Hollow structures and electronic components using them

Abstract

The present invention provides a hollow structure having a low acid ion content and low wiring corrosion when stored in high-temperature, high-humidity conditions. The present invention relates to a hollow structure in which an organic film (I) having a film thickness of 5-30 μm as a hollow structure support material and an organic film (II) having a film thickness of 5-30 μm as a hollow structure roof material are layered in said order from the upper surface of a substrate having a metal wiring, wherein, when the organic film (I) and the organic film (II) are independently evaluated by the following method for evaluating ion elution amounts, the total of the ion elution amount of the organic film (I) and the ion elution amount of the organic film (II) is no more than 4,000 ppm. (Ion elution amount evaluation method) An organic film is placed in pure water having a mass 10 times that of the organic film and is extracted in hot water for 10-20 hours at 100-121 °C, after which the supernatant of the liquid extract is used as a sample solution. The sample solution and a target ion standard solution are introduced into an ion chromatography device, the concentrations of formate ions, acetate ions, propionate ions, and sulfate ions in the sample solution are determined by a calibration curve method, and a value obtained by converting the total of said concentrations into the mass of eluted ions relative to the mass of the organic film is used as the ion elution amount.

Description

[Technical Field]

[0001] This invention relates to a hollow structure, an electronic component using the same, and a negative-type photosensitive resin composition. [Background technology]

[0002] Electronic components such as MEMS (Micro Electro Mechanical Systems) are indispensable technologies for high-speed, high-quality communication in electronic devices. Among MEMS, sensors and noise filters require a hollow structure, and photosensitive resin compositions are used for the hollow structure support material and hollow structure roof material (Patent Documents 1-3). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2014-74773 [Patent Document 2] Japanese Patent Publication No. 2013-178526 [Patent Document 3] International Publication No. 2016 / 158760 [Overview of the project] [Problems that the invention aims to solve]

[0004] Conventional hollow structures using photosensitive resin compositions have the problem of being highly corrosive to metal wiring under high temperature and high humidity conditions. [Means for solving the problem]

[0005] To solve the above problems, the present invention relates to the following. From the top surface of the substrate having metal wiring, As a hollow structure support material, an organic film (I) with a film thickness of 5 to 30 μm and A hollow structure roofing material in which organic films (II) with a film thickness of 5 to 30 μm are laminated in this order, A hollow structure in which, when the organic membrane (I) and the organic membrane (II) are evaluated individually using the ion elution evaluation method described below, the sum of the ion elution amounts of organic membrane (I) and organic membrane (II) is 4000 ppm or less. (Method for evaluating ion elution amount) The organic membrane is placed in 10 times its mass volume of pure water and hot-water extracted at 100-121°C for 10-20 hours. The supernatant of the extract is then used as the test solution. The test solution and a standard solution of the target ion 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 sum of these concentrations is converted to the mass of eluted ions relative to the mass of the organic membrane and defined as the ion elution amount. [Effects of the Invention]

[0006] This invention can suppress corrosion of metal wiring during storage under high temperature and high humidity conditions. [Brief explanation of the drawing]

[0007] [Figure 1] This is a cross-sectional view of the hollow structure of the present invention. [Figure 2] This figure shows a cross-section of the organic film used in the present invention. [Modes for carrying out the invention]

[0008] This invention relates to the upper surface of a substrate having metal wiring. As a hollow structure support material, an organic film (I) with a film thickness of 5 to 30 μm and A hollow structure roofing material in which organic films (II) with a film thickness of 5 to 30 μm are laminated in this order, The hollow structure is such that when the organic membrane (I) and the organic membrane (II) are evaluated individually using the ion elution evaluation method described below, the sum of the ion elution amounts of organic membrane (I) and organic membrane (II) is 4000 ppm or less. (Method for evaluating ion elution amount) An organic film is placed in pure water at a mass ratio of 10 times, and after hot water extraction at 100 to 121 °C for 10 to 20 hours, the supernatant of the extraction solution is used as the test solution. The test solution and the standard solution of the target ion are introduced into an ion chromatograph analyzer, 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 obtained by converting the sum of these into the mass of eluted ions relative to the mass of the organic film is defined as the ion elution amount.

[0009] The hollow structure of the present invention is a hollow structure in which an organic film (I) as a hollow structure support material and an organic film (II) as a hollow structure roofing material are laminated in this order from the upper surface of a substrate having a metal wiring.

[0010] As the substrate having a metal wiring, silicon, silicon oxide, lithium tantalate, lithium niobate, gallium arsenide, etc. on which aluminum wiring or copper wiring is formed are mainly used, but it is not limited to this.

[0011] When the total of the ion elution amounts when the organic film (I) and the organic film (II) are each evaluated alone by the following evaluation method of ion elution amount is 4000 ppm or less, corrosion of the metal wiring in the hollow structure under high temperature and high humidity conditions can be suppressed. If it is 2000 ppm or less, it is more preferable from the viewpoint of corrosion suppression. If it is 1000 ppm or less, it is further preferable, and it is most preferable that it is 500 to 0 ppm. The detection lower limit in the following evaluation method is set to 0 ppm.

[0012] Regarding the evaluation method of the ion elution amount, specifically, it is carried out as follows. Each organic membrane for evaluating the ion elution amount is evaluated by separating a predetermined amount from a hollow structure. It is also possible to evaluate the ion elution amount from the resin composition for forming each organic membrane. When evaluating the ion elution amount from the resin composition for forming each organic membrane, a cured product obtained by heat-treating a liquid or sheet-like resin composition may be used. As a method for preparing the cured product, a method of applying or laminating a resin composition on a silicon substrate, heat-treating it in an oven, immersing it in a hydrofluoric acid aqueous solution, and peeling it off, or a method of heating a resin sheet formed on polyethylene terephthalate (PET) on a hot plate and transferring it to a polytetrafluoroethylene (PTFE) film using a rubber roller, followed by heat-treating and peeling it off from the PTFE film can be mentioned.

[0013] The prepared cured product is freeze-ground using liquid nitrogen, and then 1.0 to 2.0 g of the cured product and 10 to 20 g (10 times the mass ratio with respect to the cured product) of pure water are placed in a PTFE pressure-sealed container and heat-extracted in a high-temperature device at 100 to 121 °C for 10 to 20 hours. The supernatant of the extraction liquid is filtered through a membrane filter to obtain a test solution. The pure water used here is distilled and ion-exchanged, and the one used for reagent preparation and trace analysis tests specified in JIS K 0557 (1998) is used. For the hot water pressurized extraction method procedure, Yoshimi Hashimoto: Bunseki Kagaku, 49, 8 (2000). was referred to, and for the extraction temperature conditions, Aki Kitamura: Network Polymer, 33, 3 (2012) was referred to.

[0014] This test solution is analyzed according to the ion chromatography general rule ion chromatography method of Japanese Industrial Standard JIS K 0127 (2013). Standard solutions of formic acid ion, acetic acid ion, propionic acid ion, and sulfuric acid ion are respectively introduced into an ion chromatography analyzer to prepare a calibration curve. Next, from the peak area obtained by introducing 25 μL of the test solution and the calibration curve, the concentrations of formic acid ion, acetic acid ion, propionic acid ion, and sulfuric acid ion are determined, and the total value converted to the mass of eluted ions with respect to the mass of the organic membrane is taken as the ion elution amount.

