Method for manufacturing a resin sheet with a protective film

Abstract

To provide a method of manufacturing a resin sheet with a protection film capable of eliminating foreign matters to enhance yield of wiring formation.SOLUTION: A method of manufacturing a resin sheet with a protection film provided with a substrate having a release layer, a resin composition layer including a curable resin composition, and a protection film in this order comprises steps of: bringing a first dust removable roller into contact with a surface on the release layer side of the substrate; forming the resin composition layer on the surface on the release layer side of the substrate; bringing a second dust removable roller into contact with a first surface of the protection film; and pasting the resin composition layer and the first surface of the protection film. The first dust removable roller has an adhesive force less than 2.9 N / 100 mm2. The second dust removable roller has an adhesive force less than 2.9 N / 100 mm2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing a resin sheet with a protective film. [Background technology]

[0002] Circuit boards such as printed wiring boards and semiconductor package substrates are widely used in various electronic devices. A known method for manufacturing circuit boards is a build-up method in which insulating layers and conductor layers are alternately stacked on an inner layer substrate. The insulating layer is manufactured, for example, using a resin sheet in which a resin composition layer is formed on a support. Specifically, the resin sheet is laminated on the inner layer substrate to form a resin composition layer, and the resin composition layer is cured to form the insulating layer (Patent Document 1). In order to protect the resin composition layer during storage and transportation, a protective film covering the resin composition may be provided on such a resin sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-23714 Summary of the Invention [Problem to be solved by the invention]

[0004] Foreign matter may be mixed into the resin composition layer of a resin sheet. Such foreign matter may cause a decrease in the yield of wiring that forms a circuit. Therefore, in conventional methods for producing resin sheets, the foreign matter has been removed. For example, the foreign matter has been removed by filtering the resin varnish used to form the resin composition layer.

[0005] In recent years, the need for miniaturization of electronic devices and electronic components has led to a demand for finer and denser wiring. As wiring becomes finer and denser, smaller foreign particles than before can interfere with wiring formation. For example, small foreign particles on the order of several tens of micrometers can interfere with wiring formation. However, with conventional technology, it has been difficult to avoid yield reductions caused by such small foreign particles.

[0006] The present invention has been devised in view of the above-mentioned problems, and aims to provide a method for manufacturing a resin sheet with a protective film that can eliminate foreign matter and improve the yield of wiring formation. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above-mentioned problems. As a result, the present inventors have found that the above-mentioned problems can be solved when a method for producing a resin sheet with a protective film, which includes, in this order, a support having a release layer, a resin composition layer containing a curable resin composition, and a protective film, includes the steps of contacting a first dust removal roller having an adhesive strength within a specific range with the release layer side of the support, forming a resin composition layer on the release layer side of the support, contacting a second dust removal roller having an adhesive strength within a specific range with the first surface of the protective film, and laminating the resin composition layer and the first surface of the protective film, thereby completing the present invention. That is, the present invention includes the following.

[0008] [1] A method for producing a resin sheet with a protective film, comprising, in this order: a support having a release layer, a resin composition layer containing a curable resin composition, and a protective film; The manufacturing method comprises: bringing a first dust removal roller into contact with the release layer side of the support; forming a resin composition layer on a surface of the support on which the release layer is formed; contacting a second dust removal roller with the first surface of the protective film; laminating the resin composition layer and the first surface of the protective film; First dust removal roller: 2.9N / 100mm 2 and has an adhesive strength of less than Second dust removal roller: 2.9N / 100mm 2 A method for producing a resin sheet with a protective film having an adhesive strength of less than 1000 kJ / cm. [2] The method for producing a resin sheet with a protective film according to [1], wherein the step of forming a resin composition layer on the release layer side of the support comprises applying a liquid curable resin composition. [3] The method for producing a resin sheet with a protective film according to [1] or [2], wherein the production method includes a step of contacting a third dust removal roller with the surface of the support opposite to the release layer. [4] A method for producing a resin sheet with a protective film described in any one of [1] to [3], wherein the production method includes a step of contacting a fourth dust removal roller with a second surface of the protective film opposite to the first surface. [5] The method for producing a resin sheet with a protective film according to any one of [1] to [4], wherein the curable resin composition contains a curable resin and an inorganic filler. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a method for manufacturing a resin sheet with a protective film that can eliminate foreign matter and improve the yield of wiring formation. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a front view schematically showing a manufacturing apparatus for a laminated resin sheet according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a front view schematically showing a laminated resin sheet manufacturing apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be implemented with any modifications within the scope of the claims and their equivalents.

[0012] <Outline of the manufacturing method for resin sheet with protective film> In a manufacturing method according to one embodiment of the present invention, a resin sheet with a protective film is manufactured, which comprises, in this order, a support having a release layer, a resin composition layer containing a curable resin composition, and a protective film. In the following description, the "resin sheet with a protective film" may be referred to as a "laminated resin sheet."

[0013] The method for producing a laminated resin sheet according to this embodiment includes the steps of: a step (I) of contacting a first dust removal roller having an adhesive strength within a specific range with the release layer side of the support; Step (II) of forming a resin composition layer on the release layer side of the support; a step (III) of contacting a second dust removal roller having an adhesive strength within a specific range with the first surface of the protective film; a step (IV) of bonding the resin composition layer to the first surface of the protective film; Includes:

[0014] In addition, the method for producing a laminated resin sheet according to this embodiment further comprises: Step (V) of contacting a third dust removal roller with the surface of the support opposite to the release layer. Preferably, the composition comprises a step (VI) of contacting a fourth dust removal roller with a second surface of the protective film opposite the first surface; It is preferred that the compound contains:

[0015] According to the manufacturing method of this embodiment, it is possible to easily manufacture a laminated resin sheet (a resin sheet with a protective film) that can effectively remove foreign matter and improve the yield of wiring formation.

[0016] <Step (I): Removal of dust from the release layer side of the support> The manufacturing method according to this embodiment produces a laminated resin sheet using a support having a release layer. The support has a release surface on the release layer side and a back surface on the opposite side of the release surface. Generally, the support has the release layer as the outermost layer, so that the release layer is exposed on the release surface of the support. For example, a sheet having a base layer and a release layer formed on the base layer can be used as such a support.

[0017] The method for producing a laminate resin sheet according to this embodiment includes step (I) of contacting a first dust removal roller with the release surface of the support (i.e., the surface on the release layer side). The first dust removal roller has an adhesive strength within a specific range. Therefore, by contacting the first dust removal roller with the release surface of the support, foreign matter adhering to the release surface can be transferred to the first dust removal roller, and therefore the foreign matter can be removed from the release surface. This makes it possible to prevent foreign matter from being mixed into the resin composition layer during the production process of the laminate resin sheet. Here, "mixing" foreign matter into the resin composition layer includes both the penetration of foreign matter into the resin composition layer and the adhesion of foreign matter to the surface of the resin composition layer.

[0018] Typically, the first dust removal roller has a peripheral surface as an adhesive surface, and the peripheral surface has an adhesive strength in a specific range. The adhesive strength range of the first dust removal roller is typically 2.9 N / 100 mm. 2 Less than 2.7N / 100mm 2 When the adhesive strength is less than the upper limit, it is possible to prevent the support from being wrinkled by contact with the first dust removal roller, and to prevent a part or all of the release layer from being peeled off from the support by contact with the first dust removal roller. The lower limit is not particularly limited, but is preferably 0.6 N / 100 mm from the viewpoint of more effectively removing foreign matter from the release surface of the support and significantly improving the yield of wiring formation. 2 More than 1.0N / 100mm, preferably 1.0N / 100mm 2 That's all.

[0019] The adhesive strength can be measured by pressing the measuring part of an adhesive strength tester (for example, "A3-10N" manufactured by Isshin Sangyo Co., Ltd.; the surface of the measuring part that comes into contact with the adhesive surface is a flat surface made of metal such as stainless steel) against the adhesive surface, and then pulling the measuring part back in a direction perpendicular to the adhesive surface to peel it off. Specific measurement conditions can be those described in the "Method for measuring adhesive strength of dust removal rollers" in the Examples section below.

[0020] The first dust removal roller may be, for example, a roller having an adhesive surface made of a polymer compound (such as a silicone rubber or a non-silicone rubber) that exhibits adhesiveness to foreign matter. The roller surface length of the first dust removal roller may be set according to the width of the support. The diameter of the first dust removal roller is not particularly limited as long as it can remove foreign matter adhering to the release surface of the support. The first dust removal roller may be used alone or in combination of two or more.

[0021] The first dust removal roller may be a commercially available product, such as a polymer rubber dust removal roller manufactured by YanGo (RUS series, HSS series, LPS series, SRR series, etc.), a dust removal roller manufactured by TEKNEK, or a dust removal roller manufactured by CM Systems (CTR-S series).

[0022] The first dust removal roller and the support are preferably in contact with each other at a contact pressure within an appropriate range. For example, the contact pressure between the first dust removal roller and the support is preferably in the range of 0.01 MPa to 0.1 MPa, more preferably 0.02 MPa to 0.08 MPa.

[0023] There are no limitations on the method of contacting the first dust removal roller with the release surface of the support. For example, contact may be achieved by rolling the first dust removal roller on the release surface of the fixed support. From the viewpoint of efficient removal of foreign matter, it is preferable to contact the first dust removal roller with the release surface of the support by transporting the support so that it contacts the adhesive surface of the first dust removal roller. Since the first dust removal roller usually has an adhesive surface on its circumferential surface, it is preferable to transport the support so that the release surface contacts the circumferential surface of the first dust removal roller. The first dust removal roller may rotate when it comes into contact with the release surface of the support. In this case, the first dust removal roller may rotate in response to the transport of the support, or may be rotated by a driving force applied by a driving device such as a motor. The transport direction of the support and the rotation direction of the first dust removal roller are generally the same.

[0024] Step (I) may optionally include removing foreign matter adhering to the first dust removal roller. By removing foreign matter adhering to the first dust removal roller, it is possible to prevent foreign matter from accumulating on the first dust removal roller and reducing the adhesive strength of the first dust removal roller, and it is possible to stably and effectively remove foreign matter adhering to the release surface of the support for a long period of time.

[0025] There are no limitations on the method for removing foreign matter from the first dust removal roller. For example, foreign matter may be removed from the first dust removal roller by contacting a first suction roller for removing foreign matter from the first dust removal roller with the first dust removal roller and transferring the foreign matter adhering to the first suction roller. Specifically, a first suction roller having an adhesive surface on its circumferential surface may be prepared, and the adhesive surface of the first suction roller may be brought into contact with the circumferential surface of the first dust removal roller to remove foreign matter from the first dust removal roller. The first suction roller may rotate when in contact with the first dust removal roller. In this case, the first suction roller may rotate in response to the rotation of the first dust removal roller, or may be driven to rotate by a driving force provided by a driving device such as a motor.

[0026] The first suction roller may be, for example, a roller having an adhesive layer on its peripheral surface that can adsorb foreign matter such as dust. From the viewpoint of effectively removing foreign matter from the first dust removal roller, it is preferable that the adhesive strength of the first suction roller be greater than that of the first dust removal roller. This first suction roller may be a commercially available product, such as the dust transfer adhesive tape rolls "GaplessTMULT" and "GaplessTMSRR" manufactured by YanGo Co., Ltd., or an adhesive roller manufactured by TEKNEK Co., Ltd. One first suction roller may be used alone, or two or more may be used in combination.

[0027] The removal of foreign matter from the release surface of the support by the first dust removal roller and the removal of foreign matter from the first dust removal roller by the first suction roller may be performed simultaneously or asynchronously.

[0028] <Step (II): Formation of Resin Composition Layer> The method for producing a laminated resin sheet according to this embodiment includes step (II) of forming a resin composition layer on the release surface of a support (i.e., the surface on the release layer side). In step (II), a resin composition layer is formed on the release surface of the support from which foreign matter has been removed by contact with a first dust removal roller. Therefore, step (II) is performed after step (I). Step (II) provides a resin sheet comprising a support and a resin composition layer formed on the release surface of the support.

[0029] There is no limitation on the method for forming the resin composition layer. For example, a resin composition layer prepared in advance may be laminated on the release surface of the support to form the resin composition layer on the release surface. From the viewpoint of reducing the chance of foreign matter adhesion and significantly increasing the yield of wiring formation, it is preferable to form the resin composition layer by a method including applying a liquid curable resin composition to the release surface of the support.

[0030] For example, when the curable resin composition is liquid in the application environment, the curable resin composition may be applied to the release surface of the support. Alternatively, for example, the non-volatile components of the curable resin composition and a solvent may be mixed to obtain a liquid curable resin composition, and the obtained liquid curable resin composition may be applied to the release surface of the support. Hereinafter, a liquid curable resin composition containing a solvent may be referred to as a "resin varnish." A resin composition layer can be formed by applying the curable resin composition.

[0031] There is no limitation on the method for applying the liquid curable resin composition, and for example, it can be applied using a coating device such as a die coater.

[0032] It is preferable that the release surface of the support is in a non-contact state, not in contact with other members, from the time when foreign matter is removed in step (I) until the time when the resin composition layer is provided in step (II). Therefore, when the laminated resin sheet is produced while transporting the support through a predetermined transport path, it is preferable that no member (e.g., a transport roller) that contacts the release surface of the support is provided in the section of the transport path between the first dust removal roller and the coating device.

[0033] Step (II) may include, if necessary, drying the liquid curable resin composition after application. Usually, when a resin varnish containing a solvent is applied, step (II) includes drying the applied resin varnish. Drying can remove the solvent contained in the resin composition layer.

[0034] Drying may be carried out by, for example, heating, blowing hot air, or the like. Drying conditions are not particularly limited, but drying is usually carried out so that the solvent content in the resin composition layer becomes 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the solvent, for example, when a resin varnish containing 30% by mass to 60% by mass of solvent is applied, drying may be carried out at 50°C to 150°C for 3 to 10 minutes.

[0035] By step (II), a resin composition layer can be formed on the release surface of the support. This resin composition layer contains a curable resin composition, and preferably contains only a curable resin composition. The thickness of the resin composition layer is preferably set according to the thickness of the insulating layer formed using the resin composition layer. Specifically, the thickness of the resin composition layer is preferably 200 μm or less, more preferably 70 μm or less, and particularly preferably 50 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but may be 5 μm or more, 10 μm or more, etc.

[0036] <Step (III): Removing dust from the first surface of the protective film> The protective film used in the manufacturing method according to this embodiment has a first surface and a second surface opposite to the first surface. The first surface of the protective film corresponds to the surface to be bonded to the resin composition layer.

[0037] The method for producing a laminated resin sheet according to this embodiment includes step (III) of contacting a second dust removal roller with the first surface of the protective film. The second dust removal roller has an adhesive strength within a specific range. Therefore, by contacting the second dust removal roller with the first surface of the protective film, foreign matter adhering to the first surface can be transferred to the second dust removal roller, thereby removing the foreign matter from the first surface. This makes it possible to prevent foreign matter from being mixed into the resin composition layer during the production process of the laminated resin sheet.

