Manufacturing method of laminate, laminate, and multi-layer laminate

Abstract

This method for producing a layered body includes: a step A for preparing a first layered body by layering a first resin film and a patterned metal layer; a step B for preparing a second resin film having indentations corresponding to the metal layer pattern; and a step C for mating the metal layer pattern and the indentations in the second resin film and bonding together the first layered body and second resin film.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a laminate, a laminate, and a multi-layer laminate. [Background technology]

[0002] Conventionally, sheet-like laminates in which a patterned metal layer is coated with an electrically insulating resin have been widely used. These laminates are used, for example, as planar heating elements that generate heat when electricity is applied (see, for example, Patent Document 1). Furthermore, in a broad sense, sheet-like laminates in which a patterned metal layer is coated with an electrically insulating resin are widely used as printed circuit boards for electrical circuits. For this reason, so-called chip-stacked packages in which semiconductor chips are stacked three-dimensionally have been developed for multilayer circuit boards and semiconductor packages. Interposers inserted between semiconductor chips in a multi-chip package in which functional elements are arranged three-dimensionally can also be called resin-coated metal patterns. More specifically, interposers using a polymer film with specific physical properties inserted between semiconductor chips in a multi-chip package with through electrodes can also be called resin-coated metal patterns.

[0003] Known methods for manufacturing the laminate include: (a) preparing a first laminate having a patterned metal layer laminated on a first resin film, and applying and drying a varnish for forming a second resin film on the metal layer of the first laminate; (b) preparing a first laminate having a patterned metal layer laminated on a first resin film, and arranging a resin powder for forming a second resin film on the metal layer of the first laminate, and compression-molding the resin powder; (c) arranging the patterned metal layer in the center of a mold, filling the mold with resin powder, and compression-molding the resin powder; (d) preparing a first laminate having a patterned metal layer laminated on a first resin film, and applying and drying an adhesive on the metal layer of the first laminate, and then laminating and bonding a second resin film on top of it; and (e) preparing a first laminate having a patterned metal layer laminated on a first resin film, and applying and drying an adhesive on the metal layer of the first laminate, and then laminating and bonding a second resin film on top of it. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-317524 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional methods for producing laminates require a step of applying and drying a varnish for forming a second resin film, or a step of compression molding a resin powder, which is time-consuming. Furthermore, when a manufacturing method is adopted in which a varnish for forming a second resin film is applied to the metal layer of the first laminate and then dried to form a laminate, shrinkage occurs during curing (drying), resulting in unevenness on the surface of the layer (second resin film) on the side where the varnish is applied. In other words, because there are areas below the second resin film where the metal layer is present and areas where it is not, shrinkage does not occur evenly, resulting in unevenness on the surface of the second resin film and poor flatness.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a laminate that can produce a laminate with excellent flatness in a short time, and to provide a laminate and a multilayer laminate that can be obtained by the manufacturing method. [Means for solving the problem]

[0007] The present inventors have conducted extensive research into methods for producing laminates, and as a result have found that by employing the following configuration, it is possible to produce a laminate with excellent flatness in a short period of time, thereby completing the present invention.

[0008] That is, the present invention provides the following. (1) Step A of preparing a first laminate in which a first resin film and a patterned metal layer are laminated; A step B of preparing a second resin film having recesses corresponding to the pattern of the metal layer; A method for manufacturing a laminate, comprising: a step C of bonding the first laminate and the second resin film together while fitting the pattern of the metal layer into the recess of the second resin film.

[0009] According to the above configuration, the first laminate and the second resin film can be prepared separately, so that the laminate can be produced in a short time by simply bonding the first laminate and the second resin film together. In addition, in the past, when a laminate was formed by applying a varnish for forming a second resin film layer to a first laminate and drying it, shrinkage occurred during curing, resulting in unevenness on the surface of the layer (second resin film) on the coated side and poor flatness. However, in the present invention, the first laminate and the second resin film are prepared separately and then bonded together, so this type of shrinkage does not occur. Therefore, it is possible to produce a laminate with flat, parallel surfaces on both sides. Furthermore, by making the first resin film and the second resin film symmetrical in the vertical direction, warping when heat is applied can be suppressed. That is, if there is a difference in linear expansion between the resin films (first resin film, second resin film) and the metal layer, warping will occur when heat is applied, but by making the first resin film and the second resin film symmetrical in the vertical direction, the warping force generated between the first resin film and the metal layer and the warping force generated between the second resin film and the metal layer can be offset.

[0010] (2) In the configuration of (1), a silane coupling agent layer is provided on the metal layer of the first laminate; The step C is preferably a step of bonding the first laminate and the second resin film together via the silane coupling agent layer.

[0011] According to the above-mentioned configuration, the first laminate and the second resin film are bonded together via the silane coupling agent layer, so that they can be firmly bonded together. Furthermore, unlike resin-based adhesives, the silane coupling agent is less susceptible to degradation in a thermal environment. Therefore, the laminate can withstand long-term use in a thermal environment.

[0012] (3) In the configuration of (1), a silane coupling agent layer is provided on the second resin film; The step C is preferably a step of bonding the first laminate and the second resin film together via the silane coupling agent layer.

