-additive method, in which a resist film is formed and then the patterned circuit is formed by plating.

[0003] Japanese Patent No. 7201130 discloses a laminate for semi-additive processes in which a silver particle layer and a peelable cover layer are sequentially laminated on both surfaces of an insulating substrate. The laminate for semi-additive processes disclosed in Japanese Patent No. 7201130 does not require complex surface roughening or surface modification layer formation, and does not require a vacuum device, and can form a rectangular cross-sectional shape that has high adhesion between the substrate and the conductor circuit, has little undercut, and is good in design reproducibility, making it suitable for circuit wiring.

[0004] Furthermore, Japanese Patent No. 6883010 discloses a carrier-attached copper foil in which a carrier layer, a release layer, and an ultrathin copper layer are laminated, and a method of forming a pattern circuit by a semi-additive process using the carrier-attached copper foil. In particular, in Japanese Patent No. 6883010, after a pattern circuit is formed on a carrier-attached copper foil, the carrier layer is peeled off from the portion where the pattern circuit is formed by the release layer.

[0005] Japanese Patent Application Laid-Open Publication No. 2022-25329 discloses a laminate having a carrier substrate, a temporary fixing resin layer, a titanium layer, and a copper layer arranged in this order, and discloses that a rewiring layer is formed on the laminate and a semiconductor chip is mounted on the rewiring layer. In the laminate disclosed in Japanese Patent Application Laid-Open Publication No. 2022-25329, a metal oxide surface is formed at the interface between the titanium layer and the temporary fixing resin layer by heating. When this metal oxide surface is formed, the adhesion between the temporary fixing resin layer and the titanium layer is reduced, making it possible to easily peel off the carrier substrate.

[0006] Japanese Patent No. 7045475 discloses a transfer film having a seed layer made of silver formed on a carrier member, and a method of forming a pattern circuit by forming a photosensitive layer corresponding to the pattern circuit on the seed layer and plating the photosensitive layer. In particular, Japanese Patent No. 7045475 discloses a method of forming a pattern circuit on the seed layer of the transfer film, and then peeling the carrier member from the portion where the pattern circuit is formed and removing the seed layer.

[0007] As described above, in a laminate structure in which a resin layer and a metal layer are formed on a support, there is a problem in the resin layer that the portion including the metal layer and the portion including the support may peel off in an unintended process, or conversely, the portion including the metal layer and the portion including the support cannot be easily peeled off in an intended process. However, a laminate structure in which a resin layer and a metal layer are formed on a support that can solve these problems simultaneously has not been known. Therefore, an object of the present disclosure is to provide a first laminate structure, a second laminate structure, and a method for manufacturing a printed wiring board, each including a resin layer that does not cause the portion including the metal layer and the portion including the support to peel off in an unintended process and that allows the portion including the metal layer to be easily peeled off in an intended process.

[0008] The present disclosure, which has achieved the above-mentioned object, includes the following: <1> A first laminate structure including a temporary substrate, a metal layer disposed on the temporary substrate, and at least one resin layer disposed on the metal layer, wherein at least one of the metal layer and the resin layer is a layer whose release strength is reduced by a release strength reduction treatment. <2> The first laminate structure according to <1>, wherein the layer whose release strength is reduced exhibits a release strength of 0.3 kN / m or less when subjected to a release strength reduction treatment. <3> The first laminate structure according to <1> or <2>, wherein the release strength reduction treatment is at least one treatment selected from the group consisting of heating treatment, cooling treatment, ultraviolet irradiation treatment, laser irradiation treatment, voltage application treatment, electromagnetic field application treatment, and solvent treatment. <4> The first laminate structure according to any one of <1> to <3>, wherein the layer whose release strength is reduced by the release strength reduction treatment is the resin layer. <5> The first laminate structure according to any one of <1> to <4>, wherein the metal layer contains silver nanoparticles and a dispersant. <6> The first laminate structure according to any one of <1> to <5>, wherein the metal layer is a plating seed layer. <7> The first laminate structure according to any one of <1> to <6>, wherein the metal layer contains silver nanoparticles, and the average particle size of the silver nanoparticles is 1 nm to 100 nm.

[0009] <8> A second laminate structure comprising a support, at least one resin layer disposed on the support, and a metal layer disposed on the resin layer, wherein at least one of the metal layer and the resin layer is a layer whose release strength is reduced by a release strength reduction treatment. <9> The second laminate structure according to <8>, wherein the layer whose release strength is reduced exhibits a release strength of 0.3 kN / m or less when subjected to a release strength reduction treatment. <10> The second laminate structure according to <8> or <9>, wherein the release strength reduction treatment is at least one treatment selected from the group consisting of heating treatment, cooling treatment, ultraviolet irradiation treatment, laser irradiation treatment, voltage application treatment, electromagnetic field application treatment, and solvent treatment. <11> The second laminate structure according to any one of <8> to <10>, wherein the layer whose release strength is reduced by the release strength reduction treatment is the resin layer. <12> The second laminate structure according to any one of <8> to <11>, wherein the metal layer contains silver nanoparticles and a dispersant. <13> The second laminate structure according to any one of <8> to <12>, wherein the metal layer is a plating seed layer. <14> The second laminate structure according to any one of <8> to <13>, wherein the metal layer contains silver nanoparticles, and the average particle size of the silver nanoparticles is 1 nm to 100 nm. <15> The second laminate structure according to any one of <8> to <13>, wherein the second laminate structure is for use in a semi-additive process. <16> The second laminate structure according to any one of <8> to <15>, wherein the resin layer in the first laminate structure according to any one of <1> to <7> is bonded to the support, and the temporary substrate in the first laminate structure is peeled off.

[0010] <17> A method for manufacturing a printed wiring board, the method comprising: using a second laminate structure including a support, at least one resin layer disposed on the support, and a metal layer disposed on the resin layer, wherein at least one of the metal layer and the resin layer is a layer whose peel strength is reduced by a peel force reduction treatment, forming a patterned circuit layer on the resin layer by plating using the metal layer as a plating seed layer, and peeling a portion including the support from a portion including the patterned circuit layer in a state in which the peel strength of at least one of the metal layer and the resin layer has been reduced by the peel force reduction treatment. <18> The method for manufacturing a printed wiring board according to <17>, wherein the peel force reduction treatment reduces the peel strength between the portion including the support and the portion including the patterned circuit layer to 0.3 kN / m or less. <19> The method for manufacturing a printed wiring board according to <17> or <18>, wherein the peel force reduction treatment is at least one treatment selected from the group consisting of heating treatment, cooling treatment, ultraviolet light irradiation treatment, laser irradiation treatment, voltage application treatment, electromagnetic field application treatment, and solvent treatment. <20> The method for manufacturing a printed wiring board according to any one of <17> to <19>, wherein the layer whose peel strength is reduced by the peel strength reducing treatment is the resin layer. <21> The method for manufacturing a printed wiring board according to any one of <17> to <20>, wherein the metal layer contains silver nanoparticles and a dispersant. <22> The method for manufacturing a printed wiring board according to any one of <17> to <21>, wherein the metal layer contains silver nanoparticles, the silver nanoparticles having an average particle size of 1 nm to 100 nm. <23> The method for manufacturing a printed wiring board according to any one of <17> to <22>, wherein the pattern circuit layer is formed by a semi-additive process. <24> The method for manufacturing a printed wiring board according to any one of <17> to <23>, comprising the steps of bonding a resin layer in the first laminate structure according to any one of <1> to <7> onto the support and peeling off a temporary base material in the first laminate structure to produce the second laminate structure.

[0011] According to the present disclosure, it is possible to provide a first laminate structure, a second laminate structure, and a method for manufacturing a printed wiring board, which are provided with a resin layer that prevents the portion including the metal layer from peeling off the portion including the support in an unintended process, and allows the portion including the metal layer to be easily peeled off the portion including the support in an intended process.

[0012] FIG. 1A is a schematic cross-sectional view showing an example of the relationship between a first laminate structure and a second laminate structure according to the present disclosure. FIG. 1B is a schematic cross-sectional view showing an example of the relationship between a first laminate structure and a second laminate structure according to the present disclosure. FIG. 1C is a schematic cross-sectional view showing an example of the relationship between a first laminate structure and a second laminate structure according to the present disclosure. FIG. 2A is a schematic cross-sectional view showing another example of the relationship between a first laminate structure and a second laminate structure according to the present disclosure. FIG. 2B is a schematic cross-sectional view showing another example of the relationship between a first laminate structure and a second laminate structure according to the present disclosure. FIG. 2C is a schematic cross-sectional view showing another example of the relationship between a first laminate structure and a second laminate structure according to the present disclosure. FIG. 3A is a schematic cross-sectional view showing another example of the relationship between a first laminate structure and a second laminate structure according to the present disclosure. FIG. 3B is a schematic cross-sectional view showing another example of the relationship between a first laminate structure and a second laminate structure according to the present disclosure. FIG. 3C is a schematic cross-sectional view showing another example of the relationship between a first laminate structure and a second laminate structure according to the present disclosure. FIG. 4A is a schematic cross-sectional view schematically showing another embodiment of the second laminate structure of the present disclosure. FIG. 4B is a schematic cross-sectional view schematically showing another embodiment of the second laminate structure of the present disclosure. FIG. 4C is a schematic cross-sectional view schematically showing another embodiment of the second laminate structure of the present disclosure. FIG. 4D is a schematic cross-sectional view schematically showing another embodiment of the second laminate structure of the present disclosure. FIG. 4E is a schematic cross-sectional view schematically showing another embodiment of the second laminate structure of the present disclosure. FIG. 4F is a schematic cross-sectional view schematically showing another embodiment of the second laminate structure of the present disclosure. FIG. 4G is a schematic cross-sectional view schematically showing another embodiment of the second laminate structure of the present disclosure. FIG. 5 is a schematic cross-sectional view showing a step in one embodiment of a method for producing a printed wiring board of the present disclosure. FIG. 6 is a schematic cross-sectional view showing a step in the method for producing a printed wiring board of the present disclosure subsequent to the step shown in FIG. 5. FIG. 7 is a schematic cross-sectional view showing a step in the method for producing a printed wiring board of the present disclosure subsequent to the step shown in FIG. 6. FIG. 8 is a schematic cross-sectional view showing a step in the method for producing a printed wiring board of the present disclosure subsequent to the step shown in FIG. 7. Fig. 9 is a schematic cross-sectional view showing a step in the method for manufacturing a printed wiring board according to the present disclosure, subsequent to the step shown in Fig. 8. Fig. 10 is a schematic cross-sectional view showing a step in the method for manufacturing a printed wiring board according to the present disclosure, subsequent to the step shown in Fig. 9.

[0033] Fig. 11 is a schematic cross-sectional view showing a step in the method for producing a printed wiring board according to the present disclosure subsequent to the step shown in Fig. 10. Fig. 12A is a schematic cross-sectional view showing a step in the method for producing a printed wiring board according to the present disclosure subsequent to the step shown in Fig. 11. Fig. 12B is a schematic cross-sectional view showing a step in the method for producing a printed wiring board according to the present disclosure subsequent to the step shown in Fig. 11. Fig. 13 is a schematic cross-sectional view showing an example of a peeling step in the method for producing a printed wiring board according to the present disclosure. Fig. 14 is a schematic cross-sectional view showing a step subsequent to the step shown in Fig. 9 in another embodiment of the method for producing a printed wiring board according to the present disclosure. Fig. 15A is a schematic cross-sectional view showing a step in another embodiment of the method for producing a printed wiring board according to the present disclosure subsequent to the step shown in Fig. 14. Fig. 15B is a schematic cross-sectional view showing a step in another embodiment of the method for producing a printed wiring board according to the present disclosure subsequent to the step shown in Fig. 14. Fig. 16 is a schematic cross-sectional view showing a step in another embodiment of the method for producing a printed wiring board according to the present disclosure subsequent to the step shown in Fig. 15A or 15B.

[0013] Below, an embodiment that is an example of the present disclosure will be described. These descriptions and examples are intended to illustrate the embodiment and do not limit the scope of the invention. In the following embodiments, the components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present disclosure. For example, the present disclosure allows addition, omission, substitution, modification, etc. of the number, amount, position, ratio, material, configuration, type, order, etc., within the scope that does not deviate from the spirit of the present disclosure.

[0014] In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. Furthermore, in numerical ranges described in the present disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in a composition, etc., the content or amount of each component means the total content or amount of the multiple substances present in the composition, etc., unless otherwise specified. In the present disclosure, the term "layer" includes cases where, when the region in which the layer exists is observed, the layer is formed over the entire region, as well as cases where the layer is formed only in a portion of the region.

[0015] In this disclosure, "(meth)acrylic acid" refers to one or both of methacrylic acid and acrylic acid. "(meth)acrylamide" refers to one or both of methacrylamide and acrylamide. "(meth)acrylonitrile" refers to one or both of methacrylonitrile and acrylonitrile. "(meth)acryloyloxy group" refers to one or both of methacryloyloxy group and acryloyloxy group.

[0016] In the present disclosure, the "weight average molecular weight" is a pullulan-equivalent value calculated using gel permeation chromatography (GPC).

[0017] [First Laminated Structure and Second Laminated Structure] The first laminated structure of the present disclosure includes a temporary substrate, a metal layer disposed on the temporary substrate, and at least one resin layer disposed on the metal layer, wherein at least one of the metal layer and the resin layer is a layer whose release force is reduced by a peel strength reduction treatment. The second laminated structure of the present disclosure includes a support, at least one resin layer disposed on the support, and a metal layer disposed on the resin layer, wherein at least one of the metal layer and the resin layer is a layer whose release force is reduced by a peel strength reduction treatment. Figures 1A to 1C are schematic diagrams for understanding the relationship between the first laminated structure 10 and the second laminated structure 20. In Figure 1A, the first laminated structure 10 is configured by stacking a temporary substrate 11, a metal layer 12, and a resin layer 13 in this order. The resin layer 13 in the first laminated structure 10 is adhered to the surface of a separately prepared support 14 (Figure 1B), and the temporary substrate 11 is peeled off (Figure 1C). This results in a second laminate structure 20 in which the resin layer 13 and the metal layer 12 are laminated in this order on the support 14 ( FIG. 1C ). In the first laminate structure 10 and the second laminate structure 20, at least one of the metal layer 12 and the resin layer 13 is a layer whose release force is reduced by the release force reduction treatment. That is, either one of the metal layer 12 and the resin layer 13 is a layer whose release force is reduced by the release force reduction treatment, or both the metal layer 12 and the resin layer 13 are layers whose release force is reduced by the release force reduction treatment. Here, an example of a layer whose release force is reduced by the release force reduction treatment is a layer containing a resin whose release force is reduced by the release force reduction treatment.

[0018] The first laminate structure 10 and the second laminate structure 20 of the present disclosure are not limited to the layer configurations shown in FIGS. 1A to 1C. For example, the first laminate structure 10 may include a resin layer 13 and a resin layer 15 containing another resin, as shown in FIGS. 2A to 2C. In this case, the second laminate structure 20 is configured such that the resin layer 15, the resin layer 13, and the metal layer 12 are stacked in this order on the support 14. Alternatively, as shown in FIGS. 3A to 3C, the first laminate structure 10, in which the temporary substrate 11, the metal layer 12, and the resin layer 13 are stacked in this order, is adhered to the support 14 having the resin layer 15. Then, the temporary substrate 11 is peeled off to produce the second laminate structure 20, in which the resin layer 15, the resin layer 13, and the metal layer 12 are stacked in this order on the support 14.

[0019] In the first laminate structure of the present disclosure, the temporary substrate may include a single or multiple resin layers, may be a single layer of metal foil, or may include a resin layer and a metal foil. The first laminate structure of the present disclosure may have a layer configuration other than a temporary substrate, a metal layer, and a resin layer. The first laminate structure may also have a metal layer and a resin layer on both main surfaces of the temporary substrate. In the first laminate structure, at least one of the resin layer and the metal layer may be disposed on the entire surface of the temporary substrate, may be disposed so as to protrude from the temporary substrate, or may be disposed in a partial region on the main surface of the temporary substrate. For example, in the first laminate structure, the metal layer and the resin layer can be disposed in a region excluding the end portion on the main surface of the temporary substrate. If the main surface of the temporary substrate is rectangular, the metal layer and the resin layer can be disposed in a region other than the four sides or four corners of the main surface. In the first laminate structure, as described above, by configuring the resin layer and the metal layer not to be disposed on the entire surface of the temporary substrate, the temporary substrate can be more easily peeled off.

[0020] Furthermore, in the second laminate structure of the present disclosure, the support may include one or more resin layers, may be a single layer of metal foil, or may include a resin layer and a metal foil. The second laminate structure of the present disclosure may have a layer configuration other than a support, a resin layer, and a metal layer. The second laminate structure may also have a resin layer and a metal layer on both main surfaces of the support. In the second laminate structure, at least one of the resin layer 13 and the metal layer 12 may be disposed over the entire surface of the support 14, may be disposed protruding from the support 14 (FIG. 4G), or may be disposed in a partial region of the main surface of the support 14 (FIG. 4A). Furthermore, in the second laminate structure, the metal layer 12 may be disposed in a partial region of the resin layer 13 (FIG. 4B). Furthermore, in the second laminate structure, the resin layer 13 may be disposed in a partial region on the support 14, and the metal layer 12 may be disposed in another region (FIG. 4C). In this case, an embodiment in which at least one of the resin layer 13 and the metal layer 12 is disposed on the support 14 so as to surround the peripheral portion of the other can be mentioned. For example, if the surface of the metal layer 12 that contacts the support 14 is rectangular, the resin layer 13 can be disposed on the four sides or four corners of that surface. Furthermore, in the second laminate structure, another resin layer 13A can be disposed in a partial region of the resin layer 13 ( FIG. 4D ). In this case, an embodiment in which the other resin layer 13A is disposed on the peripheral portion of the surface of the resin layer 13 that contacts the support 14 can be mentioned. For example, if the surface of the resin layer 13 that contacts the support 14 is rectangular, the other resin layer 13A can be disposed on the four sides or four corners of that surface. The other resin layer 13A may be peeled off from the support 14 in a peeling process described in detail below, or may remain on the support 14. A silicone resin or a fluororesin can be used as the other resin layer 13A. Furthermore, in the second laminated structure, the resin layer 13 can be arranged so as to cover the metal layer 12 arranged in a partial region on the support 14 (FIG. 4E). Furthermore, in the second laminated structure, the metal layer 12 can be arranged so as to cover the resin layer 13 arranged in a partial region on the support 14 (FIG. 4F). In the second laminated structure, as described above, by configuring the resin layer or metal layer so as not to cover the entire surface of the support, the portion including the support can be more easily peeled off.

[0021] 1A to 3C, the second laminate structure is not limited to being produced using the first laminate structure, and can also be produced by laminating a resin layer and a metal layer on a support. For example, a film-like resin layer, a film-like metal layer, etc. may be sequentially or simultaneously laminated on the support using a laminator or the like, or a liquid resin layer, a film-like metal layer, etc. may be coated on the support.

[0022] In the second laminate structure of the present disclosure, the layer whose release force is reduced by the release force reduction treatment (i.e., the resin layer and / or the metal layer) relatively firmly bonds the portion including the support to the remainder other than the portion including the support before the release force reduction treatment is performed, but after the release force reduction treatment is performed, the adhesive force between the portion including the support and the remainder other than the portion including the support can be reduced. That is, in the second laminate structure of the present disclosure, the adhesive force of the resin layer and / or the metal layer is reduced by the release force reduction treatment, and the portion including the support can be easily peeled from the remainder other than the portion including the support. As described above, the second laminate structure of the present disclosure prevents the remainder other than the portion including the support from peeling from the portion including the support in an unintended process, and allows the remainder other than the portion including the support to be easily peeled from the portion including the support in an intended process.

[0023] When the remaining portion other than the portion containing the support is peeled from the portion containing the support after the release force reduction treatment, the layer whose release force is reduced by the release force reduction treatment (i.e., the resin layer and / or the metal layer) remains adhered to either one or both of the remaining portion other than the portion containing the support and the portion containing the support. When the layer whose release force is reduced by the release force reduction treatment is a resin layer, the portion containing the support and the portion containing the metal layer are peeled off by the release force reduction treatment. At this time, there is no particular limitation as to whether peeling occurs at the interface between the resin layer and the support, at the interface between the resin layer and the metal layer, or due to material failure within the resin layer. Furthermore, when the layer whose release force is reduced by the release force reduction treatment is a metal layer, the portion containing the support and the portion containing the structure formed on the metal layer are peeled off by the release force reduction treatment. At this time, there is no particular limitation as to whether peeling occurs at the interface between the metal layer and the resin layer, at the interface between the metal layer and the structure on the metal layer, or due to material failure within the metal layer.

[0024] In the first laminate structure and the second laminate structure of the present disclosure, the layer whose release force is reduced by the above-mentioned release force reduction treatment (i.e., the resin layer and / or the metal layer) is preferably a layer whose release force is 0.3 kN / m or less, more preferably a layer whose release force is 0.1 kN / m or less, and even more preferably a layer whose release force is less than 0.05 kN / m, after the release force reduction treatment described in detail below. When the release force after the release force reduction treatment is in this range, the portion including the support can be easily peeled from the remaining portion other than the portion including the support, as described above. Note that the layer whose release force is reduced by the above-mentioned release force reduction treatment (i.e., the resin layer and / or the metal layer) is preferably a layer whose release force is greater than 0.3 kN / m, more preferably a layer whose release force is greater than 0.5 kN / m, before the release force reduction treatment. When the release force before the release force reduction treatment is in this range, unintentional peeling of the portion including the support from the remaining portion other than the portion including the support before the release force reduction treatment can be prevented.

[0025] <Support> In the second laminate structure of the present disclosure, the material of the support is not particularly limited, and examples thereof include polyimide resin, polyamideimide resin, polyamide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, polyarylate resin, polyacetal resin, acrylic resins such as poly(methyl meth)acrylate, polyvinylidene fluoride resin, polytetrafluoroethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, vinyl chloride resin graft copolymerized with acrylic resin, polyvinyl alcohol resin, polyethylene resin, polypropylene resin, urethane resin, cycloolefin resin, polystyrene, liquid crystal polymer (LCP), polyether ether ketone (PEEK) resin, polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), cellulose nanofiber, silicon, silicon carbide, gallium nitride, sapphire, ceramics, glass, metal, diamond-like carbon (DLC), alumina, and the like. Among these, polyimide resin, glass, silicon, metal, and ceramic are preferred as the support material, with glass and silicon being particularly preferred due to their smooth surface. In the case of metal, stainless steel or galvanized steel sheet can be used as the support material. Furthermore, it is preferred that the surface of the support be smoothed by known polishing such as electrolytic polishing, chemical polishing, or buffing, or by known surface modification such as plating, or by a combination of polishing and surface modification. In particular, when a metal such as stainless steel is used as the support, it is more preferred to smooth the surface by these methods.