[0015] In the hollow structure of the present invention, it is preferable that the ion elution amount of the organic film (I), which is the hollow structure support material, is 2000 ppm or less when evaluated by the ion elution amount evaluation method described above. If it is 2000 ppm or less, corrosion of the metal wiring inside the hollow structure can be suppressed under high temperature and high humidity conditions, if it is 1000 ppm or less, it is more preferable from the viewpoint of corrosion suppression, and if it is 500 ppm or less, it is even more preferable.

[0016] In the hollow structure of the present invention, it is preferable that the ion elution amount of the organic film (II), which is the hollow structure roofing material, is 2000 ppm or less when evaluated by the ion elution amount evaluation method described above. If it is 2000 ppm or less, corrosion of metal wiring in the hollow structure can be suppressed under high temperature and high humidity conditions, if it is 1000 ppm or less, it is more preferable from the viewpoint of corrosion suppression, and if it is 500 ppm or less, it is even more preferable.

[0017] In the hollow structure of the present invention, it is preferable that the conductivity of the test solution of the organic membrane (I) obtained by the ion elution evaluation method is 500 μS / cm or less. A conductivity of 500 μS / cm or less of the test solution reduces the diffusion of acid ions under high temperature and high humidity conditions, thereby suppressing corrosion of the metal wiring within the hollow structure. From the viewpoint of corrosion suppression, it is even more preferable that the conductivity of the test solution is 300 μS / cm or less.

[0018] The hollow structure of the present invention preferably has an conductivity of 500 μS / cm or less of the test solution of the organic membrane (II) obtained by the ion elution evaluation method. A conductivity of 500 μS / cm or less of the test solution reduces the diffusion of acid ions under high temperature and high humidity conditions, thereby suppressing corrosion of the metal wiring within the hollow structure. From the viewpoint of corrosion suppression, it is even more preferable if the conductivity of the test solution is 300 μS / cm or less. The conductivity of the test solution can be measured using the ion chromatograph described in the ion elution evaluation method.

[0019] The thickness of the organic film (I) and the organic film (II) is 5 to 30 μm. By setting the thickness within this range, it is possible to obtain a hollow structure that is sufficient to suppress corrosion of metal wiring and to utilize elastic waves. More preferably, the thickness is 10 to 20 μm in terms of obtaining sufficient hollowness and processability.

[0020] The organic film (I) and the organic film (II) can be cured products obtained by curing a resin composition containing at least one resin selected from the group consisting of polyimide, polybenzoxazole or its precursors, polyamidesiloxane, epoxy resin, acrylic resin, novolac resin, resol resin, polyhydroxystyrene, modified versions thereof in which crosslinking groups such as methylol groups, alkoxymethyl groups, or epoxy groups are introduced, and copolymers thereof.

[0021] The organic film (I) preferably contains a cured product obtained by curing a negative-type photosensitive resin composition 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, a thermally crosslinkable compound (C), an oxime-based photopolymerization initiator (D), and a polymerizable compound (E), wherein the oxime-based photopolymerization initiator (D) contains a compound represented by formula (3).

[0022] [ka]

[0023] In formula (3), Ar represents an aryl group, and Z 1 represents an organic group with 6 to 20 carbon atoms, Z 2 represents a hydrogen atom or an organic group with 1 to 20 carbon atoms.

[0024] By including polyimide, polybenzoxazole, and polyamide in the negative-type photosensitive resin composition, it is possible to obtain a hollow structure with high heat resistance, reliability against high-temperature storage and thermal shock, and high mechanical strength.

[0025] In the present invention, "alkali-soluble" means that the dissolution rate in an alkaline aqueous solution as a developer is 50 nm / min or more. Specifically, it means that when a solution obtained by dissolving a resin in γ-butyrolactone is applied onto a silicon wafer and prebaked on a hot plate at 120 °C for 4 minutes to form a prebaked film with a film thickness of 10 μm ± 0.5 μm, and the prebaked film is immersed in an alkaline aqueous solution selected from any one of a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ± 1 °C, a 1 mass% potassium hydroxide aqueous solution, and a 1 mass% sodium hydroxide aqueous solution for 1 minute and then rinsed with pure water, the dissolution rate determined from the film thickness reduction is 50 nm / min or more.

[0026] The alkali-soluble resin (A) preferably has at least one repeating unit among the repeating units represented below.

[0027] [Chemical formula]

[0028] X in the repeating unit 1 and X 2 each represent an acid dianhydride residue, X 3 represents a dicarboxylic acid residue, Y 1 (OH) p and Y 2 (OH) q and Y 3 (OH) r each represent a diamine residue. p, q, and r each represent an integer in the range of 0 to 4, and R 1 represents a hydrogen atom or an organic group having 1 to 10 carbon atoms. As the acid dianhydride and diamine, known substances can be used.

[0029] The alkali-soluble resin (A) may be end-capped with a known monoamine, acid anhydride, monocarboxylic acid, monoacid chloride compound, or monoactive ester compound.

[0030] The weight-average molecular weight (Mw) of the alkali-soluble resin (A) is calculated on a polystyrene basis by gel permeation chromatography (GPC), with the developing solvent being 99.3% by mass of N-methyl-2-pyrrolidone, 0.2% by mass of lithium chloride, and 0.5% by mass of phosphoric acid. If the Mw is 3000 or more, a cured product can be easily obtained by heat treatment. To obtain a cured product with high elongation and heat resistance, it is more preferable that the Mw be 10000 or more, and even more preferable that it be 20000 or more. Furthermore, if the Mw is 200000 or less, it can be processed as a photosensitive resin. To obtain good pattern processability, it is more preferable that the Mw be 100000 or less, and even more preferable that it be 70000 or less.

[0031] By including an oxime-based photopolymerization initiator (D) in the negative-type photosensitive resin composition, a highly sensitive and high-resolution resin composition can be obtained, enabling the narrowing of column materials for hollow structures. The oxime-based photopolymerization initiator (D) contains a compound represented by formula (3). The compound represented by formula (3) generates a small amount of low-molecular-weight acid ions upon decomposition, and while being highly sensitive, it can suppress metal wiring corrosion when cured.

[0032] Compounds represented by formula (3) 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.).

[0033] Other oxime-based photopolymerization initiators (D) 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)isophthal, "IRGACURE" (registered trademark) OXE-02, OXE-04 (trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.), and ADEKA Arcules NCI-831, NCI-930 (trade name, manufactured by ADEKA Corporation).

[0034] In addition, the following photopolymerization initiators can be used as other photopolymerization initiators, provided they do not worsen wiring corrosion due to the generation of acid ions.

[0035] Other photopolymerization initiators include, for example, benzophenones such as benzophenone, Michlaz ketone, and 4,4-bis(diethylamino)benzophenone; benzylidenes such as 3,5-bis(diethylaminobenzylidene)-N-methyl-4-piperidone; coumarins such as 7-diethylamino-3-tenonylcoumarin; anthraquinones such as 2-t-butylanthraquinone; benzoins such as benzoin methyl ether; mercaptos such as ethylene glycol di(3-mercaptopropionate); glycines such as N-phenylglycine; and α-aminoalkylphenones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

[0036] The content of the oxime-based photopolymerization initiator (D) is preferably 0.1 to 40 parts by mass, and more preferably 1 to 20 parts by mass, per 100 parts by mass of the total amount of the alkali-soluble resin (A). Furthermore, it is preferable that the compound represented by formula (3) is present in 70 to 100% by mass of the total 100% by mass of the oxime-based photopolymerization initiator (D). Within this range, good processability can be obtained, and an organic film with a total elution amount of acid ions of 2000 ppm or less can be obtained.

