Biaxially oriented polyester film for dry film resist

Abstract

Provided is a laminated biaxially oriented polyester film for a dry film resist, in which the number of protrusions having a height of 10 nm or more from a reference surface (a height zero surface) is 3000 / mm2 or less on at least one surface (surface C) that is exposed in an exposure step of the dry film resist.

Description

Technical Field

[0001] The present invention relates to a polyester film used for forming a dry film resist (hereinafter sometimes abbreviated as "DFR"), and particularly to a polyester film that can be suitably used as a support film constituting the dry film resist. Background Art

[0002] DFR is used to form circuits for printed wiring boards, semiconductor packages, flexible substrates, etc. It is formed by laminating a photosensitive layer (photoresist layer) formed from a photosensitive resin composition on a polyester film (base film), and then sandwiching the photosensitive layer with a protective film composed of a polyethylene film or the like.

[0003] In the photoresist manufacturing process, the protective film is first removed, and the exposed photosensitive layer is bonded to an object such as a substrate for printed wiring boards. In this state, a negative film is placed in close contact with a base film. Active light, such as ultraviolet light, is then irradiated from the negative film side so that it passes through the base film, exposing the photosensitive resin composition to a predetermined pattern. After exposure, the negative film is removed, and the base film is peeled off. The remaining uncured, unexposed portion of the photosensitive resin composition is removed using a solvent, etc., to form the desired pattern on the substrate.

[0004] In such dry film photoresists, the base film plays an important role in forming a photosensitive resin composition film of uniform thickness, ensuring close contact between the dry film and a substrate for wiring board fabrication without wrinkles or air inclusion, and forming a circuit with few defects caused by exposure inhibition.

[0005] In recent years, with the reduction in size and weight of electronic devices and the miniaturization and high density of printed wiring boards, high resolution and reproducibility are required to form fine patterns with wiring widths and wiring intervals of less than 5 μm.

[0006] However, since lubricants such as particles are contained in the polyester film as the base film to impart mobility, exposure is hindered by the particles during the exposure process, resulting in a problem of reduced resolution of the resist. Consequently, the resolution requirements are becoming increasingly stringent.

[0007] Therefore, a film has been proposed in which the particles added to the film are reduced in diameter and added in small amounts to achieve a film surface having both high smoothness, high transmittance, and lubricity (e.g., Patent Document 1). Furthermore, a film has been proposed in which a particle-containing surface layer (coating layer) containing minute particles is applied to the film surface, and the film has a low amount of aggregates within the film (e.g., Patent Document 2).

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-87854

[0011] Patent Document 2: Japanese Patent Application Laid-Open No. 2019-188612 Summary of the Invention

[0012] Problems to be solved by the invention

[0013] However, the films described in Patent Documents 1 and 2 are still insufficient to suppress exposure hindrance caused by fine particles in the films, as printed wiring boards have become increasingly miniaturized and denser in recent years. Furthermore, the particle-containing surface layer (coating layer) of Patent Document 2 has problems such as process contamination caused by particle shedding during the DFR manufacturing process and exposure hindrance caused by cut materials.

[0014] The present invention provides a laminated biaxially oriented polyester film for dry film resists having excellent mobility and suppression of exposure blockage in relation to a fine pattern photoresist base film that can cope with miniaturization and high density of printed wiring boards and excellent film surface durability (cutting resistance).

[0015] Means for solving problems

[0016] In order to solve the above problems, the present invention adopts the following structure.

[0017] (1) A laminated biaxially oriented polyester film for dry film resist, wherein the number of protrusions having a height of 10 nm or more from a reference plane (zero height plane) observed by a scanning white interference microscope on at least one surface (C surface) is 3000 / mm 2 Hereinafter, this C-plane is a surface (exposed surface) exposed in the exposure step of the dry film resist.

[0018] (2) The laminated biaxially oriented polyester film for dry film resist according to (1), wherein the number of protrusions having a height of 10 nm or more from a reference plane (zero height plane) observed by a scanning white interference microscope on the opposite side (side A) of the above-mentioned side C is 200 to 10,000 / mm 2 .

[0019] (3) The biaxially oriented polyester film for dry film resist according to (1) or (2), wherein the kurtosis of the surface (C surface) observed with an atomic force microscope (AFM) in a 5 μm field of view is 3 to 10.

[0020] (4) The biaxially oriented polyester film for dry film resist according to (1) or (2), wherein the aspect ratio of the protrusion diameter at a height of 1 nm from a reference plane (zero height plane) observed by a scanning white interference microscope on the surface (C surface) is 0.35 or less.

[0021] (5) The laminated biaxially oriented polyester film for dry film resist according to any one of (1) to (4), wherein the C surface is composed of a coating layer having a surface free energy of 47 mN / m or less.

[0022] (6) The laminated biaxially oriented polyester film for dry film resist according to any one of (1) to (5), which is composed of at least three layers.

[0023] (7) In a belt movement test, the laminated biaxially oriented polyester film for dry film resist according to any one of (1) to (6) is subjected to a belt movement test in which the C surface is placed in contact with a stainless steel needle and reciprocated with a load of 300 g applied to the film after humidity adjustment for 24 hours or more in an atmosphere of 23°C and 65% RH. At this time, the friction coefficient (μk1) between the C surface and the stainless steel needle is 0.9 or less, and the friction coefficient (μk5) after repeating the reciprocating movement five times is 0.9 or less.

[0024] (8) The laminated biaxially oriented polyester film for dry film resist according to (5), wherein the coating layer on the C surface does not contain inorganic particles.

[0025] (9) The laminated biaxially oriented polyester film for dry film resist according to (5), wherein the C surface is a coating layer mainly composed of a resin containing an acrylic adhesive.

[0026] (10) According to the biaxially oriented polyester film for dry film resist described in (5), the C surface is a coating layer in which the ratio (P / K) of the peak intensity (P) of fragments derived from the fluorine element to the peak intensity (K) of fragments detected at maximum intensity is less than 0.01 when the surface of the C surface is analyzed by time-of-flight secondary ion mass spectrometry.

[0027] (11) The laminated biaxially oriented polyester film for dry film resist according to (3), wherein the C surface is a film containing melamine, A coating layer of at least one compound selected from the group consisting of oxazoline, carbodiimide, and isocyanate.

[0028] (12) In the laminated biaxially oriented polyester film for dry film resist according to any one of (1) to (10), the number of coarse particles with a long diameter of 1.0 μm or more (NP1 (pieces)) when 30 fields of view of an area of ​​220 μm in the length direction and 290 μm in the width direction are observed by a laser microscope on the C surface is 20 or less.

[0029] (13) The laminated biaxially oriented polyester film for dry film resist according to any one of (1) to (11), comprising a polyester resin composition satisfying the following I to III.

[0030] I: 5ppm≤germanium content (relative to the weight ratio of the polyester resin composition)≤100ppm,

[0031] II: 5ppm≤manganese content (relative to the weight ratio of the polyester resin composition)≤40ppm,

[0032] III: 4 ppm≤sodium element content (weight ratio relative to the polyester resin composition)≤40 ppm.

[0033] Effects of the Invention

[0034] The present invention can provide a laminated biaxially oriented polyester film for dry film resists, which has excellent mobility and suppression of exposure blockage, and excellent durability (cutting resistance) of the film surface, especially when used as a base film for fine pattern photoresists with a wiring width and wiring spacing of less than 5 μm. DETAILED DESCRIPTION

[0035] Hereinafter, the present invention will be described in detail.

[0036] At least one surface (C surface) of the laminated biaxially oriented polyester film for dry film resist of the present invention is a surface exposed in the exposure step of the dry film resist (exposed surface), and the number of protrusions of 10 nm or more from a reference surface (zero height surface) observed by a scanning white interference microscope on the C surface is 3000 pieces / mm 2 The following frequencies are formed. Preferably 2000 pieces / mm 2 Below, more preferably 200 to 1000 pieces / mm 2 If the number of protrusions is outside the range of the present invention, process contamination may occur due to the falling of protrusions during the DFR production process, or exposure may be blocked by cut materials, thereby reducing the quality of fine patterns.

[0037] The laminated biaxially oriented polyester film for dry film resist of the present invention is preferably arranged in a manner that the C surface is in contact with a stainless steel needle, and is reciprocated under a load of 300g applied to the film. At this time, the friction coefficient (μk1) between the C surface and the stainless steel needle is 0.9 or less, more preferably 0.8 or less, and particularly preferably 0.75 or less. If the friction coefficient (μk1) exceeds 0.9, the operability is sometimes reduced and the durability of the C surface is reduced. Furthermore, the friction coefficient (μk5) with the needle after 5 reciprocating times is preferably 0.9 or less, more preferably 0.8 or less. If the friction coefficient (μk5) exceeds 0.9, the durability of the C surface is sometimes reduced, causing exposure obstruction caused by cutting powder and thus reducing the quality of the fine pattern.

[0038] The laminated biaxially oriented polyester film for dry film resist in the present invention refers to a film containing polyester resin as a main component. The main component here means a component that is contained in an amount exceeding 50% by mass in 100% by mass of all components of the film.

[0039] The polyester resin of the laminated biaxially oriented polyester film for dry film resist of the present invention is obtained by polycondensation of a dicarboxylic acid constituent component and a diol constituent component.

[0040] Examples of the dicarboxylic acid constituent components constituting such polyesters include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, and 4,4'-diphenyl ether dicarboxylic acid, or ester derivatives thereof.

[0041] Examples of diol components constituting such polyesters include aliphatic diols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,2-butanediol, and 1,3-butanediol; alicyclic diols such as cyclohexanedimethanol and spirodiol; and combinations of multiple linked diols.

[0042] As the polyester resin of the present invention, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene 2,6-naphthalate (PEN), and polyesters obtained by copolymerizing isophthalic acid or naphthalene dicarboxylic acid with a portion of the dicarboxylic acid component of PET, and by copolymerizing cyclohexanedimethanol, spiroglycol, or diethylene glycol with a portion of the diol component of PET, are suitable from the viewpoints of mechanical properties and transparency. Polyethylene terephthalate is particularly preferred. These raw materials may be modified forms, derivatives, or copolymers with other compounds, and may be used alone or in combination of two or more.

[0043] The C-surface of the laminated biaxially oriented polyester film for dry film resists of the present invention is preferably composed of a coating layer having a surface free energy of 47 mN / m or less. Comprising the C-surface with a coating layer free of inorganic particles is preferred from the perspectives of suppressing exposure hindrance caused by light scattering and improving surface durability. Furthermore, the presence of inorganic particles may cause exposure hindrance due to chippings caused by particle shedding, thereby reducing the quality of fine patterns.

[0044] Examples of the resin or compound that can be used to form the coating layer on the C side of the laminated biaxially oriented polyester film for dry film resist of the present invention include acrylic resins, polyester resins, urethane resins, melamine resins, Oxazoline compounds, carbodiimide compounds, isocyanate compounds, and mixtures and copolymers thereof may also be used. Among them, acrylic resins are particularly preferably contained as a main component.

