JP2008299165A - Method for producing formed body having hollow structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish a method for inexpensively producing a formed body having a high-accuracy hollow structure by photolithography using photosensitive resin compositions by a simple process with a high process yield. <P>SOLUTION: The method for producing a formed body having a hollow structure includes: a step of forming a first photosensitive resin layer insensitive to light of ≥400 nm wavelength on a substrate and irradiating the layer with light of <400 nm wavelength through a first mask; a step of forming a solid or semisolid second photosensitive resin layer sensitive to light of ≥400 nm wavelength and having a solid content of ≥90 wt.% on the first photosensitive resin layer exposed at the above step without performing development, and irradiating the second photosensitive resin layer with light of ≥400 nm wavelength through a second mask; a step of heat-treating the first and second photosensitive resin layers together; and a step of developing unexposed portions of the first and second photosensitive resin layers together. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a molded body using a photosensitive resin composition. In particular, the present invention relates to a method for producing a molded article having a high-cost hollow structure with high process yield and simple manufacturing process using photolithography.

  In recent years, a field called MEMS (microelectromechanical systems) using semiconductor technology has been actively studied, and MEMS technology is shifting to a practical stage in various fields such as sensors. Also in the MEMS field, the design and fabrication techniques of each structure (molded body) are diversified, and the required dimensions of the structure were initially from several micrometers to sub-millimeters, but recently, from the nano level to several millimeters. To a wide range. In the MEMS technology, a device is usually manufactured by laminating a functionalized film or structure on a silicon substrate. In such a manufacturing method, a structure having a high width-to-height ratio (aspect ratio) is generally difficult to produce as compared with a structure having a low aspect ratio. Various methods for producing a high aspect ratio structure have been proposed, and some of them have been industrially implemented. For example, a photolithography technique using a negative thick film photoresist (for example, trade name SU-8, manufactured by Microchem) is often used. In photolithography, patterning exposure is performed on a substrate, and then development is performed with a developer to selectively remove an exposed region or a non-exposed region, thereby creating a minute structure. In the MEMS field, it is desired to create a minute structure having a hollow structure such as a flow path or a micro component. However, when a normal photolithography technique is applied as it is, various difficulties are involved. That is, when applying ordinary photolithography to the production of a structure having a hollow structure, the process becomes complicated and long, and the yield is poor, so that a highly accurate structure cannot be produced at low cost.

  Various methods, for example, a method using a sacrificial layer or a method using a dry film resist, are known as methods for producing a molded body having a hollow structure using photolithography. For example, Non-Patent Document 1 describes a method of forming a molded body having a hollow structure such as a microchannel using a light-shielding metal thin film as a sacrificial layer. However, in such a method using a metal thin film, it is necessary to provide a metal thin film with high positional accuracy after the first photosensitive layer is exposed, the process is complicated, and the yield of the entire process may be lowered. There is.

  In Non-Patent Document 2, a dry film resist is laminated on a structure obtained by patterning a microchannel, which is an example of a molded body having a hollow structure, with a resist, and this dry film resist is patterned by photolithography. It is described that it is created. A simple structure such as a microchannel can be formed by a dry film resist, but there is a problem that deformation such as thermal sagging of the upper layer portion and swelling of the upper layer portion due to expansion of air sealed inside occurs. Such a deformation is not a problem when the purpose is simply to seal, such as a microchannel, but it is a difficulty in an application that requires high dimensional accuracy in a structure such as a sensor or an ink jet head.

  Further, Patent Document 1 firstly forms and exposes a first photosensitive resin layer on a substrate, subsequently laminates and exposes a second photosensitive resin layer, and then forms first and second photosensitive resin layers. A method of manufacturing an inkjet head that develops all at once is described. However, simply by laminating and exposing a film having the same photosensitive wavelength region as in Patent Document 1, it is exposed to the lower photosensitive resin layer simultaneously with the upper photosensitive resin layer in which the hollow structure is to be formed. Only a pattern on a step can be formed, and a molded body having a hollow structure cannot be formed. In fact, Patent Document 1 does not specifically describe the production of a molded article having a hollow structure that is the object of the present invention.

  Patent Document 2 discloses a step of applying a first nozzle constituent resin layer, forming a flow path pattern by exposure and baking, and a second photosensitive wavelength region different from that of the first nozzle constituent resin layer. And a step of forming an ink discharge port pattern by exposure and baking, and a step of developing unexposed portions in each layer of the first and second nozzle constituent resin layers in a lump. An ink jet recording head manufacturing method is described. Although a molded body having a hollow structure can be manufactured by the technique of Patent Document 2, a positive photoresist is used in this technique. In Patent Document 2, a minute protrusion is formed near the interface with the positive photoresist. There is a description that an object is generated between layers of a two-stage ink flow path. Further, this document is characterized in that different photocationic polymerization initiators are used for the resin composition for forming the first and second nozzles. Further, liquid is applied when the second layer is formed. Since the first layer and the second layer contain similar main components, the photosensitive component in the second layer is diffused to cause the first layer to diffuse. There is a possibility that the unexposed portion is intermixed and the first layer is exposed at the same time when the second layer is exposed, so that a molded body having a highly accurate hollow structure cannot be obtained.

8th International Conference on Miniaturized Systems for Chemistry and Life Sciences, September 26-30 2004, Sweden, 638-640 Sensors and Actuators, B48 (1998), paragraph 356. Japanese Patent Laid-Open No. 10-71722 JP 2006-159663 A

  An object of the present invention is to establish a method for inexpensively producing a molded body having a hollow structure with a simple process, a high process yield, and a high accuracy by photolithography using a photosensitive resin composition.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, in photolithography, the above-mentioned problems can be solved by providing two types of photosensitive resin layers that are substantially photosensitive only at a specific wavelength. The inventors have found that this can be solved, and have completed the present invention.

