Method for manufacturing resin-coated metal foil, method for manufacturing laminates, method for manufacturing printed circuit boards, and method for manufacturing semiconductor packages

Abstract

To provide a method for manufacturing a metal foil with resin in which a warpage amount can be made sufficiently small, a warpage amount can be maintained small even after being stored, and a method for manufacturing a laminate plate, a print circuit board and a semiconductor package which use the metal foil.SOLUTION: A method for manufacturing a metal foil 10 with resin which has a metal foil 1, and a resin layer 2 which is formed on one surface side of the metal foil by using a thermosetting resin composition includes a warpage correction processing for reducing a warpage of the metal foil with resin. In the warpage correction processing, a warpage correcting tool 6 is pressed on a surface of the metal foil with resin closer to a metal foil side, the metal foil with resin is conveyed in a state where the warpage correcting tool is pressed toward the resin layer side, and the metal foil with resin is continuously bent while using the warpage correcting tool as an axis by allowing the metal foil to pass on the warpage correcting tool, and the warpage correction processing is performed twice or more in the condition that bending directions of axes of the metal foil with resin become 2 or more.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present embodiment relates to a method for manufacturing a metal foil with resin, a method for manufacturing a laminate, a method for manufacturing a printed wiring board, and a method for manufacturing a semiconductor package.

Background Art

[0002] Due to the recent miniaturization and high performance of electronic devices, printed wiring boards are required to have a higher wiring density and higher integration as well as a thinner substrate than before. To meet these requirements, a metal foil with resin in which a resin layer is formed on a metal foil without using a fiber base material such as glass cloth is used in the manufacture of printed wiring boards. Since the metal foil with resin does not contain a fiber base material such as glass cloth, it can be thinned, and because it has excellent smoothness and fine wiring properties of the insulating layer, it is also suitable for higher wiring density and higher integration. Furthermore, since the metal foil with resin does not contain a fiber base material such as glass cloth, it has excellent dielectric properties and is applied to printed wiring boards and the like that require high-frequency operation.

[0003] The metal foil with resin is usually manufactured by applying a thermosetting resin composition containing a solvent on a metal foil and then heating and drying it. At this time, since the volume of the thermosetting resin composition shrinks due to the volatilization of the solvent and the B-staging of the thermosetting resin composition, the metal foil with resin may warp toward the resin layer side. The occurrence of such warping is a factor that reduces the productivity when manufacturing a printed wiring board using the metal foil with resin, so it is desirable to suppress it.

[0004] Patent Document 1 discloses a method for manufacturing resin-coated metal foil, in which a thermosetting resin composition is applied to the surface of the metal foil and heated and dried by passing it through a drying oven to achieve the B-stage, characterized in that the heating temperature at a position 80% of the total length from the inlet to the outlet of the drying oven is 100°C or more higher than the heating temperature near the inlet of the drying oven, and the heating temperature from this position to the outlet is 30°C or more lower. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2004-025624 [Overview of the project] [Problems that the invention aims to solve]

[0006] According to the technology described in Patent Document 1, it is possible to manufacture resin-coated metal foil with reduced warping at the edges. However, the manufacturing method described in Patent Document 1 has the limitation that only materials of a type suitable for its drying conditions can be used, thus limiting the freedom of material selection.

[0007] Therefore, the inventors have been investigating a method for manufacturing resin-coated metal foil with reduced warping and improved productivity. Their investigations have shown that the amount of warping can be reduced by applying a specific mechanical treatment to resin-coated metal foil that has warped. However, the reduction in warping is not sufficient, and the warping sometimes returns to its original state during storage, so improvement is desired.

[0008] In view of the current situation, this embodiment aims to provide a method for manufacturing resin-coated metal foil that can sufficiently reduce the amount of warping and maintain a low amount of warping even after storage, as well as a method for manufacturing laminates, printed circuit boards, and semiconductor packages using resin-coated metal foil manufactured by this method. [Means for solving the problem]

[0009] As a result of further investigations aimed at solving the above-mentioned problems, the present inventors have found that the present disclosure can solve the above-mentioned problems. This disclosure includes the following embodiments [1] to

[10] . [1] A method for manufacturing a resin-coated metal foil, comprising a metal foil and a resin layer formed on one side of the metal foil using a thermosetting resin composition, This includes a warp correction treatment to reduce the warping of the resin-coated metal foil, The aforementioned warping correction process involves pressing a warping correction jig against the metal foil side of the resin-coated metal foil, transporting the resin-coated metal foil while pushing the warping correction jig towards the resin layer side, and passing the resin-coated metal foil over the warping correction jig, thereby continuously bending the resin-coated metal foil around the warping correction jig as an axis. A method for manufacturing a resin-coated metal foil, comprising performing the warping correction treatment two or more times under the condition that there are two or more directions of axes in which the resin-coated metal foil bends. [2] The warping correction treatment performed two or more times is A warp correction treatment (1) in which the direction of the axis in which the resin-coated metal foil bends is set to X, The process includes (2) a warp correction treatment in which the direction of the axis in which the resin-coated metal foil bends is Y, The angle between the aforementioned direction X and the aforementioned direction Y is between 60 and 120°. The method for manufacturing resin-coated metal foil as described in [1] above. [3] The method for manufacturing resin-coated metal foil according to [2] above, wherein the angle between the direction X and the direction Y is 80 to 100°. [4] The method for manufacturing resin-coated metal foil according to [2] or [3], wherein the angle between the direction Z for conveying the resin-coated metal foil and the direction X, and the angle between the direction Z for conveying the resin-coated metal foil and the direction Y are each 30 to 150°. [5] A method for manufacturing a resin-coated metal foil according to any one of [1] to [4] above, wherein the warping correction jig is in the shape of a plate, and in the warping correction process, the end of the plate-shaped warping correction jig is pressed against the metal foil side of the resin-coated metal foil. [6] A method for manufacturing resin-coated metal foil according to any one of [1] to [5] above, wherein the distance for pushing the warp correction jig toward the resin layer is 1 to 25 mm. [7] A method for manufacturing resin-coated metal foil according to any one of [1] to [6] above, wherein the conveying speed of the resin-coated metal foil is 1 to 15 m / min. [8] A method for manufacturing a laminate, comprising forming an insulating layer using resin-coated metal foil obtained by the method for manufacturing resin-coated metal foil described in any of [1] to [7] above. [9] A method for manufacturing a printed circuit board, comprising forming a wiring pattern on a laminate obtained by the method for manufacturing a laminate described in [8] above.

