JP4701838B2 - Polyester film for ultra fine wire photoresist - Google Patents

Description

  The present invention relates to a polyester film for ultrafine wire photoresists, and more specifically, it is possible to form a photoresist layer that is excellent in transparency and slipperiness, has no scratches, has excellent resolution, and pattern formation on the surface and edges, In addition, the present invention relates to a polyester film for an ultrafine-line photoresist that has excellent wear resistance and antistatic properties, and also has good laminating properties.

  In recent years, a photoresist film used in the production of a printed circuit board or the like is usually from a support [1] / photoresist layer [4] / protective layer [5] as shown in FIG. This is a laminated structure [10] to be formed. As a support in a photoresist film, a polyester film excellent in mechanical properties, optical properties, chemical resistance, heat resistance, dimensional stability, flatness and the like has been widely used. The photoresist layer is made of a photosensitive resin, and a polyethylene film or a polyester film is used as the protective layer.

 As a method for producing a printed wiring circuit board using a photoresist film [FIG. 1 (a)] in which a photoresist layer is made of a negative photosensitive resin, a method of generally producing the printed wiring circuit board by the following procedures (1) to (6) is available. [FIGS. 1 (b) to (g)].

(1) The exposed photoresist layer 4 and the conductive base material layer 6 are in contact with the substrate 11 composed of the conductive base material layer 6 and the base material 7 made of copper, and the photoresist film 10 ′ from which the protective layer 5 has been peeled off. Adhere closely. [FIG. 1 (b)]
(2) A glass plate 8 on which a mask layer 9 which is a reverse image (negative image) of a desired circuit is closely attached to the support 1 side of the photoresist film 10 '. [FIG. 1 (c)]
(3) By irradiating light from the glass plate 8 side, the portion without the mask layer 9 is irradiated (exposed), and a hardened portion 4 ″ is generated in the photoresist layer of the photoresist film 10 ′ (4 ′ is not yet present). Uncured part by exposure) [FIG. 1 (d)]
(4) The glass plate 8 and the support 1 are removed, and the uncured portion 4 ′ of the photoresist layer is removed using an appropriate solvent. [FIG. 1 (e)]
(5) Further, by etching using an acid or the like, the uncured portion 4 ′ of the photoresist layer is removed, and the exposed portion of the conductive base material layer 6 is removed, and the cured portion 4 ″ of the photoresist layer is removed. The desired circuit 6 'is formed in the portion protected by [FIG. 1 (f)].
(6) After that, if the hardened portion 4 ″ of the photoresist layer is removed by an appropriate method, a printed circuit board in which the conductive circuit 6 ′ is formed on the base material 7 is obtained [FIG. g)]

  Recently, since high reproducibility and resolution of circuit pattern formation have been required, the circuit of the printed wiring circuit board has become extremely complicated, the wiring has become thinner, and the interval between them has become narrower. When exposing a photoresist layer in a photoresist film, light passes through the support as described above. Therefore, if the transparency of the support is low, problems such as insufficient exposure of the photoresist layer or deterioration of resolution due to light scattering occur. For this reason, it is important that the polyester film used as the support has a low haze and is highly excellent in transparency. Furthermore, when there is a scratch on the film surface, there arises a problem that the resolution is deteriorated by scattering the transmitted light.

  On the other hand, a polyester film as a support is for improving the handleability when producing a photoresist film by forming a photoresist layer on the support, or for improving the handleability of the photoresist film itself. In addition, it is important to have appropriate slipperiness. Also, in order to prevent problems such as air bubbles entering between the support and the glass plate on which the circuit pattern is formed during the manufacture of the printed circuit board shown in FIG. 1, the circuit pattern reproducibility is impaired. In addition, air permeability is also required.

In order to meet these market demands, a method is used in which particles are contained in a polyester film and fine protrusions are formed on the surface. In order to form protrusions on the film surface, particle blending technology and multilayer technology are used. And many techniques combining these are disclosed (for example, see Patent Documents 1 to 10).
Japanese Patent Laid-Open No. 10-46012 Japanese Patent Laid-Open No. 10-128930 JP 2000-221688 A JP 2001-117237 A JP 2002-60598 A JP 2002-62661 A JP 2002-72486 A JP 2002-278072 A JP 2002-341546 A JP 2003-43691 A

  In Patent Documents 3 and 4, handling properties when producing a polyester film for photoresist by blending an antistatic agent, prevention of adhesion of dust and foreign matter, and handling of the photoresist film itself using the film are disclosed. A technique for improving the performance is disclosed.

  With the above-described technique, the handling property is being improved while maintaining the transparency of the film. In particular, in the techniques of Patent Documents 3 and 4, particles are contained only in a thin surface layer formed on a polyester film as a support, and the content thereof is suppressed to a low level. It has been attracting attention because of its excellent optical properties as a polyester film for ultrafine wire photoresist.

  However, prior art methods including this technique are designed with attention paid to handling properties centered on the slipperiness of the film, and no consideration has been given to the abrasion resistance during the processing of the film. Therefore, for example, in the step of laminating a composite film in which a resist layer is laminated on a photoresist film on a wiring board, the composite film is caused by friction with a film holding device for cutting the composite film to the dimensions of the wiring board. A problem has arisen that the surface opposite to the surface on which the resist layer is formed has scratches, and the scratches reduce the light transmittance of the composite film and reduce the resolution of the resist.

