Pattern forming method and pattern forming structure

Abstract

This pattern forming method comprises: a lamination step in which a curable resin layer (3) and a support film (4) are laminated on a substrate (2); a curing step for curing the entire curable resin layer (3); a peeling step for peeling the support film (4) from the cured curable resin layer (3); a processing step for processing the curable resin layer (3) into a predetermined pattern by irradiating the curable resin layer (3) from which the support film (4) has been peeled off with excimer laser light (15) via a mask (14); and a formation step in which a plating layer (17) is formed using the curable resin layer (3) having a predetermined pattern as a mask, then the curable resin layer (3) is removed, and a wiring pattern (16) based on the plating layer (17) is formed on the substrate (2).

Description

Technical Field

[0001] The invention relates to a pattern forming method and a pattern forming structure. Background Art

[0002] In recent years, electronic devices have been further developed towards miniaturization, lightness, and multi-functionality. At the same time, the integration of LSI and chip parts has been continuously improved, and their form has also become multi-PIN and miniaturized. Therefore, the semiconductor elements, semiconductor packages, printed circuit boards, flexible wiring boards, etc. that constitute these parts are required to be high-density and high-precision.

[0003] As a conventional pattern forming method, a semi-additive process can be cited. In this method, an electroless plating layer is formed on an insulating layer, and a resist layer of a prescribed pattern is formed on the electroless plating layer using a photosensitive dry film. Thereafter, an electroplating layer is formed, and the resist layer is stripped and the electroless plating layer is removed, thereby forming wiring with a desired pattern on a substrate. However, for the refinement of the pattern, defects in the pattern of foreign matter such as particles or attachments contained in a support film (PET film) supporting the photosensitive dry film become significant and become a problem.

[0004] In order to solve this problem, a method of forming a pattern using laser ablation processing has attracted attention. For example, in the method for forming a solder resist described in Patent Document 1, a semi-cured curable resin having a support film is formed on a substrate. Then, a laser is irradiated from the support film to form a through hole in the semi-cured curable resin. Thereafter, the support film is peeled off to cure the semi-cured curable resin layer.

[0005] Previous technical literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2012 / 042846 Summary of the invention

[0008] Technical issues to be solved by the invention

[0009] However, even when a pattern is formed by laser ablation as described in Patent Document 1, there is still a possibility that the laser is refracted by particles / attachments contained in the support film and defects are generated in the formed pattern. In addition, in the method of Patent Document 1, since the laser is irradiated from the support film, holes are generated in the support film during the laser ablation process. From the perspective of the Sustainable Development Goals (SDGs), a method that can reuse the support film is desired.

[0010] The present invention is completed in order to solve the above-mentioned problems, and its purpose is to provide a pattern forming method and a pattern forming structure that can achieve high-precision patterning that meets the goal of sustainable development.

[0011] Means for solving technical problems

[0012] One aspect of the present invention involves a pattern forming method, which includes: a stacking step of stacking a curable resin layer and a support film on a substrate; a curing step of curing the entire curable resin layer; a peeling step of peeling the support film from the cured curable resin layer; a processing step of irradiating the curable resin layer after peeling the support film with an excimer laser through a mask to process the curable resin layer into a specified pattern; and a forming step of forming a plating layer using the curable resin layer of the specified pattern as a mask, removing the curable resin, and forming a wiring pattern based on the plating layer on the substrate.

[0013] In the pattern forming method, before the curable resin layer is processed into a predetermined pattern by an excimer laser, the entire curable resin layer is cured, and the support film is peeled off from the curable resin layer after curing. Therefore, when processing the cured curable resin layer, the refraction of the excimer laser in the curable resin layer and the refraction of the excimer laser caused by particles / attachments contained in the support film can be suppressed. Therefore, the generation of defects in the curable resin layer during processing is suppressed, and a high-precision wiring pattern can be formed on the substrate. In addition, in the pattern forming method, since the support film is peeled off from the curable resin layer before irradiating the excimer laser, it is possible to avoid the generation of holes in the support film due to the excimer laser. As a result, the reuse of the support film used in the process becomes easy, which can help achieve patterning that meets the sustainable development goals.

[0014] The support film may be a recycled PET film. In the pattern forming method, since the entire curable resin layer is cured, even in the case where the curable resin layer is cured by a photocuring method or in the case where the curable resin layer is cured by a thermal curing method, high transparency is not required for the support film. Therefore, by using a recycled PET film as a support film, it can help to further achieve patterning that meets the sustainable development goals.

