Dry film photoresist using photosensitive resin composition, method for preparing same, resist pattern, and display device

Abstract

The present invention relates to a dry film photoresist, a method for preparing same, a resist pattern, and a display device using same. The dry film photoresist comprises: a base film without a separate release layer; and a photosensitive resin layer that is formed on the base film and contains a cured product of a photosensitive resin composition comprising an epoxy binder, a surfactant, a cationic initiator, and a low-boiling point solvent, wherein the thickness of the photosensitive resin layer is at least 100 µm, and the resolution pitch (line / space), based on a 100 µm film, of the photosensitive resin layer following exposure and development is 20 um or less.

Description

Dry film photoresist using a photosensitive resin composition and its manufacturing method, resist pattern and display device

[0001] The present invention relates to a dry film photoresist using a photosensitive resin composition, 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] In this regard, as an example of the manufacturing process of a printed circuit board (PCB), a pretreatment process is first performed to laminate the copper-clad laminate, the PCB's primary material. Pretreatment processes include drilling, deburring, and face-off for the outer layer process, while face-off or acid washing is performed for the inner layer process. Bristle brushes and jet pumice are primarily used in the face-off process, and acid washing can include soft etching and acid washing using 5 wt% sulfuric acid.

[0005] To form a circuit on a copper-clad laminate that has undergone a pretreatment process, a dry film photoresist (hereinafter referred to as DFR) is typically laminated onto the copper layer of the copper-clad laminate. This process involves using a laminator to peel off the protective film of the DFR and laminate the photoresist layer of the DFR onto the copper surface. Typically, the lamination process is performed at a speed of 0.5 to 3.5 m / min, a temperature of 100 to 130°C, and a heated roller pressure of 10 to 90 psi.

[0006] After the printed circuit board has gone through the lamination process, the substrate is left to stabilize for at least 15 minutes. Then, a photomask with the desired circuit pattern is used to expose the photoresist of the DFR. During this process, when the photomask is irradiated with ultraviolet light, the photoresist that has been irradiated with ultraviolet light initiates polymerization in the irradiated area by the photoinitiator contained therein. Initially, the oxygen within the photoresist is consumed, then the activated monomer polymerizes, causing a crosslinking reaction. After that, the polymerization reaction progresses as a large amount of monomer is consumed. Meanwhile, the unexposed area remains in a state where the crosslinking reaction has not occurred.

[0007] Next, a developing process is performed to remove the unexposed portion of the photoresist. In the case of alkaline developable DFR, a 0.8 to 1.2 wt% aqueous potassium carbonate and sodium carbonate solution is used as the developer. In this process, the unexposed portion of the photoresist is washed away by the saponification reaction of the carboxylic acid of the binder polymer and the developer in the developer, and the cured photoresist remains on the copper surface.

[0008] Next, a circuit is formed through different processes depending on the inner and outer layer processes. In the inner layer process, a circuit is formed on the substrate through corrosion and peeling processes, while in the outer layer process, a plating and tenting process is followed by etching and solder peeling to form the desired circuit.

[0009] The above method generally involves the inclusion of a radical initiator in the photosensitive resin composition, which is hindered by oxygen during polymerization.

[0010] In addition, in the case of the existing technology of the above method, a release PET that is advantageous for cracks is used as a base film to coat a photosensitive resin composition, but at this time, release-processed components such as Si are transferred from the release PET, which may cause problems in stability and high-resolution implementation. That is, since the existing technology uses release PET as a base film when forming a pattern using a dry film photoresist, release-processed components such as Si may be transferred to the photosensitive resin composition layer for forming a dry film photoresist, which reduces pattern stability and has a limitation in manufacturing a dry film photoresist with a high resolution of 20 um or less and a resolution pitch (Line / Space) based on a coating film of 100 um or more.

[0011] In addition, there is a method of manufacturing a dry film photoresist using a hot melt method using a photosensitive resin composition that does not contain a solvent. The hot melt method is a method of manufacturing a dry film photoresist by coating a composition containing a polymer resin such as an epoxy binder, an initiator, and an additive on a base film while heating. Since this does not contain a solvent, the miscibility of each component including the polymer resin in the photosensitive resin composition is poor, and the heating of the photosensitive resin composition does not proceed evenly during coating, so the melting property of the photosensitive resin composition is reduced. This causes the coating surface of the dry film photoresist to be irregular, which may cause uneven spots. In addition, when a dry film photoresist is manufactured using the hot melt method as described above, there is a disadvantage in that the defect rate due to uneven spots is high during the film forming process.

[0012]

[0013] The present invention provides a dry film photoresist and a method for manufacturing the same using a solvent-type photosensitive resin composition capable of forming a high-resolution pattern based on a film size of 100 ㎛ or more, having high pattern stability and mechanical strength, minimizing the defect rate due to staining during a film forming process, and reducing the residual solvent content compared to the prior art.

[0014] In addition, the present invention provides a resist pattern and a display device using the above photosensitive resin composition.

[0015]

[0016] In this specification,

[0017] A substrate film without a separate release layer; and

[0018] A photosensitive resin layer containing a cured product of a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator, and a low-boiling-point solvent formed on the above-mentioned substrate film;

[0019] The thickness of the photosensitive resin layer is 100㎛ or more,

[0020] Provided is a high-resolution dry film photoresist having a resolution pitch (line / space) of 20 um or less based on a 100 um film of a photosensitive resin layer after exposure and development.

[0021] In addition, the present specification provides a method for manufacturing a dry film photoresist, including the step of coating a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator, and a low-boiling-point solvent on a polymer substrate not having a separate release layer.

[0022] The present specification also includes a pattern of a photosensitive resin layer containing a cured product of a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator, and a solvent,

[0023] The thickness of the photosensitive resin layer is 100㎛ or more,

[0024] A resist pattern is provided having a resolution pitch (line / space) of 20 um or less based on a 100 um film of a photosensitive resin layer after exposure and development.

[0025] The present specification also provides a display device including the resist pattern or a metal pattern formed by the resist pattern.

[0026]

[0027] Hereinafter, a dry film photoresist, a resist pattern, and a display device using a photosensitive resin composition according to embodiments of the invention will be described in detail.

[0028] 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.

[0029] As used herein, the singular forms also include the plural forms unless the context clearly dictates otherwise.

[0030] 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.

[0031] 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.