[0038] Typically, the second dust removal roller has a peripheral surface as an adhesive surface, and the peripheral surface has an adhesive strength in a specific range. The adhesive strength range of the second dust removal roller is typically 2.9 N / 100 mm. 2 Less than 2.7N / 100mm 2 When the adhesive strength is less than the upper limit, the occurrence of wrinkles in the protective film due to contact with the second dust removal roller can be suppressed. The lower limit is not particularly limited, but is preferably 0.6 N / 100 mm from the viewpoint of more effectively removing foreign matter from the first surface of the protective film and significantly improving the yield of wiring formation. 2 More than 1.0N / 100mm, preferably 1.0N / 100mm 2The adhesive strength of the second dust removal roller can be measured by the same method as that of the first dust removal roller.

[0039] The second dust removal roller may be the same as the first dust removal roller. The roller surface length of the second dust removal roller may be set according to the width of the protective film. The diameter of the second dust removal roller is not particularly limited as long as it can remove foreign matter adhering to the first surface of the protective film. The second dust removal roller may be used alone or in combination of two or more.

[0040] The second dust removal roller and the protective film are preferably in contact with each other at a contact pressure within an appropriate range. In one example, the range of contact pressure between the second dust removal roller and the protective film may be the same as the range of contact pressure between the first dust removal roller and the support.

[0041] There are no limitations on the method of contacting the second dust removal roller with the first side of the protective film. For example, contact may be achieved by rolling the second dust removal roller over the first side of the fixed protective film. From the viewpoint of efficient foreign matter removal, it is preferable to contact the second dust removal roller with the first side of the protective film by transporting the protective film so that it contacts the adhesive surface of the second dust removal roller. Since the second dust removal roller usually has an adhesive surface on its circumferential surface, it is preferable to transport the protective film so that its first side contacts the circumferential surface of the second dust removal roller. The second dust removal roller may rotate when it comes into contact with the first side of the protective film. In this case, the second dust removal roller may rotate in response to the transport of the protective film, or may be rotationally driven by a driving force provided by a driving device such as a motor. The transport direction of the protective film and the rotation direction of the second dust removal roller are generally the same.

[0042] Step (III) may optionally include removing foreign matter adhering to the second dust removal roller. By removing foreign matter adhering to the second dust removal roller, it is possible to prevent foreign matter from accumulating on the second dust removal roller and reducing the adhesive strength of the second dust removal roller, and it is possible to stably and effectively remove foreign matter adhering to the first surface of the protective film for a long period of time.

[0043] There are no limitations on the method for removing foreign matter from the second dust removal roller. For example, a second suction roller for removing foreign matter from the second dust removal roller may be brought into contact with the second dust removal roller, thereby removing the foreign matter from the second dust removal roller. Specifically, as with the removal of foreign matter from the first dust removal roller, a second suction roller having an adhesive surface on its circumferential surface may be brought into contact with the circumferential surface of the second dust removal roller, thereby removing the foreign matter from the second dust removal roller. The adhesive strength of the second suction roller is preferably greater than that of the second dust removal roller. The second suction roller may be the same as the first suction roller, for example. The removal of foreign matter from the first surface of the protective film by the second dust removal roller and the removal of foreign matter from the second dust removal roller by the second suction roller may be performed simultaneously or asynchronously.

[0044] <Step (IV): Bonding the resin composition layer to the first surface of the protective film> The manufacturing method according to this embodiment includes a step (IV) of bonding a resin composition layer to a first surface of a protective film. Specifically, the resin composition layer is bonded to the first surface of the protective film by laminating the resin sheet obtained in step (II) with the protective film from whose first surface foreign matter has been removed in step (III). This step (IV) results in a laminated resin sheet (resin sheet with protective film) having a support, a resin composition layer, and a protective film in this order in the thickness direction. In the obtained laminated resin sheet, the resin composition layer and the protective film are usually in direct contact. Here, "direct" contact between two members means that there is no other member between the two members in contact.

[0045] Typically, the resin sheet and the protective film are sandwiched between a pair of appropriate pressing members, and at least one pressing member is pressed toward the other pressing member to perform lamination. From the viewpoint of enabling continuous lamination and improving the production efficiency of the laminated resin sheet, it is preferable to use a rotatable pressing roller as the pressing member. Examples of such pressing rollers include a rubber roller, a metal roller, and a composite roller made of a metal core and a rubber lining.

[0046] The pressure applied between the pressing members (pressure applied to the resin sheet and the protective film) is not particularly limited as long as it allows production of a laminated resin sheet, and may be set, for example, in the range of 0.1 MPa to 3 MPa, preferably in the range of 0.2 MPa to 2.5 MPa, and more preferably in the range of 0.3 MPa to 2 MPa.

[0047] The temperature during lamination is not particularly limited as long as a laminated resin sheet can be produced, and may be room temperature (about 25°C) or heated. From the viewpoint of ensuring sufficient adhesion between the resin sheet and the protective film, lamination is preferably performed under heated conditions, and the temperature may be, for example, in the range of 50°C to 130°C, preferably 60°C to 120°C.

[0048] It is preferable that the first surface of the protective film is in a non-contact state with other members from the time when foreign matter is removed in step (III) until the time when the protective film is bonded to the resin composition layer in step (IV). Therefore, when the laminated resin sheet is produced while transporting the protective film through a predetermined transport path, it is preferable that no member (e.g., a transport roller) that contacts the first surface of the protective film is provided in the section of the transport path between the second dust removal roller and the pressing member.

[0049] <Step (V): Removal of dust from the surface opposite to the release layer of the support> The method for producing a laminated resin sheet according to this embodiment preferably includes a step (V) of contacting a third dust removal roller with the back surface of the support (i.e., the surface opposite the release layer). The third dust removal roller has adhesive force. Therefore, by contacting the third dust removal roller with the back surface of the support, foreign matter can be removed from the back surface. Therefore, in the process of producing a circuit board using the laminated resin sheet (particularly in the process of laminating the inner layer wiring and the resin sheet), foreign matter on the back surface of the support can be prevented from being mixed into the resin composition layer, thereby effectively increasing the yield of wiring formation.

[0050] Typically, the third dust removal roller has a peripheral surface as an adhesive surface, and this peripheral surface has adhesive force. The range of adhesive force of the third dust removal roller may be the same as the range of adhesive force of the first dust removal roller, from the viewpoint of obtaining the same effect as the first dust removal roller. The adhesive force of the third dust removal roller can be measured by the same method as the adhesive force of the first dust removal roller. For example, the third dust removal roller may be the same as the first dust removal roller. The third dust removal roller may be used alone or in combination of two or more.

[0051] The third dust removal roller and the support are preferably in contact with each other at a suitable contact pressure range. In one example, the range of contact pressure between the third dust removal roller and the support may be the same as the range of contact pressure between the first dust removal roller and the support.

[0052] There is no limitation on the method of contacting the third dust removal roller with the back surface of the support, and for example, the same method as the method of contacting the first dust removal roller with the release surface of the support may be used.

[0053] Step (V) may be performed before step (I), after step (I), or simultaneously with step (I). From the viewpoint of effectively suppressing incorporation of foreign matter into the resin composition layer, step (V) is preferably performed before step (IV), and more preferably before step (II).

[0054] Step (V) may optionally include removing foreign matter adhering to the third dust removal roller. By removing foreign matter adhering to the third dust removal roller, it is possible to prevent foreign matter from accumulating on the third dust removal roller and reducing the adhesive strength of the third dust removal roller, and it is possible to stably and effectively remove foreign matter adhering to the back surface of the support for a long period of time.

[0055] There are no limitations on the method for removing foreign matter from the third dust removal roller. For example, foreign matter may be removed from the third dust removal roller by contacting a third suction roller for removing foreign matter from the third dust removal roller with the third dust removal roller. Specifically, as with the removal of foreign matter from the first dust removal roller, foreign matter may be removed from the third dust removal roller by contacting the adhesive surface of a third suction roller having an adhesive surface on its circumferential surface with the circumferential surface of the third dust removal roller. The adhesive strength of the third suction roller is preferably greater than that of the third dust removal roller. The third suction roller may be the same as the first suction roller, for example. The removal of foreign matter from the back surface of the support by the third dust removal roller and the removal of foreign matter from the third dust removal roller by the third suction roller may be performed simultaneously or asynchronously.

[0056] <Step (VI): Removing dust from the second surface of the protective film> The method for producing a laminated resin sheet according to this embodiment preferably includes a step (VI) of contacting a fourth dust removal roller with the second surface of the protective film (i.e., the surface opposite to the first surface). The fourth dust removal roller has adhesive properties. Therefore, by contacting the fourth dust removal roller with the second surface of the protective film, foreign matter can be removed from the second surface. Therefore, in the process of producing a circuit board using the laminated resin sheet (particularly in the process of laminating the inner layer wiring and the resin sheet), foreign matter on the second surface of the protective film can be prevented from being mixed into the resin composition layer, thereby effectively increasing the yield of wiring formation.

[0057] Typically, the fourth dust removal roller has a peripheral surface as an adhesive surface, and this peripheral surface has adhesive force. The range of adhesive force of the fourth dust removal roller may be the same as the range of adhesive force of the second dust removal roller, from the viewpoint of obtaining the same effect as the second dust removal roller. The adhesive force of the fourth dust removal roller can be measured by the same method as the adhesive force of the first dust removal roller. For example, the fourth dust removal roller may be the same as the second dust removal roller. The fourth dust removal roller may be used alone or in combination of two or more.

[0058] The fourth dust removal roller and the protective film are preferably in contact with each other at a contact pressure within an appropriate range. In one example, the range of contact pressure between the fourth dust removal roller and the protective film may be the same as the range of contact pressure between the second dust removal roller and the protective film.

[0059] There are no limitations on the method of contacting the fourth dust removal roller with the second surface of the protective film, and for example, the same method as the method of contacting the second dust removal roller with the first surface of the protective film may be used.

[0060] Step (VI) may be performed before step (III), after step (III), or simultaneously with step (III). From the viewpoint of effectively suppressing the inclusion of foreign matter in the resin composition layer, step (VI) is preferably performed before step (IV).

[0061] Step (VI) may optionally include removing foreign matter adhering to the fourth dust removal roller. By removing foreign matter adhering to the fourth dust removal roller, it is possible to prevent foreign matter from accumulating on the fourth dust removal roller and reducing the adhesive strength of the fourth dust removal roller, and it is possible to stably and effectively remove foreign matter adhering to the second surface of the protective film for a long period of time.

[0062] There are no limitations on the method for removing foreign matter from the fourth dust removal roller. For example, a fourth suction roller for removing foreign matter from the fourth dust removal roller may be brought into contact with the fourth dust removal roller to remove the foreign matter from the fourth dust removal roller. Specifically, as with the removal of foreign matter from the first dust removal roller, a fourth suction roller having an adhesive surface on its circumferential surface may be brought into contact with the circumferential surface of the fourth dust removal roller to remove the foreign matter from the fourth dust removal roller. The adhesive strength of the fourth suction roller is preferably greater than that of the fourth dust removal roller. For example, the fourth suction roller may be the same as the first suction roller. The removal of foreign matter from the second surface of the protective film by the fourth dust removal roller and the removal of foreign matter from the fourth suction roller by the fourth suction roller may be performed simultaneously or asynchronously.

[0063] <Other matters related to the manufacturing method of the laminated resin sheet> The method for producing a laminated resin sheet according to this embodiment may be carried out using a single support and a single protective film. When a single support and a single protective film are used, a single laminated resin sheet can be produced.

[0064] From the viewpoint of efficiently producing a laminate resin sheet, it is preferable to produce a long laminate resin sheet using a long support and a long protective film. The term "long" for a certain member means that the member has a length long enough to be wound into a roll, for example, a length 10 times or more the width. By using a long support and a long protective film, it is possible to efficiently produce a long laminate resin sheet by a roll-to-roll method.

[0065] When a long support and a protective film are used, the above-mentioned steps are usually carried out while continuously transporting the support and the protective film in the longitudinal direction. In this case, the transport speed of each member, such as the support, the protective film, the resin sheet, and the laminated resin sheet, is not particularly limited and can be, for example, in the range of 0.1 m / min to 50 m / min.

[0066] The method for producing a laminate resin sheet according to this embodiment may further include any optional steps in combination with the steps described above. For example, the method for producing a laminate resin sheet may include a step of winding and recovering the produced laminate resin sheet. By winding the laminate resin sheet, a roll of the laminate resin sheet is obtained, and the laminate resin sheet can be stored and transported in this rolled state.

[0067] <First specific example of manufacturing method> A first example of a method for manufacturing a laminate resin sheet according to the present embodiment will be described below with reference to the drawings. Fig. 1 is a front view schematically showing an apparatus 1 for manufacturing a laminate resin sheet 50 according to the first example of the present invention. As shown in Fig. 1, the manufacturing apparatus 1 is configured to form a resin composition layer 20 on a long support 10 including a base material layer 11 and a release layer 12 to obtain a long resin sheet 30, and to laminate the resin sheet 30 with a long protective film 40 to obtain a laminate resin sheet 50.

[0068] The manufacturing apparatus 1 includes a support dust removal section 100 that is provided to remove foreign matter from the support 10, a layer formation section 200 that is provided to form a resin composition layer 20 on the release surface 10U of the support 10, a protective film dust removal section 300 that is provided to remove foreign matter from the protective film 40, and a laminating section 400 that is provided to bond the resin composition layer 20 of the resin sheet 30 to the first surface 40D of the protective film 40.

[0069] The support dust removal unit 100 includes a first dust removal roller 110 and a third dust removal roller 120, which are rotatable in the same direction as the conveyance direction of the support 10. The first dust removal roller 110 and the third dust removal roller 120 have adhesive surfaces with appropriate adhesive strength on their peripheral surfaces 110S and 120S, respectively. In this example, the first dust removal roller 110 and the third dust removal roller 120 are disposed opposite each other so that the support 10 can be conveyed between the first dust removal roller 110 and the third dust removal roller 120. The first dust removal roller 110 and the third dust removal roller 120 are biased toward each other so that the peripheral surface 110S of the first dust removal roller 110 can contact the release surface 10U of the support 10, and the peripheral surface 120S of the third dust removal roller 120 can contact the back surface 10D of the support 10 with an appropriate contact pressure.

[0070] The layer forming section 200 includes a coating device 210 and a drying device 220. The coating device 210 is provided so that a liquid curable resin composition 21 can be applied to the release surface 10U of the support 10. The drying device 220 is provided so that the resin composition layer 20 formed on the release surface 10U of the support 10 can be dried to remove the solvent. In this example, an example is shown and described in which the drying device 220 is provided as an oven that is provided so that the support 10 can pass through.

