JP2010054847A - Photosensitive resin composition, and method of manufacturing rugged substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition involving little bubbles even when applied to a substrate with level difference, and a fall in film thickness due to trailing at a stepped part while holding general characteristics required of a photosensitive resist. <P>SOLUTION: The photosensitive resin composition contains (A) resin containing a carboxyl group and/or a vinyl group, (B) a photopolymerization initiator having an oxime ester skeleton, (C) a photosensitizer having maximum absorption wavelength in 370-420 nm, and (D) a photo-crosslinking monomer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition and a method for producing an uneven substrate.

A ceramic base material called an AlTiC material (Al ₂ O ₃ / TiC) is used at the tip of the magnetic head slider in the hard disk. With the recent downsizing and increase in capacity of the hard disk, the tip of the magnetic head slider is used. Part (reading part) is required to be further miniaturized and finely processed.

  The fine processing of the Altic material is generally formed using a photosensitive resist (for example, Patent Document 1). That is, a photosensitive resist is applied to the surface of the Altic material by a method such as spin coating, the solvent is distilled off using a hot plate, etc., and after the development process using ultraviolet irradiation and alkali, on the Altic material A resist pattern is formed.

After the resist pattern is formed, the surface of the Altic material is ground by ion milling. In the portion where the resist pattern remains, the surface of the Altic material is not ground, and only the surface of the Altic material from which the resist has been removed by development is ground, and irregularities are formed on the surface of the Altic material. After the ion milling is completed, the photosensitive resist is peeled off from the Altic material using a solvent or an amine. This series of processes is repeated several times to form fine irregularities having several steps on the surface of the Altic material.
JP 2000-215419 A

  The characteristics required for such a photosensitive resist include: (1) characteristics capable of neatly embedding a stepped substrate by spin coating, (2) film thickness uniformity, (3) h-line of a mercury lamp or Photosensitive characteristics in violet laser light (405 nm), (4) developability with weak alkali, (5) high resolution, (6) ion milling resistance, (7) peelability, and the like.

  Conventionally, a dry film resist (negative type), which is a photosensitive resin composition, has been used for the above applications. By using a dry film resist, resolution, ion milling resistance, peelability, and uniform film thickness can be achieved, and development with weak alkali such as about 1% sodium carbonate is possible. However, when a dry film is used, it is difficult to embed a deep step with a laminate, and a gap may be generated between the steps. In addition, when the width of the step becomes wider, there is a problem that the dry film is torn after lamination, and the substrate shape that can be processed is restricted.

  In order to solve such a problem, a liquid positive resist is used. The positive resist is excellent in terms of resolution, ion milling resistance, and peelability, but has a problem that minute bubbles are involved between deep steps of the substrate after coating. In addition, when the gap between the steps is wide, the film thickness becomes thin due to skirting at the corners of the step (non-uniformity occurs). In some cases, the underlying substrate is exposed and a part that should not be ground is ground. Furthermore, since strong alkalis such as tetramethylammonium hydrate are used during development, there are problems such as an adverse effect on the environment and a danger to the worker.

  Accordingly, an object of the present invention is to prevent the bubble from being entrained even when applied to a substrate having a step while maintaining the general characteristics required for the photosensitive resist, and to reduce the film thickness due to the skirting at the step portion. An object of the present invention is to provide a photosensitive resin composition, that is, a photosensitive resin composition excellent in step embedding property and film thickness uniformity. Another object of the present invention is to provide a method for producing an uneven substrate using this photosensitive resin composition.

  In the conventional positive resist, the above problems are difficult to achieve due to restrictions on the structure and properties of the resin that can be used, and the portion irradiated with light has a high molecular weight and is irradiated with light. It has been found that the above-mentioned problem can be achieved only when the components are combined in a specific combination in a negative resist in which no part is removed by alkali development.

That is, this invention provides the photosensitive resin composition containing the following (A) component, (B) component, (C) component, and (D) component.
(A) Resin containing carboxyl group and / or vinyl group (B) Photopolymerization initiator having oxime ester skeleton (C) Photosensitizer having maximum absorption wavelength at 370 to 420 nm (D) Photocrosslinkable monomer

  Since the photosensitive resin composition of the present invention combines the components (A) to (D), bubbles are generated even when applied to a substrate having a step while maintaining general characteristics required for a photosensitive resist. It is difficult to entrain and has excellent film thickness uniformity. In particular, it is possible to prevent bubbles from being involved in a substrate having a step of 200 μm and to prevent a reduction in film thickness due to skirting at the stepped portion. Further, it exhibits particularly preferable performance as a photosensitive resist, such as a photosensitive property of h-line or violet laser light (405 nm) of a mercury lamp, developability by weak alkali, high resolution, ion milling resistance, and peelability.

  The reason why such an effect is achieved is not necessarily clear, but the step embedding property that has been a problem with the conventional positive resist is improved because the (A) in the photosensitive resin composition of the present invention is improved. It is assumed that the presence of the component contributes. Since the component (A) has good wettability with respect to the base material, particularly the Altic substrate, it is difficult for bubbles to be entrained with respect to the base material with a step, and the film thickness uniformity is related to this. It is considered that the skirting at the corner of the step is less likely to occur.