[0032] In the present invention, as a specific example of the measurement conditions, the epoxy binder resin was dissolved in tetrahydrofuran to a concentration of 1.0 (w / w)% in THF (about 0.5 (w / w)% based on solid content), filtered using a syringe filter with a pore size of 0.45 μm, 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 Keppel Detector, and the measurement was performed at 40°C.

[0033] 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.

[0034] STD A (Mp): 791,000 / 27,810 / 945

[0035] STD B (Mp): 282,000 / 10,700 / 580

[0036] STD C (Mp): 126,000 / 4,430 / 370

[0037] ST D (Mp): 51,200 / 1,920 / 162

[0038] In the present invention, a solvent having a boiling point of 130°C or lower is defined as a low-boiling-point solvent, and a solvent having a boiling point of more than 130°C is defined as a high-boiling-point solvent.

[0039]

[0040] Hereinafter, the present invention will be described in detail.

[0041]

[0042] According to one embodiment of the invention, a dry film resist may be provided, comprising: a base film not having a separate release layer; and a photosensitive resin layer formed on the base film and containing a cured product of a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator, and a low-boiling-point solvent; wherein the photosensitive resin layer has a thickness of 100 μm or more, and a resolution pitch (Line / Space) of 20 μm or less based on a 100 μm film of the photosensitive resin layer after exposure and development.

[0043] The present inventors have experimentally confirmed that when the dry film photoresist (DFR) of the above embodiment is formed using a photosensitive resin composition including a solution-type epoxy binder resin and a non-release film without a separate release layer as a base film, the resolution of the photosensitive resin layer (preferably a single layer of the photosensitive resin) can be increased, thereby improving adhesion and resolution, compared to a conventional method of forming using a hot melt type that does not contain a solvent, and have completed the invention.

[0044] In addition, since the dry film resist of the present invention is formed by a coating method using a photosensitive resin composition including a solvent, it is possible to provide an epoxy-containing dry film photoresist film with excellent coatability and no defect rate due to stains in the film forming process at a high yield. In particular, since the epoxy-containing dry film photoresist uses a non-release film, a release treatment component such as Si is not transferred to the photosensitive resin composition layer for forming the dry film photoresist. Therefore, since the present invention does not include a release treatment component such as Si or a fluorine coating layer compared to a product using a conventional release PET, the pattern stability of the photosensitive resin composition layer is excellent, and the resolution of a single layer including the photosensitive resin composition can be improved more effectively to implement a high resolution. In addition, in such cases, by forming a photosensitive resin layer using an epoxy-containing photosensitive resin composition containing a low-boiling-point solvent having a boiling point of 130°C or less, the solvent removal ability is superior to that of using a solvent having a boiling point exceeding 130°C, and bubble generation is prevented, so that the residual solvent content of the epoxy-containing dry film photoresist can be managed to be 2,000 ppm or less, or more than 1,000 ppm and 2,000 ppm or less, or 1,000 ppm or less.

[0045] Furthermore, since the above dry film photoresist uses an epoxy binder and a cationic initiator, it is not subject to oxygen interference during polymerization through exposure, unlike conventional radical initiators, and thus polymerization can proceed more easily than before.

[0046]

[0047] Specifically, the dry film photoresist may include a substrate film that does not have a separate release layer.

[0048] Existing technologies utilize a release PET when forming a pattern using a dry film photoresist utilizing a photosensitive epoxy resin composition. However, epoxy resin compositions are susceptible to cracking, which can lead to cracks forming in the final dry film photoresist, resulting in a poor pattern. Furthermore, the release component contained in the release PET can be transferred to the photosensitive epoxy resin composition layer, reducing the resolution of the pattern.

[0049] That is, in the case of general heterogeneous PET, inorganic particles such as silicon are added or fluorine coating is applied, but in the case of such additional processing of PET, there is a problem of reduced resolution due to transfer of particles and organic substances.

[0050] In contrast, the present embodiment has the characteristic of using a non-release film that has not been released as a release film.

[0051] More specifically, the substrate film of the above embodiment is characterized by using a substrate film that does not include inorganic particles or a fluorine coating layer. That is, the substrate film uses a non-release film that has not undergone any separate additional processing. The substrate film serves as a support for the photosensitive resin layer during the production of a dry film photoresist, and facilitates handling of the photosensitive resin layer having adhesive strength during exposure.

[0052] Therefore, according to one embodiment of the invention, since a non-release type substrate film is used that is not subjected to a separate release treatment or includes a fluorine coating layer as in the prior art, high image quality and pattern stability of a dry film photoresist can be secured.

[0053] 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.

[0054] In one embodiment, the substrate film may be a non-reactive PET film.

[0055]

[0056] In addition, the dry film photoresist may include an epoxy type photosensitive resin monolayer formed on the base film. The epoxy type photosensitive resin monolayer may be a photosensitive resin layer containing a cured product of a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator, and a low-boiling-point solvent. Specifically, the photosensitive resin monolayer may include a dried product or a cured product of a coating layer of a solution-type photosensitive resin composition having a certain viscosity including an epoxy binder, a surfactant, a cationic initiator, and a solvent. The dried product refers to a material obtained through a drying process of the photosensitive resin composition. In addition, the cured product refers to a material obtained through a curing process of the photosensitive resin composition.

[0057] The above photosensitive resin layer may be a dried product or a cured product dried at a temperature of 50°C or higher and 140°C or lower for 25 to 50 minutes.

[0058] The above-described dry film photoresist uses an epoxy binder and a cationic initiator, and unlike conventional radical initiators, is not affected by oxygen during polymerization through exposure. Specifically, the cationic initiator initially reacts within the photoresist, opening the epoxy ring and causing a polymerization reaction. Furthermore, the post-exposure baking process can enhance the initiator efficiency. Therefore, the above-described embodiment can enhance the resolution of the photosensitive resin layer and improve adhesion and resolution.

[0059] Moreover, since the dry film photoresist forms a photosensitive resin layer using a solvent-containing epoxy binder photosensitive resin composition rather than a conventional hot melt method, the resolution of a single layer including the photosensitive resin composition formed on the non-release type base film can be further improved. This is because the solubility of each component of the solvent-containing epoxy binder photosensitive resin composition increases due to the solvent, so that the dry film photoresist is formed on the base film without causing a stain in the coating layer, thereby realizing excellent film releasability.