[0026] The surface of the support on which the resin layer or metal layer is laminated is usually flat, but may have protrusions or an uneven structure as long as it does not affect the method for manufacturing a printed wiring board described below. The support may be made of a single material, or two or more materials may be mixed or laminated. For example, when multiple flat plate materials are laminated, they can be bonded together using an adhesive or the like. By combining two or more materials, the thickness, rigidity, elastic modulus, thermal expansion coefficient, and other physical properties of the support can be appropriately adjusted.

[0027] In addition, a resin substrate containing a thermosetting resin and an inorganic filler can also be used as the support. Examples of thermosetting resins include epoxy resins, phenolic resins, unsaturated imide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, and melamine resins. Examples of inorganic fillers include silica, alumina, talc, mica, aluminum hydroxide, magnesium hydroxide, calcium carbonate, aluminum borate, and borosilicate glass. These thermosetting resins and inorganic fillers can be used alone or in combination of two or more. In addition, a resin substrate containing a thermoplastic resin and an inorganic filler can also be suitably used as the support, and the thermoplastic resin and the inorganic filler can be used alone or in combination of two or more.

[0028] The support may be in the form of a planar flexible material, a rigid material, or a rigid-flexible material. More specifically, the support may be a commercially available material formed into a film, sheet, or plate shape. Alternatively, the support may be a material formed by applying a solution, melt, or dispersion of the above-mentioned resin to a planar shape and drying it. The support may also be a substrate formed from a solution, melt, or dispersion of the above-mentioned resin on a conductive material such as metal, or a substrate formed by laminating the above-mentioned resin material on a printed wiring board on which a pattern circuit is formed.

[0029] The thickness of the support is not particularly limited as long as it is within a range in which warping or cracking does not occur in the method for producing a printed wiring board described below, but is preferably 0.05 μm to 5000 μm. More preferably, the thickness is 0.1 to 10 times the thickness of the pattern circuit layer produced in the method for producing a printed wiring board described below, and from the viewpoint of preventing warping even after the pattern circuit layer is formed, the thickness is even more preferably 0.5 to 2 times the thickness of the pattern circuit layer.

[0030] From the viewpoint of forming the resin layer and metal layer smoothly and without defects, the support preferably has a surface Sz (maximum height at the surface) of 3 μm or less, more preferably 1 μm or less, and even more preferably 0.5 μm or less. Furthermore, it is preferable that the support has a flat surface with an Sdr (developed area ratio at the surface) of less than 5.0%. This Sdr is preferably 0.01% or more and 4.0% or less, more preferably 0.01% or more and 3.0% or less, even more preferably 0.01% or more and 1.0% or less, particularly preferably 0.01% or more and 0.50% or less, and most preferably 0.01% or more and 0.50% or less. The Sz and Sdr can be determined as optically obtained three-dimensional surface roughness using a white light interferometer, a laser microscope (e.g., Keyence Corporation VK-X3000 laser microscope), or the like (ISO25178-2; 2012).

[0031] Generally, SiO ２ Substrates made of SiN, Si single crystal, Si polycrystal, plate-shaped glass products, etc., have excellent flatness. Therefore, as the support, commercially available SiO ２ It is preferable to use a substrate, a SiN substrate, a Si single crystal substrate, a Si polycrystalline substrate, a glass sheet, a glass film, a glass plate, or the like. Alternatively, a commercially available SiO substrate having a flat surface that does not satisfy the above-mentioned ranges of Sz or Sdr may be used. ２ The substrate, SiN substrate, Si single crystal substrate, Si polycrystalline substrate, glass sheet, glass film, glass plate, etc. may be polished by a known method to impart Sz or Sdr within the above range.

[0032] The support may be surface-treated to improve adhesion to the resin layer. The surface treatment method for the support is not particularly limited, but it is preferable to appropriately select various methods that do not increase the surface roughness and cause problems in the formability of a fine circuit pattern (fine pitch pattern) in the manufacturing method of a printed wiring board described later, or the peelability of the support. Examples of such surface treatment methods include UV treatment, gas-phase ozone treatment, liquid-phase ozone treatment, corona treatment, plasma treatment, etc. These surface treatment methods can be performed by one method or by using two or more methods in combination.

[0033] <Resin Layer> In the first laminate structure and the second laminate structure of the present disclosure, it is preferable that at least one resin layer has a reduced adhesive strength due to the peel strength reduction treatment as described above. In this case, it is preferable that the resin layer is made of a material that does not peel off the support until the step of peeling off the portion including the support in the method for manufacturing a printed wiring board described below, and that can be easily peeled off in the step of peeling off the portion including the support. The resin layer may be appropriately selected from commercially available products suitable for the peel strength reduction treatment, or may be appropriately prepared. The resin layer may be made of one type of material, or two or more types may be combined.

[0034] The first laminate structure and the second laminate structure of the present disclosure may further include a resin layer whose adhesive strength is weakened by the peel strength reducing treatment and another resin layer different from the resin layer. Examples of the other resin layer include an adhesion layer for improving adhesion between the support or metal layer and the resin layer whose adhesive strength is weakened by the peel strength reducing treatment, a protective layer for protecting the support or metal layer, and a release layer for facilitating peeling of the metal layer or resin layer from the temporary substrate.

[0035] The thickness of the resin layer is not particularly limited, but is preferably 0.1 μm to 500 μm, more preferably 0.2 μm to 200 μm, from the viewpoint of being able to fill the surface irregularities of the support and facilitating removal in the cleaning step in the method for producing a printed wiring board described later. In order to fill the surface irregularities of the support, the thickness of the resin layer is preferably 0.5 times or more, more preferably 1 time or more, the Sz of the support. By reliably filling the surface irregularities of the support, the occurrence of unintended peeling and blistering can be suppressed in the method for producing a printed wiring board described later.

[0036] <Release Force Reduction Treatment> The release force reduction treatment described above can include at least one treatment selected from the group consisting of heating treatment, cooling treatment, ultraviolet irradiation treatment, laser irradiation treatment, voltage application treatment, electromagnetic field application treatment, and solvent treatment. Among these release force reduction treatments, heating treatment or cooling treatment is particularly preferred. This is because heating treatment or cooling treatment is less affected by the temporary substrate and support and has superior workability compared to other treatments. Below, these release force reduction treatments are explained, and materials corresponding to the release force reduction treatment are explained. Note that when a resin layer contains a material corresponding to the release force reduction treatment described herein, the resin layer becomes a layer whose release force is reduced by the release force reduction treatment. Furthermore, when a metal layer contains a material corresponding to the release force reduction treatment described herein, the metal layer becomes a layer whose release force is reduced by the release force reduction treatment. In the following explanation, the case where the layer whose release force is reduced by the release force reduction treatment is a resin layer is explained.

[0037] Heat treatment is, for example, a process for heating the resin layer of the second laminate structure to facilitate peeling of the portion including the support from the second laminate structure. The conditions for the heat treatment can be appropriately set depending on the material used for the resin layer. The heating temperature can be, for example, 100°C or higher, 120°C or higher, 140°C or higher, 160°C or higher, 180°C or higher, or 200°C or higher. From the viewpoint of reducing thermal damage to portions other than the resin layer, it is preferably 350°C or lower, and more preferably 300°C or lower.

[0038] Examples of resin layers suitable for heat treatment include resins that undergo weight loss at high temperatures, side-chain crystalline polymers with melting points above room temperature, resins containing sublimable compounds, resins that undergo a Diels-Alder reaction, and resins containing foaming agents that foam or expand upon heating. Resins that undergo weight loss at high temperatures include, but are not limited to, urethane resins, acrylic resins, urethane-acrylic composite resins, polyvinyl alcohol, polyvinyl acetal, polyvinyl pyrrolidone, epoxy resins, phenoxy resins, imide resins, amide resins, melamine resins, phenolic resins, urea-formaldehyde resins, and polyblock isocyanates obtained by reacting polyisocyanates with blocking agents such as phenols. Among resins that undergo weight loss at high temperatures, thermoplastic resins are preferred because of their rapid rate of weight loss and rapid peelability. Urethane resins, acrylic resins, and urethane-acrylic composite resins are particularly preferred. Furthermore, these resins can be used alone or in combination as resin layers suitable for heat treatment.

[0039] As a resin that undergoes weight loss at high temperatures, it is preferable to use one that exhibits a thermal weight loss of 20% to 50% in a nitrogen atmosphere at 300°C for 60 minutes, with a range of 30% to 45% being particularly preferable. Having a thermal weight loss within this range prevents the support from peeling off due to the heat applied during the reflow process in the printed wiring board manufacturing method described below, and allows the support to be peeled off without excessive thermal damage during heat treatment. The thermal weight loss value may be a value measured for a single resin or a value measured for a mixture of multiple resins. Commercially available resins that can be used include UN-0102 and SN-172 manufactured by Negami Chemical Industry Co., Ltd. and P7-532 manufactured by Kyoeisha Chemical Co., Ltd.

[0040] Furthermore, a thermosensitive adhesive can be used as a side-chain crystalline polymer having a melting point above room temperature. Specific examples of side-chain crystalline polymers include polymers obtained by polymerizing a (meth)acrylic acid ester having a linear alkyl group having 18 or more carbon atoms, preferably 18 to 22 carbon atoms, a (meth)acrylic acid ester having an alkyl group having 2 to 8 carbon atoms, and a polar monomer. Note that (meth)acrylic acid ester refers to an acrylic acid ester or a methacrylic acid ester. Preferred (meth)acrylic acid esters having a linear alkyl group having 18 or more carbon atoms in the side chain include (meth)acrylic acid esters having a linear alkyl group having 18 to 22 carbon atoms, such as stearyl (meth)acrylate, eicosyl (meth)acrylate, and behenyl (meth)acrylate. Examples of (meth)acrylic acid esters having an alkyl group having 2 to 8 carbon atoms include ethyl (meth)acrylate, butyl (meth)acrylate, and hexyl (meth)acrylate. Examples of polar monomers that can be used include carboxyl group-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid; and hydroxyl group-containing ethylenically unsaturated monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxyhexyl (meth)acrylate. The weight average molecular weight of the side chain crystalline polymer is preferably 400,000 to 800,000.

[0041] The resin containing a sublimable compound is one that peels the resin layer from the support or metal layer by sublimation of the sublimable compound. Examples of the sublimable compound include naphthalene, anthracene, hexachlorobenzene, iodine, naphthalenediol, and hexathiane.

[0042] A resin that undergoes a Diels-Alder reaction refers to a resin containing a thermally dissociable compound that undergoes both a Diels-Alder reaction and a retro-Diels-Alder reaction. This thermally dissociable compound has a thermally dissociable structure, and the Diels-Alder reaction proceeds upon first heating, and the retro-Diels-Alder reaction (i.e., a thermal dissociation reaction via a reverse reaction) proceeds upon second heating (at a higher temperature than the first heating). For example, when a resin containing an epoxy resin and a curing agent is used, it is sufficient that either or both of the epoxy resin and the curing agent have a thermally dissociable structure. Examples of epoxy resins containing a thermally dissociable structure include CAS registration numbers 1642327-20-5, 630109-37-4, 451456-99-8, 1354635-72-5, and 1142408-09-0. Furthermore, epoxy resins that do not contain a thermally dissociable structure can be any known epoxy resin without particular limitation. Examples of such glycidyl ethers include bisphenol A-type, F-type, S-type, and AD-type glycidyl ethers, phenol novolac-type glycidyl ethers, cresol novolac-type glycidyl ethers, bisphenol A-type novolac-type glycidyl ethers, naphthalene-type glycidyl ethers, biphenol-type glycidyl ethers, dihydroxypentadiene-type glycidyl ethers, triphenylmethane-type epoxy resins, phenol novolac-type epoxy resins, and cresol novolac-type epoxy resins.

[0043] Furthermore, examples of curing agents containing a thermally dissociable structure include CAS registration numbers 1629090-33-0, 1629090-36-3, 2170611-60-4, 1449422-51-8, 1438275-50-3, 2131218-36-3, 2270969-71-4, 2303046-97-1, and 1788898-24-7. Examples of curing agents that do not contain a thermally dissociable structure include ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,3-diaminobutane, 1,4-diaminobutane, diethylenetriamine, triethylenetriamine, tetraethylenepentamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, m-xylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, 1,2-diaminocyclohexane, 1,4-diamino-3,6-diethylcyclohexane, isophoronediamine, menthanediamine, 1,3-bisaminocyclohexane, dicyandiamide, acid anhydrides, dibasic acid dihydrazides, and melamine.

[0044] When a curing agent is used in a resin that undergoes a Diels-Alder reaction, the mixing ratio of the epoxy resin to the curing agent (molar ratio of epoxy resin to curing agent) is 1 / 0.01 to 1 / 10, more preferably 1 / 0.03 to 1 / 10, and even more preferably 1 / 0.05 to 1 / 10. In particular, when the curing agent is a compound having active hydrogen, such as a primary amine or secondary amine, a phenolic compound, a compound having a carboxylic acid group, or a thiol compound, it is preferable to mix them so that the number of moles of epoxy groups in the epoxy resin and the number of moles of active hydrogen in the curing agent are close to an equivalent ratio. For example, the ratio of epoxy groups to active hydrogen (molar number of epoxy groups / molar number of active hydrogen) is preferably 1 / 0.4 to 1 / 3, more preferably 1 / 0.7 to 1 / 2, and even more preferably 1 / 0.8 to 1 / 1.5.

[0045] Furthermore, in resins containing a foaming agent or the like that foams or expands upon heating, the foaming agent is an additive that can foam upon heating. The foaming agent is not particularly limited, but one containing a gas-generating component can be used, for example, an azo compound, an azide compound, a Meldrum's acid derivative, or the like. Other examples of foaming agents that can be used include inorganic foaming agents such as ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium boron hydroxide, and various azides; water; fluorinated alkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate; paratoluenesulfonylhydrazide, diphenylsulfone-3,3'-disulfonylhydrazide, 4,4'-oxybis(benzenesulfonyl)hydrazide, and the like. Other examples of organic blowing agents that can be used include hydrazine compounds such as p-toluenesulfonylsemicarbazide and 4,4'-oxybis(benzenesulfonylsemicarbazide); semicarbazide compounds such as p-toluenesulfonylsemicarbazide and 4,4'-oxybis(benzenesulfonylsemicarbazide); triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole; and N-nitroso compounds such as N,N'-dinitrosopentamethylenetetramine and N,N'-dimethyl-N,N'-dinitrosoterephthalamide. The blowing agent may be added to the resin layer or may be directly bonded to the resin.

[0046] Heat-expandable microspheres can be used as the foaming agent. When the resin layer containing the heat-expandable microspheres is heated, the heat-expandable microspheres expand or foam, causing unevenness at the interface, resulting in a decrease or loss of adhesive strength. When such a resin layer is present, the portion containing the support can be easily separated from the remaining portion other than the portion containing the support by heating.

[0047] The foaming agent has a foaming initiation temperature of 90°C or higher, preferably 90°C to 260°C, and more preferably 100°C to 220°C. The foaming initiation temperature corresponds to the temperature at which the adhesive strength of the resin layer becomes 10% or less of its normal adhesive strength (adhesion strength to a PET film at 23°C). The adhesive strength here refers to the adhesive strength measured according to JIS Z 0237:2000 (lamination conditions: one reciprocal motion with a 2 kg roller, peeling speed: 300 mm / min, peeling angle: 180°). The adhesive strength at the foaming initiation temperature (and the adhesive strength of the measurement sample after heating) is measured after the measurement sample is returned to room temperature (23°C). When the foaming agent is heat-expandable microspheres, the temperature at which the heat-expandable microspheres begin to expand corresponds to the foaming initiation temperature. Any suitable heat-expandable microspheres can be used as long as they can foam at the foaming initiation temperature. The heat-expandable microspheres may be, for example, microspheres having an elastic shell encapsulating a substance that expands easily upon heating. Such heat-expandable microspheres can be produced by any suitable method, such as coacervation or interfacial polymerization.

[0048] Examples of substances that expand easily when heated include low-boiling liquids such as propane, propylene, butene, normal butane, isobutane, isopentane, neopentane, normal pentane, normal hexane, isohexane, heptane, octane, petroleum ether, methane halides, and tetraalkylsilanes; and azodicarbonamide, which gasifies by thermal decomposition.

[0049] Examples of materials constituting the shell include polymers composed of nitrile monomers such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxyacrylonitrile, and fumaronitrile; carboxylic acid monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and citraconic acid; vinylidene chloride; vinyl acetate; (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, and β-carboxyethyl acrylate; styrene monomers such as styrene, α-methylstyrene, and chlorostyrene; and amide monomers such as acrylamide, substituted acrylamide, methacrylamide, and substituted methacrylamide. Polymers composed of these monomers may be homopolymers or copolymers. Examples of such copolymers include vinylidene chloride-methyl methacrylate-acrylonitrile copolymer, methyl methacrylate-acrylonitrile-methacrylonitrile copolymer, methyl methacrylate-acrylonitrile copolymer, and acrylonitrile-methacrylonitrile-itaconic acid copolymer.

[0050] Commercially available heat-expandable microspheres may be used. Specific examples of commercially available heat-expandable microspheres include "Matsumoto Microspheres" (product name, grades: F-30, F-30D, F-36D, F-36LV, F-50, F-50D, F-65, F-65D, FN-100SS, FN-100SSD, FN-180SS, FN-180SSD, F-190D, F-260D, F-2800D) manufactured by Matsumoto Yushi Seiyaku Co., Ltd., and "Expancel" (product name, grades: 053- 40, 031-40, 920-40, 909-80, 930-120), "Daiform" manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd. (grades: H750, H850, H1100, S2320D, S2640D, M330, M430, M520), and "Advancell" manufactured by Sekisui Chemical Co., Ltd. (grades: EML101, EMH204, EHM301, EHM302, EHM303, EM304, EHM401, EM403, EM501).

[0051] The average particle size of the heat-expandable microspheres before expansion at an ambient temperature of 25°C is preferably 50 μm or less, more preferably 1 μm to 50 μm, even more preferably 3 μm to 35 μm, and particularly preferably 5 μm to 35 μm. By using heat-expandable microspheres with an average particle size within this range, the influence of the heat-expandable microspheres on the surface of the resin layer before expansion (i.e., when the resin layer requires adhesiveness) is minimized, resulting in a resin layer with high adhesion to the support and excellent adhesiveness. Within this range, a larger average particle size of the heat-expandable microspheres is preferred because they expand more when heated. Heat-expandable microspheres with an average particle size within this range can provide a resin layer with excellent releasability after expansion. The average particle size of the heat-expandable microspheres can be controlled, for example, by the conditions for polymerizing the heat-expandable microspheres (e.g., the rotation speed of the stirring blade during polymerization and the polymerization temperature). When commercially available heat-expandable microspheres are used, heat-expandable microspheres having a desired average particle size can be obtained by classification using a mesh, filter, centrifugation, or other methods. The average particle size can also be measured by observing the heat-expandable microspheres used or the heat-expandable microspheres removed from the resin layer before heating using an optical microscope or an electron microscope. The average particle size can also be measured by a particle size distribution measurement method using a laser scattering method. More specifically, the average particle size can be measured by dispersing the heat-expandable microspheres used in a predetermined solvent (e.g., water) and then using a particle size distribution measurement device (e.g., "SALD-2000J" manufactured by Shimadzu Corporation).

[0052] The heat-expandable microspheres preferably have an appropriate strength so that they do not burst until their volumetric expansion coefficient reaches 5 times or more, more preferably 7 times or more, and even more preferably 10 times or more. When such heat-expandable microspheres are used, their adhesive strength can be efficiently reduced by heat treatment. The content of the heat-expandable microspheres in the resin layer can be appropriately set depending on the desired adhesive strength reduction, etc. The content of the heat-expandable microspheres is preferably 20 to 210 parts by mass, more preferably 30 to 200 parts by mass, and even more preferably 50 to 150 parts by mass, per 100 parts by mass of the resin components constituting the resin layer. Within this range, a resin layer can be produced that exhibits good adhesiveness when not heated and allows easy peeling of the support-containing portion when heated.

[0053] The content of heat-expandable microspheres in the resin layer is preferably 5 to 80% by mass, more preferably 10 to 70% by mass, and even more preferably 15 to 65% by mass, based on the mass of the resin layer. The content of heat-expandable microspheres can be calculated from the volume filling factor of heat-expandable microspheres (volume filling factor at a temperature below the expansion initiation temperature (e.g., 23°C)) obtained by X-ray CT analysis or SEM analysis, the specific gravity of the heat-expandable microspheres, and the specific gravity of the region other than the heat-expandable microspheres. For example, the content can be calculated by roughly assuming that the specific gravity of the heat-expandable microspheres is 1 and the specific gravity of the region other than the heat-expandable microspheres is 1, and in this case the content of heat-expandable microspheres falls within the above-mentioned range.

[0054] The content of the heat-expandable microspheres in the resin layer is preferably 5 to 80% by volume, more preferably 10 to 70% by volume, and even more preferably 15 to 65% by volume, based on the volume of the resin layer. The volumetric content corresponds to the volume filling factor, which can be measured by X-ray CT analysis, SEM analysis, or the like, as described above. More specifically, the volume filling factor can be measured by the method described above. Examples of resin layers containing such a foaming agent include "REVALPHA" manufactured by Nitto Denko Corporation and "ICROSTAPE" manufactured by Mitsui Chemicals Tocello, Inc.

[0055] <<Cooling Treatment>> The cooling treatment is, for example, a treatment for cooling the resin layer of the second laminate structure to facilitate peeling of the portion including the support from the second laminate structure. The conditions for the cooling treatment can be appropriately set depending on the material used for the resin layer. The cooling temperature can be, for example, room temperature or lower, 20°C or lower, 15°C or lower, 10°C or lower, 5°C or lower, 0°C or lower, -5°C or lower, or -10°C or lower.

