WO2025004499A1 - 配線板の製造方法 - Google Patents

配線板の製造方法 Download PDF

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Publication number
WO2025004499A1
WO2025004499A1 PCT/JP2024/014762 JP2024014762W WO2025004499A1 WO 2025004499 A1 WO2025004499 A1 WO 2025004499A1 JP 2024014762 W JP2024014762 W JP 2024014762W WO 2025004499 A1 WO2025004499 A1 WO 2025004499A1
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WIPO (PCT)
Prior art keywords
resin
insulating layer
layer
wiring board
manufacturing
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PCT/JP2024/014762
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English (en)
French (fr)
Japanese (ja)
Inventor
大地 岡崎
一郎 小椋
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味の素株式会社
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Priority to JP2025529462A priority Critical patent/JPWO2025004499A1/ja
Publication of WO2025004499A1 publication Critical patent/WO2025004499A1/ja

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/12—Mountings, e.g. non-detachable insulating substrates
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/46—Manufacturing multilayer circuits

Definitions

  • the present invention relates to a method for manufacturing a wiring board.
  • Wiring boards such as printed wiring boards, package substrates, and interposers generally include an insulating layer and a conductor layer on which wiring can be formed.
  • via holes or trenches may be formed in the insulating layer of a wiring board (see Patent Document 1).
  • a "via hole” refers to a hole that penetrates the insulating layer.
  • a “trench” refers to a recess that does not penetrate the insulating layer, and is generally formed in a groove shape.
  • the cross-sectional shapes of the via holes and trenches are expressed by the taper angle, which is the angle that the side of the via hole or trench makes with the plane of the insulating layer.
  • This taper angle is generally required to be close to 90°, but the taper angle of the via holes and trenches formed by the conventional method was small.
  • Patent Document 1 The inventors have proposed a method of forming via holes or trenches by plasma treatment. Specifically, the inventors have proposed a method of forming a via hole or trench by forming a mask on an insulating layer using photoresist and performing plasma treatment on the insulating layer through the mask. With plasma treatment, the insulating layer can be removed by scraping in the thickness direction, so that a taper angle close to 90° can be expected to be obtained.
  • this method requires a complicated process to form a via hole or trench.
  • the method described in Patent Document 1 requires that the mask be removed by performing a chemical treatment after the formation of the via hole or trench. Generally, chemical treatment requires time. In addition, cleaning and drying are usually required after the chemical treatment, so the number of steps increases. Furthermore, with chemical treatment, the chemical may come into contact with not only the mask but also the insulating layer, and the chemical may damage the insulating layer.
  • the present invention was devised in consideration of the above problems, and aims to provide a new manufacturing method that can easily manufacture wiring boards that have an insulating layer in which via holes or trenches with good cross-sectional shapes are formed.
  • the present inventors have conducted extensive research to solve the above problems. As a result, the present inventors have found that a wiring board having an insulating layer in which a via hole or trench having a good cross-sectional shape is formed can be easily manufactured by a manufacturing method including, in this order, a step (I) of preparing a laminate having a substrate, an insulating layer, and a thermoplastic film, a step (II) of forming a recess in the thermoplastic film, a step (III) of forming one or both of a via hole and a trench in the insulating layer by plasma treatment, and a step (IV) of peeling off the thermoplastic film, and have completed the present invention. That is, the present invention includes the following.
  • a method for manufacturing a wiring board comprising the steps of: [2] Step (I) is A step (I-1) of forming a resin composition layer containing a resin composition on a substrate; and Step (I-2) of curing the resin composition layer
  • step (II) includes forming recesses in the thermoplastic film by laser light.
  • step (II) includes pressing the thermoplastic film with a mold.
  • step (II) includes forming a recess so that the substrate is not exposed at a bottom of the recess.
  • step (III) includes irradiating the thermoplastic film with plasma to reduce the thickness of the thermoplastic film and at the same time remove the insulating layer in a portion below the recess to form one or both of a via hole and a trench.
  • the present invention provides a new manufacturing method that can easily produce wiring boards that have an insulating layer in which via holes or trenches with good cross-sectional shapes are formed.
  • FIG. 1 is a cross-sectional view that typically shows an intermediate laminate prepared in step (I) of a method for producing a wiring board according to a first embodiment of the present invention.
  • FIG. 2 is a schematic cross-sectional view illustrating a preferred example of a method for producing an intermediate laminate.
  • FIG. 3 is a schematic cross-sectional view for illustrating step (II) of the method for manufacturing a wiring board according to the first embodiment of the present invention.
  • FIG. 4 is a schematic cross-sectional view for illustrating step (II) of the method for manufacturing a wiring board according to the first embodiment of the present invention.
  • FIG. 5 is a schematic cross-sectional view for illustrating step (II) of the method for manufacturing a wiring board according to the first embodiment of the present invention.
  • FIG. 1 is a cross-sectional view that typically shows an intermediate laminate prepared in step (I) of a method for producing a wiring board according to a first embodiment of the present invention.
  • FIG. 2 is a schematic cross-
  • FIG. 6 is a schematic cross-sectional view for illustrating step (III) of the method for manufacturing a wiring board according to the first embodiment of the present invention.
  • FIG. 7 is a cross-sectional view that typically shows a wiring board obtained by the method for producing a wiring board according to the first embodiment of the present invention.
  • FIG. 8 is a schematic cross-sectional view for illustrating step (II) of the method for manufacturing a wiring board according to the second embodiment of the present invention.
  • FIG. 9 is a schematic cross-sectional view for illustrating step (II) of the method for manufacturing a wiring board according to the second embodiment of the present invention.
  • FIG. 10 is a schematic cross-sectional view for illustrating step (II) of the method for manufacturing a wiring board according to the second embodiment of the present invention.
  • FIG. 11 is a schematic cross-sectional view for illustrating step (III) of the method for manufacturing a wiring board according to the second embodiment of the present invention.
  • FIG. 12 is a cross-sectional view that typically shows a wiring board obtained by the method for producing a wiring board according to the second embodiment of the present invention.
  • FIG. 13 is a schematic cross-sectional view for illustrating step (II) of the method for manufacturing a wiring board according to the third embodiment of the present invention.
  • FIG. 14 is a schematic cross-sectional view for illustrating step (II) of the method for manufacturing a wiring board according to the third embodiment of the present invention.
  • FIG. 11 is a schematic cross-sectional view for illustrating step (III) of the method for manufacturing a wiring board according to the second embodiment of the present invention.
  • FIG. 12 is a cross-sectional view that typically shows a wiring board obtained by the method for producing a wiring board according to the second embodiment of the present invention.
  • FIG. 13 is a schematic cross-sectional view
  • FIG. 15 is a schematic cross-sectional view for illustrating step (II) of the method for manufacturing a wiring board according to the third embodiment of the present invention.
  • FIG. 16 is a schematic cross-sectional view for illustrating step (III) of the method for manufacturing a wiring board according to the third embodiment of the present invention.
  • FIG. 17 is a cross-sectional view that typically shows a wiring board obtained by the method for producing a wiring board according to the third embodiment of the present invention.
  • the method for manufacturing a wiring board according to the first embodiment of the present invention includes the steps of: A step (I) of preparing a laminate having a substrate, an insulating layer, and a thermoplastic film in this order; Step (II) of forming recesses in the thermoplastic film; A step (III) of forming a via hole and/or a trench in the insulating layer by plasma treatment; and a step (IV) of peeling off the thermoplastic film. in that order.
  • the laminate prepared in step (I) is sometimes referred to as the "intermediate laminate," the substrate provided in the intermediate laminate is sometimes referred to as the “inner layer substrate,” and the thermoplastic film provided in the intermediate laminate is sometimes referred to as the "mask film.”
  • a resin film provided with a thermoplastic resin layer is usually used as the mask film.
  • the recess formed in the mask film in step (II) refers to a portion that is recessed more than the surrounding area, and includes both a depression that does not penetrate the mask film in the thickness direction, and a through hole that penetrates the mask film in the thickness direction.
  • a recess is formed in the mask film in step (II).
  • the thickness of the mask film is relatively smaller than that of the portion other than the recess, or the mask film is absent. Therefore, when the insulating layer is subjected to a plasma treatment in step (III), the mask film functions as a plasma mask, so that the insulating layer in the portion below the recess can be selectively removed to form a via hole and/or a trench in that portion.
  • the "portion below the recess" of the insulating layer refers to the portion of the insulating layer corresponding to the recess, and more specifically, refers to the portion of the insulating layer that is in the same position as the recess when the intermediate laminate is viewed in the thickness direction. Therefore, the formed via hole and/or trench can have the same pattern shape as the pattern shape of the recess formed in the mask film. Unless otherwise specified, "pattern shape” refers to the shape viewed in the thickness direction. Then, after forming one or both of the via hole and the trench in step (III), a process (IV) is performed to peel off the mask film, thereby obtaining a wiring board having an inner layer substrate and an insulating layer.
  • the removal of a layer by plasma processing proceeds by scraping the layer in the thickness direction. Therefore, the insulating layer can be removed by plasma processing in the portion below the recess by scraping in the thickness direction. Therefore, the taper angle of the via hole and trench can be made close to 90°, and the cross-sectional shape of the via hole and trench can be improved.
  • a thin portion of the mask film may be formed around the recess, and after the thin portion is scraped by plasma processing, the insulating layer below the thin portion may be scraped, and the taper angle may not be 90°.
  • the mask film provided in the intermediate laminate is a resin film with a thermoplastic resin layer, and can usually have a higher mechanical strength than a typical plasma mask using a photoresist. Therefore, the mask film can be peeled off by simply pulling it, and no chemical treatment is required for peeling. This reduces the number of steps, allowing for simple manufacturing of the wiring board. Also, because no chemical treatment is required, chemical deterioration of the insulating layer caused by chemicals can be suppressed, and as a result, a wiring board can be obtained that has an insulating layer with excellent insulating performance and electrical properties.
  • a metal mask made of metal could be used as the plasma mask.
  • a metal mask requires patterning by exposure and development of a photosensitive material and a metal etching process using chemicals, and its production is time-consuming, costly, and cumbersome.
  • the manufacturing method of the first embodiment using a mask film can easily accommodate changes in the pattern shape of the via holes and/or trenches by changing the formation position of the recesses in the mask film. Therefore, in this sense, the manufacturing method of the first embodiment can simplify the production of wiring boards.
  • via holes and trenches having small openings can usually be formed. Specifically, this is as follows. Generally, the recesses in the mask film are formed to have a bottom surface that is the same as or smaller than the opening of the recess. Furthermore, according to plasma processing, via holes and/or trenches having openings that are the same as or smaller than the opening of the recess can be formed, specifically via holes and/or trenches having openings that are the same as or slightly larger than the bottom surface of the recess can be formed. Therefore, it is possible to manufacture wiring boards having fine circuit wiring, which can contribute to high integration.
  • the method for manufacturing a wiring board according to the first embodiment it is possible to form via holes and trenches with small openings in an insulating layer that has excellent insulating performance and electrical properties.
  • One of the advantages of the manufacturing method according to the first embodiment using plasma processing is that it is possible to achieve both an insulating layer that has excellent insulating performance and electrical properties and to form via holes and trenches with small openings in the insulating layer. The details are as follows.
  • thermosetting resin compositions tend to have excellent insulating performance and electrical properties.
  • the linear thermal expansion coefficient of the insulating layer can be reduced, so that not only is the insulating performance and electrical properties excellent, but warping during temperature changes can also be suppressed.
  • laser processing can cause resin residue (smear) in the via holes and trenches, and the process of removing the resin residue can cause unevenness in the via holes and trenches, making it difficult to reduce the openings of the via holes and trenches.
  • a resin composition containing an inorganic filler it is particularly difficult to reduce the opening diameter.
  • a method for forming an insulating layer having a via hole and a trench with a small opening has been known in the past to form an insulating layer from a photosensitive resin composition using a photolithography method.
