JP2001092118A - Photosensitive paste and electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive paste containing a high proportion of an inorganic powder of a small particle diameter, capable of sufficiently curing a photosensitive resin component because of a low light transmittance within the paste and easily forming a fine pattern. SOLUTION: In a photosensitive paste containing an inorganic powder, a photosensitive resin component and a photopolymerization initiator, an internal curing type photopolymerization initiator and a surface curing type photopolymerization initiator are used in combination as the photopolymerization initiator so as to attain sufficient curing even in a part with a low light transmittance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive paste and an electronic component manufactured using the same.

[0002]

2. Description of the Related Art With high-density and high-speed signal transmission of high-frequency electronic devices, wiring conductors formed in connection with a substrate for forming high-frequency circuits provided in these electronic devices must be fine and thick films. Is required.

Conventionally, in order to form a thick conductor film for providing wiring on a substrate, a conductive paste in which a conductive powder is mixed with an organic binder is prepared, and this is applied in a desired pattern on the substrate by screen printing. , Then firing, thereby removing the organic binder,
Sintering of conductive components has been performed.

However, in the screen printing method, the precision of the pattern plate is relatively poor, and it is difficult to form a fine pattern having a width of, for example, 100 μm or less.

Therefore, as a method of obtaining a fine pattern which has been difficult to obtain by screen printing, for example,
JP-A-54-121967, JP-A-54-135
As described in JP-A-91-91 and JP-A-59-143149, a photosensitive paste obtained by mixing a conductive powder with a photosensitive resin composition is used, and a photolithography technique is applied thereto to form a fine paste. A method of forming a conductive film of a pattern on a substrate has been proposed.

As a photosensitive resin composition constituting a paste component in such a photosensitive paste, a conventionally known photopolymerizable or photo-modified compound can be used. For example, (1) an unsaturated group or the like can be used. A mixture of a monomer or oligomer having a reactive functional group and a photopolymerization initiator such as an aromatic carbonyl compound, (2) a so-called diazo resin such as a condensate of an aromatic bisazide and formaldehyde, and (3) an epoxy compound or the like A mixture of a polymerizable compound and a photoacid generator such as a diallyl iodonium salt, (4) a naphthoquinonediazide compound, and the like can be used. Of these, particularly preferred is (1)
It is a mixture of a monomer having a reactive functional group such as an unsaturated group and a photoradical generator such as an aromatic carbonyl compound.

[0007]

In the above-mentioned photosensitive paste, the photosensitive resin composition contains a photopolymerization initiator. As the photopolymerization initiator, a surface-curing type photopolymerization initiator is used. I have. When an internal curing type photopolymerization initiator is used, the radical activity decreases due to oxygen present on the paste film surface, and the polymerization of the monomer hardly proceeds. This is because they are not easily affected by oxygen inhibition.

However, in order to obtain a conductive film having high electric conductivity by the above-described method, it is necessary to prevent defects such as disconnection and cracks due to volume shrinkage during firing, and therefore, it is difficult to obtain a conductive paste in the photosensitive paste. The proportion of the conductive powder to be mixed with the powder must be increased.

However, when the content ratio of the conductive powder increases, the transmittance of light inside the photosensitive paste film decreases, and the photosensitive paste containing a surface-curable photopolymerization initiator as a photopolymerization initiator is added. There is a problem that the curing of the paste is likely to be insufficient, which makes pattern formation difficult.

Also, in order to obtain a fine pattern, it is necessary to reduce the particle size of the conductive powder contained in the photosensitive paste. Also, there is a problem that the transmittance of light inside the paste film is low, and the curing of the photosensitive paste is likely to be insufficient, as in the case described above, so that pattern formation is difficult.

In the above description, the problem with the photosensitive paste containing conductive powder as the inorganic powder has been described. However, the same problem is encountered with the photosensitive paste containing insulating powder as the inorganic powder.

Therefore, an object of the present invention is to provide a photosensitive resin component which has a high content ratio of inorganic powder and / or a small particle size of inorganic powder, even if the transmittance of light inside is low. And can therefore be cured
An object of the present invention is to provide a photosensitive paste in which a fine pattern can be easily formed.

[0013]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, as a photopolymerization initiator in a photosensitive paste, an internal curing type photopolymerization initiator and a surface curing type The present inventors have found that by using a combination with a photopolymerization initiator, sufficient curing can be achieved even in a portion having low light transmittance, and the present invention has been accomplished.