[0015] The line width and spacing L / S of the wiring pattern can be 5 / 5 μm or less. As described above, in this pattern forming method, the generation of defects in the curable resin layer in the processing step is suppressed. Therefore, it is suitable for forming a fine wiring pattern with a line width and spacing L / S of 5 / 5 μm or less.

[0016] The aspect ratio of the wiring pattern (ratio of the height of the wiring pattern to the line width of the wiring pattern) can be 0.5 to 20. As described above, in this pattern forming method, the generation of defects in the curable resin layer during the processing step is suppressed. Therefore, it is suitable for forming a fine wiring pattern with an aspect ratio of 0.5 to 20.

[0017] The curable resin layer may be composed of a photocurable resin. In this case, the entire curable resin layer can be easily cured by light irradiation.

[0018] The curable resin layer may be composed of a thermosetting resin. In this case, the entire curable resin layer can be easily cured by heating.

[0019] A pattern forming structure according to one aspect of the present invention includes: a substrate; a curable resin layer laminated on the substrate; and a support film laminated on the curable resin layer, wherein the support film is a recycled PET film.

[0020] In this pattern forming structure, the curable resin layer can be cured as a whole before being processed into a predetermined pattern by an excimer laser, and the support film can be peeled off from the curable resin layer after curing. Therefore, when processing the cured curable resin layer, the refraction of the excimer laser in the curable resin layer and the refraction of the excimer laser caused by particles / attachments contained in the support film can be suppressed. Therefore, the generation of defects in the curable resin layer during processing is suppressed, and a high-precision wiring pattern can be formed on the substrate. In addition, in this pattern forming structure, the support film becomes a recycled PET film. By using a recycled PET film as a support film, it can help to achieve patterning that meets sustainable development goals.

[0021] Effects of the Invention

[0022] Through the present invention, patterning with high precision and in line with sustainable development goals can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic cross-sectional view showing a pattern forming structure according to one embodiment of the present invention.

[0024] Figure 2 This is a flowchart showing a pattern forming method according to one embodiment of the present invention.

[0025] Figure 3 It is a schematic cross-sectional view showing the lamination process.

[0026] Figure 4 It is a schematic cross-sectional view showing the curing process.

[0027] Figure 5It is a schematic cross-sectional view showing the peeling step.

[0028] Figure 6 It is a schematic cross-sectional view showing the processing steps.

[0029] Figure 7 Yes means Figure 6 A schematic cross-sectional view of the subsequent process.

[0030] Figure 8 It is a schematic cross-sectional view showing the forming process.

[0031] Fig. 9 Yes means Figure 8 A schematic cross-sectional view of the subsequent process. DETAILED DESCRIPTION

[0032] Hereinafter, preferred embodiments of a pattern forming method and a pattern forming structure according to one aspect of the present invention will be described in detail with reference to the accompanying drawings.

[0033] Figure 1 Schematic cross-sectional view showing a pattern forming structure according to one embodiment of the present invention. Figure 1 As shown, the pattern forming structure 1 comprises: a substrate 2; a curable resin layer 3, which is laminated on the substrate 2; and a support film 4, which is laminated on the curable resin layer 3. The substrate 2 is a wiring pattern 16 (refer to Fig. 9 ) is a component to be formed. In addition, the substrate 2 is an adherend of the curable resin layer 3. As the substrate 2, for example, a silicon wafer, a silicon wafer with a film on which a metal such as Cu is vapor-deposited, a copper-clad laminate, etc. can be cited.

[0034] The curable resin layer 3 is composed of, for example, a photocurable resin or a thermosetting resin. Among them, the curable resin layer 3 is composed of a negative photocurable resin 11. The photocurable resin 11 can use a film-like photocurable resin, or it can be applied with a liquid photocurable resin. The liquid photocurable resin 11 is manufactured by stirring each material. There is no particular restriction on the stirring (dispersion) method, and stirring can be performed by heating, etc., or stirring can be performed under an inert gas atmosphere, a reduced pressure atmosphere, or a pressurized atmosphere. Foreign matter can be removed by filtering the stirred resin composition. The film-like photocurable resin 11 is provided, for example, in a state where a solution of the photocurable resin composition is evenly coated on a support film and dried.

