Laminated body, method for producing printed wiring board, and printed wiring board

Abstract

The present invention relates to a laminate, a method for producing a printed wiring board, and a printed wiring board. The present invention provides a laminate that is easy to improve in resolution and flatness. The laminate (10) comprises an insulating layer (1), a resist-forming layer (2) overlapping the insulating layer (1), and a covering layer (3) overlapping the resist-forming layer (2). The resist-forming layer (2) comprises a dried product or a semi-cured product of a photosensitive composition.

Description

Technical Field

[0001] The present invention relates to a laminate, a method for producing a printed wiring board, and a printed wiring board, and more particularly to a laminate, a method for producing a printed wiring board produced from the laminate, and a printed wiring board produced from the laminate. Background Art

[0002] Patent document 1 (Japanese Patent Publication No. 2014-024919) discloses: a member for a touch panel in which a transparent conductive film is used as a transparent electrode to form a pattern on a transparent substrate. 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: sufficient adhesion between the transparent resin film and the electrode can be obtained, and the energy ray curable composition is used as a material for an insulating layer and / or a protective layer of a touch panel using a transparent resin film as a substrate. Summary of the invention

[0003] However, in the transparent laminated structure having a transparent substrate and a transparent conductive film as a transparent electrode of Patent Document 1, an energy ray curable composition is applied on a substrate having a thin film electrode forming a pattern, and is photocured by ultraviolet rays to form a cured product, thereby forming an insulating layer and / or a protective layer. Therefore, there is room for improvement in the resolution and flatness of the transparent conductive film.

[0004] An object of the present invention is to provide a laminated body whose resolution and flatness can be easily improved, a printed wiring board produced from the laminated body, and a method for producing the printed wiring board.

[0005] A laminated body according to one embodiment of the present invention includes an insulating layer, a resist forming layer overlapping the insulating layer, and a covering layer overlapping the resist forming layer. The resist forming layer includes a dried product or a semi-cured product of a photosensitive composition.

[0006] A method for manufacturing a printed wiring board according to one embodiment of the present invention is a method for manufacturing a printed wiring board having an insulating substrate and a resist layer, wherein the insulating substrate includes the insulating layer in the laminate, and the resist layer is made from the resist-forming layer in the laminate. The manufacturing method includes: irradiating the resist-forming layer with light through the covering layer in the laminate, thereby forming the resist layer on the insulating layer.

[0007] A printed wiring board according to one 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.

[0008] According to one embodiment of the present invention, a laminate and a printed wiring board that are easily improved in resolution and flatness can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A This is a schematic cross-sectional view showing a laminated body according to one embodiment of the present invention.

[0010] Figure 1B It is a schematic perspective view showing a rolled laminated body according to one embodiment of the present invention.

[0011] Figure 2A This is a schematic diagram showing one of the manufacturing steps of the printed wiring board according to the present embodiment.

[0012] Figure 2B This is a schematic diagram showing one of the manufacturing steps of the printed wiring board described above.

[0013] Figure 2C This is a schematic diagram showing one of the manufacturing steps of the printed wiring board described above.

[0014] Figure 2D This is a schematic diagram showing one of the manufacturing steps of the printed wiring board described above.

[0015] Figure 3 To express Figure 1A A cross-sectional view of a modified example of the laminate shown.

[0016] Description of Reference Numerals

[0017] 1 Insulation layer

[0018] 2. Resist formation layer

[0019] 3 Coating layer

[0020] 10 Laminated body

[0021] 11 Insulating substrate

[0022] 12. Resist layer

[0023] 100 Printed Wiring Board DETAILED DESCRIPTION

[0024] 1. Summary

[0025] First, the outline of the laminated body 10 according to the present embodiment will be described.

[0026] The laminate 10 of the present embodiment includes an insulating layer 1, a resist forming layer 2, and a covering layer 3. The resist forming layer 2 is stacked on the insulating layer 1, and the covering layer 3 is stacked on the resist forming layer 2. The resist forming layer 2 includes a dried product or a semi-cured product of a photosensitive composition.

[0027] In the laminated body 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 laminated body 10 of the present embodiment is provided with a coating layer 3, so that when the resist-forming layer 2 is cured, it is not easily affected by oxygen in the atmosphere (for example, oxygen hindrance), and the resist-forming layer 2 can be cured. 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-forming layer 2 can be improved, and as a result, the developability and resolution can be improved.

[0028] The laminate 10 can be used, for example, for the production of a printed wiring board. In this case, in a state where the insulating layer 1, the resist-forming layer 2, and the covering layer 3 are stacked, the resist-forming layer 2 is irradiated with light through the covering layer 3, so that the portion of the resist-forming layer 2 irradiated with light 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 needed to remove unnecessary portions, so that an electrically insulating layer (resist layer 12) can be produced from the resist-forming layer 2.

[0029] 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. In addition, the resist-forming layer 2 can be used as a permanent resist (permanent film).

[0030] Therefore, the laminated body 10 of the present embodiment can be particularly preferably used as a material for producing a printed wiring board.

[0031] 2. Details

[0032] Next, the laminated body 10 according to the present embodiment and the elements constituting the laminated body 10 will be described in detail.

[0033] <Insulation layer>

[0034] 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, to produce a printed wiring board having an electrical insulation layer. That is, the insulating layer 1 in the laminate 10 is the insulating substrate 11 in the printed wiring board 100.

[0035] As the insulating layer 1, suitable substrates such as glass, plastic, and ceramics can be cited. More specifically, for example, the insulating layer 1 includes a film made of thermoplastic resins such as polyethylene terephthalate (PET), cycloolefin polymer (COP: Cyclo Olefin Polymer), liquid crystal polymer (LCP: Liquid Crystal Polymer), polyimide (PI: Polyimide) and polycarbonate (PC: Polycarbonate). The insulating layer 1 preferably includes at least one insulating material selected from cycloolefin polymer, liquid crystal polymer, polyethylene terephthalate and polyimide. In this case, the printed wiring board 100 made of the laminate 10 has excellent low dielectric properties. Therefore, the printed wiring board 100 can be used for electronic equipment, devices, etc. for high-frequency purposes. The insulating layer 1 more preferably includes either or both of a cycloolefin polymer and a liquid crystal polymer, and the insulating layer 1 is further preferably a cycloolefin polymer.

[0036] The insulating layer 1 is preferably subjected to a surface treatment. 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 formed of a resin such as a resist forming layer 2, a catalyst layer 4 formed of a metal and a plating layer are made on the insulating layer 1, the adhesion between the insulating layer 1 and each layer can be improved. Furthermore, if the insulating layer 1 is subjected to at least one of the above-mentioned surface treatments, the peelability when peeling the coating layer 3 from the laminate 10 can be improved. The surface treatment is more preferably either or both of the corona treatment and the UV treatment.

[0037] <Resist forming layer>

[0038] The resist forming layer 2 overlaps with the insulating layer 1 in the laminate 10. The resist forming layer 2 includes a dried product or a semi-cured product of the photosensitive composition. The resist forming layer 2 has photocurability. The resist forming layer 2 preferably has electrical insulation. It should be noted that the semi-cured product referred to in the present invention is not a state in which the photosensitive composition is completely cured, but includes an uncured state.

[0039] The resist-forming layer 2 is cured by irradiating a dried or semi-cured product of the photosensitive composition with light, thereby making a resist layer 12. Therefore, the resist-forming layer 2 can be used as a permanent resist (permanent film). It should be noted that the details of the photosensitive composition will be described below. In addition, the method for making the resist-forming layer 2 will be described in detail below.

[0040] <Coating layer>

[0041] The coating layer 3 can have a function as a covering 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 prone to adverse conditions, such as the resist-forming layer 2 laminated on the insulating layer 1 is less prone to degradation and damage. In the laminate 10, when the resist-forming layer 2 is exposed by irradiating the laminate 10 with light, the coating layer 3 can help reduce oxygen hindrance when the resist-forming layer 2 is cured. As a result, the flatness of the resist layer 12 in the printed wiring board 100 made of the laminate 10 can be improved.

[0042] The coating layer 3 preferably has light transmittance. In this case, in the laminate 10, the resist forming layer 2 is easily exposed through the coating layer 3. For example, in the coating layer 3 having a thickness of 20 μm, the transmittance of light having a wavelength of 350 nm to 500 nm is preferably 70% or more, more preferably 75% or more, and further preferably 80% or more.

[0043] The coating layer 3 is preferably one or both of polyethylene terephthalate (PET) and biaxially oriented polypropylene (OPP: Oriented Polypropylene). In this case, the high transparency of the laminate 10 can be maintained. In addition, 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 formed more easily. In addition, in this case, the gas barrier property of the coating layer 3 is high, so the curability of the resist-forming layer 2 when the laminate 10 is exposed from the coating layer 3 can be well improved. Therefore, when the resist-forming layer 2 is cured to produce the resist layer 12, the developability and resolution can be further improved.

[0044] The coating layer 3 is more preferably a PET film. In this case, the resist-forming layer 2 can be made less susceptible to the effects of shrinkage cavities and the like, and it is not easy to produce adverse conditions. Therefore, by irradiating the laminate 10 with light, even if the resist-forming layer 2 is cured via the coating layer 3, the irradiated light is not easy to scatter. Therefore, the developability and resolution of the resist-forming layer 2 can be further improved. It should be noted that shrinkage cavities refer to small spherical blocks that can be produced inside the film. Furthermore, if the coating layer 3 is a PET film, gas barrier properties can be imparted to the laminate 10. Therefore, in the laminate 10, even if the resist-forming layer 2 is irradiated with light via the coating layer 3 to cure the photosensitive composition, oxygen hindrance is not easy to occur. Therefore, when the resist-forming layer 2 is cured, the exposure amount of the irradiated light can be reduced.

[0045] The surface roughness Sa of the coating layer 3 is preferably 50 nm or less. In this case, even if the coating layer 3 is peeled off from the laminate 10, a higher flatness can be given to the resist forming layer 2 (or the resist layer 12). If the resist forming layer 2 has high flatness, when a plating layer is formed on the printed wiring board 100, a conductor wiring with a more uniform shape can be formed. Therefore, the reliability of the printed wiring board 100 is improved. In addition, in this case, the transparency of the resist forming layer 2 can be improved.

[0046] The surface roughness Sa of the coating layer 3 can be measured, for example, as follows: It is measured and calculated using a laser microscope (VK-X1000 manufactured by KEYENCE) with the following settings: laser type: 404 nm semiconductor laser, measurement range: 270 μm×202 μm, objective lens: 50 times, confocal mode.

[0047] 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 through the coating layer 3. The haze value of the coating layer 3 is more preferably 2.0% or less, and further preferably 1.0% or less. It should be noted that the haze value of the coating layer 3 can be calculated based on the results of the diffuse transmittance and the total light transmittance measured using a haze meter in accordance with JIS K7136.