[0056] A resin layer suitable for cooling treatment preferably uses a thermosensitive adhesive whose adhesion strength decreases upon cooling. For example, a resin that crystallizes below its melting point and undergoes a phase transition to exhibit fluidity at temperatures above its melting point can be used for the resin layer suitable for cooling treatment. That is, the thermosensitive adhesive reversibly switches between a crystalline state and a fluid state in response to temperature changes. Thus, when the thermosensitive adhesive is heated to a temperature above its melting point, the thermosensitive adhesive exhibits fluidity, thereby exhibiting adhesive strength. Furthermore, when the thermosensitive adhesive is cooled to a temperature below its melting point, the thermosensitive adhesive crystallizes, thereby decreasing adhesive strength. Specifically, an example of a thermosensitive adhesive is a polymer blend of side-chain crystalline polymer 1 and side-chain crystalline polymer 2. Since side-chain crystalline polymer 1 and side-chain crystalline polymer 2 each have one melting point, the thermosensitive adhesive itself has two melting points. Such a side-chain crystalline polymer 1 can be a polymer of a (meth)acrylate having a linear alkyl group having 14 or more carbon atoms (hereinafter referred to as a "first (meth)acrylate") and a monomer copolymerizable with this first (meth)acrylate. Examples of the first (meth)acrylate include (meth)acrylates having a linear alkyl group having 14 to 22 carbon atoms, such as cetyl (meth)acrylate, stearyl (meth)acrylate, eicosyl (meth)acrylate, and behenyl (meth)acrylate, and these may be used alone or in combination of two or more.

[0057] The monomer copolymerizable with the first (meth)acrylate can be at least one selected from a (meth)acrylate having an alkyl group having 1 to 6 carbon atoms (hereinafter referred to as a "second (meth)acrylate") and a polar monomer.

[0058] Examples of the second (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, etc., which may be used alone or in combination of two or more. Examples of the polar monomer include carboxyl group-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid; and hydroxyl group-containing ethylenically unsaturated monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxyhexyl (meth)acrylate, which may be used alone or in combination of two or more.

[0059] The polymerization method is not particularly limited, and examples thereof include solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, etc. When the solution polymerization method is employed, the monomers exemplified above are mixed in a solvent and stirred at about 40° C. to 90° C. for about 2 hours to 6 hours, thereby polymerizing the monomers.

[0060] On the other hand, the side chain crystalline polymer 2 can be a polymer of the first (meth)acrylate used in the side chain crystalline polymer 1, a first (meth)acrylate moiety having a linear alkyl group differing in carbon number by 4 or more, preferably 4 to 8, and a monomer copolymerizable with the first (meth)acrylate. When two or more first (meth)acrylates are used in combination, the carbon number is based on the following. That is, the carbon number of the first (meth)acrylate that produces the largest difference between the carbon number of one of the first (meth)acrylates in the side chain crystalline polymer 1 and the side chain crystalline polymer 2 is based on the carbon number of the first (meth)acrylate. Specific examples of the first (meth)acrylate that can be used include the following: Example 1: Stearyl acrylate (number of carbon atoms in the linear alkyl group: 18) and cetyl acrylate (number of carbon atoms in the linear alkyl group: 16) Example 2: Behenyl acrylate (number of carbon atoms in the linear alkyl group: 22)

[0061] In this case, the first (meth)acrylate used as the reference in Example 1 is cetyl acrylate, which, of stearyl acrylate and cetyl acrylate, has the largest difference in carbon number from that of behenyl acrylate in Example 2. Examples of the monomer copolymerizable with the first (meth)acrylate include the same monomers as those exemplified for Side Chain Crystalline Polymer 1, i.e., the second (meth)acrylate and polar monomers. Examples of preferred compositions of Side Chain Crystalline Polymer 2 include the same compositions as those exemplified for Side Chain Crystalline Polymer 1, except that the number of carbon atoms in the first (meth)acrylate differs by four or more. Examples of polymerization methods include the same polymerization methods as those exemplified for Side Chain Crystalline Polymer 1.

[0062] <<Ultraviolet Irradiation Treatment>> The ultraviolet irradiation treatment is, for example, a treatment in which ultraviolet light is irradiated onto the resin layer of the second laminate structure, thereby making it easier to peel off the portion including the support from the second laminate structure. The conditions for the ultraviolet irradiation treatment can be appropriately set depending on the material used for the resin layer. For the resin layer suitable for the ultraviolet irradiation treatment, a resin composition containing a gas generating agent that generates gas upon ultraviolet irradiation, or an adhesive that hardens and loses its adhesive strength upon ultraviolet irradiation can be used.

[0063] Examples of gas generating agents that generate gas upon irradiation with ultraviolet light include tetrazole compounds or salts thereof, triazole compounds or salts thereof, azo compounds, azide compounds, xanthone acetate, carbonates, etc. These gas generating agents may be used alone or in combination of two or more. Among these, tetrazole compounds or salts thereof are preferred because of their excellent heat resistance.

[0064] The content of the gas generating agent in the resin layer is not particularly limited, but is preferably 5 parts by mass or more and 50 parts by mass or less, and more preferably 8 parts by mass or more and 30 parts by mass or less, relative to a total of 100 parts by mass of the resin layer. By containing the gas generating agent in the resin layer within the above range, the resin layer can exhibit particularly excellent releasability by ultraviolet irradiation treatment.

[0065] The resin layer containing the gas generating agent is not particularly limited, but preferably contains a thermosetting resin from the viewpoint of heat resistance. The thermoplastic resin is not particularly limited, but from the viewpoint of achieving both heat resistance and UV transmittance, a polyimide resin having a siloxane bond is particularly preferred. The weight-average molecular weight of the thermosetting resin is preferably 5,000 to 500,000, more preferably 10,000 to 200,000.

[0066] An example of an adhesive that hardens and loses its adhesive strength upon exposure to ultraviolet light is a photocurable adhesive containing a polymerizable polymer as the main component and a photopolymerization initiator. Polymerizable polymers can be obtained, for example, by reacting a (meth)acrylic polymer having a functional group in the molecule (hereinafter referred to as a functional group-containing (meth)acrylic polymer) with a compound having a functional group reactive with the functional group and a radically polymerizable unsaturated bond in the molecule (hereinafter referred to as a functional group-containing unsaturated compound). Functional group-containing (meth)acrylic polymers are polymers that exhibit adhesiveness at room temperature. Similar to typical (meth)acrylic polymers, functional group-containing (meth)acrylic polymers are obtained by copolymerizing alkyl acrylate esters and / or alkyl methacrylate esters, whose alkyl groups typically have a carbon number of 2 to 18, as the main monomers, with functional group-containing monomers and, if necessary, with other modifying monomers copolymerizable with these monomers, using standard methods. The weight-average molecular weight of functional group-containing (meth)acrylic polymers is typically around 200,000 to 2,000,000.

[0067] Examples of functional group-containing monomers include carboxyl group-containing monomers such as acrylic acid and methacrylic acid, hydroxyl group-containing monomers such as hydroxyethyl acrylate and hydroxyethyl methacrylate, epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate, isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate, and amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate. Examples of other copolymerizable modifying monomers include various monomers used in general (meth)acrylic polymers, such as vinyl acetate, acrylonitrile, and styrene.

[0068] As the functional group-containing unsaturated compound to be reacted with the functional group-containing (meth)acrylic polymer, the same as the functional group-containing monomer described above can be used depending on the functional group of the functional group-containing (meth)acrylic polymer. For example, when the functional group of the functional group-containing (meth)acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used; when the functional group is a hydroxyl group, an isocyanate group-containing monomer is used; when the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide is used; and when the functional group is an amino group, an epoxy group-containing monomer is used.

[0069] Examples of the photopolymerization initiator include those that are activated by irradiation with light having a wavelength of 250 nm to 800 nm. Examples of such photopolymerization initiators include acetophenone derivative compounds such as methoxyacetophenone; benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether; ketal derivative compounds such as benzyl dimethyl ketal and acetophenone diethyl ketal; phosphine oxide derivative compounds; bis(η5-cyclopentadienyl)titanocene derivative compounds; and photoradical polymerization initiators such as benzophenone, Michler's ketone, chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenyl ketone, and 2-hydroxymethylphenylpropane. These photopolymerization initiators may be used alone or in combination of two or more.

[0070] The photocurable pressure-sensitive adhesive preferably further contains a radically polymerizable polyfunctional oligomer or monomer. By containing the radically polymerizable polyfunctional oligomer or monomer, the photocurability is improved. The polyfunctional oligomer or monomer preferably has a weight-average molecular weight of 10,000 or less, and more preferably has a molecular weight of 5,000 or less and has 2 to 20 radically polymerizable unsaturated bonds in the molecule, so that the pressure-sensitive adhesive layer is efficiently three-dimensionally reticulated by light irradiation.

[0071] Examples of the polyfunctional oligomer or monomer include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, and the same methacrylates as above. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylates, and the same methacrylates as above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

[0072] The photocurable pressure-sensitive adhesive preferably has a glass transition temperature of 50° C. or lower. A more preferred upper limit of the glass transition temperature is 0° C. The lower limit of the glass transition temperature is not particularly limited, but is preferably −60° C. or higher.

[0073] <Laser Irradiation Treatment> Laser irradiation treatment is, for example, a treatment in which a laser is irradiated onto the resin layer of the second laminate structure to facilitate peeling of the portion containing the support from the second laminate structure. The conditions for the laser irradiation treatment can be appropriately set depending on the material used for the resin layer. A resin layer suitable for laser irradiation treatment can be a combination of a resin with photothermal conversion function that absorbs light of a predetermined wavelength and converts the light into heat, and a thermally decomposable resin. That is, when irradiated with laser light, the photothermal conversion resin generates heat, and the generated heat propagates to the adjacent thermally decomposable resin, causing the thermally decomposable resin-containing thermally decomposable layer to decompose at the interface with the photothermal conversion layer containing the photothermal conversion resin. Due to this mechanism, the peel strength of a resin layer containing a resin with photothermal conversion function and a thermally decomposable resin is reduced. In particular, the thickness of the photothermal conversion layer is preferably 5 μm to 200 μm, more preferably 10 μm to 150 μm.

[0074] In one embodiment of the photothermal conversion layer, the transmittance of light with a wavelength of 355 nm is 50% or less, more preferably 40% or less, even more preferably 35% or less, and most preferably 0%. A photothermal conversion layer with a transmittance of 355 nm within this range can be formed that easily absorbs UV laser light and generates heat. Such photothermal conversion resins are not particularly limited as long as they can absorb ultraviolet light, and examples include polyimide resins, polyether ether ketone resins, polyethylene naphthalate resins, acrylic resins, and epoxy resins. Among these, polyimide resins are preferred as the photothermal conversion resin.

[0075] The photothermal conversion resin may be a resin containing a pigment, dye, or ultraviolet absorber so as to absorb a predetermined ultraviolet ray. Any appropriate ultraviolet absorber can be used as the ultraviolet absorber as long as it is a compound that absorbs ultraviolet ray (for example, a wavelength of 355 nm). Examples of ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers. Among these, it is preferable to use a triazine-based ultraviolet absorber or a benzotriazole-based ultraviolet absorber as the ultraviolet absorber, and it is particularly preferable to use a triazine-based ultraviolet absorber.

[0076] Examples of pigments that absorb predetermined ultraviolet rays include azo-based, phthalocyanine-based, anthraquinone-based, lake-based, perylene-based, perinone-based, quinacridone-based, thioindigo-based, dioxandine-based, isoindolinone-based, quinophthalone-based pigments, etc. Examples of dyes that absorb predetermined ultraviolet rays include azo-based, phthalocyanine-based, anthraquinone-based, carbonyl-based, indigo-based, quinoneimine-based, methine-based, quinoline-based, nitro-based dyes, etc.

[0077] In another embodiment of the photothermal conversion layer, the transmittance of light with a wavelength of 1032 nm is 50% or less, more preferably 40% or less, even more preferably 35% or less, and most preferably 0%. If the transmittance of light with a wavelength of 355 nm is within this range, a photothermal conversion layer that easily absorbs IR laser light and generates heat can be formed.

[0078] In this case, the photothermal conversion layer can be made of a resin containing a predetermined dye (pigment or dye) to absorb infrared rays of a predetermined wavelength. The photothermal conversion layer that absorbs ultraviolet rays may be a single layer containing the dye in a resin, or may be a multi-layer structure consisting of a layer containing the predetermined dye and a resin layer. When a layer containing the dye is formed, it is preferable that the layer containing the dye is adjacent to the thermal decomposition layer. As the dye that absorbs infrared rays, any appropriate dye can be used in any appropriate amount as long as it can impart IR light absorption. Examples of such dyes include carbon black, cesium tungsten oxide, lanthanum hexaboride, tin-doped indium oxide, antimony-doped tin oxide, cyanine compounds, phthalocyanine compounds, dithiol metal complexes, naphthoquinone compounds, diimmonium compounds, and azo compounds. Examples of resins that constitute the resin layer include polyimide-based resins, polyethylene terephthalate-based resins, polyamide-based resins, polyether ether ketone-based resins, polyethylene naphthalate-based resins, acrylic resins, and epoxy-based resins. Among these, it is preferable to use a polyimide resin or a polyethylene terephthalate resin as the resin constituting the resin layer.Furthermore, a colored metal layer may be used as the light-to-heat conversion layer that absorbs infrared rays.

[0079] On the other hand, the pyrolysis layer containing a pyrolyzable resin can be made of acrylic resin, urethane resin, polyester resin, etc., and the 5% weight loss temperature is preferably 250°C to 400°C, more preferably 280°C to 370°C. The 5% weight loss temperature of the pyrolysis layer can be adjusted, for example, by the type and structure of the resin constituting the pyrolysis layer, the presence or absence and type of additives, etc. If the 5% weight loss temperature is too low, i.e., if the heat resistance is too low, excessive decomposition may occur throughout the pyrolysis layer when irradiated with infrared rays, which may hinder peeling.

[0080] Furthermore, the gel fraction of the pyrolysis layer is preferably 70% or more, more preferably 80% to 99%, and even more preferably 85% to 97%. A gel fraction within this range facilitates removal of the pyrolysis layer remaining on the support after peeling off the portion containing the support. Specifically, excessive heating of the pyrolysis layer due to infrared irradiation to generate heat in the photothermal conversion layer can result in the pyrolysis product of the pyrolysis layer being baked onto the support. In this case, removing the pyrolysis product from the support and recovering the support can be time-consuming. However, by maintaining the gel fraction within the above range, the pyrolysis product of the pyrolysis layer can be easily removed. An organic solvent such as toluene is used to remove the pyrolysis product from the pyrolysis layer. The gel fraction of the pyrolysis layer can be controlled by adjusting the composition of the base polymer constituting the pyrolysis layer, the type and content of the crosslinking agent added to the pyrolysis layer, and the type and content of the tackifier.

[0081] The gel fraction was measured as follows. First, about 0.5 g of the pyrolysis layer was sampled and precisely weighed (sample weight). The sample was then wrapped in a mesh sheet (trade name "NTF-1122", manufactured by Nitto Denko Corporation) and immersed in 50 ml of toluene at room temperature (25°C) for one week. Thereafter, the solvent-insoluble matter (contents of the mesh sheet) was removed from the toluene and dried at 130°C for about two hours. The dried solvent-insoluble matter was weighed (weight after immersion and drying), and the gel fraction (mass %) was calculated using the following formula (a): Formula (a): Gel fraction (mass %) = [(mass after immersion and drying) / (mass of sample)] x 100

[0082] The tensile modulus of the pyrolysis layer at 25°C is preferably 0.05 MPa to 1 GPa, more preferably 0.1 MPa to 300 MPa. If the tensile modulus of the pyrolysis layer at 25°C is within this range, it becomes easy to remove the pyrolysis layer remaining on the support after peeling off the portion including the support. For example, the pyrolysis layer remaining on the support can be swelled, and most of the pyrolysis layer as residue can be removed all at once.

[0083] The thickness of the pyrolysis layer is preferably 10 μm to 200 μm, more preferably 20 μm to 150 μm, and even more preferably 30 μm to 100 μm.

[0084] In one embodiment, when the photothermal conversion layer absorbs ultraviolet light, the thermal decomposition layer has a transmittance of 80% or more, more preferably 82% to 98%, and even more preferably 85% to 97% for light with a wavelength of 355 nm. Within such a range, when peeling is performed by irradiation with UV laser light, the laser light can be made to preferably reach the photothermal conversion layer, and peeling of the photothermal conversion layer at the interface between the thermal decomposition layer and the photothermal conversion layer is promoted.

[0085] Furthermore, when the photothermal conversion layer absorbs infrared rays, in one embodiment, the thermal decomposition layer has a transmittance of 80% or more, more preferably 85% to 98%, and even more preferably 90% to 96% for light with a wavelength of 1032 nm. Within such a range, when peeling is performed by irradiating IR laser light, the laser light can be made to preferably reach the photothermal conversion layer, and peeling of the photothermal conversion layer at the interface between the thermal decomposition layer and the photothermal conversion layer is promoted.

[0086] In the laser irradiation treatment, laser light having any appropriate wavelength is used as the laser light depending on the configuration of the resin layer. The conditions for laser light irradiation are also set to any appropriate conditions depending on the configuration of the resin layer. In one embodiment, UV laser light is used as the laser light. The wavelength of the UV laser light is preferably 150 nm to 380 nm, more preferably 240 nm to 360 nm. The output of the UV laser light is, for example, 0.1 W to 2.0 W. In another embodiment, IR laser light is used as the laser light. The wavelength of the IR laser light is preferably 800 nm to 10600 nm, more preferably 900 nm to 1200 nm. The output of the IR laser light is, for example, 0.01 W to 10 W.

[0087] <Voltage Application Treatment> The voltage application treatment is, for example, a treatment in which a voltage is applied to the resin layer of the second laminate structure to facilitate peeling of the portion containing the support from the second laminate structure. The conditions for the voltage application treatment can be appropriately set depending on the material used for the resin layer. For the resin layer suitable for the voltage application treatment, it is preferable to use an adhesive whose adhesive strength decreases upon voltage application, such as an electric peeling tape manufactured by Iwatani Corporation or an electric peeling adhesive sheet manufactured by Lintec Corporation. Alternatively, the resin layer whose peel strength decreases upon voltage application treatment can be a resin layer containing an electric peeling adhesive (electrically peeling adhesive layer). The electrically peeling adhesive layer adheres to the portion containing the support (usually a conductive support) before voltage application, and has the function of reducing the adhesive strength with the portion containing the support upon voltage application.

[0088] When the peel strength is reduced by voltage application treatment, a conductive layer may be provided in addition to the above-mentioned electrically peelable adhesive layer. The conductive layer has the function of uniformly applying a voltage to the electrically peelable adhesive layer, etc. This allows the adhesive strength of the electrically peelable adhesive layer to be uniformly reduced, thereby improving the peelability due to voltage application. When the support is conductive, the conductive layer is usually arranged on the opposite side of the electrically peelable adhesive layer from the support. That is, when the peel strength is reduced by voltage application treatment and a conductive layer is provided, it is preferable to arrange the conductive support, the electrically peelable adhesive layer, and the conductive layer in this order. Furthermore, when the support is insulating, it is preferable to form the conductive layer on both sides of the electrically peelable adhesive layer.

[0089] The aforementioned metal layer may function as the conductive layer, or a conductive layer may be provided as a separate layer from the metal layer. The material of the conductive layer is not particularly limited, but is preferably a layer formed from a metal material or a layer formed from a conductive polymer. These conductive layers may be used alone or in combination of two or more. Examples of the metal material include simple metals such as aluminum, copper, tungsten, iron, molybdenum, nickel, titanium, silver, and gold; alloys such as stainless steel, carbon steel, brass, phosphor bronze, zirconium-copper alloy, beryllium copper, iron-nickel, chromium, nickel-titanium, Kanthal, Hastelloy, and rhenium-tungsten; and tin-doped indium oxide. These metal materials may be used alone or in combination of two or more.

[0090] The thickness of the conductive layer is appropriately set depending on the application of the second laminate structure, but is preferably, for example, 1 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, or 60 μm or more. The thickness of the conductive layer is preferably 1000 μm or less, 700 μm or less, 500 μm or less, 300 μm or less, 200 μm or less, 150 μm or less, or 100 μm or less.

[0091] The thickness of the electrically peelable pressure-sensitive adhesive layer is adjusted appropriately depending on the application, etc., but is preferably 0.5 μm to 120 μm, more preferably 1 μm to 100 μm, even more preferably 10 μm to 90 μm, still more preferably 20 μm to 80 μm, and particularly preferably 30 μm to 70 μm.

[0092] The thickness ratio of the conductive support to the electrically releasing pressure-sensitive adhesive layer (support / electrically releasing pressure-sensitive adhesive layer) is preferably 1.5 or more, 2.0 or more, 3.0 or more, 5.0 or more, 8.0 or more, 10.0 or more, or 12.0 or more, and is preferably 100 or less, 80 or less, 70 or less, 60 or less, 50 or less, 40 or less, 30 or less, 25 or less, 20 or less, or 15 or less.

[0093] The electrically peelable pressure-sensitive adhesive layer is not particularly limited, but preferably contains a (meth)acrylic polymer and an ionic compound, and may further contain other components such as a crosslinking agent, a tackifier, and an additive.

[0094] The (meth)acrylic polymer has a function of imparting adhesiveness to the electrically peelable pressure-sensitive adhesive layer. The (meth)acrylic polymer is not particularly limited, but includes a structural unit derived from an alkyl (meth)acrylate and a structural unit derived from a functional group-containing monomer. In addition, if necessary, the (meth)acrylic polymer may further include a structural unit derived from another monomer.

[0095] The alkyl (meth)acrylate is not particularly limited, but examples thereof include alkyl (meth)acrylates having 1 to 30 carbon atoms. Of these, the alkyl (meth)acrylate is preferably an alkyl (meth)acrylate having 1 to 20 carbon atoms, more preferably an alkyl (meth)acrylate having 1 to 16 carbon atoms, even more preferably an alkyl (meth)acrylate having 1 to 12 carbon atoms, and particularly preferably an alkyl (meth)acrylate having 4 to 8 carbon atoms. The alkyl group in the alkyl (meth)acrylate may be a linear alkyl group or a branched alkyl group.

[0096] Specific examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate (n-propyl (meth)acrylate, i-propyl (meth)acrylate), butyl (meth)acrylate (n-butyl (meth)acrylate, i-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate), pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, tridecyl (meth)acrylate, and stearyl (meth)acrylate. Of these, the alkyl (meth)acrylate preferably includes at least one selected from the group consisting of methyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, more preferably includes at least one selected from the group consisting of methyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, and even more preferably includes at least one selected from the group consisting of methyl (meth)acrylate and butyl (meth)acrylate. The above-mentioned alkyl (meth)acrylates may be used alone or in combination of two or more.