[0035] In order to achieve a high etching rate during the laser ablation process described later, the photocurable resin 11 is designed in consideration of 1) the ease of breaking the molecular bonds when irradiated with the laser and 2) the absorbency to the wavelength of the laser. In order to satisfy 1), a compound with a lower molecular bond energy is selected. In order to satisfy 2), a component that absorbs the wavelength of the laser is contained. The photocurable resin 11 contains a polymerizable compound as component (A) and a UV absorber as component (B). Both component (A) and component (B) can be contained in large amounts or can be mixed with other components.

[0036] The polymerizable compound is selected under the assumption that the photocurable resin 11 is polymerized after being stacked on the substrate 2. By polymerizing it after stacking, the lamination or coating properties before stacking can be ensured, and the viscosity after polymerization can be suppressed. As a polymerizable compound, for example, a compound having an ethylenically unsaturated bond that can be polymerized within the molecule is used. As component (A), for example, (meth) acrylic resin, urethane acrylate, epoxy acrylate, etc. can be cited. From the viewpoint of low molecular bond energy, component (A) can be a non-aromatic photopolymerizable compound. Even when component (A) is mixed with an aromatic compound, or when a part of component (A) contains an aromatic functional group, a high etching rate during laser ablation processing can be achieved by adjusting their ratio.

[0037] The ultraviolet absorber is not particularly limited as long as it is a component that absorbs light of a desired wavelength. As the ultraviolet absorber, for example, a known absorber that can absorb lasers of ArF (wavelength: 193nm), KrF (wavelength: 248nm), XeCl (wavelength: 308nm), and XeF (wavelength: 351nm) can be used. As such an absorber, for example, a benzotriazole absorber, a triazine absorber, a salicylic acid derivative absorber, a benzophenone absorber, etc. can be cited.

[0038] The ultraviolet absorber may have a polymerizable unsaturated group. The ultraviolet absorber is divided into a type that generates free radicals by absorbing ultraviolet rays and a type that does not generate free radicals by absorbing ultraviolet rays. The ultraviolet absorber of the type that generates free radicals includes a photopolymerization initiator. By including a photopolymerization initiator, the photocurable resin 11 can be cured by ultraviolet rays before and after the laser ablation process, and the operability of the pattern forming structure 1 can be improved.

[0039] Examples of the photopolymerization initiator include aromatic ketones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 and 2-methyl-1-[4-(methylthio)phenyl-2-morpholinoacetone-1, quinones such as alkyl anthraquinone, benzoin ether compounds such as benzoin alkyl ether, benzoin, benzoin compounds such as alkyl benzoin, benzyl derivatives such as benzyl dimethyl ketal, 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer and 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, and acridine derivatives such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane. The photopolymerization initiator may be used alone or in combination of two or more.

[0040] When using a film-like photocurable resin 11, from the perspective of film-forming properties, the photocurable resin 11 may contain a binder polymer. From the perspective of stability during storage, the binder polymer is preferably a material that is compatible with the (A) component and the (B) component. The binder polymer can be a component that is softer than the polymerizable compound of the (A) component. Thus, the softness of the cured curable resin layer 3 can be ensured. As the binder polymer, for example, (meth) acrylic resins, urethane resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, polyimide resins, etc. are used. Among these resins, from the perspective of the ratio (rate) that contributes to laser ablation processing, that is, the perspective of low bond energy of the molecule, it is preferred to use (meth) acrylic resins.

[0041] As the binder polymer, it is preferred to select a resin type whose basic skeleton is non-aromatic from the viewpoint of low molecular bond energy. The non-aromatic basic skeleton here means that the basic skeleton repeated multiple times by polymerization does not contain aromatics, and does not mean that aromatics are only arranged at the end. Aromatic binder polymers and aliphatic polymers can be mixed to achieve a balance with the etching rate.

[0042] The molecular weight of the binder polymer varies depending on the state of the photocurable resin 11. When using a film-like photocurable resin 11, for example, the molecular weight can be selected in a way that strikes a balance between the film-forming property of the film and the ratio of the laser ablation processing. By fully ensuring the molecular weight, the film-forming property can be ensured and droplets during film-forming / storage can be suppressed. By not making the molecular weight too large, the reduction in the speed of the laser ablation processing can be suppressed. When using a liquid photocurable resin 11, by designing it to a low molecular weight within the range that can be applied, the ratio of the laser ablation processing can be increased.

