Photosensitive resin composition, dry film photoresist using same, method for preparing same, resist pattern, and display device

Abstract

The present invention relates to: a photosensitive resin composition comprising an epoxy resin, a photocationic initiator, a UV absorber, an additive, and a solvent, wherein the photocationic initiator is selected from the group consisting of thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium)bistetrakis(pentafluorophenyl)borate, thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium)hexafluorophosphate, triarylsulfonium bistetrakis(pentafluorophenyl)borate, triarylsulfonium hexafluorophosphate, and 4-{[4-(diphenylsulfonium)phenyl]sulfanyl}phenyl)diphenylsulfonium)hexafluorophosphate; a dry film photoresist using the same; a method for preparing the same; a resist pattern; and a display device.

Description

Photosensitive resin composition, dry film photoresist using the same and method for producing the same, resist pattern and display device

[0001] The present invention relates to a photosensitive resin composition, a dry film photoresist using the same, a method for producing the same, a resist pattern, and a display device.

[0002] The photosensitive resin composition is a photoresist that can be subjected to a photolithography process, and is used in a wide range of devices for forming various electronic components such as microelectromechanical system (MEMS) components, power inductor partition walls, and electronic circuits. It is mainly used in the form of dry film photoresist (DFR) and liquid photoresist ink.

[0003] Additionally, common dry film photoresists are widely used for laminating onto copper clad laminates.

[0004] Unlike conventional semiconductor manufacturing, devices in these fields require resists capable of high-aspect-ratio (aspect ratio refers to the height / width of a structure) fine patterning. Furthermore, as circuit line widths shrink, the aspect ratio also increases. Therefore, components requiring ultra-fine or high-density features must achieve high aspect ratios when patterning through etching to improve device performance.

[0005] In addition, a pattern is generally formed using a photosensitive resin composition including an epoxy resin such as an alkaline developable binder resin or bisphenol A novolac resin, a photopolymerization initiator, and a photopolymerizable compound.

[0006] However, since the resolution pitch of the line width / line spacing (Line / Space) of the resist pattern based on a 120㎛ film in the prior art has a limit of 8 / 15㎛, photolithography using a prior photosensitive resin composition has shown limitations in forming fine patterns of 8 / 15㎛ or less.

[0007] Therefore, it is necessary to develop a photosensitive resin composition that has excellent physical properties such as rigidity and chemical resistance while maintaining a high aspect ratio.

[0008]

[0009] The present invention provides a photosensitive resin composition capable of forming a fine pattern even on a 120㎛ film-based thick film, and having improved adhesion, resolution, rigidity, chemical resistance, and thermal expansion coefficient, and maintaining a high aspect ratio.

[0010] In addition, the present invention provides a dry film photoresist, a resist pattern, and a display device using the above photosensitive resin composition.

[0011]

[0012] In this specification,

[0013] It comprises an epoxy resin; a photocationic initiator; a UV absorber; an additive; and a solvent;

[0014] The photosensitive resin composition is provided in which the above-mentioned photocationic initiator is at least one selected from the group consisting of thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) bis tetrakis(pentafluorophenyl) borate, thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) hexafluorophosphate, triarylsulfonium bis tetrakis(pentafluorophenyl) borate, triarylsulfonium hexafluorophosphate, and 4-{[4-(diphenylsulfonium) phenyl] sulfanyl} phenyl) diphenylsulfonium) hexafluorophosphate.

[0015] The present specification also provides a dry film photoresist comprising a photosensitive resin layer containing the photosensitive resin composition.

[0016] The present specification also provides a method for producing a dry film photoresist, including a step of coating the photosensitive resin composition on a polymer substrate.

[0017] The present specification also provides a resist pattern comprising a photosensitive resin pattern containing the photosensitive resin composition.

[0018] The present specification also provides a display device including the resist pattern or a metal pattern formed by the resist pattern.

[0019]

[0020] Hereinafter, a photosensitive resin composition according to a specific embodiment of the invention and a dry film photoresist, a resist pattern, and a display device using the same will be described in more detail.

[0021] Prior to that, unless explicitly stated otherwise in this specification, technical terms are used only to refer to specific embodiments and are not intended to limit the present invention.

[0022] As used herein, the singular forms also include the plural forms unless the context clearly dictates otherwise.

[0023] As used herein, the term “including” means specifying a particular characteristic, region, integer, step, operation, element and / or component, but does not exclude the presence or addition of other particular characteristics, regions, integers, steps, operations, elements, components and / or groups.

[0024] In this specification, the weight average molecular weight refers to the weight average molecular weight equivalent to polystyrene measured by the GPC method. In the process of measuring the weight average molecular weight equivalent to polystyrene measured by the GPC method, a commonly known analytical device and a detector such as a refractive index detector and an analytical column can be used, and commonly applied temperature conditions, solvents, and flow rates can be applied.