[0097] The content of the alkyl (meth)acrylate-derived structural units is preferably 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more relative to the total amount (100% by mass) of the structural units of the (meth)acrylic polymer. Furthermore, the content of the alkyl (meth)acrylate-derived structural units is preferably 99.99% by mass or less, 99.90% by mass or less, 99.0% by mass or less, 97.0% by mass or less, 95.0% by mass or less, 90.0% by mass or less, or 85% by mass or less. By setting the content of the alkyl (meth)acrylate-derived structural units within this range, the adhesiveness before voltage application treatment can be improved, the content of the functional group-containing monomer-derived structural units can be ensured, and the cohesive force can be further improved.

[0098] The functional group-containing monomer is not particularly limited, but examples thereof include hydroxy group-containing monomers, carboxy group-containing monomers, and epoxy group-containing monomers.

[0099] The hydroxy group-containing monomer is not particularly limited, but examples thereof include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; and unsaturated alcohols such as vinyl alcohol and allyl alcohol. The alkyl group of the hydroxyalkyl (meth)acrylate preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, even more preferably 1 to 6 carbon atoms, and particularly preferably 2 to 4 carbon atoms. The alkyl group may be a linear alkyl group or a branched alkyl group. The above-mentioned hydroxy group-containing monomers may be used alone or in combination of two or more types.

[0100] The carboxy group-containing monomer is not particularly limited, but examples thereof include ethylenically unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid, ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid and citraconic acid, 2-carboxylethyl (meth)acrylate, etc. These carboxy group-containing monomers may be used alone or in combination of two or more.

[0101] The epoxy group-containing monomer is not particularly limited, but examples thereof include epoxy group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and 3-epoxycyclo-2-hydroxypropyl (meth)acrylate; glycidyl crotonate, and allyl glycidyl ether. These epoxy group-containing monomers may be used alone or in combination of two or more.

[0102] Of the above, the functional group-containing monomer preferably contains a hydroxy group-containing monomer or a carboxy group-containing monomer, more preferably contains a hydroxy group-containing monomer, and further preferably contains a hydroxyalkyl (meth)acrylate.

[0103] The content of the structural units derived from functional group-containing monomers is preferably 0.01% by mass or more, 0.10% by mass or more, 1.0% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 10.0% by mass or more, or 15% by mass or more, relative to the total amount (100% by mass) of the structural units of the (meth)acrylic polymer. Furthermore, the content of the structural units derived from functional group-containing monomers is preferably 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, or 25% by mass or less, relative to the total amount (100% by mass) of the structural units of the (meth)acrylic polymer. Setting the content of the structural units derived from functional group-containing monomers within this range can further improve cohesion, ensure the content of structural units derived from alkyl (meth)acrylate, and improve adhesion before voltage application treatment.

[0104] Other monomers besides the alkyl (meth)acrylates and functional group-containing monomers described above can also be used. Examples of other monomers include, but are not limited to, olefins such as ethylene, propylene, and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; diene monomers such as butadiene, isoprene, and chloroprene; styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, (meth)acrylamide, (meth)acrylonitrile, (meth)acryloylmorpholine, and N-vinylpyrrolidone. These other monomers may be used alone or in combination of two or more.

[0105] The content of the structural units derived from other monomers is preferably 0% by mass or more, 1% by mass or more, 5% by mass or more, 10% by mass or more, or 15% by mass, relative to the total amount (100% by mass) of the structural units of the (meth)acrylic polymer. Furthermore, the content of the structural units derived from other monomers is more preferably 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, or 5% by mass or less, relative to the total amount (100% by mass) of the structural units of the (meth)acrylic polymer.

[0106] The weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably from 50,000 to 2,000,000, more preferably from 100,000 to 1,500,000, even more preferably from 200,000 to 1,200,000, particularly preferably from 300,000 to 1,000,000, and most preferably from 400,000 to 900,000.

[0107] The content of the (meth)acrylic polymer is preferably 25% by mass to 97% by mass, more preferably 30% by mass to 95% by mass, even more preferably 40% by mass to 93% by mass, still more preferably 50% by mass to 90% by mass, and particularly preferably 60% by mass to 87% by mass, based on the total amount (100% by mass) of the active ingredients in the electrically peelable pressure-sensitive adhesive layer. When the content of the (meth)acrylic polymer is within the above range, the adhesive has high adhesiveness before the voltage application treatment, and the adhesiveness can be easily reduced by the voltage application treatment.

[0108] On the other hand, the ionic compound migrates within the electrically peelable pressure-sensitive adhesive layer upon voltage application treatment, causing a change in the composition of the surface of the electrically peelable pressure-sensitive adhesive layer, thereby reducing the adhesive strength with the portion containing the support, thereby enabling the portion containing the support in the second laminate structure to be peeled off.

[0109] The ionic compound is not particularly limited, but may include at least one selected from the group consisting of alkali metal salts, organic quaternary ammonium salts, and ionic liquids.

[0110] The alkali metal salt is not particularly limited, but examples thereof include compounds that are solid at room temperature (25° C.) but ionize into cations (alkali metal ions) and anions in a liquid. Examples of alkali metal salts include MCl, MBr, MI, and MAlCl. ４ , MAl ２ Cl ７ , MBF ４ , MPF ６ , MSCN, MClO ４ , MNO ３ , C.H. ３ COOM, C. ９ H １９ COOM, C.F. ３ COOM, C. ３ F ７ COOM, MCH ３ SO ３ , MCF ３ SO ３ , M.C. ４ F ９ SO ３ , M.C. ２ H ５ OSO ３ , M.C. ６ H １３ OSO ３ , M.C. ８ H １７ OSO ３ , M(CF ３ SO ２ ) ２ N, M (C ２ F ５ SO ２ ) ２ N, M (C ３ F ７ SO２ ) ２ N, M (C ４ F ９ SO ２ ) ２ N, M (CF ３ SO ２ ) ３ C, MAsF ６ , MSbF ６ , MNbF ６ , MTaF ６ , M(CN) ２ N, M (CF ３ SO ２ ) (CF ３ CO)N, M(CH ３ ) ２ P.O. ４ , M(C ２ H ５ ) ２ P.O. ４ , M.C.H. ３ (OC ２ H ４ ) ２ OSO ３ , M.C. ６ H ４ (CH ３ ) SO ３ , M(C ２ F ５ ) ３ PF ３ , C.H. ３ CH(OH)COOM, M(FSO ２ ) ２ In this case, M is an alkali metal atom, preferably Li, Na, or K, more preferably Na or K, and even more preferably Na. The above-mentioned alkali metal salts may be used alone or in combination of two or more kinds.

[0111] The organic quaternary ammonium salt is not particularly limited, but is solid at room temperature (25°C).Specific examples of the organic quaternary ammonium salt include ammonium bromides or ammonium chlorides such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl; ammonium tetrafluoroborates such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl; ammonium hexafluorophosphates such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl; ammonium perchlorates such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl; and ammonium sulfates such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, and triethylmethyl.The organic quaternary ammonium salts may be used alone or in combination of two or more.

[0112] The ionic liquid is not particularly limited, but examples thereof include molten salts that are liquid at room temperature (25°C) and are compounds composed of an organic cation and an anion that is its counter ion. The ionic liquid is not particularly limited, and any known and publicly used ionic liquid can be used. That is, examples of cations that constitute the ionic liquid include those having a basic skeleton of an imidazolium-based, pyridinium-based, pyrrolidinium-based, piperidinium-based, ammonium-based, and phosphonium-based cation. More specifically, examples of cationic species that constitute the ionic liquid include primary (R １ NH ３ ＋ ), second class (R １ R ２ NH ２ ＋ ), tertiary (R １ R ２ R ３ NH ＋ ), quaternary (R １ R ２ R ３ R４ N ＋ ) a chain ammonium cation (wherein R １ , R ２ , R ３ , R ４ are each independently a hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 18 carbon atoms, and having a linear or branched structure, or a hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 18 carbon atoms, and having one or more hydroxyl groups in the side chain, and having a linear or branched structure.

[0113] Furthermore, cyclic ammonium cations can be used as the cationic species in the ionic liquid. Examples of cyclic ammonium cations include oxazolium, thiazolium, imidazolium, pyrazolium, pyrrolinium, furazanium, triazolium, pyrrolidinium, imidazolidinium, pyrazolidinium, pyrrolinium, imidazolinium, pyrazolinium, pyrazinium, pyrimidinium, pyridazinium, piperidinium, piperazinium, morpholinium, indolium, and carbazolium. Further examples of other cations include chain phosphonium cations, chain sulfonium cations, and cyclic sulfonium cations. Examples of cyclic sulfonium cations include thiophenium, thiazolinium, and thiopyranium.

[0114] Examples of anions in the ionic liquid include halide ions, tetrafluoroborate, hexafluorophosphate, and bis(trifluoromethylsulfonyl)amide. Specific examples of the anion include AlCl ４ － , NO ２ － , NO ３ － , I － , B.F. ４ － , P.F. ６ － , AsF ６ － , SbF ６ － , NbF ６ － , TaF ６－ , p-CH ３ PhSO ３ － , C.H. ３ CO ２ － , C.F. ３ CO ２ － , C.H. ３ SO ３ － , C.F. ３ SO ３ － , (CF ３ SO ２ ) ３ C － , C ３ F ７ CO ２ － , C ４ F ９ SO ３ － , (CF ３ SO ２ ) ２ N － , (FSO2)2N-, (C ２ F ５ SO ２ ) ２ N － , (CF ３ SO ２ ) (CF ３ CO)N － , (CN) ２ N － Among these, the anion constituting the ionic liquid is (CF ３ SO ２ ) ２ N － or (FSO ２ ) ２ N － It is preferable that:

[0115] As the ionic liquid composed of the above-mentioned cations and anions, ionic liquids into which various functional groups have been introduced can also be used. The ionic liquids may be used alone or in combination of two or more.

[0116] Of the above, the ionic compound preferably contains at least one of an alkali metal salt and an ionic liquid, and more preferably contains an ionic liquid.

[0117] The content of the ionic compound is preferably 3 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, 9 parts by mass or more, 11 parts by mass or more, 13 parts by mass or more, or 15 parts by mass or more, relative to the total amount (100% by mass) of the active ingredients in the electrically peelable pressure-sensitive adhesive layer. The content of the ionic compound is preferably 200 parts by mass or less, 180 parts by mass or less, 160 parts by mass or less, 150 parts by mass or less, 130 parts by mass or less, or 120 parts by mass or less, relative to the total amount (100% by mass) of the active ingredients in the electrically peelable pressure-sensitive adhesive layer, and is preferably 100 parts by mass or less, 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, or 30 parts by mass or less. A content of the ionic compound within this range is preferred from the viewpoints of easily reducing adhesiveness by voltage application, maintaining high adhesiveness before voltage application, etc.

[0118] The method for separating the support-containing portion from the remaining portion by voltage application is not particularly limited. For example, one of two terminals connected to a voltage application device is connected to the conductive layer on the side opposite the support, and the other terminal is connected to another conductive layer on the conductive support or insulating support side. Applying a predetermined voltage through the two terminals connected to the voltage application device reduces the adhesive strength of the electrically peelable pressure-sensitive adhesive layer, allowing the support-containing portion to be separated from the remaining portion. A voltage application device such as the KH-100H (manufactured by Takasago Machinery Co., Ltd.) can be used. In the voltage application process, the applied voltage (applied voltage) is preferably 1 V to 200 V, more preferably 3 V to 140 V, and even more preferably 6 V to 120 V. The time for which the voltage is applied (applied time) within this range is preferably 1 second to 180 seconds, more preferably 5 seconds to 120 seconds, and even more preferably 10 seconds to 90 seconds.

[0119] <Electromagnetic Field Application Treatment> Electromagnetic field application treatment is, for example, a treatment in which an electromagnetic field is applied to the resin layer of the second laminate structure to facilitate peeling of the portion containing the support from the second laminate structure. The conditions for the electromagnetic field application treatment can be appropriately set depending on the material used for the resin layer. Note that the term "electromagnetic field" collectively refers to an electric field and a magnetic field, and "electromagnetic field application" refers to both electric field application and magnetic field application. Furthermore, the term "electromagnetic field" also refers to an alternating electromagnetic field (alternating magnetic field, alternating electric field). A resin layer suitable for the electromagnetic field application treatment preferably contains crosslinking agent filler particles exhibiting ferromagnetic, ferrimagnetic, superparamagnetic, or paramagnetic properties that generate heat when an electromagnetic field is applied, and a thermosetting resin. The crosslinking agent filler particles preferably contain crosslinking agent units chemically bonded via a group that is cleaved by heat, and the crosslinking agent units preferably have at least one functional group that undergoes a crosslinking reaction with the thermosetting resin.

[0120] The cross-linking filler particles that exhibit ferromagnetic, ferrimagnetic, superparamagnetic or paramagnetic properties and generate heat when subjected to an electromagnetic field application treatment are not particularly limited, but examples thereof include iron powder, which is a silicon dioxide-iron oxide mixed particle, iron silicalite (FeSiO ４ ), iron oxide nanoparticles (Fe ２ O ３ , Fe ３ O ４ ), or iron-zinc-iron oxide-based particles. The functional group possessed by the crosslinker unit is not particularly limited, but examples thereof include an azo group, a carbonate group, an epoxy group, an amino group, a thiol group, an alcohol group, an acrylate group, a methacrylate group, and a vinyl group.

[0121] The thermosetting resin is not particularly limited, but examples thereof include epoxy resins, polyurethane resins, acrylate resins, phenolic resins, polysulfide resins, melamine resins, urethane-acrylic composite resins, phenoxy resins, imide resins, and amide resins. In particular, it is preferable to use epoxy resins, polyurethane resins, acrylate resins, phenolic resins, polysulfide resins, or melamine resins.

[0122] As an example of the electromagnetic field application process, it is preferable to apply an induction frequency of several kilohertz to approximately 35 megahertz to a resin layer containing the crosslinking agent filler particles and the thermosetting resin. Furthermore, the first or second laminate structure containing the resin layer can be cured and exhibit adhesive strength by heating it in an oven heated to 90°C for 30 minutes. Furthermore, by applying a magnetic field to the second laminate structure at an output of 3000 W using an STS semiconductor generator M230, the portion containing the support can be peeled from the remaining portion within 60 seconds. This generator has an excitation frequency of 300 kHz and uses a three-turn coil with an inner diameter of 3 cm. This generator can selectively heat only the resin layer, making it an advantageous peeling method when part of the second laminate structure is heat-sensitive.

[0123] <<Solvent Treatment>> The solvent treatment is, for example, a treatment in which a solvent is brought into contact with the resin layer of the second laminate structure to facilitate peeling of the portion including the support from the second laminate structure. The conditions for the solvent treatment can be appropriately set depending on the material used for the resin layer.

[0124] The resin layer suitable for solvent treatment can be made of a polyimide resin or a precursor thereof. The polyimide resin or precursor thereof preferably has a tetracarboxylic acid anhydride residue and a diamine residue, the diamine residue being a polysiloxane-based diamine residue, and has a dicarboxylic acid anhydride residue and / or a monoamine residue at its terminal.

[0125] The diamine residues preferably contain polysiloxane-based diamine residues in an amount of 50 mol % to 100 mol %, more preferably 60 mol % to 100 mol %, of the total diamine residues. By containing polysiloxane-based diamine residues in an amount of 50 mol % or more of the total diamine residues, good adhesion and improved solubility in solvents can be achieved. Specific examples of polysiloxane-based diamines include α,ω-bis(3-aminopropyl)polydimethylsiloxane, α,ω-bis(3-aminopropyl)polydiethylsiloxane, α,ω-bis(3-aminopropyl)polydipropylsiloxane, α,ω-bis(3-aminopropyl)polydibutylsiloxane, α,ω-bis(3-aminopropyl)polydiphenoxysiloxane, α,ω-bis(2-aminoethyl)polydimethylsiloxane, α,ω-bis(2- Examples of the polysiloxane diamine include α,ω-bis(4-aminoethyl)polydiphenoxysiloxane, α,ω-bis(4-aminobutyl)polydimethylsiloxane, α,ω-bis(4-aminobutyl)polydiphenoxysiloxane, α,ω-bis(5-aminopentyl)polydimethylsiloxane, α,ω-bis(5-aminopentyl)polydiphenoxysiloxane, α,ω-bis(4-aminophenyl)polydimethylsiloxane, and α,ω-bis(4-aminophenyl)polydiphenoxysiloxane. The above polysiloxane diamines may be used alone or in combination of two or more.

[0126] When the amount of dicarboxylic anhydride residues is A moles and the amount of tetracarboxylic anhydride residues is B moles, the content of dicarboxylic anhydride residues is preferably 0.005≦0.5A / (0.5A+B)≦0.1, and more preferably 0.01≦0.5A / (0.5A+B)≦0.05. When the value calculated by 0.5A / (0.5A+B) is 0.005 or more, solubility in volatile solvents can be improved. Furthermore, when the value calculated by 0.5A / (0.5A+B) is 0.1 or less, heat resistance can be maintained.

[0127] Specific examples of dicarboxylic acid anhydrides include phthalic anhydride, 4-methylphthalic anhydride, 3-methylphthalic anhydride, 4-tert-butylphthalic anhydride, 4-fluorophthalic anhydride, 2-fluorophthalic anhydride, 3,4-difluorophthalic anhydride, 2,4-difluorophthalic anhydride, 2,3,4-trifluorophthalic anhydride, tetrafluorophthalic anhydride, 4-(trifluoromethyl)phthalic anhydride, 2-(trifluoromethyl)phthalic anhydride, etc. The above dicarboxylic acid anhydrides may be used alone or in combination of two or more.

[0128] When the amount of monoamine residues is C moles and the amount of diamine is D moles, the content of monoamine residues is preferably 0.005≦0.5C / (0.5C+D)≦0.1, and more preferably 0.01≦0.5C / (0.5C+D)≦0.05. When the value calculated by 0.5C / (0.5C+D) is 0.005 or more, solubility in volatile solvents can be improved. Furthermore, when the value calculated by 0.5C / (0.5C+D) is 0.1 or less, heat resistance can be maintained.

[0129] Specific examples of monoamines include aniline, p-toluene, m-toluene, 3,4-dimethylaniline, 4-tert-butylaniline, 4-fluoroaniline, 3-fluoroaniline, 2-fluoroaniline, 2,4-difluoroaniline, 2,6-difluoroaniline, 3,4-difluoroaniline, 3,5-difluoroaniline, 2,3-difluoroaniline, 2,4,6-trifluoroaniline, 2,3,5-trifluoroaniline, 2,3,4,5-tetrafluoroaniline, 2, Examples include 3,4,6-tetrafluoroaniline, 2,3,5,6-tetrafluoroaniline, pentafluoroaniline, 4-(trifluoromethyl)aniline, 3-(trifluoromethyl)aniline, 2-(trifluoromethyl)aniline, 3,5-bis(trifluoromethyl)aniline, 2,4-bis(trifluoromethyl)aniline, 2,5-bis(trifluoromethyl)aniline, 2,6-bis(trifluoromethyl)aniline, 2,3-bis(trifluoromethyl)aniline, etc. The above monoamines may be used alone or in combination of two or more.

[0130] The solvent used in the solvent treatment is preferably a volatile solvent. Specifically, the solvent preferably contains 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more, of components having a boiling point of 160° C. or less. When the solvent contains 90% by mass or more of components having a boiling point of 160° C. or less, the volatility is improved, and the portion including the support and the remainder can be dried without adding a rinsing step using a highly volatile solvent after the solvent treatment.

[0131] Examples of solvents include dipropylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, dipropylene glycol methyl ether acetate, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, and ethylene glycol monomethyl ether acetate. A single solvent may be used, or two or more solvents may be used. Particularly preferred solvents are propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, and ethylene glycol monomethyl ether acetate, which have a boiling point of 160°C or less. Furthermore, from the viewpoint of solubility, propylene glycol monomethyl ether acetate and ethylene glycol monomethyl ether acetate, which have an acetyl group, are particularly preferred solvents.

[0132] Other Release Methods: The resin layer may also be one that reduces peel strength based on a peeling principle utilizing host molecules and guest molecules. This principle, for example, uses a resin layer A containing β-cyclodextrin (β-CD) and a bipyridine functional group in its side chain, and a resin layer B containing a polymer compound having a butyl group in its side chain. In this case, a laminate A coated with resin layer A and a laminate B coated with resin layer B adhere to each other in the presence of metal ions but do not adhere to each other in the absence of metal ions. In the absence of metal ions, the host-guest interaction between β-CD and the bipyridine functional group results in a stronger interaction within resin layer A than between resin layer A and resin layer B, resulting in no adhesion between laminate A and laminate B. On the other hand, in the presence of metal ions, the bipyridine functional group in resin layer A captures the metal ions, thereby releasing the interaction between β-CD and the bipyridine functional group in resin layer A, thereby strengthening the interaction between resin layer A and resin layer B and enabling adhesion between laminate A and laminate B. By designing the resin layer based on the above principles, it is possible to reduce the peel force at a desired timing.

[0133] <Resin Having a Reactive Functional Group [Y]> The resin layer may have a reactive functional group [Y] that bonds with a reactive functional group (referred to as a reactive functional group [X]) of a dispersant contained in a metal layer, which will be described later. That is, the resin layer may contain a resin having a reactive functional group [Y]. By containing the reactive functional group [Y], adhesion to the metal layer is stabilized, and in the method for producing a printed wiring board, which will be described later, it is possible to prevent the portion containing the support from peeling off at an unintended timing other than the step of peeling off the portion containing the support. On the other hand, the resin layer may contain a resin that does not have a reactive functional group [Y]. In this case, the resin layer and the metal layer can be easily peeled off in the peeling step, which will be described in detail later, which is preferable.

[0134] Examples of such reactive functional groups [Y] include one or more functional groups selected from an epoxy group, a carboxylic acid group, a carboxylic anhydride group, a keto group, an alkylolamide group, an isocyanate group, a vinyl group, an alkyl halide group, an acryloyl group, a cyanamide group, a carbamide group, and an acyl halide group. The reactive functional group [Y] is present in an amount of preferably 50 mmol / kg to 10,000 mmol / kg, more preferably 100 mmol / kg to 8,000 mmol / kg, and even more preferably 100 mmol / kg to 5,000 mmol / kg, relative to the entire resin layer, in order to further improve adhesion to the metal layer.

