JP2002341546A - Biaxially oriented laminated polyester film for photoresist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biaxially oriented laminated polyester film useful as a supporting body layer of a photoresist which contributes to making thin-lines circuits. SOLUTION: In the biaxially oriented laminated polyester film for a photoresist, at least one outermost surface layer of the laminated film contains particles (I) having 0.8 to 2.5 μm average particle size by 0.01 to 0.1 wt.% and particles (II) having 0.05 to 0.2 μm average particle size by 0.1 to 0.8 wt.%. Moreover, the number A of coarse foreign matters having >=20 μm size in the film satisfies the condition of 0<=A<=10 (particles/m<2> ).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biaxially oriented laminated polyester film for a photoresist, and more particularly, to a biaxially oriented laminated polyester film for a photoresist excellent in improving resolution and reducing the defective rate.

[0002]

2. Description of the Related Art In recent years, photoresist films have been used for manufacturing printed wiring circuit boards and the like. A photoresist film is usually a laminated structure composed of a support layer, a photoresist layer, and a protective layer, and a biaxially oriented polyester film having excellent mechanical, chemical, and optical properties is used as the support layer. ing.

When using a photoresist film,
First, the protective layer is peeled off, the exposed photoresist layer is brought into close contact with the conductive base material attached to the substrate, and the glass plate on which the circuit is printed is brought into close contact with the support. Then
Light is irradiated from the glass plate side to expose and react the photosensitive resin of the photoresist layer, and then the unreacted portion of the photoresist layer is removed with a solvent or the like. Further, the conductive substrate exposed by removing the unreacted photoresist layer is removed by etching with an acid or the like. Even after this etching treatment, the photosensitive resin reacts and the portion of the conductive base material not removed by the solvent or the like remains as it is. Thereafter, if the remaining photoresist layer is removed by an appropriate means, a conductive base layer is formed as a circuit on the substrate.

The biaxially oriented polyester film used as the support layer is required to have a small amount of foreign matter. Therefore, for example, in Japanese Patent Laid-Open No. 10-46012,
It has been proposed to limit the number of coarse foreign substances having a size of 50 μm or more to reduce circuit defects. As the cause of such foreign matter, there may be mentioned agglomeration of a lubricant contained in the polyester film, external foreign matter mixed in at the time of charging the raw material, and a lump of thermally deteriorated polymer. We are trying to solve the foreign matter problem by properly selecting the lubricant type.

[0005] In recent years, electric and electronic devices have been reduced in size and thickness, and circuit patterns have become increasingly thin. However, in the conventional support layer, a trouble such as frequent occurrence of circuit defects occurs, which is becoming a problem.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a biaxially oriented polyester film which solves the problems of the prior art and contributes to thinning of circuits and is useful as a support layer of a photoresist. Make it an issue.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, foreign matters in the support layer which are smaller than the foreign matters which have been regarded as a problem in the past have been found to be defective. The present inventors have found that this is the cause, and that the absence of particles having an average particle size of 0.2 to 0.8 μm in the support layer leads to an improvement in resolution, and the present invention has been achieved.

That is, according to the present invention, at least one outermost layer of the laminated film contains 0.01 to 0.1% by weight of particles (I) having an average particle size of 0.8 to 2.5 μm and an average particle size of 0.05 to 0.05.
The number A of coarse foreign matters having a particle size (II) of 0.1 to 0.8 wt% and a size of 20 μm or more in the film is 0 ≦ A ≦ 10 (pieces / m ² ). It is a biaxially oriented laminated polyester film for a photoresist characterized by satisfying.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The polyester used for the biaxially oriented laminated polyester film of the present invention is a thermoplastic polyester containing an aromatic dicarboxylic acid as a main acid component and an aliphatic glycol as a main glycol component. Such polyesters are substantially linear and have film-forming properties, especially by melt-forming. Examples of the aromatic dicarboxylic acid include terephthalic acid, naphthalenedicarboxylic acid, isophthalic acid, diphenylethanedicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylsulfondicarboxylic acid, diphenylketonedicarboxylic acid, and anthracenedicarboxylic acid. Can be. Examples of the aliphatic glycol include those having 2 carbon atoms such as ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, and decamethylene glycol.
And aliphatic diols such as polymethylene glycol or 1,4-cyclohexanedimethanol.