That is, the present invention
(1) Forming a first photosensitive resin layer that is not sensitive to light having a wavelength of 400 nm or more on a substrate, irradiating light having a wavelength of less than 400 nm through a first mask, and performing development processing. In addition, a solid or semi-solid second photosensitive resin layer having a solid content of 90% by weight or more that is sensitive to light having a wavelength of 400 nm or more is formed on the first photosensitive resin layer that has been subjected to the light-sensitive treatment in the above process. And a step of irradiating light having a wavelength of 400 nm or more through the second mask, a step of collectively heat-treating the first and second photosensitive resin layers, and the first and second photosensitive properties. A method for producing a molded article having a hollow structure, comprising a step of developing unexposed portions of the resin layer in a lump;
(2) The method for producing a molded article according to (1), wherein the second photosensitive resin layer is obtained by laminating a dry film resist,
(3) The method for producing a molded article according to (2), wherein the laminating temperature is 20 to 100 ° C.
(4) The method for producing a molded body according to any one of (1) to (3), wherein the thickness of the first and second photosensitive resin layers is 10 to 100 μm,
(5) Any one of (1) to (4), wherein the photosensitive resin composition for forming the second photosensitive resin layer contains a polyfunctional epoxy resin, a cationic polymerization initiator, and a sensitizer. A method for producing the molded article according to the item,
(6) The method for producing a molded article according to (5), wherein the content of the sensitizer is 10 to 100% by weight with respect to the content of the cationic polymerization initiator,
(7) The method for producing a molded article according to (5) or (6), wherein the polyfunctional epoxy resin is a bisphenol A polyfunctional epoxy resin represented by the following formula (1):

(In Formula (1), a plurality of R's each independently represents a glycidyl group or a hydrogen atom, and n represents an integer of 1 to 30, respectively.)
(8) The method for producing a molded article according to any one of (5) to (7), wherein the sensitizer is a 9,10-dialkoxyanthracene derivative,
About.

  A method has been established for producing a compact having a simple process, a high process yield, and a highly accurate hollow structure at low cost.

Hereinafter, embodiments of the present invention will be described in detail.
In the method for producing a molded article of the present invention, a first photosensitive resin layer that is not sensitive to light having a wavelength of 400 nm or more is formed on a predetermined substrate, and light having a wavelength of less than 400 nm is transmitted through the first mask. Solid or semi-solid having a solid content of 90% by weight or more exposed to light having a wavelength of 400 nm or more on the first photosensitive resin layer subjected to the light-sensitive process by the above-described process without performing the irradiation process and the development process. Forming a second photosensitive resin layer and irradiating light having a wavelength of 400 nm or more through a second mask, subjecting the first and second photosensitive resin layers to heat treatment in a lump, and A step of collectively developing the unexposed portions of the first and second photosensitive resin layers.
In the present invention, “not sensitive to light” means that the amount of photosensitivity by light is such a small amount that a polymerization reaction does not occur even when irradiated with light, or a polymerization reaction does not cause residual development. Represents that.

First, a photosensitive resin composition (hereinafter referred to as “first photosensitive resin composition”) for forming the first photosensitive resin layer in the present invention will be described.
The first photosensitive resin composition is characterized by being exposed to light having a wavelength of less than 400 nm and not being exposed to light having a wavelength of 400 nm or more. The first photosensitive resin composition can be prepared using various photosensitive resins, but since the cured product is excellent in physical properties such as strength, chemical resistance and heat resistance, a polyfunctional epoxy resin and a cationic polymerization initiator are used. It is preferable to prepare it as a photosensitive resin composition.

  Specific examples of the polyfunctional epoxy resin that can be used include, for example, bisphenol A type epoxy resins, polyfunctional bisphenol A novolac type epoxy resins, epoxy resins obtained by reaction of alcoholic hydroxyl groups of bisphenol F type epoxy resins with epichlorohydrin, An epoxy resin obtained by reacting an alcoholic hydroxyl group of bisphenol A type epoxy resin with epichlorohydrin, an o-cresol novolac type epoxy resin, a phenolic hydroxyl group of a resin obtained by reacting di (methoxymethylphenyl) with phenol, Examples thereof include biphenylphenol novolak type epoxy resins obtained by reacting with epichlorohydrin. These polyfunctional epoxy resins can be used alone or in combination of two or more.

The epoxy equivalent of the polyfunctional epoxy resin that can be used is preferably 150 to 400. If the epoxy equivalent is less than this range, curing shrinkage will increase and warping and cracking of the cured product will easily occur, and if it exceeds this range, the crosslink density will decrease and the strength of the cured film, chemical resistance, heat resistance and crack resistance will be reduced. The properties etc. are reduced.
Moreover, 50-100 degreeC is preferable and the softening point of the polyfunctional epoxy resin which can be used has more preferable 60-90 degreeC. When the softening point is lower than this range, mask sticking during patterning is likely to occur, and further, since it softens at room temperature when used as a dry film resist, handling is difficult. On the other hand, when the softening point is higher than this range, softening is difficult when laminating the dry film resist to the substrate, and the bonding property to the substrate is deteriorated.
These polyfunctional epoxy resins can be used alone or in combination of two or more.

Multifunctional epoxy resins having such performance can be easily obtained from the market. For example, EPON SU-8 (manufactured by Resolution Performance Products) as a polyfunctional bisphenol A novolac type epoxy resin, Epicoat 157S70, Epicoat 157S65 (manufactured by Japan Epoxy Resin Co., Ltd.), YD-128 (manufactured by Tohto Kasei Co., Ltd.), Epicron N-885, Epicron N-885, Epicron N-2055 (manufactured by Dainippon Ink and Chemicals), bisphenol F type epoxy resin NER-7604 (manufactured by Nippon Kayaku Co., Ltd.) as an epoxy resin obtained by reaction of an alcoholic hydroxyl group with epichlorohydrin, as an epoxy resin obtained by reaction of an alcoholic hydroxyl group of a bisphenol A type epoxy resin with epichlorohydrin NER-1302 (manufactured by Nippon Kayaku Co., Ltd.), EOCN4400 (manufactured by Nippon Kayaku Co., Ltd.) as an o-cresol novolak type epoxy resin, resin obtained by reacting di (methoxymethylphenyl) with phenol NC-3000H (manufactured by Nippon Kayaku Co., Ltd.) as a biphenylphenol novolac type epoxy resin obtained by reacting a phenolic hydroxyl group with epichlorohydrin can be used.
Among these, even when a thick film structure is formed, a fine structure can be obtained with a high aspect ratio and high accuracy. Therefore, a polyfunctional bisphenol A novolac type epoxy resin represented by the above formula (1) (for example, a resonator) EPON SU-8) manufactured by Solution Performance Products is particularly preferred.

  As the cationic photopolymerization initiator contained in the first photosensitive resin composition, the first photosensitive resin composition is imparted with a function of being exposed to light having a wavelength of less than 400 nm and not being exposed to light having a wavelength of 400 nm or more. In addition, any material may be used as long as it has sufficient performance to cure the polyfunctional epoxy resin. Examples of such a photocationic polymerization initiator include aromatic iodonium salts and aromatic sulfonium salts. Can be mentioned. Of these, specific examples of the aromatic iodonium salt include diphenyliodonium tetrakis (pentafluorophenyl) borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, di (4-nonylphenyl) iodonium hexafluorophosphate, and the like. Can be mentioned.

