Laminate, method for manufacturing laminate, hollow structure, and electronic component

Abstract

Provided is a laminate with which there is little wiring corrosion during storage under high-temperature and high-humidity conditions. Provided is a laminate in which metal wiring (M1) having a thickness of 0.1–5 μm, a relief pattern of an organic insulating film (P1) having a thickness of 0.5–4 μm, and metal wiring (M2) having a thickness of 0.1–5 μm are formed in the order listed on a piezoelectric substrate, wherein the organic insulating film (P1) contains an alkali-soluble resin (A) and a cured product obtained by curing a photosensitive resin composition containing a naphthoquinonediazide compound (E), the naphthoquinonediazide compound (E) content is 5–25 parts by mass per 100 parts by mass of the alkali-soluble resin (A), and when the organic insulating film (P1) is measured using an ion elution amount measurement method, the ion elution amount is 2000 ppm or less.

Description

Laminate, manufacturing method of laminate, hollow structure, and electronic component

[0001] The present invention relates to a laminate, a method for manufacturing a laminate, a hollow structure, and an electronic component.

[0002] Electronic components such as MEMS (Micro Electro Mechanical Systems) are essential for high-speed, high-quality communication in electronic devices. As electronic devices become smaller, the wiring designs of electronic components become more minute and complex.

[0003] In order to increase the degree of freedom in wiring design, devices have been disclosed that use insulating materials such as polyimide at wiring intersections (Patent Documents 1 to 4).

[0004] JP 2004-282707, JP 5-167387, JP 7-30362, International Publication No. 2011 / 050351

[0005] However, laminates using conventional insulating materials have the problem of high corrosion of metal wiring under high temperature and high humidity conditions.

[0006] To solve the above problems, the present invention has the following configuration: [1] A laminate comprising: a piezoelectric substrate; a metal wiring (M1) having a thickness of 0.1 to 5 μm; a relief pattern of an organic insulating film (P1) having a film thickness of 0.5 to 4 μm; and a metal wiring (M2) having a thickness of 0.1 to 5 μm, formed in this order; the organic insulating film (P1) contains a cured product obtained by curing a photosensitive resin composition containing an alkali-soluble resin (A) and a naphthoquinone diazide compound (E); the content of the naphthoquinone diazide compound (E) is 5 to 25 parts by mass per 100 parts by mass of the alkali-soluble resin (A); and when the organic insulating film (P1) is measured using the following method for measuring ion elution, the laminate has an ion elution amount of 2,000 ppm or less. (Method for measuring ion elution amount): The organic film is placed in 10 times the mass of pure water and subjected to hot water extraction at 121°C for 20 hours, and the supernatant of the extract is used as the test liquid. The test solution and a standard solution of the target ions are introduced into an ion chromatograph, and the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions in the test solution are determined using the calibration curve method. The value converted into the mass of eluted ions relative to the mass of the organic film is taken as the amount of eluted ions. [2] A laminate comprising: a metal wiring (M1) having a thickness of 0.1 to 5 μm; a relief pattern of an organic insulating film (P1) having a film thickness of 0.5 to 4 μm; and a metal wiring (M2) having a thickness of 0.1 to 5 μm, formed in this order on a piezoelectric substrate; the organic insulating film (P1) contains a cured product obtained by curing a photosensitive resin composition containing an alkali-soluble resin (A), an oxime-based photopolymerization initiator (B), and a radically polymerizable compound (C); the content of the oxime-based photopolymerization initiator (B) is 1 to 20 parts by mass per 100 parts by mass of the alkali-soluble resin (A); the oxime-based photopolymerization initiator (B) contains a compound represented by formula (1) and a compound represented by formula (2), and the mass ratio of the compound represented by formula (1) to the compound represented by formula (2) is 1:1 to 20:1; A laminate in which the amount of ion elution is 2000 ppm or less when the organic insulating film (P1) is measured using the following method for measuring the amount of ion elution: (Method for measuring the amount of ion elution) The organic film is placed in a 10-fold amount of pure water by mass ratio, and hot water extraction is performed at 121°C for 20 hours, and the supernatant of the extract is used as a test liquid.The test solution and a standard solution of the target ions are introduced into an ion chromatograph, and the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions in the test solution are determined using the calibration curve method. The value converted into the mass of eluted ions relative to the mass of the organic film is taken as the amount of eluted ions.

[0007]

[0008] (In formula (1), Ar represents an aryl group having 6 to 20 carbon atoms, and Z １ represents an organic group represented by any one of formulas (3) to (6), and Z ２ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ３ represents an organic group represented by any one of formulas (3) to (6), and Z ４ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0009]

[0010] (In formulas (3) to (6), R １ and R ３ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; R ２ and R ５ represents a divalent organic group having 1 to 20 carbon atoms, R ４represents a monovalent organic group having 1 to 20 carbon atoms.) [3] The laminate according to [1] or [2], wherein the electrical conductivity of a test solution of the organic insulating film (P1) obtained by the method for measuring the amount of eluted ions is 500 μS / cm or less. [4] The laminate according to any one of [1] to [3], wherein the angle between the surface where the piezoelectric substrate and the metal wiring (M1) contact and the surface where the relief pattern of the organic insulating film (P1) contacts the metal wiring (M2) is 20 to 60°. [5] The laminate according to any one of [1] to [4], wherein the alkali-soluble resin (A) contains at least one selected from the group consisting of polyimide, polybenzoxazole, polyamide, precursors of any of these, and copolymers thereof. [6] The laminate according to any one of [2] to [5], wherein the mass ratio of the compound represented by formula (1) to the compound represented by formula (2) is 4:1 to 20:1. [7] The laminate according to any one of [2] to [5], wherein the radical polymerizable compound (C) further contains a compound represented by formula (7) and a compound represented by formula (8), and the mass ratio of the compound represented by formula (7) to the compound represented by formula (8) is 1:9 to 5:5.

[0011]

[0012] (In formula (7) and formula (8), R ７ ~R １７ each independently represent a hydrogen atom or a methyl group.) [8] The laminate according to any one of [1] to [7], wherein the photosensitive resin composition contains a thermally crosslinkable compound (D), the thermally crosslinkable compound (D) contains a polyfunctional epoxy group-containing compound (D-1) and a polyfunctional alkoxymethyl group-containing compound (D-2), and the content of the polyfunctional epoxy group-containing compound (D-1) is 5 to 30 parts by mass and the content of the polyfunctional alkoxymethyl group-containing compound (D-2) is 1 to 10 parts by mass per 100 parts by mass of the alkali-soluble resin (A). [9] The laminate according to any one of [1] to [7], wherein the photosensitive resin composition comprises: a step (1) of forming metal wiring (M1) on a piezoelectric substrate; a step (2) of applying a photosensitive resin composition onto the piezoelectric substrate and the metal wiring (M1), heating to 80 to 130°C and drying to form a photosensitive resin film on the substrate; and a step (3) of applying a photosensitive resin composition to the piezoelectric substrate and the metal wiring (M1) through a mask at a dose of 150 to 2000 mJ / cm ２a step (4) of heating the exposed photosensitive resin film to 80 to 130°C, a step (5) of developing the photosensitive resin film by removing unexposed areas with an alkaline aqueous solution, a step (6) of heat-treating the developed photosensitive resin film at 200 to 280°C to form a relief pattern of an organic insulating film (P1), and a step (7) of forming metal wiring (M2) on the piezoelectric substrate and the organic insulating film (P1).

[10] A method for producing a laminate according to [9], wherein in the step (5), the difference in film thickness of the exposed area of ​​the photosensitive resin film between when developed for 80 seconds and when developed for 140 seconds is 0.20 μm or less.

[11] The method for producing a laminate according to [9] or

[10] , further comprising, between the steps (5) and (6), a step (5-1) of heating the developed photosensitive resin film from a temperature of 100°C or less to 150 to 200°C at a temperature increase rate of 10°C / min or more.

[12] Between the steps (5) and (6), the developed photosensitive resin film is heated to 1000 to 3000 mJ / cm ２

[13] A hollow structure having the laminate according to any one of [1] to

[12] , a hollow structure supporting material (P2), and a hollow structure roofing material (P3).

[14] The hollow structure according to

[13] , wherein the hollow structure supporting material (P2) and the hollow structure roofing material (P3) are organic films containing at least one alkali-soluble resin (A) selected from the group consisting of polyimide, polybenzoxazole, polyamide, precursors of any of these, and copolymers thereof.

[15] The hollow structure according to

[13] or

[14] , wherein when the organic insulating film (P1) having a film thickness of 0.5 to 4 μm, the hollow structure supporting material (P2), and the hollow structure roofing material (P3) are each evaluated individually by the ion elution amount measurement method, the total amount of ion elution from the organic insulating film (P1) having a film thickness of 0.5 to 4 μm, the hollow structure supporting material (P2), and the hollow structure roofing material (P3) is 2000 ppm or less.

[16] An electronic component having a hollow structure according to any of

[13] to

[15] .

[0013] The present invention can suppress corrosion of metal wiring during storage under high temperature and high humidity conditions.

[0014] It is a figure which showed the laminate of this invention, It is a figure which showed the cross section of the laminate of this invention, It is a figure which showed the cross section of the hollow structure which contains the laminate of this invention.

[0015] The present invention provides a laminate comprising a piezoelectric substrate and, in this order, a metal wiring (M1) having a thickness of 0.1 to 5 μm, a relief pattern of an organic insulating film (P1) having a film thickness of 0.5 to 4 μm, and a metal wiring (M2) having a thickness of 0.1 to 5 μm, wherein the organic insulating film (P1) contains a cured product obtained by curing a photosensitive resin composition containing an alkali-soluble resin (A) and a naphthoquinone diazide compound (E), and the content of the naphthoquinone diazide compound (E) is 5 to 25 parts by mass per 100 parts by mass of the alkali-soluble resin (A), and the organic insulating film (P1) has an ion elution amount of 2000 ppm or less when measured by the following ion elution amount measurement method.

[0016] (Method for measuring the amount of eluted ions) The organic film is placed in 10 times the mass of pure water, and hot water extraction is performed for 20 hours at 121°C. The supernatant of the extract is used as the test liquid. The test liquid and a standard solution of the target ions are introduced into an ion chromatograph, and the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions in the test liquid are determined by the calibration curve method. The value converted into the mass of eluted ions relative to the mass of the organic film is used as the amount of eluted ions.