In the present invention, polyesters containing alkylene terephthalate and / or alkylene naphthalate as a main component are preferably used as the polyester. Among such polyesters, terephthalic acid and / or 2,6-naphthalenedicarboxylic acid account for at least 80 mol% of all dicarboxylic acid components, including polyethylene terephthalate and polyethylene-2,6-naphthalate, and 80 mol% of all glycol components. % Or more is ethylene glycol. At that time, 20 mol% or less of the total acid component is terephthalic acid and / or
Or the above-mentioned aromatic dicarboxylic acids other than 2,6-naphthalenedicarboxylic acid; and aliphatic dicarboxylic acids such as adipic acid and sebacic acid; and alicyclic carboxylic acids such as cyclohexane-1,4-dicarboxylic acid. It can be an acid or the like. In addition, 2 of all glycol components
0 mol% or less can be the above-mentioned glycols other than ethylene glycol, and for example, aromatic diols such as hydroquinone, resorcinol and 2,2-bis (4-hydroxydiphenyl) propane; 1,4-dihydroxymethylbenzene Aliphatic diols having an aromatic ring as described above;
Polyethylene glycol, polypropylene glycol,
Polyalkylene glycol (polyoxyalkylene glycol) such as polytetramethylene glycol can also be used.

The polyester includes, for example, a component derived from an oxycarboxylic acid such as an aromatic oxyacid such as hydroxybenzoic acid; an aliphatic oxyacid such as ω-hydroxycaproic acid, and a dicarboxylic acid component and an oxycarboxylic acid component. Those which copolymerize or bond at 20 mol% or less based on the total amount are also included.

The polyester may further comprise a tricarboxylic or polyfunctional polycarboxylic acid or a polyhydroxy compound such as a trifunctional compound in an amount in a substantially linear range, for example, 2 mol% or less based on the total acid components. Copolymers of melitic acid, pentaerythritol and the like are also included.

The polyester is known per se and can be produced by a method known per se.
The polyester has an intrinsic viscosity of about 0.4 measured at 35 ° C. as a solution in o-chlorophenol.
~ 0.9 is preferred.

The biaxially oriented laminated polyester film in the present invention is obtained by stretching and heat-treating an unstretched laminated film obtained by a so-called coextrusion method in which all film layers are co-melt extruded from a die of an extruder. Preferred are mentioned. The biaxially oriented laminated polyester film is not limited to a laminated film having a two-layer structure, and may be a multilayer film having a three-layer or more layer structure.

In the biaxially oriented laminated polyester film of the present invention, the number A of coarse foreign substances having a size of 20 μm or more in the film is 0 ≦ A ≦ 10, preferably 0 ≦ A ≦ 5, more preferably 0 ≦ A ≦. 3 (pieces / m ² ). When the number of the coarse foreign substances is more than 10 / m ² , the optical path of the UV light is blocked when the photoresist layer is cured, which causes a defect in the wiring circuit. Furthermore, coarse foreign particles of 50 μm or more cause poor adhesion between the photoresist layer and the photomask and adversely affect the resolution.
It is preferably ² or less.

In order to reduce the number of the coarse foreign substances to 10 / m ² or less, an average aperture of 50 to 25 made of a stainless steel fine wire having a wire diameter of 15 μm or less is used as a filter at the time of film formation.
It is preferable to filter with a non-woven type filter having a thickness of μm, preferably 10 to 20 μm. The aperture of the filter used is 2
If it exceeds 5 μm, there is no effect of reducing coarse particles in the molten polymer, while if the opening is less than 5 μm, the pressure and pressure rise during filtration become large, and it is difficult to practically use the filter as a filter industrially. is there. If the wire diameter is 15
If it exceeds μm, coarse particles cannot be collected at an average aperture of 5 to 25 μm.

