JP2007279407A - Photosensitive paste composition and flat panel display member using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive paste composition which allows high-definition pattern formation by controlling the tackiness of a film of a photosensitive paste composition used for various members such as partitions of a flat panel display so that a problem such as contamination of a photomask in exposure is not caused. <P>SOLUTION: The photosensitive paste composition comprises inorganic particles including at least glass powder and a photosensitive organic component, wherein a binder polymer contained in the photosensitive organic component has a glass transition temperature of 30-100°C, and the glass powder has a composition comprising 70-95 wt.% of Bi<SB>2</SB>O<SB>3</SB>, 3-15 wt.% of SiO<SB>2</SB>, 5-20 wt.% of B<SB>2</SB>O<SB>3</SB>, 1-10 wt.% of ZnO and 0-3 wt.% of ZrO<SB>2</SB>(expressed in terms of oxide). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photosensitive paste composition used for various members such as a partition wall of a flat panel display.

  As an image display device replacing the cathode ray tube, an image display device using an electron-emitting device which is a self-luminous discharge type display has been proposed. This is because the contrast between light and dark is much larger than that of a liquid crystal display, the viewing angle is wide, and the demand for larger screens and higher definition can be met. The electron-emitting device includes a thermal electron-emitting device and a cold cathode electron-emitting device. Cold cathode electron emission types include field emission type (field emission display: FED), metal / insulating layer / metal type (MIM type), and surface conduction type (SED). A display using a cold cathode electron source displays an image by emitting fluorescent light by irradiating a phosphor with an electron beam emitted from an electron-emitting device. Among such electron emission type flat image display devices, a CNT-FED using carbon nanotubes (CNT) as an electron emission element, a unit using an electron emission element as a light source for a backlight, etc. The development is actively carried out because the area can be easily increased. The rear glass substrate of this apparatus is provided with a matrix-like wiring that connects a plurality of electron-emitting devices and electrodes of these devices. Further, since the matrix wiring intersects at the electrode portion of the electron-emitting device, an insulating layer for insulation is provided. Furthermore, a spacer is formed as an atmospheric pressure resistant support member between the rear glass substrate and the front glass substrate, and a grid-like partition is formed to divide the light emitting region. The barrier ribs are provided in order to suppress the spread of the discharge to a certain area and perform display in a prescribed cell, and at the same time secure a uniform discharge space.

  On the other hand, a method of forming a partition wall by a photolithography technique using a photosensitive paste is known. A partition is also called a barrier, a rib, or a barrier rib. As a method for forming the partition wall, there is a method in which a photosensitive paste composition containing glass powder is applied to a front glass substrate or a back glass substrate, followed by drying, exposure, development, and baking.

In the partition formation process, the film of the photosensitive paste composition applied on the glass substrate is heated over time so that the organic solvent is scattered, but in reality, it cannot be completely scattered, The surface of the photosensitive paste film is somewhat sticky (tackiness). Therefore, in the case of contact exposure using a photomask in contact, there is a problem that the paste adheres to the photomask, and pinholes are generated in the film of the photosensitive paste composition when the photomask is removed. Furthermore, if the tackiness is large, air easily enters between the film of the photosensitive paste composition and the photomask, and when exposed to ultraviolet rays, it inhibits photosensitivity, and the photosensitive paste composition Another problem is that dust and dust are likely to adhere to the surface of the film, which worsens the pattern. In order to solve these problems, the tackiness of the film formed from the photosensitive paste composition is suppressed by performing exposure after setting the organic solvent content in the photosensitive paste composition to 6% by weight or less. Has been proposed (see Patent Document 1). However, when this method is used with a film thickness of 50 μm or more, the organic component on the substrate side of the film is less likely to be scattered, so that when the film is exposed, the substrate side of the film is not sufficiently cured and is desired. The pattern shape cannot be obtained. In order to maintain the strength and shape of the glass pattern after development, a method of setting the glass transition temperature of the polymer to −30 to 30 ° C. has been proposed (see Patent Document 2). Since the surface of the film of the conductive paste composition is sticky, pinholes are generated when contact exposure is performed.
Japanese Patent Laid-Open No. 11-67076 (paragraphs 7 and 20) JP 2004-1118050 A (paragraphs 14 and 19)

  The present invention relates to a photosensitive paste composition used for various members such as partition walls of a flat panel display, controls the tackiness of a film formed from the photosensitive paste composition, and causes problems such as contamination of a photomask during exposure. A photosensitive paste composition that can form a high-definition pattern is provided.

That is, the present invention is a photosensitive paste composition having inorganic particles containing at least glass powder and a photosensitive organic component, wherein the binder polymer contained in the photosensitive organic component has a glass transition temperature of 30 to 100 ° C., and is oxidized. things terms expressed in 70 to 95 wt% of _Bi 2 _O 3, _3~15 wt% of _SiO 2, 5 to 20 wt% of _B 2 _O 3, _1~10 wt% of ZnO, 0 to 3 wt% of ZrO ₂ is a photosensitive paste composition containing glass powder having a composition range of ₂ .

  According to the present invention, the tackiness of the film of the photosensitive paste composition can be suppressed, and even if the photosensitive paste composition comes into contact with the photomask in contact exposure using the photomask in contact with the photosensitive paste composition, Pinholes and cracks do not occur in the film, and residues after etching do not occur. Furthermore, since the distance between the film of the photosensitive paste composition and the photomask can be reduced, a higher definition pattern can be formed.

  Hereinafter, the photosensitive paste composition of the present invention, the pattern forming method using the same, and the flat panel display member produced thereby will be described.

The glass powder used for the photosensitive paste composition of the present invention is 70 to 95 wt% Bi ₂ O ₃ , ₃ to 15 wt% SiO ₂ , 5 to 20 wt% B ₂ O ₃ in terms of oxides, A glass powder satisfying the composition range of 1 to 10% by weight of ZnO and 0 to 3% by weight of ZrO ₂ is preferred, and a low softening point glass is preferred. The low softening point glass can suppress the energy and cost required for the molding process. The low softening point glass contains SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , ZnO, PbO, Bi ₂ O ₃ , ZrO ₂ , alkaline earth metal oxide, alkali metal oxide, and the like. Examples thereof include borosilicate glass, alkali silicate glass, Pb glass, and Bi glass. The glass film obtained by firing the photosensitive paste composition of the present invention may be used in a process of etching a metal such as chromium, and even in the process of etching a metal, it is difficult to dissolve glass, that is, etching with an acid. Highly resistant glass is desirable. In addition to such a requirement, since pulverization of the particle diameter is required, a bismuth-based glass that can be pulverized is preferable.

  The glass includes amorphous glass and crystallized glass, but the present invention can be used for both amorphous glass and crystallized glass. In general, amorphous glass has a property of crystallizing when heated to a crystallization temperature. In the crystallized glass, glass crystals are formed from several tens to about 90% by volume, so that the strength and the coefficient of thermal expansion can be improved. Using this, it is possible to suppress shrinkage during firing. It is also possible to use already crystallized glass. When glass that has already been crystallized is used, it is desirable to use glass having a crystallization temperature of 550 ° C. or lower. In addition to cost reduction and productivity improvement by low-temperature firing, if the firing temperature is 500 ° C. or lower, there is an advantage that an inexpensive glass substrate can be used.

  The low softening point in the present invention means that the glass softening point temperature of the glass powder is 350 to 600 ° C, more preferably 400 to 580 ° C, still more preferably 450 to 500 ° C. The glass used is preferably alkali-free glass. When alkali metals or alkaline earth metals such as sodium, lithium, potassium, barium, calcium, etc. are included, ion exchange with glass components in the glass substrate or electrode after firing or after firing is likely to occur, resulting in a decrease in electrical properties. And thermal expansion coefficient mismatch occurs, which is not preferable. As mentioned above, when using the low softening point glass by this invention, Bi-Zn type | system | group and Bi-Zr type | system | group glass are preferable, However, It is not limited to this.

As a method for producing glass powder, for example, as raw material SiO ₂ , potassium feldspar, soda feldspar, kaolin, silica sand, etc., and as Al ₂ O ₃ , alumina, aluminum hydroxide, potassium feldspar, soda feldspar, kaolin, etc. _and as the B 2 _{O 3,} and boric acid or borax, the ZnO, and zinc oxide, mixed thereof of any of such components and _Bi 2 _{O 3} and ZrO ₂ to a predetermined blend composition Then, after melting at 900 to 1200 ° C., it is rapidly cooled, and it is made into a glass frit and then pulverized into a fine powder.