[0060] In addition, since the solvent uses a low boiling point solvent having a boiling point of 130°C or less, the solvent quickly evaporates in a short period of time compared to a high boiling point solvent having a boiling point exceeding 130°C during the drying process, thereby minimizing the residual solvent content in the film. Therefore, the residual solvent content in the final film can be managed to be 2,000 ppm or less, or more than 1,000 ppm to 2,000 ppm or less, or 1,000 ppm or less, and thus, the releasability can be further improved.

[0061] In addition, the photosensitive resin single layer is composed of one layer formed by one coating, and is distinguished from a two-layer or more laminate formed by two or more coatings.

[0062] The thickness of the photosensitive resin layer is not particularly limited, but can be freely adjusted within the range of, for example, 0.01 ㎛ to 1 mm.

[0063] More specifically, the thickness of the photosensitive resin single layer may be 100 µm or more, or 120 µm or more, or 1000 µm or less, or 85 µm to 1000 µm, or 90 µm to 1000 µm, or 100 µm to 1000 µm, or 120 µm to 1000 µm. 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.

[0064] In addition, the thickness of the dry film photoresist is not particularly limited, but can be freely adjusted within a range of, for example, 0.01 ㎛ to 1 mm, and may include a thickness range of the photosensitive resin single layer. When the thickness of the dry film photoresist increases or decreases by a specific value, the physical properties measured in the dry film photoresist may also change by a specific value.

[0065] Meanwhile, the above dry film photoresist may further include a protective film on the photosensitive resin layer.

[0066] 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.

[0067] The above protective film may be made of various plastic films, and may include at least one selected from the group consisting of, for example, an acrylic film, a polyethylene (PE) film, a polyethylene terephthalate (PET) film, a triacetyl cellulose (TAC) film, a polynorbornene (PNB) film, a cycloolefin polymer (COP) film, and a polycarbonate (PC) film. The thickness of the protective film is not particularly limited, but may be freely adjusted within a range of, for example, 0.01 ㎛ to 1 mm.

[0068] A method for manufacturing the above dry film photoresist can be provided by using a coating method of a photosensitive resin composition containing a solvent, rather than a hot melt method as in the prior art, on a non-release type substrate film on which an inorganic particle or fluorine coating layer is not formed.

[0069] For example, the method for manufacturing the above dry film photoresist may include coating the photosensitive resin composition of the above embodiment once on a base film such as a non-release type polyethylene terephthalate that does not contain inorganic particles or a fluorine coating layer as in the prior art using a conventional coating method, drying the film, and laminating a non-release type polyethylene terephthalate film on the upper surface of the dried photosensitive resin single layer to manufacture a dry film. The non-release type polyethylene terephthalate film laminated on the upper surface of the photosensitive resin single layer serves as a protective film for an epoxy photosensitive resin layer that may affect high resolution due to roughness generation.

[0070] The method for coating the photosensitive resin composition of the above embodiment is not particularly limited, and for example, a coating bar or the like may be used. Specifically, the coating may be performed using COMMA coating, but other well-known coating methods may be used.

[0071] These dry film photoresists may have a residual solvent content of 1000 ppm or less or 5 to 1000 ppm based on the thickness of the entire photosensitive resin layer. The residual solvent content is measured using a column DB-5MS-UI (60 m x 320 um x 1 um) of Agilent GC-MS as in the experimental example described below and is expressed in %. The sample was dissolved in DMAc to a concentration of 10 wt% solution (10 wt% in DMAc), filtered using a syringe filter with a pore size of 0.45 μm, and then injected into GS-MS at 280°C at 1 μL, using He as the mobile phase and flowing at 1 ml / min. The temperature was maintained at 40°C for 4 minutes, then increased by 10°C per minute and maintained at 320°C for 3 minutes to measure the residual organic solvent content.

[0072] In addition, the peak area of ​​the residual solvent detected in the sample is substituted into the calibration curve formed by analyzing the standard sample diluted in DMAc with 6 concentration levels of the solvent (MEK) using the same GC-MS analysis method to obtain the content of the residual solvent (MEK) in the sample. At this time, the linearity of the standard calibration curve is 0.999 or higher and the instrument detection limit of the solvent (MEK) is 0.5 ppm. Since the sample was dissolved in DMAc at 10 wt% and analyzed, when the sample dilution ratio is taken into account, this analysis method can produce reliable results for the residual solvent (MEK) present in the sample at 5 ppm or more.

[0073]

[0074] Meanwhile, each component of the photosensitive resin composition of the present invention will be described in more detail.

[0075] The above epoxy resin may be at least one selected from the group consisting of bisphenol-type epoxy resins.

[0076] According to one embodiment of the invention, the epoxy resin may include at least one selected from the group consisting of bisphenol A novolac epoxy (BPA Novolac Epoxy) and biphenyl novolac epoxy resin (Biphenyl Epoxy).

[0077] The above bisphenol-type epoxy resin may have a weight average molecular weight of 3,000 to 5,000 g / mol and an epoxy equivalent of 200 to 300 g / eq.

[0078] The above epoxy resin may be at least one selected from the group consisting of bisphenol A novolac epoxy, bisphenol A-bisphenol A diglycidyl ether polymer, and bisphenol F epoxy.

[0079] The above surfactant is used to lower the surface tension of the epoxy resin and improve defoaming and coating properties.

[0080] The surfactant is contained in an amount of 0.01 to 1 part by weight, or 0.01 to 0.5 parts by weight, or 0.01 to 0.3 parts by weight, or 0.01 to 0.1 parts by weight, or 0.01 to 0.08 parts by weight, or 0.02 to 0.05 parts by weight, based on 100 parts by weight of the epoxy resin. If the content of the surfactant is less than 0.01 part by weight, there are problems with coating properties and defoaming, and if the content exceeds 1 part by weight, there are problems with reduced resolution.

[0081] That is, when a surfactant is added in an amount exceeding 1 part by weight, or particularly in an amount exceeding 5 parts by weight, to coat a solvent-type photosensitive resin composition on a release film, even if the surface tension is lowered, the resolution is reduced if the surfactant is added in excessive amounts.

[0082] As the above surfactant, any one selected from among fluorine-based surfactants and silicone-based surfactants can be used.

[0083] The above fluorine-based surfactant may be at least one selected from the group consisting of an oligomer having a perfluoroalkyl group including a lipophilic group, an oligomer having a perfluoroalkyl group including a hydrophilic group, and an oligomer having a perfluoroalkyl group including both hydrophobic and hydrophilic groups.

[0084] The above silicone-based surfactant may be at least one selected from the group consisting of polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, polyester-modified polymethylalkylsiloxane, polyether-modified polymethylalkylsiloxane, aralkyl-modified polymethylalkylsiloxane, and polyether-modified siloxane.