[0071] The protective film dust removal unit 300 includes a second dust removal roller 310 and a fourth dust removal roller 320 that are rotatable in the same direction as the transport direction of the protective film 40. The second dust removal roller 310 and the fourth dust removal roller 320 have adhesive surfaces with appropriate adhesive strength on their peripheral surfaces 310S and 320S, respectively. In this example, the second dust removal roller 310 and the fourth dust removal roller 320 are disposed opposite each other so that the protective film 40 can be transported between the second dust removal roller 310 and the fourth dust removal roller 320. The second dust removal roller 310 and the fourth dust removal roller 320 are biased toward each other so that the peripheral surface 310S of the second dust removal roller 310 contacts the first side 40D of the protective film 40, and the peripheral surface 320S of the fourth dust removal roller 320 contacts the second side 40U of the protective film 40 with an appropriate contact pressure.

[0072] The laminating unit 400 includes a pair of pressure rollers 410 and 420 that are rotatable in the same direction as the conveyance direction of the resin sheet 30 and the protective film 40, and a chamber 430 that houses the pressure rollers 410 and 420. The pressure roller 410 and the pressure roller 420 are disposed opposite each other so that the resin sheet 30 and the protective film 40 can be conveyed between the pressure rollers 410 and 420. A heater (not shown) is also provided within the chamber 430 so that the temperature within the chamber 430 can be appropriately adjusted.

[0073] In the method for manufacturing the laminated resin sheet 50 using the manufacturing apparatus 1, the support 10 is transported and supplied to the support dust removal section 100. The support 10 supplied to the support dust removal section 100 is transported so as to pass between the first dust removal roller 110 and the third dust removal roller 120. As the support 10 passes between the first dust removal roller 110 and the third dust removal roller 120, the circumferential surface 110S of the first dust removal roller 110 comes into contact with the release surface 10U of the support 10, and the circumferential surface 120S of the third dust removal roller 120 comes into contact with the back surface 10D of the support 10 (steps (I) and (V)). Thus, foreign matter (not shown) on the release surface 10U and the back surface 10D of the support 10 is removed. The support 10 is then sent to the layer formation section 200.

[0074] The support 10 sent to the layer forming unit 200 is supplied to a coating device 210. The coating device 210 coats the release surface 10U of the support 10 with a curable resin composition 21 to form a resin composition layer 20 (step (II)). Thereafter, the support 10 and the resin composition layer 20 are sent to a drying device 220, where the resin composition layer 20 is dried. In this example, the resin composition layer 20 is dried by passing through an oven serving as the drying device 220 set at an appropriate temperature for an appropriate period of time. The solvent is removed from the resin composition layer 20 by drying, and a resin sheet 30 including the support 10 and the resin composition layer 20 is obtained. This resin sheet 30 is sent to the laminating unit 400.

[0075] In addition, in the manufacturing method of the laminated resin sheet 50 using the manufacturing apparatus 1, the protective film 40 is transported and supplied to the protective film dust removal unit 300 separately from the support 10. The protective film 40 supplied to the protective film dust removal unit 300 is transported to pass between the second dust removal roller 310 and the fourth dust removal roller 320. As the protective film 40 passes between the second dust removal roller 310 and the fourth dust removal roller 320, the peripheral surface 310S of the second dust removal roller 310 comes into contact with the first side 40D of the protective film 40, and the peripheral surface 320S of the fourth dust removal roller 320 comes into contact with the second side 40U of the protective film 40 (steps (III) and (VI)). Thus, foreign matter (not shown) on the first side 40D and the second side 40U of the protective film 40 is removed. The protective film 40 is then sent to the laminating unit 400.

[0076] The resin sheet 30 and the protective film 40 sent to the laminating unit 400 enter a chamber 430 and are transported to pass between pressure rollers 410 and 420. When passing between the pressure rollers 410 and 420, the resin sheet 30 and the protective film 40 are pressed by the pressure rollers 410 and 420 with the resin composition layer 20 of the resin sheet 30 and the first surface 40D of the protective film 40 facing each other. Thus, the resin sheet 30 and the protective film 40 are laminated so that the resin composition layer 20 and the first surface 40D of the protective film 40 are bonded together, thereby obtaining a long laminated resin sheet 50 having the support 10, the resin composition layer 20, and the protective film 40 in this order.

[0077] <Second specific example of the manufacturing method> A second example of the method for manufacturing a laminated resin sheet according to the present embodiment will now be described with reference to the drawings. Fig. 2 is a front view schematically showing an apparatus 2 for manufacturing a laminated resin sheet 50 according to the second example of the present invention. As shown in Fig. 2, the manufacturing apparatus 2 according to this example is configured in the same manner as the manufacturing apparatus 1 according to the first example, except that it includes a support body dust removing unit 500 and a protective film dust removing unit 600 instead of the support body dust removing unit 100 and the protective film dust removing unit 300.

[0078] The support body dust removal unit 500 includes a first dust removal roller 510 and a third dust removal roller 520. The first dust removal roller 510 and the third dust removal roller 520 in this example are provided in the same manner as the first dust removal roller 110 and the third dust removal roller 120 according to the first example, except that the first dust removal roller 510 and the third dust removal roller 520 are provided at different positions in the conveyance direction of the support body 10.

[0079] The first dust removal roller 510 is provided so that the support 10 can be transported so as to wrap around a peripheral surface 510S of the first dust removal roller 510. Therefore, in this example, the release surface 10U of the transported support 10 can come into contact with the peripheral surface 510S of the first dust removal roller 510 with a contact pressure according to the transport tension of the support 10.

[0080] Furthermore, the third dust removal roller 520 is provided so that the support 10 can be transported so as to wrap around the peripheral surface 520S of the third dust removal roller 520. Therefore, in this example, the back surface 10D of the transported support 10 can come into contact with the peripheral surface 520S of the third dust removal roller 520 with a contact pressure according to the transport tension of the support 10.

[0081] Protective film dust removal unit 600 includes a second dust removal roller 610 and a fourth dust removal roller 620. In this example, second dust removal roller 610 and fourth dust removal roller 620 are provided in the same manner as second dust removal roller 310 and fourth dust removal roller 320 according to the first example, except that second dust removal roller 610 and fourth dust removal roller 620 are provided at different positions in the transport direction of protective film 40.

[0082] The second dust removal roller 610 is provided so that the protective film 40 can be transported so as to be wrapped around a peripheral surface 610S of the second dust removal roller 610. Therefore, in this example, the first surface 40D of the protective film 40 being transported can come into contact with the peripheral surface 610S of the second dust removal roller 610 with a contact pressure that corresponds to the transport tension of the protective film 40.

[0083] Furthermore, the fourth dust removal roller 620 is provided so that the protective film 40 can be transported so as to be wrapped around the circumferential surface 620S of the fourth dust removal roller 620. Therefore, in this example, the second surface 40U of the protective film 40 being transported can come into contact with the circumferential surface 620S of the fourth dust removal roller 620 with a contact pressure that corresponds to the transport tension of the protective film 40.

[0084] In the manufacturing method of the laminated resin sheet 50 using the manufacturing apparatus 2, the support 10 is supplied to the support dust removal section 500 and transported via the first dust removal roller 510 and the third dust removal roller 520. The support 10 supplied to the support dust removal section 500 has foreign matter (not shown) removed from the release surface 10U when it is transported in contact with the circumferential surface 510S of the first dust removal roller 510 (step (I)). The support 10 also has foreign matter (not shown) removed from the back surface 10D when it is transported in contact with the circumferential surface 520S of the third dust removal roller 520 (step (V)). The support 10 is then sent to the layer forming section 200. Then, as in the first example, a resin composition layer 20 is formed on the release surface 10U of the support 10 in the layer forming section 200 to obtain a resin sheet 30 (step (II)). The resin sheet 30 is then sent to the laminating section 400.

[0085] Furthermore, in the method for manufacturing the laminated resin sheet 50 using the manufacturing apparatus 2, the protective film 40 is supplied to the protective film dust removal unit 600 and transported via the second dust removal roller 610 and the fourth dust removal roller 620. When the protective film 40 supplied to the protective film dust removal unit 600 is transported in contact with the circumferential surface 610S of the second dust removal roller 610, foreign matter (not shown) is removed from the first surface 40D (step (III)), and when the protective film 40 is transported in contact with the circumferential surface 620S of the fourth dust removal roller 620, foreign matter (not shown) is removed from the second surface 40U (step (VI)). Thereafter, the protective film 40 is sent to the laminating unit 400.

[0086] As in the first example, the resin sheet 30 and protective film 40 sent to the laminating section 400 are laminated in the chamber 430 by pressure rollers 410 and 420 so that the resin composition layer 20 and the first surface 40D of the protective film 40 are bonded together, thereby obtaining a long laminated resin sheet 50 having the support 10, the resin composition layer 20, and the protective film 40 in this order.

[0087] <Laminated resin sheet to be manufactured> The above-described manufacturing method can produce a laminated resin sheet (a resin sheet with a protective film). This laminated resin sheet includes a resin composition layer formed on the release surface of a support. Since foreign matter has been removed from the release surface by contact with the first dust removal roller, it is possible to prevent foreign matter adhering to the release surface from being mixed into the resin composition layer.

[0088] Furthermore, the resin composition layer of the laminated resin sheet is in direct contact with the first surface of the protective film. Foreign matter is removed from the first surface of the protective film by contact with the second dust removal roller. Therefore, it is possible to prevent foreign matter adhering to the first surface from being mixed into the resin composition layer.

[0089] Conventionally, methods for removing foreign matter from the release surface of a support and the first surface of a protective film have been proposed, but these conventional techniques typically involve the use of a non-contact device such as an air blower to remove the foreign matter. In contrast, in the present embodiment, the foreign matter is removed using a contact device known as a dust removal roller, which allows for effective removal of the foreign matter. In particular, the method according to the present embodiment is advantageous in that it can effectively remove small foreign matter of 100 μm or less (preferably, several tens of μm or less).

[0090] Since the incorporation of foreign matter into the resin composition layer can be suppressed in this way, when a circuit board is manufactured using the laminated resin sheet manufactured in this embodiment, the yield of wiring formation can be increased. Specifically, it is possible to suppress the intrusion of foreign matter into the gaps between wirings, thereby preventing the insulation performance between wirings from being unintentionally reduced. Furthermore, it is possible to suppress distortion of the shape of the wiring or chipping of the wiring at the portion above the foreign matter due to a portion of the wiring layer being formed on the foreign matter. Therefore, since the occurrence of wiring that does not function as intended can be suppressed, it is possible to form the intended wiring with a high yield.

[0091] Furthermore, the dust removal roller used in this embodiment has an adhesive strength within an appropriate range. Therefore, excessive adhesion can be prevented from disrupting the transport of the support and protective film. Therefore, wrinkles can be prevented from occurring in the support and protective film, resulting in good transportability. Furthermore, since the first dust removal roller in particular has an adhesive strength within an appropriate range, the release layer of the support can be prevented from adhering to the first dust removal roller and being removed from the support. Therefore, the support can be smoothly peeled off from the insulating layer during the manufacture of circuit boards. Therefore, it is possible to simplify the manufacture of circuit boards and improve the yield of circuit boards.

[0092] When foreign matter on the back surface of the support is removed with the third dust removal roller, the foreign matter on the back surface can be prevented from being mixed into the resin composition layer. Furthermore, when foreign matter on the second surface of the protective film is removed with the fourth dust removal roller, the foreign matter on the second surface can be prevented from being mixed into the resin composition layer. Therefore, since the incorporation of foreign matter into the resin composition layer can be effectively prevented, the yield of wiring formation can be further increased.

[0093] The laminate resin sheet according to this embodiment can be preferably used for forming a circuit board. In a circuit board, the laminate resin sheet is usually used for forming an insulating layer. Specifically, the laminate resin sheet is preferably used for forming an insulating layer by curing a resin composition layer. Since the incorporation of foreign matter into the resin composition layer can be suppressed, the laminate resin sheet according to this embodiment can improve the yield of forming wiring on the insulating layer.

[0094] In particular, compared to techniques for removing foreign matter from general sheets, the technique according to this embodiment, which can suppress the intrusion of foreign matter into the resin composition layer in a laminated resin sheet for forming an insulating layer of a circuit board, has the following excellent significance.

[0095] When forming a wiring layer on a sheet, foreign matter on the surface of the sheet can generally hinder wiring formation. Therefore, attempts are usually made to remove the foreign matter from the surface of the sheet. However, since the resin composition layer for forming the insulating layer is required to fill the irregularities on the surface of the inner layer substrate without any gaps, it is required to have properties such as flexibility to the extent that it can be fluid at an appropriate temperature. If an attempt is made to remove foreign matter from such a flexible resin composition layer using a contact-type device, the resin composition layer may be deformed or damaged. Therefore, considering the intended use, it is difficult to remove foreign matter from the surface of the resin composition layer using a contact-type device.

[0096] Furthermore, when forming an insulating layer of a circuit board using a resin composition layer, not only foreign matter attached to the surface of the resin composition layer but also foreign matter inside the resin composition layer can hinder wiring formation. Specifically, when manufacturing a circuit board, the resin composition layer that appears after peeling off a protective film is usually laminated with an inner layer substrate, and the resin composition layer is formed on the inner layer substrate. The resin composition layer is then cured to obtain an insulating layer, and wiring is then formed on the insulating layer. At this time, the resin composition layer provided on the inner layer substrate can be subjected to chemical or physical processing. Examples of processing include curing treatments that involve reacting a curable resin with heat or light; hole formation treatments using drills, laser light, etc.; desmear treatments to remove resin residues; and plating treatments for wiring formation. When these processing treatments are performed, foreign matter that was inside the resin composition layer may appear on the surface. Such foreign matter that appears on the surface can hinder wiring formation.

[0097] Conventionally, such foreign matter inside a resin composition layer was thought to be contained in the resin composition that is the raw material for the resin composition layer. However, the present inventors have found that even when the resin composition is sufficiently removed by filtration, the foreign matter can cause a decrease in the yield of wiring formation. Furthermore, the present inventors have found that in the manufacturing process of a laminated resin sheet, foreign matter that is small enough not to have been considered a problem in the past can be mixed into the resin composition layer, and that the decrease in yield due to such small foreign matter becomes apparent as the wiring becomes finer and denser.

[0098] In contrast, the laminated resin sheet manufactured by the above-described manufacturing method can effectively eliminate small foreign matter that may cause a decrease in the yield of wiring formation while using a resin composition layer that satisfies the properties required for forming an insulating layer. Therefore, the laminated resin sheet according to this embodiment can improve the yield of wiring formation, which has been difficult to achieve with conventional techniques, and is therefore suitable for use as an insulating layer in a circuit board.

[0099] <Description of support> The support used in this embodiment will be described in detail below. The support includes a release layer. The support includes the release layer as the outermost layer, so that the release layer is exposed on the outermost surface of the support. A resin composition layer is then formed on the surface of the release layer. Usually, the support includes a base layer, and the release layer is provided on the base layer.