[0017] When the laminate of the present invention is measured by the above-mentioned method for measuring the amount of eluted ions, the organic film refers to the organic insulating film (P1).

[0018] When the organic insulating film (P1) is measured by a method for measuring the amount of eluted ions, such as formate ions, acetate ions, propionate ions, and sulfate ions, the total amount of eluted ions is 2000 ppm or less, and corrosion of the metal wiring of the laminate under high-temperature and high-humidity conditions can be suppressed. From the viewpoint of corrosion suppression, a total amount of 1000 ppm or less is more preferable, and a total amount of 500 to 0 ppm is even more preferable. The lower measurement limit of the ion elution amount measured by an ion chromatograph is 0 ppm.

[0019] Acid ions eluted from organic insulating films under high-temperature and high-humidity conditions are thought to promote ionization of metal wiring and cause corrosion. Electronic components containing piezoelectric elements and metal wiring are significantly affected by changes in their characteristics due to metal corrosion, so it is necessary to reduce the amount of acid ions eluted from organic insulating films more than ever before. The elution amounts of formate ions, acetate ions, propionate ions, and sulfate ions are preferably 2000 ppm or less, more preferably 1000 ppm or less, and even more preferably 500 to 0 ppm.

[0020] The specific method for measuring the amount of ion elution is as follows. A predetermined amount of the organic film for which the amount of ion elution is measured is separated from the laminate and measured. When measuring the amount of ion elution from a resin composition for forming an organic film, a cured product obtained by heat-treating a liquid or sheet-like resin composition may be used. Methods for preparing the cured product include coating or laminating the resin composition on a silicon substrate, heating it in an oven, immersing it in an aqueous hydrofluoric acid solution, and peeling it off, or transferring a resin sheet formed on polyethylene terephthalate (PET) to a polytetrafluoroethylene (PTFE) film heated on a hot plate using a rubber roller, followed by heat treatment and peeling it off from the PTFE film. The prepared cured product is placed in a PTFE pressurized sealed container with a 10-fold amount of pure water by mass, and subjected to hot water extraction in a high-temperature oven at 121°C for 20 hours. The supernatant of the extract is filtered through a membrane filter to obtain the test solution. The mass of the cured product is preferably 0.1 to 5.0 g, with 0.3 to 3.0 g being preferred for ease of use and stable ion extraction. If necessary, the cured film may be freeze-pulverized using liquid nitrogen. The pure water used here is distilled and ion-exchanged, and is the same as that used for reagent preparation and microanalysis tests specified in JIS K 0557 (1998). The hot water pressure extraction method procedure was based on Yoshimi Hashimoto: Analytical Chemistry (Bunseki Kagaku), 49, 8 (2000), and the extraction temperature conditions were based on Ai Kitamura: Network Polymer, 33, 3 (2012).

[0021] This test solution is analyzed in accordance with the ion chromatography method of Japanese Industrial Standards JIS K 0127 (2013) General Principles of Ion Chromatography. Standard solutions of formate ions, acetate ions, propionate ions, and sulfate ions are introduced into an ion chromatography analyzer to prepare a calibration curve. Next, 25 μL of the test solution is introduced, and the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions are determined from the peak areas and the calibration curve. The values ​​converted into the eluted ion mass relative to the mass of the organic film are used as the eluted ion amount.

[0022] The piezoelectric substrate used in the present invention is mainly lithium tantalate, lithium niobate, gallium arsenide, or a substrate having a passivation film of silicon nitride or silicon oxide formed on the upper surface thereof, but is not limited to these.

[0023] Metal wiring (M1) is formed on the piezoelectric substrate. It is preferable that the metal wiring (M1) is directly on the piezoelectric substrate, as this provides a high piezoelectric effect. Aluminum or copper is used as the material for the metal wiring (M1), but this is not limited to these. Methods for forming the metal wiring (M1) include a method of forming a metal sputtering film and etching the openings in a patterned resist, and a method of forming electrolytic plating wiring in the resist openings, but other known methods can also be used. A thickness of 0.1 to 5 μm allows electrical connection to be achieved, and the height of the entire laminate can be reduced.

[0024] A relief pattern of an organic insulating film (P1) is formed so as to cover the metal wiring (M1) formed on the piezoelectric substrate. A passivation film such as silicon nitride or silicon oxide may be formed on the metal wiring (M1) and the organic insulating film (P1) to a combined thickness of 0.1 to 5 μm, but it is preferable to form the metal wiring (M1) and the organic insulating film (P1) so that they are in contact with each other in terms of obtaining a high piezoelectric effect. The relief pattern of the organic insulating film (P1) is formed by patterning a photosensitive resin composition into a desired shape and curing it. A film thickness of the organic insulating film (P1) of 0.5 μm or more can ensure insulation properties, heat resistance, and reliability, while a film thickness of 4 μm or less can prevent disconnection of the metal wiring (M2) formed on the organic insulating film (P1) and reduce the height of the entire laminate.

[0025] A metal wiring (M2) is formed on a metal wiring (M1) and an organic insulating film (P1) formed on a piezoelectric substrate. The metal wiring (M2) is formed on the same piezoelectric substrate as the metal wiring (M1), and is insulated from the metal wiring (M1) by the organic insulating film (P1) at the points where it intersects with the metal wiring (M1). Like the metal wiring (M1), the metal wiring (M2) is made of aluminum, copper, or the like, and can be formed by forming a sputtered film and then forming plated wiring in the openings of a patterned resist, or by other known methods. A thickness of 0.1 to 5 μm allows for electrical connection and reduces the height of the entire stack.

[0026] The electrical conductivity of the test solution of the organic insulating film (P1) obtained by the method for measuring the amount of eluted ions is preferably 500 μS / cm or less. When the electrical conductivity of the test solution is 500 μS / cm or less, the diffusion of acid ions under high temperature and high humidity conditions is reduced, thereby making it possible to suppress corrosion of the metal wiring within the laminate. From the viewpoint of corrosion suppression, it is more preferable that the electrical conductivity of the test solution is 300 to 10 μS / cm. The electrical conductivity of the test solution can be measured using the ion chromatograph described in the method for measuring the amount of eluted ions.

[0027] The angle formed by the surface where the piezoelectric substrate and the metal wiring (M1) contact and the surface where the relief pattern of the organic insulating film (P1) and the metal wiring (M2) contact is preferably 20 to 60°. The angle formed by the surface where the piezoelectric substrate and the metal wiring (M1) contact and the surface where the relief pattern of the organic insulating film (P1) and the metal wiring (M2) contact is the taper angle of the relief pattern of the organic insulating film (P1) on the piezoelectric substrate, which corresponds to c in Figure 2. When this angle is 20° or more, a thickness of the organic insulating film (P1) sufficient as an insulating film can be obtained, and when it is 60° or less, breakage of the metal wiring (M2) formed on the organic insulating film (P1) can be prevented.

[0028] The organic insulating film (P1) contains a cured product obtained by curing a photosensitive resin composition containing an alkali-soluble resin (A) and a naphthoquinone diazide compound (E), and the content of the naphthoquinone diazide compound (E) is 5 to 25 parts by mass, more preferably 7 to 20 parts by mass, per 100 parts by mass of the alkali-soluble resin (A).

[0029] The naphthoquinone diazide compound (E) is likely to contain ions such as sulfate ions, which can cause wiring corrosion. By setting the content of the naphthoquinone diazide compound (E) within the above range, wiring corrosion can be suppressed.

[0030] In the present invention, alkali-soluble refers to a dissolution rate of 50 nm / min or more in an alkaline aqueous solution used as a developer. Specifically, this refers to a dissolution rate of 50 nm / min or more obtained by applying a solution of a resin dissolved in γ-butyrolactone to a silicon wafer, prebaking the resulting solution on a hot plate at 120°C for 4 minutes to form a prebaked film having a thickness of 10 μm±0.5 μm, immersing the prebaked film in an alkaline aqueous solution selected from a 2.38% by mass aqueous solution of tetramethylammonium hydroxide, a 1% by mass aqueous solution of potassium hydroxide, and a 1% by mass aqueous solution of sodium hydroxide at 23±1°C for 1 minute, and then rinsing the resulting film with pure water.

[0031] The alkali-soluble resin (A) preferably contains at least one resin selected from the group consisting of polyimide, polybenzoxazole, polyamide, precursors of any of these, epoxy resin, acrylic resin, polyhydroxystyrene, and copolymers thereof, and more preferably contains polyimide, polybenzoxazole, or polyamide. By containing these resins, a cured product with high reliability in insulation properties, heat resistance, and resistance to high-temperature storage and thermal shock can be obtained.

[0032] The alkali-soluble resin (A) preferably has at least one repeating unit selected from the repeating units shown below.

[0033]

[0034] X in the repeating unit １ and X ２ are acid dianhydride residues, X ３ represents a dicarboxylic acid residue, Y １ (OH) ｐ and Y ２ (OH) ｑ and Y ３ (OH) ｒ Each of p, q, and r represents an integer ranging from 0 to 4, and R ６ represents a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. By containing at least one of the repeating units represented by the above, a laminate with high heat resistance can be obtained. As the acid dianhydride and diamine, known substances can be used.

[0035] The alkali-soluble resin (A) may have its main chain terminals blocked with a known monoamine, acid anhydride, monocarboxylic acid, monoacid chloride compound, or monoactive ester compound.

[0036] The weight average molecular weight (Mw) of the alkali-soluble resin (A), as measured by gel permeation chromatography (GPC) in terms of polystyrene, using a developing solvent of 99.3% by mass of N-methyl-2-pyrrolidone, 0.2% by mass of lithium chloride, and 0.5% by mass of phosphoric acid, is 3,000 or more, which makes it easier to obtain a cured product by heat treatment. In order to obtain a cured product with high elongation and heat resistance, it is more preferably 10,000 or more, and even more preferably 20,000 or more. Furthermore, if it is 200,000 or less, it can be processed as a photosensitive resin, and in order to obtain good pattern processability, it is more preferably 100,000 or less, and even more preferably 70,000 or less.

