CN113453416A

CN113453416A - Laminate, method for manufacturing printed wiring board, and printed wiring board

Info

Publication number: CN113453416A
Application number: CN202110318941.XA
Authority: CN
Inventors: 樋口伦也; 西村飒太; 藤原勇佐; 桥本壮一; 荒井贵
Original assignee: Goo Chemical Industries Co Ltd
Current assignee: Goo Chemical Industries Co Ltd
Priority date: 2020-03-27
Filing date: 2021-03-25
Publication date: 2021-09-28
Also published as: TW202138193A

Abstract

The invention relates to a laminate, a method for manufacturing a printed wiring board, and a printed wiring board. The invention provides a laminate which is easy to improve resolution and flatness. The laminate (10) is provided with an insulating layer (1), a resist forming layer (2) that overlaps the insulating layer (1), and a coating layer (3) that overlaps the resist forming layer (2). The resist forming layer (2) contains a dried product or a semi-cured product of the photosensitive composition.

Description

Laminate, method for manufacturing printed wiring board, and printed wiring board

Technical Field

The present invention relates to a laminate, a method for manufacturing a printed wiring board, and more particularly, to a laminate, a method for manufacturing a printed wiring board using the laminate, and a printed wiring board using the laminate.

Background

Patent document 1 (japanese patent laid-open publication No. 2014-024919) discloses: the transparent conductive film is used as a member for a touch panel in which a transparent electrode is patterned on a transparent base material. As the transparent substrate, a transparent resin film can be used, and as the transparent conductive film, an energy ray-curable composition can be used. Patent document 1 discloses: the energy ray-curable composition can be used as a material for an insulating layer and/or a protective layer of a touch panel having a transparent resin film as a substrate, and can obtain sufficient adhesion to the transparent resin film and an electrode.

Disclosure of Invention

However, in the transparent laminated member of patent document 1 including a transparent base material and a transparent conductive film as a transparent electrode, an energy ray curable composition is applied to a substrate having an electrode with a patterned thin film, and is photocured by ultraviolet rays to be a cured product, and the cured product is formed as an insulating layer and/or a protective layer. Therefore, there is room for improvement in the resolution and flatness of the transparent conductive film.

The purpose of the present invention is to provide a laminate body that is easy to improve resolution and flatness, a printed wiring board produced from the laminate body, and a method for producing a printed wiring board.

A laminate according to an embodiment of the present invention includes: an insulating layer, a resist forming layer overlapping with the insulating layer, and a covering layer overlapping with the resist forming layer. The resist forming layer contains a dried product or a semi-cured product of the photosensitive composition.

A method for manufacturing a printed wiring board according to an embodiment of the present invention is a method for manufacturing a printed wiring board including an insulating substrate and a resist layer, the insulating substrate including the insulating layer in the laminate, and the resist layer being made of the resist-forming layer in the laminate. The manufacturing method comprises the following steps: the resist forming layer is irradiated with light through the coating layer in the laminate, thereby forming the resist layer on the insulating layer.

A printed wiring board according to an embodiment of the present invention includes: an insulating substrate including the insulating layer in the laminate, and a resist layer formed from the resist-forming layer in the laminate.

According to one embodiment of the present invention, a laminate and a printed wiring board in which resolution and flatness can be easily improved can be obtained.

Drawings

Fig. 1A is a schematic cross-sectional view showing a laminate according to an embodiment of the present invention.

Fig. 1B is a schematic perspective view showing a rolled laminate according to an embodiment of the present invention.

Fig. 2A is a schematic diagram showing one of the steps of manufacturing the printed wiring board according to the present embodiment.

Fig. 2B is a schematic view showing one of the manufacturing steps of the printed wiring board as described above.

Fig. 2C is a schematic view showing one of the manufacturing steps of the printed wiring board described above.

Fig. 2D is a schematic view showing one of the manufacturing steps of the printed wiring board described above.

Fig. 3 is a cross-sectional view showing a modification of the laminate shown in fig. 1A.

Description of the reference numerals

1 insulating layer

2 resist forming layer

3 coating layer

10 laminated body

11 insulating substrate

12 resist layer

100 printed wiring board

Detailed Description

1. Summary of the invention

First, an outline of the laminate 10 according to the present embodiment will be described.

The laminate 10 of the present embodiment includes an insulating layer 1, a resist formation layer 2, and a coating layer 3. A resist forming layer 2 is superposed on the insulating layer 1, and a covering layer 3 is superposed on the resist forming layer 2. The resist forming layer 2 contains a dried product or a semi-cured product of the photosensitive composition.

In the laminate 10, since the resist forming layer 2 contains a dried product of the photosensitive composition, it can be cured by exposure to light. Here, the stacked body 10 of the present embodiment is provided with the coating layer 3, so that the resist-forming layer 2 can be cured without being easily affected by oxygen in the atmosphere (for example, oxygen inhibition) when curing the resist-forming layer 2. That is, the resist forming layer 2 can be said to be protected by the coating layer 3. Therefore, the curability of the cured product of the resist formation layer 2 can be improved, and as a result, the developability and the resolution can be improved.

The laminate 10 can be used for manufacturing a printed wiring board, for example. In this case, the resist-forming layer 2 is irradiated with light through the covering layer 3 in a state where the insulating layer 1, the resist-forming layer 2, and the covering layer 3 are laminated, and the portion of the resist-forming layer 2 to which the light is irradiated is cured. Next, the covering layer 3 is peeled off from the resist-forming layer 2, and the resist-forming layer 2 is developed as necessary to remove unnecessary portions, whereby an electrically insulating layer (resist layer 12) can be formed from the resist-forming layer 2.

If the resist layer 12 is formed on the insulating layer 1 in this manner, the insulating layer 1 can be used as an insulating substrate in a printed wiring board. Further, the resist formation layer 2 may be used as a permanent resist (permanent film).

Therefore, the laminate 10 of the present embodiment can be particularly preferably used as a material for manufacturing a printed wiring board.

2. Detailed description of the invention

Next, the laminate 10 according to the present embodiment and the elements constituting the laminate 10 will be specifically described.

< insulating layer >

The insulating layer 1 is a layer having electrical insulation in the laminate 10. The insulating layer 1 functions as a base material (or substrate) when the laminate 10 is used, for example, for producing a printed wiring board having an electrically insulating layer. That is, the insulating layer 1 in the laminate 10 is the insulating substrate 11 in the printed wiring board 100.

Examples of the insulating layer 1 include suitable substrates such as glass, plastic, and ceramic. More specifically, the insulating layer 1 is made of a film made of a thermoplastic resin such as Polyethylene terephthalate (PET), cycloolefin Polymer (COP), Liquid Crystal Polymer (LCP), Polyimide (PI), and Polycarbonate (PC). The insulating layer 1 preferably contains at least one insulating material selected from the group consisting of cyclic olefin polymers, liquid crystal polymers, polyethylene terephthalate, and polyimide. In this case, the printed wiring board 100 produced from the laminate 10 is excellent in low dielectric characteristics. Therefore, the printed wiring board 100 can be used for electronic equipment, devices, and the like for high-frequency applications. The insulating layer 1 more preferably contains one or both of a cycloolefin polymer and a liquid crystal polymer, and the insulating layer 1 more preferably contains a cycloolefin polymer.

The insulating layer 1 is preferably surface-treated. The surface treatment is preferably at least one selected from corona treatment, UV (ultraviolet) treatment, plasma treatment, ozone treatment, primer treatment, and Electron Beam (EB: Electron Beam) treatment. In this case, when a layer made of a resin such as the resist formation layer 2, the catalyst layer 4 made of a metal, the plating layer, and the like are formed on the insulating layer 1, the adhesion between the insulating layer 1 and each layer can be improved. Further, if the insulating layer 1 is subjected to at least one of the above surface treatments, the peelability of the coating layer 3 when peeled from the laminate 10 can be improved. The surface treatment is more preferably either or both of corona treatment and UV treatment.

< resist Forming layer >

The resist formation layer 2 overlaps with the insulating layer 1 in the stacked body 10. The resist forming layer 2 contains a dried product or a semi-cured product of the photosensitive composition. The resist formation layer 2 has photocurability. The resist formation layer 2 preferably has electrical insulation. The prepreg according to the present invention includes an uncured state, not a state in which the photosensitive composition is completely cured.

The resist-forming layer 2 is cured by irradiating a dried or semi-cured product of the photosensitive composition with light, thereby forming a resist layer 12. Therefore, the resist formation layer 2 can be used as a permanent resist (permanent film). The photosensitive composition will be described in detail below. Further, the method of manufacturing the resist formation layer 2 will be described in detail below.

< coating layer >

The coating layer 3 may function as a coating material for protecting the resist forming layer 2 in the laminate 10. Therefore, in the laminate 10, the coating layer 3 can make the laminate 10 less likely to cause defects, such as deterioration or damage, of the resist forming layer 2 laminated on the insulating layer 1. In the laminate 10, when the resist-forming layer 2 is exposed by irradiating the laminate 10 with light, the coating layer 3 contributes to reducing oxygen inhibition when the resist-forming layer 2 is cured. This can improve the flatness of the resist layer 12 in the printed wiring board 100 produced from the laminate 10.

The coating layer 3 preferably has light transmittance. In this case, the resist forming layer 2 is easily exposed to light through the coating layer 3 in the laminated body 10. The light transmittance of the coating layer 3 is, for example, preferably 70% or more, more preferably 75% or more, and still more preferably 80% or more of the light transmittance of light having a wavelength of 350nm to 500nm in the coating layer 3 having a thickness of 20 μm.

The coating layer 3 is preferably one or both of polyethylene terephthalate (PET) and biaxially Oriented Polypropylene (OPP). In this case, high transparency of the laminate 10 can be maintained. Further, if the coating layer 3 has high transparency, the curability of the resist forming layer 2 in the laminate 10 can be improved, and the resist layer 12 can be easily formed more favorably. In this case, since the gas barrier property of the coating layer 3 is high, the curability of the resist forming layer 2 at the time of exposing the laminate 10 from the coating layer 3 can be improved favorably. Therefore, when the resist forming layer 2 is cured to form the resist layer 12, the developability and the resolution can be further improved.

The coating layer 3 is more preferably a PET film. In this case, the resist formation layer 2 can be made less susceptible to the effect of sink marks or the like, and defects are less likely to occur. Therefore, by irradiating the laminated body 10 with light, the irradiated light is less likely to scatter even if the resist forming layer 2 is cured through the coating layer 3. Therefore, the developability and the resolution of the resist formation layer 2 can be further improved. The shrinkage cavity is a small spherical block that can be generated inside the film. Further, if the coating layer 3 is a PET film, since the gas barrier property can be provided to the laminate 10, even if the photosensitive composition is cured by irradiating the resist-forming layer 2 with light through the coating layer 3 in the laminate 10, oxygen inhibition is less likely to occur. Therefore, the exposure amount of the irradiated light can be reduced when the resist formation layer 2 is cured.

The surface roughness Sa of the coating layer 3 is preferably 50nm or less. In this case, even if the coating layer 3 is peeled off from the laminate 10, higher flatness can be imparted to the resist-forming layer 2 (or the resist layer 12). If the resist formation layer 2 has high flatness, a conductor wiring having a more uniform shape can be formed when forming a plated layer on the printed wiring board 100. Therefore, the reliability of the printed wiring board 100 can be improved. In this case, the transparency of the resist formation layer 12 can be improved.

The surface roughness Sa of the coating layer 3 can be measured, for example, as follows. Using a laser microscope (manufactured by kirschmann, VK-X1000), a laser type: 404nm semiconductor laser, measurement range: 270 μm × 202 μm, objective lens: the measurement was performed in a 50-fold confocal mode, and the calculation was performed.