[0013] According to the above-mentioned configuration, the first laminate and the second resin film are bonded together via the silane coupling agent layer, so that they can be firmly bonded together. Furthermore, unlike resin-based adhesives, the silane coupling agent is less susceptible to degradation in a thermal environment. Therefore, the laminate can withstand long-term use in a thermal environment.

[0014] (4) In the configurations (1) to (3), The first resin film and the second resin film are preferably polyimide films.

[0015] According to the above configuration, since the first resin film and the second resin film are polyimide films, a laminate having excellent heat resistance can be obtained.

[0016] (5) In the configurations (1) to (4), The thickness of the metal layer is preferably 10 μm or more and 100 μm or less.

[0017] As described above, in the past, when a laminate was formed by applying a varnish for forming a second resin film onto a first laminate and drying it, shrinkage occurred during curing, causing unevenness on the surface of the layer on the coated side (the second resin film). This unevenness was particularly noticeable when the metal layer was thick. However, with the above-described method, the first laminate and the second resin film are prepared separately and then bonded together, eliminating the shrinkage that occurs with the conventional method. Therefore, even when the metal layer is as thick as 10 μm or more, it is possible to produce a laminate having flat, parallel surfaces on both sides.

[0018] The present invention also provides the following. (6) A first resin film, a patterned metal layer, a silane coupling agent layer, and a second resin film having recesses corresponding to the pattern of the metal layer are laminated in this order; A laminate, wherein a gap exists between a first side surface of the recess of the second resin film and a second side surface of the metal layer facing the first side surface.

[0019] In the laminate manufactured by the laminate manufacturing method, a gap exists between the side surface (first side surface) of the recess in the second resin film and the side surface (second side surface) of the metal layer facing the first side surface. This is because, in the laminate manufacturing method, the first laminate and the second resin film are prepared separately, and then the pattern (protrusion pattern) of the metal layer is fitted into the recess in the second resin film, so that the recess is formed slightly larger than the pattern (protrusion pattern) of the metal layer. In addition, in conventional laminate manufacturing methods, a varnish for forming a second resin film is applied to the metal layer of the first laminate and dried, so voids 42 are not formed as in the laminate 10 of this embodiment. The laminate (6) can be produced in a short time by the laminate production method described above, and can have flat, parallel surfaces on both sides.

[0020] The present invention also provides the following. (7) A multilayer laminate comprising two or more laminates according to (6) above.

[0021] The laminate (6) has flat, parallel surfaces on both sides, so even if two or more layers are stacked (even if stacked in multiple layers), they can remain parallel. Furthermore, because there are two or more metal layers, when used as a wiring layer, each metal layer can be assigned a different function, such as an earth layer or a power layer. As a result, the wiring layer can be resistant to noise and less likely to emit noise.

[0022] (8) A multilayer laminate comprising the laminate according to (6) above, a patterned second metal layer, and a third resin film laminated in this order.

[0023] The laminate (6) above has flat, parallel surfaces on both sides, so even if a patterned second metal layer and a third resin film are further laminated to the laminate (6) above (even when laminated in multiple layers), the parallelism can be maintained. Furthermore, compared to the multilayer laminate (7) above, the number of resin film layers can be reduced by one. Furthermore, because there are two or more metal layers, when used as wiring layers, each metal layer can be assigned a function, such as an earth layer or a power layer, for example. As a result, the wiring layer can be noise-resistant and less susceptible to noise generation. Furthermore, when the metal layers are used as a heat source and the multilayer laminate is used as a planar heating element, the two or more metal layers can uniformly distribute heat.

[0024] (9) Two laminates according to (6) are stacked together, a through hole is provided in the first resin film or the second resin film, a metal filling layer filled with metal is formed in the through hole, A multilayer laminate, characterized in that the metal filler layer of one laminate and the metal filler layer of the other laminate are electrically connected.

[0025] The laminate (6) above has flat, parallel surfaces on both sides, so that even when two or more are stacked (even when stacked in multiple layers), the parallelism can be maintained. In addition, because there are two or more metal layers, when used as wiring layers, each metal layer can be assigned a function, such as an earth layer or a power layer, making it possible to separate functions. As a result, the wiring layer is resistant to noise and does not easily emit noise. Furthermore, because the two metal layers are electrically connected, three-dimensional circuits can be formed. [Effects of the Invention]

[0026] According to the present invention, it is possible to provide a method for manufacturing a laminate that can produce a laminate with excellent flatness in a short time, and also to provide a laminate and a multilayer laminate that can be obtained by the manufacturing method. [Brief explanation of the drawings]