[0100] Examples of the substrate layer include a thermoplastic resin film, a metal foil, and a release paper, with a thermoplastic resin film and a metal foil being preferred. When a thermoplastic resin film is used as the substrate layer, examples of the thermoplastic resin contained in the substrate layer include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylic polymers such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

[0101] When a metal foil is used as the substrate layer, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0102] The surface of the base layer on the release layer side may be subjected to a surface treatment such as matte treatment, corona treatment, or antistatic treatment.

[0103] The thickness of the base layer is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm.

[0104] The release layer has the effect of reducing the force (peel strength) required to peel off the support. Specifically, the release layer can reduce the force required to peel off the support that is in contact with the resin composition layer or the insulating layer via the release layer, compared to the force required to peel off the base material layer that is in direct contact with the resin composition layer or the insulating layer that is a cured product thereof.

[0105] The release layer is usually formed from a release agent. Examples of the release agent include resins. Generally, resins used as release agents contain a release component that can impart releasability, and may further contain optional components other than the release component as needed. Thus, in one example, the release layer contains the release component and may further contain optional components as needed. In another example, the release layer may be formed by bonding some or all of the components contained in the release agent through reactions such as polymerization and crosslinking, and then curing the release agent. In this example, the release layer may contain one or more components selected from the group consisting of the release component and optional components contained in the release agent, as well as their reaction products (e.g., polymers). The release component may be a compound that can reduce the surface free energy of the release layer or the static friction coefficient of the release layer.

[0106] Examples of the releasable component include a long-chain alkyl group-containing resin, an olefin resin, a fluorine compound, and a wax-based compound.

[0107] The term "long-chain alkyl group-containing resin" refers to a resin containing a long-chain alkyl group. Furthermore, the term "long-chain alkyl group" generally refers to an alkyl group having 12 or more carbon atoms, preferably 16 or more carbon atoms. Resins containing such long carbon chains in their molecules generally have high hydrophobicity and therefore exhibit high mold releasability. The upper limit of the number of carbon atoms in the long-chain alkyl group may be, for example, 25 or less. Specific examples of long-chain alkyl group-containing resins include (meth)acrylic resins containing long-chain alkyl groups, such as long-chain acrylic acrylates (e.g., tetradecyl acrylate and octadecyl acrylate); long-chain acrylic methacrylates (e.g., tetradecyl methacrylate and octadecyl methacrylate); and polymers thereof. The term "(meth)acrylic resin" encompasses (meth)acrylic compounds and their polymers, unless otherwise specified. The term "(meth)acrylic compound" encompasses acrylic compounds containing acryloyl groups, methacryloyl compounds containing methacryloyl groups, and combinations thereof, unless otherwise specified. Furthermore, the term "polymer" encompasses both homopolymers and copolymers, unless otherwise specified.

[0108] Examples of olefin resins include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene.

[0109] The fluorine compound refers to a compound containing a fluorine atom in the molecule. Specific examples of the fluorine compound include perfluoroalkyl group-containing compounds, polymers of olefin compounds containing fluorine atoms, aromatic fluorine compounds such as fluorobenzene, and (meth)acrylic resins containing fluorine atoms. Among these, (meth)acrylic resins containing fluorine atoms are preferred. Examples of (meth)acrylic resins containing fluorine atoms include fluoroalkyl acrylates such as trifluoroethyl acrylate; fluoroaryl acrylates such as pentafluorophenyl acrylate; fluoroalkyl methacrylates such as trifluoroethyl methacrylate; fluoroaryl methacrylates such as pentafluorophenyl methacrylate; and polymers thereof.

[0110] Examples of wax-based compounds include natural waxes, synthetic waxes, and combinations thereof. Natural waxes include vegetable waxes, animal waxes, mineral waxes, and petroleum waxes. Examples of vegetable waxes include candelilla wax, carnauba wax, rice wax, Japan wax, and jojoba oil. Examples of animal waxes include beeswax, lanolin, and spermaceti. Examples of mineral waxes include montan wax, ozokerite, and ceresin. Examples of petroleum waxes include paraffin wax, microcrystalline wax, and petrolatum. Examples of synthetic waxes include synthetic hydrocarbons, modified waxes, hydrogenated waxes, fatty acids, acid amides, amines, imides, esters, and ketones. Examples of synthetic hydrocarbons include Fischer-Tropsch wax (also known as Sazoir wax) and polyethylene wax. Synthetic hydrocarbons may also include low-molecular-weight polymers (specifically, viscosity-average molecular weights of 500 to 20,000) selected from the group consisting of polypropylene, ethylene-acrylic acid copolymer, polyethylene glycol, polypropylene glycol, block conjugates of polyethylene glycol and polypropylene glycol, and graft conjugates of polyethylene glycol and polypropylene glycol. Examples of modified waxes include montan wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives. The term "derivatives" as used herein refers to compounds obtained by any of the following processes: refining, oxidation, esterification, and saponification, or a combination thereof. Examples of hydrogenated waxes include hydrogenated castor oil and hydrogenated castor oil derivatives.

[0111] The releasing component may be used alone or in combination of two or more kinds.

[0112] The amount of the releasable component in the release agent is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to 100% by mass of the non-volatile components of the release agent, and is preferably 90% by mass or less, more preferably 60% by mass or less, and even more preferably 40% by mass or less.

[0113] Furthermore, the amount of the release component in the release layer is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to 100% by mass of the release layer, and is preferably 90% by mass or less, more preferably 60% by mass or less, and particularly preferably 40% by mass or less.

[0114] Examples of optional components that the release agent may contain include any resin other than the release component. Examples of optional resins include epoxy resins, melamine resins, oxazoline compounds, carbodiimide compounds, polyester resins, urethane resins, and (meth)acrylic resins. Examples of (meth)acrylic resins as optional resins include acrylic compounds such as acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, acrylamide, N-methylolacrylamide, and diacetoneacrylamide; methacrylic compounds such as methacrylic acid, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, and hydroxypropyl methacrylate; and polymers thereof. The optional resins may be used singly or in combination of two or more.

[0115] The amount of any resin in the release agent is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 40% by mass or more, relative to 100% by mass of the non-volatile components of the release agent, and is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less.

[0116] Furthermore, the amount of any resin in the release layer is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 40% by mass or more, relative to 100% by mass of the release layer, and is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less.

[0117] Further examples of optional components include optional additives such as lubricants, inorganic particles, organic particles, surfactants, antioxidants, and thermal initiators. One type of optional additive may be used alone, or two or more types may be used in combination. The amount of the optional additive is not particularly limited, but may be, for example, 0.001% by mass or more and 10% by mass or less, relative to 100% by mass of the total of the release component and optional resin.

[0118] Examples of the above-mentioned release agents include alkyd-based release agents, polyolefin-based release agents, urethane-based release agents, melamine-based release agents, fluorine-based release agents, acrylic-based release agents, and silicone-based release agents. Among these, non-silicone-based release agents are preferred from the viewpoint of producing a circuit board having an insulating layer with excellent insulating properties. Furthermore, acrylic-based release agents are even more preferred from the viewpoint of particularly smoothly removing foreign matter. The acrylic-based release agent refers to a release agent containing a (meth)acrylic resin as one or both of the release component and the optional resin.

[0119] The thickness of the release layer is not particularly limited, but is preferably 50 nm or more, more preferably 70 nm or more, and is preferably 400 nm or less, more preferably 200 nm or less, and particularly preferably 130 nm or less.

[0120] As the support, a sheet-like member is usually used. The support may be a sheet of paper, but is preferably a long sheet from the viewpoint of enabling continuous production of the laminated resin sheet and improving production efficiency. Unless otherwise specified, a long sheet refers to a sheet having a length that can be wound into a roll, and may be, for example, a sheet having a length 10 times or more the width.

[0121] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm.

[0122] The support can be produced, for example, by a method including applying a release agent to the surface of the base layer. The release agent may further contain a solvent in combination with the non-volatile components, such as the releasable component and optional components, described above. When the release agent contains a solvent, the method for producing the support preferably includes applying the release agent and then drying it.

[0123] The solvent is preferably an aqueous solvent from the viewpoint of suppressing rapid evaporation of the solvent and forming a uniform release layer. Examples of aqueous solvents include water and mixed solvents of water and water-soluble organic solvents such as alcohol solvents, ketone solvents, glycol solvents, etc. One type of solvent may be used alone, or two or more types may be used in combination. When a solvent is used, the concentration of non-volatile components in the release agent is preferably 40% by mass or less from the viewpoint of improving the coatability and forming a uniform release layer.

[0124] Examples of methods for applying the release agent include wire bar coating, reverse coating, gravure coating, die coating, blade coating, dip coating, air knife coating, curtain coating, and roller coating.

[0125] The drying temperature of the release agent is not particularly limited. In one example, drying may be performed at a temperature in the range of 80°C to 130°C. In another example, drying may be performed at a temperature in the range of 160°C to 240°C.

[0126] A layer containing the non-volatile components of the release agent can be formed by applying a release agent to the surface of the substrate layer and drying it as necessary. This layer may be used as the release layer. Alternatively, the layer containing the non-volatile components of the release agent may be subjected to a curing treatment to obtain the release layer. Examples of the curing treatment include heating and ultraviolet irradiation. Typically, the curing treatment promotes reactions such as polymerization and crosslinking of some or all of the components contained in the release agent, thereby curing the release agent, and thus a release layer made of the cured product of the release agent can be obtained.

[0127] Furthermore, the method for producing the support may include any treatment such as a stretching treatment, if necessary.

[0128] <Protection film explanation> The protective film used in this embodiment will be described in detail below. The protective film is a film laminated on the resin composition layer in order to protect the resin composition layer from physical damage and to suppress adhesion of foreign matter such as dust, etc. Since the protective film is usually not required during the production of a circuit board, the protective film is generally laminated on the resin composition layer in a peelable manner.

[0129] Examples of the protective film include a thermoplastic resin film and a metal foil. When a thermoplastic resin film is used as the protective film, examples of the thermoplastic resin contained in the protective film include the same examples as the thermoplastic resin contained in the base layer. The protective film may also be a stretched film that has been subjected to a stretching treatment. When a metal foil is used as the protective film, examples of the metal foil include the same examples as the metal foil of the base layer. Examples of commercially available protective films include "MA430" and "MA411" (biaxially stretched polypropylene films) manufactured by Oji F-Tex Co., Ltd.

[0130] The surface of the protective film that is bonded to the resin composition layer (i.e., the first surface of the protective film) may have an arithmetic mean roughness within a specific range. Specifically, the arithmetic mean roughness of the first surface of the protective film is preferably 150 nm or more, more preferably 200 nm or more, even more preferably 250 nm or more, and preferably 2000 nm or less, more preferably 1500 nm or less, and even more preferably 1200 nm or less. The arithmetic mean roughness can be measured using a non-contact surface roughness meter. A specific example of a non-contact surface roughness meter is the "WYKO NT3300" manufactured by Veeco Instruments. The arithmetic mean roughness can be measured, for example, using a non-contact surface roughness meter in VSI mode with a 50x magnification lens and a measurement range of 121 μm × 92 μm.

[0131] The protective film may have a release layer. The release layer is usually formed as the outermost layer on the first surface side, and therefore the release layer can be exposed on the first surface of the protective film. The release layer of the protective film may be the same as the release layer of the support.

[0132] The thickness of the protective film is preferably 5 μm or more, more preferably 10 μm or more, and is preferably 75 μm or less, more preferably 50 μm or less, and even more preferably 40 μm or less. When a protective film having a release layer is used, it is preferable that the total thickness of the protective film including the release layer is within the above range.

[0133] The protective film may be a sheet film, but is preferably a long film from the viewpoint of enabling continuous production of the laminated resin sheet and improving production efficiency. Unless otherwise specified, a long film refers to a film having a length that can be wound into a roll, and can be, for example, a film having a length 10 times or more its width.

[0134] <Description of Curable Resin Composition> The curable resin composition used in this embodiment will be described in detail below. The curable resin composition is a curable resin composition, and can usually be cured by one or both of heat and light. As this curable resin composition, a composition containing a curable resin (A) can be used. Specific examples of the composition of the curable resin composition will be described below, but curable resin compositions other than those exemplified below may also be used.

[0135] -(A) Curing resin- The (A) curable resin that may be contained in the curable resin composition is usually selected from the group consisting of thermosetting resins and photocurable resins. As the (A) curable resin, only a thermosetting resin may be used, only a photocurable resin may be used, or a combination of a thermosetting resin and a photocurable resin may be used. Furthermore, the (A) curable resin may be used alone or in combination of two or more types.

[0136] The thermosetting resin may be a resin that can be cured when heat is applied. Examples of thermosetting resins include epoxy resins, phenolic resins, active ester resins, cyanate resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, thiol resins, and radical polymerizable resins. One type of thermosetting resin may be used alone, or two or more types may be used in combination.

[0137] In one example, it is preferable to use a combination of an epoxy resin and a resin capable of reacting with the epoxy resin to cure the curable resin composition. Hereinafter, a resin capable of reacting with an epoxy resin to cure the curable resin composition may be referred to as a "curing agent." Examples of curing agents include phenolic resins, active ester resins, cyanate resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. Among these, phenolic resins, active ester resins, cyanate resins, and carbodiimide resins are preferred, and phenolic resins and active ester resins are more preferred. Furthermore, one type of curing agent may be used alone, or two or more types may be used in combination.

[0138] Epoxy resin is a curable resin having an epoxy group. Examples of epoxy resins include bixylenol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol AF-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, phenol aralkyl-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexane dimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, isocyanurate-type epoxy resins, and phenolphthalimidine-type epoxy resins. The epoxy resin may be used alone or in combination of two or more.

[0139] From the viewpoint of obtaining a cured product having excellent heat resistance, the epoxy resin preferably contains an epoxy resin having an aromatic structure. The aromatic structure is a chemical structure generally defined as aromatic, and also includes polycyclic aromatic rings and aromatic heterocycles. Examples of epoxy resins containing an aromatic structure include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, bisxyleneol type epoxy resins, glycidylamine type epoxy resins having an aromatic structure, glycidyl ester type epoxy resins having an aromatic structure, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins having an aromatic structure, epoxy resins having a butadiene structure having an aromatic structure, alicyclic epoxy resins having an aromatic structure, heterocyclic epoxy resins, spiro ring-containing epoxy resins having an aromatic structure, cyclohexanedimethanol type epoxy resins having an aromatic structure, naphthylene ether type epoxy resins, trimethylol type epoxy resins having an aromatic structure, and tetraphenylethane type epoxy resins having an aromatic structure.

[0140] The (A) curable resin preferably contains an epoxy resin having two or more epoxy groups per molecule as the epoxy resin. The proportion of the epoxy resin having two or more epoxy groups per molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, based on 100% by mass of the non-volatile components of the epoxy resin.