The haze value of the coating layer 3 is preferably 3.0% or less. In this case, when the resist-forming layer 2 in the laminate 10 is irradiated with light to cure the photosensitive composition, the photosensitive composition can be cured more favorably even with the coating layer 3 interposed therebetween. The haze value of the coating layer 3 is more preferably 2.0% or less, and still more preferably 1.0% or less. The haze value of the coating layer 3 can be calculated from the results of the diffusion transmittance and the total light transmittance measured using a haze meter according to JIS K7136.

Method for producing laminate

A specific example of a method for producing the laminate 10 according to the present embodiment will be described. However, the method for producing the laminate 10 is not limited to the following method.

First, a solution of the insulating layer 1 and the photosensitive composition is prepared. A resist formation layer 2 is formed on the insulating layer 1. The resist forming layer 2 is formed by, for example, a coating method or a dry film method.

In the coating method, for example, a photosensitive composition is coated on the insulating layer 1 to form a wet coating film. The method for applying the photosensitive composition can be selected from an appropriate method, for example, a dipping method, a spray method, a spin coating method, a roll coating method, a curtain coating method, and a screen printing method. Next, in order to volatilize the organic solvent in the photosensitive composition, the wet coating film is dried at a temperature in the range of, for example, 60 to 130 ℃, whereby the resist forming layer 2 can be obtained.

In the dry film method, a photosensitive composition is first applied to an appropriate support made of polyester or the like and then dried, thereby forming a dry film as a dried product of the photosensitive composition on the support. Thus, a dry film with a support having the dry film and a support for supporting the dry film can be obtained. The dry film in the dry film with a support is superposed on the insulating layer 1, then, pressure is applied to the dry film and the insulating layer 1, and next, the support is peeled off from the dry film, thereby transferring the dry film from the support onto the insulating layer 1. Thus, the resist formation layer 2 formed of a dry film can be provided on the insulating layer 1.

Next, the coating layer 3 is formed on the resist formation layer 2. Specifically, for example, the covering layer 3 is disposed on the resist forming layer 2 so as to cover the resist forming layer 2 formed on the insulating layer 1. The coating layer 3 may be pressed by applying pressure after being disposed on the resist forming layer 2. After the coating layer 3 is disposed on the resist formation layer 2, it may be heated under pressure. This makes it possible to obtain a laminate 10 having the insulating layer 1, the resist formation layer 2, and the coating layer 3 in this order.

In the case of producing the resist-forming layer 2 by the dry film method, for example, the insulating layer 1, a dry film (a dried product or a prepreg of a photosensitive composition in a film form), and the covering layer 3 may be stacked in this order, and then, laminated as necessary, thereby producing a laminate 10 having the insulating layer 1, the resist-forming layer 2, and the covering layer 3 in this order.

When a cured product having a thickness of 10 μm is produced from the photosensitive composition in the resist-forming layer 2 in the laminate 10, the transmittance of the cured product in the wavelength range of 450nm to 800nm is preferably 80% or more. In this case, the laminate 10 is excellent in transparency, and therefore, the laminate 10 can be suitably used for optical applications. In this case, the laminate 10 has high transparency, and thus contributes to the appearance and the landscape being less likely to be damaged even when it is installed outdoors. The absorption spectrum of a cured product made of the photosensitive composition can be measured by an optical analyzer such as a spectrophotometer, for example. The specific measurement method may be the same as the method described in [ measurement of transmittance ] of the example described later. The light transmittance and absorbance can be obtained by measuring the absorption spectrum of a cured product made of the photosensitive composition. The transmittance of a cured product having a thickness dimension of 10 μm at a wavelength of light in the range of 450nm to 800nm is more preferably 85% or more, still more preferably 90% or more, and particularly preferably 95% or more. The above-mentioned "cured product having a thickness dimension of 10 μm" does not mean that the thickness of the cured product produced from the photosensitive composition of the present embodiment is 10 μm.

As shown in fig. 1B, the laminate 10 is preferably formed in a roll shape. In this case, the rolled laminate 10 can be used as it is as a material for producing a printed wiring board. Specifically, the laminate 10 in a roll shape may be cut out to an appropriate size for use. When producing the laminate 10 in a roll form, the resist-forming layer 2 is formed on the insulating layer 1 in the above-described manner, and then, for example, the coating layer 3 disposed on the resist-forming layer 2 is pressed and formed in a roll form. When the resist forming layer 2 is formed by the dry film method, the insulating layer 1, the dry film, and the covering layer 3 may be similarly stacked, and the stacked body 10 may be formed into a roll shape by laminating them and molding them into a roll shape as shown in fig. 1B.

In the production of the laminate 10 shown in fig. 3, for example, a photosensitive composition is applied to one surface (front surface) of the insulating layer 1 to produce a dry film of the photosensitive composition (also referred to as a1 st resist-forming layer 21), and then the coating layer 3 (also referred to as a1 st coating layer 31) is stacked on the 1 st resist-forming layer 21. Next, a photosensitive composition is applied to the other surface (back surface) of the insulating layer 1 to prepare a dried film of the photosensitive composition (also referred to as a2 nd resist-forming layer 22), and then the coating layer 3 (also referred to as a2 nd coating layer 32) is stacked on the 2 nd resist-forming layer 22. Then, the laminate including the 1 st covering layer 31, the 1 st resist forming layer 21, the insulating layer 1, the 2 nd resist forming layer 22, and the 2 nd covering layer 32 in this order is heated and pressurized as necessary, whereby the laminate 10 can be produced. The order of overlapping the coating layer 3 after applying the photosensitive composition and the timing of heating and pressing are not limited to the above.

The thickness of the laminate 10 is not particularly limited, and may be, for example, 20 μm or more. If the thickness of the laminate 10 is 350 μm or less, for example, when the printed wiring board 100 produced from the laminate 1 is used as an optical component such as a touch panel, a flexible printed wiring board 100 can be easily produced.

The thickness of the insulating layer 1 in the laminate 10 is not particularly limited, and may be an appropriate size, and may be, for example, 1 μm to 300 μm. In this case, the laminate 10 can be easily formed into a roll shape. In this case, the printed wiring board 100 made of the laminate 10 can be easily thinned.

The thickness (thickness) of the resist-forming layer 2 in the laminate 10 is not particularly limited, and is preferably 20 μm or less, for example. If the thickness of the resist-forming layer 2 is 0.5 μm to 20 μm, the developability and the resolution can be further improved when the resist layer 12 is formed from the resist-forming layer 2. The resist forming layer 2 is preferably 0.8 to 15 μm, more preferably 1.0 to 13 μm, and particularly preferably 1.5 to 10 μm. Within this range, the printed wiring board 100 produced from the laminate 10 can be suitably used for producing electronic materials (optical components) such as touch panels.

The thickness of the coating layer 3 in the laminate 10 is not particularly limited, and when the resist-forming layer 2 is irradiated with light through the coating layer 3, the thickness may be, for example, a thickness dimension in which the transmittance of light having a wavelength of 350nm to 500nm is 70% or more.

As shown in fig. 3, the laminate 10 may include an insulating layer 1, a plurality of resist formation layers 2, and a plurality of coating layers 3. Specifically, the laminate 10 may be one in which: resist forming layers 2(21,22) respectively overlapping both surfaces of the insulating layer 1, and covering layers 3(31,32) respectively overlapping the surfaces of the resist forming layers 2(21,22) on the opposite sides of the insulating layer 1. Further, without being limited thereto, a multilayer body 10 in which a plurality of resist formation layers 2 and a plurality of coating layers 3 are alternately stacked on the insulating layer 1 may be used. In this case, the thickness of the laminate 10 may be 50 μm or more, for example.

The laminate 10 may include layers other than the insulating layer 1, the resist formation layer 2, and the coating layer 3 described above. For example, the laminate 1 preferably includes the catalyst layer 4 between the insulating layer 1 and the resist formation layer 2. That is, the catalyst layer 4 can function as a primer layer in the production of a conductor layer such as a plating layer. If the laminate 10 includes the catalyst layer 4, the adhesion between the insulating layer 1 and the resist formation layer 2 can be further improved. Thus, if the printed wiring board 100 is produced from the laminate 10, high adhesion between the insulating substrate 11 and the resist layer 12 in the printed wiring board 100 can be maintained, and the printed wiring board 100 is less likely to suffer from problems such as peeling.

When the laminate 10 includes the catalyst layer 4, for example, a material for forming the catalyst layer 4 (hereinafter, also referred to as a catalyst layer material) is applied to the insulating layer 1 to form the catalyst layer 4, then a photosensitive composition is applied to the catalyst layer 4, and is dried by heating as necessary to form the resist-forming layer 2, and then the coating layer 3 is formed on the resist-forming layer 2.

As the material for the catalyst layer, a material having a catalytic function which can suitably improve the adhesion can be used. The catalyst material may be at least one material selected from metals such as palladium, coupling agents such as silane coupling agents, amine compounds which are compounds having amino groups, and thiol compounds having SH groups. The material for the catalyst layer may be in the form of powder or liquid. The catalyst layer 4 can be produced by, for example, coating or impregnating a material for a catalyst layer on the insulating layer 1.

The laminate 10 may include an appropriate functionality-providing layer such as a hard coat layer, an anchor layer, an adhesive layer, and an ultraviolet absorbing layer.

For example, when the printed wiring board 100 is produced from the laminate 10 shown in fig. 3, it is preferable to provide a hard coat layer (not shown) that is superimposed on at least one of the surfaces of the insulating layer 1. Further, the hard coat layer preferably contains an ultraviolet absorber. In this case, when exposing the resist formation layer 2 in the stacked body 10, the resist formation layer 2 can be inhibited from transmitting light from one surface to the other surface side. Specifically, for example, when the 1 st resist formation layer 21 is exposed, light irradiated to the 1 st resist formation layer 21 through the 1 st covering layer 31 can be suppressed from being transmitted to the 2 nd resist formation layer 22 on the opposite side of the 1 st resist formation layer 21 through the insulating layer 1. The ultraviolet absorber is not particularly limited as long as it can absorb ultraviolet rays, and specifically, it includes at least one component selected from a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, a triazine-based ultraviolet absorber, a benzoate-based ultraviolet absorber, and a cyanoacrylate-based ultraviolet absorber. The hard coat layer is a layer different from the insulating layer 1. Further, the insulating layer 1 also preferably contains an ultraviolet absorber. In this case, even if the hard coat layer (ultraviolet absorbing layer) is not used, when the resist formation layer 2 in the laminate 10 is exposed, the resist formation layer 2 can be inhibited from transmitting light from one surface to the other surface side.

< printed wiring board >

Next, the method for manufacturing the printed wiring board according to the present embodiment will be specifically described with reference to fig. 2A to 2D.

The laminate 10 described above can be used to produce the printed wiring board 100. The printed wiring board 100 of the present embodiment includes: an insulating substrate 11 including the insulating layer 1 in the laminate 10, and a resist layer 12 made of the resist-forming layer 2 in the laminate 10.

The printed wiring board 100 includes an insulating substrate 11 and a resist layer 12. In fig. 2D, the printed wiring board 100 further includes a conductor layer 13 (conductor wiring 131).

To produce the printed wiring board 100, first, the laminate 10 is prepared. In fig. 2A to 2D, the laminate 10 shown in fig. 1A, that is, the laminate 10 including the insulating layer 1, the catalyst layer 4, the resist forming layer 2, and the coating layer 3 in this order is used, but the present invention is not limited thereto, and for example, the catalyst layer 4 may not be provided. The method for producing the laminate 10 is as described above.

