TW201710803A - Photosensitive element, laminated body, method for forming resist pattern, and method for producing printed circuit board - Google Patents

Abstract

The purpose of the invention is to provide a photosensitive element in which a resist pattern having only a small number of micro-defects can be formed. Provided is a photosensitive element provided with a support film, an intermediate layer, and a photosensitive layer in the stated order, wherein the thickness of the support film is 20 [mu]m or greater, and the number of grains in the support film having a diameter of 5 [mu]m or greater is 30 grains/mm2 or less.

Description

Photosensitive element, laminated body, method of forming resist pattern, and method of manufacturing printed wiring board

The present disclosure relates to a photosensitive element, a laminate, a method of forming a resist pattern, and a method of producing a printed wiring board.

In the field of the production of printed wiring boards, a photosensitive resin composition is widely used as a resist material used in an etching treatment or a plating treatment, and a photosensitive resin composition is used on the support film. A photosensitive element of a formed layer (hereinafter also referred to as "photosensitive layer").

The printed wiring board is manufactured using the photosensitive element, for example, by the following procedure. That is, first, the photosensitive layer of the photosensitive element is laminated on a circuit formation substrate such as a copper clad laminate. At this time, lamination is performed so that the surface of the photosensitive layer opposite to the surface contacting the support film is in close contact with the surface of the circuit formation substrate on which the circuit is formed. Further, lamination is performed, for example, by heating and pressing a photosensitive layer on a circuit-forming substrate (atmospheric pressure lamination method).

Next, a mask film or the like is used to expose a desired region of the photosensitive layer via the support film, thereby generating radicals. The generated radicals pass through several reaction paths to contribute to the crosslinking reaction (photohardening reaction) of the photopolymerizable compound. Then, after the support film is peeled off, the uncured portion of the photosensitive layer is dissolved or dispersed by the developer to form a resist pattern. Then, the resist pattern is used as a resist, and an etching process or a plating process is performed to form a conductor pattern, and finally the photocured portion (resist pattern) of the photosensitive layer is peeled off (removed).

However, in the exposure method in which the support film is interposed, minute peeling may occur in the formed resist pattern.

Therefore, in recent years, a manufacturing method in which the photosensitive layer is exposed after peeling off the support film before exposure, thereby reducing minute peeling of the resist pattern, has been studied. However, when the photosensitive layer is exposed after peeling off the support film, oxygen in the air comes into contact with the generated radicals, whereby the radical is rapidly stabilized (deactivated), and photohardening reaction of the photopolymerizable compound is difficult get on. Therefore, in the production method, in order to reduce the influence of oxygen incorporation during exposure after peeling off the support film, a photosensitive element having an intermediate layer having gas barrier properties between the support film and the photosensitive layer has been studied ( For example, refer to Patent Document 1 to Patent Document 3). Prior art literature [Patent Literature]

Patent Document 1: Japanese Patent No. 5,383, 734 Patent Document 2: Japanese Patent Laid-Open No. Hei. No. Hei.

[Problems to be Solved by the Invention] In recent years, with the spread of high-fine-line package substrates, further miniaturization of conductor patterns is progressing. There is a continuing need for a photosensitive element for forming such a fine conductor pattern that a resist pattern having a small amount of detachment can be formed.

In the photosensitive element including the gas barrier intermediate layer between the support film and the photosensitive layer described in Patent Literatures 1 to 3, even if the support film is peeled off and the photosensitive layer is exposed, It is not always sufficient to satisfy the requirement of forming a resist pattern having a small amount of detachment. In particular, when an exposure machine (hereinafter also referred to as a "high-resolution exposure machine") capable of forming a high-resolution resist pattern is used, minute peeling occurring in the resist pattern is further regarded as a problem.

The present invention has been made in view of the problems of the prior art, and an object of the invention is to provide a photosensitive element, a laminated body, a method for forming a resist pattern, and a printed wiring which can form a resist pattern having a small amount of detachment. The manufacturing method of the board. [Means for solving the problem]

In order to achieve the object, the present disclosure provides a photosensitive element comprising, in order, a support film, an intermediate layer, and a photosensitive layer, the support film having a thickness of 20 μm or more, and the support film having a diameter of 5 μm The number of the above particles is 30/mm ² or less. According to the photosensitive element, a resist pattern having a small amount of detachment can be formed.

The inventors of the present invention consider that one of the reasons for the formation of an excellent resist pattern having a small amount of detachment by the photosensitive element of the present invention is the shape of a particle derived from a lubricant or the like contained in the support film. The track is difficult to transfer to the intermediate layer. That is, from the viewpoint of productivity, the support film sometimes contains a lubricant for attaching slidability to the surface of the support film. The lubricant may be contained on one or both sides of the support film by coating or blowing, and may be contained in one or both sides (including the inside) of the support film by kneading. Further, in the support film, particles other than the lubricant may be contained in the production process of the support film or the like. The presence or absence of particles such as a lubricant may cause the shape trajectory of the particles to be transferred to another layer (for example, an intermediate layer or the like) that is in contact with the particles. It is known that when the shape trajectory of the particles is transferred to the intermediate layer, even when the support film is peeled off and exposed, the exposure light is scattered due to the unevenness (the shape trajectory of the particles) on the surface of the intermediate layer. This causes the occurrence of minute detachment in the resist pattern. In particular, it is known that when exposure is performed under severe conditions of low energy (becoming low-hardening) using a high-resolution exposure machine (for example, a projection exposure machine), generation of minute peeling in the resist pattern remarkably occurs.

It is known that when an intermediate layer is formed on a support film having large particles in a surface contacting the intermediate layer, this phenomenon is likely to occur (that is, transfer of a shape trajectory of particles such as a lubricant to the intermediate layer). Further, it is also surprisingly known that when large particles are present on the surface of the support film opposite to the surface contacting the intermediate layer, in the laminating step of the photosensitive member, sometimes due to the roll The shape trajectory of the large particles existing in the surface of the support film opposite to the surface contacting the intermediate layer is transferred into the intermediate layer by pressure.

As a result of intensive studies, the inventors of the present invention found that the number of particles having a diameter of 5 μm or more in particles such as a lubricant contained in the support film is 30/mm ² or less, and the support film is used. When the thickness is 20 μm or more, the transfer of the shape trajectory from the particles such as the lubricant to the intermediate layer can be suppressed even after the intermediate layer forming step on the support film and the laminating step of the photosensitive member. Therefore, according to the photosensitive element of the present disclosure, minute detachment of the resist pattern can be made extremely small. In particular, by using a support film having a specific thickness, when large particles are present on the surface of the support film opposite to the surface contacting the intermediate layer, the influence of the particles can be suppressed, and minute peeling is formed. Excellent resist pattern. Further, even when a high-resolution exposure machine is used, minute peeling of the resist pattern can be sufficiently reduced.

Further, in the photosensitive element, the number of particles having a diameter of 5 μm or more in the surface of the support film contacting the intermediate layer may be 10 pieces/mm ² or less. According to the photosensitive element, a resist pattern having a small amount of detachment can be formed.

Further, in the photosensitive element, the intermediate layer may contain polyvinyl alcohol. According to the photosensitive element, deactivation of radicals generated by actinic rays used in exposure can be further suppressed, and the resolution of the formed resist pattern can be improved.

Further, in the photosensitive element, the support film may be a polyester film. According to the photosensitive element, the mechanical strength and heat resistance of the support film can be improved, and defects such as wrinkles of the intermediate layer which are generated when the intermediate layer is formed on the support film can be suppressed, and workability can be improved.

In addition, the present disclosure provides a method of forming a resist pattern, comprising: disposing the photosensitive layer and the intermediate layer and the support film on the substrate in this order using the photosensitive element of the present disclosure a step of removing the support film, exposing the photosensitive layer through the intermediate layer by actinic rays; and removing the uncured portion of the photosensitive layer and the intermediate layer from the substrate step. In the method of forming the resist pattern, since the resist pattern is formed by using the photosensitive element of the present invention, a resist pattern having little fine peeling can be formed.

Further, the exposure can be carried out using a high-resolution exposure machine having a lens having a numerical aperture of 0.05 or more. According to the method for forming a resist pattern, since the resist pattern is formed using the photosensitive element of the present invention, it is possible to form a resist pattern having a small amount of peeling off with high resolution.

In addition, the present disclosure provides a laminate including a substrate, a photosensitive layer, and an intermediate layer in this order, and a recess having a diameter of 3 μm or more in a surface of the intermediate layer opposite to the side of the photosensitive layer The number is 30/mm ² or less. The inventors of the present invention have found that when a laminate is produced using a photosensitive member having a support film containing particles having a diameter of 5 μm or more, a shape trajectory derived from particles having a diameter of 5 μm or more is transferred to the manufactured In the intermediate layer of the laminate, a recess having a diameter of 3 μm or more is formed. In other words, the number of the particles having a diameter of 5 μm or more contained in the support film is 30/mm ² or less, and the number of the recesses having a diameter of 3 μm or more in the surface opposite to the side of the photosensitive layer on the intermediate layer is 30 / mm ² or less is related. In addition, a laminate having a small number of recesses having a diameter of 3 μm or more and an intermediate layer of 30 pieces/mm ² or less can form a resist pattern having a small amount of detachment.

In addition, the present disclosure provides a method of forming a resist pattern, comprising: a step of exposing the photosensitive layer through the intermediate layer in the laminate of the present disclosure by using actinic rays; The step of removing the uncured portion of the photosensitive layer and the intermediate layer on the substrate. In the method of forming the resist pattern, since the resist pattern is formed by using the laminated body of the present invention, it is possible to form a resist pattern having a small amount of detachment.

Further, the present disclosure provides a method of manufacturing a printed wiring board, comprising: performing an etching treatment or a plating treatment on a substrate on which a resist pattern is formed by the method for forming a resist pattern according to the present disclosure; The step of the conductor pattern. In the method for producing a printed wiring board, the resist pattern is formed by the method for forming a resist pattern according to the present invention, so that a resist pattern having a small amount of peeling off can be formed, and a printed wiring board can be provided. A method of manufacturing a printed wiring board having a high density. [Effects of the Invention]

According to the present disclosure, it is possible to provide a photosensitive element, a laminate, a method of forming a resist pattern, and a method of producing a printed wiring board, which are capable of forming a resist pattern having a small amount of detachment.

Hereinafter, a preferred embodiment of the present disclosure will be described in detail with reference to the drawings as needed. In the following embodiments, of course, the constituent elements (including the element steps and the like) are not necessarily required except for the case where it is specifically indicated and the case where it is considered to be clearly required in principle. The same is true for numerical values and ranges thereof, and should be construed as not unduly limiting the present disclosure.

In the present specification, the term "(meth)acrylic acid" means at least one of acrylic acid and methacrylic acid corresponding thereto. In addition, other similar expressions such as (meth) acrylate are also the same.

In addition, in the present specification, the term "step" means not only an independent step, but even if it cannot be clearly distinguished from other steps, it is included in the term as long as the intended effect of the step is achieved. .