  As a method for pulverizing glass, there are a ball mill, a bead mill, an attractor, a sand mill, and the like. Of these, a ball mill and a bead mill are preferably used.

  It is preferable that the average particle diameter of the glass powder used by this invention is 0.1-5 micrometers, Furthermore, 0.1-2 micrometers is preferable, More preferably, it is 0.1-1 micrometer. By using a glass powder having an average particle size of 0.1 μm or more, a photosensitive paste composition having good dispersion stability can be obtained. By using a glass powder having an average particle size of 5 μm or less, fine photolithography in a thin film Can be processed. When the laser diffraction scattering method is used, the average particle size of the glass powder indicates the particle size when the cumulative frequency of the obtained particle size distribution is 50%. When using the BET method conversion value, after adsorbing an inert gas such as nitrogen gas and measuring the specific surface area, the particle diameter is obtained from the specific surface area assuming that the particle is a sphere, and the average particle diameter is calculated as a number average. Ask. When the particles are nano-sized or smaller, it is difficult to measure accurately due to aggregation or the like, and therefore it is preferable to use a BET method conversion value.

  As content of the glass powder in the photosensitive paste composition, 50 to 95 weight% is preferable, 70 to 95 weight% is more preferable, 80 to 90 weight% is further more preferable. By setting it to 50% by weight or more, the pattern shape at the time of firing can be made preferable, while by setting it to 95% by weight or less, good photosensitive characteristics can be obtained. If it exceeds 95% by weight, pasting becomes difficult. On the other hand, if it is less than 50% by weight, tackiness deteriorates.

  The average refractive index of the glass powder used is preferably 1.8 or more. More preferably, it is larger than 2 and smaller than 2.7. More preferably, it is 2.0 or more and 2.2 or less. When the glass composition is satisfied, the above range of average refractive index may be satisfied.

  The refractive index of the glass powder is measured using a Becke method, a V block method, an ellipsometer, or the like. Measuring the refractive index at the exposure wavelength is accurate in confirming the effect. For example, it is preferable to measure with light in a wavelength range of 350 to 650 nm using a high-speed spectroscopic ellipsometer M-2000 rotation compensator type (manufactured by JA Woollam). Furthermore, refractive index measurement with i-line (365 nm) or g-line (436 nm) is preferable. The sample used for this measurement is preferably a thin film obtained by screen-printing a photosensitive paste composition on a glass substrate and firing it at a temperature equal to or higher than the glass softening temperature of the glass powder.

  Moreover, within the range of the content of the glass powder, the specific gravity of the glass is preferably 4 or more and 7 or less, more preferably 4.5 or more and 6.5 or less, and further preferably 5.5 or more and 6.3 or less. Within this range, shrinkage during firing can be reduced, and the pattern shape after firing can be made preferable. The specific gravity of the glass powder is measured using the Archimedes method, the specific gravity bottle method, the floating method, or the like.

Thermal expansion coefficient of the glass powder is preferably 70~100 × ^{10 -7} / K value of the thermal expansion coefficient alpha _{50 to 350} in the range of 50 to 350 ° C., more preferably 72~90 × ^{10 -7} / K. Within this range, it is preferable because it matches the thermal expansion coefficient of the glass substrate and can reduce the stress applied to the glass substrate during firing.

As a bismuth-based glass powder composition satisfying such characteristics, Bi ₂ O ₃ is preferably blended in the range of 70 to 95% by weight in terms of oxide. More preferably, it is 73 to 85 weight%. If it is less than 70% by weight, the etching resistance to acid is weak, and it dissolves. If it exceeds 95% by weight, the heat-resistant temperature of the glass becomes low, and baking on the glass substrate becomes difficult. Moreover, when it exceeds 85 weight%, it will become difficult to vitrify.

SiO ₂ is preferably blended in the range of ₃ to 15% by weight. When it is less than 3% by weight, vitrification becomes difficult. If it exceeds 15% by weight, the glass softening point becomes high and baking on the glass substrate becomes difficult.

B ₂ O ₃ is preferably 5 to 20 wt%. More preferably, it is 7 to 15% by weight. By including B ₂ O ₃ , electrical, mechanical and thermal characteristics such as electrical insulation, strength, thermal expansion coefficient, and denseness can be adjusted. If it exceeds 20% by weight, the stability of the glass with respect to acid and water decreases.

ZrO ₂ is preferably contained in the range of 0 to 3% by weight, more preferably 0.01 to 2.5% by weight, and still more preferably 0.01 to 1% by weight. ZrO ₂ improves the acid resistance of the glass material, but if it exceeds 3% by weight, the glass becomes non-uniform and a residue is generated by etching with acid.

  ZnO is preferably 1 to 10% by weight, more preferably 2 to 5% by weight. If it is less than 1% by weight, the effect of improving the density is small, and if it exceeds 10% by weight, the baking temperature becomes low and it becomes difficult to control, and the insulation resistance also becomes low.

Terms of oxide expressed by 70 to 95 wt% of _Bi 2 _O 3, _3~15 wt% of _SiO 2, 5 to 20 wt% of _B 2 _O 3, _1~10 wt% of ZnO, 0 to 3 wt% By using a photosensitive paste composition containing glass powder having a composition range of ZrO ₂ , the glass can be atomized and the etching resistance to acid is increased, so that a higher definition pattern is possible.

Moreover, you may put a filler other than the said glass powder. Specific fillers include ceramic powders such as SiO ₂ , Al ₂ O ₃ , ZrO ₂ , mullite, spinel, magnesia, ZnO, titanium oxide, zircon, etc. These may be used alone or in combination. It may be used. The addition amount of the filler is preferably less than 15% by weight with respect to the total amount of inorganic components of the photosensitive paste composition. If it is more than that, cracking may occur during sintering or sintering may be insufficient. The filler is preferably one that does not melt during sintering.

  The average particle size of the filler to be used is preferably 0.01 to 0.5 μm, more preferably 0.01 to 0.05 μm. The strength of the fired member can be improved by adding a filler of 0.01 μm or more, and good photosensitive characteristics can be obtained by using a filler of 0.5 μm or less. The average particle diameter of the filler is determined by measuring the specific surface area by the BET method using nitrogen gas, then determining the particle diameter from the specific surface area assuming that the particles are spheres, and determining the average particle diameter as a number average.

  In the present invention, the photosensitive organic component has a binder polymer having a glass transition temperature (Tg) of 30 to 100 ° C. The Tg of the binder polymer is more preferably 40 to 95 ° C, still more preferably 60 to 90 ° C. By adjusting Tg to 30 ° C. or higher, the adhesiveness of the paste can be reduced, and by setting Tg to 100 ° C. or lower, the adhesiveness of the paste to the glass substrate can be maintained. On the other hand, if Tg exceeds 100 ° C., the pattern is likely to crack after the photosensitive paste composition film is exposed and developed.

  As the binder polymer, various polymers such as acrylic resin, epoxy resin, polyurethane resin, polyester resin, polyamide resin, polyimide resin, silicone resin, melamine resin, phenol resin, cellulose derivative, and polyvinyl alcohol can be used. Methacrylate, polyvinyl butyral, polyvinyl alcohol, ethyl cellulose, (meth) acrylic acid ester copolymer and the like are preferable. Furthermore, from the viewpoint of dispersibility and developability of the inorganic powder, in addition, from the viewpoint of pattern formation by photosensitivity, the binder polymer has a reactive functional group such as a carboxyl group, a hydroxyl group, and an ethylenically unsaturated double bond. It is preferable.

The glass transition temperature of the binder polymer can be controlled by the type of monomer to be copolymerized and the content ratio of the monomer constituting the polymer. In this case, the glass transition temperature of the binder polymer can be calculated from the glass transition temperature of each monomer homopolymer species constituting the binder polymer according to the following Fox equation.
Fox formula: 100 / Tg = Σ (Wn / Tgn)
Tg: glass transition temperature of binder polymer (absolute temperature)
Wn: Weight fraction (%) of each monomer homopolymer
Tgn: Glass transition temperature of each monomer homopolymer (absolute temperature)
In the present invention, monomers to be copolymerized may be selected according to the Fox formula so that the glass transition temperature of the binder polymer is 30 to 100 ° C., and they may be polymerized to obtain a binder polymer.