[0045] The acrylic resin that can be used as the resin or compound is preferably composed of alkyl methacrylate and / or alkyl acrylate.

[0046] As the alkyl methacrylate and / or alkyl acrylate, preferably used are methacrylic acid, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, maleic acid, itaconic acid, acrylamide, N-hydroxymethyl acrylamide, diacetone acrylamide, and the like. These may be used alone or in combination.

[0047] The above-mentioned compound preferably contains a reactive functional group in the side chain. By having a reactive side chain, the crosslinking degree of the coating layer becomes higher, and as a result, the mobility is improved, and it is easy to make the durability of the C surface good. As a reactive side chain, there is no particular limitation, and for example, a hydroxyl group, a carboxyl group, a tertiary amino group, a quaternary ammonium base, a sulfonic acid group or a phosphoric acid group can be mentioned. Among them, from the viewpoint of the dispersion stability of the coating composition, it is particularly preferred to include a (meth) acrylate having a hydroxyl group. As a (meth) acrylate having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, a monoester of a polyol such as polyethylene glycol mono(meth) acrylate and (meth) acrylic acid, or a compound in which ε-caprolactone and the monoester are subjected to ring-opening polymerization, etc., are particularly preferred, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.

[0048] The glass transition temperature (Tg) of the acrylic resin preferably used to control the density of protrusions having a height of 10 nm or more from a reference plane (zero height plane) observed by a scanning white interference microscope on the C surface of the present invention is preferably 40 to 100°C, more preferably 65 to 100°C.

[0049] As the polyester resin that can be used as the resin or compound, preferably, one having an ester bond in the main chain or side chain and obtained by polycondensation of dicarboxylic acid and diol.

[0050] As the dicarboxylic acid used as the raw material of the polyester resin, aromatic, aliphatic, and alicyclic dicarboxylic acids can be used. As aromatic dicarboxylic acids, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bisphenoxyethane-p,p'-dicarboxylic acid, phenylindanedicarboxylic acid, etc. can be used. As aliphatic and alicyclic dicarboxylic acids, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, etc., and ester-forming derivatives thereof can be used.

[0051] Examples of the diol component serving as a raw material for the polyester resin include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1, 6-Hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4'-thiodiphenol, bisphenol A, 4,4'-methylenediphenol, 4,4'-(2-norbornyl)diphenol, 4,4'-dihydroxydiphenol, o-, m- and p-dihydroxybenzene, 4,4'-isopropylidene diphenol, 4,4'-isopropylidenebis(2-methylphenol), cyclopentane-1,2-diol, cyclohexane-1,2'-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, etc.

[0052] Furthermore, as the polyester resin, a modified polyester copolymer, for example, a block copolymer or a graft copolymer modified with acrylic, urethane, epoxy, or the like, can also be used.

[0053] The urethane resin that can be used as the resin or compound is preferably a resin obtained by reacting a polyhydroxy compound with a polyisocyanate compound by a known urethane resin polymerization method such as emulsion polymerization and suspension polymerization.

[0054] Examples of the polyhydroxy compound include polyethylene glycol, polypropylene glycol, polyethylene glycol / propylene glycol, polybutylene glycol, 1,6-hexanediol, 1,4-butanediol, 1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone, polyhexanediol adipate, polyhexanediol sebacate, polybutylene adipate, polybutylene sebacate, trimethylolpropane, trimethylolethane, pentaerythritol, polycarbonate diol, and glycerol.

[0055] As the polyisocyanate compound, for example, hexamethylene diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, an adduct of toluene diisocyanate and trimethylene propane, an adduct of hexamethylene diisocyanate and trimethylolethane, etc. can be used.

[0056] Melamine resins that can be used as resins or compounds include, for example, melamine, methylolated melamine derivatives obtained by condensing melamine with formaldehyde, compounds partially or completely etherified by reacting lower alcohols with methylolated melamine, and mixtures thereof. Melamine resins can be monomers or condensates composed of dimers or higher, or mixtures thereof. Lower alcohols used for etherification include methanol, ethanol, isopropanol, n-butanol, and isobutanol. Examples include imino-type methylated melamine resins, methylol-type melamine resins, methylol-type methylated melamine resins, and fully alkyl-type methylated melamine resins, each containing an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group as a functional group within the molecule. Methylolated melamine resins are most preferred. The preferred addition amount is 20 to 80 parts by mass, preferably 30 to 50 parts by mass, relative to the resin solids content. If the amount of melamine resin added is below the lower limit, the function as a crosslinking agent becomes insufficient, the hardness of the C layer surface is insufficient, the friction coefficient may increase, and the movement durability may deteriorate. In addition, if the amount of melamine resin added exceeds the upper limit, crosslinking may be promoted, and the C layer surface may become hard, resulting in brittle surface protrusions and easy cutting.

[0057] In addition, it can be used as a resin or compound The oxazoline compound is a compound having The substance containing oxazoline as a functional group preferably contains at least one A monomer containing an oxazoline group and copolymerizing at least one other monomer Azoline-based copolymer.

[0058] As containing As monomers of oxazoline group, 2-vinyl-2- Oxazoline, 2-vinyl-4-methyl-2- Oxazoline, 2-vinyl-5-methyl-2- Oxazoline, 2-isopropenyl-2- Oxazoline, 2-isopropenyl-4-methyl-2- Oxazoline and 2-isopropenyl-5-ethyl-2- Oxazoline, etc., and a mixture of one or more of them can also be used. Among them, 2-isopropenyl-2- Oxazoline is also readily available industrially and is suitable.

[0059] exist Among oxazoline compounds, The at least one other monomer used in place of the monomer containing the oxazoline group is capable of reacting with the monomer containing the oxazoline group. Monomers for copolymerization with oxazoline-containing monomers include, for example, acrylic acid esters or methacrylic acid esters such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, and maleic acid; unsaturated nitriles such as acrylonitrile and methacrylonitrile; unsaturated amides such as acrylamide, methacrylamide, N-hydroxymethyl acrylamide, and N-hydroxymethyl methacrylamide; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; olefins such as ethylene and propylene; halogen-containing α,β-unsaturated monomers such as vinyl chloride, 1,1-dichloroethylene, and vinyl fluoride; and α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene. These monomers may be used alone or as a mixture of two or more.

[0060] In addition, the carbodiimide compound that can be used as a resin or compound is a compound having one or more carbodiimide groups or cyanamino groups in a tautomeric relationship therewith as functional groups in the molecule. Specific examples of such carbodiimide compounds include dicyclohexylmethanecarbodiimide, dicyclohexylcarbodiimide, tetramethylxylylenediaminecarbodiimide, and urea-modified carbodiimide. These can also be used as a mixture of one or more.

[0061] Examples of the isocyanate compound that can be used as a resin or compound include toluene diisocyanate, diphenylmethane-4,4'-diisocyanate, m-xylylene diisocyanate, hexamethylene-1,6-diisocyanate, 1,6-diisocyanate hexane, an adduct of toluene diisocyanate and hexanetriol, an adduct of toluene diisocyanate and trimethylolpropane, polyol-modified diphenylmethane-4,4'-diisocyanate, carbodiimide-modified diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, and m-phenylene diisocyanate.

[0062] Furthermore, since isocyanate groups readily react with water, blocked isocyanate compounds, in which the isocyanate groups are masked with a blocking agent, etc., are preferably used in order to improve the shelf life of the coating agent. In this case, heat is applied during the drying process after the coating composition is applied to the polyester film, thereby dissociating the blocking agent and exposing the isocyanate groups, thereby causing the crosslinking reaction to proceed.

[0063] From the viewpoint of mobility and durability, the coating layer of the present invention preferably comprises a melamine resin selected from the group consisting of A coating layer comprising at least one compound selected from the group consisting of an oxazoline compound, a carbodiimide compound, and an isocyanate compound. Among these, melamine resins and isocyanate compounds are preferred from the perspective of durability, with isocyanate compounds being particularly preferred. By containing 20 parts or more, and further 30 parts or more of these compounds relative to the resin solids content, crosslinking of the coating layer is promoted, and shedding of surface protrusions is suppressed, resulting in a highly durable coating layer.

[0064] The coating layer of the present invention may contain inorganic particles or organic particles as long as the effects of the present invention are not impaired. Preferred examples of the particles used include colloidal silica having a particle size of 5 to 80 nm. The amount added is within a range of 1% by weight or less, preferably 0.5% by weight or less, relative to the resin solids content constituting the coating layer. However, a coating layer containing no inorganic particles is most preferred, so that the number of protrusions with a height of 10 nm or more observed from the reference plane (zero height plane) observed by a scanning white interference microscope is easily controlled within the scope of the present invention.

[0065] The average thickness of the coating layer of the present invention is preferably 5 to 70 nm. Particles can be added to the coating layer, but when no particles are added, by making the average thickness less than 20 nm, preferably within the range of 5 to 15 nm, the number of protrusions with a height of more than 10 nm from the reference plane (height zero plane) observed by scanning white interference microscopy can be controlled within the range of the present invention, and good mobility and durability of the C surface can be obtained. When particles are added, it is preferred to control the ratio t / d of the particle size (d) of the added particles to the average thickness (t) of the coating layer to less than 0.9, preferably within the range of 0.5 to 0.8, from the perspective of the durability of the coating layer.

[0066] Various additives such as antioxidants, ultraviolet absorbers, pigments, mold release agents, antistatic agents, and nucleating agents may be added to the coating layer of the present invention within a range that does not impair the effects of the present invention.

[0067] The laminated biaxially oriented polyester film for dry film resist of the present invention has a laminated structure having at least two layers with a C surface, and a coating layer (C layer) constituting the C surface is provided on at least one side of the biaxially oriented polyester film of the substrate film. The substrate film can be a single film or a laminated structure having two or more layers, for example, a three-layer laminated structure such as A / B or A / B / A, A / B / D. The polymers constituting each layer can be different types of polymers or the same type of polymer. From the viewpoint of mobility and durability of the present invention, it is preferably composed of three or more layers, among which it is preferably a laminated structure having a two-layer laminated structure of A / B, i.e., a three-layer structure of A / B / C, in which a (C layer) constituting the C surface is provided on the B surface side of the substrate film, or a laminated structure having a three-layer structure of A / B / D, i.e., a four-layer structure of A / B / D / C, in which a coating layer constituting the C surface is provided on the D surface side of the substrate film.

[0068] For example, in a three-layer stacked structure of A / B / C, the thickness of each layer is 0.2 to 3 μm, preferably 0.3 to 2 μm. The thickness of the layer B is 5 to 50 μm, preferably 7 to 40 μm, and more preferably 10 to 30 μm. The thickness of the layer C, i.e., the coating layer, is preferably 5 to 70 nm, as described above.

[0069] The layer of the substrate film adjacent to the coating layer of the present invention may contain particles within a range that does not impair the effects of the present invention. However, from the perspective of the durability of the coating layer of the present invention, it is preferably substantially particle-free. The surface to which particles are added forms unevenness, so if a coating layer is formed on this surface, the composition used when providing the coating layer selectively concentrates in the recessed areas, causing the coating layer to become thicker in the recessed areas and thinner in the raised areas, resulting in an uneven thickness of the coating layer. This can reduce the durability of the coating layer, and scrapings from the coating layer can hinder exposure, thereby reducing the quality of the fine circuit pattern.