As shown in fig. 2A, the resist formation layer 2 is partially cured as shown in fig. 2B by exposing the resist formation layer 2 to light. In the present embodiment, the resist-forming layer 2 is irradiated with light through the coating layer 3 in the laminate 10. That is, the method of manufacturing the printed wiring board 100 of the present embodiment includes: the resist forming layer 2 is exposed to light from above the coating layer 3 through the coating layer 3. Thereby, the resist layer 12 is formed on the insulating layer 1 (insulating substrate 11) in the stacked body 10. The coating layer 3 may be peeled off and then exposed to light. In this case, when the resist formation layer 2 is exposed, the influence of the shrinkage cavity at the time of exposure can be reduced, which contributes to improvement of resolution.

In order to expose the resist-forming layer 2 partially through the covering layer 3, for example, as shown in fig. 2A, after a negative mask M is brought into contact with the covering layer 3, the resist-forming layer 2 is irradiated with ultraviolet rays through the covering layer 3. The negative mask M includes an exposed portion Ma that transmits ultraviolet rays and a non-exposed portion Mb that blocks ultraviolet rays, and the non-exposed portion Mb is provided at a position corresponding to, for example, the uncured portion 2b of the resist formation layer 2. The unexposed portion Mb of the negative mask M is, for example, a portion where a plating layer is formed. The negative mask M is an optical device such as a mask or a dry plate. The light source of ultraviolet rays may be selected from, for example, chemical lamps, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, LEDs, YAG, g-line (436nm), h-line (405nm), i-line (365nm), and combinations of two or more of g-line, h-line, and i-line. The light source of the ultraviolet ray is not limited to this, and any light source may be used as long as it can irradiate the ultraviolet ray that can cure the photosensitive composition.

The exposure method may be a method other than the method using the negative mask. For example, the resist forming layer 2 may be exposed to light using a direct writing method in which ultraviolet light emitted from a light source is irradiated only to a portion to be exposed (the exposure portion Ma) in order to cure the resist forming layer 2. The light source suitable for the direct writing method may be selected from, for example, a chemical lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an LED, YAG, a g-line (436nm), an h-line (405nm), an i-line (365nm), and a combination of two or more of the g-line, the h-line, and the i-line. The light source of the ultraviolet ray is not limited to this, and any light source may be used as long as it can irradiate the ultraviolet ray that can cure the photosensitive composition.

When the resist layer 12 is produced by exposing the entire surface of the resist-forming layer 2 to light (entire surface exposure), the metal-clad laminate can be produced by peeling the coating layer 3 from the laminate 10, and then plating or disposing a metal foil on the resist layer 12. Of course, when the laminate 10 includes the resist formation layer 2 (e.g., the 1 st resist formation layer 21 and the 2 nd resist formation layer 22) and the coating layer 3 (e.g., the 1 st coating layer 31 and the 2 nd coating layer 32) on both surfaces of the insulating layer 1, a metal-clad laminate may be formed on both surfaces.

If the resist formation layer 2 is exposed to light, a cured portion (cured portion 2a) and an uncured portion (uncured portion 2b) in the resist formation layer 2 may be formed in the stacked body 10. For example, as shown in fig. 2A, when the resist formation layer 2 is exposed to light through the negative mask M, the exposed portions of the dried material or the semi-cured material of the photosensitive resin composition are cured in accordance with the exposed portions Ma of the negative mask M, while the unexposed portions are not cured in accordance with the unexposed portions Mb of the negative mask M.

Next, as shown in fig. 2B, the coating layer 3 is peeled off from the exposed laminate 10, whereby the resist forming layer 2 including the cured portion 2a and the uncured portion 2B is exposed on the insulating layer 1.

Next, the exposed resist forming layer 2 is subjected to a developing process, whereby a resist layer 12 can be formed from the resist forming layer 2. Specifically, by performing the development treatment, the cured portion 2a of the resist formation layer 2 shown in fig. 2B remains, and the uncured portion 2B is removed. Thereby, as shown in fig. 2C, the resist layer 12 can be formed. In the present embodiment, the resist layer 12 is formed as the cured portion 2a because the uncured portion 2b of the resist formation layer 2 is removed as described above.

In the development treatment, a suitable developer according to the composition of the photosensitive composition can be used. The developer is, for example, an aqueous alkaline solution containing at least one of an alkali metal salt and an alkali metal hydroxide, or an organic amine. More specifically, the basic aqueous solution contains at least one component selected from sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and lithium hydroxide, for example. The solvent in the alkaline aqueous solution may be water alone or a mixture of water and a hydrophilic organic solvent such as a lower alcohol. The organic amine contains, for example, at least one component selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine.

The developer is preferably an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide, and particularly preferably an aqueous sodium carbonate solution. In this case, the work environment can be improved and the burden of waste disposal can be reduced.

Thus, the insulating layer 1 in the laminate 10 becomes the insulating substrate 11, and the substrate 20 provided with the resist layer 12 containing a cured product of the photosensitive composition on the insulating substrate 11 can be obtained.

Next, the conductive layer 13 can be formed by performing plating treatment on the substrate 20. For example, plating treatment may be performed on the resist layer 12 formed of the resist formation layer 2. That is, the resist layer 12 may also be used as a plating resist layer. Therefore, when the printed wiring board 100 is produced from the laminate 10, the printed wiring board 100 may include the conductor layer 13 including a plating layer such as hole plating. For example, the printed wiring board 100 may be provided with a conductive wiring 131 such as hole plating by exposing and developing the resist forming layer 2 in the laminate 10 and then plating the removed portion of the resist layer 12 (see fig. 2D).

Specifically, as shown in fig. 2D, in the resist layer 12, for example, the conductor layer 13 (more specifically, the conductor wiring 131) can be formed by applying plating treatment to the gap between the adjacent cured portions 2a formed by the resist-forming layer 2 (the position where the uncured portions 2b are removed). In the above description, the method has been described using the so-called full-additive method, but the method of plating is not limited thereto, and an appropriate method may be used.

Before the plating treatment is performed, the resist layer 12 may be subjected to either or both of heat treatment and UV treatment. In this case, the adhesion and plating resistance of the resist layer 12 are improved.

Further, the surface of the resist layer 12 can be roughened by performing roughening treatment on the resist layer 12 before performing the plating treatment. For example, when a part of the outer surface of the resist layer 12 and the inner surface of the gap of the resist layer are roughened as a whole, a normal desmear treatment using an oxidizing agent may be performed. For example, the outer surface of the resist layer 12 is brought into contact with an oxidizing agent to impart a rough surface to the resist layer 12. However, the method may be appropriately applied to a method of not imparting a rough surface to the cured product, such as plasma treatment, corona treatment, UV treatment, ozone treatment, or primer treatment. The oxidizing agent may be an oxidizing agent that can be obtained as a desmear solution. For example, the oxidizing agent may be constituted by a commercially available swelling liquid for desmear and desmear liquid. Such an oxidizing agent may contain, for example, at least 1 permanganate selected from sodium permanganate and potassium permanganate. The desmear treatment may be performed by performing a plasma treatment before the plating treatment. In this case, when the resist forming layer 2 is exposed to light and then subjected to a developing treatment, if a resist residue is generated, the resist residue can be removed.

In this way, the printed wiring board 100 including the insulating substrate 11, the resist layer 12, and the conductor layer 13 can be manufactured. In the present embodiment, the insulating layer 1 in the laminate 10 serves as the insulating substrate 11 in the printed wiring board 100, and the resist forming layer 2 in the laminate 10 serves as the insulating resist layer 12 in the printed wiring board 100. That is, the insulating layer 1 in the stacked body 10 can be used as an insulating base material, and the resist forming layer 2 can be used as a permanent resist.

The thickness of the resist layer 12 in the printed wiring board 100 is not particularly limited, but is preferably 0.5 to 20 μm. The thickness of the resist layer 12 is more preferably 0.8 to 15 μm, still more preferably 1.0 to 13 μm, and particularly preferably 1.5 to 10 μm. The resist layer 12 can be preferably used as, for example, an interlayer insulating layer, as described above. When the resist layer 12 is used as an interlayer insulating layer, the thickness is preferably in the range of 0.5 to 20 μm, more preferably 1 to 10 μm, in order to ensure high resolution of the interlayer insulating layer.

Photosensitive composition

Next, the components that can be contained in the photosensitive composition for producing the resist-forming layer 2 according to the present embodiment will be described in detail. In the following description, "(meth) acrylic acid" means at least one of "acrylic acid" and "methacrylic acid". For example, (meth) acrylate refers to at least one of acrylate and methacrylate.

The photosensitive composition can be suitably used for producing the resist-forming layer 2 of the present embodiment. Therefore, in the photosensitive composition of the present embodiment, an electrical insulating layer such as a plating resist layer, a solder resist layer, and an interlayer insulating layer can be particularly favorably formed from the dried dry film or from the coating film of the photosensitive composition.

(carboxyl group-containing resin)

The photosensitive composition preferably contains a carboxyl group-containing resin (a). The carboxyl group-containing resin (a) preferably contains a carboxyl group-containing resin (a1), the carboxyl group-containing resin (a1) being produced by reacting an epoxy compound (a1) having at least 2 epoxy groups with a carboxylic acid (a2) having an ethylenically unsaturated group, with an acid anhydride (A3) containing an acid dianhydride (a4), and the acid anhydride (A3).

In the present embodiment, the carboxyl group-containing resin (a) contains a carboxyl group-containing resin (a 1). The synthesis of the carboxyl group-containing resin (A1) will be specifically described.

The product (hereinafter also referred to as "product (X)") produced by the reaction of the epoxy compound (a1) and the carboxylic acid (a2) contains a product (X1) produced by the reaction of each of the two epoxy groups of the epoxy compound (a1) with the carboxyl group of the carboxylic acid (a 2). The product (X1) has a secondary hydroxyl group formed by the reaction of an epoxy group and a carboxyl group, and an ethylenically unsaturated group derived from the carboxylic acid (a 2). The product (X) may contain a product (X2) produced by reacting only one of the two epoxy groups in the epoxy compound (a1) with the carboxyl group in the carboxylic acid (a 2). The product (X2) has a secondary hydroxyl group, an ethylenically unsaturated group, and an epoxy group. The product (X) may further contain an unreacted epoxy compound (a 1). That is, the product (X) may contain a component having an epoxy group, and this component may contain at least one of the product (X2) and the epoxy compound (a 1).

The carboxyl group-containing resin (a1) produced by the reaction of the product (X) with the acid anhydride (A3) contains a component (X3) produced by the reaction of the product (X1) and the acid dianhydride (a 4). The component (X3) has a carboxyl group derived from the acid dianhydride (a 4). Further, since a crosslinking reaction based on the acid dianhydride (a4) can be generated, the molecular weight distribution of the component (X3) is easily generated. The carboxyl group-containing resin (a1) may contain an unreacted product (X1).

Further, the acid anhydride (a3) may contain an acid monoanhydride (a 5). Therefore, the carboxyl group-containing resin (a1) produced by the reaction of the product (X) with the acid anhydride (A3) contains the component (X4) produced by the reaction of the product (X1) and the acid monoanhydride (a 5). The component (X4) has a carboxyl group derived from the acid monoanhydride (a 5).

Thus, the carboxyl group-containing resin (a1) can have an appropriate molecular weight distribution. Therefore, the carboxyl group-containing resin (a1) having a desired molecular weight and polydispersity can be easily obtained. That is, a carboxyl group-containing resin (A1) having a number average molecular weight Mn of 500 to 2500 and a polydispersity Mw/Mn in the range of 1.2 to 2.8 can be obtained.

The carboxyl group-containing resin (a) preferably contains a resin having an epoxy group. If the carboxyl group-containing resin (a) contains a resin having an epoxy group, the photosensitive composition may have reactivity with the remaining carboxyl group. Therefore, the photosensitive composition can exhibit thermosetting properties.

