JP2013247177A - Resist agent for lift-off method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist agent for a lift-off method, which is used for forming a resist coating on a base material in forming a conductor pattern on the base material by a lift-off method and with which a resist coating capable of being easily removed from the base material can be formed.SOLUTION: A resist agent for a lift-off method according to the present invention contains a water soluble polyester resin. Therefor, the water solubility of a resist coating formed of the resist agent is increased extremely, so that the resist coating can be easily removed using an aqueous resist removing liquid.

Description

  The present invention relates to a lift-off method resist agent used for forming a resist film on a base material when a conductor pattern is formed on the base material by a lift-off method.

  Conventionally, a lift-off method has been adopted as one of the methods for forming a fine conductor pattern on a substrate. This lift-off method is used to form a wiring board having fine conductor wiring. In recent years, it has also been used to form transparent electrodes made of ITO or the like.

  In a general lift-off method, a photosensitive resist material is used as a resist agent. This resist agent is applied on the substrate, and then patterned by photolithography, thereby forming a resist film. Subsequently, a conductor such as metal is formed on the substrate by vapor deposition, sputtering, or the like. Subsequently, the resist film is removed from the substrate. Thereby, the conductor on the resist film is also removed together with the resist film. Thereby, a conductor pattern is formed by the conductors remaining on the substrate.

  In removing the resist film from the substrate, the resist film is dissolved by exposing the resist film to an appropriate resist removing solution according to the composition of the resist film.

  However, since the resist film is covered with a conductor, the resist removal solution does not easily penetrate into the resist film. For this reason, a part of the resist film tends to remain on the substrate without being removed.

  Therefore, Patent Document 1 proposes the following negative photosensitive resin composition for lift-off method used as a resist agent.

(A) The weight ratio of (a) :( b) is at least one photopolymerization initiator selected from the following group (a) and at least one photopolymerization initiator selected from the following group (b): A photopolymerization initiator component containing 10 to 10: 1,
(A) containing benzophenones, thioxanthones, biimidazoles (b) acetophenones, acylphosphine oxides (B) alkali-soluble resins, and (C) a diluent (D) a polymerization inhibitor or chain transfer agent When the film thickness of the cured film formed by selective exposure is 0.5 to 500 μm, the end of the cured film has an overhang or back taper-like shape, and the cured film At the end, an angle θ formed between the surface where the upper surface of the cured film intersects with the side surface and the surface where the lower surface of the cured film intersects with the substrate intersects with the substrate surface exposed by development is 85 ° to 45 °. A negative photosensitive resin composition for a lift-off method, characterized in that

  When this negative-type photosensitive resin composition for lift-off method is used, the end of the cured film has an overhang or back taper-like shape under a wide range of resist film thickness conditions. The surface including the line intersecting the lower end and the line intersecting the lower end and the base material can easily control the angle θ formed with the base material surface exposed by development within a desired range. By suppressing the film formation of the conductor on the side surface portion of the resist film, it is possible to promote the penetration of the resist removing liquid from the side surface portion of the resist film.

  However, even if permeation of the resist removal liquid from the side surface of the resist film is ensured, the resist removal liquid may not easily reach the inside of the resist film when the area of the resist film is large. In such a case, a part of the resist film tends to remain on the substrate.

Japanese Patent No. 4047588

  The present invention has been made in view of the above-described reasons, and the object of the present invention is to use a lift-off method used to form a resist film on a substrate when forming a conductor pattern on the substrate by a lift-off method. An object of the present invention is to provide a resist agent that can form a resist film that can be easily removed from a substrate.

  The resist for lift-off method according to the present invention is a resist agent for lift-off method used for forming a resist film on a base material when a conductor pattern is formed on the base material by the lift-off method. It is characterized by containing a resin.

  It is preferable that the water-soluble polyester resin is a polymerization product of a polyvalent carboxylic acid component and a polyhydric alcohol component, and the polyvalent carboxylic acid component contains sodium dimethylisophthalic acid 5-sulfonate.

  The ratio of the sodium 5-sulfonate sodium dimethylisophthalic acid to the polyvalent carboxylic acid component is preferably in the range of 10 to 80 mol%.

  It is preferable that the resist agent further contains a water-soluble polymer other than the water-soluble polyester resin.

  It is preferable that the resist agent contains the water-soluble polymer in a proportion of 1 to 600% by mass with respect to the water-soluble polyester resin.

  It is preferable that the water-soluble polyester resin has an acid group neutralized with an alkali metal compound.

  It is preferable that the resist agent further contains an inorganic filler having an average particle size of 0.03 to 10 μm.

  It is preferable that the resist agent contains the inorganic filler in a proportion of 0.1 to 400% by mass with respect to the total amount of the resin.

  According to the present invention, since the resist agent contains a water-soluble polyester resin, the water solubility of the film formed from this resist agent becomes very high, and therefore this film can be easily removed with an aqueous resist removing solution. can do. For this reason, this resist agent can be suitably used for forming a resist film on a substrate when forming a conductor pattern on the substrate by a lift-off method.