[0070] When observing 30 fields of view of the C surface of the laminated biaxially oriented polyester film for a dry film resist of the present invention using a laser microscope over an area of ​​220 μm in the longitudinal direction and 290 μm in the width direction, the number of coarse particles with a major diameter of 1.0 μm or greater (NP1 (number)) is 20 or less. The number is preferably 15 or less, and more preferably 10 or less. If more than 20 coarse particles of 1 μm or greater are present in the film, exposure may be hindered, thereby reducing the quality of fine circuit patterns.

[0071] The laminated biaxially oriented polyester film for a dry film resist of the present invention is preferably formed from a polyester resin composition having a germanium content (by weight) of 5 ppm to 100 ppm, a manganese content (by weight) of 5 ppm to 40 ppm, and a sodium content (by weight) of 4 ppm to 40 ppm, relative to the polyester resin composition. If the contents of each element exceed the upper limit, coarse matter may form during melt casting of the substrate film, hindering exposure and degrading the quality of fine circuit patterns.

[0072] The outermost surface (surface A) of the laminated biaxially oriented polyester film for dry film resist of the present invention, which is opposite to the surface C, preferably has 200 to 10,000 protrusions / mm2 with a height of 10 nm or more from a reference surface (zero height surface) as observed by a scanning white interference microscope. 2 More preferably, it is 200 to 5000 pieces / mm 2 , particularly preferably 200 to 600 pieces / mm 2 Since the A surface is the surface where the photoresist layer is formed, if the number of protrusions with a height of 10 nm or more exceeds 10,000 / mm 2 In addition, if the number of protrusions with a height of 10 nm or more is less than 200 / mm, 2 , sometimes damage occurs during the processing process, resulting in defects in fine circuit patterns.

[0073] The C-surface of the laminated biaxially oriented polyester film for a dry film resist of the present invention preferably has a kurtosis of 3 to 10 or less in a 5 μm field of view as observed by atomic force microscopy (AFM). It is more preferably 3 to 8 or less. If the kurtosis is outside this range, the protrusions formed on the C-surface may become uneven in height, size, and other aspects of the protrusion shape. This may cause external stress to be applied to locally large protrusions during various steps, thereby reducing the durability of the protrusions and causing exposure obstruction due to shavings, which is not preferred.

[0074] The C-surface of the laminated biaxially oriented polyester film for a dry film resist of the present invention preferably has a protrusion diameter aspect ratio (minor diameter / major diameter) of 0.35 or less at a height of 1 nm from a reference plane (zero height plane) as observed using a scanning white interference microscope. More preferably, it is 0.2 to 0.35. Setting the protrusion diameter aspect ratio at a height of 1 nm within the range of the present invention is believed to result in a protrusion shape that is less prone to cutting, thereby suppressing the generation of shavings during movement in various steps, which is therefore preferred.

[0075] As a method for controlling the kurtosis and aspect ratio of the C-surface of the present invention, it is preferred to use a water-soluble resin for the coating layer forming the C-surface, and to make a dilute aqueous solution with a resin solid content concentration of preferably 1% or less, more preferably 0.6% or less. It is preferably exemplified in the online coating that uniformly disperses gentle, fine flat protrusions useful for suppressing slippage and cutting during movement on the film surface, thereby controlling the kurtosis and aspect ratio of the present invention. Furthermore, it is preferred to use a water-soluble resin with a high glass transition temperature (Tg) of 65 to 100°C. If the glass transition temperature is low, protrusions may not be formed. In addition, if the coating layer forming the C-surface is a water-soluble resin, it is easy to control the kurtosis and aspect ratio, and an average emulsion diameter of 60 to 120 nm is effective. In addition, in order to obtain the kurtosis and aspect ratio of the present invention, the coating layer forming the C-surface is preferably formed by coating on a substantially particle-free substrate film surface. If particles are contained in the substrate film, it is sometimes difficult to control the aspect ratio within the range of the present invention. If the transverse stretching ratio after coating is 3 times or more, preferably 3.5 times or more, the aspect ratio of the present invention can be easily achieved.

[0076] In the coating layer of the present invention, surfactant is included, preferably fluorine-based, silicone-based, hydrocarbon-based. Fluorine-based is preferably used because it is present near the surface and is useful for uniform coating, but in the case of being used in dry film resists, there is the possibility of being transferred to the resist layer and causing exposure obstruction. For fine wiring patterns, hydrocarbons are particularly preferred, wherein acetylene-based surfactants are preferably exemplified. Preferably, by using acetylene-based surfactants, when the C-face surface is analyzed by time-of-flight secondary ion mass spectrometry, the ratio (P / K) of the peak intensity (P) of the fragments derived from fluorine element relative to the peak intensity (K) of the fragments detected with maximum intensity is 0.01 or less.

[0077] As methods for controlling the number of protrusions with a height of 10 nm or more from a reference plane (zero height plane) on the A surface observed by a scanning white interference microscope within the range of the present invention, the following methods can be preferably exemplified: (i) a method using particle addition, (ii) a method of subjecting the unstretched sheet to plasma treatment using atmospheric pressure glow discharge and then biaxially stretching, (iii) a method combining the above-mentioned particle addition and plasma treatment, and (iv) a method of providing a coating layer in the same manner as for the C surface.

[0078] When adding particles to the A layer constituting the A surface, the amount of organic particles or inorganic fine particles having a primary particle size of 0.01 to 0.2 μm or less, such as colloidal silica or alumina, can be controlled by adding the particles at a ratio of 1 wt % or less, preferably 0.05 to 0.8 wt % or less, and more preferably 0.1 to 0.5 wt % or less.

[0079] As a method for controlling the number of protrusions with a height of more than 10 nm by subjecting an unstretched sheet to a plasma treatment using atmospheric pressure glow discharge, the number of protrusions can be controlled by subjecting the A surface of the unstretched sheet to a plasma treatment using atmospheric pressure glow discharge and then subjecting the unstretched sheet to biaxial orientation stretching. The so-called atmospheric pressure is in the range of 700 torr to 780 torr. The atmospheric pressure glow discharge treatment is performed by introducing a film to be treated between opposite electrodes and a grounded roller, introducing a plasma-exciting gas into the device, applying a high-frequency voltage between the electrodes, thereby causing the gas to undergo plasma excitation and glow discharge between the electrodes. The surface of the film can thereby be finely decomposed / removed, making the bottom fine and high-density rough. Furthermore, if the A surface of the unstretched sheet to which the above-mentioned inorganic fine particles are added is subjected to a plasma treatment, the concave-convex shape with a certain degree of size formed by the particles is made significant, thereby forming surface concave-convex shapes with different shapes / sizes, such as extremely fine surface concave-convex shapes and surface concave-convex shapes with a certain degree of size.

[0080] The term "plasma-exciting gas" refers to a gas that can be excited into plasma under the above-mentioned conditions. Examples of plasma-exciting gases include rare gases such as argon, helium, neon, krypton, and xenon, nitrogen, carbon dioxide, oxygen, chlorofluorocarbons such as tetrafluoromethane, and mixtures thereof. Plasma-exciting gases may be used alone or in combination of two or more in any mixing ratio.

[0081] The frequency of the high frequency voltage in the plasma treatment is preferably in the range of 1kHz to 100kHz. In addition, the discharge treatment intensity (E value) obtained by the following method is in the range of 10 to 2000W·min / m 2 It is preferable to treat in the range of 100 to 1000 W·min / m from the viewpoint of protrusion formation, and more preferably 100 to 1000 W·min / m2 If the discharge treatment intensity (E value) is too low, the protrusions may not be sufficiently formed, and if the discharge treatment intensity (E value) is too high, the polyester film may be damaged to form foreign matter.

[0082] <Calculation Method for Discharge Treatment Intensity (E Value)>

[0083] E=Vp×Ip / (S×Wt)

[0084] E: E value (W·min / m 2 )

[0085] Vp: Applied voltage (V)

[0086] Ip: Applied current (A)

[0087] S: Processing speed (m / min)

[0088] Wt: processing width (m).

[0089] Generally speaking, when decomposing and removing the surface of a polyester film, particularly a film having both amorphous and crystalline portions such as PET and PEN, by atmospheric pressure glow discharge treatment, the decomposition and removal proceed from the soft amorphous portion. By subdividing the crystalline and amorphous portions, atmospheric pressure glow discharge treatment can form finer irregularities.

[0090] The dry film resist laminated biaxially oriented polyester film of the present invention is biaxially oriented. By performing biaxial orientation, the mechanical strength and dimensional stability of the film are improved, thereby improving mobility and windability. In addition, by applying uniform tensile stress during the stretching process, the surface smoothness can be made uniform across the entire film area. Biaxial orientation herein refers to a pattern showing biaxial orientation in wide-angle X-ray diffraction. Polyester film can generally be obtained by stretching an unstretched thermoplastic resin sheet along the sheet length and width direction, and then performing a heat treatment to complete crystal orientation. Detailed film forming conditions are described below.

[0091] As a method for obtaining the C-surface of the laminated biaxially oriented polyester film for dry film resist of the present invention, the following method is particularly preferably used in terms of cost, thickness uniformity, and controlling the number of protrusions on the C-surface of the present invention to a preferred range: on-line coating of a polyester resin selected from the group consisting of polyester resin, urethane resin, melamine resin, A method of coating a polyester film having two or more layers of A / B, online coating the above-mentioned resin composition on the surface of the polyester layer B stretched in the length direction, and then stretching and drying it in the width direction.

[0092] When a coating layer is provided on the A surface as well as the C surface, a method of coating both the A surface and the C surface by an in-line coating method is preferably exemplified.

[0093] The thickness of the laminated biaxially oriented polyester film for dry film resist of the present invention is preferably 10 μm or more, more preferably 15 μm or more. The upper limit is not particularly limited but is 50 μm or less.

[0094] As the adjustment method of the coating agent for forming the resin layer of the present invention, the solvent preferably uses an aqueous solvent, and the coating agent comprising the resin composition can be made by mixing and stirring the various above-mentioned resins that have been dispersed or dissolved in water as needed in any order with a desired weight ratio. The method for mixing and stirring can be used by vibrating the container by hand, or using an electromagnetic stirrer, a stirring blade, ultrasonic waves, a vibration dispersion method, etc. In particular, in order to obtain the C surface of the present invention, it is preferred to exemplify that a dispersant such as a fluorochemical surfactant (for example, PLUSCO-2 made by Huying Chemical Industry (Strain)) is added to the solvent and fully stirred, then the resin is added, and finally particles are added as needed after stirring, and the step of stirring is repeated.