That is, the present invention firstly provides an inorganic powder,
Including a photosensitive resin component and a photopolymerization initiator, which is directed to a photosensitive paste, in order to solve the above problems, as a photopolymerization initiator, an internal curing type photopolymerization initiator and a surface curing type photopolymerization initiator It is characterized in that it is used in combination with an agent.

[0015] The internal curing type photopolymerization initiator is cleaved by irradiation with active energy rays, and as a result, its ability to absorb a long wavelength region in the ultraviolet region or visible region provided before cleavage is lost. , Absorption by this shortens the wavelength,
As a result, the active energy rays required for cleavage can be transmitted to the inside of the monomer without being absorbed by the cleavage, although those that had been absorbed in the region near the monomer surface before cleavage can be absorbed. It refers to a photopolymerization initiator in which the initiator present is easily cleaved and the inside of the monomer is easily cured. Generally, such a difference in absorption before and after cleavage is said to indicate a bleaching effect.

On the other hand, since there is not much difference in the absorption region before and after cleavage from the surface-curing type photopolymerization initiator, active energy rays are absorbed in a region near the monomer surface and hardly reach the inside of the monomer. It refers to a photopolymerization initiator that easily causes surface hardening.

As described above, according to the photosensitive paste of the present invention, utilizing the characteristics of the internal curing type photopolymerization initiator,
Since the light transmittance inside the paste can be increased,
By combining this with a surface curing type photopolymerization initiator, the photosensitive resin component inside the paste having low light transmittance can be easily cured.

As described above, since the internal curing type photopolymerization initiator is inhibited by oxygen on the surface, the use of only the internal curing type photopolymerization initiator does not cure the paste surface. By using an internal curing type photopolymerization initiator together with a surface curing type photopolymerization initiator as in the present invention, both the paste surface and the interior can be cured.

In the photosensitive paste according to the present invention,
The photosensitive resin component comprises, in a more specific embodiment, a photosensitive polymer or oligomer and a photosensitive monomer. More specifically, the photosensitive polymer or oligomer described above includes an acrylic copolymer, and the photosensitive monomer includes a photo-radical polymerizable monomer.

Further, in the photosensitive paste according to the present invention, the photopolymerization initiator is used based on the total amount of the photosensitive paste.
It is preferable to contain 0.1 to 5% by weight.

In the photopolymerization initiator, the ratio of the internal curing type photopolymerization initiator is preferably 10 to 90% by weight.

In the photosensitive paste according to the present invention, the inorganic powder may be, for example, A
g, Au, Pt, Pd, Cu, Ni, W, Al and M
o, the conductive powder such as a powder containing at least one selected from the group consisting of glass powder and / or
Alternatively, an insulating powder such as a ceramic powder may be included. Further, both the conductive powder and the insulating powder may be included as the inorganic powder.

The present invention is also directed to an electronic component having a functional material film obtained by patterning a paste film formed of the above-described photosensitive paste by using a photolithography technique.

In such an electronic component, the above-mentioned functional material film may be a conductor film obtained by patterning a paste film formed of a conductive photosensitive paste containing conductive powder using a photolithography technique. An insulator film formed by patterning a paste film formed of a photosensitive paste for an insulator containing an insulating powder using a photolithography technique may be used.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The photosensitive paste according to the present invention is advantageously used for forming a film having a fine pattern on a substrate by using, for example, a photolithography technique. More specifically, the photosensitive paste is applied so as to form a paste film on a substrate by a known film forming method such as screen printing, spin coating or doctor blade, and dried. Next, after exposing this paste film through a mask having a desired pattern, the paste film is developed with, for example, an aqueous solution of sodium carbonate to form a pattern film having a desired pattern.
This pattern film is baked if necessary.

The photosensitive paste according to the present invention contains an inorganic powder, a photosensitive resin component, and a photopolymerization initiator composed of an internal curing type photopolymerization initiator and a surface curing type photopolymerization initiator. As the photosensitive resin composition comprising the above-described photosensitive resin component and a photopolymerization initiator, the above-described conventionally known photopolymerizable or photo-modified compounds can be used, but the photosensitive resin component is preferably , A photosensitive polymer or oligomer and a photosensitive monomer.