[0048] <<Method for producing laminate>>

[0049] An example of a specific method for producing the laminated body 10 according to the present embodiment will be described. However, the method for producing the laminated body 10 is not limited to the following method.

[0050] First, an insulating layer 1 and a solution of a photosensitive composition are prepared, and a resist-forming layer 2 is formed on the insulating layer 1. Examples of methods for forming the resist-forming layer 2 include a coating method and a dry film method.

[0051] In the coating method, for example, a photosensitive composition is coated on the insulating layer 1 to form a wet coating film. The coating method of the photosensitive composition can be selected from a suitable method, for example, dipping, spraying, spin coating, roller coating, curtain coating, and screen printing. 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 60 to 130° C., thereby obtaining the resist forming layer 2.

[0052] In the dry film method, first, a photosensitive composition is applied to a suitable support made of polyester or the like, and then dried to form a dry film as a dried product of the photosensitive composition on the support. Thus, a support-attached dry film having a dry film and a support for supporting the dry film can be obtained. The dry film in the support-attached dry film is overlapped on the insulating layer 1, and then pressure is applied to the dry film and the insulating layer 1. Next, the support is peeled off from the dry film, and the dry film is transferred from the support to the insulating layer 1. Thus, a resist-forming layer 2 formed of the dry film can be provided on the insulating layer 1.

[0053] Next, the coating layer 3 is formed on the resist-forming layer 2. Specifically, for example, the coating layer 3 is arranged on the resist-forming layer 2 so as to cover the resist-forming layer 2 formed on the insulating layer 1. After the coating layer 3 is arranged on the resist-forming layer 2, it can be pressed by applying pressure. In addition, after the coating layer 3 is arranged on the resist-forming layer 2, it can also be heated during the pressurization. In this way, a laminated body 10 having the insulating layer 1, the resist-forming layer 2, and the coating layer 3 in this order can be obtained.

[0054] When the anti-etching forming layer 2 is produced by the dry film method, for example, the insulating layer 1, the dry film (a dried or semi-cured product of a film-like photosensitive composition) and the covering layer 3 can be overlapped in sequence and pressed together as needed to produce a stacked body 10 having the insulating layer 1, the anti-etching forming layer 2 and the covering layer 3 in sequence.

[0055] When a cured product having a thickness of 10 μm is made from the photosensitive composition in the resist forming layer 2 in the laminate 10, the transmittance of the cured product in the range of 450 nm to 800 nm of the wavelength of light is preferably 80% or more. In this case, the laminate 10 has excellent transparency, so the laminate 10 can be suitable for optical use. In addition, in this case, the laminate 10 has high transparency, which helps to make the appearance and landscape less likely to be damaged even when it is set outdoors. The absorption spectrum of the cured product made from the photosensitive composition can be measured, for example, by a spectrophotometer or other spectroscopic analysis device. The specific measurement method can be the same as the method described in [Determination of Transmittance] of the embodiment described later. By measuring the absorption spectrum of the cured product made from the photosensitive composition, the light transmittance and absorbance can be obtained. The transmittance of the cured product having a thickness of 10 μm in the range of 450 nm to 800 nm of the wavelength of light is more preferably 85% or more, further preferably 90% or more, and particularly preferably 95% or more. It should be noted that the above-mentioned “cured product having a thickness 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.

[0056] The laminate 10 is as follows Figure 1BAs shown, it is preferably formed into a roll. In this case, the rolled laminate 10 can be directly used as a material for making a printed wiring board. Specifically, a suitable size can be cut from the rolled laminate 10 and used. When making the rolled laminate 10, after forming the resist forming layer 2 on the insulating layer 1 in the above-mentioned manner, for example, while pressing the coating layer 3 arranged on the resist forming layer 2, it is formed into a roll. In the case of making the resist forming layer 2 by the dry film method, the insulating layer 1, the dry film and the coating layer 3 can also be overlapped in the same way, and they can be pressed and formed into a roll, thereby making Figure 1B The laminate 10 is shown in a rolled form.

[0057] In the making Figure 3 In the case of the laminated body 10 shown in the figure, for example, a photosensitive composition is applied to one side (surface) of the insulating layer 1 to produce a dry film of the photosensitive composition (also referred to as the first resist forming layer 21), and then a covering layer 3 (also referred to as the first covering layer 31) is stacked on the first resist forming layer 21. Next, a photosensitive composition is applied to the other side (back side) of the insulating layer 1 to produce a dry film of the photosensitive composition (also referred to as the second resist forming layer 22), and then a covering layer 3 (also referred to as the second covering layer 32) is stacked on the second resist forming layer 22. Then, the laminated body having the first covering layer 31, the first resist forming layer 21, the insulating layer 1, the second resist forming layer 22, and the second covering layer 32 in this order is heated and pressurized as necessary, so that the laminated body 10 can be produced. It should be noted that the order of stacking the covering layer 3 after applying the photosensitive composition and the timing of heating and pressurizing are not limited to the above.

[0058] The thickness of laminate 10 is not particularly limited, and may be, for example, 20 μm or more. When the thickness of laminate 10 is, for example, 350 μm or less, printed wiring board 100 made of laminate 10 can be easily made flexible when used as an optical component such as a touch panel.

[0059] The thickness of the insulating layer 1 in the laminate 10 is not particularly limited and may be any appropriate size, for example, 1 μm to 300 μm. In this case, the laminate 10 can be easily rolled. In this case, the printed wiring board 100 made of the laminate 10 can be easily thinned.

[0060] The film thickness (thickness) of the resist forming layer 2 in the laminate 10 is not particularly limited, for example, preferably 20 μm or less. If the film thickness of the resist forming layer 2 is 0.5 μm to 20 μm, when the resist layer 12 is made from the resist forming layer 2, the developability and resolution can be further improved. The resist forming layer 2 is preferably 0.8 μm to 15 μm, more preferably 1.0 μm to 13 μm, and particularly preferably 1.5 μm to 10 μm. In addition, if within this range, the printed wiring board 100 made from the laminate 10 can be suitable for making electronic materials (optical parts) such as touch panels.

[0061] The thickness of the coating layer 3 in the laminate 10 is not particularly limited, and may be such a thickness that the transmittance of light having a wavelength of 350 nm to 500 nm is 70% or more when the resist forming layer 2 is irradiated with light through the coating layer 3 .

[0062] The laminate 10 is as follows Figure 3 As shown, the laminate 10 may include an insulating layer 1, a plurality of resist forming layers 2, and a plurality of coating layers 3. Specifically, the laminate 10 may be sequentially laminated with: resist forming layers 2 (21, 22) respectively overlapped on both sides of the insulating layer 1, and coating layers 3 (31, 32) respectively overlapped on the surface of the resist forming layers 2 (21, 22) opposite to the insulating layer 1. In addition, without limitation thereto, a laminate 10 may be a multilayer laminate 10 in which a plurality of resist forming layers 2 and a plurality of coating layers 3 are alternately overlapped on the insulating layer 1. In this case, the thickness of the laminate 10 may be, for example, 50 μm or more.

[0063] The laminate 10 may include layers other than the insulating layer 1, the resist forming layer 2, and the coating layer 3 described above. For example, the laminate 10 preferably includes a catalyst layer 4 between the insulating layer 1 and the resist forming layer 2. That is, the catalyst layer 4 can function as a primer layer when making 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 forming layer 2 can be further improved. Thus, if the printed wiring board 100 is made from the laminate 10, the 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 not prone to undesirable conditions such as peeling.

[0064] When the stacked body 10 has a catalyst layer 4, for example, a material for making the catalyst layer 4 (hereinafter also referred to as a catalyst layer material) can be coated on the insulating layer 1 to form the catalyst layer 4, and then a photosensitive composition is coated on the catalyst layer 4, and heated and dried as needed to produce an anti-etching forming layer 2, and then a coating layer 3 is formed on the anti-etching forming layer 2.

[0065] The catalyst layer material can be a material with a catalytic function that can appropriately improve the adhesion. The catalyst material can be, for example, at least one material selected from metals such as palladium, coupling agents such as silane coupling agents, compounds having an amino group, i.e., amine compounds, and thiol compounds containing SH groups. The catalyst layer material can be in powder form or in liquid form. The catalyst layer 4 can be made, for example, by coating or impregnating the catalyst layer material on the insulating layer 1.

[0066] The laminate 10 may include appropriate functionality imparting layers such as a hard coat layer, an anchor layer, an adhesive layer, and an ultraviolet absorbing layer.

[0067] For example, in Figure 3 When the laminated body 10 shown is used to make a printed wiring board 100, it is preferably provided with a hard coating layer (not shown) superimposed on at least one side of the surface of the insulating layer 1. In addition, the hard coating layer preferably contains an ultraviolet absorber. In this case, when the resist forming layer 2 in the laminated body 10 is exposed, the light can be suppressed from passing through one side to the other side of the resist forming layer 2. Specifically, for example, when the first resist forming layer 21 is exposed, the light irradiated to the first resist forming layer 21 through the first coating layer 31 can be suppressed from passing through the insulating layer 1 to the second resist forming layer 22 on the opposite side of the first resist forming layer 21. As the ultraviolet absorber, there is no particular limitation as long as it can absorb ultraviolet rays. Specifically, for example, at least one component selected from benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, triazine ultraviolet absorbers, benzoate ultraviolet absorbers, and cyanoacrylate ultraviolet absorbers can be cited. It should be noted that the hard coating layer is a layer different from the insulating layer 1. Insulating layer 1 also preferably contains an ultraviolet absorber. In this case, even without using a hard coat layer (ultraviolet absorbing layer), when resist-forming layer 2 in laminate 10 is exposed, light can be suppressed from penetrating from one surface to the other surface of resist-forming layer 2.

[0068] <Printed wiring board>

[0069] Next, regarding the method for manufacturing a printed wiring board according to the present embodiment, refer to Figure 2A to Figure 2D Provide specific instructions.

[0070] The laminated body 10 described above can be used to produce a 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 laminated body 10 and a resist layer 12 made of the resist forming layer 2 in the laminated body 10.

[0071] The printed wiring board 100 includes an insulating substrate 11 and a resist layer 12 . Figure 2D In the embodiment, the printed wiring board 100 further includes a conductor layer 13 (conductor wiring 131 ).

[0072] In order to manufacture the printed wiring board 100, first, the laminate 10 is prepared. Figure 2A to Figure 2D Use in Figure 1A The laminate 10 shown includes the insulating layer 1, the catalyst layer 4, the resist forming layer 2, and the covering layer 3 in this order, but is not limited thereto and may not include the catalyst layer 4. The method for producing the laminate 10 is as described above.

[0073] like Figure 2A As shown, by exposing the resist forming layer 2, Figure 2B As shown, the resist forming layer 2 is partially cured. 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 for manufacturing the printed wiring board 100 of the present embodiment includes: irradiating light from the coating layer 3 through the coating layer 3, thereby exposing the resist forming layer 2. Thus, the resist layer 12 is formed on the insulating layer 1 (insulating substrate 11) in the laminate 10. It should be noted that the exposure can also be performed after the coating layer 3 is peeled off. In this case, when the resist forming layer 2 is exposed, the influence of shrinkage cavities during exposure can be reduced, which helps to improve the resolution.