[0095] In the laminated biaxially oriented polyester film for dry film resists of the present invention, the intrinsic viscosity (IV) of the polyester film as a whole is preferably 0.50 dl / g or greater, more preferably 0.55 dl / g or greater. An IV of 0.50 dl / g or greater can prevent the polyester molecular chains from becoming short and crystallizing, which can lead to frequent breakage during the stretching process and difficulty in film formation.

[0096] Next, the method for producing the laminated biaxially oriented polyester film for dry film resist of the present invention will be described by taking examples. However, the present invention is not limited to the method obtained by the examples.

[0097] The laminated biaxially oriented polyester film for dry film resists used in the present invention can be obtained by conventional polymerization methods. For example, the film can be obtained by subjecting a dicarboxylic acid component such as terephthalic acid or its ester-forming derivative to a transesterification reaction or esterification reaction with a diol component such as ethylene glycol or its ester-forming derivative by a known method, followed by melt polymerization. Furthermore, as necessary, conventionally known alkali metals, alkaline earth metals, manganese, cobalt, zinc, antimony, germanium, and titanium compounds can be used as reaction catalysts.

[0098] The polyester obtained by melt polymerization may be subjected to solid phase polymerization at a temperature below the melting point of the polyester.

[0099] The polyester film of the present invention can be obtained by a conventionally known production method. Specifically, the polyester film of the present invention can be obtained by heating and melting the raw material, which has been dried as needed, in an extruder, and extruding it from a die onto a cooled casting drum to form a sheet (melt casting method). Alternatively, a method can be used in which the raw material is dissolved in a solvent, the solution is extruded from a die onto a support such as a casting drum or an endless belt to form a film, and then the solvent is dried and removed from the film layer to form a sheet (solution casting method).

[0100] When producing a biaxially oriented polyester film of two or more layers by melt casting, a suitable method is to use an extruder for each layer constituting the biaxially oriented polyester film, melt the raw materials of each layer, laminate them in a molten state using a merging device provided between the extruder and the die, guide them to the die, and extrude them from the die onto a casting drum to form a sheet (coextrusion method). The laminated sheet is then electrostatically bonded to a casting drum whose surface temperature has been cooled to a temperature of 20°C to 60°C, whereupon it is cooled and solidified to produce an unstretched film. In addition, by keeping the surface temperature of the casting drum below 60°C, the adhesion of the unstretched film to the casting drum can be suppressed, resulting in an unstretched film with less uneven thickness along the film's travel direction. The more preferred range of the casting drum surface temperature is 25°C to 55°C.

[0101] Regarding the stretching conditions when biaxially stretching an unstretched film, when the laminated biaxially oriented polyester film for dry film resist of the present invention contains polyester as its main component, the unstretched film is preferably stretched in the longitudinal direction by passing it over a set of rollers heated to 70°C or higher, stretching it in the longitudinal direction (i.e., the film's travel direction), and then cooling it using a set of rollers set to a temperature of 20°C to 50°C. The lower limit of the heated roller temperature during longitudinal stretching is not particularly limited as long as it does not impair the stretchability of the sheet, but it is preferably higher than the glass transition temperature of the polyester resin used. Furthermore, the preferred range for the longitudinal stretch ratio is 3x or higher and 5x or lower. A more preferred range is 3x or higher and 4x or lower. A longitudinal stretch ratio of 3x or higher allows for the progression of orientational crystallization, thereby improving film strength. On the other hand, a stretch ratio of 5x or lower can prevent the polyester resin from becoming brittle due to excessive orientational crystallization during stretching, which can lead to cracking during film formation.

[0102] The coating layer forming the C-side of the present invention is preferably formed by an in-line coating method in which a process film (uniaxially stretched film) stretched in the longitudinal direction is coated with a resin composition, then stretched in the width direction, and dried. Any known coating method can be used for coating the resin composition. Examples thereof include wire bar coating, reverse coating, gravure coating, die coating, blade coating, dip coating, air knife coating, curtain coating, and roll coating.

[0103] Regarding the stretching in the direction perpendicular to the longitudinal direction (width direction), it is preferred to guide the film to a tenter while holding both ends of the film with a clamp, and to stretch the film in the direction perpendicular to the longitudinal direction (width direction) by more than 3 times and less than 5 times in an atmosphere heated to a temperature of more than 70°C and less than 160°C. At this time, when performing the above-mentioned stretching in the width direction, it is preferred to increase the temperature in stages according to the stretching ratio. This is because the molecular chain orientation of the polyester resin progresses as the stretching in the width direction progresses, and by always continuously providing the heat required for stretching, it is possible not only to suppress the occurrence of poor stretching, but also to form the resin composition coated in the above manner with a uniform thickness in the width direction. As a specific method for performing a staged temperature increase for stretching (hereinafter sometimes referred to as stage temperature increase), it is preferred to divide the stretching temperature into at least 3 intervals in the stretching zone in the tenter, and to increase the stretching temperature in proportion to the stretching ratio.

[0104] The stretched film is then preferably heat-treated to stabilize the internal orientation structure. The thermal history temperature to which the film is subjected during the heat treatment can be confirmed by the temperature of the small endothermic peak (sometimes referred to as Tmeta) that appears just below the melting point, as measured later by a differential scanning calorimeter (DSC). The tenter set temperature is preferably set so that the maximum temperature in the tenter is between 200°C and 250°C when polyester (melting point 255°C) is the main component. When other thermoplastic resins are the main components, the temperature is preferably set between -55°C and -5°C. By setting the heat treatment temperature to 200°C or higher, the dimensional stability of the biaxially oriented polyester film can be improved. Furthermore, the cross-linking reaction between molecules can be promoted during the formation of the resin layer, forming a stronger resin layer. Furthermore, by setting the heat treatment temperature to 250°C or lower, the occurrence of film breakage associated with the melting of the polyester film can be suppressed, resulting in good production efficiency. A more preferred range is between 220°C and 245°C.

[0105] Furthermore, after the heat treatment, a relaxation treatment in a range of 1% to 10% may be performed for the purpose of imparting dimensional stability. A relaxation treatment of 1% or more can improve the dimensional stability of the biaxially oriented polyester film when used in a high-temperature environment, while a relaxation treatment of 10% or less can continuously apply appropriate tension to the biaxially oriented polyester film, thereby preventing the deterioration of thickness unevenness.

[0106] The stretch ratio is 3 times or more and 5 times or less in each of the longitudinal direction and the width direction, and the area ratio (stretch ratio in the longitudinal direction × stretch ratio in the width direction) is preferably 9 times or more and 22 times or less, more preferably 9 times or more and 20 times or less. By setting the area ratio to 9 times or more, the molecular orientation of the obtained biaxially oriented polyester film can be promoted, thereby improving the durability. By setting the area ratio to 22 times or less, the occurrence of cracking during stretching can be suppressed.

[0107] [Evaluation method of characteristics]

[0108] The method for measuring the characteristic values ​​and the method for evaluating the effects in the present invention are as follows.

[0109] (1) Number of protrusions with a height of 10 nm or more from the reference plane (zero height plane) observed by scanning white interference microscope

[0110] Using a scanning white interference microscope, measurements were performed in 100 different viewing fields. The sample was positioned so that the direction perpendicular to the sample stage's X-axis (the Y-axis) corresponded to the length of the sample film (the length direction refers to the direction the film moves during the film manufacturing process). Measurements were made under the following conditions. All images were processed using the accompanying analysis software (VS-Viewer). Particle analysis was then performed on all viewing fields under the following conditions. The number of protrusions with a height of 10 nm or greater from the reference plane (zero height) was determined, and the average value was used as the number of protrusions with a height of 10 nm or greater.

[0111] <Device>: VS-1540 made by Hitachi Hakusui Co., Ltd.

[0112] <Measurement conditions>

[0113] Objective lens: 50 times

[0114] Wavelength filter: 530white

[0115] Measurement device: Piezoelectric

[0116] Measurement mode: Wave

[0117] Measurement field size: 113μm×113μm

[0118] Image processing conditions

[0119] Interpolation: Full interpolation

[0120] Filter: Median 3×3

[0121] Surface correction: 4 times

[0122] <Particle Analysis>

[0123] Analysis: Sudden Analysis

[0124] Image correction: No

[0125] Height threshold: 10nm

[0126] Reference height: zero plane.

[0127] (reference plane: reference height = zero plane)

[0128] As the "zero plane" in the above-mentioned reference height setting, in the measurement image (113μm×113μm) obtained by microscope observation and the above-mentioned image processing, the plane of the "average value of height (Ave)" automatically calculated by the following formula (1) is set as the reference plane (height zero plane).

[0129] [Number 1]

[0130]

[0131] lx: The range length in the X direction of each measurement image subjected to the above image processing

[0132] ly: The range length in the Y direction of each measurement image subjected to the above image processing

[0133] h(x, y): The height of each image point (x, y) in the measurement image after the above image processing.

[0134] (2) The aspect ratio of the protrusion at a height of 1 nm from the reference plane (zero height plane) observed by scanning white interference microscopy

[0135] In the measurement method described in (1) above, the height threshold for <Particle Analysis> was changed to 1 nm, and 100 fields of view were measured at different locations. The aspect ratio (orthogonal diameter ÷ longest diameter) was calculated from the major and minor diameters of each protrusion, and the average of these values ​​was defined as the aspect ratio of the protrusion in that field of view. The average value of the 100 fields of view was then defined as the aspect ratio.

[0136] It should be noted that the major diameter, minor diameter, and minor-to-major ratio (orthogonal diameter÷longest diameter) are automatically calculated for each protrusion.

[0137] (3) Kurtosis

[0138] Using an atomic force microscope (AFM), 5 fields of view were measured by changing the location. Regarding sample placement, the sample was placed in a manner such that the direction perpendicular to the scanning direction of the cantilever (Y-axis direction) became the length direction of the sample film (the so-called length direction is the direction in which the film moves during the film manufacturing process), and the measurement was performed under the following AFM measurement conditions. The obtained image was analyzed using the attached analysis software (NanoScope Analysis Version 1.40). After the obtained height sensor image of the film surface was subjected to only the following flattening process, the roughness analysis mode was set as described below. The average value of the 5 fields of view was calculated and set as the kurtosis in the measurement field 5μm square.

[0139] The reference surface for the protrusion height in this measurement is the height from the threshold height (Threshold Height): 0 nm set in the flattening process and roughness mode setting described below. The surface with a height of 0 nm serves as the reference surface.

[0140] [AFM measurement method]

[0141] Equipment: Bruker atomic force microscope (AFM)

[0142] Dimention Icon with ScanAsyst

[0143] Cantilever: Silicon nitride probe ScanAsyst Air

[0144] Scan mode: ScanAsyst

[0145] Scan speed: 0.8Hz

[0146] Scanning direction: Scan along the width direction of the measurement sample prepared by the method described below

[0147] Measurement field: 5μm square

[0148] Sample lines: 512

[0149] Peak Force Set Point: 0.0195V to 0.0205V

[0150] Feedback Gain: 10-20

[0151] LP Deflection BW: 40kHz

[0152] ScanAsyst Noise Threshold: 0.5nm

[0153] Sample conditioning: 23°C, 65% RH, 24 hours of static

[0154] AFM measurement environment: 23°C, 65% RH

[0155] ·Method for preparing a measurement sample: Double-sided tape is affixed to one side of an AFM sample disk (15 mm in diameter), and the AFM sample disk is bonded to the surface opposite to the above-mentioned surface (measurement surface) of a biaxially oriented polyester film of the present invention cut to approximately 15 mm × 13 mm (length direction × width direction) to prepare a measurement sample.