[0141] Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The curable resin composition may contain only a liquid epoxy resin as the epoxy resin, or may contain only a solid epoxy resin, or may contain a combination of a liquid epoxy resin and a solid epoxy resin.

[0142] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0143] Preferred liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, and epoxy resins having a butadiene structure.

[0144] Specific examples of liquid epoxy resins include "HP4032," "HP4032D," and "HP4032SS" (naphthalene-type epoxy resins) manufactured by DIC Corporation; "828US," "828EL," "jER828EL," "825," and "Epikote 828EL" (bisphenol A-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER807" and "1750" (bisphenol F-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630," "630LSD," and "604" (glycidylamine-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycirol-type epoxy resin) manufactured by ADEKA Corporation; and "EP-3950L" and "EP-3980S" manufactured by ADEKA Corporation. Examples of epoxy resins include glycidylamine epoxy resins (EP-4088S, manufactured by ADEKA Corporation; ZX1059, manufactured by Nippon Steel Chemical & Material Co., Ltd.; a mixture of bisphenol A and bisphenol F epoxy resins (EX-721, manufactured by Nagase ChemteX Corporation; CELLOXIDE 2021P, manufactured by Daicel Corporation; PB-3600, manufactured by Daicel Corporation; JP-100 and JP-200, manufactured by Nippon Soda Co., Ltd.; and ZX1658 and ZX1658GS, manufactured by Nippon Steel Chemical & Material Co., Ltd., as liquid 1,4-glycidylcyclohexane epoxy resins. These may be used alone or in combination.

[0145] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferred.

[0146] Preferred solid epoxy resins include bixylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, naphthol novolac-type epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, phenol aralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, and phenolphthalimidine-type epoxy resins.

[0147] Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resins) manufactured by DIC Corporation; "N-690" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene type epoxy resins) manufactured by DIC Corporation; and "EXA-7311" and "EXA -7311-G3, "EXA-7311-G4", "EXA-7311-G4S", "HP6000", "HP6000L" (naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V", "ESN4" manufactured by Nippon Steel Chemical & Material Co., Ltd. 100V (naphthalene-type epoxy resin); Nippon Steel Chemical & Material's "ESN485" (naphthol-type epoxy resin); Nippon Steel Chemical & Material's "ESN375" (dihydroxynaphthalene-type epoxy resin); Mitsubishi Chemical's "YX4000H", "YX4000", "YX4000HK", and "YL7890" (bixylenol-type epoxy resin); Mitsubishi Chemical's "YL6121" (biphenyl-type epoxy resin); Mitsubishi Chemical's "YX8800" (anthracene-type epoxy resin); Mitsubishi Chemical's "YX7700" "(phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YL7760" and "YX7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.These may be used alone or in combination of two or more.

[0148] When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, the mass ratio thereof (liquid epoxy resin:solid epoxy resin) is preferably 20:1 to 1:20, more preferably 15:1 to 1:15, and particularly preferably 10:1 to 1:10.

[0149] The epoxy equivalent of the epoxy resin is preferably 50 g / eq. to 5,000 g / eq., more preferably 60 g / eq. to 3,000 g / eq., even more preferably 80 g / eq. to 2,000 g / eq., and particularly preferably 110 g / eq. to 1,000 g / eq. The epoxy equivalent represents the mass of the resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0150] The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

[0151] The amount of epoxy resin in the curable resin composition is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, relative to 100% by mass of the non-volatile components in the curable resin composition.

[0152] The amount of epoxy resin in the curable resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, relative to 100% by mass of the resin components in the curable resin composition. Unless otherwise specified, the resin components of the curable resin composition refer to the non-volatile components of the curable resin composition excluding the inorganic filler (B) described below.

[0153] The phenolic resin may be a compound having one or more, preferably two or more, hydroxyl groups bonded to an aromatic ring such as a benzene ring or a naphthalene ring per molecule. When combined with an epoxy resin, a phenolic resin can react with the epoxy resin to cure the curable resin composition, and is therefore sometimes referred to as a "phenolic curing agent." From the viewpoint of obtaining a cured product with excellent heat resistance and water resistance, a phenolic resin having a novolac structure is preferred. Furthermore, from the viewpoint of obtaining a cured product with excellent adhesion to wiring, a nitrogen-containing phenolic resin is preferred, and a triazine skeleton-containing phenolic resin is more preferred. Among these, a triazine skeleton-containing phenolic novolac resin is preferred from the viewpoint of obtaining a cured product with excellent heat resistance, water resistance, and adhesion. Specific examples of phenolic resins include "MEH-7700," "MEH-7810," and "MEH-7851" manufactured by Meiwa Chemical Industry Co., Ltd.; "NHN," "CBN," and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-375," and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; and "LA-7052," "LA-7054," "LA-3018," "LA-3018-50P," "LA-1356," "TD2090," and "TD-2090-60M" manufactured by DIC Corporation.

[0154] The amount of phenolic resin in the curable resin composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, relative to 100% by mass of non-volatile components in the curable resin composition, and is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less.

[0155] The amount of the phenolic resin in the curable resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 5% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, relative to 100% by mass of the resin components in the curable resin composition.

[0156] As the active ester resin, compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are generally preferred. When combined with an epoxy resin, active ester resins react with the epoxy resin to cure the curable resin composition, and are therefore sometimes referred to as "active ester curing agents." The active ester resin is preferably one obtained by the condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound. From the perspective of obtaining a cured product with excellent heat resistance, active ester resins obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester resins obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound are more preferred. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0157] Specifically, the active ester resin is preferably a dicyclopentadiene-type active ester resin, a naphthalene-type active ester resin containing a naphthalene structure, an active ester resin containing an acetylated product of phenol novolac, or an active ester resin containing a benzoylated product of phenol novolac, and among these, at least one selected from a dicyclopentadiene-type active ester resin and a naphthalene-type active ester resin is more preferred. As the dicyclopentadiene-type active ester resin, an active ester resin containing a dicyclopentadiene-type diphenol structure is preferred.

[0158] Commercially available active ester resins include, for example, activated ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", "HPC-8000-65T", "HPC-8000H", and "HPC-8000H-65TM" (manufactured by DIC Corporation); activated ester resins containing a naphthalene structure such as "HP-B-8151-62T", "HP-C-8151-62T", "EXB-8100L-65T", and "EXB-8150-60T"; Examples of such active ester resins include "EXB-8150-62T," "EXB-9416-70BK," "HPC-8150-60T," "HPC-8150-62T," and "EXB-8" (manufactured by DIC Corporation); "EXB9401" (manufactured by DIC Corporation) as a phosphorus-containing active ester resin; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester resin which is an acetylated product of phenol novolac; "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester resins which are benzoylated products of phenol novolac; and "PC1300-02-65MA" (manufactured by Air Water Inc.) as an active ester resin containing a styryl group and a naphthalene structure.

[0159] The amount of the active ester resin in the curable resin composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, relative to 100% by mass of the non-volatile components in the curable resin composition, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0160] The amount of the active ester resin in the curable resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 5% by mass or more, relative to 100% by mass of the resin components in the curable resin composition, and is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less.

[0161] The cyanate resin may be a compound having one or more, preferably two or more, cyanate groups in one molecule. When combined with an epoxy resin, the cyanate resin reacts with the epoxy resin to cure the curable resin composition, and therefore is sometimes called a "cyanate-based curing agent." Examples of cyanate resins include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)thioether, and bis(4-cyanatephenyl)ether; multifunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate resins include "PT30" and "PT60" manufactured by Lonza Japan (both of which are phenol novolac-type multifunctional cyanate resins), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazine-converted to form a trimer).

[0162] As the carbodiimide resin, a compound having one or more, preferably two or more, carbodiimide structures in one molecule can be used. When combined with an epoxy resin, the carbodiimide resin reacts with the epoxy resin to cure the curable resin composition, and is therefore sometimes referred to as a "carbodiimide-based curing agent." Specific examples of carbodiimide resins include aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexane-bis(methylene-t-butylcarbodiimide); aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide); poly(phenylenecarbodiimide), poly(naphthalenecarbodiimide); Examples of polycarbodiimides include aromatic polycarbodiimides such as poly(methylenediphenylenecarbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide]. Commercially available carbodiimide resins include, for example, "Carbodilite V-02B," "Carbodilite V-03," "Carbodilite V-04K," "Carbodilite V-07," and "Carbodilite V-09" manufactured by Nisshinbo Chemical Inc.; and "Stavaxol P," "Stavaxol P400," and "Hykasil 510" manufactured by Rhein Chemie.

[0163] As the acid anhydride resin, a compound having one or more, preferably two or more, acid anhydride groups in one molecule can be used. When combined with an epoxy group, the acid anhydride resin can react with the epoxy resin to cure the curable resin composition, and therefore is sometimes called an "acid anhydride curing agent." Specific examples of acid anhydride resins include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic anhydride. Examples of suitable anhydrides include hydrates, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and polymeric anhydrides such as styrene-maleic acid resin, which is a copolymer of styrene and maleic acid. Commercially available acid anhydride resins include, for example, "HNA-100," "MH-700," "MTA-15," "DDSA," and "OSA" manufactured by New Japan Chemical Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Corporation; "HN-2200" and "HN-5500" manufactured by Hitachi Chemical Co., Ltd.; and "EF-30," "EF-40," "EF-60," and "EF-80" manufactured by Clay Valley.

[0164] The amine resin may be a compound having one or more, preferably two or more, amino groups in one molecule. When combined with an epoxy group, the amine resin may react with the epoxy resin to cure the curable resin composition, and is therefore sometimes referred to as an "amine-based curing agent." Examples of the amine resin include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines, with aromatic amines being preferred. The amine resin is preferably a primary amine or secondary amine, with primary amines being more preferred. Specific examples of amine resins include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxyphenyl)propionate. Examples of suitable bis(4-aminophenoxy)benzene include bis(4-aminophenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, and bis(4-(3-aminophenoxy)phenyl)sulfone. Commercially available amine resins include, for example, "SEIKACURE-S" manufactured by Seika Corporation; "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD AA," "KAYAHARD AB," and "KAYAHARD AS" manufactured by Nippon Kayaku Co., Ltd.; "Epicure W" manufactured by Mitsubishi Chemical Corporation; and "DTDA" manufactured by Sumitomo Seika Chemicals Co., Ltd.

[0165] Benzoxazine resins, when combined with epoxy resins, can react with the epoxy resin to cure the curable resin composition, and are therefore sometimes referred to as "benzoxazine-based curing agents." Specific examples of benzoxazine resins include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation; "HFB2006M" manufactured by Showa Polymer Co., Ltd.; and "Pd" and "Fa" manufactured by Shikoku Chemicals Corporation.

[0166] Thiol resins are sometimes called "thiol-based curing agents" because they can react with epoxy resins to cure the curable resin composition when combined with them. Examples of thiol resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate.

[0167] The active group equivalent of the curing agent is preferably 50 g / eq. to 3000 g / eq., more preferably 100 g / eq. to 1000 g / eq., still more preferably 100 g / eq. to 500 g / eq., and particularly preferably 100 g / eq. to 300 g / eq. The active group equivalent represents the mass of the curing agent per equivalent of the active group.

[0168] The weight average molecular weight (Mw) range of the curing agent may be the same as the weight average molecular weight range of the epoxy resin.

[0169] When the number of epoxy groups in the epoxy resin is taken as 1, the number of active groups in the curing agent is preferably 0.05 or more, more preferably 0.1 or more, even more preferably 0.2 or more, and preferably 5.0 or less, more preferably 4.0 or less, and particularly preferably 3.0 or less. The "number of epoxy groups in the epoxy resin" refers to the total value obtained by dividing the mass of the non-volatile components of the epoxy resin present in the curable resin composition by the epoxy equivalent. Furthermore, the "number of active groups in the curing agent" refers to the total value obtained by dividing the mass of the non-volatile components of the curing agent present in the curable resin composition by the active group equivalent.

[0170] The amount of the curing agent in the curable resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 5% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, relative to 100% by mass of the non-volatile components in the curable resin composition.

[0171] The amount of the curing agent in the curable resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, relative to 100% by mass of the resin components in the curable resin composition, and is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less.

[0172] The radical polymerizable resin may be a compound having an ethylenically unsaturated bond. Therefore, the radical polymerizable resin may have a radical polymerizable group containing an ethylenically unsaturated bond. Examples of the radical polymerizable group include unsaturated hydrocarbon groups such as vinyl, allyl, 3-cyclohexenyl, 3-cyclopentenyl, 2-vinylphenyl, 3-vinylphenyl, and 4-vinylphenyl; and α,β-unsaturated carbonyl groups such as acryloyl, methacryloyl, and maleimide (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl) groups. The number of radical polymerizable groups contained in one molecule of the radical polymerizable resin may be one, but preferably two or more. Examples of the radical polymerizable resin include (meth)acrylic radical polymerizable resins, styrene radical polymerizable resins, allyl radical polymerizable resins, and maleimide radical polymerizable resins. The radical polymerizable resin may be used alone or in combination of two or more kinds.

[0173] The photocurable resin may be a resin that can be cured when exposed to light. Examples of the photocurable resin include radical polymerizable resins. One type of photocurable resin may be used alone, or two or more types may be used in combination.

[0174] The amount of the (A) curable resin in the curable resin composition is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to 100% by mass of the non-volatile components in the curable resin composition, and is preferably 70% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less.

[0175] The amount of the (A) curable resin in the curable resin composition is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, relative to 100% by mass of the resin components in the curable resin composition, and is preferably 97% by mass or less, more preferably 96% by mass or less, and particularly preferably 95% by mass or less.

[0176] -(B) Inorganic filler- The curable resin composition may contain an inorganic filler (B) as an optional component. The inorganic filler (B) is usually contained in the curable resin composition in the form of particles.

[0177] (B) Inorganic fillers are inorganic compounds. Examples of (B) inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica and alumina are preferred, and silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred. The (B) inorganic filler may be used alone or in combination of two or more.

[0178] (B) Examples of commercially available inorganic fillers include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C," "YA050C," "YA050C-MJE," "YA010C," "SC2500SQ," "SO-C4," "SO-C2," and "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30," "DAW-03," and "FB-105FD" manufactured by Denka Company, Limited; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "CellSpheres" and "MGH-005" manufactured by Taiheiyo Cement Corporation; and "Sfereek" and "BA-1" manufactured by JGC Catalysts and Chemicals Co., Ltd.

[0179] The average particle size of the (B) inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less. The average particle size of the (B) inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, a volumetric particle size distribution of the inorganic filler is prepared using a laser diffraction / scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the mixture ultrasonically for 10 minutes. The volumetric particle size distribution of the inorganic filler is measured using a laser diffraction particle size distribution analyzer with blue and red light source wavelengths using a flow cell system, and the average particle size can be calculated as the median diameter from the particle size distribution obtained. Examples of laser diffraction particle size distribution analyzers include the LA-960 manufactured by Horiba, Ltd.