[0025] As a specific example of the above measurement conditions, the epoxy binder resin was dissolved in tetrahydrofuran to a concentration of 1.0 (w / w)% in THF (approximately 0.5 (w / w)% based on solid content), filtered using a syringe filter with a 0.45 μm pore size, and 20 μl was injected into GPC. Tetrahydrofuran (THF) was used as the mobile phase of GPC, and it was introduced at a flow rate of 1.0 mL / min. The column was connected in series with one Agilent PLgel 5 μm Guard (7.5 x 50 mm) and two Agilent PLgel 5 μm Mixed D (7.5 x 300 mm), and the detector was an Agilent 1260 Infinity Ⅱ System, RI Detector, and the measurement was performed at 40°C.

[0026] Here, polystyrene standard samples (STD A, B, C, D) with various molecular weights dissolved in tetrahydrofuran at a concentration of 0.1 (w / w)% were filtered through a syringe filter with a 0.45㎛ pore size and injected into GPC, and the value of the weight average molecular weight (Mw) of the epoxy binder resin was obtained using the calibration curve formed.

[0027] STD A (Mp): 791,000 / 27,810 / 945

[0028] STD B (Mp): 282,000 / 10,700 / 580

[0029] STD C (Mp): 126,000 / 4,430 / 370

[0030] ST D (Mp): 51,200 / 1,920 / 162

[0031]

[0032] Hereinafter, the present invention will be described in detail.

[0033]

[0034] According to one embodiment of the invention, a photosensitive resin composition can be provided, comprising: an epoxy resin; a cationic initiator; a UV absorber; an additive; and a solvent; wherein the photocationic initiator is at least one selected from the group consisting of thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) bis tetrakis(pentafluorophenyl) borate, thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) hexafluorophosphate, triarylsulfonium bis tetrakis(pentafluorophenyl) borate, triarylsulfonium hexafluorophosphate, and 4-{[4-(diphenylsulfonium)phenyl]sulfanyl}phenyl)diphenylsulfonium) hexafluorophosphate.

[0035] The above photosensitive resin composition is a curable composition including an epoxy resin, and can achieve fine pitch circuit properties by introducing a UV absorber together with a specific photocation initiator and an epoxy resin.

[0036] That is, according to the present invention, fine pitch is achieved from two perspectives. First, the present invention can achieve fine pitch in thick films by introducing a specific cationic initiator with low reactivity. Second, the present invention has the characteristic of achieving fine pitch with a stable profile by introducing a multi-functional epoxy into the epoxy resin composition to improve the rigidity, chemical resistance, and coefficient of thermal expansion of the fine circuit line width.

[0037] Since the above photosensitive resin composition has circuit properties of finer pitch than those of the prior art, it is possible to implement a fine pitch with a line width / line spacing (Line / Space) of 6 / 14 um or less of a resist pattern based on a 120 um film.

[0038] In addition, the photosensitive resin composition can be applied to various display devices, but is particularly suitable for use in a partition plating method of a power inductor, and can be applied as a material required for energy efficiency and precision technology.

[0039]

[0040] Hereinafter, each component of the photosensitive resin composition of the present invention will be described in more detail.

[0041] First, the cationic initiator refers to a photocationic polymerization initiator that generates cationic species upon exposure to UV and active energy rays, and plays a key role in the curing of dry film photoresists. Therefore, the photocationic initiator utilizes a substance that possesses sufficient performance to cure epoxy resins while also including the function of a photoacid generator with low reactivity, thereby enabling the formation of fine patterns (i.e., fine pitch) in thick films.

[0042] According to one embodiment of the invention, the photocationic initiator may include at least one selected from aromatic sulfonium complexes. Specifically, the cationic initiator is selected from the group consisting of thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) bis tetrakis(pentafluorophenyl) borate (PAG-TR-21608), thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) hexafluorophosphate, triarylsulfonium bis tetrakis(pentafluorophenyl) borate, triarylsulfonium hexafluorophosphate, 4-{[4-(diphenylsulfonium)phenyl]sulfanyl}phenyl)diphenylsulfonium) hexafluorophosphate (TR-PAG-202S). There may be more than one. Preferably, it may be thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) bis tetrakis(pentafluorophenyl) borate.

[0043] The above-mentioned specific type of photocationic initiator has low reactivity and enables maintaining a high aspect ratio of 1:20 or more even in a thick film with a film thickness of 120㎛ without halation phenomenon.

[0044] The photocationic initiator is contained in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of the epoxy resin. In addition, the photocationic initiator may be contained in an amount of 0.1 to 1.5 parts by weight, or 0.1 to 1 part by weight, or 0.1 to 0.5 parts by weight based on 100 parts by weight of the epoxy resin.

[0045] If the content of the above photocationic initiator is less than 0.1 part by weight, the degree of polymerization becomes insufficient, and there is a problem of circuit loss due to reduced solvent resistance and chemical resistance, and if the content exceeds 2.0 parts by weight, the fine circuit pattern implementation may be deteriorated due to line width expansion caused by overpolymerization of the photosensitive resin composition.