[0043] The photocurable resin 11 may contain a thermosetting accelerator. The thermosetting accelerator is not particularly limited as long as it can thermoset the photocurable resin composition, and can be appropriately selected from commonly used thermosetting accelerators. By adding a thermosetting accelerator, the photocurable resin 11 can be cured at a lower temperature, thereby improving the operability of the pattern forming structure 1. As a thermosetting accelerator, for example, imidazoles, dicyandiamide derivatives, dicarboxylic acid dihydrazides, triphenylphosphine, tetraphenylphosphine tetraphenyl borate, 2-ethyl-4-methylimidazole-tetraphenyl borate, 1,8-diazabicyclo[5,4,0]undecene-7-tetraphenyl borate, etc. can be cited. The thermosetting accelerator can be used alone or in combination of two or more.

[0044] The photocurable resin 11 may contain a polymerization inhibitor. By containing a polymerization inhibitor in the photocurable resin 11, the shelf life and working life of the photocurable resin composition can be prolonged. In addition, unnecessary polymerization during laser ablation processing can be suppressed. The unnecessary polymerization mentioned here refers to the generation of free radicals from the photopolymerization initiator and polymerization caused by the laser during laser ablation processing. As a polymerization inhibitor, a material that has the effect of inhibiting polymerization of free radical polymerization is used. As a polymerization inhibitor, for example, catechols such as tert-butylcatechol, hydroquinone, methyl hydroquinone, tert-butyl hydroquinone, p-methoxyphenol and other hydroquinones, alkoxyquinones such as methyl quinone, p-benzoquinone, methyl-p-benzoquinone, tert-butyl-p-benzoquinone and other benzoquinones, etc.

[0045] The photocurable resin 11 may contain a solvent. When a liquid photocurable resin 11 is used, the photocurable resin 11 preferably contains a solvent from the viewpoint of ease of viscosity adjustment and ease of manufacturing / inspection. When a film-like photocurable resin 11 is used, the content of the solvent is preferably small. The solvent that cannot be completely removed in the coating / drying process may remain in the photocurable resin 11.

[0046] The photocurable resin 11 may contain dyes such as malachite green, Victoria blue, brilliant green and methyl violet, colorless crystal violet, diphenylamine, benzylamine, triphenylamine, diethylaniline, o-chloroaniline and other photochromic agents, thermal color development inhibitors, plasticizers such as p-toluenesulfonamide, pigments, fillers, defoamers, flame retardants, stabilizers, adhesion imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, developers, thermal crosslinking agents, etc. as needed. These components, for example, can contain about 0.01 to 20 parts by mass relative to 100 parts by mass of the total solid content of (A) component and (B) component. These materials can be used alone or in combination of two or more.

[0047] The support film 4 is composed of, for example, a heat-resistant and solvent-resistant polymer film of a polyolefin such as polypropylene, polyethylene, or a polyester such as polyethylene terephthalate. Among these films, a polyethylene terephthalate (PET) film is preferably used from the viewpoint of transparency. The PET film contains particles for improving the fluidity and demolding properties when forming the PET film. As particles, for example, inorganic particles such as calcium carbonate, calcium phosphate, silicon dioxide, kaolin, talc, titanium dioxide, aluminum oxide, barium sulfate, calcium fluoride, lithium fluoride, zeolite, and molybdenum sulfide, organic particles such as ion exchange resins, cross-linked polymers, and calcium oxalate, and precipitated particles generated during polyester polymerization can be used.

[0048] In the present embodiment, the support film 4 is a recycled PET film 12. The particles of the recycled PET film 12 may be contained in an amount of, for example, 1 to 10 parts by mass relative to 100 parts by mass of the PET film. The transparency of the recycled PET film 12 may be, for example, less than 1.5. The transparency may be measured, for example, by an integrating sphere turbidimeter.

[0049] Next, a pattern forming method using the above-mentioned pattern forming structure 1 will be described in detail.

[0050] Figure 2 FIG. 1 is a flow chart showing a pattern forming method according to an embodiment of the present invention. Figure 2 As shown, the pattern forming method includes a lamination process (step S01), a curing process (step S02), a peeling process (step S03), a processing process (step S04) and a forming process (step S05).