The carboxyl group-containing resin (a1) has an ethylenically unsaturated group derived from the carboxylic acid (a2) having an ethylenically unsaturated group and thus has photoreactivity. Therefore, the carboxyl group-containing resin (a1) can impart photosensitivity (specifically, ultraviolet curability) to the photosensitive composition. Further, since the carboxyl group-containing resin (a1) has a carboxyl group derived from the acid anhydride (a3), the photosensitive composition can be imparted with developability by an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide. Further, in the case where the acid anhydride (A3) contains the acid dianhydride (a4), the molecular weight of the carboxyl group-containing resin (a1) depends on the number of crosslinks of the acid dianhydride (a 4). Thus, a carboxyl group-containing resin (a1) having an appropriately adjusted acid value and molecular weight can be obtained. In addition, in the case where the acid anhydride (A3) contains the acid dianhydride (a4), the amount of the acid dianhydride (a4) is controlled, whereby the carboxyl group-containing resin (a1) having a desired molecular weight and acid value can be easily obtained.

The carboxyl group-containing resin (A1) preferably has a number average molecular weight of 500 to 2500. In this case, the developability of the photosensitive composition by the alkaline aqueous solution is easily improved. The number average molecular weight is more preferably 800 to 2300, still more preferably 900 to 2200, and particularly preferably 1000 to 2000.

The polydispersity Mw/Mn of the carboxyl group-containing resin (A1) is preferably 1.2 to 2.8. The polydispersity Mw/Mn of the carboxyl group-containing resin (A1) is more preferably 1.3 to 2.7, still more preferably 1.4 to 2.6, and particularly preferably 1.5 to 2.5. The polydispersity is a ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the carboxyl group-containing resin (a 1).

The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the carboxyl group-containing resin (a1) can be calculated from the results of molecular weight measurement using gel permeation chromatography. The molecular weight measurement by gel permeation chromatography can be performed, for example, under the following conditions.

GPC apparatus: shodex System 11 manufactured by Showa Denko K.K.,

column: 4 SHODEX KF-800P, KF-005, KF-003 and KF-001 are connected in series,

mobile phase: the reaction mixture of THF and water is treated by the following steps of THF,

flow rate: 1 ml/min of the mixture is added,

column temperature: at a temperature of 45 c,

a detector: the amount of the RI,

conversion: polystyrene.

The acid value of the carboxyl group-containing resin (A1) is preferably 55mgKOH/g to 130 mgKOH/g. In this case, the resolution of a cured product made of the photosensitive composition is particularly improved. The acid value of the carboxyl group-containing resin (A1) is more preferably 60mgKOH/g to 120mgKOH/g, still more preferably 60mgKOH/g to 110mgKOH/g, and particularly preferably 60mgKOH/g or more and less than 75 mgKOH/g.

The reaction conditions for synthesizing the raw material of the carboxyl group-containing resin (a1) and the carboxyl group-containing resin (a1) will be described in detail.

The epoxy compound (a1) having at least 2 epoxy groups may contain, for example, a compound having a bisphenol fluorene skeleton. The carboxyl group-containing resin (a1) is, for example, a reaction product of an epoxy compound having a bisphenol fluorene skeleton represented by the following formula (1) and a carboxylic acid (a2) having an ethylenically unsaturated group, and an acid anhydride (a 3). That is, the carboxyl group-containing resin (a1) can be synthesized by: an epoxy compound having a bisphenol fluorene skeleton represented by the following formula (1) is reacted with a carboxylic acid (a2) having an ethylenically unsaturated group, and the product thus obtained is reacted with an acid anhydride (a 3). If the photosensitive composition contains the carboxyl group-containing resin (A1), the cured product of the photosensitive composition can have high heat resistance and insulation reliability. In addition, when the carboxyl group-containing resin (A1) has a bisphenol fluorene skeleton, light in the wavelength range of 300 to 330nm is easily absorbed, and thus the resolution of a cured product made of the photosensitive composition can be improved. In addition, when the carboxyl group-containing resin (a1) has a bisphenol fluorene skeleton, the resin has a bulky structure, so that diffusion of generated radical species can be prevented, and the resolution of a cured product produced from the photosensitive composition can be improved even when the resin is exposed to light having a wavelength region of 300 to 330 nm.

R in the formula (1)₁～R₈Each of which may be hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen atom. This is because, even if hydrogen in the aromatic ring is substituted with a low molecular weight alkyl group or a halogen atom, the physical properties of the carboxyl group-containing resin (a1) are not adversely affected, and the heat resistance and flame retardancy of a cured product of the photosensitive composition containing the carboxyl group-containing resin (a1) are rather improved.

The epoxy compound (a1) may have a structure represented by the following formula (2), for example. N in the formula (2) is, for example, an integer in the range of 0 to 20. In order to appropriately control the molecular weight of the carboxyl group-containing resin (A1), the average value of n is particularly preferably in the range of 0 to 1. When the average value of n is in the range of 0 to 1, it is easy to suppress an excessive increase in molecular weight even when the acid anhydride (a3) contains an acid dianhydride. In the formula (2), R₁～R₈Each independently represents hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen atom.

The carboxylic acid having an ethylenically unsaturated group (a2) may contain, for example, a compound having only 1 ethylenically unsaturated group in one molecule. More specifically, the carboxylic acid (a2) having an ethylenically unsaturated group may contain, for example, a monomer selected from acrylic acid, methacrylic acid, ω -carboxy-polycaprolactone (n ≈ 2) monoacrylate, crotonic acid, cinnamic acid, 2-acryloyloxyethylsuccinic acid, 2-methacryloyloxyethylsuccinic acid, 2-acryloyloxyethylphthalic acid, 2-methacryloyloxyethyl phthalic acid, 2-acryloyloxypropylphthalic acid, 2-methacryloyloxypropyl phthalic acid, 2-acryloyloxyethylmaleic acid, 2-methacryloyloxyethyl maleic acid, β -carboxyethylacrylate, 2-acryloyloxyethyltetrahydrophthalic acid, 2-methacryloyloxyethyl tetrahydrophthalic acid, a monomer having a carboxyl group in the molecule, a salt thereof, and a salt thereof, At least one compound selected from 2-acryloyloxyethylhexahydrophthalic acid and 2-methacryloyloxyethylhexahydrophthalic acid. It is preferable that the carboxylic acid (a2) having an ethylenically unsaturated group contains acrylic acid.

When the epoxy compound (a1) is reacted with the carboxylic acid (a2), an appropriate method can be employed. For example, a reactive solution is obtained by adding a carboxylic acid (a2) to a solvent solution of an epoxy compound (a1), and further adding a thermal polymerization inhibitor and a catalyst as necessary, followed by stirring and mixing. The product (X) can be obtained by reacting the reactive solution at a temperature of preferably 60 to 150 ℃ and particularly preferably 80 to 120 ℃ by a usual method. The solvent in this case may contain at least one member selected from the group consisting of ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate and propylene glycol monomethyl ether acetate, and dialkyl glycol ethers. The thermal polymerization inhibitor contains, for example, at least one of hydroquinone and hydroquinone monomethyl ether. The catalyst may contain tertiary amines such as benzyldimethylamine and triethylamine, quaternary ammonium salts such as trimethylbenzylammonium chloride and methyltriethylammonium chloride, triphenylphosphine and triphenyl phosphine

At least one component of (a).

The catalyst particularly preferably contains triphenylphosphine. That is, the epoxy compound (a1) and the carboxylic acid (a2) are preferably reacted in the presence of triphenylphosphine. In this case, the ring-opening addition reaction of the epoxy group in the epoxy compound (a1) and the carboxylic acid (a2) is particularly promoted, and a reaction rate (conversion rate) of 95% or more, or 97% or more, or substantially 100% can be achieved.

When the epoxy compound (a1) and the carboxylic acid (a2) are reacted, the amount of the carboxylic acid (a2) is preferably 0.7 to 1.0 mol based on 1 mol of the epoxy group of the epoxy compound (a 1). In this case, a photosensitive composition having excellent photosensitivity and stability can be obtained.

The product (X) obtained in this manner has a hydroxyl group formed by the reaction of the epoxy group of the epoxy compound (a1) and the carboxyl group of the carboxylic acid (a 2).

The acid dianhydride (a4) is a compound having two anhydride groups. The acid dianhydride (a4) may contain an acid anhydride of a tetracarboxylic acid. The acid dianhydride (a4) may contain, for example, a dianhydride selected from 1,2,4, 5-benzenetetracarboxylic acid dianhydride, benzophenone tetracarboxylic acid dianhydride, methylcyclohexene tetracarboxylic acid dianhydride, naphthalene-1, 4,5, 8-tetracarboxylic acid dianhydride, ethylene tetracarboxylic acid dianhydride, 9 '-bis (3, 4-dicarboxyphenyl) fluorene dianhydride, glycerol bistrimellitic anhydride monoacetate, ethylene glycol bistrimellitic anhydride, 3',4,4' -diphenylsulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9 b-hexahydro-5 (tetrahydro-2, 5-dioxo-3-furanyl) naphtho [ 1,2-c ] furan-1, 3-dione, 1,2,3, 4-butanetetracarboxylic dianhydride and 3,3',4,4' -biphenyltetracarboxylic dianhydride. Particularly preferably, the acid dianhydride (a4) contains 3,3',4,4' -biphenyltetracarboxylic dianhydride. In this case, while ensuring good developability of the photosensitive composition, the adhesiveness of a film made of the photosensitive composition can be further suppressed, and the insulation reliability and plating resistance of the cured product can be further improved.

The acid anhydride (a3) may comprise an acid monoanhydride (a 5). The acid monoanhydride (a5) is a compound having one acid anhydride group. The acid monoanhydride (a5) may comprise an anhydride of a dicarboxylic acid. The acid monoanhydride (a5) may contain, for example, at least one compound selected from phthalic anhydride, 1,2,3, 6-tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, methylsuccinic anhydride, maleic anhydride, citraconic anhydride, glutaric anhydride, cyclohexane-1, 2, 4-tricarboxylic acid-1, 2-anhydride, and itaconic anhydride. In this case, while ensuring good developability of the photosensitive composition, the adhesiveness of a film made of the photosensitive composition can be further suppressed, and the insulation reliability and plating resistance of the cured product can be further improved.

When the product (X) is reacted with the acid anhydride (a3), an appropriate method can be employed. For example, the acid anhydride (a3) is added to a solvent solution of the product (X), and if necessary, a thermal polymerization inhibitor and a catalyst are added and mixed with stirring to obtain a reactive solution. The carboxyl group-containing resin (A1) can be obtained by reacting the reactive solution at a temperature of preferably 60 to 150 ℃ and particularly preferably 80 to 120 ℃ by a usual method. As the solvent, the catalyst and the polymerization inhibitor, any suitable ones may be used, and the solvent, the catalyst and the polymerization inhibitor used in the synthesis of the product (X) may be used as they are.

The catalyst particularly preferably contains triphenylphosphine. That is, it is preferable to react the product (X) with the acid anhydride (a3) in the presence of triphenylphosphine. In this case, the reaction of the secondary hydroxyl group in the product (X) with the acid anhydride (a3) is particularly promoted, and a reaction rate (conversion rate) of 90% or more, 95% or more, 97% or more, or substantially 100% can be achieved.

When the acid anhydride (a3) contains the acid dianhydride (a4), the amount of the acid dianhydride (a4) is preferably 0.01 to 0.24 mol based on 1 mol of the epoxy group of the epoxy compound (a 1). In this case, the carboxyl group-containing resin (a1) having an appropriately adjusted acid value and molecular weight can be easily obtained. The amount of the acid dianhydride (a4) is more preferably 0.04 to 0.22 mol.

