Manufacturing method of wiring boards

Abstract

The present invention provides a method for producing a wiring board, the method eliminating the need for formation and removal of a mask when a via hole or a trench is formed, enabling an insulating material layer to have excellent insulation performance and electrical characteristics, and also enabling fine wiring. The present invention specifically provides a method for producing a wiring board, the method comprising: (1) a step in which a substrate having a conductor circuit and an insulating material layer that is formed on the conductor circuit and is formed of a cured product of a thermosetting material is prepared, and a photosensitive material layer is formed on the surface of the insulating material layer by performing either or both of coating or bonding of a photosensitive material onto the surface of the insulating material layer; (2) a step in which the photosensitive material layer is exposed to light and developed so as to form a plasma mask having an opening; (3) a step in which the insulating material layer is irradiated with plasma through the plasma mask so as to form either or both of a via hole and a trench in the insulating material layer positioned at the opening of the plasma mask, while thinning the plasma mask; and (4) a step in which a conductor layer is formed on the thinned plasma mask as well as on the surface of either or both of the via hole and the trench.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a wiring board and a semiconductor device. [Background technology]

[0002] In recent years, printed circuit boards, semiconductor package substrates, wafer-level package substrates, and other types of wiring boards have required thinner designs and finer circuit wiring to enable miniaturization and higher functionality of electronic devices. As a method for manufacturing wiring boards, for example, the method described in Patent Document 1 has been proposed. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-39763 [Overview of the project] [Problems that the invention aims to solve]

[0004] Incidentally, in the manufacturing method of a printed circuit board, via holes or trenches may be formed on the insulating layer (sometimes called the "insulating material layer"). Methods for forming via holes or trenches on the insulating layer include patterning by exposure and development if the insulating layer is made of a photosensitive resin, and formation by laser irradiation, plasma treatment via a mask, or laser irradiation if the insulating layer is made of a thermosetting resin. Here, "via hole" usually refers to a hole that penetrates the insulating layer, while "trench" usually refers to a groove that does not penetrate the insulating layer.

[0005] When the insulating layer is a cured product of a photosensitive material containing a photosensitive resin, photolithography can be used, making it easy to align the mask pattern and advantageous for forming small-diameter via holes or trenches. However, it has been difficult to improve the insulating performance and electrical properties while maintaining the resolution of the photosensitive material.

[0006] On the other hand, when the insulating layer is a cured product of a thermosetting material with a high concentration of inorganic filler, the insulating performance and electrical properties of the insulating layer can be improved, but the surface irregularities caused by the inorganic filler make it difficult to form fine wiring.

[0007] As a means to solve this problem, insulating materials have been proposed that have a smooth primer layer on the surface that contains no inorganic filler or only a very small amount of it. However, when opening small diameter vias, it is difficult to accurately align the laser irradiation to the land, resulting in a problem where the occupied area of ​​the via hole or trench becomes large.

[0008] On the other hand, it is also possible to form via holes and trenches in the cured product of thermosetting materials, including thermosetting resins, using a release-type photoresist as a plasma mask. However, this requires the removal and peeling of the mask pattern, resulting in a large number of steps and a complicated operation. Furthermore, there was the issue of chemical damage to the thermosetting material as it is exposed to the release chemical during peeling.

[0009] The object of the present invention is to provide a method for manufacturing a wiring board that allows for fine wiring and does not require the removal of a mask pattern when forming via holes or trenches, and in which the insulating material layer has excellent insulating performance and electrical properties; and a semiconductor device. [Means for solving the problem]

[0010] As a result of diligent research to solve the aforementioned problems, the inventors of the present invention have found that by leaving a mask containing a photosensitive material used when forming via holes or trenches in a thermosetting material as a primer layer (permanent film), it is possible to achieve excellent insulation performance and electrical properties while enabling fine wiring, thus completing the present invention.

[0011] In other words, the present invention includes the following: [1] (1) A step of preparing a substrate comprising a conductor circuit and an insulating material layer formed of a cured product of a thermosetting material on the conductor circuit, and forming a photosensitive material layer on the surface of the insulating material layer by either coating and / or attaching a photosensitive material, (2) Exposing and developing the photosensitive material layer to form a plasma mask having openings. (3) Performing plasma irradiation on the insulating material layer through the plasma mask to form either or both of a via hole and a trench in the insulating material layer located at the openings of the plasma mask, and a step of reducing the film thickness of the plasma mask, and (4) A step of forming a conductor layer on the surface of the plasma mask with reduced film thickness and either or both of the via hole and the trench, a method for manufacturing a wiring board. [2] The step (4) is (4-1) A step of forming a plating seed layer on the surface of the plasma mask with reduced film thickness and either or both of the via hole and the trench, and (4-2) A step of performing plating on the plating seed layer to form a conductor layer, the method for manufacturing a wiring board according to [1]. [3] The conductor layer includes either or both of a conductor wiring formed at a position other than the openings of the plasma mask and a conductor via layer formed at the openings of the plasma mask, the method for manufacturing a wiring board according to [1] or [2]. [4] The method for manufacturing a wiring board according to [2], wherein the plating seed layer is formed by a dry plating method. [5] The method for manufacturing a wiring board according to any one of [1] to [4], wherein the opening diameter of the via hole or the trench is 20 μm or less. [6] The method for manufacturing a wiring board according to any one of [1] to [5], wherein the thickness of the plasma mask with reduced film thickness after the completion of step (3) is 0.1 μm or more and 20 μm or less. [7] The method for manufacturing a wiring board according to any one of [1] to [6], wherein the wiring pitch of the conductor circuit is 0.2 μm or more and 10 μm or less. [8] The method for manufacturing a wiring board according to any one of [1] to [7], wherein the arithmetic mean roughness (Ra) of the surface of the plasma mask with reduced film thickness after the completion of step (3) is 100 nm or less. [9] The method for manufacturing a wiring board according to any one of [1] to [8], wherein the roughness (Sa) of the wall surface of the via hole or the trench is 400 nm or less.

[10] The method for manufacturing a wiring board according to any one of [1] to [9], wherein the ratio (Ra / Sa) of the arithmetic mean roughness (Ra) of the surface of the plasma mask after film reduction after the completion of step (3) and the roughness (Sa) of the wall surface of the via hole or trench is 3 or less.

[11] The method for manufacturing a wiring board according to any one of [1] to

[10] , wherein the thickness of the photosensitive material layer is 1 μm or more and 100 μm or less.

[12] The method for manufacturing a wiring board according to any one of [1] to

[11] , wherein the thickness of the plasma mask after film reduction after the completion of step (3) is 0.7 or less when the thickness of the plasma mask before plasma irradiation is taken as 1.

[13] The method for manufacturing a wiring board according to any one of [1] to

[12] , wherein the absolute value of the difference between the linear thermal expansion coefficient of the cured product of the photosensitive material and the linear thermal expansion coefficient of the cured product of the insulating material in the range from 25 °C to 150 °C is 60 ppm / °C or less.

[14] The method for manufacturing a wiring board according to any one of [1] to

[13] , wherein when the thickness of the plasma mask after film reduction after the completion of step (2) is T1 and the thickness of the insulating material layer after the completion of step (2) is T2, the relationship T1 > T2 is satisfied.

[15] The method for manufacturing a wiring board according to any one of [1] to

[14] , wherein when the thickness of the plasma mask after film reduction after the completion of step (3) is T3 and the thickness of the insulating material layer after the completion of step (3) is T4, the relationship T3 < T4 is satisfied.

[16] The method for manufacturing a wiring board according to any one of [1] to

[15] , wherein the absolute value of the difference between the glass transition temperature of the photosensitive material contained in the plasma mask and the glass transition temperature of the thermosetting material is 100 °C or less.

[17] The method for manufacturing a wiring board according to any one of [1] to

[16] , wherein the via taper angle of the via hole or trench is 65 degrees or more and 90 degrees or less.

[18] The method for manufacturing a wiring board according to any one of [1] to

[17] , wherein the via expansion ratio is 105% or more and 150% or less.

[19] The method for manufacturing a wiring board according to any one of [1] to

[18] , wherein the relative dielectric constants of the cured products of the photosensitive material and the thermosetting material are both 3.5 or less.

[20] A method for manufacturing a wiring board according to any one of [1] to

[19] , wherein the elongation at break of the cured product of the photosensitive material is 10% or more, and the elongation at break of the cured product of the photosensitive material is greater than the elongation at break of the cured product of the thermosetting material.

[21] A method for manufacturing a wiring board according to any one of [1] to

[20] , wherein the etching rate in step (3) is 100 nm / min or more.

[22] A method for manufacturing a wiring board according to any one of [1] to

[21] , wherein the line (width of the conductor layer) / space (width between conductor layers) (L / S) of the conductor layer is 5 μm / 5 μm or less.

[23] A method for manufacturing a wiring board according to any one of [1] to

[22] , wherein the wiring board substrate is a multilayer wiring board substrate containing three or more conductive layers.

[24] The area of ​​the wiring board is 2500 mm² 2 The above is a method for manufacturing a wiring board as described in any of [1] to

[23] .

[25] A method for manufacturing a wiring board according to any one of [1] to

[24] , wherein the photosensitive material used in step (1) contains at least one selected from a resin that can be developed with a developer and an epoxy resin.

[26] The method for producing a wiring board according to

[25] , wherein the resin that can be developed with a developer solution contains one or more selected from an alkali-soluble resin having a phenolic hydroxyl group in its molecule, a polyimide precursor, a polybenzoxazole precursor resin, and an acrylic resin.

[27] A method for manufacturing a wiring board according to any one of [1] to

[26] , wherein the photosensitive material used in step (1) contains an inorganic filler, and the amount of the inorganic filler in the photosensitive material is 10% by mass or less with respect to 100% by mass of the nonvolatile components of the photosensitive material.

[28] A method for manufacturing a wiring board according to any one of [1] to

[27] , wherein the thermosetting material contains an inorganic filler, and the amount of the inorganic filler in the thermosetting material is 20% by mass or more with respect to 100% by mass of the nonvolatile components of the thermosetting material.

[29] The method for manufacturing a wiring board according to

[28] , wherein the content of the inorganic filler is 35% by mass or more and 90% by mass or less, based on 100% by mass of the nonvolatile components of the thermosetting material.

[30] A method for manufacturing a wiring board according to any one of [1] to

[29] , wherein the photosensitive material used in step (1) contains an inorganic filler, the average particle size of the inorganic filler in the photosensitive material is 0.2 μm or less, and the thermosetting material contains an inorganic filler, the average particle size of the inorganic filler is 0.01 μm or more.

[31] A method for manufacturing a wiring board according to any one of [1] to

[30] , wherein the coefficient of linear thermal expansion of the bulk material, consisting of the reduced plasma mask after step (3) and the insulating material layer, in the range of 25°C to 150°C is 100 ppm / °C or less.

[32] A method for manufacturing a wiring board according to any one of [1] to

[31] , wherein the photosensitive material used in step (1) is a solvent-developable negative-type photosensitive polyimide resin.

[33] A method for manufacturing a wiring board according to any one of [1] to

[32] , wherein step (1) includes at least one of applying a liquid photosensitive material and attaching a photosensitive material layer of a photosensitive resin sheet, which includes a support and a photosensitive material layer formed of a photosensitive material provided on the support.

[34] A method for manufacturing a wiring board according to any one of [1] to

[33] , wherein the total thickness of the insulating material layer and the reduced-thickness plasma mask is 15 μm or less.

[35] A method for manufacturing a wiring board according to any one of [1] to

[34] , comprising the steps of attaching a thermosetting material layer of a thermosetting resin sheet, which includes a support and a thermosetting material layer formed of a thermosetting material provided on the support, to a conductor circuit, and curing the thermosetting material layer to form an insulating material layer.

[36] (A) A step of preparing a substrate comprising a conductor circuit and an insulating material layer formed of a cured product of a thermosetting material on the conductor circuit, and forming a first photosensitive material layer by applying and / or attaching a first photosensitive material to the surface of the insulating material layer, (B) A step of exposing and developing a first photosensitive material layer to form a first plasma mask having an opening. (C) A step of irradiating an insulating material layer with plasma through a first plasma mask, forming either via holes and / or trenches in the insulating material layer located at the openings of the plasma mask, and reducing the thickness of the plasma mask. (D) A step of forming a second photosensitive material layer by either applying or attaching a second photosensitive material to cover the surface and openings of the first plasma mask, (E) A step of exposing and developing a second photosensitive material layer to form a second plasma mask having an opening. (F) A step of irradiating the first plasma mask and the insulating material layer with plasma via the second plasma mask to form via holes and trenches, or both, in the insulating material layer. (G) A step of forming a conductive layer on the surface of the first plasma mask and on either or both of the via holes and trenches, and (H) A method for manufacturing a wiring board, comprising the step of scraping the surface of a conductor layer.

[37] A wiring board manufactured by the wiring board manufacturing method described in any of [1] to

[36] .

[38] The wiring board according to

[37] , comprising a conductor circuit, an insulating material layer, a plasma mask, and a conductor layer in that order, and having via holes.

[39] The wiring board according to

[38] , comprising two or more conductor circuits, insulating material layers, plasma masks, conductor layers, and via holes.

[40] A semiconductor device containing a wiring board manufactured by the wiring board manufacturing method described in any of [1] to

[36] .

[41] The semiconductor device according to

[40] , having a fan-out structure.

[42] The semiconductor device according to

[40] , having a chiplet structure.

[43] A semiconductor device having a semiconductor chip on a wiring board manufactured by any of the manufacturing methods described in [1] to

[36] .

[44] The semiconductor device according to any one of

[40] to

[43] , wherein the semiconductor chip is a mixed system of at least a logic die and a memory die. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a method for manufacturing a wiring board that allows for fine wiring, in which there is no need to remove a mask pattern when forming via holes or trenches, and in which the insulating material layer has excellent insulating performance and electrical properties; and a semiconductor device. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of a substrate in which an insulating material layer is formed on an inner layer circuit board. [Figure 2] Figure 2 is a schematic cross-sectional view showing an example of a photosensitive material layer being formed on a substrate in which an insulating material layer is formed on an inner layer circuit board. [Figure 3] Figure 3 is a schematic cross-sectional view showing an example of how a plasma mask is formed in the first embodiment. [Figure 4] Figure 4 is a schematic cross-sectional view showing an example of how trenches and via holes are formed in the insulating material layer and the plasma mask is etched in the first embodiment. [Figure 5] Figure 5 is a schematic cross-sectional view showing an example of the state after trenches and via holes have been formed in the insulating material layer in the first embodiment. [Figure 6] Figure 6 is a schematic cross-sectional view showing an example of how a plating seed layer is formed on the surface of the reduced-thickness plasma mask and insulating material layer in the first embodiment. [Figure 7] Figure 7 is a schematic cross-sectional view showing an example of how a patterned conductor layer is formed on a plated seed layer by plating in the first embodiment. [Figure 8] Figure 8 is a schematic cross-sectional view showing an example of how a patterned conductor layer is formed in the first embodiment. [Figure 9] Figure 9 is a schematic cross-sectional view showing another example of how a plasma mask is formed in the first embodiment. [Figure 10] Figure 10 is a schematic cross-sectional view showing another example of how trenches and via holes are formed in the insulating material layer and the plasma mask is etched in the first embodiment. [Figure 11] Figure 11 is a schematic cross-sectional view showing another example of the state after trenches and via holes have been formed in the insulating material layer in the first embodiment. [Figure 12] Figure 12 is a schematic cross-sectional view showing an example of how a plating seed layer is formed on the surface of the reduced-thickness plasma mask and insulating material layer in the first embodiment. [Figure 13] Figure 13 is a schematic cross-sectional view showing another example of how a patterned conductor layer is formed on a plated seed layer by plating in the first embodiment. [Figure 14] Figure 14 is a schematic cross-sectional view showing another example of how a patterned conductor layer is formed in the first embodiment. [Figure 15] Figure 15 is a schematic cross-sectional view showing an example of how the first plasma mask is formed in the second embodiment. [Figure 16] Figure 16 is a schematic cross-sectional view showing an example of how trenches are formed in the insulating material layer and the first plasma mask is etched in the second embodiment. [Figure 17] Figure 17 is a schematic cross-sectional view showing an example of how a second photosensitive material layer is formed to cover the surface and openings of the first plasma mask in a second embodiment. [Figure 18] Figure 18 is a schematic cross-sectional view showing an example of how a second plasma mask is formed in the second embodiment. [Figure 19] Figure 19 is a schematic cross-sectional view showing an example of the state after trenches have been formed in the insulating material layer in the second embodiment. [Figure 20] Figure 20 is a schematic cross-sectional view showing an example of how a conductive layer is formed in the second embodiment. [Figure 21] Figure 21 is a schematic cross-sectional view showing an example of the state after polishing the surface of the conductive layer in the second embodiment. [Modes for carrying out the invention]

[0014] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples listed below, and can be implemented with modifications as appropriate without departing from the scope of the claims and equivalents of the present invention.

[0015] Before describing in detail the method for manufacturing a wiring board of the present invention, we will first describe the thermosetting material, photosensitive material, thermosetting resin sheet, photosensitive resin sheet, and prepreg used in the method for manufacturing a wiring board of the present invention.

[0016] [Thermosetting material] Thermosetting materials are typically used to form insulating material layers by thermosetting, provided that the cured product has sufficient hardness and insulating properties. Examples of such thermosetting materials include compositions containing thermosetting resins. In addition to thermosetting resins, thermosetting materials may optionally further contain inorganic fillers, curing accelerators, thermoplastic resins, and other additives.

[0017] The thermosetting material contains a thermosetting resin. As the thermosetting resin, conventionally known thermosetting resins used in forming the insulating material layer of printed circuit boards can be used.

[0018] Examples of thermosetting resins include epoxy resins, polyarylene ether resins, radical polymerizable resins, phenolic resins, naphthol resins, benzoxazine resins, activated ester resins, cyanate ester resins, carbodiimide resins, amine resins, and acid anhydride resins. Thermosetting resins may be used individually or in combination of two or more types in any ratio. Hereinafter, resins that react with epoxy resins to cure thermosetting materials, such as phenolic resins, naphthol resins, benzoxazine resins, activated ester resins, cyanate ester resins, carbodiimide resins, amine resins, and acid anhydride resins, are collectively referred to as "curing agents." From the viewpoint of forming an insulating material layer, the thermosetting material preferably contains both an epoxy resin and a curing agent, and more preferably contains one of the epoxy resin, activated ester resin, phenolic resin, or cyanate ester resin. The epoxy resin and curing agent may be used individually or in combination of two or more types.

[0019] Examples of epoxy resins used as thermosetting 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, 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, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, and tetraphenylethane-type epoxy resins.

[0020] The thermosetting material preferably includes an epoxy resin having two or more epoxy groups per molecule as the thermosetting resin. From the viewpoint of significantly obtaining the desired effects of the present invention, the ratio of epoxy resin having two or more epoxy groups per molecule to 100% by mass of the nonvolatile component of the epoxy resin is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

[0021] Epoxy resins include epoxy resins that are liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter sometimes referred to as "solid epoxy resins"). A thermosetting material may contain only liquid epoxy resin or only solid epoxy resin, but from the viewpoint of significantly obtaining the effects of the present invention, it is preferable to contain a combination of liquid epoxy resin and solid epoxy resin.

[0022] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

[0023] Preferred liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, glycidylamine type epoxy resin, and epoxy resin having a butadiene structure, with bisphenol A type epoxy resin and bisphenol F type epoxy resin being more preferred.