[0027] [Figure 1] 3A to 3C are cross-sectional views illustrating a method for manufacturing a laminate according to the present embodiment. [Figure 2] 3A to 3C are cross-sectional views illustrating a method for manufacturing a laminate according to the present embodiment. [Figure 3] 3A to 3C are cross-sectional views illustrating a method for manufacturing a laminate according to the present embodiment. [Figure 4] 3A to 3C are cross-sectional views illustrating a method for manufacturing a laminate according to the present embodiment. [Figure 5] 3A to 3C are cross-sectional views illustrating a method for manufacturing a laminate according to the present embodiment. [Figure 6] 3A to 3C are cross-sectional views illustrating a method for manufacturing a laminate according to the present embodiment. [Figure 7] FIG. 10 is a plan view for explaining how to determine the warpage of a laminate after heating at 300° C. [Figure 8] 8 is a cross-sectional view taken along the line AA in FIG. 7. [Figure 9] 1 is a cross-sectional view showing a multilayer laminate according to a first embodiment. [Figure 10] 10A and 10B are cross-sectional views illustrating a method for producing a multilayer laminate according to a second embodiment. [Figure 11] 10A and 10B are cross-sectional views illustrating a method for producing a multilayer laminate according to a second embodiment. [Figure 12] 10A and 10B are cross-sectional views illustrating a method for producing a multilayer laminate according to a second embodiment. [Figure 13] 10A and 10B are cross-sectional views illustrating a method for producing a multilayer laminate according to a second embodiment. [Figure 14] 10A and 10B are cross-sectional views illustrating a method for producing a multilayer laminate according to a third embodiment. [Figure 15] 10A and 10B are cross-sectional views illustrating a method for producing a multilayer laminate according to a third embodiment. [Figure 16] 10A and 10B are cross-sectional views illustrating a method for producing a multilayer laminate according to a third embodiment. [Figure 17] 10A and 10B are cross-sectional views illustrating a method for producing a multilayer laminate according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, an embodiment of the present invention will be described. Below, a method for manufacturing a laminate will be described, and in the description, the laminate will also be described.

[0029] [Method of manufacturing laminate] The method for manufacturing the laminate according to this embodiment includes the steps of: A step A of preparing a first laminate in which a first resin film and a patterned metal layer are laminated; A step B of preparing a second resin film having recesses corresponding to the pattern of the metal layer; and step C of bonding the first laminate and the second resin film together while fitting the pattern of the metal layer into the recess of the second resin film.

[0030] 1 to 6 are schematic cross-sectional views illustrating the method for producing a laminate according to this embodiment.

[0031] <Process A> In the method for producing a laminate according to this embodiment, first, as shown in FIG. 2, a first laminate 20 is prepared in which a first resin film 21 and a patterned metal layer 24 are laminated together (step A).

[0032] The method for preparing the first laminate 20 is not particularly limited, but it can be prepared, for example, by the following procedure. First, as shown in FIG. 1, a two-layer laminate is prepared in which a first resin film 21 and an unpatterned metal layer 22 are laminated. The two-layer laminate is obtained, for example, by bonding the metal layer 22 to the first resin film 21. It is preferable to use a metal foil as the metal layer 22.

[0033] Examples of bonding methods include bonding using a silane coupling agent, which will be described later. When a silane coupling agent is used for bonding, the two can be firmly bonded together. Furthermore, using a silane coupling agent for bonding is preferable in terms of reducing thermal degradation. The silane coupling agent may be applied to the first resin film 21, the metal layer 22, or both. Another bonding method includes pressure bonding. When performing pressure bonding, it is preferable to plasma-treat the surface of the first resin film 21 beforehand. Plasma-treating the surface of the first resin film 21 before performing pressure bonding can firmly bond the two. Furthermore, plasma-treating the surface of the first resin film 21 before performing pressure bonding is preferable in terms of reducing thermal degradation. Heat-pressure bonding is preferable for pressure bonding. Note that, in order to prevent thermal degradation, it is preferable not to use a resin-based adhesive when bonding the first resin film 21 and the metal layer 22.

[0034] After preparing the two-layer laminate, the unpatterned metal layer 22 is etched by a conventionally known method to form a patterned metal layer 24 (see FIG. 2). This produces a first laminate 20. The pattern of the metal layer 24 is not particularly limited. When using the resulting laminate as a planar heating element, the laminate surface may be patterned so as to generate heat as uniformly as possible. When using the resulting laminate as a wiring board, the laminate may be patterned to produce a desired wiring pattern.

[0035] The first resin film 21 is not particularly limited, but examples thereof include films of polyimide-based resins such as polyimide, polyamideimide, polyetherimide, and fluorinated polyimide (e.g., aromatic polyimide resins and alicyclic polyimide resins); copolymer polyesters such as polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalate (e.g., wholly aromatic polyesters and semi-aromatic polyesters); copolymer (meth)acrylates typified by polymethyl methacrylate; polycarbonate; polyamide; polysulfone; polyethersulfone; polyetherketone; cellulose acetate; cellulose nitrate; aromatic polyamide; polyvinyl chloride; polyphenol; polyarylate; polyphenylene sulfide; polyphenylene oxide; and polystyrene. Among these, the first resin film 21 is preferably a polyimide film. When the first resin film 21 is a polyimide film, a laminate having excellent heat resistance can be obtained. When the first resin film 21 is a polyimide film, it is preferable that imidization is completed at the stage of step A (before step C is performed). In other words, it is preferable that the first resin film 21 is not a film containing a precursor solution in which imidization has not been completed.