  The resist agent in the present embodiment contains a water-soluble polyester resin.

  The water-soluble polyester resin is a polymerization product of a polyvalent carboxylic acid component and a glycol component. It is preferable that at least one of the polyvalent carboxylic acid component and the glycol component includes a component (water solubility imparting component) for imparting water solubility to the water soluble polyester resin.

  In addition, it is judged based on technical common sense that water-soluble polyester resin has water solubility. In particular, when water at room temperature is sprayed for 20 minutes at a spraying pressure of 0.005 MPa over the entire surface of a thin film having a thickness of 20 μm formed only from a water-soluble polyester resin, it is preferable that all of the thin film is dissolved in water. Alternatively, when water at 50 ° C. is sprayed at a spray pressure of 0.005 MPa for 10 minutes on the entire surface of a thin film having a thickness of 20 μm formed only from a water-soluble polyester resin, it is preferable that all the thin film is dissolved in water. Or it is preferable that water-soluble polyester resin and normal temperature water are mixed by the mass ratio of 1: 5, and an ultrasonic wave is added to the obtained liquid for 20 minutes, and all the water-soluble polyester resin will melt | dissolve in water. Alternatively, it is preferred that when the water-soluble polyester resin and 50 ° C. water are mixed at a mass ratio of 1: 5 and ultrasonic waves are added to the obtained liquid for 10 minutes, the water-soluble polyester resin is completely dissolved in water.

  The polyvalent carboxylic acid component is composed of one or more compounds selected from divalent or higher polyvalent carboxylic acids and ester-forming derivatives of polyvalent carboxylic acids. An ester-forming derivative of a polyvalent carboxylic acid is a derivative of an anhydride, ester, acid chloride, halide or the like of a polyvalent carboxylic acid, and is a compound that reacts with a glycol component described later to form an ester. The polyvalent carboxylic acid has two or more carboxyl groups per molecule.

  The glycol component consists of one or more compounds selected from glycol and ester-forming derivatives of glycol. The ester-forming derivative of glycol is a derivative of glycol such as a diacetate compound corresponding to glycol, and is a compound that reacts with a polyvalent carboxylic acid component to form an ester.

  The polyvalent carboxylic acid preferably has no reactive functional group other than the carboxyl group. Moreover, it is preferable that glycol does not have a reactive functional group other than a hydroxyl group. In particular, it is preferable that neither the polyvalent carboxylic acid nor the glycol has a reactive functional group. In these cases, the amount of reactive functional groups in the water-soluble polyester resin is reduced, or the water-soluble polyester resin is not reactive. If it does so, the reactivity of water-soluble polyester resin will reduce, and even if water-soluble polyester resin is heated, the water-solubility of water-soluble polyester resin will become difficult to fall. In addition, the ionic polar group which the water solubility provision component mentioned later has is not contained in a reactive functional group.

  In particular, the polyvalent carboxylic acid preferably does not include any of a hydroxyl group, an ethylenically unsaturated bond, an amino group, an imino group, a hydrazino group, a nitro group, a carbonyl group, an epoxy group, and a cyano group. In addition, the glycol preferably does not include any of an ethylenically unsaturated bond, an amino group, an imino group, a hydrazino group, a nitro group, a carbonyl group, an epoxy group, and a cyano group. The water-soluble polyester resin preferably does not include any of a hydroxyl group, an ethylenically unsaturated bond, an amino group, an imino group, a hydrazino group, a nitro group, a carbonyl group, an epoxy group, and a cyano group.

  Examples of the polyvalent carboxylic acid include dicarboxylic acids such as aromatic dicarboxylic acids and aliphatic dicarboxylic acids. In particular, the polyvalent carboxylic acid is at least selected from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, and aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedioic acid. Preferably it consists of one kind. In this case, the reactivity between the polyvalent carboxylic acid component and the glycol component is improved, and the weather resistance and durability characteristics of the water-soluble polyester resin are improved. In particular, it is optimal that only aromatic dicarboxylic acids are used as the polyvalent carboxylic acid component not corresponding to the water-solubilizing component, or that the aromatic dicarboxylic acid is the main component of the polyvalent carboxylic acid component.

  In addition, glycols include ethylene glycol, diethylene glycol, butanediols such as 1,4-butanediol, hexanediols such as 1,6-hexanediol, 1,4-cyclohexanedimethanols, neopentyl glycol and the like. It is preferably composed of at least one selected from bisphenol A and the like. In this case, the reactivity between the polyvalent carboxylic acid component and the glycol component is improved, and the weather resistance and durability characteristics of the water-soluble polyester resin are improved.

  The water-soluble imparting component constitutes part of the skeleton structure of the water-soluble polyester resin, thereby introducing an ionic polar group into the water-soluble polyester resin, thereby imparting water solubility to the water-soluble polyester resin. Examples of the ionic polar group include a carboxyl group and a sulfonic acid group. The ionic polar group may be neutralized.