[0024] Specific examples of liquid epoxy resins include DIC's "HP4032," "HP4032D," and "HP4032SS" (naphthalene-type epoxy resin); Mitsubishi Chemical's "828US," "jER828EL," "825," and "Epicote 828EL" (bisphenol A-type epoxy resin); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F-type epoxy resin); Mitsubishi Chemical's "jER152" (phenol novolac-type epoxy resin); and Mitsubishi Chemical's "630" and "630LSD" (glycidylamine-type epoxy resin). Examples include: "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Co., Ltd.; "Celoxide 2021P" (alicyclic epoxy resin with an ester skeleton) manufactured by Daicel Corporation; "PB-3600" (epoxy resin with a butadiene structure) manufactured by Daicel Corporation; and "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd. These may be used individually or in combination of two or more types.

[0025] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups per molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups per molecule is more preferred.

[0026] Preferred solid epoxy resins include bixylenol-type epoxy resin, naphthalene-type epoxy resin, naphthalene-type tetrafunctional epoxy resin, cresol novolac-type epoxy resin, dicyclopentadiene-type epoxy resin, trisphenol-type epoxy resin, naphthol-type epoxy resin, biphenyl-type epoxy resin, naphthylene ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, bisphenol AF-type epoxy resin, and tetraphenylethane-type epoxy resin, with naphthalene-type epoxy resin being more preferred.

[0027] Preferred solid epoxy resins include naphthalene-type tetrafunctional 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, and tetraphenylethane-type epoxy resins, with naphthalene-type tetrafunctional epoxy resins, naphthol-type epoxy resins, and biphenyl-type epoxy resins being more preferred. Specific examples of solid epoxy resins include DIC's "HP4032H" (naphthalene-type epoxy resin), "HP-4700", "HP-4710" (naphthalene-type tetrafunctional epoxy resin), "N-690" (cresol novolac-type epoxy resin), "N-695" (cresol novolac-type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (dicyclopentadiene-type epoxy resin), "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether-type epoxy resin); and Nippon Kayaku's "EPPN-502H" (trisphenol-type epoxy resin), "NC7000L" (naphthol novolac-type epoxy resin), "NC3000H", "NC30 Examples include "00", "NC3000L", and "NC3100" (biphenyl-type epoxy resins); "ESN475V" (naphthalene-type epoxy resin) and "ESN485" (naphthol novolac-type epoxy resin) from Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YL6121" (biphenyl-type epoxy resins), "YX4000HK" (bixylenol-type epoxy resin) and "YX8800" (anthracene-type epoxy resin) from Mitsubishi Chemical Corporation; "PG-100" and "CG-500" from Osaka Gas Chemical Co., Ltd.; and "YL7760" (bisphenol AF-type epoxy resin), "YL7800" (fluorene-type epoxy resin), "jER1010" (solid bisphenol A-type epoxy resin) and "jER1031S" (tetraphenylethane-type epoxy resin) from Mitsubishi Chemical Corporation. These can be used individually or in combination of two or more types.

[0028] When using a combination of liquid epoxy resin and solid epoxy resin as the thermosetting resin, their mass ratio (liquid epoxy resin:solid epoxy resin) is preferably 1:0.1 to 1:20, more preferably 1:0.3 to 1:18, and particularly preferably 1:0.5 to 1:15. By having the mass ratio of liquid epoxy resin to solid epoxy resin within this range, the desired effects of the present invention can be remarkably obtained. Furthermore, when typically used in the form of a thermosetting resin sheet, appropriate tackiness is provided. Also, when typically used in the form of a thermosetting resin sheet, sufficient flexibility is obtained, improving handling. Furthermore, a cured product with sufficient breaking strength can usually be obtained.

[0029] The epoxy equivalent of the epoxy resin used as a thermosetting resin is preferably 50 g / eq. to 5000 g / eq., more preferably 50 g / eq. to 3000 g / eq., even more preferably 80 g / eq. to 2000 g / eq., and even more preferably 110 g / eq. to 1000 g / eq. This range ensures that the cured product of the thermosetting material has sufficient crosslinking density. The epoxy equivalent is the mass of epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0030] The weight-average molecular weight (Mw) of the epoxy resin used as a thermosetting resin is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500, from the viewpoint of significantly obtaining the desired effects of the present invention. The weight-average molecular weight of the epoxy resin is the weight-average molecular weight on a polystyrene basis, measured by gel permeation chromatography (GPC).

[0031] From the viewpoint of obtaining a cured product exhibiting good mechanical strength and insulation reliability, the epoxy resin content as a thermosetting resin is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, when the non-volatile components in the thermosetting material are considered to be 100% by mass. From the viewpoint of significantly obtaining the desired effects of the present invention, the upper limit of the epoxy resin content is preferably 60% by mass or less, more preferably 55% by mass or less, and particularly preferably 50% by mass or less.

[0032] Unless otherwise specified, the content of each component in the thermosetting material is the value when the non-volatile components in the thermosetting material are set to 100% by mass, and non-volatile components refer to all non-volatile components in the thermosetting material excluding the solvent.

[0033] As for the epoxy resin content as a thermosetting resin, from the viewpoint of significantly obtaining the effects of the present invention, when the resin component in the thermosetting material is taken as 100% by mass, it is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. The resin component refers to the non-volatile components in the thermosetting material, excluding the inorganic filler.

[0034] Polyarylene ether resins, as thermosetting resins, are not particularly limited in type, as long as they have a polyarylene ether skeleton and exhibit crosslinking properties through the reaction of functional groups such as terminal hydroxyl groups. Examples of polyarylene ether resins include polyphenylene ether resins and polynaphthylene ether resins, which may be homopolymers or copolymers. Examples of polyphenylene ether resin homopolymers include 2,6-diC 1~3 Examples include those containing alkyl-1,4-phenylene ether units, and copolymers thereof include, for example, 2,6-diC 1~3 Alkyl-1,4-phenylene ether unit with 2,3,6-triC 1~3Examples include grafts, blocks, or random copolymers containing combinations of alkyl-1,4-phenylene ether units. Examples of polyarylene ether resins include "Noryl(registered trademark) SA90" manufactured by SABIC.

[0035] The number-average molecular weight (Mn) of the polyarylene ether resin is preferably 200 to 5,000, more preferably 400 to 3,000, and even more preferably 600 to 2,500. The Mn of the polyarylene ether resin can be measured as a polystyrene equivalent by the GPC method.

[0036] The type of radical polymerizable resin used as a thermosetting resin is not particularly limited, as long as it has one or more (preferably two or more) radical polymerizable unsaturated groups per molecule. Examples of radical polymerizable resins include resins having one or more radical polymerizable unsaturated groups selected from maleimide groups, vinyl groups, allyl groups, styryl groups, vinylphenyl groups, acryloyl groups, methacryloyl groups, fumaroyl groups, and maleoil groups. In particular, from the viewpoint of producing a cured product that exhibits both good insulation and good heat resistance, it is preferable that the radical polymerizable resin contains one or more selected from maleimide resins, (meth)acrylic resins, and styryl resins.

[0037] The type of maleimide resin is not particularly limited, as long as it has one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl groups) per molecule. Examples of maleimide resins include maleimide resins containing an aliphatic skeleton (preferably an aliphatic skeleton including a cyclic structure with 10 or more carbon atoms, more preferably an aliphatic skeleton with 36 carbon atoms derived from dimeramine), such as "BMI-3000J", "BMI-5000", "BMI-1400", "BMI-1500", "BMI-1700", and "BMI-689" (all from Designer Molecules Inc.); maleimide resins containing an indan skeleton, as described in the Japan Institute of Invention and Innovation, Technical Report No. 2020-500211; and maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000", "BMI-1000" (manufactured by Yamato Kasei Co., Ltd.), and "BMI-80" (manufactured by Kei-I Kasei Co., Ltd.).

[0038] The type of (meth)acrylic resin is not particularly limited as long as it has one or more (preferably two or more) (meth)acryloyl groups in one molecule, and may be a monomer or oligomer. Here, the term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups. Examples of methacrylic resins include (meth)acrylate monomers, as well as (meth)acrylic resins such as "A-DOG" (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), "DCP-A" (manufactured by Kyoeisha Chemical Co., Ltd.), "NPDGA", "FM-400", "R-687", "THE-330", "PET-30", and "DPHA" (all manufactured by Nippon Kayaku Co., Ltd.).

[0039] The styryl resin is not particularly limited in type, as long as it has one or more (preferably two or more) styryl groups or vinylphenyl groups in one molecule, and may be a monomer or oligomer. Examples of styryl resins include "OPE-2St", "OPE-2St 1200", and "OPE-2St 2200" (all manufactured by Mitsubishi Gas Chemical Co., Ltd.). In addition to styrene monomers, examples of styryl resins include homopolymers of aromatic divinyl compounds such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl)ether, or copolymers of these aromatic divinyl compounds with aromatic monovinyl compounds such as styrene, vinyltoluene, ethylstyrene, and vinylnaphthalene.

[0040] As the active ester resin used as the thermosetting resin, a resin having one or more active ester groups per molecule can be used. Among these, resins 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 preferred as the active ester resin. The active ester resin is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester resin obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferred.

[0041] 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.

[0042] Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, 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 novolac. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by the condensation of two phenol molecules with one dicyclopentadiene molecule.

[0043] Preferred examples of active ester resins include active ester resins containing a dicyclopentadiene-type diphenol structure, active ester resins containing a naphthalene structure, active ester resins containing an acetylated phenol novolac, and active ester resins containing a benzoylated phenol novolac. Among these, active ester resins containing a naphthalene structure and active ester resins containing a dicyclopentadiene-type diphenol structure are more preferred. The term "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0044] Commercially available active ester resins include: Active ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC-8000H-65TM", and "EXB-8000L-65TM" (manufactured by DIC); and naphthalene-type active ester resins containing a naphthalene structure such as "EXB9416-70BK", "EXB-8100L-65T", "EXB-8150L-65T", "EXB-8150-65T", "HPC-8150-60T", and "HPC-8150-62T" (manufactured by DIC), and "PC1300-02-65T" (Air Examples include: Water Co., Ltd.'s "DC808" (Mitsubishi Chemical Corporation) as an active ester resin containing acetylated phenol novolac; "YLH1026" (Mitsubishi Chemical Corporation) as an active ester resin containing benzoylated phenol novolac; "DC808" (Mitsubishi Chemical Corporation) as an active ester resin that is an acetylated phenol novolac; "YLH1026" (Mitsubishi Chemical Corporation), "YLH1030" (Mitsubishi Chemical Corporation), "YLH1048" (Mitsubishi Chemical Corporation) as active ester resins that are benzoylated phenol novolac; and "EXB-8500-65T" (DIC Corporation).

[0045] From the viewpoint of significantly obtaining the effects of the present invention, the content of the active ester resin as a thermosetting resin is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on 100% by mass of the nonvolatile components in the thermosetting material.

[0046] From the viewpoint of significantly obtaining the effects of the present invention, the content of the active ester resin as a thermosetting resin is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, when the resin component in the thermosetting material is considered to be 100% by mass.

[0047] As thermosetting resins, phenolic resins and naphthol resins are preferred if they have a novolac structure from the viewpoint of heat resistance and water resistance. Furthermore, from the viewpoint of adhesion to the conductive layer, nitrogen-containing phenolic resins are preferred, and triazine skeleton-containing phenolic resins are more preferred.

[0048] Specific examples of phenolic resins and naphthol resins include, for example, "MEH-7700," "MEH-7810," and "MEH-7851" from Meiwa Kasei Co., Ltd., "NHN," "CBN," and "GPH" from Nippon Kayaku Co., Ltd., "SN170," "SN180," "SN190," "SN475," "SN485," "SN495," "SN-495V," "SN375," and "SN395" from Nippon Steel Chemical & Material Co., Ltd., and "TD-2090," "LA-7052," "LA-7054," "LA-1356," "LA-3018-50P," and "EXB-9500" from DIC Corporation.

[0049] From the viewpoint of significantly obtaining the effects of the present invention, the content of phenolic resin or naphthol resin as a thermosetting resin is preferably 1% by mass or more, more preferably 1.5% by mass or more, even more preferably 2% by mass or more, preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, based on 100% by mass of nonvolatile components in the thermosetting material.

[0050] From the viewpoint of significantly obtaining the effects of the present invention, the content of phenolic resin or naphthol resin as a thermosetting resin is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, when the resin component in the thermosetting material is considered to be 100% by mass.

[0051] Examples of cyanate ester resins used as thermosetting 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; polyfunctional cyanate resins derived from phenol novolacs and cresol novolacs, etc.; and prepolymers in which these cyanate resins are partially triazined. Specific examples of cyanate ester resins include "PT30," "PT30S," and "PT60" (phenol novolac type polyfunctional cyanate ester resins) manufactured by arxada, "ULL-950S" (polyfunctional cyanate ester resin), "BA230," and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazined to form trimers).

[0052] From the viewpoint of significantly obtaining the effects of the present invention, the content of the cyanate ester resin as a thermosetting resin is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, based on 100% by mass of the nonvolatile components in the thermosetting material.

[0053] From the viewpoint of significantly obtaining the effects of the present invention, the content of the cyanate ester resin as a thermosetting resin is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, when the resin component in the thermosetting material is taken as 100% by mass.

[0054] Examples of thermosetting resins such as benzoxazine-based resins, carbodiimide-based resins, and acid anhydride-based resins are those described in Japanese Patent Publication No. 2020-75977.

[0055] When the thermosetting resin contains epoxy resin and a curing agent, the ratio of epoxy resin to all curing agents is preferably in the range of 1:0.01 to 1:5, more preferably 1:0.05 to 1:3, and even more preferably 1:0.1 to 1:2, as expressed in the ratio [total number of epoxy groups in the epoxy resin]:[total number of active groups in the curing agent]. Here, "total number of epoxy groups in the epoxy resin" is the sum of all values ​​obtained by dividing the mass of the non-volatile components of the epoxy resin present in the thermosetting material by the epoxy equivalent. Similarly, "total number of active groups in the curing agent" is the sum of all values ​​obtained by dividing the mass of the non-volatile components of the curing agent present in the thermosetting material by the active group equivalent. By setting the ratio of epoxy resin to curing agent within this range, a cured body with excellent flexibility can be obtained.

[0056] From the viewpoint of obtaining the effects of the present invention, the content of the curing agent in the thermosetting resin is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, based on 100% by mass of the nonvolatile components in the thermosetting material.

[0057] From the viewpoint of significantly obtaining the effects of the present invention, the content of the curing agent as a thermosetting resin is preferably 5% by mass or more, more preferably 8% by mass or more, even more preferably 10% by mass or more, preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less, when the resin component in the thermosetting material is considered to be 100% by mass.

[0058] From the viewpoint of significantly obtaining the effects of the present invention, the content of the thermosetting resin is preferably 6% by mass or more, more preferably 13% by mass or more, even more preferably 20% by mass or more, preferably 65% ​​by mass or less, more preferably 60% by mass or less, and even more preferably 55% by mass or less, based on 100% by mass of the nonvolatile components in the thermosetting material.

[0059] From the viewpoint of significantly obtaining the effects of the present invention, the content of the thermosetting resin is preferably 15% by mass or more, more preferably 23% by mass or more, even more preferably 30% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less, when the resin component in the thermosetting material is taken as 100% by mass.

[0060] The thermosetting material preferably contains an inorganic filler. By incorporating an inorganic filler into the thermosetting resin, the electrical properties of the insulating material layer can be improved. The inorganic filler may be used alone or in combination of two or more types.

[0061] Inorganic compounds can be used as materials for inorganic fillers. Examples of 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 zirconate titanate, 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 also preferred.

[0062] Examples of commercially available inorganic fillers include, for example, "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", "YA010C", "SC2500SQ", "SO-C4", "SO-C2", "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30", "DAW-03", "FB-105FD" manufactured by Denka Co., Ltd.; "Silfill NSS-3N", "Silfill NSS-4N", "Silfill NSS-5N" manufactured by Tokuyama Corporation; "Selfiers" and "MGH-005" manufactured by Taiheiyo Cement Corporation; "Esferic" and "BA-1" manufactured by JGC Catalysts & Chemicals Ltd., etc.

[0063] The specific surface area of the inorganic filler is preferably 1 m 2 / g or more, more preferably 2 m 2 / g or more, particularly preferably 3 m 2 / g or more. There is no particular limitation on the upper limit, but preferably it is 60 m 2 / g or less, 50 m 2 / g or less or 40 m 2 / g or less. The specific surface area can be measured using a BET full-automatic specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) by adsorbing nitrogen gas on the sample surface and using the BET multipoint method.

[0064] The average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.03 μm or more, particularly preferably 0.05 μm or more, and preferably 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less.

[0065] The average particle size of inorganic fillers can be measured by the laser diffraction-scattering method based on Mie scattering theory. Specifically, a volume-based particle size distribution of the inorganic filler is created using a laser diffraction-scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A sample consisting of 100 mg of inorganic filler and 10 g of methyl ethyl ketone can be weighed into a vial and dispersed using ultrasound for 10 minutes. Using a laser diffraction-type particle size distribution analyzer, the volume-based particle size distribution of the inorganic filler is measured using a flow cell method with blue and red light source wavelengths, and the average particle size can be calculated as the median diameter from the obtained particle size distribution. An example of a laser diffraction-type particle size distribution analyzer is the "LA-960" manufactured by Horiba, Ltd.

[0066] Inorganic fillers are preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of surface treatment agents include vinylsilane coupling agents, (meth)acrylic coupling agents, fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, and titanate coupling agents. Surface treatment agents may be used individually or in any combination of two or more types.

[0067] Examples of commercially available surface treatment agents include Shin-Etsu Chemical Co., Ltd.'s "KBM1003" (vinyltriethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM503" (3-methacryloxypropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM803" (3-mercaptopropyltrimethoxysilane), and Shin-Etsu Chemical Co., Ltd.'s "KBE903" (3-aminopropyltriethoxy Examples include sisilane, 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), Shin-Etsu Chemical Co., Ltd.'s "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane), etc.

[0068] From the viewpoint of improving the dispersibility of the inorganic filler, the degree of surface treatment by the surface treatment agent is preferably within a predetermined range. Specifically, 100 parts by mass of the inorganic filler is preferably surface-treated with 0.2 to 5 parts by mass of the surface treatment agent, preferably with 0.2 to 3 parts by mass, and preferably with 0.3 to 2 parts by mass.

[0069] The degree of surface treatment by a 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 should be 0.02 mg / m². 2 The above is preferred, and 0.1 mg / m² 2 The above is more preferable, 0.2 mg / m² 2 The above is even more preferable. On the other hand, from the viewpoint of suppressing the increase in the melt viscosity of the resin varnish and the melt viscosity in sheet form, 1 mg / m 2 The following is preferred: 0.8 mg / m² 2 The following is more preferable: 0.5 mg / m² 2 The following is even more preferable.

[0070] The amount of carbon per unit surface area of ​​an inorganic filler can be measured after surface treatment of the inorganic filler with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK 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 solids, the amount of carbon per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. A carbon analyzer such as the "EMIA-320V" manufactured by Horiba, Ltd. can be used.

[0071] The inorganic filler content is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 25% by mass or more, even more preferably 30% by mass or more, even more preferably 35% by mass or more, particularly preferably 40% by mass or more, preferably 90% by mass or less, more preferably 87% by mass or less, and even more preferably 83% by mass or less, based on 100% by mass of the nonvolatile components in the thermosetting material.

[0072] Thermosetting materials may contain curing accelerators as needed. Examples of curing accelerators include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators. Among these, amine-based curing accelerators are preferred. Curing accelerators may be used individually or in combination of two or more types.

[0073] Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred.

[0074] Another example of a curing accelerator is the one described in Japanese Patent Publication No. 2020-75977.

[0075] The content of the curing accelerator is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, even more preferably 0.01% by mass or more, preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less, based on 100% by mass of the nonvolatile components in the thermosetting material.

