JP2020154127A - Photosensitive resin composition, cured film of the same, and method for manufacturing high-frequency device - Google Patents

Abstract

To provide a photosensitive resin composition that can give a cured product by thermal curing even at a relatively low temperature and is preferably applicable for manufacturing a high-frequency device.SOLUTION: The photosensitive resin composition comprises an alkali-soluble resin (A) and a solvent (C), and is used for forming a permanent film in a high-frequency device. In a DSC curve obtained by differential scanning calorimetry of a film of the composition as a measurement target formed by drying a volatile component of the composition at 120 for 4 minutes and measured from 30°C to 300°C at a temperature elevation rate of 10°C/min, an exothermic peak top is present at a temperature of 200°C or lower. A cured product of the composition prepared by heating at 200°C for 90 minutes shows a dielectric loss tangent (tanδ) of 0.025 or less at 10 GHz by a cavity resonator method.SELECTED DRAWING: Figure 1

Description

The present invention relates to a photosensitive resin composition, a cured film thereof, and a method for producing a high frequency device.

Various photosensitive resin compositions have been studied for forming permanent films such as interlayer insulating films for electronic devices.

As an example, in Patent Document 1, a polymer containing a structural unit having a group in which an acid group is protected by an acid-degradable group, a photoacid generator, and a solvent are contained, and the polymer is a specific general. A photosensitive resin composition containing a structural unit represented by the formula is described. According to Patent Document 1, this photosensitive resin composition has high sensitivity, and the obtained cured film exhibits excellent corrosion resistance and low dielectric constant.

As another example, Patent Document 2 describes a structural unit derived from an itaconic acid diester monomer, a structural unit derived from an aromatic vinyl monomer, and an α, β-unsaturated carboxylic acid monomer. A photosensitive resin composition containing an itaconic acid diester copolymer having a structural unit to be treated and a structural unit (a4) having a glycidyl group and an esterified product having a quinonediazide group is described. According to Patent Document 2, this photosensitive resin composition maintains a residual film ratio when forming a pattern film, has no development residue, is excellent in developability, and has heat resistance, transmittance, and resistance even after post-baking. It is said that a pattern film having excellent low dielectric properties can be formed without impairing the physical properties of the coating film such as solvent properties.

Japanese Unexamined Patent Publication No. 2017-049372 Japanese Unexamined Patent Publication No. 2012-198304

In designing an interlayer insulating film, simply having a small dielectric constant (relative permittivity) may not be sufficient.
For example, in the manufacture of high-frequency devices, there is a problem that high-frequency energy loss becomes large unless an appropriate interlayer insulating film is used. Nowadays, information communication devices that transmit and receive radio waves are becoming more and more popular, and it is necessary to solve this problem.

Further, with the sophistication and complexity of high-frequency devices, it may be required to lower the heating temperature when curing the composition as much as possible. However, there is a concern that the curing reaction of the conventional photosensitive resin composition for forming an interlayer insulating film does not proceed sufficiently when cured at a low heating temperature. If the curing reaction does not proceed sufficiently and reactive functional groups remain, it may affect the loss of dielectric constant and high frequency energy.

The present invention has been made in view of such circumstances. One of the objects of the present invention is to provide a photosensitive resin composition which can obtain a cured film even by thermosetting at a relatively low temperature and is preferably applicable to the production of a high frequency device.

As a result of diligent studies, the present inventors have completed the inventions provided below and solved the above problems.

According to the present invention
A photosensitive resin composition containing an alkali-soluble resin (A) and a solvent (C).
The differential scanning calorimetry was performed from 30 ° C. to 300 ° C. at a heating rate of 10 ° C./min, using a film formed by drying the volatile components of the photosensitive resin composition at 120 ° C. for 4 minutes as a measurement target. In the obtained DSC curve, the exothermic peak top exists below 200 ° C.
The dielectric loss tangent (tan δ) at 10 GHz by the cavity resonator method of the cured product obtained by heating and curing the photosensitive resin composition at 200 ° C. for 90 minutes is 0.025 or less.
Provided are photosensitive resin compositions used to form permanent films in high frequency devices.

Further, according to the present invention,
A cured film of the above photosensitive resin composition is provided.

Further, according to the present invention,
A high frequency device including the cured film is provided.

Further, according to the present invention,
A film forming step of forming a photosensitive resin film using the above photosensitive resin composition, and
Provided is a method for manufacturing a high frequency device, which comprises a pattern forming step of exposing and developing the photosensitive resin film to obtain a pattern and a curing step of heating and curing the pattern.

According to the present invention, there is provided a photosensitive resin composition that can obtain a cured film even by thermosetting at a relatively low temperature and is preferably applicable to the production of high frequency devices.

It is a figure for demonstrating the apparatus for measuring the dielectric property by a cavity resonator method.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drawings are for illustration purposes only.

In the present specification, the notation of "a to b" in the description of the numerical range means a or more and b or less unless otherwise specified. For example, "1 to 5% by mass" means "1% by mass or more and 5% by mass or less".

In the notation of a group (atomic group) in the present specification, the notation that does not indicate whether it is substituted or unsubstituted includes both those having no substituent and those having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
The notation "(meth) acrylic" herein represents a concept that includes both acrylic and methacrylic. The same applies to similar notations such as "(meth) acrylate".
Unless otherwise specified, the term "organic group" as used herein means an atomic group obtained by removing one or more hydrogen atoms from an organic compound. For example, the "monovalent organic group" represents an atomic group obtained by removing one hydrogen atom from an arbitrary organic compound.

As used herein, the term "high frequency device" is used in the usual sense in the fields of electrical machinery / semiconductors / information and communications. Specifically, the high-frequency device refers to all devices equipped with a circuit or element for processing a high-frequency signal in the microwave band or millimeter wave band. High frequency devices are used especially for devices that require wireless communication.

<Photosensitive resin composition>
The photosensitive resin composition of the present embodiment contains an alkali-soluble resin (A) and a solvent (C). It is then used to form a permanent film in high frequency devices.
The differential scanning calorimetry was performed from 30 ° C. to 300 ° C. at a heating rate of 10 ° C./min, using a film formed by drying the volatile components of this photosensitive resin composition at 120 ° C. for 4 minutes as a measurement target. In the obtained DSC curve, the exothermic peak top exists at 200 ° C. or lower.
Further, the dielectric loss tangent (tan δ) at 10 GHz by the cavity resonator method of the cured product obtained by heating and curing this photosensitive resin composition at 200 ° C. for 90 minutes is 0.01 or less.

The present inventor has studied improvement guidelines for photosensitive resin compositions from various viewpoints so that a cured film can be obtained even by heat curing at a relatively low temperature.
As a result of the examination, the present inventor designed the photosensitive resin composition so that the exothermic peak top exists at 200 ° C. or lower in the DSC curve obtained by the measurement under the above conditions, and thus the relatively high frequency device maker requires it. It has been found that sufficient curing is possible even at low temperatures.

Further, based on past findings, the present inventor can design the photosensitive resin composition so that the dielectric loss tangent (tan δ) of the cured product obtained by curing the photosensitive resin composition becomes small. I thought it would be effective in suppressing the loss. Then, when the photosensitive resin composition is cured under the above conditions, the photosensitive resin composition is designed so that the dielectric loss tangent (tan δ) at 10 GHz by the cavity resonator method is 0.01 or less, thereby achieving a high frequency. Succeeded in suppressing the loss of energy.

In preparing the photosensitive resin composition of the present embodiment, it is important to select an appropriate material and to mix the same.
Although speculative, according to the findings of the present inventor, in particular, in order to reduce the dielectric loss tangent (tan δ) of the cured product, a polar group in the cured product, for example, a hydroxy group often contained in the alkali-soluble resin (A) is used. It is important to limit its thermal movement, such as by "capping" it. Further, in relation to low temperature curability, it is preferable that such a "cap" is made by heating at a relatively low temperature.

For the above "cap", the photosensitive resin composition of the present embodiment preferably contains at least one of the acylating agent (b1) described later and the low molecular weight compound (b2) having a carboxy group, as an example. .. Further, as another example, it is also preferable to use the photosensitive resin composition of the present embodiment as the alkali-soluble resin (A) that causes a ring closure reaction by heating at a relatively low temperature. As yet another example, it is also preferable to use an appropriate amount of an appropriate cross-linking agent (D) described later.

In the DSC curve obtained by the measurement under the above conditions, it is preferable that the heat generation peak area obtained from the DSC curve is 5.5 mJ / mg or more as an index different from the heat generation peak top position. There is no particular upper limit, but from the viewpoint of realistic formulation design, it is, for example, 10 mJ / mg or less.
The calorific value is considered to correlate with the "cap amount" of the polar group in the cured product. By designing the photosensitive resin composition so that the calorific value peak area is 5.5 mJ / mg or more, It is considered that the polar groups in the cured product are likely to be sufficiently capped, and the dielectric loss tangent is likely to be smaller (and thus, the loss of high frequencies is likely to be smaller).

As a reminder, the above description does not limit the scope of the present invention.

The components contained in the photosensitive resin composition of the present embodiment will be described.

[Alkali-soluble resin (A)]
The photosensitive resin composition of the present embodiment contains an alkali-soluble resin.
The alkali-soluble resin is, for example, a polyamide resin such as a phenol resin, a hydroxystyrene resin, a (meth) acrylic resin, a cyclic olefin resin, a polybenzoxazole precursor or a polyimide precursor (polyamic acid) (in the main chain by shrink polymerization). Examples thereof include a resin in which an amide group is formed), a resin obtained by dehydrating and closing a polyamide resin (polybenzoxazole resin or polyimide resin), and the like.
The photosensitive resin composition may contain only one kind of alkali-soluble resin, or may contain two or more kinds of alkali-soluble resins.

In the present embodiment, the alkali-soluble resin is particularly preferably a polyamide resin. Polyamide resins are suitable for insulating film applications because they are dehydrated and ring-closed by heating and have a resin structure with extremely excellent heat resistance.
As the polyamide resin, for example, it is preferable to use an aromatic polyamide containing an aromatic ring as the structural unit of polyamide, and it is more preferable to use a polyamide resin containing a structural unit represented by the following formula (PA1). As a result, the molecular chains of the polyamide resin are hydrogen-bonded via amide bonds, and the aromatic ring portions are densely arranged. It is considered that this contributes to further restricting the molecular motion in the cured film, and further reduces the dielectric loss tangent and the relative permittivity.
In the present embodiment, the aromatic ring refers to a benzene ring; a fused aromatic ring such as a naphthalene ring, an anthracene ring, or a pyrene ring; or a heteroaromatic ring such as a pyridine ring or a pyrrole ring. The polyamide resin of the present embodiment preferably contains a benzene ring as an aromatic ring from the viewpoint of forming the dense structure.