[0037] The present invention also provides a laminate comprising: a piezoelectric substrate; a metal wiring (M1) having a thickness of 0.1 to 5 μm; a relief pattern of an organic insulating film (P1) having a film thickness of 0.5 to 4 μm; and a metal wiring (M2) having a thickness of 0.1 to 5 μm, formed in this order on the piezoelectric substrate; the organic insulating film (P1) contains a cured product obtained by curing a photosensitive resin composition containing an alkali-soluble resin (A), an oxime-based photopolymerization initiator (B), and a radically polymerizable compound (C); the content of the oxime-based photopolymerization initiator (B) is 1 to 20 parts by mass per 100 parts by mass of the alkali-soluble resin (A); the oxime-based photopolymerization initiator (B) contains a compound represented by formula (1) and a compound represented by formula (2), and the mass ratio of the compound represented by formula (1) to the compound represented by formula (2) is 1:1 to 20:1; The organic insulating film (P1) is a laminate in which the amount of ion elution is 2000 ppm or less when measured using the following method for measuring the amount of ion elution. (Method for measuring the amount of ion elution) The organic film is placed in pure water in an amount 10 times by mass, and hot water extraction is performed at 121°C for 20 hours. The supernatant of the extract is used as a test liquid. The test liquid and a standard solution of the target ions are introduced into an ion chromatograph, and the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions in the test liquid are determined using a calibration curve method. The value converted into the mass of eluted ions relative to the mass of the organic film is used as the amount of ion elution.

[0038]

[0039] (In formula (1), Ar represents an aryl group having 6 to 20 carbon atoms, and Z １represents an organic group represented by any one of formulas (3) to (6), and Z ２ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ３ represents an organic group represented by any one of formulas (3) to (6), and Z ４ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0040]

[0041] (In formulas (3) to (6), R １ and R ３ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; R ２ and R ５ represents a divalent organic group having 1 to 20 carbon atoms, R ４ represents a monovalent organic group having 1 to 20 carbon atoms.) When the organic insulating film (P1) is measured by a method for measuring the amount of eluted ions, such as formate ions, acetate ions, propionate ions, and sulfate ions, if the total amount of eluted ions is 2000 ppm or less, corrosion of the metal wiring of the laminate under high-temperature and high-humidity conditions can be suppressed; if the total amount is 1000 ppm or less, this is more preferable from the viewpoint of corrosion suppression, and if it is 500 to 0 ppm, this is even more preferable. The lower measurement limit of the ion elution amount measurement by an ion chromatograph is 0 ppm.

[0042] Acid ions eluted from organic insulating films under high-temperature and high-humidity conditions are thought to promote ionization of metal wiring and cause corrosion. Electronic components containing piezoelectric elements and metal wiring are significantly affected by changes in their characteristics due to metal corrosion, so it is necessary to reduce the amount of acid ions eluted from organic insulating films more than ever before. The elution amounts of formate ions, acetate ions, propionate ions, and sulfate ions are preferably 2000 ppm or less, more preferably 1000 ppm or less, and even more preferably 500 to 0 ppm.

[0043] The specific method for measuring the amount of ion elution is as follows. A predetermined amount of the organic film for which the amount of ion elution is measured is separated from the laminate and measured. When measuring the amount of ion elution from a resin composition for forming an organic film, a cured product obtained by heat-treating a liquid or sheet-like resin composition may be used. Methods for preparing the cured product include coating or laminating the resin composition on a silicon substrate, heating it in an oven, immersing it in an aqueous hydrofluoric acid solution, and peeling it off, or transferring a resin sheet formed on polyethylene terephthalate (PET) to a polytetrafluoroethylene (PTFE) film heated on a hot plate using a rubber roller, followed by heat treatment and peeling it off from the PTFE film. The prepared cured product is placed in a PTFE pressurized sealed container with a 10-fold amount of pure water by mass, and subjected to hot water extraction in a high-temperature oven at 121°C for 20 hours. The supernatant of the extract is filtered through a membrane filter to obtain the test solution. The mass of the cured product is preferably 0.1 to 5.0 g, with 0.3 to 3.0 g being preferred for ease of use and stable ion extraction. If necessary, the cured film may be freeze-pulverized using liquid nitrogen. The pure water used here is distilled and ion-exchanged, and is the same as that used for reagent preparation and microanalysis tests specified in JIS K 0557 (1998). The hot water pressure extraction method procedure was based on Yoshimi Hashimoto: Analytical Chemistry (Bunseki Kagaku), 49, 8 (2000), and the extraction temperature conditions were based on Ai Kitamura: Network Polymer, 33, 3 (2012).

[0044] This test solution is analyzed in accordance with the ion chromatography method of Japanese Industrial Standards JIS K 0127 (2013) General Principles of Ion Chromatography. Standard solutions of formate ions, acetate ions, propionate ions, and sulfate ions are introduced into an ion chromatography analyzer to prepare a calibration curve. Next, 25 μL of the test solution is introduced, and the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions are determined from the peak areas and the calibration curve. The values ​​converted into the eluted ion mass relative to the mass of the organic film are used as the eluted ion amount.

[0045] The piezoelectric substrate used in the present invention is mainly lithium tantalate, lithium niobate, gallium arsenide, or a substrate having a passivation film of silicon nitride or silicon oxide formed on the upper surface thereof, but is not limited to these.

[0046] Metal wiring (M1) is formed on the piezoelectric substrate. It is preferable that the metal wiring (M1) is directly on the piezoelectric substrate, as this provides a high piezoelectric effect. Aluminum or copper is used as the material for the metal wiring (M1), but this is not limited to these. Methods for forming the metal wiring (M1) include a method of forming a metal sputtering film and etching the openings in a patterned resist, and a method of forming electrolytic plating wiring in the resist openings, but other known methods can also be used. A thickness of 0.1 to 5 μm allows electrical connection to be achieved, and the height of the entire laminate can be reduced.

[0047] A relief pattern of an organic insulating film (P1) is formed so as to cover the metal wiring (M1) formed on the piezoelectric substrate. A passivation film such as silicon nitride or silicon oxide may be formed on the metal wiring (M1) and the organic insulating film (P1) to a combined thickness of 0.1 to 5 μm, but it is preferable to form the metal wiring (M1) and the organic insulating film (P1) so that they are in contact with each other in terms of obtaining a high piezoelectric effect. The relief pattern of the organic insulating film (P1) is formed by patterning a photosensitive resin composition into a desired shape and curing it. A film thickness of the organic insulating film (P1) of 0.5 μm or more can ensure insulation properties, heat resistance, and reliability, while a film thickness of 4 μm or less can prevent disconnection of the metal wiring (M2) formed on the organic insulating film (P1) and reduce the height of the entire laminate.

[0048] A metal wiring (M2) is formed on a metal wiring (M1) and an organic insulating film (P1) formed on a piezoelectric substrate. The metal wiring (M2) is formed on the same piezoelectric substrate as the metal wiring (M1), and is insulated from the metal wiring (M1) by the organic insulating film (P1) at the points where it intersects with the metal wiring (M1). Like the metal wiring (M1), the metal wiring (M2) is made of aluminum, copper, or the like, and can be formed by forming a sputtered film and then forming plated wiring in the openings of a patterned resist, or by other known methods. A thickness of 0.1 to 5 μm allows for electrical connection and reduces the height of the entire stack.

[0049] The electrical conductivity of the test solution of the organic insulating film (P1) obtained by the method for measuring the amount of eluted ions is preferably 500 μS / cm or less. When the electrical conductivity of the test solution is 500 μS / cm or less, the diffusion of acid ions under high temperature and high humidity conditions is reduced, thereby making it possible to suppress corrosion of the metal wiring within the laminate. From the viewpoint of corrosion suppression, it is more preferable that the electrical conductivity of the test solution is 300 to 10 μS / cm. The electrical conductivity of the test solution can be measured using the ion chromatograph described in the method for measuring the amount of eluted ions.

[0050] The angle formed by the surface where the piezoelectric substrate and the metal wiring (M1) contact and the surface where the relief pattern of the organic insulating film (P1) and the metal wiring (M2) contact is preferably 20 to 60°. The angle formed by the surface where the piezoelectric substrate and the metal wiring (M1) contact and the surface where the relief pattern of the organic insulating film (P1) and the metal wiring (M2) contact is the taper angle of the relief pattern of the organic insulating film (P1) on the piezoelectric substrate, and corresponds to c in FIG. 2 . When this angle is 20° or more, a thickness of the organic insulating film (P1) sufficient as an insulating film can be obtained, and when it is 60° or less, breakage of the metal wiring (M2) formed on the organic insulating film (P1) can be prevented. The organic insulating film (P1) contains a cured product obtained by curing a photosensitive resin composition containing an alkali-soluble resin (A), an oxime-based photopolymerization initiator (B), and a radically polymerizable compound (C).

[0051] When the photosensitive resin composition contains the oxime-based photopolymerization initiator (B), a resin composition with high sensitivity and high resolution can be obtained even in a thin film having a film thickness of 0.5 to 4 μm, and therefore a fine relief pattern of the organic insulating film (P1) can be formed.

[0052] The compound represented by formula (1) generates a small amount of low-molecular-weight acid ions upon decomposition, thereby suppressing metal wiring corrosion when cured. The compound represented by formula (2) generates a large amount of acetate ions, but is highly sensitive even in thin films with a film thickness of 0.5 to 4 μm, allowing photocuring of the resin composition with a small amount. By ensuring that the mass ratio of the compound represented by formula (1) to the compound represented by formula (2) is within the above range, a highly sensitive and high-resolution resin composition can be obtained while reducing the acid ion content, thereby producing a laminate having a fine relief pattern of the organic insulating film (P1) and reduced metal wiring corrosion. The above-mentioned effects can be achieved by providing 1 to 20 parts by mass of the oxime-based photopolymerization initiator (B) relative to 100 parts by mass of the alkali-soluble resin (A) and a mass ratio of the compound represented by formula (1) to the compound represented by formula (2) of 1:1 to 20:1. The mass ratio of the compound represented by formula (1) to the compound represented by formula (2) is more preferably 4:1 to 20:1.

[0053]

[0054] In formula (1), Ar represents an aryl group having 6 to 20 carbon atoms, and Z １ represents an organic group represented by any one of formulas (3) to (6), and Z ２ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ３ represents an organic group represented by any one of formulas (3) to (6), and Z ４ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0055]

[0056] In formulas (3) to (6), R １ and R ３ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; R ２ and R ５represents a divalent organic group having 1 to 20 carbon atoms, R ４ represents a monovalent organic group having 1 to 20 carbon atoms.