[0076] The content of the curing accelerator is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 1.0% by mass or less, based on 100% by mass of the resin component in the thermosetting material.

[0077] The thermosetting material may optionally contain a thermoplastic resin. Examples of thermoplastic resins include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polyimide resin, polyamide-imide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polyetheretherketone resin, and polyester resin, with phenoxy resin being preferred. The thermoplastic resin may be used alone or in combination of two or more types.

[0078] The weight-average molecular weight of the thermoplastic resin, in terms of polystyrene, is preferably 8,000 or more, more preferably 10,000 or more, and even more preferably 20,000 or more. The upper limit is preferably 100,000 or less, more preferably 70,000 or less, even more preferably 60,000 or less, and particularly preferably 50,000 or less.

[0079] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The ends of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Phenoxy resins may be used individually or in combination of two or more types. Specific examples of phenoxy resins include "1256" and "4250" (both phenoxy resins containing a bisphenol A skeleton), "YX8100" (phenoxy resin containing a bisphenol S skeleton), and "YX6954" (phenoxy resin containing a bisphenol acetophenone skeleton), all manufactured by Mitsubishi Chemical Corporation. Other examples include "FX280" and "FX293" from Nippon Steel Chemical & Material Corporation, and "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", and "YL7482" from Mitsubishi Chemical Corporation.

[0080] Other examples of thermoplastic resins include, for example, those described in Japanese Patent Publication No. 2020-75977.

[0081] The thermoplastic resin content is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, when the non-volatile components in the thermosetting material are considered to be 100% by mass. The upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

[0082] The thermoplastic resin content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, when the resin component in the thermosetting material is considered as 100% by mass. The upper limit is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less.

[0083] Thermosetting materials may contain other additives in addition to the components described above. Examples of other additives include polymerization initiators, organometallic compounds, colorants, polymerization inhibitors, leveling agents, thickeners, defoamers, UV absorbers, adhesion enhancers, adhesion promoters, antioxidants, fluorescent whitening agents, surfactants, flame retardants, dispersants, stabilizers, photopolymerization initiators, and photosensitizers. These other additives may be used individually or in combination of two or more.

[0084] Thermosetting materials may contain solvents as volatile components. Examples of solvents include ketones such as methyl ethyl ketone (MEK) and cyclohexanone; aromatic hydrocarbons such as xylene and tetramethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, and ethyl diglycol acetate; aliphatic hydrocarbons such as octane and decane; petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha; and ether ester solvents such as propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. These can be used individually or in combination of two or more types.

[0085] The thermosetting material may contain a solvent, but it is preferable that the amount is small. The amount of solvent contained in the thermosetting material is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less, based on 100% by mass of the nonvolatile components in the thermosetting material.

[0086] The method for preparing thermosetting materials is not particularly limited, and examples include mixing and dispersing the constituent components together with a solvent, if necessary, using a kneading device or stirring device.

[0087] Cured products of thermosetting materials typically exhibit a high glass transition temperature (Tg). Therefore, when an insulating material layer is formed using this cured product, an insulating material layer with a high glass transition temperature can be obtained. The glass transition temperature of the cured product is preferably 130°C or higher, more preferably 140°C or higher, and even more preferably 150°C or higher. The upper limit is not particularly limited, but for example, it may be 400°C or lower. The glass transition temperature can be measured by the method described in the examples below.

[0088] Cured products of thermosetting materials typically exhibit a low coefficient of linear thermal expansion (CTE). Therefore, when an insulating material layer is formed using this cured product, an insulating material layer with a low coefficient of linear thermal expansion can be obtained. The coefficient of linear thermal expansion of the cured product is preferably 100 ppm / °C or less, more preferably 80 ppm / °C or less, and even more preferably 75 ppm / °C or less. The lower limit is not particularly limited, but can be, for example, 0.01 ppm / °C or more. The coefficient of linear thermal expansion can be measured by the method described in the examples below.

[0089] Cured products of thermosetting materials typically exhibit a high modulus of elasticity at 23°C. Therefore, an insulating material layer with excellent crack resistance can be obtained. The modulus of elasticity of the cured product at 23°C is preferably 1.0 GPa or higher, more preferably 1.5 GPa or higher, and even more preferably 2.0 GPa or higher. There is no particular upper limit, but it can be 50 GPa or less, for example. The modulus of elasticity can be measured by the method described in the examples below.

[0090] Cured products of thermosetting materials typically exhibit high elongation (elongation at break). Therefore, an insulating material layer with high elongation at break can be obtained. The elongation at break of the cured product is preferably 0.5% or more, more preferably 1.0% or more, and particularly preferably 1.5% or more. There is no particular upper limit, and it may be, for example, 10% or less. The elongation can be measured according to the method described in the examples below.

[0091] Cured products of thermosetting materials typically exhibit a low dielectric loss tangent. Therefore, an insulating material layer with a low dielectric loss tangent can be obtained. The dielectric loss tangent of the cured product is preferably 0.03 or less, more preferably 0.02 or less, and even more preferably 0.01 or less. There is no particular lower limit to the dielectric loss tangent, and it can be, for example, 0.0005 or more. The dielectric loss tangent can be measured by the method described in the examples below.

[0092] Cured products of thermosetting materials typically exhibit a low dielectric constant. Therefore, an insulating material layer with a low dielectric constant can be obtained. The dielectric constant of the cured product is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.5 or less. The lower limit is not particularly limited, but can be, for example, 0.0001 or more. The dielectric constant can be measured by the method described in the examples below.

[0093] [Photosensitive material] The photosensitive material is used to form a plasma mask and should have excellent resolution. The photosensitive material may be either a positive-type photosensitive material or a negative-type material. Examples of such photosensitive materials include compositions containing a resin that can be developed with a developer such as an alkaline aqueous solution. In addition to the resin that can be developed with a developer, the photosensitive material may optionally further contain epoxy resin, crosslinking agents, photopolymerization initiators, photoacid generators, adhesion aids, organic fillers, and other additives.

[0094] The photosensitive material contains a resin that can be developed with a developer. As the resin that can be developed with a developer, conventionally known resins used in forming the solder resist layer of printed circuit boards may be used. Among these, examples of resins that can be developed with a developer include alkali-soluble resins having phenolic hydroxyl groups in their molecules, polybenzoxazole precursor resins, polyimide precursors, p-hydroxystyrene / styrene copolymers, acrylic resins, and methacrylic resins. Preferably, the resin that can be developed with a developer contains one or more selected from alkali-soluble resins having phenolic hydroxyl groups in their molecules, polyimide precursors, polybenzoxazole precursor resins, and acrylic resins. The resin that can be developed with a developer may be used alone or in combination of two or more types.

[0095] Examples of alkali-soluble resins containing phenolic hydroxyl groups in their molecules include Asahi Organic Chemicals' "TR4020G"; Asahi Organic Chemicals' AV Light series such as "TR4050G", "TR4080G", "TR5020G", "TR5050G", "TR6020G", "TR6050G", and "TR6080G"; Sumitomo Bakelite's photoresist resin series; Gun-ei Chemical Industry's Resito series; and DIC's "PR-30-40P", "PR-100L", "PR-100H", "PR-50", "PR-55", and "PR-56". Phenolite series such as "-1", "PR-56-2", "WR-101", "WR-102", "WR-103", "WR-104"; Lignite Corporation's "LF-100", "LF-110", "LF-120", "LF-200", "LF-400", "LF-500"; Meiwa Kasei Corporation's base resin series for photoresists; Meiwa Kasei Corporation's "MEHC-7851SS", "MEHC-78004S", "MEHC-7851-SS", "MEHC-7851-S", "MEHC-7851-M", "MEHC-7851-H", "M EHC-7800-4S, MEHC-7800-SS, MEHC-7800-S, MEHC-7800-M, MEHC-7800-H, GPH-65, GPH-103, MEHC-7841-4S manufactured by Nippon Kayaku; BisE manufactured by Honshu Kagaku Co., Ltd. ", "BisP-TMC"; manufactured by Mitsui Chemicals Fine Co., Ltd. "BisA", "BisF", "BisP-M", "BisP-AP", "BisP-MIBK", "BisP-B", "Bis-Z", "BisP-CP", "o,o'-BPF", "BisP-IOTD", " BisP-IBTD", "BisP-DED", "BisP-BA", "Bis-C", "Bis26X-A", "BisOPP-A", "BisOTBP-A", "BisOCHP-A", "BisOFP-A", "BisOC-Z", "BisOC-FL", " BisOC-CP", "BisOCHP-Z", "methylenebisP-CR", "TM-BPF", "BisOC-F", "Bis3M6B-IBTD", "BisOC-IST", "BisP-IST", "BisP-PRM", "BisP-LV", etc.

[0096] Examples of polybenzoxazole precursor resins, polyimide precursors, p-hydroxystyrene / styrene copolymers, and acrylic resins are described in Japanese Patent Publication No. 2018-169547, Japanese Patent Publication No. 2018-169627, International Publication No. 2010 / 134207, International Publication No. 2014 / 069202, Japanese Patent Publication No. 2020-101813, International Publication No. 2018 / 232214, and others.

[0097] Other examples of resins that can be developed with a developer include radical polymerizable resins, specifically resins having radical polymerizable unsaturated groups such as ethylenically unsaturated groups, such as acrylic resins and methacrylic resins. Examples of resins having radical polymerizable unsaturated groups are those described in publications such as Japanese Patent Publication No. 2020-15859, Japanese Patent Publication No. 2020-52288, and Japanese Patent Publication No. 2018-169547.

[0098] The weight-average molecular weight of the resin that can be developed with the developing solution is preferably 100 or more, more preferably 150 or more, even more preferably 200 or more, and may also be 300 or more, 500 or more, 700 or more, 1000 or more, etc. The upper limit is preferably 150,000 or less, more preferably 100,000 or less, even more preferably 50,000 or less, and may also be 10,000 or less, 5,000 or less, 1,000 or less, 800 or less, 500 or less, etc.

[0099] The content of the resin that can be developed with the developing solution is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 35% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, when the nonvolatile components of the photosensitive material are taken as 100% by mass.

[0100] Unless otherwise specified, the content of each component in the photosensitive material is the value when the non-volatile components in the photosensitive material are taken as 100% by mass, and the non-volatile components refer to all non-volatile components in the photosensitive material excluding the solvent.

[0101] The photosensitive material may contain epoxy resin. Epoxy resins are described in the [Thermosetting Materials] section. One type of epoxy resin may be used alone, or two or more types may be used in combination.

[0102] The photosensitive material may contain a crosslinking agent to improve the strength of the cured product of the photosensitive material. The crosslinking agent may be used alone or in combination of two or more types.

[0103] Examples of crosslinking agents include compounds containing two or more alkoxymethyl groups in their molecules.

[0104] Examples of compounds containing two or more alkoxymethyl groups in a molecule include amino resins containing two or more alkoxymethyl groups in a molecule, and phenolic resins containing two or more alkoxymethyl groups in a molecule. Among these, amino resins containing two or more alkoxymethyl groups in a molecule are preferred because they have superior photosensitivity. Examples of amino resins containing two or more alkoxymethyl groups in a molecule include melamine resins and urea resins, with melamine resins being preferred.

[0105] Specific examples of melamine resin include "MW-390," "MW-100LM," "MW-30HM," and "MX-750LM" from Sanwa Chemical Co., Ltd., and the Cymel series from Ornex Japan Co., Ltd. Specific examples of urea resin include "MX-270," "MX-279," and "MX-280" from Sanwa Chemical Co., Ltd., and the Cymel series from Ornex Japan Co., Ltd.

[0106] The crosslinking agent content is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, when the nonvolatile components of the photosensitive material are considered to be 100% by mass.

[0107] The photosensitive material may contain a photopolymerization initiator. The photopolymerization initiator can accelerate the reaction of a resin that can be developed with a developer. The photopolymerization initiator may be used alone or in combination of two or more types.

[0108] Examples of photopolymerization initiators include photoacid generators. Photoacid generators can generate acid when irradiated with active light such as ultraviolet light. For example, the generated acid can accelerate the reaction of alkali-soluble resins having phenolic hydroxyl groups in their molecules, and compounds containing two or more alkoxymethyl groups in their molecules.

[0109] As a photoacid generator, a compound that can generate acid upon irradiation with active light can be used. Examples of photoacid generators include halogen-containing compounds, diazoketone compounds, sulfone compounds, diazomethane compounds, and diazoquinone compounds.

[0110] Examples of halogen-containing compounds that can be used as photoacid generators include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds. Suitable specific examples of halogen-containing compounds include 2-[2-(furan-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(5-methylfuran-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-(methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(4-methoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, and 2-[2-(3,4-dimethylphenyl] Examples of s-triazine derivatives include s-triazine derivatives such as s(4-chlorophenyl)ethenyl-4,6-bis(trichloromethyl)-s-triazine, 1,10-dibromo-n-decane, 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane, phenyl-bis(trichloromethyl)-s-triazine, 4-methoxyphenyl-bis(trichloromethyl)-s-triazine, styryl-bis(trichloromethyl)-s-triazine, and naphthyl-bis(trichloromethyl)-s-triazine. Specific examples of halogen-containing compounds include Sanwa Chemical's "TFE-triazine," "TME-triazine," "MP-triazine," "MOP-triazine," and "dimethoxytriazine" (halogen-containing compound photoacid generators with a triazine skeleton).

[0111] Examples of diazoketone compounds, sulfone compounds, and diazoquinone compounds are those described in Japanese Patent Publication No. 2018-169627, International Publication No. 2010 / 134207, International Publication No. 2014 / 069202, Japanese Patent Publication No. 2020-101813, and International Publication No. 2018 / 232214.

[0112] Other examples of photopolymerization initiators include photoradical generators. Photoradical generators can effectively accelerate the reaction when using radical polymerizable resins. Examples of photoradical generators include those described in Japanese Patent Publication No. 2020-15859, Japanese Patent Publication No. 2020-52288, and Japanese Patent Publication No. 2018-169627.

[0113] The content of the photopolymerization initiator is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, preferably 3% by mass or less, and more preferably 1.5% by mass or less, when the nonvolatile components in the photosensitive material are considered to be 100% by mass.

[0114] The photosensitive material may contain a thermoacid generator. The thermoacid generator can generate acid when the plasma mask is heated, which promotes the crosslinking reaction between the resin, which can be developed with a developer solution, and the crosslinking agent. The thermoacid generator may be used alone or in combination of two or more types in any ratio.

[0115] Examples of thermal acid generators include onium salt compounds, and examples of onium salt compounds include those described in literature such as Japanese Patent Publication No. 2018-169627.

[0116] The content of the thermal acid generator is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, preferably 3% by mass or less, and more preferably 1.5% by mass or less, when the nonvolatile components in the photosensitive material are considered to be 100% by mass.

[0117] The photosensitive material may contain an adhesion enhancer. The adhesion enhancer may be a compound that improves the adhesion strength between the insulating material layer and the plasma mask. The adhesion enhancer may be used alone or in combination of two or more types in any ratio.

[0118] Examples of adhesion enhancers include γ-aminopropyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, 3-methacryloxypropyldimethoxymethylsilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, dimethoxymethyl-3-piperidinopropylsilane, diethoxy-3-glycidoxypropylmethylsilane, N-(3-diethoxymethylsilylpropyl)succinimide, N-[3-(triethoxysilyl)propyl]phthalamidic acid, benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamide)-4,4'-dicarboxylic acid, benzene-1,4-bis(N-3-triethoxysilyl]propylamide)-2,5-Dicarboxylic acid, 3-(triethoxysilyl)propyl succinic anhydride, N-phenylaminopropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-(trialkoxysilyl)propyl succinic anhydride, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethylmethyldimethoxysilane, 3-mercaptopropyldiethoxymethoxysilane, 3-mercaptopropylethoxydimethoxysilane, 3-mercaptopropyltripropoxysilane, 3-mercaptopropyldiethoxypropoxysilane, 3-mercaptopropylethoxydipropoxysilane, 3-mercaptopropyldimethoxypropoxysilane, 3-mercaptopropylmethoxydipropoxysilane, 2-mercap Examples of silane coupling agents include toethyltrimethoxysilane, 2-mercaptoethyldiethoxymethoxysilane, 2-mercaptoethylethoxydimethoxysilane, 2-mercaptoethyltripropoxysilane, 2-mercaptoethyltripropoxysilane, 2-mercaptoethylethoxydipropoxysilane, 2-mercaptoethyldimethoxypropoxysilane, 2-mercaptoethylmethoxydipropoxysilane, 4-mercaptobutyltrimethoxysilane, 4-mercaptobutyltriethoxysilane, 4-mercaptobutyltripropoxysilane, N-(3-triethoxysilylpropyl)urea, N-(3-trimethoxysilylpropyl)urea, and compounds having an aminotriazine ring and an ethoxysilyl group; and aluminum-based adhesive aids such as aluminum tris(ethylacetate), aluminum tris(acetylacetonate), and ethylacetate aluminum diisopropylate.

[0119] The content of the adhesion aid is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, based on 100% by mass of the nonvolatile components of the photosensitive material.

[0120] The photosensitive material may contain an organic filler. Examples of organic fillers include urethane particles, rubber particles, polyamide particles, and silicone particles. Among these, urethane particles are preferred. Examples of urethane particles include "MM-101SW," "MM-101SWA," "MM-101SM," "MM-101SMA," and "MM-110SMA" manufactured by Negami Kogyo Co., Ltd. The organic filler may be used alone or in combination of two or more types in any ratio.

[0121] The average particle size of the organic filler is preferably 0.005 μm or more, more preferably 0.2 μm or more, preferably 1 μm or less, and more preferably 0.6 μm or less. The average particle size of the organic filler can be measured using dynamic light scattering. Specifically, the average particle size of the organic filler can be measured by uniformly dispersing the organic filler in a suitable organic solvent using ultrasound, creating a particle size distribution of the organic filler on a mass basis using a concentrated particle size analyzer (FPAR-1000; manufactured by Otsuka Electronics Co., Ltd.), and using the median diameter as the average particle size.

[0122] The content of the organic filler is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, when the nonvolatile components of the photosensitive material are taken as 100% by mass.

[0123] The photosensitive material may or may not contain an inorganic filler. If the photosensitive material contains an inorganic filler, the amount of the inorganic filler may be less than the lower limit of the range of inorganic filler content in thermosetting materials, for example, 10% by mass or less relative to 100% by mass of the nonvolatile components of the photosensitive material. The amount of inorganic filler in the photosensitive material is usually preferably within the range of inorganic filler content in thermosetting materials.

[0124] When the photosensitive material contains an inorganic filler, the average particle size of the inorganic filler is preferably 0.2 μm or less, more preferably 0.15 μm or less, even more preferably 0.1 μm or less, preferably 0.01 μm or more, more preferably 0.03 μm or more, and particularly preferably 0.05 μm or more.

[0125] The photosensitive material may contain other additives in addition to the components described above. Examples of other additives include polymerization inhibitors, defoamers, surfactants, thermoplastic resins, colorants, thickeners, flame retardants, etc. The photosensitive material may also contain components that the thermosetting material described above may contain. These other additives may be used individually or in combination of two or more types.

[0126] The photosensitive material may contain a solvent as a volatile component. The solvent is the same as the solvent that may be contained in the thermosetting material.

[0127] The photosensitive material may contain a solvent, but the amount is preferably small. The amount of solvent contained in the photosensitive material is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, based on 100% by mass of the nonvolatile components in the photosensitive material.

[0128] The method for preparing the photosensitive material is not particularly limited, and examples include a method of kneading and dispersing the constituent components together with a solvent, if necessary, using a kneading or stirring device. A preferred embodiment of the photosensitive material is a solvent-developable negative-type photosensitive material containing a polyimide precursor, i.e., a solvent-developable negative-type photosensitive polyimide resin. The photosensitive material is preferably in liquid form.