[0036] The thickness of the first resin film 21 is not particularly limited, but from the viewpoint of making the obtained laminate thin, it is preferably 100 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less. The lower limit of the thickness is not particularly limited, but is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more.

[0037] The metal layer 24 (metal layer 22) is not particularly limited, but is preferably one that can be easily patterned, such as Cu, Ni, Al, Ti, Fe, Ag, Au, or an alloy thereof. Stainless steel (SUS) is also preferred as the metal layer 24 (metal layer 22).

[0038] The thickness of the metal layer 24 (metal layer 22) is not particularly limited, but can be 3 μm or more, 10 μm or more, 20 μm or more, etc. In this embodiment, the first laminate and the second resin film are prepared separately and then bonded together, so that cure shrinkage of the resin films (first resin film, second resin film) does not occur during laminate production. Therefore, even if the thickness of the metal layer 24 is as thick as 10 μm or more, it is possible to produce a laminate having flat and parallel surfaces on both sides. The upper limit of the thickness of the metal layer 24 (metal layer 22) is not particularly limited, but can be, for example, 100 μm or less. Depending on the application of the laminate, the thickness of the metal layer 24 (metal layer 22) can also be less than 3 μm.

[0039] As shown in FIG. 3, a silane coupling agent layer 26 may be provided on the metal layer 24 of the first laminate 20.

[0040] The silane coupling agent layer 26 is later placed physically or chemically between the metal layer 24 and the second resin film 32 when the first laminate 20 and the second resin film 32 are bonded together, and has the effect of adhering the metal layer 24 and the second resin film 32 together.

[0041] The silane coupling agent used in this embodiment is not particularly limited, but preferably contains a coupling agent having an amino group.Preferred specific examples of the silane coupling agent include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, , 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methyltriethoxysilane Examples of suitable alkylsilanes include methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatepropyltriethoxysilane, tris-(3-trimethoxysilylpropyl)isocyanurate, chloromethylphenethyltrimethoxysilane, chloromethyltrimethoxysilane, aminophenyltrimethoxysilane, aminophenethyltrimethoxysilane, and aminophenylaminomethylphenethyltrimethoxysilane.

[0042] In addition to the above, examples of the silane coupling agent include n-propyltrimethoxysilane, butyltrichlorosilane, 2-cyanoethyltriethoxysilane, cyclohexyltrichlorosilane, decyltrichlorosilane, diacetoxydimethylsilane, diethoxydimethylsilane, dimethoxydimethylsilane, dimethoxydiphenylsilane, dimethoxymethylphenylsilane, dodecyltrichlorosilane, dodecyltrimethoxysilane, ethyltrichlorosilane, hexyltrimethoxysilane, octadecyltriethoxysilane, octadecyltrimethoxysilane, n-octyltrichlorosilane, n-octyltriethoxysilane, n-octyltrimethoxysilane, triethoxyethylsilane, triethoxymethylsilane, trimethoxymethylsilane, and trimethoxyphenylsilane. , pentyltriethoxysilane, pentyltrichlorosilane, triacetoxymethylsilane, trichlorohexylsilane, trichloromethylsilane, trichlorooctadecylsilane, trichloropropylsilane, trichlorotetradecylsilane, trimethoxypropylsilane, allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, dimethoxymethylvinylsilane, trichlorovinylsilane, triethoxyvinylsilane, vinyltris(2-methoxyethoxy)silane, trichloro-2-cyanoethylsilane, diethoxy(3-glycidyloxypropyl)methylsilane, 3-glycidyloxypropyl(dimethoxy)methylsilane, 3-glycidyloxypropyltrimethoxysilane, and the like can also be used.

[0043] Among the above-mentioned silane coupling agents, the silane coupling agent having one silicon atom in one molecule is particularly preferred, for example, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, aminophenyltrimethoxysilane, aminophenethyltrimethoxysilane, aminophenylaminomethylphenethyltrimethoxysilane etc. When particularly high heat resistance is required, it is desirable to use an aromatic group to connect between Si and amino group.