[0037] The negative-type photosensitive resin composition of the present invention comprises at least one alkali-soluble resin (A) selected from the group consisting of polyimide, polybenzoxazole, polyamide, precursors thereof, and copolymers thereof, A thermally crosslinkable compound (C) and Oxime-based photopolymerization initiator (D), A negative-type photosensitive resin composition containing a polymerizable compound (E), The content of the oxime-based photopolymerization initiator (D) is 1 to 20 parts by mass per 100 parts by mass of the alkali-soluble resin (A), and it is preferable that the compound represented by formula (3) is present in an amount of 70 to 100% by mass of the total 100% by mass of the oxime-based photopolymerization initiator (D).

[0038] [ka]

[0039] (In formula (3), Ar represents an aryl group, Z 1 represents an organic group with 6 to 20 carbon atoms, Z 2 (This represents a hydrogen atom or an organic group with 1 to 20 carbon atoms.) The aforementioned thermally crosslinkable compound (C) refers to a compound having crosslinkable groups other than radical polymerizable groups that can bond with resins and similar molecules. Examples of thermally crosslinkable compounds (C) include polyfunctional epoxy group-containing compounds (C-1) and polyfunctional alkoxymethyl group-containing compounds (C-2). By including the thermally crosslinkable compound (C), a crosslinked structure is formed during heat treatment through a condensation reaction with the resin and similar molecules, resulting in a hollow structure with high chemical resistance, high elasticity, and low bending. Furthermore, because reflow during heat treatment is less likely to occur, it contributes to the rectangular shape of the hollow structure support material, which increases the contact area with the roofing material and results in a hollow structure with high adhesion between the support material and the roofing material.

[0040] Examples of polyfunctional epoxy group-containing compounds (C-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, epoxy group-containing silicones such as polymethyl(glycidyloxypropyl)siloxane, and novolac epoxy resins.

[0041] Specifically, TECHMORE VG3101L (product name, manufactured by Printec Co., Ltd.), “TEPIC” (registered trademark) VL, “TEPIC” (registered trademark) UC (product name, manufactured by Nissan Chemical Industries, Ltd.), “Epiclon” (registered trademark) 850-S, “Epiclon” (registered trademark) HP-4032, “Epiclon” (registered trademark) HP-7200, “Epiclon” (registered trademark) HP-820, “Epiclon” (registered trademark) HP-4700, “Epiclon” (registered trademark) EXA-4710, “Epiclon” (registered trademark) HP-4770, “Epiclon” (registered trademark) EXA-859CRP, “Epiclon” (registered trademark) Examples include EXA-1514, “Epiclon” (registered trademark) EXA-4880, “Epiclon” (registered trademark) EXA-4850-150, “Epiclon” (registered trademark) EXA-4850-1000, “Epiclon” (registered trademark) EXA-4816, “Epiclon” (registered trademark) EXA-4822 (all product names, manufactured by Dainippon Ink and Chemicals, Inc.), Licaresin (registered trademark) BEO-60E (product name, manufactured by Shin Nippon Rika Co., Ltd.), EP-4003S, EP-4000S (both product names, manufactured by ADEKA Corporation), JER157s70 (product name, manufactured by Mitsubishi Chemical Corporation), etc.

[0042] Specifically, polyfunctional alkoxymethyl group-containing compounds (C-2) having two functional groups include DM-BI25X-F, 46DMOC, 46DMOIPP, 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 D ML-BisOC-Z, DML-BisOCHP-Z, DML-PFP, DML-PSBP, DML-MB25, DML-MTrisPC, DML-Bis25X-34XL, DML-Bis25X-PCHP (all product names, manufactured by Honshu Chemical Industry Co., Ltd.), "Nicalac" (registered trademark) MX-290 (product name, manufactured by Sanwa Chemical Co., Ltd.), Ba-type benzoxazine, Bm-type benzoxazine (all product names, manufactured by Shikoku Chemicals Co., Ltd.), 2,6-dimethoxymethyl-4-t Products containing three of these compounds, such as butylphenol, 2,6-dimethoxymethyl-p-cresol, and 2,6-diacetoxymethyl-p-cresol, include TriML-P, TriML-35XL, and TriML-TrisCR-HAP (all trade names, manufactured by Honshu Chemical Industry Co., Ltd.). Products containing four of these compounds include TM-BIP-A (trade name, manufactured by Asahi Organic Chemicals Industry Co., Ltd.), TML-BP, TML-HQ, TML-pp-BPF, TML-BPA, and TMOM-BP (all trade names, manufactured by Honshu Chemical). Examples of products containing six different compounds include HML-TPPHBA, HML-TPHAP, HMOM-TPPHBA, HMOM-TPPHBA, HMOM-TPHAP (all product names, manufactured by Honshu Chemical Industry Co., Ltd.), HML-TPPHBA, HMOM-TPHAP (all product names, manufactured by Honshu Chemical Industry Co., Ltd.), HML-TPPHBA, HMOM-TPHAP (all product names, manufactured by Honshu Chemical Industry Co., Ltd.), HML-TPPHBA, HMOM-TPHAP (all product names, manufactured by Honshu Chemical Industry Co., Ltd.), HML-TPPHBA, HMOM-TPHAP (all product names, manufactured by Honshu Chemical Industry Co., Ltd.).

[0043] The polyfunctional epoxy group-containing compound (C-1) can provide chemical resistance while reducing organic acid content, but tends to decrease alkali solubility. On the other hand, the polyfunctional alkoxymethyl group-containing compound (C-2) provides high chemical resistance, but tends to contain impurities such as formate ions. For this reason, it is preferable to include these compounds in appropriate amounts.

[0044] The content of the thermally crosslinkable compound (C) is preferably 1 to 40 parts by mass, and more preferably 10 to 30 parts by mass, per 100 parts by mass of the alkali-soluble resin (A). By setting the content of the thermally crosslinkable compound (C) within this range, a hollow structure with a total elution amount of acid ions of 2000 ppm or less can be obtained, resulting in a hollow structure with high chemical resistance, high elasticity, high rectangular shape, and high adhesion between the support material and the roofing material.

[0045] Furthermore, it is preferable that the content of the polyfunctional epoxy group-containing compound (C-1) is 5 to 30 parts by mass and the content of the polyfunctional alkoxymethyl group-containing compound (C-2) is 1 to 10 parts by mass per 100 parts by mass of the alkali-soluble resin (A).

[0046] By keeping the content of the thermally crosslinkable compound (C) within this range, it is possible to obtain a hollow structure with high chemical resistance, a highly rectangular shape, and high adhesion between the support material and the roofing material, while suppressing the acid ion content.

[0047] A polymerizable compound (E) is a compound that has one or more functional groups capable of radical polymerization within its molecule.