[0135] Examples of the resin layer having the reactive functional group [Y] include urethane resin, acrylic resin, core-shell type composite resin of urethane resin and acrylic resin, epoxy resin, phenoxy resin, imide resin, amide resin, melamine resin, aminotriazine-modified novolac resin, phenol resin, urea-formaldehyde resin, blocked isocyanate obtained by reacting polyisocyanate with a blocking agent such as phenol, polyvinyl alcohol, polyvinylpyrrolidone, etc. Furthermore, these resins can be used alone or in combination of two or more.

[0136] The aminotriazine-modified novolac resin is a novolac resin in which an aminotriazine ring structure and a phenol structure are bonded via a methylene group. The aminotriazine-modified novolac resin can be obtained, for example, by co-condensing an aminotriazine compound such as melamine, benzoguanamine, or acetoguanamine with a phenol compound such as phenol, cresol, butylphenol, bisphenol A, phenylphenol, naphthol, or resorcinol and formaldehyde at approximately neutral pH in the presence of a weak alkaline catalyst such as an alkylamine or without a catalyst, or by reacting an alkyl ether of an aminotriazine compound such as methyl-etherified melamine with the phenol compound.

[0137] The aminotriazine-modified novolak resin preferably contains substantially no methylol groups. The aminotriazine-modified novolak resin may contain molecules in which only aminotriazine structures are methylene-linked, molecules in which only phenol structures are methylene-linked, or the like, which are produced as by-products during the production of the aminotriazine-modified novolak resin. Furthermore, the aminotriazine-modified novolak resin may contain a small amount of unreacted raw materials.

[0138] Examples of the phenol structure include a phenol residue, a cresol residue, a butylphenol residue, a bisphenol A residue, a phenylphenol residue, a naphthol residue, and a resorcinol residue. The term "residue" as used herein refers to a structure in which at least one hydrogen atom bonded to a carbon atom of an aromatic ring has been removed. For example, in the case of phenol, this refers to a hydroxyphenyl group.

[0139] Examples of the triazine structure include structures derived from aminotriazine compounds such as melamine, benzoguanamine, and acetoguanamine.

[0140] The phenol structure and the triazine structure can each be used alone or in combination of two or more. Furthermore, since adhesion can be further improved, the phenol structure is preferably a phenol residue, and the triazine structure is preferably a structure derived from melamine. Furthermore, since adhesion can be further improved, the hydroxyl value of the aminotriazine-modified novolac resin is preferably in the range of 50 mgKOH / g to 200 mgKOH / g, more preferably in the range of 80 mgKOH / g to 180 mgKOH / g, and even more preferably in the range of 100 mgKOH / g to 150 mgKOH / g. The aminotriazine-modified novolac resin can be used alone or in combination of two or more. Furthermore, when an aminotriazine-modified novolac resin is used as the compound having an aminotriazine ring, it is preferable to use an epoxy resin in combination.

[0141] Examples of the epoxy resin include bisphenol A type epoxy resins, bisphenol F type epoxy resins, biphenyl type epoxy resins, cresol novolac type epoxy resins, phenol novolac type epoxy resins, bisphenol A novolac type epoxy resins, alcohol ether type epoxy resins, tetrabromobisphenol A type epoxy resins, naphthalene type epoxy resins, phosphorus-containing epoxy compounds having a structure derived from a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative, epoxy resins having a structure derived from a dicyclopentadiene derivative, epoxidized products of fats and oils such as epoxidized soybean oil, etc. These epoxy resins can be used alone or in combination of two or more.

[0142] Among the epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, biphenyl epoxy resins, cresol novolac epoxy resins, phenol novolac epoxy resins, bisphenol A novolac epoxy resins, and naphthalene epoxy resins are preferred because they can further improve adhesion, and bisphenol A epoxy resins and naphthalene epoxy resins are particularly preferred. The epoxy group (functional group [Y]) of the epoxy resin reacts with the basic nitrogen atom-containing group contained in the metal layer to form a covalent bond, thereby improving the adhesion at the interface between the metal layer and the resin layer.

[0143] The epoxy equivalent of the epoxy resin is preferably in the range of 100 g / equivalent to 300 g / equivalent, more preferably in the range of 120 g / equivalent to 250 g / equivalent, and even more preferably in the range of 150 g / equivalent to 200 g / equivalent, because this allows for further improvement in adhesion.

[0144] When the resin layer is a layer containing an aminotriazine-modified novolac resin and an epoxy resin, the molar ratio [(x) / (y)] of the phenolic hydroxyl group (x) in the aminotriazine-modified novolac resin to the epoxy group (y) in the epoxy resin is preferably in the range of 0.1 to 5, more preferably in the range of 0.2 to 3, and even more preferably in the range of 0.3 to 2, in order to further improve adhesion.

[0145] A curing accelerator may be used in combination to accelerate the reaction between the aminotriazine-modified novolac resin and the epoxy resin. Examples of the curing accelerator include amine compounds having a primary, secondary, or tertiary amino group. The amine compound may be any of aliphatic, alicyclic, and aromatic compounds. The curing accelerator may also include mercaptans, acid anhydrides, boron acid fluorides, boric acid esters, organic acid hydrazides, Lewis acids, organometallic compounds, onium salts, and cationic compounds.

[0146] It is also preferable to use a material containing a phenoxy resin. It is preferable to use a phenoxy resin having a weight-average molecular weight in the range of 10,000 to 100,000. By using a phenoxy resin having a weight-average molecular weight in this range for the resin layer, the elongation of the polymer can be improved, and the elastic modulus can be further improved. This improves the transfer rate of the resin layer and metal layer after thermocompression bonding the surface of the resin layer to the support using the first laminate structure and then peeling off the temporary substrate.

[0147] Furthermore, by using a phenoxy resin having a weight-average molecular weight within this range, deterioration such as polymer decomposition due to heat can be suppressed in the manufacturing method of a printed wiring board described below, and the adhesion of the metal layer can be maintained. Phenoxy resin is a polyhydroxy polyether obtained by reacting a divalent phenol compound with epichlorohydrin, or by reacting a divalent epoxy compound with a divalent phenol compound. Examples of divalent phenol compounds include bisphenols. Examples of phenoxy resins include phenoxy resins having a bisphenol A structure (skeleton), phenoxy resins having a bisphenol F structure, phenoxy resins having a bisphenol S structure, phenoxy resins having a bisphenol M structure, phenoxy resins having a bisphenol P structure, and phenoxy resins having a bisphenol Z structure. Other examples include phenoxy resins having skeletal structures such as novolac structure, anthracene structure, fluorene structure, dicyclopentadiene structure, norbornene structure, naphthalene structure, biphenyl structure, and adamantane structure. These phenoxy resins may be used alone or in combination of two or more. Among these, those having a bisphenol structure are preferred, with bisphenol A, bisphenol F, and bisphenol S being more preferred. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group.

[0148] Furthermore, if the weight-average molecular weight of the phenoxy resin is 10,000 or more, heat resistance is improved, and if the weight-average molecular weight is 100,000 or less, solubility in organic solvents is improved, and the viscosity of the coating liquid when forming the resin layer becomes appropriate, resulting in good handling. The weight-average molecular weight of the phenoxy resin is preferably 20,000 to 80,000, more preferably 22,000 to 70,000. The weight-average molecular weight of the phenoxy resin can be adjusted by the molar ratio of the epoxy resin to the phenolic resin and the reaction time in the above reaction. The weight-average molecular weight of the phenoxy resin was measured by gel permeation chromatography (GPC) and converted into standard polystyrene. For the GPC measurement, a high-speed GPC apparatus (HLC-8420GPC, manufactured by Tosoh Corporation) was used as the measuring device, and TSKgel G5000HxL / G4000HxL / G3000HxL / G2000HxL (manufactured by Tosoh Corporation) columns connected in series were used, and tetrahydrofuran was used as the eluent, and measurement was performed using an RI detector. Furthermore, while phenoxy resin generally refers to a high-molecular-weight epoxy resin, "epoxy resin" refers to one having a weight-average molecular weight of less than 10,000, and is to be distinguished from the above-mentioned phenoxy resin.

[0149] As the phenoxy resin, commercially available ones may be used. For example, Mitsubishi Chemical Corporation's 1256, 1255HX30 (both phenoxy resins containing a bisphenol A skeleton), 4250, 4275 (bis A / bis F mixed type), YL6794, YL7213, YL7290, YL7482, YL7553, YX8100 (phenoxy resins containing a bisphenol S skeleton), X6954 (phenoxy resins containing a bisphenol acetophenone skeleton), Examples of suitable phenoxy resins include YX7200 (phenoxy resin containing a cyclohexane skeleton), YP-70 (bisphenol F type phenoxy resin), ZX356-2 (phenoxy resin containing bisphenol A and bisphenol F skeletons), YPB-40PXM40 (bromine-containing phenoxy resin), ERF-001M30 (phosphorus-containing phenoxy resin), FX-280, FX-293, FX-310 (phenoxy resin containing a fluorene skeleton), and PKHA, PKHB, PKHB+, PKHC, PKHH, PKHJ, and PKFE manufactured by Gabriel Phenoxies.

[0150] <Metal Layer> The metal layer can be used as a plating seed layer. That is, the metal layer serves as a plating seed layer when forming a pattern circuit layer (described later) by a plating process during the manufacture of a printed wiring board or semiconductor device. The film thickness of the metal layer may be appropriately selected depending on the specifications and application of the printed wiring board or semiconductor device. Specifically, a range of 1 nm to 5 μm is preferred, and a range of 1 nm to 3 μm is more preferred. Furthermore, the film thickness of the metal layer is more preferably in the range of 10 nm to 1 μm, since this facilitates the formation of a conductive layer by the plating process in the manufacturing method of a printed wiring board (described later) and the metal layer removal process by etching (described later). Furthermore, the surface resistivity of the metal layer is preferably 0.01 Ω / □ to 20 Ω / □, more preferably 0.1 Ω / □ to 10 Ω / □, and even more preferably 0.3 Ω / □ to 5 Ω / □.

[0151] As described above, the metal layer may contain a material suitable for the release force reducing treatment described in the section <Release Force Reducing Treatment>. In this case, the metal layer becomes a layer whose release force is reduced by the release force reducing treatment. Note that, hereinafter, the metal layer will be described as a layer that does not contain a material suitable for the release force reducing treatment described in the section <Release Force Reducing Treatment> and whose release force is not reduced by the release force reducing treatment.

[0152] The metal layer can be provided on one or both surfaces of the temporary substrate in the first laminate structure, or on the surface of the resin layer in the second laminate structure. Examples of methods for forming a metal layer include a method of coating a metal particle dispersion on the temporary substrate or resin layer. The method for coating the metal particle dispersion is not particularly limited as long as a metal layer can be formed, and various coating methods can be adopted. The coating method can be appropriately selected depending on the shape, size, and degree of rigidity of the temporary substrate or resin layer. Specific coating methods include, for example, gravure printing, offset printing, flexography, pad printing, gravure offset printing, letterpress printing, letterpress reversal printing, screen printing, microcontact printing, reverse printing, air doctor coater printing, blade coater printing, air knife coater printing, squeeze coater printing, impregnation coater printing, transfer roll coater printing, kiss coater printing, cast coater printing, spray coater printing, inkjet printing, die coater printing, spin coater printing, bar coater printing, and dip coater printing. In this case, the metal layer may be formed on both sides of the temporary substrate simultaneously, or may be formed on one side and then formed on the other side. Also, when a resin layer is formed on both sides of the support, the metal layer may be formed on the resin layer formed on both sides of the support simultaneously, or may be formed on one side and then formed on the other side.

[0153] As the material for the metal layer, various conductive substances such as gold, platinum, palladium, ruthenium, tin, copper, nickel, iron, cobalt, titanium, indium, and iridium can be used, as long as the plating step and etching step in the method for producing a printed wiring board described below can be carried out without any problems. Among these, silver is preferably used because it has the highest electrical conductivity and is not oxidized in air, resulting in a decrease in electrical conductivity.

[0154] When silver is used as the material for constituting the metal layer, a metal material other than silver can be used in combination. In this case, the proportion of the metal material other than silver is preferably 5 parts by mass or less, more preferably 2 parts by mass or less, per 100 parts by mass of silver in order to enable the plating step in the method for producing a printed wiring board described below to be carried out and to ensure the etching removability of the metal layer.

[0155] The components constituting the metal layer can be confirmed by using known analytical methods such as X-ray fluorescence, atomic absorption spectrometry, and ICP method.

[0156] More specifically, the metal layer may contain silver nanoparticles and a dispersant. That is, the metal layer may be formed by coating a particle dispersion in which silver nanoparticles are dispersed in a dispersant. The particle dispersion is a dispersion in which conductive particles such as silver nanoparticles are dispersed in a dispersant. The shape of the conductive particles such as silver nanoparticles is not particularly limited as long as it satisfactorily forms the metal layer, and various shapes such as spherical, lenticular, polyhedral, tabular, rod-like, and wire-like shapes can be mentioned. These conductive particles such as silver nanoparticles can be used alone or in combination of two or more different shapes.

[0157] On the other hand, the metal layer may not contain a dispersant. When the metal layer does not contain a dispersant, the conductivity of the metal layer can be improved. In this case, there are advantages in that the plating growth in the plating step described below is fast and the film thickness is stable.

[0158] Furthermore, in the step of exposing a pattern circuit to actinic light on a resist layer in the method for producing a printed wiring board described below, in order to suppress reflection of the actinic light from the metal layer, a light-absorbing pigment or dye such as graphite or carbon, cyanine compounds, phthalocyanine compounds, dithiol metal complexes, naphthoquinone compounds, diimmonium compounds, or azo compounds may be contained in the metal layer as a light absorber. These pigments or dyes may be appropriately selected according to the wavelength of the actinic light used. These pigments or dyes may be used alone or in combination of two or more. Furthermore, to contain these pigments or dyes in the metal layer, these pigments or dyes may be blended into the particle dispersion. Furthermore, it is preferable that these pigments or dyes be in a range that does not inhibit the formation of the metal layer, allows the electroplating step in the method for producing a printed wiring board described below to be performed, and ensures etching removability.

[0159] When the metal layer contains silver nanoparticles, the average particle size of the silver nanoparticles is preferably 1 nm to 100 nm, more preferably 2 nm to 100 nm, and even more preferably 5 nm to 50 nm. Note that, when the silver nanoparticles have a shape other than spherical, the average particle size refers to the average particle size of the short axis of the silver nanoparticles. If the average particle size of the silver nanoparticles is below the lower limit of this range, the silver nanoparticles may aggregate and settle. Furthermore, if the average particle size of the silver nanoparticles is above the upper limit of this range, the silver particles may be too large to be fully dispersed and may gradually settle. Therefore, by setting the average particle size of the silver nanoparticles within this range, the homogeneity of the metal layer is further improved, and the removability by the etching solution described below is further improved, allowing for the formation of fine pattern circuits.

[0160] The metal layer may also contain conductive particles other than the silver nanoparticles described above, such as silver particles. When the conductive particles other than the silver nanoparticles described above are spherical or polyhedral, their average particle diameter is preferably in the range of 100 nm to 20,000 nm. The conductive particles other than silver nanoparticles, such as silver particles, are not particularly limited, but are preferably spherical, lenticular, rod-shaped, or wire-shaped, and more preferably spherical.

[0161] The "average particle size" of nanometer-sized particles is a volume average value measured by diluting the silver nanoparticles or conductive particles with a good dispersion solvent and measuring the volume average value by dynamic light scattering. For this measurement, a "Nanotrac UPA-150" manufactured by Microtrac Corporation can be used.

[0162] The dispersant contained in the particle dispersion can maintain dispersion stability for a long period of time without causing aggregation, fusion, or precipitation of conductive particles such as silver nanoparticles. Such dispersants are preferably dispersants having a functional group that coordinates with conductive particles such as silver nanoparticles, such as dispersants having functional groups such as a carboxyl group, an amino group, a cyano group, an acetoacetyl group, a phosphorus atom-containing group, a thiol group, a thiocyanato group, or a glycinato group. In particular, when silver nanoparticles are used, it is preferable to use a dispersant having a nitrogen atom-containing functional group such as an amino group.

[0163] The dispersant may be a commercially available dispersant or a uniquely synthesized low- or high-molecular-weight dispersant, and may be appropriately selected depending on the purpose, such as the solvent for dispersing conductive particles such as silver nanoparticles, the type of the temporary substrate or resin layer to which the particle dispersion is applied, etc. Suitable dispersants include, for example, dodecanethiol, 1-octanethiol, triphenylphosphine, dodecylamine, polyethylene glycol, polyvinylpyrrolidone, polyethyleneimine, polyvinylpyrrolidone; fatty acids such as myristic acid, octanoic acid, and stearic acid; and polycyclic hydrocarbon compounds having a carboxyl group such as cholic acid, glycyrrhizic acid, and abintin acid.

[0164] Although a resin having a reactive functional group [Y] has been described as the resin contained in the resin layer, a compound having a reactive functional group [X] capable of bonding with the reactive functional group [Y] may be used as a dispersant in the metal layer. Bonding of the reactive functional group [X] with the reactive functional group [Y] improves adhesion between the metal layer and the resin layer. On the other hand, the metal layer may contain a resin that does not have a reactive functional group [X]. This is preferable because the resin layer and the metal layer can be easily peeled off in the peeling step, which will be described in detail later.

[0165] Examples of compounds having a reactive functional group [X] include compounds having an amino group, an amide group, an alkylolamide group, a carboxyl group, a carboxyl anhydride group, a carbonyl group, an acetoacetyl group, an epoxy group, an alicyclic epoxy group, an oxetane ring, a vinyl group, an allyl group, a (meth)acryloyl group, a (blocked) isocyanate group, an (alkoxy)silyl group, and the like, and silsesquioxane compounds. In particular, the reactive functional group [X] is preferably a basic nitrogen atom-containing group, since this can further improve the adhesion between the resin layer and the metal layer. Examples of the basic nitrogen atom-containing group include an imino group, a primary amino group, and a secondary amino group.

[0166] The dispersant may contain one or more basic nitrogen atom-containing groups in one molecule. When the dispersant contains multiple basic nitrogen atoms, some of the basic nitrogen atom-containing groups interact with conductive particles such as silver nanoparticles to contribute to the dispersion stability of the particles, and the remaining basic nitrogen atom-containing groups contribute to improving adhesion to the resin layer.

[0167] The dispersant is preferably a polymer dispersant because it has the stability and coatability of a dispersion of conductive particles such as silver nanoparticles, and can form a metal layer that exhibits good adhesion on the temporary substrate. Preferred polymer dispersants include polyalkyleneimines such as polyethyleneimine and polypropyleneimine, and compounds in which polyoxyalkylene is added to the polyalkyleneimines.

[0168] The compound in which a polyoxyalkylene is added to the polyalkyleneimine may be a compound in which the polyethyleneimine and the polyoxyalkylene are bonded in a linear chain, or a compound in which the polyoxyalkylene is grafted onto a side chain of the main chain made of the polyethyleneimine.

[0169] Specific examples of the compound in which a polyoxyalkylene is added to the polyalkyleneimine include a block copolymer of polyethyleneimine and polyoxyethylene, a compound in which a polyoxyethylene structure is introduced by addition reaction of ethylene oxide with some of the imino groups present in the main chain of polyethyleneimine, and a compound in which an amino group of a polyalkyleneimine, a hydroxyl group of a polyoxyethylene glycol, and an epoxy group of an epoxy resin are reacted with each other.

[0170] Commercially available polyalkyleneimines include "PAO2006W," "PAO306," "PAO318," and "PAO718" from the "Epomin (registered trademark) PAO series" manufactured by Nippon Shokubai Co., Ltd. The number average molecular weight of the polyalkyleneimine is preferably in the range of 3,000 to 30,000.

[0171] The amount of the dispersant required to disperse conductive particles such as silver nanoparticles is preferably in the range of 0.01 parts by mass to 50 parts by mass relative to 100 parts by mass of the particles. Furthermore, since a metal layer exhibiting good adhesion can be formed on the temporary substrate or resin layer, the amount is preferably in the range of 0.1 parts by mass to 10 parts by mass relative to 100 parts by mass of the particles. Furthermore, since the plating properties of the metal layer can be improved, the amount is more preferably in the range of 0.1 parts by mass to 7 parts by mass.

[0172] The method for producing a particle dispersion is not particularly limited, and various methods can be used. For example, conductive particles such as silver nanoparticles produced using a gas-phase method such as low-vacuum gas evaporation may be dispersed in a solvent, or a metal compound may be reduced in a liquid phase to directly prepare a particle dispersion. In both the gas-phase and liquid-phase methods, the solvent composition of the dispersion during production and the dispersion during application can be changed as needed by solvent exchange or solvent addition. Of the gas-phase and liquid-phase methods, the liquid-phase method is particularly preferred due to the stability of the dispersion and the simplicity of the production process. For example, the liquid-phase method can be used to produce a particle dispersion by reducing metal ions in the presence of the polymer dispersant.

[0173] The particle dispersion may further contain, as necessary, organic compounds such as surfactants, leveling agents, viscosity modifiers, film-forming aids, antifoaming agents, and preservatives. Examples of the surfactants include nonionic surfactants such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene sorbitol tetraoleate, and polyoxyethylene-polyoxypropylene copolymers; anionic surfactants such as fatty acid salts such as sodium oleate, alkyl sulfate ester salts, alkylbenzenesulfonates, alkyl sulfosuccinates, naphthalenesulfonates, polyoxyethylene alkyl sulfates, sodium alkanesulfonates, and sodium alkyldiphenylethersulfonates; and cationic surfactants such as alkylamine salts, alkyltrimethylammonium salts, and alkyldimethylbenzylammonium salts.

[0174] As the leveling agent, a general leveling agent can be used, for example, a silicone-based compound, an acetylene diol-based compound, a fluorine-based compound, etc. As the viscosity modifier, a general thickening agent can be used, for example, an acrylic polymer that can be thickened by adjusting the alkalinity, a synthetic rubber latex, a urethane resin that can be thickened by molecular association, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, hydrated castor oil, amide wax, oxidized polyethylene, metal soap, dibenzylidene sorbitol, etc.