[0074] In order to partially expose the resist-forming layer 2 through the cover layer 3, for example, Figure 2A As shown, after the negative mask M is abutted against the coating layer 3, the resist forming layer 2 is irradiated with ultraviolet rays through the coating layer 3. The negative mask M has an exposure portion Ma that allows ultraviolet rays to pass through and a non-exposure portion Mb that shields ultraviolet rays, and the non-exposure portion Mb is arranged at a position that matches, for example, the uncured portion 2b of the resist forming layer 2. The non-exposure portion Mb in the negative mask M is, for example, a portion for making a plating layer. The negative mask M is, for example, an optical tool such as a mask or a dry plate. The light source of ultraviolet rays can 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 ultraviolet rays is not limited to this, as long as it is a light source that can irradiate ultraviolet rays that can cure the photosensitive composition.

[0075] The exposure method can be a method other than the method using a negative mask. For example, the resist forming layer 2 can be exposed using a direct drawing method, which is to irradiate only the part (exposure part Ma) that needs to be exposed in order to cure the resist forming layer 2 by irradiating the ultraviolet rays emitted from the light source. The light source suitable for the direct drawing method can 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, a YAG, a g line (436nm), an h line (405nm), an i line (365nm), and a combination of two or more of a g line, an h line, and an i line. The light source of ultraviolet rays is not limited thereto, as long as it is a light source that can irradiate ultraviolet rays that can cure the photosensitive composition.

[0076] It should be noted that, when the entire surface of the resist-forming layer 2 is exposed (entire surface exposure) to produce the resist layer 12, the coating layer 3 is peeled off from the laminate 10, and then a plating treatment or a metal foil is arranged on the resist layer 12, thereby a metal-clad laminate can be produced. Of course, when the laminate 10 has a resist-forming layer 2 (for example, a first resist-forming layer 21 and a second resist-forming layer 22) and a coating layer 3 (for example, a first coating layer 31 and a second coating layer 32) on both sides of the insulating layer 1, a double-sided metal-clad laminate can also be produced.

[0077] If the resist-forming layer 2 is exposed, a cured portion (cured portion 2a) and an uncured portion (uncured portion 2b) in the resist-forming layer 2 may be formed in the laminate 10. Figure 2A As shown, when the resist forming layer 2 is exposed via the negative mask M, the exposed portion of the dried or semi-cured photosensitive resin composition corresponding to the exposed portion Ma of the negative mask M is cured, while on the other hand, the unexposed portion corresponding to the non-exposed portion Mb of the negative mask M is not cured.

[0078] Next, the exposed laminate 10 is Figure 2B As shown, the coating layer 3 is peeled off, thereby exposing the resist-forming layer 2 including the cured portion 2 a and the uncured portion 2 b on the insulating layer 1 .

[0079] Next, the exposed resist forming layer 2 is subjected to a development process, so that the resist layer 12 can be produced from the resist forming layer 2. Specifically, by carrying out the development process, Figure 2B The cured portion 2a of the resist forming layer 2 shown in FIG. 1 will remain, and the uncured portion 2b will be removed. Figure 2C As shown, the resist layer 12 can be formed. In this embodiment, the resist layer 12 is formed with the cured portion 2a because the uncured portion 2b of the resist forming layer 2 is removed as described above.

[0080] In the development treatment, an appropriate developer corresponding to the composition of the photosensitive composition can be used. The developer is, for example, an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide, or an organic amine. More specifically, the alkaline aqueous solution contains, for example, at least one component selected from sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide and lithium hydroxide. 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 monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine.

[0081] 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 working environment can be improved and the burden of waste disposal can be reduced.

[0082] Thus, the insulating layer 1 in the laminate 10 becomes the insulating substrate 11 , and the substrate 20 having the resist layer 12 including the cured product of the photosensitive composition on the insulating substrate 11 can be obtained.

[0083] Next, the substrate 20 is plated to form the conductor layer 13. For example, the resist layer 12 formed from the resist forming layer 2 can be plated. That is, the resist layer 12 can also be used as a plated resist layer. Therefore, when the printed wiring board 100 is produced from the laminate 10, the printed wiring board 100 can have a conductor layer 13 including a plated layer such as hole plating. For example, in the printed wiring board 100, after the resist forming layer 2 in the laminate 10 is exposed and developed, the removed portion of the resist layer 12 is plated to form a conductor wiring 131 such as hole plating (see Figure 2D ).

[0084] Specifically, if Figure 2D As shown in FIG. 1 , in the resist layer 12, the gaps between the adjacent cured portions 2a formed by the resist forming layer 2 (the positions after removing the uncured portions 2b) are plated, so that, for example, a conductor layer 13 (more specifically, a conductor wiring 131) can be produced. It should be noted that, in the above description, the method is described using the so-called full additive method, but the method of the plating treatment is not limited thereto, and an appropriate method can be used.

[0085] Before the above-mentioned plating treatment is performed, the resist layer 12 may be subjected to either or both of a heat treatment and a UV treatment. In this case, the adhesiveness and plating resistance of the resist layer 12 are improved.

[0086] In addition, before the above-mentioned plating treatment is implemented, the resist layer 12 is subjected to a roughening treatment, so that the surface of the resist layer 12 can be roughened. For example, when a part of the outer surface of the resist layer 12 and the inner side surface in the gap of the resist layer are roughened as a whole, a common desmearing treatment using an oxidant can be performed. For example, the outer surface of the resist layer 12 is contacted with an oxidant to give a rough surface to the resist layer 12. But not limited to this, plasma treatment, corona treatment, UV treatment, ozone treatment, primer treatment, etc. can also be appropriately used to not give a rough surface to the cured product. The oxidant can be an oxidant that can be obtained as a desmearing liquid. For example, the oxidant can be constituted by a commercially available desmearing swelling liquid and a desmearing liquid. Such an oxidant can contain, for example, at least one permanganate selected from sodium permanganate and potassium permanganate. In addition, the desmearing treatment can also be implemented by performing a plasma treatment before the above-mentioned plating treatment is implemented. In this case, when the resist forming layer 2 is exposed and then subjected to development treatment, if resist residue is generated, the resist residue can be removed.

[0087] In this way, a printed wiring board 100 including an insulating substrate 11, a resist layer 12, and a conductor layer 13 can be manufactured. In this embodiment, the insulating layer 1 in the laminate 10 becomes the insulating substrate 11 in the printed wiring board 100, and the resist-forming layer 2 in the laminate 10 becomes the insulating resist layer 12 in the printed wiring board 100. That is, the insulating layer 1 in the laminate 10 can be used as an insulating base material, and the resist-forming layer 2 can be used as a permanent resist.

[0088] The thickness of the resist layer 12 in the printed wiring board 100 is not particularly limited, but is preferably 0.5 μm to 20 μm. The thickness of the resist layer 12 is more preferably 0.8 μm to 15 μm, further preferably 1.0 μm to 13 μm, and particularly preferably 1.5 μm to 10 μm. As described above, the resist layer 12 can be preferably used as, for example, an interlayer insulating layer. When the resist layer 12 is used as an interlayer insulating layer, in order to ensure high resolution of the interlayer insulating layer, it is preferably in the range of 0.5 μm to 20 μm, and more preferably in the range of 1 μm to 10 μm.

[0089] <<Photosensitive composition>>

[0090] Next, the components that may be contained in the photosensitive composition for preparing the resist-forming layer 2 according to the present embodiment will be described in detail. It should be noted that in the following description, "(meth)acrylic acid" refers to at least one of "acrylic acid" and "methacrylic acid". For example, (meth)acrylate refers to at least one of acrylate and methacrylate.

[0091] The photosensitive composition can be suitably used to prepare the resist-forming layer 2 of this embodiment. Therefore, in the photosensitive composition of this embodiment, an electrical insulating layer such as a plating resist layer, a solder resist layer, and an interlayer insulating layer can be particularly well formed from the dried product, i.e., a dry film, or a coating film of the photosensitive composition.

[0092] (Carboxyl resin)

[0093] 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), which is produced by reacting an epoxy compound (a1) having at least two epoxy groups with a carboxylic acid (a2) having an ethylenically unsaturated group, and an acid anhydride (a3), wherein the acid anhydride (a3) ​​contains an acid dianhydride (a4).

[0094] In this embodiment, the carboxyl group-containing resin (A) contains a carboxyl group-containing resin (A1). The synthesis of the carboxyl group-containing resin (A1) is specifically described.

[0095] The product (hereinafter also referred to as "product (X)") generated by the reaction of the epoxy compound (a1) and the carboxylic acid (a2) contains a product (X1) generated by the reaction of the two epoxy groups in the epoxy compound (a1) with the carboxyl group in the carboxylic acid (a2). The product (X1) has a secondary hydroxyl group generated by the reaction of the epoxy group and the carboxyl group, and an ethylenically unsaturated group from the carboxylic acid (a2). The product (X) may also contain a product (X2) generated by the reaction of only one of the two epoxy groups in the epoxy compound (a1) with the carboxyl group in the carboxylic acid (a2). The product (X2) has a secondary hydroxyl group, an ethylenically unsaturated group and an epoxy group. The product (X) may also contain unreacted epoxy compound (a1). That is, the product (X) sometimes contains a component having an epoxy group, and the component may contain at least one of the product (X2) and the epoxy compound (a1).

[0096] The carboxyl-containing resin (A1) generated by the reaction of product (X) and acid anhydride (a3) ​​contains the component (X3) generated by the reaction of product (X1) and acid dianhydride (a4). Component (X3) has a carboxyl group from acid dianhydride (a4). In addition, since a cross-linking reaction based on acid dianhydride (a4) can be produced, component (X3) is prone to molecular weight distribution. In addition, carboxyl-containing resin (A1) may also include unreacted product (X1).

[0097] Furthermore, the acid anhydride (a3) ​​may contain an acid monoanhydride (a5). Therefore, the carboxyl-containing resin (A1) generated by the reaction of the product (X) with the acid anhydride (a3) ​​contains a component (X4) generated by the reaction of the product (X1) and the acid monoanhydride (a5). The component (X4) has a carboxyl group derived from the acid monoanhydride (a5).

[0098] Thus, the carboxyl-containing resin (A1) can have a moderate molecular weight distribution. Therefore, a carboxyl-containing resin (A1) having a desired molecular weight and polydispersity can be easily obtained. That is, a carboxyl-containing resin (A1) having a number average molecular weight Mn of 500 to 2500 and a polydispersity Mw / Mn of 1.2 to 2.8 can be obtained.

[0099] 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 residual carboxyl group. Therefore, the photosensitive composition may exhibit thermosetting properties.