[0057] Examples of the compound represented by formula (1) include 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(o-benzoyloxime), 1,2-propanedione-1-[4-(phenylthio)phenyl]-2-(o-benzoyloxime)-3-cyclopentane, "IRGACURE" (registered trademark) OXE-01 (trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.), and PBG-305 (trade name, manufactured by Changzhou Strong Electronic New Materials Co., Ltd.).

[0058] Examples of the compound represented by formula (2) include 1-phenyl-1,2-butanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, bis(α-isonitrosopropiophenone oxime)isophthalic acid, "IRGACURE" (registered trademark) OXE-02 (trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.), and ADEKA ARCLES NCI-831 and NCI-930 (trade names, manufactured by ADEKA Corporation).

[0059] Furthermore, as other photopolymerization initiators, the following photopolymerization initiators can be used within a range that does not worsen wiring corrosion due to the generation of acid ions.

[0060] Other examples of the photopolymerization initiator include benzophenone, Michler's ketone, benzophenones such as 4,4-bis(diethylamino)benzophenone, benzylidenes such as 3,5-bis(diethylaminobenzylidene)-N-methyl-4-piperidone, coumarins such as 7-diethylamino-3-thenonylcoumarin, anthraquinones such as 2-t-butylanthraquinone, benzoins such as benzoin methyl ether, mercapto compounds such as ethylene glycol di(3-mercaptopropionate), glycines such as N-phenylglycine, and α-aminoalkylphenones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butane-1-2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

[0061] The content of the oxime photopolymerization initiator (B) is preferably 0.1 to 40 parts by mass per 100 parts by mass of the total amount of the alkali-soluble resin (A). An amount of 0.1 part by mass or more is preferred in that sufficient radicals are generated by light irradiation, improving sensitivity, while an amount of 40 parts by mass or less provides good processability and enables the production of a laminate with a total acid ion elution amount of 2000 ppm or less. To obtain high sensitivity while suppressing the acid ion content, the content of the oxime photopolymerization initiator (B) is more preferably 5 to 20 parts by mass per 100 parts by mass of the total amount of the alkali-soluble resin (A).

[0062] In the present invention, alkali-soluble refers to a dissolution rate of 50 nm / min or more in an alkaline aqueous solution used as a developer. Specifically, this refers to a dissolution rate of 50 nm / min or more obtained by applying a solution of a resin dissolved in γ-butyrolactone to a silicon wafer, prebaking the resulting solution on a hot plate at 120°C for 4 minutes to form a prebaked film having a thickness of 10 μm±0.5 μm, immersing the prebaked film in an alkaline aqueous solution selected from a 2.38% by mass aqueous solution of tetramethylammonium hydroxide, a 1% by mass aqueous solution of potassium hydroxide, and a 1% by mass aqueous solution of sodium hydroxide at 23±1°C for 1 minute, and then rinsing the resulting film with pure water.

[0063] The alkali-soluble resin (A) preferably contains at least one resin selected from the group consisting of polyimide, polybenzoxazole, polyamide, precursors of any of these, epoxy resin, acrylic resin, polyhydroxystyrene, and copolymers thereof, and more preferably contains polyimide, polybenzoxazole, or polyamide. By containing these resins, a cured product with high reliability in insulation properties, heat resistance, and resistance to high-temperature storage and thermal shock can be obtained.

[0064] The alkali-soluble resin (A) preferably has at least one repeating unit selected from the repeating units shown below.

[0065]

[0066] X in the repeating unit １ and X ２ are acid dianhydride residues, X ３ represents a dicarboxylic acid residue, Y １ (OH) ｐ and Y ２ (OH) ｑ and Y ３ (OH) ｒ Each of p, q, and r represents an integer ranging from 0 to 4, and R ６ represents a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. By containing at least one of the repeating units represented by the above, a laminate with high heat resistance can be obtained. As the acid dianhydride and diamine, known substances can be used.

[0067] The alkali-soluble resin (A) may have its main chain terminals blocked with a known monoamine, acid anhydride, monocarboxylic acid, monoacid chloride compound, or monoactive ester compound.

[0068] The weight average molecular weight (Mw) of the alkali-soluble resin (A), as measured by gel permeation chromatography (GPC) in terms of polystyrene, using a developing solvent of 99.3% by mass of N-methyl-2-pyrrolidone, 0.2% by mass of lithium chloride, and 0.5% by mass of phosphoric acid, is 3,000 or more, which makes it easier to obtain a cured product by heat treatment. In order to obtain a cured product with high elongation and heat resistance, it is more preferably 10,000 or more, and even more preferably 20,000 or more. Furthermore, if it is 200,000 or less, it can be processed as a photosensitive resin, and in order to obtain good pattern processability, it is more preferably 100,000 or less, and even more preferably 70,000 or less.

[0069] The radically polymerizable compound (C) refers to a compound having one or more radically polymerizable functional groups in the molecule.Specific examples of the radical polymerizable compound (C) include ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, neopentyl glycol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, dimethylol-tricyclodecane diacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, Thuritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, 1,3-diacryloyloxy-2-hydroxypropane, 1,3-dimethacryloyloxy-2-hydroxypropane, N,N-methylenebisacrylamide, BP-6EM, DCP-A (trade name, Kyoeisha Chemical Co., Ltd.) Examples of the ethylene oxide-modified bisphenol A diacrylate include ethylene oxide-modified bisphenol A dimethacrylate, ethylene oxide-modified isocyanuric acid diacrylate, and ethylene oxide-modified triacrylates such as ARONIX (registered trademark) M-315 (trade name, manufactured by Toagosei Co., Ltd.).Among these, it is preferred that the radical polymerizable compound (C) contains a compound represented by formula (7) and a compound represented by formula (8), and the mass ratio of the compound represented by formula (7) to the compound represented by formula (8) is 1:9 to 5:5.

[0070]

[0071] In formula (7) and formula (8), R ７ ~R １７ Each of the radical polymerizable compound (C) independently represents a hydrogen atom or a methyl group. When the radical polymerizable compound (C) contains the compound represented by formula (7) and the compound represented by formula (8) in the above-mentioned mass ratio, it is possible to obtain a photosensitive resin composition that is highly sensitive even in a thin film having a film thickness of 0.5 to 4 μm, while reducing the angle formed between the relief pattern of the organic insulating film (P1) and the metal wiring (M2) in the laminate.

[0072] The total mass of the compound represented by formula (7) and the compound represented by formula (8) is preferably 10 to 50 parts by mass relative to 100 parts by mass of the radical polymerizable compound (C). When the total mass is within this range, a highly sensitive photosensitive resin composition and a laminate having high chemical resistance and high heat resistance can be obtained.

[0073] The content of the radical polymerizable compound (C) is preferably 5 to 200 parts by mass per 100 parts by mass of the alkali-soluble resin (A), and more preferably 5 to 150 parts by mass from the viewpoint of compatibility. By setting the content of the radical polymerizable compound (C) to 5 parts by mass or more per 100 parts by mass of the alkali-soluble resin (A), it is possible to prevent elution of exposed areas during development and obtain a resin composition with a high film retention rate after development. By setting the content of the radical polymerizable compound (C) to 200 parts by mass or less per 100 parts by mass of the alkali-soluble resin (A), it is possible to suppress whitening of the film during film formation.

[0074] The thermally crosslinkable compound (D) refers to a compound other than the radically polymerizable compound (C) that has a crosslinkable group capable of bonding with a resin and molecules of the same type. A compound having both a radically polymerizable group and a thermally crosslinkable group is referred to as the radically polymerizable compound (C). Examples of the thermally crosslinkable compound (D) include a polyfunctional epoxy group-containing compound (D-1) and a polyfunctional alkoxymethyl group-containing compound (D-2). By including the thermally crosslinkable compound (D), a crosslinked structure is formed during heat treatment through a condensation reaction with the resin and molecules of the same type, resulting in a cured product with high chemical resistance. The polyfunctional epoxy group-containing compound (D-1) can achieve chemical resistance while reducing acid ions, but tends to reduce alkali solubility. On the other hand, the polyfunctional alkoxymethyl group-containing compound (D-2) can achieve high chemical resistance, but is prone to containing formate ions and other impurities. For this reason, it is preferable to include these compounds in appropriate amounts.

[0075] The content of the thermally crosslinkable compound (D) is preferably 1 to 50 parts by mass relative to 100 parts by mass of the alkali-soluble resin (A). Furthermore, the thermally crosslinkable compound (D) preferably contains a polyfunctional epoxy group-containing compound (D-1) and a polyfunctional alkoxymethyl group-containing compound (D-2), and the content of the polyfunctional epoxy group-containing compound (D-1) is preferably 5 to 30 parts by mass and the content of the polyfunctional alkoxymethyl group-containing compound (D-2) is preferably 1 to 10 parts by mass relative to 100 parts by mass of the alkali-soluble resin (A).

[0076] By setting the contents of the polyfunctional epoxy group-containing compound (D-1) and the polyfunctional alkoxymethyl group-containing compound (D-2) within this range, a laminate having high chemical resistance can be obtained while suppressing the acid ion content.

[0077] Examples of the polyfunctional epoxy group-containing compound (D-1) include, but are not limited to, bisphenol A type epoxy resins, bisphenol F type epoxy resins, alkylene glycol type epoxy resins such as propylene glycol diglycidyl ether, polyalkylene glycol type epoxy resins such as polypropylene glycol diglycidyl ether, and epoxy group-containing silicones such as polymethyl(glycidyloxypropyl)siloxane.

[0078] Specifically, TECHMORE VG3101L (trade name, manufactured by Printec Co., Ltd.), "TEPIC" (registered trademark) VL, "TEPIC" (registered trademark) UC (trade name, manufactured by Nissan Chemical Industries, Ltd.), "Epicron" (registered trademark) 850-S, "Epicron" (registered trademark) HP-4032, "Epicron" (registered trademark) HP-7200, "Epicron" (registered trademark) HP-820, "Epicron" (registered trademark) HP-4700, "Epicron" (registered trademark) EXA-4710, "Epicron" (registered trademark) HP-4770, "Epicron" (registered trademark) EXA-859CRP, Examples of such resins include "Epicron" (registered trademark) EXA-1514, "Epicron" (registered trademark) EXA-4880, "Epicron" (registered trademark) EXA-4850-150, "Epicron" (registered trademark) EXA-4850-1000, "Epicron" (registered trademark) EXA-4816, "Epicron" (registered trademark) EXA-4822 (all trade names, manufactured by Dainippon Ink and Chemicals, Inc.), Rikaresin (registered trademark) BEO-60E (trade name, manufactured by New Japan Chemical Co., Ltd.), EP-4003S, EP-4000S (all trade names, manufactured by ADEKA Corporation).