The biaxially oriented laminated polyester film of the present invention contains at least one outermost layer containing two types of particles, large and small. Assuming that the outermost layer containing these particles is layer A, the layer A is formed on at least one side of the laminated film, but may be formed on both sides of the film. When particles are contained in the outermost layers on both sides of the laminated film, the type and content of the particles may be the same or different. Therefore, the biaxially oriented laminated polyester film is an A / B type 2 using two kinds of polymers.
It may be a laminated film having a layer structure, a three-layer structure of A / B / A type, or a three-layer structure such as A / B / A ′ type using three kinds of polymers. Furthermore, a laminated film of four or more layers using two or more polymers, for example, A /
The B / C / B / A type, A / B / A / B / A type and the like are not limited as long as the characteristics of the present invention are satisfied. The polyester constituting the inner layer such as the layer B and the layer C is A
The polyester constituting the layer may be the same or different, but is preferably the same. The polyester constituting the inner layer may contain particles or may not contain particles. However, when particles are contained, the content of the particles in the layer A is preferably smaller than that of the layer A.

The thickness of the outermost layer (layer A) containing the above particles is usually 0.2 to 5 μm, preferably 0.5 to 3 μm, and further within this thickness range, and In consideration of the prevention of falling off of I), it is preferable to determine the particle size, the addition amount and the like. Further, as long as the effects of the present invention are not impaired, the surface of the A layer may be subjected to a corona discharge treatment, a surface modification treatment such as application of various coating agents, etc., for the purpose of improving adhesiveness, slipperiness and the like. Good.

The particles (I) and particles (II) contained in the outermost layer (layer A) of the biaxially oriented laminated polyester film in the present invention include, for example, silica, alumina, calcium carbonate, calcium phosphate, talc, zeolite, kaolin and the like. And organic particles made of a heat-resistant polymer such as crosslinked polystyrene, crosslinked acrylic resin, and crosslinked silicone. Among such particles, in order to obtain particularly high transparency and slipperiness, synthetic silica particles,
Crosslinked silicone particles and alumina particles are preferred. In addition,
Particles (I) and particles (II) may be of the same type or of different types.

The outermost layer (layer A) of the biaxially oriented laminated polyester film contains particles (I) and particles (II) having different average particle diameters. 0.8 to 2.5 μm, preferably 1.0 to 2.0 μm. The average particle size of the particles (II) is 0.05 to 0.1.
It is 2 μm, preferably 0.05 to 0.15 μm. This is because the presence of particles having an average particle size of 0.2 to 0.8 μm has the most adverse effect on the light transmittance at a wavelength of 365 nm during exposure. In order not to exist. From this viewpoint, it is conceivable to include only the large particles (I) exceeding 0.8 μm or to include the small particles (II) smaller than 0.2 μm.
It is necessary to contain particles having an average particle size of the species, which makes it possible to achieve both slipperiness and transparency in the film. For example, even if only the particles (I) are added, small projections for roughening the background are insufficient on the film surface, which causes fine scratches. Further, when only the particles (II) are added, the sliding of the film is not improved because the particle system is small.

When the average particle size of the particles (I) exceeds 2.5 μm, large projections are present on the film surface.
Problems such as insufficient adhesion to the photomask and reduction in resolution occur. In addition, since fine projections cannot be provided on the background of the film surface, it causes fine scratches and the like. On the other hand, the average particle size of the particles (I) is 0.8 μm
If it is less than this, the resolution is adversely affected as described above. If the average particle size of the particles (II) is less than 0.05 μm, fine projections cannot be provided on the film surface.
No improvement in slipperiness and abrasion resistance of the film is observed. On the other hand, when the average particle diameter of the particles (II) exceeds 0.2 μm, the slipperiness is improved, but as described above, the resolution is adversely affected.