[10] A method for manufacturing a semiconductor package, comprising mounting a semiconductor element on a printed circuit board obtained by the method for manufacturing a printed circuit board described in [9] above. [Effects of the Invention]

[0010] According to this embodiment, it is possible to provide a method for manufacturing resin-coated metal foil that can sufficiently reduce the amount of warping and maintain a small amount of warping even after storage, as well as a method for manufacturing laminates, printed circuit boards, and semiconductor packages using resin-coated metal foil manufactured by this method. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing one aspect of resin-coated metal foil. [Figure 2] This is a schematic diagram showing another embodiment of resin-coated metal foil. [Figure 3]It is a schematic cross-sectional view showing one aspect of the warpage correction process. [Figure 4] It is a schematic cross-sectional view showing one aspect of the warpage correction jig. [Figure 5] It is a schematic plan view showing one aspect of the warpage correction process.

Mode for Carrying Out the Invention

[0012] The numerical range indicated by using "~" described in this specification indicates a numerical range including the numerical value described before "~" as the minimum value and the numerical value described after "~" as the maximum value. For example, the notation of the numerical range "X~Y" (X and Y are real numbers) means a numerical range that is X or more and Y or less. And the description of "X or more" in this specification means X and numerical values exceeding X, and the same applies when the numerical values are different. Also, the description of "Y or less" in this specification means Y and numerical values less than Y. In the numerical range described in this specification, the lower limit value or the upper limit value of the numerical range may be replaced with the value shown in the examples. Each component and material exemplified in this specification may be used alone or in combination of two or more, unless otherwise specified. In this specification, the content of each component in the resin composition means the total amount of the plurality of substances corresponding to each component in the resin composition, unless otherwise specified, when there are a plurality of substances corresponding to each component in the resin composition. In this specification, the "resin composition" includes a mixture of each component described later and a material obtained by B-staging the mixture. Here, in this specification, B-staging means making it in the state of B-stage defined in JIS K6900 (1994), and is also referred to as semi-curing. Aspects obtained by arbitrarily combining the matters described in this specification are also included in this embodiment. The mechanism of action described in this specification is a speculation and does not limit the mechanism by which the resin composition according to this embodiment exhibits its effects.

[0013] 1]<\ [Method for Producing Metal Foil with Resin] The manufacturing method of the metal foil with resin of this embodiment is a manufacturing method of a metal foil with resin, which has a metal foil and a resin layer formed by using a thermosetting resin composition on one surface side of the metal foil, and includes a warp correction process for reducing the warp of the metal foil with resin, and the warp correction process is a process of continuously bending the metal foil with resin around the warp correction jig by pressing the warp correction jig against the surface on the metal foil side of the metal foil with resin, transporting the metal foil with resin in a state where the warp correction jig is pushed into the resin layer side, and passing it over the warp correction jig, and the warp correction process is performed two or more times under the condition that the number of directions of the axis around which the metal foil with resin bends is two or more. This is the manufacturing method of the metal foil with resin.

[0014] According to the manufacturing method of this embodiment, a metal foil with resin having a sufficiently small warp amount and maintaining a small warp amount even after storage can be manufactured. The reason for this is not clear, but it is presumed as follows. In the warp correction process included in the manufacturing method of this embodiment, since the metal foil with resin is bent with the metal foil on the inside, a stretching load is applied to the outer resin layer, and it is considered that the stress generated by the volume shrinkage of the resin layer is released thereby. At this time, although the phenomenon occurring in the resin layer is not clear, it is considered that fine cracks that cannot be visually confirmed occur in the resin layer, and the stress in the stretching direction is irreversibly released. However, if the warp correction process is performed with only one direction of the axis around which the metal foil with resin bends, in addition to the small amount of warp reduction, the warp tends to increase during storage. As a cause of this, in the warp correction process with only one direction of the axis around which it bends, stress in a direction orthogonal to the stretching direction tends to remain, and due to volume shrinkage of the resin layer caused by progress of curing, volatilization of residual solvent, etc. during storage, it is considered that the remaining stress increases. On the other hand, the manufacturing method of this embodiment involves applying warp correction treatment two or more times so that there are two or more axes of bending of the resin-coated metal foil. Therefore, it is possible to release stress in directions that were not released by the first warp correction treatment through the second and subsequent warp correction treatments. As a result, it is believed that even if volume shrinkage of the resin layer occurs during storage, the increase in warping can be suppressed.

[0015] The following describes each component that makes up the resin-coated metal foil manufactured by the manufacturing method of this embodiment, and then details the warp correction treatment.

[0016] Figure 1 is a schematic diagram of a resin-coated metal foil 10, which is one embodiment of the resin-coated metal foil obtained by the manufacturing method of this embodiment. The resin-coated metal foil 10 has a structure in which a resin layer 2 is formed on one surface of the metal foil 1. Figure 2 is a schematic diagram of a resin-coated metal foil 20, which is another embodiment of the resin-coated metal foil obtained by the manufacturing method of this embodiment. The resin-coated metal foil 20 has a structure in which a resin layer 2 is formed on one surface of the metal foil 1. Furthermore, on the surface of the metal foil 1 opposite to the resin layer 2, a release layer 3 and a carrier foil 4 are laminated in that order. The resin-coated metal foil obtained by the manufacturing method of this embodiment may have the metal foil 1 and the resin layer 2 directly laminated together, or it may have another layer between the metal foil 1 and the resin layer 2.