Further, in the present specification, the numerical range indicated by "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. Further, in the numerical range recited in the specification, the upper limit or the lower limit of the numerical range of one stage may be replaced with the upper limit or the lower limit of the numerical range of the other stage. In addition, within the numerical ranges described in the specification, the upper or lower limit of the numerical range may be replaced with the value shown in the embodiment. In addition, in the present specification, the term "layer" includes a partially formed shape structure in addition to the shape structure formed over the entire surface when viewed as a plan view.

[Photosensitive Element] As shown in FIG. 1, the photosensitive element 1 of the present embodiment includes the support film 2, the intermediate layer 3, and the photosensitive layer 4 in this order, and may further include another layer such as the protective layer 5. Hereinafter, each layer in the photosensitive element of the present embodiment will be described in detail.

<Support film> In the photosensitive element of the present embodiment, the thickness of the support film is 20 μm or more, and the number of particles having a diameter of 5 μm or more contained in the support film is 30/mm ² or less. When the thickness of the support film and the number of particles contained in the support film are within the above range, the transfer of the shape track of the particles such as the lubricant present in the support film toward the intermediate layer can be suppressed, and the exposure can be suppressed. The scattering of actinic rays used (for example, diffuse reflection) allows excellent pattern formability to be obtained, and a resist pattern having little fine peeling can be formed. On the other hand, in the case of the conventional photosensitive element, even when the support film is peeled off before the exposure step from the viewpoint of improving the resolution, the transfer of the shape trajectory of the particles such as a lubricant into the intermediate layer is performed. Light scattering is also generated in the exposure step, and minute peeling is likely to occur in the developed resist pattern. Further, when a high-resolution exposure machine is used, the influence by the light scattering is further increased, and minute peeling is more likely to occur in the resist pattern after development. When such a photosensitive element is used for the production of a printed wiring board, there is a cause of an open failure at the time of etching and a short-circuit defect at the time of plating, and the manufacturing yield of the printed wiring board is lowered.

The thickness of the support film is 20 μm or more, but may be 25 μm or more or 45 μm or more. By setting the thickness of the support film to 20 μm or more, the transfer of the particle shape trajectory of the self-supporting film toward the intermediate layer can be suppressed during lamination of the photosensitive element, so that when the photosensitive layer is exposed through the intermediate layer, The scattering of the exposure light can be suppressed, and a resist pattern with little small peeling can be formed. In particular, when the surface of the support film opposite to the surface contacting the intermediate layer contains particles having a diameter of 5 μm or more, and when the photosensitive element is laminated on the substrate to produce a laminate, the support film is removed. In the case where the foreign matter adheres to the surface of the support film opposite to the surface contacting the intermediate layer due to the influence of static electricity or the like, the thickness of the support film can be made larger than 20 μm. The particle shape trajectory from the particles and the foreign matter adhering due to the influence of static electricity or the like is suppressed from being transferred to the intermediate layer, and as a result, minute detachment in the resist pattern can be remarkably suppressed. Further, the thickness of the support film may be 200 μm or less or 100 μm or less. By setting the thickness of the support film to 200 μm or less, there is a tendency that economic benefits are easily obtained. In addition, the "thickness of the support film" means the length of the support film in the direction orthogonal to the surface direction, and the "particle shape trajectory" means "the shape trajectory derived from particles such as a lubricant".

The number of particles having a diameter of 5 μm or more contained in the support film is 30/mm ² or less, but the diameter is 5 μm from the viewpoint of further preventing scattering of the exposure light caused by the transfer of the particle shape trajectory. The number of the above particles may be 25 pieces/mm ² or less, 20 pieces/mm ² or less, 10 pieces/mm ² or less, 5 pieces/mm ² or less, or 1 piece/mm ² or less. When the number of particles having a diameter of 5 μm or more is 30/mm ² or less, it is difficult to cause minute peeling in the resist pattern formed by using the photosensitive element of the present embodiment, and minute peeling can be formed. Less resist pattern. In addition, when such a photosensitive element is used for the production of a printed wiring board, it is possible to suppress occurrence of an open failure at the time of etching and a short-circuit defect at the time of plating, and it is possible to suppress a decrease in the manufacturing yield of the printed wiring board. Further, the lower limit of the number of particles having a diameter of 5 μm or more contained in the support film is 0/mm ² .

Here, the particles having a diameter of 5 μm or more contained in the support film have a diameter of 5 μm or more when observed with a polarizing microscope (however, when the shape of the observed particles is not circular) It refers to particles of the diameter of the circumcircle of its shape, and refers to particles present in the surface of the support film. In addition, the particles are not particularly limited as long as they impart unevenness to the layer in contact with the support film, and include, for example, a lubricant contained in order to impart slidability to the surface of the support film, and intentionally attached to the support film. Organic particles or inorganic particles (hereinafter also referred to as "blowed particles"), foreign matter, aggregates (for example, agglomerates of lubricants, aggregates of blown particles, or gels of polymers, as raw materials) The monomer, the catalyst used in the production of the support film, the inorganic fine particles or organic fine particles contained as needed, and the aggregate formed by the aggregation of the organic fine particles, and the lubricant layer (layer containing the lubricant) are applied to the support. A bulge caused by a lubricant, an adhesive, or the like which is generated on the film. The shape of the particles is not particularly limited, and may be a regular shape such as a spherical shape or an irregular shape. Further, the material of the particles is not particularly limited, and may be an organic substance or an inorganic substance such as a metal. In addition, when the particles having a diameter of 5 μm or more are 30/mm ² or less, particles having a small particle diameter or particles having excellent dispersibility may be used as the particles.

Further, the number of particles having a diameter of 5 μm or more can be measured using a polarizing microscope. More specifically, the both sides of the support film are observed by a polarizing microscope, and the number of particles having a diameter of 5 μm or more present on both surfaces of the support film is accumulated, and the obtained amount is set as the diameter contained in the support film. The number of particles of 5 μm or more. Further, when the support film is transparent (that is, the haze value is 5% or less), the focus is aligned on the surface, and one surface and the other surface of the support film are separately observed, and particles having a diameter of 5 μm or more are measured. Quantity. The measurement area was set to a size of 1 mm square, and at least 10 sites were measured, and the average value thereof was defined as the number of particles having a diameter of 5 μm or more contained in the support film. Further, the aggregate formed by the primary particles having a diameter of 5 μm or more and the primary particles having a diameter of less than 5 μm may be counted as one. In the present specification, the term "agglomeration" refers to a state in which particles (for example, primary particles) are in contact with each other or close to 1 μm or less to form an aggregate larger than each particle.

Further, the number of particles having a diameter of 2 μm or more and less than 5 μm contained in the support film may be 1000 pieces/mm ² or less, 500 pieces/mm ² or less, or 10 pieces/mm ² or less. Further, the lower limit of the number of the particles is 0 / mm ² . The number of particles having a diameter of 2 μm or more and less than 5 μm is related to the number of particles having a diameter of 5 μm or more. If the number of particles having a diameter of 5 μm or more is small, the diameter is 2 μm or more and less than 5 μm. The number of particles is also reduced.

Further, the number of particles having a diameter of less than 2 μm contained in the support film is not particularly limited. That is, it is convenient for the support film to contain a plurality of particles having a diameter of less than 2 μm, and the effect on light scattering is not large. As a factor, in the exposure step, when the photosensitive layer is irradiated with light, the photohardening reaction of the photosensitive layer is performed not only in the light irradiation portion but also in the lateral direction in which the light is not directly irradiated (relative to the light irradiation direction). The vertical direction is slightly performed. Therefore, when the particle diameter is as small as less than 2 μm, even in the case where the photohardening reaction is carried out in the lateral direction, it is difficult to transfer the particle shape trajectory generated by the portion where the hardening is insufficient to the intermediate layer, and It is difficult to cause minute peeling in the formed resist pattern. On the other hand, it is known that when the particle diameter is as large as 5 μm or more, in the case where the photohardening reaction is carried out in the lateral direction, the particle shape trajectory generated by the portion where the hardening is insufficient is easily transferred to the intermediate layer, This causes a slight drop in the formed resist pattern. In particular, it is known that a high-resolution exposure machine having a numerical value NA (numerical aperture) of 0.05 or more, for example, a projection exposure machine using an energy-attenuated actinic ray, is not directly irradiated with light. The photohardening in the region is difficult to proceed, so that minute peeling in the formed resist pattern is more likely to occur.

The support film may have particles such as a lubricant on a surface of the support film opposite to the surface contacting the intermediate layer, or may have particles such as a lubricant on the surface of the support film contacting the intermediate layer. Further, from the viewpoint of further preventing scattering of the exposure light caused by the transfer of the particle-shaped trajectory, the number of particles having a diameter of 5 μm or more in the surface of the support film contacting the intermediate layer may be 10 pieces/ Mm ² or less, 5 pieces/mm ² or less, or 1 piece/mm ² or less. Further, the lower limit of the number of the particles is 0 / mm ² . With such a range, there is a tendency that a small resist pattern having less detachment tends to be formed. When a lubricant is added to the support film, a lubricant layer can be formed on the support film by a known method such as roll coating, flow coating, spray coating, curtain flow coating, dip coating, or slit die coating. In order to exhibit the function of the lubricant, a lubricant having a lubricant or a lubricant layer may contain 1000/mm ² or more of a lubricant having a diameter of less than 1 μm.

A layer (region) having no particles may also be present in the support film. In the support film, the thickness of the layer having no particles may be 17 μm or more, 19 μm or more, or 21 μm or more. When the thickness of the layer having no particles is 17 μm or more, there is a tendency that the minute peeling generated in the resist pattern can be further suppressed. In particular, even when foreign matter adheres to the surface of the support film opposite to the surface contacting the intermediate layer due to the influence of static electricity or the like, there is a tendency that the slight drop occurring in the resist pattern can be further suppressed. . In addition, the "thickness of the layer having no particles" means the length of the region where the particles are not present in the direction (thickness direction) orthogonal to the plane direction of the support film, and more specifically, the thickness direction The maximum value of the distance between the planes perpendicular to the thickness direction (straight line in cross section) where the two closest particles are opposite to each other. Further, when the layer having the particles exists only on one side of the support film, the "thickness of the layer having no particles" means the surface of the support film opposite to the side where the layer having the particles exists, and is closest to the layer The distance between the surface of the surface of the particle that is perpendicular to the thickness direction (the straight line in the cross-sectional view) that is in contact with the opposite side of the surface. The thickness of the layer having no particles can be measured by observing the cross section of the support film by a scanning electron microscope (SEM). Further, in the case of observation by SEM, processing by a focused ion beam processing observation apparatus (Focused Ion Beam (FIB)) can also be performed. Further, the average surface depth of the particles having a diameter of 5 μm or more contained in the support film may be 2 μm or less, 1 μm or less, or 0.5 μm or less. Here, the average surface depth of the particles having a diameter of 5 μm or more refers to the average value of the depth at which the particles having a diameter of 5 μm or more are embedded in the support film when the cross section of the support film is observed by a scanning electron microscope. .