  In addition, in the laminating process, the problem of flaws on the film surface due to friction with the roll for pressing the composite film on the wiring board and the contamination of the composite film surface due to the resin powder generated due to the flaws have become apparent. Therefore, development of a polyester film for an ultrafine-line photoresist having improved transparency and handling properties and improved wear resistance has been strongly desired.

  The present invention has been made against the background of the problems of the prior art, and can form a photoresist layer that is excellent in transparency and slipperiness, has no scratch on the surface, and has excellent resolution and pattern formation on the surface and edges. Another object of the present invention is to provide a polyester film for an ultrafine-line photoresist having excellent wear resistance and antistatic properties and good laminating properties.

It was possible to solve the problem, fine wire photoresist polyester film of the present invention, a polyester film as a support, a laminated polyester film formed by providing a resist layer on one surface of the support, laminated polyester On the surface opposite to the resist layer side of the film, 5 to 20% by mass of particles (a) having an average particle diameter of 0.01 to 0.1 μm and 0.1% of particles (b) having an average particle diameter of 1 to 3 μm. A resin composition layer containing 1 to 1% by mass, 1 to 3% by mass of a wax agent, and 1 to 10% by mass of an antistatic agent is laminated, and the polyester film contains substantially no particles. (1) The haze of the laminated film is 1.0% or less. (2) The surface of the laminated film opposite to the resist layer side is (A) surface specific resistance measured in an environment of a temperature of 23 ° C. and a humidity of 65% RH ( Ω / □) The number (log (Ω / □)) is 13 or less, (B) the wear resistance index defined by the following formula is 15% or less, and (3) the surface on the resist layer side and the side opposite to the resist layer side Both of the surfaces of the above are characterized by having scratches having a length of 1 mm or less and a depth of 0.5 μm or less of less than 1.0 / m ² .
Abrasion resistance index (%)
= (Area of scratched part (in observation part) / total area of observation part) × 100

In this case, it is preferable that the average surface roughness (Ra) of the surface opposite to the surface on which the resist layer is laminated of the polyester film is 0.002 to 0.015 μm.

  Moreover, it is preferable that a polyester film is a biaxially-oriented polyester film whose thickness is 12-25 micrometers.

  The resin composition layer contains particles (a) having an average particle size of 0.01 to 0.1 μm that are colloidal silica, and particles (b) having an average particle size of 1 to 3 μm are porous silica. preferable.

  Furthermore, the resin composition layer preferably contains 0.1 to 10 (mass%) of a silicon-based and / or fluorine-based surfactant.

  The polyester film for ultrafine photoresist of the present invention has excellent transparency, slipperiness, antistatic properties and abrasion resistance, and has no scratch on the surface, and is suitable as a support for ultrafine photoresist films. It is. The photoresist film using the polyester film for ultrafine-line photoresist of the present invention as a support is excellent in the resolution of the photoresist layer, the pattern formability of the surface and edges, and the adhesion of the photoresist layer. Excellent handling and durability when manufacturing a photoresist film using the polyester film for ultrafine photoresist of the present invention as a support, such as blocking and abrasion resistance, etc. It is useful for industrial use.

Hereinafter, the present invention will be described in detail.
It is important that the polyester film for ultrafine photoresist of the present invention satisfies the following characteristics at the same time. That is, a laminated polyester film comprising a polyester film as a support and a resist layer provided on one side of the support, wherein (1) the haze of the laminated film is 1.0% or less, and (2) the resist layer of the laminated film The surface opposite to the side has (A) a logarithm of surface resistivity (Ω / □) measured in an environment of a temperature of 23 ° C. and a humidity of 65% RH of 13 or less, and (B) defined by the following formula: Abrasion resistance index is 15% or less, and (3) scratches having a length of 1 mm or less and a depth of 0.5 μm or less on the resist layer side surface and the surface opposite to the resist layer side are 1. It has the property of being less than 0 / m ² .
Abrasion resistance index (%)
= (Area of scratched part (in observation part) / total area of observation part) × 100

  The polyester film constituting the ultrafine wire photoresist polyester film of the present invention (hereinafter sometimes simply referred to as a main layer film) is preferably a biaxially oriented polyester film having a thickness of 12 to 25 μm, comprising polyethylene terephthalate, Aromatic linear polyesters composed of aromatic dicarboxylic acids such as polyethylene naphthalate and diols, aliphatic linear polyesters composed of aliphatic dicarboxylic acids and diols, and copolymers thereof The thing which consists of a polyester-type resin which mainly consists of this polyester is mentioned. Among these, those made of an aromatic linear polyester resin such as polyethylene terephthalate and polyethylene naphthalate are preferable. Moreover, the main material film of the present invention may be formed by mixing one or more of the above-mentioned polyester-based resins. Such a main material film may be a single layer or a multilayer of two or more layers. The thickness of the film is preferably 12 to 25 μm, particularly preferably 13 to 20 μm, and more preferably 14 to 20 μm. If the thickness exceeds 25 μm, the resolution tends to decrease. If the thickness is less than 12 μm, the strength is insufficient, and in particular, tearing may occur during the peeling operation, which is not preferable.