[0129] Commercially available photosensitive materials may be used. Examples of commercially available products include "SU-8 3010" manufactured by Nippon Kayaku Co., Ltd.

[0130] Cured photosensitive materials typically exhibit a high glass transition temperature (Tg). Therefore, when a plasma mask is formed using this cured material, a plasma mask with a high glass transition temperature can be obtained. The glass transition temperature of the cured material is preferably 130°C or higher, more preferably 140°C or higher, and even more preferably 150°C or higher. The upper limit is not particularly limited, but for example, it may be 400°C or lower. The glass transition temperature can be measured by the method described in the examples below.

[0131] Cured photosensitive materials typically exhibit a low coefficient of linear thermal expansion (CTE). Therefore, when a plasma mask is formed using this cured material, a plasma mask with a low coefficient of linear thermal expansion can be obtained. The coefficient of linear thermal expansion of the cured material is preferably 100 ppm / °C or less, more preferably 80 ppm / °C or less, and even more preferably 75 ppm / °C or less. The lower limit is not particularly limited, but can be, for example, 0.01 ppm / °C or more. The coefficient of linear thermal expansion can be measured by the method described in the examples below.

[0132] Cured photosensitive materials typically exhibit a high elastic modulus at 23°C. Therefore, plasma masks with excellent crack resistance can be obtained. The elastic modulus of the cured material at 23°C is preferably 1.0 GPa or higher, more preferably 1.5 GPa or higher, and even more preferably 2.0 GPa or higher. There is no particular upper limit, but it can be 50 GPa or less. The elastic modulus can be measured by the method described in the examples below.

[0133] Cured photosensitive materials typically exhibit high elongation (elongation at break). Therefore, a plasma mask with high elongation at break can be obtained. The elongation at break of the cured material is preferably 10% or more, more preferably 20% or more, and particularly preferably 30% or more. There is no particular upper limit, and it may be, for example, 80% or less, 70% or less, or 60% or less. The elongation can be measured according to the method described in the examples below.

[0134] In this invention, it is preferable that the elongation at break of the cured product of the photosensitive material is greater than the elongation at break of the cured product of the thermosetting material.

[0135] Cured photosensitive materials typically exhibit a low dielectric loss tangent. Therefore, a plasma mask with a low dielectric loss tangent can be obtained. The dielectric loss tangent of the cured material is preferably 0.05 or less, more preferably 0.04 or less, and even more preferably 0.03 or less. There is no particular lower limit to the dielectric loss tangent, and it can be, for example, 0.0005 or more. The dielectric loss tangent can be measured by the method described in the examples below.

[0136] Cured photosensitive materials typically exhibit a low dielectric constant. Therefore, a plasma mask with a low dielectric constant can be obtained. The dielectric constant of the cured material is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.5 or less. The lower limit is not particularly limited, but can be, for example, 0.0001 or more. The dielectric constant can be measured by the method described in the examples below. In the present invention, it is preferable that both the dielectric constant of the cured photosensitive material and the dielectric constant of the cured thermosetting material are 3.5 or less.

[0137] [Thermosetting resin sheets and photosensitive resin sheets] The thermosetting resin sheet includes a support and a thermosetting material layer formed of a thermosetting material provided on the support. The thermosetting material is as described in the [Thermosetting Material] section.

[0138] The photosensitive resin sheet includes a support and a photosensitive material layer formed of a photosensitive material provided on the support. The photosensitive material is as described in the [Photosensitive Material] section.

[0139] Hereinafter, thermosetting material layers and photosensitive material layers may be collectively referred to as "material layers," and thermosetting resin sheets and photosensitive resin sheets may be collectively referred to as "resin sheets."

[0140] The thickness of the thermosetting material layer is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 40 μm or less, 30 μm or less, or 20 μm or less, from the viewpoint of making printed circuit boards thinner and providing a cured product with excellent insulating properties even if the cured product of the thermosetting material layer is a thin film. The lower limit of the thickness of the thermosetting material layer is not particularly limited, but can usually be 1 μm or more, 3 μm or more, etc.

[0141] From the viewpoint of significantly obtaining the effects of the present invention, the thickness of the photosensitive material layer is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 40 μm or less. From the viewpoint of leaving a residual film on the insulating material layer as a plasma mask, the lower limit of the thickness of the photosensitive material layer is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more.

[0142] Examples of support materials include films made of plastic materials, metal foils, and release paper, with films made of plastic materials and metal foils being preferred.

[0143] When using a film made of plastic material as a support, examples of plastic materials include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetylcellulose (TAC), polyether sulfide (PES), polyether ketones, and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0144] When using metal foil as a support, examples of metal foil include copper foil and aluminum foil, with copper foil being preferred. As for copper foil, foil made of single-metal copper may be used, or foil made of an alloy of copper with another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

[0145] The support may have a matte finish, corona treatment, or antistatic treatment applied to the surface that is joined to the material layer.

[0146] Furthermore, as the support, a support with a release layer having a release layer on the surface that joins with the material layer may be used. Examples of release agents used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available products may be used as the support with a release layer, such as PET films having a release layer mainly composed of alkyd resin-based release agents such as "SK-1", "AL-5", and "AL-7" from Lintec Corporation, "Lumirror T60" from Toray Industries, Inc., "Purex" from Teijin Corporation, and "Unipeel" from Unitika Corporation; and "U2-NR1" from DuPont Films Corporation.

[0147] 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. When using a support with a release layer, it is preferable that the overall thickness of the support with the release layer is within the above range.

[0148] In one embodiment, the resin sheet may further include other layers as needed. Such other layers include, for example, a protective film similar to the support, provided on the side of the material layer that is not bonded to the support (i.e., the side opposite to the support). The thickness of the protective film is not particularly limited, but for example, it is 1 μm to 40 μm. By laminating the protective film, the adhesion of dust and other debris to the surface of the material layer and scratches can be suppressed.

[0149] Resin sheets can be manufactured, for example, by preparing a resin varnish by dissolving a thermosetting material or a photosensitive material in an organic solvent, applying this resin varnish to a support using a die coater or the like, and then drying it to form a material layer. The solvents mentioned above can be used.

[0150] Drying may be carried out by known methods such as heating or blowing hot air. The drying conditions are not particularly limited, but the material layer should be dried so that the content of the organic solvent in the material layer is 10% by mass or less, preferably 5% by mass or less. Depending on the boiling point of the organic solvent in the resin varnish, for example, when using a resin varnish containing 30% to 60% by mass of organic solvent, the material layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0151] Resin sheets can be stored by rolling them up. If the resin sheet has a protective film, it can be used after removing the protective film.

[0152] [Prepreg] The prepreg is formed by impregnating a sheet-like fibrous substrate with the thermosetting material described above.

[0153] The sheet-like fibrous substrate used for the prepreg can be one of those commonly used as prepreg substrates, such as glass cloth, aramid nonwoven fabric, or liquid crystal polymer nonwoven fabric. From the viewpoint of thinning the wiring board, the thickness of the sheet-like fibrous substrate is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. The lower limit of the thickness of the sheet-like fibrous substrate is not particularly limited, and is usually 10 μm or more. The thickness of the prepreg can be in the same range as the sheet-like fibrous substrate described above.

[0154] Prepregs can be manufactured by methods such as the hot melt method and the solvent method.

[0155] [Manufacturing method for wiring boards] The first embodiment of the method for manufacturing a wiring board of the present invention is: (1) A step of preparing a substrate comprising a conductor circuit and an insulating material layer formed of a cured product of a thermosetting material on the conductor circuit, and forming a photosensitive material layer on the surface of the insulating material layer by either coating or attaching a photosensitive material or both. (2) A step of exposing and developing a photosensitive material layer to form a plasma mask having an opening, (3) A step of irradiating an insulating material layer with plasma through a plasma mask to form via holes and trenches, or both, in the insulating material layer located at the openings of the plasma mask, and reducing the thickness of the plasma mask, (4) The process includes forming a conductive layer on the surface of the reduced-thickness plasma mask and on either or both of the via holes and trenches.

[0156] As described above, conventionally, via holes or trenches in an insulating material layer were formed by creating a mask such as a dry film or metal foil on the insulating material layer, creating a mask pattern by patterning the mask, and then performing plasma treatment or laser treatment through the mask pattern to peel off or remove the mask pattern. The present invention's method for manufacturing a wiring board leaves a plasma mask, equivalent to the conventional mask pattern, as a primer layer (permanent film), so there is no need to remove the mask pattern as in the conventional method. In the present invention, since the plasma mask is left as is, it is possible to suppress chemical damage to the insulating material layer by the stripping solution used when removing the mask pattern, and as a result, the insulating material layer has excellent insulating performance and electrical properties, and the insulating performance after HAST testing can be improved. In particular, since cured products of thermosetting materials tend to have better insulating performance and electrical properties than cured products of photosensitive materials, a combination of an insulating material layer formed from a cured product of a thermosetting material and a plasma mask formed from a cured product of a photosensitive material can effectively improve insulating performance and electrical properties. Furthermore, since a photosensitive material layer is formed on an insulating material layer, the alignment of the mask pattern becomes easier, making it possible to form small-diameter via holes or trenches.

[0157] <Process (1)> In step (1), a substrate is prepared on which an insulating material layer is formed on an inner layer circuit board on which a conductive circuit is formed, and a photosensitive material layer is formed on the insulating material layer of the substrate by either coating and / or laminating (laminating) a photosensitive material. In step (1), as shown in Figure 1 as an example, a substrate 10 is prepared on which an insulating material layer 11 is formed on the conductive circuit of an inner layer circuit board 12 on which a conductive circuit (not shown) is formed. The insulating material layer 11 includes a cured product of a thermosetting material, from the viewpoint of obtaining the effects of the present invention in particular.

[0158] The process of carrying out step (1) may include the step of (1-1) preparing an inner layer circuit board on which a conductor circuit is formed. An inner layer circuit board on which a conductor circuit is formed usually comprises a support substrate and a metal layer provided on the surface of the support substrate. The metal layer is usually exposed on the surface of the inner layer circuit board and functions as a conductor circuit.

[0159] Examples of materials for the support substrate include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. Examples of materials for the metal layer include copper foil, copper foil with carriers, and materials for the conductive layer described later, with copper foil being preferred.

[0160] The conductive circuit can be formed in the same manner as the conductive layer formation in step (4) described later.

[0161] When a conductor circuit is a patterned conductor circuit, the line (conductor layer width) / space (width between conductor layers) (L / S) of the conductor circuit, i.e., the wiring pitch of the conductor circuit, is preferably 5 μm / 5 μm or less (i.e., wiring pitch of 10 μm or less), more preferably 4 μm / 4 μm or less (wiring pitch of 8 μm or less), and even more preferably 3 μm / 3 μm or less (wiring pitch of 6 μm or less) from the viewpoint of fine wiring. The lower limit of the line / space ratio of the conductor circuit is preferably 0.1 μm / 0.1 μm or more (wiring pitch of 0.2 μm or more), more preferably 0.5 μm / 0.5 μm or more (wiring pitch of 1 μm or more), and even more preferably 1 μm / 1 μm or more (wiring pitch of 2 μm or more). The wiring pitch does not need to be the same throughout the entire conductor circuit.

[0162] In carrying out step (1), the process may include (1-2) forming a thermosetting material layer on the conductor circuit of the inner layer circuit board and forming an insulating material layer by thermal curing the thermosetting material layer. Examples of forming the insulating material layer include a method of forming an insulating material layer by directly applying a thermosetting material to the conductor circuit of the inner layer circuit board and thermal curing it, a method of forming an insulating material layer by attaching (laminating) a thermosetting resin sheet on the conductor circuit of the inner layer circuit board and thermal curing the thermosetting material layer, and a method of forming an insulating material layer by laminating a prepreg on the conductor circuit of the inner layer circuit board and thermal curing it. In particular, from the viewpoint of obtaining the effects of the present invention in a remarkable manner, it is preferable that step (1-2) is a step of laminating a thermosetting material layer of a thermosetting resin sheet on the conductor circuit of the inner layer circuit board and thermal curing the thermosetting material layer to form an insulating material layer. The thermosetting material, thermosetting resin sheet, and prepreg are as described above. Furthermore, the insulating material layer may be a single layer or multiple layers may be laminated together.

[0163] Lamination of the inner circuit board and the thermosetting resin sheet can be performed, for example, by heating and pressing the thermosetting resin sheet onto the inner circuit board from the support side. Examples of the member used to heat and press the thermosetting resin sheet onto the inner circuit board (hereinafter also referred to as the "heat-pressing member") include a heated metal plate (such as a SUS end plate) or a metal roll (such as a SUS roll). It is preferable to press the thermosetting resin sheet via an elastic material such as heat-resistant rubber, rather than directly pressing the heat-pressing member onto the thermosetting resin sheet, so that the thermosetting resin sheet can adequately follow the surface irregularities of the inner circuit board.

[0164] Lamination of the inner layer circuit board and the thermosetting resin sheet may be carried out by vacuum lamination. In vacuum lamination, the heat-pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heat-pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa, and the heat-pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

[0165] Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include vacuum pressure laminators manufactured by Meiki Seisakusho Co., Ltd., vacuum applicators manufactured by Nikko Materials Co., Ltd., and batch-type vacuum pressure laminators.

[0166] After lamination, the laminated thermosetting resin sheets may be smoothed by pressing a heat-sealing member from the support side under normal pressure (atmospheric pressure). The pressing conditions for the smoothing process can be the same as the heat-sealing conditions for lamination. The smoothing process can be performed using a commercially available laminator. Lamination and smoothing may be performed continuously using the commercially available vacuum laminator mentioned above.

[0167] The support may be removed before the thermosetting resin sheet is laminated and then heat-cured, or after the thermosetting material layer has been heat-cured, or before the photosensitive material layer is formed on the insulating material layer.

[0168] After laminating a thermosetting resin sheet onto an inner circuit board, the thermosetting material layer is thermocured to form an insulating material layer. The thermocuring conditions for the thermosetting material layer are not particularly limited, and conditions commonly used when forming an insulating material layer for printed circuit boards may be used.

[0169] For example, the curing conditions for the thermosetting material layer vary depending on the type of thermosetting material, but 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 can be preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0170] Prior to thermal curing the thermosetting material layer, the thermosetting material layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermal curing the thermosetting material layer, the thermosetting material layer may be preheated at a temperature of 50°C or higher but less than 120°C (preferably 60°C or higher but less than 115°C, more preferably 70°C or higher but less than 110°C) for 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).

[0171] The thickness of the insulating material layer is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 40 μm or less, 30 μm or less, or 20 μm or less, and preferably 1 μm or more, more preferably 3 μm or more.

[0172] When forming an insulating material layer by directly applying a thermosetting material to the conductive circuit of an inner layer circuit board, the conditions for forming the insulating material layer are the same as those for forming an insulating material layer using a thermosetting resin sheet. Examples of methods for applying the thermosetting material include the wire bar coating method, reverse coating method, gravure coating method, die coating method, blade coating method, dip coating method, air knife coating method, curtain coating method, and roller coating method. Furthermore, when forming an insulating material layer using a prepreg, the conditions for forming the insulating material layer are the same as those for forming an insulating material layer using a thermosetting resin sheet.

[0173] Furthermore, step (1) includes the step of forming a photosensitive material layer 20 by either applying or attaching a photosensitive material to the surface of the insulating material layer 11 (1-3), as shown in an example in Figure 2. Details of the photosensitive material layer 20 include a method of forming a photosensitive material layer by directly applying a photosensitive material to the surface of the insulating material layer, and a method of attaching (laminating) a photosensitive resin sheet having a photosensitive material layer to the surface of the insulating material layer. The photosensitive material and the photosensitive resin sheet are as described above. The photosensitive material layer may be a single layer or multiple layers may be laminated.

[0174] The absolute value of the difference between the linear thermal expansion coefficient of the cured photosensitive material (plasma mask) and the linear thermal expansion coefficient of the cured thermosetting material (insulating material layer) is preferably 60 ppm / °C or less, more preferably 55 ppm / °C or less, and even more preferably 50 ppm / °C or less. There is no particular lower limit, but it is preferably 0 ppm / °C or more, more preferably 0.5 ppm / °C or more, and even more preferably 1 ppm / °C or more. By selecting a photosensitive material (or the photosensitive material layer if the photosensitive material layer 20 is formed from a photosensitive resin sheet) such that the absolute value of the difference in the linear thermal expansion coefficients of the cured photosensitive material falls within this range, the effects of the present invention can be significantly obtained.

[0175] The absolute value of the difference between the glass transition temperature (Tg) of the photosensitive material that may be included in the plasma mask and the glass transition temperature (Tg) of the thermosetting material that may be included in the insulating material layer is preferably 100°C or less, more preferably 90°C or less, and even more preferably 80°C or less. There is no particular lower limit, but it is preferably 0°C or more, more preferably 0.5°C or more, and even more preferably 1°C or more. By selecting the photosensitive material (or the photosensitive material layer if the photosensitive material layer 20 is formed from a photosensitive resin sheet) such that the absolute value of the difference in glass transition temperatures of the cured photosensitive material falls within this range, the effects of the present invention can be significantly obtained.

[0176] The linear thermal expansion coefficient of the bulk material, which is a laminate of a cured photosensitive material (plasma mask) and a cured thermosetting material (insulating material layer), is preferably 100 ppm / °C or less, more preferably 50 ppm / °C or less, and even more preferably 45 ppm / °C or less. There is no particular lower limit, but it can be 1 ppm / °C or more, 10 ppm / °C or more, etc. By selecting the photosensitive material (the photosensitive material layer when the photosensitive material layer 20 is formed from a photosensitive resin sheet) and the thermosetting material (the thermosetting material layer when the insulating material layer is formed from a thermosetting resin sheet) so that the linear thermal expansion coefficient of the bulk material is within such a range, the effects of the present invention can be significantly obtained.

[0177] The lamination conditions for the insulating material layer and the photosensitive resin sheet may be the same as those for the lamination conditions for the inner layer circuit board and the thermosetting resin sheet.

[0178] When a photosensitive material layer is formed by directly applying a photosensitive material to the surface of an insulating material layer, the method of applying the photosensitive material may be the same as the method of applying a thermosetting material directly to the conductor circuit of an inner layer circuit board. In this case, the photosensitive material is preferably in liquid form.

[0179] The thickness of the photosensitive material layer is the same as the thickness of the photosensitive material layer in the photosensitive resin sheet.

[0180] <Process (2)> In step (2), as shown in Figure 3 as an example, the photosensitive material layer 20 is exposed and developed by irradiating it with active energy rays to form a plasma mask 21 having openings 211. For details of exposure, the surface of the photosensitive material layer is irradiated with active energy rays through a photomask (not shown in Figure 3) to cure the photosensitive material layer. In step (2), a plasma mask 21 having multiple openings 211 may be formed, as shown in Figure 9 as an example.

[0181] Examples of active energy rays include ultraviolet light, visible light, electron beams, and X-rays, with ultraviolet light being preferred. The amount and duration of ultraviolet light irradiation can be appropriately set according to the photosensitive material layer. Examples of exposure methods include contact exposure, in which a mask pattern is brought into close contact with the photosensitive material layer for exposure, and non-contact exposure, in which a parallel light beam is used for exposure without bringing the mask pattern into close contact with the photosensitive material layer.

[0182] After exposure, development is performed to remove the exposed or unexposed areas of the photosensitive material layer, thereby forming a plasma mask. Development may be performed by either wet development or dry development. Examples of development methods include the dip method, paddle method, spray method, brushing method, and scraping method.

[0183] In step (2), if necessary, after development, a descam treatment may be performed by plasma treatment to remove any remaining residue such as deposits on the surface of the plasma mask.