  • the insulating layer can be formed from a material other than a photosensitive resin composition, and therefore the insulating layer can be formed from a material with excellent insulating performance and electrical properties (for example, a cured product of a thermosetting resin composition). Therefore, it is possible to form via holes and trenches with small openings in an insulating layer with excellent insulating performance and electrical properties.
  • plasma processing is performed using the mask film as a plasma mask, making it easy to align the recesses in the mask film with the via holes and trenches formed in the insulating layer.
  • the conventional method generally involves performing a desmear process using an oxidizing agent solution after the via holes or trenches are formed to remove the resin residue.
  • the manufacturing method according to the first embodiment does not require a desmear treatment using an oxidizing agent solution. Since the desmear treatment using an oxidizing agent solution is not required, the manufacturing method according to the first embodiment makes it possible to manufacture a wiring board by a dry process. For example, when an intermediate laminate is manufactured by a dry manufacturing method including laminating a resin sheet and an inner layer substrate and curing the resin composition layer of the resin sheet, the intermediate laminate can be prepared by a dry process in step (I).
  • a dry recess formation method such as laser processing and an imprint method can form a recess in the mask film by a dry process in step (II).
  • a dry conductor layer formation step such as a sputtering method and a vapor deposition method can form a conductor layer by a dry process in step (V). Therefore, when these steps are combined with step (III) of forming via holes and/or trenches by plasma treatment, steps (I) to (V) can be carried out dry to achieve the manufacture of wiring boards using a dry process.
  • the surface of the insulating layer is generally roughened by the oxidizer solution, resulting in an increase in the surface roughness of the insulating layer.
  • the plasma process employed in the first embodiment does not require the desmear process, so the increase in the surface roughness of the insulating layer can be suppressed. Therefore, in the wiring board manufactured by the manufacturing method according to the embodiment described above, the surface roughness of the insulating layer can be reduced, thereby reducing the transmission loss of the conductor layer formed on the surface of the insulating layer.
  • the method for manufacturing a wiring board according to the first embodiment includes a step (I) of preparing an intermediate laminate.
  • Fig. 1 is a cross-sectional view showing an intermediate laminate 10 prepared in step (I) of the method for manufacturing a wiring board according to the first embodiment of the present invention.
  • an intermediate laminate 10 including an inner layer substrate 100, an insulating layer 200, and a mask film 300 in this order in the thickness direction is prepared.
  • the inner layer substrate 100 is usually a member having a support substrate 110 capable of supporting the inner layer substrate 100.
  • the support substrate 110 include a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, and a thermosetting polyphenylene ether substrate.
  • the inner layer substrate 100 may include a conductor layer 120.
  • this conductor layer 120 may be referred to as the "inner layer conductor layer” 120.
  • the inner layer conductor layer 120 may generally form the circuit wiring of the wiring board.
  • the inner layer conductor layer 120 may be formed inside the support substrate 110, or may be formed on the surface of the support substrate 110. In the first embodiment, an example in which the inner layer conductor layer 120 is formed on the surface of the support substrate 110 will be shown and described.
  • the via hole is usually formed so that the inner layer conductor layer 120 appears at the bottom of the via hole.
  • the inner conductor layer 120 typically contains a conductive material.
  • the same conductive material as the conductor layer (circuit conductor layer) that can be formed in step (V) described below can be used.
  • the inner conductor layer 120 may have a single-layer structure, or a multi-layer structure including two or more single metal layers or alloy layers made of different types of metals or alloys.
  • the thickness of the inner conductor layer 120 depends on the design of the desired wiring board, but is generally 3 ⁇ m to 35 ⁇ m, and preferably 5 ⁇ m to 30 ⁇ m.
  • the minimum line/space ratio of the inner conductor layer 120 is preferably small.
  • line refers to the wiring width
  • space refers to the spacing between the wirings.
  • the range of the minimum line/space ratio of the inner conductor layer 120 is preferably 5 ⁇ m/5 ⁇ m or less, more preferably 4 ⁇ m/4 ⁇ m or less, and even more preferably 3 ⁇ m/3 ⁇ m or less, and preferably 0.1 ⁇ m/0.1 ⁇ m or more, more preferably 0.5 ⁇ m/0.5 ⁇ m or more, and even more preferably 1 ⁇ m/1 ⁇ m or more.
  • the wiring pitch of the inner conductor layer 120 is preferably 10 ⁇ m or less, more preferably 8 ⁇ m or less, and even more preferably 6 ⁇ m or less, and preferably 0.2 ⁇ m or more, more preferably 1 ⁇ m or more, and even more preferably 2 ⁇ m or more.
  • the line/space ratio and wiring pitch may each be uniform or non-uniform throughout the inner conductor layer 120.
  • the inner conductor layer 120 can be formed, for example, in the same manner as the method for forming the circuit conductor layer in step (V) described below.
  • the insulating layer 200 is formed on the inner layer substrate 100.
  • the insulating layer 200 may be provided on one side or both sides of the inner layer substrate 100.
  • the insulating layer 200 is formed so as to be in direct contact with the inner layer substrate 100.
  • the "direct" contact between two members means that there is no other member between the two members.
  • the insulating layer 200 may be formed so as to be in direct contact with the inner layer conductor layer 120.
  • the insulating layer 200 is an insulating layer, and is generally formed from a cured product of a resin composition. Therefore, the insulating layer 200 includes a cured product of a resin composition, and preferably includes only a cured product of a resin composition.
  • a material including a curable resin (A) and, as necessary, any optional component can be used.
  • a photocurable resin composition or a thermosetting resin composition may be used. Among them, from the viewpoint of improving the dielectric properties of the insulating layer 200, a thermosetting resin composition is preferred.
  • Examples of the (A) curable resin as the (A) component include thermosetting resin and photocurable resin.
  • As the (A) curable resin only a thermosetting resin may be used, only a photocurable resin may be used, or a combination of a thermosetting resin and a photocurable resin may be used. From the viewpoint of obtaining an insulating layer 200 with excellent dielectric properties, it is preferable that the (A) curable resin contains a thermosetting resin.
  • One type of (A) curable resin may be used alone, or two or more types may be used in combination.
  • thermosetting resin a resin that can be cured when heat is applied can be used.
  • thermosetting resins include epoxy resins, phenolic resins, active ester resins, cyanate ester resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, polyarylene ether resins, and radical polymerizable resins.
  • One type of thermosetting resin may be used alone, or two or more types may be used in combination.
  • the (A) curable resin contains a combination of an epoxy resin and a resin that can react with the epoxy resin to cure the resin composition.
  • the resin that can react with the epoxy resin to cure the resin composition may be referred to as a "curing agent" hereinafter.
  • the curing agent include phenolic resin, active ester resin, cyanate ester resin, carbodiimide resin, acid anhydride resin, amine resin, and benzoxazine resin.
  • One type of curing agent may be used alone, or two or more types may be used in combination.
  • a phenolic resin and an active ester resin may be used in combination as the curing agent.
  • the curable resin preferably contains an epoxy resin having two or more epoxy groups in one molecule as the epoxy resin.
  • the ratio of the epoxy resin having two or more epoxy groups in one molecule to 100% by mass of the non-volatile components 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.
  • Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as “liquid epoxy resins”) and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as “solid epoxy resins”).
  • the resin composition may contain only liquid epoxy resins as the epoxy resin, or may contain only solid epoxy resins, or may contain a combination of liquid epoxy resins and solid epoxy resins.
  • the liquid epoxy resin is preferably one that has two or more epoxy groups in one molecule.
  • Preferred liquid epoxy resins are bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, glycidyl amine type epoxy resins, and epoxy resins having a butadiene structure, with cyclohexane type epoxy resins being more preferable.
  • liquid epoxy resins include DIC's "HP4032", “HP4032D”, and “HP4032SS” (naphthalene type epoxy resins); Mitsubishi Chemical's “828US”, “jER828EL”, “825", and “Epicoat 828EL” (bisphenol A type epoxy resins); Mitsubishi Chemical's “jER807” and “1750” (bisphenol F type epoxy resins); Mitsubishi Chemical's “jER152” (phenol novolac type epoxy resin); Mitsubishi Chemical's "630” and “630LSD” (glycidylamine type epoxy resins).
  • Epoxy resins "ZX1059” (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical &Material; "EX-721” (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX; "Celloxide 2021P” (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel; “PB-3600” (epoxy resin having a butadiene structure) manufactured by Daicel; "ZX1658” and “ZX1658GS” (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Material. These may be used alone or in combination of two or more types.
  • a solid epoxy resin As a solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable.
  • solid epoxy resins include DIC's "HP4032H” (naphthalene type epoxy resin); DIC's “HP-4700” and “HP-4710" (naphthalene type tetrafunctional epoxy resin); DIC's "N-690” (cresol novolac type epoxy resin); DIC's "N-695" (cresol novolac type epoxy resin); DIC's "HP-7200", “HP-7200HH", and “HP-7200H” (dicyclopentadiene type epoxy resin); "EXA-7311", “EXA-7311-G3", “EXA-7311-G4", "EXA-7311-G4S”, "HP6000", "HP6000L” (naphthylene ether type epoxy resin) manufactured by DIC Corporation; "EPPN-502H” (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; “NC7000L” (naphthol novolac type epoxy resin) manufactured by Nippon
  • the mass ratio thereof 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.
  • the resin composition layer of the resin sheet can have appropriate adhesion and sufficient flexibility, improving the handleability of the resin sheet.
  • an insulating layer 200 having sufficient breaking strength can usually be obtained.
  • the epoxy equivalent range of the epoxy resin is preferably 50 g/eq. to 5,000 g/eq., more preferably 60 g/eq. to 3,000 g/eq., even more preferably 80 g/eq. to 2,000 g/eq., and particularly preferably 110 g/eq. to 1,000 g/eq.
  • the epoxy equivalent represents the mass of resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.
  • the weight average molecular weight (Mw) of the epoxy resin is preferably in the range of 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500.
  • the weight average molecular weight of the resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).
  • the amount of epoxy resin is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.
  • the resin components of the resin composition refer to the non-volatile components of the resin composition excluding the inorganic filler (B) described below.
  • phenolic resin a compound having one or more, preferably two or more, hydroxyl groups in one molecule bonded to an aromatic ring such as a benzene ring or a naphthalene ring can be used.
  • a phenolic resin having a novolac structure is preferred.
  • a nitrogen-containing phenolic resin is preferred, and a triazine skeleton-containing phenolic resin is more preferred.
  • a triazine skeleton-containing phenolic novolac resin is preferred from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion.
  • phenolic resins include “MEH-7700”, “MEH-7810", and “MEH-7851” manufactured by Meiwa Kasei Co., Ltd.; “NHN”, “CBN”, and “GPH” manufactured by Nippon Kayaku Co., Ltd.; “SN-170”, “SN-180”, “SN-190”, “SN-475”, “SN-485”, “SN-495”, “SN-375”, and “SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; and "TD-2090", “LA-7052”, “LA-7054”, “LA-3018”, “LA-3018-50P", “LA-1356”, “TD2090”, “TD-2090-60M”, and “EXB-9500” manufactured by DIC Corporation.
  • the amount of phenolic resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, relative to 100% by mass of non-volatile components in the resin composition, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.
  • the amount of phenolic resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.
  • the active ester resin a resin having one or more active ester groups per molecule can be used.
  • a resin 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, is preferred.
  • the active ester resin is preferably one 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.
  • 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.
  • the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.
  • phenol compounds or naphthol compounds include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, ⁇ -naphthol, ⁇ -naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak.
  • dicyclopentadiene-type diphenol compounds refer to diphenol compounds obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.
  • 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 product of phenol novolac, and active ester resins containing a benzoylated product of phenol novolac.
  • active ester resins containing a naphthalene structure and active ester resins containing a dicyclopentadiene-type diphenol structure are more preferred.
  • a "dicyclopentadiene-type diphenol structure” refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.