[0085] The above cationic initiator refers to a photocationic polymerization initiator that generates cationic species upon exposure to UV and active energy rays, and plays an important role in the curing of dry film photoresists. Therefore, the cationic initiator has the characteristic of enabling the formation of fine patterns (i.e., fine pitch) in thick films by using a substance that has the function of a photoacid generator with low reactivity while having sufficient performance to cure epoxy resin.

[0086] According to one embodiment of the invention, the cationic initiator may include at least one selected from an aromatic sulfonium complex and an iodonium cationic initiator. Specifically, the cationic initiator is 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-(diphenyl sulfonium)phenyl]sulfanyl}phenyl)diphenylsulfonium) hexafluorophosphate), phenyl(4-methoxyphenyl)iodonium hexafluoride, N,N-dimethyl-N-benzyltrifluoromethanesulfonic acid, It may be at least one selected from the group consisting of 4-methylphenyl(4-(2-methylpropylphenyl))iodonium hexafluoride and phenyl(4-methoxyphenyl)iodonium arsenide hexafluoride. Preferably, the cationic initiator may be thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) bis tetrakis(pentafluorophenyl) borate.

[0087]

[0088] The above-mentioned specific type of cationic initiator has low reactivity and enables maintaining a high aspect ratio of 1:20 even in a thick film with a film thickness of 120 μm without halogenation.

[0089] The cationic initiator is contained in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the epoxy resin.

[0090] If the content of the above cationic initiator is less than 0.5 parts by weight, the degree of polymerization becomes insufficient, which may cause a problem in that the exposed portion dissolves in the developer, and if the content exceeds 5 parts by weight, the resolution of the photosensitive resin composition may deteriorate.

[0091]

[0092] In addition, as described above, in the present invention, the solvent is a low-boiling-point solvent having a boiling point of 130°C or lower that can dissolve each component for processability. The low-boiling-point solvent having a boiling point of 130°C or lower can achieve faster volatilization in the drying process than a high-boiling-point solvent having a boiling point exceeding 100°C, and thus has the advantage of minimizing the residual solvent content on the film.

[0093] At this time, if the boiling point of the solvent exceeds 130℃, the volatility is lower than that of the low-boiling-point solvent when the film is dried, so the residual solvent remains on the film, and the content of the residual solvent exceeds 2,000 ppm, which causes a problem in film release. In addition, in order to control bubbles generated during the film manufacturing process, a high-boiling-point solvent with a boiling point exceeding 130℃ can be mixed and used at 10% or less, but in this case, even if the bubbles generated during the process can be controlled, there is difficulty in managing the residual solvent in the film as described above.

[0094] In addition, even if a low-boiling-point solvent of 130°C or less is included in an epoxy-containing photosensitive resin composition, when a high-boiling-point solvent of a boiling point exceeding 130°C is mixed, there is a limit to reducing the residual solvent content due to the high boiling point of the high-boiling-point solvent, making it difficult to manage it to 2000 ppm or less.

[0095] Accordingly, in one embodiment of the invention, by using only a low-boiling-point solvent having a boiling point of 130°C or lower and not including a high-boiling-point solvent as a solvent in the photosensitive resin composition, the content of residual solvent in the final film can be lowered compared to the case where the high-boiling-point solvent is used, and the content of residual solvent can be managed to be 2,000 ppm or less, or more than 1,000 ppm and 2,000 ppm or less, or 1,000 ppm or less.

[0096] The low-boiling-point solvent may be a low-boiling-point solvent having a boiling point of 130°C or lower, 120°C or lower, 110°C or lower, 100°C or lower, 90°C or lower, or 80°C or lower. In addition, the low-boiling-point solvent may be a low-boiling-point solvent having a boiling point of 10°C or higher, 20°C or higher, or 30°C or higher.

[0097] In addition, the low boiling point solvent may be ethyl methyl ketone (MEK or EMK), dimethoxyethane tetrahydrofuran, ethyl propionate, 1-methoxy-2-propanol, propylene glycol dimethyl ether, methyl isobutyl ketone, methanol, ethanol, and isopropyl alcohol, and one or more of these may be mixed and used.

[0098] The amount of the solvent added may be 10 to 40 parts by weight (solid content) or 20 to 30 parts by weight per 100 parts by weight of the epoxy resin. If the solvent is used in an amount less than 10 parts by weight, there is a problem of reduced yield, and if the solvent is used in an amount exceeding 40 parts by weight, there is a problem of film release not occurring due to residual solvent.

[0099] Additionally, additives may be further included within a range that does not impair the purpose of the present invention.

[0100] For example, the additive may include various additives such as UV absorbers, leveling agents, curing accelerators, fillers, reaction retardants, anti-aging agents, antioxidants, pigments (dyes), plasticizers, flame retardants, surfactants, dispersants, dehydrating agents, adhesives, and antistatic agents.

[0101] Specifically, the additive may include a leveling agent, and the leveling agent may use polyether modified polysiloxane.

[0102] In addition, the content of the above additive is not particularly limited, but for example, it may be included in an amount of 0.5 to 20 parts by weight per 100 parts by weight of the epoxy resin.

[0103]

[0104] 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 a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator, and a low-boiling-point solvent on a polymer substrate not having a separate release layer.

[0105] The polymer substrate without the above-described separate release layer refers to the substrate film without the above-described separate release layer. Therefore, the content of the polymer substrate without the above-described separate release layer includes all of the content described above in the above-described embodiment. Accordingly, the low-boiling-point solvent is a low-boiling-point solvent having a boiling point of 130°C or lower, and may be at least one selected from the group consisting of ethyl methyl ketone, dimethoxyethane tetrahydrofuran, ethyl propionate, 1-methoxy-2-propanol, propylene glycol dimethyl ether, methyl isobutyl ketone, methanol, ethanol, and isopropyl alcohol.

[0106] Additionally, the content of silicon or fluorine on the surface of the polymer substrate may be 1000 ppmw or less. The above "1000 ppmw or less" means that silicon or fluorine, which has a release function, is substantially not included, as a separate release layer is not provided.

[0107] The method for coating the above photosensitive resin composition on a polymer substrate without a separate release layer can be performed according to methods well known in the art. For example, comma coating, die coating, etc. can be used, but are not limited thereto.

[0108] In addition, after the step of coating the photosensitive resin composition on a polymer substrate without a separate release layer, the step of drying the coated photosensitive resin composition may be further included.