[0100] The carboxyl-containing resin (A1) has an ethylenically unsaturated group from a carboxylic acid (a2) having an ethylenically unsaturated group, and therefore has photoreactivity. Therefore, the carboxyl-containing resin (A1) can impart photosensitivity (specifically, ultraviolet curability) to the photosensitive composition. In addition, the carboxyl-containing resin (A1) has a carboxyl group from anhydride (a3), and therefore, the photosensitive composition can be imparted with developability brought by an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide. Furthermore, in the case where the anhydride (a3) ​​contains an acid dianhydride (a4), the molecular weight of the carboxyl-containing resin (A1) depends on the number of crosslinks of the acid dianhydride (a4). Therefore, a carboxyl-containing resin (A1) whose acid value and molecular weight are appropriately adjusted can be obtained. In addition, in the case where the anhydride (a3) ​​contains an acid dianhydride (a4), by controlling the amount of the acid dianhydride (a4), a carboxyl-containing resin (A1) with a desired molecular weight and acid value can be easily obtained.

[0101] The number average molecular weight of the carboxyl group-containing resin (A1) is preferably 500 to 2500. In this case, the developability of the photosensitive composition with an alkaline aqueous solution can be easily improved. The number average molecular weight is more preferably 800 to 2300, further preferably 900 to 2200, and particularly preferably 1000 to 2000.

[0102] The polydispersity Mw / Mn of the carboxyl-containing resin (A1) is preferably 1.2 to 2.8. The polydispersity Mw / Mn of the carboxyl-containing resin (A1) is more preferably 1.3 to 2.7, further preferably 1.4 to 2.6, and particularly preferably 1.5 to 2.5. It should be noted that the polydispersity is the ratio (Mw / Mn) of the weight average molecular weight (Mw) of the carboxyl-containing resin (A1) to the number average molecular weight (Mn).

[0103] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the carboxyl group-containing resin (A1) can be calculated from the molecular weight measurement results using gel permeation chromatography. The molecular weight measurement using gel permeation chromatography can be performed, for example, under the following conditions.

[0104] GPC equipment: SHODEX SYSTEM 11 manufactured by Showa Denko K.K.,

[0105] Column: 4 SHODEX KF-800P, KF-005, KF-003, KF-001 connected in series,

[0106] Mobile phase: THF,

[0107] Flow rate: 1ml / min,

[0108] Column temperature: 45°C,

[0109] Detector: RI,

[0110] Conversion: Polystyrene.

[0111] The acid value of the carboxyl-containing resin (A1) is preferably 55 mgKOH / g to 130 mgKOH / g. In this case, the resolution of the cured product prepared from the photosensitive composition is particularly improved. The acid value of the carboxyl-containing resin (A1) is more preferably 60 mgKOH / g to 120 mgKOH / g, further preferably 60 mgKOH / g to 110 mgKOH / g, and particularly preferably 60 mgKOH / g or more and less than 75 mgKOH / g.

[0112] The raw materials of the carboxyl group-containing resin (A1) and the reaction conditions for synthesizing the carboxyl group-containing resin (A1) are described in detail.

[0113] The epoxy compound (a1) having at least two epoxy groups may contain, for example, a compound having a bisphenol fluorene skeleton. The carboxyl resin (A1) is, for example, a reaction product of the following product and an acid anhydride (a3), and the product is a product generated by the reaction 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. That is, the carboxyl resin (A1) can be synthesized as follows: 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 obtained thereby is reacted with an acid anhydride (a3). If the photosensitive composition contains the carboxyl resin (A1), the cured product of the photosensitive composition can have high heat resistance and insulation reliability. In addition, when the carboxyl resin (A1) has a bisphenol fluorene skeleton, it is easy to absorb light in the wavelength region of 300 to 330 nm, and therefore, the resolution of the cured product made from the photosensitive composition can be improved. When the carboxyl group-containing resin (A1) has a bisphenol fluorene skeleton, it has a bulky structure and can therefore prevent the diffusion of generated radical species, thereby improving the resolution of a cured product produced from the photosensitive composition even when exposed to light having no wavelength in the 300 to 330 nm range.

[0114]

[0115] R1 to R8 in formula (1) may be hydrogen, or an alkyl group or a halogen atom having 1 to 5 carbon atoms. This is because even if the hydrogen in the aromatic ring is replaced by a low molecular weight alkyl group or a halogen atom, there is no adverse effect on the physical properties of the carboxyl-containing resin (A1). Rather, the heat resistance or flame retardancy of the cured product of the photosensitive composition containing the carboxyl-containing resin (A1) is improved.

[0116] The epoxy compound (a1) may have a structure such as that shown in the following formula (2). In formula (2), n is, for example, an integer in the range of 0 to 20. In order to appropriately control the molecular weight of the carboxyl-containing resin (A1), the average of n is particularly preferably in the range of 0 to 1. If the average of n is in the range of 0 to 1, it is easy to suppress the increase in excess molecular weight even when the acid anhydride (a3) ​​contains an acid dianhydride. In addition, in formula (2), R1 to R8 are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen atom.

[0117]

[0118] The carboxylic acid (a2) having an ethylenically unsaturated group may contain, for example, a compound having only one ethylenically unsaturated group in one molecule. More specifically, the carboxylic acid (a2) having an ethylenically unsaturated group may contain, for example, at least one compound selected from acrylic acid, methacrylic acid, ω-carboxyl-polycaprolactone (n≈2) monoacrylate, crotonic acid, cinnamic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl phthalic acid, 2-acryloyloxypropyl phthalic acid, 2-methacryloyloxypropyl phthalic acid, 2-acryloyloxyethyl maleic acid, 2-methacryloyloxyethyl maleic acid, β-carboxyethyl acrylate, 2-acryloyloxyethyl tetrahydrophthalic acid, 2-methacryloyloxyethyl tetrahydrophthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid and 2-methacryloyloxyethyl hexahydrophthalic acid. It is preferred that the carboxylic acid (a2) having an ethylenically unsaturated group contains acrylic acid.

[0119] When the epoxy compound (a1) and the carboxylic acid (a2) are reacted, an appropriate method can be adopted. For example, carboxylic acid (a2) is added to a solvent solution of the epoxy compound (a1), and a thermal polymerization inhibitor and a catalyst are further added as needed, and stirred and mixed to obtain a reactive solution. The reactive solution is reacted at a temperature of preferably 60°C to 150°C, particularly preferably 80°C to 120°C, using a common method, to obtain a product (X). The solvent in this case may contain, for example, 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, propylene glycol monomethyl ether acetate, and at least one component of 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 triphenylphosphine. at least one ingredient in.

[0120] The catalyst particularly preferably contains triphenylphosphine. That is, it is preferred to react the epoxy compound (a1) with the carboxylic acid (a2) in the presence of triphenylphosphine. In this case, the ring-opening addition reaction between 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.

[0121] When the epoxy compound (a1) and the carboxylic acid (a2) are reacted, the amount of the carboxylic acid (a2) is preferably 0.7 mol to 1.0 mol per 1 mol of the epoxy group of the epoxy compound (a1). In this case, a photosensitive composition having excellent photosensitivity and stability can be obtained.

[0122] The product (X) obtained in this manner has a hydroxyl group generated by the reaction between the epoxy group of the epoxy compound (a1) and the carboxyl group of the carboxylic acid (a2).

[0123] The acid dianhydride (a4) is a compound having two acid anhydride groups. The acid dianhydride (a4) may contain an anhydride of a tetracarboxylic acid. The acid dianhydride (a4) may contain, for example, at least one compound selected from 1,2,4,5-benzenetetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, methylcyclohexenetetracarboxylic dianhydride, tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, glycerol ditrimellityl anhydride monoacetate, ethylene glycol ditrimellityl anhydride, 3,3',4,4'-diphenyl sulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-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. In particular, the acid dianhydride (a4) preferably contains 3,3',4,4'-biphenyltetracarboxylic dianhydride. In this case, good developability of the photosensitive composition can be ensured, and the tackiness of the film produced from the photosensitive composition can be further suppressed while further improving the insulation reliability and plating resistance of the cured product.

[0124] Acid anhydride (a3) ​​may include acid monoanhydride (a5). Acid monoanhydride (a5) is a compound having an acid anhydride group. Acid monoanhydride (a5) may contain an anhydride of a dicarboxylic acid. 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, good developability of the photosensitive composition can be ensured, and while further suppressing the viscosity of the film made by the photosensitive composition, the insulation reliability and plating resistance of the cured product can be further improved.

[0125] When the product (X) reacts with the anhydride (a3), an appropriate method can be used. For example, anhydride (a3) ​​is added to a solvent solution of the product (X), and a thermal polymerization inhibitor and a catalyst are further added as needed, and stirred and mixed to obtain a reactive solution. Using a common method, the reactive solution is reacted at a temperature preferably of 60°C to 150°C, particularly preferably 80°C to 120°C, to obtain a carboxyl-containing resin (A1). As solvents, catalysts and polymerization inhibitors, appropriate substances can be used, or the solvents, catalysts and polymerization inhibitors used in the synthesis of the product (X) can be directly used.

[0126] The catalyst particularly preferably contains triphenylphosphine. That is, it is preferred that the product (X) and the acid anhydride (a3) ​​are reacted in the presence of triphenylphosphine. In this case, the reaction between the secondary hydroxyl group in the product (X) and 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.

[0127] When the acid anhydride (a3) ​​contains the acid dianhydride (a4), the amount of the acid dianhydride (a4) is preferably 0.01 mol to 0.24 mol relative to 1 mol of the epoxy group of the epoxy compound (a1). In this case, a carboxyl-containing resin (A1) having an acid value and a molecular weight appropriately adjusted can be easily obtained. The amount of the acid dianhydride (a4) is more preferably 0.04 mol to 0.22 mol.

[0128] In addition, when the acid anhydride (a3) ​​further contains an acid monoanhydride (a5), the amount of the acid monoanhydride (a5) is preferably 0.05 mol to 0.7 mol per 1 mol of the epoxy group of the epoxy compound (a1). In this case, a carboxyl group-containing resin (A1) having an appropriately adjusted acid value and molecular weight can be easily obtained.

[0129] It is also preferred to react the product (X) with the acid anhydride (a3) ​​under air bubbling. In this case, excessive increase in molecular weight of the produced carboxyl group-containing resin (A1) can be suppressed, and the developability of the photosensitive composition with an alkaline aqueous solution can be particularly improved.

[0130] Components other than the carboxyl group-containing resin (A1) in the photosensitive composition will be described.

[0131] 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).