The polyamide resin containing the structural unit represented by the formula (PA1) is a precursor of the polybenzoxazole resin. The polyamide resin containing the structural unit represented by the formula (PA1) is dehydrated and ring-closed by heat treatment at a temperature of, for example, 150 to 380 ° C. under the conditions of 30 minutes to 50 hours to obtain a polybenzoxazole resin. be able to. Here, the structural unit of the formula (PA1) becomes the structural unit represented by the following formula (PBO1) by dehydration ring closure.

When the alkali-soluble resin is a polyamide resin containing a structural unit represented by the formula (PA1), for example, the photosensitive resin composition may be heat-treated as described above to dehydrate and close the ring to obtain a polybenzoxazole resin. .. That is, the heat-treated photosensitive resin composition contains a polybenzoxazole resin which is an alkali-soluble resin.

When the alkali-soluble resin is a polyamide resin containing a structural unit represented by the formula (PA1), the resin film and high-frequency device described later are produced, and then the heat treatment is performed to dehydrate and close the ring to polybenzoxazole. It may be a resin. When a polybenzoxazole resin is obtained by dehydrating and ring-opening the polyamide resin, the tensile elongation at break and the glass transition temperature can be increased. This is convenient from the viewpoint of improving the strength and heat resistance of the resin film and the high frequency device.

The polyamide resin can be obtained, for example, as follows.
First, in the polymerization step (S1), the polyamide is polymerized by polycondensing the diamine monomer and the dicarboxylic acid monomer. Next, the low molecular weight component is removed by the low molecular weight component removing step (S2) to obtain a polyamide resin containing polyamide as a main component.

(Polymerization step (S1))
In the polymerization step (S1), the diamine monomer and the dicarboxylic acid monomer are polycondensed. The polycondensation method for polymerizing the polyamide is not limited, and specific examples thereof include melt polycondensation, acid chloride method, and direct polycondensation.

Instead of the dicarboxylic acid monomer, a compound selected from the group consisting of tetracarboxylic dianhydride, trimellitic acid anhydride, dicarboxylic acid dichloride or active ester type dicarboxylic acid may be used. Specific examples of the method for obtaining the active ester-type dicarboxylic acid include a method in which the dicarboxylic acid is reacted with 1-hydroxy-1,2,3-benzotriazole or the like.

The diamine monomer used for the polymerization of the polyamide resin and the dicarboxylic acid monomer will be described below. The diamine monomer and the dicarboxylic acid monomer may be prepared one by one, or two or more of them may be used in combination.

-Diamine monomer The diamine monomer that can be used is not limited. For example, it is preferable to use a diamine monomer containing an aromatic ring in the structure, and it is more preferable to use a diamine monomer containing a phenolic hydroxyl group in the structure. Here, as the diamine monomer containing a phenolic hydroxyl group in the structure, for example, a diamine monomer represented by the following general formula (DA1) is preferable. By producing a polyamide resin using such a diamine monomer as a raw material, the conformation of the polyamide resin can be controlled, and the molecular chains of the polyamide resin can form a denser structure. It is considered that this "tighter structure of molecular chains" contributes to further restricting the molecular motion in the cured film, and further reduces the dielectric loss tangent and the relative permittivity.

When the diamine monomer represented by the following general formula (DA1) is used, the polyamide resin contains a structural unit represented by the following general formula (PA2). That is, the polyamide resin preferably contains, for example, a structural unit represented by the following general formula (PA2).

In the general formula (DA1), R ⁴ is one selected from the group consisting of hydrogen atom, carbon atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, silicon atom, chlorine atom, fluorine atom and bromine atom. It is a group formed by two or more kinds of atoms. R ^5- R ¹⁰ independently represent hydrogen or an organic group having 1 to 30 carbon atoms.

In formula ^{(PA2), R 4, R} 5 -R 10 are the same as in the general formula (DA1).

R ⁴ in the general formula (DA1) and (PA2), a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, a chlorine atom, a fluorine atom, is selected from the group consisting of bromine A group formed by one or more atoms.
R ⁴ is a divalent group. Here, the divalent group indicates the valence. That is, it shows that R ⁴ has two bonds that bond with other atoms.

When R ⁴ in the general formulas (DA1) and (PA2) contains a carbon atom, R ⁴ is, for example, a group having 1 to 30 carbon atoms, preferably a group having 1 to 10 carbon atoms, and preferably has 1 carbon atom. It is more preferably a group of ~ 5, and further preferably a group having 1 to 3 carbon atoms.

When R ⁴ in the general formulas (DA1) and (PA2) contains a carbon atom, specific examples of R ⁴ include an alkylene group, an arylene group, a halogen-substituted alkylene group, and a halogen-substituted arylene group.
The alkylene group may be, for example, a linear alkylene group or a branched chain alkylene group. Specific examples of the linear alkylene group include methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decanylene group, trimethylene group and tetramethylene group. , Pentamethylene group, hexamethylene group and the like. Specific examples of the branched alkylene group include -C (CH ₃ ) _2- , -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, and -C (CH ₃ ) (CH ₂ ). Alkylmethyl groups such as CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) _2- ; -CH (CH ₃ ) CH _2- , -CH ( _{CH 3) CH (CH 3)} -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH 3) 2 -CH 2 - alkyl, such as ethylene Methyl group and the like.
Specific examples of the arylene group include a phenylene group, a biphenylene group, a naphthylene group, an anthrylene group, and two or more arylene groups bonded to each other.
As the halogen-substituted alkylene group and the halogen-substituted arylene group, specifically, those in which the hydrogen atom in the above-mentioned alkylene group and arylene group is replaced with a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom are used. Can be done. Among these, those using a hydrogen atom substituted with a fluorine atom are preferable.

When R ⁴ in the general formulas (DA1) and (PA2) does not contain a carbon atom, the R ⁴ specifically includes a group consisting of an oxygen atom or a sulfur atom.

R ^5- R ¹⁰ in the general formulas (DA1) and (PA2) are independently hydrogen or an organic group having 1 to 30 carbon atoms, for example, hydrogen or an organic group having 1 to 10 carbon atoms. Is preferable, hydrogen or an organic group having 1 to 5 carbon atoms is more preferable, hydrogen or an organic group having 1 to 3 carbon atoms is more preferable, and hydrogen or an organic group having 1 to 2 carbon atoms is preferable. Is more preferable. As a result, the aromatic rings of the polyamide resin can be closely arranged. Therefore, the molecular structure can be frozen and the adhesion can be improved by the coordination in which the alkali-soluble resin and the metal molecule are more strongly bound.

Specific examples of the organic group having 1 to 30 carbon atoms ^R 5 ^{-R 10} in formula (DA1) and (PA2), methyl group, ethyl group, n- propyl group, an isopropyl group, n- butyl group, isobutyl Alkyl groups such as groups, sec-butyl groups, tert-butyl groups, pentyl groups, neopentyl groups, hexyl groups, heptyl groups, octyl groups, nonyl groups and decyl groups; alkenyl groups such as allyl groups, pentenyl groups and vinyl groups; Alquinyl groups such as ethynyl groups; Alkylidene groups such as methylidene group and ethylidene group; Aryl groups such as tolyl group, xsilyl group, phenyl group, naphthyl group and anthracenyl group; Aralkyl groups such as benzyl group and phenethyl group; Adamanthyl group and cyclopentyl group Cycloalkyl groups such as groups, cyclohexyl groups and cyclooctyl groups; alkaline groups such as tolyl groups and xsilyl groups can be mentioned.

Specific examples of the diamine monomer represented by the general formula (DA1) include 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane and 4,4'-methylenebis (2-amino-3). , 6 dimethylphenol), 4,4'-methylenebis (2-aminophenol), 1,1-bis (3-amino4-hydroxyphenyl) ethane, 3,3'-diamino-4,4'-dihydroxydiphenyl ether, etc. Can be mentioned. By using these diamine monomers, the aromatic rings of the polyamide resin can be closely arranged. It is considered that this contributes to further restricting the molecular motion in the cured film, and further reduces the dielectric loss tangent and the relative permittivity.
As the diamine monomer, only one type may be used, or two or more types may be used in combination.
The structural formulas of these diamine monomers are shown below.

-Dicarboxylic acid monomer The dicarboxylic acid monomer that can be used for polymerization is not particularly limited. For example, it is preferable to use a dicarboxylic acid monomer containing an aromatic ring in the structure.
As the dicarboxylic acid monomer containing an aromatic ring, for example, one represented by the following general formula (DC1) is preferably used.
For example, when a dicarboxylic acid monomer represented by the following general formula (DC1) is used, the polyamide resin contains a structural unit represented by the following general formula (PA3). That is, the polyamide resin preferably contains, for example, a structural unit represented by the following general formula (DC1). It is considered that this contributes to further restricting the molecular motion in the cured film, and further reduces the dielectric loss tangent and the relative permittivity.

In the general formula (DC1), R ¹¹ is one selected from the group consisting of hydrogen atom, carbon atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, silicon atom, chlorine atom, fluorine atom and bromine atom. It is a group formed by two or more kinds of atoms. R ^12- R ¹⁹ independently represent hydrogen or an organic group having 1 or more and 30 or less carbon atoms.

In the general formula (PA3), R ¹¹ and R ^12- R ¹⁹ are the same as those in the general formula (DC1).
R ¹¹ in the general formulas (DC1) and (PA3) is selected from the group consisting of hydrogen atom, carbon atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, silicon atom, chlorine atom, fluorine atom and bromine atom. A group formed by one or more atoms.
R ¹¹ is a divalent group. Here, the divalent group indicates the valence. That is, it shows that R ¹¹ has two bonds that bond with other atoms.

When R ¹¹ in the general formulas (DC1) and (PA3) contains a carbon atom, R ¹¹ is, for example, a group having 1 to 30 carbon atoms, preferably a group having 1 to 10 carbon atoms, and preferably has 1 carbon atom. It is more preferably a group of ~ 5, and further preferably a group having 1 to 3 carbon atoms.