  The Tg of the obtained binder polymer was measured using a DSC-50 type measuring device manufactured by Shimadzu Corporation, and the sample was heated at a heating rate of 20 ° C./min under a nitrogen stream at a rate of 20 ° C./min. The temperature at which the seizure starts is defined as Tg.

  As the glass transition temperature of each monomer homopolymer, for example, technical data of a monomer manufacturer such as Mitsubishi Rayon Co., Ltd., or a polymer data handbook (published by Baifukan, edited by the Society of Polymer Science (Basics), 1986 The first edition of the month). For example, methyl methacrylate (105 ° C), methacrylic acid (228 ° C), ethyl acrylate (-22 ° C), glycidyl methacrylate (74 ° C), methyl acrylate (10 ° C), styrene (100 ° C), etc. .

  Moreover, it is preferable that the thermal decomposition temperature of a binder polymer is 500 degrees C or less, Furthermore, it is 450 degrees C or less, 150 degreeC or more, More preferably, it is 400 degreeC or more. When a binder polymer having a thermal decomposition temperature of 150 ° C. or higher is used, the thermal stability of the photosensitive paste composition is maintained, and in each step from applying the paste to pattern processing, it is good without impairing the photosensitivity. Pattern processing is possible. If a binder polymer of 500 ° C. or lower is used, cracks, peeling, warping and deformation in the firing process can be prevented. The technique for adjusting the thermal decomposition temperature of the binder polymer can be achieved by selecting a monomer as a copolymerization component. In particular, by using a monomer that thermally decomposes at a low temperature as a copolymerization component, the thermal decomposition temperature of the copolymer can be lowered. Examples of components that thermally decompose at a low temperature include methyl methacrylate, isobutyl methacrylate, α-methylstyrene, and the like. The thermal decomposition temperature is set with a sample of about 20 mg using a TG measuring device (TGA-50, manufactured by Shimadzu Corporation), the flow rate is 20 ml / min in an air atmosphere, and the heating rate is 0.6 to 20 ° C./min. The temperature is raised to 700 ° C. As a result, a chart plotting the relationship between temperature (vertical axis) and weight change (horizontal axis) is printed, and the tangent line between the part before decomposition (part parallel to the horizontal axis) and the part under decomposition is drawn, and the intersection The temperature can be measured by a method such as the thermal decomposition temperature.

  Furthermore, the weight average molecular weight of the binder polymer used is preferably 3000 to 100,000. More preferably, it is 5,000 to 80,000. By setting the weight average molecular weight to 3000 to 100,000, the solubility of the developer is maintained, and as a result, finer patterning becomes possible. If it is less than 3000, the alkali solubility is too high and a good pattern cannot be obtained, and the tackiness deteriorates. In addition, since the viscosity of the binder polymer increases in proportion to the weight average molecular weight, in order to reduce the viscosity of the photosensitive paste and maintain the workability in the filtration, degassing and coating processes, the weight of the binder polymer It is preferable to lower the average molecular weight. The weight average molecular weight of the binder polymer was measured by size exclusion chromatography using tetrahydrofuran as a mobile phase. The column was Shodex KF-803, and the weight average molecular weight was calculated in terms of polystyrene.

  The content of the binder polymer in the photosensitive organic component is preferably 1 to 50% by weight with respect to the photosensitive organic component. More preferably, it is 5 to 40% by weight. By setting the content in the range of 1 to 50% by weight, it is possible to achieve both pattern processability and characteristics such as shrinkage during firing.

  In the present invention, the photosensitive agent contained in the photosensitive organic component may be a negative type that is cured by light or a positive type that is solubilized by light. In the present invention, the photosensitive agent contained in the photosensitive organic component is one selected from the group consisting of a) an ethylenically unsaturated group-containing compound and a photopolymerization initiator, b) a glycidyl ether compound, an alicyclic epoxy compound, and an oxetane compound. One or more compounds selected from the above cationic polymerizable compounds and photocationic polymerization initiators, c) quinonediazide compounds, diazonium compounds and azide compounds are preferably used. For the selected photosensitizer, the type of binder polymer is not particularly limited.

  The ethylenically unsaturated group-containing compound in component a) is preferably a (meth) acrylic compound because of its abundance of variations. The content of the ethylenically unsaturated group-containing compound is preferably 50 to 99% by weight, more preferably 60 to 90% by weight, based on the photosensitive organic component. By making it 50% by weight or more, fine pattern processing becomes possible, and by making it 99% by weight or less, the pattern shape after firing can be kept good. Moreover, it is preferable to use what has a sensitivity especially to visible light with a wavelength of 400-450 nm among photopolymerization initiators of a) component, and these can be used 1 type (s) or 2 or more types in this invention. A photoinitiator is added in 0.05-50 weight% with respect to the photosensitive organic component, More preferably, it is 1-35 weight%. Within this range, the sensitivity is good and the remaining ratio of the exposed portion can be increased.

  The component b) contains one or more cationically polymerizable compounds and a photocationic polymerization initiator selected from the group consisting of glycidyl ether compounds, alicyclic epoxy compounds, and oxetane compounds. The proportion of the glycidyl ether compound in the photosensitive organic component is preferably 1 to 75% by weight, more preferably 5 to 35% by weight. By making it within this range, the pattern shape can be kept good. The amount of the cationic photopolymerization initiator used is preferably in the range of 0.01 to 15% by weight in the photosensitive organic component.

  As the component c), one or more compounds selected from diazonium compounds and azide compounds are preferably used. The proportion of the quinonediazide compound in the photosensitive organic component is preferably 1 to 96% by weight, more preferably 3 to 80% by weight. When the quinonediazide compound is less than 1% by weight, the change in solvent solubility due to the quinonediazide compound during exposure is reduced, resulting in poor pattern formation. On the other hand, when it is more than 96% by weight, the amount of low molecular weight components is increased. Dispersion is poor and it becomes difficult to obtain a paste. The proportion of the diazonium compound in the photosensitive organic component is preferably 5 to 80% by weight, more preferably 10 to 50% by weight. If the amount of the diazonium compound is too small, curing may be insufficient. Conversely, if the amount is too large, a problem may occur in the storage stability of the composition. The proportion of the azide compound in the photosensitive organic component is preferably 5 to 70% by weight, more preferably 10 to 50% by weight. When the amount of the azide compound is too small, curing of the photosensitive component may be insufficient, and when the amount is too large, the stability of the composition may be adversely affected.

  Moreover, you may add cage-like silsesquioxane to the photosensitive paste composition in order to maintain the pattern shape at the time of baking.

  A preferable binder polymer in the case of using the component a) as a photosensitive agent contained in the photosensitive organic component is a binder obtained by copolymerization of the above-described ethylenically unsaturated double bond-containing compound or by copolymerization. It can be obtained by adding an ethylenically unsaturated group-containing compound having a reactive functional group to a part of the reactive functional group of the polymer. Specifically, a carboxyl group and an ethylenically unsaturated double bond are obtained by adding an epoxy group-containing acrylate compound such as glycidyl methacrylate to a part of the carboxyl group of a binder polymer having an unsaturated carboxylic acid as a copolymer component. A binder polymer having is obtained.

  Specific examples of the preferred binder polymer include those obtained by adding glycidyl methacrylate to a methyl methacrylate-methacrylic acid-styrene copolymer, and those obtained by adding glycidyl methacrylate to an isobutyl methacrylate-2-ethylhexyl methacrylate-acrylic acid copolymer. And those obtained by adding glycidyl methacrylate to an ethyl acrylate-methyl acrylate-methacrylic acid copolymer, and those obtained by adding glycidyl methacrylate to a methyl methacrylate-methacrylic acid-ethyl acrylate copolymer. Of these, methyl methacrylate-methacrylic acid-styrene copolymer added with glycidyl methacrylate, methyl methacrylate-methacrylic acid-ethyl acrylate copolymer added with glycidyl methacrylate, methyl methacrylate-methacrylic acid-ethyl acrylate A copolymer obtained by adding glycidyl methacrylate to the copolymer is particularly preferable, and a copolymer obtained by adding glycidyl methacrylate to a copolymer of methyl methacrylate-methacrylic acid-ethyl acrylate is preferable.