[0044] A coupling layer other than the silane coupling agent layer 26 may be provided on the metal layer 24 of the first laminate 20. In addition to the above, examples of the coupling agent for forming the coupling layer include 1-mercapto-2-propanol, methyl 3-mercaptopropionate, 3-mercapto-2-butanol, butyl 3-mercaptopropionate, 3-(dimethoxymethylsilyl)-1-propanethiol, 4-(6-mercaptohexaloyl)benzyl alcohol, 11-amino-1-undecenethiol, 11-mercaptoundecylphosphonic acid, 11-mercaptoundecyltrifluoroacetic acid, 2,2'-(ethylenedioxy)diethanethiol, 11-mercaptoundecyltri(ethylene glycol), (1-mercaptoundic-11-yl)tetra(ethylene glycol), Chole), 1-(methylcarboxy)undec-11-yl)hexa(ethylene glycol), hydroxyundecyl disulfide, carboxyundecyl disulfide, hydroxyhexadodecyl disulfide, carboxyhexadecyl disulfide, tetrakis(2-ethylhexyloxy)titanium, titanium dioctyloxybis(octylene glycolate), zirconium tributoxymonoacetylacetonate, zirconium monobutoxyacetylacetonate bis(ethylacetoacetate), zirconium tributoxymonostearate, acetoalkoxyaluminum diisopropylate, 3-glycidyloxypropyltrimethoxysilane, 2,3-Butanedithiol, 1-Butanethiol, 2-Butanethiol, Cyclohexanethiol, Cyclopentanethiol, 1-Decanethiol, 1-Dodecanethiol, 2-Ethylhexyl 3-Mercaptopropionate, Ethyl 3-Mercaptopropionate, 1-Heptanethiol, 1-Hexadecanethiol, Hexyl Mercaptan, Isoamyl Mercaptan, Isobutyl Mercaptan, 3-Mercaptopropionic Acid, 3-Methoxybutyl 3-Mercaptopropionate, 2-Methyl-1-butanethiol, 1-Octadecanethiol, 1-Octanethiol Other examples of imidazoles that can be used include 1-pentadecanethiol, 1-pentanethiol, 1-propanethiol, 1-tetradecanethiol, 1-undecanethiol, 1-(12-mercaptododecyl)imidazole, 1-(11-mercaptoundecyl)imidazole, 1-(10-mercaptodecyl)imidazole, 1-(16-mercaptohexadecyl)imidazole, 1-(17-mercaptoheptadecyl)imidazole, 1-(15-mercapto)dodecanoic acid, 1-(11-mercapto)undecanoic acid, and 1-(10-mercapto)decanoic acid.

[0045] The silane coupling agent can be applied (a silane coupling agent layer can be formed) by applying a silane coupling agent solution to the metal layer 24 or by vapor deposition. In this case, the silane coupling agent layer 26 may be formed not only on the metal layer 24 but also on the first resin film 21. That is, the silane coupling agent solution may be applied to the first resin film 21 when applied to the metal layer 24, or may be vapor-deposited on the first resin film 21 when vapor-depositing the silane coupling agent solution on the metal layer 24. The silane coupling agent layer may also be formed on the side surface of the patterned metal layer 24. However, even when the silane coupling agent layer is formed on the side surface of the metal layer 24, it is preferable that the silane coupling agent layer formed on the side surface of the metal layer 24 is not bonded to the first side surface 36 (see FIG. 6 ) of the recess 34 of the second resin film 32. Since the silane coupling agent layer formed on the side of the metal layer 24 is not bonded to the first side surface 36 of the recess 34 of the second resin film 32, the resulting laminate (for example, the laminate 10 described below) is an easily flexible laminate. The silane coupling agent layer may be formed on the surface of the recesses 34 of the second resin film 32. The silane coupling agent layer may be formed on both the metal layer 24 and the recesses 34 of the second resin film 32.

[0046] The thickness of the silane coupling agent layer 26 is not particularly limited, but may be large enough to cover the entire surface of the metal layer 24 .

[0047] <Process B> In addition, in the manufacturing method of the laminate according to this embodiment, apart from the step A, a second resin film 32 having recesses 34 corresponding to the pattern (convex pattern) of the metal layer 24 is prepared (step B), as shown in FIG.

[0048] The method for preparing the second resin film 32 having the recesses 34 is not particularly limited, but for example, it can be prepared by the following procedure.

[0049] First, as shown in FIG. 4, an unpatterned second resin film 31 is prepared.

[0050] The material of the second resin film 31 is not particularly limited, but the same material as that of the first resin film 21 can be used. In particular, the second resin film 31 is preferably a polyimide film. When the second resin film 31 is a polyimide film, a laminate with excellent heat resistance can be obtained. The material of the first resin film 21 and the material of the second resin film 31 may be the same or different.

[0051] The thickness of the second resin film 31 is not particularly limited, but from the viewpoint of making the obtained laminate thin, it is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. The lower limit of the thickness is not particularly limited, but is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more. When the upper and lower resin films of the resulting laminate 10 are to have the same thickness, the thickness of the second resin film 31 is preferably the sum of the thickness of the first resin film 21 and the thickness of the metal layer 24 .

[0052] Next, the unpatterned second resin film 31 is etched by a conventionally known method to form recesses 34 corresponding to the pattern (protruding pattern) of the metal layer 24. When a polyimide film is used as the second resin film 31, etching is performed by a conventionally known method using, for example, an alkaline agent. This results in a second resin film 32 having recesses 34 (see FIG. 5). The depth of the recesses 34 is preferably approximately the same as the thickness of the metal layer 24. Furthermore, the size (width) of the recesses 34 is preferably set slightly larger than the width of the pattern (protruding pattern) of the metal layer 24. This is to ensure a reliable fit when the pattern (protruding pattern) of the metal layer 24 and the recesses 34 of the second resin film 32 are later fitted together.

[0053] <Process C> After the steps A and B, as shown in FIG. 6, the first laminate 20 and the second resin film 32 are bonded together while the pattern of the metal layer 24 is fitted into the recesses 34 of the second resin film 32 (step C).