When R ¹¹ in the general formulas (DC1) and (PA3) contains a carbon atom, specific examples of R ¹¹ include an alkylene group, an arylene group, a halogen-substituted alkylene group, and a halogen-substituted arylene group.
The alkylene group may be, for example, a linear alkylene group or a branched chain alkylene group. Specific examples of the linear alkylene group include methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decanylene group, trimethylene group and tetramethylene group. , Pentamethylene group, hexamethylene group and the like. Specific examples of the branched alkylene group include -C (CH ₃ ) _2- , -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, and -C (CH ₃ ) (CH ₂ ). Alkylmethyl groups such as CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) _2- ; -CH (CH ₃ ) CH _2- , -CH ( _{CH 3) CH (CH 3)} -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH 3) 2 -CH 2 - alkyl, such as ethylene Methyl group and the like.
Specific examples of the arylene group include a phenylene group, a biphenylene group, a naphthylene group, an anthrylene group, and two or more arylene groups bonded to each other.
As the halogen-substituted alkylene group and the halogen-substituted arylene group, specifically, those in which the hydrogen atom in the above-mentioned alkylene group and arylene group is replaced with a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom are used. Can be done. Among these, those using a hydrogen atom substituted with a fluorine atom are preferable.

When R ¹¹ in the general formulas (DC1) and (PA3) does not contain a carbon atom, the R ¹¹ specifically includes a group composed of an oxygen atom or a sulfur atom.

R ^12- R ¹⁹ in the general formulas (DC1) and (PA3) are independently hydrogen or an organic group having 1 to 30 carbon atoms, for example, hydrogen or an organic group having 1 to 10 carbon atoms. Is preferable, hydrogen or an organic group having 1 to 5 carbon atoms is more preferable, hydrogen or an organic group having 1 to 3 carbon atoms is more preferable, and hydrogen is even more preferable.

Specific examples of the organic group having 1 to 30 carbon atoms of R ^12- R ¹⁹ in the general formulas (DC1) and (PA3) include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group and isobutyl. Alkyl groups such as groups, sec-butyl groups, tert-butyl groups, pentyl groups, neopentyl groups, hexyl groups, heptyl groups, octyl groups, nonyl groups and decyl groups; alkenyl groups such as allyl groups, pentenyl groups and vinyl groups; Alquinyl groups such as ethynyl groups; Alkylidene groups such as methylidene group and ethylidene group; Aryl groups such as tolyl group, xsilyl group, phenyl group, naphthyl group and anthracenyl group; Aralkyl groups such as benzyl group and phenethyl group; Adamanthyl group and cyclopentyl group Cycloalkyl groups such as groups, cyclohexyl groups and cyclooctyl groups; alkaline groups such as tolyl groups and xsilyl groups can be mentioned.

Specifically, as the dicarboxylic acid monomer, diphenyl ether 4,4'-dicarboxylic acid, isophthalic acid, terephthalic acid, 4,4'-biphenyldicarboxylic acid and the like can be used. As the dicarboxylic acid monomer, among the above specific examples, it is preferable to use diphenyl ether 4,4'-dicarboxylic acid or isophthalic acid, and it is more preferable to use diphenyl ether 4,4'-dicarboxylic acid. As a result, the aromatic rings of the polyamide resin can be closely arranged. It is considered that this contributes to further restricting the molecular motion in the cured film, and further reduces the dielectric loss tangent and the relative permittivity.

In obtaining the polyamide resin, it is preferable to modify the amino group existing at the terminal of the polyamide resin at the same time as the polymerization step (S1) or after the polymerization step (S1). The modification can be carried out, for example, by reacting a diamine monomer or a polyamide resin with a specific acid anhydride or a specific monocarboxylic acid. Therefore, it is preferable that the terminal amino group of the polyamide resin is modified with a specific acid anhydride or a specific monocarboxylic acid. The specific acid anhydride and the specific monocarboxylic acid have one or more functional groups consisting of a group consisting of an alkenyl group, an alkynyl group, and a hydroxyl group. Further, as the specific acid anhydride and the specific monocarboxylic acid, those containing a nitrogen atom are preferable. This makes it possible to improve the adhesion between the photosensitive resin composition after post-baking and a metal such as Al or Cu.

Specifically, the above-mentioned "specific acid anhydride" includes maleic anhydride, citraconic anhydride, 2,3-dimethylmaleic anhydride, 4-cyclohexene-1,2-dicarboxylic acid anhydride, and exo-3. , 6-Epoxy-1,2,3,6-tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, methyl-5-norbornene-2,3-dicarboxylic acid anhydride, itaconic acid anhydride Examples thereof include hetic anhydride, 4-ethynyl phthalic anhydride, 4-phenylethynyl phthalic anhydride, and 4-hydroxyphthalic anhydride. As the specific acid anhydride, only one kind may be used, or two or more kinds may be used in combination.

When the amino group existing at the end of the polyamide resin is modified with a specific ring-shaped acid anhydride, the ring-shaped specific acid anhydride opens the ring. Here, after modifying the polyamide resin, a structural unit derived from a specific acid anhydride having a ring shape may be closed to form an imide ring. Examples of the ring-closing method include heat treatment.

Specific examples of the above-mentioned "specific monocarboxylic acid" include 5-norbornene-2-carboxylic acid, 4-hydroxybenzoic acid, and 3-hydroxybenzoic acid. As the specific monocarboxylic acid, only one kind may be used, or two or more kinds may be used in combination.

In obtaining the polyamide resin, the carboxyl group existing at the terminal of the polyamide resin may be modified at the same time as the polymerization step (S1) or after the polymerization step (S1). The modification can be carried out, for example, by reacting a dicarboxylic acid monomer or a polyamide resin with a specific nitrogen atom-containing complex aromatic compound. Therefore, it is preferable that the carboxyl group at the terminal of the polyamide resin is modified with a specific nitrogen atom-containing complex aromatic compound.
Although the details are unknown, it is the finding of the present inventor that the polyamide resin tends to be easily dehydrated and ring-closed by substituting the carboxyl group at the end of the polyamide resin with an appropriate group. That is, it is considered that the polyamide resin is ring-closed at a relatively low temperature to realize curing at a relatively low temperature. Further, since the polar groups such as hydroxy groups are reduced by ring closure, it is easy to design the dielectric loss tangent to be small, and thus it is easy to reduce the loss of high frequency energy when the cured product is formed.
The specific nitrogen atom-containing complex aromatic compound described above is, for example, an azole compound having an amino group. 1- (5-1H-triazoyl) methylamino group, 3- (1H-pyrazoyl) amino group, 4- (1H-pyrazoyl) amino group, 5- (1H-pyrazoyl) amino group, 1- (3-1H-) Pyrazoyl) methylamino group, 1- (4-1H-pyrazoyl) methylamino group, 1- (5-1H-pyrazoyl) methylamino group, (1H-tetrasol-5-yl) amino group, 1- (1H-tetrasol) It has one or more functional groups consisting of a group consisting of a -5-yl) methyl-amino group and a 3- (1H-tetrazol-5-yl) benz-amino group.
Specific examples of the "specific nitrogen atom-containing complex aromatic compound" include azole compounds such as 5-aminotetrazole.

(Low molecular weight component removing step (S2))
Following the polymerization step (S1), a low molecular weight component removing step (S2) is performed to remove the low molecular weight component, and a polyamide resin containing a polyamide resin as a main component can be obtained.

The organic layer containing the mixture of the low molecular weight component and the polyamide resin is concentrated by filtration or the like, and then dissolved again in an organic solvent such as water / isopropanol. As a result, the precipitate can be filtered off to obtain a polyamide resin from which low molecular weight components have been removed.

As the polyamide resin, for example, one obtained by condensing a diamine monomer represented by the general formula (DA1) and a dicarboxylic acid monomer represented by the general formula (DC1) is preferable. That is, as the polyamide resin, those having the structural units of the general formulas (PA2) and (PA3) are preferable, and those having the structural units of the general formulas (PA2) and (PA3) alternately are more preferable.

As another aspect, in the present embodiment, the alkali-soluble resin is preferably a cyclic olefin-based resin. Cyclic olefin resins have high heat resistance due to their chemical structure and are suitable for insulating film applications.
The cyclic olefin resin that can be used is not particularly limited. For example, a polymerization reaction product or a copolymerization reaction product obtained by polymerizing or copolymerizing one or more selected from the group consisting of norbornene and norbornene derivatives can be used.
The cyclic olefin resin preferably contains a structural unit derived from a monomer having a cyclic olefin structure described below. Further, more preferably, it contains a structural unit derived from a monomer having a cyclic acid anhydride structure described below.

-Structural unit derived from a monomer having a cyclic olefin structure As a structural unit derived from a monomer having a cyclic olefin structure, a structural unit derived from a norbornene-based monomer represented by the following general formula (a1) is preferably mentioned.
In the general formula (a1), R ₆ , R ₇ , R ₈ and R ₉ are independently hydrogen, halogen atoms, or organic groups having 1 to 30 carbon atoms, and n is 0, 1 or 2.

R _{6 to} R ₉ in the general formula (a1) can be, for example, hydrogen, a halogen atom, or an organic group having 1 to 30 carbon atoms independently.
R _{6 to} R ₉ are preferably independent hydrogen, halogen atoms, or organic groups having 1 to 10 carbon atoms, and more preferably independently hydrogen, halogen atoms, or 1 to 3 carbon atoms, respectively. Of the organic groups, more preferably, they are independently hydrogen, halogen atoms, or organic groups having 1 carbon atom.
The organic groups constituting R _{6 to} R ₉ (for example, organic groups having 1 to 30 carbon atoms) may contain one or more atoms selected from O, N, S, P and Si in the structure. .. Further, any two of R _{6 to} R ₉ may be bonded to each other to form an alkylidene group, a monocyclic or polycyclic structure.

More specifically, as the organic group constituting R _{6 to} R ₉ , for example, an alkyl group, an alkenyl group, an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, an alkalil group, a cycloalkyl group, and a group containing a heterocyclic structure. And so on.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group and heptyl group. , Octyl group, nonyl group, decyl group and the like.
Examples of the alkenyl group include an allyl group, a pentaenyl group, a vinyl group and the like.
Examples of the alkynyl group include an ethynyl group and the like.
Examples of the alkylidene group include a methylidene group and an ethylidene group.
Examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group and the like.
Examples of the aralkyl group include a benzyl group and a phenethyl group.
Examples of the alkaline group include a tolyl group and a xsilyl group.
Examples of the cycloalkyl group include monocyclic or polycyclic groups such as an adamantyl group, a cyclopentyl group, a cyclohexyl group and a cyclooctyl group.
Examples of the group containing a heterocyclic structure include a group containing an epoxy group, a group containing an oxetanyl group, and the like.