  Component (A) is a vinyl group-containing resin obtained by reacting a vinyl group-containing carboxylic acid with an epoxy resin, or a carboxyl group and vinyl group-containing resin obtained by reacting an acid anhydride with the vinyl group-containing resin. Is preferred.

  By using such a component (A), wettability to a base material, particularly an Altic substrate is improved, entrainment of bubbles is remarkably reduced, and film thickness uniformity is further improved. Moreover, even if it is aqueous | water-based weak alkaline liquids, such as 1% sodium carbonate aqueous solution, high developability comes to be exhibited.

  The epoxy resin is preferably an epoxy resin having an aromatic ring, and the component (D) preferably contains 2,2-bis (4-((meth) acryloxy polyalkoxy) phenyl) propane as the component (D).

  (A) component using the epoxy resin provided with an aromatic ring can improve the adhesiveness to the base material of the photosensitive resin composition, and 2, 2-bis (4-(( When (meth) acryloxy polyalkoxy) phenyl) propane is included, it is compatible with this to form a good cured film. Further, 2,2-bis [4-((meth) acryloxypolyalkoxy) phenyl] propane also exhibits an effect of improving the peelability of the cured product of the photosensitive resin composition.

  A vinyl group-containing resin obtained by reacting a vinyl group-containing carboxylic acid with an epoxy resin having an aromatic ring (benzene ring) skeleton (for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin), or By using a carboxyl group and a vinyl group-containing resin obtained by reacting an acid anhydride with this vinyl group-containing resin as the component (A), the ion milling resistance is improved.

From the viewpoint of further improving the photosensitivity while maintaining good step embedding property and film thickness uniformity, the content of the component (B) is 0.1 to 5 with respect to the total weight of the photosensitive resin composition. The component (C) is preferably a compound having an absorption spectrum of a solution dissolved in N-methylpyrrolidone having a molar extinction coefficient of 1000 M ⁻¹ cm ⁻¹ or more at 405 nm, and the content of the compound Is preferably 0.00.1 to 3% by mass relative to the total weight of the photosensitive resin composition.

  The photosensitive resin composition described above can be compatible with laser direct imaging. That is, it can be cured by blue laser light having a central wavelength in the wavelength region of 350 to 360 nm and / or violet laser light having a central wavelength in the wavelength region of 400 to 410 nm.

  This invention provides the manufacturing method of an uneven | corrugated board | substrate provided with the etching process of laminating | stacking said photosensitive resin composition on a board | substrate and carrying out the dry etching of the exposed part of a board | substrate after exposure and image development.

  According to this manufacturing method, when the photosensitive resin composition is laminated on the substrate, even when the photosensitive resin composition is applied to the substrate having a step, it is difficult to entrain air bubbles, and the film thickness is not easily lowered due to the skirting at the step portion. Therefore, it becomes possible to manufacture a substrate with a finer pattern.

In the above manufacturing method, ion milling can be employed as dry etching, and an AlTiC material (Al ₂ O ₃ / TiC) for a magnetic head slider can be used as a substrate. With regard to Altic materials, it has been difficult to form fine patterns with conventional negative-type and positive-type photosensitive resists, but such problems are solved by using the photosensitive resin composition of the present invention, and more accurate. A high substrate can be formed.

  ADVANTAGE OF THE INVENTION According to this invention, the photosensitive resin composition which has a sensitivity in h line | wire (405 nm) of the mercury lamp generally used for the image formation of the photosensitive resin composition, and has high resolution is provided. Furthermore, the cured product obtained by patterning has sufficient ion milling resistance and functions effectively in the processing of the magnetic head slider. The photosensitive resin composition according to the present invention is not limited to the application to magnetic head slider processing, but is widely used in micron-order fine component processing applications by utilizing the characteristics of adhesion to various substrates and high resolution. Can be used.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  The photosensitive resin composition of the present invention has (A) a resin containing a carboxyl group and / or a vinyl group, (B) a photopolymerization initiator having an oxime ester skeleton, and (C) a maximum absorption wavelength at 370 to 420 nm. It contains a photosensitizer and (D) a photocrosslinkable monomer. Hereinafter, each component will be described in detail.

  The component (A) is a resin containing at least one of a carboxyl group and a vinyl group. Such resins include (A1) a vinyl group-containing resin obtained by reacting an epoxy resin with a vinyl group-containing carboxylic acid, and (A2) reacting an epoxy resin with a vinyl group-containing carboxylic acid and further reacting with an acid anhydride. A carboxyl group- and vinyl group-containing resin is preferable. In addition, as a vinyl group containing carboxylic acid in (A1) component and (A2) component, vinyl group containing monocarboxylic acid is preferable.