[0054] In this embodiment, since the silane coupling agent layer 26 is provided on the metal layer 24 of the first laminate 20, in the step C, the first laminate 20 and the second resin film 32 are bonded together via the silane coupling agent layer 26. Since the first laminate 20 and the second resin film 32 are bonded together via the silane coupling agent layer 26, they can be firmly bonded together. Furthermore, unlike resin-based adhesives, silane coupling agents are less susceptible to degradation in a thermal environment. Therefore, they can withstand long-term use in a thermal environment.

[0055] However, in the method for manufacturing a laminate according to the present invention, the silane coupling agent layer 26 does not need to be provided. In this case, the first laminate 20 and the second resin film 32 can be bonded together by pressure bonding. When pressure bonding is performed, it is preferable to plasma treat the surface of the second resin film 32 beforehand. Plasma treating the surface of the second resin film 32 before pressure bonding allows the two to be firmly bonded together. Plasma treating the surface of the second resin film 32 before pressure bonding is also preferable in terms of reducing thermal degradation. Heat-pressure bonding is preferred for pressure bonding. Note that it is preferable not to use a resin-based adhesive when bonding the first laminate 20 and the second resin film 32, in order to prevent thermal degradation.

[0056] Through the above steps, the laminate 10 is obtained.

[0057] In the above-described embodiment, a case where a silane coupling agent layer is provided on the metal layer of the first laminate has been described. However, the present invention is not limited to this example. Instead of providing a silane coupling agent layer on the metal layer of the first laminate, a silane coupling agent layer may be provided on the second resin film. Even in this configuration, in step C, the first laminate and the second resin film can be bonded together via the silane coupling agent layer.

[0058] The laminate 10 obtained by the above-described laminate manufacturing method has the following configuration: The laminate 10 has a first resin film 21, a patterned metal layer 24, a silane coupling agent layer 26, and a second resin film 32 having recesses 34 corresponding to the pattern of the metal layer 24 laminated in this order, and a gap 42 exists between a first side surface 36 of the recesses 34 of the second resin film 32 and a second side surface 25 of the metal layer 24 facing the first side surface 36. The laminate 10 can be produced in a short time by the laminate manufacturing method described above. Furthermore, since the first laminate and the second resin film are prepared separately and then bonded together, the laminate 10 can have flat, parallel surfaces on both sides.

[0059] The laminate 10 preferably has a warpage of 5% or less, more preferably 3% or less, and even more preferably 1% or less, measured by the following measurement method after heating at 300°C.

[0060] <Warpage of laminate after heating at 300℃> The warpage (%) of a laminate after heating at 300°C refers to the degree of deformation in the thickness direction relative to the plane direction of the laminate before and after heating at 300°C. Specifically, it refers to a value obtained by the following procedure. FIG. 7 is a plan view illustrating how to determine the warpage of a laminate after heating at 300°C, and FIG. 8 is a cross-sectional view taken along line AA. First, as shown in FIGS. 7 and 8, a 100 mm × 100 mm test piece 100 (laminate) is prepared. At room temperature, the test piece 100 is placed on a surface plate 110 so as to form a concave shape, and the average value of the distances from the flat surfaces of the four corners (h1rt, h2rt, h3rt, h4rt: in mm) is defined as the "original warpage (mm)." Next, after heat treatment at 300°C for 1 hour, the test piece is placed on a flat surface so as to form a concave shape, and the average value of the distances from the flat surfaces of the four corners (h1, h2, h3, h4: in mm) is defined as the "warpage (mm)." The difference between the "amount of warp" and the "original amount of warp" is taken as the "amount of warp before and after heat treatment at 300°C." The "warp (%) of the laminate after heating at 300°C" is a value expressed as a percentage (%) of the curl amount relative to the distance (70.7 mm) from each vertex to the center of the test piece. The measurement value is the average value of 10 points (10 test pieces). However, even if there are not enough laminates to sample 10 points, measurements are still taken on 3 or more sheets. Specifically, it is calculated using the following formula. Original warpage (mm) = (h1rt+h2rt+h3rt+h4rt) / 4 Warpage (mm) = (h1 + h2 + h3 + h4) / 4 Warpage (mm) before and after heat treatment at 300°C = (warpage) - (original warpage) Warpage of laminate after heating at 300°C (%) = 100 × (warpage before and after heat treatment at 300°C) / 70.7

[0061] Next, the multilayer laminate according to this embodiment and a method for manufacturing the multilayer laminate will be described.

[0062] [First embodiment] Fig. 9 is a cross-sectional schematic diagram showing a multilayer laminate according to the first embodiment. As shown in Fig. 9, the multilayer laminate 50 according to the first embodiment has a configuration in which two of the above-described laminates 10 are stacked. In the multilayer laminate 50, the first resin film 21 of one laminate 10 (the upper laminate 10 in Fig. 9) and the second resin film 32 of the other laminate 10 (the lower laminate 10 in Fig. 9) are stacked so as to face each other.

[0063] The multilayer laminate 50 is obtained by laminating two laminates 10 together.