In the photosensitive element of one embodiment of the present embodiment, the thickness of the support film may be 20 μm or more, and the surface roughness Rz of the surface of the support film contacting the intermediate layer may be 500 nm or less. When the thickness of the support film and the surface roughness of the surface of the support film contacting the intermediate layer are within the above range, excellent pattern formability can be obtained, and a resist pattern having little small peeling can be formed. Further, from the viewpoint of further suppressing generation of minute detachment of the resist pattern, the surface roughness Rz may be 300 nm or less, 100 nm or less, or 80 nm or less. The surface roughness Rz may be 1 nm or more, 5 nm or more, 15 nm or more, or 25 nm or more from the viewpoint of the adhesion between the support film and the intermediate layer. In the present specification, the surface roughness Rz refers to a value measured by a commercially available surface roughness shape measuring machine in accordance with the method specified in JIS B0601. For example, it can be measured under the conditions of a measurement width of 4000 μm and a speed of 0.6 mm/s using HANDYSURF E-35A (manufactured by Tokyo Seimitsu Co., Ltd.).

In the present embodiment, since the support film is removed before the exposure, the support film having high transparency may not be used, but the haze value of the support film may be 0.01% to 5.0%, 0.01% to 2.0%, or 0.01% to 1.5%. , 0.01% to 1.0%, or 0.01% to 0.5%. When the haze value is 0.01% or more, the support film itself tends to be easily produced, and when it is 5.0% or less, it tends to be easily obtained. Here, the "haze value" means haze. The haze value in the present disclosure means a value measured using a commercially available haze meter (turbidity meter) according to the method specified in JIS K 7105. The haze value can be measured, for example, by a commercially available turbidity meter such as NDH-5000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

The material of the support film can be used without particular limitation. For example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene-2,6-naphthalate (Polyethylene-2, Polyesters such as 6-Naphthalate, PEN), and polyolefins such as polypropylene and polyethylene. By using a polyester film as a support film, there is a tendency to improve the mechanical strength and heat resistance of the support film. In addition, by using a polyester film, it is possible to suppress defects such as wrinkles of the intermediate layer which are generated when the intermediate layer is formed on the support film, and the workability tends to be improved. Furthermore, the support film may be a single layer or a plurality of layers.

Further, the support film can be obtained from a commercially available general industrial film as a support film which can be used as a support film for a photosensitive element. Specifically, for example, "QS series" (manufactured by Toray Co., Ltd.), "A4100" (manufactured by Toyobo Co., Ltd.), and "KFX" (Dynasty DuPont film) are used as a PET film. Teijin DuPont Films), etc.).

<Intermediate Layer> The photosensitive element of the present embodiment has an intermediate layer between the support film and the photosensitive layer. Thereby, even if the support film is peeled off and exposed, the deterioration of the resolution of the formed resist pattern can be suppressed. Further, from the viewpoint of further improving the gas barrier properties, the adhesion of the support film to the intermediate layer may be smaller than the adhesion of the intermediate layer to the photosensitive layer. That is, it can be said that when the support film is peeled off from the photosensitive element, unintentional peeling of the intermediate layer and the photosensitive layer is suppressed. In addition, the intermediate layer may also be referred to as an oxygen barrier layer. Further, the intermediate layer may have water solubility or may have solubility to a developing solution. The intermediate layer is a layer formed using a resin composition for forming an intermediate layer to be described later.

(Resin composition for forming an intermediate layer) The resin contained in the resin composition for forming an intermediate layer has an oxygen permeability coefficient of 1 × 10 ^-13 cm ³ (STP) from the viewpoint of workability and oxygen shielding property. Cm / (cm ² · s / Pa) or less, 1 × 10 ^-14 cm ³ (STP) cm / (cm ² · s / Pa) or less, or 1 × 10 ^-15 cm ³ (STP) cm / (cm ²・s・Pa) is below. The resin composition for forming an intermediate layer may contain a water-soluble resin. The solubility of the formed intermediate layer tends to increase by the inclusion of the water-soluble resin. Further, since it is easy to maintain the layer separation of the formed intermediate layer and the photosensitive layer for a long time, stability tends to be improved. Examples of the water-soluble resin include polyvinyl alcohol and polyvinylpyrrolidone. The resin composition for forming an intermediate layer may contain polyvinyl alcohol from the viewpoint that the oxygen permeability coefficient is low and the deactivation of radicals generated by actinic rays used in the exposure can be further suppressed. The polyvinyl alcohol can be obtained, for example, by saponifying a polyvinyl acetate obtained by polymerizing vinyl acetate. The degree of saponification of the polyvinyl alcohol used in the present embodiment may be 50 mol% or more, 70 mol% or more, or 80 mol% or more. By using polyvinyl alcohol having a degree of saponification of 50 mol% or more, the gas barrier properties of the intermediate layer can be further improved, and the resolution of the formed resist pattern tends to be further improved. In addition, the "saponification degree" in this specification is a value measured by JIS K 6726 (1994) (test method of polyvinyl alcohol) prescribed by the Japanese Industrial Standard. Further, the upper limit of the degree of saponification may be 100 mol%.

The average degree of polymerization of the polyvinyl alcohol may be 300 to 3,500, 300 to 2,500, or 300 to 1,000. Further, the polyvinylpyrrolidone may have an average degree of polymerization of 10,000 to 100,000 or 10,000 to 50,000. The polyvinyl alcohol may be used in combination of two or more kinds of polyvinyl alcohols having different degrees of saponification, viscosity, degree of polymerization, and modified species.

Further, the resin composition for forming an intermediate layer may contain a resin having solubility in a developing solution. The resin having solubility in the developer may, for example, contain the component (A) used in the photosensitive resin composition described later, and may contain the component (B). By containing a resin having solubility in a developing solution, the adhesion between the formed intermediate layer and the photosensitive layer tends to be improved, and there is a tendency that the photosensitive layer is easily formed on the formed intermediate layer.

In order to improve the handleability of the resin composition or to adjust the viscosity and storage stability, the resin composition for forming an intermediate layer may contain at least one solvent as needed. Examples of the solvent include water, an organic solvent, and the like. Examples of the organic solvent include methanol, acetone, toluene, and a mixed solvent thereof. From the viewpoint of improving the efficiency of drying when forming the intermediate layer, methanol may be contained. In addition, when the resin composition for forming an intermediate layer contains a water-soluble resin, water, and methanol, the content of methanol may be 1 part by mass to 100 parts by mass based on 100 parts by mass of water. Parts by mass, 10 parts by mass to 80 parts by mass, or 20 parts by mass to 60 parts by mass. The content of the water-soluble resin may be from 1 part by mass to 50 parts by mass, or from 10 parts by mass to 30 parts by mass, per 100 parts by mass of the water.

Further, a well-known additive such as a surfactant, a plasticizer, or a leveling agent may be blended in the resin composition for forming an intermediate layer. Examples of the leveling agent include an anthrone-based leveling agent. Examples of the commercially available product of the anthrone-based leveling agent include Polyflow KL-401 (Kyoeisha Chemical Co., Ltd.). Manufacturing) and so on. When the leveling agent is contained, the content of the leveling agent may be 0.01 parts by mass to 2.0 parts by mass or 0.05 parts by mass based on 100 parts by mass of the resin composition for forming an intermediate layer, from the viewpoint of easiness of formation of the intermediate layer. ～1.0 parts by mass.

The surfactant may include an anthrone-based surfactant or a fluorine-based surfactant from the viewpoint of improving the peeling property of the support film. These surfactants may be used alone or in combination of two or more. When the surfactant is contained, the content of the surfactant may be 0.01 parts by mass to 1.0 part by mass, or 0.05 part by mass, based on 100 parts by mass of the resin composition for forming an intermediate layer, from the viewpoint of easiness of formation of the intermediate layer. ～0.5 parts by mass, or 0.1 parts by mass to 0.3 parts by mass.

As the plasticizer, for example, a polyol compound may be contained from the viewpoint of improving the ease of formation of the intermediate layer. Examples thereof include glycerol such as glycerin, diglycerin, and triglycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, and polypropylene glycol (poly). Alkyl glycols, trimethylolpropane, etc. These plasticizers may be used alone or in combination of two or more.

The thickness of the intermediate layer is not particularly limited, but may be 12 μm or less, 10 μm or less, or 8 μm or less from the viewpoint of developability. Further, the thickness of the intermediate layer may be 1.0 μm or more, 1.5 μm or more, or 2 μm or more from the viewpoint of easiness of formation and resolution of the intermediate layer.

Further, the intermediate layer in the present embodiment may have photosensitivity, but its photosensitivity is lower than that of the photosensitive layer. In addition, the intermediate layer may not have photosensitivity. When the intermediate layer does not have photosensitivity, there is a tendency that the photosensitivity stability of the photosensitive layer is further improved. In addition, the term "photosensitivity" refers to, for example, a case where the photosensitive layer is exposed, and if necessary, a heat treatment after exposure, and then a developing solution for removing an uncured portion of the photosensitive layer is used to develop the photosensitive layer. A resist pattern can be formed.

<Photosensitive layer> The photosensitive layer of the present embodiment is a layer formed using a photosensitive resin composition to be described later. The photosensitive resin composition can be used in combination with a desired purpose as long as it is a resin composition whose properties are changed by light irradiation (for example, photocuring), and may be either negative or positive. The photosensitive resin composition may contain (A) a binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator. Further, (D) a photosensitizer, (E) a polymerization inhibitor or other components may be contained as needed. Hereinafter, each component used in the photosensitive resin composition of the present embodiment will be described in more detail.

(A) Adhesive Polymer (A) The binder polymer (hereinafter also referred to as "(A) component)" can be produced, for example, by radical polymerization of a polymerizable monomer. Examples of the polymerizable unitary substance include a polymerizable styrene derivative substituted with an α-position or an aromatic ring such as styrene, vinyl toluene or α-methylstyrene, and diacetone. An acrylamide such as acrylamide, an ether of a vinyl alcohol such as acrylonitrile or vinyl-n-butyl ether, an alkyl (meth)acrylate or a benzyl (meth)acrylate such as benzyl methacrylate, Tetrahydrofurfuryl methacrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylate 2 , 2,2-trifluoroethyl ester, 2,2,3,3-tetrafluoropropyl (meth)acrylate, (meth)acrylic acid, α-bromoacrylic acid, α-chloroacrylic acid, β-furanyl (A Acrylic acid, β-styryl (meth)acrylic acid, maleic acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monoethyl ester, maleic acid Maleic acid monoester such as monoisopropyl ester, fumaric acid, cinnamic acid, α-cyano cinnamic acid, itaconic acid, crotonic acid and propiolic acid. These may be used alone or in combination of two or more.