[0132] The carboxyl-containing resin (A) may contain only the carboxyl-containing resin (A1), or may contain a photosensitive resin (A2) other than the carboxyl-containing resin (A1). The photosensitive resin (A2) contains, for example, the following resin, which is a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group, and a reactant of an ethylenically unsaturated compound having an epoxy group. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound without a carboxyl group. The photosensitive resin (A2) may be obtained by reacting a part of the carboxyl group in the polymer with an ethylenically unsaturated compound having an epoxy group. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound without a carboxyl group. The ethylenically unsaturated compound having a carboxyl group contains compounds such as acrylic acid, methacrylic acid, ω-carboxyl-polycaprolactone (n≈2) monoacrylate, pentaerythritol triacrylate, and pentaerythritol trimethacrylate. The ethylenically unsaturated compound without a carboxyl group includes, for example, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, and compounds such as linear or branched aliphatic or alicyclic (wherein the ring may have a portion of unsaturated bonds) (meth)acrylates. The ethylenically unsaturated compound having an epoxy group preferably includes glycidyl (meth)acrylate.

[0133] (Photopolymerization Initiator)

[0134] The photosensitive composition preferably contains a photopolymerization initiator (B). The photopolymerization initiator (B) is a component that can improve the photosensitivity of the photosensitive composition. The photopolymerization initiator (B) preferably contains at least one selected from, for example, α-aminoalkylphenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, and oxime ester-based photopolymerization initiators. In this case, when the photosensitive composition is exposed to light such as ultraviolet rays, high photosensitivity can be imparted to the photosensitive composition. The photopolymerization initiator (B) further preferably contains an acylphosphine oxide-based photopolymerization initiator. In this case, high photosensitivity can be imparted to the photosensitive composition, and, with less coloring, high transparency can be maintained.

[0135] The α-aminoalkylphenone-based photopolymerization initiator may contain, for example, at least one component selected from 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-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.

[0136] 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-phosphinate, 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)- At least one component of a bisacylphosphine oxide-based photopolymerization initiator such as bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-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.

[0137] The oxime ester photopolymerization initiator may contain at least one component selected from, for example, 1,2-octanedione-1-[4-(phenylthio)-2-(O-benzoyloxime)] and ethylone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime).

[0138] The photosensitive composition may further contain a suitable photopolymerization accelerator and a sensitizer, etc. For example, the photosensitive composition may contain hydroxyketones selected from 1-hydroxy-cyclohexyl-phenyl-ketone, methyl phenylglyoxylate, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1-one and 2-hydroxy-2-methyl-1-phenyl-propane-1-one; benzoin and its alkyl ethers; acetophenones such as acetophenone and benzyl dimethyl ketal; anthraquinones such as 2-methylanthraquinone; Thioxanthones such as 4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diisopropylthioxanthone; benzophenones such as benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, bis(diethylamino)benzophenone; xanthones such as 2,4-diisopropylxanthone; and α-hydroxyketones such as 2-hydroxy-2-methyl-1-phenyl-propane-1-one; at least one component of compounds containing nitrogen atoms such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholine-1-propanone. The photosensitive composition may contain a photopolymerization initiator (B) and a suitable photopolymerization accelerator and sensitizer such as tertiary amines such as ethyl p-dimethylbenzoate, isopentyl p-dimethylaminobenzoate, and 2-dimethylaminoethyl benzoate. The photosensitive composition may contain at least one of a photopolymerization initiator for visible light exposure and a photopolymerization initiator for near infrared exposure as required. The photosensitive adhesive composition may contain a photopolymerization initiator (B) and a coumarin derivative such as 7-diethylamino-4-methylcoumarin as a sensitizer for laser exposure, a carbocyanine pigment system, a xanthene pigment system, etc.

[0139] (Photopolymerizable compound)

[0140] 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 a photopolymerizable monomer and a photopolymerizable prepolymer. As a photopolymerizable monomer, it may contain, for example, a monofunctional (meth)acrylate such as 2-hydroxyethyl (meth)acrylate; and at least one compound selected from a multifunctional (meth)acrylate such as diethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ε-caprolactone-modified pentaerythritol hexaacrylate, tricyclodecane dimethanol di(meth)acrylate, etc.

[0141] The photopolymerizable prepolymer may contain, for example, at least one compound selected from 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 oligomeric (meth)acrylate prepolymer may contain, for example, at least one component selected from epoxy (meth)acrylate, polyester (meth)acrylate, urethane (meth)acrylate, alkyd resin (meth)acrylate, silicone resin (meth)acrylate, and spiro resin (meth)acrylate.

[0142] 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 two unsaturated bonds in one molecule or a compound having three unsaturated bonds in one molecule. In this case, the resolution when the dried film prepared from the photosensitive composition is exposed and developed is improved, and the developability of the photosensitive composition by an alkaline aqueous solution is particularly improved.

[0143] (Other ingredients)

[0144] 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 addition, in this case, the plating resistance and insulation properties of the cured product made from the photosensitive composition can be improved.

[0145] The epoxy compound (D) may contain, for example, a crystalline epoxy resin (D1). In addition, the epoxy compound (D) may further contain an amorphous epoxy resin (D2). Here, a "crystalline epoxy resin" is an epoxy resin having a melting point, and an "amorphous epoxy resin" is an epoxy resin having no melting point.

[0146] The crystalline epoxy resin (D1) preferably contains, for example, 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: Nippon Steel & Sumitomo Metal Chemical Co., Ltd., trade name YDC-1312), a biphenyl-type crystalline epoxy resin (specific example: Mitsubishi Chemical Corporation, trade name YX-4000), a diphenyl ether-type crystalline epoxy resin ( Specific examples include: product number YSLV-80DE manufactured by Nippon Steel Chemical & Materials Co., Ltd.), bisphenol type crystalline epoxy resin (specific example: trade name YSLV-80XY manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), tetraphenolethane type crystalline epoxy resin (specific example: product number GTR-1800 manufactured by Nippon Kayaku Co., Ltd.), bisphenolfluorene type crystalline epoxy resin (specific example: epoxy resin having structure (S7)) One or more components.

[0147] The crystalline epoxy resin (D1) preferably has two epoxy groups in one molecule. In this case, the cured product can be made less likely to crack during repeated temperature changes.

[0148] The crystalline epoxy resin (D1) preferably has an epoxy equivalent of 150 g / eq to 300 g / eq. The epoxy equivalent is the gram weight of the crystalline epoxy resin (D1) containing 1 gram equivalent of epoxy groups. The crystalline epoxy resin (D1) has a melting point. Examples of the melting point of the crystalline epoxy resin (D1) include 70°C to 180°C.

[0149] In particular, the epoxy compound (D) preferably contains a crystalline epoxy resin (D1-1) having a melting point of 110°C or less. In this case, the developability of the photosensitive agent composition based on an alkaline aqueous solution is particularly improved. In addition, in this case, the resolution (opening) of the cured layer made from the photosensitive composition is also improved. The crystalline epoxy resin (D1-1) having a melting point of 110°C or less may contain, for example, at least one component selected from a biphenyl type epoxy resin (specific example: product number YX-4000 manufactured by Mitsubishi Chemical Corporation), a biphenyl ether type epoxy resin (specific example: product number YSLV-80DE manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), and a bisphenol type epoxy resin (specific example: product number YSLV-80XY manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), and a bisphenol fluorene type crystalline epoxy resin (specific example: an epoxy resin having structure (S7)).

[0150] The amorphous epoxy resin (D2) preferably contains, for example, a phenol novolac epoxy resin (specific example: product number EPICLON N-775 manufactured by DIC Corporation), a cresol novolac epoxy resin (specific example: product number EPICLON N-695 manufactured by DIC Corporation), a bisphenol A novolac epoxy resin (specific example: product number EPICLON N-865 manufactured by DIC Corporation), a bisphenol A epoxy resin (specific example: product number jER1001 manufactured by Mitsubishi Chemical Corporation), a bisphenol F epoxy resin (specific example: product number jER4004P manufactured by Mitsubishi Chemical Corporation), a bisphenol S ... epoxy resin (specific example: product number EPICLON N-865 manufactured by DIC Corporation), a bisphenol A epoxy resin (specific example: product number jER1001 manufactured by Mitsubishi Chemical Corporation), a bisphenol F epoxy resin (specific example: product number jER4004P manufactured by Mitsubishi Chemical Corporation), a bisphenol S epoxy resin (specific example: product number EPICLON N-695 manufactured by DIC Corporation), a bisphenol A epoxy resin (specific example: product number EPICLON N-695 manufactured by DIC Corporation), a bisphenol A epoxy resin (specific example: product number EPICLON N-865 manufactured by DIC Corporation), a bisphenol A epoxy resin (specific example: product number EXA-1514), bisphenol AD ​​type epoxy resin, biphenyl novolac type epoxy resin (specific example: product number NC-3000 manufactured by Nippon Kayaku Co., Ltd.), hydrogenated bisphenol A type epoxy resin (specific example: product number ST-4000D manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), naphthalene type epoxy resin (specific example: product numbers EPICLON HP-4032, EPICLON HP-4700, and EPICLON HP-4770 manufactured by DIC Corporation), tert-butylcatechol type epoxy resin (specific example: product number EPICLON HP-820 manufactured by DIC Corporation), dicyclopentadiene type epoxy resin (specific example: product number EPICLON HP-820 manufactured by DIC Corporation), HP-7200), adamantane epoxy resin (specific example: product number ADAMANTATEX-E-201 manufactured by Idemitsu Kosan Co., Ltd.), special difunctional epoxy resin (specific examples: product numbers YL7175-500 and YL7175-1000 manufactured by Mitsubishi Chemical Corporation; product numbers EPICLON TSR-960, EPICLON TER-601, EPILON TSR-250-80BX, EPICLON1650-75MPX, EPICLON EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822 and EPICLON EXA-9726; product number YSLV-120TE manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), rubber core-shell polymer modified bisphenol A type epoxy resin (specific example: product number MX-156 manufactured by KANEKA CORPORATION), rubber core-shell polymer modified bisphenol F type epoxy resin (specific example: product number MX-136 manufactured by KANEKA CORPORATION), and at least one component of bisphenol F type epoxy resin containing rubber particles (specific example: product number Kane Ace MX-130 manufactured by KANEKA CORPORATION).

[0151] When the photosensitive composition contains an epoxy compound (D), the photosensitive composition preferably contains both a crystalline epoxy resin (D1) and an amorphous epoxy resin (D2). In this case, the plating resistance and insulation properties of a cured product prepared from the photosensitive composition can be further improved.

[0152] 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 will be improved. The phosphorus-containing epoxy resin may be contained in a crystalline epoxy resin (D1), or may be contained in an amorphous epoxy resin (D2). Phosphorus-containing epoxy resins are, for example, phosphoric acid-modified bisphenol F-type epoxy resins (specific examples are: product numbers EPICLON EXA-9726 and EPICLON EXA-9710 manufactured by DIC Corporation), product number EPOTOHTO FX-305 manufactured by Nippon Steel & Sumitomo Metal Chemical Corporation, etc.

[0153] 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 a bisphenol fluorene skeleton (S1) represented by the formula (1) described above.