The component (A1) is preferably a novolac type epoxy resin represented by the general formula (I), a bisphenol Α type epoxy resin or a bisphenol F type epoxy resin represented by the general formula (II), and a salicyl represented by the general formula (III) A resin obtained by reacting at least one kind of epoxy resin (i) selected from the group consisting of aldehyde type epoxy resins and vinyl group-containing monocarboxylic acid (ii) is used. In the formula, X is a hydrogen atom or glycidyl group (wherein hydrogen atom / glycidyl group (molar ratio) is 0/100 to 30/70), R is a hydrogen atom or methyl group, and n is an integer of 1 or more. And n is preferably an integer of 2 to 100.

  The component (A2) is a carboxyl group- and vinyl group-containing resin obtained by reacting an epoxy resin with a vinyl group-containing carboxylic acid and further reacting with an acid anhydride. As such a component (A2), (A1) The reaction product obtained by reacting the component) with a saturated or unsaturated group-containing polybasic acid anhydride (iii) is preferred.

  In the reaction during the production of the component (A1), it is considered that the vinyl group-containing monocarboxylic acid (ii) has undergone an addition reaction with the epoxy group of the epoxy resin (i), and the reaction product is a resin having a vinyl group. Become. When the epoxy resin (i) originally has a hydroxyl group, the resulting reaction product can contain a vinyl group and a hydroxyl group (the hydroxyl group of the epoxy resin (i) and the monocarboxylic acid containing vinyl group (ii)). In some cases, an ester bond is formed by the reaction of the carboxyl group of).

  On the other hand, in the reaction at the time of producing the component (A2), a hydroxyl group is formed by an addition reaction between the epoxy group of the epoxy resin (i) and the carboxyl group of the vinyl group-containing monocarboxylic acid (ii). Presumed that the generated hydroxyl group (including the original hydroxyl group in the epoxy resin (i)) and the acid anhydride group of the saturated or unsaturated group-containing polybasic acid anhydride (iii) undergo a half-ester reaction. Is done.

であるビスフェノールΑ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂は、例えば、一般式（IV）で示されるビスフェノールΑ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂の水酸基とエピクロルヒドリンを反応させることにより得ることができる。なお、一般式（IV）において、Ｒは、水素原子又はメチル基、ｎは１以上の整数である。 The novolak type epoxy resin represented by the general formula (I) includes a phenol novolak type epoxy resin and a cresol novolak type epoxy resin, and is obtained by reacting a phenol novolak resin and a cresol novolak resin with epichlorohydrin by a known method.
In addition, in the general formula (II), X is a glycidyl group.

The bisphenol-Α type epoxy resin and bisphenol F-type epoxy resin can be obtained, for example, by reacting the hydroxyl groups of the bisphenolΑ-type epoxy resin and bisphenol F-type epoxy resin represented by the general formula (IV) with epichlorohydrin. In the general formula (IV), R is a hydrogen atom or a methyl group, and n is an integer of 1 or more.

In order to promote the reaction between the hydroxyl group and epichlorohydrin, the reaction is preferably carried out in a polar organic solvent such as dimethylformamide, dimethylacetamide or dimethylsulfoxide in the presence of an alkali metal hydroxide at a reaction temperature of 50 to 120 ° C. When the reaction temperature is less than 50 ° C, the reaction is slow, and when the reaction temperature is 120 ° C, many side reactions occur.

  Specific examples of the salicylaldehyde type epoxy resin represented by the general formula (III) include FΑE-2500, EPPN-501H, EPPN-502H (above, Nippon Kayaku Co., Ltd., trade name) and the like.

  Examples of the vinyl group-containing monocarboxylic acid (ii) include acrylic acid, dimer of acrylic acid, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, α- Cyanocinnamic acid and the like, and a half-ester compound, a vinyl group-containing monoglycidyl ether or a vinyl group-containing monoglycidyl ester which is a reaction product of a hydroxyl group-containing acrylate and a saturated or unsaturated dibasic acid anhydride or The half-ester compound which is a reaction product with an unsaturated dibasic acid anhydride is mentioned. These half ester compounds are obtained by reacting a hydroxyl group-containing acrylate, a vinyl group-containing monoglycidyl ether or a vinyl group-containing monoglycidyl ester with a saturated or unsaturated dibasic acid anhydride in an equimolar ratio. These vinyl group-containing monocarboxylic acids (ii) can be used alone or in combination of two or more.

  Examples of the hydroxyl group-containing acrylate used in the synthesis of the half ester compound as an example of the vinyl group-containing monocarboxylic acid (ii) include, for example, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, Examples include hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol pentaacrylate, pentaerythritol pentamethacrylate. Vinyl group-containing monoglyce The ether or vinyl group-containing monoglycidyl ester, glycidyl acrylate, glycidyl methacrylate and the like.

  Examples of the saturated or unsaturated dibasic acid anhydride used in the synthesis of the half ester compound include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, and ethyltetrahydrophthalic anhydride. Examples thereof include acid, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride and the like.