[0175] As the film-forming aid, a general film-forming aid can be used, for example, an anionic surfactant such as dioctyl sulfosuccinate sodium salt, a hydrophobic nonionic surfactant such as sorbitan monooleate, polyether-modified siloxane, silicone oil, etc. As the defoaming agent, a general defoaming agent can be used, for example, a silicone-based defoaming agent, a nonionic surfactant, polyether, higher alcohol, polymer-based surfactant, etc. As the preservative, a general preservative can be used, for example, an isothiazolin-based preservative, a triazine-based preservative, an imidazole-based preservative, a pyridine-based preservative, an azole-based preservative, a pyrithione-based preservative, etc.

[0176] <Temporary substrate> The temporary substrate in the first laminate structure of the present disclosure is not particularly limited as long as it can form a metal layer, and for example, a resin such as PET or a metal foil such as copper foil can be used. As the temporary substrate, it is preferable to use one that is smooth and has no irregularities on the surface and / or back surface on which the metal layer is formed. By smoothing the surface and / or back surface on which the metal layer is formed, when forming the metal layer or the resin layer formed on the metal layer by coating, or when transferring the metal layer and resin layer from the first laminate structure to the support, it becomes easy to form the resin layer or metal layer without cracks or defects. The Sz of the surface and / or back surface on which the metal layer is formed in the temporary substrate is preferably 3000 nm or less, more preferably 1000 nm or less, and even more preferably 100 nm or less.

[0177] The temporary substrate needs to be finally peeled off after the metal layer and the resin layer are transferred onto the support. Therefore, it is preferable to select a temporary substrate that can be easily peeled off at the interface with the metal layer. Examples of the temporary substrate include polymer films such as aromatic polyesters such as polyethylene terephthalate, polybutylene terephthalate (PBT), polyethylene naphthalate, and polybutylene naphthalate; fluorine-based resins such as polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, vinylidene fluoride resin, trifluorochloroethylene resin, trifluorochloroethylene-ethylene copolymer, tetrafluoroethylene-perfluorodioxol copolymer, vinyl fluoride resin, and polyvinylidene fluoride; polymethylpentene (TPX), polypropylene (PP) [including biaxially oriented polypropylene (OPP) and non-axially oriented polypropylene (CPP)], and polyethylene (PE) [high density Polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE) and other olefin resins; polystyrene (PS); polyvinyl chloride (PVC), polyimide, polyimide resins such as transparent polyimide; polyamide resins such as polyamideimide and polyamide; polycarbonate, acrylonitrile-butadiene-styrene (ABS) resin, polymer alloys of ABS and polycarbonate, acrylic resins such as poly(meth)methyl acrylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polycarbonate, polyethylene, polypropylene, polyurethane, liquid crystal polymer (LCP), polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), epoxy resins, etc. Among them, as the temporary substrate, it is preferable to use aromatic polyester, polyethylene, olefin resin, fluorine-based resin, polyimide resin, LCP, polyphenylene sulfide.

[0178] Metals may also be used as the temporary substrate. Examples of metals that can be used include copper, aluminum, aluminum alloys, titanium, stainless steel, beryllium copper, phosphor bronze, nickel, nichrome, nickel alloys, tin, zinc, lead, gold, tantalum, molybdenum, niobium, iron, and silver. Alternatively, inorganic materials such as silicone, ceramics, and glass can be suitably used as the temporary substrate.

[0179] The shape of the temporary substrate is not particularly limited, and is preferably a film or sheet shape due to its good handleability. The film thickness of the temporary substrate is usually preferably in the range of 1 μm to 5,000 μm, more preferably in the range of 1 μm to 300 μm, more preferably in the range of 1 μm to 200 μm, more preferably in the range of 1 μm to 100 μm, and even more preferably in the range of 1 μm to 70 μm. Since the temporary substrate is no longer needed after the metal layer and resin layer are transferred onto the support, it is preferable that the temporary substrate be thin enough not to lose workability from a cost perspective.

[0180] As a method for transferring a metal layer, a resin layer, etc. onto a support, the surface of the resin layer on the temporary substrate can be bonded to the support using heat and pressure, and for example, a thermal lamination method, a thermal roll transfer method, a pressing method, a vacuum pressing method, etc. can be suitably used.

[0181] The first laminate structure of the present disclosure may have a peelable cover layer on the side opposite the temporary substrate. That is, the first laminate structure of the present disclosure may include a temporary substrate, a metal layer and a resin layer disposed on the temporary substrate, and a peelable cover layer disposed on the side opposite the temporary substrate. The peelable cover layer can protect the metal layer and the resin layer. There are no particular limitations on the peelable cover layer, and various commercially available resin or metal films can be used. For example, polyethylene, polypropylene, and polyethylene terephthalate films can be suitably used.

[0182] The peelable cover layer may be a film of polyethylene, polypropylene, polyethylene terephthalate, or the like, having a silicone layer thereon to improve peelability. The peelable cover layer may be a film of polyethylene, polypropylene, polyethylene terephthalate, or the like, having adhesive properties to provide adhesion. The thickness of the peelable cover layer is preferably 10 μm to 100 μm, more preferably 15 μm to 70 μm, from the viewpoints of improving the handleability of the film and protecting the metal layer, resin layer, and the like. The peelable cover layer can be laminated on the resin layer after coating the resin layer. For example, when the resin layer is coated using a roll coater, the peelable cover layer can be laminated by winding it up together with the resin layer during winding. It is even more preferable for the peelable cover layer to be adhesive. This prevents defects from occurring in the resin layer due to contact with the transport roll.

[0183] <Method 1 for manufacturing printed wiring board> A method for manufacturing a printed wiring board according to the present disclosure includes the steps of: using a second laminate structure including a support, at least one resin layer disposed on the support, and a metal layer disposed on the resin layer, wherein at least one of the metal layer and the resin layer contains a resin whose peel strength is reduced by a peel force reduction treatment; forming a pattern circuit layer on the resin layer by plating using the metal layer as a plating seed layer; and peeling a portion including the support from a portion including the pattern circuit layer in a state in which the peel strength of the resin layer has been reduced by the peel force reduction treatment.

[0184] One embodiment of the method for manufacturing a printed wiring board according to the present disclosure will be described with reference to FIGS. 5 to 12A and 12B. First, in the method for manufacturing a printed wiring board according to the present disclosure, a second laminate structure 20 including the support 14, resin layer 13, and metal layer 12 described above is prepared, as shown in FIG. 5. While FIG. 5 illustrates the second laminate structure 20 shown in FIG. 1C as an example, the same process applies when using the second laminate structure 20 shown in FIGS. 2C, 3C, and 4A to 4G. Next, as shown in FIG. 6, a resist layer 30 is formed on the metal layer 12. Next, as shown in FIG. 7, a patterned layer having a shape corresponding to the desired wiring is formed. Next, as shown in FIG. 8, the metal layer 12 is used as a plating seed layer to form a patterned circuit layer 31 made of metal in the areas where the resist layer 30 is not formed. Next, as shown in FIG. 9, the resist layer 30 is removed from the second laminate structure 20. Next, in this embodiment, as shown in FIG. 10, the metal layer 12 exposed to the outside where the patterned circuit layer 31 is not formed is removed. Next, as shown in Fig. 11 , a sealing material layer 32 is formed so as to embed the formed pattern circuit layer 31. Next, the above-mentioned peel force reducing treatment is performed to peel off the portion including the pattern circuit layer 31 from the portion including the support 14. At this time, as shown in Figs. 12A and 12B , peeling may occur at the interface between the support 14 and the resin layer 13 (Fig. 12A), at the interface between the resin layer 13 and the metal layer 12, or due to internal cohesive failure of the resin layer 13 (Fig. 12B).

[0185] In addition, the method for manufacturing a printed wiring board disclosed herein may include a step of bonding the resin layer 13 in the first laminate structure 10 to the support 14 as shown in Figures 1A to 3C, and peeling off the temporary substrate 11 in the first laminate structure 10 to produce the second laminate structure 20.

[0186] 5 to 12A and 12B , in the method for manufacturing a printed wiring board according to the present disclosure, a resist layer 30 is patterned on a metal layer 12, and a circuit is formed by a semi-additive process using the metal layer 12 as an electroplating seed layer.

[0187] <Resist Patterning Step> The resist layer 30 may be formed by attaching a film or by applying a liquid. For the purpose of improving adhesion to the metal layer 12, the surface of the metal layer 12 or the film resist may be subjected to a surface treatment such as cleaning treatment with an acidic or alkaline cleaning solution, corona treatment, plasma treatment, UV treatment, gas-phase ozone treatment, liquid-phase ozone treatment, or treatment with a surface treatment agent. These surface treatments may be performed by one method or two or more methods in combination.

[0188] Examples of treatments using surface treatment agents include a treatment method using a rust inhibitor consisting of a triazole compound, a silane coupling agent, and an organic acid, as described in JP-A-7-258870; a treatment method using an organic acid, a benzotriazole rust inhibitor, and a silane coupling agent, as described in JP-A-2000-286546; a treatment method using a substance having a structure in which a nitrogen-containing heterocycle such as triazole or thiadiazole and a silyl group such as a trimethoxysilyl group or a triethoxysilyl group are bonded via an organic group having a thioether (sulfide) bond, as described in JP-A-2002-363189; and a treatment method using a compound having a structure in which a triazine ring and an amino group are bonded via an organic group having a thioether (sulfide) bond, as described in WO2013 / 186941. a method of treating with a silane compound having the formula (I) or (II), a method of treating with an imidazole silane compound obtained by reacting a formyl imidazole compound with an aminopropyl silane compound as described in JP 2015-214743 A, a method of treating with an azole silane compound as described in JP 2016-134454 A, a method of treating with an aromatic compound having an amino group and an aromatic ring in one molecule, a polybasic acid having two or more carboxyl groups, and a solution containing halide ions as described in JP 2017-203073 A, a method of treating with a surface treatment agent containing a triazole silane compound as described in JP 2018-16865 A, and the like can be used.

[0189] The resist layer 30 can be preferably a photosensitive resist that can be patterned with light, and the pattern is exposed to active light through a photomask or using a direct exposure device. The exposure dose can be set appropriately as needed. The latent image formed in the photosensitive resist by exposure is removed using a developer, thereby patterning the resist layer 30 into the desired shape.

[0190] Examples of the developer include a dilute aqueous alkali solution of 0.3% by mass to 2% by mass of sodium carbonate, potassium carbonate, or the like. A surfactant, an antifoaming agent, or a small amount of an organic solvent to promote development may be added to the dilute aqueous alkali solution. Furthermore, development is carried out by immersing the exposed substrate in the developer or by spraying the developer onto the resist with a spray or the like, and this development can form a patterned resist in which the pattern-forming portion has been removed.

[0191] As the resist, commercially available resist ink, liquid resist, or dry film resist can be used, and may be appropriately selected depending on the desired pattern resolution, the type of exposure machine to be used, the type of chemical solution to be used in the plating process in the subsequent step, pH, etc.

[0192] Examples of commercially available resist inks include "Plating Resist MA-830" and "Etching Resist X-87" manufactured by Taiyo Ink Mfg. Co., Ltd.; etching resist and plating resist from NAZDAR; and "Etching Resist PLAS FINE PER" series and "Plating Resist PLAS FINE PPR" series manufactured by GOO Chemical Industry Co., Ltd. Examples of electrodeposition resists include "Eagle Series" and "Peper Series" manufactured by The Dow Chemical Company. Examples of commercially available dry films include "Photec" series manufactured by Resonac Inc.; "ALPHO" series manufactured by Nikko Materials Co., Ltd.; "Sunfort" series manufactured by Asahi Kasei Corporation; and "Riston" series manufactured by DuPont.

[0193] To efficiently produce patterned circuits, it is convenient to use a dry film resist, and particularly when forming fine patterned circuits, a dry film for semi-additive processing may be used. Commercially available dry films for this purpose include, for example, "ALFO LDF500" and "NIT2700" manufactured by Nikko Materials Co., Ltd., "Sunfort UFG-258" manufactured by Asahi Kasei Corporation, "RD Series (RD-2015, 1225)" and "RY Series (RY-5319, 5325)" manufactured by Resonac Inc., and "PlateMaster Series (PM200, 300)" manufactured by DuPont.

[0194] <Electrolytic plating process> After forming a resist layer 30 having a predetermined pattern, electrolytic plating is performed using the metal layer 12 as a plating seed layer to form a metal film on the metal layer 12 exposed to the outside, thereby forming a pattern circuit layer 31.

[0195] The metal constituting the pattern circuit layer 31 formed by electroplating is not particularly limited, but it is preferably a metal different from the metal layer 12 so that only the metal layer 12 can be selectively removed in the etching process described below, and generally, copper is more preferable from the viewpoint of electrical conductivity and reliability.

[0196] In the electrolytic plating step, the metal layer 12 is used as a cathode electrode for electrolytic copper plating, and the metal layer 12 exposed by development is treated by electrolytic copper plating to form a copper-containing patterned circuit layer 31. Before forming the patterned circuit layer 31 by electrolytic copper plating, the surface of the metal layer 12 may be subjected to a surface treatment, if necessary. Examples of such surface treatments include cleaning with an acidic or alkaline cleaning solution, corona treatment, plasma treatment, UV treatment, gas-phase ozone treatment, liquid-phase ozone treatment, and treatment with a surface treatment agent, provided that the surface of the metal layer 12 and the formed patterned resist layer 30 are not damaged. These surface treatments can be performed by one method or by a combination of two or more methods.

[0197] In the electrolytic plating process, when forming the pattern circuit layer 31, annealing may be performed after plating for the purpose of alleviating stress in the plating film and improving adhesion. Annealing may be performed before the etching process described below, after the etching process, or before or after the etching.

[0198] The annealing temperature may be selected appropriately within the range of 40°C to 300°C depending on the heat resistance and intended use, but a range of 40°C to 250°C is preferred, and a range of 40°C to 200°C is more preferred for the purpose of suppressing oxidative degradation of the plating film. Furthermore, the annealing time is preferably 10 minutes to 10 days when the temperature range is 40°C to 200°C, and about 5 minutes to 10 hours when annealing at temperatures above 200°C. When annealing the plating film, a rust inhibitor may be applied to the plating film surface as appropriate.

[0199] <Resist Stripping Step> The method for stripping the resist layer 30 is not particularly limited, and may be performed under the recommended conditions described in the catalog, specifications, etc. of the photosensitive resist used. The resist stripping solution may be a commercially available resist stripping solution or a 1.5% to 3% by mass aqueous solution of sodium hydroxide or potassium hydroxide set at 45°C to 60°C. The resist layer 30 can be stripped by immersing the formed pattern circuit layer 31 in the stripping solution, or by spraying the stripping solution with a spray or the like.

[0200] <Metal Layer Etching Step> In this embodiment, after peeling off the resist layer 30, the metal layer 12 exposed to the outside, on which the pattern circuit layer 31 is not formed, is removed by etching. The etching solution used to remove the metal layer 12 is preferably one that selectively etches only the metal layer 12 and does not etch the pattern circuit layer 31. From this viewpoint, the metal layer 12 preferably contains silver nanoparticles.

[0201] Such etching solutions include mixtures of carboxylic acids and hydrogen peroxide. Examples of carboxylic acids include acetic acid, formic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, oxalic acid, malonic acid, succinic acid, benzoic acid, salicylic acid, phthalic acid, isophthalic acid, terephthalic acid, gallic acid, mellitic acid, cinnamic acid, pyruvic acid, lactic acid, malic acid, citric acid, fumaric acid, maleic acid, aconitic acid, glutaric acid, adipic acid, and amino acids. These carboxylic acids can be used alone or in combination. Among these carboxylic acids, acetic acid is preferably used primarily because it is easy to manufacture and handle as an etching solution.

[0202] When a mixture of carboxylic acid and hydrogen peroxide is used as an etching solution, it is believed that the hydrogen peroxide reacts with the carboxylic acid to produce percarboxylic acid (peroxycarboxylic acid). The produced percarboxylic acid is presumed to preferentially dissolve the silver constituting the metal layer 12 while suppressing the dissolution of the metal constituting the pattern circuit layer 31.

[0203] When the metal layer 12 contains silver nanoparticles and the pattern circuit layer 31 contains copper, it is particularly suitable to use the etching solution SVE-810E manufactured by ADEKA Corporation. By using the etching solution SVE-810E manufactured by ADEKA Corporation, the copper-containing pattern circuit layer 31 is not roughened by the etching solution, and a smooth and rectangular circuit can be obtained.

[0204] The mixing ratio of the mixture of carboxylic acid and hydrogen peroxide is preferably in the range of 2 to 100 moles of hydrogen peroxide per 1 mole of carboxylic acid, and more preferably in the range of 2 to 50 moles of hydrogen peroxide, since this can suppress dissolution of the copper-containing pattern circuit layer 31.

[0205] The mixture of carboxylic acid and hydrogen peroxide is preferably an aqueous solution diluted with water. The content of the mixture of carboxylic acid and hydrogen peroxide in the aqueous solution is preferably in the range of 2% by mass to 65% by mass, more preferably 2% by mass to 30% by mass, of the total etching solution, since this can suppress the effect of a temperature rise in the etching solution.

[0206] The water used for the dilution is preferably water from which ionic substances and impurities have been removed, such as ion-exchanged water, pure water, or ultrapure water. A protective agent may be further added to the etching solution to protect the pattern circuit layer 31 and inhibit dissolution. An azole compound is preferably used as the protective agent. Examples of azole compounds include imidazole, pyrazole, triazole, tetrazole, oxazole, thiazole, selenazole, oxadiazole, thiadiazole, oxatriazole, and thiatriazole. Specific examples of azole compounds include 2-methylbenzimidazole, aminotriazole, 1,2,3-benzotriazole, 4-aminobenzotriazole, 1-bisaminomethylbenzotriazole, aminotetrazole, phenyltetrazole, 2-phenylthiazole, and benzothiazole. These azole compounds can be used alone or in combination. The concentration of the azole compound in the etching solution is preferably in the range of 0.001% to 2% by mass, and more preferably in the range of 0.01% to 0.2% by mass.

[0207] Furthermore, it is preferable to add polyalkylene glycol as a protective agent to the etching solution, as this can suppress dissolution of the copper-containing pattern circuit layer 31. Examples of polyalkylene glycol include water-soluble polymers such as polyethylene glycol, polypropylene glycol, and polyoxyethylene-polyoxypropylene block copolymers. Among these, polyethylene glycol is preferable. Furthermore, the number-average molecular weight of the polyalkylene glycol is preferably in the range of 200 to 20,000. The concentration of the polyalkylene glycol in the etching solution is preferably in the range of 0.001% by mass to 2% by mass, and more preferably in the range of 0.01% by mass to 1% by mass.

[0208] Furthermore, in order to suppress fluctuations in pH, additives such as sodium salts, potassium salts, and ammonium salts of organic acids may be added to the etching solution as needed.

[0209] After removing the metal layer 12 with an etching solution, a cleaning operation may be performed in addition to water washing to prevent the adhesion and residue of silver components dissolved in the etching solution. For the cleaning operation, a cleaning solution that dissolves silver oxide, silver sulfide, and silver chloride but hardly dissolves silver is preferably used. Specifically, an aqueous solution containing a thiosulfate or tris(3-hydroxyalkyl)phosphine, or an aqueous solution containing a mercaptocarboxylic acid or a salt thereof is preferably used as the cleaning chemical. Examples of thiosulfates include ammonium thiosulfate, sodium thiosulfate, and potassium thiosulfate. Examples of the tris(3-hydroxyalkyl)phosphines include tris(3-hydroxymethyl)phosphine, tris(3-hydroxyethyl)phosphine, and tris(3-hydroxypropyl)phosphine. These thiosulfates or tris(3-hydroxyalkyl)phosphines can be used alone or in combination of two or more. When an aqueous solution containing a thiosulfate is used, its concentration may be appropriately set depending on the process time, the characteristics of the cleaning device to be used, and the like. The concentration is preferably in the range of 0.1% by mass to 40% by mass, and more preferably in the range of 1% by mass to 30% by mass from the viewpoints of cleaning efficiency and stability of the chemical solution during continuous use.

[0210] Furthermore, when an aqueous solution containing tris(3-hydroxyalkyl)phosphine is used, the concentration can be appropriately set depending on the process time, the characteristics of the cleaning equipment used, etc., but is preferably in the range of 0.1% by mass to 50% by mass, and more preferably in the range of 1% by mass to 40% by mass from the viewpoints of cleaning efficiency and stability of the chemical solution during continuous use. Examples of mercaptocarboxylic acids include thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, cysteine, and N-acetylcysteine. Examples of salts of mercaptocarboxylic acids include alkali metal salts, ammonium salts, and amine salts. When an aqueous solution of mercaptocarboxylic acid or a salt thereof is used, the concentration is preferably in the range of 0.1% by mass to 20% by mass, and more preferably in the range of 0.5% by mass to 15% by mass from the viewpoints of cleaning efficiency and process costs when treating large quantities.

[0211] Examples of methods for carrying out the above cleaning operation include a method of etching away the metal layer 12 on which the pattern circuit layer 31 is not formed, and then immersing the entire surface in a cleaning solution, and a method of spraying the cleaning solution onto the surface on which the metal layer 12 was formed with a spray or the like. The cleaning solution can be used at room temperature (25°C), but may also be set to a temperature of, for example, 30°C, since this allows for stable cleaning without being affected by the outside air temperature.

[0212] The step of removing the metal layer 12 on which the pattern circuit layer 31 is not formed with an etching solution and the cleaning operation can be repeated as necessary.

[0213] In the method for producing a printed wiring board according to the present disclosure, as described above, after the metal layer 12 on which the pattern circuit layer 31 is not formed is removed with an etching solution, a cleaning operation may be further performed as necessary to further improve the insulation of the portion on which the pattern circuit layer 31 is not formed. For this cleaning operation, for example, an alkaline permanganate solution prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of potassium hydroxide or sodium hydroxide can be used.

[0214] Examples of cleaning using an alkaline permanganate solution include immersing the entire surface in an alkaline permanganate solution set at 20°C to 60°C, and spraying the alkaline permanganate solution onto the surface on which the metal layer 12 was formed using a spray or the like. The surface on which the metal layer 12 was formed may be treated with a water-soluble organic solvent having an alcoholic hydroxyl group before cleaning in order to improve the wettability of the alkaline permanganate solution and improve cleaning efficiency. Examples of such organic solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, and isopropyl alcohol. These organic solvents can be used alone or in combination of two or more.