  The acid value of such a binder polymer is preferably 50 to 140 (mgKOH / g). By setting the acid value to 140 or less, the allowable development width can be widened, and by setting the acid value to 50 or more, the solubility in the alkali developer in the unexposed area is maintained, and a high-definition pattern is obtained. be able to. The acid value is measured by dissolving 1 g of the binder polymer in 100 mL of ethanol and then titrating with a 0.1N aqueous potassium hydroxide solution. Furthermore, the double bond density of the binder polymer is preferably 0.1 to 2.7 mmol / g, more preferably 0.2 to 1.6 mmol / g. When the double bond density is less than 0.1 mmol / g, pattern formation by exposure is not sufficient, film loss is large, and developability is remarkably deteriorated. On the other hand, in the range exceeding 2.7 mmol / g, cracks, peeling, warping, etc. occur in the firing step.

  In the present invention, a photosensitive paste composition containing an organic solvent is applied onto a substrate to form a film, and then dried to remove the solvent.

  As a method for drying the film of the photosensitive paste composition, a commonly used method such as a hot air oven, far-infrared rays, hot plate, natural drying, reduced-pressure drying or the like can be used, but a hot-air oven or far infrared rays should be used. Is preferred. With this method, the film of the photosensitive paste composition can be dried uniformly in the depth direction.

  The drying temperature is not particularly limited as long as the photosensitive organic substance does not cause thermal polymerization. However, the drying time is longer at a room temperature level. If the drying temperature is too high, the photosensitive monomer or oligomer may be thermally decomposed. From such a point, the range of 40 to 150 ° C is preferable in the present invention, and more preferably 60 to 120 ° C. Here, the drying temperature means the temperature of hot air in the case of a hot air oven, for example.

  In addition, it is important to control the residual amount of the organic solvent in the photosensitive paste composition before exposure to 3% by weight or less, preferably 1% by weight or less. When it exceeds 3% by weight, tackiness is deteriorated.

  In addition, a precaution during drying is to keep the substrate coated with the photosensitive paste composition film horizontal. This is because when the substrate is tilted, the paste flows and film thickness unevenness occurs.

  It is preferable that the tack value of the film | membrane of the photosensitive paste composition obtained by drying by this invention is either 0-4. Within this range, tackiness is suppressed, and contact exposure can be easily used. If it is outside this range, pinholes may occur in the film of the photosensitive paste composition, or the photosensitive paste composition may adhere to the photomask, which may make it difficult to perform contact exposure. Contact exposure is possible by using a film of the photosensitive paste composition having a tack value of 0 to 4, and as a result, a gap is formed between the film of the photosensitive paste composition and the photomask. Higher-definition pattern formation is possible than in the case of the alignment method in which the is provided. Furthermore, since the labor for cleaning the photomask can be reduced, the cost can be reduced.

  The tack value depends on the glass transition temperature of the binder polymer, the molecular weight of the binder polymer, the amount of the organic solvent, the ratio of inorganic particles in the photosensitive paste composition, and the like, but is greatly influenced by the glass transition temperature of the binder polymer.

  By using a photosensitive paste composition in which the glass transition temperature of the binder polymer contained in the photosensitive organic component is 30 to 100 ° C., the tack value can be kept in the range of 0 to 4.

  Evaluation of the tack value in the present invention is as follows. A photosensitive paste composition is uniformly and entirely coated on a glass substrate using screen printing, and a film of the photosensitive paste composition is prepared by drying in a hot air oven. Drying in a hot air oven was performed at 85 ° C. for 20 minutes. The size of the substrate to be evaluated is a size that can be used in the tilting ball tack device described in JIS Z 0237 (2000). In the evaluation, 30 ° was used as the inclination angle. The ball size of the material specified in JIS G 4805 (1999) is a total of 31 types from 1/16 to 1 of “Ball Nominal” in JIS B 1501 (Showa 63) (5/64, 7 / 64, 9/64, 15/64, and 17/64 are excluded), and the value 32 times the “ball nominal” is called the ball number, which is used as an index of tackiness. A glass plate (thickness 1.3 mm, 12.5 cm square) with the photosensitive paste composition applied surface is attached to a predetermined position on the inclined plate of the inclined ball tack device, and balls of various sizes are gated. After slowly setting the gate, roll the ball slowly, find the largest ball that stops completely in the measuring section (the ball does not move for more than 5 seconds), and determine the ball number at that time. It was set as the tack value of the photosensitive paste composition. Even when the smallest ball did not stop, it was set to 0. A glass plate having the same thickness as that of the glass coated with the photosensitive paste composition was placed on the runway, and a PET film having a thickness of 20 μm was stuck thereon. In addition, the measurement was performed in a black screen so that the paste was not exposed.

  The refractive index of the photosensitive organic component contained in the photosensitive paste composition of the present invention is in the range of 1.4 to 1.7, and within the refractive index range of the glass powder, the refractive index difference is 0.3. It is very large with ~ 1.3. However, the photosensitive organic component contains a compound that absorbs the exposure wavelength, emits light having a wavelength longer than the exposure wavelength, and the emitted light cures or solubilizes the photosensitive organic component (hereinafter referred to as compound (A)). If this is the case, the same effect as that when the difference in refractive index is small will be achieved. Originally, it is desirable that the refractive index difference is small, but when the refractive index difference has to be large, especially when the average refractive index of the inorganic powder is N1 and the average refractive index of the photosensitive organic component is N2, | N1 Even when −N2 | ≧ 0.29, the compound (A) is contained, and the compound (A) absorbs ultraviolet rays to suppress scattering and is longer than ultraviolet rays irradiated with high transparency. By emitting fluorescence with a wavelength from the compound (A), it is possible to cure a portion far from the exposure surface. When | N1-N2 | <0.29, the light beam is hardly scattered and the portion far from the exposure surface is also cured, so that the effect of containing the compound (A) is reduced. The photosensitive organic component is cured or solubilized by the action of both exposure and light emitted from the compound (A).

  The compound (A) used in the present invention is preferably a compound that absorbs ultraviolet rays and emits blue fluorescence. Examples of the compound (A) used in the present invention include fluorescent whitening agents such as coumarin fluorescent whitening agents, oxazole fluorescent whitening agents, stilbene fluorescent whitening agents, imidazole fluorescent whitening agents, and triazole fluorescent whitening agents. Agents, imidazolone-based, oxacyanine-based, methine-based, pyridine-based, anthrapyridazine-based, and carbostyril-based fluorescent whitening agents are used, and compounds selected from a) to c) contained in the photosensitive organic component, Since compatibility with a binder polymer etc. is good, Preferably a coumarin type | system | group fluorescent whitening agent or an oxazole type | system | group fluorescent whitening agent is used. If these compounds are used, they function effectively. In particular, a coumarin-based optical brightener is preferable because of its high solubility in polar solvents. The solubility of the compound (A) in the polar solvent is preferably 2 g / 100 g solvent or more, more preferably 50 g / 100 g solvent or more. From the viewpoint of solubility, a coumarin derivative is particularly preferable. These may be used alone or in combination.

  The content of the compound (A) in the present invention is preferably 0.1 to 30% by weight with respect to the photosensitive organic component, and particularly preferably 2 to 20% by weight in the field emission member and fluorescent light emitting device described later. 5 to 15% by weight is more preferable. Within this range, fine pattern processing is possible.

  The absorption wavelength range for absorbing the ultraviolet rays of the compound (A) used in the present invention is a wavelength range of 320 to 410 nm, more preferably a wavelength range of 350 to 380 nm, and still more preferably 360 to 375 nm. Moreover, the fluorescence emission wavelength region of the compound (A) is a wavelength region of 400 to 500 nm, more preferably a wavelength region of 400 to 450 nm, and further preferably 430 to 445 nm. If it is within this range, it effectively absorbs ultraviolet rays at the time of exposure, suppresses scattering, and emits fluorescence in the above wavelength range, which is more transmissive than the irradiated ultraviolet rays, to the deep part, that is, the part far from the exposure surface The photosensitive organic component can be cured.

  Moreover, it is preferable that the molar extinction coefficient of a compound (A) is 20000 or more in the range of content of the said compound (A). Moreover, it is preferable that it is 60000 or less. In this range, it is possible to effectively absorb ultraviolet rays, suppress scattering of ultraviolet rays during exposure, and cure the photosensitive organic component to a deeper portion.