[0017] <Metal foil> Examples of metal foils include copper foil, tin foil, tin-lead alloy foil, and nickel foil. Among these, copper foil is preferred. Preferably, the copper foil has a copper content of 95% by mass or more. From the perspective of use in semiconductor packaging, it is preferable that the metal foil conforms to JIS standards (electrolytic copper foil for printed circuit boards: JIS C6512, rolled copper foil for printed circuit boards: JIS C6513) or IPC standards (IPC 4562 standard Grade 1, 2, 3).

[0018] The surface of the metal foil that forms the resin layer may be roughened for better adhesion. The roughening treatment can be applied by forming roughening particles on the surface of the metal foil. As roughened particles, for example, electrodeposited particles consisting of elements selected from copper, nickel, phosphorus, tungsten, arsenic, molybdenum, chromium, cobalt, and zinc, or electrodeposited particles consisting of alloys containing one or more of these elements are preferred. The coarse particles may be used individually or in combination of two or more types.

[0019] In addition to the roughening treatment described above, the metal foil may also have secondary particles, tertiary particles, a rust-preventive layer, a heat-resistant layer, etc., formed by, for example, elements selected from nickel, cobalt, copper, and zinc, or alloys containing one or more of these elements. Furthermore, in addition to the above layers, the surface may be further treated with surface treatments such as chromate treatment or silane coupling treatment.

[0020] The thickness of the metal foil can be adjusted as appropriate depending on the application of the resin-coated metal foil, and is not particularly limited, but is preferably 0.1 to 35 μm, more preferably 0.3 to 15 μm, even more preferably 0.5 to 5 μm, and particularly preferably 1 to 2 μm. When the thickness of the metal foil is greater than or equal to the lower limit, the handling properties of the resin-coated metal foil obtained by the manufacturing method of this embodiment tend to improve further. On the other hand, when the thickness of the metal foil is less than or equal to the upper limit, the resin-coated metal foil obtained by the manufacturing method of this embodiment tend to be more suitable for thinner substrates.

[0021] <Carrier foil> The carrier foil is a support that is provided as needed to improve handling when the metal foil is thin. Therefore, the carrier foil is removed during the manufacturing process of printed circuit boards and the like. In this embodiment, the carrier foil is not included in the metal foil that constitutes the resin-coated metal foil. Examples of carrier foils include copper foil, aluminum foil, and nickel foil. Among these, copper foil is preferred.

[0022] The thickness of the carrier foil is preferably 5 to 50 μm, more preferably 7 to 35 μm, and even more preferably 10 to 25 μm, from the viewpoint of improving the handling of the resin-coated metal foil and from the viewpoint of production costs. When the thickness of the carrier foil is greater than or equal to the lower limit, the handling properties of the resin-coated metal foil obtained by the manufacturing method of this embodiment tend to improve further. On the other hand, when the thickness of the carrier foil is less than or equal to the upper limit, the cost of the resin-coated metal foil obtained by the manufacturing method of this embodiment tends to be reduced further.

[0023] <Exfoliation layer> The release layer is a layer provided between the metal foil and the carrier layer as needed to facilitate the separation of the carrier foil from the metal foil. In this embodiment, the release layer is not included in the metal foil constituting the resin-coated metal foil. Examples of the release layer include a layer containing one or more metals selected from chromium, nickel, cobalt, iron, molybdenum, titanium, tungsten, phosphorus, copper, and aluminum. These metals may be alloys, hydrates, oxides, etc. The release layer may be a single layer or multiple layers. The release layer can be formed by wet plating methods such as electroplating, electroless plating, and dipping plating; or by dry plating methods such as sputtering, chemical vapor deposition (CVD), and physical vapor deposition (PDV).

[0024] <Resin layer> The resin layer is a layer formed on one side of the metal foil using a thermosetting resin composition. The resin layer is typically used as an insulating layer in applications such as printed circuit boards. The thickness of the resin layer can be adjusted as appropriate depending on the application of the resin-coated metal foil, and is not particularly limited, but is preferably 5 to 70 μm, more preferably 10 to 50 μm, and even more preferably 15 to 30 μm. When the thickness of the resin layer is greater than or equal to the lower limit, the insulating properties of the insulating layer formed from the resin-coated metal foil obtained by the manufacturing method of this embodiment tend to improve further. On the other hand, when the thickness of the resin layer is less than or equal to the upper limit, the resin-coated metal foil obtained by the manufacturing method of this embodiment tends to be more suitable for thinning substrates.

[0025] The composition of the thermosetting resin composition used to form the resin layer can be appropriately determined depending on the application of the resin-coated metal foil. Examples of thermosetting resins contained in the thermosetting resin composition 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. Among these, epoxy resins and unsaturated imide resins are preferred, unsaturated imide resins are more preferred, and maleimide resins are even more preferred. The maleimide resin may be a prepolymer obtained by Michael addition of a maleimide compound and a diamine compound. Thermosetting resins may be used individually or in combination of two or more types.