[0215] The concentration of the alkaline permanganate solution may be appropriately selected as needed, but is preferably one in which 0.1 to 10 parts by mass of potassium permanganate or sodium permanganate is dissolved in 100 parts by mass of a 0.1 to 10% by mass aqueous solution of potassium hydroxide or sodium hydroxide, and from the viewpoint of cleaning efficiency, more preferably one in which 1 to 6 parts by mass of potassium permanganate or sodium permanganate is dissolved in 100 parts by mass of a 1 to 6% by mass aqueous solution of potassium hydroxide or sodium hydroxide.

[0216] When cleaning with an alkaline permanganate solution is performed, it is preferable to treat the surface on which the metal layer 12 was formed with a solution having a neutralizing / reducing effect after cleaning with the alkaline permanganate solution. Examples of the solution having a neutralizing / reducing effect include an aqueous solution containing 0.5% by mass to 15% by mass of dilute sulfuric acid or an organic acid. Examples of the organic acid include formic acid, acetic acid, oxalic acid, citric acid, ascorbic acid, and methionine.

[0217] The cleaning with the alkaline permanganate solution may be carried out after cleaning for the purpose of preventing the adhesion and residue of silver components dissolved in the etching solution, or alternatively, only cleaning with the alkaline permanganate solution may be carried out instead of cleaning for the purpose of preventing the adhesion and residue of silver components dissolved in the etching solution.

[0218] <Molding Process, etc.> In the method for manufacturing a printed wiring board according to the present disclosure, as described above, after forming the pattern circuit layer 31, a molding process is performed in which the encapsulant layer 32 is formed to embed the pattern circuit layer 31. Although details will be omitted, the molding process can be performed after performing the processes of forming an insulating layer on the pattern circuit layer 31 and further forming multiple pattern circuits, forming openings in the insulating layer to electrically connect the pattern circuits on the upper and lower layers, removing dust (desmear) generated in various processes, and mounting components on the formed pattern circuits.

[0219] In the molding process, the encapsulant layer 32 can be formed using, for example, an encapsulant used in the manufacture of semiconductor devices, without particular limitation. For example, the encapsulant layer 32 can be formed using a thermoplastic resin or a thermosetting resin by compression molding, transfer molding, inkjet molding, or other methods. It is particularly preferable to use a thermosetting resin as the encapsulant. The thermosetting resin is not particularly limited, but epoxy resins such as cresol novolac epoxy resin, phenol novolac epoxy resin, biphenyl diepoxy resin, and naphthol novolac epoxy resin are suitable. The encapsulant may also be a composition containing the above-mentioned thermosetting resin and additives such as a filler and / or a flame retardant. The encapsulant may be, for example, a solid material, a liquid material, a granular material, or a film material. When a film material is used, a compression encapsulation molding machine, a vacuum laminating machine, or the like is used. For example, using these devices, the patterned circuit layer 31 can be covered with a film material that has been heat-melted under conditions of 40°C to 180°C (or 60°C to 150°C), 0.1 MPa to 10 MPa (or 0.5 MPa to 8 MPa), and 0.5 minutes to 10 minutes, thereby forming the encapsulant layer 32. The thickness of the encapsulant film may be 50 μm to 2000 μm, 70 μm to 1500 μm, or 100 μm to 1000 μm. After the encapsulant layer 32 is formed, the encapsulating structure may be divided into a plurality of portions including the patterned circuit layer 31.

[0220] <Peeling Step> In the peeling step in the method for manufacturing a printed wiring board according to the present disclosure, the portion including the support 14 is peeled from the portion including the pattern circuit layer 31 in a state in which the peel strength of the resin layer 13 has been reduced by a peel strength reduction treatment. Here, the peel strength reduction treatment is at least one treatment selected from the group consisting of the heating treatment, cooling treatment, ultraviolet irradiation treatment, laser irradiation treatment, and voltage application treatment. In the peeling step, first, the peel strength reduction treatment is performed according to the type of resin contained in the resin layer 13.

[0221] In particular, in the peeling step, it is preferable to perform the above-described peel force reduction treatment so that the peel force required to peel the portion including the support 14 from the portion including the patterned circuit layer 31 is 0.3 kN / m or less. Specifically, when a heating treatment is performed as the peel force reduction treatment, the entire structure can be heated to 200°C or higher using, for example, a hot plate or a batch oven. Specifically, when a cooling treatment is performed as the peel force reduction treatment, for example, a cool plate, a batch refrigerator, or a freezer may be used, or a peeling device equipped with a cooling function may be used. When a cooling treatment is performed as the peel force reduction treatment, the peeling step may be performed after cooling to a predetermined temperature depending on the resin contained in the resin layer 13, or the peeling step may be performed by supercooling below a predetermined temperature and then returning to the appropriate temperature. Furthermore, specifically, when peeling is performed by ultraviolet irradiation, commercially available ultraviolet irradiation devices can be used. Commercially available ultraviolet irradiation devices include, for example, ultra-high pressure mercury lamps and UV lamps. Furthermore, when peeling is performed by laser irradiation, commercially available laser irradiation devices can be used. Commercially available laser irradiation devices include, for example, solid-state lasers, liquid lasers, gas lasers, and semiconductor lasers. Furthermore, when peeling is performed by applying a voltage, a commercially available voltage application device can be used. The commercially available voltage application device can be, for example, one whose terminals are connected to a DC power source or an AC power source.

[0222] Furthermore, in the peeling process, a half-cutting process may be performed after the peel strength reduction process to facilitate peeling. Specifically, a cut is made in the thickness direction from the encapsulant layer 32 to divide the encapsulant layer 32 into a central portion including the pattern circuit layer 31 and a peripheral portion. The cut may reach the support 14 or may reach only the middle of the resin layer 13. If the cut does not reach the support 14, recycling of the support 14 becomes easier. Then, while the central portion is fixed, the peripheral portion is pressed down using a pressing member or the like, or the support 14 is fixed to a stage via dicing tape and vacuum-adsorbed, thereby peeling only the central portion from the support 14. This allows the portion including the support 14 and the portion including the pattern circuit layer 31 to be easily peeled off.

[0223] 12A and 12B, this peeling step involves peeling the interface between the support 14 and the resin layer 13, with the resin layer 13 being included in the portion including the pattern circuit layer 31 (FIG. 12A), and peeling the interface between the resin layer 13 and the metal layer 12, with the resin layer 13 being included in the portion including the support 14 (FIG. 12B). Either of these cases is acceptable, but when the interface between the support 14 and the resin layer 13 is peeled, the support 14 can be easily reused.

[0224] 2C and 3C , peeling may occur between the metal layer 12 and the resin layer 13, leaving the resin layer 13 in the portion including the support 14, or peeling may occur between the resin layer 13 and the resin layer 15, leaving the resin layer 13 in the portion including the pattern circuit layer 31. Alternatively, peeling may occur between the metal layer 12 and the resin layer 13, leaving the resin layer 13 in the portion including the support 14, or peeling may occur between the resin layer 13 and the resin layer 15, leaving the resin layer 13 in the portion including the pattern circuit layer 31.

[0225] If the resin layer 13 remains in the area including the support 14, the remaining components can be removed by plasma treatment, solvent cleaning, physical polishing, or the like. ４ -O ２Plasma is preferred, as it can simultaneously remove the remaining resin layer 13 and the partially remaining metal layer 12. The various etching solutions described above can be used to clean the partially remaining metal layer 12. In particular, when the metal layer 12 is silver, the etching solution SVE-810E manufactured by ADEKA Corporation can be suitably used.

[0226] In the peeling process, a peeling jig 16 and a suction stage 17 can be used, as shown in FIG. 13 . That is, the peeling jig 16 is attached to the back surface of the support 14, and the upper surface of the encapsulant layer 32 is fixed to the suction stage 17. In this state, by driving the peeling jig 16 in a direction away from the suction stage 17, the portion including the support 14 can be peeled off together with the peeling jig 16. By using the peeling jig 16 and the suction stage 17, the portion including the support 14 can be easily peeled off without damaging it. This facilitates recycling of the support 14. The support 14 and the peeling jig 16 can be fixed together using, but not limited to, commercially available adhesives, pressure-sensitive adhesives, die bonding tape, dicing tape, etc. The size of the peeling jig 16 is not particularly limited, but it is preferably larger than the support 14, preferably 1.1 to 100 times the area of ​​the support 14. Furthermore, the suction stage 17 can be, for example, a vacuum suction stage device.

[0227] <Printed Wiring Board Manufacturing Method 2> Another embodiment of the printed wiring board manufacturing method of the present disclosure will be described. In the printed wiring board manufacturing method described as another embodiment, the steps shown in FIGS. 5 to 9 are the same as those in the embodiment described above. That is, in this embodiment, a second laminate structure 20 is also prepared, a resist layer 30 is formed on the metal layer 12, a patterned circuit layer 31 is formed, and the resist layer 30 is removed. In this embodiment, next, as shown in FIG. 14, a sealant layer 32 is formed so as to embed the patterned circuit layer 31 formed on the metal layer 12. Next, the above-mentioned peel force reduction treatment is performed, and the portion including the metal layer 12 and the patterned circuit layer 31 is peeled from the portion including the support 14. At this time, as shown in FIGS. 15A and 15B, peeling may occur at the interface between the support 14 and the resin layer 13 ( FIG. 15A ), at the interface between the resin layer 13 and the metal layer 12 ( FIG. 15B ), or due to internal cohesive failure of the resin layer 13. In this embodiment, next, if the resin layer 13 remains in the portion including the metal layer 12 and the pattern circuit layer 31, the resin layer 13 is removed. The resin layer 13 can be removed, for example, using an alkaline permanganate solution as a wet process or CF ４ -O ２ In addition, when the metal layer 12 contains silver nanoparticles, the resin layer 13 may be removed by a wet process using the aforementioned etching solution, or by a dry process using CF ４ -O ２ , O ２ It may also be removed by plasma such as

[0228] In this embodiment, after the above-described peel strength reducing treatment or the subsequent removal of the resin layer 13 is completed, the metal layer 12 remaining on the opposite side of the sealing material layer 32 is removed by etching, as shown in Fig. 16. For the removal of the metal layer 12 by etching, the details described in the above <Metal layer etching step> can be applied.

[0229] As described above, according to the printed wiring board manufacturing method 1 and the printed wiring board manufacturing method 2 of the present disclosure, it is possible to avoid problems such as the metal layer 12 peeling from the support 14 due to the resin layer 13 or the pattern circuit layer 31 peeling from the support 14 before the peel force reduction treatment. Furthermore, according to the printed wiring board manufacturing method 1 and the printed wiring board manufacturing method 2 of the present disclosure, the adhesive strength of the resin layer 13 is reduced by the peel force reduction treatment, so that the portion including the support 14 and the portion including the pattern circuit layer 31 can be easily peeled away. In this way, according to the printed wiring board manufacturing method 1 and the printed wiring board manufacturing method 2 of the present disclosure, printed wiring boards including the pattern circuit layer 31 can be manufactured with a high yield.

[0230] In the present disclosure, a method for manufacturing a printed wiring board has been described in which the portion including the support 14 can be easily separated from the portion including the patterned circuit layer 31, as described above. Here, the term "printed wiring board" refers not only to ordinary printed wiring boards but also to various electronic components having a patterned metal layer on the surface of a substrate, such as connectors, electromagnetic shields, antennas such as RFID (Radio Frequency Identification), film capacitors, etc. The term "printed wiring board" also refers to a build-up layer of a printed circuit board, a mold film of a PLP (Panel Level Package), and a redistribution layer (RDL).

[0231] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" and "%" are all by mass unless otherwise specified.

[0232] [Preparation of Metal Coating Fluid 1] Under a nitrogen atmosphere, a chloroform (30 ml) solution containing 9.6 parts by mass of p-toluenesulfonic acid chloride was added dropwise to a mixture containing 20 parts by mass of methoxypolyethylene glycol (number average molecular weight 2,000), 8.0 parts by mass of pyridine, and 20 ml of chloroform while ice-cooling and stirring for 30 minutes, followed by stirring for 4 hours at a bath temperature of 40° C., and then 50 ml of chloroform was mixed in. The resulting product was then washed with 100 ml of a 5 mass% aqueous hydrochloric acid solution, then washed with 100 ml of a saturated aqueous sodium bicarbonate solution, then washed with 100 ml of a saturated saline solution, dried over anhydrous magnesium sulfate, filtered, concentrated under reduced pressure, washed several times with hexane, filtered, and dried under reduced pressure at 80° C. to obtain a methoxypolyethylene glycol having a p-toluenesulfonyloxy group.

[0233] 5.39 parts by mass of methoxypolyethylene glycol having a p-toluenesulfonyloxy group, 20 parts by mass of polyethyleneimine (manufactured by Aldrich, weight average molecular weight 25,000), 0.07 parts by mass of potassium carbonate, and 100 ml of N,N-dimethylacetamide were mixed and stirred at 100°C for 6 hours under a nitrogen atmosphere. Next, 300 ml of a mixed solution of ethyl acetate and hexane (ethyl acetate / hexane volume ratio = 1 / 2) was added, and the mixture was vigorously stirred at room temperature, and the resulting solid product was filtered. The solid was washed with 100 ml of a mixed solution of ethyl acetate and hexane (ethyl acetate / hexane volume ratio = 1 / 2) and then dried under reduced pressure to obtain a compound in which polyethylene glycol was bound to polyethyleneimine.

[0234] 138.8 parts by mass of an aqueous solution containing 0.592 parts by mass of the resulting compound in which polyethylene glycol is bound to polyethyleneimine was mixed with 10 parts by mass of silver oxide, and the mixture was stirred for 30 minutes at 25° C. Next, 46 parts by mass of dimethylethanolamine was gradually added with stirring, and the mixture was stirred for 30 minutes at 25° C. Subsequently, 15.2 parts by mass of a 10% by mass aqueous ascorbic acid solution was gradually added with stirring, and stirring was continued for 20 hours to obtain a silver dispersion.

[0235] A mixed solvent of 200 ml of isopropyl alcohol and 200 ml of hexane was added to the resulting silver dispersion and stirred for 2 minutes, followed by centrifugal concentration at 3000 rpm for 5 minutes. After removing the supernatant, a mixed solvent of 50 ml of isopropyl alcohol and 50 ml of hexane was added to the precipitate and stirred for 2 minutes, followed by centrifugal concentration at 2000 rpm for 10 minutes. After removing the supernatant, 20 parts by mass of water was added to the precipitate and stirred for 2 minutes, and the organic solvent was removed under reduced pressure. After adding 10 parts by mass of water and stirring and dispersing, the dispersion was left to freeze in a -40 °C freezer for 24 hours, and then treated in a freeze dryer (Tokyo Rikakikai Co., Ltd. FDU-2200) for 24 hours to obtain silver nanoparticles containing a dispersant having a basic nitrogen atom-containing group, consisting of flake-shaped masses with a gray-green metallic luster.

[0236] The obtained powder of silver nanoparticles (average particle diameter 30 nm) containing a dispersant having a basic nitrogen atom-containing group was dispersed in a mixed solvent of 45 parts by mass of ethanol and 55 parts by mass of ion-exchanged water to prepare 5 parts by mass of metal coating solution 1. The obtained silver particles were heated in an electric furnace at 500°C for 1 hour, and the proportion of dispersant was calculated from the ash content, confirming that it was 5 parts by mass per 100 parts by mass of silver solids. The metal layer formed by metal coating solution 1 was designated metal layer 1 having an amino group as the reactive functional group [X].

[0237] [Preparation of Resin Coating Liquid 1] In a nitrogen-substituted vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 100 parts by mass of polyester polyol (a polyester polyol obtained by reacting 1,4-cyclohexanedimethanol, neopentyl glycol, and adipic acid), 17.6 parts by mass of 2,2-dimethylolpropionic acid, 21.7 parts by mass of 1,4-cyclohexanedimethanol, and 106.2 parts by mass of dicyclohexylmethane-4,4′-diisocyanate were reacted in a mixed solvent of 178 parts by mass of methyl ethyl ketone to obtain a urethane prepolymer solution having an isocyanate group at its terminal.

[0238] Next, 13.3 parts by mass of triethylamine was added to the urethane prepolymer solution to neutralize the carboxyl groups of the urethane prepolymer, and 380 parts by mass of water was then added and thoroughly stirred to obtain an aqueous dispersion of the urethane prepolymer.

[0239] To the aqueous dispersion of the urethane prepolymer obtained above, 8.8 parts by weight of a 25% by weight ethylenediamine solution was added and stirred to chain-extend the urethane prepolymer. Subsequently, aging and desolvation were performed to obtain an aqueous dispersion of a urethane resin (non-volatile content: 30% by weight). The weight-average molecular weight of the urethane resin was 53,000.

[0240] Next, 140 parts by mass of deionized water and 100 parts by mass of the aqueous dispersion of the urethane resin obtained above were placed in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, a dropping funnel for dropping the monomer mixture, and a dropping funnel for dropping the polymerization catalyst, and the temperature was raised to 80°C while blowing in nitrogen. Thereafter, with stirring, a monomer mixture consisting of 60 parts by mass of methyl methacrylate, 30 parts by mass of n-butyl acrylate, and 10 parts by mass of N-n-butoxymethylacrylamide, and 20 parts by mass of a 0.5% by mass aqueous ammonium persulfate solution were added dropwise from separate dropping funnels over 120 minutes while maintaining the temperature inside the reaction vessel at 80°C.

[0241] After the dropwise addition was completed, the mixture was stirred at the same temperature for another 60 minutes, then cooled to 40°C. The mixture was diluted with deionized water to a nonvolatile content of 2% by mass, and filtered through a 200-mesh filter cloth to obtain Resin Coating Solution 1, a core-shell composite resin with the urethane resin as the shell layer and a vinyl resin derived from methyl methacrylate or other raw materials as the core layer. The resin layer formed by Resin Coating Solution 1 was designated Resin Layer 1, which had an isocyanate group as the reactive functional group [Y]. To measure the thermal weight loss of Resin Layer 1, Resin Coating Solution 1 was spread thinly on an aluminum pan and dried at 130°C for 60 minutes to obtain a dried film of Resin Layer 1. The thermal weight loss of this layer was measured using a TA5500 manufactured by TA Instruments after holding it at 300°C for 60 minutes under a nitrogen atmosphere, resulting in a weight loss of 39%.

[0242] [Preparation of Resin Coating Liquid 2] 60 parts by mass of phenoxy resin 4250 (Mitsubishi Chemical Corporation bisphenol A / bisphenol F mixed type, weight average molecular weight 60,000, solids content 100% by mass), 33 parts by mass of aminotriazine novolak resin (DIC Corporation "Phenolite LA-7052", solids content 60% by mass), 17 parts by mass of epoxy resin (DIC Corporation "EPICLON EXA-830CRP"; bisphenol F type epoxy resin, epoxy group equivalent 162 g / equivalent), 3 parts by mass of trimellitic anhydride, and 0.5 parts by mass of "TBZ" manufactured by Shikoku Kasei Co., Ltd. as a curing catalyst were mixed, diluted with cyclohexanone so that the non-volatile content was 2% by mass, and uniformly mixed to obtain a resin coating liquid 2. The resin layer formed by the resin coating liquid 2 was designated as resin layer 2 having an epoxy group as the reactive functional group [Y]. The thermal weight loss of the resin layer 2 was measured in the same manner as for the resin layer 1, and the weight loss was found to be 15%.

[0243] [Preparation of Resin Coating Liquid 3] 40 parts by mass of phenoxy resin 4250 (Mitsubishi Chemical Corporation, bisphenol A / bisphenol F mixed type, weight average molecular weight 60,000, solids content 100% by mass), 60 parts by mass of epoxy resin (DIC Corporation, "HP4032D"; naphthalene-type epoxy resin, epoxy group equivalent 136-148 g / equivalent), and 7 parts by mass of "2E4MZ" curing catalyst manufactured by Shikoku Kasei Co., Ltd. were mixed, diluted with cyclohexanone to a non-volatile content of 15% by mass, and mixed uniformly to obtain Resin Coating Liquid 3. The resin layer formed by Resin Coating Liquid 3 was designated Resin Layer 3 having an epoxy group as the reactive functional group [Y]. The thermal weight loss of Resin Layer 3 was measured in the same manner as Resin Layer 1, and the weight loss was 17%.

[0244] [Preparation of Resin Coating Liquid 4] 60 parts by mass of phenoxy resin 4250 (Mitsubishi Chemical Corporation, bisphenol A / bisphenol F mixed type, weight average molecular weight 60,000, solids content 100% by mass), 40 parts by mass of epoxy resin (DIC Corporation, "HP4032D"; naphthalene-type epoxy resin, epoxy group equivalent 136-148 g / equivalent), and 7 parts by mass of "2E4MZ" curing catalyst manufactured by Shikoku Kasei Co., Ltd. were mixed, diluted with cyclohexanone to a non-volatile content of 15% by mass, and mixed uniformly to obtain Resin Coating Liquid 4. The resin layer formed by Resin Coating Liquid 4 was designated Resin Layer 4 having an epoxy group as the reactive functional group [Y]. The thermal weight loss of Resin Layer 4 was measured in the same manner as Resin Layer 1, and the weight loss was 22%.

[0245] [Resin Layers 5 to 8] The following resin layers 5 to 8 were prepared. Resin Layer 5: Cool-off type PlafiX CS2325NA2 (thickness 25 μm) manufactured by Nitta Corporation Resin Layer 6: SELFA HW01 (thickness 120 μm) manufactured by Sekisui Chemical Co., Ltd. Resin Layer 7: Acrylic adhesive LKG-1705 manufactured by Fujikura Kasei Co., Ltd. Resin Layer 8: Temporary bonding agents TZNR-CTRL9 and TZNR-A7005 manufactured by Tokyo Ohka Kogyo Co., Ltd.

[0246] [Preparation of Resin Coating Liquid 5] In a nitrogen-substituted vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 100 parts by mass of polyester polyol (a polyester polyol obtained by reacting 1,4-cyclohexanedimethanol, neopentyl glycol, and adipic acid), 17.6 parts by mass of 2,2-dimethylolpropionic acid, 21.7 parts by mass of 1,4-cyclohexanedimethanol, and 106.2 parts by mass of dicyclohexylmethane-4,4′-diisocyanate were reacted in a mixed solvent of 178 parts by mass of methyl ethyl ketone to obtain a urethane prepolymer solution having an isocyanate group at its terminal.

[0247] Next, 14.0 parts by mass of triethylamine was added to the urethane prepolymer solution to neutralize the carboxyl groups of the urethane prepolymer, and 380 parts by mass of water was then added and thoroughly stirred to obtain an aqueous dispersion of the urethane prepolymer.