  The water solubility-imparting component is contained in, for example, a polyvalent carboxylic acid component. Examples of the water solubility-imparting component contained in the polyvalent carboxylic acid component include dicarboxylic acids having a metal sulfonate group, trivalent or higher polyvalent carboxylic acids, and ester-forming derivatives thereof.

  Among these water-solubilizing components, dicarboxylic acids having a metal sulfonate group and ester-forming derivatives thereof (hereinafter collectively referred to as dicarboxylic acids having a metal sulfonate group, etc.) include, for example, 5-sulfoisophthalic acid, 2-sulfo Examples thereof include alkali metal salts such as isophthalic acid, 4-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfonaphthalene-2,6-dicarboxylic acid, and ester-forming derivatives thereof. In order to impart good water solubility to the water-soluble polyester resin, the alkali metal is preferably sodium, potassium or lithium.

  When a dicarboxylic acid having a metal sulfonate group or the like is used as a water-solubilizing component, the metal sulfonate group effectively remains in the water-soluble polyester resin, so that excellent water solubility is imparted to the water-soluble polyester resin. In particular, when 5-sodium sulfoisophthalic acid or an ester thereof (for example, sodium 5-sulfonate dimethylisophthalic acid) is used as a water-solubilizing component, a sodium sulfonate group effectively remains in the water-soluble polyester resin. Excellent water solubility is imparted to the water-soluble polyester resin.

  Further, when a trivalent or higher polyvalent carboxylic acid and an ester-forming derivative thereof (hereinafter collectively referred to as a trivalent or higher polyvalent carboxylic acid or the like) are used as the water-solubilizing component, the trivalent or higher polyvalent carboxylic acid is used. A carboxyl group resulting from an acid or the like remains in the water-soluble polyester resin, so that water-solubility is imparted to the water-soluble polyester resin. The carboxyl group remaining in the water-soluble polyester resin is preferably neutralized with a basic compound such as ammonia, alkanolamine, or alkali metal compound. As the basic compound, a non-volatile compound is preferably used, and an alkali metal compound such as an alkali metal hydroxide is particularly preferably used. In this case, even if the water-soluble polyester resin is heated, the water-solubility of the water-soluble polyester resin is further hardly lowered.

  Examples of the trivalent or higher polyvalent carboxylic acid include hemimellitic acid, trimellitic acid, trimedic acid, merophanic acid, pyromellitic acid, benzenepentacarboxylic acid, meritic acid, cyclopropane-1,2,3-tricarboxylic acid, Examples thereof include polyvalent carboxylic acids such as cyclopentane-1,2,3,4-tetracarboxylic acid and ethanetetracarboxylic acid.

  In particular, it is preferable that the water-solubilizing component is composed of at least one selected from trimellitic acid and its ester-forming derivatives. In this case, the carboxyl group effectively remains in the water-soluble polyester resin, and further excellent hydrophilicity is imparted to the water-soluble polyester resin.

  As the water solubility-imparting component, only one kind may be used among the above-mentioned trivalent or higher polyvalent carboxylic acids and the like, and dicarboxylic acids having a metal sulfonate group, or two or more kinds may be used in combination.

  When the polyvalent carboxylic acid component contains a water-solubilizing component, the ratio of the water-solubilizing component to the polyvalent carboxylic acid component is preferably in the range of 10 to 80 mol%. When this ratio is 10 mol% or more, sufficiently high water solubility is imparted to the water-soluble polyester resin. Moreover, when this ratio is 80 mol% or less, it is suppressed that the hygroscopic property of the resist film formed from a resist agent becomes excessively large, and thus the handleability and blocking resistance of the resist film are improved. The ratio of the water-solubilizing component is preferably in the range of 10 to 60 mol%.

  In particular, the polyvalent carboxylic acid component contains sodium dimethylisophthalic acid 5-sulfonate as a water-soluble imparting component, and the ratio of sodium dimethylisophthalic acid 5-sulfonate to the polyvalent carboxylic acid component is in the range of 10 to 80 mol%. It is preferable that In this case, sufficiently high water solubility is imparted to the water-soluble polyester resin. The proportion of sodium dimethylisophthalic acid 5-sulfonate is preferably in the range of 10 to 60 mol%.

  The ratio of the polyvalent carboxylic acid component to the glycol component is the total number of carboxyl groups and ester-forming derivative groups contained in the polyvalent carboxylic acid component, and the total number of hydroxyl groups and ester-formable derivative groups contained in the glycol component. Is preferably adjusted so that the molar ratio is in the range of 1: 1.1 to 2.5. In this case, the ratio of trivalent or higher polyvalent carboxylic acid or the like, which is a water-solubilizing component, is regarded as dicarboxylic acid and the ratio is calculated.

  The water-soluble polyester resin is produced by polymerizing a polyvalent carboxylic acid component and a glycol component by a known polyester production method.

  For example, when the polyvalent carboxylic acid component is a polyvalent carboxylic acid and the glycol component is glycol, a direct esterification reaction in which the polyvalent carboxylic acid and glycol are reacted in a one-step reaction is employed.