Among these, an alkyl (meth)acrylate may be contained from the viewpoint of plasticity improvement. The (meth)acrylic acid alkyl ester may, for example, be a compound represented by the following formula (II), and a compound in which an alkyl group of these compounds is substituted with a hydroxyl group, an epoxy group, a halogen group or the like. H ₂ C=C(R ⁶ )-COOR ⁷ (II)

In the formula (II), R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ represents an alkyl group having 1 to 12 carbon atoms. Examples of the alkyl group having 1 to 12 carbon atoms represented by R ⁷ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a decyl group, and a decyl group. A base, a dodecyl group, and structural isomers of such groups.

Examples of the (meth)acrylic acid alkyl ester represented by the above formula (II) include methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. Methyl)butyl acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate And (meth) methacrylate, decyl (meth) acrylate, eleven (meth) acrylate, dodecyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

Further, the component (A) may contain a carboxyl group from the viewpoint of alkali developability. The component (A) having a carboxyl group can be produced, for example, by radically polymerizing a polymerizable monomer having a carboxyl group with another polymerizable monomer. The polymerizable monomer having a carboxyl group may be (meth)acrylic acid or methacrylic acid. Further, the acid group (A) having a carboxyl group may have an acid value of from 50 mgKOH/g to 250 mgKOH/g.

The carboxyl group content of the component (A) (the polymerizable monomer having a carboxyl group relative to the total amount of the polymerizable monomer for the binder polymer) from the viewpoint of improving the alkali developability and alkali resistance in a well-balanced manner The mixing ratio of the body may be 12% by mass to 50% by mass, 12% by mass to 40% by mass, 15% by mass to 35% by mass, or 15% by mass to 30% by mass. When the carboxyl group content is 12% by mass or more, the alkali developability tends to be improved, and when it is 50% by mass or less, the alkali resistance tends to be excellent.

Further, from the viewpoint of adhesion and chemical resistance, the component (A) can be used as a polymerizable unitary amount of styrene or a styrene derivative. When the styrene or styrene derivative is used as a polymerizable unitary substance, the content (relative to the polymerization for the component (A)) is obtained from the viewpoint of improving adhesion and chemical resistance. The blending ratio of the styrene or the styrene derivative in the total amount of the monomeric body may be 10% by mass to 60% by mass, or 15% by mass to 50% by mass. When the content is 10% by mass or more, the adhesion tends to be improved. When the content is 60% by mass or less, the release sheet can be prevented from becoming large during development, and the time required for peeling can be suppressed from becoming prolonged. .

Further, from the viewpoint of the resolution and the aspect ratio, the (A) component may also use benzyl (meth)acrylate as a polymerizable unitary body. From the viewpoint of further improving the resolution and the aspect ratio, the content of the structural unit derived from benzyl (meth)acrylate in the component (A) may be 15% by mass to 50% by mass.

These binder polymers may be used alone or in combination of two or more. When the component (A) used in combination of two or more types is used, for example, two or more kinds of binder polymers containing different polymerizable single-components, and two or more kinds of binder polymers having different weight average molecular weights, And two or more kinds of binder polymers with different degrees of dispersion.

The component (A) can be produced by a usual method. Specifically, it can be produced, for example, by radical polymerization of alkyl (meth)acrylate, (meth)acrylic acid, and styrene.

The weight average molecular weight of the component (A) may be 20,000 to 300,000, 40,000 to 150,000, 40,000 to 120,000, or 50,000 to 80,000 from the viewpoint of improving the mechanical strength and alkali developability in a well-balanced manner. When the weight average molecular weight of the component (A) is 20,000 or more, the development liquid resistance tends to be excellent, and when it is 300,000 or less, the development time tends to be suppressed. Incidentally, the weight average molecular weight in the present specification is a value obtained by conversion using a gel permeation chromatography (GPC) and converted by a calibration curve prepared using standard polystyrene.

The content of the component (A) may be 30 parts by mass to 80 parts by mass, 40 parts by mass to 75 parts by mass, or 50% based on 100 parts by mass of the total solid content of the component (A) and the component (B) to be described later. Parts by mass to 70 parts by mass. When the content of the component (A) is within this range, the coating property of the photosensitive resin composition and the strength of the photocured portion are further improved.

(B) Photopolymerizable Compound The photosensitive resin composition of the present embodiment may contain (B) a photopolymerizable compound (hereinafter also referred to as "(B) component"). The component (B) is not particularly limited as long as it is a photopolymerizable compound and a photocrosslinkable compound. For example, a compound having at least one ethylenically unsaturated bond in the molecule can be used.

The (B) component is, for example, a photopolymerizable compound having an ethylenically unsaturated bond described in International Publication No. 2015/177947. These may be used alone or in combination of two or more.

The component (B) may contain a bisphenol type (meth) acrylate compound from the viewpoint of improving the analytical property, the adhesion, and the inhibition of the end portion of the resist in a well-balanced manner. The bisphenol type (meth) acrylate compound may be a compound represented by the following formula (III). [Chemical 1]

In the formula (III), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group. X and Y each independently represent an ethylidene group or a propyl group, and XO and YO each independently represent an oxyethyl group (hereinafter, sometimes referred to as "EO group") or an oxypropyl group (hereinafter, sometimes referred to as "PO base"). p ₁ , p ₂ , q ₁ and q ₂ each independently represent a numerical value of 0 to 40. However, both p ₁ + q ₁ and p ₂ + q ₂ are 1 or more. When X is an ethyl group and Y is a propyl group, p ₁ + p ₂ is from 1 to 40, and q ₁ + q ₂ is from 0 to 20. When X is a propyl group and Y is an ethyl group, p ₁ + p ₂ is 0 to 20, and q ₁ + q ₂ is 1 to 40. Since p ₁ , p ₂ , q ₁ and q ₂ represent the number of structural units of the EO group or the PO group, an integer value is represented in a single molecule, and a rational number as an average value is represented in an aggregate of a plurality of molecules. Further, the EO group and the PO group may be continuously present in a block form, or may be randomly present.

When a bisphenol type (meth) acrylate compound is used as the component (B), the total amount of solid components of the component (A) and the component (B) is the same as the total chemical resistance of the component (A) and the component (B). The content of the compound may be from 1% by mass to 50% by mass, or from 3% by mass to 40% by mass.

In addition, from the viewpoint of further improvement in chemical resistance, the content of the bisphenol type (meth) acrylate compound may be 30% by mass to 99% by mass, based on the total amount of the solid content of the component (B). % to 97% by mass, or 60% by mass to 95% by mass.

Further, from the viewpoint of improving the resolution, the total amount of the solid components of the component (A) and the component (B) is such that the total number of the EO group and the PO group is from 1 to 7 is represented by the formula (III). The content of the compound represented may be 1% by mass to 40% by mass, 2% by mass to 38% by mass, or 3% by mass to 28% by mass.

In addition, from the viewpoint of further improving the followability of the unevenness of the substrate, a compound obtained by reacting a polyol with an α,β-unsaturated carboxylic acid may be contained. As such a compound, a polyalkylene glycol di(meth)acrylate having both an EO group and a PO group in the molecule, dipentaerythritol (meth)acrylate having an EO group, or the like can be used. As a compound which can be obtained commercially, the dipentaerythritol (meth) acrylate which has an EO group, for example, "DPEA-12" manufactured by Nippon Kayaku Co., Ltd., etc. are mentioned. The content of the dipentaerythritol (meth) acrylate having an EO group may be 1% by mass to 10% by mass based on the total amount of the solid components of the component (A) and the component (B). Or 1.5% by mass to 5% by mass.

As a compound which can be obtained commercially as a polyalkylene glycol di(meth)acrylate having both an EO group and a PO group, for example, an EO group: 6 (average value) and a PO group are exemplified: 12 (average value) polyalkylene glycol dimethacrylate ("FA-023M", "FA-024M" manufactured by Hitachi Chemical Co., Ltd.) and the like.

Further, in the molecule of the polyalkylene glycol di(meth)acrylate having both the EO group and the PO group, the EO group and the PO group may be continuously present in a block manner, or may be randomly presence. Further, the PO group may be any of an oxy-n-propyl group or an oxy-iso-propyl group. Further, in the (poly)oxyisopropanyl group, the secondary carbon of the propyl group may be bonded to the oxygen atom, and the primary carbon may be bonded to the oxygen atom.

The content of the component (B) may be 20 parts by mass to 70 parts by mass, 25 parts by mass to 60 parts by mass, or 30 parts by mass to 100 parts by mass based on the total of the solid content of the component (A) and the component (B). 50 parts by mass. When the content of the component (B) is within this range, the resolution and adhesion of the photosensitive resin composition and the suppression of the edge portion of the resist are improved, and the light sensitivity and coating property are also improved. .

(C) Photopolymerization Initiator The photosensitive resin composition of the present embodiment may contain at least one (C) photopolymerization initiator (hereinafter also referred to as "(C) component"). The component (C) is not particularly limited as long as it is a component capable of polymerizing the component (B), and can be appropriately selected from the usual photopolymerization initiators.

As the component (C), for example, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, 2-methyl-1-[4- An aromatic ketone such as (methylthio)phenyl]-2-morpholinyl-acetone-1, an anthracene such as an alkyl hydrazine, a benzoin ether compound such as benzoin alkyl ether, a benzoin compound such as benzoin or alkylbenzoin, benzyl a benzyl derivative such as dimethyl ketal, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole 2,4,5-triarylimidazole dimer such as dimer, acridine derivative such as 9-phenyl acridine or 1,7-(9,9'-acridinyl)heptane, and the like. These may be used alone or in combination of two or more.

Among these, a 2,4,5-triarylimidazole dimer may be contained from the viewpoint of analytical improvement. As the 2,4,5-triarylimidazole dimer, for example, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)- 4,5-bis-(m-methoxyphenyl)imidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer. Among these, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer may be contained from the viewpoint of improvement in photostability stability.

As a 2,4,5-triarylimidazole dimer, for example 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole can be used as B-CIM ( It is commercially available from Hodogaya Chemical Industry Co., Ltd.).

The component (C) may contain at least one of 2,4,5-triarylimidazole dimers, and may further contain a 2,4,5-triarylimidazole dimer, from the viewpoint of further improving light absorption and adhesion and further suppressing light absorption of the component (C). 2-(2-Chlorophenyl)-4,5-diphenylimidazole dimer. Furthermore, the structure of the 2,4,5-triarylimidazole dimer may be symmetrical or asymmetric.

The content of the component (C) may be 0.01 parts by mass to 30 parts by mass, 0.1 parts by mass to 10 parts by mass, and 1 part by mass to 7 parts by mass based on 100 parts by mass of the total of the solid components of the component (A) and the component (B). Parts, 1 part by mass to 6 parts by mass, 1 part by mass to 5 parts by mass, or 2 parts by mass to 5 parts by mass. When the content of the component (C) is 0.01 parts by mass or more, the photosensitivity, the resolution, and the adhesion tend to be improved. When the content is 30 parts by mass or less, the resist shape tends to be excellent.