In addition, when the acid anhydride (a3) further contains the acid monoanhydride (a5), the amount of the acid monoanhydride (a5) is preferably 0.05 to 0.7 mol based on 1 mol of the epoxy group of the epoxy compound (a 1). In this case, the carboxyl group-containing resin (a1) having an appropriately adjusted acid value and molecular weight can be easily obtained.

It is also preferable to react the product (X) with the acid anhydride (a3) under air bubbling. In this case, excessive increase in the molecular weight of the carboxyl group-containing resin (a1) produced can be suppressed, and the developability of the photosensitive composition by the alkaline aqueous solution is particularly improved.

The components other than the carboxyl group-containing resin (a1) in the photosensitive composition will be described.

As described above, the photosensitive composition contains, for example, a carboxyl group-containing resin (a) containing a resin having an ethylenically unsaturated group and a carboxyl group, a photopolymerization initiator (B), and a photopolymerizable compound (C).

The carboxyl group-containing resin (a) may contain only the carboxyl group-containing resin (a1) or may contain a photosensitive resin (a2) other than the carboxyl group-containing resin (a 1). The photosensitive resin (a2) contains, for example, a resin which is a reaction product of a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group and an ethylenically unsaturated compound having an epoxy group. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group. The photosensitive resin (a2) can be obtained by reacting a part of the carboxyl groups in the polymer with an ethylenically unsaturated compound having an epoxy group. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group. The ethylenically unsaturated compound having a carboxyl group contains compounds such as acrylic acid, methacrylic acid, ω -carboxy-polycaprolactone (n ≈ 2) monoacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, and the like. The ethylenically unsaturated compound having no carboxyl group includes compounds such as 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, linear or branched aliphatic or alicyclic (meth) acrylates in which a part of unsaturated bonds may be present in the ring), and the like. The ethylenically unsaturated compound having an epoxy group preferably contains glycidyl (meth) acrylate.

(photopolymerization initiator)

The photosensitive composition preferably contains a photopolymerization initiator (B). The photopolymerization initiator (B) is a component capable of improving the photosensitivity of the photosensitive composition. The photopolymerization initiator (B) preferably contains at least 1 kind selected from, for example, an α -aminoalkylbenzophenone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator. In this case, when the photosensitive composition is exposed by irradiation with light such as ultraviolet light, high photosensitivity can be imparted to the photosensitive composition. The photopolymerization initiator (B) preferably further contains an acylphosphine oxide photopolymerization initiator. In this case, the photosensitive composition can be provided with high photosensitivity, and the composition can maintain high transparency with little coloration.

The α -aminoalkylphenone-based photopolymerization initiator may contain at least one component selected from, for example, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, and 2- (dimethylamino) -2- [ (4-methylphenyl) methyl ] -1- [4- (4-morpholino) phenyl ] -1-butanone.

The acylphosphine oxide-based photopolymerization initiator may contain, for example, a monoacylphosphine oxide-based photopolymerization initiator selected from 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4, 6-trimethylbenzoyl-ethyl-phenyl-phosphinic acid ester and the like, and bis- (2, 6-dichlorobenzoyl) -phenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -2, 5-dimethylphenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) phenylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2, at least one component selected from bisacylphosphine oxide photopolymerization initiators such as 4, 4-trimethylpentylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2, 5-dimethylphenylphosphine oxide, bis- (2,4, 6-trimethylbenzoyl) phenylphosphine oxide, and (2,5, 6-trimethylbenzoyl) -2,4, 4-trimethylpentylphosphine oxide.

The oxime ester photopolymerization initiator may contain at least one component selected from 1, 2-octanedione-1- [4- (phenylthio) -2- (oxo-benzoyloxime) ], and ethanone-1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -1- (O-acetyloxime).

The photosensitive composition may further contain an appropriate photopolymerization accelerator, sensitizer, and the like. For example, the photosensitive composition may contain a hydroxyketone selected from the group consisting of 1-hydroxy-cyclohexyl-phenyl-ketone, methyl phenylglyoxylate, 1- [4- (2-hydroxyethoxy) -phenyl ] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl ] phenyl } -2-methyl-propan-1-one, and 2-hydroxy-2-methyl-1-phenyl-propan-1-one; benzoin and alkyl ethers thereof; acetophenones such as acetophenone and benzyl dimethyl ketal; anthraquinones such as 2-methylanthraquinone; thioxanthones such as 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone and 2, 4-diisopropylthioxanthone; benzophenones such as benzophenone, 4-benzoyl-4' -methyldiphenyl sulfide, and bis (diethylamino) benzophenone; xanthones such as 2, 4-diisopropylxanthone; and α -hydroxyketones such as 2-hydroxy-2-methyl-1-phenyl-propan-1-one; at least one component selected from compounds containing nitrogen atoms such as 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholine-1-one. The photosensitive composition may contain a photopolymerization initiator (B) and an appropriate photopolymerization accelerator such as tertiary amine-based photopolymerization initiators including ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, and 2-dimethylaminoethyl benzoate, and a sensitizer. The photosensitive composition may contain at least one of a photopolymerization initiator for visible light exposure and a photopolymerization initiator for near-infrared light exposure as necessary. The photosensitive adhesive composition may contain a photopolymerization initiator (B), a coumarin derivative such as 7-diethylamino-4-methylcoumarin, a cyanine series, a xanthene series, or the like as a sensitizer for laser exposure.

(photopolymerizable Compound)

The photosensitive composition preferably contains a photopolymerizable compound (C). The photopolymerizable compound (C) can impart photocurability to the photosensitive composition. The photopolymerizable compound (C) preferably contains at least one selected from the group consisting of a photopolymerizable monomer and a photopolymerizable prepolymer. Examples of the photopolymerizable monomer include monofunctional (meth) acrylates selected from 2-hydroxyethyl (meth) acrylate; and at least one compound selected from polyfunctional (meth) acrylates such as diethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epsilon-caprolactone-modified pentaerythritol hexaacrylate, and tricyclodecane dimethanol di (meth) acrylate.

The photopolymerizable prepolymer may contain, for example, at least one compound selected from the group consisting of a prepolymer obtained by polymerizing a monomer having an ethylenically unsaturated bond and then adding an ethylenically unsaturated group, and an oligomeric (meth) acrylate prepolymer. The oligo (meth) acrylate prepolymer may contain at least one component selected from the group consisting of epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate, alkyd (meth) acrylate, silicone (meth) acrylate, and spiro (meth) acrylate, for example.

In particular, the photopolymerizable compound (C) preferably contains at least one of a difunctional unsaturated compound and a trifunctional unsaturated compound, that is, at least one of a compound having 2 unsaturated bonds in one molecule or a compound having 3 unsaturated bonds in one molecule. In this case, the resolution in the case of exposing and developing a dry film made of the photosensitive composition is improved, and the developability of the photosensitive composition by an alkaline aqueous solution is particularly improved.

(other Components)

The photosensitive composition may contain components other than those described above. For example, the photosensitive composition preferably further contains an epoxy compound (D). In this case, thermosetting properties can be imparted to the photosensitive composition. In this case, the plating resistance and the insulation property of the cured product made of the photosensitive composition can be improved.

The epoxy compound (D) may contain, for example, a crystalline epoxy resin (D1). The epoxy compound (D) may further contain a non-crystalline epoxy resin (D2). Here, the "crystalline epoxy resin" is an epoxy resin having a melting point, and the "amorphous epoxy resin" is an epoxy resin having no melting point.

The crystalline epoxy resin (D1) preferably contains, for example, a compound selected from the group consisting of 1,3, 5-tris (2, 3-epoxypropyl) -1,3, 5-triazine-2, 4,6(1H,3H,5H) -trione, a hydroquinone-type crystalline epoxy resin (specific example: the trade name YDC-1312 manufactured by Nippon Tekko Kasei K.K.), a biphenyl-type crystalline epoxy resin (specific example: the trade name YX-4000 manufactured by Mitsubishi Kasei K.K.), a diphenyl ether-type crystalline epoxy resin (specific example: the product number YSLV-80DE manufactured by Nippon Tekko Kasei K.K.), a bisphenol-type crystalline epoxy resin (specific example: the product number YSLV-80XY manufactured by Nippon Teshi Kasei K.K.), and a tetraphenol ethane-type crystalline epoxy resin (specific example: the product number GTR-1800 manufactured by Nippon Kasei K.K.), One or more components selected from bisphenol fluorene type crystalline epoxy resins (specifically, epoxy resins having a structure (S7)).

The crystalline epoxy resin (D1) preferably has 2 epoxy groups in 1 molecule. In this case, the cured product can be made less likely to crack during repeated temperature changes.

The crystalline epoxy resin (D1) preferably has an epoxy equivalent of 150 to 300 g/eq. The epoxy equivalent is a gram weight of the crystalline epoxy resin (D1) containing 1 gram equivalent of epoxy group. The crystalline epoxy resin (D1) has a melting point. The melting point of the crystalline epoxy resin (D1) is, for example, 70 to 180 ℃.

In particular, the epoxy compound (D) preferably contains a crystalline epoxy resin (D1-1) having a melting point of 110 ℃ or lower. In this case, the developability of the photosensitive agent composition by the alkaline aqueous solution is particularly improved. In this case, the resolution (aperture opening property) of the cured product layer made of the photosensitive composition is also improved. The crystalline epoxy resin (D1-1) having a melting point of 110 ℃ or lower may contain at least one component selected from, for example, biphenyl type epoxy resins (specific example: product No. YX-4000 made by Mitsubishi chemical corporation), biphenyl ether type epoxy resins (specific example: product No. YSLV-80DE made by Nippon Tekken chemical Co., Ltd.), bisphenol type epoxy resins (specific example: product No. YSLV-80XY made by Nippon Tekken chemical Co., Ltd.), and bisphenol fluorene type crystalline epoxy resins (specific example: epoxy resins having the structure (S7)).

The amorphous epoxy resin (D2) preferably contains a compound selected from the group consisting of a phenol novolak-type epoxy resin (specifically, product No. EPICLON N-775 manufactured by DIC), a cresol novolak-type epoxy resin (specifically, product No. EPICLON-695 manufactured by DIC), a bisphenol A novolak-type epoxy resin (specifically, product No. EPICLON-865 manufactured by DIC), a bisphenol A-type epoxy resin (specifically, product No. jER1001 manufactured by Mitsubishi chemical corporation), a bisphenol F-type epoxy resin (specifically, product No. jER4004P manufactured by Mitsubishi chemical corporation), a bisphenol S-type epoxy resin (specifically, product No. EPICLON EXA-1514 manufactured by DIC), a bisphenol AD-type epoxy resin, and a biphenol novolak-type epoxy resin (specifically, product No. 3000-NC manufactured by Nippon chemical Co., Ltd.), Hydrogenated bisphenol A type epoxy resin (specific example: product No. ST-4000D manufactured by Nippon Tekken chemical Co., Ltd.), naphthalene type epoxy resin (specific example: product No. EPICLON HP-4032, EPICLON HP-4700, EPICLON HP-4770 manufactured by DIC), tert-butyl catechol type epoxy resin (specific example: product No. EPICLON HP-820 manufactured by DIC), dicyclopentadiene type epoxy resin (specific example: product No. EPICLON HP-7200 manufactured by DIC), adamantane type epoxy resin (specific example: product No. ADAMANATEX-E-201 manufactured by shinkansen Kagaku K.K.), and special bifunctional type epoxy resin (specific example: product Nos. YL7175-500 and YL7175-1000 manufactured by Mitsubishi chemical Co., Ltd.; product No. EPICLON-TSR-960 manufactured by Mitsubishi chemical Co., Ltd.), EPICLON TER-601, EPILON TSR-250-80BX, EPICLON 1650-75MPX, EPICLON EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLON EXA-9726; product number YSLV-120TE manufactured by seiki chemical corporation), a rubber-like core-shell polymer-modified bisphenol a type epoxy resin (specific examples are: product No. MX-156 manufactured by KANEKA CORPORATION), a rubber-like core-shell polymer-modified bisphenol F type epoxy resin (specific examples are: product number MX-136 manufactured by KANEKA CORPORATION), and a bisphenol F type epoxy resin containing rubber particles (specific examples are: at least one component selected from Kane Ace MX-130) of KANEKA CORPORATION.