  In the reaction of the epoxy resin (i) and the vinyl group-containing monocarboxylic acid (ii) in the present invention, the vinyl group-containing monocarboxylic acid (ii) is 0.8 per 1 equivalent of the epoxy group of the epoxy resin (i). It is preferable to make it react by the ratio used as -1.05 equivalent, More preferably, it is 0.9-1.0 equivalent.

  The epoxy resin (i) and the vinyl group-containing monocarboxylic acid (ii) are dissolved and reacted in an organic solvent. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, toluene, xylene, tetramethylbenzene and the like. Aromatic hydrocarbons, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, glycol ethers such as propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether, Esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, aliphatic hydrocarbons such as octane, decane, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, sorbene Petroleum solvents such as naphtha.

  Further, it is preferable to use a catalyst to promote the reaction. Examples of the catalyst used include triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylmethylammonium iodide, and triphenylphosphine. The amount of the catalyst used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass in total of the epoxy resin (i) and the vinyl group-containing monocarboxylic acid (ii).

  In this case, it is preferable to use a polymerization inhibitor for the purpose of preventing polymerization during the reaction. Examples of the polymerization inhibitor include hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, and the amount used is 100 parts by mass in total of the epoxy resin (i) and the vinyl group-containing monocarboxylic acid (ii). The amount is preferably 0.1 to 1 part by mass. The reaction temperature is preferably 60 to 150 ° C, more preferably 80 to 120 ° C.

  Use vinyl group-containing monocarboxylic acid (ii) with polybasic acid anhydrides such as trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, biphenyltetracarboxylic anhydride as necessary Can do.

  Examples of the saturated or unsaturated group-containing polybasic acid anhydride (iii) used when obtaining the component (A2) include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, and methyltetrahydroanhydride. Examples include phthalic acid, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride, and the like.

  In the reaction of the component (A1) with the saturated or unsaturated group-containing polybasic acid anhydride (iii), the saturated or unsaturated group-containing polybasic acid anhydride (iii) with respect to 1 equivalent of the hydroxyl group in the component (A1). ) To 0.1 to 1.0 equivalents, the acid value of the component (A) can be adjusted.

  (A) It is preferable that the acid value of a component is 30-150 mgKOH / g, and it is still more preferable that it is 50-120 mgKOH / g. When the acid value is less than 30 mgKOH / g, the solubility of the photocurable resin composition in a dilute alkali solution is lowered, and when it exceeds 150 mgKOH / g, the electric properties of the cured film tend to be lowered. The reaction temperature between the component (A1) and the saturated or unsaturated group-containing polybasic acid anhydride (iii) is preferably 60 to 120 ° C.

  If necessary, as the epoxy resin (i), for example, a hydrogenated bisphenol-type epoxy resin, and as the component (A), a hydroxyethyl acrylate modified product of styrene-maleic anhydride copolymer or styrene-maleic anhydride A part of styrene-maleic acid resin such as hydroxyethyl acrylate modified product of acid copolymer may be used in combination.

  (A) The number average molecular weight of a component can be used in the range of 500-10000 in polystyrene conversion, Preferably it is 1000-7000, More preferably, it is 1500-5000. If the number average molecular weight is less than 500, the alkali developer resistance tends to be poor, and there may be a problem that the photocured part is peeled off during development. On the other hand, if the number average molecular weight is higher than 10,000, the developability becomes poor, and the resolution tends to deteriorate and the development residue tends to occur.

  (A) The solid content acid value of a component can be used in the range of 30-170 mgKOH / g, Preferably it is 50-130 mgKOH / g, More preferably, it is 60-120 mgKOH / g. When the solid content acid value is lower than 30, the developability tends to be poor, and the resolution tends to be lowered and the development residue tends to occur. On the other hand, when the solid content acid value is higher than 170, the resistance to alkali developing solution is poor, and the photocured portion is peeled off during development. In the present invention, regarding the component (A), the varnish state (containing the solvent) is referred to as the acid value, and the acid value in the state of the resin only after the solvent is removed is referred to as the solid content acid value.

  Examples of commercially available (A) component include CCR-1159H, CCR-1194H, CCR-1206H (both manufactured by Nippon Kayaku Co., Ltd.).

  For the purpose of further improving the effect of the present invention, an acrylic resin, a styrene resin, an epoxy resin, an amide resin, an amide epoxy resin, an alkyd resin, a phenol resin, etc. are used in combination with the photosensitive resin composition. Can be used.

  The component (B) in the present invention is a photopolymerization initiator containing an oxime ester skeleton, such as 1,2-octanedione, 1- [4- (phenylthio) phenyl] -2- (o-benzoyloxime), 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone-1- (o-acetyloxime), 1-phenyl-1,2-propanedione-2- [ O- (ethoxycarbonyl) oxime] and the like. As commercial products, OXE01, OXE02 (both manufactured by Ciba Specialty Chemicals Co., Ltd.), PDO (manufactured by LAMBSON), and the like are available.

In the present invention, the “oxime ester skeleton” means a skeleton (group) represented by the following (a) (in the formula, * means that a bond is formed at this part).

  For the purpose of improving the effect of the present invention, a photopolymerization initiator not containing the oxime ester group can be used in combination.