(D) Photosensitizer The photosensitive resin composition of the present embodiment may contain (D) a photosensitizer (hereinafter also referred to as "(D) component"). By containing the component (D), the absorption wavelength of the actinic rays used in the exposure can be effectively utilized.

Examples of the component (D) include pyrazolines, dialkylaminobenzophenones, anthraquinones, coumarins, xanthones, oxazoles, and benzoxazoles. Thiazoles, benzothiazoles, triazoles, stilbenes, triazines, thiophenes, naphthyl imines and triarylamines. These may be used alone or in combination of two or more. The component (D) may contain a pyrazoline, an anthracene, or a dialkylaminobenzophenone, from the viewpoint of more effectively utilizing the absorption wavelength of actinic rays used in the exposure, wherein It may also contain dialkylaminobenzophenones. Examples of the dialkylamino benzophenone-based compound which can be obtained commercially are, for example, "EAB" manufactured by Hodogaya Chemical Industry Co., Ltd., and the like.

When the component (D) is contained, the content thereof may be 1.0 part by mass or less, 0.5 part by mass or less, 0.15 part by mass or less, or 0.12 part by mass based on 100 parts by mass of the total solid content of the component (A) and the component (B). The following, or 0.10 parts by mass or less. When the content of the component (D) is 1.0 part by mass or less based on 100 parts by mass of the total solid content of the component (A) and the component (B), the resist shape and the end portion of the resist can be suppressed. Deterioration and a tendency to make the resolution better. In addition, the content of the component (D) may be 0.01 parts by mass or more based on 100 parts by mass of the total solid content of the component (A) and the component (B), from the viewpoint of the high light sensitivity and the high resolution.

(E) Polymerization Inhibitor The photosensitive resin composition of the present embodiment may contain (E) a polymerization inhibitor (hereinafter also referred to as "(E) component"). By containing the component (E), there is a tendency that the exposure amount required for photocuring the photosensitive resin composition can be adjusted to an exposure amount most suitable for exposure by a projection exposure machine.

In view of further improving the analytical property, the component (E) may contain a compound represented by the following formula (I). [Chemical 2]

In the formula (I), R ⁵ represents a halogen atom, a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an amine group, an aryl group, a decyl group or an alkyl group having 1 to 10 carbon atoms. a carboxyalkyl group having a carbon number of 1 to 10, an alkoxy group having 1 to 20 carbon atoms or a heterocyclic group, wherein m and n are integers of 2 or more, and n is an integer of 0 or more, And an integer selected by the mode of m+n=6, when n is an integer of 2 or more, R ⁵ may be the same or different. Further, the aryl group may be substituted with an alkyl group having 1 to 20 carbon atoms.

From the viewpoint of further improving the compatibility with the component (A), R ⁵ may be a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. The alkyl group having 1 to 20 carbon atoms represented by R ⁵ may be an alkyl group having 1 to 4 carbon atoms. For the purpose of further improving the clarification, m may be 2 or 3 or 2.

The compound represented by the above formula (I) may be an alkylcatechol from the viewpoint of further enhancing the analytical property.

The content of the component (E) may be 0.03 parts by mass to 0.3 parts by mass, 0.03 parts by mass to 0.2 parts by mass, and 0.05 parts by mass to 0.15% by mass based on 100 parts by mass of the total of the solid components of the component (A) and the component (B). Parts, or 0.05 parts by mass to 0.1 parts by mass. When the content of the component (E) is 0.3 parts by mass or less, the exposure time can be shortened, and the productivity of the mass production tends to be improved. In addition, when the content of the component (E) is 0.03 parts by mass or more, the photoreaction of the photocured portion can be sufficiently performed, and the reaction rate can be improved to suppress the swelling property of the resist. The resolution is getting better.

In addition, the content of the component (E) may be 0.05 parts by mass to 0.4 parts by mass, 0.05 parts by mass to 0.2 parts by mass, or 0.05 parts by mass to 0.1 parts by mass per 100 parts by mass of the solid component of the component (A). When the content of the component (E) is 0.05 parts by mass or more with respect to the component (A), there is a tendency to improve the thermal stability of the photosensitive resin composition; when it is relative to the component (A), the content of the component (E) When it is 0.4 parts by mass or less, the yellowing of the photosensitive resin composition tends to be suppressed.

(Other components) The photosensitive resin composition of the present embodiment may contain 0.01 parts by mass to 20 parts by mass, respectively, per 100 parts by mass of the total solid content of the component (A) and the component (B). The additive described in 2015/177947 is disclosed. These additives may be used alone or in combination of two or more.

In addition, the photosensitive resin composition of the present embodiment may contain at least one of organic solvents as needed in order to improve the handleability of the photosensitive resin composition or to adjust the viscosity and the storage stability. As the organic solvent, an organic solvent which is usually used can be used without particular limitation. Specifically, for example, an organic solvent described in International Publication No. 2015/177947 can be mentioned. These may be used alone or in combination of two or more.

<Protective layer> The photosensitive element of the present embodiment can laminate a protective layer on the surface of the photosensitive layer opposite to the surface contacting the intermediate layer. As the protective layer, for example, a polymer film of polyethylene or polypropylene or the like can be used. Further, the same polymer film as the support film may be used, or a different polymer film may be used.

Hereinafter, a method of manufacturing a photosensitive element in which a support film, an intermediate layer, a photosensitive layer, and a protective layer are sequentially laminated will be described.

<Method for Producing Photosensitive Element> First, for example, a water-soluble resin containing polyvinyl alcohol is slowly added to water heated to 70° C. to 90° C. so that the solid content is 10% by mass to 20% by mass. The mixture was stirred for about 1 hour to be uniformly dissolved to obtain a resin composition for forming an intermediate layer containing polyvinyl alcohol. In the present specification, the term "solid content" means a non-volatile component other than a substance which volatilizes water, an organic solvent, etc. of a resin composition. In other words, it means a component other than a solvent such as water removal or an organic solvent which remains without being volatilized in the drying step, and also includes a component which is liquid, saccharide or waxy at room temperature of about 25 °C.

Next, the resin composition for forming an intermediate layer is applied onto a support film and dried to form an intermediate layer. Further, when the density of the particles such as the lubricant is different on both surfaces of the support film, the intermediate layer may be formed on the surface of the support film having a small amount of the resin composition for forming the intermediate layer. The coating of the resin composition for forming an intermediate layer onto the support film can be carried out, for example, by a known method such as roll coating, face wheel coating, gravure coating, air knife coating, die coating, bar coating, spray coating, or the like. get on.

In addition, as long as at least a part of the solvent such as water can be removed, the drying of the resin composition for forming an intermediate layer to be applied is not particularly limited, but it can be dried at 70 to 150 ° C for 5 minutes to 30 minutes. After drying, the amount of residual solvent in the intermediate layer can be 2% by mass or less from the viewpoint of preventing the solvent from diffusing in the subsequent step.

Then, a photosensitive resin composition may be applied to the intermediate layer of the support film on which the intermediate layer is formed, and the photosensitive resin composition may be applied in the same manner as the application of the resin composition for forming the intermediate layer, and a photosensitive layer may be formed on the intermediate layer. By laminating the protective layer on the photosensitive layer formed as described above, a photosensitive element having a support film, an intermediate layer, a photosensitive layer, and a protective layer in this order can be produced. Further, by bonding an intermediate layer formed on the support film to a photosensitive layer formed on the protective layer, a photosensitive element having a support film, an intermediate layer, a photosensitive layer, and a protective layer in this order can be obtained. When the photosensitive element of the present embodiment is produced by such bonding, workability tends to be improved.

The thickness of the photosensitive layer in the photosensitive element can be appropriately selected depending on the use, but it may be 1 μm to 200 μm, 5 μm to 100 μm, or 10 μm to 50 μm in terms of the thickness after drying. When the thickness of the photosensitive layer is 1 μm or more, industrial coating tends to be easy, and productivity is improved. In addition, when the thickness of the photosensitive layer is 200 μm or less, the photosensitivity is high and the photocurability of the bottom of the resist is excellent, so that a resist pattern having excellent resolution and aspect ratio tends to be formed.

The melt viscosity of the photosensitive layer in the photosensitive element at 110 ° C can be appropriately selected depending on the type of the substrate that is in contact with the photosensitive layer, but after drying, it can be 50 Pa·s to 10000 Pa·s at 100 ° C, 100. Pa·s to 5000 Pa·s, or 200 Pa·s to 1000 Pa·s. When the melt viscosity at 110 ° C is 50 Pa·s or more, wrinkles and voids do not occur in the lamination step, and productivity tends to be improved. In addition, when the melt viscosity at 110 ° C is 10,000 Pa·s or less, the adhesion to the substrate in the lamination step is increased, and the adhesion tends to be reduced.

The photosensitive element of the present embodiment can be suitably used, for example, in a method of forming a resist pattern to be described later and a method of producing a printed wiring board.

[Method of Forming Resist Pattern] The method of forming a resist pattern according to the present embodiment includes: (i) using the photosensitive element, and the photosensitive layer and the intermediate layer and the support film in this order a step of being disposed on the substrate (hereinafter also referred to as "(i) photosensitive layer and intermediate layer forming step"); (ii) removing the support film, and sensitizing the photosensitive layer through the intermediate layer a step of exposing the layer (hereinafter also referred to as "(ii) exposure step"); and (iii) a step of removing the uncured portion and the intermediate layer of the photosensitive layer from the substrate (hereinafter also referred to as It is "(iii) development step"); other steps may be included as needed. Further, the resist pattern may be referred to as a photocured material pattern of a photosensitive resin composition, and may also be referred to as a concavo-convex pattern. Further, the resist pattern in the present embodiment can be used as a resist in accordance with the purpose, and can be used for other uses such as a protective film.

((i) Photosensitive layer and intermediate layer forming step) In the photosensitive layer and intermediate layer forming step, a photosensitive layer and an intermediate layer are formed on the substrate using the photosensitive element. The substrate is not particularly limited, and a substrate for circuit formation including a conductive layer and a conductor layer formed on the insulating layer, or a pad (such as a substrate for a lead frame) such as an alloy substrate can be used.

As a method of forming a photosensitive layer and an intermediate layer on a substrate, for example, when a photosensitive element having a protective layer is used, after the protective layer is removed, the photosensitive layer of the photosensitive element is bonded to the substrate while being heated. The photosensitive layer and the intermediate layer are formed on the substrate. Thereby, a laminate including the substrate, the photosensitive layer, the intermediate layer, and the support film in this order can be obtained.

When the photosensitive layer and the intermediate layer forming step are carried out using a photosensitive element, it can be carried out under reduced pressure from the viewpoint of adhesion and followability. The heating at the time of crimping can be carried out at a temperature of 70 ° C to 130 ° C, and the crimping can be carried out at a pressure of 0.1 MPa to 1.0 MPa (1 kgf / cm ² to 10 kgf / cm ² ), but these conditions may be required And suitable for selection. Further, when the photosensitive layer of the photosensitive element is heated to 70 to 130 ° C, it is not necessary to preheat the substrate in advance, but in order to further improve adhesion and followability, preheating of the substrate may be performed.