  For example, when the polyvalent carboxylic acid component is an ester-forming derivative of a polyvalent carboxylic acid and the glycol component is glycol, this is an ester exchange reaction between the ester-forming derivative of the polyvalent carboxylic acid and the glycol. The water-soluble polyester resin may be produced through the first stage reaction and the second stage reaction in which the reaction product of the first stage reaction is polycondensed.

  The method for producing a water-soluble polyester resin through the first stage reaction and the second stage reaction will be described more specifically. In the transesterification reaction which is the first stage reaction, all raw materials used for the production of the water-soluble polyester resin may be contained in the reaction system from the beginning. For example, the dicarboxylic acid diester and the glycol compound are held in a reaction vessel and gradually heated to 150 to 260 ° C. under an inert gas atmosphere such as nitrogen gas and under normal pressure, whereby the ester The exchange reaction proceeds.

  The polycondensation reaction which is the second stage reaction proceeds within a temperature range of 160 to 280 ° C. under a reduced pressure of, for example, 6.7 hPa (5 mmHg) or less.

  In this first-stage reaction and second-stage reaction, any known titanium, antimony, lead, zinc, magnesium, calcium, manganese, alkali metal compounds, etc. may be added to the reaction system at any time as a catalyst. good.

  Furthermore, when a trivalent or higher polyvalent carboxylic acid is used as the water-solubilizing component, the water-soluble polyester resin obtained as described above can be neutralized with a basic compound such as an alkali metal compound. preferable.

  The number average molecular weight of the water-soluble polyester resin is preferably in the range of 3000 to 50000. Thus, when the number average molecular weight is 3000 or more, a resist film is easily formed from a resist agent. Moreover, if this number average molecular weight is 50000 or less, the water solubility of water-soluble polyester resin will become high enough, and the water solubility of the resist film formed from a resist agent will improve effectively. The number average molecular weight of the water-soluble polyester resin is preferably in the range of 5000 to 35000.

  In addition, the number average molecular weight of water-soluble polyester resin is derived | led-out from the measurement result by gel permeation chromatography (polystyrene conversion).

  The degree of water solubility of the water-soluble polyester resin is adjusted by setting the number average molecular weight of the water-soluble polyester resin and the proportion of the water-soluble imparting component used for producing the water-soluble polyester resin in a well-balanced manner. Is done. That is, the number average molecular weight of the water-soluble polyester resin and the ratio of the water-soluble imparting component used for producing the water-soluble polyester resin are appropriately set so that the water-solubility of the water-soluble polyester resin is sufficiently high. It is preferable.

  Further, the ratio of the water-soluble polyester resin in the resist agent is not particularly limited, but is preferably in the range of 1 to 100% by mass with respect to the solid content (nonvolatile component) in the resist agent, and 5 to 90% by mass. % Is more preferable, and a range of 5 to 80% by mass is particularly preferable.

  The resist agent preferably further contains a water-soluble polymer other than the water-soluble polyester resin. In this case, the viscosity of the resist agent is adjusted by the water-soluble polymer, and the coating property of the resist agent is improved. This water-soluble polymer preferably has a property of increasing viscosity when dissolved in water.

  Water-soluble polymers include, for example, polysaccharides such as hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, organic acid salts such as sodium alginate and ammonium alginate, polyvinyl alcohol, polyethylene glycol, polyacrylamide, sodium polyacrylate, polyvinyl pyrrolidone, etc. Contains one or more selected compounds. In particular, the water-soluble polymer preferably contains hydroxypropylcellulose.

  The ratio of the water-soluble polymer in the resist agent is preferably in the range of 1 to 600% by mass with respect to the water-soluble polyester resin. In this case, the viscosity of the resist agent is appropriately adjusted by the water-soluble polymer, and good heat resistance of the resist film formed from the resist agent is maintained. This ratio is more preferably in the range of 5 to 400% by mass, and particularly preferably in the range of 10 to 370% by mass.

  In particular, when a resist agent is applied by a screen printing method, in order to improve fine workability, the resist agent contains a water-soluble polymer, so that the resist agent has a viscosity of 100 to 1000 dPa · s. It is preferable to be adjusted to. In this case, the conductor pattern can be miniaturized. The viscosity of the resist agent is more preferably in the range of 200 to 900 dPa · s, and particularly preferably in the range of 300 to 850 dPa · s.

  The resist agent preferably further contains an inorganic filler having an average particle size of 0.03 to 10 μm. In this case, the resist film formed from the resist agent includes a resin matrix and an inorganic filler. The resin matrix is mainly composed of a water-soluble polyester resin, and an inorganic filler is dispersed in the resin matrix. The liquid easily enters the interface between the resin matrix and the inorganic filler in the resist film, so that the liquid easily enters the resist film. As a result, when the resist film is heated and then exposed to an aqueous resist removal solution, the resist film is further easily removed.

  The inorganic filler is not particularly limited, but preferably contains one or more selected from calcium carbonate, barium sulfate, silica, talc, and clay.