[0154] The photosensitive composition preferably contains a solvent (E). The solvent (E) may contain at least one compound selected from water, ethanol, isobutyl alcohol, 1-butanol, isopropyl alcohol, hexanol, ethylene glycol, 3-methyl-3-methoxybutanol and other linear alcohols, branched alcohols, secondary alcohols or polyols; ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; petroleum-based aromatic mixed solvents such as Swasol series (manufactured by Maruzen 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 and carbitol acetate; and dialkyl glycol ethers. The solvent (E) preferably contains at least one alcohol solvent (E1) in polypropylene glycol alkyl ethers such as propylene glycol monomethyl ether, ethanol, isobutyl alcohol, 1-butanol, isopropyl alcohol, hexanol, ethylene glycol, 3-methyl-3-methoxybutanol, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol methyl ether and dipropylene glycol methyl ether. That is, the photosensitive composition preferably contains an alcohol solvent (E1). In this case, when preparing the photosensitive composition, the coating and uniformity of the photosensitive composition can be further improved. In addition, even in the case where a thermoplastic film is used for the substrate, the dissolution of the substrate can be difficult to produce and it is not easy to damage the substrate. The solvent (E) more preferably contains propylene glycol monomethyl ether. In this case, the coating and uniformity of the photosensitive composition can be further improved, and good drying properties can be obtained. It is further preferred to contain propylene glycol monomethyl ether in a ratio of 50% by mass or more relative to the solvent (E).

[0155] The photosensitive composition may contain blocked isocyanates selected from toluene diisocyanate series, dimorpholine diisocyanate series, isophorone diisocyanate series and hexamethylene diisocyanate series blocked with caprolactam, oxime, malonate, etc.; butylated urea resin; various thermosetting resins other than the above; ultraviolet curing epoxy (meth) acrylate; a resin obtained by adding (meth) acrylic acid to epoxy resins such as bisphenol A type, novolac type, cresol novolac type, and alicyclic type; and at least one resin selected from polymer compounds such as diallyl phthalate resin, phenoxy resin, urethane resin, and fluororesin.

[0156] 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, etc.; amine compounds such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzylamine, etc.; hydrazine compounds such as adipic acid hydrazide and sebacic acid hydrazide; phosphorus compounds such as triphenylphosphine; acid anhydrides; phenols; thiols; Lewis acid amine complexes; and At least one component in the salt. Commercial products of these components are, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (all trade names of imidazole compounds) manufactured by Shikoku Chemicals Co., Ltd., U-CAT3503N, UCAT3502T (all trade names of blocked isocyanate compounds of dimethylamine) manufactured by San-Apro Ltd., DBU, DBN, U-CATSA102, U-CAT5002 (all bicyclic amidine compounds and salts thereof).

[0157] 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), s-triazine derivatives such as 2,4-diamino-6-methacryloyloxyethyl-s-triazine, 2-vinyl-4,6-diamino-s-triazine, 2-vinyl-4,6-diamino-s-triazine·isocyanuric acid adduct, and 2,4-diamino-6-methacryloyloxyethyl-s-triazine·isocyanuric acid adduct, and silane coupling agents.

[0158] The photosensitive composition may contain a rheology control agent. The rheology control agent can easily optimize the viscosity of the photosensitive composition. Examples of the rheology control agent include urea-modified intermediate polar polyamide (BYK Corporation product number BYK-430, BYK-431), polyhydroxycarboxylic acid amide (BYK Corporation product number BYK-405), modified urea (BYK Corporation product number BYK-410, BYK-411, BYK-420), polymer urea derivatives (BYK Corporation product number BYK-415), urea-modified urethane (BYK Corporation product number BYK-425), polyurethane (BYK Corporation product number BYK-428), castor oil wax, polyethylene wax, polyamide wax, bentonite, kaolin, and clay.

[0159] The photosensitive composition may contain at least one component selected from the group consisting of a curing accelerator, a colorant, a copolymer such as silicone and acrylate, a leveling agent, a thixotropic agent, a polymerization inhibitor, an antihalation agent, a flame retardant, a defoaming agent, an antioxidant, a surfactant, and a polymer dispersant.

[0160] The amounts of the components in the photosensitive composition can be appropriately adjusted so that the photosensitive composition has photocurability and can be developed in an alkaline solution.

[0161] The amount of the carboxyl group-containing resin (A) is preferably 50% to 90% by mass, more preferably 55% to 85% by mass, and further preferably 60% to 80% by mass, relative to the solid content of the photosensitive composition. In addition, the amount of the carboxyl group-containing resin (A1) is preferably 50% to 90% by mass, more preferably 55% to 85% by mass, and further preferably 60% to 80% by mass, relative to the solid content of the photosensitive composition.

[0162] The amount of the photopolymerization initiator (B) is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, and further preferably 2 to 10% by mass, relative to the carboxyl group-containing resin (A).

[0163] The amount of the photopolymerizable compound (C) is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 25 to 45% by mass, relative to the carboxyl group-containing resin (A).

[0164] When the photosensitive composition contains an epoxy compound (D), the amount of the epoxy compound (D) is preferably greater than 0 equivalent and less than 2 equivalents, more preferably greater than 0 equivalent and less than 1 equivalent, further preferably greater than 0 equivalent and less than 0.8 equivalent, and particularly preferably greater than 0 equivalent and less than 0.5 equivalent, relative to 1 equivalent of the carboxyl group contained in the carboxyl group-containing resin (A).

[0165] When the photosensitive composition contains a solvent (E), the amount of the solvent (E) is preferably 50% by mass to 95% by mass based on the entire photosensitive composition. In this case, when the photosensitive composition is applied, the coating properties of the photosensitive composition can be improved.

[0166] When preparing the photosensitive composition of the present embodiment, it 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. In addition, the photosensitive composition can be prepared by mixing using an appropriate mixing method such as a three-roll mill, a ball mill, a sand mill, etc. In the case where the raw material contains a liquid component, a component with low viscosity, etc., the part of the raw material other than the liquid component, the component with low viscosity, etc. can be first mixed and a mixture can be prepared, and then the liquid component, the component with low viscosity, etc. are added to the obtained mixture for mixing, thereby preparing the photosensitive composition. In the case where the photosensitive composition contains a solvent (E), a part or all of the solvent in the raw material can be mixed first, and then mixed with the remaining raw material.

[0167] The photosensitive composition of this embodiment is suitable for materials of electrically insulating layers such as solder resist layers, interlayer insulating layers, and plating resist layers. In particular, as described above, the photosensitive composition can have high transparency and high developability, and is therefore suitable for electrically insulating materials for optical applications.

[0168] As described above, for the photosensitive composition, when a dry film having a thickness of 10 μm is prepared from the photosensitive composition, the light transmittance at a wavelength of 450 to 800 nm is preferably 80% or more, more preferably 85% or more, further preferably 90% or more, and particularly preferably 95% or more. If it is within this range, the film prepared from the photosensitive composition can be made into a cured film with high transparency, and the laminate 10 can be particularly suitable for optical applications.

[0169] The photosensitive composition involved in the present embodiment preferably has the property that even a film with a thickness of 25 μm can be developed in a sodium carbonate aqueous solution. In this case, a sufficiently thick electrically insulating layer can be made from the photosensitive composition using photolithography, and therefore, the photosensitive composition can be widely used in making interlayer insulating layers, solder resist layers, etc. in printed wiring boards. Of course, an electrically insulating layer thinner than 25 μm can also be made from the photosensitive composition.

[0170] Whether a film with a thickness of 25 μm can be developed in a sodium carbonate aqueous solution can be confirmed by the following method. A photosensitive composition is applied to a suitable substrate to form a wet coating, and the wet coating is heated at 80°C for 40 minutes to form a film with a thickness of 25 μm. The film is directly abutted against a negative mask having an exposed portion that transmits ultraviolet light and a non-exposed portion that shields ultraviolet light, and the film is exposed to 500 mJ / cm 2The film was exposed by irradiating ultraviolet rays under the conditions of. After exposure, the following treatment was performed: a 1% Na2CO3 aqueous solution at 30°C was sprayed on the film at a spray pressure of 0.2MPa for 90 seconds, and then pure water was sprayed at a spray pressure of 0.2MPa for 90 seconds. The film was observed after the treatment. As a result, when the portion corresponding to the non-exposed portion of the film was removed and no residue was observed, it was determined that the film with a thickness of 25μm could be developed in a sodium carbonate aqueous solution. It should be noted that for films of other thicknesses (for example, 30μm), it can be confirmed in the same way whether they can be developed in a sodium carbonate aqueous solution.

[0171] [Example]

[0172] Hereinafter, specific examples of the present invention will be given, but the present invention is not limited to the examples.

[0173] (1) Synthesis of photosensitive resin A

[0174] In a four-necked flask equipped with a reflux cooler, a thermometer, an air blowing tube and a stirrer, 252 parts by mass of a bisphenol fluorene type epoxy compound (an epoxy compound represented by formula (2) with an epoxy equivalent of 252 g / eq in which all R1 to R8 in formula (2) are hydrogen), 72 parts by mass of acrylic acid, 1.5 parts by mass of triphenylphosphine, 0.2 parts by mass of 4-methoxyphenol and 200 parts by mass of propylene glycol monomethyl ether acetate were added. These were stirred under air bubbling to prepare a mixture. The mixture was stirred in the flask under air bubbling and heated under the conditions of a heating temperature of 115° C. and a heating time of 12 hours. Thus, a solution of an intermediate was prepared.

[0175] 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 under air bubbling and heated at a heating temperature of 115°C and a heating time of 6 hours, and further stirred under air bubbling and heated at a heating temperature of 60°C and a heating time of 6 hours. Thus, a 65% by mass solution of 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.

[0176] (2) Preparation of photosensitive composition

[0177] [Examples 1 to 9 and Comparative Example 1]

[0178] The components shown in Table 1 described later were added to a flask at the mass ratios (parts by mass) shown in Table 1, and stirred and mixed at a temperature of 35° C. to prepare a photosensitive composition. The details of the components shown in the table are as follows.

[0179] Photopolymerization initiator A: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by IGM Resins BV, product number: Omnirad TPO H).

[0180] Photopolymerization initiator B: 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by IGM Resins BV, product number: Omnirad 184).

[0181] · Photopolymerizable compound: tricyclodecane dimethanol diacrylate.

[0182] Antioxidant: Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (manufactured by BASF Japan Co., Ltd., product number: Irganox 1010).

[0183] Surface modifier: Surfactant (DIC Corporation, product number: MEGAFAC F-557)

[0184] Solvent: Propylene glycol monomethyl ether.

[0185] [Table 1]

[0186] Photosensitive resin composition 65 mass % solution of photosensitive resin A 156 Photopolymerization Initiator A 6 Photopolymerization initiator B 1 Photopolymerizable compounds 35 Antioxidants 1 Surface modifiers 0.2 Solvents 270

[0187] [Examples 10-11]

[0188] In Example 10, the components shown in Table 2 below were added to a flask at the mass ratio (mass parts) shown in Table 2, and then stirred and mixed at a temperature of 35° C. to prepare a photosensitive composition. In Example 11 described later, the components shown in Table 3 below were added to a flask at the mass ratio (mass parts) shown in Table 3, and then stirred and mixed at a temperature of 35° C. to prepare a photosensitive composition. Among the components shown in Tables 2 and 3, the parts common to Table 1 are the same as those in Table 1, and the details of the other components are as follows.