As one aspect, when R _{6 to} R ₉ contain an alkyl group, the film forming property of the film formed by using the photosensitive resin composition can be improved. Further, by containing an aryl group as R _{6 to} R ₉ , it is possible to suppress film loss during development using an alkaline developer in the lithography process for the film made of the photosensitive resin composition.

In one embodiment, in the above-mentioned group containing an alkyl group, an alkenyl group, an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, an alkalil group, a cycloalkyl group, and a heterocyclic structure, one or more hydrogen atoms are halogen atoms. It may be replaced by such as. Halogen atoms include fluorine, chlorine, bromine, and iodine. Of these, a haloalkyl group in which one or more hydrogen atoms of the alkyl group are substituted with halogen atoms is preferable. By using at least one of R _{6 to} R ₉ as a haloalkyl group, the dielectric constant of the film composed of the photosensitive resin composition can be lowered.

In one aspect, from the viewpoint of enhancing the light transmission of the film formed by the photosensitive resin composition, it is preferable that any one of R ₆ , R ₇ , R ₈ and R ₉ is hydrogen, and R ₆ and R _{7 are used.} , R ₈ and R ₉ are all hydrogen.

As one aspect, at least one of R _{6 to} R ₉ is a group containing a heterocyclic structure, more specifically, for the purpose of improving curability when formed into a film, improving mechanical properties, or further improving adhesiveness. Preferably, it is a group containing an epoxy group or a group containing an oxetanyl group.
Examples of the group containing an epoxy group include an epoxy group, a glycidyl group or a glycidyloxy group with respect to the above-mentioned alkyl group, alkenyl group, alkynyl group, alkylidene group, aryl group, aralkyl group, alkaline group or cycloalkyl group. Examples thereof include a group substituted with a group obtained by removing hydrogen from the OH group of glycidol.
Examples of the group containing an oxetanyl group include the above-mentioned alkyl group, alkenyl group, alkynyl group, alkylidene group, aryl group, aralkyl group, alkaline group or cycloalkyl group, and 3-ethyl-3-hydroxymethyloxetane. Examples thereof include a group in which a group obtained by removing hydrogen from an OH group is substituted.

As one aspect, it is preferable that at least one of R _{6 to} R ₉ is a carboxy group or a group containing a carboxy group for the purpose of improving the solubility in an alkaline aqueous solution.
Examples of the group containing a carboxy group include the above-mentioned alkyl group, alkenyl group, alkynyl group, alkylidene group, aryl group, aralkyl group, alkaline group or cycloalkyl group substituted with a carboxy group.

N in the general formula (a1) is, for example, 0, 1 or 2, preferably 0 or 1, and more preferably 0.

The alkali-soluble resin may contain only one type of structural unit derived from a monomer having a cyclic olefin structure, or may contain two or more types. For example, in order to improve both the curability and mechanical properties of the film and the solubility in an alkaline developer, the alkali-soluble resin has a structure in which at least one of R _{6 to} R ₉ is a group containing a heterocyclic structure. It may contain both a unit and a structural unit in which at least one of R _{6 to} R ₉ is a carboxy group or a group containing a carboxy group.
When the alkali-soluble resin contains a structural unit derived from a monomer having a cyclic olefin structure, the content ratio thereof is, for example, 5 to 90 mol%, preferably 10 to 80 mol%, based on all the structural units in the resin.

-Structural unit derived from a monomer having a cyclic acid anhydride structure The alkali-soluble resin contains a structural unit derived from a monomer having a cyclic acid anhydride structure, so that the solubility of the resin in an alkaline developer can be particularly enhanced. it can. That is, the developability can be improved.

As the structural unit derived from the monomer having a cyclic acid anhydride structure, the structural unit represented by the following general formulas (a2-1), (a2-2), (a2-3) or (a2-4) is preferably used. Can be mentioned.
In the general formula (a2-1) and the general formula (a2-2), R ₁₄ , R ₁₅ and R ₁₆ are independently organic groups having 1 to 30 carbon atoms, respectively.

The organic groups having 1 to 30 carbon atoms constituting R ₁₄ , R ₁₅ and R ₁₆ may contain any one or more of O, N, S, P and Si in the structure. Further, the organic groups constituting R ₁₄ , R ₁₅ and R ₁₆ can be free of acidic functional groups. This makes it easy to control the acid value.

Examples of the organic group constituting R ₁₄ , R ₁₅ and R ₁₆ include an alkyl group, an alkenyl group, an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, an alkalil group, a cycloalkyl group, and a heterocyclic group.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group and heptyl group. , Octyl group, nonyl group, decyl group and the like.
Examples of the alkenyl group include an allyl group, a pentaenyl group, a vinyl group and the like.
Examples of the alkynyl group include an ethynyl group and the like.
Examples of the alkylidene group include a methylidene group and an ethylidene group.
Examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group and the like.
Examples of the aralkyl group include a benzyl group and a phenethyl group.
Examples of the alkaline group include a tolyl group and a xylyl group.
Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group and the like.
Examples of the heterocyclic group include an epoxy group and an oxetanyl group.

In these alkyl group, alkenyl group, alkynyl group, alkylidene group, aryl group, aralkyl group, alkalil group, cycloalkyl group, and heterocyclic group, one or more hydrogen atoms may be substituted with halogen atoms. Halogen atoms include fluorine, chlorine, bromine, and iodine. Of these, a haloalkyl group in which one or more hydrogen atoms of the alkyl group are substituted with halogen atoms is preferable.

The alkali-soluble resin preferably contains at least the structural units represented by the general formula (a2-1) and / or the general formula (a2-3).
The alkali-soluble resin may contain only one of the structural units represented by the general formulas (a2-1), (a2-2), (a2-3) or (a2-4), or two or more. May include.

As a supplement for reference, the structural units represented by the general formulas (a2-1), (a2-2) and (a2-4) are introduced into the alkali-soluble resin as follows, for example. be able to.
(I) First, the structural unit represented by the general formula (a2-3) is introduced into the alkali-soluble resin.
(Ii) After that, the structural unit is opened by appropriate means and conditions.

To explain the above (ii) more concretely, for example, a monohydric alcohol acts on a resin containing a structural unit represented by the general formula (a2-3), whereby the general formula (a2-3) is used. A part of the represented structural unit changes to the structural unit represented by the general formula (a2-1).

Of course, at the time of polymerization, by using a monomer directly corresponding to the structural unit represented by the general formula (a2-1), (a2-2) or (a2-4), the general formula can be contained in the alkali-soluble resin. The structural unit represented by (a2-1), (a2-2) or (a2-4) may be introduced.

The alkali-soluble resin may contain only one type of structural unit derived from a monomer having a cyclic acid anhydride structure, or may contain two or more types.
When the alkali-soluble resin contains a structural unit derived from a monomer having a cyclic acid anhydride structure, the content ratio thereof is, for example, 10 to 80 mol%, preferably 20 to 60 mol%, based on all the structural units in the resin. ..

The lower limit of the content of the alkali-soluble resin in the photosensitive resin composition is preferably 30 parts by mass or more, preferably 40 parts by mass or more, when the total solid content of the photosensitive resin composition is 100 parts by mass. It is more preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and particularly preferably 70 parts by mass or more. This makes it easier to sufficiently increase the heat resistance of the cured film obtained by curing the photosensitive resin composition.
The upper limit of the content of the alkali-soluble resin in the photosensitive resin composition is, for example, when the total solid content of the photosensitive resin composition is 100 parts by mass from the viewpoint of the blending balance with other components. , 95 parts by mass or less, more preferably 90 parts by mass or less, and further preferably 85 parts by mass or less.
The total solid content of the photosensitive resin composition indicates the total amount of the components contained in the photosensitive resin composition excluding the solvent.

[Acylating agent (b1)]
As described above, the photosensitive resin composition of the present embodiment preferably contains an acylating agent (b1) as a component that "caps" the polar group.
The acylating agent (b1) is particularly limited as long as it can be acylated by reacting with polar functional groups such as hydroxy groups contained in the composition by heat when curing the photosensitive resin composition. Not done.

Examples of the known acylating agent (b1) include carboxylic acid anhydrides and carboxylic acid halides. More specifically, acetic anhydride, acetyl chloride, trifluoroacetic anhydride, chloroacetic anhydride, chloroacetyl chloride, dichloroacetic anhydride, trichloroacetic anhydride and the like can be mentioned.

As the acylating agent (b1), it is preferable to use an acylazole compound, that is, a compound in which an acyl group is substituted on the azole ring.
Acylazole compounds are acylated not only because of their effectiveness (high acylation ability) and availability, but also because they do not contain halogen atoms, which are not desirable when considering the use of permanent films for high-frequency devices. It is preferable as the agent (b1).

Examples of the azole ring of the acyl azole compound (a compound in which an acyl group is substituted in the azole ring) include an imidazole ring, a triazole ring, and a tetrazole ring.

More specific examples of the acylazole compound include the following.
A compound in which an acyl group is substituted with imidazoles such as imidazole, 2-methylimidazole, 2-undecyl-4-methylimidazole, and 2-phenylimidazole.
A compound in which an acyl group is substituted with benzimidazoles such as benzimidazole, 2-methylbenzimidazole, 2-undecylbenzoimidazole, 2-phenylbenzoimidazole, and 2-mercaptobenzimidazole.
1,2,3-triazole, 1,2,4-triazole, 5-phenyl-1,2,4-triazole, 5-amino-1,2,4-triazole, benzotriazole, 1-methylbenzotriazole, tolyl A compound in which an acyl group is substituted with a triazole-based compound such as triazole.
1H-tetrazole, 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-mercapto-1H-tetrazole, 1-phenyl-5-mercapto-1H-tetrazole, 1- A compound in which an acyl group is substituted with a tetrazole-based compound such as cyclohexyl-5-mercapto-1H-tetrazole or 5,5'-bis-1H-tetrazole.

Specifically, the acylazole compound can be a compound represented by the following general formula (b-I) or (b-II).

In the general formulas (b-I) and (b-II), Az represents an azole ring, R represents a monovalent organic group, and X represents a divalent organic group. In the general formula (b-II), the two Az may have the same structure or different structures.
From the viewpoint of reactivity, it is preferable that the N atom site of the azole ring forms a bond with the carbon atom of the carbonyl in Az.

More specifically, as the azole ring of AZ, a structure obtained by removing one hydrogen atom from the above-mentioned imidazoles, benzimidazoles, triazole compounds, tetrazole compounds and the like can be mentioned.
The azole ring of AZ may be unsubstituted or have a substituent. Examples of the substituent when having a substituent include an alkyl group, an aryl group, and an aralkyl group.