  Examples of the photopolymerization initiator not containing an oxime ester group include benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4′-diaminobenzophenone. 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl-1- [4- (methylthio) phenyl] -2 -Aromatic ketones such as morpholino-propanone-1, 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1 -Chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenantharaquinone, quinones such as 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, benzoin methyl ether, benzoin ethyl ether Benzoin ether compounds such as benzoin phenyl ether, benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin, benzyl derivatives such as benzyldimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (O-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4, 5-diphenylimidazo Dimer, 2,4,5-triarylimidazole dimer such as 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 9-phenylacridine, 1,7-bis (9 , 9′-acridinyl) heptane and the like.

  The content of the component (B) is preferably 0.1 to 10 parts by mass, and 0.3 to 5 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (D). Is more preferable, and 0.5 to 3 parts by mass is particularly preferable. If this content is less than 0.1 parts by mass, the sensitivity to light is poor and image formation tends to be impossible, and if it exceeds 10 parts by mass, the sensitivity tends to be excessive and dimensional stability tends to be poor.

  The component (C) in the present invention is a photosensitizer having a maximum absorption wavelength at 370 to 420 nm. Examples of the photosensitizer used as the component (C) include pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones. Pyrarizones are particularly preferable from the viewpoint of improving sensitivity and fine wire adhesion.

  By using such a photosensitizer, it is possible to have sufficiently high sensitivity to h-line (405 nm) of a mercury lamp and exposure light of a direct drawing exposure method. When the maximum absorption wavelength of the sensitizing dye is less than 370 nm, the sensitivity of the mercury lamp to h-line (405 nm) or direct drawing exposure light tends to decrease, and when it exceeds 420 nm, the stability decreases even in a yellow light environment. Tend. As the sensitizing dye having a maximum absorption wavelength of 370 to 420 nm, for example, pyrarizones, anthracenes, coumarins, xanthones and the like are preferable.

  It is preferable that content of the said photosensitizer shall be 0.1-1 mass part with respect to 100 mass parts of total amounts of (A) component and (D) component, and 0.02-0.5. It is more preferable to set it as a mass part, and it is especially preferable to set it as 0.03-0.3 mass part. If the content is less than 0.01 part by mass, the sensitivity to light is poor and image formation tends to be impossible, and if it exceeds 1 part by mass, the sensitivity tends to be excessive and dimensional stability tends to be poor. .

  In addition, (C) component can be used individually by 1 type or in combination of 2 or more types.

  The component (D) in the present invention is a photocrosslinkable monomer. The component (D) may be any monomer that undergoes a polymerization reaction such as a radical reaction by light, and is preferably a compound having a vinyl group or a (meth) acryloyl group. Although at least one such polymerizable functional group may be present in the molecule, the number of the functional groups is preferably 2 or more, more preferably 2 to 8, and more preferably 2 to 6. More preferably.

  Since the peelability of the cured product is excellent, the component (D) preferably contains 2,2-bis (4-((meth) acryloxy polyalkoxy) phenyl) propane.

  Specifically, a (meth) acrylate having an ethylene oxide chain and / or a propylene oxide chain is effective for exhibiting peelability. The number of acryloyl groups in one molecule is not particularly limited, but a photocrosslinkable monomer having 2 to 3 acryloyl groups is particularly preferable.

As the photocrosslinkable monomer having 2 to 3 acryloyl groups in the molecule, for example, bisphenol A type di (meth) acrylate represented by the general formula (V) (as commercial products, FA-321M, FA-323M Available, Hitachi Chemical Co., Ltd.), trimethylolpropane ethylene oxide modified triacrylate (TMPEOTA, Daiichi Kogyo Seiyaku Co., Ltd.), monoethanolamine modified trimethylolpropane ethylene oxide modified triacrylate (Hitaroid 7836, Hitachi) Kasei Kogyo Co., Ltd.). Among these, bisphenol A type di (meth) acrylate represented by the general formula (V) is preferable.

In the general formula (V), R ² and R ³ each independently represent a hydrogen atom or a methyl group, preferably a methyl group. In the general formula (V), X ² and X ³ each independently represent an alkylene group having 2 to 6 carbon atoms. Examples of the alkylene group having 2 to 6 carbon atoms include methyl, ethyl, N-propyl, isopropyl, N-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and isopentyl. Group, neopentyl group, hexyl group, structural isomers thereof and the like, and ethylene group is preferable from the viewpoint of resolution and peelability.

The isopropylene group is a group represented by —CH (CH ₃₎ CH ₂ —, and is bonded to — (X ² —O) — and — (X ³ —O) — in the general formula (V). There are two types of directions, a case where the methylene group is bonded to oxygen and a case where the methylene group is not bonded to oxygen. One direction may be used, or two types of bonding directions may be mixed. . Also, - (X ² -O) - and - (X ³ -O) - When the repeating units is 2 or more each, the two or more X ² and 2 or more X ^3, also be respectively different, the same Well, when X ² and X ³ are composed of two or more alkylene groups, two or more of — (X ² —O) — and — (X ³ —O) — may be present randomly. However, it may exist in blocks.