Specific examples of the aromatic sulfonium salt include 4-thiophenyldiphenylsulfonium hexafluoroantimonate (manufactured by San Apro Co., Ltd., CPI-101A), 4- {4- (2-chlorobenzoyl) phenylthio } Phenylbis (4-fluorophenyl) sulfonium hexafluoroantimonate (Asahi Denka Kogyo Co., Ltd., SP-172) and 4-thiophenyldiphenylsulfonium hexafluoroantimonate containing aromatic sulfonium hexa Examples thereof include a mixture of fluoroantimonates (manufactured by Dow Chemical, UVI-6974), and these aromatic sulfonium salts are more preferably used because they are thermally stable compared to aromatic iodonium salts.
These cationic photopolymerization initiators may be used alone or in combination of two or more.

  Since the cationic photopolymerization initiator component has an action of absorbing light, a large amount of the cationic photopolymerization initiator component is used in the case of a thick film (specifically, 50 μm or more) (specifically, 15% by weight). In the case of a small amount of use (specifically, less than 3% by weight), it is difficult to obtain a sufficient curing rate. Become. In the case of a thin film, sufficient performance is exhibited by addition of a small amount (specifically, 1% by weight or more). On the other hand, when a large amount of the cationic photopolymerization initiator component is used, there is no problem with respect to the light transmission to the deep part, but an expensive initiator is used unnecessarily, which is not economical. From these points, the content ratio of the cationic photopolymerization initiator component is 1 wt% to 15 wt% in the solid content of the total content of the polyfunctional epoxy resin component and the photo cationic polymerization initiator component as the solid content of the photosensitive resin. % Is preferable, and 3 to 10% by weight is particularly preferable.

  In forming the first photosensitive resin layer using the photosensitive resin composition containing the polyfunctional epoxy resin and the cationic photopolymerization initiator, the substrate is used as a coating liquid using an organic solvent as described below. It is convenient to apply to. As such solvents, all commonly used organic solvents that can dissolve each component can be used. Examples of usable organic solvents include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. , Aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene, glycol ethers such as dipropylene glycol dimethyl ether and dipropylene glycol diethyl ether, ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether Esters such as acetate and γ-butyrolactone, alcohols such as methanol, ethanol, ceresolve and methyl ceresolve, aliphatic hydrocarbons such as octane and decane, petroleum Ether, petroleum naphtha, hydrogenated petroleum naphtha, an organic solvent, or the like, such as petroleum-based solvents such as solvent naphtha.

  These solvents can be used alone or in admixture of two or more. The organic solvent used here is added for the purpose of adjusting the film thickness and applicability when applied to the substrate, the solubility of the polyfunctional epoxy resin and the photocationic polymerization initiator, the volatility of each component, In order to appropriately maintain the liquid viscosity of the coating liquid, the content in the coating liquid is preferably 5% by weight to 95% by weight, and particularly preferably 10% by weight to 90% by weight.

  The first photosensitive resin composition may contain a miscible reactive epoxy monomer for the purpose of improving the reactivity of the photosensitive resin layer, the physical properties of the cured film, the pattern performance, and the like. As the reactive epoxy monomer, a glycidyl ether compound can be used, for example, diethylene glycol diglycidyl ether, hexanediol diglycidyl ether, dimethylolpropane diglycidyl ether, polypropylene glycol diglycidyl ether (manufactured by Asahi Denka Kogyo Co., Ltd., ED506), Examples thereof include trimethylolpropane triglycidyl ether (manufactured by Asahi Denka Kogyo Co., Ltd., ED505), pentaerythritol tetraglycidyl ether, and the like. These can be used alone or in admixture of two or more. Reactive epoxy monomer components are often in liquid form, and if the component is in liquid form, blending more than 20% by weight may cause problems such as mask sticking due to stickiness of the film after removal of the solvent. There is sex. From this point, when these monomer components are blended, the blending ratio is determined based on the total content of the polyfunctional epoxy resin, the photocationic polymerization initiator, and the reactive epoxy monomer as the solid content of the photosensitive resin layer. The content is preferably 1 to 10% by weight, particularly 2 to 7% by weight.

  In the first photosensitive resin composition, a miscible adhesion-imparting agent may be used for the purpose of further improving the adhesion of the photosensitive resin layer to the substrate. As the adhesion-imparting agent, a coupling agent such as a silane coupling agent or a titanium coupling agent can be used, and a silane coupling agent is preferable.

Examples of the silane coupling agent include 3-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyl tris (2-methoxyethoxy) silane, 3-methacryloxypropyltrimethoxysilane, 2 -(3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3 -Aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, etc. are mentioned.
These adhesiveness imparting agents can be used alone or in combination of two or more. When a large amount of the adhesion-imparting agent is used, the softening point of the photosensitive resin layer before curing is lowered and mask sticking is caused. Depending on the base material, it can be used within a range that does not adversely affect the effect even in a small amount, and its use ratio is preferably 15% by weight or less, particularly preferably 5% by weight. % By weight or less.

  An ion catcher may be added to the first photosensitive resin composition when it is necessary to reduce the adverse effect of the ions derived from the photocationic polymerization initiator on the photosensitive resin layer. The ion catchers that can be used include trismethoxyaluminum, trisethoxyaluminum, trisisopropoxyaluminum, isopropoxydiethoxyaluminum, alkoxyaluminum such as trisbutoxyaluminum, phenoxyaluminum such as trisphenoxyaluminum and trisparamethylphenoxyaluminum, and trisacetoxyaluminum. , Tris stearato aluminum, Tris butyrate aluminum, Tris propionate aluminum, Tris acetyl acetonato aluminum, Tris trifluoroacetyl acetonato aluminum, Tris ethyl acetoaceto aluminum, Diacetyl acetonato dipivaloyl metanato aluminum, Diisopropoxy (Ethyl acetoacetate) Aluminum etc. An organoaluminum compound, and the like. These components can be used alone or in combination of two or more. Moreover, the compounding quantity is 10 weight% or less with respect to the said solid content.

  Various additives, such as a thermoplastic resin, a coloring agent, a thickener, an antifoamer, a leveling agent, can be used for a 1st photosensitive resin composition as needed. Examples of the thermoplastic resin include polyethersulfone, polystyrene, and polycarbonate, and examples of the colorant include phthalocyanine blue, phthalocyanine green, iodine green, crystal violet, titanium oxide, carbon black, and naphthalene black. Examples of the thickener include olben, benton and montmorillonite, and examples of the antifoaming agent include antifoaming agents such as silicone type, fluorine type and polymer type. When these additives are used, the content thereof is preferably about 0.1 to 30% by weight, for example, in the photosensitive resin layer of the present invention, but this amount may be appropriately increased or decreased depending on the purpose of use. obtain.