  • active ester resins include, for example, 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 Corporation); and naphthalene-type active ester resins containing a naphthalene structure such as "HP-B-8151-62T”, “EXB9416-70BK”, “EXB-8100L-65T”, “EXB-8150L-65T”, “EXB-8150-65T", “HPC-8150-60T”, “HPC-8150-62T” (manufactured by DIC Corporation), and "PC1300 -02-65T” (manufactured by Air Water Corporation); "DC808” (manufactured by Mitsubishi Chemical Corporation) as an active ester resin containing
  • the range of the amount of active ester resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, relative to 100% by mass of non-volatile components in the resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.
  • the range of the amount of active ester resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 5% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, based on 100% by mass of the resin components in the resin composition.
  • cyanate ester resins examples include those described in JP 2020-75977 A.
  • the range of the active group equivalent of the curing agent is preferably 50 g/eq. to 3000 g/eq., more preferably 100 g/eq. to 1000 g/eq., even more preferably 100 g/eq. to 500 g/eq., and particularly preferably 100 g/eq. to 300 g/eq.
  • the active group equivalent represents the mass of the curing agent per equivalent of active group.
  • the range of the number of active groups in the curing agent is preferably 0.01 or more, more preferably 0.1 or more, even more preferably 0.2 or more, and preferably 5.0 or less, more preferably 4.0 or less, even more preferably 3.0 or less.
  • the "number of epoxy groups in the epoxy resin” refers to the total value obtained by dividing the mass of the non-volatile components of the epoxy resin present in the resin composition by the epoxy equivalent.
  • the “number of active groups in the curing agent” refers to the total value obtained by dividing the mass of the non-volatile components of the curing agent present in the resin composition by the active group equivalent.
  • the range of the amount of the curing agent is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, relative to 100% by mass of non-volatile components in the resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.
  • the amount of the curing agent is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less.
  • the polyarylene ether resin a resin having a polyarylene ether skeleton and a functional group capable of reacting with heat to form a bond can be used.
  • the functional group include a hydroxy group.
  • the polyarylene ether resin preferably has a functional group such as a hydroxy group at the end.
  • the polyarylene ether resin include a polyphenylene ether resin and a polynaphthylene ether resin, which may be a homopolymer or a copolymer.
  • examples of the homopolymer include those containing 2,6-diC 1-3 alkyl-1,4-phenylene ether units.
  • copolymer examples include those containing a combination of 2,6-diC 1-3 alkyl-1,4-phenylene ether units and 2,3,6-triC 1-3 alkyl-1,4-phenylene ether units.
  • C 1-3 alkyl refers to an alkyl having 1 to 3 carbon atoms.
  • the copolymer may be any of a graft copolymer, a block copolymer, and a random copolymer.
  • An example of a commercially available polyarylene ether resin is Noryl (registered trademark) SA90 manufactured by SABIC.
  • 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 value by the GPC method.
  • radical polymerizable resin a resin having one or more (preferably two or more) radical polymerizable unsaturated groups in one molecule can be used.
  • radical polymerizable unsaturated groups include maleimide groups, vinyl groups, allyl groups, styryl groups, vinylphenyl groups, acryloyl groups, methacryloyl groups, fumaroyl groups, and maleoyl groups.
  • the radical polymerizable resin may have one type of radical polymerizable unsaturated group alone, or may have two or more types in combination.
  • the radical polymerizable resin contains one or more types selected from maleimide resins, (meth)acrylic resins, and styryl resins.
  • maleimide resin a resin having one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) in one molecule can be used.
  • Commercially available maleimide resins include, for example, "BMI-3000J”, “BMI-5000”, “BMI-1400”, “BMI-1500”, “BMI-1700”, and “BMI-689” (all manufactured by Designer Molecules Inc.), which have an aliphatic skeleton (preferably an aliphatic skeleton containing a cyclic structure having 10 or more carbon atoms, more preferably a carbon atom derived from a dimer diamine).
  • Maleimide resins containing an aliphatic skeleton of 36 maleimide resins containing an indane skeleton, as described in the Japan Institute of Invention and Innovation Disclosure Technical Bulletin No. 2020-500211; 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 Daiwa Kasei Co., Ltd.), and “BMI-80” (manufactured by Keiai Kasei Co., Ltd.).
  • the (meth)acrylic resin a resin having one or more (preferably two or more) (meth)acryloyl groups in one molecule can be used.
  • the (meth)acrylic resin may be a monomer or an oligomer.
  • the term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups.
  • a (meth)acrylate monomer can be mentioned.
  • (meth)acrylic resins for example, “A-DOG” (manufactured by Shin-Nakamura Chemical 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.) can be mentioned.
  • styryl resin a resin having one or more (preferably two or more) styryl groups or vinylphenyl groups in one molecule can be used.
  • the styryl resin may be a monomer or an oligomer. Examples of the styryl resin include "OPE-2St”, “OPE-2St 1200", and “OPE-2St 2200” (all manufactured by Mitsubishi Gas Chemical Co., Ltd.). Styryl monomers may be used as the styryl resin.
  • styryl resin examples 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; as well as copolymers of these aromatic divinyl compounds with aromatic monovinyl compounds such as styrene, vinyltoluene, ethylstyrene, and vinylnaphthalene.
  • aromatic divinyl compounds such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,
  • the weight average molecular weight (Mw) of the radical polymerizable resin is preferably 40,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, and particularly preferably 3,000 or less.
  • the lower limit is not particularly limited, but can be, for example, 150 or more.
  • the amount of (A) curable resin is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, based on 100% by mass of the resin components in the resin composition, and is preferably 99% by mass or less.
  • the resin composition may contain an inorganic filler (B) as an optional component.
  • the inorganic filler (B) as the component (B) is usually contained in the resin composition in the form of particles, and can be contained in the insulating layer 200 while maintaining its particulate form.
  • the particles of the inorganic filler (B) themselves are not processed when forming the via holes and trenches, so the taper angle tends to be small.
  • the surface roughness of the walls of the via holes and trenches tends to be high due to the detachment of the particles of the inorganic filler (B).
  • the particles of the inorganic filler (B) themselves can be scraped off by plasma processing, so that the via holes and trenches can be formed while suppressing the detachment of the particles of the inorganic filler (B). Therefore, according to the manufacturing method of the first embodiment, the taper angle can be effectively increased even when a resin composition containing the inorganic filler (B) is used. Therefore, from the viewpoint of effectively utilizing such advantages, it is preferable that the resin composition contains the inorganic filler (B).
  • the inorganic filler may be used alone or in combination of two or more types.
  • Inorganic compounds can be used as the material for the inorganic filler.
  • 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.
  • silica and alumina are preferred, and silica is particularly preferred.
  • examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica.
  • spherical silica is preferred as the silica.
  • 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", and “SO-C1” manufactured by Admatechs Co., Ltd.; "UFP-30”, “DAW-03", and "FB-105FD” manufactured by Denka Co., Ltd.; “Silfil NSS-3N", “Silfil NSS-4N", and “Silfil NSS-5N” manufactured by Tokuyama Corporation; and “Cellspheres” and "MGH-005" manufactured by Taiheiyo Cement Corporation.
  • the specific surface area of the inorganic filler (B) is preferably 1 m 2 /g or more, more preferably 2 m 2 /g or more, and even more preferably 3 m 2 /g or more. There is no particular upper limit, but it can be preferably 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 by using a BET fully automatic specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) to adsorb nitrogen gas onto the surface of a sample and using a BET multipoint method.
  • the average particle size of (B) the inorganic filler is preferably 0.01 ⁇ m or more, more preferably 0.03 ⁇ m or more, particularly preferably 0.05 ⁇ m or more, and is preferably 5 ⁇ m or less, more preferably 2 ⁇ m or less, and even more preferably 1 ⁇ m or less.
  • the average particle size of the inorganic filler (B) can be measured by a laser diffraction/scattering method based on the Mie scattering theory. Specifically, a particle size distribution of the inorganic filler (B) is created on a volume basis using a laser diffraction/scattering particle size distribution measuring device, and the median diameter is taken as the average particle size.
  • the measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the mixture ultrasonically for 10 minutes.
  • the inorganic filler is treated with a surface treatment agent.
  • the surface treatment agent include vinyl silane coupling agents, (meth)acrylic coupling agents, fluorine-containing silane coupling agents, amino silane coupling agents, epoxy silane coupling agents, mercapto silane coupling agents, silane coupling agents, alkoxy silanes, organo silazane compounds, and titanate coupling agents.
  • One type of surface treatment agent may be used alone, or two or more types may be used in combination.
  • surface treatment agents include, for example, 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-aminopropyltriethoxysilane).
  • Examples include Shin-Etsu Chemical's "KBM573” (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical's “SZ-31” (hexamethyldisilazane), Shin-Etsu Chemical's "KBM103” (phenyltrimethoxysilane), Shin-Etsu Chemical's "KBM-4803” (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical's "KBM-7103” (3,3,3-trifluoropropyltrimethoxysilane).
  • the degree of surface treatment with the surface treatment agent is preferably within a specific range from the viewpoint of improving the dispersibility of the (B) inorganic filler.
  • 100 parts by mass of the (B) inorganic filler is preferably surface-treated with 0.2 parts by mass to 5 parts by mass of the surface treatment agent, more preferably with 0.2 parts by mass to 3 parts by mass, and even more preferably with 0.3 parts by mass to 2 parts by mass.
  • the degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler (B).
  • the amount of carbon per unit surface area of the inorganic filler (B) is preferably 0.02 mg/m 2 or more, more preferably 0.1 mg/m 2 or more, and even more preferably 0.2 mg/m 2 or more, from the viewpoint of improving the dispersibility of the inorganic filler (B).
  • it is preferably 1 mg/m 2 or less, more preferably 0.8 mg/m 2 or less, and even more preferably 0.5 mg/m 2 or less.
  • the amount of carbon per unit surface area of the (B) inorganic filler can be measured after the surface-treated (B) inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with the 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 (B) inorganic filler can be measured using a carbon analyzer.
  • a carbon analyzer An example of a carbon analyzer that can be used is the "EMIA-320V" manufactured by Horiba, Ltd.
  • the range of the amount of (B) inorganic filler is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, based on 100% by mass of the non-volatile components in the resin composition, and is preferably 98% by mass or less, more preferably 95% by mass or less, even more preferably 90% by mass or less.
  • the resin composition may contain a (C) curing accelerator as an optional component.
  • the (C) curing accelerator can function as a catalyst for the curing reaction of the (A) curable resin.
  • the (C) curing accelerator does not include the components corresponding to the above-mentioned (A) to (B).
  • Examples of the (C) curing accelerator 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.
  • the (C) curing accelerator may be used alone or in combination of two or more types.
  • Amine-based curing accelerators include, for example, trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc., with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred.
  • trialkylamines such as triethylamine and tributylamine
  • 4-dimethylaminopyridine such as triethylamine and tributylamine
  • benzyldimethylamine 2,4,6-tris(dimethylaminomethyl)phenol
  • 1,8-diazabicyclo(5,4,0)-undecene etc.
  • curing accelerator (C) examples include those described in JP 2020-75977 A.
  • the range of the amount of (C) curing accelerator is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more, and is preferably 1% by mass or less, more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less, based on 100% by mass of non-volatile components in the resin composition.
  • the range of the amount of (C) curing accelerator 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, based on 100% by mass of the resin components in the resin composition, and is preferably 5% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less.
  • the resin composition may contain a (D) thermoplastic resin as an optional component.
  • the (D) thermoplastic resin as component (D) does not include the components corresponding to the above-mentioned (A) to (C).
  • thermoplastic resins include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polyimide resins, polyamideimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polyether ether ketone resins, and polyester resins, with phenoxy resins being preferred.
  • One type of thermoplastic resin may be used alone, or two or more types may be used in combination.
  • 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 terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group.
  • phenoxy resin may be used alone, or two or more types may be used in combination.