[0079] Specific examples of the polyfunctional alkoxymethyl group-containing compound (D-2) having two functional groups include DM-BI25X-F, 46DMOC, 46DMOCIPP, and 46DMOEP (all trade names, manufactured by Asahi Organic Chemicals Co., Ltd.), DMLMBPC, DML-MBOC, DML-OCHP, DML-PC, DML-PCHP, DML-PTBP, DML-34X, DML-EP, DML-POP, DML-OC, dimethylol-Bis-C, dimethylol-BisOC-P, and DML- ML-BisOC-Z, DML-BisOCHP-Z, DML-PFP, DML-PSBP, DML-MB25, DML-MTrisPC, DML-Bis25X-34XL, DML-Bis25X-PCHP (all trade names, manufactured by Honshu Chemical Industry Co., Ltd.), "Nicalac" (registered trademark) MX-290 (trade name, manufactured by Sanwa Chemical Co., Ltd.), B-a type benzoxazine, B-m type benzoxazine (all trade names, manufactured by Shikoku Chemical Industry Co., Ltd.), 2,6-dimethoxymethyl-4- t-butylphenol, 2,6-dimethoxymethyl-p-cresol, 2,6-diacetoxymethyl-p-cresol, etc.; those having three of these compounds include TriML-P, TriML-35XL, and TriML-TrisCR-HAP (all trade names, manufactured by Honshu Chemical Industry Co., Ltd.); those having four of these compounds include TM-BIP-A (trade name, manufactured by Asahi Organic Materials Co., Ltd.), TML-BP, TML-HQ, TML-pp-BPF, TML-BPA, and TMOM-BP (all trade names, manufactured by Honshu Chemical Industry Co., Ltd.). Examples of those having six include HML-TPPHBA, HML-TPPHAP, HMOM-TPPHBA, HMOM-TPPHAP (all trade names, manufactured by Honshu Chemical Industry Co., Ltd.), "NIKALAC" (registered trademark) MW-390, and "NIKALAC" (registered trademark) MW-100LM (all trade names, manufactured by Sanwa Chemical Co., Ltd.).

[0080] In addition, the photosensitive resin composition may contain a known surfactant or adhesion improver, which can improve the wettability and adhesion to the substrate.

[0081] The photosensitive resin composition also contains a solvent. Examples of the solvent include aprotic polar solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, N,N-dimethylisobutyric acid amide, N,N-dimethylpropanamide, 3-methoxy-N,N-dimethylpropanamide, and N,N-dimethyllactamide, as well as aromatic hydrocarbons. The photosensitive resin composition may contain two or more of these solvents.

[0082] The solids concentration and viscosity of the photosensitive resin composition are adjusted by the content of the solvent, and the solids concentration of the photosensitive resin composition for forming the organic insulating film (P1) is preferably 30 to 50 mass %, and the viscosity is preferably 50 to 300 mPa·s. Here, the solids concentration refers to the mass % of the total amount of all compounds other than the solvent, relative to 100 mass % of the photosensitive resin composition. Therefore, the content of the solvent is preferably 50 to 70 mass % relative to 100 mass % of the photosensitive resin composition. Within this range, a relief pattern of the organic insulating film (P1) having a film thickness of 0.5 to 4 μm can be formed with a uniform film thickness.

[0083] As the photosensitive resin composition for obtaining the organic insulating film (P1), in addition to the above-mentioned photosensitive resin composition, a photosensitive resin composition using a photoacid generator as a cationic polymerization initiator and an epoxy compound or an oxetane compound as a cationic polymerizable compound can also be used, as long as the amount of ion elution from the organic film is not increased.

[0084] The method for producing the laminate of the present invention includes the steps of: (1) forming metal wiring (M1) on a piezoelectric substrate; (2) applying a photosensitive resin composition onto the piezoelectric substrate and the metal wiring (M1), heating and drying at 80 to 130°C to form a photosensitive resin film on the substrate; and (3) applying a photosensitive resin composition to the piezoelectric substrate and the metal wiring (M1) through a mask at 150 to 2000 mJ / cm. ２the step (3) of exposing the photosensitive resin film to an exposure amount of 1000 ppm; the step (4) of heating the exposed photosensitive resin film to 80 to 130°C; the step (5) of developing the photosensitive resin film by removing the unexposed portions of the photosensitive resin film with an alkaline aqueous solution; the step (6) of heating the developed photosensitive resin film at 200 to 280°C to form a relief pattern of the organic insulating film (P1); and the step (7) of forming metal wiring (M2) on the piezoelectric substrate and the organic insulating film (P1), in this order.

[0085] The method for manufacturing a laminate of the present invention will be described in detail. In step (1), metal wiring (M1) is formed on a piezoelectric substrate. One example of a method for forming the metal wiring (M1) is to form a sputtered film of titanium or the like on the piezoelectric substrate as a seed layer, and then form a sputtered film of aluminum or copper on top of that. The metal in the openings is removed using a photosensitive resist, or aluminum or copper is plated and grown in the openings in the resist to form metal wiring, and then the resist is removed with a stripping solution and the seed layer is removed with an etching solution.

[0086] Next, in step (2), the photosensitive resin composition is applied onto the piezoelectric substrate and the metal wiring (M1) by spin coating or the like, and then heated to 80 to 130°C using a hot plate and dried to form a photosensitive resin film on the substrate. Other application methods include spray application, roll coating, screen printing, blade coater, die coater, calendar coater, meniscus coater, bar coater, roll coater, comma roll coater, gravure coater, screen coater, and slit die coater.

[0087] Next, in step (3), the photosensitive resin film on the metal wiring (M1) is exposed to light through a mask using an aligner or stepper device. The actinic rays used for exposure are preferably i-line (365 nm), h-line (405 nm), or g-line (436 nm) from a mercury lamp. In order to sufficiently cure the photosensitive resin film while suppressing temperature increases in the photosensitive resin film and the substrate, a dose of 150 to 2000 mJ / cm is used. ２ The exposure is performed at an exposure amount of .

[0088] Next, in step (4), the exposed photosensitive resin film is heated to 80 to 130° C. This step can promote the curing reaction of the exposed portion of the photosensitive resin film. In the case of a positive photosensitive resin composition containing a naphthoquinone diazide compound (E) or the like, step (4) does not need to be performed.

[0089] Next, in step (5), the unexposed areas of the photosensitive resin film are removed and developed with an alkaline aqueous solution. Preferred developers are aqueous solutions of alkaline compounds such as tetramethylammonium hydroxide, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, and hexamethylenediamine.

[0090] Next, in step (6), the developed photosensitive resin film is heat-treated at 200 to 280°C to form a relief pattern of the organic insulating film (P1). The heat treatment is preferably performed using an oven under a nitrogen atmosphere. One example of the heat treatment method is to increase the temperature from 50°C at a rate of 4°C / min, heat-treat at 140°C for 30 minutes, and then further increase the temperature at a rate of 4°C / min and heat-treat at 200°C for 60 minutes. The heat treatment temperature is preferably 200 to 350°C, more preferably 200 to 280°C, in terms of reducing damage to the substrate and obtaining good organic film properties.

[0091] Finally, in step (7), metal wiring (M2) is formed on the piezoelectric substrate and the organic insulating film (P1). The metal wiring (M1) on the piezoelectric substrate and the metal wiring (M2) cross each other with the relief pattern of the organic insulating film (P1) in between, allowing for free wiring design without short circuits. The metal wiring (M2) is formed in the same manner as in step (1).

[0092] In the step (5), the difference in film thickness of the exposed portion of the photosensitive resin film between the 80-second development and the 140-second development is preferably 0.20 μm or less. By having the difference in film thickness of the exposed portion of the photosensitive resin film between the 80-second development and the 140-second development be 0.20 μm or less, a laminate having a uniform film thickness and excellent chemical resistance and insulating properties can be obtained.

[0093] The method for producing a laminate of the present invention may include, between steps (5) and (6), a step (5-1) of heating the developed photosensitive resin film from a temperature of 100°C or less to 150 to 200°C at a heating rate of 10°C / min or more. When heated to 150 to 200°C, the end of the relief pattern of the photosensitive resin film softens, thereby reducing the angle between the surface where the piezoelectric substrate and the metal wiring (M1) contact and the surface where the relief pattern of the organic insulating film (P1) contacts the metal wiring (M2). In order to increase the heating rate, the heating method preferably involves placing the photosensitive resin film at 100°C or less on a hot plate heated to 150 to 200°C. One example is a method in which the developed photosensitive resin film is placed on a hot plate at 170°C, heated for 5 minutes, and then cooled to room temperature.

[0094] In addition, between the steps (5) and (6), the developed photosensitive resin film is exposed to 1000 to 3000 mJ / cm ２ The oxime-based photopolymerization initiator (B) remaining in the cured film without being decomposed during the exposure in step (3) can serve as a source of acid ions under high temperature and high humidity conditions. By including step (5-2), the oxime-based photopolymerization initiator (B) that was not decomposed during the exposure in step (3) can be decomposed, thereby reducing the amount of acid ions eluted from the laminate. In order to suppress a temperature rise of the substrate, a light exposure of 1000 to 2000 mJ / cm is used. ２ is preferred.

[0095] When both the step (5-1) and the step (5-2) are performed, it does not matter which of the step (5-1) and the step (5-2) is performed first.

[0096] The laminate of the present invention can be used as a substrate for a hollow structure. The hollow structure of the present invention comprises the laminate, a hollow structure support material (P2), and a hollow structure roofing material (P3). The hollow structure support material (P2) and the hollow structure roofing material (P3) are preferably organic films containing at least one alkali-soluble resin selected from the group consisting of polyimide, polybenzoxazole, polyamide, precursors of any of these, and copolymers thereof. By containing these resins, a hollow structure with high heat resistance can be formed.