[0046] The above epoxy resin may be at least one selected from the group consisting of a) bisphenol-type epoxy resin and bisphenol-type novolac epoxy resin, and b) at least one selected from the group consisting of biphenyl epoxy resin and multi-functional epoxy resin.

[0047] According to one embodiment of the invention, the epoxy resin may include a) at least one selected from the group consisting of bisphenol A novolac epoxy (BPA Novolac Epoxy) and bisphenol epoxy resin (BPA Epoxy), and b) at least one multifunctional epoxy selected from the group consisting of biphenyl epoxy and novolac-type epoxy resin.

[0048] The above photosensitive resin composition can maintain a high aspect ratio by improving rigidity, chemical resistance, and coefficient of thermal expansion by including the above multifunctional epoxy, thereby making it easier to form a fine pattern than before.

[0049] In addition, the epoxy resin can more effectively secure a high aspect ratio when it includes a mixture of a) bisphenol A novolac epoxy (BPA Novolac Epoxy) and a bisphenol epoxy resin (BPA Epoxy), and b) a multifunctional epoxy containing a biphenyl epoxy and a novolac-type epoxy resin.

[0050] In this case, the weight ratio of a) and b) may be 90:10 to 70:30 based on 100 parts by weight of the total epoxy resin. If the weight ratio of a) and b) exceeds 90:10 and the content of the multifunctional epoxy resin is too low, the degree of polymerization becomes insufficient and the content of the multifunctional epoxy resin is reduced, resulting in a problem of circuit loss. If the weight ratio exceeds 70:30 and the content of the multifunctional epoxy resin is too high, the implementation of the fine circuit pattern may be deteriorated due to line width expansion caused by overpolymerization of the photosensitive resin composition.

[0051] The above bisphenol-type novolac epoxy resin and bisphenol-type epoxy resin may have a weight average molecular weight of 1,500 to 5,000 g / mol. The above bisphenol-type novolac epoxy resin and bisphenol-type epoxy resin may have an epoxy equivalent of 100 to 260 g / eq.

[0052] The above multifunctional epoxy resin may have three or more functional groups and a weight average molecular weight of 800 to 1,500 g / mol. The above multifunctional epoxy resin may have an epoxy equivalent of 120 to 200 g / eq. The above multifunctional epoxy resin may have three or more, four or more, or five or more, and two or less functional groups. Accordingly, the coatability of the dry film photoresist, the mechanical strength of the resist itself after circuit formation, chemical resistance, and thermal expansion coefficient may be improved.

[0053] The epoxy resin of the above a) may be at least one selected from the group consisting of bisphenol A novolac epoxy (KEB-3180M80), bisphenol A-bisphenol A diglycidyl ether polymer (YD-011), and bisphenol F-bisphenol F diglycidyl ether. The type of the epoxy resin of the above a) is not limited thereto, and any product having the above-described composition may be used.

[0054] The multifunctional epoxy resin of the above b) is a multifunctional cationic polymerizable epoxy compound, and for example, it may be at least one selected from the group consisting of phenol-salicylicaldehyde epoxy resin (KES-7270M70, 3 functional groups), phenol novolac epoxy (KEP-1142), biphenyl epoxy (KES-7370 and benz novolac epoxy (KES-7274), and DCPD phenol novolac. The type of the epoxy resin of the above a) is not limited thereto, and any product having the above-described composition can be used.

[0055] Meanwhile, the UV absorber uses a liquid UV absorber of the hydroxyphenylbenzotriazole series, which has excellent coating properties and heat stability and durability of a photocuring film using an epoxy resin and a photocationic initiator.

[0056] The above UV absorber may be, for example, at least one selected from the group consisting of TINUVIN (registered trademark) 384-2, 292, 477, 770, and 479.

[0057] The above UV absorber is contained in an amount of 0.01 to 2.0 parts by weight based on 100 parts by weight of the epoxy resin.

[0058] The amount of the solvent added is not particularly limited, but may be included in an amount of 1.0 to 10.0 parts by weight per 100 parts by weight of the epoxy resin, for example.

[0059] The solvent is not limited in type as long as it can dissolve each component and is chemically stable, and examples thereof include alcohol, ether, glycol ether, ethylene glycol alkyl ether acetate, diethylene glycol, propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, propylene glycol alkyl ether propionate, aromatic hydrocarbons, ketones, esters, etc.

[0060] Specifically, the solvent may be at least one selected from the group consisting of butanol, dimethylformamide, N-methyl-2-pyrrolidone, gamma-butyrolactone, butylcapitol, butyl cellosolve, methyl cellosolve, butyl acetate, diethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, methyl 3-methoxy propionate, ethyl 3-ethoxy propionate, propylene glycol methyl ether propionate, dipropylene glycol dimethyl ether, cyclohexanone, and propylene glycol monomethyl ether acetate (PGMEA).