[0048] Polymerizable compounds (E) specifically 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-tricyclodecanediacrylate, and pentaerythritol. Re-acrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, 1,3-diacryloyloxy-2-hydroxypropane, 1,3-dimethacryloyloxy-2-hydroxypropane, N,N-methylenebisacrylamide, BP-6EM, DCP-A (product name, manufactured by Kyoeisha Chemical Co., Ltd.), AH-600 (product name, manufactured by Kyoeisha Chemical Co., Ltd.) Examples include, but are not limited to, isocyanurate ethylene oxide modified triacrylates such as "Aronics" (registered trademark) M-315 (trade name, manufactured by Toagosei Co., Ltd.), AT-600 (product name, manufactured by Kyoeisha Chemical Co., Ltd.), UA-306H (product name, manufactured by Kyoeisha Chemical Co., Ltd.), UA-306T (product name, manufactured by Kyoeisha Chemical Co., Ltd.), ethylene oxide modified bisphenol A diacrylate, ethylene oxide modified bisphenol A dimethacrylate, isocyanurate ethylene oxide modified diacrylate, and isocyanurate ethylene oxide modified triacrylate such as "Aronics" (registered trademark) M-315 (product name, manufactured by Toagosei Co., Ltd.). These can be contained individually or in combination of two or more types.

[0049] The polymerizable compound (E) preferably contains a compound represented by formula (4).

[0050] [ka]

[0051] By including the compound represented by formula (4), good pattern machinability and heat resistance are obtained, making it possible to narrow the width of the hollow structure support material and obtain a cured product with high heat resistance.

[0052] The content of polymerizable compound (E) is preferably 5 to 200 parts by mass per 100 parts by mass of alkali-soluble resin (A), and more preferably 5 to 150 parts by mass from the viewpoint of compatibility. By setting the content of polymerizable compound (E) to 5 parts by mass or more, the elution of exposed areas during development is prevented, and a resin composition with a high residual film rate after development can be obtained. By setting the content of polymerizable compound (E) to 200 parts by mass or less, whitening of the film during film formation can be suppressed.

[0053] Furthermore, it is preferable that the compound represented by formula (4) is present in an amount of 55 to 90% by mass of the total amount of polymerizable compound (E) (100% by mass). An amount of 55% by mass or more allows for high resolution and heat resistance, while an amount of 90% by mass or less maintains the flexibility of the cured product and allows for high mechanical strength.

[0054] Polymerizable compound (E) may be included alone or in combination of two or more types.

[0055] In addition to the negative-type photosensitive resin composition described above, other photosensitive resin compositions for obtaining the organic film (I) may also be used, provided that they do not increase the amount of ion elution of the organic film. These may include negative-type photosensitive resin compositions using a photoacid generator as a cationic polymerization initiator and epoxy compounds, oxetane compounds, or epoxy resins as cationic polymerizable compounds, or positive-type photosensitive resin compositions using naphthoquinone diazide compounds as photoacid generators.

[0056] The organic film (I) preferably includes a cured product obtained by curing a positive-type photosensitive resin composition 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, and a naphthoquinone diazide compound (B) and a thermally crosslinkable compound (C).

[0057] Examples of the naphthoquinone diazide compound (B) include a polyhydroxy compound esterified with the sulfonic acid of quinone diazide, a polyamino compound esterified with the sulfonic acid of quinone diazide via a sulfonamide bond, and a polyhydroxypolyamino compound esterified and / or via a sulfonamide bond. Not all functional groups of these polyhydroxy compounds, polyamino compounds, and polyhydroxypolyamino compounds are to be substituted with quinone diazide, but it is preferable that on average 40 mol% or more of the total functional groups are substituted with quinone diazide. By including such a quinone diazide compound, a positive-type photosensitive resin composition that is sensitive to the i-line (wavelength 365 nm), h-line (wavelength 405 nm), and g-line (wavelength 436 nm) of mercury lamps, which are common ultraviolet rays, can be obtained.

[0058] The naphthoquinone diazide compound (B) preferably contains a compound represented by formula (1) and / or formula (2).

[0059] [ka]

[0060] Since the compounds represented by formulas (1) and (2) are stable to heat, the generation of sulfate ions during heat treatment is suppressed, and hollow structures with a low acid ion content can be obtained.

[0061] The content of the naphthoquinone diazide compound (B) is preferably 1 to 30 parts by mass, and more preferably 10 to 20 parts by mass, per 100 parts by mass of the alkali-soluble resin (A). By setting the content of the quinone diazide compound within this range, a hollow structure with a total elution amount of acid ions of 2000 ppm or less can be obtained, resulting in high resolution, and thus the hollow structure support material can be made narrower. Narrowing the hollow structure support material is important for reducing the overall size of the MEMS package while maintaining the hollow space of the hollow structure.

[0062] In addition, the above-mentioned positive-type or negative-type photosensitive resin composition may contain surfactants or adhesion improvers, thereby improving wettability and adhesion to the substrate.

[0063] In the hollow structure of the present invention, the photosensitive resin composition for obtaining the organic film (I) is preferably in liquid or sheet form. The liquid positive or negative photosensitive resin composition preferably contains a solvent. Examples of solvents 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. Two or more of these may be included.

[0064] The solvent content is preferably 100 to 1,500 parts by mass per 100 parts by mass of alkali-soluble resin (A), and within this range, a cured product with a film thickness of 5 to 30 μm as an organic film (I) can be formed.

[0065] The organic film (I) contains 30 to 80% by mass of inorganic particles per 100% by mass of organic film (I), and the organic film (II) contains 0 to 80% by mass of inorganic particles per 100% by mass of organic film (II), or A highly elastic hollow structure can be obtained by having organic film (II) contain 30 to 80% by mass of inorganic particles per 100% by mass of organic film (II), and organic film (I) contain 0 to 80% by mass of inorganic particles per 100% by mass of organic film (I). By making the hollow structure highly elastic, it is possible to create a hollow structure that is resistant to bending.

[0066] Organic film (I) becomes highly elastic by containing 30 to 80% by mass of inorganic particles per 100% by mass of organic film (I). In this case, it is preferable that organic film (II) also contains 30 to 80% by mass of inorganic particles per 100% by mass of organic film (II), but it may be less than 30% by mass. However, it is undesirable from the viewpoint of processability for organic film (II) to contain more than 80% by mass of inorganic particles. Similarly, organic film (II) becomes highly elastic by containing 30 to 80% by mass of inorganic particles per 100% by mass of organic film (II). In this case, it is preferable that organic film (I) also contains 30 to 80% by mass of inorganic particles per 100% by mass of organic film (I), but it may be less than 30% by mass. However, it is undesirable from the viewpoint of processability for organic film (I) to contain more than 80% by mass of inorganic particles.

[0067] By keeping the inorganic particle content within the above range, good processability can be obtained when it is used as a photosensitive resin composition, and a high elastic modulus can be obtained as a cured product.

[0068] As inorganic particles, glass particles are preferred from the viewpoint of processability of the photosensitive resin composition for obtaining organic films. In this invention, glass refers to materials that do not have sharp peaks (full width at half maximum of 2° or less) representing the crystal structure of specific components in 2θ-θ powder X-ray analysis.

[0069] The glass particles preferably contain at least two elements selected from the group consisting of silicon dioxide, aluminum oxide, and boron oxide, and more preferably contain rare earth oxides. Yttrium oxide or lanthanide oxide are preferred as the rare earth oxides.