As the photosensitive polymer or oligomer,
Particularly preferably used are those containing an acrylic copolymer having a carboxyl group in the side chain, and this acrylic copolymer is obtained by copolymerizing an unsaturated carboxylic acid and an ethylenically unsaturated compound. It can be manufactured by the following.

As the unsaturated carboxylic acid, acrylic acid,
Examples include methacrylic acid, maleic acid, fumaric acid, vinyl acetic acid, and anhydrides thereof. On the other hand, as the ethylenically unsaturated compound, methyl acrylate, acrylates such as ethyl acrylate, methyl methacrylate, methacrylates such as ethyl methacrylate,
And fumarate esters such as monoethyl fumarate. Further, an unsaturated bond may be introduced by subjecting a copolymer obtained by copolymerizing these compounds to an oxidation treatment or the like.

As the photosensitive monomer, those containing a photo-radical polymerizable monomer having a reactive functional group such as an unsaturated group are preferably used.
Hexanediol triacrylate, tripropylene glycol triacrylate, trimethylolpropane triacrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, lauryl acrylate, 2
-Phenoxyethyl acrylate, isodecyl acrylate, isooctyl acrylate, tridecyl acrylate, caprolactone acrylate, ethoxylated nonylphenol acrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate,
Diethylene glycol diacrylate, tetraethylene glycol diacrylate, triethylene glycol diacrylate, ethoxylated bisphenol A diacrylate, propoxylated neopentyl glycol diacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate , Pentaerythritol triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate,
Pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hydroxypentaacrylate, ethoxylated pentaerythritol tetraacrylate, tetrahydrofurfuryl methacrylate, cyclohexyl methacrylate, isodecyl methacrylate, lauryl methacrylate, triethylene glycol dimethacrylate, ethylene glycol dimethacrylate , Tetraethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, diethylene glycol dimethacrylate,
1,9-nonanediol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, ethoxylated bisphenol A dimethacrylate, trimethylolpropane trimethacrylate,
Ethoxylated isocyanuric acid diacrylate, ethoxylated paracumylphenol acrylate, ethylhexyl carbitol acrylate, N-vinyl-2-pyrrolidone, isobornyl acrylate, polypropylene glycol diacrylate, polyethylene glycol diacrylate, dipentaerythritol pentaacrylate,
And dipentaerythritol hexaacrylate.

Representative internal curing type photopolymerization initiators that can be suitably used in the present invention include 2-benzyl-2-dimethylamino-1- (4) represented by the following structural formula (1). -Morpholinophenyl) -butanone-1.

[0031]

Embedded image

Specific examples of other suitable internal curing type photopolymerization initiators include the following compounds. (1) bis (2,6-dimethoxybenzoyl) -2,
4,4-trimethylpentylphosphine oxide,
(2) bis (2,6-dimethylbenzoyl) -2,4
4-trimethylpentylphosphine oxide, (3)
Bis (2,4,6-trimethylbenzoyl) -2,4
4-trimethylpentylphosphine oxide, and (4) bis (2,6-dichlorobenzoyl) -2,4,
4-trimethylpentylphosphine oxide.

On the other hand, surface curing type photopolymerization initiators can be generally classified into self-cleaving type and hydrogen abstraction type.

When benzophenone, 2,4-dimethylthioxanthone or the like is used as the hydrogen abstraction type, it is usually used in combination with a photosensitizer. As the photosensitizer, an amine compound is generally used, and specific examples include triethanolamine and methyldiethanolamine.

However, when these amine compounds are used, the initial coloring of the polymer becomes large. Therefore, it is rather preferable to use a self-cleaving type photopolymerization initiator. Examples of the self-cleaving photopolymerization initiator include an acetophenone-based photopolymerization initiator and an α-dicarbonyl-based photopolymerization initiator, and these are more preferable in terms of the colorless and transparent cured product.

As described above, the surface-curing type photopolymerization initiator preferably used is 2-methyl-1- [4- (methylthio) phenyl] -2 represented by the following structural formula (2).
-Morpholinopropan-1-one.