  Absorption wavelength of ultraviolet rays, emission wavelength of fluorescence and molar extinction coefficient were measured with a spectrofluorometer (F-2500, manufactured by Hitachi, Ltd.) and an ultraviolet-visible spectrophotometer (MultiSpec 1500, manufactured by Shimadzu Corporation). It can be measured.

  In the present invention, the coumarin fluorescent whitening agent has a coumarin structure represented by the following formula in the molecule. Specific examples of the coumarin fluorescent brightener include 7-diethyldiamino-4-methylcoumarin, 7-hydroxy-4-methylcoumarin, 7-ethylamino-4-methylcoumarin, 7-dimethylamino-4- Examples thereof include methylcoumarin and 7-amino-4-methylcoumarin.

  It is also effective to add an ultraviolet absorber to the photosensitive paste composition of the present invention. Unlike the purpose of using the compound (A), the purpose of adding the ultraviolet absorber is to suppress the amount of ultraviolet light that passes through the film of the photosensitive paste composition. When the amount of ultraviolet rays is large, the margin of exposure conditions becomes narrow. Moreover, high aspect ratio, high definition, and high resolution can be obtained by adding an absorbent having a high ultraviolet absorption effect. As the ultraviolet absorber, an organic dye, particularly an organic dye having a high UV absorption coefficient in a wavelength range of 350 to 450 nm is preferably used. Even when an organic dye is added as an ultraviolet absorber, it is preferable because it does not remain in the glass film after firing and the deterioration of the insulating film characteristics due to the ultraviolet absorber can be reduced. As such a compound, an azo dye or a benzophenone dye is preferable because the absorption wavelength can be easily controlled in a desired wavelength region. The addition amount of the organic dye in the photosensitive organic component is preferably 0.05 to 5% by weight with respect to the photosensitive organic component. More preferably, it is 0.1 to 1 weight%. If it is less than 0.05% by weight, the effect of adding an ultraviolet absorber is reduced, and if it exceeds 5% by weight, the properties of the insulating film after firing are deteriorated.

  A sensitizer is added in order to improve sensitivity. In the present invention, one or more of these can be used. Some sensitizers can also be used as photopolymerization initiators. When adding a sensitizer, the addition amount is preferably 0.05 to 30% by weight, more preferably 0.1 to 20% by weight, based on the photosensitive component. If the amount of the sensitizer is too small, the effect of improving the photosensitivity is not exhibited, and if the amount of the sensitizer is too large, the residual ratio of the exposed portion may be too small.

  Furthermore, it is preferable to add a polymerization inhibitor. When adding a polymerization inhibitor, the addition amount is preferably 0.001 to 1% by weight with respect to the photosensitive paste composition.

  Moreover, you may add a plasticizer and antioxidant. When adding a plasticizer, the addition amount is preferably 0.5 to 10% by weight with respect to the photosensitive paste composition. When adding antioxidant, the addition amount is preferably 0.001 to 1% by weight with respect to the photosensitive paste composition.

  The average refractive index of the photosensitive organic component is determined by the following method. The photosensitive organic component is coated on glass and dried, and then directly measured using an ellipsometer. Measuring the refractive index at the exposure wavelength is accurate in confirming the effect. In particular, it is preferable to measure with light in the wavelength range of 350 to 650 nm. Furthermore, refractive index measurement with i-line (365 nm) or g-line (436 nm) is preferable. Alternatively, first, the refractive index at a desired wavelength is measured for each component constituting the photosensitive organic component by the V block method. Next, it is obtained by adding the respective refractive indexes according to the weight% of the photosensitive organic component. For example, a certain photosensitive organic component is composed of A (50% by weight) and B (50% by weight), A has a refractive index at a certain wavelength of 1.46, and B has a refractive index at the same wavelength as A. In the case of 1.58, the average refractive index of the photosensitive organic component is (1.46 × 0.5) + (1.58 × 0.5) = 0.73 + 0.79 = 1.52.

  The photosensitive paste composition of the present invention can be prepared as follows. The photosensitive organic component is mixed with a binder polymer having a glass transition temperature of 30 to 100 ° C. and, if necessary, a compound selected from the components a) to c), a compound (A), various additives, etc., and then filtered. Prepare an organic vehicle. To this, pretreated glass powder is added as necessary, and homogeneously mixed and dispersed by a kneader such as a ball mill to produce a photosensitive paste composition.

  The viscosity of the photosensitive paste composition is appropriately adjusted depending on the addition ratio of inorganic components, thickeners, organic solvents, plasticizers, precipitation inhibitors, etc., but the range is 2 to 200 Pa · s (Pascal · seconds). . For example, when applying to a glass substrate by a spin coat method, 2-5 Pa.s is preferable. In order to obtain a film thickness of 10 to 20 μm by applying it once by the screen printing method, 50 to 200 Pa · s is preferable. In the case of using a blade coater method or a die coater method, 2 to 20 Pa · s is preferable.

  Examples of the organic solvent used to adjust the viscosity of the paste include methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, and 3-methoxy-3-methyl-1. -Butanol, tetrahydrofuran, dimethyl sulfoxide, γ-butyrolactone, bromobenzene, chlorobenzene, dibromobenzene, dichlorobenzene, bromobenzoic acid, chlorobenzoic acid, etc., and organic solvent mixtures containing one or more of these are used .

  The photosensitive paste composition of the present invention is preferably used for various members of a flat panel display, a fluorescent light emitting tube (cold cathode tube) member, and the like, but is particularly preferable as a field emission member typified by an insulating layer of a field emission display. Used.

  Field emission refers to field emission. Field emission refers to a cathode made of a conductor such as a semiconductor or metal in a vacuum, and when an anode is placed near the surface, electrons move from the cathode surface toward the anode in vacuum. A physical phenomenon that is released into In the present invention, the field emission member refers to a member using such field emission. Specific examples include, but are not limited to, field emission displays, backlights for liquid crystal displays, field emission lamps, electron beam sources for scanning electron microscopes, and micro vacuum tubes.

  When manufacturing a field emission member from the photosensitive paste composition of this invention, it is preferable to use a glass substrate as a board | substrate. As the glass substrate, soda lime glass or heat resistant glass (PD200 manufactured by Asahi Glass Co., Ltd., PP8 manufactured by Nippon Electric Glass Co., Ltd., CS25 manufactured by Saint-Gobain Co., Ltd., CP600V manufactured by Central Glass Co., Ltd.) can be preferably used. Moreover, a ceramic substrate, a metal substrate, a semiconductor substrate (AlN, CuW, CuMo, SiC substrate, etc.), and various plastic films can also be used. On these substrates, if necessary, one or more insulators, semiconductors, and conductors, or a combination thereof may be formed.

  Next, as an example, a method for manufacturing a field emission member will be described with reference to a method for manufacturing an insulating layer of a field emission display.

  As a substrate, a photosensitive paste composition is applied over the whole or a part of a glass substrate on which an ITO electrode is formed. As a coating method, general methods such as screen printing, bar coater, roll coater, and slit die coater can be used. The coating thickness can be adjusted by selecting the number of coatings, the screen mesh, and the viscosity of the photosensitive paste composition. However, in consideration of shrinkage due to drying or baking, the thickness after drying is 5 to 100 μm, preferably 5 to 60 μm. More preferably, it is preferably applied so as to be 5 to 40 μm.

  When the photosensitive paste composition is applied a plurality of times, the photosensitive paste composition to be applied for the first time and the second and subsequent times may be the same photosensitive paste composition or different photosensitive paste compositions. It may be. Moreover, when apply | coating the photosensitive paste composition in multiple times, it is preferable to dry after application | coating of the photosensitive paste composition of the 1st time, and before application | coating of the photosensitive paste composition of the 2nd time or later. If it does so, the photosensitive paste composition apply | coated 1st time will dry, and the reduction | decrease of the thickness of the coating film at the time of the 2nd photosensitive paste composition application | coating can be prevented. The drying temperature and time vary depending on the composition of the photosensitive paste composition, but it is preferably applied at 50 to 100 ° C. for about 5 to 30 minutes. Moreover, it is desirable to perform drying with a hot air oven or far infrared rays.