[0061] Additionally, additives may be included within a range that does not impair the purpose of the present invention.

[0062] For example, the additive may include various additives such as a leveling agent, a curing accelerator, a filler, a reaction retardant, an anti-aging agent, an antioxidant, a pigment (dye), a plasticizer, a flame retardant, a surfactant, a dispersant, a dehydrating agent, an adhesive agent, and an antistatic agent.

[0063] Specifically, the additive may include a leveling agent, and the leveling agent may use polyether modified polysiloxane.

[0064] In addition, the content of the above additive is not particularly limited, but for example, it may be included in an amount of 0.01 to 3.0 parts by weight per 100 parts by weight of the epoxy resin.

[0065]

[0066] According to another embodiment of the invention, a dry film photoresist comprising a photosensitive resin layer containing the photosensitive resin composition of the above embodiment can be provided. The contents of the photosensitive resin composition include all of the contents described above in the above embodiment.

[0067] Specifically, the photosensitive resin layer may include a dried product or a cured product of the photosensitive resin composition of the above embodiment. The dried product refers to a material obtained through a drying process of the photosensitive resin composition of the above embodiment. The cured product refers to a material obtained through a curing process of the photosensitive resin composition of the above embodiment. The thickness of the photosensitive resin layer is not particularly limited, but can be freely adjusted within a range of, for example, 0.01 ㎛ to 1 mm.

[0068] The thickness of the above dry film photoresist is not particularly limited, but can be freely adjusted within a range of, for example, 0.01 μm to 1 mm. When the thickness of the above dry film photoresist increases or decreases by a specific value, the physical properties measured in the dry film photoresist can also change by a specific value.

[0069] The above dry film photoresist may further include a substrate film and a protective film. The substrate film serves as a support for the photosensitive resin layer during the manufacture of the dry film photoresist, and facilitates handling of the photosensitive resin layer having adhesive strength during exposure.

[0070] The above-mentioned base film may be any of various plastic films, and may include, for example, one or more plastic films selected from the group consisting of acrylic films, polyethylene terephthalate (PET) films, triacetyl cellulose (TAC) films, polynorbornene (PNB) films, cycloolefin polymer (COP) films, and polycarbonate (PC) films. The thickness of the above-mentioned base film is not particularly limited, but may be freely adjusted within the range of, for example, 0.01 ㎛ to 1 mm.

[0071] The above protective film serves as a protective cover that prevents damage to the resist during handling and protects the photosensitive resin layer from foreign substances such as dust, and is laminated on the back surface of the photosensitive resin layer where the base film is not formed. The above protective film serves to protect the photosensitive resin layer from the outside, and requires appropriate releasability and adhesiveness so that it can be easily removed when applying the dry film photoresist to a post-process, and so that it does not deform during storage and distribution.

[0072] The above protective film may be made of various plastic films, and may include, for example, one or more plastic films selected from the group consisting of acrylic films, polyethylene (PE) films, polyethylene terephthalate (PET) films, triacetylcellulose (TAC) films, polynorbornene (PNB) films, cycloolefin polymer (COP) films, and polycarbonate (PC) films. The thickness of the protective film is not particularly limited, but may be freely adjusted within the range of, for example, 0.01 ㎛ to 1 mm.

[0073] Examples of a method for manufacturing the above dry film photoresist are not particularly limited, and for example, a photosensitive resin composition of the above embodiment may be coated on a conventional base film such as polyethylene terephthalate using a conventional coating method, followed by drying, and laminating the upper surface of the dried photosensitive resin layer using a conventional protective film such as polyethylene to manufacture a dry film.

[0074] The method for coating the photosensitive resin composition of the above embodiment is not particularly limited, and for example, a method such as a coating bar can be used.

[0075] The step of drying the above-mentioned coated photosensitive resin composition can be performed by a heating means such as a hot air oven, a hot plate, a hot air circulation furnace, or an infrared furnace, and can be performed at a temperature of 50°C or higher and 120°C or lower.

[0076]

[0077] In addition, according to another embodiment of the present invention, a method for manufacturing a dry film photoresist can be provided, including a step of coating the photosensitive resin composition on a polymer substrate.

[0078] The above polymer substrate refers to the substrate film described above. Therefore, the content of the polymer substrate includes all of the content described above in the above embodiment.

[0079] The method for coating the above photosensitive resin composition on a polymer substrate can be performed according to a method well known in the art. For example, comma coating, slot die, lip die, spin coating, etc. can be used, but are not limited thereto.

[0080] Additionally, after the step of coating the photosensitive resin composition on a polymer substrate, a step of drying the coated photosensitive resin composition may be further included.

