JP2011032401A - Resist ink and method for producing resist pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist ink having excellent resist tendencies as well as printability to be used for obtaining optimum fine images desired for various electronic parts by etching, and to provide a method for forming a resist pattern using the ink. <P>SOLUTION: The resist ink contains: an alkaline soluble resin having an acid value of at least 150 (gKOH/g) and a weight average molecular weight of 500-5,000 and solid at 25°C; and an organic solvent having a vapor pressure of at most 0.02 kPa at 20°C and a swelling rate of a silicone blanket of 5-20%; wherein the viscosity at 25°C is 5-20 Pa s. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resist ink that can be suitably used as a resist material when forming a fine pattern using an etching process in the manufacture of various electronic components that require a fine pattern.

  Until now, photolithography (photolithography) capable of high-definition patterning has been used for manufacturing various electrical components. For example, when forming an electrode pattern for a touch panel using a conductor such as ITO (indium tin oxide), a resist film is applied on the entire surface of the conductor film, exposed using a mask, and an uncured portion. After removing the resist, unnecessary conductor film is removed by etching, and used resist is removed. However, the photolithography method has many problems such as a long production process, use of a mask, exposure, and application of a resist on the entire surface, resulting in an increase in running cost. In order to shorten the production process, it is desired to manufacture various electronic components by a printing method.

  As a technique related to the photolithography method, a resist ink (photo-curable printing ink) for forming a circuit pattern of a wiring board by an etching method is known (see, for example, Patent Documents 1 to 4). This resist ink is a pattern that is printed by screen printing, ordinary gravure printing, or the like, and is then cured by ultraviolet rays, so that a resist pattern is obtained, and a mask is unnecessary. However, a fine pattern comparable to the photolithography method cannot be formed by screen printing or gravure printing.

  A resist pattern forming method using a flat gravure plate in which a pattern is formed by etching in a plate is also known (see, for example, Patent Document 5). However, the absorption of the solvent into the blanket was not sufficiently considered, and the transfer to the substrate was not always sufficient.

JP-A-11-172176 JP-A-11-172177 JP-A-11-172178 JP-A-11-172179 JP-T-2006-523750

  A first object of the present invention is to provide a resist ink that is excellent in printability as well as resist suitability, which is used for obtaining an optimum (fine) image desired for various electronic components by etching. A second problem is to provide a method for forming a resist pattern that is excellent in fine line reproducibility, continuous printability, and on-machine stability.

  In order to solve this problem, the present invention firstly has an acid value of 150 (gKOH / g) or more, a weight average molecular weight of 500 to 5,000, and an alkali-soluble resin which is solid at 25 ° C., and 20 A resist ink comprising an organic solvent having a vapor pressure of 0.02 kPa or less at 5 ° C., a silicone blanket swelling ratio of 5 to 20%, and a viscosity at 25 ° C. of 5 to 20 Pa · s. I will provide a.

  Furthermore, the present invention secondly includes a step of supplying a resist ink to at least an intaglio printing plate having a resist pattern, a step of pressing a silicone blanket and transferring the resist ink onto the blanket, and a resist ink on the blanket. A resist pattern forming method comprising a step of transferring onto an etchable layer previously formed on a substrate, wherein the resist ink has an acid value of 150 (gKOH / g) or more and a weight average molecular weight of 500 to 5 And an organic solvent that is solid at 25 ° C. and an organic solvent having a vapor pressure at 20 ° C. of 0.02 kPa or less and a silicone blanket swelling ratio of 5 to 20%. Resist pattern formation method characterized by being a resist ink having a viscosity of 5 to 20 Pa · s To provide.

  In the present invention, the silicone blanket swelling ratio of the organic solvent means that a 2 cm square silicone blanket (silicone blanket T-60 C / C manufactured by Kinyo Co., Ltd.) is immersed in the solvent for 10 hours in an environment of 25 ° C. The mass increase rate of the blanket.

  In this specification, the viscosity of the resist ink is defined by a value measured with a Raleigh viscometer.