When the photosensitive composition contains the epoxy compound (D), the photosensitive composition preferably contains both the crystalline epoxy resin (D1) and the amorphous epoxy resin (D2). In this case, the plating resistance and the insulation property of the cured product made of the photosensitive composition can be further improved.

The epoxy compound (D) may contain a phosphorus-containing epoxy resin. In this case, the flame retardancy of the cured product of the photosensitive composition is improved. The phosphorus-containing epoxy resin may be contained in the crystalline epoxy resin (D1), or may also be contained in the amorphous epoxy resin (D2). Examples of the phosphorus-containing epoxy resin include phosphoric acid-modified bisphenol F type epoxy resins (specific examples are EPICLON EXA-9726 and EPICLON EXA-9710, product numbers of DIC corporation), EPOTHOTO FX-305, product number of Nissian Ciki Kaisha, and the like.

The epoxy compound (D) may contain an epoxy compound (D3) having a bisphenol fluorene skeleton. The epoxy compound (D3) includes, for example, the epoxy compound (a1) having the bisphenol fluorene skeleton (S1) represented by the formula (1) described above.

The photosensitive composition preferably contains a solvent (E). The solvent (E) may contain a straight-chain alcohol, a branched-chain alcohol, a secondary alcohol or a polyhydric alcohol selected from water, ethanol, isobutanol, 1-butanol, isopropanol, hexanol, ethylene glycol, 3-methyl-3-methoxybutanol and the like; ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; petroleum aromatic mixed solvents such as Swasol series (manufactured by Wanshan petrochemical Co., Ltd.) and Solvesso series (manufactured by Exxon chemical Co., Ltd.); cellosolves such as cellosolve and butyl cellosolve; carbitols such as carbitol and butyl carbitol; alkylene glycol alkyl ethers such as ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, and propylene glycol methyl ether; polypropylene glycol alkyl ethers such as dipropylene glycol methyl ether; acetates such as ethyl acetate, butyl acetate, cellosolve acetate, carbitol acetate, etc.; and at least one compound of dialkyl glycol ethers. The solvent (E) preferably contains at least one alcohol solvent (E1) selected from the group consisting of propylene glycol monomethyl ether, ethanol, isobutanol, 1-butanol, isopropanol, hexanol, ethylene glycol, 3-methyl-3-methoxybutanol, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol methyl ether, and polypropylene glycol alkyl ethers such as dipropylene glycol methyl ether. That is, the photosensitive composition preferably contains an alcohol solvent (E1). In this case, the coating property and uniformity of the photosensitive composition can be further improved when the photosensitive composition is prepared. In addition, even when a thermoplastic film is used as the substrate, the substrate is less likely to be dissolved, and the substrate is less likely to be damaged. More preferably, the solvent (E) comprises propylene glycol monomethyl ether. In this case, the coating property and uniformity of the photosensitive composition can be further improved, and good drying property can be obtained. Further, propylene glycol monomethyl ether is preferably contained in a proportion of 50% by mass or more relative to the solvent (E).

The photosensitive composition may contain a blocked isocyanate selected from the group consisting of tolylene diisocyanate, dimorpholinodiisocyanate, isophorone diisocyanate and hexamethylene diisocyanate blocked with caprolactam, oxime, malonate and the like; butylated urea resin; various thermosetting resins other than the above; ultraviolet-curable epoxy (meth) acrylate; resins obtained by adding (meth) acrylic acid to bisphenol a type, novolak type, cresol novolak type, alicyclic type, and other epoxy resins; and at least one resin selected from the group consisting of diallyl phthalate resin, phenoxy resin, urethane resin, fluorine resin, and other polymer compounds.

The photosensitive composition may contain a curing agent for curing the epoxy compound (D). The curing agent may contain, for example, imidazole derivatives selected from imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole, and the like; amine compounds such as dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, and 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic dihydrazide and sebacic dihydrazide; phosphorus compounds such as triphenylphosphine; an acid anhydride; phenol; a thiol; a lewis acid amine complex; and

at least one component of a salt. The commercial products of these components are, for example, four countries2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (all trade names of imidazole compounds), U-CAT3503N manufactured by San-Apro Ltd, UCAT3502T (all trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATA AC 102, and U-CAT5002 (all bicyclic amidine compounds and salts thereof) manufactured by Kagaku Co.

The photosensitive composition may contain an adhesion-imparting agent. Examples of the adhesion imparting agent include guanamine derivatives such as acetoguanamine (2, 4-diamino-6-methyl-1, 3, 5-triazine) and benzoguanamine (2, 4-diamino-6-phenyl-1, 3, 5-triazine), and s-triazine derivatives such as 2, 4-diamino-6-methacryloyloxyethyl-s-triazine, 2-vinyl-4, 6-diamino-s-triazine isocyanuric acid adduct, 2, 4-diamino-6-methacryloyloxyethyl-s-triazine isocyanuric acid adduct, and silane coupling agents.

The photosensitive composition may contain a rheology control agent. The viscosity of the photosensitive composition can be easily optimized by the rheology control agent. Examples of the rheology control agent include urea-modified medium polarity polyamides (BYK-430 and BYK-431, product numbers of BYK corporation), polyhydroxycarboxylic acid amides (BYK-405, product number of BYK corporation), modified ureas (BYK-410, BYK-411 and BYK-420, product number of BYK corporation), high molecular urea derivatives (BYK-415, product number of BYK corporation), urea-modified urethanes (BYK-425, product number of BYK corporation), polyurethanes (BYK-428, product number of BYK corporation), castor oil wax, polyethylene wax, polyamide wax, bentonite, kaolin, and clay.

The photosensitive composition may contain a curing accelerator; a colorant; copolymers such as silicone and acrylic ester; leveling agent; a thixotropic agent; a polymerization inhibitor; an antihalation agent; a flame retardant; defoaming agents; an antioxidant; a surfactant; and at least one component of a polymeric dispersant.

The amount of the component in the photosensitive composition can be appropriately adjusted so that the photosensitive composition is photocurable and developable in an alkaline solution.

The amount of the carboxyl group-containing resin (a) is preferably 50 to 90% by mass, more preferably 55 to 85% by mass, and still more preferably 60 to 80% by mass, based on the amount of the solid component in the photosensitive composition. The amount of the carboxyl group-containing resin (a1) is preferably 50 to 90 mass%, more preferably 55 to 85 mass%, and still more preferably 60 to 80 mass% with respect to the amount of the solid component in the photosensitive composition.

The amount of the photopolymerization initiator (B) is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, and still more preferably 2 to 10% by mass, based on the carboxyl group-containing resin (a).

The amount of the photopolymerizable compound (C) is preferably 5 to 60 mass%, more preferably 10 to 50 mass%, and still more preferably 25 to 45 mass% based on the carboxyl group-containing resin (a).

When the photosensitive composition contains the epoxy compound (D), the total amount of the epoxy groups contained in the epoxy compound (D) is preferably more than 0 equivalent to 2 equivalents, more preferably more than 0 equivalent to 1 equivalent, further preferably more than 0 equivalent to 0.8 equivalent, and particularly preferably more than 0 equivalent to 0.5 equivalent, relative to 1 equivalent of the carboxyl groups contained in the carboxyl group-containing resin (a).

When the photosensitive composition contains the solvent (E), the amount of the solvent (E) is preferably 50 to 95% by mass based on the entire photosensitive composition. In this case, the coating property of the photosensitive composition can be improved when the photosensitive composition is coated.

The photosensitive composition of the present embodiment can be prepared by an appropriate method. For example, the photosensitive composition can be prepared by mixing and stirring the raw materials of the photosensitive composition. The photosensitive composition can be prepared by kneading the components by an appropriate kneading method using, for example, a three-roll mill, a ball mill, a sand mill, or the like. When the raw materials contain a liquid component, a component having a low viscosity, or the like, the photosensitive composition can be prepared by first kneading the raw materials except for the liquid component, the component having a low viscosity, or the like to prepare a mixture, and then adding the liquid component, the component having a low viscosity, or the like to the obtained mixture and mixing them. When the photosensitive composition contains the solvent (E), a part or all of the solvent in the raw materials may be mixed first, and then the mixture may be mixed with the remaining raw materials.

The photosensitive composition according to the present embodiment is suitable for a material of an electrically insulating layer such as a solder resist layer, an interlayer insulating layer, or a plating resist layer. In particular, as described above, the photosensitive composition is suitable for an electrically insulating material for optical applications because it has high transparency and high developability.

As described above, in the case of producing a dry film having a thickness of 10 μm from the photosensitive composition, the light transmittance at a wavelength of 450 to 800nm is preferably 80% or more, more preferably 85% or more, further preferably 90% or more, and particularly preferably 95% or more. When the amount is within this range, a film made of the photosensitive composition can be formed into a cured film having high transparency, and the laminate 10 can be particularly suitably used for optical applications.

The photosensitive composition according to the present embodiment preferably has a property that a film having a thickness of 25 μm can be developed in an aqueous sodium carbonate solution. In this case, since a sufficiently thick electrically insulating layer can be formed from the photosensitive composition by photolithography, the photosensitive composition can be widely used for forming an interlayer insulating layer, a solder resist layer, and the like in a printed wiring board. Of course, an electrically insulating layer having a thickness of less than 25 μm may be formed from the photosensitive composition.

Whether or not a coating film having a thickness of 25 μm can be developed in an aqueous sodium carbonate solution can be confirmed by the following method. A photosensitive composition was applied to an appropriate substrate to prepare a wet coating film, and the wet coating film was heated at 80 ℃ for 40 minutes to form a coating film having a thickness of 25 μm. The film was brought into direct contact with a negative mask having an exposed portion for transmitting ultraviolet rays and a non-exposed portion for blocking ultraviolet rays, and the film was coated at a thickness of 500mJ/cm²The conditions (2) are irradiated with ultraviolet rays to perform exposure. After exposure, the following treatments were performed:spraying 1% Na at 30 deg.C to the skin membrane under 0.2MPa₂CO₃The aqueous solution was sprayed for 90 seconds, and then pure water was sprayed at a spray pressure of 0.2MPa for 90 seconds. As a result of observing the coating after the treatment, when the portion of the coating corresponding to the non-exposed portion was removed and no residue was observed, it was judged that the coating having a thickness of 25 μm could be developed in an aqueous sodium carbonate solution. It should be noted that, for films of other thicknesses (for example, 30 μm), whether or not they can be developed in an aqueous sodium carbonate solution can be similarly checked.

[ examples ] A method for producing a compound

Specific examples of the present invention are given below. However, the present invention is not limited to the examples.

(1) Synthesis of photosensitive resin A

A bisphenol fluorene type epoxy compound (R in formula (2) represented by formula (2)) was charged into a four-necked flask equipped with a reflux condenser, a thermometer, an air blowing tube and a stirrer₁～R₈An epoxy compound having an epoxy equivalent of 252g/eq based on the total of hydrogen) 252 parts by mass, 72 parts by mass of acrylic acid, 1.5 parts by mass of triphenylphosphine, 0.2 part by mass of 4-methoxyphenol, and 200 parts by mass of propylene glycol monomethyl ether acetate. The mixture was prepared by stirring them under air bubbling. The mixture was stirred in a flask with bubbling of air and heated at a heating temperature of 115 ℃ for 12 hours. Thus, a solution of the intermediate was prepared.