  The first photosensitive resin composition includes inorganic substances such as barium sulfate, barium titanate, silicon oxide, amorphous silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, and mica powder. A filler can be used. The content is 0 to 60% by weight in the photosensitive resin layer.

Next, the photosensitive resin composition (hereinafter referred to as “second photosensitive resin composition”) for forming the second photosensitive resin layer will be described.
The second photosensitive resin composition is characterized in that it is exposed to light having a wavelength of 400 nm or more. The second photosensitive resin composition can be prepared using various photosensitive resins, but since the cured product is excellent in physical properties such as strength, chemical resistance and heat resistance, it is a polyfunctional epoxy resin, a cationic polymerization initiator. And a photosensitive resin composition containing a sensitizer is preferable.

  Specific examples of the polyfunctional epoxy resin that can be used include, for example, bisphenol A type epoxy resins, polyfunctional bisphenol A novolac type epoxy resins, epoxy resins obtained by reaction of alcoholic hydroxyl groups of bisphenol F type epoxy resins with epichlorohydrin, An epoxy resin obtained by reacting an alcoholic hydroxyl group of bisphenol A type epoxy resin with epichlorohydrin, an o-cresol novolac type epoxy resin, a phenolic hydroxyl group of a resin obtained by reacting di (methoxymethylphenyl) with phenol, Examples thereof include biphenylphenol novolak type epoxy resins obtained by reacting with epichlorohydrin. These polyfunctional epoxy resins can be used alone or in combination of two or more.

The epoxy equivalent of the polyfunctional epoxy resin that can be used is preferably 150 to 400. If the epoxy equivalent is less than this range, curing shrinkage will increase and warping and cracking of the cured product will easily occur, and if it exceeds this range, the crosslink density will decrease and the strength of the cured film, chemical resistance, heat resistance and crack resistance will be reduced. The properties etc. are reduced.
Moreover, 50-100 degreeC is preferable and the softening point of the polyfunctional epoxy resin which can be used has more preferable 60-90 degreeC. When the softening point is lower than this range, mask sticking during patterning is likely to occur, and further, since it softens at room temperature when used as a dry film resist, handling is difficult. On the other hand, when the softening point is higher than this range, softening is difficult when laminating the dry film resist to the substrate, and the bonding property to the substrate is deteriorated.
These polyfunctional epoxy resins can be used alone or in combination of two or more.

Multifunctional epoxy resins having such performance can be easily obtained from the market. For example, EPON SU-8 (manufactured by Resolution Performance Products) as a polyfunctional bisphenol A novolac type epoxy resin, Epicoat 157S70, Epicoat 157S65 (manufactured by Japan Epoxy Resin Co., Ltd.), YD-128 (manufactured by Tohto Kasei Co., Ltd.), Epicron N-885, Epicron N-885, Epicron N-2055 (manufactured by Dainippon Ink and Chemicals), bisphenol F type epoxy resin NER-7604 (manufactured by Nippon Kayaku Co., Ltd.) as an epoxy resin obtained by reaction of an alcoholic hydroxyl group with epichlorohydrin, as an epoxy resin obtained by reaction of an alcoholic hydroxyl group of a bisphenol A type epoxy resin with epichlorohydrin NER-1302 (manufactured by Nippon Kayaku Co., Ltd.), EOCN4400 (manufactured by Nippon Kayaku Co., Ltd.) as an o-cresol novolak type epoxy resin, resin obtained by reacting di (methoxymethylphenyl) with phenol NC-3000H (manufactured by Nippon Kayaku Co., Ltd.) as a biphenylphenol novolac type epoxy resin obtained by reacting a phenolic hydroxyl group with epichlorohydrin can be used.
Among these, even when a thick film structure is formed, a fine structure can be obtained with a high aspect ratio and high accuracy. Therefore, a polyfunctional bisphenol A novolac type epoxy resin represented by the above formula (1) (for example, a resonator) EPON SU-8) manufactured by Solution Performance Products is particularly preferred.

  The cationic photopolymerization initiator contained in the second photosensitive resin composition may be anything as long as it has sufficient performance to cure the polyfunctional epoxy resin, but is an aromatic iodonium salt. And aromatic sulfonium salts. Specific examples of the aromatic iodonium salt include diphenyliodonium tetrakis (pentafluorophenyl) borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, di (4-nonylphenyl) iodonium hexafluorophosphate, and the like.

  Specific examples of the aromatic sulfonium salt include 4-thiophenyldiphenylsulfonium hexafluoroantimonate (manufactured by San Apro Co., Ltd., CPI-101A), 4- {4- (2-chlorobenzoyl) phenylthio } Phenylbis (4-fluorophenyl) sulfonium hexafluoroantimonate (Asahi Denka Kogyo Co., Ltd., SP-172) and 4-thiophenyldiphenylsulfonium hexafluoroantimonate containing aromatic sulfonium hexa Examples thereof include a mixture of fluoroantimonates (manufactured by Dow Chemical, UVI-6974), and these aromatic sulfonium salts are more preferably used because they are thermally stable compared to aromatic iodonium salts.

  These cationic photopolymerization initiators may be used alone or in combination of two or more. When there are too few photocationic polymerization initiator components, it becomes difficult to obtain a sufficient curing rate. Moreover, when many photocationic polymerization initiator components are used, it is not economical. From these points, the usage ratio of the cationic photopolymerization initiator component is 1% by weight to 15% by weight based on the solid content of the total of the polyfunctional epoxy resin and the cationic photopolymerization initiator as the solid content of the photosensitive resin. Is preferable, and 3 to 10% by weight is particularly preferable.

  Any sensitizer contained in the second photosensitive resin composition can be used as long as it absorbs light having a wavelength of 400 nm or more and the photocationic initiator used in combination has a sensitizing action. However, an anthracene compound having an alkoxy group at the 9th and 10th positions (9,10-dialkoxyanthracene derivative) is preferable because of its excellent solubility in the resin component. As an alkoxy group, C1-C4 alkoxy groups, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, are mentioned, for example. The 9,10-dialkoxyanthracene derivative may further have a substituent. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, C1-C4 alkyl group such as methyl group, ethyl group, propyl group and butyl group, sulfonic acid alkyl ester group, and carboxylic acid. Examples include alkyl ester groups. Examples of the alkyl in the sulfonic acid alkyl ester group and the carboxylic acid alkyl ester include C1-C4 alkyl such as methyl, ethyl, propyl, and butyl. The substitution position of these substituents is preferably the 2-position.