  • 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) manufactured by Mitsubishi Chemical Corporation.
  • thermoplastic resins include those described in JP 2020-75977 A.
  • the weight average molecular weight of the (D) thermoplastic resin is usually greater than 5,000, 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.
  • the range of the amount of (D) thermoplastic resin 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, based on 100% by mass of non-volatile components in the resin composition, and is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less.
  • the range of the amount of (D) thermoplastic resin is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 1% by mass or more, based on 100% by mass of the resin components in the resin composition, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.
  • the resin composition may further contain (E) an optional additive as an optional component.
  • optional additives as the (E) component include polymerization initiators, organometallic compounds, colorants, polymerization inhibitors, leveling agents, thickeners, defoamers, UV absorbers, adhesion improvers, adhesion promoters, antioxidants, fluorescent brighteners, surfactants, flame retardants, dispersants, stabilizers, photopolymerization initiator assistants, and photosensitizers.
  • Optional additives may be used alone or in combination of two or more.
  • the resin composition may further contain a volatile component (F) solvent in combination with the non-volatile components (A) to (E) described above.
  • the solvent (F) include ketone solvents such as methyl ethyl ketone (MEK) and cyclohexanone; aromatic hydrocarbon solvents such as xylene and tetramethylbenzene; glycol ether solvents 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; ester solvents such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, and ethyl diglycol acetate; aliphatic hydrocarbon solvents such as octane and decan
  • the resin composition may contain a (F) solvent, but it is preferable that the amount of the (F) solvent is small.
  • the amount of the (F) solvent contained in the resin composition is preferably 10 mass% or less, more preferably 8 mass% or less, and even more preferably 5 mass% or less, based on 100 mass% of the non-volatile components in the resin composition.
  • the lower limit of the amount of the (F) solvent may be 0 mass% or more than 0 mass% based on 100 mass% of the non-volatile components in the resin composition.
  • the above-mentioned resin composition can usually be cured to obtain a cured product having excellent dielectric properties. Therefore, the insulating layer 200 formed by the cured product of the resin composition can have excellent dielectric properties.
  • the dielectric constant of the insulating layer 200 is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.5 or less.
  • the lower limit of the dielectric constant is not particularly limited, but may be, for example, 0.0001 or more.
  • the dielectric tangent of the insulating layer 200 is preferably 0.03 or less, more preferably 0.02 or less, and even more preferably 0.01 or less.
  • the lower limit of the dielectric tangent is not particularly limited, but may be, for example, 0.0005 or more.
  • the dielectric constant and dielectric tangent can be measured by the cavity resonance perturbation method at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C.
  • an Agilent Technologies HP8362B can be used as a measuring device.
  • the thickness of the insulating layer 200 is preferably 100 ⁇ m or less, more preferably 50 ⁇ m or less, and even more preferably 40 ⁇ m or less, and may be 30 ⁇ m or less or 20 ⁇ m or less.
  • the lower limit of the thickness of the insulating layer 200 is not particularly limited, and may be, for example, 1 ⁇ m or more, 3 ⁇ m or more, etc.
  • the mask film 300 is formed on the insulating layer 200. Usually, the mask film 300 is formed so as to be in direct contact with the insulating layer 200.
  • the mask film 300 is a film including a thermoplastic resin layer 310, and can function as a mask (plasma mask) for the plasma treatment in the step (III).
  • the thermoplastic resin layer 310 is a layer that supports the mask film 300, and can usually function as a base material for the mask film 300.
  • the thermoplastic resin layer 310 contains a thermoplastic resin, and may contain only a thermoplastic resin.
  • a thermoplastic resin film containing a thermoplastic resin may be used as this thermoplastic resin layer 310.
  • Thermoplastic resins contained in the thermoplastic resin layer 310 include, for example, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylic polymers such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc.
  • PET polyethylene terephthalate
  • PEN polyethylene naphthalate
  • acrylic polymers such as polycarbonate (PC) and polymethyl methacrylate (PMMA)
  • cyclic polyolefins such as polycarbonate (PC) and polymethyl methacrylate (PMMA)
  • TAC triacetyl cellulose
  • PES polyether sulfide
  • polyimide polyether ketone
  • One type of thermoplastic resin may be used alone, or two or more types may be used in combination.
  • the thermoplastic resin contained in the thermoplastic resin layer 310 preferably has a glass transition temperature lower than that of the cured product of the resin composition that can be contained in the insulating layer.
  • the difference between the glass transition temperature of the thermoplastic resin contained in the thermoplastic resin layer 310 and the glass transition temperature of the cured product of the resin composition that can be contained in the insulating layer 200 is preferably 0.5°C or higher, more preferably 1°C or higher, even more preferably 5°C or higher, and preferably 100°C or lower, more preferably 90°C or lower, and even more preferably 80°C or lower.
  • the glass transition temperature of the thermoplastic resin contained in the thermoplastic resin layer 310 is lower than the glass transition temperature of the cured product of the resin composition that can be contained in the insulating layer 200, a recess can be smoothly formed in the mask film 300 using an imprint method in the step (II).
  • the glass transition temperature can be measured using a thermomechanical analyzer (DMA) in "tensile mode” at a temperature increase rate of 2°C/min from 25°C to 240°C.
  • the glass transition temperature is determined as the temperature at which the loss tangent (tan ⁇ ), calculated as the ratio of the measured storage modulus (E') to the loss modulus (E"), is maximum.
  • the thermoplastic resin contained in the thermoplastic resin layer 310 preferably has a linear thermal expansion coefficient close to that of the cured product of the resin composition that may be contained in the insulating layer 200.
  • the absolute value of the difference between the linear thermal expansion coefficient of the thermoplastic resin contained in the thermoplastic resin layer 310 and the linear thermal expansion coefficient of the cured product of the resin composition that may be contained in the insulating layer 200 is preferably 60 ppm/°C or less, more preferably 55 ppm/°C or less, and even more preferably 50 ppm/°C or less.
  • the lower limit there is no particular limit to the lower limit, and it may be, for example, 0 ppm/°C or more, 0.5 ppm/°C or more, or 1 ppm/°C or more.
  • the linear thermal expansion coefficient of the thermoplastic resin contained in the thermoplastic resin layer 310 and the linear thermal expansion coefficient of the cured product of the resin composition that may be contained in the insulating layer 200 are close to each other, the difference in expansion between the mask film 300 and the insulating layer 200 can be reduced during the plasma treatment in step (III). Therefore, the influence of the expansion caused by the heat of the plasma treatment is reduced, and the taper angle, position, and dimensions of the via hole and/or trench can be prevented from deviating significantly from the design values.
  • the linear thermal expansion coefficient can be measured by thermomechanical analysis using a tensile load method using a thermomechanical analyzer (Rigaku's "Thermo Plus TMA8310").
  • thermomechanical analysis is performed twice consecutively under the measurement conditions of a load of 1 g and a heating rate of 5°C/min (the first time is heated to 200°C, and the second time is heated to 260°C).
  • the average linear thermal expansion coefficient (CTE; ppm/°C) in the range from 25°C to 150°C can be calculated as the linear thermal expansion coefficient of the cured product and the thermoplastic resin.
  • the thickness of the thermoplastic resin layer 310 is not limited as long as the desired via holes and/or trenches can be formed in the insulating layer 200.
  • the specific range of the thickness of the thermoplastic resin layer 310 is preferably 5 ⁇ m or more, more preferably 10 ⁇ m or more, even more preferably 12 ⁇ m or more, even more preferably 14 ⁇ m or more, even more preferably 15 ⁇ m or more, and is preferably 75 ⁇ m or less, more preferably 60 ⁇ m or less, even more preferably 50 ⁇ m or less, even more preferably 40 ⁇ m or less, even more preferably 30 ⁇ m or less.
  • the mask film 300 may have an optional layer (not shown) in combination with the thermoplastic resin layer 310.
  • an optional layer a layer containing a material that can be removed by the plasma treatment in step (III) is preferable.
  • a layer of a material that is difficult to remove by plasma treatment e.g., a metal layer
  • the optional layer can be used as the optional layer, as long as it can be removed when forming the recess in step (II).
  • An example of an optional layer that may be provided on the mask film 300 is a release layer.
  • the release layer may be formed so as to bond to the insulating layer 200 by a release agent.
  • release agents include alkyd resins, polyolefin resins, urethane resins, and silicone resins.
  • Commercially available products may be used as the mask film 300 with such a release layer.
  • "SK-1", “AL-5”, and “AL-7” manufactured by Lintec Corporation, “Lumirror T60” manufactured by Toray Industries, “Purex” manufactured by Teijin Limited, and “Unipeel” manufactured by Unitika Limited, which are PET films having a release layer mainly composed of an alkyd resin-based release agent, may be used as the mask film 300.
  • the thickness of the release layer is preferably 10 nm or more, more preferably 30 nm or more, and even more preferably 50 nm or more, and is preferably 1000 nm or less, more preferably 500 nm or less, and even more preferably 300 nm or less.
  • the range of the total thickness of the thermoplastic resin layer 310 and the release layer may be the same as the range of the thickness of the thermoplastic resin layer 310 described above.
  • An example of an optional layer that may be provided on the mask film 300 is a barrier layer.
  • the barrier layer can suppress the transmission of water vapor through the mask film 300.
  • the barrier layer may be formed on the opposite side of the thermoplastic resin layer 310 from the release layer.
  • the barrier layer may be an inorganic film, an organic film, or a composite film containing a combination of an inorganic film and an organic film.
  • inorganic films include metal foils such as aluminum and copper; silica vapor deposition films; silicon nitride films; silicon oxide films; and magnesium oxide films.
  • methods for forming inorganic films include chemical vapor deposition methods using heat, plasma, ultraviolet light, and the like; and physical vapor deposition methods using vapor deposition and sputtering.
  • organic films include polyvinyl alcohol films, ethylene-vinyl alcohol copolymer films, and polyvinylidene chloride films.
  • methods for forming organic films include a method of applying an organic compound onto the thermoplastic resin layer 310 using a coating device such as a die coater, comma coater, gravure coater, or bar coater.
  • the thickness of the barrier layer is preferably 0.1 ⁇ m or more, more preferably 0.2 ⁇ m or more, even more preferably 0.4 ⁇ m or more, even more preferably 0.5 ⁇ m or more, even more preferably 0.6 ⁇ m or more, even more preferably 0.8 ⁇ m or more, even more preferably 1 ⁇ m or more, and is preferably 10 ⁇ m or less, more preferably 5 ⁇ m or less, even more preferably 3 ⁇ m or less.
  • An optional layer that may be provided on the mask film 300 is, for example, an adhesive layer.
  • an adhesive layer may be provided between the thermoplastic resin layer 310 and the barrier layer.
  • Adhesives that may be used in the adhesive layer include, for example, water-based adhesives, solvent-based adhesives, hot melt adhesives, and active energy ray curable adhesives that can be cured by active energy rays such as ultraviolet rays.
  • the thickness of the adhesive layer is preferably 0.1 ⁇ m or more, more preferably 0.3 ⁇ m or more, and even more preferably 0.5 ⁇ m or more, and is preferably 10 ⁇ m or less, more preferably 8 ⁇ m or less, and even more preferably 5 ⁇ m or less.
  • the mask film 300 usually has a higher mechanical strength than conventional masks using a photosensitive resin composition such as a photoresist. Therefore, the mask film 300 can be simply pulled and peeled off in step (IV).
  • the tensile modulus of the mask film 300 is preferably 100 MPa or more, more preferably 500 MPa or more, and even more preferably 1000 MPa or more, and is preferably 30 GPa or less, more preferably 20 GPa or less, and even more preferably 15 GPa or less.
  • the tensile modulus of the film can be measured at 23°C in accordance with JIS K7127.