[0070] The refractive index of the glass particles is preferably 1.55 to 1.75. The refractive index can be measured by the V-block method, and in this invention, the refractive index is defined as the result measured at a wavelength of 405 nm. A refractive index of 1.55 to 1.75 makes it possible to obtain good pattern processability by reducing scattering and reflection during exposure when processing the photosensitive resin composition for obtaining the organic film.

[0071] The average particle size of the inorganic particles used in this invention is preferably 0.1 to 3.0 μm. This range allows for good processability when used in a photosensitive resin composition and a high elastic modulus as a cured product.

[0072] In the hollow structure of the present invention, the photosensitive resin composition for obtaining the organic film (II) is preferably in sheet form. By using a sheet-like photosensitive resin composition as a roofing material, a hollow structure can be formed. By applying the above-mentioned photosensitive resin composition onto a support film and then drying it, a photosensitive sheet having a photosensitive layer on the support film can be obtained.

[0073] Next, an example of a method for forming the hollow structure of the present invention will be described with reference to the drawings. A cross-sectional view of the hollow structure of the present invention is shown in Figure 1. First, a photosensitive resin composition for forming the organic film (I)2 is applied to a substrate 1 having metal wiring 4. The substrate 1 mainly consists of silicon, silicon oxide, lithium tantalate, lithium niobate, and gallium arsenide, on which aluminum or copper wiring is formed, but is not limited to these. The thickness of the metal wiring 4 is preferably 0.1 to 5 μm.

[0074] Methods for coating the photosensitive resin composition used in the organic film (I) include rotary coating using a spin coater, spray coating, roll coating, screen printing, blade coater, die coater, calender coater, meniscus coater, bar coater, roll coater, comma roll coater, gravure coater, screen coater, and slit die coater. The coating film thickness varies depending on the coating method, the solid content concentration of the composition, viscosity, etc., but is usually applied so that the film thickness after drying is 5 to 30 μm. The solid content concentration of the composition is preferably 50 to 70%, and the viscosity is preferably 500 to 5000 cP. Within this range, the above coating film thickness can be formed.

[0075] When using a photosensitive resin composition used in an organic film (I) as a photosensitive sheet, the photosensitive resin composition is applied to a substrate, the organic solvent is removed, and the photosensitive sheet is manufactured. A PET film or the like can be used as the substrate to which the photosensitive resin composition is coated. When a photosensitive sheet is bonded to a substrate such as a silicon wafer, if it is necessary to peel off the PET film that serves as the substrate, it is preferable to use a PET film coated with a release agent such as silicone resin on its surface, as this allows for easy separation of the photosensitive sheet from the PET film.

[0076] Methods for applying the photosensitive resin composition onto a PET film include screen printing, spray coating, bar coating, blade coating, die coating, and spin coating. Methods for removing organic solvents include heating with an oven or hot plate, vacuum drying, and heating with electromagnetic waves such as infrared rays or microwaves. If the removal of organic solvents is insufficient, the cured product obtained in the subsequent curing treatment may be uncured or have poor thermomechanical properties. The thickness of the PET film is not particularly limited, but from the viewpoint of workability, it is preferably in the range of 30 to 80 μm. In addition, a cover film may be laminated to the surface to protect the surface of the photosensitive sheet from dust and other contaminants in the atmosphere. Furthermore, if the solid content concentration of the photosensitive resin composition is low and a photosensitive sheet of the desired film thickness cannot be produced, two or more photosensitive sheets after organic solvent removal may be laminated together.

[0077] When laminating the photosensitive sheet manufactured using the above method onto another substrate, you can use a laminating device such as a roll laminator or vacuum laminator, or you can manually laminate it onto the substrate heated on a hot plate using a rubber roller. After lamination to the substrate, allow it to cool completely before peeling off the PET film.

[0078] To improve the adhesion between the substrate and the photosensitive resin composition, the substrate can be pre-treated with the aforementioned silane coupling agent. For example, a solution prepared by dissolving 0.5 to 20% by mass of the silane coupling agent in a solvent such as isopropanol, ethanol, methanol, water, tetrahydrofuran, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, or diethyl adipate is used for surface treatment by spin coating, dipping, spray coating, or steam treatment. In some cases, heat treatment at 50°C to 300°C is then performed to promote the reaction between the substrate and the silane coupling agent. Next, the substrate coated with the photosensitive resin composition or laminated with a photosensitive sheet is dried to obtain a photosensitive resin composition film. Drying is preferably performed using an oven, hot plate, or infrared light at a temperature of 50°C to 150°C for 1 minute to several hours.

[0079] Next, the photosensitive resin composition coating is exposed by irradiating it with a chemical beam through a mask having a desired pattern. Chemical beams that can be used for exposure include ultraviolet light, visible light, electron beams, and X-rays, but in this invention, it is preferable to use the i-line (365 nm), h-line (405 nm), and g-line (436 nm) of a mercury lamp. In the case of a negative type, in order to allow the reaction caused by exposure to proceed to the substrate surface, it is preferable to use a hot plate after exposure and heat at a temperature of 50°C to 150°C for 1 minute to 1 hour.

[0080] To form a pattern, after exposure, a developer is used to remove the exposed areas in the case of positive film, or the unexposed areas in the case of negative film. Preferred developers are 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.

[0081] In some cases, polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, and dimethylacrylamide, alcohols such as glycerin, methanol, ethanol, and isopropanol, esters such as ethyl lactate and propylene glycol monomethyl ether acetate, and ketones such as cyclopentanone, cyclohexanone, isobutyl ketone, and methyl isobutyl ketone may be added to these alkaline solutions, either individually or in combination of several.

[0082] In some cases, organic solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents can also be used as developers. Development can be carried out by spraying the above-mentioned developer onto the film surface, immersing in the developer, applying ultrasonic waves while immersed, or spraying the developer while rotating the substrate. After development, rinsing with water is preferable. Here, alcohols such as ethanol and isopropyl alcohol, or esters such as ethyl lactate and propylene glycol monomethyl ether acetate may be added to the water for rinsing.

[0083] After development, a temperature of 150°C to 500°C is applied to promote the volatilization of the solvent, the ring-closing reaction of the resin, and the cross-linking reaction of the thermo-crosslinkable compound. In this invention, the cured product refers to the resin composition that has undergone this heat treatment. This heat treatment method can be selected from a method of gradually increasing the temperature by selecting a temperature, or a method of continuously increasing the temperature within a certain temperature range for 5 minutes to 5 hours. An example of the former is a method of heat treatment at 130°C and 200°C for 30 minutes each. An example of the latter is a method of linearly increasing the temperature from room temperature to 400°C over 2 hours. In this invention, the heat treatment temperature is preferably 150 to 350°C, and more preferably 170 to 300°C in that it reduces damage to the substrate and allows for good organic film properties to be obtained.

[0084] As shown in Figure 1, an organic film (I) 2 is formed on the substrate 1, and then an organic film (II) 3 is formed using a photosensitive sheet material. The method for forming the organic film (II) 3 can be the same as the method for forming the organic film (I) from a photosensitive sheet.