  The manufacturing method of the polyester film for ultrafine wire photoresists of the present invention is not particularly limited as long as it is a biaxially stretched film, and can be selected from generally used methods. The biaxial stretching method is not particularly limited, and a generally used sequential biaxial stretching method, simultaneous biaxial stretching method, or the like can be used.

  The polyester film for an ultrafine wire photoresist of the present invention has a haze of 1.0% or less, preferably 0.8% or less, and more preferably 0.6% or less. If it exceeds 1.0%, the resolution tends to decrease, which is not preferable.

  In the present invention, the logarithm of the surface resistivity (Ω / □) at 23 ° C. and 65% RH on the surface opposite to the surface on which the resist layer of the polyester film for ultrafine wire photoresist is laminated is 13 or less. is there. The logarithm of such surface resistivity is preferably 12 or less, and more preferably 11 or less. When the logarithm of the surface resistivity exceeds 13, the charge of the polyester film is increased, the process for producing the main layer film, the handling property when producing the photoresist film using the polyester film as a support, dust and foreign matter This is not preferable because the adhesion of the photoresist film increases and the handling property of the photoresist film itself using the polyester film for photoresist of the present invention as a support deteriorates.

  In the present invention, the abrasion resistance index of the surface opposite to the surface on which the resist layer of the polyester film for ultrafine wire photoresist is laminated is 15% or less. Such an abrasion resistance index is preferably 13% or less, and more preferably 11% or less. When the abrasion resistance index exceeds 15%, the film is scratched by a process such as a process of laminating a resist layer or a laminating process of laminating a composite film combined with a resist on a wiring board. It is not preferable because the transparency of the film is deteriorated and the resolution is lowered, or the film surface is contaminated with shavings caused by scratches, which may cause a decrease in resolution and a pattern formation failure due to a local exposure failure.

  Further, in the present invention, there is a scratch having a length of 1 mm or more or a depth of 0.5 μm or more on the surface on which the resist layer of the polyester film for ultrafine wire photoresist is laminated and the surface opposite to the surface on which the resist layer is laminated. It is important not to. A scratch having a length or depth longer than this scatters light during exposure of the photoresist, thereby impairing the reproducibility of the circuit pattern.

  Furthermore, in this invention, it is preferable that the average surface roughness (Ra) of the surface on the opposite side to the surface where the resist layer of the said polyester film for ultra fine wire photoresists is laminated | stacked is 0.002-0.015 micrometer. The average surface roughness (Ra) is preferably 0.0025 to 0.0145 μm, and more preferably 0.003 to 0.014 μm. If the thickness is less than 0.002 μm, the slipping property of the film is deteriorated, so that the handling property is deteriorated or scratches are generated due to friction between films in the winding process, which is not preferable. Conversely, if it exceeds 0.015 μm, the transparency of the film tends to decrease, which is not preferable.

Method of imparting said characteristics, the surface on which the resist layer is laminated 5-20 wt% average particle diameter 0.01~0.1μm of particles (a) on the opposite side, the average particle size of 1~3μm In a preferred embodiment, a resin composition layer containing 0.1 to 1% by mass of particles (b), 1 to 3% by mass of a wax agent and 1 to 10% by mass of an antistatic agent is laminated. is there. In a more preferred embodiment, the particle (a) is colloidal silica and the particle (b) is porous silica. With such an embodiment, while maintaining the high transparency important for high resolution of the photoresist, the handling property and wear resistance of the polyester film for ultrafine photoresist and the composite film in which the resist layer is combined with the film are improved. Can be improved easily.

  The average primary particle size and average particle size of the particles were determined by microscopic observation, and details thereof were described in the evaluation method described later.

  The resin used to form the resin composition layer is arbitrarily selected as long as it is transparent, can fix the particles, wax, antistatic agent, etc. to the polyester film surface and is resistant to abrasion. However, it is preferable to select from at least one resin selected from the group of polyester resins, polyurethane resins, acrylic resins, amino resins, epoxy resins, and oxazoline resins. The resin may be a commercially available product or a custom-made product having a specific composition. Moreover, the classification of a non-crosslinked product or a crosslinked product is not limited. The kind of crosslinking agent is not ask | required, either. The resin is used in the form of an organic solvent solution or dispersion or an aqueous solvent solution or dispersion. In particular, a dispersion of an aqueous solvent, that is, a form of a water-dispersed resin is preferable in terms of working environment and applicability.

In the present invention, the particles contained in the resin composition layer are two kinds of particles having different average particle diameters, and a specific amount of colloidal silica is used as the small particles (a) and a specific amount of porous silica is used as the large particles (b). However, it is preferable from the viewpoint of improving slipperiness and wear resistance while maintaining transparency.
The particles (a) preferably contain 7 to 17% by mass of colloidal silica having an average particle size of 0.02 to 0.08 μm based on the resin component, and have an average particle size of 0.03 to 0.06 μm. More preferably, 5 to 14% by mass of colloidal silica is blended. The particles (b) more preferably contain 0.2 to 0.9% by mass of porous silica having an average particle size of 1.1 to 2.5 μm based on the resin component. More preferably, 0.3 to 0.8% by mass of porous silica of 2 to 2.0 μm is contained.