The outermost layer (layer A) of the biaxially oriented laminated polyester film of the present invention contains particles (I) having an average particle size of 0.8 to 2.5 μm from the viewpoint of achieving both the slipperiness and transparency of the film. Is preferably contained at 0.01 to 0.1 wt%, more preferably 0.02 to 0.07 t%. Particles having an average particle size of 0.01 to 0.2 μm (I
Preferably contains 0.1 to 0.8 wt% of I),
More preferably, the content is 0.2 to 0.6 wt%.

The particle size distribution of the particles used in the present invention is preferably sharp. That is, as described above, the polyester film of the present invention is characterized in that particles having an average particle diameter in a specific range are not contained or are as small as possible. Although the particles having a broad particle size distribution cannot be known from the glance of the average particle size, particles having a particle size considerably deviating from the average particle size are actually contained, which is not preferable. The particle size distribution value (d ₂₅ / d ₇₅ ), which is an index representing the sharp difference in the particle size distribution, is preferably 2 or less, and more preferably 1.8.
The following is preferred. Examples of such particles having a sharp particle size distribution include spherical silica particles and spherical crosslinked silicone particles. Here, the particle size distribution value is defined below.

[0024]

## EQU1 ## Particle size distribution value = d ₂₅ / d ₇₅ (where d ₂₅ and d ₇₅ are the integrated volumes of the particle groups measured from the large particle side, and 25% and 75% of the total volume of each particle group).
(Μm). )

The particles are usually formed at any time during the reaction for forming the polyester, for example, at any time during the transesterification or polycondensation reaction in the case of transesterification, or at any time in the case of the direct polymerization method. , Added to the reaction system (preferably as a slurry in glycol). In particular, at the beginning of the polycondensation reaction, for example, an intrinsic viscosity of about 0.
It is preferred that the particles be added to the reaction system before reaching 3.

The biaxially oriented laminated polyester film of the present invention has 10 projections / 10 cm ^{2 on the} outermost layer surface.
Below, further 7 pieces / 10cm ² or less, especially 5 pieces / 10
cm ² or less. This makes it possible to increase the adhesion to the photomask and increase the resolution. The term “rough protrusion” as used herein means a protrusion having a height of 0.58 μm or more, which is determined by measurement described later.

The biaxially oriented laminated polyester film of the present invention has an air bleeding index S of 5 ≦ S ≦ 40 (mmHg / hr) in order to enable high-speed handling.
Furthermore, 10 ≦ S ≦ 38 (mmHg / hr), especially 15 ≦ S
It is preferable to satisfy ≦ 35 (mmHg / hr). S <
At 5 (mmHg / hr), the slip property is insufficient and the winding property at high speed is inferior. On the other hand, when S> 40 (mmHg / hr), the slip property is too good to cause roll defects such as end face deviation.

The biaxially oriented laminated polyester film of the present invention has a parallel light transmittance at a wavelength of 365 nm of 75 to 90%, more preferably 80 to 87%, particularly 82 to 85%.
%. Here, the parallel light transmittance is
It means the parallel component of the light beam transmitted through the film.
The higher the parallel light transmittance is, the smaller the diffused light component is. Therefore, a resist having a sharp shape can be formed by exposure, which contributes to thinning of a resist pattern. In that sense, ideally lubricants (particles) in the film
Is preferably 0, but a minimum amount of lubricant must be added to make the film slippery. The upper limit of the parallel light transmittance depends on the amount of the lubricant to be added.

The biaxially oriented laminated polyester film of the present invention has a haze of 3.0% or less, more preferably 2.5% or less.
The following is preferred.