[0064] As described above, examples of a method for bonding one laminate 10 to another laminate 10 include a method of bonding them via a silane coupling agent layer. Specifically, examples include a method of forming a silane coupling agent layer on the first resin film 21 of one laminate 10 and then bonding it to the other laminate 10, and a method of forming a silane coupling agent layer on the second resin film 32 of the other laminate 10 and then bonding it to the one laminate 10. When a silane coupling agent is used for bonding, the two can be firmly bonded together. Furthermore, using a silane coupling agent for bonding is preferable because it causes less thermal degradation. Another bonding method includes pressure bonding. When pressure bonding is performed, it is preferable to plasma treat the resin films (first resin film 21 and / or second resin film 32) that will be bonded together in advance. Plasma treatment followed by pressure bonding allows the two films to be firmly bonded together. Plasma treatment followed by pressure bonding is also preferable in that it reduces thermal degradation. Heat-pressure bonding is preferred for pressure bonding. Note that it is preferable not to use a resin-based adhesive when bonding the first resin film 21 and the metal layer 22 together, in order to prevent thermal degradation.

[0065] In the above-mentioned multilayer laminate 50, the first resin film 21 of one laminate 10 and the second resin film 32 of the other laminate 10 are laminated so as to face each other, but the multilayer laminate of the present invention is not limited to this example, and may be laminated so as to face each other the first resin film of one laminate and the first resin film of the other laminate, or so as to face each other the second resin film of one laminate and the second resin film of the other laminate.

[0066] In the above-described multilayer laminate 50, two laminates 10 are stacked, but the multilayer laminate according to the present invention is not limited to this example and may include three or more laminates 10. The third layer may be stacked using the same method as described above.

[0067] According to the multilayer laminate of the first embodiment, since both sides of the laminate 10 are flat and parallel, even when two or more layers are stacked (even when stacked in multiple layers), the parallelism can be maintained. Furthermore, since there are two or more metal layers, when used as wiring layers, each metal layer can be assigned a function, such as an earth layer and a power layer. As a result, the wiring layer can be resistant to noise and does not easily generate noise.

[0068] [Second embodiment] 10 to 13 are cross-sectional schematic views illustrating a method for manufacturing a multilayer laminate according to the second embodiment. As shown in Fig. 13, a multilayer laminate 70 according to the second embodiment has a configuration in which a laminate 10, a patterned second metal layer 64, and a third resin film 72 are laminated in this order.

[0069] The multilayer laminate 70 can be produced by the following method.

[0070] First, the laminate 10 is prepared.

[0071] 10, an unpatterned second metal layer 62 is bonded to the first resin film 21 of the laminate 10. The second metal layer 62 may be the same as the metal layer 22. As a method for bonding the second metal layer 62, as described above, bonding using a silane coupling agent or pressure bonding (more preferably pressure bonding after plasma treatment) may be used.

[0072] Next, as shown in FIG. 11, the unpatterned second metal layer 62 is etched by conventional methods to form a patterned second metal layer 64.

[0073] 12, a third resin film 72 having recesses 74 corresponding to the pattern (protruding pattern) of the second metal layer 64 is prepared. The third resin film 72 can be prepared by the same method as the second resin film 32.

[0074] 13, the pattern of the second metal layer 64 and the recessed portion 74 of the third resin film 72 are fitted together and bonded together. As a bonding method, similar to that described above, bonding using a silane coupling agent or pressure bonding (more preferably pressure bonding after plasma treatment) can be used. A gap similar to the gap 42 exists between the side surface of the recessed portion 74 of the third resin film 72 and the side surface of the second metal layer 64 facing the side surface. The material of the third resin film 72 is not particularly limited, but the same material as that of the first resin film 21 can be used. In particular, the third resin film 72 is preferably a polyimide film. When the third resin film 72 is a polyimide film, a laminate with excellent heat resistance can be obtained. The material of the third resin film 72, the material of the first resin film 21, and the material of the second resin film 32 may be the same as or different from one another.

[0075] Through the above steps, a multilayer laminate 70 is obtained.

[0076] In the above-described multilayer laminate 70, the case where the patterned second metal layer 64 and the third resin film 72 are laminated in this order on the first resin film 21 of the laminate 10 has been described. However, the multilayer laminate according to the present invention is not limited to this example, and the patterned second metal layer and the third resin film may also be laminated in this order on the second resin film 32 of the laminate 10.

[0077] The above-described multilayer laminate 70 has been described as including two metal layers: metal layer 24 and second metal layer 64. However, the multilayer laminate according to the present invention is not limited to this example, and may include three or more metal layers. To include three or more metal layers, an additional patterned metal layer and an additional resin film may be laminated on either side of the multilayer laminate 70 using the method described with reference to FIGS. 10 to 12.