  • the total thickness of the mask film 300 is not limited as long as the desired via holes and/or trenches can be formed in the insulating layer 200. From the viewpoint of preventing via holes and masks from being formed in areas other than under the recesses in step (III), it is preferable that the total thickness of the mask film 300 is greater than the thickness of the insulating layer 200.
  • the specific range of the total thickness of the mask film 300 is preferably 10 ⁇ m or more, more preferably 15 ⁇ m or more, and even more preferably 20 ⁇ m or more, and is preferably 80 ⁇ m or less, more preferably 70 ⁇ m or less, and even more preferably 60 ⁇ m or less.
  • the surface of the mask film 300 facing the insulating layer 200 may be subjected to a surface treatment such as matte treatment, corona treatment, or antistatic treatment.
  • step (I) for example, the intermediate laminate 10 may be prepared by purchasing it from the market, or the intermediate laminate 10 may be prepared by manufacturing it.
  • step (I) is A step (I-1) of forming a resin composition layer on the inner layer substrate 100; and Step (I-2) of curing the resin composition layer
  • the intermediate laminate 10 may be manufactured by a method including:
  • step (I) may include, in this order, a step (I-1) of forming a resin composition layer on the inner layer substrate 100, a step of laminating the resin composition layer and the mask film 300, and a step (I-2) of curing the resin composition layer to form an insulating layer.
  • step (I-1) may include, in this order, applying a resin composition onto the inner layer substrate 100 and drying the applied resin composition as necessary.
  • step (I) includes forming a resin composition layer on the inner layer substrate 100 using a resin sheet including a mask film 300 and a resin composition layer, and then curing the resin composition layer to form the insulating layer 200.
  • the operation of this preferable step (I) is described below.
  • FIG. 2 is a schematic cross-sectional view illustrating a preferred example of a method for manufacturing an intermediate laminate 10.
  • step (I-1) includes laminating a resin sheet 20 including a mask film 300 and a resin composition layer 210, and an inner layer substrate 100 such that the resin composition layer 210 and the inner layer substrate 100 are bonded.
  • the resin sheet 20 comprises a mask film 300 and a resin composition layer 210 formed on the mask film 300.
  • the mask film 300 comprises a release layer (not shown)
  • the resin composition layer 210 is typically formed so as to be in direct contact with the release layer.
  • the resin composition layer 210 contains the resin composition described above, and preferably contains only the resin composition.
  • the thickness range of the resin composition layer 210 can be the same as the thickness range of the insulating layer 200.
  • the resin sheet 20 can be manufactured, for example, by a method including preparing a resin composition and forming a resin composition layer 210 containing the resin composition on the mask film 300.
  • the resin composition can be manufactured, for example, by mixing components that can be contained in the resin composition.
  • the resin composition is manufactured by mixing non-volatile components such as components (A) to (E) and a solvent (F).
  • the above components may be mixed in part or in whole simultaneously, or may be mixed sequentially.
  • the temperature may be appropriately set, and thus heating and/or cooling may be performed temporarily or throughout.
  • stirring or shaking may be performed in the process of mixing each component.
  • the resin composition can be applied onto the mask film 300 to form a resin composition layer.
  • the resin composition can be mixed with a solvent to prepare a resin varnish as a liquid resin composition, and the resin varnish can be applied onto the mask film 300 to form a resin composition layer.
  • the solvent include the same ones as the (F) solvent described as a component of the resin composition. Drying may be performed after application.
  • Examples of methods for applying the resin composition include wire bar coating, reverse coating, gravure coating, die coating, blade coating, dip coating, air knife coating, curtain coating, and roller coating, with die coating being preferred.
  • Drying may be performed by a drying method such as heating or blowing hot air. Drying conditions may be set so that the content of the solvent in the resin composition layer 210 is usually 10% by mass or less, preferably 5% by mass or less. For example, when using a resin composition containing 30% by mass to 60% by mass of solvent, the resin composition layer 210 may be formed by drying at 50°C to 150°C for 1 minute to 10 minutes.
  • a protective film similar to the mask film 300 may be further provided on the surface of the resin composition layer 210 that is not joined to the mask film 300 (i.e., the surface opposite the mask film 300).
  • the thickness of the protective film is not particularly limited, but is, for example, 1 ⁇ m to 40 ⁇ m. By providing a protective film, it is possible to prevent dirt from adhering to and scratches on the surface of the resin composition layer 210.
  • the resin sheet 20 can be stored in a roll. If the resin sheet 20 has a protective film, the resin sheet 20 can be used by peeling off the protective film.
  • step (I-1) includes preparing a resin sheet 20, and then laminating the resin sheet 20 and the inner layer substrate 100 so that the resin composition layer 210 and the inner layer substrate 100 are bonded.
  • the resin sheet 20 and the inner layer substrate 100 can be laminated, for example, by heat-pressing the resin sheet 20 to the inner layer substrate 100 from the mask film 300 side.
  • the member that heat-presses the resin sheet 20 to the inner layer substrate 100 include a heated metal plate (such as a SUS panel) or a metal roll (such as a SUS roll).
  • the heat-pressing member may be pressed directly onto the resin sheet 20, or may be pressed via an elastic material (not shown) such as heat-resistant rubber so that the resin sheet 20 can sufficiently conform to the surface irregularities of the inner layer substrate 100.
  • the resin sheet 20 and the inner layer substrate 100 may be laminated by a vacuum lamination method.
  • the heat-pressure bonding temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C.
  • the heat-pressure bonding pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa to 1.47 MPa.
  • the heat-pressure bonding time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds.
  • the lamination may be performed under reduced pressure conditions, preferably at a pressure of 26.7 hPa or less.
  • Lamination can be performed using a commercially available vacuum laminator.
  • commercially available vacuum laminators include a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., and a batch type vacuum pressure laminator.
  • the step (I-1) may include performing a smoothing process on the laminated resin sheet 20 after laminating the resin sheet 20 and the inner layer substrate 100, for example by pressing a heat-pressure bonding member from the mask film 300 side under normal pressure (atmospheric pressure).
  • the pressing conditions for the smoothing process may be the same as the heat-pressure bonding conditions for the lamination described above.
  • the smoothing process may be performed using a commercially available laminator. Note that the lamination and smoothing process may be performed successively using the commercially available vacuum laminator described above.
  • a resin composition layer 210 is formed on the inner layer substrate 100 in step (I-1), followed by step (I-2) of curing the resin composition layer 210.
  • step (I-2) By curing the resin composition layer 210 in step (I-2), an insulating layer 200 containing a cured product of the resin composition is formed, as shown in FIG. 1.
  • the curing conditions for the resin composition layer 210 are not particularly limited, and appropriate conditions may be adopted depending on the composition of the resin composition contained in the resin composition layer 210.
  • a resin composition layer 210 containing a thermosetting resin can be cured by thermal curing under appropriate conditions.
  • the curing conditions for the resin composition layer 210 may vary depending on the type of thermosetting material, such as a thermosetting resin.
  • 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 is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.
  • the step (I-2) may include preheating the resin composition layer 210 at a temperature lower than the curing temperature before thermally curing the resin composition layer 210.
  • the resin composition layer 210 may be preheated for typically 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes) at a temperature typically between 50°C and 120°C (preferably between 60°C and 115°C, and more preferably between 70°C and 110°C).
  • Fig. 3 is a schematic cross-sectional view for explaining step (II) of the method for manufacturing a wiring board according to the first embodiment of the present invention.
  • the method for manufacturing a wiring board according to the first embodiment includes, after step (I) of preparing an intermediate laminate 10, step (II) of forming a recess 400 in the mask film 300 of the intermediate laminate 10, as shown in Fig. 3.
  • the recess 400 formed includes a portion where the thickness of the mask film 300 is relatively small and a portion where the mask film 300 is absent.
  • the recess 400 is usually formed to have an opening 400K on the surface 300U of the mask film 300 opposite the inner layer substrate 100.
  • the recess 400 is usually formed to be open to the outside through the opening 400K.
  • the recess 400 thus formed is generally formed such that the surface 300U of the mask film 300 is recessed at the recess 400.
  • the recess 400 can have a bottom surface 400B as the bottom portion close to the inner layer substrate 100, and a side surface 400S formed from the bottom surface 400B to the opening 400K.
  • a recess 400 may be formed so as to penetrate the mask film 300.
  • the recess 400 may be formed only in the mask film 300 and not in the insulating layer 200.
  • the bottom surface 400B of the recess 400 may be formed by the surface 200U of the insulating layer 200 opposite the inner layer substrate 100.
  • FIG. 4 is a schematic cross-sectional view for explaining step (II) of the method for manufacturing a wiring board according to the first embodiment of the present invention.
  • the recess 400 may be formed not only in the mask film 300 but also in the insulating layer 200.
  • the bottom surface 400B of the recess 400 may be formed in the insulating layer 200.
  • a portion 300S close to the opening 400K may be formed in the mask film 300, and a portion 200S close to the bottom surface 400B may be formed in the insulating layer 200.
  • FIG. 5 is a schematic cross-sectional view for explaining step (II) of the method for manufacturing a wiring board according to the first embodiment of the present invention.
  • step (II) as illustrated in FIG. 5, the recess 400 may be formed so as not to penetrate the mask film 300.
  • the bottom surface 400B of the recess 400 may be formed within the mask film 300.
  • the specific position of the bottom surface 400B of the recess 400 in the thickness direction of the intermediate laminate 10 is as follows. That is, as shown in FIG. 5, the surface 200U of the insulating layer 200 opposite the inner layer substrate 100 is taken as the reference (0 ⁇ m), and the position closer to the inner layer substrate 100 is represented as positive (+), and the position farther from the inner layer substrate 100 is represented as negative (-).
  • the position of the bottom surface 400B of the recess 400 relative to the surface 200U of the insulating layer 200 opposite the inner layer substrate 100 is preferably -5 ⁇ m or more, more preferably -4 ⁇ m or more, even more preferably -3 ⁇ m or more, even more preferably -2 ⁇ m or more in the thickness direction, and is preferably +5 ⁇ m or less, more preferably +4 ⁇ m or less, even more preferably +3 ⁇ m or less, even more preferably +2 ⁇ m or less.
  • the specific position of the bottom surface 400B of the recess 400 in the thickness direction of the intermediate laminate 10 is as follows: That is, as shown in FIG. 5, the surface 200U of the insulating layer 200 opposite the inner layer substrate 100 is set as the reference (0 ⁇ m), and a position closer to the inner layer substrate 100 is represented as positive (+), and a position farther from the inner layer substrate 100 is represented as negative (-).
  • the distance from the surface 200U of the insulating layer 200 opposite the inner layer substrate 100 to the bottom surface 400B of the recess 400 is represented as a relative value with respect to the thickness of the insulating layer 200 in step (I) (i.e., the thickness of the insulating layer 200 at the portion where the recess 400 is to be formed before the recess 400 is formed) being 100%.
  • the position of the bottom surface 400B of the recess 400 relative to the surface 200U of the insulating layer 200 opposite the inner layer substrate 100 is preferably -80% or more, more preferably -60% or more, even more preferably -40% or more, and preferably +80% or less, more preferably +60% or less, even more preferably +40% or less in the thickness direction.
  • the dimension W 400K of the opening 400K of the recess 400 formed in step (II) can be set according to the dimension of the opening of the via hole and/or trench to be formed in the insulating layer 200.
  • the dimension W 400K of the opening 400K represents the minimum dimension of the opening 400K as viewed from the thickness direction, unless otherwise specified. Therefore, for example, when the opening 400K is formed in a circular shape as viewed from the thickness direction, the dimension W 400K of the opening 400K represents the diameter of the circular opening 400K. Also, for example, when the opening 400K is formed in a linear shape as viewed from the thickness direction, the dimension W 400K of the opening 400K represents the width of the linear opening 400K.
  • the specific range of the dimension W 400K of the opening 400K of the recess 400 is preferably 3 ⁇ m or more, more preferably 5 ⁇ m or more, even more preferably 10 ⁇ m or more, and preferably 50 ⁇ m or less, more preferably 40 ⁇ m or less, even more preferably 30 ⁇ m or less, and may be 25 ⁇ m or less.