The biaxially oriented laminated polyester film in the present invention is basically formed by melt-forming (co-extrusion film-forming) two or more kinds of polyesters, biaxially stretching and further heat-treating. However, the method and conditions of each of these steps can be adopted from known methods and conditions. In more detail, first, the polyester is melted and co-extruded into a sheet from a slit-shaped die,
It is cooled and solidified by a casting drum to form an unstretched laminated sheet.
0 ° C., stretching in the longitudinal and transverse directions at a stretching ratio of 3 to 5 times,
Thereafter, it is preferable to perform heat treatment at 200 to 250 ° C.

The biaxially oriented laminated polyester film thus obtained has excellent adhesion to the photoresist layer, transparency, and slipperiness, and can be suitably used as a photoresist film.

The biaxially oriented laminated polyester film of the present invention can be used as a support layer of a photoresist film, and a photoresist film and a protective layer can be laminated thereon by a conventional method to form a photoresist film. By using this photoresist film, it is possible to efficiently form a thin circuit pattern corresponding to the miniaturization and thinning of electric and electronic devices.

[0033]

EXAMPLES The present invention will be further described below with reference to examples. In addition, each characteristic in an Example was calculated | required by the following method.

1. Number of coarse foreign substances The size and number of foreign substances in the film should be enlarged 20 times with transmitted light using a universal projector, and foreign substances having a maximum length of 20 μm or more should be counted as coarse foreign substances and counted. Ask for. The measurement area is 1 m ² .

2. Number of Coarse Protrusions Two 10 cm × 10 cm films are superimposed, and a sodium D line (wavelength: 0.58 nm) is applied from below. The protrusion height is determined based on the number of observed interference rings. The interference ring has a protrusion height of 0.29 μm per ring.
Is calculated, and the number of projections having two or more interference rings per unit area is calculated, and is set as the number of coarse projections.

3. Haze Based on JIS K-7105, the haze value of the film is measured using an integrating sphere type haze measuring device manufactured by Nippon Precision Engineering Co., Ltd.

4. Air bleeding index: 20 pieces of film cut to 8 cm x 5 cm are stacked, and in the lower 19 pieces, an equilateral triangular hole having a side of 2 mm is made in the center, and a digital Beck smoothness tester (manufactured by Toyo Seiki) is used. An air release index (mmHg / hr) per unit time is measured.

5. Parallel light transmittance integrating sphere spectrophotometer (Shimadzu MPC-3100)
Is used to measure the light transmittance of one film at a wavelength of 365 nm. At this time, the sample film is placed at a distance of 30 cm from the entrance of the integrating sphere, and the transmittance of parallel rays is obtained by preventing the diffused light component from entering the integrating sphere.

6. Average particle size of the particles The powder is scattered so that the individual particles do not overlap as much as possible, a metal deposition film is formed on this surface with a thickness of 200 to 300 angstroms by a gold sputter device, and a 10,000 to 30,000 times magnification with a scanning electron microscope. And image processing is performed using Luzex 500 manufactured by Nippon Regulator Co., Ltd., and the average particle size is determined from 100 particles.

7. Characteristics of photoresist film Printed circuit (L / S) using photoresist film
= 20/20 μm) to evaluate the resolution and circuit defects. That is, the photoresist layer of the photoresist film from which the protective layer was peeled off was adhered to the copper plate provided on the glass fiber-containing epoxy resin plate, and the glass plate on which the circuit was printed was further adhered thereon, and from the glass plate side. After exposure to ultraviolet light, the photoresist film is peeled off, washed and etched to form a circuit, and the resolution and circuit defects are visually observed and observed with a microscope, and evaluated according to the following criteria. (A) Resolution ：: High resolution and a clear circuit were obtained Δ: Slightly poor clarity and phenomena such as thickening of lines were observed ×: Poor clarity and a circuit that could be put to practical use was obtained I couldn't. (B) Circuit defects ：: No circuit defects were recognized Δ: Some circuit defects were recognized ×: Circuit defects occurred frequently and could not be put to practical use.