[0085] Figure 2 shows a cross-section of the organic film (I) cut perpendicular to the wall surface of the substrate 1 and organic film (I) 2. This is an enlarged view of the area enclosed by the dashed line in Figure 1. In a cross-section perpendicular to the upper surface of the substrate and the wall surface of the organic film (I), when the length of the contact surface between the organic film (I) and the substrate is x, and the length of the contact surface between the organic film (I) and the organic film (II) is y, it is preferable that 1 ≥ y / x ≥ 0.6. By satisfying the above range, even when the width of the hollow structure support material is reduced, the adhesion area with the organic film (II) of the roofing material can be secured, and a hollow structure that is less prone to peeling can be obtained. x is preferably in the range of 5 to 100 μm, more preferably in the range of 10 to 50 μm, and even more preferably in the range of 10 to 30 μm, from the viewpoint of ensuring sufficient hollow space and adhesion with the roofing material.

[0086] The electronic component of the present invention is an electronic component having a hollow structure of the present invention, such as a MEMS. [Examples]

[0087] The present invention will be described below with reference to examples, but the present invention is not limited to these examples. First, we will explain the evaluation methods used in each example and comparative example.

[0088] (1) Creation of the circuit board A titanium (Ti) sputtered film was fabricated on a silicon substrate by sputtering to a thickness of 100 nm. Copper was then sputtered onto the Ti sputtered film to a thickness of 250 nm. After sputtering, a copper plating film with a thickness of 5 μm was formed by electroplating.

[0089] (2) Formation of hollow structure A photosensitive varnish was applied to the substrate using a spin coater, and a pre-baked film with a thickness of 10-13 μm was obtained by baking it at 120°C for 3 minutes using a hot plate. Next, a mask having a grid pattern with a width of 30 μm and spacing of 200 μm was used, and 500-1000 mJ / cm² was applied using a GHI aligner. 2 The film was exposed to light. After exposure, it was developed with a 2.38% by mass aqueous solution of tetramethylammonium (TMAH) for 100-200 seconds, and then rinsed with pure water to obtain a developed film with a thickness of 10 μm, a width of 30 μm, and a grid-like residual pattern with 200 μm spacing. The developed film was heated in an inert oven under a nitrogen stream at an oxygen concentration of 20 ppm or less at a heating rate of 3.5 °C per minute to 200 °C, and then heat-treated at 200 °C for 1 hour to form a hollow structure support material with a thickness of 10 μm made of organic film (I). Next, a photosensitive sheet with a thickness of 20-23 μm was laminated as the organic film (II) using a laminating apparatus (Takatori Co., Ltd., VTM-200M) under the following conditions: stage temperature 80°C, roll temperature 80°C, vacuum degree 150 Pa, lamination speed 5 mm / sec, and lamination pressure 0.2 MPa. A ghi aligner was used to apply 500-1000 mJ / cm². 2 After exposure, the material was heated in an inert oven under a nitrogen stream at an oxygen concentration of 20 ppm or less, at a heating rate of 3.5°C per minute to 200°C, and then heat-treated at 200°C for 1 hour to form a hollow structure roofing material with a thickness of 20 μm due to the organic film (II).

[0090] (3) Evaluation of corrosion resistance of hollow structures The hollow structure prepared in (2) was stored for 100 hours at 121°C, 100% humidity, and 2 atmospheres using an accelerated life test apparatus (saturation pressure cooker test apparatus), and then the hollow portion was cut using a dicing apparatus. The copper-plated cross section of the substrate was polished with a cross-section polisher (JEOL IB-09010CP) and then observed using a scanning electron microscope (Hitachi S-4800). The thickness of the copper oxide formed on the copper plating was measured, and those with a thickness of 150 nm or less were designated as A, those with a thickness between 150 nm and 200 nm were designated as B, and those with a thickness greater than 200 nm were designated as C.

[0091] (4) Evaluation of adhesion between hollow structural support material and roofing material The hollow structures prepared in (2) were observed using an optical microscope to check for delamination. Structures with no delamination or bubbles between organic film (I) and organic film (II) were designated as A, structures with no delamination but with bubbles were designated as B, and structures with delamination were designated as C.

[0092] (5) Evaluation of acid ion elution amount and conductivity (5-1) Evaluation of acid ion elution and conductivity of organic membrane (I) First, a cured organic film (I) was prepared using the following method.

[0093] A photosensitive varnish was applied to a 38 μm thick PET film using a commarol coater, dried at 80°C for 8 minutes, and then laminated with a 10 μm thick PP film as a protective film to obtain a photosensitive sheet. The thickness of the photosensitive sheet was adjusted to 30 μm.

[0094] After attaching this photosensitive sheet to a PTFE film heated on a 120°C hot plate using a rubber roller, the PET film is peeled off. In the case of a negative, expose it, A photosensitive sheet on a PTFE film was heated in an inert oven under a nitrogen stream at an oxygen concentration of 20 ppm or less, at a heating rate of 3.5°C per minute to 200°C, and then heated at 200°C for 1 hour to obtain a cured product. 。

[0095] Next, the cured material peeled from the PTFE film was freeze-dried using liquid nitrogen, and 2.0 g was weighed out and placed in a sealed PTFE pressure-resistant decomposition container with 20 g of pure water. This container was then stored for 20 hours at 121°C, 100% humidity, and 2 atmospheres using an accelerated life test apparatus (saturated pressure cooker test apparatus). The supernatant of the extract was filtered through a membrane filter with a pore size of 0.45 μm to obtain the test solution.

[0096] Next, according to the Japanese Industrial Standard JIS K 0127 (2013) General Rules for Ion Chromatography, standard solutions of formate ion, acetate ion, propionate ion, and sulfate ion were introduced into an ion chromatograph analyzer (Dionex ICS-3000) to create calibration curves. 25 μL of the sample solution was introduced, and the concentrations of formate ion, acetate ion, propionate ion, and sulfate ion in the sample solution were determined from the obtained peaks and calibration curves, and the total amount of eluted ions was calculated. The eluted ion amount, calculated as the mass of eluted ions relative to the mass of the organic membrane, was classified as A if it was 500 ppm or less, B if it was between 500 ppm and 2000 ppm, and C if it was greater than 2000 ppm. Furthermore, samples with conductivity of 300 μS / cm or less, measured using the same ion chromatograph, were classified as A; samples with conductivity between 300 μS / cm and 500 μS / cm were classified as B; and samples with conductivity above 500 μS / cm were classified as C.

[0097] (5-2) Evaluation of acid ion elution and conductivity of organic membrane (II) Using a photosensitive sheet, a cured organic film (II) was prepared in the same manner as in (5-1), and the total amount of eluted ions and the conductivity of the test solution were determined.

[0098] (5-3) Total amount of acid ions eluted from organic membrane (I) and organic membrane (II) The total amount of ions eluted obtained in (5-1) and (5-2) was calculated. Samples with a total of 1000 ppm or less were designated as A, those with a total between 1000 ppm and 4000 ppm were designated as B, and those with a total greater than 4000 ppm were designated as C.

[0099] (6) Evaluation of the cross-sectional shape of the organic film (I) The hollow structure formed in (2) was cut using a dicing device, and the cross-section in the short-side direction of the lattice pattern of the organic film (I) was observed and measured using a scanning electron microscope (Hitachi S-4800). Let x be the length of the contact surface between substrate 1 and organic film (I), and let y be the length of the contact surface between organic film (II) and organic film (I). Then, those where 1≧y / x≧0.8 were designated as A, those where 0.8>y / x≧0.6 were designated as B, and those where 0.6>y / x were designated as C.