[0109] 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.

[0110] However, it is preferable that the drying be performed for 25 to 50 minutes or 30 to 40 minutes in the above temperature range, and the process efficiency can be optimized while the solvent is effectively removed without remaining bubbles in the dried resin monolayer under the above conditions. 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 higher and 140°C or lower, and this may be a photosensitive resin monolayer. Through this, the thickness of the photosensitive resin layer may be 100 μm or more, and the resolution pitch (Line / Space) based on a 100 μm film of the photosensitive resin layer after exposure and development may be 20 μm or less.

[0111] 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.

[0112] The epoxy-containing dry film photoresist of the above embodiment coats a layer of a photosensitive resin composition containing a low boiling point solvent of 130°C or less, an epoxy binder resin, on a non-release film, so that the release component is not transferred to the coating layer of the photosensitive resin composition, thereby enabling high resolution of 20 μm pitch or less, and the content of residual solvent in the film can be managed to at least 2000 ppm or less, thereby exhibiting excellent releasability. In addition, since the present invention uses a non-release film with excellent stability, the pattern stability of the dry film photoresist can also be secured. This epoxy-containing dry film photoresist exhibits a film release force of 10 gf or less, so that it can be used in automated equipment.

[0113]

[0114] The present specification also provides a resist pattern comprising a photosensitive resin pattern containing the photosensitive resin composition.

[0115] 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 a coating layer of a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator, and a solvent of the above embodiment, wherein the photosensitive resin layer has a thickness of 100 μm or more, and a resolution pitch (Line / Space) based on a 100 μm film of the photosensitive resin layer after exposure and development is 20 μm or less. The content of the photosensitive resin composition includes all of the content described above in the above embodiment.

[0116] The pattern of the photosensitive resin layer may be a photosensitive composition in the form of a pattern having an opening.

[0117] Examples of methods for forming a pattern of the photosensitive resin layer include a method in which a photosensitive resin layer of the dry film photoresist of the other embodiment is laminated on a substrate, followed by exposure, post-exposure baking, and development. Furthermore, a method in which a photosensitive resin layer of the photosensitive element of the other embodiment is laminated on a substrate, followed by exposure, post-exposure baking, and development is also included.

[0118] 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.

[0119] The exposure process preferably uses a Laser Direct exposure device that includes a light source such as UV, visible light, laser, and especially light with a wavelength of 350 to 410 nm, especially i-line (365 nm) or h-line (405 nm). When using a Laser Direct exposure device, the exposure energy can be operated under the condition of 150 mJ / cm2 to 600 mJ / cm2, and when using a general lamp exposure device, the exposure energy can be operated under the condition of 600 mJ / cm2 or less, which is useful for manufacturing images of PCBs, lead frames, MEMS, biosensors, and other display devices.

[0120] The post-exposure baking process can be performed using an oven or a hot plate. A preferred example is a hot air oven, and the baking process is performed at 70-90°C for 10-60 minutes.

[0121] If the baking temperature is 90°C or higher or the baking time is 60 minutes or longer, some curing will occur in the non-exposed area, resulting in a decrease in resolution. If the baking temperature is 70°C or lower and less than 10 minutes, the degree of curing will be insufficient in the exposed area, resulting in the pattern being warped.

[0122] 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.

[0123] 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.

[0124] After the development process using the above organic developer, a rinsing process using IPA (isopropyl alcohol) may be performed. Furthermore, after the rinsing process, an additional baking process may be performed in an oven at 70 to 90°C for 10 to 60 minutes to remove any remaining IPA.

[0125] In the case where the dry film photoresist of the above other embodiment 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.

[0126] In addition, when the dry film photoresist of the above-described 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 may be further performed before the exposure process.

[0127]

[0128] 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.

[0129] It may be a resist pattern including a pattern of a photosensitive resin layer containing the photosensitive resin composition of the above embodiment.

[0130] The pattern of the photosensitive resin layer may be a photosensitive composition in the form of a pattern having an opening.

[0131] 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 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 exemplified.

[0132] Therefore, after forming a photosensitive resin layer through a step of drying the photosensitive resin composition, a step of exposing and developing the photosensitive resin layer may be included.

[0133] The above photosensitive resin layer can implement a dry film photoresist that simultaneously satisfies the characteristics of a minimum line width of a single photosensitive resin layer of 5 ㎛ or less after exposure and development, which is a fine line adhesion.

[0134] The above exposure process can be carried out using light sources well known in this field, such as UV, visible light, and laser, and among them, a laser direct including a light source with a wavelength of 375 nm or less can be used. For a more specific example, the above exposure process can be carried out using 200 mJ / cm 2 It can be investigated by the exposure amount.

[0135] 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. In a preferred example, when a hot air oven is used, the baking process may be performed in the oven at 70 to 90°C for 10 to 60 minutes.

[0136] 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.

[0137] Accordingly, according to the above other implementation example, a circuit board or MEMS, semiconductor packaging and biosensor, or display device including a resist pattern or a metal pattern formed by the resist pattern of the above other implementation example can be provided. The content of the resist pattern includes all of the content described above in the above other implementation example.

[0138] The specific details of the above circuit board or the purpose and device are not particularly limited, and various conventionally known technical configurations can be applied without limitation.

[0139] 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.

[0140] Specifically, by etching or plating the lower substrate exposed by the resist pattern described above, 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 mat, a semiconductor bump, etc. can be manufactured. If necessary, after the etching or plating, the resist pattern can be removed by peeling from the substrate using an aqueous solution having a stronger acidity than the developer. For example, a resist pattern including a cured product of an epoxy binder can be removed by peeling from the substrate using an aqueous sulfuric acid solution.

[0141] The above applications include use as high-resolution PR in MEMS, or as an insulating or passivation film in biochips, sensors, and semiconductor packaging.

[0142] More specifically, the resist pattern can be applied to microelectromechanical system (MEMS) components.

[0143] 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 images on high-resolution MEMS, PCB lead frames, PDPs, other display devices, semiconductor devices, etc. through a known process.

[0144]

[0145] According to the present invention, when providing an epoxy-containing dry film photoresist, a non-release film (e.g., non-release PET) without a separate release layer is used as a base film, thereby ensuring pattern stability of the dry film photoresist, and also exhibiting a film release force of 10 gf or less, so that it can be used in automated equipment. In addition, in the present invention, a solvent-type, non-solvent-containing, hot melt-type, epoxy binder-containing photosensitive resin composition (i.e., PR) is used, thereby improving coating properties in the film forming process, thereby reducing the stain defect rate, and thereby providing an epoxy-containing dry film photoresist with a high yield while improving quality.