The following are exemplified as particularly preferable structures of the azole ring of AZ. In the following examples, R'is a hydrogen atom or a monovalent substituent (alkyl group, aryl group, aralkyl group, etc.), and is preferably a hydrogen atom.

Examples of the monovalent organic group of R in the general formulas (b-I) and (b-II) include an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group and the like. The carbon number of R is, for example, 1 to 20, preferably 1 to 10. R is preferably an aryl group, more preferably a phenyl group.

Examples of the divalent organic group of X in the general formulas (b-I) and (b-II) include a group obtained by removing one hydrogen atom from the monovalent organic group of R. X is preferably an arylene group, more preferably a phenylene group.

Specific examples of the acylazole compound include, for example, International Publication No. 2009/031602, JP-A-9-183846, Chem. Lett. 2018, 47, 100-102, Chem. Lett. It is listed in 2018, 47, 221-224 and the like.
Particularly desirable acylazole compounds include the following.

When the photosensitive resin composition contains an acylating agent (b1), the content thereof is preferably 1 to 30 parts by mass, more preferably 1 when the content of the alkali-soluble resin (A) is 100 parts by mass. It is ~ 15 parts by mass, more preferably 1 to 10 parts by mass. By appropriately adjusting the amount of the acylating agent (b1), it is possible to sufficiently reduce the dielectric loss tangent and further suppress the loss of high frequency while maintaining other performances such as developability.

[Low molecular weight compound having a carboxy group (b2)]
The photosensitive resin composition of the present embodiment preferably contains a low molecular weight compound (b2) having a carboxy group. The reactivity of the low molecular weight compound (b2) having a carboxy group (hereinafter, also simply referred to as compound (b2)) with the polar functional group contained in the composition is slightly lower than that of the acylating agent (b1). there is a possibility. However, the compound (b2) is considered to react well with the amino group and the like in the resin, and in this respect, for example, when the alkali-soluble resin (A) is a polyamide resin, it is contained in the polyamide resin or the residual monomer. It is considered that the dielectric loss tangent can be lowered by reacting with a plastic amino group or the like. Further, it is presumed by the present inventor that the compound (b2) itself tends to have a relatively small dielectric loss tangent, which is also considered to be the reason why the dielectric loss tangent can be reduced by the compound (b2). ..

As the compound (b2), a polyfunctional carboxylic acid, specifically a dicarboxylic acid, is preferable because it is expected to have an effect as a cross-linking agent.
From another viewpoint, considering the heat resistance of the cured film and the like, the compound (b2) preferably has a cyclic structure such as an alicyclic structure or an aromatic ring structure.
From another viewpoint, considering water solubility (solubility in an alkaline developer), the molecular weight of compound (b2) is preferably relatively small. Specifically, the molecular weight of compound (b2) is preferably 300 or less, more preferably 180 or less. There is no particular lower limit on the molecular weight, but it is, for example, 90 or more in terms of suppressing volatilization.

Specific examples of compound (b2) are shown below. Of course, compound (b2) is not limited to the following.
Aliper (di) carboxylic acids such as acetic acid, propionic acid, butyric acid, isobutyric acid, pivalic acid, valeric acid, hexanic acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid, decanoic acid, undecanoic acid, adipic acid , Sebacic acid, azelaic acid, dodencan diic acid, etc. with 2 to 16 carbon atoms.
Cycloalkane (di) carboxylic acid, for example, cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, 1,4-cyclohexanedicarboxylic acid, etc. (the number of carbon atoms in the cycloalkane moiety is preferably 5 to 12).
Aromatic (di) carboxylic acids such as isophthalic acid, 2-chloroterephthalic acid, 2,5-dichloroterephthalic acid, 2-methylterephthalic acid, 4,4-stylbenzicarboxylic acid, naphthalenedicarboxylic acid, 4,4-biphenyl Dicarboxylic acid, orthophthalic acid, diphenoxyetanedicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylsulfone dicarboxylic acid and the like (the number of carbon atoms in the aromatic moiety is preferably 6 to 20).

When the photosensitive resin composition contains the compound (b2), the photosensitive resin composition may contain only one kind of the compound (b2) or two or more kinds.
When the photosensitive resin composition contains the compound (b2), the amount thereof is preferably 1 to 100 parts by mass, more preferably 30 to 70 parts by mass, when the content of the alkali-soluble resin (A) is 100 parts by mass. It is a department. As a result, the dielectric loss tangent can be made sufficiently small while sufficiently obtaining other performances.

As a reminder, the photosensitive resin composition of the present embodiment may contain only one of the compounds corresponding to the above (b1) or (b2), or may contain two or more of them.

[Solvent (C)]
The photosensitive resin composition of the present embodiment contains a solvent (C).
The solvent (C) typically comprises an organic solvent. Specific examples thereof include organic solvents such as ketone solvents, ester solvents, ether solvents, alcohol solvents, lactone solvents, and carbonate solvents.

More specifically, acetone, methyl ethyl ketone, toluene, propylene glycol methyl ethyl ether, propylene glycol dimethyl ether, butyl acetate, propylene glycol 1-monomethyl ether 2-acetate, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate. , Benzyl alcohol, propylene carbonate, ethylene glycol diacetate, propylene glycol diacetate, propylene glycol monomethyl ether acetate, anisole, N-methylpyrrolidone, cyclohexanone, cyclopentanone and other organic solvents.

In one aspect, the solvent preferably comprises a urea compound and / or an amide compound having a non-cyclic structure (linear or branched chain structure). This has the effect of enhancing the adhesion between the cured product of the photosensitive resin composition and the metal substrate (particularly, the substrate having Al and / or Cu on the surface).
The urea compound refers to a compound having a urea bond, that is, a urea bond. Further, the amide compound means a compound having an amide bond, that is, an amide. Specific examples of the amide include a primary amide, a secondary amide, and a tertiary amide.

As the urea compound or the acyclic amide compound, those having a large number of nitrogen atoms in the molecular structure are preferable. Specifically, it is preferable that the number of nitrogen atoms in the molecular structure is two or more. This makes it possible to increase the number of lone electron pairs. Therefore, the adhesion to the metal can be improved.

Specific examples of the structure of the urea compound include a cyclic structure and a non-cyclic structure. The structure of the urea compound is preferably acyclic. As a result, the adhesion between the cured product of the photosensitive resin composition and the metal can be improved. The reason for this is presumed as follows. It is presumed that the urea compound having a non-cyclic structure is more likely to form a coordination bond than the urea compound having a cyclic structure. It is considered that this is because the urea compound having a non-cyclic structure has less binding of molecular motion than the urea compound having a cyclic structure, and further, the degree of freedom of deformation of the molecular structure is large. Therefore, when a urea compound having a non-cyclic structure is used, it is considered that a strong coordination bond can be formed and the adhesion can be improved.

Examples of urea compounds include tetramethylurea (TMU), tetrabutylurea, 1,3-dimethoxy-1,3-dimethylurea, N, N'-diisopropyl-O-methylisourea, O, N, N'-tri. Examples thereof include isopropylisourea, O-tert-butyl-N, N'-diisopropylisourea, O-ethyl-N, N'-diisopropylisourea, O-benzyl-N, N'-diisopropylisourea and the like. .. Of these, tetramethylurea (TMU) is preferred. The details are unknown, but it is probably because a strong metal coordination bond can be formed and the adhesion to the metal substrate can be improved.

Specific examples of the acyclic amide compound include 3-methoxy-N, N-dimethylpropanamide, N, N-dimethylformamide, N, N-dimethylpropionamide, N, N-diethylacetamide, and 3-. Butoxy-N, N-dimethylpropanamide, N, N-dibutylformamide and the like can be mentioned.

The photosensitive resin composition may contain only one type of solvent, or may contain two or more types of solvent. That is, the solvent may be a single solvent or a mixed solvent.
When the solvent contains a urea compound and / or an amide compound having a non-cyclic structure (a linear structure or a branched chain structure), the amount thereof is preferably 10 to 100 mass by mass with respect to the entire solvent. %, More preferably 20 to 100% by mass, still more preferably 30 to 100% by mass, and particularly preferably 50 to 100% by mass.

The amount of the solvent (total amount in the case of a mixed solvent) is not particularly limited, but is used in an amount such that the solid content concentration of the composition is, for example, 10 to 70% by mass, preferably 15 to 60% by mass. By appropriately adjusting the amount of the solvent, for example, the film thickness when the photosensitive resin composition is applied onto the substrate to form a film can be adjusted.

[Crosslinking agent (D)]
The photosensitive resin composition of the present embodiment preferably contains a cross-linking agent (D).
The cross-linking agent (D) is not particularly limited as long as it can react with the polar functional groups of the components (for example, alkali-soluble resin) in the photosensitive resin composition to form a cross-linked structure.
By containing the cross-linking agent (D) in the photosensitive resin composition, effects such as improvement of mechanical properties of the cured film and improvement of durability of the cured film (leading to improvement of yield and reliability of high frequency devices) can be obtained. Can be done.

The cross-linking agent (D) preferably has one or more cross-linking groups selected from the group consisting of an epoxy group and an oxetanyl group as the cross-linking group. In other words, the cross-linking agent (D) is an epoxy compound or an oxetane compound.

Examples of the epoxy compound include known epoxy resins.
Examples of the epoxy resin include epoxy resins having two or more epoxy groups in one molecule. As the epoxy resin, monomers, oligomers, and polymers in general can be used, and the molecular weight and molecular structure thereof are not particularly limited.
Examples of the epoxy resin include phenol novolac type epoxy resin, cresol novolac type epoxy resin, cresol naphthol type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, phenoxy resin, naphthalene skeleton type epoxy resin, and bisphenol A type epoxy resin. , Bisphenol A diglycidyl ether type epoxy resin, bisphenol F type epoxy resin, bisphenol F diglycidyl ether type epoxy resin, bisphenol S diglycidyl ether type epoxy resin, glycidyl ether type epoxy resin, cresol novolac type epoxy resin, aromatic polyfunctional Examples thereof include epoxy resins, aliphatic epoxy resins, aliphatic polyfunctional epoxy resins, alicyclic epoxy resins, and polyfunctional alicyclic epoxy resins.