  In general formula (V), p + q is a positive integer selected to be 4 to 40, preferably 6 to 34, more preferably 8 to 30, and more preferably 8 to 28. Particularly preferred is 8-20, very particularly preferred, 8-16 is very particularly preferred, and 8-12 is very particularly preferred. If this p + q is less than 4, the peelability tends to decrease, and if it exceeds 40, the hydrophilicity increases, and the resist image tends to peel off during development.

  Examples of the compound represented by the general formula (V) include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane, 2,2-bis (4-((meth) acrylic). Loxypolypropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) Examples thereof include bisphenol A-based (meth) acrylate compounds such as propane. These may be used alone or in combination of two or more.

  Examples of 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2- Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) propane 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy nonaethoxy) ) Phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, 2, 2-bis (4-((meth) acryloxydodecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4- ( (Meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexa) Decaethoxy) phenyl) propane and the like, and 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is BPE-50. (Product name) manufactured by Shin-Nakamura Chemical Co., Ltd., and commercially available as 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is BPE-1300 (Shin-Nakamura Chemical) It is commercially available as a product name manufactured by Kogyo Co., Ltd. These may be used alone or in combination of two or more.

  Examples of 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydipropoxy) phenyl) propane, 2,2- Bis (4-((meth) acryloxytripropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetrapropoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxypentapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptapropoxy) phenyl) propane 2,2-bis (4-((meth) acryloxyoctapropoxy) phenyl) propane, 2,2-bis (4-((meth) acrylic) Xinonapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxydecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecapropoxy) phenyl) propane 2,2-bis (4-((meth) acryloxydodecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecapropoxy) phenyl) propane, 2,2-bis ( 4-((meth) acryloxytetradecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecapropoxy) phenyl) propane, 2,2-bis (4-((meth)) And acryloxyhexadecapropoxy) phenyl) propane. These may be used alone or in combination of two or more.

  Examples of the 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxyoctapropoxy) phenyl) propane. 2,2-bis (4-((meth) acryloxytetraethoxytetrapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxyhexapropoxy) phenyl) propane and the like. . These may be used alone or in combination of two or more.

  In order to further improve the effect of the present invention, a crosslinkable monomer having 4 or more unsaturated groups in the molecule can be used in combination.

  Examples of the crosslinkable monomer having 4 or more unsaturated groups in the molecule include tetramethylol methane tri (meth) acrylate, tetramethylol methane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth). ) Acrylates and the like, and these can be used alone or in combination of two or more.

  A crosslinkable monomer having one unsaturated group in the molecule can also be used. Examples of the crosslinkable monomer having one unsaturated group in the molecule include alkyl (meth) acrylates having 1 to 20 carbon atoms, phenoxypolyethyleneoxy (meth) acrylate, nonylphenoxypolyethyleneoxy (meth) acrylate γ-chloro- β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloloxyalkyl-o-phthalate and the like can be mentioned.

  The content of the component (D) is preferably 3 to 80 parts by mass, more preferably 5 to 50 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (D). It is especially preferable to set it as 10-30 mass parts. If the content is less than 3 parts by mass, the sensitivity tends to be poor, and image formation tends to be impossible. If the content exceeds 80 parts by mass, the sensitivity becomes excessive and dimensional stability becomes poor, and the dryness to the touch after solvent removal is poor. Tend to get worse.

  The photosensitive resin composition of the present invention comprises the above-described components (A) to (D) as essential components. In addition to these essential components, a solvent (for example, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, An additive component such as γ-butyrolactone may be added. When the photosensitive resin composition of the present invention contains a solvent, the viscosity of the solution (25 ° C. viscosity by an EH viscometer) is 0.1 to 10 Pa · s, preferably 0.5 to 5 Pa · s. It is preferable to contain an amount of the solvent that is preferably 1 to 2 Pa · s.

  The photosensitive resin composition of the present invention is sensitive to the h-ray of a mercury lamp having a wavelength of 405 nm and gives a photosensitive resin composition having high resolution. Furthermore, since the cured product obtained by patterning has sufficient ion milling resistance, the effect is particularly exerted in the processing of the magnetic head slider.

  The fine processing of the AlTiC material that is the material of the magnetic head slider is generally formed using a photosensitive resist. That is, the photosensitive resin composition of the present invention is applied to the surface of the Altic material by a method such as spin coating, dried using a hot plate or the like for removing the solvent, irradiated with ultraviolet rays, and then weakly alkaline. Through a development process using a solution, a resist pattern can be formed on the Altic material.

  Thereafter, the surface of the Altic material is ground by ion milling. In the portion where the resist pattern remains, the surface of the Altic material is not ground, but only the surface of the Altic material from which the resist has been removed by development is ground, forming irregularities on the surface of the Altic material. After the ion milling is completed, the photosensitive resist is peeled off from the Altic material using a solvent or an amine. This series of processes is repeated several times to form fine irregularities having several steps on the surface of the Altic material.