[0156] Number of sample measurements: Measurements were performed five times while changing the location so that the samples were at least 5 μm apart.

[0157] Measured values: The above analysis is performed on the images of the five measured locations, and the respective numerical values ​​are measured, and the average value thereof is treated as the respective numerical values ​​of the sample.

[0158] Flattening

[0159] Flatten Order: 3rd

[0160] Flatten Z Threshholding Direction: No thresholding

[0161] Find Threshold for: the whole image

[0162] Flatten Z Threshold % (Flatten Z Threshold %): 0.00%

[0163] Mark Excluded Data: Yes

[0164] [Roughness mode setting]

[0165] (Stop Band Inputs Tag)

[0166] Use Threshold: Off

[0167] Threshold Height: 0nm

[0168] Feature Direction: Same as above

[0169] X Axis: Absolute

[0170] Number of Histogram Bins: 512

[0171] Bound Particles: Yes

[0172] Non-Representative Particles: No

[0173] Particle Filter Sigma: 1.00

[0174] (Peak Inputs)

[0175] Peak: On

[0176] Peak threshold reference: Zero

[0177] Peak threshold value type: Rms

[0178] Peak threshold value: 100%

[0179] Zero Crossing: Off

[0180] When calculating the above numerical values, no specific peaks or regions in the analysis image are selected.

[0181] · No specific location is selected in all the histograms of diameter (Diameter), height (Height), and area (Area).

[0182] (4) Calculation method of surface free energy

[0183] The film was left in an atmosphere at room temperature (23°C) and relative humidity (65%) for 24 hours. Then, in the same atmosphere, the contact angle of pure water was measured at five points on the surface of the resin layer of the film using a DropMaster DM-501 contact angle gauge manufactured by Kyowa Interface Science Co., Ltd. The average of the three measured values, excluding the maximum and minimum values, was used as the contact angle for each solution.

[0184] Next, using the contact angles of the four solutions obtained, the dispersion force, polar force, hydrogen bonding force, and surface energy (the sum of the dispersion force and polar force) of the present invention were calculated using the geometric mean method based on the formula proposed by Hata et al., which "separates the surface free energy (γ) of a solid into three components: a dispersion force component (γS d), a polar force component (γS p), and a hydrogen bonding force component (γS h), and extends the Fowkes formula (extended Fowkes formula)."

[0185] A specific calculation method is shown below. The meaning of each symbol is described below. When γ SL is the tension at the interface between a solid and a liquid, the following formula (2) holds.

[0186] γS L: Surface energy of the resin layer and the known solutions listed in the table

[0187] γS: Surface energy of the resin layer

[0188] γL: Surface energy of known solutions listed in the table

[0189] γS d: Dispersion force component of the surface energy of the resin layer

[0190] γSp: Polar force component of the surface energy of the resin layer

[0191] γS h: Hydrogen bonding component of the surface energy of the resin layer

[0192] γL d: Dispersive force component of the surface energy of the known solutions listed in the table

[0193] γL p: Polar force component of the surface energy of known solutions listed in the table

[0194] γL h: Hydrogen bonding component of the surface energy of the known solutions listed in the table: γSL = γS + γL - 2(γS d·γL d) 1 / 2 - 2(γS p·γL p) 1 / 2 - 2(γS h·γL h) 1 / 2 ···Formula (2).

[0195] Furthermore, the state when a smooth solid surface and a liquid droplet come into contact at a contact angle (θ) is expressed by the following formula (Young's formula).

[0196] γS=γSL+γLcosθ···Equation (3).

[0197] When these equations (2) and (3) are combined, the following equation is obtained.

[0198] (γS d·γL d)1 / 2+(γS p·γL p)1 / 2+(γS h·yL h)1 / 2=γL(1+cosθ) / 2···Equation (4).

[0199] In practice, the contact angles (θ) of four solutions—water, ethylene glycol, formamide, and diiodomethane—and the known surface tension components (γL d, γL p, γL h) of these solutions are substituted into equation (4) and the four simultaneous equations are solved. The surface energy (γ), dispersion force component (γS d), polar force component (γS p), and hydrogen bonding force component (γS h) of the solid are calculated.

[0200] (5) Number average particle size of particles

[0201] The film cross section is observed at 10,000 times using a transmission electron microscope (TEM). At this time, when particles below 1 cm are confirmed on the photograph, the TEM observation magnification is changed to 50,000 times for observation. The slice thickness of the TEM is set to about 100 nm, and 100 visual fields are measured at different locations. The equivalent circular diameter is obtained for all dispersed particles captured in the photograph, and the number distribution of particles is plotted with the equivalent circular diameter as the horizontal axis and the number of particles as the vertical axis, and the equivalent circular diameter of its peak value is set to the average particle size of the particles. Here, when agglomerated particles are confirmed on the photograph observed at 10,000 times, they are not included in the above-mentioned figure. In the case where there are two or more particles with different particle sizes in the film, the number distribution of the equivalent circular diameter becomes a distribution with more than two peaks. In this case, the equivalent circular diameter of each peak value is set to the number average particle size of each particle.

[0202] Measurement equipment: Transmission electron microscope (TEM) H-7100FA manufactured by Hitachi

[0203] Measurement conditions: Acceleration voltage 100 kV

[0204] Measurement magnification: 10,000 times, 50,000 times

[0205] Sample conditioning: Ultra-thin film sectioning method

[0206] Observation surface: TD-ZD cross section (TD: width direction, ZD: thickness direction).

[0207] (6) Particle content

[0208] The results were calculated from the amount of particles blended into the polyester film material and are shown in the table.

[0209] In addition, it can also be calculated by analyzing the film according to the following method.

[0210] (6)-1 Elemental analysis of particles

[0211] The polyester is removed from the film by plasma ashing to expose the particles. The treatment conditions are selected so that the polymer is ashed but the particles are not damaged as much as possible. The particles are observed using a scanning electron microscope (SEM), and the particle images are processed using an image analyzer. According to the particle size distribution obtained in (5) above, the SEM magnification is set to 30,000 times, and 20 fields of view are observed by changing the observation position. Energy dispersive X-ray spectroscopy (EDX) is used to perform elemental analysis on all observed particles to clarify the relationship between particles and elements.

[0212] (6)-2 Particle content

[0213] The surface of each laminated part is shaved off with a single blade, and o-chlorophenol is added to 1 g of the cutting powder. The polymer is dissolved at 100°C for 1 hour while stirring. Then, in a separation ultracentrifuge 40P model equipped with a rotor RP30 manufactured by Hitachi, Ltd., 30cc of the above-mentioned solution is injected into each unit and the speed is slowly increased to 30,000 rpm. The separation of the particles is completed after reaching 30,000 rpm for 60 minutes. The supernatant is then removed and the separated particles are collected. Ortho-chlorophenol at room temperature is added to the collected particles, and after uniform suspension, ultracentrifugation is performed. The separated particles are repeatedly subjected to a differential scanning calorimetry (DSC) until the melting peak corresponding to the polymer is no longer detected. The separated particles obtained by this operation are vacuum dried at 120°C for 16 hours, and the mass is measured. The obtained value is set as the total content of the particles, and the ratio (mass %) relative to the cutting powder (1g) is set as the content of the particles.

[0214] When the contained particles include organic particles, a solvent that dissolves the polymer but not the organic particles is selected, the polymer is dissolved without overheating and refluxing, and the particles are centrifuged to calculate the particle content (mass %) in each layer. Whether the contained particles are organic or inorganic can be determined by observing the particles using commonly known methods such as SEM-EDX and confirming whether inorganic matter is detected.

[0215] (7) Film thickness

[0216] The thickness of 10 films stacked together was measured at 5 random locations using a direct-reading thickness gauge in accordance with JIS K7130 (1992) A-2 method. The average value was divided by 10 to obtain the film thickness.

[0217] (8) Thickness of the resin layer

[0218] The biaxially oriented polyester film was dyed with ruthenium tetroxide (RuO4) and / or osmium tetroxide (OsO4). The biaxially oriented polyester film was frozen and cut along the film thickness direction to obtain 10 ultrathin section samples (10 pieces) for observing the cross-section of the resin layer. Each sample cross-section was observed using a TEM (transmission electron microscope: H7100FA model, manufactured by Hitachi, Ltd.) at a magnification of 10,000 to 1,000,000 times to obtain a cross-sectional photograph. The measured values ​​of the thickness of the resin layer having the above-mentioned surface at these 10 points (10 pieces) were averaged to obtain the thickness of the resin layer.

[0219] (9) Intrinsic viscosity (IV)

[0220] A measurement sample (polyester resin (raw material) or the polyester film of the present invention) was dissolved in 100 ml of o-chlorophenol (solution concentration C (measurement sample weight / solution volume) = 1.2 g / 100 ml), and the viscosity of the solution at 25°C was measured using an Ostwald viscometer. The viscosity of the solvent was also measured in the same manner. Using the resulting solution viscosity and solvent viscosity, [η] was calculated using the following formula (5), and the resulting value was defined as the intrinsic viscosity (IV) of the entire polyester film.

[0221] ηsp / C=[η]+K[n] 2 ·C···Formula (5)

[0222] (Here, ηsp = (solution viscosity / solvent viscosity) - 1, and K is the Huggins constant (set to 0.343).)

[0223] In addition, when the solution in which the measurement sample was dissolved contained insoluble matter such as inorganic particles, the measurement was performed using the following method.

[0224] (1-1) A measurement sample is dissolved in 100 mL of o-chlorophenol to prepare a solution having a concentration higher than 1.2 g / 100 mL. Here, the weight of the measurement sample applied to o-chlorophenol is referred to as the measurement sample weight.

[0225] (1-2) Next, the solution containing the insoluble matter is filtered, and the weight of the insoluble matter and the volume of the filtrate after filtration are measured.

[0226] (1-3) Add o-chlorophenol to the filtrate after filtration and adjust the concentration (measured sample weight (g) - weight of insoluble matter (g)) / (volume of filtrate after filtration (mL) + volume of added o-chlorophenol (mL)) to 1.2 g / 100 mL.

[0227] (For example, when a concentrated solution having a measurement sample weight of 2.0 g / solution volume of 100 mL is prepared, and the weight of the insoluble matter when the solution is filtered is 0.2 g, and the volume of the filtrate after filtration is 99 mL, an additional 51 mL of o-chlorophenol is added to adjust the concentration. ((2.0 g - 0.2 g) / (99 mL + 51 mL) = 1.2 g / 100 mL))

[0228] (1-4) The solution obtained in (1-3) was used to measure the viscosity at 25°C using an Ostwald viscometer. The obtained solution viscosity and solvent viscosity were used to calculate [η] using the above formula (5), and the obtained value was set as the intrinsic viscosity (IV).