[0146] In addition, since the present invention forms a dry film photoresist pattern through a drying process using a low-boiling-point solvent having a boiling point of less than 130°C in the photosensitive resin composition containing the solvent type epoxy binder, the solvent can be removed in a short time during the drying process, thereby minimizing the residual solvent content in the film. Accordingly, the present invention can more effectively manage the residual solvent content of the dry film photoresist, and for example, can manage the residual solvent content to be less than in the prior art, that is, 2000 ppm or less, 1000 to 2000 ppm or less, or 1000 ppm or less.

[0147]

[0148] FIG. 1 is a schematic diagram illustrating a manufacturing process of a dry film photoresist according to one embodiment of the invention.

[0149] Figure 2 shows an electron microscope photograph of a pattern after development to evaluate the resolution of examples and comparative examples.

[0150] Figure 3 shows the release values ​​and appearance photographs of the film during release to evaluate the yields of the examples and comparative examples.

[0151]

[0152] 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.

[0153]

[0154] Example 1

[0155] A photosensitive resin composition was prepared containing 100 parts by weight of BPA no-block epoxy binder (KEB-3165M80 from Kolon Industries), 0.05 parts by weight of surfactant (Flow 425 product from Evonik), 1 part by weight of cationic initiator, and 25 parts by weight of solvent.

[0156] Cationic initiator: PAG-TR-21608, Thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium) bis tetrakis(pentafluorophenyl) borate

[0157] Solvent: methyl ethyl ketone

[0158]

[0159] The above photosensitive resin composition was placed in a stirrer and stirred at 600 rpm for 3 hours.

[0160] After stirring, natural defoaming was performed for more than 12 hours, and then vacuum defoaming was performed at a pressure of 0.095 MPa for 1 hour.

[0161] After defoaming, the sample was filtered using a 25㎛ filter and then coated. The viscosity of the sample was 3,000 to 4,000 cP.

[0162] Thereafter, a comma coating of the above resin composition was performed on a PET base film (CT505 from Kolon Industries) having a thickness of 36 ㎛ to a thickness of 120 ㎛, and the coating area was 450 cm wide and 100 m long. After coating, drying was performed at a temperature of 130°C for 40 minutes.

[0163] That is, the photosensitive resin composition obtained above was applied once using a COMMA coater on a PET film that did not include a release treatment method, and dried in a dryer at 130°C for 40 minutes to form a photosensitive resin layer. The total thickness of the photosensitive resin layer after drying was 120 μm. In addition, the residual solvent content of the photosensitive resin layer was adjusted to 62 ppm using the above method.

[0164] A dry film photoresist was manufactured by laminating a PET protective film on a dried photosensitive resin layer. The protective film used was the same as the PET base film.

[0165]

[0166] Example 2

[0167] A dry film photoresist was manufactured under the same conditions as Example 1, but with a drying time of 30 minutes. As a result, the residual solvent content of the dry film photoresist was 1271 ppm.

[0168]

[0169] Example 3

[0170] A dry film photoresist was prepared in the same manner as in Example 1, except that phenyl(4-methoxyphenyl)iodonium hexafluoride was used instead of PAG-TR-21608 as the cationic initiator in the photosensitive resin composition of Example 1. As a result, the residual solvent content of the dry film photoresist was 73 ppm.

[0171]

[0172] Example 4

[0173] A dry film photoresist was prepared in the same manner as in Example 1, except that 1 part by weight of the surfactant was used in the photosensitive resin composition of Example 1. As a result, the residual solvent content of the dry film photoresist was 79 ppm.

[0174]

[0175] Comparative Example 1

[0176] Under the same conditions as Example 1, the sample was prepared and coated with a hot melt composition containing no solvent.

[0177] Specifically, a dry film photoresist was manufactured by excluding the solvent from the composition of the photosensitive resin composition of Example 1, stirring the mixture in a solid state (solvent-free) while heating it to 160°C, and coating it to a thickness of 120 μm on a non-release PET having a thickness of 36 μm. As a result, the residual solvent content of the dry film photoresist was below the detection limit (5 ppm or less).

[0178]

[0179] Comparative Example 2

[0180] A dry film photoresist was prepared in the same manner as in Example 1, except that the drying time was adjusted to 20 minutes. As a result, the residual solvent content of the dry film photoresist was 2,520 ppm.

[0181]

[0182] Comparative Example 3

[0183] A dry film photoresist was manufactured in the same manner as in Example 1, except that a 36 ㎛ thick silicone-released PET film was used as a base film, and a hot melt photosensitive resin composition containing no solvent of Comparative Example 1 was coated on the silicone-released PET film.

[0184] At this time, the silicone-released PET film is a polyethylene terephthalate film in which a release layer is formed on one side of a support film using a silicone resin by an ILC (in-line coating) method. As a result, the residual solvent content of the dry film photoresist was below the detection limit (5 ppm or less).

[0185]

[0186] Comparative Example 4

[0187] A dry film photoresist was manufactured in the same manner as in Example 1, except that a silicone-released PET film of Comparative Example 3 with a thickness of 36 μm was used as the substrate film. As a result, the residual solvent content of the dry film photoresist was 78 ppm.

[0188]

[0189] Comparative Example 5

[0190] A dry film photoresist was prepared in the same manner as in Example 1, except that a silicone-released PET film of Comparative Example 3 with a thickness of 36 ㎛ was used as a base film, and 5 parts by weight of a surfactant was used in the photosensitive resin composition of Example 1. As a result, the residual solvent content of the dry film photoresist was 188 ppm.

[0191]

[0192] Comparative Example 6

[0193] A dry film photoresist was prepared in the same manner as in Example 1, except that a 36 ㎛ thick silicone-released PET film was used as the substrate film and the drying time was adjusted to 20 minutes. As a result, the residual solvent content of the dry film photoresist was 2,820 ppm.

[0194]

[0195] Comparative Example 7

[0196] A dry film photoresist was manufactured in the same manner as in Example 1, except that a 36 ㎛ thick silicone-released PET film was used as the base film, 5 parts by weight of the surfactant in the photosensitive resin composition of Example 1 was used, and the drying time was adjusted to 20 minutes. As a result, the residual solvent content of the dry film photoresist was 2,975 ppm.