[0051] like Figure 3 As shown, the lamination step S01 is a step of laminating a curable resin layer 3 and a support film 4 on a substrate 2. The lamination method on the substrate 2 varies depending on whether the photocurable resin 11 is in a liquid state or in a film state. When the photocurable resin 11 is in a liquid state, the photocurable resin 11 can be laminated by applying and drying the photocurable resin composition to the substrate 2. As a coating method for the photocurable resin composition, for example, a spray coating method, a roll coating method, a spin coating method, a slit die coating method, a rod coating method, an inkjet method, a screen printing method, a gravure coating method, a curtain coating method, a knife coating method, etc. can be cited.

[0052] Considering the decrease in film thickness due to the volatilization of the solvent during drying and the flow of the photocurable resin composition, the film thickness of the photocurable resin 11 before drying is preferably greater than the target value. In order to make the film thickness of the photocurable resin 11 after drying smaller, the photocurable resin composition can contain a large amount of solvent, and the film thickness reduction rate during drying can be increased by the volatilization of the solvent. The residual solvent rate after drying can be 10% by mass or less, or 5% by mass or less, or 2% by mass or less.

[0053] The film thickness of the photocurable resin 11 after drying is, for example, 1 to 200 μm. The film thickness of the photocurable resin 11 after drying can be 5 to 100 μm, or 10 to 50 μm. By setting the film thickness to be 1 μm or more, coating can be easily achieved industrially. By setting the film thickness to be 200 μm or less, insufficient volatilization of the solvent and the occurrence of abnormal appearance can be suppressed. When the film thickness is set to be 100 μm or more, it is also possible to adopt a method in which after applying the photocurable resin composition with a film thickness of 100 μm or less, two or more layers of the photocurable resin composition are laminated to each other.

[0054] The photocurable resin 11 formed by coating or the like can be heated at 50 to 250° C. The heating temperature can be 50 to 200° C. The heating can be carried out in an inert atmosphere such as nitrogen, or under reduced pressure. There is no particular limitation on the drying time. The drying process can include heating and cooling, or can be kept at a constant temperature. When drying including heating and cooling is carried out, the surface of the photocurable resin 11 after drying tends to become flatter.

[0055] When the photocurable resin 11 is in the form of a film, the photocurable resin 11 can be laminated by heating the photocurable resin 11 and pressing the substrate 2. From the viewpoint of adhesion and followability to the substrate 2, the pressing of the photocurable resin 11 can be performed under reduced pressure. The heating temperature can be, for example, room temperature to 130°C. The pressure during pressing can be, for example, about 0.01 to 1.0 MPa (0.1 to 10 kgf / cm 2 In order to further improve the lamination property, the substrate 2 may be subjected to a preheating treatment or a heating treatment after lamination.

[0056] The curing step S02 is a step for curing the entire curable resin layer 3. Figure 4 As shown, in the curing step S02, light 13 is irradiated onto the entire surface of the photocurable resin 11 through the support film 4, so that the entire photocurable resin 11 is cured. The light 13 is, for example, ultraviolet light. As a light source of the light 13, for example, an ultraviolet lamp can be used. The irradiation intensity of the light 13 is, for example, 1 to 100 mW. The irradiation time of the light 13 is, for example, 1 to 1000 seconds.

[0057] The curing here means that the curable resin layer 3 is completely or substantially completely cured. The curing rate F of the curable resin layer 3 after the curing step is, for example, 50% to 100%. The curing rate F can be 85% or more, or 90% or more. When the curing time of the curable resin composition in the solution is set to T1 and the curing time of the curable resin composition after the curing step is set to T2, the curing rate F can be calculated by F=((T1-T2) / T1)×100. For example, the curing time is measured according to Item 5.7 "Curing Time Test" of JIS C6521.

[0058] like Figure 5 As shown, the peeling step S03 is a step of peeling the support film 4 from the cured curable resin layer 3. When the support film 4 is peeled off from the curable resin layer 3, for example, it is implemented by an automatic peeler. The peeled support film 4 can be reused to form a wiring pattern on another substrate. In the case where a film-like photocurable resin 11 is used in the lamination step, the peeled support film 4 can be reused as a support film for the photocurable resin 11.

[0059] The processing step S04 is a step of processing the curable resin layer 3 into a predetermined pattern. Figure 6 As shown in FIG. 1 , in the processing step, the curable resin layer 3 after the support film 4 is peeled off is irradiated with an excimer laser 15 via a mask 14 to process the curable resin layer 3 into a predetermined pattern. That is, in the processing step, the curable resin layer 3 after curing is subjected to laser ablation processing using the excimer laser 15. Figure 7 As shown, the curable resin layer 3 after the support film 4 is peeled off is processed into a linear shape, and a mask is formed on the substrate 2 when forming a plating layer in the subsequent forming step S05.