[0097] In the hollow structure, when the organic insulating film (P1) having a film thickness of 0.5 to 4 μm, the hollow structure supporting material (P2), and the hollow structure roofing material (P3) are each evaluated individually using the ion elution amount measurement method, it is preferable that the total amount of ion elution of the organic insulating film (P1) having a film thickness of 0.5 to 4 μm, the hollow structure supporting material (P2), and the hollow structure roofing material (P3) is 2000 ppm or less.

[0098] When the hollow structure is evaluated using the ion elution amount measurement method, the organic film refers to the organic insulating film (P1) having a film thickness of 0.5 to 4 μm, the hollow structure support material (P2), or the hollow structure roofing material (P3). When the total ion elution amount of the organic insulating film (P1), the hollow structure support material (P2), and the hollow structure roofing material (P3) is 2000 ppm or less, corrosion of the metal wiring inside the hollow structure can be suppressed. The electronic component of the present invention has the hollow structure. By having the hollow structure, corrosion can be suppressed and electronic components with little deterioration can be obtained. Examples of electronic components having hollow structures include MEMS.

[0099] The hollow structure support material (P2) and the hollow structure roof material (P3) can be formed by curing a photosensitive resin composition, similar to the organic insulating film (P1). The film thickness of the hollow structure support material (P2) is preferably 5 to 20 μm, and the photosensitive resin composition for obtaining the hollow structure support material (P2) is preferably in liquid or sheet form. When the photosensitive resin composition for obtaining the hollow structure support material (P2) is used in liquid form, the solids concentration is preferably 50 to 60 mass% and the viscosity is preferably 500 to 3000 mPa·s. By using the composition in this range, a hollow structure support material (P2) with a uniform thickness of 5 to 20 μm can be formed.

[0100] The thickness of the hollow structure roofing material (P3) is preferably 10 to 50 μm, and the photosensitive resin composition for obtaining the hollow structure roofing material (P3) is preferably in the form of a sheet. The photosensitive sheet is prepared by the method described below.

[0101] Examples of methods for applying the photosensitive resin composition to obtain the hollow structure support material (P2) include spin coating using a spin coater, spray coating, roll coating, screen printing, blade coater, die coater, calendar coater, meniscus coater, bar coater, roll coater, comma roll coater, gravure coater, screen coater, and slit die coater. The coated substrate is then dried to obtain a photosensitive resin film. Drying is preferably carried out using an oven, a hot plate, infrared rays, or the like at a temperature in the range of 50°C to 150°C for 1 minute to several hours.

[0102] When the photosensitive resin composition for obtaining the hollow structure support material (P2) and the hollow structure roofing material (P3) is used as a photosensitive sheet, the photosensitive resin composition is applied to a substrate and then dried to remove the organic solvent, thereby producing a photosensitive sheet.

[0103] A PET film or the like can be used as the substrate to which the photosensitive resin composition is applied. When the photosensitive sheet is used by laminating it to a substrate such as a silicon wafer, if it is necessary to peel off and remove the PET film serving as the substrate, it is preferable to use a PET film whose surface is coated with a release agent such as a silicone resin, because this allows the photosensitive sheet and the PET film to be easily peeled off.

[0104] The photosensitive resin composition can be applied to a PET film using screen printing, a spray coater, a bar coater, a blade coater, a die coater, a spin coater, or the like. Methods for removing the organic solvent include heating using an oven or hot plate, vacuum drying, and heating using electromagnetic waves such as infrared rays or microwaves. If the organic solvent is not sufficiently removed, the cured product obtained in the subsequent curing process may be uncured or may have poor thermal properties. The thickness of the PET film is not particularly limited, but from the viewpoint of workability, a thickness of 30 to 80 μm is preferable. A cover film may be attached to the surface of the photosensitive sheet to protect it from dust in the atmosphere. If the solids concentration of the photosensitive resin composition is low and a photosensitive sheet of the desired thickness cannot be produced, two or more photosensitive sheets may be attached together after the organic solvent has been removed.

[0105] When the photosensitive sheet produced by the above method is laminated onto another substrate, a laminating device such as a roll laminator or vacuum laminator may be used, or the sheet may be manually laminated onto a substrate heated on a hot plate using a rubber roller. After lamination onto the substrate, the sheet is sufficiently cooled and then the PET film is peeled off. The photosensitive resin film obtained by applying the liquid photosensitive resin composition to a substrate and drying it, or the photosensitive sheet laminated onto the substrate, is cured by steps (3) to (6) similar to those described in the method for forming the laminate.

[0106] The laminate and hollow structure of the present invention will be described with reference to the drawings. FIG. 1 shows a view of the laminate of the present invention from the top of a piezoelectric substrate 1. The metal wiring (M2) 4 is a wiring formed on the same piezoelectric substrate 1 as the metal wiring (M1) 2, and is insulated from the metal wiring (M1) 2 by an organic insulating film (P1) 3 at the intersection with the metal wiring (M1) 2. FIG. 2 shows a cross section perpendicular to the piezoelectric substrate along the line connecting a and b. The angle formed by the surface where the piezoelectric substrate and the metal wiring (M1) meet and the surface where the relief pattern of the organic insulating film (P1) meets the metal wiring (M2) is the taper angle of the relief pattern of the organic insulating film (P1) on the piezoelectric substrate, and is the angle indicated by c in FIG. 2. FIG. 3 shows a hollow structure formed by a hollow structure support material 5 and a hollow structure roofing material 6, having the laminate of the present invention at the location indicated by 7.

[0107] The present invention will be described below with reference to examples, but the present invention is not limited to these examples. First, the evaluation methods used in each example and comparative example will be described.

[0108] (1) Evaluation of Ion Leaching Amount and Electrical Conductivity of Organic Insulating Film (P1) First, a cured organic insulating film (P1) was prepared by the following method. A photosensitive varnish was applied to a 38 μm-thick PET film using a comma roll coater, and dried at 80° C. for 8 minutes. After that, a 10 μm-thick PP film was laminated as a protective film to obtain a photosensitive sheet. The thickness of the photosensitive sheet was adjusted to 30 μm.

[0109] This photosensitive sheet was laminated using a rubber roller to a PTFE film heated on a hot plate at 120°C, and then the PET film was peeled off. The photosensitive sheet on the PTFE film was heated to 250°C at a heating rate of 3.5°C per minute in an inert oven under a nitrogen stream with an oxygen concentration of 20 ppm or less, and then heat-treated at 250°C for 1 hour to obtain a cured product.

[0110] The cured product was then peeled off from the PTFE film and freeze-pulverized using liquid nitrogen. 2.0 g of the resulting mixture was placed in a sealed PTFE pressure-resistant decomposition vessel together with 20 g of pure water, and stored for 20 hours at 121°C, 100% humidity, and 2 atmospheres using a highly accelerated life tester (saturated pressure cooker tester). The supernatant of the extract was filtered through a membrane filter with a 0.45 μm pore size to obtain the test solution.

[0111] Next, in accordance with the Japanese Industrial Standards JIS K 0127 (2013) Ion Chromatography General Principles Ion Chromatography method, standard solutions of formate ions, acetate ions, propionate ions, and sulfate ions were introduced into an ion chromatograph analyzer (Dionex ICS-3000), and a calibration curve was created. 25 μL of test solution was introduced, and the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions in the test solution were determined from the resulting peaks and the calibration curve, and the total amount of eluted ion mass was calculated. The amount of ion elution calculated as the eluted ion mass relative to the mass of the organic film was rated as A for 500 ppm or less, B for more than 500 ppm to 2000 ppm, and C for more than 2000 ppm. Furthermore, the conductivity of the test solution measured with the same ion chromatograph was rated as A if it was 300 μS / cm or less, B if it was more than 300 μS / cm and 500 μS / cm or less, and C if it was more than 500 μS / cm.

[0112] (2) Evaluation of heat resistance of organic insulating film (P1) 15 mg of the cured product peeled off from the PTFE film in (1) was weighed out and heated from 25°C to 400°C at a heating rate of 10°C / min using a thermogravimetric analyzer (TGA-50 manufactured by Shimadzu Corporation) to evaluate heat resistance. When the temperature at which the weight decreased by 5% from the weight before heating was 350°C or higher, it was rated as A; when the temperature was 300°C or higher but lower than 350°C, it was rated as B; and when it was lower than 300°C, it was rated as C.

[0113] (3) Evaluation of Laminate (3-1) Preparation of Laminate A 1 μm thick copper sputtered film was formed on a lithium tantalate substrate by electroplating using a resist patterned by sputtering a 50 nm thick titanium substrate. A 30 μm wide Cu wiring pattern with 100 μm intervals was formed as metal wiring (M1) on the sputtered film by etching via the resist pattern.

[0114] A photosensitive varnish with a viscosity of 50 to 300 mPa s was applied onto the lithium tantalate substrate and metal wiring (M1) using a spin coater, and baked at 120°C for 3 minutes using a hot plate to obtain a photosensitive resin film. Next, a mask with a 90-µm square pattern spaced 40 µm apart was used, and a ghi aligner was used to apply 300 mJ / cm ２ The film was exposed to light at 250°C for 1 hour. After exposure, the film was developed with a 2.38% by mass aqueous solution of tetramethylammonium (TMAH) for 100 seconds and then rinsed with pure water to form a 90-µm square pattern with a film thickness of 2.0 to 4.0 µm on each side on the metal wiring (M1). Using an inert oven, the film was heated to 250°C at a rate of 3.5°C per minute under a nitrogen stream with an oxygen concentration of 20 ppm or less, and then heat-treated at 250°C for 1 hour to form a relief pattern of the organic insulating film (P1).

[0115] A lithium tantalate substrate, a metal wiring (M1), and a relief pattern of an organic insulating film (P1) were sputtered with 50 nm of titanium by a sputtering method, and a Cu wiring pattern with a thickness of 2 μm, a width of 30 μm at 100 μm intervals, and a width of 30 μm was formed as a metal wiring (M2) by electroplating using a patterned resist so as to intersect with the metal wiring (M1) through the relief pattern of the organic insulating film (P1). As a result, a laminate was obtained on the piezoelectric substrate having a wiring pattern in which the metal wiring (M1) and the metal wiring (M2) intersected in a lattice shape through the relief pattern of the organic insulating film (P1).