  The colloidal silica is usually a colloidal dispersion in which ultrafine particles of silicic acid anhydride (silica) are stably dispersed in water, and marketed under brand names such as Lu Pont of du Pont and Snowtex of Nissan Chemical. Has been supplied to. Various production methods are known for these colloidal silicas, but they are generally produced by a method using an ion exchange resin. That is, a sodium silicate aqueous solution is passed through a cation exchange resin to form a sol, which is heated and aged to 60 ° C. or more to grow into independent dispersed particles, and a sol that has passed through an ion exchange resin composition layer is newly added thereto. Thus, it is produced by a method such as a method of forming a stabilized sol by polymerizing and depositing the particle size. Such colloidal silica sol may be an organic solvent type or an aqueous dispersion type. What is necessary is just to select suitably according to the solvent used for melt | dissolution and dispersion | distribution of the said resin. Such sols include those stabilized with an alkali system and those stabilized with an acid system, and such selection may be appropriately selected depending on the type of resin and active ray crosslinking agent used.

  The porous silica is composed of an aggregate of primary particles having an average particle diameter of 0.01 to 0.1 μm, and preferably has a pore volume in the range of 0.5 to 2.0 ml / g. . Since such porous silica has less decrease in the transparency of the coating film than nonporous silica, the slipperiness can be improved with a small decrease in transparency.

  The wax agent is not particularly limited as long as it does not impair transparency, and conventionally known wax agents can be used, but it is more preferable to use a polymer wax component. For example, a polyethylene type, a polypropylene type, and a fatty acid type are mentioned. These wax components preferably have a weight average molecular weight of 1,000 to 10,000, more preferably 1,500 to 6,000. When the molecular weight is less than 1,000, transfer contamination due to oozing from the inside of the resin composition layer to the surface tends to occur, and when the molecular weight exceeds 10,000, the effect of improving slipperiness is insufficient. become. The blending amount of these wax components with respect to the resin component is more preferably 1.2 to 2.8% by mass, and further preferably 1.4 to 2.6% by mass. By blending the two types of particles and waxes having different particle sizes into the resin component at the blending ratio, it is possible to maintain a high degree of transparency and to impart slipperiness and wear resistance. It is possible to easily impart the characteristics to be provided as a polyester film for a line photoresist.

The antistatic agent is a compound used for the purpose of imparting antistatic properties, for example, an unsaturated monomer having a sulfonate group (for example, sodium vinylsulfonate, sodium methallylsulfonate, styrenesulfonic acid). Polymer-type antistatic agents comprising one or more polymers of sodium, ammonium vinyl sulfonate, potassium methacryl sulfonate, lithium styrene sulfonate, etc., and R-SO ₃ X (where R is an alkyl group, aryl Or an aromatic group having an alkyl group, wherein X is a metal ion (for example, Li, Na, K, etc.), ammonium ion, amine ion, phosphate ester ion) low molecular weight antistatic agent or It has a sulfonate group with excellent heat resistance and a function to develop antistatic properties. , It is not limited to the compound. From the viewpoint of the water resistance of the coating film, it is preferable to use a polymeric antistatic agent.

  Examples of the alkyl sulfonate include sodium pentane sulfonate, sodium octane sulfonate, lithium octane sulfonate, potassium octane sulfonate, sodium tetradecyl sulfonate, and the like.

  Examples of the aryl sulfonate include sodium benzyl sulfonate, sodium toluyl sulfonate, and sodium naphthyl sulfonate. Furthermore, examples of the aromatic sulfonate having an alkyl group include alkyl (carbon number: 8 to 20) benzenesulfonic acid metal salt (for example, Li, K, Na salt) such as sodium dodecylbenzenesulfonate, alkylnaphthalene. Examples include sodium sulfonate and sodium alkylphenyl ether disulfonate.

  The polymer antistatic agent comprising a polymer of an unsaturated monomer having a sulfonate group uses, for example, a styrene resin containing a sulfonate group component in the molecule such as polystyrene sulfonate. It is preferable.

  This polymer antistatic agent is characterized by the high hydrophilicity of its sulfonic acid component. Examples of the styrene resin containing a sulfonate group component in the molecule include homopolymers such as sodium salt, potassium salt, lithium salt, ammonium salt, and phosphonium salt of polystyrene sulfonic acid, acrylic acid ester, and methacrylic acid ester. Examples include a copolymer of an acrylic monomer and a styrene sulfonic acid monomer. For example, it is preferable to use a styrene resin containing a sulfonate group component in the molecule such as polystyrene sulfonate. The polystyrene sulfonate has a weight average molecular weight of 1,000 to 150,000, preferably 10,000 to 70,000. When the molecular weight is less than 1,000, it becomes difficult to obtain the water resistance of the coating film, and when it exceeds 150,000, uniform mixing with the copolymerized polyester tends to be difficult.

  The blending amount of the antistatic agent is preferably 2 to 9% by mass, and more preferably 3 to 8% by mass. If the blending amount of the antistatic agent is less than 1% by mass, the antistatic property deteriorates, which is not preferable. On the other hand, when the blending amount of the antistatic agent exceeds 10% by mass, the effect of improving the antistatic property is saturated, and the production process of the film or the roll of the processing step with the antistatic agent is not preferable. .