Based on the evaluation method described above, tackiness is evaluated, and then a pattern is formed by performing exposure and development using a glass substrate on which the photosensitive paste composition has been applied entirely or partially. The shape of the pattern varies depending on the field emission member. In the case of the insulating layer of the field emission display, a pattern including a circular hole having a diameter of 3 to 100 μm or a square having a side of 3 to 100 μm is formed. More preferably, it is 3-50 micrometers, More preferably, it is 3-20 micrometers. If it exists in this range, the effect of the photosensitive paste composition can fully be exhibited. For the exposure, a method of exposing using a photomask and a method of direct drawing exposure using a laser beam or the like can be used. However, exposure using a photomask can shorten the exposure time. As an exposure apparatus in this case, a stepper exposure machine, a proximity exposure machine, or the like can be used. Examples of the active light source used include visible light, near ultraviolet light, ultraviolet light, near infrared light, electron beam, X-ray, and laser light. Among these, ultraviolet light is preferable, and as the light source, for example, Low pressure mercury lamp, high pressure mercury lamp, super high pressure mercury lamp, halogen lamp, germicidal lamp, etc. can be used. Among these, an ultrahigh pressure mercury lamp is suitable. Although exposure conditions vary depending on the coating thickness, exposure is performed for 0.5 to 30 minutes using an ultrahigh pressure mercury lamp having an output of 5 to 1000 W / m ² . In particular, it is preferable to perform exposure with an exposure amount of about 0.05 to 1 J / cm ² .

  Thereafter, development is performed using a developing solution. In this case, the immersion method, the spray method, the shower method, and the brush method are used. Among these, the shower method is preferable in that uniform development can be realized. The flow rate and pressure of the developer when developing by the shower method vary depending on the type and concentration of the developer, but the flow rate is preferably 50 to 200 ml / min, more preferably 100 to 170 ml / min. The pressure is preferably 0.05 to 0.2 MPa, more preferably 1 to 1.6 kg / min. As the developer, an organic solvent or an aqueous solution in which an organic component in the photosensitive paste composition can be dissolved or dispersed is used. Further, an aqueous solution containing an organic solvent may be used. When the photosensitive paste composition contains a compound having a functional group such as a carboxyl group, a phenolic hydroxyl group, or a silanol group, it can be developed even in an alkaline aqueous solution. A metal alkali aqueous solution such as sodium hydroxide, calcium hydroxide, sodium carbonate aqueous solution or the like can be used as the alkaline aqueous solution. However, it is preferable to use an organic alkaline aqueous solution because an alkaline component can be easily removed during firing. As the organic alkali, a general amine compound can be used. Specific examples include tetramethylammonium hydroxide, trimethylbenzylammonium hydroxide, monoethanolamine, and diethanolamine. The concentration of the alkali component in the aqueous alkali solution is preferably 0.01 to 10% by weight, more preferably 0.1 to 5% by weight. If the alkali concentration is too low, the unexposed portion is not removed, and if the alkali concentration is too high, the pattern portion may be peeled off and the exposed portion may be corroded. It is preferable in terms of process control that the temperature of the developer during development is 20 to 50 ° C.

  In addition, it is preferable to add a surfactant to the developer in order to improve the wettability of the photosensitive paste composition to the coating film, the uniformity of development and the reduction of residues. As the surfactant, nonionic, anionic, cationic, and amphoteric surfactants can be used. The addition amount of the surfactant is preferably in the range of 0.01 to 20% by weight, more preferably 0.05 to 10% by weight, and still more preferably 0.1 to 5% by weight. If the addition amount exceeds 20% by weight, the developability may be insufficient. If the addition amount is less than 0.01% by weight, the effect of adding a surfactant may be difficult to be exhibited.

  Moreover, it is preferable to perform ultrasonic treatment in a developing solution at the time of development, and further, frequency modulation ultrasonic treatment in which frequency modulation ultrasonic treatment is modulated in a wavelength range of 20 to 50 KHz is particularly preferable. By such ultrasonic treatment, a great effect can be obtained in forming a fine and uniform pattern and reducing the residue.

  By the method as described above, a pattern including a circular hole having a thickness of 5 to 100 μm and a diameter of 3 to 100 μm or a side of 3 to 100 μm can be formed on the substrate from the photosensitive paste composition of the present invention. .

  Thereafter, directly or as necessary, after forming a gate electrode, an emitter, or the like, baking is performed in a baking furnace. The firing atmosphere, temperature, and time can be appropriately selected depending on the type of the photosensitive paste composition and the substrate, and firing is performed in an atmosphere of air, nitrogen, hydrogen, or the like. Baking is performed by holding at a temperature of 400 to 600 ° C. for 10 to 60 minutes. As the firing furnace, a batch-type firing furnace or a belt-type continuous firing furnace can be used. Moreover, you may heat at 50-300 degreeC in the above each process for the purpose of drying and a preliminary reaction.

  Through the above steps, an insulating layer for a field emission display having a pattern including a circular hole having a thickness of 5 to 100 μm and a diameter of 3 to 100 μm or a square of 3 to 100 μm on one side formed on the substrate is obtained. In order to reduce the voltage of the field emission display, it is necessary to make the distance between the gate electrode portion and the electron-emitting device closer. Therefore, the thickness of the insulating layer is preferably 30 μm or less. In addition, in order to achieve high resolution and uniform luminance, the holes formed in the insulating layer are preferably 30 μm or less.

  The gate electrode is formed by the following method. After obtaining an insulating layer on which a desired pattern is formed, a chromium film is formed by uniformly forming a chromium-based thin film by sputtering or vapor deposition. Alternatively, pattern formation may be performed using a photosensitive conductor paste or the like. Next, a positive resist is applied to the entire surface of the chromium film by a known coating method such as spin coating or screen printing, and prebaked with a hot plate or the like. Next, a photomask with a desired pattern is placed on the chromium film provided with the above resist layer, and an etching mask is formed from the positive resist remaining on the chromium film through the steps of ultraviolet irradiation, exposure and development. To do. Next, the chromium film that is not covered with the etching mask is etched for several minutes with an acidic etching solution (cerium nitrate cerium nitrate: 9 wt% + perchloric acid: 6 wt%, etc.). Remove the part. Thereafter, the etching mask is peeled off using a peeling solution and washed with water, whereby a chromium film in which only unnecessary portions are etched remains, and a gate electrode is formed. At this time, it is necessary that the insulating layer on which a desired pattern is formed is difficult to dissolve in the etching solution.

  The electron-emitting device is formed by the following method. The formation method differs depending on the electron emission source. In the case of a Spindt type metal chip (or microchip) mainly made of molybdenum, the vapor deposition method is used. In the case of using CNT, a photosensitive CNT paste is used inside the pattern. A step of irradiating light from the rear surface of the substrate after being applied by a screen printing method or the like, and selectively exposing only a portion inside the pattern of the CNT paste, and a portion of the CNT paste that is not exposed. Is formed by a method of leaving the exposed CNTs.

  In addition to such an insulating layer and gate electrode, the substrate on which the electron-emitting device is formed is used as a back plate, and after sealing with a separately manufactured front plate, wiring is performed and high brightness and contrast are achieved. A high field emission display can be obtained.

  Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited to this. The concentration in Examples and Comparative Examples is% by weight unless otherwise specified.

  The materials used for the photosensitive paste composition are as follows.

Organic component <Binder polymer I>
Weight average obtained by addition reaction of 0.4 equivalent of glycidyl methacrylate (GMA) to a carboxyl group of a copolymer composed of 40 parts by weight of methyl methacrylate, 30 parts by weight of ethyl acrylate, and 30 parts by weight of methacrylic acid It is a polymer having a molecular weight of 18000, an acid value of 111 mgKOH / g, a double bond density of 1.4 mmol / g, and a viscosity of 13.4 Pa · s. The thermal decomposition temperature was 422 ° C. and Tg was 38 ° C.

  The weight average molecular weight of the binder polymer was measured by size exclusion chromatography using tetrahydrofuran as a mobile phase. The column was Shodex KF-803, and the weight average molecular weight was calculated in terms of polystyrene.

  The acid value was determined by dissolving 1 g of the binder polymer in 100 mL of ethanol and then titrating with a 0.1N potassium hydroxide aqueous solution.

  The viscosity was measured with a rotational viscometer (RVDVII +, manufactured by Brookfield) at a temperature of 25 ± 0.1 ° C., a rotational speed of 10 rpm, and a viscosity 5 minutes after the start of measurement.