  The inorganic filler preferably contains one or more extender pigments selected from metal oxides such as titanium oxide and metal hydroxides such as aluminum hydroxide. In this case, the appearance of the resist film is improved by improving the whiteness of the resist film formed from the resist agent, and the flame retardancy of the resist film is improved.

  As described above, the average particle size of the inorganic filler is in the range of 0.03 to 10 μm. For this reason, when the resist film is heated and then exposed to an aqueous cleaning agent, the resist film is further easily removed. That is, when the average particle size is 0.03 μm or more, the liquid particularly easily enters from the interface between the resin matrix and the inorganic filler, and the liquid easily penetrates into the resist film. Further, when the average particle size is 10 μm or less, the smoothness of the surface of the resist film is improved, so that voids are hardly generated in the resist film. The average particle diameter is preferably in the range of 0.03 to 5 μm, and particularly preferably in the range of 0.08 to 1.5 μm. The average particle size of the inorganic filler is measured by a centrifugal sedimentation light transmission method.

  Moreover, it is preferable that the ratio of the inorganic filler in a resist agent is the range of 0.1-400 mass% with respect to the resin whole quantity in a resist agent. In this case, when the resist film is heated and then exposed to an aqueous cleaning agent, the resist film is further easily removed. That is, when this ratio is 0.1% by mass or more, the resist film is easily removed, and heat resistance and moldability are improved. On the other hand, if this ratio is larger than 400% by mass, the ratio of water-soluble functional groups in the resist film is reduced, so that sufficient water solubility is not ensured. The ratio of the inorganic filler is more preferably in the range of 0.1 to 350% by mass, and particularly preferably in the range of 50 to 300% by mass. However, if an inorganic filler is a hydrophilic filler, it will not be limited to the said ratio.

  Moreover, it is also preferable that a resist agent contains a thixotropic property imparting agent. In this case, an appropriate thixotropy is imparted to the resist agent, thereby improving the coating property of the resist agent. In addition, a decrease in the viscosity of the resist agent when the resist agent applied on the substrate is heated is suppressed, and thus a change in shape due to the flow of the resist agent is suppressed. A known material is used as the thixotropic agent. For example, the thixotropic agent preferably contains at least one selected from organic bentonite, finely divided silica, montmorillonite, and hydrotalcite.

  In addition, the resist agent may contain appropriate additives such as penetrants, flame retardants, antistatic agents, pigments, dyes, antioxidants, ultraviolet absorbers, antifoaming agents, rust preventives, and dispersion aids as necessary. You may contain.

  The resist agent preferably contains an aqueous solvent. The aqueous solvent is water or a mixed solvent containing water and a hydrophilic organic solvent. In this case, the water-soluble polyester resin is dissolved or dispersed in the aqueous solvent in the resist agent, so that the resist agent is more easily applied when the resist film is formed from the resist agent. The hydrophilic organic solvent preferably contains at least one selected from, for example, alcohols such as methanol, ethanol, 2-propanol and propylene glycol; glycol ethers such as propylene glycol monomethyl ether, ethyl cellosolve and butyl cellosolve; cyclohexanone and the like. .

  Further, the aqueous solvent is a mixed solvent containing water and alcohol, the ratio of water in the resist agent is in the range of 5 to 80% by mass, and the ratio of alcohol in the resist agent is in the range of 5 to 50% by mass. It is preferable. In this case, slipping of the squeegee during screen printing is improved, and separation of the screen printing plate from the film is also improved, so that continuous printability is improved.

  This resist agent is used to form a resist film on a base material when a conductor pattern is formed on the base material by a lift-off method.

  The material of the base material is not particularly limited, and examples thereof include an appropriate resin film, glass, quartz, various metals, ceramics, and paper. When a resin film is used, for example, a film formed from a resin such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polymethyl methacrylate (PMMA), or silicone is used.

  When the conductor pattern is formed by the lift-off method, first, a resist agent is applied on the base material in an appropriate pattern. As a coating method of the resist agent, a brush coating method, a screen printing method, a gravure printing, a spray method, a dipping method, a bar coater, a roll coater, or other known coating means may be employed. Subsequently, the resist agent is dried as necessary. As a result, a patterned resist film is formed on the substrate without a curing reaction. The thickness of the resist film is not particularly limited, but is preferably 0.5 to 10 μm.

  Here, in this embodiment, since the resist agent is prepared to have an optimum viscosity by containing a high-viscosity water-soluble resin and an inorganic filler, it is easy to apply the resist agent in a fine pattern, Conventionally, it can be applied in a fine pattern that has been difficult unless it is a photographic method. For example, it can be applied in a line shape having a width of 30 μm. For this reason, a fine conductor pattern is easily formed by using the resist agent according to the present embodiment.

  Moreover, since the resist agent by this embodiment contains a highly flexible water-soluble polyester resin, it has high adhesiveness to various metals and resins. For this reason, a resist agent is easily applied on a substrate made of various materials, and thus a resist film is easily formed on a substrate made of various materials.

Subsequently, a conductor is formed on the substrate by a dry method such as vapor deposition or sputtering. Examples of the conductor include metals such as Al, Ti, Pb, Ni, Cu, Ag, Au, Cr, Sn, and In, and oxides such as ITO, Al ₂ O ₃ , and SiO ₂ .