[0078] According to the multilayer laminate of the second embodiment, since both surfaces of the laminate 10 are flat and parallel, even if a patterned second metal layer and a third resin film are further laminated to the laminate 10 (even when laminated in multiple layers), the parallelism can be maintained. Furthermore, compared to the multilayer laminate of the first embodiment, the number of resin film layers can be reduced by one. Furthermore, since there are two or more metal layers, when used as wiring layers, each metal layer can be assigned a function, for example, as an earth layer or a power layer, and the function can be separated. As a result, the wiring layer can be resistant to noise and does not generate noise easily. Furthermore, when the metal layers are used as a heat source and the multilayer laminate is used as a planar heating element, the two or more metal layers can uniformly distribute heat.

[0079] [Third embodiment] 14 to 17 are cross-sectional schematic views illustrating a method for manufacturing a multilayer laminate according to the third embodiment. As shown in Fig. 17, a multilayer laminate 80 according to the third embodiment has two laminates 10 stacked together, a first resin film 21 has a through-hole 82, a metal-filled layer 84 filled with metal is formed in the through-hole 82, and the metal-filled layer 84 of one laminate 10 and the metal-filled layer 84 of the other laminate 10 are electrically connected to each other.

[0080] The multilayer laminate 80 can be produced by the following method.

[0081] First, the laminate 10 is prepared.

[0082] 14, through holes 82 are formed in the first resin film 21 of the laminate 10, reaching the metal layer 24. The through holes 82 can be formed by a conventionally known method. For example, the through holes 82 can be formed by laser processing.

[0083] 15, the through holes 82 are filled with metal to form a metal filling layer 84. The method for forming the metal filling layer 84 is not particularly limited, but for example, the metal filling layer 84 is formed by filling with a metal paste (silver paste or the like).

[0084] In the same manner, another laminate 10 having a metal filling layer 84 is produced.

[0085] Next, the two laminates 10 each having a metal filling layer 84 are bonded together. At this time, the laminates 10 are bonded together after being aligned so that the metal filling layer 84 of one laminate 10 and the metal filling layer 84 of the other laminate 10 are electrically connected.

[0086] Through the above steps, a multilayer laminate 80 is obtained.

[0087] In the above-described multilayer laminate 80, a case has been described in which a metal filling layer 84 is formed in the first resin film 21 of the laminate 10. However, the multilayer laminate according to the present invention is not limited to this example. For example, a metal filling layer may be formed in the second resin film 32 of the laminate 10, and two laminates 10 having the metal filling layer formed in the second resin film 32 may be bonded together. Alternatively, a metal filling layer may be formed in the first resin film 21 of one laminate 10, while a metal filling layer may be formed in the second resin film 32 of the other laminate 10, and the two laminates 10 may be bonded together so that the metal filling layers are electrically connected to each other.

[0088] The multilayer laminates of the first to third embodiments may be used by further bonding the multilayer laminates together, for example, by bonding the multilayer laminate of the first embodiment to the multilayer laminate of the second embodiment. The bonding method is not particularly limited, but as already explained, bonding using a silane coupling agent or pressure bonding is preferred.

[0089] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described examples, and appropriate design changes can be made within the scope of the configuration of the present invention. [Explanation of symbols]

[0090] 10 Laminate 20 First laminate 21 First resin film 22 Unpatterned metal layer 24 Patterned Metal Layer 25 Second aspect 26 Silane coupling agent layer 31 Unpatterned second resin film 32 Patterned second resin film 34 Recess 36 First aspect 42 void 50, 70, 80 multilayer laminate 62 Unpatterned second metal layer 64 Patterned second metal layer 72 Third resin film 74 recess 82 Through hole 84 Metal filled layer

Claims

1. A step A of preparing a first laminate in which a first resin film and a patterned metal layer are laminated; a step B of preparing a second resin film having recesses corresponding to the pattern of the metal layer; A method for manufacturing a laminate, comprising: a step C of bonding the first laminate and the second resin film while fitting the pattern of the metal layer into the recess of the second resin film.

2. a silane coupling agent layer is provided on the metal layer of the first laminate; 2. The method for producing a laminate according to claim 1, wherein the step C is a step of bonding the first laminate and the second resin film together via the silane coupling agent layer.

3. a silane coupling agent layer is provided on the second resin film; 2. The method for producing a laminate according to claim 1, wherein the step C is a step of bonding the first laminate and the second resin film together via the silane coupling agent layer.

4. 4. The method for manufacturing a laminate according to claim 1, wherein the first resin film and the second resin film are polyimide films.

5. 4. The method for manufacturing a laminate according to claim 1, wherein the thickness of the metal layer is 10 μm or more and 100 μm or less.

6. a first resin film, a patterned metal layer, a silane coupling agent layer, and a second resin film having recesses corresponding to the pattern of the metal layer laminated in this order; A laminate, characterized in that a gap exists between a first side surface of the recess of the second resin film and a second side surface of the metal layer facing the first side surface.

7. A multilayer laminate comprising two or more laminates according to claim 6 stacked together.

8. A multilayer laminate comprising the laminate according to claim 6, a patterned second metal layer, and a third resin film laminated in this order.

9. Two laminates according to claim 6 are stacked together, a through hole is provided in the first resin film or the second resin film, a metal filling layer filled with metal is formed in the through hole, A multilayer laminate, characterized in that the metal filling layer of one laminate and the metal filling layer of the other laminate are electrically connected.

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