[0081] The step of drying the above-mentioned coated photosensitive resin composition can be performed by a heating means such as a hot air oven, a hot plate, a hot air circulation furnace, or an infrared furnace, and can be performed at a temperature of 50°C or higher and 140°C or lower, or 80 to 135°C or 85 to 130°C.

[0082] However, it is preferable that the drying be performed for 25 to 50 minutes or 30 to 40 minutes in the above temperature range. That is, the photosensitive resin layer is a dried or cured product dried for 25 to 50 minutes at a temperature of 50°C or more and 140°C or less, and may be a single layer of photosensitive resin. Accordingly, the thickness of the photosensitive resin layer may be 85 μm or more or 100 μm or more, and the resolution pitch of the line width / line spacing (Line / Space) of the resist pattern based on a 120 μm film of the photosensitive resin layer after exposure and development may be 6 / 14 μm or less. In addition, the resist pattern can implement a fine pitch with a resolution pitch of the line width / line spacing (Line / Space) based on a 120 μm film of 5 / 11 μm or less. Therefore, according to the present invention, it is possible to implement a fine pattern of 6 / 14 μm or less for a dry film resist.

[0083] In addition, if the drying is performed at a temperature exceeding 140°C for less than 25 minutes, the solvent and air bubbles may remain within the dried resin monolayer due to the increase in the solvent evaporation rate, which may cause the resolution pitch of the photosensitive resin monolayer to increase after exposure and development, making it difficult to implement a fine circuit pattern. In addition, if the drying is performed at a temperature below 50°C for more than 50 minutes, the drying time may increase excessively, which may cause a problem of reduced process efficiency.

[0084]

[0085] According to another embodiment of the invention, a resist pattern may be provided, which includes a pattern of a photosensitive resin layer containing a cured product of the photosensitive resin composition of the above embodiment. The contents of the photosensitive resin composition include all of the contents described above in the above embodiment.

[0086] The pattern of the photosensitive resin layer may be a photosensitive composition in the form of a pattern having an opening.

[0087] The above resist pattern can form a fine pattern with high precision by maintaining a high aspect ratio of 1:20 or more, or 1:21 or more, or 1:22 or more, or 1:24 or more.

[0088] In this specification, aspect ratio may mean “height / width of a structure” (i.e., film thickness / pattern linewidth).

[0089] Examples of methods for forming the photosensitive resin pattern include a method in which the photosensitive resin composition of the dry film photoresist of the other embodiment is coated on a substrate, a photosensitive resin layer is laminated on the substrate through drying using the above-described method, and then exposure, baking, and development are performed. In addition, a method in which the photosensitive resin layer of the photosensitive element of the other embodiment is laminated on a substrate, and then exposure and development are performed is also performed.

[0090] The thickness of the photosensitive resin single layer may be 100 ㎛ or more, or 120 ㎛ or more, or 1000 ㎛ or less, or 85 ㎛ to 1000 ㎛, or 100 ㎛ to 1000 ㎛, or 120 ㎛ to 1000 ㎛. Such a photosensitive resin single layer can be formed at a fine pitch after exposure, post-exposure baking, and development through the above-described method, thereby manufacturing a high-resolution fine circuit pattern.

[0091] As the substrate, a copper-clad laminate, a glass substrate on which transparent electrodes such as ITO and IZO are sputtered or deposited, a film substrate, a glass substrate coated with dielectric paste, a silicon wafer, a glass wafer on which amorphous silicon is deposited, a silicon wafer on which a metal thin film such as copper, tantalum, or molybdenum is sputtered, etc. can be used.

[0092] The above exposure process can be performed using a light source well known in this field, such as UV, visible light, or laser, and among them, it is preferable to use a laser direct exposure device including a light source with a wavelength of 350 to 410 nm, particularly an i-line (365 nm) light source. When using a laser direct exposure device, the exposure energy can be operated under a condition of 300 to 700 mJ / ㎠ or less, and when using a general lamp exposure device, the exposure energy can be operated under a condition of 200 mJ / ㎠ or less, which is useful for manufacturing images of PCBs, lead frames, PDPs, and other display devices.

[0093] Additionally, a post-exposure baking process may be performed to enhance the efficiency of the cationic initiator. The post-exposure baking process may utilize a hot air oven or a hot plate. As a preferred example, when a hot air oven is used, the baking process may be performed at 70 to 90°C for 10 to 60 minutes.

[0094] The developing process can be carried out by a dipping method, a shower method, a spray method, a brush method, etc., and as a developer, unlike a developer of a general photoresist, an organic developer including an organic solvent such as PGMEA is used instead of an alkaline developer. Such an organic developer may include organic solvents such as methyl-2-hydroxy isobutyrate, ethylene glycol methyl ether acetate, 2-methoxy-1-methylethyl ester, propylene acetate, dibutyl ether, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate (PGMEA), and propylene glycol dimethyl ether, and these may be used alone or in combination of two or more. According to a preferred embodiment, the developer may be PGMEA.