  ADVANTAGE OF THE INVENTION According to this invention, the resist ink which is excellent in printing aptitude as well as resist aptitude used in order to obtain the optimal (fine) image desired as various electronic components by an etching can be provided. In addition, it is possible to provide a method for forming a resist pattern that is excellent in fine line reproducibility, continuous printability, and on-machine stability.

  The present invention will be described below based on the best mode.

(Resist ink)
The resist ink of the present invention has an acid value of 150 (gKOH / g) or more, a weight average molecular weight of 500 to 5,000, an alkali-soluble resin that is solid at 25 ° C., and a vapor pressure at 20 ° C. An organic solvent having a silicone blanket swelling ratio of 5 to 20% is contained at 0.02 kPa or less, and a viscosity at 25 ° C. is 5 to 20 Pa · s.

(Resist pattern formation method)
The resist pattern forming method of the present invention uses the resist ink of the present invention described above, and at least a step of supplying the resist ink to the intaglio printing plate having the resist pattern, pressing the silicone blanket, and transferring the resist ink onto the blanket And a step of transferring the resist ink on the blanket onto an etchable layer previously formed on the substrate.

  The resist ink of the present invention can be used to form an etching resist pattern by an offset method using a silicone blanket using an intaglio printing plate. As each component used in the resist ink of the present invention, it is desirable to appropriately select and use a component that can withstand the etching solution. However, as a whole composition, the formed pattern has desired etching resistance. Can be used.

  The alkali-soluble resin used in the resist ink of the present invention is an alkali-soluble resin having an acid value of 150 (gKOH / g) or more, a weight average molecular weight of 500 to 5,000, and a solid at 25 ° C. The acid value is preferably 200 or more. If the acid value is less than 150 (gKOH / g), a residue remains during alkali cleaning. If the weight average molecular weight is less than 500, it is difficult to obtain a sufficient viscosity necessary for printing, and if it exceeds 5,000, the elasticity of the ink becomes strong and the process of supplying resist ink to the intaglio printing plate having a resist pattern is defective. Occurs.

  Examples of such alkali-soluble resins include rosin ester resins, acrylic resins, ester resins, and urethane resins. Particularly preferred are rosin ester resins and acrylic resins.

  The organic solvent used in the resist ink of the present invention is an organic solvent having a vapor pressure at 20 ° C. of 0.02 kPa or less and a silicone blanket swelling ratio of 5 to 20%. When the vapor pressure at 20 ° C. exceeds 0.02 kPa, the viscosity of the ink increases on the printing press, and stable continuous printability cannot be obtained.

  In the resist pattern forming method of the present invention, the silicone blanket is required to have transferability from an intaglio and transferability to a substrate. In particular, in order to obtain sufficient transferability to the substrate, it is necessary to absorb the organic solvent in the resist ink at a certain ratio on the blanket surface. Insufficient absorption tends to cause delamination of the resist ink layer at the time of transfer to the substrate, and conversely if absorbed beyond a certain ratio, the resist ink dries on the blanket surface, causing transfer failure to the substrate. easy. In the present specification, the degree of absorption of the organic solvent into the silicone blanket is defined by the aforementioned “swelling rate”.

  That is, when an organic solvent having a silicone blanket swelling ratio of less than 5% is used, the resist ink layer is likely to delaminate in the transfer process from the silicone blanket to the base material, and the organic solvent having a silicone blanket swelling ratio exceeding 20%. When is used, the resist ink is excessively dried on the blanket surface, and transfer defects are likely to occur. Under such circumstances, it is a main object of the present invention to provide a resist ink most suitable for a resist pattern forming method using a silicone blanket.

  As such an organic solvent, a 2 cm square silicone blanket (silicone blanket T-60 C / C manufactured by Kinyo Co., Ltd.) is immersed in the solvent in a 25 ° C. environment for 10 hours, and the blanket has a mass increase rate of 5 to 5. An organic solvent that is 20% can be selected.

  Particularly preferred is diethylene glycol monobutyl ether acetate or diethylene glycol monoethyl ether acetate. As a result of combining several solvents, the swelling rate of the silicone blanket is preferably 5 to 20%.