((ii) Exposure Step) In the exposure step, the support film is removed, and the photosensitive layer is exposed through the intermediate layer by actinic rays. Thereby, the exposed portion irradiated with the actinic ray can be photocured to form a photocured portion (latent image), and the unexposed portion to which the actinic ray is not irradiated can be photocured to form a photocured portion. When the photosensitive layer and the intermediate layer are formed using the photosensitive element, the support film existing on the photosensitive layer is peeled off and exposed. By exposing the photosensitive layer through the intermediate layer, the resolution is improved, and the fine fall of the resist pattern can be further suppressed.

As the exposure method, a known exposure method can be applied, and for example, a method of irradiating an actinic ray in an image form via a negative mask pattern or a positive mask pattern called an artwork is exemplified ( Mask exposure method); Laser Direct Imaging (LDI) exposure method; or method of using an actinic ray of an image projected with a reticle and illuminating an image through a lens (projection exposure mode) Wait. Among them, a projection exposure method can be used from the viewpoint of further suppressing the occurrence of minute detachment of the resist pattern. That is, the photosensitive element or the like of the present embodiment is applied to a projection exposure method. Further, the projection exposure method may also be referred to as an exposure method using actinic rays of energy attenuation.

The light source of the actinic ray is not particularly limited as long as it is a commonly used light source, and for example, a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, an argon laser, or the like can be used. A gas source such as a gas laser, a solid-state laser such as a Yttrium Aluminum Garnet (YAG) laser, or a semiconductor laser such as a gallium nitride-based blue-violet laser. Further, a light source such as a photographic floodlight bulb or a sun light that efficiently emits visible light or the like can be used. Among these, in terms of improving the analyticity and alignment well in a well-balanced manner, a light source capable of radiating an i-ray monochromatic light having a wavelength of 365 nm and a h-ray single color capable of radiating an exposure wavelength of 405 nm can be used. A light source of light or a light source that emits an actinic ray of an exposure wavelength of an ihg mixed ray, and a light source that emits i-ray monochromatic light having a wavelength of 365 nm may also be used. Examples of the light source that can emit the i-ray monochromatic light having a wavelength of 365 nm can be, for example, an ultrahigh pressure mercury lamp.

((iii) Developing Step) In the developing step, the uncured portion and the intermediate layer of the photosensitive layer are removed from the substrate. A resist pattern including a photocured portion obtained by photohardening the photosensitive layer is formed on a substrate by a developing step. When the intermediate layer is water-soluble, after the intermediate layer is removed by water washing, the uncured portion other than the photo-cured portion is removed by a developing solution, and when the intermediate layer has solubility to the developing solution, the developing solution may be used. The uncured portion other than the photocured portion is removed together with the intermediate layer. The development method can be exemplified by wet development.

In the case of wet development, development can be carried out by a known wet development method using a developer corresponding to the photosensitive resin composition. Examples of the wet development method include a immersion method, a liquid coating method, a high pressure spray method, a method using brushing, slap, scraping, shaking, etc., and the most suitable one is high pressure from the viewpoint of improving the analytical property. Spray method. These wet development methods may be developed by using one type alone or by combining two or more methods.

The developer is appropriately selected in accordance with the configuration of the photosensitive resin composition. For example, an alkaline aqueous solution and an organic solvent developing solution are mentioned.

From the viewpoint of safety, stability, and workability, an alkaline aqueous solution can be used as the developer. As the base of the alkaline aqueous solution, for example, an alkali hydroxide such as a hydroxide of lithium, sodium or potassium, a carbonate such as lithium, sodium, potassium or ammonium carbonate or a hydrogencarbonate, or a base such as potassium phosphate or sodium phosphate can be used. Metal phosphate, alkali metal pyrophosphate such as sodium pyrophosphate or potassium pyrophosphate, sodium borate, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2 - hydroxymethyl-1,3-propanediol, 1,3-diamino-2-propanol and morpholine.

As the alkaline aqueous solution for development, a thin solution of 0.1% by mass to 5% by mass of sodium carbonate, a thin solution of 0.1% by mass to 5% by mass of potassium carbonate, and a thin portion of 0.1% by mass to 5% by mass of sodium hydroxide can be used. A solution, a thin solution of 0.1% by mass to 5% by mass of sodium tetraborate or the like. Further, the pH of the alkaline aqueous solution used for development may be in the range of 9 to 11, and the temperature of the alkaline aqueous solution may be adjusted in accordance with the developability of the photosensitive layer. Further, in the alkaline aqueous solution, for example, a surfactant, an antifoaming agent, a small amount of an organic solvent for promoting development, or the like may be mixed. In addition, examples of the organic solvent used in the alkaline aqueous solution include 3-acetone alcohol, acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethanol, and isopropanol. Butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monobutyl ether.

Examples of the organic solvent used in the organic solvent developing solution include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, and cyclohexanone. Methyl isobutyl ketone and γ-butyrolactone. In view of the prevention of the ignition, the organic solvent can be added as an organic solvent developer so as to be in the range of 1% by mass to 20% by mass.

(Other Steps) In the method for forming a resist pattern according to the present embodiment, after the uncured portion is removed in the developing step, heating at 60 ° C to 250 ° C or 0.2 J/cm ² may be included as needed. Exposure at an exposure amount of 10 J/cm ² , whereby the resist pattern is further hardened.

[Laminate] The laminate of the present embodiment includes a substrate, a photosensitive layer, and an intermediate layer in this order, and a support film may be further provided on a surface of the intermediate layer opposite to the photosensitive layer side. Further, in the laminated body of the present embodiment, the diameter of the surface of the intermediate layer opposite to the photosensitive layer side (wherein, when the shape of the concave portion is not circular, the diameter of the circumcircle of the shape) is 3 The number of the recesses of μm or more is 30/mm ² or less. Further, the number of the concave portions having a diameter of 3 μm or more may be 25 pieces/mm ² or less, 20 pieces/mm ² or less, 10 pieces/mm ² or less, 5 pieces/mm ² or less, or 1 piece/mm ² or less. The lower limit of the number of the recesses is 0/mm ² . Further, the number of the concave portions can be measured using a scanning electron microscope. By setting the number of the recesses having a diameter of 3 μm or more to 30/mm ² or less, it is difficult to cause minute peeling in the resist pattern formed using the laminate, and it is possible to form a small resist with little peeling off. Agent pattern. In addition, when such a laminate is used for the production of a printed wiring board, it is possible to suppress an open failure caused during etching and a short-circuit defect occurring during plating, and it is possible to suppress a decrease in the yield of the printed wiring board. In addition, from the viewpoint of forming a resist pattern having less fine peeling, the number of recesses having a diameter of 1.2 μm or more and less than 3 μm may be 1000/mm ² or less and 500/mm ² or less. Or 10 / mm ² or less, but the lower limit of the number of the recesses is 0 / mm ² . Further, from the same viewpoint, the depth of the concave portion may be 5 μm or less. Further, from the same viewpoint, in the laminated body, the support film may not be provided on the surface of the intermediate layer opposite to the photosensitive layer, that is, in the laminated body, the intermediate layer is opposite to the photosensitive layer. The face can be exposed.

The number of the recesses having a diameter of 3 μm or more in the surface of the intermediate layer opposite to the photosensitive layer can be reduced by reducing the number of particles contained in the support film, particularly the number of particles having a diameter of 5 μm or more. Similarly, the number of the recesses having a diameter of 1.2 μm or more and less than 3 μm in the surface of the intermediate layer opposite to the photosensitive layer can be reduced by reducing the number of particles contained in the support film, particularly 2 μm in diameter. The number of particles above 5 μm is reduced.

The number of the recesses having a diameter of 3 μm or more can be measured by observation using a scanning electron microscope (for example, SU-1500 (manufactured by Hitachi, Ltd.)). Observation can be performed at any of 10 locations. The measurement area was set to a size of 1 mm square, and arbitrary ten parts were measured, and the average value was made into the number of the recessed part of the intermediate layer of the diameter of 3 micrometers or more. Further, when the laminate has a support film, the support film can be peeled off and then measured.

The substrate is not particularly limited, and the same substrate as that exemplified in the method for forming the resist pattern can be used. The surface roughness Rz of the substrate may be 100 nm or less, 80 nm or less, or 50 nm or less from the viewpoint of analytical improvement. Further, the surface roughness Rz of the substrate is not particularly limited, but may be 1 nm or more.

The laminate of the present embodiment can also be produced by pressure-bonding the photosensitive element to a substrate so that the photosensitive layer of the photosensitive element is in close contact with the substrate. The laminate of the present embodiment can be used in a method of forming a resist pattern including a step of exposing a photosensitive layer via an intermediate layer in a laminate by using actinic rays; The step of removing the uncured portion of the photosensitive layer and the intermediate layer from the substrate. Thereby, a resist pattern having a small amount of detachment can be formed.

[Manufacturing Method of Printed Wiring Board] The method of manufacturing a printed wiring board according to the present embodiment includes forming an etching treatment or a plating treatment on a substrate on which a resist pattern is formed by the method of forming the resist pattern. The step of the conductor pattern may include other steps such as a resist pattern removing step as needed. The method for producing a printed wiring board according to the present embodiment can be suitably used for the formation of a conductor pattern by using a method of forming a resist pattern using the photosensitive element or the laminated body, and is more suitably applied by A method of forming a conductor pattern by plating. Furthermore, the conductor pattern can also be referred to as a circuit.

In the etching process, a resist pattern formed on a substrate having a conductor layer is used as a mask, and a conductor layer of a substrate not covered with a resist is etched away to form a conductor pattern.

The etching treatment method is appropriately selected corresponding to the conductor layer to be removed. Examples of the etching liquid include a copper chloride solution, a ferric chloride solution, an alkali etching solution, and a hydrogen peroxide-based etching liquid. From the viewpoint of a good etching factor, a ferric chloride solution can be used.

On the other hand, in the plating treatment, a resist pattern formed on a substrate having a conductor layer is used as a mask, and copper or solder is plated on the conductor layer of the substrate not covered with the resist. After the plating treatment, the resist is removed by removal of a resist pattern to be described later, and the conductor layer covered with the resist is further etched to form a conductor pattern.

The plating treatment may be an electrolytic plating treatment or an electroless plating treatment, and may be an electroless plating treatment. Examples of the electroless plating treatment include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high throw solder plating, and watts bath (nickel sulfate). - Nickel plating such as nickel chloride plating and nickel sulfamate plating, gold plating such as hard gold plating and soft gold plating.

After the etching treatment or the plating treatment, the resist pattern on the substrate is removed. The removal of the resist pattern can be performed, for example, by an aqueous solution which is more alkaline than the aqueous alkaline solution used in the development step. As the strongly alkaline aqueous solution, for example, a 1% by mass to 10% by mass aqueous sodium hydroxide solution, a 1% by mass to 10% by mass aqueous potassium hydroxide solution, or the like can be used. Among these, a 1% by mass to 5% by mass aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution can also be used.