[0229] (10) Number of coarse particles with a major diameter of 1.0 μm or more (NP1)

[0230] On the C-surface side of the substrate film, a shape analysis laser microscope (VK-X250 manufactured by KEYENCE) was used with a 50x objective lens to automatically observe 150 fields of view in an area of ​​220 μm × 290 μm. This was repeated 10 times for a total of 1500 fields of view (=95.7 mm). 2 ) observation. The centerline of each field of view was calculated based on the total number of measured pixels per field of view (1024 × 768 pixels). When measuring the number of foreign matter, the imported image was binarized and the number of foreign matter with a major diameter of 1.0 μm or larger was measured using a particle analysis module (Keyence VKH1XG). This was defined as the number of coarse particles (NP1).

[0231] (11) Content of metal elements in the substrate film

[0232] 5 g of the sample was placed in a platinum dish and melt-carbonized using an electric heater. The sample was then completely ashed in an electric furnace (700° C.) for 1.5 hours. The ashed product was then dissolved in 5 mL of concentrated hydrochloric acid and pure water was added to form a 10% aqueous hydrochloric acid solution to serve as a measurement sample. The solution was then quantified using atomic absorption spectrometry (flame: acetylene-air, germanium-only acetylene-nitrous oxide).

[0233] In addition, the atomic absorption spectrophotometer used was "ZA-3300" manufactured by Hitachi High-Tech Science & Technology Co., Ltd.

[0234] (12) Calculation method of the movement durability and friction coefficient (μk1, μk5) of the resin layer

[0235] The film was cut into strips 12.65 mm wide. The resulting strips were humidified at 23°C and 65% RH for at least 24 hours using a belt travel tester, SFT-700 (manufactured by Yokohama System Laboratories). The resin layer surface (C side) of the film was placed in contact with a stainless steel needle and reciprocated five times while applying a load of 300 g. This test was repeated three times with each film sample replaced. The stainless steel needle was photographically observed, and the travel durability was evaluated using the following criteria.

[0236] Here, the guide diameter is 6 mm, the guide material is SUS27 (surface roughness 0.2S), the winding angle is 90°, the moving distance is 10 cm, and the moving speed is 3.3 cm / second.

[0237] AA: No chips were generated after three visual and photographic observations.

[0238] A: The generation of shavings was confirmed by photographic observation at least once.

[0239] B: Generation of chips could be confirmed by photographic observation two or more times.

[0240] C: Generation of chips was visually confirmed one or more times.

[0241] As for the durability evaluation, AA to B were good, and AA was the most excellent.

[0242] The friction coefficient μk is calculated by the following formula (6). The friction coefficient μk5 after five reciprocating movements is determined by finding the maximum load during the fifth movement and determining it as T2.

[0243] μk=1 / θln(T2 / T1)···Equation (6)

[0244] (θ=2 / π, T2: maximum load during movement, T1: initial load (300g)

[0245] (13) Resist resolution

[0246] Photoresist evaluation using the projection exposure method was performed by the following methods a. to c.

[0247] a. A photosensitive resin layer was applied to surface C of the laminated polyester film of the present invention using a gravure coating method in a darkroom to a coating thickness of 15 μm. The photosensitive resin layer used was a mixture comprising a thermoplastic resin (a copolymer of methacrylic acid, methyl methacrylate, ethyl acrylate, and butyl methacrylate); a photosensitive material (trimethylolpropane triacrylate and polyethylene glycol (number average molecular weight 600) dimethacrylate); a photopolymerization initiator (benzophenone and dimethylaminobenzophenone); a stabilizer (hydroquinone); and a colorant (methyl violet).

[0248] b. The obtained laminate consisting of a laminated polyester film and a photosensitive resin layer is overlapped in such a manner that the photosensitive resin layer is in contact with a 6-inch Si wafer with one side mirror-polished, and laminated using a rubber roller. A photomask patterned with chromium metal is arranged thereon, and projection exposure is performed from the photomask (from the P3 layer side of the laminated polyester film of the present invention) using an ultraviolet light stepper equipped with a projection lens (ultraviolet light with a peak at a wavelength of 365 nm).

[0249] c. After peeling the laminated polyester film from the photosensitive resin layer, the photosensitive resin layer was placed in a container containing a 1% sodium carbonate aqueous solution and developed for approximately 1 minute. The layer was then removed from the developer and washed with water for approximately 1 minute. The resulting resist wiring pattern, with 30 lines having an L / S (μm) ratio of 5 / 5 μm (Line and Space), was observed using a scanning electron microscope (SEM) at approximately 800 to 3000 magnifications.

[0250] The number of the 30 observed resist wiring patterns with linear defects of 0.3 μm or more on the long sides of the wiring pattern upper surfaces was determined, and the fine wiring resist shape of the film was evaluated as follows.

[0251] AAA: The number of defective strips is less than 1.

[0252] AA: The number of defective strips is 2 or more and 3 or less.

[0253] A: The number of defective strips is 4 or more and 7 or less.

[0254] B: The number of defective strips is 8 or more and 10 or less.

[0255] C: There are 11 or more missing pieces.

[0256] As for the fine wiring resist shape evaluation, AAA to B were good, and AAA was the most excellent.

[0257] (14) Time-of-flight secondary ion mass spectrometry

[0258] Pulsed ions (primary ions) are irradiated onto the surface of a sample held in an ultrahigh vacuum. The ions (secondary ions) released from the sample surface acquire a certain kinetic energy and are directed toward a time-of-flight mass spectrometer. Each secondary ion, accelerated with the same energy, passes through the analyzer at a speed corresponding to its mass. However, since the distance to the detector is constant, the time it takes to reach the detector (time of flight) becomes a function of mass. By precisely measuring the distribution of this time of flight, the mass distribution of the secondary ions, or mass spectrum, is obtained. The ratio (P / K) of the peak intensity (P) of the fluorine-derived fragments obtained under the following measurement conditions to the peak intensity (K) of the fragments detected at maximum intensity is calculated.

[0259] Equipment: TOF.SIMS5 (manufactured by IONTOF)

[0260] Primary ion: Bi3++

[0261] Primary ion acceleration voltage: 30kV

[0262] Pulse width: 11.3ns

[0263] Post-stage acceleration: 9.5kV

[0264] Secondary ion polarity: positive only

[0265] Mass range: 0-1500 (m / z)

[0266] Grating size: 300μm

[0267] Number of scans: 16

[0268] Number of pixels (1 side): 256 pixels

[0269] Measurement vacuum degree (before sample introduction): 4×10 -7 Below Pa.

[0270] Example

[0271] Hereinafter, the present invention will be described with reference to Examples, but the present invention is not necessarily limited to these.

[0272] (Raw Materials 1-A) Preparation of PET Pellets: 194 parts by mass of dimethyl terephthalate and 124 parts by mass of ethylene glycol were added to a transesterification reactor, and the contents were heated to 140°C to dissolve. Manganese acetate tetrahydrate (23 ppm as manganese relative to the weight of the polyester resin composition) and antimony trioxide (60 ppm as antimony relative to the weight of the polyester resin composition) were then added while stirring the contents. The transesterification reaction was carried out at 140-230°C while distilling off methanol. Next, a 5% by mass solution of trimethyl phosphate in ethylene glycol (19 ppm as phosphorus relative to the weight of the polyester resin composition) and a 5% by mass solution of sodium dihydrogen phosphate dihydrate in ethylene glycol (14 ppm as sodium and 19 ppm as phosphorus relative to the weight of the polyester resin composition) were added.

[0273] The addition of the ethylene glycol solution of trimethylphosphoric acid caused the temperature of the reaction contents to drop. Therefore, stirring was continued while distilling off the excess ethylene glycol until the temperature of the reaction contents returned to 230°C. After the temperature of the reaction contents in the transesterification reactor reached 230°C, the reaction contents were transferred to the polymerization reactor.

[0274] After the transfer, the reaction system was slowly heated from 230°C to 275°C, and the pressure was reduced to 0.1 kPa. The time required to reach both the final temperature and final pressure was set at 60 minutes. After the reaction was allowed to proceed for 2 hours (3 hours after the start of polymerization) after reaching the final temperature and final pressure, the stirring torque of the polymerization apparatus reached a specified value (the specific value varies depending on the specifications of the polymerization apparatus; in this polymerization apparatus, the value indicated by polyethylene terephthalate having an intrinsic viscosity of 0.62 was set as the specified value). The reaction system was then purged with nitrogen to return to normal pressure, the polycondensation reaction was terminated, and the pellets were discharged into cold water in a strip shape and immediately cut to obtain PET pellets (raw material 1-A) of polyethylene terephthalate having an intrinsic viscosity of 0.62.

[0275] (Raw Material 1-B) Production of PET Pellets: To an esterification reactor charged with 105 parts by weight of bishydroxyethyl terephthalate (hereinafter referred to as BHT) melted at 250°C, a slurry consisting of 86 parts by weight of terephthalic acid and 37 parts by weight of ethylene glycol (1.15 times the molar ratio of terephthalic acid) was slowly added to allow an esterification reaction to proceed. The temperature within the reaction system was controlled to maintain a range of 245-250°C, and the esterification reaction was completed when the reaction rate reached 95%.

[0276] 105 parts by weight of molten BHT (equivalent to 100 parts by weight of PET) was added to the polymerization apparatus from the esterification reactor, and the temperature was set at 255°C. An ethylene glycol solution of manganese acetate tetrahydrate (23 ppm as manganese relative to the weight of the polyester resin composition) and germanium dioxide (45 ppm as germanium relative to the weight of the polyester resin composition) were added. Subsequently, an ethylene glycol solution of phosphoric acid (19 ppm as phosphorus relative to the weight of the polyester resin composition) and sodium dihydrogen phosphate dihydrate (14 ppm as sodium relative to the weight of the polyester resin composition) were added. The germanium dioxide was completely dissolved in a 20% aqueous solution of tetraethylammonium hydroxide, and then the ethylene glycol solution was added.

[0277] Then, the temperature in the polymerization apparatus was gradually raised to 290° C., and the pressure was reduced from atmospheric pressure to below 133 Pa, and a polymerization reaction was carried out until a predetermined stirring torque was exhibited at 290° C. After the polymerization reaction was completed, the reaction system was returned to atmospheric pressure under nitrogen, and the molten polyester in the polymerization apparatus was discharged into a water tank in the form of a strand, cooled, and then cut to obtain a polyester resin composition (raw material 1-B) having an intrinsic viscosity of 0.62.

[0278] (Raw Material 1-V) Preparation of PET Pellets: PET pellets of polyethylene terephthalate (PET) having an intrinsic viscosity of 0.54 were obtained (Raw Material 1-V) by adjusting the polymerization time in the same manner as in the preparation of PET pellets (Raw Material 1-A).