[0026] The thermosetting resin composition may also contain, in addition to the thermosetting resin, inorganic fillers, curing agents, curing accelerators, thermoplastic resins, elastomers, organic fillers, flame retardants, and other additives. Each of these may be used individually or in combination of two or more. Examples of inorganic fillers include silica, alumina, talc, mica, aluminum hydroxide, magnesium hydroxide, calcium carbonate, aluminum borate, and borosilicate glass. Examples of curing agents include phenol compounds, amine compounds, and acid anhydrides. It is preferable to select the curing agent appropriately depending on the type of thermosetting resin. Examples of curing accelerators include imidazoles and their derivatives; organophosphorus compounds; secondary amines, tertiary amines, quaternary ammonium salts, and the like. Examples of thermoplastic resins and elastomers include polyphenylene ether and its derivatives, polybutadiene and its derivatives, and styrene-based thermoplastic elastomers. Examples of organic fillers include polytetrafluoroethylene (PTFE) particles; crosslinked NBR particles obtained by copolymerizing acrylonitrile and butadiene as copolymers of acrylonitrile and butadiene, copolymers of acrylonitrile, butadiene and carboxylic acids such as acrylic acid; and so-called core-shell rubber particles with a core of polybutadiene, NBR, silicone rubber, etc., and a shell of an acrylic acid derivative. Examples of flame retardants include phosphorus-based flame retardants, metal hydrates, and halogen-based flame retardants. Other additives include UV absorbers such as benzotriazoles; antioxidants such as hindered phenol antioxidants and styrene-phenol antioxidants; photopolymerization initiators such as benzophenones, benzyl ketals, and thioxanthones; fluorescent whitening agents such as stilbene derivatives; adhesion enhancers such as urea compounds and silane coupling agents.

[0027] The content of the thermosetting resin in the thermosetting resin composition is preferably 30 to 95 parts by mass, more preferably 40 to 90 parts by mass, and even more preferably 50 to 80 parts by mass, based on 100 parts by mass of the total amount of resin components in the thermosetting resin composition. The content of thermoplastic resin in the thermosetting resin composition is preferably 1 to 40 parts by mass, more preferably 5 to 37 parts by mass, and even more preferably 15 to 35 parts by mass, based on 100 parts by mass of the total amount of resin components in the thermosetting resin composition. The elastomer content in the thermosetting resin composition is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, based on 100 parts by mass of the total resin components in the thermosetting resin composition. The amount of curing accelerator in the thermosetting resin composition is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 4 parts by mass, and even more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the total amount of resin components in the thermosetting resin composition. The amount of inorganic filler in the thermosetting resin composition is preferably 20 to 300 parts by mass, more preferably 30 to 150 parts by mass, and even more preferably 40 to 100 parts by mass, based on 100 parts by mass of the total amount of resin components in the thermosetting resin composition. The content of organic fillers in the thermosetting resin composition is preferably 20 to 300 parts by mass, more preferably 30 to 150 parts by mass, and even more preferably 40 to 100 parts by mass, based on 100 parts by mass of the total amount of resin components in the thermosetting resin composition. Herein, in this specification, "resin component" means resin and compounds that form resin through a curing reaction, and for example, thermosetting resins, thermoplastic resins, elastomers, etc. are considered resin components. Furthermore, if a thermosetting resin composition contains, as an optional component, a resin or a compound that forms resin through a curing reaction in addition to the above components, these optional components are also included in the resin component. On the other hand, curing accelerators, inorganic fillers, and organic fillers are not included in the resin component.

[0028] Thermosetting resin compositions may contain organic solvents to facilitate layer formation. Thermosetting resin compositions containing organic solvents are sometimes referred to as "resin varnishes." Examples of organic solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; acetic acid ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. The organic solvent may be used individually or in combination of two or more. Among these, toluene and methyl isobutyl ketone are preferred from the viewpoint of solubility.

[0029] When a thermosetting resin composition contains an organic solvent, the solid content is not particularly limited, but from the viewpoint of facilitating coating properties and control of the resin layer thickness, it is preferably 25 to 80% by mass, more preferably 30 to 65% by mass, and even more preferably 35 to 50% by mass. In this embodiment, "solid content" refers to components other than the solvent, and includes liquid, syrup-like, or waxy substances at room temperature around 25°C.

[0030] Thermosetting resin compositions can be manufactured by mixing the above components with an organic solvent as needed, using a known stirrer or the like. During mixing, each component may be dissolved or dispersed while being stirred. Furthermore, the order in which the raw materials are mixed, the mixing temperature, the mixing time, and other conditions are not particularly limited and can be set arbitrarily according to the type of raw materials, etc. Next, the manufacturing method of this embodiment will be described.

[0031] <Preparation of resin-coated metal foil before warp correction treatment> The resin-coated metal foil before warp correction treatment is obtained, for example, by applying a resin varnish to the metal foil and then heat-drying it. It is preferable that the heat-drying process removes the organic solvent contained in the resin varnish and also B-stages the thermosetting resin. The heating temperature in the heat drying process is preferably 80 to 200°C, more preferably 90 to 170°C, and even more preferably 100 to 150°C, from the viewpoint of productivity and appropriately B-staging the thermosetting resin. The heating time in the heat drying process is preferably 0.5 to 30 minutes, more preferably 1 to 10 minutes, and even more preferably 2 to 5 minutes, from the viewpoint of productivity and appropriately B-stage the thermosetting resin. However, the heating temperature and heating time in the heat drying process are conditions that are adjusted according to the type of material used in the resin layer, the content of the organic solvent, and the intended use of the resulting resin-coated metal foil, and are therefore not limited to the above range. The preferred embodiments of the metal foil, thermosetting resin composition, and resin layer are as described above.

[0032] <Curvature correction treatment> Next, we will explain the warping correction process, referring to the diagrams. Figure 3 shows a schematic cross-sectional diagram illustrating a method for applying warp correction treatment to resin-coated metal foil 10. For convenience, in the following drawings, both the resin-coated metal foil before and after warp correction treatment will be referred to as resin-coated metal foil 10. Furthermore, the resin-coated metal foil 10 before warp correction treatment is assumed to be warped upwards towards the resin layer 2.