  In this invention, it is a more preferable embodiment to mix | blend 0.1-10 mass% of silicon-type and / or fluorine-type surfactant with the said resin composition layer. Silicone surfactants include dimethyl silicon, amino silane, acrylic silane, vinyl benzyl silane, vinyl benzyl silyl amino silane, glycid silane, mercapto silane, dimethyl silane, polydimethyl siloxane, polyalkoxy siloxane, hydrodiene modified siloxane, vinyl modified siloxane, Vitroxy modified siloxane, amino modified siloxane, carboxyl modified siloxane, halogenated modified siloxane, epoxy modified siloxane, methacryloxy modified siloxane, mercapto modified siloxane, fluorine modified siloxane, alkyl group modified siloxane, phenyl modified siloxane, alkylene oxide modified siloxane, etc. .

  Fluorosurfactants include ethylene tetrafluoride, perfluoroalkyl ammonium salt, perfluoroalkyl sulfonic acid amide, sodium perfluoroalkyl sulfonate, perfluoroalkyl potassium salt, perfluoroalkyl carboxylate, perfluoroalkyl sulfone. Acid salts, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl trimethyl ammonium salts, perfluoroalkyl amino sulfonates, perfluoroalkyl phosphate esters, perfluoroalkyl alkyl compounds, perfluoroalkyl alkyl betaines, perfluoroalkyl halides, etc. Is mentioned.

  As for the compounding quantity of the said surfactant, it is more preferable that it is 0.1-9 mass%, and it is further more preferable that it is 0.3-8 mass%. By blending the surfactant, the affinity for the main material film during coating of the resin composition layer is improved, and a coating film having a good appearance can be obtained.

  In the present invention, it is important to maintain high transparency and to provide slipperiness and wear resistance. Therefore, at the time of adjusting the coating liquid, in order to prevent particle aggregation caused by the temperature difference between the materials at the time of mixing the liquid materials, it is a more preferable embodiment to perform temperature control on the raw material before adjustment. Further, it is more preferable to add each material while constantly stirring the coating solution tank to be adjusted. Furthermore, it is a preferred embodiment that a filter for removing micro-aggregates contained in the raw material before adjustment or generated by component aggregation during the adjustment is provided in front of the coating apparatus.

  In the present invention, the method for laminating the resin composition layer is not limited, but it is preferable to form the resin composition layer by a so-called in-line coating method in which the polyester film is laminated on an unstretched film or a uniaxially stretched film. It is an aspect. The in-line coating method improves the adhesion and adhesion durability between the main material film and the resin composition layer. Moreover, it is excellent in economical efficiency and is suitable.

  As a method for providing the resin composition layer, a gravure coating method, a kiss coating method, a dip method, a spray coating method, a curtain coating method, an air knife coating method, a blade coating method, a reverse roll coating method and the like are used. Can be applied.

  In the present invention, it is important to maintain high transparency and to provide slipperiness and wear resistance. For this purpose, it is important to suppress aggregation of particles in the coating solution for forming the resin composition layer as much as possible. For example, when the liquid temperature of the coating liquid decreases, the aggregation of the particles increases. On the other hand, since wettability deteriorates when the liquid temperature of the coating liquid rises, it is also one of preferred embodiments to perform extremely strict temperature management of the liquid temperature within ± 1 ° C. By introducing such an embodiment, it is possible to stably maintain the high quality possessed by the polyester film for ultrafine-line photoresist of the present invention.

  The thickness of the resin composition layer is not particularly limited, but in the present invention, the final thickness after drying is preferably 0.01 to 0.2 μm, more preferably 0.015 to 0.16 μm, Preferably it is 0.02-0.12 micrometer. If it is less than 0.01 μm, the effect of improving the slipperiness and wear resistance is reduced. Conversely, if it exceeds 0.2 μm, the effect of improving the slipperiness and wear resistance is saturated and the transparency is lowered, which is not preferable. .

  The resin composition layer may contain a known additive such as an antioxidant, a heat stabilizer, a weather stabilizer, and an organic lubricant as long as the effects of the present invention are not impaired.

  In the present invention, when the resin composition layer is laminated, since the slipperiness and wear resistance of the polyester film for ultrafine wire photoresist are imparted, the main layer from the viewpoint of transparency. It is not necessary to include particles in the film.

In addition, the above-mentioned “the film of the main layer does not need to contain particles” means that particles are not actively contained, and in the sense that no particles are contained in the obtained film. Absent. This is because even if particles are not actively added to the film, contaminants derived from foreign substances and raw material resin or dirt attached to the line or equipment in the film manufacturing process may be peeled off and mixed into the film. Because there is. For example, the content of particles in the obtained film is 50 ppm or less, preferably 10 ppm or less, and most preferably the detection limit or less when inorganic elements are quantified by fluorescent X-ray analysis in the case of inorganic particles. If so, it is considered that the particles are substantially not contained.

  Therefore, in order to reduce the haze of the laminated film to 1.0% or less, in the polyester film of the support, the biaxially stretched polyester film of the main layer does not substantially contain particles, and a resist layer is formed on the support. A laminated structure in which particles are contained only in the resin composition layer laminated on the opposite surface of the laminated main layer film is a preferred embodiment in the present invention.