  As the 9,10-dialkoxyanthracene derivative, for example, 9,10-dialkoxy such as 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-dibutoxyanthracene, etc. In addition to anthracene, 9,10-dimethoxy-2-ethylanthracene, 9,10-diethoxy-2-ethylanthracene, 9,10-dipropoxy-2-ethylanthracene, 9,10-dimethoxy-2-chloroanthracene, 9, Examples include 10-dimethoxyanthracene-2-sulfonic acid methyl ester, 9,10-diethoxyanthracene-2-sulfonic acid methyl ester, and 9,10-dimethoxyanthracene-2-carboxylic acid methyl ester. These can be used alone or in admixture of two or more. Among the sensitizers, 9,10-dialkoxyanthracene is preferable because of its excellent solubility in the resin component, and 9,10-dibutoxyanthracene is particularly preferable.

  It is preferable that the optimum amount of the sensitizer is appropriately changed according to the wavelength of light used for the photosensitive resin layer. If the amount of the sensitizer used is too small, sensitization to the photocationic polymerization initiator is not sufficient, and sufficient curing and resolution may not be obtained. In addition, if the amount of the sensitizer used is too large, the light absorption at the upper part of the photosensitive resin layer is strong, and the exposure amount of the lower layer part is lower than that of the upper layer part of the photosensitive resin layer. May not be obtained. Therefore, the usage-amount of a sensitizer is 1-200 weight% with respect to a photocationic polymerization initiator, Preferably it is 10-100 weight%, More preferably, it is 30-100 weight%. When exposure is performed in a wavelength range where the sensitizer can obtain sufficient light absorption (for example, a wavelength of 400 nm or more and a wavelength relatively close to 400 nm such as 405 nm), it is possible to adjust without being restricted by the above range. It is.

  In the second photosensitive resin composition, if necessary, as in the first photosensitive resin composition, a solvent, a reactive monomer, an adhesion imparting agent, an ion catcher, a thermoplastic resin, a colorant Various additives such as thickeners, antifoaming agents, leveling agents, and inorganic fillers can be contained. These contents are appropriately determined as in the case of the first photosensitive resin composition.

Furthermore, the process of the manufacturing method of a molded object is demonstrated.
The first and / or second photosensitive resin composition can be used after being processed into a dry film resist. That is, the 1st and / or 2nd photosensitive resin composition is diluted with a solvent as needed, and a roll coater, a die coater, a knife coater, a bar coater, a gravure coater, an applicator, etc. are used on a support film. After coating, the film is dried in a drying oven set at 45 to 100 ° C., and a predetermined amount of solvent is removed. If necessary, a dry film resist can be obtained by laminating a cover film or the like. At this time, the thickness of the resist on the support film is usually adjusted to 1 to 1,000 μm, preferably 2 to 100 μm. As the support film and the cover film, for example, a film of polyester, polypropylene, polyethylene, cellulose triacetate, polyimide, or the like is used. As these films, a film which has been subjected to a release treatment with a silicon release treatment agent or a non-silicon release treatment agent may be used as necessary.

  In the present invention, the substrate is not particularly limited as long as the first photosensitive resin layer can be uniformly formed and does not cause dissolution or deformation during the formation of the first photosensitive resin layer and in the subsequent steps. Examples of such substrate materials include inorganic materials such as silicon, quartz, glass, sapphire, metal, and ceramics, and organic materials such as polyimide and acrylic. A wafer is most preferred. The thickness of the substrate is usually 100 μm to 5 mm, preferably 200 μm to 1 mm, but is not limited thereto.

  The first photosensitive resin layer in the present invention is formed by applying the photosensitive resin composition for forming the first photosensitive resin layer diluted with a solvent on the substrate, if necessary, by spin coating, bar coating, roll After applying by a method such as coating, the solvent can be appropriately dried by a hot plate or oven. It is necessary to dry to such an extent that mask sticking does not occur, the drying temperature is preferably 40 to 150 ° C., more preferably 50 to 120 ° C., and the drying time varies depending on the film thickness, but usually 1 minute to 24 hours is preferable. .

  The first photosensitive resin layer may be formed by laminating a dry film resist as described above. The film thickness of the dry film resist is usually 1-1000 μm, preferably 10-100 μm, and several layers may be laminated to form the first photosensitive resin layer. The laminating pressure of the dry film resist is 0.05 to 10 MPa, preferably 0.1 to 3 MPa. The laminating temperature is preferably 20 to 150 ° C., more preferably 40 to 100 ° C., although it depends on the softening point of the dry film resist. If the laminating temperature is too low, the resist is not sufficiently softened and air bubbles are likely to be formed during laminating, and if it is too high, the production efficiency is lowered.

  The thickness of the first photosensitive resin layer thus formed is usually 1 to 1,000 μm, preferably 10 to 100 μm, and more preferably 10 to 50 μm. If the photosensitive resin layer is too thin, it takes time to develop and remove the uncured photosensitive resin layer inside the hollow structure, and the developer tends to cause swelling, peeling, and cracking in the pattern. Even if the resin layer is too thick, it takes time to form the resin layer.

Next, the first photosensitive resin layer thus formed is irradiated with light having a wavelength of less than 400 nm through a predetermined mask. Examples of the exposure apparatus used when irradiating and exposing light having a wavelength of less than 400 nm include aligners, steppers, and proximity exposure apparatuses that can selectively irradiate light having a wavelength of less than 400 nm. A filter may be used in combination. The amount of energy that is required when this will depend on the composition of the photosensitive resin layer, usually 10~1,0000mJ / cm ^2, preferably 50~7,000mJ / cm ^2.
The mask used when the first photosensitive resin layer is exposed is appropriately selected and used so as to be suitable for forming the target hollow structure.

The method of laminating the second photosensitive resin layer in the present invention may be any method as long as it is a method of laminating without mixing with the first photosensitive resin layer, but the solid content is 90% by weight on another substrate. A method of forming the above solid or semi-solid photosensitive resin layer and transferring it onto the first photosensitive resin layer is preferable. As a method of laminating the second photosensitive resin layer, the photosensitive resin composition for forming the second photosensitive resin layer is processed into a dry film resist as described above, and the first photosensitive resin layer is formed. The method of laminating on top is preferred. The laminating pressure of the dry film resist is 0.05 to 10 MPa, preferably 0.1 to 3 MPa. Although the temperature of the lamination depends on the softening point of the dry film resist, it is preferably 20 to 100 ° C, more preferably 35 to 85 ° C. If the laminating temperature is too low, the resist is not sufficiently softened and air bubbles are likely to be formed during laminating. If it is too high, the shape of the molded product is deteriorated and the production efficiency is lowered by intermixing with the first photosensitive resin layer. .
The thickness of the second photosensitive resin layer formed in this way is usually 1 for the convenience of handling the dry film resist and for efficiently forming the photosensitive resin layer having the required thickness by one lamination. ˜1,000 μm, preferably 10 to 100 μm, more preferably 10 to 50 μm.