[0100] (7) Evaluation of the weight loss temperature of the organic film (I) In (5-1), 15 mg of the cured material peeled from the PTFE film was measured and its heat resistance was evaluated by heating it from 25°C to 400°C at a heating rate of 10°C / min using a thermogravimetric analyzer (Shimadzu TGA-50). Samples that lost 5% of their weight from the weight before heating were classified as A if the temperature was 350°C or higher, B if it was between 300°C and 350°C, and C if it was below 300°C.

[0101] (8) Evaluation of the elastic modulus of organic film (I) In (5-1), the cured material peeled from the PTFE film was cut into strips measuring 10 mm x 5 mm, and the storage modulus at 50°C was measured by heating the material from 25°C to 400°C using a dynamic viscoelasticity measuring device (Shimadzu Corporation DMS6100) at a frequency of 1 Hz and a heating rate of 10°C / min.

[0102] (9) Evaluation of the elastic modulus of organic film (II) A cured organic film (II) was prepared using a photosensitive sheet in the same manner as in (5-1). The cured material peeled from the PTFE film was cut into 10 mm x 5 mm strips, and the storage modulus was measured in the same manner as in (8). (10) Evaluation of sealing efficiency of hollow structures (2) Of the 100 hollow structures formed in a grid pattern on the substrate, the number of squares in which the hollow structure roofing material did not come into contact with the substrate and formed a hollow was counted, and the percentage was calculated as the normal rate. Those with a rate of 90% or more were designated as A, and those between 80% and 90% were designated as B.

[0103] The abbreviated names and structures of the compounds used in the following examples and comparative examples are as follows. (acid dianhydride) ODPA: 3,3',4,4'-diphenyl ether tetracarboxylic acid dianhydride (Diamine) BAHF: 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane RT-1000: Jeffermin RT-1000 (product name, manufactured by HUNTSMAN Co., Ltd.) SiDA:1,1,3,3-tetramethyl-1,3-bis(3-aminopropyl)disiloxane (Terminal encapsulant) MAP:3-aminophenol NA:5-norbornene-2,3-dicarboxylic acid (solvent) NMP:N-methyl-2-pyrrolidone GBL: γ-Butyrolactone EL: Ethyl lactate (Thermal crosslinkable compound) HMOM-TPHAP (product name, manufactured by Honshu Chemical Industry Co., Ltd.) is a polyfunctional alkoxymethyl group-containing compound. VG-3101L (TECHMORE VG3101L, product name, manufactured by Printec Co., Ltd.) is a polyfunctional epoxy group-containing compound. MW-100LM (NIKALAC MW-100LM, product name, manufactured by Sanwa Chemical Co., Ltd.) is a polyfunctional alkoxymethyl group-containing compound. TEPIC-VL (product name, manufactured by Nissan Chemical Industries, Ltd.) JER157s70 (product name, manufactured by Mitsubishi Chemical Corporation)

[0104] [ka]

[0105] (Adhesion improving agent) KBM-403 (product name, manufactured by Shin-Etsu Chemical Co., Ltd.) 3-Glycidoxypropyltriethoxysilane (Surfactants) PF77: Polyflow 77 (product name, manufactured by Kyoeisha Chemical Co., Ltd.) Acrylic polymer (Oxime-based photopolymerization initiator) PBG-305 (product name, manufactured by Changzhou Strong Electronics New Materials Co., Ltd.) NCI-831 (ADEKA Arcles product name, manufactured by ADEKA Corporation) OXE-02 ("IRGACURE" brand name, manufactured by Ciba Specialty Chemicals Co., Ltd.)

[0106] [ka]

[0107] (Polymerizable compound (acrylic monomer)) BP-6EM ("Light Ester" BP-6EM, product name, manufactured by Kyoeisha Chemical Co., Ltd.) M-315 ("Aronix" brand name, manufactured by Toagosei Co., Ltd.) DCP-A (Light Acrylate DCP-A, product name, manufactured by Kyoeisha Chemical Co., Ltd.)

[0108] [ka]

[0109] (Photoacid generator (cationic polymerization initiator)) CPI-310B (product name, manufactured by Sunapro Co., Ltd.)

[0110] [ka]

[0111] (Naphthoquinone diazide compound) Naphthoquinone diazide compound B1 Naphthoquinone diazide compound B2 Naphthoquinone diazide compound B3

[0112] [ka]

[0113] Synthesis Example 1: Synthesis of dicarboxylic acid derivative (a) Under a nitrogen atmosphere, 27.2 g (0.4 mol) of imidazole was placed in a 250 ml three-necked flask, and 100 g of methylene chloride was added and stirred at room temperature. This was cooled to below -5°C, and a liquid containing 29.5 g (0.1 mol) of 4,4'-diphenyl ether dicarboxylic acid dichloride dispersed in 100 g of methylene chloride was added dropwise over 1 hour, ensuring that the temperature of the reaction solution did not exceed 0°C. After the addition, the reaction solution was stirred for a further 3 hours at room temperature, and the precipitate formed during the reaction was filtered. The filtered precipitate was washed several times with pure water and dried in a vacuum oven at 50°C for 100 hours to obtain the dicarboxylic acid derivative (a) shown in the following formula.

[0114] [ka]

[0115] Synthesis Example 2: Synthesis of alkali-soluble resin (A) polyimide A1 Under a stream of dry nitrogen, 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 along 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 added to 2 L of water to obtain a white precipitate. This 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 polyimide A1 powder.

[0116] Synthesis Example 3: Synthesis of alkali-soluble resin (A) polybenzoxazole precursor A2 Under a stream of dry nitrogen, BAHF (15.57 g, 0.045 mol) and RT-1000 (5.00 g, 0.0050 mol) were dissolved in 100 g of NMP. Dicarboxylic acid derivative (a) (15.23 g, 0.043 mol) was added to this solution along with 25 g of NMP, and the mixture was reacted at 85°C for 3 hours. Next, SiDA (0.62 g, 0.0025 mol), ODPA (0.78 g, 0.0025 mol), and NA (2.46 g, 0.015 mol) were added along with 25 g of NMP, and the mixture was reacted at 85°C for 1 hour. After the reaction was complete, the mixture was cooled to room temperature, and acetic acid (13.20 g, 0.25 mol) was added along with 25 g of NMP, and the mixture was stirred at room temperature for 1 hour. After stirring, the solution was added to 1.5 L of water to obtain a white precipitate. This precipitate was collected by filtration, washed three times with water, and then dried in a forced-air dryer at 50°C for three days to obtain a powder of polybenzoxazole precursor A2.