  In this embodiment, since the resist agent contains a non-reactive water-soluble polyester resin, the resist agent is applied as described above, or the solvent is removed by further heating, but the curing reaction is not accompanied. A resist film is formed. For this reason, unreacted low molecular weight organic components may remain in the resist film when a reaction curable resist agent containing a thermosetting resin or a photocurable resin is used. In this embodiment, the low molecular weight organic component hardly remains in the resist film. For this reason, even when the conductor film is formed by vapor deposition, sputtering, or the like, even if the resist film is placed under reduced pressure, the organic component having a low molecular weight is not easily released from the resist film. For this reason, it is difficult for such an organic component to adversely affect the film formation of the conductor. As a result, the film formability of the conductor is improved.

  Subsequently, the resist film is exposed to an aqueous resist removal solution, whereby the resist film is removed from the substrate, and thereby the conductor on the resist film is also removed from the substrate. Thereby, a conductor pattern is formed by the conductors remaining on the substrate.

  Water can be used as the aqueous resist removing solution. In addition, a mixed solution containing water and a hydrophilic organic solvent can be used as the aqueous resist removing solution. Examples of the hydrophilic organic solvent include alcohols such as methanol, ethanol, 2-propanol, and 1,2-propanediol; ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethyl cellosolve, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, Glycol ethers such as butyl cellosolve, ethylene glycol monoisobutyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether; cyclohexanone; nonionic, anionic, and cationic surfactants It is preferable to contain at least one selected from In particular, the aqueous cleaning agent is preferably water.

  The resist film is exposed to a resist removing solution by an appropriate method. For example, the resist film is sprayed toward the conductor covering the resist film, or the resist film and the conductor covering the resist film are immersed in the resist removing liquid, whereby the resist film is exposed to the resist processing liquid.

  Even if most of the resist film is covered with a conductor, the thin film formed by vapor deposition, sputtering, etc. is microscopically non-uniform and has many fine gaps. Can reach the resist film. In this case, even if the amount of the resist removal solution reaching the resist film is small, in this embodiment, the resist film has a better water solubility than the conventional product, so that the resist film is easily removed from the substrate. . For this reason, the resist film and the conductor on the resist film are less likely to remain on the substrate. As a result, a conductor pattern is easily formed on the substrate.

  Further, as described above, since the resist agent contains a water-soluble polyester resin, it can be prepared as an aqueous composition, and the resist film formed from the resist agent is easily removed by an aqueous resist removal solution. . For this reason, when the resist agent is used, the occupational safety and the environmental conservation are excellent.

  Examples of the present invention will be described below. However, the present invention is not limited only to the following examples. In the following, “part” means “part by mass” and “%” means “mass%” unless otherwise specified.

[Synthesis Example 1]
As raw materials, 130.1 parts of dimethyl terephthalic acid, 35.0 parts of dimethyl isophthalic acid, 44.4 parts of sodium dimethylisophthalic acid 5-sulfonate, 62.1 parts of ethylene glycol, 118.2 parts of 1,6-hexanediol, And 0.1 part of a catalyst (potassium titanium oxalate) was prepared.

  These raw materials are put into a reactor to prepare a solution, and this solution is heated to 200 ° C. with stirring and mixing in an atmospheric pressure and nitrogen atmosphere, and then gradually heated to 260 ° C. over 4 hours. This completes the transesterification reaction. Next, this solution was gradually depressurized at a temperature of 260 ° C., and then kept under the conditions of 250 ° C. and 0.67 hPa (0.5 mmHg) for 1 hour to proceed the polycondensation reaction. As a result, a polyester resin having a number average molecular weight of about 9600 was obtained.

  25 parts of this polyester resin and 75 parts of water were put in a container, and these were stirred at 80 to 95 ° C. for 2 hours to dissolve the polyester resin in water. As a result, an aqueous solution A having a polyester resin concentration of 25% was obtained.

[Synthesis Example 2]
As raw materials, 101.0 parts of dimethylterephthalic acid, 35.0 parts of dimethylisophthalic acid, 88.8 parts of sodium dimethylisophthalic acid 5-sulfonate, 62.1 parts of ethylene glycol, 118.2 parts of 1,6-hexanediol, And 0.1 part of a catalyst (potassium titanium oxalate) was prepared.

  These raw materials are put into a reactor to prepare a solution, and this solution is heated to 200 ° C. with stirring and mixing in an atmospheric pressure and nitrogen atmosphere, and then gradually heated to 260 ° C. over 4 hours. This completes the transesterification reaction. Next, this solution was gradually depressurized at a temperature of 260 ° C., and then maintained at 260 ° C. and 0.67 hPa (0.5 mmHg) for 2 hours to proceed the polycondensation reaction. Thereby, a polyester resin having a number average molecular weight of about 30,000 was obtained.