[0033] In Figure 3, the two rolls 5, 5 are set apart, and the resin-coated metal foil 10 is positioned so that the two resin layers face the two rolls 5, 5 and are in contact with them. A warp correction jig 6 is pressed against the metal foil 1 side of the resin-coated metal foil 10, and the warp correction jig 6 is pushed into the resin layer 2 side of the resin-coated metal foil 10. The resin-coated metal foil 10, into which the warp correction jig 6 is pressed, is pushed up at the contact point with the warp correction jig 6 such that the height of the lower surface of the metal foil 1 is a distance of 8, with the height of the upper surface of the resin layer 2 that contacts the two rolls 5, 5 as the reference. At the contact point with the warp correction jig 6, the resin-coated metal foil 10 is bent with the metal layer 1 facing inward. In this state, the resin-coated metal foil 10 is transported in direction Z and passed over the warp correction jig 6, causing the resin-coated metal foil 10 to be continuously bent with the warp correction jig 6 as the axis and the metal foil 1 facing inward.

[0034] (Roll 5, 5) The two rolls 5,5 are set apart so that the warp correction jig 6 is positioned between them. By positioning rolls on either side of the warp correction jig 6, the resin-coated metal foil 10 can be pressed down by the two rolls 5, 5 when the warp correction jig 6 is pushed towards the resin layer 2, thereby effectively reducing the warping of the resin-coated metal foil 10. Furthermore, by adjusting the positions of the two rolls 5, 5, the angle at which the resin-coated metal foil 10 bends at the point of contact with the warp correction jig 6, as well as the contact area between the resin-coated metal foil 10 and the warp correction jig 6, can be adjusted. The distance 5' between the two rolls 5,5 is the distance from the center of one roll 5 to the center of the other roll 5. From the viewpoint of reducing warping, the distance 5' is preferably 50 to 300 mm, more preferably 60 to 200 mm, and even more preferably 70 to 200 mm. The material and shape of the two rolls 5,5 are not particularly limited, and known materials and shapes can be applied.

[0035] (Warping correction jig 6) The warp correction jig 6 is positioned between the two rolls 5, 5. The warp correction jig 6 is preferably located within ±5 mm of the midpoint of the two rolls 5, 5, and more preferably located at the midpoint of the two rolls 5, 5.

[0036] The distance 8 for pushing the warp correction jig 6 towards the resin layer 2 is preferably 1 to 25 mm, more preferably 2 to 20 mm, and even more preferably 3 to 18 mm, from the viewpoint of reducing warp.

[0037] Examples of materials for the warp correction jig 6 include metal, resin, and wood. Among these, metal and resin are preferred from the viewpoint of durability, and metal is more preferred.

[0038] The warp correction jig 6 is plate-shaped, and in the warp correction process, it is preferable to press the end of the plate-shaped warp correction jig 6 against the metal foil 1 side of the resin-coated metal foil 10. Figures 4(a) and (b) show schematic cross-sectional views of a plate-shaped warp correction jig. The end of the warp correction jig 6 that contacts the metal foil 10, as shown in Figure 4(a), is approximately triangular in cross-sectional view. The end of the warp correction jig 6 refers to the area enclosed by the dotted line in Figure 4(a). The angle 7 of the approximately triangular vertex that contacts the metal foil 10 is not particularly limited, but is preferably 30 to 80°, more preferably 40 to 75°. The cross-sectional shape of the end of the warp correction jig may be other than the shape described above. For example, it may be arc-shaped, as shown in the warp correction jig 6a in Figure 4(b). The diameter d of the arc is preferably 1 to 7 mm, more preferably 1 to 6 mm, and even more preferably 2 to 5 mm.

[0039] From the viewpoint of not damaging the surface of the metal foil 1 of the resin-coated metal foil 10, it is preferable to install a protective film such as a Teflon® sheet between the metal foil 1 and the warp correction jig 6. The thickness of the protective film is not particularly limited, but from the viewpoint of not hindering the warp reduction effect, it is preferably 0.3 to 3 mm, more preferably 0.4 to 2 mm, and even more preferably 0.5 to 1.5 mm.

[0040] (Conveying speed of resin-coated metal foil) The transport speed of the resin-coated metal foil is not particularly limited, but is preferably 1 to 15 m / min, more preferably 1 to 10 m / min, and even more preferably 1 to 5 m / min.

[0041] (Bending axis of resin-coated metal foil) In the manufacturing method of this embodiment, the warping correction treatment is performed two or more times under the condition that there are two or more axes of bending of the resin-coated metal foil. The number of warp correction treatments is not particularly limited, as long as the resin-coated metal foil has two or more axes of bending and includes two or more warp correction treatments. For example, it may be 2 to 5 times, or 2 to 3 times, but 2 times is preferable.

[0042] In the manufacturing method of this embodiment, the warping correction treatment performed two or more times includes a warping correction treatment (1) in which the direction of the axis of bending of the resin-coated metal foil is X, and a warping correction treatment (2) in which the direction of the axis of bending of the resin-coated metal foil is Y, wherein the angle between direction X and direction Y is preferably 30 to 150°, more preferably 60 to 120°, even more preferably 80 to 100°, and particularly preferably 90°.

[0043] The following explanation will use Figures 5(a) and (b) as an example to describe the warping correction process, specifically the case where warping correction process (1) and warping correction process (2) are performed, and the angle between direction X and direction Y is 90°. Note that the illustrations of rolls 5, 5 are omitted in Figures 5(a) and (b).

[0044] Figure 5(a) is a schematic plan view illustrating the warping correction process (1). The resin-coated metal foil 10 is transported with its longitudinal direction as the transport direction Z, and the warp correction jig 6 is installed so that the direction R of the bending axis of the resin-coated metal foil 10 is perpendicular to the transport direction Z. By performing the warp correction process (1) in this orientation, the resin-coated metal foil 10 is continuously bent with the metal foil 1 facing inward, around the bending axis direction R in Figure 5(a), that is, the short direction of the resin-coated metal foil 10 as the axis. Let X be the direction of the axis around which the resin-coated metal foil 10 bends in the warp correction process (1). After this process, the warp correction process (2) is performed.