[0197]

[0198] Comparative Example 8

[0199] A dry film photoresist was manufactured in the same manner as in Example 1, except that a 36 ㎛ thick silicone-released PET film was used as the base film, 1.5 parts by weight of the surfactant in the photosensitive resin composition of Example 1 was used, and the drying time was adjusted to 20 minutes. As a result, the residual solvent content of the dry film photoresist was 2,670 ppm.

[0200]

[0201] Comparative Example 9

[0202] A dry film photoresist was manufactured in the same manner as in Example 1, except that methyl ethyl ketone and PGMEA were mixed in a ratio of 3:1 in the photosensitive resin composition of Example 1. As a result, the residual solvent content of the dry film photoresist was 3,175 ppm, exceeding 2,000 ppm.

[0203]

[0204] <Experimental Example>

[0205] After forming a laminated stack including a dry film photoresist using the process of Fig. 1, the physical properties were evaluated using the following method. The results are shown in Table 1.

[0206]

[0207] (Specimen manufacturing process)

[0208] The protective film on one side of the dry film photoresist manufactured in the above examples and comparative examples was removed and roll lamination (80-90℃, 4.0Kgf / cm) was performed on the substrate. 2 ) was done.

[0209] After removing the PET film on the opposite side, it was exposed with an exposure device having a wavelength of 355 nm.

[0210] After exposure, the exposed film was placed in a convection oven and baked at 80 to 85°C for 15 to 30 minutes.

[0211] After PEB (Post Exposure Bake), it was developed in PGMEA for 10 to 20 minutes and rinsed with IPA for 10 minutes.

[0212] Then, bake in an oven at 80℃ for 10 minutes to remove the remaining IPA.

[0213] Afterwards, heat treatment was performed on the remaining film as needed, and if removal was required, it was peeled off in a 98% sulfuric acid solution.

[0214]

[0215] 1. Yield

[0216] In case of yield, if there were stains (line stains, breaks, bubbles, foreign substances) and thickness deviations of 5% or more, they were treated as defective.

[0217] ○: The area of ​​the stain occurrence area is 10 m or less (yield 90%) / △: The area of ​​the stain occurrence area is more than 10 m but less than 20 m (yield less than 90% but more than 80%) / X: The area of ​​the stain occurrence area is more than 20 m (yield less than 80%)

[0218]

[0219] 2. Resolution

[0220] For resolution, the pattern was evaluated at a wavelength of 355 nm using a 1:1 Line & Space mask and analyzed by SEM.

[0221] That is, after peeling off the PET film, which is the support of the dry film photoresist, from the laminated body that went through the process of Fig. 1, using an LDI (Laser Direct imaging system) exposure device (Model: Paragon Ultra80), ultraviolet rays of 355 nm wavelength are irradiated at 200 mJ / cm 2 After irradiating with an exposure dose of , it was left for 10 minutes. Afterwards, it was heat-cured in a convection oven at 85℃ for 20 minutes.

[0222] Afterwards, the heat-cured film is dipped in PGMEA (propylene glycol monomethyl ether acetate) at 30°C and developed for 20 minutes while being treated with ultrasonication (600 MW, 1 MHz).

[0223] After development, rinse in IPA for 10 minutes and dry in a conventional oven for 10 minutes.

[0224] In the laminated body after the process was completed, the minimum gap between the photosensitive resin layers was measured using a ZEISS AXIOPHOT Microscope and evaluated at 1:1 resolution. The smaller this value, the better the 1:1 resolution value can be evaluated.

[0225] Thereafter, the results were evaluated using the following method based on the drawing of Fig. 2. Fig. 2 shows electron microscope photographs (evaluation criteria) of patterns after development for evaluating the resolution of examples and comparative examples. At this time, the resolution was evaluated as follows based on a pattern spacing of 20 μm as shown in Fig. 2. In addition, the pattern wall and space spacing in Fig. 2 are each 10 μm.

[0226] ○: No pattern abnormality in Line + Space Size 20um or less / △: No pattern abnormality in Line + Space Size 21~23um / X: Not open and residue, line collapse occurs in 20~23um

[0227]

[0228] 3. Film release

[0229] In case of film release, the film was prepared with a peel test of 25 X 80 nm and released at 90 degrees using 3M Scotch tape (equipment MICRO TXA-40 / speed 20 mm / sec).

[0230] Thereafter, the results were evaluated using the following method based on the drawing of Fig. 3. Fig. 3 shows the release values ​​and appearance photographs (evaluation criteria) at the time of film release for evaluating the yields of the examples and comparative examples.

[0231] ◎: Load 5gf or less, ○: Load 10gf or less, X: Load exceeding 10gf (0~1sec excluding initial film lifting section), Film release stains occur when exceeding 10gf

[0232]

[0233] 4. Residual organic solvent content

[0234] The above residual solvent content was measured using Agilent's GC-MS with a column DB-5MS-UI (60 m x 320 um x 1 um) and expressed in %. The sample was dissolved in DMAc to a concentration of 10 wt% solution (10 wt% in DMAc), filtered using a syringe filter with a pore size of 0.45 μm, and injected into GS-MS at 280°C at 1 μl, using He as the mobile phase at a flow rate of 1 ml / min. The temperature was maintained at 40°C for 4 minutes, then increased by 10°C per minute and maintained at 320°C for 3 minutes to measure the residual organic solvent content.

[0235] In addition, the peak area of ​​the residual solvent detected in the sample was substituted into the calibration curve formed by analyzing the standard sample diluted with DMAc at 6 concentration levels using the same GC-MS analysis method to obtain the content of residual solvent (MEK) in the sample. At this time, the linearity of the standard calibration curve was 0.999 or higher and the instrument detection limit of the solvent (MEK) was 0.5 ppm. Therefore, since the sample was dissolved in DMAc at 10 wt% and analyzed, it is possible to obtain reliable results for residual solvent (MEK) present in the sample exceeding 5 ppm using this analysis method when the sample dilution ratio is taken into account.