  Therefore, in the preferred embodiment described above, it is not necessary to form a functional layer for the purpose of imparting slipperiness or the like on the surface on which the resist layer of the main film is laminated. If such measures are not taken, it is recommended because the effects of the present invention can be expressed more remarkably. However, as long as the effects of the present invention are not hindered, the film is used as the main layer of the support. A method of containing particles and a method of laminating a functional layer on the surface on which the resist layer is formed are not excluded.

  With respect to scratches on the film surface, in addition to taking measures for preventing scratches that occur in the above-described processing steps, sufficient consideration is required regarding the occurrence of scratches in the manufacturing process of the film that is the main layer. For example, if the roll surface roughness of an applicator roll or the like in the coating process is large, scratches are generated. Therefore, the surface roughness of the roll or the like is preferably 0.2 S or less. In addition, a method of installing a roll cleaner in the preheating inlet and the cooling roll in the longitudinal stretching process is also one of the preferred embodiments in order to prevent the generation of scratches such as deposits, deposits and foreign matters on the roll surface. .

  In addition, there is a method in which the cleanliness in the film production process is class 1,000 or less (1000 particles or less of 0.5 μm or more in a volume per cubic foot). It is also a preferred embodiment to use clean air of class 100 or less for the blower cooling device for cooling the anti-roll surface in the process.

  In addition, it is also preferable to take measures to prevent scratches due to friction by minimizing the speed difference generated between the film and the roll by precisely controlling the speed of the roll through which the film passes in the film manufacturing process. It is.

  Further, there may be mentioned a method of cleaning the roll by an operation of scraping off defects on the roll using an abrasive before the film production. In addition, in order to prevent the film from adsorbing dust or the like due to the generation of static electricity and causing a defect, there is a method of providing a static eliminator so that the charge amount of the film becomes ± 1500 V or less in all steps. The process from the casting of the film, which is the main layer of the support, to the tenter described later is a process in which scratches are likely to occur. It is also possible to lay out this section compactly and make the passage time less than 5 minutes. Since it can contribute to suppression, it is preferable.

  Hereinafter, the effectiveness of the present invention will be described with reference to examples, but the present invention is not limited thereto. In addition, the evaluation method of the physical property in the following examples is as follows.

(1) Average primary particle diameter and average particle diameter of particles The average primary particle diameter and average particle diameter of the particles were determined by microscopic observation, and the measurement was performed according to the following method.
(A) Take a photograph of the particles with an electron microscope, measure the maximum diameter of 300 to 500 particles at a magnification such that the size of one smallest particle is 2 to 5 mm, and average the average value of the average value. The particle size or average particle size was used.
(B) The average particle size of the particles in the coating layer of the laminated film was obtained by photographing a cross section of the laminated film at a magnification of 120,000 using a transmission electron microscope (TEM), The maximum diameter was determined.
(C) As for the average particle diameter of the particles P2 made of aggregates, 300 to 500 pieces of the cross-section of the coating layer of the laminated film were photographed at 200 times magnification using an optical microscope, and the maximum diameter was measured.

(2) Film thickness Using a digital thickness measuring instrument manufactured by Mitutoyo, the film thickness was an average value measured for 10 points in the width direction.

(3) Resin composition layer thickness A cross section of the film was cut into ultrathin sections, and observed with a TEM (transmission electron microscope) by RuO ₄ staining, OsO ₄ staining, or staining both sections by double staining of both. I took a photo. The thickness of the resin composition layer was measured from the photograph of the obtained film cross section. The resin composition layer thickness was an average value of 30 in the measurement visual field.

(4) Haze Based on JIS K-7105, the haze was measured using a haze meter (TC-H3DP, manufactured by Tokyo Denshoku Co., Ltd.). The measured value was an average value of 10 points.

(5) Average surface roughness (Ra)
The surface roughness of the resin composition layer coated surface was measured using a three-dimensional non-contact surface shape measuring instrument (Ryoka System Co., Ltd., Micromap). The measurement area was 1.7 mm × 1.2 mm, and the measurement results at three points were averaged and evaluated.

(6) Antistatic properties (surface resistivity)
The film was cut into a size of 5 cm × 10 cm and seasoned for 24 hours under environmental conditions of a temperature of 23 ° C. and a humidity of 65% RH. Thereafter, the surface antistatic property of the surface on which the resin composition layer of the film was laminated was measured using a surface specific resistor (surface specific resistance meter, manufactured by Mitsubishi Yuka Co., Ltd.), applied voltage 500 V, temperature 23 ° C., humidity 65%. The surface resistivity (Ω / □) was measured under RH environmental conditions and expressed in logarithm (log (Ω / □)). The measured value was an average value of 5 points.

(7) Abrasion resistance (Abrasion resistance index)
Using a Gakushin type friction fastness tester (manufactured by Yamaguchi Kagaku Sangyo Co., Ltd.), friction was applied to the resin laminated surface of a sample having a width of 3 cm and a length of 20 cm under a condition of 10 reciprocations with a load of 500 gf. The object used was an aluminum foil, and the machinability of the resin composition layer was evaluated by surface observation and image analysis of the resin composition layer after friction loading, and the wear resistance index was obtained by the following formula.
Abrasion resistance index (%)
= (Area of scratched part (in observation part) / total area of observation part) × 100

  In addition, this abrasion resistance index (%) can be calculated | required in the following procedure as (100-percentage of the histogram integrated area of the brightness | luminance 85 or more part in an image analysis).