[0045] Figure 5(b) is a schematic plan view illustrating the warping correction process (2). The resin-coated metal foil 10, which has undergone warp correction treatment (1), is transported with its short side as the transport direction Z, and the warp correction jig 6 is set up so that the direction R of the bending axis of the resin-coated metal foil 10 is perpendicular to the transport direction Z. By performing the warp correction treatment (2) in this orientation, the resin-coated metal foil 10 is continuously bent with the metal foil 1 facing inward, around the bending axis direction R in Figure 5(b), that is, the longitudinal direction of the resin-coated metal foil 10 as the axis. Let Y be the direction of the axis around which the resin-coated metal foil bends in the warp correction treatment (2). As described above, by applying the warp correction treatment (1) and the warp correction treatment (2), the resin-coated metal foil 10 is subjected to a bending process with both the short direction X and the long direction Y as axes.

[0046] In the schematic plan views of Figures 5(a) and (b), the warping correction jig 6 is installed such that the direction R of the bending axis of the resin-coated metal foil 10 is perpendicular to the transport direction Z of the resin-coated metal foil 10. However, the direction R of the bending axis of the resin-coated metal foil 10 is not limited to being perpendicular to the transport direction Z. The angle between the direction Z and direction X for conveying the resin-coated metal foil 10, and the angle between the direction Z and direction Y for conveying the resin-coated metal foil 10, are not particularly limited, but are preferably 30 to 150°, more preferably 40 to 140°, and even more preferably 50 to 130°, respectively.

[0047] <Other processing> In the manufacturing method of this embodiment, a roll nip treatment may be performed in which the resin-coated metal foil before warp correction treatment or the resin-coated metal foil obtained after warp correction treatment is passed through the gap between a pair of opposing rolls and pressurized. From the viewpoint of reducing warping, it is preferable that the roll in contact with the metal foil is a resin roll, and the roll in contact with the resin layer is a metal roll.

[0048] The shape of the resin roll and metal roll is not particularly limited as long as they are rotatable, and examples include cylindrical bodies and cylindrical shapes. Among these, cylindrical bodies with a perfectly circular cross-section are preferred from the viewpoint of homogeneity of the resulting resin-coated metal foil. Examples of resin rolls include fluororesin rolls, polyimide resin rolls, polyurethane resin rolls, and polyolefin resin rolls. Among these, polyurethane resin rolls are preferred. Examples of metal rolls include stainless steel rolls and chromium-molybdenum steel rolls. Among these, stainless steel rolls are preferred from the viewpoint of mechanical strength, wear resistance, and ease of handling. The metal rolls may be surface-treated to suppress surface scratches and wear. Examples of surface treatment methods for metal rolls include nickel plating, electroless nickel plating, nickel-boron plating, hard chromium plating, and parkerizing. Among these, hard chromium plating is preferred. Both the resin roll and the metal roll should preferably have smooth surfaces, from the viewpoint of homogeneity of the resulting resin-coated metal foil.

[0049] The diameters of the resin rolls and metal rolls are not particularly limited, but from the viewpoint of preventing crack formation and reducing warping, they are preferably 100 to 500 mm, more preferably 200 to 400 mm, and even more preferably 250 to 300 mm, respectively.

[0050] The conveying speed of the resin-coated metal foil is not particularly limited, but from the viewpoint of productivity and warp correction effect, it is preferably 1 to 15 m / min, more preferably 1 to 10 m / min, and even more preferably 1 to 5 m / min.

[0051] The roll load is not particularly limited, but is preferably 0.3 to 12 tons, more preferably 1 to 12 tons, and even more preferably 3 to 12 tons. When the roll load is above the lower limit, a more superior warp correction effect tends to be obtained. On the other hand, when the roll load is below the upper limit, unintended deformation of the resin-coated metal foil due to the load tends to be suppressed.

[0052] The resin rolls and metal rolls may have a heat source inside the roll and a mechanism that can heat the roll surface. In that case, the resin rolls and metal rolls may be heated, but from the viewpoint of suppressing deterioration of the resin-coated metal foil, it is preferable not to heat them. The surface temperatures of the resin rolls and metal rolls are not particularly limited, but from the viewpoint of productivity, warp correction effect, and suppression of deterioration of the resin-coated metal foil, they are preferably 10 to 40°C, more preferably 15 to 35°C, and even more preferably 20 to 30°C, respectively.

[0053] The roll nip process may involve passing the resin-coated metal foil through the gap between the opposing pair of rolls only once, or it may involve passing it through two or more times. When the resin-coated metal foil is passed through the gap between the opposing pair of rolls two or more times, the combination of rolls used for the first pass and the combination of rolls used for the second pass may be the same or different.

[0054] [Manufacturing method for laminated boards] The method for manufacturing a laminate according to this embodiment is a method for manufacturing a laminate in which an insulating layer is formed using resin-coated metal foil obtained by the method for manufacturing resin-coated metal foil according to this embodiment. The manufacturing method for the laminate of this embodiment involves laminating the resin-coated metal foil of this embodiment onto a core material such as a prepreg, with the resin layer facing the core material, and then heat-pressure molding. This causes the resin layer to harden and form an insulating layer. The conditions for heat-pressure molding are not particularly limited, but for example, the temperature can be 100-300°C, the time 10-300 minutes, and the pressure 1.5-5 MPa.

[0055] [Manufacturing method for printed circuit boards] The method for manufacturing a printed circuit board according to this embodiment is a method for manufacturing a printed circuit board in which a wiring pattern is formed on a laminate obtained by the method for manufacturing a laminate according to this embodiment. Known methods for forming wiring patterns include the subtractive method, the fully additive method, the semi-additive process (SAP), and the modified semi-additive process (m-SAP). Subsequently, if necessary, a multilayer printed circuit board can be manufactured by laminating the resin-coated metal foil of this embodiment or another resin-coated metal foil and then repeatedly applying heat and pressure molding to create a multilayer structure.