  The thermal decomposition temperature is set with a sample of about 20 mg using a TG measuring device (TGA-50, manufactured by Shimadzu Corporation), the flow rate is 20 ml / min in an air atmosphere, and the heating rate is 0.6 to 20 ° C./min. The temperature is raised to 700 ° C. As a result, a chart in which the relationship between temperature (vertical axis) and weight change (horizontal axis) is plotted is printed, the tangent line between the part before decomposition and the part during decomposition is drawn, and the temperature at the intersection is defined as the thermal decomposition temperature. . The glass transition point is determined by using a DSC-50 type measuring device manufactured by Shimadzu Corporation, raising the temperature at a rate of temperature increase of 20 ° C./min under a sample weight of 10 mg under a nitrogen stream, and starting the deviation of the baseline. Tg.

<Binder polymer II>
Weight average obtained by addition reaction of 0.4 equivalent of glycidyl methacrylate (GMA) to a carboxyl group of a copolymer composed of 40 parts by weight of methyl methacrylate, 20 parts by weight of ethyl acrylate, and 40 parts by weight of methacrylic acid It is a polymer having a molecular weight of 16000, an acid value of 105 mgKOH / g, a double bond density of 2.5 mmol / g, and a viscosity of 11.2 Pa · s. The thermal decomposition temperature was 430 ° C. and Tg was 74 ° C.

<Binder polymer III>
A weight-average molecular weight of 31000 obtained by addition reaction of 0.4 equivalent of glycidyl methacrylate (GMA) to a carboxyl group of a copolymer comprising 50 parts by weight of methyl methacrylate, 30 parts by weight of styrene, and 20 parts by weight of methacrylic acid. , An acid value of 58 mgKOH / g, a double bond density of 1.4 mmol / g, and a viscosity of 7.7 Pa · s. The thermal decomposition temperature was 421 ° C and Tg was 94 ° C.

<Binder polymer IV>
Weight average obtained by addition reaction of 0.4 equivalent of glycidyl methacrylate (GMA) to a carboxyl group of a copolymer composed of 30 parts by weight of methyl acrylate, 40 parts by weight of ethyl acrylate, and 30 parts by weight of methacrylic acid It is a polymer having a molecular weight of 17000, an acid value of 100 mgKOH / g, a double bond density of 1.5 mmol / g, and a viscosity of 8.2 Pa · s. The thermal decomposition temperature was 390 ° C. and Tg was 22 ° C.

<Binder polymer V>
Weight average molecular weight 22000 obtained by addition reaction of 0.4 equivalent of glycidyl methacrylate (GMA) to a carboxyl group of a copolymer composed of 50 parts by weight of methyl methacrylate, 30 parts by weight of styrene, and 20 parts by weight of methacrylic acid. , An acid value of 52 mg KOH / g, a double bond density of 0.34 mmol / g, and a viscosity of 13.3 Pa · s. The thermal decomposition temperature was 402 ° C. and Tg was 106 ° C.

<Binder polymer VI>
A weight average molecular weight of 34,000 obtained by addition reaction of 0.4 equivalent of glycidyl methacrylate (GMA) to a carboxyl group of a copolymer composed of 30 parts by weight of methyl methacrylate, 30 parts by weight of styrene, and 40 parts by weight of methacrylic acid. , An acid value of 102 mgKOH / g, a double bond density of 2.7 mmol / g, and a viscosity of 8.3 Pa · s. The thermal decomposition temperature was 433 ° C. and Tg was 118 ° C.

<Glass powder I>
As glass powder, Bi ₂ O ₃ (74 wt%), SiO ₂ (7.2 wt%), B ₂ O ₃ (10 wt%), ZnO (2.3 wt%), ZrO ₂ (2.2 wt%) %) And Al ₂ O ₃ (2.5% by weight) glass powder. This glass powder had a glass softening point of 509 ° C., an average particle size of 0.5 μm, a specific gravity of 5.86 _g / cm ³ , and a refractive index ( _ng ) of 2.15.

  The glass softening point is obtained by putting glass powder in a platinum cell, and using a differential thermal analyzer (TG8120, manufactured by Rigaku Denki Co., Ltd.), performing a differential thermal analysis at a temperature increase rate of 20 ° C./minute from room temperature to 700 ° C., The temperature at which the endotherm ends through the minimum point of the endothermic portion that appears first was defined as the softening point (Ts). The average particle diameter was measured using a laser diffraction / scattering measuring device (Microtrac particle size distribution meter HRA, manufactured by Nikkiso Co., Ltd.). The specific gravity was measured by processing the glass into a size of about 5 × 5 × 5 mm and using the Archimedes method.

  The refractive index was measured for light having a wavelength of 436 nm at 25 ° C. by ellipsometry using an ellipsometer after a glass film was formed on quartz glass.

<Glass powder II>
Bi ₂ O ₃ (82 wt%), SiO ₂ (4.9 wt%), B ₂ O ₃ (8.1 wt%), ZnO (1.5 wt%), ZrO ₂ (0.15 wt%) A glass powder having a composition of Al ₂ O ₃ (2.2% by weight) was used. This glass powder had a glass softening point of 462 ° C., an average particle diameter of 0.5 μm, a specific gravity of 6 g / cm ³ , and a refractive index ( _ng ) of 2.31.

<Glass powder III>
Bi ₂ O ₃ (77.2 wt%), SiO ₂ (6.9 wt%), B ₂ O ₃ (10.2 wt%), ZnO (2.5 wt%), ZrO ₂ (0 wt%) A glass powder having a composition of Al ₂ O ₃ (2.7% by weight) was used. This glass powder had a glass softening point of 493 ° C., an average particle diameter of 0.5 μm, a specific gravity of 6.1 g / cm ³ , and a refractive index ( _ng ) of 2.21.

<Glass powder IV>
Bi ₂ O ₃ (67 wt%), SiO ₂ (7.6 wt%), B ₂ O ₃ (13.7 wt%), ZnO (8 wt%), ZrO ₂ (0 wt%), Al ₂ O ₃ (3.2% by weight) of glass powder was used. This glass powder had a glass softening point of 534 ° C., an average particle size of 1.4 μm, a specific gravity of 5.4 g / cm ³ , and a refractive index ( _ng ) of 1.98.

<Glass powder V>
Bi ₂ O ₃ (70.2 wt%), SiO ₂ (9.7 wt%), B ₂ O ₃ (11.5 wt%), ZnO (3.8 wt%), ZrO ₂ (3.3 wt%) %) And Al ₂ O ₃ (4% by weight) glass powder. This glass powder had a glass softening point of 529 ° C., an average particle diameter of 0.5 μm, a specific gravity of 5.33 _g / cm ³ , and a refractive index ( _ng ) of 1.95.

<Glass powder VI>
As glass powder, Bi ₂ O ₃ (70 wt%), SiO ₂ (16 wt%), B ₂ O ₃ (9.2 wt%), ZnO (2.3 wt%), ZrO ₂ (0 wt%) A glass powder having a composition of Al ₂ O ₃ (2.5 wt%) was used. This glass powder had a glass softening point of 590 ° C., an average particle diameter of 1.6 μm, a specific gravity of 5.0 g / cm ³ , and a refractive index ( _ng ) of 1.95.

<Glass powder VII>
PbO (70 wt%), _SiO 2 (13 _{wt%), B 2 O 3 (} 10 wt%), ZnO (4% by weight), _ZrO 2 (0 _{wt%), Al 2 O 3 (} 3 wt%) Glass powder of composition was used. This glass powder had a glass softening point of 589 ° C., an average particle size of 1.2 μm, and a refractive index ( _ng ) of 2.11.

<Filler I>
As the filler, magnesia (manufactured by Ube Materials Co., Ltd.) having an average particle diameter of 70 nm was used.

  The average particle size was determined by measuring the specific surface area by the BET method using nitrogen gas, then determining the particle size from the specific surface area assuming that the particles are spheres, and determining the average particle size as the number average.

<Compound (A) I>
Coumarin derivative (manufactured by Nippon Kayaku Co., Ltd., trade name Kayight B) The maximum absorption wavelength of ultraviolet light in a 3-methoxy-3-methyl-1-butanol solution was 370 nm, and the maximum emission wavelength of fluorescence was 441 nm. .