  • the dimension W 400K of the openings 400K of those recesses 400 may be the same or different.
  • the method for forming the recess 400 is not particularly limited.
  • the recess 400 can be formed, for example, by laser processing.
  • the recess 400 is usually formed by irradiating the mask film 300 side of the intermediate laminate 10 with laser light having a wavelength that can be absorbed by the mask film 300.
  • step (II) may include forming the recess 400 in the mask film 300 by laser light.
  • the laser light source examples include a CO2 laser (carbon dioxide gas laser) device, a UV-YAG laser device, a UV laser device, a YAG laser device, and an excimer laser device.
  • a UV laser device and an excimer laser device are preferred in that they can smoothly form small recesses 400.
  • Preferred specific examples include a UV laser device with a wavelength of 266 nm and an excimer laser device with a wavelength of 248 nm.
  • the conditions for irradiating the laser light are preferably set so that a recess 400 having an opening 400K of the desired dimensions can be formed.
  • the number of shots is preferably set so that a recess 400 having a bottom 400B at a desired position can be formed. In general, the greater the number of shots, the deeper the recess 400 can be formed.
  • the number of shots of the laser light is usually 1 to 100 shots, and from the viewpoint of increasing the processing speed and improving productivity, is preferably in the range of 1 to 80 shots, and more preferably in the range of 1 to 60 shots. When the number of shots is 2 or more, the laser light may be irradiated in either burst mode or cycle mode.
  • the pulse width of the laser light is preferably 0.5 ⁇ sec or more, more preferably 0.7 ⁇ sec or more, even more preferably 1 ⁇ sec or more, and preferably 40 ⁇ sec or less, more preferably 35 ⁇ sec or less, even more preferably 30 ⁇ sec or less.
  • the pulse widths may be the same or different.
  • the thermoplastic resin layer 310 may be irradiated with laser light of relatively low energy, so that the pulse width of the second and subsequent shots may be shorter than the pulse width of the first shot.
  • FIG. 3 an example is shown in which laser light L is irradiated onto surface 300U of mask film 300 to form recess 400 having bottom surface 400B on surface 200U of insulating layer 200 opposite inner layer substrate 100.
  • Plasma treatment> 6 is a schematic cross-sectional view for explaining step (III) of the method for manufacturing a wiring board according to the first embodiment of the present invention.
  • the method for manufacturing a wiring board according to the first embodiment includes step (III) of forming one or both of a via hole 500 and a trench (not shown) in the insulating layer 200 by plasma treatment, as shown in FIG. 6, after step (II) of forming a recess 400 in the mask film 300 of the intermediate laminate 10.
  • step (III) of forming the via hole 500 in step (III) will be shown and explained.
  • step (III) involves irradiating the mask film 300 of the intermediate laminate 10 with plasma, as indicated by arrow P.
  • the thickness of the mask film 300 is reduced by the plasma irradiation.
  • the insulating layer 200 is selectively removed from the portion below the recess 400 to form either or both of the via hole 500 and the trench.
  • the insulating layer 200 is irradiated with plasma through the recess 400, and the insulating layer 200 is etched.
  • the mask film 300 is removed at the recess 400, and then the insulating layer 200 is irradiated with plasma through the recess 400, and the insulating layer 200 is etched. Etching proceeds in the portion of the insulating layer 200 below the recess 400, but etching does not proceed in the other portions because they are protected by the mask film 300.
  • the insulating layer 200 is selectively removed in the portion below the recess 400, and the via hole 500 and/or trench can be formed. Specifically, the insulating layer 200 is removed to the extent that the surface 100U of the inner layer substrate 100 is exposed by penetrating the insulating layer 200, and the via hole 500 is formed. On the other hand, the insulating layer 200 is removed so as not to penetrate the insulating layer 200, forming a trench. In areas other than the recess 400, the mask film 300 is thinned by etching.
  • the plasma treatment can be performed by treating the surface 200U of the insulating layer 200 and the surface 300U of the mask film 300 with plasma generated by introducing a gas into a plasma generating device.
  • methods for generating plasma include microwave plasma, which generates plasma by microwaves, high frequency plasma, which uses high frequency waves, atmospheric pressure plasma, which is generated under atmospheric pressure, and atmospheric pressure plasma, which is generated under a vacuum, and the like. Of these, atmospheric pressure plasma, which is generated under a vacuum, is preferred.
  • the plasma used in step (III) is preferably RF plasma, which is excited by high frequency waves.
  • the gas to be turned into plasma can be one capable of forming a via hole 500 and/or a trench in the insulating layer 200.
  • gases include O 2 ; fluorine-based gas; inert gas such as Ar and N 2 ; and the like.
  • the fluorine-based gas refers to a gas containing fluorine atoms, and examples thereof include fluorocarbon gases such as CF 4 , C 4 F 6 , C 4 F 8 , CH 2 F 2 , and CHF 3 ; and SF 6. These gases may be used alone or in combination of two or more. Among them, a gas containing one or more selected from the group consisting of O 2 and SF 6 is preferred.
  • a mixed gas containing O 2 and one or more selected from the group consisting of CF 4 , Ar, and N 2 ; and a mixed gas containing SF 6 and one or more selected from the group consisting of Ar and O 2 ; are more preferred.
  • a mixed gas containing O2 and CF4 ; a mixed gas containing SF6 , Ar, and O2 ; is more preferable, and a mixed gas containing O2 and CF4 is particularly preferable.
  • the mixture ratio of those gases is preferably 1/99 or more, more preferably 30/70 or more, even more preferably 70/30 or more, and preferably 99/1 or less, more preferably 90/10 or less.
  • sccm is a unit of gas flow rate, and the amount of gas flowing per minute is expressed as the volume ( cm3 ) when the gas is at 0°C and 1 atm.
  • the degree of vacuum in the processing environment during plasma processing is preferably 10 mTorr or more, more preferably 20 mTorr or more, even more preferably 30 mTorr or more, and is preferably 2000 mTorr or less, more preferably 1000 mTorr or less, even more preferably 500 mTorr or less.
  • the plasma exposure time in the plasma treatment can be set according to the depth of the via hole 500 and/or trench to be formed.
  • the plasma exposure time is set so that the mask film 300 remains on the insulating layer 200 after the plasma treatment.
  • the specific treatment time is preferably 1 minute or more, more preferably 2 minutes or more, even more preferably 3 minutes or more, and preferably 120 minutes or less, more preferably 100 minutes or less, and even more preferably 60 minutes or less.
  • the etching rate by plasma treatment 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.
  • the insulating layer 200 is etched in the portion below the recess 400 by the plasma treatment in step (III). It is preferable that the amount of etching of the insulating layer 200 in step (III) is within a specific range.
  • the “amount of etching of the insulating layer 200” refers to the amount of reduction in the thickness of the insulating layer 200 in the portion below the recess 400 due to etching.
  • the amount of etching of the insulating layer 200 is preferably 30% or more, more preferably 40% or more, and even more preferably 50% or more, relative to 100% of the thickness of the insulating layer 200 in the etched portion (i.e., the portion under the recess 400) in step (I).
  • the upper limit is 100% or less.
  • the amount of etching of the insulating layer 200 is preferably 1 ⁇ m or more, more preferably 2 ⁇ m or more, and further preferably 3 ⁇ m or more. There is no particular upper limit, and it can be 50 ⁇ m or less.
  • the thickness of the mask film 300 is generally reduced by the plasma treatment. Therefore, the thickness of the mask film 300 immediately after the end of step (III) is usually smaller than the thickness of the mask film 300 immediately before the start of step (III).
  • the thickness of the mask film 300 immediately after the end of step (III) is preferably 1 ⁇ m or more, more preferably 3 ⁇ m or more, and even more preferably 5 ⁇ m or more, and preferably 50 ⁇ m or less, more preferably 40 ⁇ m or less, and even more preferably 30 ⁇ m or less.
  • the thickness of the mask film 300 immediately after the end of step (III) is preferably 20% or more, more preferably 30% or more, and even more preferably 40% or more, relative to the thickness of the mask film 300 immediately before the start of step (III), which is 100%, and is usually less than 100%.
  • the method for manufacturing a wiring board according to the first embodiment includes a step (IV) of peeling off the mask film 300 after the step (III) of forming one or both of the via hole 500 and the trench (not shown).
  • Fig. 7 is a cross-sectional view showing a wiring board 30 obtained by the method for manufacturing a wiring board according to the first embodiment of the present invention. By peeling off the mask film 300, as shown in Fig. 7, a wiring board 30 is obtained which includes the inner layer substrate 100 and the insulating layer 200 in which the via hole 500 and one or both of the trench are formed.
  • the mask film 300 may be peeled off manually or mechanically using an automatic peeling device. Typically, the mask film 300 is peeled off by pulling it relative to the circuit board 100 and the insulating layer 200.
  • peeling methods include a method in which the circuit board 100 and the insulating layer 200 are transported with the mask film 300 fixed and the mask film 300 is peeled off; a method in which the circuit board 100 and the insulating layer 200 are fixed and the mask film 300 is pulled and the mask film 300 is peeled off; a method in which the circuit board 100 and the insulating layer 200 are transported while the mask film 300 is pulled and the mask film 300 is peeled off; etc.
  • the angle that the peeling direction of the mask film 300 makes with respect to the surface of the insulating layer 200 is not particularly limited, but is preferably 70° or less, more preferably 50° or less, even more preferably 30° or less, and is usually 0° or more.
  • the peeling speed of the mask film 300 is preferably 1 m/min to 20 m/min, more preferably 3 m/min to 10 m/min.
  • the temperature conditions for peeling off the mask film 300 are not particularly limited, but it is preferable to perform the peeling at room temperature (preferably 10°C to 40°C).
  • the via hole 500 and/or trench formed in the insulating layer 200 of the obtained wiring board 30 can have a large taper angle ⁇ .
  • the taper angle ⁇ represents the angle that the side surface 500S of the via hole 500 and the trench make with respect to the layer plane of the insulating layer 200, as described above.
  • the bottom surface 500B of the via hole 500 and the trench is parallel to the layer plane of the insulating layer 200, so the taper angle ⁇ is represented by the angle between the side surface 500S and the plane including the bottom surface 500B.
  • the range of this taper angle ⁇ is preferably 65° or more, more preferably 70° or more, and even more preferably 75° or more.
  • the upper limit is usually 90° or less, and may be 88° or less, 85° or less, etc.
  • the dimension W 500K of the via hole 500 and/or trench opening 500K formed in the insulating layer 200 can be generally the same as or smaller than the dimension W 400K of the opening 400K of the recess 400 formed in the mask film 300. Therefore, it is possible to make the dimension W 500K of the via hole 500 and/or trench opening 500K small.
  • the dimension W 500K of the via hole 500 and/or trench opening 500K represents the minimum dimension of the opening 500K as viewed from the thickness direction, unless otherwise specified. Therefore, for example, when the opening 500K is formed in a circular shape as viewed from the thickness direction, the dimension W 500K of the opening 500K represents the diameter of the circular opening 500K. Also, for example, when the opening 500K is formed in a linear shape as viewed from the thickness direction, the dimension W 500K of the opening 500K represents the width of the linear opening 500K.
  • the ratio of the dimension W 500K of the opening 400K of the recess 400 to the dimension W 400K of the opening 500K of the via hole 500 and/or trench formed in the insulating layer 200 in the portion below the recess 400 is called the opening dimension ratio (W 500K /W 400K ).
  • the range of this opening dimension ratio is usually 1.0 or less, preferably 0.95 or less, more preferably 0.9 or less, and even more preferably 0.85 or less. There is no lower limit, but it is usually larger than 0.0, and can be, for example, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, etc.
  • a specific dimension W500K of the opening 500K of the via hole 500 and/or trench can be set according to the design of the wiring board 30, and is preferably small from the viewpoint of utilizing the advantage of the present embodiment that the dimension W500K can be made small.