(Surface observation)
After black ink was uniformly applied to the surface opposite to the resin laminated surface after the friction load, the surface of the resin composition layer was observed using a digital HD microscope VH-7000 manufactured by Keyence Corporation. The measurement magnification was 100 times.

(Image analysis)
The surface observation image was subjected to image analysis using Adobe Photoshop Ver7.0. The threshold when performing two gradations was set to 85, and the ratio according to the luminance from the histogram was defined as the wear resistance index (%). The average value of the five measurement results was evaluated.

(8) Appearance of film resin composition layer coated surface The film was cut into a size of 1 m × 1 m, illuminated with fluorescent lamp reflected light, and visually evaluated on the coated surface appearance of the resin composition layer. The evaluation was performed on 10 points.
○: Appearance of coated surface is uniform by visual confirmation ×: Unevenness is observed on resin coated surface by visual confirmation

(9) Scratches Films were cut into dimensions of 1 m × 1 m, and the number of scratches having a length of 1 mm or more or a depth of 0.5 μm or more was evaluated. The method for confirming scratches was evaluated by counting visible scratches in light of fluorescent lamp transmitted light. The length and depth of the wound were confirmed by further observing the visually confirmed wound with a micromap (TABLE TOP ISOLATOR, manufactured by Nicon). Evaluation was performed on 10 points, and the average was adopted.
○: 0 scratches per 1 m ² in length of 1 mm or more or 0.5 μm or more in the sample Δ: 1-10 scratches per 1 m ² in length of 1 mm or more or 0.5 μm or more in depth ×: 11 or more scratches per 1 m ² having a length of 1 mm or more or a depth of 0.5 μm or more in the sample

Example 1
(Preparation of coating solution)
<composition>
(I) Coating resin Water-dispersible polyester resin (Toyobo Co., Ltd., Vylonal MD1200) was blended so that the resin solid content concentration was 30% by mass.
(Ii) Wax agent High crystalline polyethylene (E68A, manufactured by Toho Chemical Co., Ltd.) was blended so as to be 1.8% by mass with respect to the resin component.
(Iii) Surfactant A fluorinated surfactant (F1405, manufactured by Dainippon Ink Co., Ltd.) was blended so as to be 2% by mass relative to the resin component.
The coating resin, wax agent, and surfactant used in advance were stored in a room controlled at 24 ° C. ± 1 ° C. in a temperature control room.
(Iv) Particles As particles (a), an aqueous dispersion (Snowtex) of colloidal silica having an average particle size of 0.05 μm was blended so that the mass of silica was 8% by mass with respect to the resin component. Next, as the particles (b), porous silica having an average particle size of 1.8 μm was blended so as to be 0.5 mass% with respect to the resin component.
(V) Antistatic agent Alkyl sulfonate (TB214) was blended so as to be 0.5% by mass with respect to the resin component.

<Formulation method>
(1) A liquid mixture of pure water / isopropyl alcohol was put into a preparation tank for adjusting the coating liquid, and sufficiently mixed with a stirring blade.
(2) Into the mixed solution, materials blended so as to satisfy the composition were added in the order described in (i) to (v) with stirring. In addition, after adding each material, while stirring and mixing was continued, an interval of 5 minutes was provided until the next material was charged.
The temperature of the tank in which the coating solution was prepared and the final tank when performing in-line coating were controlled at 24 ° C. ± 1 ° C.

(Preparation of laminated film)
A polyethylene terephthalate resin containing no particles was dried, melt-extruded and cooled and solidified according to a conventional method to obtain an unstretched film. The unstretched film was stretched 3.5 times in the longitudinal direction between a pair of 85 ° C. rolls having different peripheral speeds to obtain a uniaxially stretched film. Further, the coating solution prepared by the above method was applied to one side of the uniaxially stretched film by a reverse roll coating method, dried with hot air at 70 ° C., and then stretched 3.5 times in the transverse direction at 98 ° C. with a tenter. Heat-fixed at 200-210 degreeC, the 16-micrometer-thick biaxially stretched polyester film which has a resin composition layer was obtained. The final thickness of the resin composition layer was 0.1 μm. In addition, the liquid temperature of the coating liquid in the coating process was set and controlled at 24 ° C. ± 1 ° C. The evaluation results are shown in Table 1.

Example 2
In Example 1, a biaxially stretched polyester film was obtained in the same manner as in Example 1 except that a water-dispersible urethane resin was used as the resin in the coating solution. The evaluation results are shown in Table 1.

Example 3
In Example 1, the type of the antistatic agent in the coating solution was changed to a polymer type antistatic agent, and the amount was changed to 0.07% by mass. A film was obtained. The evaluation results are shown in Table 1.

Example 4
In Example 1, a biaxially stretched polyester film was obtained in the same manner as in Example 1 except that a silicon-based surfactant was used as the surfactant in the coating solution. The evaluation results are shown in Table 1.

Example 5
In Example 1, a biaxially stretched polyester film was prepared in the same manner as in Example 1 except that the addition amount of the particles in the coating solution was changed to 5% by mass for the particles (a) and 1% by mass for the particles (b). Got. The evaluation results are shown in Table 1.