[0189] Silica sol: Silica sol manufactured by Nissan Chemical, trade name: MEK-ST-ZL (solid content: 30 wt %, particle size: 45 nm, solvent: MEK (methyl ethyl ketone)).

[0190] Carbon black dispersion (carbon black 15 wt%, dispersant 5 wt%, solvent MEK).

[0191] [Table 2]

[0192] Photosensitive resin composition 65 mass % solution of photosensitive resin A 156 Photopolymerization Initiator A 6 Photopolymerization initiator B 1 Photopolymerizable compounds 35 Antioxidants 1 Surface modifiers 0.2 Silica Sol 100 Solvents 170

[0193] [Table 3]

[0194] Photosensitive resin composition 65 mass % solution of photosensitive resin A 156 Photopolymerization Initiator A 6 Photopolymerization initiator B 1 Photopolymerizable compounds 35 Antioxidants 1 Surface modifiers 0.2 Carbon black dispersion 0.6 Solvents 270

[0195] [Measurement of transmittance]

[0196] The photosensitive composition prepared in (2) above was applied to a film made of polyethylene terephthalate (PET) using an applicator to form a wet coating. The coating was dried under the conditions of 120°C for 5 minutes to form a dry film (dry film) with a thickness of 10 μm on the PET film. Next, an ultra-high pressure mercury lamp was used to irradiate the entire surface of the dry film formed on the PET film at 400 mJ / cm 2 The exposed film was irradiated with ultraviolet rays under the conditions of . The exposed film was subjected to development treatment. During the development treatment, a 1% Na2CO3 aqueous solution at 30°C was sprayed on the film at a spray pressure of 0.05 MPa for 60 seconds. Next, pure water was sprayed on the film at a spray pressure of 0.05 MPa for 60 seconds.

[0197] Next, a metal halide lamp was used at 1000 mJ / cm 2 The film is irradiated with ultraviolet rays under the conditions to cure the photosensitive composition. The cured product (cured film) produced on the PET film is placed on an ultraviolet-visible near-infrared spectrophotometer (manufactured by Shimadzu Corporation, product number UV-3100PC), and the transmittance of the cured product at 450 to 800 nm is measured. As a reference, a PET film is used as an insulating layer. The transmittance curves of the cured products with a thickness of 10 μm obtained in Examples 1 to 9 and Comparative Example 1 all show a transmittance of more than 95% in any wavelength region of 450 to 800 nm.

[0198] It should be noted that in Example 10, the transmittance curve of the cured product with a thickness of 10 μm obtained showed a transmittance of 90 to 95% in the wavelength region of 450 to 800 nm, and in Example 11, the transmittance curve of the cured product with a thickness of 10 μm obtained showed a transmittance of 80 to 85% in the wavelength region of 450 to 800 nm.

[0199] (3) Preparation of test pieces

[0200] For Examples 1 to 11 and Comparative Example 1, test pieces of the laminate were prepared as follows.

[0201] [Example 1]

[0202] First, a 130 μm thick COP (cycloolefin polymer) film was prepared as an insulating layer. Then, a single surface of the COP film was heated at 100 W·min / m 2 Corona treatment was performed. The photosensitive composition prepared in (2) above was applied to the corona-treated surface of the COP by a spin coater to form a wet coating. The coating was dried by heating at 120°C for 5 minutes, thereby preparing a 2 μm thick anti-etching agent forming layer (hereinafter also referred to as a dry film) on the COP film. Next, a PET film (surface roughness Sa: 32 nm (both sides), haze: 2.6%, thickness: 16 μm) was laminated on the dry film at 50°C as a coating layer to prepare a test piece (size: width 100 mm, length 100 mm and thickness 148 μm) having an insulating layer, a dry film (anti-etching agent forming layer) and a coating layer. The conditions for the heating and lamination were a pressure of 0.5 MPa, a heating temperature of 50°C and a heating and pressing time of 45 seconds.

[0203] In the following evaluation (4-3), in Example 3, a surface treatment for making the electroless copper plating adhered was performed. In Examples 1 to 2, 4 to 11, and Comparative Example 1, a surface treatment for making the electroless copper plating adhered was performed after the corona treatment. Then, the dried film and the coating layer were sequentially overlapped in the same manner as described above, and then, the electroless copper plating treatment was further performed to prepare the test piece.

[0204] [Example 2]

[0205] In Example 1, the test piece was prepared in the same manner as in Example 1, except that the PET film (surface roughness Sa: 32 nm (both sides), haze: 2.6%, thickness: 16 μm) as the coating layer was changed to a PET film having a surface roughness Sa: 5 nm (both sides), haze: 0.6%, thickness: 16 μm.

[0206] [Example 3]

[0207] In Example 2, a test piece was prepared 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.

[0208] [Example 4]

[0209] In Example 1, a test piece was prepared in the same manner as in Example 1 except that the surface of the COP as the insulating layer was not subjected to the corona treatment.

[0210] [Example 5]

[0211] In Example 1, a test piece was prepared in the same manner as in Example 1 except that the covering layer was changed to a biaxially stretched polypropylene (OPP) film (surface roughness Sa: 50 nm (both sides), haze: 0.3%, thickness: 40 μm).

[0212] [Example 6]

[0213] In Example 1, a test piece was prepared in the same manner as in Example 1, except that the coating layer was changed to an OPP film (surface roughness Sa: 30 nm (both surfaces), haze: 1%, thickness: 20 μm).

[0214] [Example 7]

[0215] In Example 1, a test piece was prepared in the same manner as in Example 1, except that the covering layer was changed to a polyethylene (PE) film (Sa: 60 nm (both sides), haze: 17%, thickness 20 μm).

[0216] [Example 8]

[0217] In Example 2, a test piece was prepared 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.

[0218] [Example 9]

[0219] In Example 2, a test piece was prepared in the same manner as in Example 2 except that the thickness of the resist forming layer was changed to 15 μm.

[0220] [Example 10]

[0221] In Example 2, a test piece was prepared by the same method as in Example 2, except that the photosensitive resin composition described in Table 2 was used to prepare the resist-forming layer.

[0222] [Example 11]

[0223] In Example 2, a test piece was prepared by the same method as in Example 2, except that the photosensitive resin composition described in Table 3 was used to prepare the resist-forming layer.

[0224] [Comparative Example 1]

[0225] In Example 1, a test piece was prepared in the same manner as in Example 1 except that the covering layer was not superimposed.

[0226] (4) Evaluation

[0227] (4-1) Resolution

[0228] In the test pieces of Examples 1 to 11 and Comparative Example 1, a negative mask made of soda lime glass having a pattern including lines with line widths of 4 μm and 6 μm and having a non-exposed portion was used on the dried film from above the coating layer, and an ultra-high pressure mercury lamp was used at a concentration of 150 mJ / cm 2 The dried film was exposed to ultraviolet light under the conditions of 150 mJ / cm. After that, the coating layer was peeled off and the exposed film was developed. It should be noted that in Example 7, in which PE was used as the coating layer, the exposure dose was 150 mJ / cm 2 Under the exposure conditions of 150 mJ / cm , compared with Examples 1 to 6 and Examples 8 to 11 in which PET or OPP was used as the coating layer, a tendency of reduced UV transmittance was observed. 2 Increase to 400mJ / cm 2 The ultraviolet rays are irradiated under the conditions of, and then, the exposed film is subjected to a development treatment.

[0229] During the development process, a 1% Na2CO3 aqueous solution at 30°C was sprayed on the film at a spray pressure of 0.05 MPa for 60 seconds. Next, pure water was sprayed on the film at a spray pressure of 0.05 MPa for 60 seconds. This removed the unexposed part of the film and formed a pattern of removed lines on the film. After that, a metal halide lamp was used to spray 1000 mJ / cm 2 Additional UV curing was performed. The state of the test piece obtained after the exposure and development treatment was observed and evaluated according to the following criteria. The results are shown in Tables 4 and 5.

[0230] A: The UV curing reaction of the dried film proceeds sufficiently, and the cured film does not peel off at the UV irradiated portion during development, and a space with a line width of 4 μm can be resolved.

[0231] B: The UV curing reaction of the dried film proceeds sufficiently, and the cured film does not peel off at the UV irradiated portion during development. A space with a line width of 4 μm cannot be resolved, but a space with a line width of 6 μm can be resolved.

[0232] C: The UV curing reaction of the dried film proceeds sufficiently, and the cured film does not peel off at the UV irradiated portion during development, but the space between the line width of 4 μm and 6 μm cannot be distinguished.

[0233] D: The UV curing reaction of the dried film did not proceed sufficiently, and a portion of the cured film peeled off at the UV irradiated portion during development.

[0234] (Inspection)

[0235] The above results suggest that, compared with Example 7 in which PE was laminated as the covering layer, in Examples 1 to 5, when PET and OPP were laminated as the covering layer, the UV curing reaction of the dry film was facilitated. In addition, it was found that even at low exposure (150 mJ / cm 2 ) can also achieve sufficient UV curing. It can be considered that this is because the exposure is carried out in a state covered with a coating layer with low gas permeability, thereby better reducing the oxygen barrier during exposure.

[0236] In addition, a comparison between Examples 1 to 4 and Examples 8 to 11 and Examples 5 to 7 suggests that, in particular, when PET is used as a coating layer, it is less susceptible to the scattering of exposure light caused by the presence of foreign matter such as shrinkage holes in the coating layer than in the case of OPP or PE, thereby improving the resolution.

[0237] Furthermore, according to the results of Examples 1 to 4 and Examples 8 to 11, when PET is used as the covering layer, the smaller the surface roughness Sa, the more the scattering of the exposure light is suppressed, and the better the resolution is.

[0238] It should be noted that, in the evaluation after (4-2) for Example 7, the exposure was increased to 400 mJ / cm 2 The ultraviolet rays were irradiated under the conditions of , and then the exposed film was subjected to development treatment. Evaluation was performed using the test pieces after exposure and development treatment.

[0239] In addition, as in Comparative Example 1, when the exposure was performed without overlapping the coating layer, the low exposure dose (150 mJ / cm 2 ) was not sufficiently cured by UV, and part of the coating film peeled off at the UV irradiation site during development. Therefore, the evaluation after (4-2) was not performed.

[0240] (4-2) Adhesion

[0241] For the test piece exposed and developed in (4-1) above, a cross was drawn in a checkerboard pattern (width of about 1 mm) on the resist layer of the test piece according to JIS D0202, and then the peeling state after the peeling test using a cellophane adhesive tape was visually observed. The results were evaluated according to the following criteria, and the results are shown in Tables 4 to 5.