Further, as the epoxy resin, a trifunctional or higher functional epoxy resin (that is, a resin having three or more epoxy groups in one molecule) can also be mentioned. As the polyfunctional epoxy resin, those having 3 to 20 functionalities are more preferable.
Examples of the polyfunctional epoxy resin include 2- [4- (2,3-epoxypropoxy) phenyl] -2- [4- [1,1-bis [4-([2,3-epoxypropoxy] phenyl)). Ethyl] phenyl] propane, phenol novolac type epoxy, tetrakis (glycidyloxyphenyl) ethane, α-2,3-epoxypropoxyphenyl-ω-hydropoly (n = 1-7) {2- (2,3-epoxypropoxy) Bendilidene-2,3-epoxypropoxyphenylene}, 1-chloro-2,3-epoxypropane, formaldehyde, 2,7-naphthalenediol polycondensate, dicyclopentadiene type epoxy resin and the like can be mentioned.

Examples of the oxetane compound include compounds having two or more oxetanyl groups in one molecule.
For example, 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene, bis [1-ethyl (3-oxetanyl)] methyl ether, 4,4'-bis [(3-ethyl-3). -Oxetanyl) methoxymethyl] biphenyl, 4,4'-bis (3-ethyl-3-oxetanylmethoxy) biphenyl, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, diethylene glycol bis (3-ethyl-3-3) Oxetanylmethyl) ether, bis (3-ethyl-3-oxetanylmethyl) diphenoate, trimethylpropanthris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, poly [[3-[(3-Ethyl-3-oxetanyl) methoxy] propyl] silaseskioxane] derivative, oxetanyl silicate, phenol novolac-type oxetane, 1,3-bis [(3-ethyloxetane-3-yl) methoxy] Examples include benzene.

In one aspect, the cross-linking agent (D) preferably does not contain conjugated double bonds, such as those contained in aromatic rings (eg, benzene rings). Although the details are unknown, it is presumed that the dielectric loss tangent becomes smaller because the cross-linking agent (D) does not contain delocalized π electrons. Then, it is considered that a permanent film having a smaller high frequency energy loss can be formed.

When the photosensitive resin composition contains a cross-linking agent (D), the photosensitive resin composition may contain only one type of cross-linking agent or two or more types. For example, two or more kinds of epoxy compounds may be contained, two or more kinds of oxetane compounds may be contained, or an epoxy compound and an oxetane compound may be used in combination.
When the photosensitive resin composition contains the cross-linking agent (D), the amount thereof is preferably 1 to 300 parts by mass, more preferably 50 to 150 parts when the content of the alkali-soluble resin (A) is 100 parts by mass. It is a mass part. As a result, the dielectric loss tangent can be sufficiently reduced while sufficiently obtaining other performances. Further, it is possible to sufficiently obtain effects such as improvement of mechanical properties of the cured film and improvement of durability of the cured film.

[Photosensitizer (E)]
The photosensitive resin composition of the present embodiment preferably contains a photosensitive agent.
As the photosensitizer (E), for example, a photoacid generator that generates an acid by absorbing light energy can be used.

Examples of the photosensitizer (E) include diazoquinone-based photosensitizers, diaryliodonium salts, onium salts such as triarylsulfonium salts or sulfonium-borate salts, 2-nitrobenzyl ester compounds, N-iminosulfonate compounds, and imidesulfonate compounds. Examples thereof include 2,6-bis (trichloromethyl) -1,3,5-triazine compound and dihydropyridine compound.

The photosensitizer (E) preferably contains a diazoquinone-based photosensitizer. In particular, when the photosensitive resin composition is designed to be of a positive type (the exposed portion dissolves when developed with an alkaline developer after pattern exposure), the photosensitive agent (E) preferably contains a quinonediazide compound. Thereby, sensitivity, resolving power, developability and the like can be improved.

Examples of the diazoquinone-based photosensitizer include those shown below. In the following, n ₂ is an integer of 1 to 4.

In each of the above diazoquinone-based photosensitizers, Q is a structure represented by the following formula (a), the following formula (b) and the following formula (c), or a hydrogen atom. However, at least one of the Qs of each diazoquinone compound has a structure represented by the following formula (a), the following formula (b) and the following formula (c).
The Q of the diazoquinone-based photosensitizer preferably includes the following formula (a) or the following formula (b). Thereby, the transparency of the photosensitive resin composition can be improved. Therefore, the appearance of the photosensitive resin composition can be improved.

The lower limit of the content of the photosensitizer (E) in the photosensitive resin composition is preferably 1 part by mass or more when the alkali-soluble resin is 100 parts by mass from the viewpoint of obtaining an appropriately high sensitivity. It is more preferably 3 parts by mass or more, and further preferably 5 parts by mass or more.
Further, the upper limit of the content of the photosensitive agent (E) in the photosensitive resin composition is, for example, 30 parts by mass or less when the alkali-soluble resin is 100 parts by mass in consideration of the blending amount with other components. It is preferably 20 parts by mass or less, and more preferably 20 parts by mass or less.

[Adhesion aid (F)]
The photosensitive resin composition of the present embodiment preferably contains an adhesion aid (F). As a result, the adhesion to the substrate can be improved. That is, the reliability of the high frequency device can be improved.

As the adhesion aid (F), for example, one or more of a triazole compound, an aminosilane, an imide compound and the like can be used. It is considered that these compounds easily interact with the substrate (particularly the substrate containing metal) due to the action of the lone electron pair derived from the nitrogen atom, and contribute to the improvement of adhesion.

Specific examples of the triazole compound include 4-amino-1,2,4-triazole, 4H-1,2,4-triazole-3-amine, 4-amino-3,5-di-2-pyridyl-. 4H-1,2,4-triazole, 3-amino-5-methyl-4H-1,2,4-triazole, 4-methyl-4H-1,2,4-triazole-3-amine, 3,4- Diamino-4H-1,2,4-triazole, 3,5-diamino-4H-1,2,4-triazole, 1,2,4-triazole-3,4,5-triamine, 3-pyridyl-4H- 1,2,4-Triazole, 4H-1,2,4-Triazole-3-Carboxamide, 3,5-diamino-4-methyl-1,2,4-Triazole, 3-Pyridyl-4-methyl-1, Examples thereof include 1,2,4-triazole such as 2,4-triazole and 4-methyl-1,2,4-triazole-3-carboxamide.
Only one type of triazole compound may be used, or two or more types may be used in combination.

Examples of the aminosilane include known or commercially available silane coupling agents having an amino group.
Specifically, as aminosilane, a condensate of cyclohexene-1,2-dicarboxylic acid anhydride and 3-aminopropyltriethoxysilane, 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride and 3-amino. Condensate of propyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-Aminopropyltriethoxysilane, 3-Aminopropyltrimethoxysilane, 3-Aminopropyltriethoxysilane, 3-Triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3 -Aminopropyltrimethoxysilane, N, N'bis [3- (trimethoxysilyl) propyl] ethylenediamine, N, N'-bis- (3-triethoxysilylpropyl) ethylenediamine, N, N'-bis [3- (Methyldimethoxysilyl) propyl] ethylenediamine, N, N'-bis [3- (methyldiethoxysilyl) propyl] ethylenediamine, N, N'-bis [3- (dimethylmethoxysilyl) propyl] ethylenediamine, N- [3 -(Methyldimethoxysilyl) propyl] -N'-[3- (trimethoxysilyl) propyl] ethylenediamine, N, N'-bis [3- (trimethoxysilyl) propyl] diaminopropane, N, N'-bis [ Examples thereof include 3- (trimethoxysilyl) propyl] diaminohexane and N, N'-bis [3- (trimethoxysilyl) propyl] diethylenetriamine.
Aminosilane may be used alone or in combination of two or more.

Specific examples of the imide compound include the compounds exemplified below. Only one of these may be used, or two or more thereof may be used in combination.

[Surfactant (G)]
The photosensitive resin composition of the present embodiment preferably contains a surfactant (G). This makes it possible to improve coatability, film thickness uniformity, and the like.

The applicable surfactant (G) is not particularly limited. Specifically, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; and polyoxyethylene aryl such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether. Ethers; Nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; Ftop EF301, Ftop EF303, Ftop EF352 (manufactured by Shin-Akita Kasei Co., Ltd.), Mega Fuck F171, Mega Fuck F172, Mega Fuck F173, Mega Fuck F177, Mega Fuck F444, Mega Fuck F470, Mega Fuck F471, Mega Fuck F475, Mega Fuck F482, Mega Fuck F477 (manufactured by DIC), Florard FC-430, Florard FC-431, Novell FC4430, Novell FC4432 (manufactured by 3M Japan), Surfron S-381, Surfron S-382, Surfron S-383, Surfron S-393, Surfron SC-101, Surfron SC-102, Surfron SC-103 , Surflon SC-104, Surflon SC-105, Surflon SC-106, (manufactured by AGC Seimi Chemical Co., Ltd.) and other fluorosurfactants commercially available; organosiloxane copolymer KP341 (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) (Meta) acrylic acid-based copolymer Polyflow No. 57, 95 (manufactured by Kyoeisha Chemical Co., Ltd.) and the like.

Among these, it is preferable to use a fluorine-based surfactant having a perfluoroalkyl group. Examples of the fluorine-based surfactant having a perfluoroalkyl group include Megafuck F171, Megafuck F173, Megafuck F444, Megafuck F470, Megafuck F471, Megafuck F475, Megafvck F482, and Megafvck. One or more selected from F477 (manufactured by DIC), Surflon S-381, Surfron S-383, Surfron S-393 (manufactured by AGC Seimi Chemical), Noveck FC4430 and Noveck FC4432 (manufactured by 3M Japan) Is preferably used.

Further, as the surfactant (G), a silicone-based surfactant (for example, polyether-modified dimethylsiloxane) can also be preferably used. Specifically, as silicone-based surfactants, Toshiba Dow Corning's SH series, SD series and ST series, Big Chemie Japan's BYK series, Shin-Etsu Chemical Co., Ltd.'s KP series, and NOF Corporation's Disform ( Examples include the (registered trademark) series and the TSF series of Toshiba Silicone Co., Ltd.

When the photosensitive resin composition contains the surfactant (G), only one type may be contained, or two or more types may be contained.
The upper limit of the content of the surfactant (G) in the photosensitive resin composition is preferably 1% by mass (10000 ppm) or less based on the entire photosensitive resin composition (including the solvent), and is 0. It is more preferably 5.5% by mass (5000 ppm) or less, and further preferably 0.1% by mass (1000 ppm) or less.
Further, the lower limit of the content of the surfactant (G) in the photosensitive resin composition is, for example, the entire photosensitive resin composition (including the solvent) from the viewpoint of sufficiently obtaining the effect of the surfactant. It is 0.001% by mass (10 ppm) or more with respect to.
By appropriately adjusting the amount of the surfactant (G), it is possible to improve the coatability and the uniformity of the coating film while maintaining other performances.