[0236] Base film coating method Resolution (20 um pitch) Film release Residual organic solvent content Yield Example 1 AC○◎62 ppm○2 AC○○1,271 ppm○3 AC○◎73 ppm○4 AC○◎79 ppm○Comparative example 1 ADX○5 ppm or less X2 ACXX2,520 ppm○3 BDX○5 ppm or less X4 BCX○78 ppm X5 BCX○188 ppm○6 BCX○2,820 ppm X7 BCX○2,975 ppm○8 BC△○2,670 ppm△9 ACXX3,175 ppm○Note) 1) Base film - Non-release PET: A, release PET (silicon release-treated PET film): B2) Coating method - Solvent type: C, Hot melt type: D

[0237] As shown in the results in Table 1 above, Examples 1 to 4 were able to implement higher resolution than the Comparative Examples, and both film releasability and yield were improved. In contrast, Comparative Examples 1 to 9 formed a dry film photoresist including a photosensitive resin layer by a hot melt method rather than a solution-type photosensitive resin composition as in the present disclosure (Comparative Examples 1 and 3), or the release component was separately treated on the base film (Comparative Examples 3 to 8), and thus could not satisfy the high resolution, film releasability, and yield. In particular, Comparative Examples 1 and 3 had low yields, making it impossible to implement high resolution. In addition, Comparative Example 2 had a drying time of the photosensitive resin coating layer shorter than the drying time range of the present disclosure, so that the residual solvent content exceeded 2000 ppm, and as a result, the film releasability was poor due to release stains during release, and it was impossible to implement high resolution.

[0238] Furthermore, Comparative Example 3 used a PET film subjected to silicone release treatment and a hot melt type photosensitive resin composition that did not contain a solvent, so that the residual solvent content exceeded 2000 ppm, as in Comparative Example 2, resulting in a low yield and making it impossible to implement high resolution.

[0239] In addition, Comparative Examples 5 and 7 required the addition of an excessive amount of surfactant (5 parts by weight or more) to lower the surface tension in order to coat the solvent-type photosensitive resin composition on the release film, which resulted in a decrease in resolution.

[0240] That is, Comparative Examples 5 and 7 added an excess amount of surfactant (5 parts by weight or more) to lower the surface tension when coating a photosensitive resin composition including a solvent onto a silicone-released PET film. However, Comparative Examples 5 and 7 showed a decrease in resolution due to the excessive addition of surfactant. In particular, the residual solvent content of Comparative Example 7 was 2975 ppm, which was more than that of the examples, making it impossible to achieve high resolution.

[0241] In Comparative Example 6, even if a dry film photoresist is manufactured by lowering the surfactant content by solvent type, the content of residual organic solvent exceeds 2000 ppm as in Comparative Example 2 due to the use of a release film as a base film, and in particular, the yield is reduced and the silicone release treatment component is transferred to the photosensitive resin layer, resulting in poor pattern stability and making it difficult to implement high resolution.

[0242] Comparative Example 8 used 1.5 parts by weight of surfactant, which is less than the excess of 5 parts by weight, but both the resolution and yield were lower than those of Examples 1 and 2.

[0243] Additionally, in Comparative Example 9, even though a low-boiling-point solvent (methyl ethyl ketone) was included, the residual solvent content exceeded 2000 ppm due to mixing a high-boiling-point solvent (PGMEA), and the film release property was poor due to release stains during release, and high resolution implementation was impossible.

Claims

1. A substrate film without a separate release layer; and A photosensitive resin layer containing a cured product of a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator, and a low boiling point solvent formed on the above-mentioned substrate film; The thickness of the photosensitive resin layer is 100㎛ or more, A dry film photoresist having a resolution pitch (line / space) of 20 um or less based on a 100 um film of the photosensitive resin layer after exposure and development.

2. In paragraph 1, The above-mentioned base film does not include inorganic particles or a fluorine coating layer, and includes at least one selected from the group consisting of an acrylic film, a polyethylene terephthalate (PET) film, a triacetyl cellulose (TAC) film, a polynorbornene (PNB) film, a cycloolefin polymer (COP) film, and a polycarbonate (PC) film. Dry film photoresist.

3. In paragraph 1, The above photosensitive resin layer is a dry film photoresist, which is a dried product or cured product dried at a temperature of 50°C or higher and 140°C or lower for 25 to 50 minutes.

4. In paragraph 1, A dry film photoresist having a residual solvent content of 2000 ppm or less.

5. In paragraph 1, The above photosensitive resin composition For 100 parts by weight of epoxy binder, 0.01 to 1.00 parts by weight of surfactant, 0.5 to 5.0 parts by weight of cationic initiator, and A dry film photoresist comprising 10 to 40 parts by weight of a solvent.

6. In paragraph 1, The above epoxy binder is a dry film photoresist containing a bisphenol type epoxy resin.

7. In paragraph 1, A dry film photoresist comprising at least one cationic initiator selected from an aromatic sulfonium complex and an iodonium cationic initiator.

8. In paragraph 7, A dry film photoresist, wherein the cationic 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, phenyl(4-methoxyphenyl)iodonium hexafluoride, N,N-dimethyl-N-benzyltrifluoromethanesulfonic acid, 4-methylphenyl(4-(2-methylpropylphenyl))iodonium hexafluoride, and phenyl(4-methoxyphenyl)iodonium arsenide hexafluoride.

9. In paragraph 1, A dry film photoresist, wherein the low boiling point solvent is a low boiling point solvent having a boiling point of 130°C or lower, and is at least one selected from the group consisting of ethyl methyl ketone, dimethoxyethane tetrahydrofuran, ethyl propionate, 1-methoxy-2-propanol, propylene glycol dimethyl ether, methyl isobutyl ketone, methanol, ethanol, and isopropyl alcohol.

10. A method for producing a dry film photoresist, comprising: a step of coating a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator, and a low boiling point solvent on a polymer substrate not having a separate release layer; 11. In paragraph 1, A method for producing a dry film photoresist, wherein the low-boiling-point solvent is a low-boiling-point solvent having a boiling point of 130°C or lower, and is at least one selected from the group consisting of ethyl methyl ketone, dimethoxyethane tetrahydrofuran, ethyl propionate, 1-methoxy-2-propanol, propylene glycol dimethyl ether, methyl isobutyl ketone, methanol, ethanol, and isopropyl alcohol.

12. In paragraph 10, A method for manufacturing a dry film photoresist, wherein the content of silicon or fluorine on the surface of the polymer substrate is 1000 ppmw or less.

13. A photosensitive resin layer pattern containing a cured product of a photosensitive resin composition including an epoxy binder, a surfactant, a cationic initiator and a solvent, The thickness of the photosensitive resin layer is 100㎛ or more, A resist pattern having a resolution pitch (line / space) of 20 um or less based on a 100 um film of the photosensitive resin layer after exposure and development.

14. A display device including a metal pattern formed by the resist pattern of claim 13 or the resist pattern of claim 12.

Images