Examples of the method of removing the resist pattern include a immersion method and a spray method, and these may be used singly or in combination.

When the resist pattern is removed after the plating treatment is performed, the conductor layer covered with the resist is etched by an etching process to form a conductor pattern, whereby a desired printed wiring board can be manufactured. The method of the etching treatment at this time is appropriately selected in accordance with the conductor layer to be removed. For example, the etching solution can be applied.

The method for producing a printed wiring board according to the present embodiment can be applied not only to the manufacture of a single-layer printed wiring board, but also to the production of a multilayer printed wiring board, and also to a printed wiring board having a small-diameter through hole. Manufacturing.

The method for producing a printed wiring board of the present embodiment can be suitably used for the production of a high-density package substrate, particularly a wiring board using a semi-additive method. In addition, an example of the manufacturing process of the wiring board by the semi-additive method is shown in FIG. 2 (a) - FIG. 2 (f).

In FIG. 2(a), a substrate (circuit formation substrate) on which the conductor layer 40 is formed on the insulating layer 50 is prepared. The conductor layer 40 is, for example, a copper layer. In FIG. 2(b), the photosensitive layer 30 and the intermediate layer 20 are formed on the conductor layer 40 of the substrate by the photosensitive layer and intermediate layer forming steps. In FIG. 2(c), by the exposure step, the actinic ray 80 on which the image of the reticle is projected is irradiated onto the photosensitive layer 30 via the intermediate layer 20, and a photocured portion is formed on the photosensitive layer 30. In FIG. 2(d), a region other than the photo-cured portion (including the intermediate layer) formed by the exposure step is removed from the substrate by a developing step, whereby a resist as a photo-curing portion is formed on the substrate. Agent pattern 32. In FIG. 2(e), the plating layer 60 is formed on the conductor layer 40 of the substrate not covered with the resist by a plating process using the resist pattern 32 as a photocured portion as a mask. In FIG. 2(f), the resist pattern 32 as the photocured portion is peeled off by an aqueous solution of a strong alkali, and then the conductor layer 40 covered by the resist pattern 32 is removed by flash etching. The conductor pattern 70 including the plating layer 62 after the etching treatment and the conductor layer 42 after the etching treatment is formed. The material of the conductor layer 40 and the plating layer 60 may be the same or different. When the conductor layer 40 and the plating layer 60 are made of the same material, the conductor layer 40 and the plating layer 60 can be integrated. Although the projection exposure method has been described with reference to FIGS. 2(a) to 2(f), the resist pattern 32 may be formed by a mask exposure method or a direct writing exposure method.

The preferred embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above embodiments. [Examples]

Hereinafter, the present disclosure will be more specifically described based on examples, but the present disclosure is not limited to the following examples. In addition, "parts" and "%" are quality standards unless otherwise specified.

First, the binder polymer (A-1) shown in the following Table 2 and Table 3 was synthesized according to Synthesis Example 1.

<Synthesis Example 1> 125 g of methacrylic acid as a polymerizable monomer, 25 g of methyl methacrylate, 125 g of benzyl methacrylate, and 225 g of styrene and 1.5 g of azobisisobutyronitrile were mixed. Prepare solution a.

Separately, 1.2 g of azobisisobutyronitrile was dissolved in 100 g of a mixture of methyl sesasil 60 g and 40 g of toluene (mass ratio: 3:2) to prepare a solution b.

On the other hand, a mixture of methyl sarbuta and toluene having a mass ratio of 3:2 is added to a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel, and a nitrogen introduction tube (hereinafter, also referred to as "mixing" Liquid x") 400 g, stirred while blowing nitrogen gas, and heated to 80 °C.

The solution a was added dropwise to the mixed solution x in the flask over 4 hours and the dropping rate was fixed, and then stirred at 80 ° C for 2 hours. Then, the solution b was added dropwise to the solution in the flask over 10 minutes and the dropping rate was fixed, and the solution in the flask was stirred at 80 ° C for 3 hours. Further, the solution in the flask was heated to 90 ° C for 30 minutes, and the mixture was kept at 90 ° C for 2 hours, and then cooled to room temperature to obtain a solution of the binder polymer (A-1). The solution of the binder polymer (A-1) was prepared in such a manner that the non-volatile component (solid content) became 50% by mass after the addition of the mixed solution x.

The binder polymer (A-1) had a weight average molecular weight of 50,000 and an acid value of 163 mgKOH/g. Further, the acid value was determined by a neutralization titration method. Specifically, it is measured by adding 30 g of acetone to 1 g of the solution of the binder polymer, and further uniformly dissolving the solution, and then adding an appropriate amount as an indicator to the solution of the binder polymer. The phenolphthalein was titrated using a 0.1 N aqueous KOH solution. The weight average molecular weight is determined by gel permeation chromatography (GPC) and converted using a calibration curve of standard polystyrene. The conditions for GPC are shown below.

-GPC condition - Pump: Hitachi L-6000 (manufactured by Hitachi, Ltd.) Pipe column: The following three total (column specifications: 10.7 mm φ × 300 mm, all manufactured by Hitachi Chemical Co., Ltd.) Gelpack GL-R420 Gelpack GL-R430 Gelpack GL-R440 Dissolution: tetrahydrofuran sample concentration: 120 mg of a binder polymer having a solid content of 50% by mass was prepared and dissolved in 5 mL of tetrahydrofuran to prepare a sample. Measurement temperature: 25 ° C Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI (manufactured by Hitachi, Ltd.)

<Preparation of Resin Composition for Intermediate Layer Formation> Next, each component shown in Tables 1 and 2 below was mixed in an amount (unit: parts by mass) shown in the table to obtain an intermediate layer. Resin composition 1 and resin composition 2 for intermediate layer formation. In addition, the preparation amount other than the solvent and the organic solvent in Table 1 and Table 2 is the compounding quantity of solid content.

[Table 1]

[Table 2]

<Preparation of Photosensitive Resin Composition> Then, each component shown in the following Table 3 was mixed in the amounts (unit: parts by mass) shown in the table, whereby a photosensitive resin composition was obtained. In addition, the compounding amount other than the organic solvent in Table 3 is the compounding quantity based on solid content.

[table 3]

The details of each component in Tables 1 to 3 are as follows. *1: Polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd., saponification degree = 80 mol%) *2: polyvinylpyrrolidone K-30 (manufactured by Nippon Shokubai Co., Ltd.) *3 : Polyflow KL-401 (manufactured by Kyoeisha Chemical Co., Ltd.)

(A) component: binder polymer *4: (A-1) (adhesive polymer (A-1) obtained in Synthesis Example 1) methacrylic acid / methyl methacrylate / benzyl methacrylate /styrene = 25/5/25/45 (mass ratio), weight average molecular weight = 50,000, solid content = 50% by mass, methyl sarxinsu / toluene = 3 / 2 (mass ratio) solution

(B) component: Photopolymerizable compound having an ethylenically unsaturated bond *5: FA-321M (manufactured by Hitachi Chemical Co., Ltd.) 2,2-bis(4-(methacryloxy)pentaethoxy) Phenyl)propane*6:FA-024M (manufactured by Hitachi Chemical Co., Ltd.) EOPO modified dimethacrylate*7:BP-2EM (manufactured by Kyoeisha Chemical Co., Ltd.) 2,2-double (4- (Methethyloxypolyethoxy)phenyl)propane*8:BPE-80N (manufactured by Shin-Nakamura Chemical Co., Ltd.) 2,2-bis(4-(methacryloxy)polyethoxylate Phenyl)propane*9:DPEA-12 (manufactured by Nippon Kayaku Co., Ltd.) Ethylene oxide modified dipentaerythritol hexaacrylate

(C) Component: Photopolymerization initiator *10: B-CIM (manufactured by Hodogaya Chemical Industry Co., Ltd.) 2,2'-bis(2-chlorophenyl)-4,4',5,5'- Tetraphenylbiimidazole

(D) Component: Photosensitizer *11: EAB (manufactured by Hodogaya Chemical Industry Co., Ltd.) 4,4'-bis(diethylamino)benzophenone

(E) component: polymerization inhibitor *12: TBC (manufactured by Dainippon Ink and Chemicals, Inc.) 4-t-butylcatechol

[Examples 1 to 14 and Comparative Examples 1 to 4] <Preparation of photosensitive element> As the support film of the photosensitive element, PET films shown in the following Tables 4 to 6 were prepared. The results of measuring the number of particles having a diameter of 5 μm or more contained in each PET film are shown in Tables 4 to 6 below. In addition, the PET film is transparent.

The number of particles having a diameter of 5 μm or more was obtained by observing both surfaces of the support film by a polarizing microscope, and measuring the number of particles having a diameter of 5 μm or more, respectively, and accumulating the numbers. Further, in this observation, the focus was aligned on the surface to observe one surface and the other surface of the support film, respectively. Further, the number n of measurement regions (sizes of 1 mm square) of the support film was set to 10, and the average value thereof was determined.

(Production of the intermediate layer) When the density of the particles (lubricant) is different on both surfaces of the PET film, the resin composition for forming the intermediate layer 1 or the resin composition 2 for forming the intermediate layer is less than the lubricant of the PET film. The intermediate layer 1 or the intermediate layer 2 is formed thereon.

When the intermediate layer 1 is formed by using the resin composition 1 for forming an intermediate layer, each component of the resin composition for intermediate layer formation other than water is gradually added to water at room temperature, and after all the addition, the mixture is heated to 90 °C. After reaching 90 ° C, it was stirred for 1 hour and then cooled to room temperature. Then, the intermediate layer-forming resin composition 1 was applied onto a PET film (support film) so as to have a uniform thickness, and dried by a hot air convection dryer at 95 ° C for 10 minutes to form a dried thickness. It is an intermediate layer 1 of 5 μm.

When the intermediate layer 2 is formed by using the resin composition 2 for forming an intermediate layer, the resin composition 2 for an intermediate layer formation (acrylic resin composition) is applied onto the support film so that the thickness becomes uniform, and 100 is used. The hot air convection dryer at °C was dried for 10 minutes to form an intermediate layer 2 having a thickness of 5 μm after drying.

(Production of Photosensitive Layer) Next, the photosensitive resin composition was applied to the intermediate layer of the support film so that the thickness became uniform, and dried by a hot air convection dryer at 100 ° C for 10 minutes to form a dried film. A photosensitive layer having a thickness of 10 μm. Hereinafter, the photosensitive layer formed using the photosensitive resin composition 1 is also referred to as a photosensitive layer 1, and the photosensitive layer formed using the photosensitive resin composition 2 is also referred to as a photosensitive layer 2.

Then, a polyethylene film (protective layer) (manufactured by Tamapoly Co., Ltd., "NF-15") was attached to the photosensitive layer, and a PET film (support film) was sequentially laminated. Photosensitive elements of the intermediate layer, the photosensitive layer, and the protective layer. Further, in the case of Example 1 in the following Table 4, it is shown that the intermediate layer 1 is formed on the QS63 (support film) using the resin composition for forming an intermediate layer, and then the photosensitive resin composition 1 is used in the intermediate layer. The photosensitive layer 1 is formed on 1.