[0279] (Raw material 2-a) Preparation of particle-containing PET pellets: 90 parts by mass of the above-mentioned PET pellets (raw material 1-B) and 10 parts by mass of a 5% by mass aqueous slurry of cross-linked polystyrene particles having an average particle size of 0.15 μm (0.5 parts by mass based on cross-linked polystyrene particles) were supplied to a co-rotating vented twin-screw compounding extruder heated to 280°C. The air vents were maintained at a reduced pressure of less than 1 kPa to remove water, thereby obtaining particle-containing pellets (raw material 2-a) having a characteristic viscosity of 0.62 and containing 0.5% by mass of cross-linked polystyrene particles.

[0280] (Raw material 2-b) Preparation of particle-containing PET pellets: 90 parts by mass of the above-mentioned PET pellets (raw material 1-B) and 10 parts by mass of a 5% by mass aqueous slurry of cross-linked polystyrene particles having an average particle size of 0.30 μm (0.5 parts by mass based on cross-linked polystyrene particles) were supplied to a co-rotating vented twin-screw compounding extruder heated to 280°C. The air vents were maintained at a reduced pressure of less than 1 kPa to remove water, thereby obtaining particle-containing pellets (raw material 2-b) having a characteristic viscosity of 0.62 and containing 0.5% by mass of cross-linked polystyrene particles.

[0281] (Raw material 2-c) Preparation of PET pellets containing particles: During the polymerization of the aforementioned raw material 1-B, colloidal silica particles having an average particle size of 60 nm dispersed in ethylene glycol were added in an amount of 1% by mass relative to PET, and were filtered with high precision using a filter that captures more than 95% of foreign matter of 5 μm or larger, to obtain particles containing particles (raw material 2-c) having a characteristic viscosity of 0.62.

[0282] (Raw material 2-d) Preparation of PET pellets containing particles: During the polymerization of the aforementioned raw material 1-B, delta-type alumina particles having an average primary particle size of 20 nm dispersed in ethylene glycol were added in an amount of 1% by mass relative to PET, and were filtered with high precision using a filter that captures more than 95% of foreign matter of 5 μm or larger, to obtain particles containing particles (raw material 2-d) having a characteristic viscosity of 0.62.

[0283] (2) Preparation of resin composition

[0284] [Resin composition 1] 0.6 parts by mass of a fluorine-based surfactant (Plus Code RY-2 manufactured by Huying Chemical Industry Co., Ltd.) was added to 96.9 parts by mass of pure water and thoroughly stirred. Then, 1.5 parts by mass of a water-dispersible acrylic copolymer composed of methyl methacrylate / ethyl ethylacrylate / acrylic acid / N-hydroxymethyl acrylamide (solid content concentration of 40%, glass transition temperature of 80°C) was added and stirred. 1.0 part by mass of a methylolated melamine resin (solid content concentration of 25%) was added (relative to 40 parts by mass of the acrylic resin solid content) and stirred again to prepare a coating agent having an acrylic resin solid content concentration of 0.6%.

[0285] [Resin composition 2] A resin composition was prepared in the same manner as in the resin composition 1 except that the amount of pure water was changed to 97.4 parts by mass and the amount of the methylolated melamine resin added was changed to 0.5 parts by mass.

[0286] [Resin composition 3] 0.6 parts by mass of a fluorine-based surfactant (Plus Code RY-2 manufactured by Huying Chemical Industry Co., Ltd.) was added to 97.9 parts by mass of pure water, and after sufficient stirring, 1.5 parts by mass of a water-dispersible acrylic copolymer composed of methyl methacrylate / ethyl ethylacrylate / acrylic acid / N-hydroxymethyl acrylamide (solid content concentration of 40%, glass transition temperature of 80°C) was added and stirred to adjust a coating agent with an acrylic resin solid content concentration of 0.6%.

[0287] [Resin composition 4] 0.6 parts by mass of a fluorine-based surfactant (Plus Code RY-2 manufactured by Huying Chemical Industry Co., Ltd.) was added to 84.5 parts by mass of pure water and thoroughly stirred. Then, 9.7 parts by mass of a water-dispersible acrylic copolymer composed of methyl methacrylate / ethyl ethylacrylate / acrylic acid / N-hydroxymethyl acrylamide (solid content concentration of 25%, glass transition temperature of 65°C) was added and stirred. 5 parts by mass of a methylolated melamine resin (solid content concentration of 25%) (50 parts by mass relative to the acrylic resin solid content) was added and stirred again. 0.2 parts by mass of colloidal silica particles having an average particle size of 80 nm (solid content concentration of 10%) (0.7 parts by mass relative to the acrylic resin solid content) was added and further stirred to prepare a coating agent having an acrylic resin solid content concentration of 2.5%.

[0288] [Resin composition 5] 0.6 parts by mass of a fluorine-based surfactant (Plus Code RY-2 manufactured by Huying Chemical Industry Co., Ltd.) was added to 84.6 parts by mass of pure water and thoroughly stirred. Then, 9.7 parts by mass of a water-dispersible acrylic copolymer composed of methyl methacrylate / ethyl ethylacrylate / acrylic acid / N-hydroxymethyl acrylamide (solid content concentration of 25%, glass transition temperature of 65°C) was added and stirred. 5 parts by mass of a methylolated melamine resin (solid content concentration of 25%) (50 parts by mass relative to the acrylic resin solid content) and 0.1 part by mass of colloidal silica particles (solid content concentration of 10%) having an average particle size of 80 nm (0.4 parts by mass relative to the acrylic resin solid content) were added and further stirred to prepare a coating agent having an acrylic resin solid content concentration of 2.5%.

[0289] [Resin composition 6] 0.6 parts by mass of a fluorine-based surfactant (Plus Code RY-2 manufactured by Huying Chemical Industry Co., Ltd.) was added to 95.1 parts by mass of pure water, and the mixture was thoroughly stirred. Then, 2.3 parts by mass of a water-dispersible acrylic copolymer composed of methyl methacrylate / ethyl ethylacrylate / acrylic acid / N-hydroxymethyl acrylamide (solid content concentration of 25%, glass transition temperature of 60°C) was added and stirred. 1.9 parts by mass of a methylolated melamine resin (solid content concentration of 25%) was added (relative to 80 parts by mass of the acrylic resin solid content), and the mixture was further stirred to prepare a coating agent having an acrylic resin solid content concentration of 0.6%.

[0290] [Resin composition 7] 0.6 parts by mass of a fluorine-based surfactant (Plus Code RY-2 manufactured by Huying Chemical Industry Co., Ltd.) was added to 95.1 parts by mass of pure water, and the mixture was thoroughly stirred. Then, 2.3 parts by mass of a water-dispersible acrylic copolymer composed of methyl methacrylate / ethyl ethylacrylate / acrylic acid / N-hydroxymethyl acrylamide (solid content concentration of 25%, glass transition temperature of 42°C) was added and stirred. 1.9 parts by mass of a hydroxymethylated melamine resin (solid content concentration of 25%) was added (relative to 80 parts by mass of the acrylic resin solid content), and the mixture was further stirred to prepare a coating agent having an acrylic resin solid content concentration of 0.6%.

[0291] [Resin composition 8] 0.6 parts by mass of a fluorine-based surfactant (Plus Code RY-2 manufactured by Huying Chemical Industry Co., Ltd.) was added to 96.8 parts by mass of pure water, and after sufficient stirring, 1 part by mass of a water-dispersible acrylic copolymer composed of methyl methacrylate / ethyl ethylacrylate / acrylic acid / N-hydroxymethyl acrylamide (solid content concentration of 40%, glass transition temperature of 80°C) was added and stirred. 1.6 parts by mass of an isocyanate compound (solid content concentration of 27.5%) was added (relative to 40 parts by mass of the acrylic resin solid content), and stirred again to adjust the coating agent to have an acrylic resin solid content concentration of 0.4%.

[0292] [Resin composition 9] 0.6 parts by mass of an acetylene surfactant (Olfin EXP4123 manufactured by Nissin Chemical Industry) was added to 96.8 parts by mass of pure water and stirred thoroughly. Then, 1 part by mass of a water-dispersible acrylic copolymer composed of methyl methacrylate / ethyl ethylacrylate / acrylic acid / N-hydroxymethyl acrylamide (solid content concentration of 40%, glass transition temperature of 80°C) was added and stirred. 1.6 parts by mass of an isocyanate compound (solid content concentration of 27.5%) was added (relative to 40 parts by mass of the acrylic resin solid content) and stirred again to prepare a coating agent having an acrylic resin solid content concentration of 0.4%.

[0293] (Example 1)

[0294] Using two extruders, E1 and E2, 50 parts by mass of PET pellets (raw material 1-A) and 50 parts by mass of PET pellets (raw material 1-V) as raw materials for layer A were dried under reduced pressure at 180°C for 3 hours and then supplied to extruder E1 heated to 280°C. PET pellets (raw material 1-B) as raw materials for layer B were dried under reduced pressure at 180°C for 3 hours and then supplied to extruder E2 also heated to 280°C. In order to laminate them into two layers, the lamination thickness ratio (A layer | B layer) was set to 1 | 43 in the T-die, and the layers were merged in such a way that the B layer side became the casting drum surface side. While applying static charge to the casting drum with a surface temperature of 35°C, the film was tightly cooled and solidified to obtain a laminated unstretched film. The unstretched film was guided between the opposite electrode and the grounded roller, and nitrogen was introduced into the device. When the treatment intensity (E value) became 250W·min / m 2 The surface of the A layer was treated with atmospheric pressure glow discharge plasma under the conditions of .

[0295] After treatment, the laminated unstretched film was guided to a stretching roller group heated to 60°C to 100°C in the longitudinal direction and stretched by a total of 3.8 times by stretching operation. Then, the resin composition 1 was coated on the surface of the B layer using a rod coater. After the coated film was guided to a tenter and preheated to 80°C, it was stretched by 1.6 times in each of three equal length zones with temperatures set at 90°C, 110°C, and 130°C, and stretched by a total of 4.1 times in the width direction while step-by-step heating. It was heat treated at 235°C for 20 seconds at a fixed length and subjected to a 5% relaxation treatment in the width direction. A laminated biaxially oriented polyester film with a film thickness of 16 μm and a coating layer with a thickness of about 10 nm was obtained. The physical properties of the obtained laminated biaxially oriented polyester film are shown in Table 1.

[0296] (Examples 2 to 7)

[0297] A laminated biaxially oriented polyester film having a coating layer with a thickness of 16 μm on one side was obtained in the same manner as in Example 1 except that the resin composition and the thickness of the resin layer applied as the C layer were changed as shown in Table 1.

[0298] (Example 8)

[0299] The raw materials for layer A were changed to 90 parts by mass of PET particles (raw material 1-A) and 10 parts by mass of particles containing colloidal silica particles having an average particle size of 60 nm (raw material 2-c), and the surface of layer A was not subjected to plasma treatment. Except for this, the same operation as in Example 1 was carried out to obtain a laminated biaxially oriented polyester film having a coating layer with a thickness of 16 μm on one side.