[Other ingredients]
The photosensitive resin composition of the present embodiment may contain various components other than the above.
As an example, the photosensitive resin composition of the present embodiment may contain an antioxidant. As the antioxidant, one or more selected from a phenol-based antioxidant, a phosphorus-based antioxidant and a thioether-based antioxidant can be used. The antioxidant can suppress the oxidation of the resin film formed by the photosensitive resin composition.
As another example, the photosensitive resin composition of the present embodiment may contain a filler. As the filler, an appropriate filler can be selected according to the mechanical properties and thermal properties required for the resin film made of the photosensitive resin composition. Specific examples of the filler include an inorganic filler and an organic filler.
In addition, the photosensitive resin composition of the present embodiment may contain a sensitizer, a filming agent, a component for adjusting solubility in a developing solution and hydrophilicity (phenol compound, polyol compound, etc.) and the like.

[Dielectric properties]
As described above, the dielectric loss tangent (tan δ) at 10 GHz by the cavity resonator method of the cured product obtained by heating the photosensitive resin composition of the present embodiment at 200 ° C. for 90 minutes and curing it is 0.025 or less. It is preferably 0.02 or less, more preferably 0.01 or less. The dielectric loss tangent is basically preferably a value closer to 0.

The relative permittivity of the cured product obtained by heating the photosensitive resin composition of the present embodiment at 200 ° C. for 90 minutes at 10 GHz by the cavity resonator method is preferably less than 4.0, more preferably 3. It is less than 5.5. The smaller the relative permittivity, the more preferable, but in reality, the relative permittivity is usually 2.0 or more.
Not only the dielectric loss tangent but also the relative permittivity of the cured product of the photosensitive resin composition is small, so that the performance of the high frequency device can be further improved.
The method for measuring the dielectric property by the cavity resonator method will be described in detail in Examples.

[Manufacturing method (preparation method)]
The method (preparation method) for producing the photosensitive resin composition of the present embodiment is not particularly limited. For example, each component other than the solvent (C) can be prepared by dissolving or dispersing in the solvent (C).

<Manufacturing method of cured film, high frequency device, high frequency device>
A cured film can be obtained by curing the photosensitive resin composition of the present embodiment. Further, the photosensitive resin composition of the present embodiment is preferably used for forming a cured film in a high frequency device.

The permanent film is typically a resin obtained by applying a photosensitive resin composition to some substrate, prebaking, exposing, developing, patterning into a desired shape, and then curing by post-baking. It is composed of a membrane. The permanent film can be used as a protective film, an interlayer film, a dam material, etc. in a high frequency device.

The high-frequency device is manufactured, for example, by (i) a film forming step of forming a photosensitive resin film using the photosensitive resin composition of the present embodiment, and (ii) exposing and developing the photosensitive resin film to form a pattern. It can be carried out by a series of steps including a pattern forming step of obtaining and a curing step of heating and curing the (iii) pattern.
Hereinafter, these steps will be described.

(I) Film forming step In the film forming step, a photosensitive resin film made of a photosensitive resin composition is formed on the surface of the substrate.
The material of the substrate is not particularly limited. For example, silicon wafers, ceramic substrates, aluminum substrates, SiC wafers, SiC wafers, GaN wafers, copper-clad laminates, glass substrates, plastic substrates and the like can be mentioned.
The substrate may be an unprocessed substrate or a substrate on which electrodes, elements, irregularities and the like are formed on the surface. Moreover, some surface treatment may be performed.

The method for forming the photosensitive resin film using the photosensitive resin composition is not particularly limited. For example, it can be performed by rotary coating using a spinner, spray coating using a spray coater, bar coating, dipping, printing, roll coating, an inkjet method, or the like.
Drying of the photosensitive resin composition applied to the surface of the substrate is typically carried out by heat treatment with a hot plate, hot air, an oven or the like. The heating temperature is usually 80 to 140 ° C, preferably 100 to 130 ° C. The heating time is usually about 30 to 600 seconds, preferably about 30 to 300 seconds.

The film thickness of the photosensitive resin film is not particularly limited, and may be appropriately adjusted according to the pattern to be finally obtained. For example, the thickness of the finally obtained cured film (permanent film) can be adjusted to be about 5 to 10 μm. The film thickness can be adjusted by changing the content of the solvent in the photosensitive resin composition, the coating method, the coating conditions, and the like.

(Ii) Pattern forming step In the pattern forming step, a pattern can be obtained by exposing and developing the photosensitive resin film formed in (i) above.

The exposure can typically be performed by irradiating the photosensitive resin film with an active ray such as through a photomask.
Examples of the active light beam include X-ray, electron beam, ultraviolet light, visible light and the like. In terms of wavelength, light having a wavelength of 200 to 500 nm is preferable. From the viewpoint of pattern resolution and handleability, the light source is preferably g-line, h-line or i-line of a mercury lamp, and i-line is particularly preferable. Further, two or more light rays may be mixed and used. As the exposure apparatus, a contact aligner, a mirror projection or a stepper is preferable.
The amount of light for exposure may be appropriately adjusted depending on the amount of the photosensitizer in the photosensitive resin film and the like. Typically, it is about 10 to 1000 mJ / cm ² .

After the exposure, the photosensitive resin film may be heated again if necessary (heating after exposure: Post Exposure Bake). The temperature is, for example, 80 to 140 ° C, preferably 100 to 130 ° C. The time is, for example, 30 to 600 seconds, preferably 30 to 300 seconds.

A pattern can be obtained by developing the exposed photosensitive resin film with a developing solution.
In the developing step, development can be carried out using a suitable developer, for example, by a method such as a dipping method, a paddle method, or a spray method. By the development, the exposed portion (in the case of the positive type) or the unexposed portion (in the case of the negative type) of the photosensitive resin film is eluted and removed, and a pattern is obtained.

The developer that can be used is not particularly limited. For example, an alkaline aqueous solution or an organic solvent can be used.
Specific examples of the alkaline aqueous solution include (i) an inorganic alkaline aqueous solution such as sodium hydroxide, sodium carbonate, sodium silicate and ammonia, (ii) an organic amine aqueous solution such as ethylamine, diethylamine, triethylamine and triethanolamine, and (iii). Examples thereof include an aqueous solution of a quaternary ammonium salt such as tetramethylammonium hydroxide and tetrabutylammonium hydroxide.
Specific examples of the organic solvent include a ketone solvent such as cyclopentanone, an ester solvent such as propylene glycol monomethyl ether acetate (PGMEA) and butyl acetate, and an ether solvent such as propylene glycol monomethyl ether.
A water-soluble organic solvent such as methanol or ethanol, a surfactant, or the like may be added to the developing solution.

In this embodiment, it is preferable to use an aqueous solution of tetramethylammonium hydroxide as a developing solution. The concentration of tetramethylammonium hydroxide in this aqueous solution is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass.

After development, additional processing may be performed before moving on to the next step.
For example, after development, the substrate and / or pattern may be washed with a rinse solution. Examples of the rinsing solution include distilled water, methanol, ethanol, isopropanol, propylene glycol monomethyl ether and the like. These may be used alone or in combination of two or more.

(Iii) Curing step
In the curing step, the pattern obtained in (ii) above is heated and cured.
The heating temperature is typically 150-400 ° C, preferably 170-300 ° C, more preferably 170-250 ° C. By setting this temperature range, it is considered that the entire membrane can be uniformly crosslinked. The heating time is not particularly limited, but is, for example, in the range of 15 to 300 minutes, preferably 20 to 180 minutes.
The heat treatment can be performed by a hot plate, an oven, a temperature-increasing oven in which a temperature program can be set, or the like. The atmospheric gas for the heat treatment may be air or an inert gas such as nitrogen or argon. Further, it may be heated under reduced pressure.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the range in which the object of the present invention can be achieved are included in the present invention.

Embodiments of the present invention will be described in detail based on Examples and Comparative Examples. The present invention is not limited to the examples.

<Preparation of alkali-soluble resin 1>
An alkali-soluble resin 1 which is a polyamide resin was prepared by the following procedure.
The following was placed in a four-port glass separable flask equipped with a thermometer, a stirrer, a raw material inlet and a dry nitrogen gas inlet tube.
-206.58 g (0.800 mol) of diphenyl ether-4,4'-dicarboxylic acid represented by the following formula (DC2) and 216.19 g of 1-hydroxy-1,2,3-benzotriazole / monohydrate (monohydrate). 170.20 g (0.346 mol) of a mixture of dicarboxylic acid derivatives obtained by reacting with 1.600 mol).
-5-Aminotetrazole 4.01 g (0.047 mol)
・ 45.22 g (0.196 mol) of 4,4'-methylenebis (2-aminophenol) represented by the following formula (DA2)
56.24 g (0.196 mol) of 4,4'-methylenebis (2-amino-3,6 dimethylphenol) represented by the following formula (DA3).

Then, 578.3 g of N-methyl-2-pyrrolidone was added into the separable flask to dissolve each raw material component. Next, the reaction was carried out at 90 ° C. for 5 hours using an oil bath.
Next, 24.34 g (0.141 mol) of 4-ethynylphthalic anhydride and 121.7 g of N-methyl-2-pyrrolidone were added to the separable flask, and the reaction was carried out at 90 ° C. for 2 hours with stirring. I let you. Then, the reaction was terminated by cooling to 23 ° C.

The filtrate obtained by filtering the reaction mixture in the separable flask was put into a solution of water / isopropanol = 7/4 (volume ratio). Then, the precipitate was filtered off and washed thoroughly with water. After that, the desired alkali-soluble resin 1 was obtained by drying under vacuum. The weight average molecular weight Mw of the obtained alkali-soluble resin 1 was 18081.

<Preparation of alkali-soluble resin 2>
Norbornene and maleic anhydride were copolymerized at a molar ratio of 1: 1 by a radical polymerization method to obtain an alkali-soluble resin 2. The quantity average molecular weight Mn of the alkali-soluble resin 2 was 7800, and the weight average molecular weight Mw was 13600.