[0037]

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Other specific examples of the surface-curing type photopolymerization initiator which can be suitably used in the present invention are as follows. Acetophenone-based photopolymerization initiator: (1) 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, (2) 1
-Phenyl-2-hydroxy-2-methylpropane-1
-One, (3) 1-hydroxycyclohexylphenyl ketone, (4) 1- (4-isopropylphenyl) -2
-Hydroxy-2-methylpropan-1-one. α-Dicarbonyl photopolymerization initiator: (1) 1,2-diphenylethanedione, (2) methylphenylglyoxylate.

These surface-curable polymerization initiators are:
One or two or more can be used simultaneously.

The addition amount of the photopolymerization initiator including both the above-mentioned internal curing type and surface curing type is preferably 0.1 to 5% by weight based on the total amount of the photosensitive paste. More preferably, it is 0.2 to 3% by weight. If it is less than 0.1% by weight, curing by light tends to be insufficient, and if it exceeds 5% by weight, the curability becomes too large, and it becomes difficult to obtain a fine pattern.

In the photopolymerization initiator, the ratio of the internal curing type photopolymerization initiator to the surface curing type photopolymerization initiator is preferably 10 to 90% by weight,
More preferably, it is 20 to 85% by weight. 10% by weight
If the amount is less than the above, the cross-sectional shape of the pattern film is likely to be inverted trapezoid because of insufficient curing, and if it exceeds 90% by weight, the pattern formation becomes difficult due to insufficient surface curing. .

As the inorganic powder, depending on the use of the photosensitive paste, a conductive powder, an insulating powder, or both may be used.

As the conductive powder, for example, one or more of Ag powder, Au powder, Pt powder, Pd powder, Cu powder, Ni powder, W powder, Al powder, Mo powder and the like can be used. Further, an alloyed powder may be used.

The conductive powder may be spherical, plate-like, massive,
Although it may have any shape such as a rod shape, it is preferable that there is no aggregation and good dispersibility, and the average particle diameter is preferably 0.05 to 10 μm, more preferably, It is 0.5 to 5 μm. When the average particle size of the conductive powder is less than 0.05 μm, the cohesive force of the particles is large, and it is difficult to obtain a conductive paste having good dispersibility. On the other hand, the average particle size of the conductive powder is 10 μm. If it exceeds, it is difficult to obtain a fine wiring pattern.

The content of the conductive powder in the photosensitive paste is preferably from 60 to 90% by weight, more preferably from 65 to 85% by weight. If the content of the conductive powder is less than 60% by weight, disconnection or cracking due to shrinkage during firing is likely to occur, and it is difficult to obtain a proper pattern. On the other hand, the content of the conductive powder is 90% by weight. If the amount exceeds the range, the amount of the photosensitive resin component is insufficient, and it is difficult to obtain sufficient curing.

In the photosensitive paste according to the present invention, when an insulating powder is used as the inorganic powder,
As the insulating powder, a glass powder and / or a ceramic powder can be advantageously used. Known glass powders such as borosilicate glass powder can be used as the glass powder, and known ceramic powders of crystallized glass, glass composite, and non-glass can be used as the ceramic powder.

More specifically, as the glass powder, S
iO ₂ -PbO system, SiO ₂ -ZnO system, SiO ₂ -B
i ₂ O ₃ system, SiO ₂ -K ₂ O system, SiO ₂ -Na ₂ O
System, SiO ₂ —PbO—B ₂ O ₃ system, SiO ₂ —ZnO
—B ₂ O ₃ system, SiO ₂ —Bi ₂ O ₃ —B ₂ O ₃ system, S
iO ₂ -K ₂ O-B ₂ O ₃ system, SiO ₂ -Na ₂ O-B
A glass powder such as ₂ O ₃ can be used.

As the ceramic powder, for example, Al, Ag, Cu, Ni, Ti, Ba, Pb, Zr, M
An oxide, boride, nitride, silicide, or the like of at least one metal selected from the group consisting of n, Cr, Sr, Fe, Y, Nb, La, Si, Zn, and Ru can be used.

These insulating powders may have any shape such as spherical, plate-like, lump-like and rod-like as in the case of the above-mentioned conductive powder, but have no aggregation and good dispersibility. Is preferable, so that the average particle size is 0.1.
It is preferably from 1 to 10 μm.

When the photosensitive paste contains the above-mentioned glass powder and is used as a paste for forming an insulator, the content ratio of this glass powder is 4%.
0 to 80% by weight is preferred. Content ratio of glass powder is 4
If the amount is less than 0% by weight, the insulating property of the insulating film after firing is lowered, which is likely to be defective. On the other hand, if the amount is more than 80% by weight, a fine pattern is hardly obtained due to light scattering by the glass powder. is there.