  As a stripping solution used when stripping the photocured product of the photosensitive resin composition, an organic solvent such as N-methylpyrrolidone is preferable, and when a water-soluble amine such as monoethanolamine, trimethylamine, or triethylamine is used, A resist is particularly preferable because it has high peelability. As the amine-based stripping solution, the above amines may be used alone or in combination of two or more.

(Examples 1-7 and Comparative Examples 1 and 2)

  As shown in Table 1, each of the components (A) to (D) was mixed in a predetermined amount, and mixed and stirred using a predetermined disper until dissolved. Further, diethylene glycol monoethyl ether acetate was added, and the mixture was diluted so that the viscosity measured with an EH type viscometer was 1.0 to 2.0 Pa · s to obtain a photosensitive resin composition.

Example 1
(A) Component, acid-modified bisphenol F type epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., trade name: ZFR-1158 or ZFR-1553H), 80 parts by mass, photocrosslinking agent, ethylene oxide modified bisphenol A type di 30 parts by mass of acrylate (manufactured by Hitachi Chemical Co., Ltd., trade name: FA-321M) and mixed with photopolymerization initiator, OXE01 (1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime), 2 parts by mass, trade name, manufactured by Ciba Specialty Chemicals Co., Ltd., Coumarin photosensitizer, NF-MC (manufactured by Nippon Chemical Industry Co., Ltd., trade name, local maximum) Absorption wavelength: 371.7 nm) 0.2 parts by mass was added to prepare a photosensitive resin composition. The “acid-modified bisphenol F-type epoxy acrylate” is a resin obtained by reacting an acid anhydride with a reaction product obtained by reacting a bisphenol F-type epoxy resin and epoxy acrylate.

(Example 2)
Instead of the coumarin photosensitizer, 0.2 part by mass of pyrazoline photosensitizer, NF-EO (trade name, manufactured by Nippon Chemical Industry Co., Ltd., maximum absorption wavelength: 387.2 nm) was added. Except for the above, a photosensitive resin composition was produced under the same conditions as in Example 1.

(Example 3)
As a photopolymerization initiator, 2 parts by mass of PDO (1-phenyl-1,2-propanedione-2- [O- (ethoxycarbonyl) oxime], trade name, manufactured by LAMBSON) was added in place of OXE01. A photosensitive resin composition was produced under the same conditions as in Example 2 except that.

Example 4
(A) Instead of acid-modified bisphenol F type epoxy acrylate, 80 parts by mass of acid-modified cresol novolac type epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., trade name: CCR-1159H) was added. 2 is a photosensitive resin composition produced under the same conditions as in Example 1. The “acid-modified cresol novolac epoxy acrylate” is a resin obtained by reacting an acid anhydride with a reaction product obtained by reacting a cresol novolac epoxy resin with an epoxy acrylate.

(Example 5)
A photosensitive resin composition was produced under the same conditions as in Example 4 except that NF-EO was added instead of 0.2 parts by mass to 0.4 parts by mass as a photosensitizer.

(Example 6)
A photosensitive resin composition was prepared under the same conditions as in Example 4 except that 0.05 part by mass of N-phenylglycine was further added as a hydrogen donor.

(Example 7)
A photosensitive resin composition was produced under the same conditions as in Example 4 except that 0.05 parts by mass of t-butylcatechol was further added as a polymerization inhibitor.

(Comparative Example 1)
IC907 (2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, manufactured by Ciba Specialty Chemicals, Inc., trade name: Irgacure 907) 2 instead of OXE01 as a photopolymerization initiator 0.2 parts by mass of thioxanthone photosensitizer, DETX (manufactured by Nippon Kayaku Co., Ltd., trade name: Kayacure DETX-S, maximum absorption wavelength 383 nm) instead of coumarin photosensitizer A photosensitive resin composition was produced under the same conditions as in Example 1 except that.

(Comparative Example 2)
IC369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure 369) 2 instead of Irgacure 907 as a photopolymerization initiator The photosensitive resin composition was produced on the conditions similar to the comparative example 1 except having added the mass part.

In the laminating process for forming the photosensitive resin composition on the substrate, the coating was performed under the following conditions.
(Coating conditions)
Coating equipment: Spin coater (Mikasa Co., Ltd.)
Substrate: Silicon wafer rotation speed and rotation time: Rotate at 1000 rpm for 10 seconds, then rotate at 2000 rpm for 30 seconds Film thickness: about 15 μm

<Production of test substrate>
After coating the photosensitive resin compositions of Examples 1 to 7 and Comparative Examples 1 and 2 based on the above conditions, drying was performed using a box-type oven to remove the solvent from the coating film. The set temperature of the oven was set to 80 ° C., the substrate coated with the photosensitive resin composition was placed in the oven, left for 40 minutes, and then taken out. Thereby, the evaluation board | substrate with which the photosensitive resin type composition which consists of a photosensitive resin type composition was laminated | stacked on the silicon wafer was obtained.