[0116] (3-2) Evaluation of Taper Angle of Organic Insulating Film (P1) The laminate prepared in (3-1) was cut perpendicular to the lithium tantalate substrate using a dicing device, and the angle formed by the surface where the lithium tantalate substrate and the metal wiring (M1) contact and the surface where the relief pattern of the organic insulating film (P1) and the metal wiring (M2) contact was observed using a scanning electron microscope (S-4800 manufactured by Hitachi, Ltd.) and evaluated as the taper angle. An angle of 20 to 50° was rated as A, an angle of more than 50° but not more than 60° as B, and an angle of less than 20° or more than 60° as C.

[0117] (3-3) Evaluation of the variation in the thickness loss of the organic insulating film (P1) after development In (3-1), the difference in thickness ΔT between the exposed area before and after development when the development time of the photosensitive resin film is 80 seconds ８０ (film thickness before development - film thickness after development) and the film thickness difference ΔT between the exposed area before and after development for 140 seconds １４０ The difference between the film thickness before development and the film thickness after development (ΔT １４０ -ΔT ８０ ) was defined as the fluctuation in the film loss due to development, and the absolute value of the fluctuation in the film loss due to development was rated as A when it was 0.2 μm or less, B when it was more than 0.2 μm and 0.6 μm or less, and C when it was more than 0.6 μm.

[0118] (3-4) Chemical Resistance of Organic Insulating Film (P1) The laminate obtained in (3-1) was immersed in N-methylpyrrolidone at 70° C. for 30 minutes. (Thickness of organic insulating film (P1) after immersion) - (Thickness of organic insulating film (P1) before immersion) was measured, and a thickness of 0.2 μm or less was rated A, a thickness of more than 0.2 μm and 0.5 μm or less was rated B, and a thickness of more than 0.5 μm was rated C.

[0119] (4) Evaluation of hollow structures (4-1) Measurement of ion elution amount of hollow structure support material (P2) and hollow structure roofing material (P3) First, a cured product of hollow structure support material (P2) was prepared by the following method. Photosensitive varnish was applied to a 38 μm thick PET film using a comma roll coater, and dried at 80 ° C for 8 minutes. After that, a 10 μm thick PP film was laminated as a protective film to obtain a photosensitive sheet. The thickness of the photosensitive sheet was adjusted to 30 μm.

[0120] This photosensitive sheet was laminated to a PTFE film heated on a hot plate at 120 ° C. using a rubber roller, and then the PET film was peeled off. The photosensitive sheet on the PTFE film was heated to 200 ° C. at a heating rate of 3.5 ° C. per minute under a nitrogen stream with an oxygen concentration of 20 ppm or less using an inert oven, and then heated at 200 ° C. for 1 hour to obtain a cured product. The cured product of the hollow structure roofing material (P3) was prepared in the same manner as the cured product of the hollow structure support material (P2) using a photosensitive sheet. The amount of ion elution was measured for each of the cured products of the hollow structure support material (P2) and the hollow structure roofing material (P3) in the same manner as in (1).

[0121] (4-2) Formation of hollow structure A photosensitive varnish was applied to the laminate obtained in (3-1) using a spin coater, and baked on a hot plate at 120°C for 3 minutes to obtain a pre-baked film. Next, a mask having a 30 μm wide grid pattern with 500 μm intervals was used, and a ghi aligner was used to apply 500 mJ / cm ２ After exposure, the film was developed for 150 seconds with a 2.38% by mass aqueous solution of tetramethylammonium (TMAH), and then rinsed with pure water to obtain a developed film having a lattice-like pattern with a thickness of 10 μm, a width of 30 μm, and intervals of 500 μm. The developed film was heated to 200°C at a heating rate of 3.5°C per minute under a nitrogen stream with an oxygen concentration of 20 ppm or less, and then heat-treated at 200°C for 1 hour to form a hollow structure support material (P2). Next, the photosensitive sheet was laminated using a laminating device (manufactured by Takatori Corporation, VTM-200M) under the following conditions: stage temperature 80°C, roll temperature 80°C, vacuum level 150 Pa, application speed 5 mm / sec, and application pressure 0.2 MPa. 500 mJ / cm using a ghi aligner. ２ After exposure, the film was heated to 200°C at a rate of 3.5°C per minute under a nitrogen stream with an oxygen concentration of 20 ppm or less using an inert oven, and then heat-treated at 200°C for 1 hour to form a hollow structure roofing material (P3).

[0122] (4-3) Evaluation of Corrosion Resistance of Hollow Structures The hollow structures prepared in (4-2) were stored for 100 hours under conditions of 121°C, 100% humidity, and 2 atmospheres using a highly accelerated life tester, and then the hollow portions were cut using a dicing machine. The copper-plated cross section of the substrate was polished with a cross-section polisher (IB-09010CP, manufactured by JEOL), and the boundary between the metal wiring (M1) and the organic insulating film (P1) was observed using a scanning electron microscope (S-4800, manufactured by Hitachi, Ltd.). The thickness of the copper oxide formed on the metal wiring (M1) was measured, and a value of A was used for those that were 50 nm or less, B for those that were greater than 50 nm but less than 150 nm, and C for those that were 150 nm or more.

[0123] The names and structures of the abbreviations of the compounds used in the following examples and comparative examples are as follows: (Acid dianhydride) ODPA: 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (Diamine) BAHF: 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane SiDA: 1,1,3,3-tetramethyl-1,3-bis(3-aminopropyl)disiloxane (End-capping agent) MAP: 3-aminophenol (Solvent) NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone (Oxime photopolymerization initiator) PBG-305 (trade name, manufactured by Changzhou Strong Electronic New Materials Co., Ltd., compound of formula (1)) NCI-831 (Adeka Arcles trade name, manufactured by ADEKA Corporation, compound of formula (2)) OXE-02 ("IRGACURE" trade name, manufactured by Chiba Specialty Chemicals Co., Ltd., compound of formula (2)) (Radical polymerizable compound) M-315 ("Aronix" trade name, manufactured by Toagosei Co., Ltd.) DPHA: dipentaerythritol hexaacrylate (compound of formula (3)) DPPA: dipentaerythritol pentaacrylate (compound of formula (4)) (Thermal crosslinkable compound) Polyfunctional epoxy group-containing compound (D-1): VG-3101L ("TECHMORE" VG3101L trade name, manufactured by Printec Co., Ltd.) TEPIC-VL (trade name, manufactured by Nissan Chemical Industries, Ltd.) 157s70 ("jER" trade name, manufactured by Mitsubishi Chemical Corporation) Polyfunctional alkoxymethyl group-containing compound (D-2): HMOM-TPHAP (trade name, manufactured by Honshu Chemical Industry Co., Ltd.) MW-100LM (NIKALAC MW-100LM trade name, manufactured by Sanwa Chemical Co., Ltd.) (Photoacid generator (cationic polymerization initiator)) CPI-310B (trade name, manufactured by San-Apro Co., Ltd.) (Naphthoquinone diazide compounds) Naphthoquinone diazide compound A Naphthoquinone diazide compound B

[0124]

[0125]

[0126]

[0127]

[0128]

[0129] Synthesis Example 1: Alkali-Soluble Resin (A) Synthesis of Resin A Under a dry nitrogen stream, 15.51 g (0.050 mol) of ODPA and 1.09 g (0.010 mol) of MAP were dissolved in 100 g of NMP. 15.57 g (0.043 mol) of BAHF and 0.62 g (0.003 mol) of SiDA were added together with 20 g of NMP, and the mixture was reacted at 60°C for 1 hour, followed by stirring at 200°C for 4 hours. After stirring, the solution was poured into 2 L of water to obtain a white precipitate. The precipitate was collected by filtration, washed three times with water, and then dried in a vacuum dryer at 50°C for 72 hours to obtain a powder of polyimide resin A.

[0130] Synthesis Example 2: Synthesis of Alkali-Soluble Resin (A) and Resin B: A total of 20 g of p-t-butoxystyrene and styrene in a molar ratio of 3:1 was added to a mixed solution containing 500 ml of tetrahydrofuran and 0.01 mol of sec-butyllithium as an initiator, and polymerization was carried out with stirring for 3 hours. The polymerization termination reaction was carried out by adding 0.1 mol of methanol to the reaction solution. Next, to purify the polymer, the reaction mixture was poured into methanol, and the precipitated polymer was dried, yielding a white polymer. The polymer was further dissolved in 400 ml of acetone, and a small amount of concentrated hydrochloric acid was added at 60°C. The mixture was stirred for 7 hours, then poured into water to precipitate the polymer. The p-t-butoxystyrene was deprotected to convert it to hydroxystyrene, and the resulting mixture was washed and dried to obtain polyhydroxystyrene resin B, a copolymer of p-hydroxystyrene and styrene.

[0131] Synthesis Example 3 Synthesis of Naphthoquinone Diazide Compound A Under a dry nitrogen stream, 21.23 g (0.05 mol) of TrisP-PA (trade name, manufactured by Honshu Chemical Industry Co., Ltd.) and 37.62 g (0.14 mol) of 5-naphthoquinone diazide sulfonyl chloride were dissolved in 450 g of 1,4-dioxane and the solution was allowed to reach room temperature. To this solution, 15.58 g (0.154 mol) of triethylamine mixed with 50 g of 1,4-dioxane was added dropwise so that the temperature in the system did not exceed 35°C. After the dropwise addition, the mixture was stirred at 30°C for 2 hours. The triethylamine salt was filtered, and the filtrate was poured into water. The precipitate was then collected by filtration. This precipitate was dried in a vacuum dryer to obtain naphthoquinone diazide compound A represented by the following formula:

[0132] Synthesis Example 4 Synthesis of naphthoquinone diazide compound B Under a dry nitrogen stream, 21.23 g (0.05 mol) of TrisP-PA and 37.62 g (0.14 mol) of 4-naphthoquinone diazide sulfonyl chloride were dissolved in 450 g of 1,4-dioxane and the resulting solution was cooled to room temperature. Using 15.18 g of triethylamine mixed with 50 g of 1,4-dioxane, naphthoquinone diazide compound B represented by the following formula was obtained in the same manner as in Synthesis Example 3.

[0133] Preparation Examples 1 to 25, 28 to 31 Preparation of Photosensitive Varnishes P1-1 to 29 Photosensitive varnish materials were added and stirred as shown in Tables 1 and 2 to obtain photosensitive varnishes P1-1 to 29 for forming the organic insulating film (P1).

[0134]

[0135]

[0136] Preparation Example 26 Preparation of Photosensitive Varnish P2-1 The ingredients for the photosensitive varnish shown in Tables 1 and 2 were mixed and stirred to obtain photosensitive varnish P2-1 for forming a hollow structure support material (P2).