Next, the second photosensitive resin layer thus formed is irradiated with light having a wavelength of 400 nm or more through a predetermined mask. Examples of the exposure apparatus used when irradiating and exposing light having a wavelength of 400 nm or more include aligners, steppers, projections and the like that can selectively irradiate light having a wavelength of 400 nm or more. May be. The amount of energy required at this time is approximately 50 to 10,000 mJ / cm ² depending on the composition of the photosensitive resin layer.
The mask used when the second photosensitive resin layer is exposed is appropriately selected and used so as to be suitable for forming the target hollow structure.

  Next, a step of collectively curing only the exposed portions of the first and second photosensitive resin layers is performed by heat treatment. The heat treatment is performed using a hot plate, an oven or the like at 60 to 150 ° C., preferably 75 to 120 ° C. for 1 to 30 minutes.

Next, development processing is performed.
In the present invention, the unirradiated first and second photosensitive resin layers are collectively developed. The step of developing the unirradiated first and second photosensitive resin layers in a lump is a method of immersing the whole substrate provided with the first and second photosensitive resin layers in the developer or spraying the developer. It is performed by the method of spraying. For development, a paddle type, spray type, shower type, or other developing device may be used, and ultrasonic irradiation may be performed as necessary. The developer may be any solvent that can dissolve the uncured first photosensitive resin layer and the second photosensitive resin layer at the same time. For example, γ-butyrolactone, triethylene glycol dimethyl ether, propylene An organic solvent such as glycol monomethyl ether acetate can be used.
In the dipping method, the treatment is usually performed at 15 to 60 ° C. for 1 minute to 2 hours. Moreover, in the method of spraying a developing solution with a spray etc., it is normally 15-60 degreeC, Preferably it is carried out at 20-40 degreeC.

  In the present invention, if necessary, a heat treatment can be further performed after the development treatment for the purpose of increasing the strength of the molded body. This heat treatment is performed by a hot plate or an oven, for example, by heating at a temperature of 100 to 200 ° C. for 15 minutes to 3 hours.

  The hollow structure in the present invention is a structure having a portion supported by a substrate via another structure without directly contacting the substrate, and a specific example of the hollow structure is shown in FIG. Such a beam structure, a convex hollow structure shown in FIG. 2 (2), a single beam structure shown in FIG. 2 (3), and a eaves structure shown in FIG. 2 (4) I can do it. Specific examples of the molded body having these hollow structures include MEMS parts such as an inkjet head and a microsensor.

  The method for producing a molded article having a hollow structure according to the present invention can significantly reduce the number of production steps compared to the conventional method, increase the process yield, and provide a molded article having a low-cost and high-precision hollow structure.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, these Examples are only the illustrations for demonstrating this invention suitably, and do not limit this invention at all. In Examples and Comparative Examples, “part” means “part by weight” and “%” means “% by weight” unless otherwise specified.

Example 1
(Formation of first photosensitive resin layer and photosensitivity)
According to the composition (unit is part) shown in Table 1 below, a polyfunctional epoxy resin, a photocationic polymerization initiator, and other components were mixed to obtain a first photosensitive resin composition.

Table 1 Composition of first photosensitive resin composition Multifunctional epoxy resin (trade name: EPON SU-8)
(Resolution Performance Products) 80
Multifunctional epoxy resin (trade name: NC-3000H, manufactured by Nippon Kayaku Co., Ltd.) 20
Photocationic polymerization initiator (trade name: UVI-6974,
50% propylene carbonate solution manufactured by Dow Chemical Company)
Solvent (cyclopentanone) 40
Reactive monomer (trade name: ED506, manufactured by Asahi Denka Kogyo Co., Ltd.) 4
Adhesion imparting agent (trade name: S-510, manufactured by Chisso Corporation) 2
Leveling agent (trade name: F-470, manufactured by Dainippon Ink Co., Ltd.) 0.06

After spin-coating the first photosensitive resin composition obtained above onto a silicon wafer, the solvent was removed by heating at 65 ° C. for 5 minutes and at 95 ° C. for 15 minutes using a hot plate, A first photosensitive resin layer having a film thickness was formed (FIG. 1A). Next, the first photosensitive resin layer was exposed through a first mask with L / S = 100 μm / 245 μm using light having a wavelength of 365 nm with an exposure apparatus (manufactured by USHIO INC.). The amount of energy at the time of exposure was 250 mJ / cm ² (FIG. 1B).
(Formation of second photosensitive resin layer and photosensitivity)
A polyfunctional epoxy resin, a photocationic polymerization initiator, a sensitizer, and other components were mixed according to the composition shown in Table 2 below (unit is part) to obtain a second photosensitive resin composition.

Table 2 Composition of second photosensitive resin composition Multifunctional epoxy resin (trade name: EPON SU-8)
(Resolution Performance Products) 80
Multifunctional epoxy resin (trade name: NC-3000H, manufactured by Nippon Kayaku Co., Ltd.) 20
Photocationic polymerization initiator (trade name: UVI-6974,
Dow Chemical Co., 50% propylene carbonate solution) 9
Sensitizer (9,10-dibutoxyanthracene) 0.45
Solvent (Ethyl methyl ketone) 40
Reactive monomer (trade name: ED506, manufactured by Asahi Denka Kogyo Co., Ltd.) 4
Adhesion imparting agent (trade name: S-510, manufactured by Chisso Corporation) 2
Leveling agent (trade name: F-470, manufactured by Dainippon Ink Co., Ltd.) 0.06

The second photosensitive resin composition obtained above is applied onto a polypropylene film having a thickness of 60 μm using an applicator, and heated in an oven at 65 ° C. for 5 minutes and at 80 ° C. for 30 minutes. Then, a dry film resist having a film thickness of 30 μm was prepared. This dry film resist was laminated on the above-mentioned exposed first photosensitive resin layer using a laminator under the conditions of 45 ° C. and 0.2 MPa. After lamination, the polypropylene film was peeled off at room temperature to form a second photosensitive resin layer (FIG. 1 (c)). Next, light having a wavelength of 436 nm is used for the second photosensitive resin layer through the second mask with L / S = 100 μm / 245 μm whose line direction intersects with the first mask at right angles using the light having the wavelength of 436 nm. It exposed (FIG.1 (d)). The amount of energy at the time of exposure was 6600 mJ / cm ² .