Example 6
In Example 1, the addition amount of the particles in the coating solution was changed to 20% by mass for the particles (a) and 0.1% by mass for the particles (b). A stretched polyester film was obtained. The evaluation results are shown in Table 1.

Comparative Example 1
In Example 1, a biaxially stretched polyester film was obtained in the same manner as in Example 1 except that only the particles (a) were used as the particles in the coating solution. The evaluation results are shown in Table 1.

Comparative Example 2
In Example 1, a biaxially stretched polyester film was obtained in the same manner as in Example 1 except that only the particles (b) were used as the particles in the coating solution. The evaluation results are shown in Table 1.

Comparative Example 3
In Example 1, a biaxially stretched polyester film was obtained in the same manner as in Example 1 except that only the wax agent was used without adding particles to the coating solution. The evaluation results are shown in Table 1.

Comparative Example 4
In Example 1, a biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the wax agent and the surfactant were not added to the coating solution. The evaluation results are shown in Table 1.

Comparative Example 5
In Example 1, a biaxially stretched polyester film was obtained in the same manner as in Example 1 except that no antistatic agent was added to the coating solution. The evaluation results are shown in Table 1.

Comparative Example 6
In Example 1, 25% by mass of colloidal silica having an average particle size of 0.1 μm was added as particles (a) as particles in the coating solution, and 2% by mass of porous silica having an average particle size of 2.5 μm was added as particles (b). Except that, a biaxially stretched polyester film was obtained in the same manner as in Example 1. The evaluation results are shown in Table 1.

Comparative Example 7
In Example 1, a biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the addition amount of the wax agent in the coating solution was 3.5% by mass. The evaluation results are shown in Table 1. In Comparative Example 7, the antistatic property was inferior. This is presumably because the antistatic charge used was a low molecular weight type, and the effect of the wax agent prevented the antistatic agent from moving to the film surface.

  The polyester film for ultrafine wire photoresist of the present invention has excellent transparency, slipperiness, antistatic property and abrasion resistance, and therefore can be suitably used as a support for ultrafine wire photoresist film. The photoresist film using the polyester film for ultrafine-line photoresist of the present invention as a support is excellent in the resolution of the photoresist layer, the pattern formability of the surface and edges, and the adhesion of the photoresist layer, Furthermore, because it is excellent in handling and durability, such as blocking resistance and abrasion resistance when producing a photoresist film using the polyester film for ultrafine photoresist of the present invention as a support, it is used for laminating and the like. Can also be used, and has excellent processability. Therefore, the technical idea of the present invention is also applied to other industrial films such as a base film of an optical functional film that is particularly suitable as a support for an ultrafine wire photoresist and requires high transparency. It is possible to contribute to the industry.

1 (a), (b), (c), (d), (e), (f), and (g) show the structure of a photoresist film and the production of a printed wiring circuit board using the photoresist film. It is explanatory drawing of a process.

Explanation of symbols

1 Support 2 Main Layer Film (Main Layer of Polyester Film for Fine Wire Photoresist)
3 Resin composition layer (sublayer of polyester film for ultrafine wire photoresist)
4 Photoresist layer 5 Protective layer 6 Conductive base material layer 7 Base material 8 Glass plate 9 Mask layer 10 Photoresist film 11 Substrate

Claims (5)

A polyester film as a support, a laminated polyester film having a resist layer on one side of the support,
On the surface opposite to the resist layer side of the laminated polyester film, 5 to 20 mass% of particles (a) having an average particle diameter of 0.01 to 0.1 μm and 0 particles (b) having an average particle diameter of 1 to 3 μm are added. A resin composition layer containing 1 to 1% by mass, 1 to 3% by mass of a wax agent, and 1 to 10% by mass of an antistatic agent is laminated,
The polyester film is substantially free of particles,
(1) The haze of the laminated film is 1.0% or less,
(2) The surface of the laminated film opposite to the resist layer side is (A) logarithm (log (Ω / □) of the surface resistivity (Ω / □) measured in an environment of a temperature of 23 ° C. and a humidity of 65% RH. □)) is 13 or less, (B) the wear resistance index defined by the following formula is 15% or less,
(3) The surface of the resist layer side and the surface opposite to the resist layer side both have a length of 1 mm or less and a depth of 0.5 μm or less of less than 1.0 / m ^2. Polyester film for ultra fine wire photoresist.
Abrasion resistance index (%)
= (Area of scratched part (in observation part) / total area of observation part) × 100   2. The polyester film for ultrafine wire photoresist according to claim 1, wherein an average surface roughness (Ra) of the surface opposite to the resist layer side of the laminated film is 0.002 to 0.015 μm.   3. The polyester film for ultrafine wire photoresist according to claim 1, wherein the base material is a biaxially oriented polyester film having a thickness of 12 to 25 μm. The polyester film for an ultrafine wire photoresist according to any one of claims 1 to 3, wherein the particles (a) are colloidal silica and the particles (b) are porous silica. The ultrafine wire photoresist according to any one of claims 1 to 4, wherein the resin composition layer contains 0.1 to 10% by mass of at least one of a silicon-based surfactant and a fluorine-based surfactant. Polyester film.