The photosensitive paste contains the above-mentioned conductive powder and is used as a paste for forming a conductor. Insulating powder is further added to such a conductive paste. In this case, the content of the insulating powder is preferably 0.1 to 10% by weight. If the content of the insulating powder is less than 0.1% by weight, the bondability with the substrate is low, and it is difficult to obtain a good pattern. This causes a decrease in conductivity and a decrease in solderability.

The photosensitive paste according to the present invention may further contain, if necessary, a storage stabilizer such as a polymerization inhibitor, an antioxidant, a dye, a pigment, an antifoaming agent, a surfactant and the like. can do.

Hereinafter, the photosensitive paste according to the present invention will be described more specifically based on examples.

Photosensitive pastes were prepared as Examples 1 to 9 falling within the scope of the present invention and Comparative Examples 1 to 6 falling outside the scope of the present invention.

More specifically, each of the photosensitive pastes according to the examples contains an inorganic powder, an acrylic copolymer, and a photo-radical polymerizable monomer.
Including both an internal curing type photopolymerization initiator and a surface curing type photopolymerization initiator, and each photosensitive paste according to the comparative example includes an inorganic powder, an acrylic copolymer, and a photoradical polymerizable monomer. The photopolymerization initiator contains only one of a surface curing type photopolymerization initiator and an internal curing type photopolymerization initiator.

More specifically, in these examples and comparative examples, as the inorganic powder, Ag powder, AgPt powder, SiO ₂
-PbO-B ₂ O ₃ based glass powder and Al ₂ O ₃ (alumina) powder was used as appropriate respectively.

In each of the examples and comparative examples, a methyl methacrylate-methacrylic acid copolymer was used as the acrylic copolymer constituting the photosensitive resin component, and the photoradical polymerizable monomer was also Trimethylolpropane triacrylate was used.

In each of the examples, the internal curing type photopolymerization initiator was 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-
1 was used. In Comparative Examples, those containing an internal curing type photopolymerization initiator as the photopolymerization initiator used this 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1.

In each of the examples, the surface-curing type photopolymerization initiator was 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-.
ON and 2,4-diethylthioxanthone were used, respectively. In Comparative Examples, those containing a surface-curing type photopolymerization initiator as the photopolymerization initiator were those 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, and 2,4-Diethylthioxanthone was used respectively.

The inorganic powder, acrylic copolymer, photo-radical polymerizable monomer, internal curing type polymerization initiator, and surface curing type polymerization initiator are added together with ethyl carbitol acetate as an organic solvent as follows. Examples 1 to 9 and Comparative Examples 1 to 5 by sufficiently mixing at various composition ratios and kneading with three rolls.
To prepare each photosensitive paste.

[0061]

Example 1 Ag powder (average particle size: 3.0 μm) 75% by weight Methyl methacrylate-methacrylic acid copolymer 4 0.5% by weight Trimethylolpropane triacrylate 5.2% by weight 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 0.14% by weight ・ 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one 1.0% by weight · 2,4-diethylthioxanthone 0.26% by weight・ Ethyl carbitol acetate 13.9% by weight

[0062]

Example 2 AgPt powder (average particle size: 3.0 μm) 65% by weight Methyl methacrylate-methacrylic acid copolymer 6.3 % By weight Trimethylolpropane triacrylate 7.2% by weight 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 0.41% by weight ・ 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one …………………… 1.3% by weight ・ 2,4-diethylthioxanthone ............ 0.33% by weight ・ Ethyl Carbitol acetate 19.46% by weight

[0063]

Example 3 Ag powder (average particle size: 3.0 μm) 85% by weight Methyl methacrylate-methacrylic acid copolymer 2 0.7% by weight-Trimethylolpropane triacrylate ... 3.2% by weight-2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 ... 0.19% by weight ・ 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one ……………………………… 0.46% by weight ・ 2,4-diethylthioxanthone …………… 0.11% by weight Ethyl carbitol acetate 8.34% by weight

[0064]