[0137] Preparation Example 27 Preparation of Photosensitive Sheet P3-1 A photosensitive varnish was obtained by adding and stirring the ingredients for the photosensitive varnish as shown in Tables 1 and 2. This photosensitive varnish was applied to a 38 μm thick PET film using a comma roll coater and dried at 80° C. for 8 minutes, after which a 10 μm thick PP film was laminated as a protective film to obtain a photosensitive sheet P3-1 for forming a hollow structure roofing material (P3).

[0138] Examples 1 to 21 Photosensitive varnishes P1-1 to P1-21 were used as materials for the organic insulating film (P1), photosensitive varnish P2-1 was used as a material for the hollow structure support material (P2), and photosensitive sheet P3-1 was used as a material for the hollow structure roofing material (P3), and the evaluations (1) to (4) above were carried out. The material combinations and evaluation results are shown in Tables 3 and 4.

[0139] Example 22 In the procedure for preparing the laminate (2-1) above, after the development of the photosensitive resin film, a heat treatment was carried out using a hot plate at 170°C for 5 minutes. Otherwise, the evaluations (1) to (4) above were carried out in the same manner as in Examples 1 to 21. The material combinations and the evaluation results are shown in Tables 3 and 4.

[0140] Example 23 In the procedure for preparing the laminate (2-1) above, after the development of the photosensitive resin film, a heat treatment was carried out using a hot plate at 200°C for 5 minutes. Except for this, the evaluations (1) to (4) above were carried out in the same manner as in Examples 1 to 21. The material combinations and the evaluation results are shown in Tables 3 and 4.

[0141] Example 24 In the procedure for producing the laminate (2-1), after the development of the photosensitive resin film, the entire photosensitive resin film was irradiated with 2000 mJ / cm 2 using a ghi aligner without using a mask. ２ Except for this, the evaluations (1) to (4) were carried out in the same manner as in Examples 1 to 21. The material combinations and the evaluation results are shown in Tables 3 and 4.

[0142] Comparative Examples 1 to 8: Photosensitive varnishes P1-22 to P1-29 were used as the organic insulating film (P1), photosensitive varnish P2-1 was used as the hollow structure support material (P2), and photosensitive sheet P3-1 was used as the hollow structure roofing material (P3), and the evaluations (1) to (4) were carried out. The material combinations and evaluation results are shown in Tables 3 and 4.

[0143] In Comparative Examples 6 and 7, the film was completely dissolved during development, and therefore, it was not possible to prepare a laminate.

[0144]

[0145]

[0146] 1 Piezoelectric substrate 2 Metal wiring (M1) 3 Organic insulating film (P1) 4 Metal wiring (M2) 5 Hollow structure support material (P2) 6 Hollow structure roof material (P3) 7 Area shown in Figure 2 c Angle between the surface where the piezoelectric substrate and metal wiring (M1) contact and the surface where the relief pattern of the organic insulating film (P1) contacts the metal wiring (M2)

Claims

1. On a piezoelectric substrate, Metal wiring (M1) with a thickness of 0.1 to 5 μm A relief pattern of an organic insulating film (P1) having a film thickness of 0.5 to 4 μm. A laminate in which metal wiring (M2) having a thickness of 0.1 to 5 μm is formed in this order, the organic insulating film (P1) contains a cured product obtained by curing a photosensitive resin composition containing an alkali-soluble resin (A), an oxime-based photopolymerization initiator (B), and a radical-polymerizable compound (C); the content of the oxime-based photopolymerization initiator (B) is 1 to 20 parts by mass relative to 100 parts by mass of the alkali-soluble resin (A); the oxime photopolymerization initiator (B) contains a compound represented by formula (1) and a compound represented by formula (2), and the mass ratio of the compound represented by formula (1) to the compound represented by formula (2) is 1:1 to 20:1; A laminate in which the amount of ion elution of the organic insulating film (P1) is 2000 ppm or less when measured by the following method for measuring the amount of ion elution. (Method for measuring the amount of eluted ions) The organic film is placed in 10 times the mass of pure water and subjected to hot water extraction at 121°C for 20 hours, after which the supernatant of the extract is used as the test solution. The test solution and a standard solution of the target ions are introduced into an ion chromatograph, and the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions in the test solution are determined by the calibration curve method. The value converted into the mass of eluted ions relative to the mass of the organic film is used as the amount of eluted ions. 【Chemistry 1】 (In formula (1), Ar represents an aryl group having 6 to 20 carbon atoms, Z 1 represents an organic group represented by any one of formulas (3) to (6), Z 2 represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. In formula (2), Z 3 represents an organic group represented by any one of formulas (3) to (6), and Z 4 represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.) 【Chemistry 2】 (In formulas (3) to (6), R 1 and R 3 represent a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, R 2 and R 5 represent a divalent organic group having 1 to 20 carbon atoms, and R 4 represents a monovalent organic group having 1 to 20 carbon atoms.)

2. On a piezoelectric substrate, Metal wiring (M1) with a thickness of 0.1 to 5 μm A relief pattern of an organic insulating film (P1) having a film thickness of 0.5 to 4 μm. A laminate in which metal wiring (M2) having a thickness of 0.1 to 5 μm is formed in this order, the organic insulating film (P1) contains a cured product obtained by curing a photosensitive resin composition containing an alkali-soluble resin (A) and a naphthoquinone diazide compound (E); the content of the naphthoquinone diazide compound (E) is 5 to 25 parts by mass relative to 100 parts by mass of the alkali-soluble resin (A), A laminate in which the amount of ion elution of the organic insulating film (P1) is 2000 ppm or less when measured by the following method for measuring the amount of ion elution. (Method for measuring the amount of eluted ions) The organic film is placed in 10 times the mass of pure water and subjected to hot water extraction at 121°C for 20 hours, after which the supernatant of the extract is used as the test solution. The test solution and a standard solution of the target ions are introduced into an ion chromatograph, and the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions in the test solution are determined by the calibration curve method. The value converted into the mass of eluted ions relative to the mass of the organic film is used as the amount of eluted ions.

3. 3. The laminate according to claim 1, wherein the electrical conductivity of a test solution of the organic insulating film (P1) obtained by the method for measuring the amount of eluted ions is 500 μS / cm or less.

4. 3. The laminate according to claim 1, wherein an angle formed between a surface where the piezoelectric substrate and the metal wiring (M1) contact and a surface where the relief pattern of the organic insulating film (P1) and the metal wiring (M2) contact is 20 to 60°.

5. 3. The laminate according to claim 1, wherein the alkali-soluble resin (A) contains at least one resin selected from the group consisting of polyimide, polybenzoxazole, polyamide, a precursor of any of these, and a copolymer thereof.

6. 2. The laminate according to claim 1, wherein the mass ratio of the compound represented by formula (1) to the compound represented by formula (2) is 4:1 to 20:

1.

7. The laminate according to claim 1, wherein the radical polymerizable compound (C) further contains a compound represented by formula (7) and a compound represented by formula (8), and the mass ratio of the compound represented by formula (7) to the compound represented by formula (8) is 1:9 to 5:

5. 【Transformation 3】 (In formula (7) and formula (8), R ７ ~R １７ each independently represents a hydrogen atom or a methyl group.

8. 3. The laminate according to claim 1 or 2, wherein the photosensitive resin composition contains a thermally crosslinkable compound (D), the thermally crosslinkable compound (D) contains a polyfunctional epoxy group-containing compound (D-1) and a polyfunctional alkoxymethyl group-containing compound (D-2), and the content of the polyfunctional epoxy group-containing compound (D-1) is 5 to 30 parts by mass and the content of the polyfunctional alkoxymethyl group-containing compound (D-2) is 1 to 10 parts by mass per 100 parts by mass of the alkali-soluble resin (A).

9. A step (1) of forming metal wiring (M1) on a piezoelectric substrate; a step (2) of applying a photosensitive resin composition onto the piezoelectric substrate and the metal wiring (M1), and heating and drying the composition at 80 to 130°C to form a photosensitive resin film on the substrate; 150 to 2000 mJ / cm through a mask ２ (3) a step of exposing the photosensitive resin film to an exposure amount of (4) a step of heating the exposed photosensitive resin film to 80 to 130°C; (5) a step of developing the photosensitive resin film by removing the unexposed areas of the photosensitive resin film with an alkaline aqueous solution; a step (6) of heating the developed photosensitive resin film at 200 to 280°C to form a relief pattern of the organic insulating film (P1); Step (7) of forming metal wiring (M2) on the piezoelectric substrate and the organic insulating film (P1). A method for producing a laminate, comprising the steps of:

10. 10. The method for producing a laminate according to claim 9, wherein in the step (5), a difference in film thickness of the exposed portion of the photosensitive resin film between when the photosensitive resin film is developed for 80 seconds and when the photosensitive resin film is developed for 140 seconds is 0.20 μm or less.

11. The method for producing a laminate according to claim 9 or 10, further comprising, between the step (5) and the step (6), a step (5-1) of heating the developed photosensitive resin film from a temperature of 100°C or less to 150 to 200°C at a temperature increase rate of 10°C / min or more.

12. Between the steps (5) and (6), the developed photosensitive resin film is exposed to 1000 to 3000 mJ / cm ２ The method for producing a laminate according to claim 9 or 10, comprising a step (5-2) of exposing the film to an exposure amount of 1000 ppm or more.

13. A hollow structure comprising the laminate according to claim 1 or 2, a hollow structure support material (P2) and a hollow structure roof material (P3).

14. The hollow structure described in claim 13, wherein the hollow structure support material (P2) and the hollow structure roof material (P3) are organic films containing at least one alkali-soluble resin (A) selected from the group consisting of polyimide, polybenzoxazole, polyamide, precursors of any of these, and copolymers thereof.

15. The hollow structure according to claim 13, wherein when the organic insulating film (P1) having a film thickness of 0.5 to 4 μm, the hollow structure supporting material (P2), and the hollow structure roofing material (P3) are each evaluated individually using the ion elution amount measurement method, the total amount of ion elution from the organic insulating film (P1) having a film thickness of 0.5 to 4 μm, the hollow structure supporting material (P2), and the hollow structure roofing material (P3) is 2000 ppm or less.

16. An electronic component having the hollow structure according to claim 13.

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