8. Winding property (sliding property) Through a winding step including a slit at the time of film formation and a step of preparing the above photoresist film, the winding property (sliding property) is evaluated in the following three stages. ：: There was no wrinkle in the film, and there was no problem. Δ: Wrinkles were occasionally formed in the film.

Examples 1 to 9 To dimethyl terephthalate and ethylene glycol were added manganese acetate as a transesterification catalyst, antimony trioxide as a polymerization catalyst, phosphorous acid as a stabilizer, and a lubricant of the type and amount shown in Table 1. After that, transesterification and polycondensation reaction were carried out by a conventional method to produce polyethylene terephthalate (PET) pellets A for surface layer having an intrinsic viscosity of 0.65.

In addition, pellets of polyethylene terephthalate containing no lubricant were produced in the same manner as described above except that the lubricant shown in Table 1 was not added. The polyethylene terephthalate (PET) pellets A for the core layer were prepared by mixing the polyethylene terephthalate pellets and the polyethylene terephthalate (PET) pellets for the surface layer A to make the lubricant concentration 1/4 of the PET for the surface layer. PET for this core layer
Is determined in consideration of using recycled pellets of film waste during production on an industrial scale.

Next, the obtained PET pellets A and B were each dried at 170 ° C. for 3 hours, and then supplied to the hoppers of two extruders, melted at a melting temperature of 290 ° C., and formed into a fine stainless steel wire having a wire diameter of 12 μm. Average aperture 20 μm
Was filtered with a nonwoven fabric type filter, combined with a multi-manifold die, and cast on a rotating drum to obtain an unstretched laminated film. The unstretched laminated film thus obtained was stretched under the conditions shown in Table 1. The thickness and the layer configuration of each film layer were adjusted by the rotation speed ratio of two extruders.

Using the biaxially oriented laminated polyester film thus obtained, a photoresist layer and a protective layer were laminated to form a printed circuit, and its characteristics were evaluated. The results are as shown in Table 1.

As is clear from Table 1, the biaxially oriented laminated polyester films obtained in Examples 1 to 9 have transparency,
Good slipperiness and photoresist film properties,
Excellent handleability. In addition, each of the films had a small number of coarse foreign substances and did not contain particles having an average particle diameter of 0.2 to 0.8 μm, so that a polyester film for photoresist having few circuit defects and good resolution was obtained.

[Comparative Example 1] The filter opening was 20 μm
A biaxially oriented laminated polyester film was produced in the same manner as in Example 1 except that the film thickness was changed from 30 μm to 30 μm, and the characteristics as a photoresist film were evaluated. Table 1 shows the results. In this film, foreign matters having a size of 20 μm or more increased, and defects occurred during circuit formation.

Comparative Example 2 The average particle size and the amount of the lubricant were changed as shown in Table 1, and the filter opening was set to 20 μm.
A biaxially oriented laminated polyester film was produced in the same manner as in Example 1 except that m was changed to 30 μm, and properties as a photoresist film were evaluated.
Table 1 shows the results. This film is 20 μm in size
The above foreign substances increased and defects occurred during circuit formation.

Comparative Example 3 Particles which are Large Particles as Lubricant
A biaxially oriented laminated polyester film was produced in the same manner as in Example 1 except that only (I) was used and the amount was changed to the level shown in Table 1, and properties as a photoresist film were evaluated. . Table 1 shows the results.
This film had many fine scratches on the surface, resulting in a decrease in resolution.

Comparative Example 4 Particles as Small Particles as Lubricants
A biaxially oriented laminated polyester film was produced in the same manner as in Example 1 except that only (II) was used and the amount was changed to the level shown in Table 1, and properties as a photoresist film were evaluated. . Table 1 shows the results.
This film was at a level where the handleability was unsatisfactory even when the addition amount of the particles (II) was increased.