  • a specific range of the dimension W500K of the opening 500K is preferably 1 ⁇ m or more, more preferably 2 ⁇ m or more, and even more preferably 3 ⁇ m or more, and is preferably 50 ⁇ m or less, more preferably 40 ⁇ m or less, even more preferably 30 ⁇ m or less, and particularly preferably 20 ⁇ m or less.
  • the dimension W 500B of the bottom surface 500B of the via hole 500 and/or trench formed in the insulating layer 200 can be made small.
  • the dimension W 500B of the bottom surface 500B of the via hole 500 and/or trench represents the minimum dimension of the bottom surface 500B as viewed in the thickness direction, unless otherwise specified. Therefore, for example, when the bottom surface 500B is formed in a circular shape as viewed in the thickness direction, the dimension W 500B of the bottom surface 500B represents the diameter of the circular bottom surface 500B. Also, for example, when the bottom surface 500B is formed in a linear shape as viewed in the thickness direction, the dimension W 500B of the bottom surface 500B represents the width of the linear bottom surface 500B.
  • the dimension W 500B of the bottom 500B of the via hole 500 and/or trench is equal to or less than the dimension W 500K of the opening 500K of the via hole 500 and/or trench, and may be smaller than the dimension W 500K of the opening 500K.
  • a specific range of the dimension W500B of the bottom surface 500B of the via hole 500 and/or trench is preferably 1 ⁇ m or more, more preferably 3 ⁇ m or more, even more preferably 5 ⁇ m or more, and is preferably 50 ⁇ m or less, more preferably 30 ⁇ m or less, even more preferably 20 ⁇ m or less, and particularly preferably 10 ⁇ m or less.
  • the method for manufacturing wiring board 30 according to the first embodiment may further include any step in combination with the above-mentioned steps (I) to (IV).
  • the method for manufacturing wiring board 30 according to the first embodiment may include step (V) of forming a conductor layer (not shown) on insulating layer 200.
  • the conductor layer formed in step (V) may be referred to as a "circuit conductor layer” hereinafter.
  • Step (V) is usually performed after step (IV).
  • a circuit conductor layer is formed on the surface 200U of the insulating layer 200 opposite the inner layer substrate 100.
  • the circuit conductor layer may also be formed in the via holes 500 and/or trenches.
  • the circuit conductor layer includes a conductive material, and preferably includes only a conductive material.
  • the conductive material is not particularly limited.
  • the circuit conductor 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 circuit conductor layer may be a single metal layer or an alloy layer. Examples of the alloy layer include layers formed of an alloy of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy).
  • a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.
  • the circuit conductor layer may have a single-layer structure, or a multi-layer structure having two or more single metal layers or alloy layers containing different types of metals or alloys.
  • the layer in contact with the insulating layer 200 is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.
  • circuit conductor layer There are no limitations on the method for forming the circuit conductor layer. Examples of methods for forming the circuit conductor layer include plating, sputtering, vapor deposition, and combinations of these. Among these, from the viewpoint of manufacturing a wiring board by a dry process, sputtering and vapor deposition are preferred, and sputtering is even more preferred. Furthermore, from the viewpoint of smooth formation of the circuit conductor layer, it is preferable to form the circuit conductor layer by a plating method. In a preferred example, a circuit conductor layer having a desired pattern shape is formed by plating on the insulating layer 200 by an appropriate method such as a semi-additive method or a full-additive method.
  • the thickness of the circuit conductor layer depends on the desired design of the wiring board 30, but from the viewpoint of thinness, it is preferably 1 ⁇ m or more, more preferably 2 ⁇ m or more, and even more preferably 3 ⁇ m or more, and is preferably 35 ⁇ m or less, more preferably 30 ⁇ m or less, even more preferably 20 ⁇ m or less, and even more preferably 10 ⁇ m or less.
  • the lines of the circuit conductor layer are preferably small.
  • the specific range of the lines of the circuit conductor layer is preferably 5 ⁇ m or less, more preferably 4 ⁇ m, and even more preferably 3 ⁇ m.
  • the lower limit of the lines is not particularly limited, but is preferably 0.1 ⁇ m or more, more preferably 0.5 ⁇ m or more, and even more preferably 1 ⁇ m or more.
  • the space of the circuit conductor layer is preferably small.
  • the specific range of the space of the circuit conductor layer is preferably 5 ⁇ m or less, more preferably 4 ⁇ m, and even more preferably 3 ⁇ m.
  • the lower limit of the space is not particularly limited, but is preferably 0.1 ⁇ m or more, more preferably 0.5 ⁇ m or more, and even more preferably 1 ⁇ m or more.
  • the range of the minimum line/space ratio of the circuit conductor layer is preferably 5 ⁇ m/5 ⁇ m or less, more preferably 4 ⁇ m/4 ⁇ m or less, even more preferably 3 ⁇ m/3 ⁇ m or less, and preferably 0.1 ⁇ m/0.1 ⁇ m or more, more preferably 0.5 ⁇ m/0.5 ⁇ m or more, even more preferably 1 ⁇ m/1 ⁇ m or more.
  • the wiring pitch of the circuit conductor layer is preferably 10 ⁇ m or less, more preferably 8 ⁇ m or less, even more preferably 6 ⁇ m or less, and preferably 0.2 ⁇ m or more, more preferably 1 ⁇ m or more, even more preferably 2 ⁇ m or more.
  • the line/space ratio and pitch may each be uniform or non-uniform throughout the circuit conductor layer.
  • each of the steps (I), (II), (III), and (IV) may be performed only once, or may be performed twice or more. Therefore, the manufacturing method of the wiring board 30 according to the first embodiment may include performing the steps (I), (II), (III), and (IV) twice or more in this order. In addition, the manufacturing method of the wiring board 30 according to the first embodiment may include performing any step twice or more, for example, performing the steps (I), (II), (III), (IV), and (V) twice or more in this order.
  • the wiring board manufactured by performing the first steps (I), (II), (III), (IV), and (V) may be used as an inner layer substrate to perform the second steps (I), (II), (III), (IV), and (V).
  • a wiring board having a multilayer structure can be manufactured.
  • a multilayer wiring board having two or more conductor layers or three or more conductor layers may be manufactured.
  • step (II) using the imprinting method includes pressing the mask film with a mold, as described below.
  • step (II) is performed after step (I) of preparing an intermediate laminate 10 as in the first embodiment.
  • step (II) as shown in FIG. 8, a mold 600 having a convex portion 610 having a shape corresponding to the concave portion 400 to be formed (see FIG. 10) is prepared. Then, as shown in FIG. 9, the mask film 300 is pressed by the mold 600 so that the convex portion 610 abuts against the mask film 300.
  • the concave portion 400 having a shape corresponding to the convex portion 610 is formed in the mask film 300. Therefore, when the mold 600 is removed after pressing, the mask film 300 having the concave portion 400 is obtained as shown in FIG. 10.
  • the concave portion 400 formed in the second embodiment may be the same as the concave portion 400 formed in the first embodiment.
  • the material of the mold 600 there are no particular limitations on the material of the mold 600, as long as it is capable of forming the recess 400.
  • materials for the mold 600 include metal, silicon, etc.
  • the pressing temperature is preferably 100°C or higher, more preferably 120°C or higher, even more preferably 140°C or higher, and is preferably 350°C or lower, more preferably 320°C or lower, even more preferably 300°C or lower.
  • the pressing pressure applied by the mold 600 is preferably 1 MPa or more, more preferably 3 MPa or more, even more preferably 10 MPa or more, and is preferably 100 MPa or less, more preferably 70 MPa or less, even more preferably 50 MPa or less.
  • FIG. 11 is a schematic cross-sectional view for explaining step (III) of the method for manufacturing a wiring board according to the second embodiment of the present invention.
  • the method for manufacturing a wiring board according to the second embodiment includes, after step (II), step (III) of forming one or both of a via hole 500 and a trench (not shown) in the insulating layer 200 by plasma treatment, as shown in FIG. 11.
  • step (III) according to the first embodiment step (III) according to the second embodiment includes irradiating the mask film 300 of the intermediate laminate 10 with plasma.
  • the plasma treatment reduces the thickness of the mask film 300, and at the same time selectively removes the insulating layer 200 in the portion below the recess 400, forming one or both of the via hole 500 and the trench.
  • FIG. 12 is a cross-sectional view showing a wiring board 40 obtained by the wiring board manufacturing method according to the second embodiment of the present invention.
  • the wiring board manufacturing method according to the second embodiment includes a step (IV) of peeling off the mask film 300 after step (III).
  • the mask film 300 according to the second embodiment can be peeled off in the same manner as the mask film 300 according to the first embodiment.
  • a wiring board 40 is obtained, as shown in FIG. 12, which includes an inner layer substrate 100 and an insulating layer 200 in which a via hole 500 and/or a trench are formed.
  • the method for manufacturing the wiring board 40 according to the second embodiment can provide the same advantages as the method for manufacturing the wiring board 30 according to the first embodiment. Furthermore, compared to the laser processing method, the imprint method makes it easier to improve the cross-sectional shape of the recess 400 formed in the mask film 300. Specifically, the imprint method can easily make the taper angle of the recess 400 close to 90°.
  • the "taper angle of the recess 400" refers to the angle that the side surface 400S of the recess 400 makes with respect to the layer plane of the mask film 300. Therefore, the manufacturing method according to the second embodiment can easily increase the taper angle ⁇ of the via hole 500 and/or trench formed in the insulating layer 200.
  • the manufacturing method according to the second embodiment may include any step, just like the manufacturing method according to the first embodiment. Also, the manufacturing method according to the second embodiment may perform steps (I) to (IV) and any step once, or may perform them twice or more, just like the manufacturing method according to the first embodiment.
  • a method for manufacturing a wiring board according to a third embodiment of the present invention which includes step (II) of combining and forming the first recess and the second recess, will be described. Since trenches, which may have a complex pattern shape, are generally formed efficiently by imprinting, the third embodiment will be described by showing an example in which the imprinting method is employed in step (II) as in the second embodiment. Furthermore, in the third embodiment, parts similar to those in the first and second embodiments will be described with the same reference numerals as those in the first and second embodiments.
  • the method for manufacturing a wiring board according to the third embodiment is the same as the method for manufacturing a wiring board according to the second embodiment, except that in step (II), a first recess for forming a via hole and a second recess for forming a trench are combined and formed in the mask film.
  • step (II) is performed after step (I) of preparing an intermediate laminate 10 as in the first and second embodiments.
  • step (II) as shown in FIG. 13, a mold 700 having a first convex portion 710 having a shape corresponding to the first concave portion 410 (see FIG. 15) and a second convex portion 720 having a shape corresponding to the second concave portion 420 (see FIG. 15) is prepared. Then, as shown in FIG.
  • the mask film 300 is pressed by the mold 700 so that the first convex portion 710 and the second convex portion 720 abut against the mask film 300.
  • the first concave portion 410 having a shape corresponding to the first convex portion 710 and the second concave portion 420 having a shape corresponding to the second convex portion 720 are formed in the mask film 300. Therefore, when the mold 700 is removed after pressing, a mask film 300 having a first recess 410 and a second recess 420 is obtained as shown in FIG. 15.
  • the first recess 410 corresponding to a via hole is formed deeper than the second recess 420 corresponding to a trench.
  • the position of the bottom surface 410B of the first recess 410 and the position of the bottom surface 420B of the second recess 420 may be set within the range of the position of the bottom surface 400B of the recess 400 described in the first embodiment.
  • the dimension W 410K of the opening 410K of the first recess 410 and the dimension W 420K of the opening 420K of the second recess 420 may be set within the range of the dimension W 400K of the opening 400K of the recess 400 described in the first embodiment.
  • step (III) of the method for manufacturing a wiring board according to the third embodiment of the present invention includes step (III) of forming a via hole 510 and a trench 520 in the insulating layer 200 by plasma treatment after step (II), as shown in FIG. 16.