[0184] From the viewpoint of significantly obtaining the effects of the present invention, the thickness of the plasma mask is preferably 0.1 μm or more, more preferably 0.3 μm or more, even more preferably 0.5 μm or more, preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less.

[0185] When the thickness of the plasma mask after step (2) is T1 (μm) and the thickness of the insulating material layer after step (2) is T2 (μm), it is preferable that the relationship T1 > T2 is satisfied from the viewpoint of significantly obtaining the effects of the present invention.

[0186] <Process (3)> In step (3), as shown in Figure 4 as an example, plasma irradiation is performed from above the insulating material layer 11 via the plasma mask 21 to form either or both via holes 30 and trenches (not shown) in the insulating material layer 11 located at the openings 211 of the plasma mask 21, and at the same time etching of the plasma mask 21 is performed to reduce the thickness of the plasma mask 21. As shown in Figure 5 as an example, after the completion of step (3), the plasma mask 21 is etched and reduced in thickness by plasma irradiation, but remains on the insulating material layer 11 as a primer layer (permanent film).

[0187] The thickness of the plasma mask after plasma irradiation, i.e., the thickness of the reduced plasma mask after step (3), is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and 0.15 or more, compared to the thickness of the plasma mask before plasma irradiation (which is set to 1), from the viewpoint of significantly obtaining the effects of the present invention. Preferably it is 0.7 or less, more preferably 0.6 or less, and even more preferably 0.5 or less. In conventional methods for manufacturing printed circuit boards, the mask is removed or peeled off after forming via holes or trenches, so the thickness of the mask after plasma treatment is at most 0.05, compared to the thickness of the mask before plasma treatment (which is set to 1).

[0188] From the viewpoint of obtaining the effects of the present invention in particular, the thickness of the reduced plasma mask after step (3) is preferably 0.1 μm or more, more preferably 0.3 μm or more, even more preferably 0.5 μm or more, preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less.

[0189] The total thickness of the reduced plasma mask and insulating material layer after step (3) is preferably 20 μm or less, more preferably 15 μm or less, even more preferably 13 μm or less, preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more, from the viewpoint of significantly obtaining the effects of the present invention.

[0190] In step (3), the plasma treatment is performed by using plasma generated by introducing gas into a plasma generator to treat the insulating material layer located at the opening and the surface of the plasma mask, thereby forming via holes or trenches on the surface of the insulating material layer located at the opening, and reducing the thickness of the plasma mask by etching. There are no particular restrictions on the method of generating the plasma, and examples include microwave plasma generated by microwaves, high-frequency plasma using high frequency, atmospheric pressure plasma generated under atmospheric pressure, and atmospheric pressure plasma generated under vacuum, with atmospheric pressure plasma generated under vacuum being preferred.

[0191] Furthermore, the plasma used in step (3) is preferably an RF plasma excited by high frequency.

[0192] As the gas used to create the plasma, a gas containing at least one of Ar, O2, CF4, and SF6 is preferred, and a mixed gas containing O2 and CF4 is more preferred.

[0193] The mixing ratio of the mixed gas containing O2 and CF4 (CF4 / O2: unit is sccm) is preferably 99 / 1 to 1 / 99, more preferably 90 / 10 to 30 / 70, and more preferably 90 / 10 to 70 / 30, from the viewpoint of making the thickness of the conductive layer formed in the via hole or trench uniform.

[0194] The plasma irradiation time in plasma processing is not particularly limited, but is preferably 1 minute or more, more preferably 2 minutes or more, and even more preferably 3 minutes or more. There is no particular upper limit, but is preferably 120 minutes or less, more preferably 100 minutes or less, and even more preferably 60 minutes or less.

[0195] This invention forms via holes or trenches in the insulating material layer located at the opening of the plasma mask during plasma processing, thereby reducing the diameter of the via holes or trenches. The opening diameter is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The lower limit is not particularly limited, but can be 1 μm or more, for example.

[0196] From the viewpoint of significantly obtaining the effects of the present invention, the etching rate by plasma irradiation is preferably 100 nm / min or more, more preferably 110 nm / min or more, and even more preferably 120 nm / min or more. There is no particular upper limit, but it is preferably 2000 nm / min or less, more preferably 1500 nm / min or less, and even more preferably 1000 nm / min or less.

[0197] In this invention, via holes or trenches are formed by plasma treatment, so the via taper angle of the via holes or trenches can be set to around 90 degrees. The via taper angle is preferably 65 degrees or more, more preferably 70 degrees or more, and even more preferably 72 degrees or more. There is no particular upper limit, but it is preferably 90 degrees or less, more preferably 88 degrees or less, and even more preferably 85 degrees or less. The via taper angle refers to the angle between the wall surface of the via hole or trench and the via bottom.

[0198] The arithmetic mean roughness (Ra) of the plasma mask surface after plasma treatment is preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 60 nm or less, from the viewpoint of significantly obtaining the effects of the present invention. There is no particular lower limit, but it can be 1 nm or more, 10 nm or more, etc. The arithmetic mean roughness can be measured by the method described in the examples below.

[0199] The roughness (Sa) of the wall surface of the via hole or trench after plasma treatment is preferably 400 nm or less, more preferably 350 nm or less, and even more preferably 300 nm or less, from the viewpoint of significantly obtaining the effects of the present invention. There is no particular lower limit, but it can be 110 nm or more, 150 nm or more, etc. The roughness (Sa) represents the arithmetic mean height as defined in ISO 25178 and can be measured by the method described in the examples below.

[0200] The ratio (Ra / Sa) of the arithmetic mean roughness (Ra) of the plasma mask surface after film reduction after plasma treatment and the roughness (Sa) of the wall surface of the via hole or trench after plasma treatment is preferably 3 or less, more preferably 2 or less, still more preferably 1 or less, 0.5 or less from the viewpoint of significantly obtaining the effects of the present invention, and is preferably 0.01 or more, more preferably 0.05 or more, still more preferably 0.1 or more.

[0201] The via expansion ratio is preferably 150% or less, more preferably 145% or less, still more preferably 140% or less from the viewpoint of significantly obtaining the effects of the present invention, and is preferably 100% or more, still more preferably 105% or more, more preferably 110% or more. The via expansion ratio means the ratio of how much the diameter of the boundary between the plasma mask and the insulating material layer in the via hole or trench after the end of step (3) has expanded with the diameter of the bottom of the pattern of the plasma mask after the end of step (2) as 100%. Those exceeding 100% mean that the diameter has expanded, and those less than 100% mean that the diameter has shrunk. In the present invention, even when plasma treatment is performed in step (3), it is possible to suppress the diameter of the bottom of the pattern of the plasma mask from becoming too large, so that fine wiring can be performed. The via expansion ratio can be measured by the method described in the examples below.

[0202] When the thickness of the plasma mask after film reduction after the end of step (3) is T3 (μm) and the thickness of the insulating material layer after the end of step (3) is T4 (μm), it is preferable to satisfy the relationship of T3 < T4 from the viewpoint of significantly obtaining the effects of the present invention.

[0203] <Step (4)> Step (4) is the step of forming a conductive layer on the surface of the reduced-thickness plasma mask and on either or both of the via holes and trenches exposed at the openings of the plasma mask. Details of the conductive layer include either or both of the conductive wiring formed at locations other than the openings of the plasma mask and the conductive via layer formed at the openings of the plasma mask. The conductive material used for the conductive layer is not particularly limited. In a preferred embodiment, the conductive layer includes 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 conductive layer may be a single-metal layer or an alloy layer, and examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy). In particular, from the viewpoint of versatility in conductor layer formation, cost, and ease of patterning, single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy, copper-nickel alloy, or copper-titanium alloy are preferred, and single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy are more preferred.

[0204] The conductor layer may be a single-layer structure, or it may be a multi-layer structure in which two or more single-metal layers or alloy layers made of different types of metals or alloys are stacked. When the conductor layer is a multi-layer structure, the layer in contact with either the via hole or the trench is preferably a single-metal layer of chromium, zinc, or titanium, or an alloy layer of nickel-chromium alloy.

[0205] The thickness of the conductor layer depends on the desired printed circuit board design, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0206] The conductor layer can be formed by any suitable conventional method known, such as plating, sputtering, or vapor deposition, and is preferably formed by plating. In one preferred embodiment, for example, a patterned conductor layer having a desired wiring pattern is formed by plating on the surface of a plasma mask that has been thinned by a conventionally known technique such as a semi-additive method or a fully additive method, and on either or both of the via holes and trenches.

[0207] In carrying out step (4), as shown in Figure 6 as an example, the step of (4-1) forming a plating seed layer 41 on the surface of the reduced plasma mask 21 and on the surface of either or both of the via holes 30 and trenches (not shown). The plating seed layer may be formed by dry plating or by wet plating. Examples of dry plating include physical vapor deposition (PVD) methods such as sputtering, ion plating, and vacuum deposition, and chemical vapor deposition (CVD) methods such as thermal CVD and plasma CVD. An example of wet plating is electroless plating. In step (4-1), it is preferable to form the plating seed layer by dry plating, and among these, it is more preferable to form the plating seed layer by sputtering from the viewpoint of realizing fine wiring.

[0208] When forming a conductive layer by sputtering, typically, a conductive seed layer is first formed by sputtering on the surface of the reduced-thickness plasma mask and on either or both of the via holes and trenches, and then a conductive sputtered layer is formed on the conductive seed layer by sputtering. Before forming the conductive seed layer by sputtering, the surface of the reduced-thickness plasma mask and either or both of the via holes and trenches may be cleaned by reverse sputtering. If trenches are present, an optional diffusion prevention layer may be provided to improve insulation reliability. Various gases can be used for reverse sputtering, but Ar, O2, and N2 are preferred. If the seed layer is Cu and Cu alloy, Ar or O2 or an Ar, O2 mixed gas is preferred; if the seed layer is Ti, Ar or N2 or an Ar, N2 mixed gas is preferred; and if the seed layer is Cr and Cr alloy (such as nichrome), Ar or O2 or an Ar, O2 mixed gas is preferred. Sputtering can be performed using various sputtering devices such as magnetron sputtering and mirrortron sputtering. Examples of metals used to form the conductive seed layer include Cr, Ni, Ti, and nichrome. Cr and Ti are particularly preferred. The thickness of the conductive seed layer is usually preferably 5 nm or more, more preferably 10 nm or more, preferably 1000 nm or less, and more preferably 500 nm or less. Examples of metals that form the conductive sputter layer include Cu, Pt, Au, and Pd. Cu is particularly preferred. The thickness of the conductive sputter layer is usually preferably 50 nm or more, more preferably 100 nm or more, preferably 3000 nm or less, and more preferably 1000 nm or less.

[0209] During the formation of the conductive seed layer, the surface roughness (Ra value) formed on the surface of the reduced plasma mask and on either or both of the via holes and trenches is preferably 150 nm or less, more preferably in the range of 10 to 150 nm, and even more preferably 10 to 120 nm or less, as measured after the conductive seed layer is removed by etching.

[0210] After forming a plating seed layer 41 by sputtering, the process may further include (4-2) a step of forming a conductor layer by plating on the plating seed layer 41, as shown in an example in Figure 7. Specifically, after forming the plating seed layer, a mask pattern (not shown) is formed that exposes a portion of the plating seed layer. The mask pattern can be formed, for example, by bonding a dry film to the plating seed layer and exposing, developing, and washing it under predetermined conditions. In the case of trench-embedded wiring, the wiring can be formed by polishing after trench embedding by plating using a polishing process such as CMP.

[0211] As the dry film, a photosensitive dry film made of a photoresist composition can be used. Examples of such dry films include novolac resin and acrylic resin dry films. Commercially available dry films may also be used; for example, "Photec RY-5115" from Resonaq Corporation and "ALPHO 20A263" from Nikko Materials Corporation can be used.

[0212] Next, an electroplated layer 42 is formed on the exposed plated seed layer 41 by electroplating. If there are via holes and trenches, or both, the electroplated layer 42 may be formed on the exposed plated seed layer 41 by electroplating, and either the via holes and trenches, or both, may be filled by electroplating to form filled vias.

[0213] After forming the electroplating layer 42, as shown in Figure 8 as an example, a mask pattern (not shown) is removed, and the unnecessary plating seed layer 41 is removed by an etching process such as flash etching to form the conductive layer 40. After removing the mask pattern, annealing may be performed as needed. In Figure 8, the conductive layer 40 is a patterned conductive layer, but it may also be a conductive layer without a pattern.

[0214] The mask pattern can be removed using an alkaline stripping solution, such as a sodium hydroxide solution.

[0215] Annealing can be performed, for example, by heating the inner layer substrate at 150-200°C for 20-90 minutes.

[0216] Flash etching is typically performed using an etchant such as an etching solution. For example, when the material of the patterned conductor layer is copper, the etching solution can be an etching solution mainly composed of hydrogen peroxide (hydrogen peroxide-based etching solution), an acidic etching solution, or an alkaline etching solution.

[0217] From the viewpoint of significantly obtaining the effects of the present invention, the temperature of the etching solution is preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, preferably 60°C or lower, more preferably 50°C or lower, and even more preferably 40°C or lower.

[0218] From the viewpoint of miniaturization, the thickness of the conductive layer is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less. The lower limit is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more.

[0219] When the conductor layer is a patterned conductor layer, the line width of the patterned conductor layer is preferably 5 μm or less, more preferably 4 μm, and even more preferably 3 μm, from the viewpoint of fine wiring. The lower limit of the conductor layer line width is not particularly limited, but is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more.

[0220] When the conductor layer is a patterned conductor layer, the spacing between the patterned conductor layers (width between conductor layers) is preferably 5 μm or less, more preferably 4 μm, and even more preferably 3 μm, from the viewpoint of fine wiring. The lower limit of the conductor layer lines is not particularly limited, but is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more.

[0221] When the conductor layer is a patterned conductor layer, the line (conductor layer width) / space (width between conductor layers) (L / S) of the patterned conductor layer is preferably 5 μm / 5 μm or less (i.e., a pattern with a wiring pitch of 10 μm or less), more preferably 4 μm / 4 μm or less (a pattern with a wiring pitch of 8 μm or less), and even more preferably 3 μm / 3 μm or less (a pattern with a wiring pitch of 6 μm or less), from the viewpoint of fine wiring. The lower limit of the line / space ratio of the conductor layer is preferably 0.1 μm / 0.1 μm or more (a pattern with a wiring pitch of 0.2 μm or more), more preferably 0.5 μm / 0.5 μm or more (a pattern with a wiring pitch of 1 μm or more), and even more preferably 1 μm / 1 μm or more (a pattern with a wiring pitch of 2 μm or more). The wiring pitch does not need to be the same throughout the entire conductor layer.

[0222] When manufacturing a printed circuit board, steps (1) to (4) may be repeated as needed to form a multilayer printed circuit board.

[0223] The wiring board obtained by the wiring board manufacturing method of the first embodiment is preferably formed in the order of a conductor circuit, an insulating material layer, a plasma mask, and a conductor layer, as shown in Figure 8 as an example, and has via holes, and more preferably contains two or more of each of the conductor circuit, insulating material layer, plasma mask, conductor layer, and via holes.

[0224] In the first embodiment, for the sake of explanation, Figures 4 to 8 describe an embodiment having only via holes 30. However, the first embodiment may have both via holes 30 and trenches 31, or it may have only trenches. In detail, as shown in Figure 10 as an example, plasma irradiation is performed from above the insulating material layer 11 via a plasma mask 21 to form either or both via holes 30 and trenches 31 in the insulating material layer 11 located at the openings 211 of the plasma mask 21, and etching of the plasma mask 21 is performed simultaneously to reduce the thickness of the plasma mask 21, leaving the plasma mask 21 as a primer layer (permanent film) on the insulating material layer 11, as shown in Figure 11 as an example. Then, as shown in Figure 12 as an example, a plating seed layer 41 is formed on the surface of the reduced-thickness plasma mask 21 and on either or both of the via holes 30 and trenches 31, and as shown in Figure 13 as an example, plating is further performed on the plating seed layer 41. As shown in Figure 14 as an example, the conductor layer 40 is formed by removing the unnecessary plating seed layer 41 by an etching process such as flash etching.

[0225] A second embodiment of the method for manufacturing a wiring board of the present invention is: (A) A step of preparing a substrate comprising a conductor circuit and an insulating material layer formed of a cured product of a thermosetting material on the conductor circuit, and forming a first photosensitive material layer on the surface of the insulating material layer by either coating and / or attaching a first photosensitive material, (B) A step of exposing and developing a first photosensitive material layer to form a first plasma mask having an opening. (C) A step of irradiating an insulating material layer with plasma through a first plasma mask, forming either via holes and / or trenches in the insulating material layer located at the openings of the plasma mask, and reducing the thickness of the plasma mask. (D) A step of forming a second photosensitive material layer by either applying or attaching a second photosensitive material to cover the surface and openings of the first plasma mask, (E) A step of exposing and developing a second photosensitive material layer to form a second plasma mask having an opening. (F) A step of irradiating the first plasma mask and the insulating material layer with plasma via the second plasma mask to form via holes and trenches, or both, in the insulating material layer. (G) A step of forming a conductive layer on the surface of the first plasma mask and on either or both of the via holes and trenches, and (H) Includes the step of scraping the surface of the conductive layer.

[0226] In the second embodiment, since the first plasma mask is left as is, chemical damage to the insulating material layer by the stripping solution used when removing the mask pattern can be suppressed. As a result, the insulating material layer has excellent insulating performance and electrical properties, and the insulating performance after the HAST test can be improved. In particular, since the cured product of a thermosetting material tends to have better insulating performance and electrical properties than the cured product of a photosensitive material, the combination of an insulating material layer formed from a cured thermosetting material and a first plasma mask formed from a cured photosensitive material can effectively improve insulating performance and electrical properties. Furthermore, since the photosensitive material layer is formed on the insulating material layer, alignment of the mask pattern becomes easier, and it becomes possible to form small-diameter via holes or trenches.

[0227] <Process (A)> Step (A) is the same as step (1) in the first embodiment. The first photosensitive material is the same as the photosensitive material in the first embodiment.

[0228] <Process (B)> In step (B), as shown in Figure 15 as an example, the first photosensitive material layer 22 is exposed and developed by irradiating it with active energy rays to form a first plasma mask having an opening 212. In detail of the exposure, the surface of the first photosensitive material layer 22 is irradiated with active energy rays through a photomask (not shown in Figure 15) to cure the first photosensitive material layer 22.

[0229] The exposure and development method for the first photosensitive material layer is the same as the exposure and development method in step (B) of the first embodiment. Furthermore, the thickness of the first plasma mask is the same as the thickness of the plasma mask in step (B) of the first embodiment.

[0230] When the thickness of the first plasma mask after the completion of process (B) is T1A (μm) and the thickness of the insulating material layer after the completion of process (B) is T2A (μm), it is preferable that the relationship T1A > T2A is satisfied from the viewpoint of significantly obtaining the effects of the present invention.

[0231] <Process (C)> In step (C), as shown in an example in Figure 16, plasma irradiation is performed from above the insulating material layer 11 through the first plasma mask 24 to form either or both via holes (not shown) and trenches 31 in the insulating material layer 11 located at the opening 212 of the first plasma mask 24, and simultaneously etching of the first plasma mask 24 to reduce the thickness of the first plasma mask 24. Step (C) can be performed in the same manner as step (3) of the first embodiment.

[0232] <Process (D)> In step (D), as shown in Figure 17 as an example, a second photosensitive material layer 23 is formed by either coating or attaching the second photosensitive material to cover the surface of the first plasma mask 24 and the opening 212. The coating and attachment of the second photosensitive material are the same as in step (1) in the first embodiment. The second photosensitive material may be the same as or different from the first photosensitive material.