[0300] (Example 9)

[0301] The raw materials for layer A were changed to 98 parts by mass of PET particles (raw material 1-A) and 2 parts by mass of particles containing cross-linked polystyrene particles with an average particle size of 150 nm (raw material 2-a). Except for this, the same operation as in Example 8 was carried out to obtain a laminated biaxially oriented polyester film having a coating layer on one side with a thickness of 16 μm.

[0302] (Example 10)

[0303] A laminated biaxially oriented polyester film having a coating layer with a thickness of 16 μm on one side was obtained in the same manner as in Example 1 except that the resin composition and the thickness of the resin layer applied as the C layer were changed as shown in Table 1.

[0304] (Example 11)

[0305] A laminated biaxially oriented polyester film having a coating layer with a thickness of 16 μm on one side was obtained in the same manner as in Example 1 except that the resin composition and the thickness of the resin layer applied as the C layer were changed as shown in Table 1.

[0306] (Example 12)

[0307] A laminated biaxially oriented polyester film having a coating layer with a thickness of 16 μm on one side was obtained in the same manner as in Example 1 except that the resin composition and the thickness of the resin layer applied as the C layer were changed as shown in Table 1.

[0308] (Example 13)

[0309] A laminated biaxially oriented polyester film having a coating layer having a thickness of 16 μm on one side was obtained in the same manner as in Example 8 except that the resin composition and the thickness of the resin layer applied as the C layer were changed as shown in Table 1.

[0310] (Example 14)

[0311] The resin composition and resin layer thickness applied as the C layer were changed as shown in Table 1. Furthermore, the same resin composition as the C layer was also applied to the opposite side A. The same operation was carried out as in Example 1 to obtain a laminated biaxially oriented polyester film having a coating layer with a thickness of 16 μm on both sides.

[0312] (Comparative Example 1)

[0313] Using two extruders, E1 and E2, 50 parts by mass of PET pellets (raw material 1-A) and 50 parts by mass of PET pellets (raw material 1-V) as raw materials for layer A were dried under reduced pressure at 180°C for 3 hours and then fed into extruder E1, which was heated to 280°C. As raw materials for layer B, 78 parts by mass of PET pellets (raw material 1-A), 2 parts by mass of pellets containing cross-linked polystyrene particles with an average particle size of 300 nm (raw material 2-b), and 20 parts by mass of pellets containing colloidal silica particles with an average particle size of 60 nm (raw material 2-c) were dried under reduced pressure at 180°C for 3 hours and then fed into extruder E2, which was similarly heated to 280°C. To form a two-layer laminate, these layers were combined in a T-die with a laminate thickness ratio (layer A | layer B) of 1 | 4:3, with the layer B side facing the casting drum surface. The layers were then cooled and solidified in close contact with the casting drum, which had a surface temperature of 35°C, while an electrostatic charge was applied. This produced a laminated unstretched film. The unstretched film was guided between the opposing electrodes and the grounded roller, and nitrogen was introduced into the apparatus. The treatment intensity (E value) was set to 250 W·min / m 2The surface of layer A was treated with plasma using atmospheric pressure glow discharge under the conditions of . After the treatment, the laminated unstretched film was guided in the longitudinal direction to a stretching roller group heated to 60°C to 100°C and stretched by a total of 3.8 times by stretching operation. Then, after the film was guided to a tenter and preheated to 80°C, it was stretched by 1.6 times in each of three equal length zones with temperatures set at 90°C, 110°C, and 130°C, and stretched by a total of 4.1 times in the width direction while step-by-step heating. It was heat treated at 235°C for 20 seconds at a fixed length and 5% relaxation treatment was applied in the width direction. A laminated biaxially oriented polyester film with a film thickness of 16μm was obtained. The physical properties of the obtained laminated biaxially oriented polyester film are shown in Tables 1 and 2. It should be noted that since no coating layer was provided, the surface of layer B was evaluated.

[0314] (Comparative Example 2)

[0315] Using two extruders E1 and E2, 30 parts by mass of PET pellets (raw material 1-A) as the raw materials for layer A and 70 parts by mass of pellets containing alumina particles (raw material 2-d) were dried under reduced pressure at 180°C for 3 hours and then supplied to the extruder E1 heated to 280°C. PET pellets (raw material 1-A) as the raw materials for layer B were dried under reduced pressure at 180°C for 3 hours and then supplied to the extruder E2 similarly heated to 280°C. In order to laminate them into three layers, the laminate thickness ratio (A layer | B layer | A layer) was set to 1|42|1 in a T-die for merging, and while applying static charge to the casting drum with a surface temperature of 35°C, the film was tightly cooled and solidified to obtain a laminated unstretched film. The laminated unstretched film was guided in the longitudinal direction to a stretching roller group heated to 60°C to 100°C and stretched by a total of 3.8 times by stretching operation. The resin composition 1 was then applied to the surface of the B layer using a rod coater. The coated film was guided to a tenter and preheated to 80°C. It was then stretched by 1.6 times in each of three equal-length sections, set at 90°C, 110°C, and 130°C, while being gradually heated, for a total of 4.1 times in the width direction. The film was then heat-treated at 235°C for 20 seconds while maintaining a constant length, and then relaxed by 5% in the width direction. A 16 μm-thick laminated biaxially oriented polyester film was obtained. The physical properties of the resulting laminated biaxially oriented polyester film are shown in Table 1.

[0316] (Comparative Example 3)

[0317] Using two extruders, E1 and E2, 90 parts by mass of PET pellets (raw material 1-A) and 10 parts by mass of pellets containing alumina particles (raw material 2-d) as raw materials for layer A were dried under reduced pressure at 180°C for 3 hours and then fed into extruder E1, which was heated to 280°C. 76 parts by mass of PET pellets (raw material 1-A), 4 parts by mass of pellets containing cross-linked polystyrene particles with an average particle size of 150 nm (raw material 2-a), and 20 parts by mass of pellets containing colloidal silica particles with an average particle size of 60 nm (raw material 2-c), as raw materials for layer B, were dried under reduced pressure at 180°C for 3 hours and then fed into extruder E2, which was similarly heated to 280°C. In order to laminate them into two layers, the lamination thickness ratio (A layer | B layer) was set to 1 | 43 in the T-die, and the B layer side was merged in a manner that the casting drum surface side was formed. While applying static charge to the casting drum with a surface temperature of 35°C, the film was cooled and solidified in a close contact manner to obtain a laminated unstretched film. The laminated unstretched film was guided along the length direction to a stretching roller group heated to 60°C to 100°C and stretched by a total of 3.8 times by stretching operation. The resin composition 5 was then applied to the surface of the B layer using a rod coater. After the coated film was guided to a tenter and preheated to 80°C, it was stretched by 1.6 times in each section in three equal length intervals set at 90°C, 110°C, and 130°C, and a total of 4.1 times was stretched in the width direction while being staged and heated. A heat treatment was performed at 235°C for 20 seconds at a fixed length, and a 5% relaxation treatment was performed along the width direction. The physical properties of the obtained laminated biaxially oriented polyester film are shown in Table 1.

[0318] Industrial availability

[0319] The laminated biaxially oriented polyester film for dry film resist of the present invention has 3000 protrusions / mm in height of 10 nm or more from the reference plane (zero height plane) on at least one surface (C surface). 2 Hereinafter, the C surface is the surface (exposure surface) exposed in the exposure process of the dry film resist, so it can reproduce fine patterns such as the width of the wiring and the spacing of the wiring less than 5μm as the printed wiring board becomes smaller and denser with high resolution, and can be suitably used as a base film for dry film resist.

[0320] [Table 1]

[0321]

[0322] [Table 2]

[0323]

Claims

1. A laminated biaxially oriented polyester film for dry film resist, wherein on at least one surface (C surface), the number of protrusions having a height of 10 nm or more from a reference surface (height zero plane) observed by a scanning white interference microscope is 3000 / mm 2 Hereinafter, the C-plane is a surface to be exposed in the exposure step of the dry film resist, that is, an exposure surface.

2. The laminated biaxially oriented polyester film for dry film resist according to claim 1, wherein the number of protrusions having a height of 10 nm or greater from a reference plane (ie, height zero plane) observed by a scanning white interference microscope on the surface A opposite to the surface C is 200 to 10,000 / mm 2 . 3 . The biaxially oriented polyester film for dry film resist according to claim 1 , wherein the kurtosis of the surface (C-plane) observed with an atomic force microscope (AFM) in a 5 μm field of view is 3 to 10.

4. The biaxially oriented polyester film for dry film resist according to claim 1 or 2, wherein the aspect ratio of the protrusion diameter at a height of 1 nm from a reference plane (height zero plane) observed by a scanning white interference microscope on the surface (C plane) is 0.35 or less. 5 . The laminated biaxially oriented polyester film for dry film resist according to claim 1 , wherein the C surface is composed of a coating layer having a surface free energy of 47 mN / m or less. 6 . The laminated biaxially oriented polyester film for dry film resist according to claim 1 , which is composed of at least three layers.

7. The laminated biaxially oriented polyester film for a dry film resist according to claim 1 or 2, wherein in a belt movement test, after humidity control for 24 hours or more in an atmosphere of 23°C and 65% RH, the C-surface is placed in contact with a stainless steel needle and reciprocated with a load of 300 g applied to the film, the friction coefficient μk1 between the C-surface and the stainless steel needle is 0.9 or less, and the friction coefficient μk5 after repeating the reciprocating movement five times is 0.9 or less. 8 . The laminated biaxially oriented polyester film for dry film resist according to claim 5 , wherein the coating layer on the C surface does not contain inorganic particles. 9 . The laminated biaxially oriented polyester film for dry film resist according to claim 5 , wherein the C surface is a coating layer mainly composed of a resin containing an acrylic adhesive.

10. The biaxially oriented polyester film for dry film resist according to claim 5, wherein the C surface is a coating layer in which, when the surface of the C surface is analyzed by time-of-flight secondary ion mass spectrometry, the ratio of the peak intensity P of fragments derived from the fluorine element to the peak intensity K of fragments detected with maximum intensity, i.e., P / K, is not more than 0.

01.

11. The laminated biaxially oriented polyester film for dry film resist according to claim 5, wherein the C surface is a film containing melamine, A coating layer of at least one compound selected from the group consisting of oxazoline, carbodiimide, and isocyanate.

12. The laminated biaxially oriented polyester film for dry film resist according to claim 1 or 2, wherein on the C surface, when an area of ​​220 μm in the length direction and 290 μm in the width direction is observed for 30 fields of view using a laser microscope, the number NP1 of coarse particles with a major axis of 1.0 μm or more is 20 or less, wherein the unit of NP1 is one.

13. The laminated biaxially oriented polyester film for dry film resist according to claim 1 or 2, comprising a polyester resin composition satisfying the following I to III: I: 5ppm≤germanium content, i.e., the weight ratio of germanium to the polyester resin composition is ≤100ppm, II: 5ppm≤manganese content, i.e., the weight ratio of manganese to the polyester resin composition is ≤40ppm, III: 4 ppm ≤ sodium content, that is, the weight ratio of sodium to the polyester resin composition is ≤ 40 ppm.

Images