Example 4 Ag powder (average particle diameter: 0.6 μm) 65% by weight Methyl methacrylate-methacrylic acid copolymer 6 0.3% by weight Trimethylolpropane triacrylate 7.2% by weight 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 0.61% by weight ・ 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one ………………………… 14% by weight ・ 2,4-diethylthioxanthone …………… 0.29% by weight Ethyl carbitol acetate 19.46% by weight

[0065]

Example 5 Ag powder (average particle diameter: 0.6 μm) 85% by weight Methyl methacrylate-methacrylic acid copolymer 2 0.7% by weight-Trimethylolpropane triacrylate ... 3.2% by weight-2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 ... 0.38% by weight ・ 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one …………………………… 0.3% by weight ・ 2,4-diethylthioxanthone …………… 0.08% by weight・ Ethyl carbitol acetate: 8.34% by weight

[0066]

Example 6 Ag powder (average particle diameter: 0.6 μm) 80% by weight SiO ₂ —PbO—B ₂ O ₃ based glass powder (average particle diameter: 3.0 μm) ……………………………………………………… 5.0% by weight ・ Methyl methacrylate-methacrylic acid copolymer 2.7% by weight-Trimethylolpropane triacrylate ... 3.2% by weight-2-benzyl-2-dimethylamino-1- (4-morpholinophenyl)- Butanone-1 0.49% by weight ・ 2-methyl-1- [4- (methylthio) phenyl] -2-morpho Rinopropan-1-one 0.2% by weight ・ 2,4-diethylthioxa 0.07% by weight ・ Ethyl carbitol acetate 8.34% by weight

[0067]

Example 7: Ag powder (average particle size: 0.6 μm)... 74% by weight ・ Al ₂ O ₃ powder (average particle size: 3.0 μm) 1.0% by weight-Methyl methacrylate-methacrylic acid copolymer ... 4.5% by weight-Trimethylolpropane triacrylate ... 5.2% by weight % 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 1.12 1.12 % By weight • 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one ……………………………………… 0 .22% by weight ・ 2,4-diethylthioxanthone... ...... 0.06% by weight ・ Ethyl carbitol ace Over door .................................... 13.9% by weight

[0068]

EXAMPLE 8 _{· SiO 2 -PbO-B 2 O} 3 based glass powder (average particle size: 3.0μm) ...... ............................................................... 65% by weight-Methyl methacrylate-methacrylic acid copolymer ... 6.3% by weight-Trimethylolpropane triacrylate ... 7.2 % By weight ・ 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1......... 73% by weight ・ 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one ………………………………………………… 0.25% by weight ・ 2,4-diethylthioxanthone 0.06% by weight ・ Ethyl carbitol ace Over door ................................. 19.46% by weight

[0069]

Example 9: Al ₂ O ₃ powder (average particle size: 3.0 μm) 65% by weight Methyl methacrylate-methacrylic acid copolymer 6 0.3% by weight Trimethylolpropane triacrylate 7.2% by weight 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 1.84% by weight ・ 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one ……………………………… 0.16% by weight ・ 2,4-diethylthioxanthone ............ 0.04% by weight ・Ethyl carbitol acetate 19.46% by weight

[0070]

[Comparative Example 1]-Ag powder (average particle size: 3.0 µm) ... 75% by weight-Methyl methacrylate-methacrylic acid copolymer ... 4 0.5% by weight Trimethylolpropane triacrylate 5.2% by weight 2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one …………………………………… 1.1% by weight ・ 2,4-diethylthioxanthone ………………… 0.3% by weight・ Ethyl carbitol acetate 13.9% by weight

[0071]

[Comparative Example 2]-AgPt powder (average particle size: 0.6 µm) ... 65% by weight-Methyl methacrylate-methacrylic acid copolymer ... 6.3 % By weight-Trimethylolpropane triacrylate ... 7.2% by weight-2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one ... ………………… 1.6% by weight ・ 2,4-diethylthioxanthone ............ 0.44% by weight ・ Ethyl carb Tall acetate 19.46% by weight

[0072]

[Comparative Example 3]-Ag powder (average particle size: 0.6 µm) ... 85% by weight-Methyl methacrylate-methacrylic acid copolymer ... 2 0.7% by weight-Trimethylolpropane triacrylate ... 3.2% by weight-2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one ... ………………………… 0.6% by weight ・ 2,4-diethylthioxanthone …………… 0.16% by weight Ethyl carbitol acetate 8.34% by weight