[0233] <Process (E)> In step (E), as shown in Figure 18 as an example, the second photosensitive material layer 23 is exposed and developed by irradiating it with active energy rays to form a second plasma mask 25 having an opening 212 and a predetermined pattern. In detail of the exposure, the surface of the second photosensitive material layer is irradiated with active energy rays through a photomask (not shown in Figure 18) to cure the second photosensitive material layer.

[0234] The exposure and development method for the second photosensitive material layer is the same as the exposure and development method in step (B) of the first embodiment. Also, the thickness of the second plasma mask is the same as the thickness of the plasma mask in step (B) of the first embodiment.

[0235] <Process (F)> In step (F), as shown in Figure 19 as an example, the first plasma mask 24 and the insulating material layer 11 are irradiated with plasma through the second plasma mask to form either or both via holes (not shown) and trenches 31 in the insulating material layer 11. In this step, etching of the first plasma mask 24 may be performed simultaneously to further reduce the thickness of the first plasma mask 24. In step (F), the second plasma mask may be completely removed by plasma etching, or some may remain.

[0236] The plasma treatment is the same as the plasma treatment in step (3) of the first embodiment.

[0237] Furthermore, the thickness of the first plasma mask after the completion of step (F) is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and 0.15 or more, when the thickness of the plasma mask before plasma irradiation is taken as 1, from the viewpoint of significantly obtaining the effects of the present invention. Preferably 0.7 or less, more preferably 0.6 or less, and even more preferably 0.5 or less. Note that in conventional methods for manufacturing printed circuit boards, the mask is removed or peeled off after forming via holes or trenches, so the thickness of the mask after plasma treatment is at most 0.05 when the thickness of the mask before plasma treatment is taken as 1.

[0238] The thickness of the first plasma mask after the completion of process (F) is the same as, or reduced than, the thickness of the reduced plasma mask after the completion of process (3) in the first embodiment.

[0239] <Process (G)> In step (G), as shown in Fig. 20, a conductor layer 40 is formed on either one or both of the surfaces of the first plasma mask 24 and the via holes and trenches 31. The formation of the conductor layer is the same as the formation of the conductor layer in step (4) of the first embodiment. When performing step (G), it may include (G-1) a step of forming a plating seed layer 41 on the surface of the first plasma mask 24 and on either one or both of the surfaces of the via holes (not shown) and trenches 31. The plating seed layer is the same as the plating seed layer in step (4) of the first embodiment. Also, a barrier metal layer may be formed instead of the plating seed layer.

[0240] After forming the plating seed layer, it may further include (G-2) a step of performing electrolytic plating on the plating seed layer 41 and embedding either one or both of the via holes and trenches by electrolytic plating to form a field via. Specifically, an electrolytic plating layer 42 is formed on the exposed plating seed layer 41 by electrolytic plating. For either one or both of the via holes and trenches, an electrolytic plating layer 42 is formed on the exposed plating seed layer 41 by electrolytic plating treatment, and either one or both of the via holes and trenches are embedded by electrolytic plating treatment to form a field via. The electrolytic plating is the same as the formation of the electrolytic plating layer in step (4) of the first embodiment.

[0241] <Step (H)> In step (H), the surface of the conductor layer is polished, that is, as shown in Fig. 21, the surface of the conductor layer 40 is polished so that the first plasma mask 24 is exposed. As the polishing method, a method capable of polishing the surface of the conductor layer can be used. Examples of such polishing methods include, for example, CMP (chemical mechanical polishing), buff polishing, belt polishing, etc. Among them, CMP is preferable.

[0242] After the completion of the process (H), a barrier metal layer may be formed on the surface of the conductor layer as necessary. Also, when manufacturing a wiring board, the processes (A) to (H) may be repeatedly carried out as necessary to form a multilayer wiring board.

[0243] The area of the wiring board is preferably 2500 mm 2 or more, more preferably 3000 mm 2 or more, and even more preferably 3500 mm 2 or more. There is no particular limitation on the upper limit, but it can be 10000 mm 2 or less, etc.

[0244] The wiring board obtained by the manufacturing method of the present invention may be a multilayer wiring substrate in which a plurality of conductor layers are laminated. The conductor layer in the multilayer wiring substrate is preferably 3 layers or more.

[0245] [Semiconductor device] The semiconductor device of the present invention includes a wiring board obtained by the manufacturing method of the present invention. Examples of the semiconductor device include various semiconductor devices used in electrical products (e.g., computers, mobile phones, digital cameras, and televisions, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, and airplanes, etc.).

[0246] The semiconductor device of the present invention may have a fan-out structure or a chiplet structure. Also, the semiconductor device of the present invention has a semiconductor chip on the wiring board obtained by the manufacturing method of the present invention, and it is preferable that the semiconductor chip is at least a mixed mounting system of a logic die and a memory die.

Examples

[0247] Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "mass %", respectively, unless otherwise specified. Also, the operations described below were carried out in an environment of normal temperature and pressure unless otherwise specified.

[0248] Inorganic fillers 1 and 2 are as follows: Inorganic filler 1: Spherical silica (Denka "UFP-30", average particle size 0.078 μm, specific surface area 30.7 m 2 (g) is surface-treated with N-phenyl-3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM573). Inorganic filler 2: Spherical silica (Admatex "SO-C2", average particle size: 0.5 μm, specific surface area: 5.8 m²) 2 (g) was surface-treated with N-phenyl-8-aminooctyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM6803).

[0249] <Preparation of thermosetting material 1> 6 parts bixylenol-type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK", epoxy equivalent approx. 185g / eq.), 5 parts naphthalene-type epoxy resin (Nippon Steel & Sumitomo Metal Chemical Corporation "ESN475V", epoxy equivalent approx. 332g / eq.), 15 parts bisphenol AF-type epoxy resin (Mitsubishi Chemical Corporation "YL7760", epoxy equivalent approx. 238g / eq.), naphthylene ether-type epoxy resin (DIC Corporation "HP6000L", epoxy... Two parts of (approximately 213 g / eq.) cyclohexanone, two parts of cyclohexane-type epoxy resin (Mitsubishi Chemical Corporation's "ZX1658GS", approximately 135 g / eq. epoxy equivalent), and twenty parts of phenoxy resin (Mitsubishi Chemical Corporation's "YX7800BH30", a 1:1 solution of cyclohexanone:methyl ethyl ketone (MEK) with a solid content of 30% by mass, Mw=20000) were heated and dissolved with stirring in a mixed solvent of twenty parts of solvent naphtha and ten parts of cyclohexanone. After cooling to room temperature, 20 parts of a prepolymer (BA230S, manufactured by arxada, with a cyanate equivalent of 232 g / eq.) in which part or all of bisphenol A dicyanate has been triazinated into a trimer, and 0.05 parts of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP)) were mixed together and uniformly dispersed using a high-speed rotary mixer. The mixture was then filtered through a cartridge filter (SHP020, manufactured by ROKITECHNO) to prepare thermosetting material 1.

[0250] <Preparation of Thermosetting Material 2> 6 parts bixylenol-type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK", epoxy equivalent approx. 185g / eq.), 5 parts naphthalene-type epoxy resin (Nippon Steel & Sumitomo Metal Chemicals Corporation "ESN475V", epoxy equivalent approx. 332g / eq.), 15 parts bisphenol AF-type epoxy resin (Mitsubishi Chemical Corporation "YL7760", epoxy equivalent approx. 238g / eq.), naphthylene ether-type epoxy resin (DIC Corporation "HP6000L", epoxy equivalent) Two parts of (approximately 213 g / eq.) epoxy resin, two parts of cyclohexane-type epoxy resin (Mitsubishi Chemical Corporation's "ZX1658GS", approximately 135 g / eq. epoxy equivalent), and two parts of phenoxy resin (Mitsubishi Chemical Corporation's "YL7500BH30", a 1:1 solution of cyclohexanone:methyl ethyl ketone (MEK) with a solid content of 30% by mass, Mw=44000) were heated and dissolved with stirring in a mixed solvent of 20 parts of solvent naphtha and 10 parts of cyclohexanone. After cooling to room temperature, four parts of a triazine skeleton-containing cresol novolac curing agent (DIC Corporation's "LA-3018-50P", hydroxyl group equivalent approximately 151 g / eq., 2-methoxypropanol solution with 50% solids), six parts of an active ester curing agent (DIC Corporation's "HP-B-8151-62T", active group equivalent 238 g / eq., toluene solution with 62% solids), thirty parts of inorganic filler 1, and 0.05 parts of an amine curing accelerator (4-dimethylaminopyridine (DMAP)) were mixed and uniformly dispersed using a high-speed rotary mixer. The mixture was then filtered through a cartridge filter (ROKITECHNO Corporation's "SHP020") to prepare thermosetting material 2.

[0251] <Preparation of thermosetting material 3> 6 parts bixylenol-type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK", epoxy equivalent approximately 185g / eq.), 5 parts naphthalene-type epoxy resin (Nippon Steel & Sumitomo Metal Chemicals Corporation "ESN475V", epoxy equivalent approximately 332g / eq.), 15 parts bisphenol AF-type epoxy resin (Mitsubishi Chemical Corporation "YL7760", epoxy equivalent approximately 238g / eq.), naphthylene ether-type epoxy resin (DIC Corporation "HP6000L", ) Two parts of (approximately 213 poxy equivalents), two parts of cyclohexane-type epoxy resin (Mitsubishi Chemical Corporation's "ZX1658GS," approximately 135 g / eq. epoxy equivalents), and two parts of phenoxy resin (Mitsubishi Chemical Corporation's "YL7500BH30," a 1:1 solution of cyclohexanone and methyl ethyl ketone (MEK) with a solid content of 30% by mass, Mw=44000) were heated and dissolved with stirring in a mixed solvent of 20 parts solvent naphtha and 10 parts cyclohexanone. After cooling to room temperature, four parts of a triazine skeleton-containing cresol novolac curing agent (DIC Corporation's "LA-3018-50P", hydroxyl group equivalent approximately 151 g / eq., 2-methoxypropanol solution with 50% solids), six parts of an active ester curing agent (DIC Corporation's "HP-B-8151-62T", active group equivalent 238 g / eq., toluene solution with 62% solids), sixty parts of inorganic filler 1, and 0.05 parts of an amine curing accelerator (4-dimethylaminopyridine (DMAP)) were mixed and uniformly dispersed using a high-speed rotary mixer. The mixture was then filtered through a cartridge filter (ROKITECHNO Corporation's "SHP020") to prepare thermosetting material 3.

[0252] <Preparation of thermosetting material 4> 6 parts bixylenol-type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK", epoxy equivalent approximately 185g / eq.), 5 parts naphthalene-type epoxy resin (Nippon Steel & Sumitomo Metal Chemicals Corporation "ESN475V", epoxy equivalent approximately 332g / eq.), 15 parts bisphenol AF-type epoxy resin (Mitsubishi Chemical Corporation "YL7760", epoxy equivalent approximately 238g / eq.), naphthylene ether-type epoxy resin (DIC Corporation "HP6000L", ) Two parts of (approximately 213 poxy equivalents), two parts of cyclohexane-type epoxy resin (Mitsubishi Chemical Corporation's "ZX1658GS," approximately 135 g / eq. epoxy equivalents), and two parts of phenoxy resin (Mitsubishi Chemical Corporation's "YL7500BH30," a 1:1 solution of cyclohexanone and methyl ethyl ketone (MEK) with a solid content of 30% by mass, Mw=44000) were heated and dissolved with stirring in a mixed solvent of 20 parts solvent naphtha and 10 parts cyclohexanone. After cooling to room temperature, four parts of a triazine skeleton-containing cresol novolac curing agent (DIC Corporation's "LA-3018-50P", hydroxyl group equivalent of approximately 151 g / eq., 2-methoxypropanol solution with 50% solids), six parts of an active ester curing agent (DIC Corporation's "HP-B-8151-62T", active group equivalent of 238 g / eq., toluene solution with 62% solids), solvent IP150 (Idemitsu Kosan Co., Ltd.), 150 parts of inorganic filler 2, and 0.05 parts of an amine curing accelerator (4-dimethylaminopyridine (DMAP)) were mixed and uniformly dispersed using a high-speed rotary mixer, and then filtered through a cartridge filter (ROKITECHNO Corporation's "SHP050") to prepare thermosetting material 4.

[0253] The components used in the preparation of thermosetting materials 1 to 4 and their respective proportions are shown in the table below. [Table 1] *In the table, the curing agent content represents the curing agent content when the resin component in the thermosetting material is considered to be 100% by mass, while the cyanate ester resin, activated ester resin, phenolic resin, and inorganic filler content represents the content when the non-volatile component in the thermosetting material is considered to be 100% by mass.

[0254] <Production of the thermosetting resin sheet 1> As the support, a PET film (Toray Industries, Inc.'s "Lumirror R80", thickness 38 μm, softening point 130 °C, "release PET") that had been subjected to a release treatment with an alkyd resin-based release agent ("AL-5" manufactured by Lintec Corporation) was prepared. The thermosetting material 1 was uniformly applied onto the release agent of the support using a die coater such that the thickness of the thermosetting material layer after drying would be 5 μm, and dried at 70 °C to 95 °C for 2 minutes, thereby obtaining a thermosetting material layer on the release PET. Next, the rough surface of a polypropylene film ("Alpha MA-411" manufactured by Oji Fibrex Corporation, thickness 15 μm) as a protective film was laminated onto the surface of the resin sheet that was not joined to the support so as to be joined to the thermosetting material layer. Thereby, the thermosetting resin sheet 1 for forming an insulating material layer composed of the release PET (support), the thermosetting material layer, and the protective film in that order was obtained.

[0255] <Production of the thermosetting resin sheet 2> In the production of the thermosetting resin sheet 1, the thermosetting material 1 was changed to the thermosetting material 2. The thermosetting resin sheet 2 was produced in the same manner as the production of the thermosetting resin sheet 1 except for the above matters.

[0256] <Production of the thermosetting resin sheet 3> In the production of the thermosetting resin sheet 1, the thermosetting material 1 was changed to the thermosetting material 3. The thermosetting resin sheet 3 was produced in the same manner as the production of the thermosetting resin sheet 1 except for the above matters.

[0257] <Production of the thermosetting resin sheet 4> In the production of the thermosetting resin sheet 1, the thermosetting material 1 was changed to the thermosetting material 4. The thermosetting resin sheet 4 was produced in the same manner as the production of the thermosetting resin sheet 1 except for the above matters.

[0258] <Preparation of the photosensitive material 1> A negative-type photosensitive material 1 was obtained by mixing 10 parts by mass of alkali-soluble resin ("TR4020G" manufactured by Asahi Organic Chemicals Co., Ltd.), 5 parts by mass of alkali-soluble resin ("MEHC-7851SS" manufactured by Meiwa Chemicals Co., Ltd.), 5 parts by mass of alkali-soluble resin ("BisE" manufactured by Honshu Chemical Co., Ltd.), 5 parts by mass of a compound containing at least two alkoxymethyl groups in its molecule ("MW-390" manufactured by Sanwa Chemical Co., Ltd.), 0.05 parts by mass of photoacid generator ("MP-triazine" manufactured by Sanwa Chemical Co., Ltd.), 2 parts by mass of organic filler ("MM-101SM" manufactured by Negami Kogyo Co., Ltd.), and 12 parts by mass of MEK (manufactured by Junsei Chemical Co., Ltd.).

[0259] <Preparation of photosensitive material 2> (Synthesis of polybenzoxazole precursor resin) 443.2 g (0.90 mol) of a dicarboxylic acid derivative obtained by reacting 1 mole of diphenyl ether-4,4'-dicarboxylic acid with 2 moles of 1-hydroxybenzotriazole, and 366.3 g (1.00 mol) of hexafluoro-2,2-bis(3-amino-4-hydroxyphenyl)propane were placed in a four-necked separable flask equipped with a thermometer, stirrer, raw material inlet, and dry nitrogen gas inlet tube, and 3000 g of N-methyl-2-pyrrolidone was added to dissolve it. The reaction was then carried out at 75°C for 16 hours using an oil bath.

[0260] Next, 32.8 g (0.20 mol) of 5-norbornene-2,3-dicarboxylic acid anhydride dissolved in 100 parts by mass of N-methyl-2-pyrrolidone was added, and the mixture was stirred for a further 3 hours to complete the reaction. After filtering the reaction mixture, the mixture was added to a water / isopropanol = 1 / 3 solution, the precipitate was filtered, and after thorough washing with water, it was dried under vacuum to obtain the target polybenzoxazole precursor resin (A-1), in which general formulas (5-4) and (5-5) were randomly copolymerized, with a number average molecular weight of 12,000.

[0261] (Synthesis of photosensitive diazoquinone compounds) 12.74 g (0.030 mol) of the phenol compound shown in formula (1) below and 7.59 g (0.075 mol) of triethylamine were placed in a four-necked separable flask equipped with a thermometer, stirrer, raw material inlet, and dry nitrogen gas inlet tube, and 103 g of acetone was added to dissolve them. After cooling this reaction solution to below 10°C, 20.15 g (0.075 mol) of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride was gradually added dropwise along with 100 g of acetone, ensuring that the temperature did not exceed 10°C. After stirring at below 10°C for 5 minutes, the reaction was completed by stirring at room temperature for 5 hours. After filtering the reaction mixture, the reaction mixture was added to a water / methanol = 3 / 1 (volume ratio), the precipitate was filtered and thoroughly washed with water, and then dried under vacuum to obtain the photosensitive diazoquinone compound shown in formula (2) below. [ka] [ka] In formula (2), Q represents a hydrogen atom or a group represented by formula (3), and 83% of the total Q is the group represented by formula (3). In equation (3), * represents a bond.

[0262] (Preparation of photosensitive material 2) 100 g of synthesized polybenzoxazole precursor resin (A-1), 19 g of a photosensitive diazoquinone compound represented by formula (2), 4 g of a hindered phenol antioxidant represented by formula (5), 10 g of a phenol compound represented by formula (4), and 8 g of 3-methacryloxypropyltrimethoxysilane were dissolved in 200 g of γ-butyrolactone, and then filtered through a 0.2 μm Teflon® filter to obtain positive-type photosensitive material 2.

[0263] <Preparation of photosensitive material 3> (Synthesis of Polymer A) 155.1 g of 4,4'-oxydiphthalic acid dianhydride (ODPA) was placed in a 2 L separable flask, and 131.2 g of 2-hydroxyethyl methacrylate (HEMA) and 400 mL of γ-butyrolactone were added. The mixture was stirred at room temperature, and 81.5 g of pyridine was added while stirring to obtain the reaction mixture. After the exothermic reaction was complete, the mixture was allowed to cool to room temperature and left for 16 hours.

[0264] Next, under ice cooling, a solution of 206.3 g of dicyclohexylcarbodiimide (DCC) dissolved in 180 mL of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring. Subsequently, 45.1 g of 4,4'-diaminodiphenyl ether (DADPE) suspended in 350 mL of γ-butyrolactone was added over 60 minutes with stirring. After further stirring at room temperature for 2 hours, 30 mL of ethyl alcohol was added and stirred for 1 hour, and then 400 mL of γ-butyrolactone was added. The precipitate formed in the reaction mixture was removed by filtration to obtain the reaction solution.

[0265] The resulting reaction solution was added to 3 L of ethyl alcohol to produce a precipitate consisting of crude polymer. The crude polymer was filtered off and dissolved in 1.5 L of γ-butyrolactone to obtain a crude polymer solution. The obtained crude polymer solution was added dropwise to 28 L of water to precipitate the polymer, and the resulting precipitate was filtered off and then vacuum dried to obtain a powdered polymer (polymer A).