[0095] Accordingly, the photosensitive resin layer may be developed with one or more organic solvents selected from the group consisting of methyl-2-hydroxy isobutyrate, ethylene glycol methyl ether acetate, 2-methoxy-1-methylethyl ester, propylene acetate, dibutyl ether, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, and propylene glycol dimethyl ether.

[0096] In the case where the dry film photoresist or photosensitive element of the above other embodiments has a protective film on the photosensitive resin layer, a process of removing the protective film may be further performed prior to the lamination process of the photosensitive resin layer on a circuit board or a substrate for manufacturing a display device.

[0097] In addition, when the dry film photoresist or photosensitive element of the above other embodiment has a polymer substrate or substrate film laminated on one side of the photosensitive resin layer, a process of removing the polymer substrate or substrate film immediately after the exposure process may be further performed.

[0098]

[0099] According to another embodiment of the invention, a display device may be provided, including the resist pattern or a metal pattern formed by the resist pattern. In addition, the resist pattern or the metal pattern formed by the resist pattern may be included in a circuit board.

[0100] That is, a circuit board or display device including a resist pattern of the other embodiment or a metal pattern formed by the resist pattern of the other embodiment can be provided. The content of the resist pattern includes all of the content described above in the other embodiment.

[0101]

[0102] The specific details of the above circuit board or display device are not particularly limited, and various conventionally known technical configurations can be applied without limitation.

[0103] The above metal pattern can be formed by the above-described resist pattern. Specifically, the metal pattern can be formed by etching or plating through openings included in the resist pattern. That is, the metal pattern can include underlying metal remaining after etching of the underlying metal of the resist pattern through the openings included in the resist pattern, or metal plated in the openings included in the resist pattern.

[0104] For example, by etching or plating the lower substrate exposed by the above-described resist pattern, a partition wall of a power inductor, a microelectromechanical system (MEMS) component, an electronic circuit, a conductor pattern, a printed wiring board, a lead frame, an ITO electrode, a black matrices, a semiconductor bump, etc. can be manufactured. If necessary, after the etching or plating, the resist pattern can be removed by peeling it from the substrate using an aqueous solution having a stronger alkalinity than the developer.

[0105] As described above, the resist pattern can have a resolution pitch (Line / Space) of 6 / 14 um or less in terms of line width / line spacing (Line / Space) based on a 120 um film, and can implement a fine pitch of 5 / 11 um or less.

[0106] The above resist pattern can be applied to the bulkhead of a power inductor or a microelectromechanical system (MEMS) component, and most preferably to the bulkhead of a power inductor.

[0107] Accordingly, by using the dry film photoresist of the present invention, a circuit having a fine line width can be formed through a subsequent conventional etching / plating process, and productivity can be maximized in creating an image for a power inductor, MEMS, PCB lead frame, PDP, other display devices, semiconductor devices, etc. having a fine line width through a known process.

[0108]

[0109] The present invention provides a photosensitive resin composition that introduces a UV absorber together with a specific photocation initiator and an epoxy resin, so that the line width / line spacing (Line / Space) of a resist pattern based on a 120 μm film can be 6 / 14 μm or less. In particular, the resist pattern is implemented in a fine pitch with a resolution pitch (Line / Space) of 6 / 14 μm or less based on a 120 μm film, thereby maximizing power inductor efficiency and MEMS precision. Therefore, according to the present invention, the conventional resolution (line width / line spacing: 8 / 15 μm) limit based on a 120 μm film can be overcome.

[0110] In addition, the photosensitive resin composition of the present invention is a material that can be applied in various ways to wearable electronic devices that are becoming increasingly miniaturized as high-resolution film materials.

[0111]

[0112] Hereinafter, the functions and effects of the invention will be described in more detail through specific examples. However, these examples are provided merely as examples of the invention and do not define the scope of the invention.

[0113]

[0114] <Examples, Comparative Examples, and Reference Examples: Preparation of Photosensitive Resin Compositions and Dry Film Photoresists>

[0115] A photosensitive resin composition was prepared by mixing each component according to the composition and content in Table 1 below (unit: g).

[0116]

[0117] (mixing ingredients)

[0118] (A) Epoxy resin

[0119] Epoxy resin of the above a): A-1, A-2

[0120] A-1: Bisphenol A novolac epoxy (KEB-3180M80, Kolon Industries)

[0121] A-2: Bisphenol A epoxy (YD-011, Kukdo Chemical)

[0122] Multifunctional epoxy resin of the above b): A-3, A-4

[0123] A-3: Biphenyl epoxy (KES-7370, Kolon Industries)

[0124] A-4: Multifunctional epoxy (Novolac epoxy, KES-7270M70, Kolon Industries)

[0125] (B) Photocationic initiator:

[0126] B-1: PAG-TR-21608, Thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) bis tetrakis(pentafluorophenyl) borate

[0127] B-2: Irgacure 290

[0128] B-3: GSID26-1

[0129] B-4: GSID26-1

[0130] (C) UV absorber

[0131] C-1: Tinuvin 384-2, Benzenepropanoic acid, 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-, C7-9-branched and linear alkyl esters

[0132] (D) Leveling agent: Tego Flow 425 (Polyether modified polysiloxane)

[0133] (E) Solvent: PGMEA

[0134]

[0135] The photosensitive resin composition obtained above was coated on a PET film having a thickness of 36 μm using a coating bar to form a photosensitive resin layer, and dried at 100°C for 60 minutes using a hot air oven to form a photosensitive resin layer having a thickness of 120 μm.