[0073]

[Comparative Example 4] · Ag powder (average particle diameter: 3.0 [mu] m) .................................... 70 _{wt% · SiO 2 -PbO-B 2} O 3 based glass powder (average particle diameter: 3.0 μm) ……………………………………………………… 5.0% by weight ・ Methyl methacrylate-methacrylic acid copolymer 4.5% by weight Trimethylolpropane triacrylate 5.2% by weight 2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopro Pan-1-one .................................... 1.1% by weight ・ 2,4-diethylthioxanthone ………………… 0.3% by weight ・ Ethyl carbitol acetate 13.9% by weight

[0074]

[Comparative Example 5] _{· SiO 2 -PbO-B 2 O} 3 based glass powder (average particle size: 1.0 .mu.m) ...... ............................................................... 65% by weight-Methyl methacrylate-methacrylic acid copolymer ... 6.3% by weight-Trimethylolpropane triacrylate ... 7.2 % By weight ・ 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one …………………………………………… 1.6% by weight ・ 2,4-diethylthioxanthone ............ 0.44% by weight ・ Ethyl carbitol acetate ............ 19.46% by weight

[0075]

[Comparative Example 6]-Ag powder (average particle size: 3.0 µm) ... 75% by weight-Methyl methacrylate-methacrylic acid copolymer ... 4 0.5% by weight Trimethylolpropane triacrylate 5.2% by weight 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 ……………………… 1.4% by weight ・ Ethyl carbitol acetate ……………… 13.9% by weight Type and content of conductive powder and / or insulating powder, content of internal curing photopolymerization initiator, and surface curing photopolymerization initiator contained in each of Examples 1 to 9 and Comparative Examples 1 to 6 Are shown in Table 1 below so that the contents can be listed.

[0076]

[Table 1]

Next, Examples 1 to 9 and Comparative Examples 1 to 6
Was applied on an alumina substrate by screen printing, and then dried at 90 ° C. for 1 hour to form a 20 μm thick paste film. Next, the paste film was exposed to 1000 mJcm ^-2 of light from an ultra-high pressure mercury lamp through a mask to expose the paste film, and then developed with a 0.5% by weight aqueous solution of sodium carbonate.

With respect to the pattern film of each sample patterned as described above, the presence or absence of peeling after development, the measurement of resolution by microscopic observation, and the evaluation of the cross-sectional shape at the line-like portion were performed. The resolution is obtained by determining how wide a fine pattern is obtained in line / space. These results are shown in Table 2. Table 2 also shows the content ratio (% by weight) of the internal curing type photopolymerization initiator and the surface curing type photopolymerization initiator in 100% by weight of the aforementioned photopolymerization initiator.

[0079]

[Table 2]

As can be seen from Table 2, according to Examples 1 to 9, a pattern film having a fine pattern was obtained with excellent resolution and without peeling after development. Since the curable photopolymerization initiator and the surface curable photopolymerization initiator are used in combination, it can be seen that a sufficient cured state is achieved in the photosensitive paste.

In particular, in Examples 3, 5 and 6, as shown in Table 1, the content ratio of the conductive powder or the content ratio of the conductive powder and the insulating powder was as high as 85% by weight.
In Examples 4 to 7, the average particle size of the conductive powder was 0.6 μm.
, And in each case, the light transmittance into the paste film is low, but nevertheless, as described above,
It should be noted that a satisfactory state of cure has been achieved.

Incidentally, in the photopolymerization initiator used,
The ratio of the internal curing type photopolymerization initiator is preferably selected within the range of 10 to 90% by weight as in Examples 1 to 9, but is more preferably 20 as in Examples 2 to 8. ~ 8
It is selected within the range of 5% by weight. By selecting the ratio of the internal curing type photopolymerization initiator within the range of 20 to 85% by weight,
As in Examples 2 to 8 in Table 2, a resolution of 30 μm or less,
And a rectangular cross-sectional shape can be reliably obtained.

On the other hand, in Comparative Examples 1 to 5, only a surface-curing type photopolymerization initiator was used as a photopolymerization initiator, so that a sufficient cured state was not achieved in the photosensitive paste. The resolution was inferior, peeling after development occurred in the fine pattern portion, and the cross-sectional shape became an inverted trapezoid, so that a pattern film having a fine pattern could not be formed.