[0180] (B) The specific surface area of ​​the inorganic filler is preferably 1 m 2 / g or more, more preferably 2m 2 / g or more, more preferably 3m 2 / g or more, preferably 60m 2 / g or less, more preferably 50m 2 / g or less, more preferably 40m 2 The specific surface area can be measured in accordance with the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) and calculating the specific surface area using the BET multipoint method.

[0181] (B) The inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a mercaptosilane coupling agent, a silane coupling agent, an alkoxysilane, an organosilazane compound, and a titanate coupling agent. One type of surface treatment agent may be used alone, or two or more types may be used in any combination.

[0182] Examples of commercially available surface treatment agents include Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd.'s "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM-4803" (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical Co., Ltd.'s "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane).

[0183] The degree of surface treatment with the surface treatment agent preferably falls within a specific range from the viewpoint of improving the dispersibility of (B) the inorganic filler. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2% to 5% by mass of the surface treatment agent, more preferably with 0.2% to 3% by mass of the surface treatment agent, and even more preferably with 0.3% to 2% by mass of the surface treatment agent.

[0184] The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of ​​the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of ​​the inorganic filler is set to 0.02 mg / m 2 More than 0.1 mg / m is preferable. 2 More preferably, 0.2 mg / m or more 2 On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the curable resin composition, it is more preferable that the content be 1.0 mg / m 2 Less than 0.8 mg / m is preferred 2 Less than 0.5 mg / m is more preferable. 2 The following is even more preferred:

[0185] (B) The amount of carbon per unit surface area of ​​the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. The carbon analyzer that can be used is the "EMIA-320V" manufactured by Horiba, Ltd.

[0186] The amount of (B) inorganic filler in the curable resin composition is preferably 10% by mass or more, more preferably 30% by mass or more, even more preferably 50% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 80% by mass or less, relative to 100% by mass of the non-volatile components of the curable resin composition.

[0187] -(C) Curing accelerator- The curable resin composition may contain, as an optional component, a curing accelerator (C), which functions as a curing catalyst that accelerates the curing of the curable resin (A).

[0188] The (C) curing accelerator may be an appropriate one depending on the type of (A) curable resin. For example, when the (A) curable resin contains an epoxy resin, examples of the (C) curing accelerator that can accelerate the curing of the epoxy resin include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators. One type of (C) curing accelerator may be used alone, or two or more types may be used in combination.

[0189] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hydrogenhexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, and tetraphenylphosphonium tetra-p-tolylborate. aromatic phosphonium salts such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone adducts such as triphenylphosphine-p-benzoquinone adduct; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine aromatic phosphines such as benzene, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether;

[0190] Examples of the urea-based curing accelerator include 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. aromatic dimethylureas such as toluene bis(dimethylurea), 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea].

[0191] Examples of guanidine curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0192] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-methylimidazole. Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct Examples of imidazole compounds include 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. Commercially available imidazole curing accelerators include "1B2PZ," "2E4MZ," "2MZA-PW," "2MZ-OK," "2MA-OK," "2MA-OK-PW," "2PHZ," "2PHZ-PW," "Cl1Z," "Cl1Z-CN," "Cl1Z-CNS," and "C11Z-A" manufactured by Shikoku Chemicals Corporation; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0193] Examples of metal-based curing accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organic copper complexes such as copper(II) acetylacetonate, organic zinc complexes such as zinc(II) acetylacetonate, organic iron complexes such as iron(III) acetylacetonate, organic nickel complexes such as nickel(II) acetylacetonate, and organic manganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0194] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. Commercially available amine curing accelerators may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0195] The amount of the (C) curing accelerator in the curable resin composition is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.05% by mass or more, and is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and particularly preferably 0.2% by mass or less, relative to 100% by mass of the non-volatile components in the curable resin composition.

[0196] The amount of the (C) curing accelerator in the curable resin composition is, relative to 100% by mass of the resin components in the curable resin composition, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.10% by mass or more, and is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, even more preferably 0.5% by mass or less.

[0197] -(D) Polymer resin- The curable resin composition may contain a (D) polymer resin as an optional component. Examples of the (D) polymer resin include phenoxy resin, polyimide resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyetheretherketone resin, and polyester resin. The (D) polymer resin may be used alone or in combination of two or more.

[0198] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenolacetophenone, novolac, biphenyl, fluorene, dicyclopentadiene, norbornene, naphthalene, anthracene, adamantane, terpene, and trimethylcyclohexane. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both of which are phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YL7500BH30," "YL7800BH40," "YX6954BH30," "YX7553," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," "YL7482," and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation; and the like.

[0199] Specific examples of polyimide resins include "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., and "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd.

[0200] Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, with polyvinyl butyral resins being preferred. Specific examples of polyvinyl acetal resins include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, and Denka Butyral 6000-EP, manufactured by Denki Kagaku Kogyo Co., Ltd.; and S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series, manufactured by Sekisui Chemical Co., Ltd.

[0201] Examples of polyolefin resins include ethylene copolymer resins such as low-density polyethylene, very low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; and polyolefin polymers such as polypropylene and ethylene-propylene block copolymer.

[0202] Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxy group-containing polybutadiene resins, phenolic hydroxy group-containing polybutadiene resins, carboxy group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, isocyanate group-containing polybutadiene resins, urethane group-containing polybutadiene resins, and polyphenylene ether-polybutadiene resins.

[0203] Specific examples of polyamide-imide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins also include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imides) manufactured by Hitachi Chemical Co., Ltd.

[0204] A specific example of the polyethersulfone resin is "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0205] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0206] A specific example of the polyphenylene ether resin is NORYL SA90 manufactured by SABIC, etc. A specific example of the polyetherimide resin is ULTEM manufactured by GE, etc.

[0207] Examples of polycarbonate resins include hydroxyl group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxyl group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, and urethane group-containing carbonate resins. Specific examples of polycarbonate resins include "FPC0220" manufactured by Mitsubishi Gas Chemical Company, Inc., "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Chemicals Corporation, and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) manufactured by Kuraray Co., Ltd. Specific examples of polyether ether ketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd.

[0208] Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

[0209] The (D) polymer resin usually has a large molecular weight. Specifically, the weight average molecular weight (Mw) of the (D) polymer resin is preferably greater than 5,000, more preferably at least 8,000, even more preferably at least 10,000, and even more preferably at least 20,000, and is preferably at most 100,000, more preferably at most 70,000, even more preferably at most 60,000, and even more preferably at most 50,000.

[0210] The amount of the (D) polymer resin in the curable resin composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 1% by mass or more, relative to 100% by mass of the non-volatile components in the curable resin composition, and is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0211] The amount of the (D) polymer resin in the curable resin composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more, relative to 100% by mass of the resin components in the curable resin composition, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0212] -(E) Optional Additives- The curable resin composition may further contain an optional additive (E) as an optional non-volatile component in addition to the above-described components (A) to (D). Examples of the optional additive (E) include organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silanes; adhesion promoters such as triazole-based adhesion promoters, tetrazole-based adhesion promoters, and triazine-based adhesion promoters; and antioxidants such as hindered phenol-based antioxidants. flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers; polymerization initiation aids such as tertiary amines; photosensitizers such as pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones; and organic particles. (E) The optional additives may be used alone or in combination of two or more.

[0213] -(F) Solvent- The curable resin composition may further contain a (F) solvent as an optional volatile component in addition to the non-volatile components (A) to (E) described above. An organic solvent is typically used as the (F) solvent. Examples of the organic solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol-based solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples of suitable solvents include ether ester solvents such as ethyl acetate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. (F) Solvents may be used singly or in combination of two or more.

[0214] The amount of (F) solvent is not particularly limited, but when all components in the curable resin composition are taken as 100% by mass, it may be, for example, 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, or may be 0% by mass.

[0215] -Method for producing curable resin composition- The curable resin composition can be produced, for example, by mixing components that can be contained in the curable resin composition. The components may be mixed partially or entirely at the same time, or may be mixed sequentially. The temperature may be appropriately set during the process of mixing each component, and thus heating and / or cooling may be performed temporarily or throughout. Furthermore, stirring or shaking may be performed during the process of mixing each component.

[0216] -Characteristics of curable resin composition- A cured product can be obtained by curing the curable resin composition. This cured product is preferably used to form an insulating layer of a circuit board. The insulating layer contains a cured product of the curable resin composition, and preferably contains only the cured product. Typically, volatile components such as (F) solvent contained in the curable resin composition can volatilize due to heat applied during curing, so the cured product can contain non-volatile components of the curable resin composition or reaction products thereof.

[0217] The cured product of the curable resin composition preferably has excellent dielectric properties. Specifically, the cured product of the curable resin composition preferably has a low relative dielectric constant. In one example, the relative dielectric constant of the cured product is preferably 5 or less, more preferably 4 or less, and particularly preferably 3 or less. There is no particular restriction on the lower limit, and it may be, for example, 1.5 or more, 2.0 or more, etc.

[0218] Furthermore, it is preferable that the cured product of the curable resin composition has a low dielectric loss tangent. In one example, the dielectric loss tangent of the cured product is preferably 0.05 or less, more preferably 0.04 or less, and particularly preferably 0.03 or less. There is no particular restriction on the lower limit, and it can be, for example, 0.001 or more, 0.002 or more, etc.

[0219] The dielectric constant and dielectric loss tangent of the cured product of the curable resin composition can be measured by a cavity resonance perturbation method under conditions of a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. When the curable resin composition is thermosetting, the dielectric constant and dielectric loss tangent can be measured using a cured product obtained by thermally curing the curable resin composition under conditions of 180°C and 90 minutes. When the curable resin composition is photocurable, the dielectric constant and dielectric loss tangent can be measured using a cured product obtained by thermally curing the curable resin composition under conditions of 1 J / cm. 2 After irradiating the resin with ultraviolet light, the resin is heated at 180°C for 90 minutes to obtain a cured product, which can be used for measurement.

[0220] <Description of a method for manufacturing a circuit board using a laminated resin sheet> Hereinafter, a method for producing a circuit board will be described as an example of an application of the laminated resin sheet according to this embodiment. A circuit board usually includes an insulating layer obtained by curing a resin composition layer. This circuit board can be produced, for example, by a method including the following steps (i) to (iii): (i) A step of peeling off the protective film from the laminated resin sheet to obtain a resin sheet. (ii) A step of laminating a resin sheet on the inner layer substrate so that the resin composition layer and the inner layer substrate are bonded to each other. (iii) A step of curing the resin composition layer to form an insulating layer.

[0221] The method for manufacturing a circuit board according to this example includes step (i) of peeling a protective film from a laminated resin sheet to obtain a resin sheet. By peeling off the protective film, the resin composition layer is exposed, which makes it possible to bond the resin composition layer to an inner layer substrate in step (ii).

[0222] Typically, the protective film is peeled off by pulling it relative to the resin sheet. For example, the resin sheet may be transported with the protective film fixed, and the protective film may be peeled off. Alternatively, the resin sheet may be fixed and the protective film may be pulled, and the protective film may be peeled off. Furthermore, the resin sheet may be transported while the protective film is being pulled, and the protective film may be peeled off.

[0223] Typically, the protective film is relatively pulled in a peeling direction that forms a specific angle with respect to the surface of the resin composition layer, thereby achieving peeling of the protective film. There is no particular limitation on the range of the angle that the peeling direction forms with respect to the surface of the resin composition layer. The peeling direction may be, for example, parallel to the surface of the resin composition layer, perpendicular to the surface, or any other direction. Furthermore, there are no particular limitations on the temperature conditions for peeling. From the viewpoint of reducing the energy required for manufacturing the circuit board, peeling of the protective film is typically performed at room temperature or a temperature close to room temperature.

[0224] The method for producing a circuit board according to this example includes, after step (i), step (ii) of laminating a resin sheet on the inner layer substrate, such that the resin composition layer and the inner layer substrate are bonded to each other.

[0225] The "inner layer substrate" used in step (ii) is a member that serves as the base material of a circuit board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may have a conductor layer on one or both sides, and this conductor layer may be patterned. Such a conductor layer can function as inner layer wiring. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate is sometimes referred to as an "inner layer circuit board." Furthermore, intermediate products on which an insulating layer and / or a conductor layer is to be further formed during the production of a circuit board are also included in the aforementioned "inner layer substrate." When the circuit board is a circuit board with built-in components, an inner layer substrate with built-in components may be used.

[0226] The inner layer substrate and the resin sheet can be laminated, for example, by thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of a member for thermocompression bonding the resin sheet to the inner layer substrate (hereinafter also referred to as a "thermocompression bonding member") include a heated metal plate (such as a SUS end plate) or a metal roll (SUS roll). Note that rather than pressing the thermocompression bonding member directly onto the resin sheet, it is preferable to press it via an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently conform to the surface irregularities of the inner layer substrate.

[0227] The lamination of the inner layer substrate and the resin sheet may be carried out by a vacuum lamination method. In the vacuum lamination method, the thermocompression temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, the thermocompression pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. The lamination is preferably carried out under reduced pressure conditions of 26.7hPa or less.

[0228] The lamination can be performed using a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., or a batch vacuum pressure laminator.

[0229] After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression member from the support side. The pressing conditions for the smoothing treatment may be the same as the thermocompression conditions for lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

[0230] The method for producing a circuit board according to this example includes, after step (ii), step (iii) of curing the resin composition layer to form an insulating layer. The resin composition layer can be cured by a method suitable for the curable resin composition, such as thermal curing or photocuring. Specific curing conditions for the resin composition layer may be those typically used when forming an insulating layer for a circuit board.

[0231] For example, when a thermosetting curable resin composition, such as a curable resin composition containing a thermosetting resin, is used, curing of the curable resin composition may proceed as thermal curing. Therefore, in this case, step (iii) may include thermally curing the resin composition layer. The thermal curing conditions for the resin composition layer may vary depending on the type of curable resin composition. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. The curing time may be preferably 5 to 120 minutes, more preferably 10 to 100 minutes, and even more preferably 15 to 100 minutes.

[0232] Furthermore, when the resin composition layer is thermally cured, the method for producing a circuit board preferably includes preheating the resin composition layer at a temperature lower than the curing temperature before the thermal curing. For example, prior to thermal curing of the resin composition layer, the resin composition layer may be preheated at a temperature of typically 50°C to 150°C, preferably 60°C to 140°C, and more preferably 70°C to 130°C for typically 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

[0233] On the other hand, when a photocurable curable resin composition, such as a curable resin composition containing a photocurable resin, is used, the curing of the curable resin composition may proceed as photocuring. Therefore, in this case, step (iii) may include photocuring the resin composition layer. The photocuring conditions of the curable resin composition may vary depending on the type of curable resin composition. For example, the resin composition layer in the irradiated area may be photocured by an exposure treatment in which the resin composition layer is irradiated with actinic rays. Examples of actinic rays include ultraviolet rays, visible rays, electron beams, and X-rays, with ultraviolet rays being particularly preferred. The irradiation dose of ultraviolet rays is, for example, 10 mJ / cm. 2 ~1000mJ / cm 2 In this case, exposure may be carried out through the support, or after peeling off the support.