(Curing and developing the photosensitive part)
Next, the entire substrate provided with the first and second photosensitive resin layers was heat-treated at 95 ° C. for 6 minutes using a hot plate to cure the exposed portion. The substrate was gradually cooled to room temperature (23 ° C.) and then immersed in a developing solution to dissolve and remove only the unexposed portion (FIG. 1 (e)). Development was carried out using propylene glycol monomethyl ether acetate as a developer at room temperature while slowly stirring the developer. The molded body after development was washed sequentially with propylene glycol monomethyl ether acetate and isopropyl alcohol, and dried by blowing dry nitrogen to obtain a cross-shaped molded body having a desired hollow structure (FIG. 1 (f)). ).

Example 2
Examples except that the first photosensitive resin layer was formed by laminating a dry film resist obtained from the photosensitive resin composition having the composition (unit is part) described in Table 3 below by the method described later. In the same manner as in No. 1, a cross-shaped shaped body having a desired hollow structure was obtained.

Table 3 Composition of photosensitive resin composition for dry film resist Multifunctional epoxy resin (trade name: EPON SU-8
(Resolution Performance Products) 80
Multifunctional epoxy resin (trade name: NC-3000H, manufactured by Nippon Kayaku Co., Ltd.) 20
Photocationic polymerization initiator (trade name: UVI-6974,
50% propylene carbonate solution manufactured by Dow Chemical Company)
Solvent (Ethyl methyl ketone) 40
Reactive monomer (trade name: ED506, manufactured by Asahi Denka Kogyo Co., Ltd.) 5
Adhesion imparting agent (trade name: S-510, manufactured by Chisso Corporation) 2
Leveling agent (trade name: F-470, manufactured by Dainippon Ink, Inc.) 0.2

(Formation of dry film resist and first photosensitive resin layer)
The first photosensitive resin composition having the composition shown in Table 3 is applied on a polypropylene film having a thickness of 60 μm using an applicator, and heated in an oven at 65 ° C. for 5 minutes and at 80 ° C. for 30 minutes. Thus, the solvent was removed, and a dry film resist having a film thickness of 30 μm was produced. This dry film resist was laminated on a silicon wafer using a laminator under the conditions of 80 ° C. and 0.2 MPa.

Example 3
Example 1 was the same as Example 1 except that the amount of sensitizer (9,10-dibutoxyanthracene) was changed to 0.045 parts, the exposure wavelength was changed to 405 nm, and the exposure amount was changed to 600 mJ / cm ^2. Thus, a cross-shaped shaped body having a hollow structure was obtained.

Example 4
A cross beam having a hollow structure in the same manner as in Example 1 except that the amount of the sensitizer (9,10-dibutoxyanthracene) is changed to 1.08 parts and the exposure amount is changed to 2200 mJ / cm ² in Example 1. A shaped molded body was obtained.

Example 5
A cross beam having a hollow structure in the same manner as in Example 1 except that the amount of the sensitizer (9,10-dibutoxyanthracene) is changed to 1.575 parts and the exposure amount is changed to 1100 mJ / cm ² in Example 1. A shaped molded body was obtained.

Example 6
A cross beam having a hollow structure in the same manner as in Example 1 except that the amount of the sensitizer (9,10-dibutoxyanthracene) is changed to 3.15 parts and the exposure amount is changed to 770 mJ / cm ² in Example 1. A shaped molded body was obtained.

Example 7
A cross beam having a hollow structure in the same manner as in Example 1 except that the amount of the sensitizer (9,10-dibutoxyanthracene) in Example 1 was changed to 4.5 parts and the exposure amount was changed to 440 mJ / cm ^2. A shaped molded body was obtained.

Comparative Example With reference to Non-Patent Document 1, a comparative molded body having a hollow structure was formed using a method of laminating a dry film resist on a structure after pattern formation.
As the dry film resist, the dry film resist produced in Example 2 for forming the first photosensitive resin layer was used. First, a dry film resist was laminated on a substrate (silicon wafer) using the laminator under the conditions of 80 ° C. and 0.2 MPa to obtain a first photosensitive resin layer. Next, this first photosensitive resin layer was exposed through a first mask having L / S = 100 μm / 245 μm using light having a wavelength of 365 nm with the exposure apparatus. The amount of energy at the time of exposure was 250 mJ / cm ² . Subsequently, heat treatment was performed at 95 ° C. for 6 minutes using a hot plate, and only the exposed portion was cured. After the substrate was slowly cooled to room temperature, it was infiltrated with a developing solution, and only the unexposed portion was dissolved and removed for development. The development was carried out using propylene glycol monomethyl ether acetate as a developer while slowly stirring the developer at room temperature. The molded product after development was washed successively with propylene glycol monomethyl ether acetate and isopropyl alcohol, and then dried by blowing dry nitrogen. A dry film resist was laminated on the structure after development under the conditions of 45 ° C. and 0.2 MPa using the laminator to obtain a second photosensitive resin layer. Next, the second photosensitive resin layer is subjected to the same conditions as the first photosensitive resin layer, and a second mask with L / S = 100 μm / 245 μm whose line direction intersects with the first mask at right angles. Exposed through. The amount of energy at this time was 250 mJ / cm ² . After the exposure, heat treatment was performed at 95 ° C. for 6 minutes using a hot plate to cure the exposed portion of the second photosensitive resin layer. After the substrate was slowly cooled to room temperature, development and drying were carried out in the same manner as the first photosensitive resin layer to obtain a cross-shaped molded body for comparison having a hollow structure.

(Evaluation of molded body)
The performance of each of the cross-shaped shaped bodies obtained in Examples 1 to 7 and the comparative example was evaluated by dividing into the following four items (hollow structure, shape of beam portion, thermal sag, formation of single beam portion). The evaluation method for each item will be specifically described below with reference to a schematic diagram of the molded body (FIG. 3).