Next, 15.4 parts by mass of 1,2,3, 6-tetrahydrophthalic anhydride, 58.8 parts by mass of 3,3',4,4' -biphenyltetracarboxylic dianhydride, and 15 parts by mass of propylene glycol monomethyl ether acetate were added to the solution of the intermediate in the flask. They were stirred with bubbling of air and heated at a heating temperature of 115 ℃ for 6 hours, and further stirred with bubbling of air and heated at a heating temperature of 60 ℃ for 6 hours. Thus, a 65 mass% solution of the photosensitive resin a was obtained. The polydispersity (Mw/Mn) of photosensitive resin A was 1.99, the number average molecular weight (Mn) was 1460, and the acid value was 71 mgKOH/g.

(2) Preparation of photosensitive composition

Examples 1 to 9 and comparative example 1

The components shown in table 1 described later were added to a flask in the mass ratio (parts by mass) shown in table 1, and stirred and mixed at a temperature of 35 ℃. The details of the components shown in the table are as follows.

Photopolymerization initiator a: 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide (product number: Omnirad TPO H, manufactured by IGM Resins B.V. Co.).

Photopolymerization initiator B: 1-hydroxy-cyclohexyl-phenyl-ketone (product number: Omnirad 184, manufactured by IGM Resins B.V.).

Photopolymerizable compound: tricyclodecane dimethanol diacrylate.

Antioxidant: pentaerythritol tetrakis (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate) (product No. Irganox 1010, manufactured by BASF Japan K.K.).

Surface modifier: surfactant (product No. MEGAFAC F-557, product name, available from DIC corporation)

Solvent: propylene glycol monomethyl ether.

[ Table 1]

	Photosensitive resin composition
		65% by mass solution of photosensitive resin A	156
Photopolymerization initiator A	6
		Photopolymerization initiator B	1
Photopolymerizable compound	35
		Antioxidant agent	1
Surface modifier	0.2
		Solvent(s)	270

[ examples 10 to 11]

In example 10, the components shown in the following table 2 were charged into a flask in the mass ratio (parts by mass) shown in table 2, and then stirred and mixed at a temperature of 35 ℃. In example 11 described later, the components shown in table 3 below were charged into a flask in the mass ratios (parts by mass) shown in table 3, and then stirred and mixed at a temperature of 35 ℃. Of the components shown in tables 2 and 3, the same portions as those in table 1 are the same as those in table 1, and the details of the other components are as follows.

Silica sol: daily chemical silica sol, trade name: MEK-ST-ZL (solid content 30 wt%, particle diameter 45nm, solvent MEK (methyl ethyl ketone)).

Carbon black dispersion (15 wt% of carbon black, 5 wt% of dispersant, solvent MEK).

[ Table 2]

	Photosensitive resin composition
		65% by mass solution of photosensitive resin A	156
Photopolymerization initiator A	6
		Photopolymerization initiator B	1
Photopolymerizable compound	35
		Antioxidant agent	1
Surface modifier	0.2
		Silica sol	100
Solvent(s)	170

[ Table 3]

	Photosensitive resin composition
		65% by mass solution of photosensitive resin A	156
Photopolymerization initiator A	6
		Photopolymerization initiator B	1
Photopolymerizable compound	35
		Antioxidant agent	1
Surface modifier	0.2
		Carbon black dispersion	0.6
Solvent(s)	270

[ measurement of transmittance ]

The photosensitive composition prepared in (2) above was applied to a film made of Polyethylene terephthalate (PET) by an applicator to form a wet coating film. The coating film was dried by heating at 120 ℃ for 5 minutes to form a dry film (dry film) having a thickness of 10 μm on a PET film. Next, the whole surface of the dried film produced on the PET film was set to 400mJ/cm using an ultra-high pressure mercury lamp²The condition (2) is ultraviolet ray irradiation. The exposed coating is subjected to a development treatment. In the development treatment, 1% Na of 30 ℃ was sprayed on the film at a spray pressure of 0.05MPa₂CO₃The aqueous solution was for 60 seconds. Then, pure water was sprayed to the film at a spray pressure of 0.05MPa for 60 seconds.

Next, a metal halide lamp was used at 1000mJ/cm²The photosensitive composition is cured by irradiating the film with ultraviolet light. The cured product (cured film) prepared on the PET film was set in an ultraviolet-visible near-infrared spectrophotometer (product No. UV-3100PC, Shimadzu corporation), and the transmittance of the cured product was measured at 450 to 800 nm. For reference, a PET film as an insulating layer was used. The transmittance curves of the cured products having a thickness of 10 μm obtained in examples 1 to 9 and comparative example 1 all showed a transmittance of 95% or more in any wavelength region of 450 to 800 nm.

The transmittance curve of the cured product having a thickness of 10 μm obtained in example 10 shows a transmittance of 90 to 95% in a wavelength region of 450 to 800nm, and the transmittance curve of the cured product having a thickness of 10 μm obtained in example 11 shows a transmittance of 80 to 85% in a wavelength region of 450 to 800 nm.

(3) Production of test piece

Test pieces of the laminates were produced as described below for examples 1 to 11 and comparative example 1.

[ example 1]

First, a COP (cyclic olefin polymer) film having a thickness of 130 μm was prepared as an insulating layer. Then, 100 W.min/m was applied to one surface of the COP film²And carrying out corona treatment. On the corona-treated surface of the COP, the photosensitive composition prepared in (2) above was applied by a spin coater to form a wet coating film. The coating film was heated and dried at 120 ℃ for 5 minutes, thereby forming a resist-forming layer (hereinafter, also referred to as a dry film) having a thickness of 2 μm on the COP film. Then, a PET film (surface roughness Sa: 32nm (both surfaces), haze: 2.6%, thickness: 16 μm) as a coating layer was hot-pressed at50 ℃ onto the dried film, and the laminate was laminated to prepare a test piece (dimension: width 100mm, length 100mm, and thickness 148 μm) provided with an insulating layer, a dried film (resist-forming layer), and a coating layer. The conditions of heating and pressing are 0.5MPa of pressure, 50 ℃ of heating temperature and heating and pressing timeFor 45 seconds.

In the following evaluation (4-3), after the surface treatment for adhesion of electroless copper plating was performed in example 3, and in examples 1 to 2,4 to 11 and comparative example 1, after the surface treatment for adhesion of electroless copper plating was performed, a coating film and a coating layer were sequentially stacked and dried by the same method as described above, and then, electroless copper plating was further performed, thereby producing a test piece.

[ example 2]

In example 1, the surface roughness Sa of the PET film (surface roughness Sa: 32nm (both sides), haze: 2.6%, thickness: 16 μm) as the coating layer was changed to: 5nm (two-sided), haze: 0.6%, thickness: a test piece was produced in the same manner as in example 1 except that the PET film had a thickness of 16 μm.

[ example 3]

A test piece was produced in the same manner as in example 2, except that the film thickness of the dry film (resist-forming layer) was changed to 12 μm in example 2.

[ example 4]

A test piece was produced in the same manner as in example 1, except that the surface of COP as an insulating layer was not subjected to corona treatment in example 1.

[ example 5]

A test piece was produced in the same manner as in example 1 except that in example 1, the coating layer was changed to a biaxially oriented polypropylene (OPP) film (surface roughness Sa: 50nm (both sides), haze: 0.3%, thickness: 40 μm).

[ example 6]

A test piece was produced in the same manner as in example 1 except that in example 1, the coating layer was changed to an OPP film (surface roughness Sa: 30nm (both sides), haze: 1%, thickness: 20 μm).

[ example 7]

A test piece was produced in the same manner as in example 1 except that in example 1, the coating layer was changed to a Polyethylene (PE) film (Sa: 60nm (both sides), haze: 17%, and thickness: 20 μm).

[ example 8]

A test piece was produced in the same manner as in example 2, except that the insulating layer was changed to a PET film and the thickness of the insulating layer was changed to 38 μm in example 2.

[ example 9]

A test piece was produced in the same manner as in example 2, except that the thickness of the resist-forming layer was changed to 15 μm in example 2.

[ example 10]

A test piece was produced in the same manner as in example 2, except that in example 2, a resist-forming layer was produced from the photosensitive resin composition described in table 2.

[ example 11]

A test piece was produced in the same manner as in example 2, except that in example 2, a resist-forming layer was produced from the photosensitive resin composition described in table 3.

Comparative example 1

A test piece was produced in the same manner as in example 1, except that the coating layer was not stacked in example 1.

(4) Evaluation of

(4-1) resolution

In the test pieces of examples 1 to 11 and comparative example 1, a soda-lime glass negative mask having a pattern including lines with line widths of 4 μm and 6 μm and having a non-exposed portion was used on the dry coating film from above the coating layer, and passed through an ultrahigh-pressure mercury lamp at 150mJ/cm²The dry film was subjected to near-field exposure to ultraviolet light. After the coating layer is peeled off, the exposed coating film is subjected to a developing treatment. In example 7 in which PE was used for the coating layer, the exposure amount was 150mJ/cm²In the case of the exposure conditions of (3), the UV transmittance tends to be lower than in examples 1 to 6 and examples 8 to 11 in which PET or OPP is used as a coating layer, and therefore, the exposure amount is from 150mJ/cm²Increased to 400mJ/cm²The film is exposed to ultraviolet light, and then the exposed film is subjected to a developing treatment.

On-displayIn the shadow treatment, 1% Na of 30 ℃ is sprayed on the film at a spray pressure of 0.05MPa₂CO₃The aqueous solution was for 60 seconds. Then, pure water was sprayed to the film at a spray pressure of 0.05MPa for 60 seconds. Thereby, the unexposed portion of the film is removed, and a pattern with lines removed is formed on the film. Thereafter, the mixture was passed through a metal halide lamp at 1000mJ/cm²Additional UV curing was performed. The state of the test piece obtained after the exposure and development treatments was observed and evaluated according to the following criteria, and the results are shown in tables 4 to 5.

A: the UV curing reaction of the dried film proceeded sufficiently, and the cured film was not peeled off at the UV irradiation position during development, and the space with a line width of 4 μm was resolved.

B: the UV curing reaction of the dried film proceeded sufficiently, and the cured film did not peel off at the UV irradiation position during development, and the space with a line width of 4 μm could not be resolved, but the space with a line width of 6 μm could be resolved.

C: the UV curing reaction of the dried film proceeded sufficiently, and the cured film did not peel off at the UV irradiation during development, but the spaces with line widths of 4 μm and 6 μm were not distinguishable.

D: the UV curing reaction of the dried film did not sufficiently proceed, and a part of the cured film was peeled off by UV irradiation during development.

(examination)

According to the above results, it is suggested that: in examples 1 to 5, when exposure was performed in a state where PET and OPP were laminated as the coating layer, UV curing reaction for drying the film was more easily performed, compared to example 7 in which PE was laminated as the coating layer. Furthermore, it was found that even at a low exposure (150 mJ/cm)²) In this case, sufficient UV curing can be achieved. This is considered to be because the exposure is performed in a state where the coating layer having low gas permeability is coated, and oxygen inhibition at the time of exposure can be more favorably reduced.

Further, comparing examples 1 to 4 and examples 8 to 11 with examples 5 to 7 suggests that: in particular, when PET is used as the coating layer, the coating layer is less susceptible to the influence of scattering of the light of exposure due to the presence of foreign matter such as a shrinkage cavity in the coating layer than in the case of OPP or PE, and thus the resolution can be improved.