[0234] In the exposure treatment, the resin composition layer may be irradiated with actinic rays through a mask having a pattern formed thereon. Exposure methods using a mask include a contact exposure method in which exposure is performed by bringing the mask into contact with the workpiece, and a non-contact exposure method in which exposure is performed using parallel light without contact, and either method may be used.

[0235] Step (iii) may include carrying out a development treatment after the exposure treatment. The development treatment can remove the non-photocured portions (unexposed portions) to form a pattern in the insulating layer. The development is usually carried out by wet development. In wet development, a safe, stable, and easy-to-use developer is used, such as an alkaline aqueous solution, a water-based developer, or an organic solvent. Of these, a development step using an alkaline aqueous solution is preferred. Examples of development methods that can be used include spraying, swing immersion, brushing, and scraping.

[0236] Furthermore, when the resin composition layer is photocured, a post-baking treatment may be carried out as necessary after the photocuring and development. Examples of the post-baking treatment include ultraviolet irradiation treatment using a high-pressure mercury lamp and heating treatment using a clean oven. The ultraviolet irradiation treatment is carried out, for example, at 0.05 J / cm 2 ~10J / cm2 The heat treatment can be carried out, for example, preferably at 150°C to 250°C for 20 to 180 minutes, more preferably at 160°C to 230°C for 30 to 120 minutes.

[0237] The manufacturing method of a circuit board usually includes a step (iv) of removing the support. The removal of the support may be performed before the curing of the resin composition layer, but is preferably performed after the curing of the resin composition layer. When the resin composition layer is cured while covered with the support, adhesion of foreign matter to the surface of the resin composition layer in the curing step can be suppressed. Furthermore, when the support is removed after the curing of the resin composition layer, the support can be particularly easily removed.

[0238] When manufacturing a circuit board, the following steps may be further performed: (v) drilling holes in the insulating layer, (vi) roughening the insulating layer, and (vii) forming a conductor layer as wiring. These steps (v) to (vii) may be performed according to various methods known to those skilled in the art and used in manufacturing circuit boards. When the support is removed after step (iii), the removal of the support may be performed between steps (iii) and (v), between steps (v) and (vi), or between steps (vi) and (vii). Furthermore, if necessary, the formation of insulating layers and conductor layers in steps (i) to (vii) may be repeated to form a multilayer circuit board, such as a multilayer printed wiring board.

[0239] Step (v) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (v) may be performed using a processing method such as drilling, laser processing, or plasma processing, depending on the composition of the curable resin composition used to form the insulating layer. The dimensions and shape of the holes may be determined appropriately depending on the design of the circuit board.

[0240] Step (vi) is a step of roughening the insulating layer. Typically, step (vi) also involves removing smears (resin residues) that may be generated during hole formation. The roughening procedure and conditions are not particularly limited, and known procedures and conditions commonly used in forming insulating layers for circuit boards can be used. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order.

[0241] Examples of swelling liquids used in the roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Examples of the alkaline solution include sodium hydroxide solution and potassium hydroxide solution. Examples of commercially available swelling liquids include "Swelling Dip Securigance P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan. Swelling treatment using a swelling liquid can be performed by immersing the insulating layer in the swelling liquid at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in the swelling liquid at 40°C to 80°C for 5 to 15 minutes.

[0242] Examples of oxidizing agents used in the roughening treatment include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0243] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan can be cited. Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, a preferred method is to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0244] Step (vii) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer may be a single metal layer or an alloy layer. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among these, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

[0245] The conductor layer may have a single layer structure, or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

[0246] Typically, the conductor layer is patterned so that it can function as wiring. In this case, it is preferable that the minimum line / space ratio of the conductor layer is small. The minimum line / space ratio of the conductor layer is preferably 100 μm / 100 μm or less (i.e., a pitch of 200 μm or less), more preferably 80 μm / 80 μm or less, even more preferably 50 μm / 50 μm or less, and even more preferably 30 μm / 30 μm or less. The lower limit may be, for example, 0.5 μm / 0.5 μm or more. The pitch may be uniform or nonuniform throughout the conductor layer. The minimum pitch of the conductor layer may be, for example, 200 μm or less, 160 μm or less, 100 μm or less, or 60 μm or less. Here, "line" refers to the wiring width of the conductor layer, and "space" refers to the distance between the wirings.

[0247] The thickness of the conductor layer depends on the desired design of the circuit board, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0248] In one embodiment, the conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of the insulating layer using a conventionally known technique such as a semi-additive method or a full-additive method. From the viewpoint of ease of production, the semi-additive method is preferred. An example of forming a conductor layer using a semi-additive method will be described below.

[0249] First, a plating seed layer is formed on the surface of an insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary plating seed layer is removed by etching or the like, thereby forming a conductor layer having the desired wiring pattern.

[0250] The method for manufacturing a circuit board may include any additional steps in addition to the steps described above. For example, the method for manufacturing a circuit board may include a step of providing a semiconductor chip so that the semiconductor chip is bonded to the conductor layer. Specifically, when manufacturing a circuit board for a semiconductor chip package including a semiconductor chip, the method for manufacturing a circuit board may include a step of providing the semiconductor chip. The semiconductor chip may be bonded under appropriate conditions that allow conductive connection between the terminal electrodes of the semiconductor chip and the conductor layer formed on the insulating layer. For example, conditions used in flip-chip mounting may be used. The semiconductor chip may be bonded via an insulating adhesive or by reflow bonding. Furthermore, if necessary, the provided semiconductor chip may be filled with a mold underfill material.

[0251] The method for manufacturing a circuit board may also include, for example, a step of forming a sealing layer, a step of forming a solder resist layer, and a step of dicing the manufactured circuit board into individual pieces.

[0252] Examples of the circuit boards manufactured include printed wiring boards and semiconductor chip packages. Examples of semiconductor chip packages include FC-CSP, MIS-BGA package, ETS-BGA package, fan-out type WLP (Wafer Level Package), fan-in type WLP, fan-out type PLP (Panel Level Package), and fan-in type PLP. In these semiconductor chip packages, it is preferable to form a rewiring formation layer using an insulating layer obtained by curing the above-mentioned resin composition layer. However, the circuit board manufactured using the laminated resin sheet according to this embodiment is not limited to the examples exemplified here.

[0253] The circuit board can be used to manufacture a semiconductor device. The semiconductor layer includes the circuit board described above. Examples of the semiconductor device include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical equipment, televisions, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, aircraft, etc.). [Example]

[0254] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples shown below. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Furthermore, the temperature and pressure conditions were room temperature (25°C) and atmospheric pressure (1 atm), unless otherwise specified.

[0255] <Method for measuring adhesive strength of dust removal roller> The adhesive strength of the dust removal rollers used in the following Examples and Comparative Examples is as follows: Here, the adhesive strength of each dust removal roller refers to the adhesive strength of the adhesive tape forming the surface of the dust removal roller or the circumferential surface of the dust removal roller, and specifically refers to the adhesive strength measured by the following measurement method. The adhesive tape was wound around a core so that the adhesive layer was on the outside of the roll to obtain a dust removal roller. An adhesive strength tester (Isshin Sangyo Co., Ltd., A3-10N) was placed perpendicular to the circumferential surface of the dust removal roller. The maximum load (N / 100mm) when the measuring part was pressed against the adhesive layer and pulled back was measured. 2 The measurement was carried out three times, and the average value of the three maximum loads measured was taken as the adhesive strength. Adhesive tape 1: Nichiban "Karitome No. 207" (adhesive strength 2.3N / 100mm 2 ) Adhesive tape 2: Nichiban "Sealing Masking Tape No. 2563" (adhesive strength 2.7N / 100mm) 2 ) Dust removal roller 3: Technoroll "Clean Dash E" (adhesive strength 3.0N / 100mm 2 ) Dust removal roller 4: Audio-Technica HC-730 (adhesive strength 0.6N / 100mm 2 )

[0256] Example 1 (1. Production of a support provided with a release layer containing an acrylic resin) (1-1. Production of acrylic resin (A)) Into a temperature-controllable reactor equipped with a stirrer, thermometer, and condenser, 500 parts by weight of toluene, 80 parts by weight of stearyl methacrylate (alkyl chain carbon number: 18), 15 parts by weight of methacrylic acid, 5 parts by weight of 2-hydroxyethyl methacrylate, and 1 part of azobisisobutyronitrile were added dropwise using a dropper at a reaction temperature of 85°C over 4 hours to carry out a polymerization reaction. The mixture was then aged at the same temperature for 2 hours to complete the reaction, yielding acrylic resin (A). This acrylic resin (A) was dissolved in water containing 5% by weight of isopropyl alcohol and 5% by weight of n-butyl cellosolve to obtain a resin solution containing acrylic resin (A) as a mold-releasing component.

[0257] (1-2. Production of acrylic resin (B)) Methyl methacrylate (a), hydroxyethyl methacrylate (b), and aromatic urethane acrylate oligomer (EBECRYL 220 manufactured by Daicel-Allnex Corporation, with 6 acryloyl groups) (c) were charged into a stainless steel reaction vessel in a mass ratio of (a) / (b) / (c) = 94 / 1 / 5. Furthermore, 2 parts by mass of sodium dodecylbenzenesulfonate was added as an emulsifier to the reaction vessel for a total of 100 parts by mass of (a) + (b) + (c), and the mixture was stirred to prepare mixed solution (1).

[0258] Next, a reactor equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel was prepared. 60 parts by mass of the mixed solution (1), 200 parts by mass of isopropyl alcohol, and 5 parts by mass of potassium persulfate as a polymerization initiator were added to the reactor and heated to 60°C to prepare mixed solution (2). Mixed solution (2) was maintained at 60°C for 20 minutes.

[0259] Next, a mixed solution (3) consisting of 40 parts by mass of the mixed solution (1), 50 parts by mass of isopropyl alcohol, and 5 parts by mass of potassium persulfate was prepared. The mixed solution (3) was added dropwise to the mixed solution (2) using a dropping funnel over 2 hours to prepare a mixed solution (4).

[0260] Thereafter, the mixed solution (4) was heated to 60°C and maintained in this state for 2 hours. The obtained mixed solution (4) was cooled to 50°C or below and then transferred to a container equipped with a stirrer and a pressure reducing device. 60 parts by mass of 25% aqueous ammonia and 900 parts by mass of pure water were added to this container, and the isopropyl alcohol and unreacted monomers were recovered under reduced pressure while heating to 60°C, thereby obtaining a composition containing an acrylic resin (B) as an arbitrary resin dispersed in pure water.

[0261] (1-3. Production of release agents) An intermediate composition was obtained by mixing a resin solution containing acrylic resin (A) and a composition containing acrylic resin (B) so that the mass ratio (solid mass ratio) of the acrylic resin (A) to the acrylic resin (B) was (A) / (B) = 20 / 80. Furthermore, a fluorine-based surfactant ("PLASCOAT (registered trademark) RY-2" manufactured by GOO Chemical Industry Co., Ltd.) was added to this intermediate composition in an amount of 0.1 part by mass per 100 parts by mass of the entire intermediate composition, thereby obtaining a release agent as a liquid acrylic resin composition.

[0262] (1-4. Production of support) A PET film (Toray Industries, Inc.'s "T60" (thickness: 38 μm)) was prepared as the substrate layer. A release agent was applied to one side of this substrate layer using a gravure coater and dried to form a release layer with a thickness of 0.1 μm. Through the above operations, a long support comprising a substrate layer and a release layer containing an acrylic resin was obtained.

[0263] (2. Preparation of Resin Composition) Tetramethylbisphenol type epoxy resin (Mitsubishi Chemical Corporation "YX4000H", epoxy equivalent 194g / eq.) 8 parts, biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd. "NC3000L", epoxy equivalent approximately 271g / eq.) 10 parts, naphthalene type epoxy resin (DIC Corporation "HP6000L", epoxy equivalent approximately 213g / eq.) 2 parts, bifunctional epoxy resin (Nippon Steel Chemical Co., Ltd. "ZX1658GS", epoxy equivalent approximately 133g / eq.) 2 parts, phenolic hardener with triazine skeleton and cresol novolac structure (DIC Corporation "LA-3018-50P", phenolic hydroxyl group equivalent approximately 151g / eq., 2-methoxypropanol solution with 50% solids) 4 parts, active ester A resin varnish was prepared as a liquid resin composition by mixing 6 parts of a phenoxy resin (DIC Corporation "HP-C-8151-62T," active ester group equivalent weight approximately 238 g / eq., 62% solids in a toluene solution), 5 parts of a phenoxy resin (Mitsubishi Chemical Corporation "YL7800BH40," 40% solids in a MEK and cyclohexane solution), 40 parts of an inorganic filler (average particle size 0.5 μm, surface treatment amount: 0.6% by mass of amino silane coupling agent per 100% by mass of inorganic filler) that had been surface-treated with an amino silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM573," N-phenyl-3-aminopropyltrimethoxysilane), and 1 part of an MEK solution containing 5% solids of a curing accelerator (4-dimethylaminopyridine).

[0264] (3. Manufacturing of laminated resin sheets) The following operations were carried out while transporting the support and the protective film to produce a laminated resin sheet.

[0265] (3-1. Adhesion of copper powder as foreign matter to the support) Copper powder of 100 μm mesh was intentionally attached to both sides of the support as foreign matter.

[0266] (3-2. Dust removal from the support) A roll laminator ("VA770" manufactured by Taisei Laminator Co., Ltd.) equipped with a pair of rotatably opposing nip rollers was prepared. An adhesive tape 1 ("Karitome No. 207" manufactured by Nichiban Co., Ltd., adhesive strength 2.3 N / 100 mm) was applied to the pair of nip rollers. 2 The support was fed into the roll laminator and passed between the pair of dust removal rollers, whereby the dust removal rollers were brought into contact with both sides of the support, thereby removing dust.

[0267] (3-3. Formation of Resin Composition Layer) The resin varnish was uniformly applied onto the release layer of the support using a die coater so that the thickness of the resin composition layer obtained after drying would be 18 μm, and then dried in an oven to obtain a resin sheet. The resin sheet had a layer structure of substrate layer / release layer / resin composition layer.

[0268] (3-4. Adhesion of copper powder as foreign matter to protective film) A polypropylene film (Oji F-Tex Co., Ltd., biaxially oriented polypropylene film, product name "MA411," thickness 15 μm) with a roughened surface (arithmetic mean roughness 250 nm) and a smooth surface was prepared as a protective film. Copper powder with a 100 μm mesh was intentionally attached to both sides of this protective film as foreign matter.