  25 parts of this polyester resin and 75 parts of water were put in a container, and these were stirred at 80 to 95 ° C. for 2 hours to dissolve the polyester resin in water. As a result, an aqueous solution B having a polyester resin concentration of 25% was obtained.

[Synthesis Example 3]
As raw materials, 62.1 parts of dimethylterephthalic acid, 35.0 parts of dimethylisophthalic acid, 148.1 parts of sodium dimethylisophthalic acid 5-sulfonate, 62.1 parts of ethylene glycol, 118.2 parts of 1,6-hexanediol, And 0.1 part of a catalyst (potassium titanium oxalate) was prepared.

  These raw materials are put into a reactor to prepare a solution, and this solution is heated to 200 ° C. with stirring and mixing in an atmospheric pressure and nitrogen atmosphere, and then gradually heated to 260 ° C. over 4 hours. This completes the transesterification reaction. Next, this solution was gradually depressurized at a temperature of 260 ° C., and then maintained at 260 ° C. and 0.67 hPa (0.5 mmHg) for 2 hours to proceed the polycondensation reaction. As a result, a polyester resin having a number average molecular weight of about 26000 was obtained.

  25 parts of this polyester resin and 75 parts of water were put in a container, and these were stirred at 80 to 95 ° C. for 2 hours to dissolve the polyester resin in water. As a result, an aqueous solution C having a polyester resin concentration of 25% was obtained.

[Synthesis Example 4]
As raw materials, 120.4 parts of dimethyl terephthalic acid, 35.0 parts of dimethyl isophthalic acid, 62.1 parts of ethylene glycol, 118.2 parts of 1,6-hexanediol, and 0.1 part of catalyst (potassium titanium oxalate) Prepared.

  These raw materials are put into a reactor to prepare a solution, and this solution is heated to 200 ° C. with stirring and mixing in an atmospheric pressure and nitrogen atmosphere, and then gradually heated to 260 ° C. over 4 hours. This completes the transesterification reaction. Next, 38.4 parts of trimellitic anhydride is added to the solution, and then the solution is gradually depressurized at a temperature of 250 ° C., followed by conditions of 250 ° C. and 0.67 hPa (0.5 mmHg). For 30 minutes to allow the polycondensation reaction to proceed. As a result, a polyester resin having an acid value of 55.2 mgKOH / g and a number average molecular weight of about 8200 was obtained.

  25 parts of this polyester resin, 71.2 parts of water, and 3.8 parts of 25% sodium hydroxide aqueous solution are put in a container, and these are stirred at 80-95 ° C. for 2 hours to dissolve the polyester resin in water. I let you. As a result, an aqueous solution D having a polyester resin concentration of 25% was obtained.

[Synthesis Example 5]
As raw materials, 139.8 parts of dimethyl terephthalic acid, 35.0 parts of dimethyl isophthalic acid, 29.6 parts of sodium dimethylisophthalic acid 5-sulfonate, 62.1 parts of ethylene glycol, 118.2 parts of 1,6-hexanediol, And 0.1 part of a catalyst (potassium titanium oxalate) was prepared.

  These raw materials are put into a reactor to prepare a solution, and this solution is heated to 200 ° C. with stirring and mixing in an atmospheric pressure and nitrogen atmosphere, and then gradually heated to 260 ° C. over 4 hours. This completes the transesterification reaction. Next, this solution was gradually depressurized at a temperature of 260 ° C., and then kept at 250 ° C. and 0.67 hPa (0.5 mmHg) for 30 minutes to proceed the polycondensation reaction. As a result, a polyester resin having a number average molecular weight of about 5100 was obtained.

  25 parts of this polyester resin and 75 parts of water were put in a container, and these were stirred at 80 to 95 ° C. for 2 hours to dissolve the polyester resin in water. As a result, an aqueous solution E having a polyester resin concentration of 25% was obtained.

  The raw material compositions in Synthesis Examples 1 to 5, the mixing molar ratio of the polyvalent carboxylic acid component and the polyol component, and the number average molecular weights of the polyester resins obtained in Synthesis Examples 1 to 5 are summarized in Table 1 below.

[Evaluation of water solubility of polyester resin]
(Water-soluble before heating)
Each of the aqueous solutions A to E obtained in Synthesis Examples 1 to 5 was coated on a substrate with a brush and then dried at 100 ° C. for 20 minutes to form a film.

  This film was immersed in water at 50 ° C. for 5 minutes. Meanwhile, ultrasonic waves were applied to water for 5 minutes with an ultrasonic cleaner.

Based on the results, the water solubility of the film was evaluated as follows.
○: The film was completely dissolved.
Δ: 80% or more of the film was dissolved.
X: Not dissolved at all.

(Water-soluble after heating)
Each of the aqueous solutions A to E obtained in Synthesis Examples 1 to 5 was coated on a substrate with a brush and then dried at 100 ° C. for 20 minutes to form a film.

  This substrate and the film on it were heated in an oven at 270 ° C. for 10 minutes, and then allowed to stand at room temperature for 15 minutes.

  Subsequently, the film was immersed in water at 50 ° C. for 5 minutes. Meanwhile, ultrasonic waves were applied to water for 5 minutes with an ultrasonic cleaner.