  The resist ink of the present invention is characterized in that the viscosity at 25 ° C. is 5 to 20 Pa · s. If the viscosity is less than 5 Pa · s, pinhole defects are likely to occur at the corners of the image line or at the intersections of the matrix. If the viscosity exceeds 20 Pa · s, the inking property on the intaglio is inferior and the image line is linear. Is inferior.

  The resist ink of the present invention may further contain a polyether having a weight average molecular weight of 500 to 5,000. The addition of a liquid or semi-solid polyether having a weight average molecular weight of 500 to 5,000 and a temperature of 30 ° C. exhibits the effect of fine line reproducibility with a line width of 10 μm or less. The content ratio of the polyether relative to the resin solid part in the resist ink is preferably 0.1 to 3%.

  Examples of such polyethers include PTG-L1000, PTG-L2000, PTG-L3000, PTG850, PTG1000, PTG1400, PTG1800, PTG2000, PTG3000, PTMG650, PTMG850, PTMG1000, PTMG1300, PTMG1500, manufactured by Hodogaya Chemical Co., Ltd. Examples include PTMG1800, PTMG2000, and PTMG3000. Particularly preferred are PTG-L1000, PTG-L2000, PTMG650, PTMG850, and PTMG1000.

(Resist ink composition)
The ratio of the alkali-soluble resin and the organic solvent in the resist ink of the present invention is preferably in the range of 75:25 to 55:45, and more preferably 70:30 to 60:40. The content of the alkali-soluble resin in the resist ink is preferably 75 to 55% by mass, more preferably 70 to 60% by mass. The content of the polyether in the resist ink as an optional component can be 0.1 to 3% depending on the target line width. More preferably, it is 0.5% to 1.5%.

  In the resist ink of the present invention, in addition to the above-mentioned components, coloring components such as dyes and pigments, various additives such as pigment dispersants, antifoaming agents, and plasticizers can be appropriately blended.

  The resist ink of the present invention can be produced by kneading and homogenizing the above raw materials.

  The resist pattern forming method of the present invention includes a step of supplying a resist ink to a groove portion of an intaglio printing plate, a step of pressing a silicone blanket against the surface of the intaglio printing plate, and transferring a resist ink of the intaglio printing plate groove portion to the surface of the blanket, A step of transferring the resist ink to the substrate.

  As the intaglio printing plate used in the resist pattern forming method of the present invention, an ordinary gravure plate, an intaglio plate formed by exposing, developing and washing a photosensitive resin on a glass plate, an intaglio plate formed by chemical etching and laser etching on a glass plate Can be used.

  The silicone blanket used in the resist pattern forming method of the present invention is a sheet having a layer structure such as a silicone rubber layer, a PET layer, and a sponge layer. Usually, it is used in a state of being wound around a rigid cylinder called a blanket cylinder.

(Base material)
The base material on which the resist pattern is formed using this resist ink is not particularly limited, and examples thereof include plastic, paper, glass, ceramics, and metal. Specifically, glass or PET film on which ITO is vapor-deposited, glass or PET film on which aluminum or molybdenum is vapor-deposited or uniformly coated, and the like can be mentioned.

  Hereinafter, the present invention will be specifically described with reference to examples. Here, “%” is “% by mass” unless otherwise specified.

(Selection of organic solvent)
After measuring the mass of a silicone blanket cut into 2 cm square (Silicon blanket T-60 C / C manufactured by Kinyo Co., Ltd.), it was immersed in 50 g of each solvent for 10 hours in a 25 ° C. environment, and the solvent adhering to the surface was wiped off. The mass was measured. The mass change of the blanket before and after the solvent immersion was calculated as the blanket swelling rate.

(Preparation of Example 1 ink)
As an alkali-soluble resin, 65 g of Becacite J896 (manufactured by DIC: acid value 200 (gKOH / g), weight average molecular weight 900), diethylene glycol monobutyl ether acetate (manufactured by Daicel Chemical Industries, Ltd .: vapor pressure at 20 ° C.) as an organic solvent , 0.01 kPa, silicone blanket swelling ratio, 11%) 35 g was added and heated and stirred at 80 ° C. to obtain Example 1 ink (ink viscosity of about 10 Pa · s).