[0269] (3-5. Dust removal from protective film) A roll laminator ("VA770" manufactured by Taisei Laminator Co., Ltd.) equipped with a pair of rotatably opposing nip rollers was prepared. An adhesive tape 1 ("Karitome No. 207" manufactured by Nichiban Co., Ltd., adhesive strength 2.3 N / 100 mm) was applied to the pair of nip rollers. 2 The protective film was fed into the roll laminator and passed between the pair of dust removal rollers, whereby the dust removal rollers were brought into contact with both sides of the protective film to remove dust.

[0270] (3-6. Lamination) The resin sheet and the protective film were fed to a roll laminator ("VA770" manufactured by Taisei Laminator Co., Ltd.) and laminated by the roll laminator. The lamination was carried out by pressing at a temperature of 70°C and a pressure of 0.3 MPa. A laminated resin sheet having a layer structure of substrate layer / release layer / resin composition layer / protective film was obtained by lamination.

[0271] (4. Manufacturing of evaluation circuit boards) (4-1. Lamination of resin sheet and inner layer substrate) A copper-clad laminate (Panasonic Electric Works, R1515A, copper layer thickness 18 μm, substrate thickness 0.8 mm) was prepared as the inner layer substrate. The protective film was peeled off from the laminated resin sheet to obtain a resin sheet with a layer structure of base layer / release layer / resin composition layer. The resin sheet was then laminated onto both sides of the inner layer substrate using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator CVP700) so that the resin composition layer was bonded to the inner layer substrate. Lamination was performed by reducing the pressure to 5 hPa or less for 30 seconds, and then pressing the substrate at 100°C and a pressure of 0.7 MPa for 30 seconds. The substrate was then heat-pressed at 100°C and a pressure of 0.55 MPa for 60 seconds to smooth the surface.

[0272] (4-2. Curing of Resin Composition Layer) The inner layer substrate laminated with the resin sheet was placed in an oven at 180° C. and heated for 30 minutes. The resin composition layer was thermally cured by heating, and an insulating layer was formed.

[0273] (4-3. Wiring formation) Next, wiring as a conductor layer was formed by a semi-additive process (SAP) that utilizes the exposed surface profile of the insulating layer according to the following procedure.

[0274] (1) Removal of the support: The support was peeled off to leave the insulating layer as the outermost layer.

[0275] (2) Electroless plating process: The surface of the insulating layer exposed by peeling off the support was subjected to an electroless plating process (a copper plating process using a chemical solution manufactured by Atotech Japan) including the following steps 1 to 6, to form an electroless copper plating layer.

[0276] 1. Alkaline cleaning (cleaning the surface of the insulating layer and adjusting the charge): The surface of the insulating layer was cleaned using Cleaning Cleaner Securiganth 902 (trade name) at 60° C. for 5 minutes.

[0277] 2. Soft etching (cleaning the surface of the insulating layer): The surface of the insulating layer was treated with an aqueous solution of sodium peroxodisulfate acidified with sulfuric acid at 30° C. for 1 minute.

[0278] 3. Pre-dip (adjusting the surface charge of the insulating layer for Pd deposition): The surface of the insulating layer was treated with Pre. Dip Neoganth B (trade name) at room temperature for 1 minute.

[0279] 4. Adding activator (adding Pd to the surface of the insulating layer): The surface of the insulating layer was treated with Activator Neoganth 834 (trade name) at 35° C. for 5 minutes.

[0280] 5. Reduction (reducing Pd attached to the insulating layer): The surface of the insulating layer was treated with a mixed solution of Reducer Neoganth WA (trade name) and Reducer Acceralator 810 mod. (trade name) at 30° C. for 5 minutes.

[0281] 6. Electroless copper plating process (Cu is deposited on the surface of the insulating layer (Pd surface)): The surface of the insulating layer was treated with a mixture of Basic Solution Printganth MSK-DK (trade name), Copper solution Printganth MSK (trade name), Stabilizer Printganth MSK-DK (trade name), and Reducer Cu (trade name) at 35°C for 20 minutes to form an electroless copper plating layer. The thickness of the formed electroless copper plating layer was 0.8 μm.

[0282] (3) Plating resist formation, exposure and development: After the electroless plating layer was formed, plating resist (Showa Denko's pattern-forming dry film "RY5115," 15 μm thick) was laminated on both sides of the electroless plating layer. Next, a 15 cm square glass mask (exposure mask) with a wiring pattern (details are given below) was placed on the plating resist, and the resist was exposed (exposure dose 210 mJ) using a stepper (Ushio Inc.'s projection exposure system "UX-2240"). After aging for 30 minutes at room temperature, the plating resist was developed (pattern formation) by spraying a 1 wt % sodium carbonate aqueous solution at 30°C for 30 seconds using a spray-type developer.

[0283] Glass mask wiring pattern: A glass mask having 25 comb-tooth patterns (wiring width 25 μm, spacing 25 μm, wiring length 10 mm, 16 lines) in which wiring from the anode and wiring from the cathode faced each other was used.

[0284] (4) Electroplating process: Next, electrolytic copper plating was carried out using a chemical solution manufactured by Atotech Japan, to form an electrolytic copper plating layer having a thickness of 8 μm to 10 μm. This electrolytic copper plating yielded a multilayer substrate comprising an electroless copper plating layer and an electrolytic copper plating layer on an insulating layer.

[0285] (5) Stripping of plating resist: The resulting multilayer substrate was immersed in a resist stripper for printed circuit boards, "R100S," manufactured by Mitsubishi Gas Chemical Co., Inc., at 50°C for 120 seconds while using ultrasonic waves, to strip the plating resist.

[0286] (6) Flash Etching: The multilayer substrate was then immersed in a copper seed layer etchant for semi-additive processes, "Melstrip SE-300," at 25°C to remove unnecessary portions of the electroless copper plating layer, yielding a circuit board for evaluation with comb-tooth wiring. The comb-tooth wiring was formed by a conductor layer including an electroless copper plating layer and an electrolytic copper plating layer, and had the same pattern shape as the comb-tooth pattern of the glass mask when viewed in the thickness direction.

[0287] <Example 2> When removing dust from the protective film in step (3-5), adhesive tape 2 (Nichiban Co., Ltd. "Sealing Masking Tape No. 2563", adhesive strength 2.7 N / 100 mm) was used instead of adhesive tape 1. 2 A laminated resin sheet and an evaluation circuit board were produced in the same manner as in Example 1, except that ) was used.

[0288] Example 3 When removing dust from the support in step (3-2), adhesive tape 2 (Nichiban Co., Ltd. "Sealing Masking Tape No. 2563", adhesive strength 2.7 N / 100 mm) was used instead of adhesive tape 1. 2 A laminated resin sheet and an evaluation circuit board were produced in the same manner as in Example 1, except that ) was used.

[0289] Example 4 When removing dust from the support in step (3-2) and the protective film in step (3-5), adhesive tape 2 (Nichiban Co., Ltd. "Sealing Masking Tape No. 2563", adhesive strength 2.7 N / 100 mm) was used instead of adhesive tape 1. 2 A laminated resin sheet and an evaluation circuit board were produced in the same manner as in Example 1, except that ) was used.

[0290] <Example 5> When removing dust from the support in step (3-2) and the protective film in step (3-5), a dust removal roller 4 ("HC-730" manufactured by Audio Technica, adhesive strength 0.6 N / 100 mm) was used instead of the dust removal roller obtained by fixing the adhesive tape 1 to a nip roller. 2 A laminated resin sheet and an evaluation circuit board were produced in the same manner as in Example 1, except that ) was used.

[0291] Example 6 In the dust removal of the support in step (3-2), a dust removal roller 4 ("HC-730" manufactured by Audio Technica, adhesive strength 0.6 N / 100 mm) was used instead of the dust removal roller obtained by fixing the adhesive tape 1 to the nip roller. 2 ) was used, and when removing dust from the protective film in step (3-5), adhesive tape 2 (Nichiban Co., Ltd. "Sealing Masking Tape No. 2563", adhesive strength 2.7 N / 100 mm) was used instead of adhesive tape 1. 2 A laminated resin sheet and an evaluation circuit board were produced in the same manner as in Example 1, except that ) was used.

[0292] <Comparative Example 1> When removing dust from the support in step (3-2), a dust removal roller 3 ("Clean Dash E" manufactured by Technoroll Co., Ltd., adhesive strength 3.0 N / 100 mm) was used instead of the dust removal roller obtained by fixing the adhesive tape 1 to the nip roller. 2 A laminated resin sheet and an evaluation circuit board were produced in the same manner as in Example 1, except that ) was used.

[0293] <Comparative Example 2> When removing dust from the protective film in step (3-5), a dust removal roller 3 ("Clean Dash E" manufactured by Technoroll Co., Ltd., adhesive strength 3.0 N / 100 mm) was used instead of the dust removal roller obtained by fixing the adhesive tape 1 to the nip roller. 2 A laminated resin sheet and an evaluation circuit board were produced in the same manner as in Example 1, except that ) was used.

[0294] <Comparative Example 3> A laminated resin sheet and an evaluation circuit board were manufactured in the same manner as in Example 1, except that dust removal from the support in step (3-2) and dust removal from the protective film in step (3-5) were carried out by treating for 10 seconds using an air-blowing static eliminator ("BF-6MB" manufactured by Shishido Electrostatic Corporation). The treatment using the air-blowing static eliminator is a non-contact static elimination process that removes foreign matter by wind force while eliminating static electricity using an ionizer.

[0295] <Comparative Example 4> A laminated resin sheet and an evaluation circuit board were manufactured in the same manner as in Example 1, except that dust removal from the support in step (3-2) and dust removal from the protective film in step (3-5) were carried out by treating for 10 seconds using a non-contact ultrasonic cleaner ("USW-102" manufactured by Hugle). The treatment using the non-contact ultrasonic cleaner is a non-contact static elimination treatment that removes foreign matter using ultrasonic waves.

[0296] <Comparative Example 5> A laminated resin sheet and an evaluation circuit board were produced in the same manner as in Example 1, except that dust removal from the support in step (3-2) and dust removal from the protective film in step (3-5) were carried out by treatment using an air gun. The treatment using an air gun is a non-contact static elimination treatment that removes foreign matter by air sprayed from an air gun.

[0297] <Test 1. Evaluation of peelability of support> In the step (4-3) of peeling the support, the case where the support could be peeled off smoothly from the insulating layer was evaluated as "Good", and the case where a part or all of the support was stuck to the insulating layer and the support could not be peeled off smoothly was evaluated as "Poor". The fact that the support could not be peeled off smoothly indicates that a part or all of the release layer was lost due to adhesion to the dust removal roller during the dust removal step of the support, resulting in a decrease in the releasability of the support.

[0298] <Test 2. Evaluation of transportability during dust removal of support and protective film> In step (3-2), when the support was transported while being in contact with the dust removal roller, it was observed whether wrinkles occurred on the support. In step (3-5), when the protective film was transported while being in contact with the dust removal roller, it was observed whether wrinkles occurred on the protective film. When no wrinkles occurred, it was evaluated as "Good", and when wrinkles occurred, it was evaluated as "Poor".

[0299] <Test 3. Evaluation of wiring formation yield> The insulation resistance of the comb-tooth wiring on the evaluation circuit board was measured using a resistance measuring instrument (J-RAS "ECM-100"). The insulation resistance was 1 x 10 7 The ratio of comb-tooth wiring with a resistance of Ω or more is 60% or more (i.e., 1×10 7 When the number of comb-tooth wirings with a resistance of 100 Ω or more was 15 or more, it was evaluated as "Good", and when it was less than 60%, it was evaluated as "Poor".

[0300] <Result> The results of the above-mentioned Examples and Comparative Examples are shown in the table below.

[0301] [Table 1]

[0302] [Table 2]

[0303] <Consideration> From the examples and comparative examples, it was confirmed that the manufacturing method of the present invention was able to produce a laminated resin sheet (resin sheet with protective film) that can eliminate foreign matter and improve the yield of wiring formation.

[0304] Although the above-described examples and comparative examples show the results of using an acrylic release agent, the present inventors have confirmed that even when a release agent other than an acrylic release agent is used, it is possible to produce a laminated resin sheet that is capable of eliminating foreign matter and improving the yield of wiring formation, although to different degrees. [Explanation of symbols]

[0305] 1 Manufacturing equipment 2 Manufacturing equipment 10 Support 10U Release surface (side of release layer) 10D Back side (opposite side from release layer) 11 Base material layer 12 Release layer 20 Resin composition layer 21 Curable resin composition 30 Resin sheet 40 Protective Film 40D front page 40U second side 50 Laminated resin sheet (resin sheet with protective film) 100 Support dust removal section 110 First dust removal roller 110S circumferential surface 120 Third dust removal roller 120S circumferential surface 200 layer forming section 210 Coating equipment 220 Drying equipment 300 Protective film dust removal unit 310 Second dust removal roller 310S circumferential surface 320 Fourth Dust Removal Roller 320S circumferential surface 400 Laminating Department 410 Pressure roller 420 Pressure Roller 430 Chamber 500 Support dust removal section 510 First dust removal roller 510S circumferential surface 520 Third dust removal roller 520S circumferential surface 600 Protective film dust removal part 610 Second dust removal roller 610S circumferential surface 620 Fourth Dust Removal Roller 620S circumferential surface

Claims

1. A method for producing a resin sheet with a protective film, comprising, in this order: a support; a resin composition layer containing a curable resin composition; and a protective film; The support includes a base layer and a release layer formed on the base layer; The manufacturing method comprises: a step (I) of contacting a first dust removal roller with the release layer side of the support; Step (II) of forming a resin composition layer on the release layer side of the support; (III) contacting a second dust removal roller with the first surface of the protective film; and step (IV) of bonding the resin composition layer to the first surface of the protective film; The first dust removal roller is 2.9N / 100mm ２ and has an adhesive strength of less than The second dust removal roller is 2.9N / 100mm ２ A method for producing a resin sheet with a protective film having an adhesive strength of less than 1000 kJ / cm.

2. The method for producing a resin sheet with a protective film according to claim 1, wherein step (II) of forming a resin composition layer on the release layer side of the support comprises applying a liquid curable resin composition.

3. The method for producing a resin sheet with a protective film according to claim 1 , further comprising the step (V) of bringing a third dust removal roller into contact with the surface of the support opposite to the release layer.

4. The method for producing a resin sheet with a protective film according to claim 1, further comprising a step (VI) of contacting a second surface of the protective film opposite the first surface with a fourth dust removal roller.

5. The method for producing a resin sheet with a protective film according to claim 1 , wherein the curable resin composition comprises a curable resin and an inorganic filler.

6. A method for manufacturing a resin sheet with a protective film as described in claim 1, wherein the base layer and the protective film are thermoplastic resin films.

7. Step (I) includes removing foreign matter adhering to the first dust removal roller; The method for producing a resin sheet with a protective film according to claim 1 , wherein step (III) comprises removing foreign matter adhering to the second dust removal roller.

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