[0242] A: There is absolutely no change in any of the 100 crosses.

[0243] B: Only 1 to 5 of the 100 cross portions were slightly lifted.

[0244] C: Peeling occurred in 5 to 10 of the 100 cross portions.

[0245] D: Peeling occurred in 11 to 100 of the 100 cross portions.

[0246] (Inspection)

[0247] By comparing Example 1 with Example 4, it can be confirmed that in the COP substrate, by performing corona treatment, the adhesion of the cured film to the substrate can be improved. It can be inferred that this is due to the corona treatment of the insulating layer as the substrate, thereby imparting polar groups to the insulating layer and producing changes in wettability. It can be considered that even if any treatment such as UV irradiation, plasma treatment, ozone treatment, EB treatment and primer treatment (adhesive layer, catalyst layer, anchoring agent (coupling agent, amino compound, etc.) is implemented, the same effect can be obtained.

[0248] Furthermore, as in Examples 1 to 11, it was confirmed that even when PET, OPP or PE was laminated as a covering layer and then exposed, the adhesion of the cured film to the insulating layer could be improved. This is believed to be because oxygen hindrance during exposure was reduced, resulting in accelerated photoreaction.

[0249] (4-3) Plating resistance

[0250] After surface treatment for making the electroless copper plating close to the insulating layer, the test piece after exposure and development treatment prepared in the same manner as (4-2) was immersed in an electroless Ni plating solution to perform electroless plating treatment. For the obtained test piece after plating treatment, a tape peeling test was performed in accordance with JIS D0202. Then, evaluation was performed according to the following criteria, and the results are shown in Tables 4 to 5.

[0251] A: No peeling of the resist occurred.

[0252] B: The resist was slightly discolored, but no peeling occurred.

[0253] C: The resist is partially peeled off.

[0254] D: The resist peels off significantly.

[0255] (Inspection)

[0256] As in Examples 1 to 11, by performing exposure with reduced oxygen hindrance, good plating resistance can be obtained.

[0257] (4-4) Flatness

[0258] The test pieces after exposure and development prepared in (4-2) were observed with a laser microscope, and the flatness of the cured film surface was evaluated according to the following criteria. The results are shown in Tables 4 and 5.

[0259] A: No pits or depressions with a side length of 2 μm or more were found.

[0260] B: Pits or depressions with a side length of 2 to 3 μm were found.

[0261] C: Pits or depressions with a side length of 3 to 4 μm were found.

[0262] D: Pits or depressions with a side length of 4 μm or more are found.

[0263] [Table 4]

[0264]

[0265] [Table 5]

[0266]

[0267] (Summarize)

[0268] As is clear from the above-described embodiment, the present invention includes the following aspects. In the following, in order to clarify only the correspondence relationship with the embodiment, the reference numerals are enclosed in parentheses.

[0269] The laminate (10) according to the first embodiment comprises an insulating layer (1), a resist-forming layer (2) overlapping the insulating layer (1), and a covering layer (3) overlapping the resist-forming layer (2). The resist-forming layer (2) comprises a dried product or a semi-cured product of a photosensitive composition.

[0270] According to the first embodiment, the laminate (10) is provided with a coating layer (3), so that when the resist-forming layer (2) is cured, it is not easily affected by oxygen in the atmosphere (e.g., oxygen hindrance), and the resist-forming layer (2) can be cured. Therefore, the curability of the cured product of the resist-forming layer (2) can be improved, and as a result, according to the laminate (10), it is easy to improve resolution and flatness.

[0271] The second mode of the laminate (10) is used to prepare a printed wiring board (100) in the first mode, wherein the insulating substrate (11) in the printed wiring board (100) is prepared from the insulating layer (1), and the resist layer (12) in the printed wiring board (100) is prepared from the resist forming layer (2).

[0272] According to the second embodiment, by forming a resist layer (12) on the insulating layer (1) in the laminate (10), the insulating layer (1) can be used as an insulating substrate (11) in a printed wiring board (100). In addition, the resist forming layer (2) can be used as a permanent resist (permanent film).

[0273] A third embodiment of the laminate (10) is a laminate according to the first or second embodiment, wherein the insulating layer (1) comprises at least one insulating material selected from the group consisting of cycloolefin polymers, liquid crystal polymers, polyethylene terephthalate and polyimide.

[0274] According to the third embodiment, the printed wiring board (100) produced from the laminate (10) has excellent low dielectric properties. Therefore, the printed wiring board (100) can be used in electronic equipment and devices for high-frequency use.

[0275] A fourth embodiment of the laminate (10) is the laminate according to any one of the first to third embodiments, wherein the covering layer (3) comprises either or both of polyethylene terephthalate and biaxially stretched polypropylene.

[0276] According to the fourth embodiment, the high transparency of the laminate (10) can be maintained. In addition, in this case, the curability of the resist-forming layer (2) in the laminate (10) is easily improved, and the resist layer (12) can be formed more effectively. In addition, in this case, when the laminate (10) is exposed from above the coating layer (3), the curability of the resist-forming layer (2) can be further improved. Therefore, when the resist-forming layer (2) is cured to produce the resist layer (12), it is easy to further improve the developability and resolution.

[0277] The laminate (10) of the fifth embodiment is the laminate (10) according to any one of the first to fourth embodiments, wherein the photosensitive composition contains a carboxyl group-containing resin (A), a photopolymerization initiator (B), and a photopolymerizable compound (C).

[0278] According to the fifth aspect, the resist forming layer (2) in the laminate (10) can be cured by irradiating the resist forming layer (2) with light, thereby making it easy to form the resist layer (12) from the resist forming layer (2).

[0279] A sixth aspect of the laminate (10) is that in any one of the first to fifth aspects, the film thickness of the resist forming layer (2) is 20 μm or less.

[0280] According to the sixth aspect, when the resist layer (12) is produced from the resist forming layer (2), the developability and the resolution can be further improved.

[0281] The seventh embodiment of the laminate (10) is: in any one of the first to sixth embodiments, when a cured product having a thickness of 10 μm is prepared from the photosensitive composition, the transmittance of light having a wavelength of 450 nm to 800 nm is 80% or more.

[0282] According to the seventh embodiment, the laminate (10) has excellent transparency, so the laminate (10) can be used for optical purposes. In addition, in this case, the laminate (10) has high transparency, which helps to prevent the appearance and landscape from being damaged even when it is installed outdoors.

[0283] The laminate (10) of the eighth embodiment is: in any one of the first to seventh embodiments, the insulating layer (1) is subjected to at least one surface treatment selected from the group consisting of corona treatment, UV treatment, plasma treatment, ozone treatment, primer treatment and EB treatment.

[0284] According to the eighth aspect, the adhesion between the insulating layer (1) and the layer formed on the insulating layer (1) can be improved. Furthermore, in this case, the peeling property when peeling the covering layer (3) from the laminate (10) can be improved.

[0285] A ninth aspect of the laminate (10) is the laminate (10) according to any one of the first to eighth aspects, wherein the surface roughness Sa of the coating layer (3) is 50 nm or less.

[0286] According to the ninth embodiment, even if the coating layer (3) is peeled off from the laminate (10), the resist forming layer (2) (or the resist layer (12)) can be given a higher flatness. In this case, when forming a plating layer on the printed wiring board (100), it is easy to form a conductor wiring with a more uniform shape. Therefore, it is easy to improve the reliability of the printed wiring board (100). In addition, in this case, it is easy to further improve the transparency of the resist forming layer (2).

[0287] A tenth embodiment of the laminate (10) is the laminate (10) according to any one of the first to ninth embodiments, wherein the covering layer (3) has a haze value of 3.0% or less.

[0288] According to the tenth embodiment, 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 through the covering layer (3) in the laminate (10).

[0289] The 11th aspect of the method for producing a printed wiring board is a method for producing a printed wiring board (100), the printed wiring board (100) comprising: an insulating substrate (11) including the insulating layer (1) in the laminate (10) of any one of the first to tenth aspects, and a resist layer (12) made from the resist-forming layer (2) in the laminate (10). The present production method comprises: irradiating the resist-forming layer (2) with light through the coating layer (3) in the laminate (10), thereby forming the resist layer (12) on the insulating layer (1).

[0290] According to the eleventh aspect, when the resist forming layer (2) is exposed to light, the influence of shrinkage cavitation during exposure can be reduced, which contributes to an improvement in resolution.

[0291] The printed wiring board (100) of the twelfth embodiment comprises: an insulating substrate (11) including the above-mentioned insulating layer (1) in the stacked body (10) of any one of the first to tenth embodiments, and a resist layer (12) made from the above-mentioned resist forming layer (2) in the above-mentioned stacked body (10).

[0292] According to the twelfth embodiment, 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 produced.

Claims

1. A laminate comprising an insulating layer, a resist forming layer overlapping the insulating layer without inserting a conductor circuit therebetween, and a covering layer overlapping the resist forming layer; The resist-forming layer comprises a dried or semi-cured product of a photosensitive composition; The resist-forming layer is a layer for making a resist layer, and the resist layer is used as a plating resist layer; The photosensitive composition contains a carboxyl resin A, a photopolymerization initiator B and a photopolymerizable compound C. The carboxyl-containing resin A contains a carboxyl-containing resin A1, and the carboxyl-containing resin A1 is produced by reacting the following product with an acid anhydride a3, wherein the product is produced by reacting an epoxy compound a1 having at least two epoxy groups with a carboxylic acid a2 having an ethylenically unsaturated group; When a cured product having a thickness of 10 μm is prepared from the photosensitive composition, the transmittance of light having a wavelength of 450 nm to 800 nm is 80% or more; The insulating layer is subjected to at least one surface treatment selected from the group consisting of corona treatment, UV treatment, plasma treatment, ozone treatment, primer treatment and EB treatment.

2. The laminate according to claim 1, which is used for the production of a printed wiring board. The insulating substrate in the printed wiring board is made from the insulating layer. The 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 includes at least one insulating material selected from the group consisting of cycloolefin polymer, liquid crystal polymer, polyethylene terephthalate, and polyimide.

4. The laminate according to claim 1 or 2, wherein: The covering layer includes either or both of polyethylene terephthalate and biaxially stretched polypropylene.

5. The laminate according to claim 1 or 2, wherein: The resist forming layer has a film thickness of 20 μm or less.

6. The laminate according to claim 1 or 2, wherein: The surface roughness Sa of the coating layer is 50 nm or less.

7. The laminate according to claim 1 or 2, wherein: The covering layer has a haze value of 3.0% or less.

8. A method for manufacturing a printed wiring board, comprising manufacturing a printed wiring board having 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 7, and the resist layer is made of the resist-forming layer in the laminate; The resist forming layer is irradiated with light through the cover layer in the laminated body, thereby forming the resist layer on the insulating layer. 9 . A printed wiring board comprising: an insulating substrate including the insulating layer in the laminate according to claim 1 ; and a resist layer made from the resist-forming layer in the laminate.

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