[0117] Synthesis Example 4: Synthesis of alkali-soluble resin (A) polyhydroxystyrene A3 To a mixed solution of 500 ml of tetrahydrofuran and 0.01 moles of sec-butyllithium as an initiator, 20 g total of pt-butoxystyrene and styrene were added in a molar ratio of 3:1, and polymerization was carried out with stirring for 3 hours. Polymerization was terminated by adding 0.1 moles of methanol to the reaction solution. Next, to purify the polymer, the reaction mixture was poured into methanol, and the precipitated polymer was dried to obtain a white polymer. Furthermore, it was dissolved in 400 ml of acetone, stirred at 60°C with a small amount of concentrated hydrochloric acid for 7 hours, poured into water to precipitate the polymer, deprotected the pt-butoxystyrene to convert it to hydroxystyrene, and washed and dried to obtain polyhydroxystyrene A3, a copolymer of p-hydroxystyrene and styrene.

[0118] Preparation Examples 1-25: Preparation of Photosensitive Varnishes 1-25 The materials for the photosensitive varnish were added and stirred as shown in Tables 1 and 2 to obtain photosensitive varnishes 1 to 25 with a viscosity of 2000 cP.

[0119] Preparation Examples 26, 27: Preparation of photosensitive varnishes 26, 27 As shown in Table 2, the materials for the photosensitive varnish were added and stirred to obtain a photosensitive varnish 25 with a viscosity of 2000 cP. The inorganic particles used were glass particles A containing 45% by mass of silicon dioxide, 25% by mass of aluminum oxide, 4% by mass of boron oxide, and 26% by mass of yttrium oxide. The refractive index of glass particles A at a wavelength of 405 nm was 1.61, and the average particle diameter was 1.2 μm.

[0120] [Table 1]

[0121] [Table 2]

[0122] Preparation Examples 28-32: Preparation of Photosensitive Sheets 1-5 As shown in Table 2, the materials for the photosensitive varnish were added and stirred. The resulting photosensitive varnish was applied to a 38 μm thick PET film using a commarol coater, dried at 80°C for 8 minutes, and then laminated with a 10 μm thick PP film as a protective film to obtain 23 μm thick photosensitive sheets 1-5.

[0123] Examples 1-31, Comparative Examples 1-6 The photosensitive varnishes from Preparation Examples 1 to 27 were used as the material for organic film (I), and the photosensitive sheets from Preparation Examples 28 to 32 were used as the material for organic film (II). Steps (1) and (2) above were performed to obtain hollow structures, and evaluations (3) to (10) were carried out. In Example 17 only, in the formation of the hollow structure in step (2), propylene glycol monomethyl ether acetate was used for development instead of a 2.38 mass% aqueous solution of tetramethylammonium (TMAH). The combinations of materials for organic film (I) and (II) and the evaluation results are shown in Tables 3 to 5.

[0124] [Table 3]

[0125] [Table 4]

[0126] [Table 5] [Explanation of Symbols]

[0127] 1 circuit board 1(a) Top surface of the substrate 2 Organic film (I) 2(a) Wall surface of organic film (I) 3 Organic film (II) 4 Metal wiring (Al, Cu, etc.)

Claims

1. From the top surface of the substrate having metal wiring, As a hollow structure support material, an organic film (I) with a film thickness of 5 to 30 μm and A hollow structure roofing material in which organic films (II) with a film thickness of 5 to 30 μm are laminated in this order, A hollow structure in which, when the organic membrane (I) and the organic membrane (II) are evaluated individually using the ion elution evaluation method described below, the sum of the ion elution amounts of organic membrane (I) and organic membrane (II) is 4000 ppm or less. (Method for evaluating ion elution amount) The freeze-dried organic membrane is placed in 10 times its mass volume of pure water and hot-water extracted at 121°C for 20 hours. The supernatant of the extract is then used as the test solution. The test solution and a standard solution of the target ion 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 sum of these concentrations is converted to the mass of eluted ions relative to the mass of the organic membrane and defined as the ion elution amount.

2. The hollow structure according to claim 1, wherein the amount of ions eluted when the organic membrane (I) is evaluated by the ion elution evaluation method described above is 2000 ppm or less.

3. The hollow structure according to claim 1 or 2, wherein the amount of ions eluted when the organic membrane (II) is evaluated by the ion elution evaluation method described above is 2000 ppm or less.

4. The hollow structure according to any one of claims 1 to 3, wherein the conductivity of the test solution of the organic membrane (I) obtained by the ion elution amount evaluation method is 500 μS / cm or less.

5. The hollow structure according to any one of claims 1 to 4, wherein the conductivity of the test solution of the organic membrane (II) obtained by the ion elution amount evaluation method is 500 μS / cm or less.

6. The aforementioned organic film (I) At least one alkali-soluble resin (A) selected from the group consisting of polyimide, polybenzoxazole, polyamide, any precursor thereof, and copolymers thereof, Naphthoquinone diazide compound (B), A hollow structure according to any one of claims 1 to 5, comprising a cured product obtained by curing a positive-type photosensitive resin composition containing a thermally crosslinkable compound (C).

7. The hollow structure according to claim 6, wherein the naphthoquinone diazide compound (B) contains a compound represented by formula (1) and / or formula (2). 【Chemistry 1】

8. The organic film (I) At least one alkali-soluble resin (A) selected from the group consisting of polyimide, polybenzoxazole, polyamide, any precursor thereof, and copolymers thereof, A thermally crosslinkable compound (C), Oxime-based photopolymerization initiator (D), A hollow structure according to any one of claims 1 to 5, comprising a cured product obtained by curing a negative-type photosensitive resin composition containing a polymerizable compound (E), wherein the oxime-based photopolymerization initiator (D) contains a compound represented by formula (3). 【Chemistry 2】 (In formula (3), Ar represents an aryl group, Z １ represents an organic group with 6 to 20 carbon atoms, Z ２ (This represents a hydrogen atom or an organic group with 1 to 20 carbon atoms.)

9. The polymerizable compound (E) contains a compound represented by formula (4), The hollow structure according to claim 8, wherein the polymerizable compound (E) contains 55 to 90% by mass of the compound represented by formula (4) out of 100% by mass of the total amount. 【Transformation 3】

10. The hollow structure according to any one of claims 6 to 9, wherein the thermally crosslinkable compound (C) contains a polyfunctional epoxy group-containing compound (C-1) and a polyfunctional alkoxymethyl group-containing compound (C-2), and the content of the polyfunctional epoxy group-containing compound (C-1) is 5 to 30 parts by mass and the content of the polyfunctional alkoxymethyl group-containing compound (C-2) is 1 to 10 parts by mass per 100 parts by mass of alkali-soluble resin (A).

11. The organic film (I) contains 30 to 80% by mass of inorganic particles in 100% by mass of organic film (I), and the organic film (II) contains 0 to 80% by mass of inorganic particles in 100% by mass of organic film (II), or The hollow structure according to any one of claims 1 to 10, wherein the organic film (II) contains 30 to 80% by mass of inorganic particles in 100% by mass of the organic film (II), and the organic film (I) contains 0 to 80% by mass of inorganic particles in 100% by mass of the organic film (I).

12. The hollow structure according to claim 11, wherein the inorganic particles are glass particles having a refractive index of 1.55 to 1.

75.

13. The hollow structure according to any one of claims 1 to 12, wherein, in a cross section perpendicular to the upper surface of the substrate and the wall surface of the organic film (I), the length of the contact surface between the organic film (I) and the substrate is x, and the length of the contact surface between the organic film (I) and the organic film (II) is y, such that 1 ≥ y / x ≥ 0.

6.

14. An electronic component having a hollow structure according to any one of claims 1 to 13.

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