[0056] [Manufacturing method for semiconductor package] The semiconductor package manufacturing method of this embodiment is a method for manufacturing a semiconductor package in which a semiconductor element is mounted on a printed circuit board obtained by the printed circuit board manufacturing method of this embodiment. Specifically, one example is a method in which semiconductor elements such as semiconductor chips and memory are mounted at predetermined positions on a printed circuit board obtained by the manufacturing method of this embodiment using a known method, and the semiconductor elements are sealed with a sealing resin or the like. [Examples]

[0057] The embodiment will be described in detail below with reference to examples. However, this embodiment is not limited to the following examples.

[0058] [Measurement of warping amount] The resin-coated metal foil obtained in each example was cut to a size of 500mm x 400mm, placed on a flat table, and the height of the curl at the four corners was measured with a ruler. The maximum value among these measurements was evaluated as the amount of curl (mm). The target amount of curl was 10mm or less. The amount of warping was measured immediately after the manufacture of the resin-coated metal foil and defined as the "initial value." The amount of warping measured after storing the resin-coated metal foil with the initial value for 7 days under conditions of 25°C and 60% humidity was defined as the "value after 7 days of storage." "Immediately after manufacturing the resin-coated metal foil" means immediately after the warp correction treatment (2) in Example 1, Example 2, Comparative Example 3 and Comparative Example 6; immediately after drying for resin layer formation in Comparative Example 1; immediately after the warp correction treatment (1) in Comparative Examples 2 and 5; and immediately after the roll nip treatment in Comparative Example 4.

[0059] [Appearance Evaluation] The surface of the resin layer side of the resin-coated metal foil obtained in each example was visually inspected, and those without peeling of the resin layer were considered "good."

[0060] [Manufacturing of thermosetting resin compositions] Manufacturing Example 1 Each component was mixed in the proportions shown in Table 1 (unit: parts by mass), and a varnish-like thermosetting resin composition with a solid content of 40% by mass was prepared using toluene, methyl isobutyl ketone, and propylene glycol monomethyl ether as organic solvents.

[0061] [Table 1]

[0062] [Manufacturing of resin-coated metal foil] Example 1 (1) Manufacturing of resin-coated metal foil before warp correction treatment The thermosetting resin composition obtained in Production Example 1 was applied to a copper foil with a carrier foil (manufactured by Mitsui Mining & Smelting Co., Ltd., product name "MT18FL-1.5", copper foil thickness: 1.5 μm, carrier foil thickness: 18 μm), and heated and dried at 130°C for 3 minutes to form a 20 μm thick resin layer on one side of the copper foil. The copper foil with the resin layer formed as described above was used as the resin-coated metal foil before warp correction treatment. The resin-coated metal foil before warp correction treatment exhibited a state of being warped upwards towards the resin layer.

[0063] (2) Implementation of warping correction treatment Next, the resin-coated metal foil before warp correction treatment was subjected to warp correction treatment (1) and warp correction treatment (2) in the following procedure.

[0064] (i) Curvature correction treatment (1) As shown in Figure 3, the resin-coated metal foil 10 before warp correction treatment was placed in a position where it could be transported with both sides of the resin layer facing towards the two rolls 5, 5 that were placed separately from each other. Next, the end of the plate-shaped warp correction jig 6 was pressed against the metal foil 1 side of the resin-coated metal foil 10, and the warp correction jig 6 was pushed into the resin layer 2 side of the resin-coated metal foil 10. In this state, the resin-coated metal foil 10 was transported in the transport direction Z shown in Figure 3, and the resin-coated metal foil 10 was passed over the warp correction jig 6, causing the resin-coated metal foil 10 to bend continuously around the warp correction jig 6 as an axis. In the warp correction process (1), as shown in the schematic plan view in Figure 5(a), the resin-coated metal foil 10 was transported with its longitudinal direction as the transport direction Z, and the warp correction jig 6 was set up so that the direction R of the bending axis of the resin-coated metal foil 10 was perpendicular to the transport direction Z. As a result, the resin-coated metal foil 10 was continuously bent with the metal foil 1 facing inward, around the bending axis direction R in Figure 5(a), that is, the short direction of the resin-coated metal foil 10 as the axis. In the warp correction process (1), the direction of the axis around which the resin-coated metal foil 10 bends is denoted as X.

[0065] Details of the warp correction jig 6 and other conditions are as follows: Warping correction jig 6: It is a plate-shaped (3mm thick) made of SUS (stainless steel), and the cross-sectional shape of the end is approximately triangular. The angle of the approximately triangular vertex that contacts the metal foil 10 (7 in Figure 4(a)) is 50°. A Teflon® sheet (1mm thick) is placed over the area that contacts the resin-coated metal foil 10. Roll diameter of roll 5.5: 20mm Distance between rolls 5 and 5: 100mm Position of warp correction jig 6: Center point between rolls 5, 5 The distance to push in the warp correction jig 6 (the distance shown as 8 in Figure 3): 10 mm

[0066] (ii) Curvature correction treatment (2) Next, as shown in the schematic plan view of Figure 5(b), the resin-coated metal foil 10 was transported with its short side as the transport direction Z, and the warp correction jig 6 was set up so that the direction R of the bending axis of the resin-coated metal foil 10 was perpendicular to the transport direction Z, and the warp correction process was performed in the same procedure as in "Warp Correction Process (1)" described above. As a result, the resin-coated metal foil 10 was continuously bent with the metal foil 1 facing inward, with the bending axis direction R in Figure 5(b), that is, the longitudinal direction of the resin-coated metal foil 10 as the axis. In this warp correction process (2), the direction of the axis in which the resin-coated metal foil 10 bends is denoted as Y. Through the above warp correction treatments (1) and (2), the resin-coated metal foil 10 was subjected to a process that bent it with both the short direction (direction X) and the long direction (direction Y) as axes.