Example 2 Preparation of Ink
As an alkali-soluble resin, 65 g of Becacite J896 (manufactured by DIC: acid value 200 (gKOH / g), weight average molecular weight 900), diethylene glycol monobutyl ether acetate (manufactured by Daicel Chemical Industries, Ltd .: vapor pressure at 20 ° C.) as an organic solvent , 0.01 kPa, silicone blanket swelling ratio, 11%) 34 g, 1 g of PTG-L1000 (Hodogaya Chemical Co., Ltd.) was added, and the mixture was heated and stirred at 80 ° C. to obtain Example 2 ink (ink viscosity about 10 Pa · s). .

(Comparative Example 1 Preparation of Ink)
62 g of Beccasite J896 (manufactured by DIC: acid value 200 (gKOH / g), weight average molecular weight 900) as an alkali-soluble resin, and diethylene glycol monobutyl ether acetate (manufactured by Daicel Chemical Industries, Ltd .: vapor pressure at 20 ° C.) as an organic solvent. , 0.01 kPa, silicone blanket swelling ratio, 11%) 38 g was added, and the mixture was heated and stirred at 80 ° C. to obtain Comparative Example 1 ink. (Ink viscosity about 4 Pa · s)

(Comparative Example 2 Preparation of Ink)
68 g of Beccasite J896 (manufactured by DIC: acid value 200 (gKOH / g), weight average molecular weight 900) as an alkali-soluble resin, and diethylene glycol monobutyl ether acetate (manufactured by Daicel Chemical Industries, Ltd .: vapor pressure at 20 ° C.) as an organic solvent. , 0.01 kPa, silicone blanket swelling ratio, 11%) 32 g was added, and the mixture was heated and stirred at 80 ° C. to obtain Comparative Example 2 ink. (Ink viscosity about 30 Pa · s)

(Comparative Example 3 Preparation of Ink)
As an alkali-soluble resin, Becacite J896 (manufactured by DIC: acid value 200 (gKOH / g), weight average molecular weight 900) 68.2 g, diethylene glycol monobutyl ether (manufactured by Daicel Chemical Industries, Ltd .: vapor at 20 ° C.) as an organic solvent Pressure, 0.003 kPa, silicone blanket swelling ratio, 31.8 g) was added, and the mixture was heated and stirred at 80 ° C. to obtain Comparative Example 3 ink. (Ink viscosity about 10 Pa · s)

(Comparative Example 4 Preparation of Ink)
As an alkali-soluble resin, Actflow CBB-3098 (manufactured by Soken Chemical Co., Ltd .: acid value 100 (gKOH / g, liquid resin at 25 ° C.), weight average molecular weight 2000) 65 g, diethylene glycol monobutyl ether acetate (Daicel Chemical Industries, Ltd.) as an organic solvent Manufactured: 35 g of vapor pressure at 20 ° C., 0.01 kPa, silicone blanket swelling ratio, 11%) was added and stirred to obtain Comparative Example 4 ink (ink viscosity of about 2 Pa · s).

(Comparative Example 5 Preparation of Ink)
As an alkali-soluble resin, Bekkasite J896 (manufactured by DIC: acid value 200 (gKOH / g), weight average molecular weight 900) 65 g, as an organic solvent, ethylene glycol monomethyl ether (manufactured by Daicel Chemical Industries, Ltd .: vapor pressure at 20 ° C.) , 0.70 kPa, silicone blanket swelling ratio, 11%) 35 g was added, and the mixture was heated and stirred at 80 ° C. to obtain a comparative example 5 ink (ink viscosity of about 8 Pa · s).

(Formation of resist pattern)
A photosensitive resin was uniformly coated on a glass plate with a spin coater, exposed through a mask, and then developed and washed to form an experimental intaglio. In addition, the thin line pattern formed three patterns of a 100 μm width reproducibility evaluation portion, a 20 μm width reproducibility evaluation portion, and a 10 μm width reproducibility evaluation portion.