[0266] (Preparation of photosensitive material 3) 100 g of polymer A was dissolved together with 4 g of the photopolymerization initiator (1-[4-(Phenylthio)phenyl]-3-cyclopentyl propane-1,2-dione-2-(o-benzoyloxime)) and 4 g of tetraethylene glycol dimethacrylate in a mixed solvent consisting of 80 g of N-methyl-2-pyrrolidone and 20 g of ethyl lactate. The viscosity of the resulting solution was adjusted to approximately 35 poise by adding a small amount of the mixed solvent to obtain a negative-type photosensitive material 3.

[0267] <Preparation of photosensitive material 4> (Synthesis of p-hydroxystyrene / styrene copolymer A1) 100 parts by mass of pt-butoxystyrene and styrene were prepared in a molar ratio of 85:15. These were dissolved in 150 parts by mass of propylene glycol monomethyl ether, and under a nitrogen atmosphere, the reaction temperature was maintained at 70°C. Polymerization was carried out by stirring at approximately 160 rpm for 10 hours with 4 parts by mass of azobisisobutyronitrile. Subsequently, sulfuric acid was added to the reaction solution, and the reaction temperature was maintained at 90°C for 10 hours to deprotect pt-butoxystyrene and convert it to hydroxystyrene. Ethyl acetate was added to the obtained copolymer, and the mixture was washed with water five times. The ethyl acetate phase was separated, and the solvent was removed to obtain p-hydroxystyrene / styrene copolymer A1 (hereinafter, p-hydroxystyrene / styrene copolymer A1 may be referred to as "A1").

[0268] (Preparation of photoacid generator and crosslinking agent) As a photoacid generator, we prepared 1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]ethane 1-naphthoquinone-2-diazide-5-sulfonic acid ester (esterification rate approximately 90%, manufactured by AZ Electronic Materials, "TPPA528") (hereinafter, this photoacid generator may be referred to as "B1"). As a crosslinking agent, we prepared hexakis(methoxymethyl)melamine (manufactured by Sanwa Chemical Co., Ltd., "Nicalac MW-30HM") (hereinafter, this crosslinking agent may be referred to as "C1").

[0269] (Synthesis of acrylic resin D1) 55 g of ethyl lactate was weighed into a 100 ml three-necked flask equipped with a stirrer, nitrogen inlet tube, and thermometer, and separately weighed polymerizable monomers (34.7 g n-butyl acrylate (BA), 2.2 g lauryl acrylate (LA), 3.9 g acrylic acid (AA), 2.6 g hydroxybutyl acrylate (HBA), and 1.7 g 1,2,2,6,6-pentamethylpiperidine-4-yl methacrylate (Resonac, "FA-711MM")) and 0.29 g azobisisobutyronitrile (AIBN) were added. At room temperature, approximately While stirring at a rotation speed of 160 rpm, nitrogen gas was flowed at a flow rate of 400 ml / min for 30 minutes to remove dissolved oxygen. Afterward, the nitrogen gas flow was stopped, the flask was sealed, and the temperature was raised to 65°C in a constant temperature water bath for approximately 25 minutes. The polymerization reaction was carried out at this temperature for 10 hours to obtain acrylic resin D1 (hereinafter, acrylic resin D1 may be referred to as "D1"). The polymerization rate at this time was 99%. The weight-average molecular weight of D1 was approximately 22000. The molar ratio of polymerizable monomers in D1 is as follows. BA / LA / AA / HBA / FA711MM=75.5 / 2.5 / 15 / 5 / 2(mol%)

[0270] (Preparation of photosensitive material 4) 80 parts of A1, 20 parts of B1, 5 parts of C1, 20 parts of D1, 120 parts of ethyl lactate as a solvent, and 2 parts of a 50% methanol solution of ureapropyltriethoxysilane as a coupling agent were mixed together, and this mixture was pressure filtered using a 3 μm pore Teflon® filter to prepare photosensitive material 4.

[0271] (Prepare 5 photosensitive materials) As the photosensitive material 5, epoxy resin photosensitive material SU-8 3010 (manufactured by Nippon Kayaku Co., Ltd.) was used.

[0272] <Preparation of photosensitive resin sheet A> A PET film (Toray Industries' "Lumirror T60", 38 μm thick) was prepared as a support. Photosensitive material 1 was uniformly applied to the PET film using a die coater so that the thickness of the photosensitive material layer after drying was 10 μm, and a photosensitive resin sheet A having a photosensitive material layer on a release PET was obtained by drying at 80°C to 110°C for 6 minutes.

[0273] [Example 1] <Fabrication of evaluation boards> (1) Preparation of silicon wafers As a substrate, a silicon wafer with a copper layer laminated on one side (copper foil thickness 1 μm, substrate thickness 0.8 mm, 8-inch size) was prepared and dried in an oven at 130°C for 30 minutes.

[0274] (2) Lamination of thermosetting resin sheets The protective film of thermosetting resin sheet 1 was removed, and the sheet was laminated to one side of the silicon wafer using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., 2-stage build-up laminator, CVP700) so that the thermosetting material layer was in contact with the silicon wafer. Lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, and then pressing at 130°C and a pressure of 0.74 MPa for 45 seconds. Subsequently, a hot press was performed at 120°C and a pressure of 0.5 MPa for 75 seconds.

[0275] (3) Thermosetting of the thermosetting material layer A silicon wafer laminated with a thermosetting resin sheet 1 was placed in a 100°C oven for 30 minutes, then transferred to a 180°C oven for another 30 minutes to heat-cur the thermosetting material layer and form an insulating material layer, after which the support was peeled off. This resulted in a substrate A with an insulating material layer with a thickness of 5 μm.

[0276] (4) Lamination of photosensitive resin sheet A A photosensitive resin sheet A was laminated onto the insulating material layer of substrate A. Specifically, lamination was performed using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., 2-stage build-up laminator, CVP700) so that the photosensitive material layer of substrate A and the photosensitive resin sheet A were in contact. Lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, and then pressing at 80°C and a pressure of 0.74 MPa for 45 seconds. Subsequently, a hot press was performed at 80°C and a pressure of 0.5 MPa for 75 seconds.

[0277] (5) Patterning of the photosensitive material layer After laminating a photosensitive resin sheet A, substrate A was baked at 80°C for 30 seconds and exposed for 1800 msec using a Ushio UX-2240. After exposure, substrate A was baked at 75°C for 180 seconds and then developed with a 2.38% TMAH solution under paddle conditions of 30 seconds x 2. The developed pattern was subjected to descam treatment using a SAMCO plasma apparatus (O2: flow rate 50 sccm, RF power: 500 W, process pressure: 12 Pa, processing time: 1 minute). Subsequently, 5000 mJ / cm³ was applied. 2 A plasma mask with a φ5 μm mask pattern was obtained by performing post-bake with varying exposure levels and finally post-curing. Post-curing was performed by heating at 50°C for 30 minutes followed by 30 minutes of resting, heating at 100°C for 30 minutes followed by 30 minutes of resting, and heating at 190°C at 60°C followed by cooling to 50°C over 30 minutes or more.

[0278] (6) Formation of via holes and plasma dry etching of plasma mask Using a plasma dry etching apparatus (PlasmaPro100 manufactured by Oxford Instruments, with a CF4 / O2 mixing ratio of 80:20 (sccm), vacuum level: 50 mTorr, RF power: 120 W, ICP power: 100 W), plasma treatment was performed on the plasma mask obtained in (5) to form via holes in the insulating material layer. This plasma treatment was performed to the extent that the plasma mask was not completely removed but remained on the insulating material layer.

[0279] (7) Measurement of arithmetic mean roughness (Ra) The arithmetic mean roughness (Ra) of the plasma mask surface after via hole formation was measured using a non-contact surface roughness meter (WYKO NT3300, B. In Instruments). This measurement was performed in VSI mode with a 50x lens, and the measurement range was set to 121 μm × 92 μm.

[0280] (8) Measurement of wall surface roughness (Sa) in the beer hall After forming via holes in the insulating material layer, the mask pattern was polished to create a cross-section, and the roughness of the via hole walls was measured. A laser microscope (Keyence Corporation, "VK-X3000") was used to measure the roughness of the via hole walls.

[0281] (9) Measurement of via taper angle and via expansion ratio The cross-sections before and after via hole formation were observed using a Hitachi High-Tech FIB-SEM (Ethos NX5000), and the via taper angle and via expansion ratio were measured.

[0282] (10) Formation of the conductive layer After forming via holes in the plasma mask, sputtering was performed using a sputtering apparatus (Canon Anelva "E-400S") to form a 10 nm thick titanium layer, followed by a 100 nm thick copper layer. Then, after annealing by heating at 150°C for 30 minutes, etching resist was formed according to the semi-additive method. After exposure and development, a comb-tooth pattern with L / S = 1 / 1 μm (line width 1 mm) was formed, followed by copper sulfate electroplating to form a 2 μm thick conductive layer. After the conductive pattern formation, annealing was performed by heating at 200°C for 60 minutes. The resulting substrate is referred to as "Substrate B".

[0283] <Evaluation of fine wiring (visual evaluation)> The comb-shaped wiring on substrate B was examined using a microscope (Keyence VHX-7000) and evaluated according to the following criteria. Here, "skipped wiring" refers to a situation where the conductor layer was not formed in the intended location, and the comb-shaped pattern of the conductor layer is interrupted midway. 〇: No wiring jump is observed in the comb blade pattern. ×: Wiring jump is observed in the comb blade pattern.

[0284] <Evaluation of insulation after HAST test> The comb blade pattern of substrate B was embedded in the thermosetting material layer of thermosetting resin sheet 1 and cured. Specifically, the protective film of the thermosetting resin sheet was peeled off, and using a batch-type vacuum pressure laminator (manufactured by Nichco Materials Co., Ltd., 2-stage build-up laminator, CVP700), it was laminated so that the thermosetting material layer contacted the conductor layer of substrate B. The lamination was carried out by reducing the pressure for 30 seconds to make the atmospheric pressure 13 hPa or less, and crimping at 130 °C and a pressure of 0.74 MPa for 45 seconds. Next, a hot press was performed at 120 °C and a pressure of 0.5 MPa for 75 seconds. The substrate B after lamination was heated under the conditions of 180 °C for 90 minutes to cure the thermosetting material layer, the electrode part where the comb blade patterns were connected was exposed, a voltage of 1.0 V was applied, and a test of 130 °C 85RH% 200 h was carried out, and the insulation was confirmed according to the following criteria. 〇: The resistance value exceeds 10 6 Ω. ×: The resistance value is 10 6 Ω or less.

[0285] <Measurement of bulk linear thermal expansion coefficient (bulk CTE)> The bulk linear thermal expansion coefficient was obtained using the following calculation formula. Bulk linear thermal expansion coefficient = linear thermal expansion coefficient of the plasma mask after film reduction × (thickness of the plasma mask after film reduction / thickness of the plasma mask after film reduction + thickness of the insulating material layer) + linear thermal expansion coefficient of the insulating material layer × (thickness of the insulating material layer / thickness of the plasma mask after film reduction + thickness of the insulating material layer)

[0286] [Example 2] In Example 1, thermosetting resin sheet 1 was changed to thermosetting resin sheet 2. Except for the above matters, substrate A was produced and evaluated in the same manner as in Example 1.

[0287] [Example 3] In Example 1, thermosetting resin sheet 1 was replaced with thermosetting resin sheet 3. Except for the above, substrate A was fabricated and evaluated in the same manner as in Example 1.

[0288] [Example 4] In Example 1, thermosetting resin sheet 1 was replaced with thermosetting resin sheet 4. Except for the above, substrate A was fabricated and evaluated in the same manner as in Example 1.

[0289] [Example 5] In Example 2, (4) lamination of photosensitive resin sheet A was replaced with (4-1) formation of a coating film of photosensitive material 2, and (5) patterning of the photosensitive material layer was replaced with (5-1) patterning of the coating film of photosensitive material 2. Except for the above, substrate A was fabricated and evaluated in the same manner as in Example 2.

[0290] (4-1) Formation of a coating film of photosensitive material 2 Photosensitive material 2 was applied onto a silicon wafer using a spin coater, and then pre-baked on a hot plate at 120°C for 4 minutes to obtain a coating film with a thickness of approximately 10 μm.

[0291] (5-1) Patterning of the coating film of photosensitive material 2 The coating was exposed to an i-line stepper (Nikon "4425i") at an exposure dose of 280 mJ / cm². 2 The material was exposed under the following conditions. Next, paddle development was performed using a 2.38% aqueous tetramethylammonium hydroxide solution, adjusting the development time so that the difference in film thickness between the pre-baked and unexposed areas after development was 1 μm. After that, a pattern was formed by rinsing with pure water for 10 seconds, and a plasma mask was obtained.

[0292] [Example 6] In Example 2, (4) lamination of photosensitive resin sheet A was replaced with (4-2) formation of a coating film of photosensitive material 3, and (5) patterning of the photosensitive material layer was replaced with (5-2) patterning of the coating film of photosensitive material 3. Except for the above, substrate A was fabricated and evaluated in the same manner as in Example 2.

[0293] (4-2) Formation of a coating film of photosensitive material 3 A photosensitive material 3 was applied to a silicon wafer using a spin coater, and then dried to obtain a coating film with a thickness of 10 μm.

[0294] (5-2) Patterning of the coating film of photosensitive material 3 The coating was exposed to light at 500 mJ / cm² using a ghi stepper (Prisma-ghi, manufactured by Ultratech). 2 The coating was exposed under the specified conditions. Next, the coating was spray-developed using cyclopentanone in a developing machine (Dainippon Screen Mfg. Co., Ltd., "D-SPIN636"). Then, a pattern was formed on the coating by rinsing with propylene glycol methyl ether acetate to remove the unexposed areas. The pattern on the coating was cured in a nitrogen atmosphere at 200°C for 2 hours using a temperature-boosting programmable curing furnace (Koyo Lindbergh Corporation, "VF-2000") to obtain a cured pattern (plasma mask) with a thickness of approximately 9 μm.

[0295] [Example 7] In Example 2, (4) lamination of photosensitive resin sheet A was replaced with (4-3) formation of a coating film of photosensitive material 4, and (5) patterning of the photosensitive material layer was replaced with (5-3) patterning of the coating film of photosensitive material 4. Except for the above, substrate A was fabricated and evaluated in the same manner as in Example 2.

[0296] (4-3) Formation of a coating film of photosensitive material 4 Photosensitive material 4 was spin-coated onto a silicon wafer substrate and heated at 120°C for 4 minutes to form a coating film with a thickness of 10 μm.

[0297] (5-3) Patterning of the coating film of the photosensitive material 4 The coating was exposed to i-line (365nm) light using an i-line stepper (Canon FPA-3000iW). The exposure dose was 460 mJ / cm². 2The image was exposed to light. After exposure, it was developed using a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH). Subsequently, the pattern was heated in a vertical diffusion furnace (Koyo Thermo Systems Co., Ltd., "μ-TF") in nitrogen at a temperature of 200°C (heating time 1.5 hours) for 2 hours to obtain a plasma mask.

[0298] [Example 8] In Example 2, (4) lamination of photosensitive resin sheet A was replaced with (4-4) formation of a coating film of photosensitive material 5, and (5) patterning of the photosensitive material layer was replaced with (5-4) patterning of the coating film of photosensitive material 5. Except for the above, substrate A was fabricated and evaluated in the same manner as in Example 2.

[0299] (4-4) Formation of a coating film of the photosensitive material 5 A photosensitive material 5 was spin-coated onto a silicon wafer substrate and heated at 95°C for 10 minutes to form a coating film with a thickness of 10 μm.

[0300] (5-4) Patterning of the coating film of photosensitive material 5 The coating was exposed to i-line (365nm) light using an i-line stepper (Canon FPA-3000iW). The exposure dose was 200 mJ / cm². 2 The image was exposed to light. After exposure, it was baked at 95°C for 5 minutes. Next, it was developed using SU-8 Developer (manufactured by Nippon Kayaku Co., Ltd.). Then, the pattern was heated in a vertical diffusion furnace (Koyo Thermo Systems Co., Ltd., "μ-TF") in nitrogen at a temperature of 200°C (heating time 1.5 hours) for 2 hours to obtain a plasma mask.

[0301] [Comparative Example 1] In Example 2, (3) thermosetting of the thermosetting material layer, (4) lamination of the photosensitive resin sheet A, and (5) patterning of the photosensitive material layer were changed to the following steps. Except for the above, the substrate B was fabricated and evaluated in the same manner as in Example 2.

[0302] After laminating the thermosetting resin sheet 2, the support was peeled off, and copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., "MT-EX") was laminated onto the thermosetting material layer by reducing the pressure to 13 hPa or less for 30 seconds, pressing it at 130°C and a pressure of 0.74 MPa for 45 seconds, and then performing a hot press at 120°C and a pressure of 0.5 MPa for 75 seconds.

[0303] A silicon wafer laminated with copper foil was placed in a 100°C oven for 30 minutes, and then transferred to a 180°C oven for another 30 minutes to heat-cur the thermosetting material layer and form an insulating material layer.

[0304] After peeling off the copper foil carrier support, a photosensitive film (Showa Denko Materials, "RY5115") was attached using a laminating device (Nikko Materials, "V-160"), and exposed to light at 125 mJ using a Ushio Inc. UX-2240. The photosensitive film was developed with Mitsubishi Gas Chemical's EF-105A, diluted five times with pure water, to obtain a φ7 μm mask pattern.

[0305] This mask was prepared by dissolving the copper foil with an etching solution (JCU Corporation, "SACII-710W3C", approximately 1020 mL of Millipore water, 36 g of CuSO4·5H2O, 80 mL of 75% H2SO4, 24 mL of SACII, and 260 mL of 35% H2O). Then, the mask pattern was peeled off using 180 mL of stripping solution (Mitsubishi Gas Chemical Corporation, "R-100S"), 97 mL of stripping solution (Mitsubishi Gas Chemical Corporation, "R-101"), and 923 mL of Millipore water to obtain a φ12 μm Cu mask pattern.

[0306] In Comparative Example 1, we attempted to form via holes and a conductor layer using a Cu mask pattern. However, due to the high surface roughness and the difficulty in etching for forming the plating seed layer, we were unable to form a conductor layer with a wiring pattern of L / S = 1 / 1 μm.

[0307] [Comparative Example 2] In Example 2, steps (4) lamination of photosensitive resin sheet A, (5) patterning of the photosensitive material layer, and (6) formation of via holes were changed to the following steps. Except for the above, substrate B was fabricated and evaluated in the same manner as in Example 2.

[0308] After curing the thermosetting material layer of the thermosetting resin sheet 2, a photosensitive film (Showa Denko Materials, "RY5115") was attached using a laminating device (Nikko Materials, "V-160"), and exposed to light at 125 mJ using a Ushio Inc. UX-2240. The photosensitive film was developed with Mitsubishi Gas Chemical's EF-105A, diluted five times with pure water, to obtain a φ7 μm mask pattern.

[0309] A plasma dry etching system (Oxford Instruments PlasmaPro100, CF4 / O2 mixture ratio 80:20 (sccm), vacuum: 50 mTorr, RF power: 120 W, ICP power: 100 W) was used to perform plasma treatment on a mask pattern, forming via holes in the insulating material layer. Subsequently, the mask pattern was removed using a stripping solution (Mitsubishi Gas Chemical Company, "R-100S"). It was confirmed that areas of the insulating material layer that came into contact with the stripping solution during the mask pattern removal were chemically damaged.

[0310] [Comparative Example 3] In Example 2, steps (4) lamination of photosensitive resin sheet A, (5) patterning of the photosensitive material layer, and (6) formation of via holes were changed to the following steps. Except for the above, substrate B was fabricated and evaluated in the same manner as in Example 2.

[0311] An aperture was created on the insulating material layer of substrate A using a UV laser (LUK-2K21 (Viamechanics)), and then wet desmear treatment was performed.