Further, according to the results of examples 1 to 4 and examples 8 to 11, in the case where PET is used for the coating layer, the smaller the surface roughness Sa is, the more the scattering of the exposure light is suppressed, and the resolution is better.

Note that, for example 7, in the evaluation after (4-2), the exposure amount was increased to 400mJ/cm²The conditions (2) are irradiated with ultraviolet rays, and then the exposed coating is subjected to a developing treatment. Evaluation was performed using the test piece after the exposure and development treatment.

Further, in the case of exposure without overlapping the coating layer as in comparative example 1, the exposure amount was low (150 mJ/cm) due to the influence of oxygen inhibition at the time of exposure²) The UV curing reaction in the exposure (2) is insufficient, and a part of the coating film is peeled off at the time of development by UV irradiation. Therefore, the evaluation after (4-2) was not performed.

(4-2) adhesion

The test piece exposed and developed in (4-1) above was cross-cut in a checkered pattern (width of about 1mm) on the resist layer of the test piece in accordance with JIS D0202, and then the peeled state after the peeling test using a cellophane adhesive tape was visually observed. The results were evaluated according to the criteria shown below and are shown in tables 4 to 5.

A: no change was seen at all in the 100 cross sections.

B: only 1 to 5 points of the 100 cross parts are slightly raised.

C: 5-10 parts of 100 cross parts are stripped.

D: peeling occurred at 11-100 points out of 100 cross-shaped parts.

(examination)

As a result of comparison between example 1 and example 4, it was confirmed that the adhesion of the cured film to the substrate could be improved by performing the corona treatment on the COP substrate. This is presumably because the insulating layer serving as a base material is subjected to corona treatment to impart a polar group to the insulating layer, thereby changing wettability. It is considered that the same effect can be obtained even if any treatment such as UV irradiation, plasma treatment, ozone treatment, EB treatment, primer treatment (adhesive layer, catalyst layer, anchor agent (coupling agent, amino compound, etc.)), and the like is performed.

Further, as in examples 1 to 11, it was confirmed that adhesion of the cured film to the insulating layer could be improved even when PET, OPP or PE was laminated as a coating layer and exposed to light. This is considered to be because oxygen inhibition at the time of exposure is reduced, and the photoreaction is promoted.

(4-3) plating resistance

After the surface treatment for bringing the electroless copper plating into close contact with the insulating layer, the exposed and developed test piece prepared in the same manner as in (4-2) was immersed in an electroless Ni plating solution to carry out electroless plating. The obtained test piece after the plating treatment was subjected to a tape peeling test in accordance with JIS D0202. Then, the evaluation was carried out according to the criteria shown below, and the results are shown in tables 4 to 5.

A: the resist was not stripped.

B: some discoloration of the resist was visible, but no lift-off occurred.

C: a part of the resist is peeled off.

D: the resist was largely peeled off.

(examination)

As in examples 1 to 11, good plating resistance was obtained by performing exposure while reducing oxygen inhibition.

(4-4) flatness

The test pieces after exposure and development produced in (4-2) were observed with a laser microscope, and the flatness of the cured film surface was evaluated according to the criteria shown below, and the results are shown in tables 4 to 5.

A: no pits or depressions having a side length of 2 μm or more were observed.

B: pits or depressions having a side length of 2 to 3 μm can be found.

C: pits or depressions having a side length of 3 to 4 μm can be found.

D: pits or depressions having a length of one side of 4 μm or more can be found.

[ Table 4]

[ Table 5]

(conclusion)

As is apparent from the above embodiments, the present invention includes the following embodiments. In the following, in order to clearly show the correspondence with the embodiments, parentheses are added to the reference numerals.

A laminate (10) according to claim 1 is provided with an insulating layer (1), a resist formation layer (2) that overlaps with the insulating layer (1), and a coating layer (3) that overlaps with the resist formation layer (2). The resist forming layer (2) contains a dried product or a semi-cured product of a photosensitive composition.

According to the first aspect, the coating layer (3) is provided in the laminate (10), so that the resist forming layer (2) can be cured without being easily affected by oxygen in the atmosphere (for example, oxygen inhibition) when the resist forming layer (2) is cured. Therefore, the curability of the cured product of the resist forming layer (2) can be improved, and as a result, the resolution and the flatness can be easily improved by the laminate (10).

The laminate (10) according to claim 2 is: in the 1 st aspect, the insulating layer (1) is used to manufacture a printed wiring board (100), the insulating substrate (11) in the printed wiring board (100) is manufactured from the insulating layer (1), and the resist layer (12) in the printed wiring board (100) is manufactured from the resist-forming layer (2).

According to the second aspect, when the resist layer (12) is formed on the insulating layer (1) in the laminate (10), the insulating layer (1) can be used as the insulating substrate (11) in the printed wiring board (100). Further, the resist formation layer (2) may be used as a permanent resist (permanent film).

A laminate (10) according to claim 3 is: in the

embodiment

1 or 2, the insulating layer (1) includes at least one insulating material selected from the group consisting of a cycloolefin polymer, a liquid crystal polymer, polyethylene terephthalate, and polyimide.

According to the 3 rd aspect, the printed wiring board (100) produced from the laminate (10) is excellent in low dielectric characteristics. Therefore, the printed wiring board (100) can be used in electronic equipment, devices, and the like for high-frequency applications.

A laminate (10) according to claim 4 is: in any one of 1 st to 3, the coating layer (3) includes one or both of polyethylene terephthalate and biaxially stretched polypropylene.

According to the 4 th aspect, the high transparency of the laminate (10) can be maintained. In this case, the curability of the resist forming layer (2) in the laminate (10) is easily improved, and the resist layer (12) is easily formed more satisfactorily. In this case, the curability of the resist forming layer (2) can be further improved when the laminate (10) is exposed from above the coating layer (3). Therefore, when the resist forming layer (2) is cured to form the resist layer (12), the developability and the resolution can be further improved easily.

A laminate (10) according to claim 5 is: in any one of 1 st to 1 st aspects of the present invention, the photosensitive composition contains a carboxyl group-containing resin (a), a photopolymerization initiator (B), and a photopolymerizable compound (C).

According to the 5 th aspect, the resist-forming layer (2) in the laminated body (10) can be cured by irradiating light, and the resist layer (12) can be easily produced from the resist-forming layer (2).

A laminate (10) according to claim 6 is: in any one of the 1 st to 1 st aspects, the resist formation layer (2) has a film thickness of 20 μm or less.

According to the 6 th aspect, the developability and the resolution can be further improved when the resist layer (12) is formed from the resist forming layer (2).

A laminate (10) according to claim 7 is: in the 1 st aspect of the 1 st to 6, when a cured product having a thickness of 10 μm is produced from the photosensitive composition, the transmittance of light having a wavelength of 450nm to 800nm is 80% or more.

According to the 7 th aspect, the laminate (10) is excellent in transparency, and therefore, the laminate (10) can be suitably used for optical applications. In this case, the laminate (10) has high transparency, and thus contributes to the appearance and the landscape being less likely to be damaged even when installed outdoors.

The laminate (10) according to embodiment 8 is: in any 1 of the modes 1 to 7, the insulating layer (1) is subjected to at least one surface treatment selected from corona treatment, UV treatment, plasma treatment, ozone treatment, primer treatment, and EB treatment.

According to the 8 th aspect, the adhesion between the insulating layer (1) and the layer formed on the insulating layer (1) can be improved. Further, in this case, the peelability of the coating layer (3) when peeled from the laminate (10) can be improved.

The laminate (10) according to claim 9 is: in any one of modes 1 to 8, the surface roughness Sa of the coating layer (3) is 50nm or less.

According to the 9 th aspect, even if the coating layer (3) is peeled off from the laminate (10), higher flatness can be imparted to the resist forming layer (2) (or the resist layer (12)). In this case, when a plated layer is formed on the printed wiring board (100), conductor wiring having a more uniform shape is easily formed. Therefore, the reliability of the printed wiring board (100) is easily improved. In this case, the transparency of the resist forming layer (12) can be further improved.

The laminate (10) according to claim 10 is: in the 1 st aspect of any one of claims 1 to 9, the coating layer (3) has a haze value of 3.0% or less.

According to the 10 th aspect, when the photosensitive composition is cured by irradiating light to the resist forming layer (2) in the laminate (10), the photosensitive composition can be more favorably cured even through the coating layer (3) in the laminate (10).

A method for manufacturing a printed wiring board according to claim 11 is a method for manufacturing a printed wiring board (100), the printed wiring board (100) including: an insulating substrate (11) comprising the insulating layer (1) in the laminate (10) according to any one of the aspects 1 to 10, and a resist layer (12) formed from the resist-forming layer (2) in the laminate (10). The manufacturing method comprises the following steps: the resist forming layer (2) is irradiated with light through the coating layer (3) in the laminate (10), thereby forming the resist layer (12) on the insulating layer (1).

According to the 11 th aspect, when the resist formation layer (2) is exposed, the influence of the shrinkage cavity at the time of exposure can be reduced, which contributes to improvement of resolution.

A printed wiring board (100) according to claim 12 is provided with: an insulating substrate (11) comprising the insulating layer (1) in the laminate (10) according to any one of the aspects 1 to 10, and a resist layer (12) formed from the resist-forming layer (2) in the laminate (10).

According to the 12 th aspect, a printed wiring board (100) including an insulating substrate (11), a resist layer (12) having excellent resolution and flatness, and a conductor layer (13) can be manufactured.

Claims

1. A laminate is provided with an insulating layer, a resist forming layer overlapping with the insulating layer, and a coating layer overlapping with the resist forming layer;

the resist-forming layer contains a dried substance or a semi-cured substance of a photosensitive composition.

2. The laminate according to claim 1, which is used for production of a printed wiring board,

an insulating substrate in the printed wiring board is made of the insulating layer,

a resist layer in the printed wiring board is produced from the resist-forming layer.

3. The laminate according to claim 1 or 2, wherein the insulating layer comprises at least one insulating material selected from the group consisting of a cyclic olefin polymer, a liquid crystal polymer, polyethylene terephthalate, and polyimide.

4. The laminate according to claim 1 or 2, wherein the coating layer comprises one or both of polyethylene terephthalate and biaxially stretched polypropylene.

5. The laminate according to claim 1 or 2, wherein the photosensitive composition comprises a carboxyl group-containing resin (a), a photopolymerization initiator (B), and a photopolymerizable compound (C).

6. The laminate according to claim 1 or 2, wherein the resist formation layer has a film thickness of 20 μm or less.

7. The laminate according to claim 1 or 2, wherein, when a cured product having a thickness dimension of 10 μm is produced from the photosensitive composition, the transmittance of light having a wavelength of 450nm to 800nm is 80% or more.

8. The laminate according to claim 1 or 2, wherein the insulating layer is subjected to at least one surface treatment selected from corona treatment, UV treatment, plasma treatment, ozone treatment, primer treatment, and EB treatment.

9. The laminate according to claim 1 or 2, wherein the coating layer has a surface roughness Sa of 50nm or less.

10. The laminate according to claim 1 or 2, wherein the coating layer has a haze value of 3.0% or less.

11. A method for manufacturing a printed wiring board, comprising an insulating substrate and a resist layer, wherein the insulating substrate comprises the insulating layer in the laminate according to any one of claims 1 to 10, and the resist layer is formed from the resist-forming layer in the laminate;

the resist forming layer is irradiated with light through the covering layer in the stacked body, thereby forming the resist layer on the insulating layer.

12. A printed wiring board is provided with: an insulating substrate comprising the insulating layer in the laminate according to any one of claims 1 to 10, and a resist layer made of the resist-forming layer in the laminate.