<Preparation of a laminated body> Copper-clad laminate (a substrate, manufactured by Hitachi Chemical Co., Ltd., "MCL-E-67"), which is an epoxy glass material having a copper foil having a thickness of 12 μm laminated on both sides The surface was subjected to an acid treatment and washed with water, and then dried by a gas stream. The copper clad laminate was heated to 80 ° C, and the protective layer was peeled off, and the photosensitive members were respectively pressure-bonded to the copper clad laminate so that the photosensitive layer contacted the copper surface. The crimping was carried out using a hot roll at 110 ° C at a roll speed of 1.0 m/min under a pressure of 0.40 MPa. In this manner, a laminate in which a substrate, a photosensitive layer, an intermediate layer, and a support film are laminated in this order is obtained. These laminates were used as test pieces in the test shown below. As a laminating machine, HLM-3000 (manufactured by Taisei-laminator Co., Ltd.) was used.

<Evaluation of the laminated body> The support film was peeled off from the laminated body, and the diameter of the surface of the intermediate layer opposite to the photosensitive layer side was 3 using a scanning electron microscope SU-1500 (manufactured by Hitachi, Ltd.). A concave portion (hereinafter also referred to as "intermediate layer concave portion") of μm or more is observed. The number n of measurement areas (sizes of 1 mm square) of the intermediate layer was set to 10, and the average value thereof was determined and evaluated by the following criteria. The results are shown in Tables 4 to 6 below. A: The number of the recesses having a diameter of 3 μm or more is less than five. B: The number of the concave portions having a diameter of 3 μm or more is 5 or more and 30 or less. C: The number of the recesses having a diameter of 3 μm or more exceeds 30.

<Photosensitivity measurement test> The support film was peeled off from the test piece, and a Hitachi 41-step ladder plate was placed on the intermediate layer of the test piece, and a projection exposure machine (Ushio) having a high-pressure mercury lamp having a wavelength of 365 nm was used. Manufactured by the Electric Co., Ltd., "UX-2240SM-XJ01", NA: 0.063), in order to adjust the amount of irradiation, the number of stages of the resist pattern after development (the number of resist hardened sections) is determined to be seven stages. Irradiation energy (exposure amount), the photosensitive layer was exposed through the intermediate layer.

Then, using a 1% by mass aqueous sodium carbonate solution at 30 ° C, the photosensitive layer was spray-developed at twice the minimum development time, and the unexposed portion was removed. Here, in the case where the intermediate layer is water-soluble (in the case of the intermediate layer 1), the photosensitive layer is developed after washing with water. Further, in the case where the intermediate layer has solubility in the developing solution (in the case of the intermediate layer 2), the unexposed portion is removed together with the intermediate layer by development. Further, the shortest development time is obtained by measuring the time during which the unexposed portion is completely removed by the development processing.

Thereafter, the number of stages of the resist pattern (photohardenable portion) formed on the substrate at each exposure amount was measured. Then, a calibration curve of the exposure amount and the number of stages was prepared, and the exposure amount (unit: mJ/cm ² ) in which the number of stages was changed to seven stages was determined, and the light sensitivity of the photosensitive resin composition was obtained. The results are shown in Tables 4 to 6 below. The smaller the value of the exposure amount, the better the light sensitivity.

<Measurement measurement test> The support film was peeled off from the test piece, and the line width/space width of the pattern for evaluation of the resolution was z/z (z = 2 to 20 (changed at intervals of 1 μm)) (unit: μm) The glass mask of the wiring pattern is placed on the intermediate layer of the test piece, and a projection exposure machine ("UX-2240SM-XJ01" manufactured by Uchihiro Electric Co., Ltd.) having a high-pressure mercury lamp having a wavelength of 365 nm is used, and Hitachi 41 is used. The number of remaining stages after development of the stepped trapezoidal plate becomes 7-stage irradiation energy, and the photosensitive layer is exposed through the intermediate layer. After the exposure, the same development processing as the photo-sensitivity measurement test was performed. After the development treatment, the resist pattern was observed using an optical microscope. The minimum value (unit: μm) of the spatial width between the line portions (exposure portions) in which the unexposed portions are completely removed by the development process is used as an index for the evaluation of the resolution. Furthermore, the smaller the value, the better the resolution. The results are shown in Tables 4 to 6 below.

<Evaluation of the occurrence of the detachment in the resist pattern> Using the scanning electron microscope SU-1500 (manufactured by Hitachi, Ltd.), the line width of the resist pattern obtained in the resolution measurement test was 15 strips of a resist pattern of 10 μm (the length orthogonal to the line width was 1 mm) were observed and evaluated by the following criteria. The results are shown in Tables 4 to 6 below. In addition, the SEM photograph of the resist pattern obtained in Example 3 is shown in FIG. 3, and the SEM photograph of the resist pattern obtained in Comparative Example 1 is shown in FIG. A: Less than 5 minute peelings having a diameter of 3 μm or more in the formed resist pattern. B: In the formed resist pattern, the fine peeling having a diameter of 3 μm or more is 5 or more and less than 20. C: 20 or more fine peelings having a diameter of 3 μm or more in the formed resist pattern.

[Table 4]

[table 5]

[Table 6]

The details of the support film in Tables 4 to 6 are as follows. QS63: a biaxially oriented PET film having a lubricant layer on one side and a lubricant layer on the other side, but containing a very small amount of lubricant (Toray Co., Ltd., and intermediate layer) The number of particles having a diameter of 5 μm or more in the contact surface (hereinafter, simply referred to as "the number of particles in the intermediate layer"): 1 / mm ² or less, surface roughness on the surface in contact with the intermediate layer Rz: 66 nm A1517: Biaxially oriented PET film having a two-layer structure with a lubricant layer on one side (manufactured by Toyobo Co., Ltd., the number of particles in the intermediate layer: 10/mm ² or less, the surface on the surface in contact with the intermediate layer is rough) Degree Rz: 35 nm) A4100: Biaxially oriented PET film having a two-layer structure with a lubricant layer on one side (manufactured by Toyobo Co., Ltd., the number of particles in the intermediate layer: 10/mm ² or less, in contact with the intermediate layer) Surface roughness Rz: 35 nm) G2H: Biaxially oriented PET film with a single layer structure (lubricant kneading type) containing lubricant (manufactured by Teijin DuPont Film Co., Ltd., number of particles in the middle layer: more than 10 /m m ² ; surface roughness on the surface in contact with the intermediate layer Rz: 920 nm) HPE: a three-layered biaxially oriented PET film having a lubricant layer on the back side of the watch (manufactured by Teijin DuPont Film Co., Ltd., intermediate layer) Number of particles: more than 10 / mm ² ; surface roughness Rz: 700 nm on the surface in contact with the intermediate layer KFX: biaxially oriented PET film with a lubricant layer on one side (Dynasty DuPont film) Manufactured by the company, the number of particles in the middle layer: 10 / mm ² or less, surface roughness Rz: 50 nm on the surface in contact with the intermediate layer)

In the case of using a high-resolution projection exposure machine, when the exposure was performed under the condition that the number of remaining phases became seven, the amount of light in the resist pattern was small, and the thickness of the resist pattern was small. Here, in Comparative Examples 1 to 4, a lot of minute peeling occurred in the resist pattern.

In addition, when exposure is performed under the condition that the number of remaining stages becomes 11 stages using a projection exposure machine, the resist pattern is compared with the evaluation (when exposure is performed under the condition that the number of remaining stages becomes 7 stages). The number of tiny sheddings is reduced. In addition, when the exposure exposure method or the LDI exposure method is used instead of the projection exposure method, when the exposure is performed under the condition that the number of remaining stages becomes seven, the occurrence of minute peeling in the resist pattern is compared with the evaluation. The number is also small. [Industrial availability]

According to the present disclosure, it is possible to provide a photosensitive element, a laminate, a method of forming a resist pattern, and a method of producing a printed wiring board, which are capable of forming a resist pattern having a small amount of detachment.

1‧‧‧Photosensitive components
2‧‧‧Support film
3, 20‧‧‧ middle layer
4, 30‧‧‧Photosensitive layer
5‧‧‧Protective layer
32‧‧‧resist pattern
40‧‧‧Conductor layer
42‧‧‧The etched conductor layer
50‧‧‧Insulation
60‧‧‧ plating layer
62‧‧‧etched plating layer
70‧‧‧ conductor pattern
80‧‧‧Acradiation rays

Fig. 1 is a schematic cross-sectional view showing an embodiment of a photosensitive element of the present disclosure. 2(a) to 2(f) are diagrams schematically showing an example of a manufacturing procedure of a printed wiring board by a semi-additive method. 3 is a scanning electron microscope (SEM) photograph of a resist pattern obtained in Example 3. FIG. 4 is a SEM photograph of a resist pattern obtained in Comparative Example 1.

1‧‧‧Photosensitive components

2‧‧‧Support film

3‧‧‧Intermediate

4‧‧‧Photosensitive layer

5‧‧‧Protective layer

Claims (9)

A photosensitive element comprising, in order, a support film, an intermediate layer and a photosensitive layer, wherein the thickness of the support film is 20 μm or more, and the number of particles having a diameter of 5 μm or more contained in the support film is 30/ Below mm ² . The photosensitive element according to claim 1, wherein the number of particles having a diameter of 5 μm or more in the surface of the support film in contact with the intermediate layer is 10 pieces/mm ² or less. The photosensitive member according to claim 1 or 2, wherein the intermediate layer comprises polyvinyl alcohol. The photosensitive element according to any one of claims 1 to 3, wherein the support film is a polyester film. A method of forming a resist pattern, comprising: using the photosensitive element according to any one of claims 1 to 4, the photosensitive layer and the intermediate layer and the support film a step of disposing on the substrate in this order; removing the support film, exposing the photosensitive layer through the intermediate layer by actinic rays; and removing the photosensitive layer from the substrate The step of hardening the portion and the intermediate layer. The method of forming a resist pattern according to claim 5, wherein the exposure is performed using a high-resolution exposure machine having a lens having a numerical aperture of 0.05 or more. A laminated body comprising a substrate, a photosensitive layer and an intermediate layer in this order, and in the surface of the intermediate layer opposite to the side of the photosensitive layer, the number of the recesses having a diameter of 3 μm or more is 30/mm ² or less. A method for forming a resist pattern, comprising: a step of exposing the photosensitive layer by using the intermediate layer in the laminate according to claim 7 of the invention; and using the actinic ray; The step of removing the uncured portion of the photosensitive layer and the intermediate layer on the substrate. A method of manufacturing a printed wiring board, comprising: etching a substrate on which a resist pattern is formed by a method of forming a resist pattern according to claim 5, 6, or 8 of claim 5 Processing or plating treatment to form a conductor pattern.