<Preparation of test plate>
After the evaluation substrate returned to room temperature, exposure was performed on the photosensitive resin composition layer by the following method. As an exposure apparatus, a scattered light type exposure machine (manufactured by Oak Manufacturing Co., Ltd., HMW-551D, light source: ultra-high pressure mercury lamp) is used, and a 41-step tablet (manufactured by Hitachi Chemical Co., Ltd.) and a fine wire adhesion measurement mask are exposed. 100 mJ / cm ² (Oak Manufacturing Co., Ltd.) under vacuuming conditions under the condition of placing directly on the conductive resin coating and further placing an i-line cut filter (manufactured by Sigma Koki Co., Ltd., trade name: SCF-100160R-39L). Manufactured and measured by UV-351). Further, alkali development was performed according to the following treatment. The exposed substrate is left under atmospheric conditions for 5 minutes or more, then a 1% sodium carbonate aqueous solution set at 30 ° C. is sprayed onto the substrate at a pressure of 0.18 MPa, and then pure water is sprayed onto the substrate at a pressure of 0.10 MPa. And washed with water.

  The obtained test plate was evaluated for sensitivity, fine wire adhesion, resolution, peelability and ion milling resistance, and the results are shown in Table 2.

(Light sensitivity)
The photosensitivity of the photosensitive resin composition was evaluated by measuring the number of steps of the step tablet of the photocured film formed on the test plate. The light sensitivity is indicated by the number of steps of the step tablet, and the higher the number of steps of the step tablet, the higher the light sensitivity.

(Line adhesion)
The narrowest line width (μm) remaining on the test plate was read.

(Resolution)
The line width obtained after alkali development in the portion of the design value 20 μm of the negative wire adhesion evaluation negative mask was measured using an optical microscope.

(Peelability)
After alkali development, the test plate was put into N-methylpyrrolidone set at 70 ° C., and the presence or absence of the peeling residue after taking out after 60 seconds was confirmed. In any of the cured products shown in Examples 1 to 7, no peeling residue was observed, and it was found that the cured product had good peelability.

(Ion milling resistance)
A Hitachi ion milling device (trade name E-3500) was placed on an evaluation substrate (the photosensitive resin composition was photocured) on which a photosensitive resin composition of Examples 1 to 7 and Comparative Examples 1 and 2 was laminated on a silicon wafer. (Manufactured by Hitachi High-Technologies Corporation) (gas used: argon, milling rate: 100 μm / hour). Those in which no cracks or peeling occurred in the photocured film were considered good, and those in which cracks or peeling occurred in the photocured film were judged defective.

It was evaluated whether or not bubbles were involved in a substrate having a step of 200 μm, and whether or not the film thickness was reduced due to skirting at the stepped portion. In any of Examples 1 to 7, bubbles were involved. In addition, no decrease in film thickness due to skirting at the step portion was observed.

Claims (10)

The photosensitive resin composition containing the following (A) component, (B) component, (C) component, and (D) component.
(A) Resin containing carboxyl group and / or vinyl group (B) Photopolymerization initiator having oxime ester skeleton (C) Photosensitizer having maximum absorption wavelength at 370 to 420 nm (D) Photocrosslinkable monomer   The component (A) is a vinyl group-containing resin obtained by reacting an epoxy resin with a vinyl group-containing carboxylic acid, or a carboxyl group and vinyl group-containing resin obtained by reacting an acid anhydride with the vinyl group-containing resin. The photosensitive resin composition of Claim 1.   The photosensitive resin composition according to claim 2, wherein the epoxy resin is an epoxy resin having an aromatic ring.   (D) The photosensitive resin composition as described in any one of Claims 1-3 in which a component contains 2, 2-bis (4- ((meth) acryloxy polyalkoxy) phenyl) propane.   The content of (B) component is 0.1-5 mass% with respect to the total weight of the said photosensitive resin composition, The photosensitive resin composition as described in any one of Claims 1-4. . Component (C) is a compound having a molar extinction coefficient of 1000 M ⁻¹ cm ⁻¹ or more at 405 nm in the absorption spectrum of a solution dissolved in N-methylpyrrolidone, and the content of the compound is determined by the photosensitive resin composition. The photosensitive resin composition as described in any one of Claims 1-5 which is 0.00.1-3 mass% with respect to the total weight of.   The photosensitivity as described in any one of Claims 1-6 hardened | cured by the blue laser beam which has a center wavelength in the wavelength range of 350-360 nm, and / or the purple laser beam which has a center wavelength in the wavelength range of 400-410 nm. Resin composition.   A method for producing a concavo-convex substrate, comprising an etching step of laminating the photosensitive resin composition according to any one of claims 1 to 7 on a substrate and subjecting the exposed portion of the substrate to dry etching after exposure and development. .   The method for manufacturing a concavo-convex substrate, wherein the dry etching is ion milling. The method for manufacturing a concavo-convex substrate according to claim 8 or 9, wherein the substrate is an AlTiC material (Al ₂ O ₃ / TiC) for a magnetic head slider.