[0136] A dry film photoresist was manufactured by laminating a protective film (polyethylene) on top of a dried photosensitive resin layer.

[0137]

[0138] <Experimental Example>

[0139] The physical properties of the dry film photoresists manufactured in the above examples, comparative examples, and reference examples were measured using the following methods, and the results are shown in Table 1.

[0140]

[0141] 1. Resolution (Line / Space, unit: ㎛)

[0142] The protective film of the dry film photoresist manufactured in the above examples, comparative examples and reference examples was peeled off so that the photosensitive resin layer of the dry film photoresist came into contact with the copper layer surface of the brush-polished 1.6 mm thick copper-clad laminate, at a substrate preheating roll temperature of 120°C, a laminator roll temperature of 115°C and a roll pressure of 4.0 kgf / cm2. And, a laminate was formed by laminating using HAKUTO MACH 610i under the condition of a roll speed of 0.5 min / m.

[0143] After peeling off the support PET film of the dry film photoresist from the above laminate, the organic coating film was irradiated with ultraviolet rays of wavelength 355 nm using Paragon-8000m from Orbotech and a 41-step tablet from Stouffer Graphic Arts Equipment at an exposure dose such that the number of remaining steps was 17, and then left for 15 minutes and cured using a hot air oven at 85°C for 20 minutes. After that, development was performed using dipping conditions with a 98% PGMEA solution, and the resolution was measured.

[0144] In the developed laminate, the minimum gap between the photosensitive resin layers was measured using a ZEISS AXIOPHOT Microscope to evaluate the resolution. The smaller this value, the better the resolution.

[0145]

[0146] 2. Copper plating resistance evaluation

[0147] After the development was completed, a 2.5-inch acrylic tape was attached to the specimen whose copper plating pattern was measured after 90 μm of copper plating. After separating the acrylic tape from the specimen at a 90° angle using SurTA (ChemiLAB) equipment, the presence or absence of copper plating pattern lifting was checked. The copper plating resistance was measured using this tape test method.

[0148] (Evaluation criteria)

[0149] ○: No lifting or peeling of pattern plating

[0150] X: Pattern plating lifting and peeling

[0151]

[0152] 3. Aspect ratio

[0153] The aspect ratio was calculated from the film thickness of 120 ㎛ in Table 1 and the line width (L, pattern line width) values ​​of the resolution of the examples, comparative examples, and reference examples above (film thickness / pattern line width).

[0154]

[0155] Compounding ingredients, implementation, comparative example, reference example, 12345671234512, epoxy resin (A)A-1:KEB-3180M8078.078.078.078.078.070.056.578.078.050.560.7178.049.078.0A-2:YD-0116.06.06.06.06.06.015.510.06.06.09.513.546.08.06.0A-3:KES-73707.47.47.47.47.46.523.57.47.432.013.547.428.07.4A-4:KES-7270M702.62.62.62.62.63.05.02.62.62.610.02.6Photocationic initiator (B)B-1:TR-PAG-216080.40.40.12.00.40.40.40.40.4B-2:TR-PAG-202S1.0B-3:Irgacure 2900.40.40.61B-4:GSID26-10.4UV Absorbent C-1:Tinuvin384-20.011.900.010.010.010.010.010.010.010.012.50Leveling agent D:Polysiloxane0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.1Solvent E:PGMEA5.493.604.895.793.894.494.495.495.497.511.55.54.493.00Film manufacturing thickness (㎛)120120120120120120120120120120120120120120120120120Resolution (L / S)(㎛)5 / 116 / 145 / 156 / 145 / 136 / 135 / 126 / 209 / 188 / 158 / 158 / 176 / 208 / 17 Copper plating resistance evaluation (plating thickness 80㎛)○○○○○○○○X○○○○○Aspect ratio1:241:201:241:201:241:201:241:201:131:151:151:151:201:15Molecular weight(g / mol)2,9872,9982,9413,0052,9142,7682,4912,8962,9572,5952,8312,9732,5472,976