Evaluation Items and Criteria (1) Hollow Structure: The shape of the space portion 13 having a ceiling portion made of a cured second photosensitive resin layer indicated by 11 in FIG. This shape was determined by visual feeling using an optical microscope. And when the molded object which has a hollow structure was obtained, it evaluated as "(circle)", and when the molded object which has a hollow structure was not obtained, it evaluated as "x".
(2) Shape of the beam portion: Of the cured second photosensitive resin layer indicated by 11 in FIG. 3, it is the shape of the portion 14 having bridge piers made of the first photosensitive resin layer cured on both sides. . This shape is obtained by measuring the profile of the upper surface of the beam portion (cured second photosensitive resin layer) with a stylus-type film thickness meter, and when the difference between the highest point and the lowest point is less than 3 μm, “◯ “When the difference between the uppermost point and the lowermost point was 3 μm or more, it was evaluated as“ x ”.
(3) Thermal sagging: The shape of the portion 15 of the cured second photosensitive resin layer 11 shown in FIG. 3 that hangs down along the cured first photosensitive resin layer that is a bridge pier. This shape was measured using an optical microscope after breaking the molded body together with the substrate. When the thermal sag at the contact point between the beam portion (cured second photosensitive resin layer) and the cured first photosensitive resin layer is less than 0.5 μm below the upper surface of the cured photosensitive resin layer, “◯” is indicated. When the thermal sagging at the contact point between the beam portion (cured second photosensitive resin layer) and the cured first photosensitive resin layer is 0.5 μm or more below the upper surface of the cured photosensitive resin layer, “×” evaluated.
(4) Formation of a single beam portion: Of the cured second photosensitive resin layer indicated by 11 in FIG. 3, the shape of the portion 16 having a bridge pier made of the first photosensitive resin layer cured only on one side. It is. This shape was judged based on whether or not a portion 5 mm away from the end of the cured first photosensitive resin layer on the side of the single beam was floating in the air without contacting the substrate. And when the part which left | separated 5 mm one beam side from the hardened | cured 1st photosensitive resin layer terminal part is not contacting a board | substrate and is floating in the hollow, it is "(circle)" and 5 mm one beam side from the 1st layer support part When the distant place was in contact with the substrate and was not floating in the air, it was evaluated as “x”.
In Table 4, based on the said evaluation method, the cross-shaped molded object (FIG. 4 (a)) obtained in Examples 1-7 of this invention and the molded object for a comparison obtained by the comparative example (FIG. 4). The results of evaluating the performance of (b)) are shown.

Table 4 Performance test results
Examples Comparative examples
1 2 3 4 5 6 7
Hollow structure ○ ○ ○ ○ ○ ○ ○ ○
Beam shape ○ ○ ○ ○ ○ ○ ○ ×
Thermal dripping ○ ○ ○ ○ ○ ○ ○ ×
Formation of single beam part ○ ○ ○ ○ ○ ○ ○ ×

The performances of the molded bodies obtained in Examples 1 to 7 were good results for any of the evaluation items tested.
More specifically, in Examples 1 to 7, deformation of the beam portion and the single beam portion and thermal sag in the pier portion did not occur, and it was confirmed that the hollow structure was formed with high accuracy. However, in the comparative example, a drip of several tens of μm is generated in the beam portion (14 in FIG. 3), and the single beam portion is deformed so as to come into contact with the substrate at a portion several hundred μm away from the pier portion. It was. At the same time, thermal sag of the bridge pier occurred, and the hollow structure was inferior in accuracy.

  Based on the above results, a first photosensitive resin layer that is not exposed to light having a wavelength of 400 nm or more is formed on the substrate, irradiated with light having a wavelength of less than 400 nm through a predetermined mask, and then developed. Without applying, a solid or semi-solid second photosensitive resin layer having a solid content of 90% by weight or more which is exposed to light having a wavelength of 400 nm or more is laminated on the first photosensitive resin layer, After exposing only the second photosensitive resin layer with light having a wavelength of 400 nm or more through a mask different from the mask, the first and second photosensitive resin layers are collectively heated to cure only the exposed portions. The number of manufacturing steps, process yield, and dimensional accuracy are greatly improved by the manufacturing method of the molded body having a hollow structure, which is obtained by collectively developing the unexposed portions of the first and second photosensitive resin layers. It was confirmed that it was improved.

It is the schematic of the process which showed typically an example of the production method of the molded object (sectional drawing) by this invention, (a) is the formation process of the 1st photosensitive resin layer, (b) is the 1st photosensitive resin. The layer patterning step, (c) is the second photosensitive resin layer forming step, (d) is the second photosensitive resin layer patterning step, (e) is the developing step, and (f) is the molded body. It is an example of a molded body (cross-sectional view) having a hollow structure, (1) a molded body having a beam structure, (2) a molded body having a convex hollow structure, (3) a molded body having a single beam structure, And (4) shows the molded object which has an eaves structure. The schematic diagram of the cross-shaped molded object (sectional drawing) which has a hollow structure for demonstrating performance evaluation is shown. It is an example of a cross-shaped shaped body (cross-sectional view), (a) is a cross-shaped shaped body obtained in Examples 1 to 7, and (b) is a comparative cross-shaped shaped body obtained in a comparative example. Show.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 1st photosensitive resin layer 3-1 1st mask 3-2 2nd mask 4 2nd photosensitive resin layer 5 Developer 6 Hollow structure 7 Molded object 10 Substrate 11 Cured 2nd photosensitive resin layer 12 Curing First photosensitive resin layer 13 Hollow structure 14 Beam portion 15 Heat sag portion

16 Single beam part

Claims (8)

  A step of forming a first photosensitive resin layer that is not sensitive to light having a wavelength of 400 nm or more on the substrate, irradiating light having a wavelength of less than 400 nm through the first mask, without performing a development treatment, A solid or semi-solid second photosensitive resin layer having a solid content of 90% by weight or more that is sensitive to light having a wavelength of 400 nm or more is formed on the first photosensitive resin layer that has been subjected to the photosensitive treatment in the process, A step of irradiating light having a wavelength of 400 nm or more through the mask of 2, a step of performing a heat treatment on the first and second photosensitive resin layers at once, and a step of applying the first and second photosensitive resin layers A method for producing a molded article having a hollow structure, comprising a step of developing unexposed portions in a lump.   The method for producing a molded article according to claim 1, wherein the second photosensitive resin layer is obtained by laminating a dry film resist.   The manufacturing method of the molded object of Claim 2 whose lamination temperature is 20-100 degreeC.   The manufacturing method of the molded object as described in any one of Claims 1 thru | or 3 whose thickness of the 1st and 2nd photosensitive resin layer is 10-100 micrometers.   The shaping | molding as described in any one of Claims 1 thru | or 4 in which the photosensitive resin composition for forming a 2nd photosensitive resin layer contains a polyfunctional epoxy resin, a cationic polymerization initiator, and a sensitizer. Body manufacturing method.   The manufacturing method of the molded object of Claim 5 whose content of a sensitizer is 10 to 100 weight% with respect to content of a cationic polymerization initiator. The manufacturing method of the molded object of Claim 5 or 6 whose polyfunctional epoxy resin is a bisphenol A type polyfunctional epoxy resin shown by following formula (1).

(In Formula (1), a plurality of R's each independently represents a glycidyl group or a hydrogen atom, and n represents an integer of 1 to 30, respectively.)   The method for producing a molded article according to any one of claims 5 to 7, wherein the sensitizer is a 9,10-dialkoxyanthracene derivative.