  As the silicone blanket, a T-60 C / C blanket manufactured by Kinyo Co., Ltd. having a layer structure of a silicone rubber layer, a PET layer, and a sponge layer was used.

  After inking Example 1 ink on the intaglio plate formed above using a doctor blade, the blanket cylinder on which the blanket was wound was pressed with a nip width of about 10 cm, and the patterned Example 1 ink was placed on the blanket. Transferred. Thereafter, the ink of Example 1 on the blanket was transferred to an ITO glass substrate having a thickness of 10 nm, and a transfer pattern was formed.

  The same operation was performed with the ink of Example 2 and Comparative Examples 1 to 5, and the following evaluation methods were used. The evaluation results are shown in Table 2.

(Ink viscosity)
It measured with the Raleigh viscometer at 25 degreeC.

(Inking or not)
After the ink was braided on the intaglio, the intaglio was observed with an optical microscope (x1000).

(Fine line reproducibility)
The transfer patterns corresponding to the 100 μm width reproducibility evaluation portion, the 20 μm width reproducibility evaluation portion, and the 10 μm width reproducibility evaluation portion described above were visually evaluated under an optical microscope (× 1000).

(cornering)
Observe the specific transfer pattern of 100 μm width with a right-angle crank and the end of the 100 μm width straight line under an optical microscope (× 1000), and visually check for the presence of pinhole defects occurring in the part perpendicular to the printing direction evaluated.

(Continuous printability)
The transfer pattern corresponding to the 100 μm width reproducibility evaluation part, the 20 μm width reproducibility evaluation part, and the 10 μm width reproducibility evaluation part when the transfer pattern is formed 10 times continuously is visually observed under an optical microscope (× 1000). evaluated.

(Onboard stability)
The ink was stretched to a thickness of about 10 μm and allowed to stand for 10 hours, and the viscosity of the ink was measured before and after that to confirm that there was no thickening of 10% or more.

(Blanket residue)
Visual evaluation was performed using the transfer failure due to insufficient adhesive force occurring during the transfer process to the substrate and the transfer failure due to insufficient internal cohesion of the resist ink as resist ink residues remaining on the blanket surface.

  Since Comparative Example 3-5 ink exhibited the phenomenon of transfer failure and internal cohesive force destruction in the evaluation of the blanket residue 1 described above, the subsequent evaluation was not performed.

  The present invention can be used as a resist ink for etching in the production of various electric parts and electronic parts. Examples of the final product include a touch panel electrode and a display pixel electrode.

Claims (5)

An alkali-soluble resin having an acid value of 150 (gKOH / g) or more, a weight average molecular weight of 500 to 5,000, and a solid at 25 ° C., and a vapor pressure at 20 ° C. of 0.02 kPa or less, a silicone blanket A resist ink comprising an organic solvent having a swelling rate of 5 to 20% and a viscosity at 25 ° C. of 5 to 20 Pa · s. The resist ink according to claim 1, wherein the alkali-soluble resin is at least one selected from a rosin ester resin, an acrylic resin, an ester resin, and a urethane resin. The resist ink according to claim 1, wherein the organic solvent contains diethylene glycol monobutyl ether acetate or diethylene glycol monoethyl ether acetate. The resist ink according to any one of claims 1 to 3, further comprising a polyether having a weight average molecular weight of 500 to 5,000 and liquid or semi-solid at 30 ° C. At least a step of supplying a resist ink to an intaglio printing plate having a resist pattern, a step of pressing a silicone blanket and transferring the resist ink onto the blanket, and an etching formed on the substrate in advance with the resist ink on the blanket A resist pattern forming method comprising a step of transferring onto a possible layer, wherein the resist ink has an acid value of 150 (gKOH / g) or more, a weight average molecular weight of 500 to 5,000, and a solid at 25 ° C. And an organic solvent having a vapor pressure of 0.02 kPa or less at 20 ° C. and a silicone blanket swelling ratio of 5 to 20%, and a viscosity at 25 ° C. of 5 to 20 Pa · s. A resist pattern forming method, which is a resist ink.