  • Step (III) according to the third embodiment includes irradiating the mask film 300 of the intermediate laminate 10 with plasma, as in step (III) according to the first and second embodiments. The thickness of the mask film 300 is reduced by the plasma treatment.
  • the insulating layer 200 is selectively removed in the portion below the first recess 410 to form a via hole 510, and the insulating layer 200 is selectively removed in the portion below the second recess 420 to form a trench 520.
  • FIG. 17 is a cross-sectional view showing a wiring board 50 obtained by the wiring board manufacturing method according to the third embodiment of the present invention.
  • the wiring board manufacturing method according to the third embodiment includes a step (IV) of peeling off the mask film 300 after step (III).
  • the mask film 300 according to the third embodiment can be peeled off in the same manner as the mask film 300 according to the first and second embodiments.
  • a wiring board 50 is obtained that includes an inner layer substrate 100 and an insulating layer 200 in which a via hole 510 and a trench 520 are formed, as shown in FIG. 17.
  • the method for manufacturing wiring board 50 according to the third embodiment can provide the same advantages as the method for manufacturing wiring board 30 according to the first embodiment and the method for manufacturing wiring board 40 according to the second embodiment.
  • the manufacturing method according to the third embodiment may include any step, as in the manufacturing methods according to the first and second embodiments. Furthermore, the manufacturing method according to the third embodiment may perform steps (I) to (IV) and any step once, or may perform them twice or more times, as in the manufacturing methods according to the first and second embodiments.
  • the wiring board manufactured by the above-mentioned manufacturing method includes an inner layer substrate and an insulating layer. Moreover, the wiring board usually includes conductor layers such as an inner layer conductor layer and a circuit conductor layer, and these conductor layers can form circuit wiring. Examples of such wiring boards include printed wiring boards, interposers, and package substrates. Examples of packages to which the package substrate can be applied include fan-in type packages and fan-out type packages.
  • the area of the wiring board is preferably 2500 mm2 or more, more preferably 3000 mm2 or more, even more preferably 3500 mm2 or more, and preferably 10000 mm2 or less.
  • a semiconductor device can be manufactured using the above-mentioned wiring board.
  • the semiconductor device includes a wiring board.
  • Examples of the semiconductor device include various semiconductor devices used in electrical products (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft).
  • the semiconductor device may have a fan-out structure or a chiplet structure.
  • the semiconductor device may also have a semiconductor chip on a wiring board.
  • the semiconductor chip is preferably a mixed system of a logic die and a memory die.
  • Example 1 (1-1. Production of Thermosetting Resin Composition) Bixylenol type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK”, epoxy equivalent: approx. 185 g/eq.) 6 parts, naphthalene type epoxy resin (Nippon Steel Sumikin Chemical (now Nippon Steel Chemical & Material) Corporation “ESN475V”, epoxy equivalent: approx. 332 g/eq.) 5 parts, bisphenol AF type epoxy resin (Mitsubishi Chemical Corporation "YL7760”, epoxy equivalent: approx.
  • thermosetting resin composition was prepared by mixing 110 parts of a cellulose acetate copolymer (polyvinyl chloride/g) and 0.05 parts of an amine curing accelerator (4-dimethylaminopyridine (DMAP)), dispersing the mixture uniformly in a high-speed rotary mixer, and filtering the mixture through a cartridge filter ("SHP050" manufactured by ROKITECHNO CORPORATION).
  • a cellulose acetate copolymer polyvinyl chloride/g
  • DMAP 4-dimethylaminopyridine
  • a masking film was prepared that had a polyethylene naphthalate film ("Teonex Q83" manufactured by Toyobo Co., Ltd., thickness 25 ⁇ m) as a thermoplastic resin layer and a release layer formed on one side of the polyethylene naphthalate film.
  • a thermosetting resin composition was uniformly applied onto the release layer of the masking film with a die coater so that the thickness of the resin composition layer after drying was 5 ⁇ m, and the resin composition layer was formed by drying at 70°C to 95°C for 2 minutes.
  • a rough surface of a polypropylene film (“Alphan MA-411" manufactured by Oji F-Tex Co., Ltd., thickness 15 ⁇ m) was laminated as a protective film on the surface of the resin composition layer that was not bonded to the masking film so as to be bonded to the resin composition layer.
  • a silicon wafer (copper layer thickness 1 ⁇ m, inner layer substrate thickness 0.8 mm, 8 inch size) with a copper layer formed on one side was prepared as an inner layer substrate. This inner layer substrate was placed in an oven at 130° C. and dried for 30 minutes.
  • Step (I) ⁇ Laminating resin sheets: The protective film was peeled off from the resin sheet.
  • a batch-type vacuum pressure laminator (a two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.) was used to laminate a resin sheet on one side of the inner layer substrate so that the resin composition layer and the inner layer substrate were in contact with each other.
  • the lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, and pressing at a temperature of 130°C and a pressure of 0.74 MPa for 45 seconds. Next, a heat press was performed at a temperature of 120°C and a pressure of 0.5 MPa for 75 seconds.
  • Step (II) Laser processing was performed on the mask film side surface of the intermediate laminate A using a UV laser ("LU-2L212/M50L" manufactured by Via Mechanics) to form a circular hole-shaped recess having a circular opening and a bottom surface in the mask film when viewed from the thickness direction.
  • a UV laser (“LU-2L212/M50L” manufactured by Via Mechanics) to form a circular hole-shaped recess having a circular opening and a bottom surface in the mask film when viewed from the thickness direction.
  • laser light was irradiated while adjusting the number of shots so that a recess of the desired depth was formed.
  • Example 1 the number of shots was adjusted so that the bottom surface of the recess was formed at a position -1.5 ⁇ m from the surface of the insulating layer opposite the inner layer substrate (i.e., a position 1.5 ⁇ m away from the surface of the insulating layer on the opposite side to the inner layer substrate).
  • a plasma treatment was performed using a plasma dry etching device ("PlasmaPro100" manufactured by Oxford Instruments) with the mask film as a plasma mask, and a via hole penetrating the insulating layer was formed in the insulating layer.
  • the via hole was formed in a circular hole shape with a circular opening and a bottom surface when viewed from the thickness direction, and the copper layer of the inner layer substrate was exposed at the bottom surface.
  • the plasma treatment was performed using CF4 and O2 ( CF4 / O2 mixture ratio 80/20 (sccm)) as gas under the conditions of vacuum degree: 50 mTorr, RF power: 120 W, and ICP power: 100 W.
  • the plasma treatment was performed to such an extent that the mask film was not completely removed and remained on the insulating layer.
  • step (IV)) After the via holes were formed in the insulating layer, the mask film remaining on the insulating layer was pulled and peeled off to obtain an evaluation board corresponding to a wiring board including an inner layer substrate and an insulating layer.
  • the cross-section of the evaluation substrate was observed using an FIB-SEM (Hitachi High-Tech Corporation's "Ethos NX5000"), and the via holes formed in the insulating layer were observed to measure the top diameter, bottom diameter, and taper angle of the via holes.
  • the top diameter of the via hole refers to the diameter of the opening of the via hole
  • the bottom diameter of the via hole refers to the diameter of the bottom surface of the via hole.
  • the taper angle was evaluated according to the following criteria. "Excellent" taper angle > 65° "Bad” taper angle ⁇ 65°
  • Example 2 In step (1-5), the evaluation board was manufactured and evaluated in the same manner as in Example 1, except that the number of shots for laser processing was adjusted so that the bottom surface of the recess was formed at a position of 0 ⁇ m based on the surface of the insulating layer opposite the inner layer substrate (i.e., the position of the surface of the insulating layer).
  • Example 3 In step (1-5), the evaluation board was manufactured and evaluated in the same manner as in Example 1, except that the number of laser processing shots was adjusted so that the bottom surface of the recess was formed at a position +1.0 ⁇ m from the surface of the insulating layer opposite the inner layer substrate (i.e., a position 1.0 ⁇ m away from the surface of the insulating layer toward the inner layer substrate).
  • step (1-2) the mask film was changed to a film having a polyimide film (Ube Industries, Ltd., "Upilex-S", thickness 13 ⁇ m) as a thermoplastic resin layer and a release layer formed on one side of the polyimide film.
  • step (1-5) the number of shots of laser processing was adjusted so that the bottom surface of the recess was formed at a position -0.5 ⁇ m from the surface of the insulating layer on the opposite side to the inner layer substrate (i.e., a position 0.5 ⁇ m away from the surface of the insulating layer on the opposite side to the inner layer substrate). Except for the above, the evaluation board was manufactured and evaluated in the same manner as in Example 1.
  • Steps (1-1) to (1-4) were performed in the same manner as in Example 1 to obtain an intermediate laminate A including an inner layer substrate, an insulating layer (thickness 5 ⁇ m), and a mask film in this order.
  • the mask film was peeled off from the intermediate laminate A.
  • the surface of the insulating layer exposed by peeling off the mask film was laser processed using a UV laser ("LU-2L212/M50L" manufactured by Via Mechanics) to form a via hole in the insulating layer.
  • the laser light was irradiated while adjusting the number of shots so that the copper layer of the inner layer substrate was exposed at the bottom of the via hole.
  • the laser processing obtained an evaluation substrate including an inner layer substrate and an insulating layer in which a via hole was formed.
  • the evaluation substrate thus obtained was evaluated by the same method as in step (1-8) of Example 1.
  • Example 2 The steps (1-1) to (1-4) were carried out in the same manner as in Example 1 to obtain an intermediate laminate A having an inner layer substrate, an insulating layer (thickness 5 ⁇ m), and a mask film in this order.
  • a UV laser (“LU-2L212/M50L” manufactured by Via Mechanics) was used to perform laser processing on the mask film side surface of the intermediate laminate A to form via holes penetrating the mask film and the insulating layer.
  • the laser light was irradiated while adjusting the number of shots so that the copper layer of the inner layer substrate was exposed at the bottom of the via hole.
  • the mask film was peeled off to obtain an evaluation substrate having an inner layer substrate and an insulating layer in which a via hole was formed.
  • the evaluation substrate thus obtained was evaluated by the same method as in step (1-8) of Example 1.
  • the protective film was peeled off from the resin sheet produced in Example 1, and the resin composition layer was cured by heating at 200°C for 90 minutes to obtain an insulating layer. After peeling off the mask film, the relative dielectric constant and dielectric loss tangent of the insulating layer were measured. The measurement was performed by a cavity resonance perturbation method using a measuring device ("HP8362B" manufactured by Agilent Technologies) at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. As a result of the measurement, the relative dielectric constant of the insulating layer was 3.4 and the dielectric loss tangent was 0.0054.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Power Engineering (AREA)
  • Production Of Multi-Layered Print Wiring Board (AREA)
  • Printing Elements For Providing Electric Connections Between Printed Circuits (AREA)
  • Laminated Bodies (AREA)
PCT/JP2024/014762 2023-06-29 2024-04-12 配線板の製造方法 WO2025004499A1 (ja)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005008909A (ja) * 2003-06-16 2005-01-13 Canon Inc 構造体の製造方法
JP2007072374A (ja) * 2005-09-09 2007-03-22 Tokyo Ohka Kogyo Co Ltd ナノインプリント用の膜形成組成物およびパターン形成方法
WO2018066203A1 (ja) * 2016-10-05 2018-04-12 国立大学法人北陸先端科学技術大学院大学 複合部材及びその製造方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005008909A (ja) * 2003-06-16 2005-01-13 Canon Inc 構造体の製造方法
JP2007072374A (ja) * 2005-09-09 2007-03-22 Tokyo Ohka Kogyo Co Ltd ナノインプリント用の膜形成組成物およびパターン形成方法
WO2018066203A1 (ja) * 2016-10-05 2018-04-12 国立大学法人北陸先端科学技術大学院大学 複合部材及びその製造方法

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