Based on the results, the water solubility of the film was evaluated as follows.
○: The film was completely dissolved.
Δ: 80% or more of the film was dissolved.
X: Not dissolved at all.

  The above results are shown in Table 2 below.

[Preparation and evaluation of resist agent]
(Preparation of resist agent)
As raw materials, aqueous solutions A to E obtained in Synthesis Examples 1 to 5, 25% aqueous solution of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., product number PVA-217), hydroxypropyl cellulose (manufactured by Nippon Soda Co., Ltd., product number NISSO HPC-SL) ) 25% aqueous solution, calcium carbonate (manufactured by Shiraishi Calcium Co., Ltd., product name: Shirareika CCR, average particle size 0.08 μm), calcium carbonate (manufactured by Shiraishi Calcium Co., Ltd., product name: Silver-W, average particle size 1.5 μm) ), Finely divided silica (manufactured by Nippon Aerosil Co., Ltd., product name: AEROSIL200, average particle size of about 0.012 μm), and propylene glycol were prepared.

  In each of Examples 6 to 21 and Comparative Examples 1 and 2, the raw materials were blended in the proportions shown in the table below, and kneaded with a three-roll mill to prepare a paste-like resist agent.

(Resist agent viscosity)
The viscosity of the resist agent obtained in each Example and Comparative Example was obtained by attaching a rotor (No. (3 ° × R14)) to a cone plate type viscometer TV-30 manufactured by Toki Sangyo Co. , Measured at 25 ° C. and 5 rpm. The results are shown in the table below.

(Removability of resist film)
A resist agent is applied on a film made of PEN (polyethylene naphthalate) resin using a bar coater in Examples 1 to 5, and in Examples 6 to 21 and Comparative Examples 1 and 2, the line width is 100 μm by screen printing. It applied so that a negative pattern might be formed. The resist agent on this film was dried by heating at 80 ° C. for 20 minutes. Thereby, a resist film was formed on the film. In any of the examples and comparative examples, the thickness of the resist film was 2 to 3 μm.

On this film, a metal film having a thickness of 0.04 μm was formed by depositing Al by sputtering. As a sputtering apparatus, an SPC series manufactured by Canon Anelva Co., Ltd. was used, and the sputtering conditions were a vacuum degree of 10 ⁻⁴ Pa and an applied voltage of 5.1 kV.

  Subsequently, in order to remove the resist film on the film, running water (flow rate 1.94 L / min, water temperature 50 ° C.) was brought into contact with the surface of the film on which the metal film was formed for 3 minutes.

  Also, the same test as described above was performed when the thickness of the metal film was changed to 0.4 μm.

The surface of the film after the test was observed, and the results were evaluated as follows and are shown in the table below.
○: Resist film remains on the film.
Δ: Residue of the resist film is slightly observed on the film.
X: Resist film residue was found on the entire film.

(Fine processability of resist film)
For Examples 6 to 21 and Comparative Examples 1 and 2, the shape of the conductor pattern having a line width of 100 μm formed on the film in the above “resist peelability test” was observed with a microscope, and the result was obtained as a conductor. The following evaluation is made based on the shakiness of the pattern and the pattern width, and is shown in the table below.
○: The variation of the conductor pattern width is within ± 20%, and the line is not rattled.
Δ: The variation in the conductor pattern width is within ± 40%, and the lines are slightly shaky.
X: The variation in the conductor pattern width is ± 40% or more, and the line is not stable.

  As shown in the above results, in Examples 1 to 21, the resist film was easily peeled off with water, and a conductor pattern was formed. In particular, in Examples 6 to 12 and 15 to 21, the line shape of the conductor pattern was also good. Moreover, in Examples 1-16 and 18-20, even if the thickness of the conductor was 0.4 micrometer, the peelability of the resist film was favorable.

Claims (8)

A resist agent for lift-off method used for forming a resist film on a base material when a conductor pattern is formed on the base material by a lift-off method, characterized by containing a water-soluble polyester resin. The water-soluble polyester resin is a polymerization product of a polyvalent carboxylic acid component and a polyhydric alcohol component, and the polyvalent carboxylic acid component contains sodium 5-sulfonate dimethylisophthalic acid. Resist agent. The resist agent according to claim 2, wherein a ratio of the sodium dimethylisophthalic acid 5-sulfonate to the polyvalent carboxylic acid component is in the range of 10 to 80 mol%. The resist agent according to claim 1, further comprising a water-soluble polymer other than the water-soluble polyester resin. The resist agent of Claim 4 which contains the said water-soluble polymer in the ratio of 1-600 mass% with respect to the said water-soluble polyester resin. The resist agent according to claim 1, wherein the water-soluble polyester resin includes an acid group that is neutralized with an alkali metal compound. The resist agent according to claim 1, further comprising an inorganic filler having an average particle size of 0.03 to 10 μm. The resist agent of Claim 7 which contains the said inorganic filler in the ratio of 0.1-400 mass% with respect to resin whole quantity.