Comparative Examples 5 and 6 A biaxially oriented laminated polyester film was produced in the same manner as in Example 1 except that the average particle size and the amount of the lubricant were changed as shown in Table 1, and a photoresist was further prepared. The properties as a film for use were evaluated. Table 1 shows the results. When the average particle diameter of the particles (I) was reduced or the average particle diameter of the particles (II) was increased to include particles having an average particle diameter of 0.2 to 0.8 μm, the resolution was reduced. .

Comparative Example 7 A biaxially oriented laminated polyester film was produced in the same manner as in Example 1 except that the average particle size and the amount of the lubricant were changed as shown in Table 1, and a photoresist film was further produced. Was evaluated. Table 1 shows the results. When the particle size of the particles (I) was increased, the adhesion to the photomask was deteriorated and the resolution was lowered.

Comparative Example 8 A biaxially oriented laminated polyester film was produced in the same manner as in Example 1 except that the average particle size and the amount of the lubricant were changed as shown in Table 1, and a photoresist film was further produced. Was evaluated. Table 1 shows the results. When the particle size of the particles (II) was reduced, the slipperiness of the film deteriorated. In addition, the surface was finely scratched and the resolution was reduced.

Comparative Examples 9 and 10 A biaxially oriented laminated polyester film was produced in the same manner as in Example 1 except that the average particle size and the amount of the lubricant were changed as shown in Table 1.
Further, the properties as a photoresist film were evaluated. Table 1 shows the results. If the added amount of the particles (I) or (II) is too large, the transparency of the film is impaired and the resolution is lowered.

[Comparative Examples 11 and 12] A biaxially oriented laminated polyester film was produced in the same manner as in Example 1 except that the average particle size and the amount of the lubricant were changed as shown in Table 1, and a photoresist was further prepared. The properties as a film for use were evaluated. Table 1 shows the results. When the added amount of the particles (I) or (II) is small, the handleability is significantly deteriorated.

[0056]

[Table 1]

[0057]

According to the present invention, it is possible to provide a biaxially oriented polyester film which is excellent in improving resolution and reducing the rejection rate and which contributes to circuit thinning, and which is useful as a photoresist support layer. it can.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kei Mizutani 3-37-19 Koyama, Sagamihara City, Kanagawa Prefecture Teijin Dupont Film Co., Ltd. Sagamihara Research Center F-term (reference) 2H025 AA02 AA18 AB15 DA19 DA21 4F100 AK41A AK41B AK41C AK41D AK41E BA02 BA03 BA04 BA05 BA06 BA07 BA10A BA10C BA10D BA10E BA13 DE01A EH20 EH202 EJ38 EJ382 GB43 YY00A 5E339 CC01 CD01 CE16 DD04

Claims (4)

[Claims] 1. The method according to claim 1, wherein at least one outermost layer of the laminated film contains particles (I) having an average particle size of 0.8 to 2.5 μm in an amount of 0.01%.
The number A of coarse foreign substances having a particle size of 0.1 to 0.8 wt% and a particle size of 20 μm or more in the film is 0.1 to 0.8 wt% and an average particle diameter of 0.05 to 0.2 μm. 0 ≦ A
A biaxially oriented laminated polyester film for a photoresist, which satisfies ≦ 10 (pieces / m ² ). 2. The biaxially oriented laminate for a photoresist according to claim 1, wherein the number N of the coarse projections having a height of 0.58 μm or more on the outermost layer surface satisfies 0 ≦ N ≦ 5 (pieces / 10 cm ² ). Polyester film. 3. The air bleeding index S is 5 ≦ S ≦ 40 (mm
The biaxially oriented laminated polyester film for a photoresist according to claim 1 or 2, which satisfies Hg / hr). 4. The parallel light transmittance T at 365 nm is 75 ≦
The biaxially oriented laminated polyester film for a photoresist according to any one of claims 1 to 3, which satisfies T ≦ 90 (%).