[0248] To the aqueous dispersion of the urethane prepolymer obtained above, 8.8 parts by weight of a 25% by weight ethylenediamine solution was added and stirred to chain-extend the urethane prepolymer. Subsequently, aging and desolvation were performed to obtain an aqueous dispersion of a urethane resin (non-volatile content: 30% by weight). The weight-average molecular weight of the urethane resin was 51,000.

[0249] Next, 140 parts by mass of deionized water and 100 parts by mass of the aqueous dispersion of the urethane resin obtained above were placed in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, a dropping funnel for dropping the monomer mixture, and a dropping funnel for dropping the polymerization catalyst, and the temperature was raised to 80°C while blowing in nitrogen. Thereafter, with stirring, a monomer mixture consisting of 70 parts by mass of methyl methacrylate and 30 parts by mass of n-butyl acrylate and 20 parts by mass of a 0.5% by mass aqueous ammonium persulfate solution were added dropwise from separate dropping funnels over 120 minutes while maintaining the temperature inside the reaction vessel at 80°C.

[0250] After the dropwise addition was completed, the mixture was stirred at the same temperature for an additional 60 minutes, then cooled to 40°C and diluted with deionized water to a nonvolatile content of 2% by mass. The mixture was then filtered through a 200-mesh filter cloth to obtain Resin Coating Solution 5, a core-shell composite resin with the urethane resin as the shell layer and a vinyl resin derived from methyl methacrylate or the like as the core layer. The resin layer formed by Resin Coating Solution 5 was designated Resin Layer 9, which does not have a reactive functional group [Y]. The thermal weight loss of Resin Layer 9 was measured in the same manner as for Resin Layer 1, and was found to be 41%.

[0251] [Preparation of Silver Etching Solution] A silver etching solution was prepared by adding 2.6 parts by mass of acetic acid to 47.4 parts by mass of water, and then adding 50 parts by mass of 35% by mass of hydrogen peroxide water. The molar ratio of hydrogen peroxide to carboxylic acid (hydrogen peroxide / carboxylic acid) in this silver etching solution was 13.6, and the content of the mixture of hydrogen peroxide and carboxylic acid in the silver etching solution was 22.4% by mass.

[0252] (Example 1) On the surface on which the release layer of the temporary substrate ("NH-206" manufactured by Toyobo Co., Ltd., release PET film; thickness 50 μm) is formed, metal coating liquid 1 is applied using a small desktop coater ("K Printing Profer" manufactured by RK Print Coat Instruments Co., Ltd.) and dried at 150 ° C. for 5 minutes, thereby forming a silver layer corresponding to the metal layer 1 with a thickness of 0.1 μm after drying. Similarly, the metal coating liquid 1 is again applied on this silver layer so that the thickness after drying is 0.2 μm, and a metal layer 1 containing silver nanoparticles is produced. Thereafter, resin coating liquid 1 is applied using a small desktop coater ("K Printing Profer" manufactured by RK Print Coat Instruments Co., Ltd.) and dried at 120 ° C. for 3 minutes, forming a layer corresponding to the resin layer 13 with a thickness of 1.5 μm after drying. In this manner, a first laminate structure was produced in which the metal layer 1 and the resin layer 1 were arranged in this order on the surface of the temporary substrate.

[0253] Next, the surface of a 0.7 mm thick glass support was wiped with ethanol, immersed in acetone and isopropanol for 5 minutes each, and then vacuum oxygen plasma treatment was performed on one main surface (Nordson Advanced Technologies Co., Ltd. AP-1000, gas flow rate 145 sccm, output 500 W, treatment time 300 seconds, chamber pressure 80 mTorr). Then, the resin layer in the first laminate structure was attached to one main surface of the vacuum oxygen plasma-treated support using a vacuum laminator (Nikko Materials Co., Ltd. CVP-600) under conditions of 140 ° C, 3.5 MPa, and 5 minutes. Thereafter, the temporary substrate was peeled off and dried at 250 ° C for 5 minutes to produce a second laminate structure in which a resin layer and a metal layer were arranged in this order on one main surface of the support. The surface resistivity of the metal layer was 1 Ω / □ when measured with a PSP probe using a Loresta GX MCP-T700.

[0254] Next, a pattern circuit was formed by the following semi-additive method using the obtained second laminate structure. In this example, a plating resist ("RY-5125" manufactured by Resonac Corporation, thickness 25 μm) was attached to the surface of the metal layer at 110°C, 0.4 MPa, and 1 m / min, and then treated for 2 minutes (316 mJ / cm) with an exposure machine ("BOX-W10" manufactured by Sanhayato Corporation).２ ) was subjected to an exposure treatment, and then the substrate was immersed in a developer (aqueous solution of 1% by mass of sodium carbonate) for 5 minutes and subjected to a development treatment to form a resist layer corresponding to the shape of the pattern circuit.

[0255] Thereafter, the metal layer was used as a plating seed layer to perform copper plating on the surface on which the resist layer was formed. That is, the metal layer on which the resist layer was formed was set on the cathode side, and the phosphorus-containing copper was set on the anode side, and an electrolytic plating solution containing copper sulfate was used at a current density of 2 A / dm ２ A copper plating layer (12 μm thick) was formed on the metal layer by electroplating at 25°C for 27 minutes. The electroplating solution used was 70 g / L copper sulfate, 200 g / L sulfuric acid, 50 mg / L chloride ions, and 5 ml / L additive (Top Lucina SF-M, Okuno Chemical Industries Co., Ltd.). The resist layer was then stripped by immersion in 3% by weight sodium hydroxide for 3 minutes. The entire substrate was then immersed in a silver etching solution at 25°C for 30 seconds to remove the metal layer except for the area where the patterned circuit was formed, yielding a test substrate with a patterned circuit layer formed on the support. Note that the peel strength of the resin layer 1 was reduced by heat treatment in the test substrate prepared in this example.

[0256] The peel strength (referred to as "peel strength 1") of the test substrate obtained above was measured at room temperature (23°C) using a Nordson DAGE 4000Plus. It was 0.3 kN / m, indicating that the substrate did not peel easily. The lead width used for the measurement was 5 mm, and the peel angle was 90°. While peel strength tends to increase with increasing metal layer thickness, in this example, measurements of peel strength 1 and peel strength 2 (described below) were performed using the measured value for a metal layer thickness of 8 μm as the reference. The adhesion was evaluated based on the measured peel strength before heating according to the following criteria. The test substrate was then heated at 300°C for 5 minutes (peel strength reduction treatment), and the peel strength (referred to as "peel strength 2") was measured. It was 0.09 kN / m, indicating that the substrate peeled easily. Furthermore, when the cross-sectional shape of the pattern circuit layer after peeling was observed with an SEM (magnification: 1000x), there was no reduction in the wiring height or wiring width, and the pattern circuit showed a rectangular shape without undercuts, and had a smooth surface.

[0257] Example 2 A pattern circuit layer was formed in the same manner as in Example 1 except that the support was stainless steel (SUS: Misumi shim plate, CIRASF-299-299-0.3), and peel strength 1 and peel strength 2 were measured.

[0258] Example 3 A pattern circuit layer was formed in the same manner as in Example 1 except that the support was made of ceramic (alumina, thickness 0.5 mm), and peel strength 1 and peel strength 2 were measured.

[0259] Example 4 A patterned circuit layer was formed in the same manner as in Example 1, except that the support was a silicon wafer (diameter: 3 inches (approximately 76.2 mm), thickness: 0.7 mm), and peel strength 1 and peel strength 2 were measured.

[0260] Example 5 A patterned circuit layer was formed in the same manner as in Example 1, except that the support was polyimide (manufactured by Toray Industries, Inc., thickness 50 μm), and peel strength 1 and peel strength 2 were measured.

[0261] Example 6 A pattern circuit layer was formed in the same manner as in Example 1, except that the support was an epoxy glass substrate (manufactured by PCB Materials, thickness 1.6 mm), and peel strength 1 and peel strength 2 were measured.

[0262] Example 7 A resin layer 5 for improving adhesion was formed on a 0.7 mm thick glass support using a roll laminator (VA-770 manufactured by Taisei Laminator Co., Ltd.) at 60 ° C, 0.5 MPa, and a speed of 0.1 m per minute. After heating on a hot plate at 200 ° C for 10 minutes, a first laminate structure in which resin layer 4 was used instead of resin layer 1 in Example 1 was laminated on top of the resin layer 5 formed on the support using a vacuum laminator (CVP-600 manufactured by Nikko Materials Co., Ltd.) at 120 ° C, 3.5 MPa, and 3 minutes. A second laminate structure was produced in which the support, resin layer 5, resin layer 4, and metal layer 1 were laminated in this order. Thereafter, a test substrate was obtained in the same manner as in Example 1. Peel strength 1 was measured using the obtained test substrate. In this example, peel strength 2 was measured while cooling to 5 ° C on a cool plate. Note that in the test substrate produced in this example, the peel strength of the resin layer 5 was reduced by the cooling process. The resin layer 4 is not a layer that reduces the peel strength in the present disclosure.

[0263] Example 8 A test substrate was obtained in the same manner as in Example 7, except that the support was stainless steel (SUS: the same as in Example 2). Peel strength 1 and peel strength 2 were measured using the obtained test substrate.

[0264] Example 9 A test substrate was obtained in the same manner as in Example 7, except that the support was made of ceramic (the same as in Example 3). Peel strength 1 and peel strength 2 were measured using the obtained test substrate.

[0265] Example 10 A patterned circuit layer was formed in the same manner as in Example 7, except that the support was a silicon wafer (diameter: 3 inches (approximately 76.2 mm), thickness: 0.7 mm), and peel strength 1 and peel strength 2 were measured.

[0266] Example 11 A patterned circuit layer was formed in the same manner as in Example 7, except that the support was polyimide (manufactured by Toray Industries, Inc., thickness 50 μm), and peel strength 1 and peel strength 2 were measured.

[0267] Example 12 A patterned circuit layer was formed in the same manner as in Example 7, except that the support was an epoxy glass substrate (manufactured by PCB Materials, thickness 1.6 mm), and peel strength 1 and peel strength 2 were measured.

[0268] (Example 13) A resin layer 5 for improving adhesion was formed on a 0.7 mm thick glass support using a roll laminator (same as in Example 7) at 60 ° C, 0.5 MPa, and a speed of 0.1 m per minute. The resulting layer was then heated on a hot plate at 200 ° C for 10 minutes. After this, a first laminate structure was prepared using resin layer 3 instead of resin layer 1 in Example 1. A second laminate structure was then prepared using a vacuum laminator (same as in Example 7) in the same manner as in Example 7, in which the support, resin layer 5, resin layer 3, and metal layer 1 were laminated in this order. Peel strength 1 was then measured in the same manner as in Example 1. In this example, peel strength 2 was measured while cooling to 5 ° C on a cool plate. In the test substrate prepared in this example, the peel strength of resin layer 5 was reduced by the cooling treatment. Resin layer 3 is not a layer in which peel strength is reduced in the present disclosure.

[0269] (Example 14) A resin layer 5 for improving adhesion was formed on a 0.7 mm thick glass support using a roll laminator (same as in Example 7) at 60 ° C, 0.5 MPa, and a speed of 0.1 m per minute. The resulting layer was then heated on a hot plate at 200 ° C for 10 minutes. A first laminate structure was then prepared using a vacuum laminator (same as in Example 7), in which resin layer 2 was used instead of resin layer 1 in Example 1. A second laminate structure was then prepared in the same manner as in Example 7, in which the support, resin layer 5, resin layer 2, and metal layer 1 were laminated in this order. Peel strength 1 was then measured in the same manner as in Example 1. In this example, peel strength 2 was measured while cooling to 5 ° C on a cool plate. In the test substrate prepared in this example, the peel strength of the resin layer 5 was reduced by the cooling process.

[0270] (Example 15) A resin layer 6 was formed on a glass support having a thickness of 0.7 mm using a roll laminator (the same as in Example 7) at 100°C, 0.5 MPa, and a speed of 0.1 m per minute. An ultra-high pressure mercury lamp was used to form the resin layer 6 at 405 nm and 3000 mJ / cm ２ After the exposure, a second laminate structure was produced in which the support, resin layer 6, resin layer 4, and metal layer 1 were laminated in this order using a first laminate structure in which resin layer 4 was used instead of resin layer 1 in Example 1. Thereafter, peel strength 1 was measured in the same manner as in Example 1. In this example, the peel strength was 12,000 mJ / cm at 254 nm. ２ After the exposure, peel strength 2 was measured. In the test substrate prepared in this example, the peel strength of the resin layer 6 was reduced by the UV irradiation treatment.

[0271] (Example 16) In this example, a resin layer 7 was applied to a support using a spin coater (MS-B100 manufactured by Mikasa Co., Ltd.) at a rotation speed of 1000 rpm for 30 seconds, and then dried on a hot plate at 100°C for 2 minutes. Metal coating solution 1 was then applied thereon using a small desktop coater ("K Printing Profer" manufactured by RK Printcoat Instruments Co., Ltd.) and dried at 150°C for 5 minutes, thereby coating a silver layer corresponding to metal layer 1 so that the thickness after drying was 0.1 μm, thereby producing a second laminate structure. Thereafter, peel strength 1 was measured in the same manner as in Example 1. In this example, the peel strength was 80 mW / cm ２ High pressure mercury lamp: 100 mJ / cm ２After the exposure, the peel strength 2 was measured. In the test substrate prepared in this example, the peel strength of the resin layer 7 was reduced by the UV irradiation treatment.

[0272] Example 17 In this example, resin layer 8 was applied to a support using a spin coater (MS-B100 manufactured by Mikasa Co., Ltd.) at a rotation speed of 3000 rpm for 60 seconds, and then heated on a hot plate at 90°C for 4 minutes and then dried at 250°C for 6 minutes. Metal coating solution 1 was then applied thereon using a small desktop coater ("K Printing Profer" manufactured by RK Printcoat Instruments Co., Ltd.) and dried at 150°C for 5 minutes, thereby coating a silver layer corresponding to metal layer 1 to a thickness of 0.1 μm after drying to produce a second laminate structure. Thereafter, peel strength 1 was measured in the same manner as in Example 1. In this example, the wavelength was 355 nm, the beam width was approximately 10 μm, the beam length was approximately 1.5 mm, and the energy density was 0.5 J / cm. ２ The peel strength 2 was measured after irradiating the test substrate with a line laser at 0.75 W output and 10 kHz frequency, pulse scanning, so that the spacing between the line centers was approximately 10 μm in the width direction and an overlap of approximately 0.2 mm or more in the length direction. Note that in the test substrate prepared in this example, the peel strength of the resin layer 8 was reduced by the laser irradiation treatment.

[0273] (Example 18) Peel strength 1 and peel strength 2 were measured in the same manner as in Example 1, except that a second laminate structure was produced using a first laminate structure in which resin layer 9 not having functional group Y was used instead of resin layer 1. In the test substrate produced in this example, the peel strength of resin layer 9 was reduced by heat treatment.

[0274] Comparative Example 1 A carrier-attached copper foil was produced by depositing a 100 nm-thick nickel alloy layer (metal layer 2) and a 0.3 μm-thick ultrathin copper layer (metal layer 3) in this order on a glass sheet as a support. Each layer was produced using a sheet-fed DC sputtering device (MLS464, manufactured by Canon Tokki Corporation). A patterned circuit layer was produced in the same manner as in Example 1, except for using this carrier-attached copper foil. A sulfuric acid-hydrogen peroxide aqueous solution was used to remove the metal layer. When the patterned circuit layer was observed after the support was peeled off, the cross-sectional shape of the patterned circuit layer was found to be reduced in wiring height and wiring width, and exhibited an undercut inverted trapezoidal shape with a rough surface. The test substrate produced in this example did not have a layer whose release force would be reduced by a peel force reduction treatment.

[0275] Comparative Example 2 Peel strength 1 and peel strength 2 were measured in the same manner as in Example 1, except that a second laminate structure was produced using a first laminate structure in which resin layer 3 was used instead of resin layer 1. Resin layer 3 in the test substrate produced in Comparative Example 2 did not show a decrease in peel strength even when subjected to a heat treatment, as in Example 1. This is because the test substrate produced in this example did not have a layer whose peel strength would be reduced by a peel strength reducing treatment.

[0276] (Comparative Example 3) Peel strength 1 and peel strength 2 were measured in the same manner as in Example 1, except that a second laminate structure was prepared by applying metal coating solution 1 to a support using a spin coater (MS-B100 manufactured by Mikasa Co., Ltd.) at a rotation speed of 2000 rpm for 30 seconds. The second laminate structure in the test substrate prepared in Comparative Example 3 had a peel strength 1 of 0.1 kN / m or less and had no process resistance. The test substrate prepared in this example did not have a layer whose peel strength would be reduced by a peel strength reducing treatment.

[0277] Comparative Example 4 A pattern circuit layer was formed in the same manner as in Comparative Example 3 except that the support was stainless steel (SUS: Misumi shim plate, CIRASF-299-299-0.3), and peel strength 1 and peel strength 2 were measured.

[0278] The following evaluations were made on the examples and comparative examples. The results are shown in Table 1. <Evaluation of process resistance> A: Peel strength 1 is 0.5 kN / m or more. B: Peel strength 1 is more than 0.3 kN / m and less than 0.5 kN / m. C: Peel strength 1 is more than 0.1 kN / m and 0.3 kN / m or less. D: Peel strength 1 is 0.1 kN / m or less. <Evaluation of peelability> A: Peel strength 2 is less than 0.05 kN / m. B: Peel strength 2 is 0.05 kN / m or more and 0.3 kN / m or less. C: Peel strength 2 is more than 0.3 kN / m. <Circuit shape> A: There is no reduction in wiring height and wiring width, and the circuit shows a rectangular shape without undercuts, and the surface is smooth. B: Any of the above wiring height, wiring width, rectangular shape, and surface does not apply.

[0279]

[0280] As shown in Table 1, when at least one resin layer disposed on a support contains a resin whose release strength is reduced by the release strength reduction treatment, the portion containing the metal layer and the portion containing the support could be easily peeled after the release strength reduction treatment. This demonstrated that it is possible to manufacture a printed wiring board having a patterned circuit layer with an excellent shape formed by using a metal layer as a plating seed layer.

[0281] The disclosure of Japanese Patent Application No. 2024-102313, filed on June 25, 2024, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards mentioned in this disclosure are incorporated by reference into this disclosure to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A first laminated structure comprising a temporary substrate, a metal layer disposed on the temporary substrate, and at least one resin layer disposed on the metal layer, wherein at least one of the metal layer and the resin layer is a layer whose peel strength is reduced by a peel strength reduction treatment.

2. The first laminate structure according to claim 1, wherein the layer with reduced peel strength has a peel strength of 0.3 kN / m or less when subjected to a peel strength reducing treatment.

3. The first laminate structure described in claim 1, wherein the peel strength reducing treatment is at least one treatment selected from the group consisting of heating treatment, cooling treatment, ultraviolet irradiation treatment, laser irradiation treatment, voltage application treatment, electromagnetic field application treatment, and solvent treatment.

4. The first laminate structure according to claim 1, wherein the layer whose release force is reduced by the release force reducing treatment is the resin layer.

5. The first laminate structure of claim 1, wherein the metal layer comprises silver nanoparticles and a dispersant.

6. The first laminate structure according to claim 1, wherein the metal layer is a plating seed layer.

7. The first laminate structure according to claim 1, wherein the metal layer contains silver nanoparticles, and the average particle size of the silver nanoparticles is 1 nm to 100 nm.

8. A second laminated structure comprising a support, at least one resin layer disposed on the support, and a metal layer disposed on the resin layer, wherein at least one of the metal layer and the resin layer is a layer whose peel strength is reduced by a peel strength reducing treatment.

9. The second laminate structure according to claim 8, wherein the layer with reduced peel strength has a peel strength of 0.3 kN / m or less when subjected to a peel strength reducing treatment.

10. The second laminate structure described in claim 8, wherein the peel strength reducing treatment is at least one treatment selected from the group consisting of heating treatment, cooling treatment, ultraviolet irradiation treatment, laser irradiation treatment, voltage application treatment, electromagnetic field application treatment, and solvent treatment.

11. The second laminate structure according to claim 8, wherein the layer whose release force is reduced by the release force reducing treatment is the resin layer.

12. The second laminate structure of claim 8, wherein the metal layer comprises silver nanoparticles and a dispersant.

13. The second laminate structure according to claim 8, wherein the metal layer is a plating seed layer.

14. The second laminate structure according to claim 8, wherein the metal layer contains silver nanoparticles, and the average particle size of the silver nanoparticles is 1 nm to 100 nm.

15. The second laminate structure according to claim 8, which is for use in a semi-additive process.

16. A method for manufacturing a printed wiring board, comprising: a step of forming a pattern circuit layer on the resin layer by plating using the metal layer as a plating seed layer using a second laminated structure comprising a support, at least one resin layer disposed on the support, and a metal layer disposed on the resin layer, wherein at least one of the metal layer and the resin layer has a peel strength reduced by a peel strength reduction treatment; and a step of peeling off a portion including the support from a portion including the pattern circuit layer in a state in which the peel strength of at least one of the metal layer and the resin layer has been reduced by a peel strength reduction treatment.

17. The method for producing a printed wiring board according to claim 16, wherein the peel force reducing treatment reduces the peel force for peeling the portion including the support from the portion including the pattern circuit layer to 0.3 kN / m or less.

18. The method for manufacturing a printed wiring board according to claim 16, wherein the peel strength reducing treatment is at least one treatment selected from the group consisting of heating treatment, cooling treatment, ultraviolet irradiation treatment, laser irradiation treatment, voltage application treatment, electromagnetic field application treatment, and solvent treatment.

19. The method for producing a printed wiring board according to claim 16, wherein the layer whose peel strength is reduced by the peel strength reducing treatment is the resin layer.

20. The method for manufacturing a printed wiring board according to claim 16, wherein the metal layer contains silver nanoparticles and a dispersant.

21. The method for manufacturing a printed wiring board according to claim 16, wherein the metal layer contains silver nanoparticles, and the average particle size of the silver nanoparticles is 1 nm to 100 nm.

22. The method for producing a printed wiring board according to claim 16, wherein the pattern circuit layer is formed by a semi-additive process.

23. A method for manufacturing a printed wiring board as described in claim 16, comprising the steps of bonding a resin layer in the first laminate structure as described in any one of claims 1 to 7 onto the support, and peeling off the temporary base material in the first laminate structure to produce the second laminate structure.

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