[0312] Subsequently, an attempt was made to form a conductor layer with a wiring pattern of L / S = 1 / 1 μm by forming a plated seed layer using electroless plating. However, due to the high arithmetic mean roughness (Ra) of the insulating material layer surface, the non-uniformity of the electroless plating resulted in poor wiring formation, and the layer could not be formed.

[0313] [Comparative Example 4] In Example 1, (2) lamination of the thermosetting resin sheet, (3) thermosetting of the thermosetting material layer, (4) lamination of the photosensitive resin sheet A, (5) patterning of the photosensitive material layer, and (6) formation of via holes were changed to the following steps. Except for the above, substrate B was fabricated and evaluated in the same manner as in Example 1.

[0314] The protective film of photosensitive resin sheet A was removed, and the photosensitive material layer was laminated to one side of the silicon wafer using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., 2-stage build-up laminator, CVP700) so that the photosensitive material layer was in contact with the silicon wafer. Lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, and then pressing at 130°C and a pressure of 0.74 MPa for 45 seconds. Subsequently, a hot press was performed at 120°C and a pressure of 0.5 MPa for 75 seconds.

[0315] After laminating a photosensitive resin sheet A, substrate A was baked at 80°C for 30 seconds and exposed for 1800 msec using a Ushio UX-2240. After exposure, substrate A was baked at 75°C for 180 seconds and then developed with a 2.38% TMAH solution under paddle conditions of 30 seconds x 2. The developed pattern was subjected to descam treatment using a SAMCO plasma apparatus (O2: flow rate 50 sccm, RF power: 500 W, process pressure: 12 Pa, processing time: 1 minute). Subsequently, 5000 mJ / cm³ was applied. 2 An insulating material layer with via holes was obtained by performing post-baking based on exposure levels and finally post-curing.

[0316] [Comparative Example 5] In Comparative Example 1, thermosetting resin sheet 2 was replaced with thermosetting resin sheet 1. Except for the above, substrate B was fabricated and evaluated in the same manner as in Comparative Example 1.

[0317] In Comparative Example 5, an attempt was made to form via holes and a conductive layer using a Cu mask pattern. However, due to the high surface roughness of the cured thermosetting material, etching for forming the plating seed layer was difficult, and therefore it was not possible to form a conductive layer with a wiring pattern of L / S = 1 / 1 μm.

[0318] [Comparative Example 6] In Comparative Example 2, thermosetting resin sheet 2 was replaced with thermosetting resin sheet 1. Except for the above, substrate B was fabricated and evaluated in the same manner as in Comparative Example 2.

[0319] [Comparative Example 7] In Comparative Example 3, thermosetting resin sheet 2 was replaced with thermosetting resin sheet 1. Except for the above, substrate B was fabricated and evaluated in the same manner as in Comparative Example 3. In Comparative Example 7, an attempt was made to form a conductive layer with a wiring pattern of L / S = 1 / 1 μm by forming a plating seed layer by electroless plating. However, due to the high arithmetic mean roughness (Ra) of the insulating material layer surface, the non-uniformity of the electroless plating resulted in poor wiring formation, and the wiring could not be formed.

[0320] [Table 2] [Table 3]

[0321] <Preparation of hardened material samples> Photosensitive materials 1 to 5 were each coated onto a release PET sheet using a blade to a thickness of 140 μm. The solution on the release PET sheet was heated at 80°C for 20 minutes using a heating device to form a photosensitive resin sheet with a photosensitive material layer. The photosensitive material layer was peeled off the release PET sheet, and the photosensitive material layer was attached to a metal frame with heat-resistant tape. An additional curing period was performed at 200°C for 120 minutes (only the photosensitive resin sheet using photosensitive material 2 was cured at 230°C for 120 minutes) to prepare a cured sample. For photosensitive material 1, the curing temperature was 3000 mJ / cm². 2 Exposure was performed under these conditions, followed by additional thermal curing.

[0322] Thermosetting materials 1 to 4 were uniformly applied to a polyimide film using a die coater so that the thickness of the thermosetting material layer after drying was 20 μm. A resin sheet having a thermosetting material layer on a polyimide film was then prepared by drying at 70°C to 95°C for 2 minutes. Next, after curing at 200°C for 120 minutes, the polyimide film was peeled off to obtain a cured sample.

[0323] <Measurement of glass transition temperature and linear thermal expansion coefficient> The cured sample obtained above was cut into pieces 20 mm long and 6 mm wide to obtain evaluation cured materials. For these evaluation cured materials, a thermomechanical analyzer (TMA) manufactured by Rigaku Corporation was used to obtain the first TMA curve using the tensile loading method, with a heating rate of 5°C / min from 25°C to 250°C. Subsequently, the same measurement was performed on the same evaluation cured material, and a second TMA curve was obtained using the tensile loading method, with a heating rate of 5°C / min from 25°C to 250°C. From the second TMA curve obtained, the glass transition temperature Tg (°C) and the coefficient of linear thermal expansion (CTE: (ppm / °C)) were determined.

[0324] <Measurement of Dielectric Loss Tangent and Dielectric Constant> The cured material samples obtained above were cut into test pieces with a width of 2 mm and a length of 80 mm. Three of these test pieces were measured using the cavity resonance perturbation method with an Agilent Technologies HP8362B at a measurement frequency of 5.8 GHz and a measurement temperature of 23 °C, and the average values ​​were determined as the dielectric loss tangent and dielectric constant.

[0325] <Evaluation of elastic modulus and elongation at break> For thermosetting materials, cured samples were cut into dumbbell-shaped No. 1 specimens to obtain test pieces. For photosensitive materials, the No. 1 dumbbell-shaped samples were exposed and developed, the photosensitive material layer was attached to a metal frame with heat-resistant tape, and cured at 200°C for an additional 120 minutes (only the photosensitive resin sheet using photosensitive material 2 was cured at 230°C for 120 minutes) to prepare test pieces. For photosensitive material 1, the curing temperature was 3000 mJ / cm². 2 Exposure was performed under the specified conditions, followed by additional heat curing. The resulting test specimens were subjected to tensile strength measurements using an Orientec RTC-1250A tensile testing machine, and the modulus of elasticity and elongation at break were measured at 23°C. The measurements were performed in accordance with JIS K7127. Ten measurements were taken (n=10), and the average value of the top three elongations was calculated.

[0326] [Table 4] [Explanation of Symbols]

[0327] 10 circuit boards 11. Insulating material layer 12. Inner layer circuit board 20 Photosensitive material layer 21. Plasma mask (permanent film) 22 First photosensitive material layer 23. Second photosensitive material layer 24. First Plasma Mask (Permanent Film) 25. The second plasma mask 211 Opening 212 Opening 30 Beer Hall 31 Trench 40 Pattern Conductor Layers 41 Plating seed layer 42 Electroplating layer

Claims

1. (1) A step of preparing a substrate comprising a conductor circuit and an insulating material layer formed of a cured product of a thermosetting material on the conductor circuit, and forming a photosensitive material layer on the surface of the insulating material layer by either coating or attaching a photosensitive material or both. (2) A step of exposing and developing a photosensitive material layer to form a plasma mask having an opening, (3) A step of irradiating an insulating material layer with plasma through a plasma mask to form via holes and trenches, or both, in the insulating material layer located at the openings of the plasma mask, and reducing the thickness of the plasma mask, (4) A method for manufacturing a wiring board, comprising the step of forming a conductive layer on the surface of a reduced-thickness plasma mask and on either or both of the surfaces of via holes and trenches, The photosensitive material used in step (1) contains at least one selected from a resin that can be developed with a developer and an epoxy resin, A method for manufacturing a wiring board, wherein the resin that can be developed with a developing solution contains one or more selected from an alkali-soluble resin having a phenolic hydroxyl group in its molecule, a polyimide precursor, a polybenzoxazole precursor resin, and an acrylic resin.

2. (1) A step of preparing a substrate comprising a conductor circuit and an insulating material layer formed of a cured product of a thermosetting material on the conductor circuit, and forming a photosensitive material layer on the surface of the insulating material layer by either coating or attaching a photosensitive material or both. (2) A step of exposing and developing a photosensitive material layer to form a plasma mask having an opening, (3) A step of irradiating an insulating material layer with plasma through a plasma mask to form via holes and trenches, or both, in the insulating material layer located at the openings of the plasma mask, and reducing the thickness of the plasma mask, (4) A method for manufacturing a wiring board, comprising the step of forming a conductive layer on the surface of a reduced-thickness plasma mask and on either or both of the surfaces of via holes and trenches, Step (4) is (4-1) A step of forming a plating seed layer on the surface of the reduced-thickness plasma mask and on either or both of the via holes and trenches, and (4-2) The process includes a step of forming a conductive layer by plating on a plating seed layer, Step (4-2) is (4-2-1) A step of forming a mask pattern that exposes a portion of the plating seed layer. (4-2-2) A step of forming an electroplated layer on an exposed plated seed layer by electroplating, and (4-2-3) A method for manufacturing a wiring board, comprising the steps of removing a mask pattern and removing an unnecessary plating seed layer by etching.

3. Step (4) is (4-1) A step of forming a plating seed layer on the surface of the reduced-thickness plasma mask and on either or both of the via holes and trenches, and (4-2) A method for manufacturing a wiring board according to claim 1, comprising the step of performing plating on a plating seed layer to form a conductor layer.

4. A method for manufacturing a wiring board according to claim 1 or 2, wherein the conductor layer includes either or both of the following: a conductor wiring formed at a location other than the opening of the plasma mask, and a conductor via layer formed at the opening of the plasma mask.

5. A method for manufacturing a wiring board according to claim 2 or 3, wherein a plating seed layer is formed by a dry plating method.

6. A method for manufacturing a wiring board according to claim 1 or 2, wherein the diameter of the opening of the via hole or trench is 20 μm or less.

7. The method for manufacturing a wiring board according to claim 1 or 2, wherein the thickness of the reduced plasma mask after the completion of step (3) is 0.1 μm or more and 20 μm or less.

8. A method for manufacturing a wiring board according to claim 1 or 2, wherein the wiring pitch of the conductor circuit is 0.2 μm or more and 10 μm or less.

9. The method for manufacturing a wiring board according to claim 1 or 2, wherein the arithmetic mean roughness (Ra) of the reduced plasma mask surface after step (3) is 100 nm or less.

10. A method for manufacturing a wiring board according to claim 1 or 2, wherein the roughness (Sa) of the wall surface of a via hole or trench is 400 nm or less.

11. The method for manufacturing a wiring board according to claim 1 or 2, wherein the ratio (Ra / Sa) of the arithmetic mean roughness (Ra) of the reduced plasma mask surface after step (3) to the roughness (Sa) of the wall surface of the via hole or trench is 3 or less.

12. A method for manufacturing a wiring board according to claim 1 or 2, wherein the thickness of the photosensitive material layer is 1 μm or more and 100 μm or less.

13. The method for manufacturing a wiring board according to claim 1 or 2, wherein the thickness of the reduced plasma mask after the completion of step (3) is 0.7 or less, when the thickness of the plasma mask before plasma irradiation is set to 1.

14. A method for manufacturing a wiring board according to claim 1 or 2, wherein the absolute value of the difference between the linear thermal expansion coefficient of the cured photosensitive material and the linear thermal expansion coefficient of the cured insulating material in the range of 25°C to 150°C is 60 ppm / °C or less.

15. A method for manufacturing a wiring board according to claim 1 or 2, wherein the thickness of the reduced plasma mask after step (2) is T1, and the thickness of the insulating material layer after step (2) is T2, satisfying the relationship T1 > T2.

16. A method for manufacturing a wiring board according to claim 1 or 2, wherein when the thickness of the reduced plasma mask after step (3) is T3 and the thickness of the insulating material layer after step (3) is T4, the relationship T3 < T4 is satisfied.

17. A method for manufacturing a wiring board according to claim 1 or 2, wherein the absolute value of the difference between the glass transition temperature of the photosensitive material contained in the plasma mask and the glass transition temperature of the thermosetting material is 100°C or less.

18. A method for manufacturing a wiring board according to claim 1 or 2, wherein the via taper angle of the via hole or trench is 65 degrees or more and 90 degrees or less.

19. A method for manufacturing a wiring board according to claim 1 or 2, wherein the via expansion rate is 105% or more and 150% or less.

20. A method for manufacturing a wiring board according to claim 1 or 2, wherein the relative permittivity of the cured photosensitive material and the relative permittivity of the cured thermosetting material are both 3.5 or less.

21. A method for manufacturing a wiring board according to claim 1 or 2, wherein the elongation at break of the cured product of the photosensitive material is 10% or more, and the elongation at break of the cured product of the photosensitive material is greater than the elongation at break of the cured product of the thermosetting material.

22. A method for manufacturing a wiring board according to claim 1 or 2, wherein the etching rate in step (3) is 100 nm / min or more.

23. A method for manufacturing a wiring board according to claim 1 or 2, wherein the line (width of the conductor layer) / space (width between conductor layers) (L / S) of the conductor layer is 5 μm / 5 μm or less.

24. A method for manufacturing a wiring board according to claim 1 or 2, wherein the wiring board substrate is a multilayer wiring board substrate containing three or more conductive layers.

25. The area of ​​the wiring board is 2500 mm². ２ The method for manufacturing a wiring board according to claim 1 or 2.

26. The method for manufacturing a wiring board according to claim 2, wherein the photosensitive material used in step (1) contains at least one selected from a resin that can be developed with a developer and an epoxy resin.

27. The method for producing a wiring board according to claim 26, wherein the resin that can be developed with a developing solution contains one or more selected from an alkali-soluble resin having a phenolic hydroxyl group in its molecule, a polyimide precursor, a polybenzoxazole precursor resin, and an acrylic resin.

28. A method for manufacturing a wiring board according to claim 1 or 2, wherein the photosensitive material used in step (1) contains an inorganic filler, and the amount of the inorganic filler in the photosensitive material is 10% by mass or less with respect to 100% by mass of the nonvolatile components of the photosensitive material.

29. A method for manufacturing a wiring board according to claim 1 or 2, wherein the thermosetting material contains an inorganic filler, and the amount of the inorganic filler in the thermosetting material is 20% by mass or more based on 100% by mass of the non-volatile components of the thermosetting material.

30. The method for manufacturing a wiring board according to claim 29, wherein the content of the inorganic filler is 35% by mass or more and 90% by mass or less, based on 100% by mass of the nonvolatile components of the thermosetting material.

31. A method for manufacturing a wiring board according to claim 1 or 2, wherein the photosensitive material used in step (1) contains an inorganic filler, the average particle size of the inorganic filler in the photosensitive material is 0.2 μm or less, and the thermosetting material contains an inorganic filler, the average particle size of the inorganic filler is 0.01 μm or more.

32. The method for manufacturing a wiring board according to claim 1 or 2, wherein the coefficient of linear thermal expansion of the bulk material, consisting of the reduced plasma mask after step (3) and the insulating material layer, in the range of 25°C to 150°C is 100 ppm / °C or less.

33. The method for manufacturing a wiring board according to claim 1 or 2, wherein the photosensitive material used in step (1) is a solvent-developable negative-type photosensitive polyimide resin.

34. A method for manufacturing a wiring board according to claim 1 or 2, wherein step (1) includes at least one of: applying a liquid photosensitive material; and attaching a photosensitive material layer of a photosensitive resin sheet, which includes a support and a photosensitive material layer formed of a photosensitive material provided on the support.

35. A method for manufacturing a wiring board according to claim 1 or 2, wherein the total thickness of the insulating material layer and the reduced-thickness plasma mask is 15 μm or less.

36. A method for manufacturing a wiring board according to claim 1 or 2, comprising the steps of attaching a thermosetting material layer of a thermosetting resin sheet, which includes a support and a thermosetting material layer formed of a thermosetting material provided on the support, to a conductor circuit, and curing the thermosetting material layer to form an insulating material layer.

37. (A) A step of preparing a substrate comprising a conductor circuit and an insulating material layer formed of a cured product of a thermosetting material on the conductor circuit, and forming a first photosensitive material layer by applying and / or attaching a first photosensitive material to the surface of the insulating material layer, (B) A step of exposing and developing a first photosensitive material layer to form a first plasma mask having an opening. (C) A step of irradiating an insulating material layer with plasma through a first plasma mask to form via holes and trenches, or both, in the insulating material layer located at the openings of the plasma mask, and reducing the thickness of the plasma mask. (D) A step of forming a second photosensitive material layer by either applying or attaching a second photosensitive material to cover the surface and openings of the first plasma mask, (E) A step of exposing and developing a second photosensitive material layer to form a second plasma mask having an opening. (F) A step of irradiating the first plasma mask and the insulating material layer with plasma via the second plasma mask to form via holes and trenches, or both, in the insulating material layer. (G) A step of forming a conductive layer on the surface of the first plasma mask and on either or both of the via holes and trenches, and (H) A method for manufacturing a wiring board, which includes a step of scraping the surface of a conductor layer, The photosensitive material used in step (1) contains at least one selected from a resin that can be developed with a developer and an epoxy resin, A method for manufacturing a wiring board, wherein the resin that can be developed with a developing solution contains one or more selected from an alkali-soluble resin having a phenolic hydroxyl group in its molecule, a polyimide precursor, a polybenzoxazole precursor resin, and an acrylic resin.

38. (A) A step of preparing a substrate comprising a conductor circuit and an insulating material layer formed of a cured product of a thermosetting material on the conductor circuit, and forming a first photosensitive material layer by applying and / or attaching a first photosensitive material to the surface of the insulating material layer, (B) A step of exposing and developing a first photosensitive material layer to form a first plasma mask having an opening. (C) A step of irradiating an insulating material layer with plasma through a first plasma mask to form via holes and trenches, or both, in the insulating material layer located at the openings of the plasma mask, and reducing the thickness of the plasma mask. (D) A step of forming a second photosensitive material layer by either applying or attaching a second photosensitive material to cover the surface and openings of the first plasma mask, (E) A step of exposing and developing a second photosensitive material layer to form a second plasma mask having an opening. (F) A step of irradiating the first plasma mask and the insulating material layer with plasma via the second plasma mask to form via holes and trenches, or both, in the insulating material layer. (G) A step of forming a conductive layer on the surface of the first plasma mask and on either or both of the via holes and trenches, and (H) A method for manufacturing a wiring board, which includes a step of scraping the surface of a conductor layer, Step (4) is (4-1) A step of forming a plating seed layer on the surface of the reduced-thickness plasma mask and on either or both of the via holes and trenches, and (4-2) The process includes a step of forming a conductive layer by plating on a plating seed layer, Step (4-2) is (4-2-1) A step of forming a mask pattern that exposes a portion of the plating seed layer. (4-2-2) A step of forming an electroplated layer on an exposed plated seed layer by electroplating, and (4-2-3) A method for manufacturing a wiring board, comprising the steps of removing a mask pattern and removing an unnecessary plating seed layer by etching.

39. A wiring board manufactured by the wiring board manufacturing method described in any one of claims 1, 2, 37, or 38.

40. The wiring board according to claim 39, comprising a conductor circuit, an insulating material layer, a plasma mask, and a conductor layer in that order, and having via holes.

41. The wiring board according to claim 40, comprising two or more conductor circuits, insulating material layers, plasma masks, conductor layers, and via holes.

42. A semiconductor device containing a wiring board manufactured by the wiring board manufacturing method described in any one of claims 1, 2, 37, or 38.

43. The semiconductor device according to claim 42, having a fan-out structure.

44. A semiconductor device according to claim 42, having a chiplet structure.

45. A semiconductor device having a semiconductor chip on a wiring board manufactured by the manufacturing method described in any one of claims 1, 2, 37, or 38.

46. The semiconductor device according to claim 42, wherein the semiconductor chip is a mixed system of at least a logic die and a memory die.