[0060] As the light source of the excimer laser 15, for example, there can be cited F2 excimer laser (wavelength: 157nm), ArF excimer laser (wavelength: 193nm), KrF excimer laser (wavelength: 248nm), XeCl excimer laser (wavelength: 308nm), XeF excimer laser (wavelength: 351nm), etc. In general, the higher the energy density of each shot of excimer laser 15 on the surface of the curable resin layer 3, the higher the ratio of laser ablation processing. However, when the energy density is above a certain level, the ratio of laser ablation processing is saturated. Although it also depends on the processing area or the cost of the processing equipment, considering the above situation, the energy density of each shot of excimer laser 15 on the surface of the curable resin layer 3 can be, for example, 10 to 2000mJ / cm 2 , can also be 100~1500mJ / cm 2 .

[0061] The optical system of the excimer laser 15 can use a focusing optical system or an imaging optical system. When the curable resin layer 3 is processed into a predetermined pattern, it is preferred to use an imaging optical system from the perspective of throughput. The reduction projection magnification of the imaging optical system can be, for example, 1 to 300 times, or 1 to 20 times.

[0062] The forming step S05 is a step of forming the wiring pattern 16 on the substrate. Figure 8 As shown, in the formation process, the curable resin layer 3 of a predetermined pattern is used as a mask to form the plating layer 17. As the constituent material of the plating layer 17, for example, Cu, Ni, Sn, etc. can be cited. As a method for forming the plating layer 17, for example, electroplating can be used. When forming the plating layer 17, a desmear treatment can be performed on the surface of the substrate 2 in advance, and a seed layer for forming the plating layer 17 can be provided on the surface.

[0063] like Fig. 9 As shown, after forming the plating layer 17, the curable resin layer 3 is removed, and a wiring pattern 16 based on the plating layer 17 is formed on the substrate 2. In the case where a seed layer is formed on the surface of the substrate 2, the seed layer is removed by etching or the like after removing the curable resin layer 3, and the wiring patterns 16, 16 are electrically separated from each other. As a method for removing the curable resin layer 3, for example, a wet stripping method using an inorganic alkali aqueous solution or an organic alkali aqueous solution and an organic solvent, a dry etching method using plasma treatment, and the like can be cited.

[0064] As the salt base of the alkaline aqueous solution used in the wet stripping method, for example, alkali hydroxides such as lithium, sodium or potassium hydroxides, alkali metal carbonates such as lithium, sodium, potassium or ammonium carbonates and bicarbonates, alkali metal phosphates such as potassium phosphate and sodium phosphate, alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate, borax (sodium tetraborate), sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1,3-diamino-2-propanol, morpholine, etc. can be used. As the wet stripping method, for example, methods using immersion, puddle, spray, brushing, patting, scraping, shaking and dipping can be cited.

[0065] In the present embodiment, the line width and spacing L / S of the wiring pattern 16 obtained after the forming process are 5 / 5 μm or less. That is, in the present embodiment, the line width L of the wiring pattern 16 is 5 μm or less, and the spacing S between adjacent wiring patterns 16 and 16 is 5 μm or less. In addition, in the present embodiment, the aspect ratio of the wiring pattern 16 (the ratio of the height H of the wiring pattern 16 to the line width L of the wiring pattern 16) is 0.5 to 20. The aspect ratio of the wiring pattern 16 can be 1 to 10.

[0066] As described above, in this pattern forming method, before the curable resin layer 3 is processed into a predetermined pattern by the excimer laser 15, the entire curable resin layer 3 is cured, and after curing, the curable resin layer 3 is peeled off from the support film 4. Therefore, when processing the cured curable resin layer 3, the refraction of the excimer laser 15 in the curable resin layer 3 and the refraction of the excimer laser 15 caused by particles / attached substances contained in the support film 4 can be suppressed. Therefore, the generation of defects in the curable resin layer 3 during processing is suppressed, and a high-precision wiring pattern 16 can be formed on the substrate 2. In addition, in this pattern forming method, since the support film 4 is peeled off from the curable resin layer 3 before irradiation with the excimer laser 15, the generation of holes in the support film 4 due to the excimer laser 15 can be avoided. As a result, the reuse of the support film 4 used in the process becomes easy, which can contribute to the realization of patterning that meets the goal of sustainable development.