<Compound (A) II>
Oxazole derivative (Nippon Kayaku Co., Ltd., trade name Kaylight O) The absorption maximum wavelength of ultraviolet light in a 3-methoxy-3-methyl-1-butanol solution was 374 nm, and the maximum emission wavelength of fluorescence was 436 nm. In Table 1, the compound that absorbs the exposure wavelength in the photosensitive organic component, emits light having a wavelength longer than the exposure wavelength, and the emitted light cures or solubilizes the photosensitive organic component is represented as compound (A). To do.

Example 1
As the photosensitive organic component, 7 parts by weight of an acrylic monomer (Nippon Kayaku Co., Ltd. Karayad TPA-330), which is an ethylenically unsaturated group-containing compound, and 7 parts by weight of the above binder polymer II (solvent (3-methyl- 10 parts by weight of 3-methoxybutanol), photopolymerization initiator (manufactured by Nippon Kayaku Co., Ltd., 2,4-dimethyl oxanthone and Ciba Specialty Chemicals, Inc., trade name Irgacure 369 at a weight ratio of 1: 2. 2 parts by weight, 3 parts by weight of compound (A) I, 0.2 parts by weight of ultraviolet light absorber (azo organic dye 4-aminoazobenzene: manufactured by Wako Pure Chemical Industries, Ltd.), and dispersant (San Nopco) 0.3 part by weight of a product name “Nopcosperth 092” manufactured by Co., Ltd. and 0.5 part by weight of a polymerization inhibitor (p-methoxyphenol) were used. The refractive index of the obtained photosensitive organic component was measured for light having a wavelength of 436 nm at 25 ° C. by an ellipsometry method using an ellipsometer after the coating and drying steps. The refractive index ( _ng ) was 1.52.

  Next, 80 parts by weight of glass powder II was mixed with the photosensitive organic component. This was passed 5 times with 3 rolls to prepare a photosensitive paste composition. The photosensitive paste composition was further filtered using a 400 mesh filter.

The photosensitive paste composition was uniformly applied on a glass substrate using screen printing, and was held at 80 ° C. for 15 minutes and dried to form 10 sheets of the photosensitive paste composition having a thickness of 15 μm. When the tack property of this paste film was evaluated, the tack value of 10 sheets was 0 or 2. Thereafter, a negative chrome mask having a 15 μm via pattern / 60 μm pitch was brought into direct contact with the paste film, and was exposed to ultraviolet light from the upper surface with an ultrahigh pressure mercury lamp having an output of 0.5 kW. The exposure amount was 0.5 J / cm ² . This was performed 10 times in sequence.

  Next, a 0.1% by weight aqueous solution of sodium carbonate maintained at 25 ° C. is developed for 50 seconds in a shower, and then washed with water using a shower spray to remove the non-light-cured portion and about 15 μm on the glass substrate. A via pattern having a hole diameter of 5 mm was formed.

  Of the 100 photomask via patterns, the ratio of pattern formation was evaluated as the via processing rate (%). The pattern formed here indicates a state where light is transmitted through a via of about 15 μm at a magnification of 500 times. As a result, 100 via patterns were formed on all 10 sheets, and the via processing rate was 100%. When the surface of this sample was observed, no cracks were observed in the pattern.

The substrate after pattern formation was heated to a temperature near the softening point of the glass powder at a temperature rising rate of 4 ° C./min, and held for 20 minutes for firing. Next, a chromium film having a thickness of 100 nm was formed on the patterned substrate after firing by sputtering. A positive photoresist (trade name AZ1500, manufactured by AZ Electronic Materials Co., Ltd.) was applied to the obtained patterned substrate with a chromium film by a spin coater method, and then baked at 100 ° C. for 1 minute. The film thickness of the photoresist was 1.5 μm. After that, using a negative chrome mask having a 25 μm via pattern / 60 μm pitch, a 37.5 μm via pattern / 90 μm pitch, UV exposure was performed from the top surface with an ultra-high pressure mercury lamp with an output of 0.5 kW. The exposure amount was 100 mJ / cm ² .

  Next, after dipping and shaking for 60 seconds in a resist developer maintained at 25 ° C. (trade name AZ400K manufactured by AZ Electronic Materials Co., Ltd. diluted 5 times), washed with pure water for 30 seconds, 120 ° C. for 2 minutes A resist pattern was obtained by performing post-baking. A chromium etching solution prepared with a composition of 9 wt% cerium nitrate cerium nitrate, 6 wt% perchloric acid, and 85 wt% pure water was kept at 25 ° C., immersed for 180 seconds, and then washed pure. After the chrome etching, the resist was removed by washing with acetone.

  Surface observation was performed using a scanning electron microscope (SEM) of the obtained patterned substrate after chromium etching, and the number of lumps having a size of 0.3 μm or more was visually observed in an area of 3 μm square at a magnification of 15,000. When the average value repeated 10 times was evaluated by changing the observation place, there was one lump having a size of 0.3 μm or more and few residues.

Example 2
Based on the composition described in Table 1, a photosensitive paste composition was prepared without using the compound (A) in Example 1, and the tack value, pattern processability, presence or absence of cracks after development, and residues after etching were determined. evaluated. The tack value was 0 for all 10 sheets.

Examples 3 and 4 and Comparative Examples 1 to 4
Based on the composition described in Table 1, except that the types of glass powder in Example 1 are different, a photosensitive paste composition is similarly prepared, and tack value, pattern workability, presence or absence of cracks after development, after etching The residue was evaluated. The tack value was 0 in all 10 sheets of Examples 3 and 4 and Comparative Examples 1 to 4.

Example 5
A photosensitive paste composition was prepared in the same manner as in Example 1 except that the compound (A) in Example 1 was different, and the tack value, pattern processability, presence or absence of cracks after development, and residues after etching were evaluated. The tack value was 0 for all 10 sheets.

Example 6
A photosensitive paste composition was prepared in the same manner as in Example 1 except that a filler was added as an inorganic component in Example 1. The tack value, pattern processability, presence or absence of cracks after development, and residues after etching were determined. evaluated. The tack value was 2 or 3.

Examples 7, 8 and Comparative Examples 5-7
A photosensitive paste composition was prepared in the same manner as in Example 1 except that the type of binder polymer in Example 1 was different, and the tack value, pattern processability, presence or absence of cracks after development, and residues after etching were evaluated. The tack value was 2 or 3 or 4 in Example 7. In Example 8, it was 0 in all 10 sheets. In Comparative Example 5, it was 6 or 7 or 8. In Comparative Examples 6 and 7, it was 0 in all 10 sheets in any Comparative Example.

Examples 9-12
A photosensitive paste composition was prepared in the same manner as in Example 1 except that the amount of the compound (A) added in Example 1 was different, and the tack value, pattern processability, presence or absence of cracks after development, and residues after etching were determined. evaluated. The tack value was 0 in all 10 sheets in Examples 9 to 11. In Example 12, it was 0 or 2.

Examples 13 and 14
A photosensitive paste composition was prepared in the same manner as in Example 1 except that the weight concentration of the glass powder in Example 1 was different, and the tack value, pattern workability, presence of cracks after development, and residues after etching were evaluated. . The tack value was 0 for all 10 sheets in Example 13. In Example 14, it was 2 or 3.

Claims (4)

A photosensitive paste composition having at least inorganic particles containing glass powder and a photosensitive organic component, wherein the glass transition temperature of the binder polymer contained in the photosensitive organic component is 30 to 100 ° C., and 70 in terms of oxide. 95 wt% of _Bi 2 _O 3, _3~15 wt% of _SiO 2, 5 to 20 wt% of _B 2 _O 3, _1~10 wt% of ZnO, 0 to 3 wt% of the composition range of the ZrO ₂ A photosensitive paste composition containing glass powder. The photosensitive paste composition according to claim 1, wherein the film has a tack value of 0 to 4 formed on the substrate. When the average refractive index of the inorganic powder is N1 and the average refractive index of the photosensitive organic component is N2, | N1-N2 | ≧ 0.29, which absorbs the exposure wavelength and emits light having a wavelength longer than the absorbed wavelength. The emitted light contains a compound that cures or solubilizes the photosensitive organic component, and the content of the compound is 0.1 to 30% by weight based on the photosensitive organic component. Photosensitive paste composition. A flat panel display member having a pattern formed on the photosensitive paste composition according to claim 1 and then fired, and having the fired pattern on a substrate.