[0156] As shown in the results in Table 1 above, Examples 1 to 7 can be designed to enable the formation of fine patterns by exhibiting excellent resolution, substrate adhesion, and copper plating resistance by using a photocationic initiator (PAG) with lower reactivity than the comparative examples. In addition, due to the low reactivity of PAG, a high aspect ratio (1:20 or more) can be maintained even for a thick film with a film thickness of 120 μm without a halation phenomenon. In addition, Examples 1 to 7 can maintain a high aspect ratio by introducing a multi-functional epoxy and including an epoxy resin mixture with an optimal composition to improve rigidity, chemical resistance, and thermal expansion coefficient. In particular, in the case of Example 1, it can be seen that a resolution pitch of 5 / 11 um can be realized in terms of line width / line spacing (Line / Space) based on a 120 um film. On the other hand, Comparative Examples 1 to 4 used a general photocationic initiator different from the Examples, and although some of the Comparative Examples showed good aspect ratios or plating resistance results, the resolution was worse than that of the Examples.

[0157] In addition, Comparative Example 5 did not include a UV absorber even though it included a photocationic initiator with low reactivity, so the resolution was worse than that of the examples.

[0158] Therefore, Comparative Example 1 has poor plating characteristics, and Comparative Examples 2 to 5 have a low aspect ratio of 1:15 or less and poor resolution, making it impossible to form fine patterns compared to the examples.

[0159] In addition, Reference Example 1, even though it used the same cationic initiator as Example 1, had a weight ratio of 60:40 between the epoxy resin of a) and the polyfunctional epoxy resin of b), which resulted in a large content of polyfunctional epoxy resin, resulting in a resolution of 6 / 20 um, which was relatively poorer than the Examples. In addition, Reference Example 2 had an excessive content of UV absorber, resulting in a low aspect ratio of 1:15, and a resolution of 8 / 17 um, which resulted in a pattern that was not as finely implemented as the Examples.

[0160] Therefore, the comparative examples and reference examples cannot improve device performance because it is difficult to form fine patterns compared to the present invention.

Claims

1. Contains an epoxy resin; a photocationic initiator; a UV absorber; an additive; and a solvent; A photosensitive resin composition wherein the above-mentioned photocationic initiator is at least one selected from the group consisting of thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) bis tetrakis(pentafluorophenyl) borate, thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) hexafluorophosphate, triarylsulfonium bis tetrakis(pentafluorophenyl) borate, triarylsulfonium hexafluorophosphate, and 4-{[4-(diphenylsulfonium) phenyl] sulfanyl} phenyl) diphenylsulfonium) hexafluorophosphate.

2. In paragraph 1, A photosensitive resin composition wherein the cationic initiator is thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) bis tetrakis(pentafluorophenyl) borate.

3. In paragraph 1, A photosensitive resin composition comprising 0.1 to 2.0 parts by weight of the cationic initiator relative to 100 parts by weight of the epoxy resin.

4. In paragraph 1, A photosensitive resin composition comprising: a) at least one selected from the group consisting of bisphenol-type epoxy resins and bisphenol-type novolac epoxy resins; and b) at least one selected from the group consisting of multi-functional epoxy resins.

5. In paragraph 4, A photosensitive resin composition comprising a) at least one epoxy resin selected from the group consisting of bisphenol A novolac epoxy (BPA Novolac Epoxy) and bisphenol epoxy resin (BPA Epoxy), and b) at least one multifunctional epoxy selected from the group consisting of biphenyl epoxy and novolac-type epoxy resin.

6. In paragraph 4, A photosensitive resin composition wherein the weight ratio of the above a) and b) is 90:10 to 70:30 based on 100 parts by weight of the total of the entire epoxy resin.

7. In paragraph 1, The photosensitive resin composition wherein the bisphenol-type epoxy resin and biphenyl epoxy resin have a weight average molecular weight of 1,500 to 5,000 g / mol.

8. In paragraph 1, The above multifunctional epoxy resin is a photosensitive resin composition having three or more functional groups and a weight average molecular weight of 800 to 1,500 g / mol.

9. In paragraph 1, A photosensitive resin composition comprising 0.01 to 2.0 parts by weight of the UV absorbent relative to 100 parts by weight of the epoxy resin.

10. In paragraph 1, A photosensitive resin composition wherein the additive is at least one selected from the group consisting of a leveling agent, a curing accelerator, a filler, a reaction retardant, an anti-aging agent, an antioxidant, a pigment (dye), a plasticizer, a flame retardant, a surfactant, a dispersant, a dehydrating agent, an adhesive imparting agent, and an antistatic agent.

11. A dry film photoresist comprising a photosensitive resin layer containing a cured product of the photosensitive resin composition of claim 1.

12. A method for producing a dry film photoresist, comprising: a step of coating the photosensitive resin composition on a polymer substrate.

13. A resist pattern including a pattern of a photosensitive resin layer containing a cured product of the photosensitive resin composition of claim 1.

14. A resist pattern in clause 13, wherein the aspect ratio is maintained at 1:20 or more.

15. A display device including the resist pattern of claim 13, or a metal pattern formed by the resist pattern of claim 13.