[0067] In this embodiment, the support film 4 is a recycled PET film 12. In this pattern forming method, since the entire curable resin layer 3 is cured, even in the case of curing the curable resin layer 3 by photocuring or by thermal curing, high transparency is not required for the support film 4. Therefore, by using the recycled PET film 12 as the support film 4, it is possible to contribute to further achieving patterning that meets the goal of sustainable development.

[0068] In this embodiment, the line width and spacing L / S of the wiring pattern 16 is 5 / 5 μm or less. As described above, in this pattern forming method, the generation of defects in the curable resin layer 3 during the processing step is suppressed. Therefore, it is suitable for forming a fine wiring pattern 16 with a line width and spacing L / S of 5 / 5 μm or less.

[0069] In the present embodiment, the aspect ratio of the wiring pattern 16 is 0.5 to 20. As described above, in this pattern forming method, the generation of defects in the curable resin layer during the processing step is suppressed. Therefore, it is suitable for forming a fine wiring pattern with an aspect ratio of 0.5 to 20.

[0070] In the present embodiment, the curable resin layer 3 may be composed of the photocurable resin 11. Thus, the curing of the entire curable resin layer 3 can be easily performed by light irradiation.

[0071] Furthermore, in the pattern forming structure 1, the entire curable resin layer 3 can be cured before the curable resin layer 3 is processed into a predetermined pattern by the excimer laser 15, and the support film 4 can be peeled off from the curable resin layer 3 after curing. Therefore, when processing the cured curable resin layer 3, the refraction of the excimer laser 15 in the curable resin layer 3 and the refraction of the excimer laser 15 caused by particles / attached substances contained in the support film 4 can be suppressed. Therefore, the generation of defects in the curable resin layer 3 during processing is suppressed, and a high-precision wiring pattern 16 can be formed on the substrate. Furthermore, in the pattern forming structure 1, the support film 4 becomes a recycled PET film 12. By using the recycled PET film 12 as the support film 4, it is possible to contribute to patterning that meets the sustainable development goals.

[0072] The present invention is not limited to the above-mentioned embodiment. For example, in the above-mentioned embodiment, the support film 4 is a recycled PET film 12, but the support film 4 may be a PET film before recycling. The PET film before recycling may be used when the pattern forming method is first implemented, and the PET film 12 obtained by recycling the PET film may be used when the pattern forming method is implemented for the second time or later.

[0073] The curable resin layer 3 may be composed of a thermosetting resin. In this case, the curing of the entire curable resin layer 3 can be simply performed by heating. As a thermosetting resin, for example, phenolic resin, epoxy resin, melamine resin, alkyd resin, silicone resin, and thermosetting polyimide can be used. When a thermosetting resin is used, the curing conditions in the curing step S02 can be set to, for example, baking in an oven at a temperature of 120° C. or higher for more than 30 minutes.

[0074] Explanation of symbols

[0075] 1- pattern forming structure, 2- substrate, 3- curable resin layer, 4- support film, 11- photocurable resin, 12- recycled PET film, 14- mask, 15- excimer laser, 16- wiring pattern, 17- plating layer.

Claims

1. A pattern forming method comprising the following steps: A lamination step of laminating a curable resin layer and a support film on a substrate; A curing step to cure the entire curable resin layer; A peeling step of peeling the support film from the cured curable resin layer; a processing step of irradiating the curable resin layer after the support film is peeled off with an excimer laser through a mask to process the curable resin layer into a predetermined pattern; and The forming step is to form a plating layer by using the curable resin layer of the predetermined pattern as a mask, remove the curable resin, and form a wiring pattern based on the plating layer on the substrate.

2. The pattern forming method according to claim 1, wherein: The support film is a recycled PET film.

3. The pattern forming method according to claim 1 or 2, wherein: The line width and spacing L / S of the wiring pattern is 5 / 5 μm or less.

4. The pattern forming method according to any one of claims 1 to 3, wherein: The aspect ratio of the wiring pattern is 0.5-20.

5. The pattern forming method according to any one of claims 1 to 4, wherein: The curable resin layer is composed of a photocurable resin.

6. The pattern forming method according to any one of claims 1 to 4, wherein: The curable resin layer is composed of a thermosetting resin.

7. A pattern forming structure, comprising: substrate; a curable resin layer laminated on the substrate; and a support film, laminated on the curable resin layer, The support film is a recycled PET film.

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