<Preparation of photosensitizer 1>
The photosensitizer 1 which is a diazoquinone compound was synthesized by the following procedure.
In a four-port separable flask equipped with a thermometer, a stirrer, a raw material inlet, and a dry nitrogen gas introduction tube, 11.04 g (0.026 mol) of phenol represented by the following formula (P-1) and 1, 18.81 g (0.070 mol) of 2-naphthoquinone-2-diazide-5-sulfonyl chloride and 170 g of acetone were added and stirred to dissolve.
Next, a mixed solution of 7.78 g (0.077 mol) of triethylamine and 5.5 g of acetone was slowly added dropwise while cooling the flask in a water bath so that the temperature of the reaction solution did not exceed 35 ° C. After reacting as it was at room temperature for 3 hours, 1.05 g (0.017 mol) of acetic acid was added, and the reaction was further carried out for 30 minutes.
The reaction mixture was then filtered and the filtrate was then added to a mixed solution of water / acetic acid (990 mL / 10 mL). Then, the precipitate was collected by filtration, washed thoroughly with water, and then dried under vacuum. As a result, the photosensitizer 1 represented by the structure of the following formula (Q-1) was obtained.

<Preparation of adhesion aid>
Adhesion aid 1 was prepared according to the following procedure.
Cyclohexene-1,2-dicarboxylic acid anhydride (45.6 g, 300 mmol) is dissolved in N-methyl-2-pyrrolidone (970 g) in an appropriately sized reaction vessel equipped with a stirrer and a condenser, and a constant temperature bath. The temperature was adjusted to 30 ° C. Next, 3-aminopropyltriethoxysilane (62 g, 280 mmol) was charged into a dropping funnel, and the mixture was added dropwise to the solution over 60 minutes. After the dropping was completed, the mixture was stirred under the conditions of 30 ° C. for 18 hours to obtain the adhesion aid 1 represented by the following formula (S2).

Further, as the adhesion aid 2, N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine (manufactured by Shin-Etsu Chemical Co., Ltd., X-12-5263HP) was prepared.
Further, 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503P) was prepared as the adhesion aid 3.

<Preparation of acylating agent>
As the acylating agent 1, a compound having the following structure obtained from Iharanikkei Co., Ltd. was prepared.

<Preparation of carboxylic acid>
As carboxylic acid 1, 1,4-cyclohexanedicarboxylic acid was prepared.

<Preparation of cross-linking agent>
The following three types were prepared as cross-linking agents.
・ Crosslinking agent 1: NC-3000 (Nippon Kayaku Co., Ltd., structure below)
-Crosslinking agent 2: TEPIC-FL (Nissan Chemical Industries, Ltd., structure below)
-Crosslinking agent 3: JP-100 (Nippon Soda, the following structure, m = 4-7, m + n = 16-25)

<Preparation of additives>
Paraxylene glycol was prepared as Additive 1.

<Preparation of solvent>
The following three types of solvents were prepared.
-Solvent 1: Tetramethylurea (TMU)
-Solvent 2: γ-Butyrolactone (GBL)
-Solvent 3: Propylene glycol monomethyl ether acetate (PGMEA)

<Preparation of surfactant>
As the surfactant 1, a fluorine-based surfactant (FC4430, manufactured by 3M Japan Ltd.) was prepared.

<Preparation of photosensitive resin composition>
First, of the components shown in the table below, only the solvent was prepared. When two or more kinds of solvents were used, a mixed solvent was first prepared.
Next, each raw material component other than the solvent is added to the prepared solvent, stirred, and filtered through a PTFE membrane filter having a pore size of 0.2 μm to obtain a photosensitive resin composition of each Example and each Comparative Example. Obtained.
In the table below, the amount of the surfactant added is the concentration (ppm) of the photosensitive resin composition containing the mixed solvent with respect to the entire varnish.

<Measurement of dielectric characteristics by cavity resonator method>
First, a test piece was obtained using the above-mentioned photosensitive resin composition.
Specifically, the photosensitive resin composition prepared above was applied onto a Si substrate and prebaked at 120 ° C. for 4 minutes to form a resin film having a coating film thickness of 12 μm.
This was heated at 200 ° C. for 90 minutes in a nitrogen atmosphere using an oven to cure the resin film, and a cured film having a film thickness of 10 μm was obtained.
After cooling to room temperature, the cured film was diced to a size of 3 mm × 8 cm and treated with hydrofluoric acid (immersed in a 2 mass% hydrofluoric acid aqueous solution). After removing the substrate from hydrofluoric acid, the cured film was peeled off from the Si substrate, and this was used as a test piece.
The test piece was pretreated by placing it in an environment of 22 ± 1 ° C. and 60 ± 5% RH for 12 hours.

As measuring devices, a network analyzer HP8510C, a synthesized sweeper HP83651A and a test set HP8517B (all manufactured by Agilent Technologies) were prepared. These devices and a cylindrical cavity resonator were set up as schematically shown in FIG. The dimensions of the cylindrical cavity resonator are φ42 mm in inner diameter and 30 mm in height, and the resonator is designed so that the TE ₀₁₁ mode is in the vicinity of 10 GHz when no sample is inserted.

The resonance frequency, 3 dB bandwidth, transmission power ratio, etc. were measured in the state where the test piece was inserted in the resonator and in the state where the test piece was not inserted. Then, the dielectric properties such as the dielectric loss tangent were obtained by analytically calculating these measurement results with software. The measurement mode was TE ₀₁₁ mode.

<Differential scanning calorimetry>
First, the above photosensitive resin composition was applied onto a Si substrate and prebaked at 120 ° C. for 4 minutes to obtain a resin film.
A DSC curve was obtained by measuring a part of this resin film by differential scanning calorimetry from 30 ° C. to 300 ° C. at a heating rate of 10 ° C./min. Then, the temperature at the top of the exothermic peak was read from the curve.

The composition of the photosensitive resin composition, the measurement results of the dielectric properties, and the results of the differential scanning calorimetry are summarized in Tables 1 and 2 below.

<Evaluation of high frequency energy loss (Examples 1 to 7, Comparative Example 1)>
A high-frequency device for evaluation was produced in which a permanent film was formed from the photosensitive resin composition of Comparative Example 1.
Further, as the photosensitive resin composition, a high frequency device for evaluation was produced in the same manner as described above except that the permanent film was formed not by the one of Comparative Example 1 but by those of Examples 1 to 7.
When the loss of high frequency (particularly in the millimeter wave region) was evaluated for each device, all of the high frequency devices in which the permanent film was formed by the photosensitive resin compositions of Examples 1 to 7 were the photosensitive resin compositions of Comparative Example 1. The loss of high frequency was less than that of the high frequency device in which the permanent film was formed.

<Evaluation of high frequency energy loss (Examples 2-1 to 2-4, Comparative Example 2-1)>
A high-frequency device for evaluation was produced in which a permanent film was formed from the photosensitive resin composition of Comparative Example 2-1.
Further, as the photosensitive resin composition, a high-frequency device for evaluation was produced in the same manner as above except that the permanent film was formed not by the one of Comparative Example 2-1 but by those of Examples 2-1 to 2-4. did.
When the loss of high frequency (particularly in the millimeter wave region) was evaluated for each device, all of the high frequency devices in which the permanent film was formed by the photosensitive resin composition of Examples 2-1 to 2-4 were found in Comparative Example 2-1. The loss of high frequency was less than that of the high frequency device in which the permanent film was formed by the photosensitive resin composition of.

In the production of the high-frequency device for evaluation, the photosensitive resin composition was cured at 200 ° C., but no particular defect due to poor curing was observed. That is, it was possible to obtain a cured film that was sufficiently cured even by heating at a relatively low temperature.

From the above, the photosensitive resin composition of the present embodiment (containing the alkali-soluble resin (A) and the solvent (C), and the DSC curve obtained under specific conditions has an exothermic peak top temperature of 200 ° C. or less, which is specific. The dielectric loss tangent of the cured product cured under the conditions is 0.01 or less), so that a cured film can be obtained even by thermosetting at a relatively low temperature, and it is preferably applicable to the production of high-frequency devices. I found out.

Claims (14)

A photosensitive resin composition containing an alkali-soluble resin (A) and a solvent (C).
The differential scanning calorimetry was performed from 30 ° C. to 300 ° C. at a heating rate of 10 ° C./min, using a film formed by drying the volatile components of the photosensitive resin composition at 120 ° C. for 4 minutes as a measurement target. In the obtained DSC curve, the exothermic peak top exists below 200 ° C.
The dielectric loss tangent (tan δ) at 10 GHz by the cavity resonator method of the cured product obtained by heating and curing the photosensitive resin composition at 200 ° C. for 90 minutes is 0.025 or less.
A photosensitive resin composition used to form a permanent film in a high frequency device. The photosensitive resin composition according to claim 1.
A photosensitive resin composition containing an acylating agent (b1). The photosensitive resin composition according to claim 2.
A photosensitive resin composition in which the acylating agent (b1) contains an acylazole compound. The photosensitive resin composition according to claim 2 or 3.
A photosensitive resin composition in which the content of the acylating agent (b1) is 1 to 30 parts by mass when the content of the alkali-soluble resin (A) is 100 parts by mass. The photosensitive resin composition according to claims 1 to 4.
A photosensitive resin composition containing a low molecular weight compound (b2) having a carboxy group. The photosensitive resin composition according to any one of claims 1 to 5.
The alkali-soluble resin (A) is a photosensitive resin containing one or more resins selected from the group consisting of polyamide resins, polybenzoxazole resins, polyimide resins, phenol resins, hydroxystyrene resins and cyclic olefin resins. Composition. The photosensitive resin composition according to any one of claims 1 to 6.
The alkali-soluble resin (A) is a photosensitive resin composition which is a polyamide resin in which a carboxyl group at the terminal is modified with an azole compound having an amino group. The photosensitive resin composition according to claims 1 to 7.
A photosensitive resin composition containing a cross-linking agent (D). The photosensitive resin composition according to claim 8.
A photosensitive resin composition in which the cross-linking agent (D) has one or more cross-linking groups selected from the group consisting of an epoxy group and an oxetanyl group as cross-linking groups. The photosensitive resin composition according to any one of claims 1 to 9.
A photosensitive resin composition containing a diazoquinone-based photosensitive agent. The photosensitive resin composition according to any one of claims 1 to 10.
A photosensitive resin composition obtained by heating the photosensitive resin composition at 200 ° C. for 90 minutes and curing the cured product, which has a relative permittivity of less than 4.0 at 10 GHz by the cavity resonator method. The cured film of the photosensitive resin composition according to any one of claims 1 to 11. A high frequency device comprising the cured film according to claim 12. A film forming step of forming a photosensitive resin film using the photosensitive resin composition according to any one of claims 1 to 11.
A method for manufacturing a high-frequency device, comprising a pattern forming step of exposing and developing the photosensitive resin film to obtain a pattern and a curing step of heating and curing the pattern.

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