[0067] Example 2 In Example 1, a resin-coated metal foil was obtained in the same manner as in Example 1, except that, before the "warping correction treatment (1)," a roll nip treatment was performed on the resin-coated metal foil, in which pressure was applied through the gap between a pair of rolls, one of which was a resin roll and the other was a metal roll. The conditions for the roll nip treatment were as follows: Roll on the resin layer side: Stainless steel roll (hard chrome plated) with a roll diameter of 300 mm. Metal layer side roll: Polyurethane resin roll with a roll diameter of 300 mm Feed speed: 2.0 m / min Roll load (tons): 10 Number of times performed: 1

[0068] Comparative Example 1 A resin-coated metal foil was obtained in the same manner as in Example 1, except that "warping correction treatment (1)" and "warping correction treatment (2)" were not performed.

[0069] Comparative Example 2 A resin-coated metal foil was obtained in the same manner as in Example 1, except that the "warping correction treatment (2)" was not performed.

[0070] Comparative Example 3 A resin-coated metal foil was obtained in the same manner as in Example 1, except that the "warping correction treatment (1)" was not performed.

[0071] Comparative Example 4 In Example 2, a resin-coated metal foil was obtained in the same manner as in Example 2, except that "warping correction treatment (1)" and "warping correction treatment (2)" were not performed.

[0072] Comparative Example 5 In Example 2, a resin-coated metal foil was obtained in the same manner as in Example 2, except that the "warping correction treatment (2)" was not performed.

[0073] Comparative Example 6 In Example 2, a resin-coated metal foil was obtained in the same manner as in Example 2, except that the "warping correction treatment (1)" was not performed.

[0074] [Table 2]

[0075] As can be seen from the results shown in Table 2, the resin-coated metal foils obtained by the manufacturing methods of Examples 1 and 2 of this embodiment have a smaller initial amount of warping than the resin-coated metal foils of Comparative Examples 1 to 6, and maintain a small amount of warping even after being stored for 7 days. [Explanation of Symbols]

[0076] 1 Metal foil 2 resin layers 3. Exfoliation layer 4 Carrier foil 5 rolls 5' distance between rolls 5,5 6, 6a Curvature correction jig 7. Angle of the tip of the warp correction jig 8. Distance to push the warp correction jig into the resin layer. 10, 20 Resin-coated metal foil A End of a warp correction jig d diameter Z-direction of transport R Direction of the bending axis of the resin-coated metal foil

Claims

1. A method for manufacturing a resin-coated metal foil, comprising a metal foil and a resin layer formed on one side of the metal foil using a thermosetting resin composition and in a B-stage state, This includes a warp correction treatment to reduce the warping of the resin-coated metal foil, The aforementioned warping correction process involves pressing a warping correction jig against the metal foil side of the resin-coated metal foil, transporting the resin-coated metal foil while pushing the warping correction jig towards the resin layer side, and passing the resin-coated metal foil over the warping correction jig, thereby continuously bending the resin-coated metal foil around the warping correction jig as an axis. The aforementioned warping correction process is performed two or more times under the condition that there are two or more axes in which the resin-coated metal foil bends. The aforementioned warping correction treatment performed two or more times includes a warping correction treatment (1) in which the direction of the axis in which the resin-coated metal foil bends is X, and a warping correction treatment (2) in which the direction of the axis in which the resin-coated metal foil bends is Y. The angle between the aforementioned direction X and the aforementioned direction Y is between 60 and 120°. The direction Z in which the resin-coated metal foil is transported in the warping correction process (1) is the longitudinal direction of the resin-coated metal foil. A method for manufacturing resin-coated metal foil, wherein the direction Z for transporting the resin-coated metal foil in the warping correction process (2) is the short-side direction of the resin-coated metal foil.

2. The method for manufacturing a resin-coated metal foil according to claim 1, wherein the angle between the aforementioned direction X and the aforementioned direction Y is 80 to 100°.

3. The method for manufacturing a resin-coated metal foil according to claim 1 or 2, wherein the angle between the direction Z and the direction X for transporting the resin-coated metal foil, and the angle between the direction Z and the direction Y for transporting the resin-coated metal foil, are each 30 to 150°.

4. The method for manufacturing a resin-coated metal foil according to claim 1 or 2, wherein the warping correction jig is in the shape of a plate, and in the warping correction process, the end of the plate-shaped warping correction jig is pressed against the metal foil side surface of the resin-coated metal foil.

5. The method for manufacturing a resin-coated metal foil according to claim 1 or 2, wherein the distance at which the warping correction jig is pressed toward the resin layer is 1 to 25 mm.

6. The method for manufacturing a resin-coated metal foil according to claim 1 or 2, wherein the conveying speed of the resin-coated metal foil is 1 to 15 m / min.

7. The method for producing a resin-coated metal foil according to claim 1 or 2, wherein the thermosetting resin contained in the thermosetting resin composition comprises one or more selected from the group consisting of epoxy resin, phenolic resin, unsaturated imide resin, cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, amino resin, unsaturated polyester resin, allyl resin, dicyclopentadiene resin, silicone resin, triazine resin, and melamine resin.

8. A method for manufacturing a laminate, comprising forming an insulating layer using a resin-coated metal foil obtained by the method for manufacturing a resin-coated metal foil according to claim 1 or 2.

9. A method for manufacturing a printed circuit board, comprising forming a wiring pattern on a laminate obtained by the method for manufacturing a laminate according to claim 8.

10. A method for manufacturing a semiconductor package, comprising mounting a semiconductor element on a printed circuit board obtained by the method for manufacturing a printed circuit board described in claim 9.

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