Further, in Comparative Example 6, since only the internal curing type photopolymerization initiator was used as the photopolymerization initiator, the photosensitive paste was insufficiently cured, and after the development, all the paste films were peeled off and the pattern film was removed. Was impossible to form.

Next, an electronic component manufactured using the photosensitive paste according to the present invention will be described.

FIG. 1 is a perspective view showing the appearance of a chip coil 1 as an example of the above-mentioned electronic component, and FIG. 2 is an exploded perspective view showing a component body 2 of the chip coil 1 shown in FIG. It is.

The chip coil 1 has an insulating substrate 3,
On the insulating substrate 3, insulator films 4, 5, 6, and 7 formed by using the photosensitive paste for insulator according to the present invention are sequentially laminated. Also, on each of the insulating substrate 3 and the insulating films 4, 5, and 6, a conductive film 8, which is formed using the conductive photosensitive paste according to the present invention,
9, 10 and 11 are located respectively.

The component body 2 is constituted by the insulating substrate 3, the insulator films 4 to 7 and the conductor films 8 to 11, and the external terminals 12 are provided on the opposed end faces of the component body 2.
And 13 are provided.

The above-described conductor films 8 to 11 are made of insulating films 4 to 6 so as to form a predetermined coil pattern as a whole.
Via-hole connecting portions 14 through
Electrical connection is made via a line 16. The via-hole connecting portions 14 to 16 are indicated by dashed lines in FIG.
Are omitted from illustration of the through conductors that respectively provide the following.

More specifically, the conductor film 8 is connected to the conductor film 9 via a via-hole connection portion 14 provided in the insulator film 4.
And the conductor film 9 is also electrically connected to the insulator film 5.
Is electrically connected to the conductive film 10 via a via-hole connecting portion 15 provided in the insulating film 6, and the conductive film 10 is electrically connected to the conductive film 1 through a via-hole connecting portion 16 provided in the insulator film 6.
1 electrically. The conductor films 8 to 11 connected to form a coil pattern in this manner
, Ie, one end of the conductor film 8 and one end of the conductor film 11 are connected to the external terminals 12 and 13, respectively.
Is electrically connected to

An example of a method for manufacturing such a chip coil 1 according to the present invention will be described below.

As shown in FIG. 2, first, a photosensitive paste for a conductor according to the present invention is applied on an insulating substrate 3 made of, for example, alumina. In applying the photosensitive paste, any method such as a screen printing method, a spin coating method, and a doctor blade method may be used.

Next, the conductor paste film applied and formed as described above is dried and then exposed through a photomask having a predetermined pattern.

Next, after performing a development process to remove unnecessary portions of the conductor paste film, a spiral conductor film 8 is formed, for example, by baking in air under predetermined conditions.

Next, the photosensitive paste for an insulator according to the present invention is applied on the insulating substrate 3 so as to cover the conductor film 8. For this application, the same method as in the case of applying the above-mentioned photosensitive paste for a conductor can be applied.

Next, after drying the insulator paste film applied and formed as described above, a predetermined hole (not shown) having a diameter of, for example, 50 μm for the via hole connection portion 14 is formed. The insulating paste film is exposed through a photomask having a pattern.

Next, after performing a developing process to remove unnecessary portions, the insulating film 4 having a hole for the via-hole connecting portion 14 is formed by, for example, firing in air under predetermined conditions. Form.

Next, a conductive paste is filled in the holes for the above-described via-hole connection portions 14 and dried to form the via-hole connection portions 14 in the insulator film 4.

Then, a spiral conductor film 9 is formed on the insulator film 4 by the same method as in the formation of the conductor layer 8 described above.

Thereafter, the insulator film 5, the conductor film 10, the insulator film 6, and the conductor film 11 are sequentially formed in the same manner as described above. After the protection insulator film 7 is formed, the external terminals 12 and 13 are provided to complete the chip coil 1 having the appearance as shown in FIG.

According to the above-described manufacturing method, the insulator films 4 to
Since the photosensitive paste for an insulator according to the present invention is used for the formation of 7, particularly, fine holes for via-hole connecting portions 14 to 16 to be provided in the insulator films 4 to 6 are formed. It can be formed easily and easily with excellent accuracy in shape and position.

Further, since the conductor films 8 to 11 are also formed using the photosensitive paste for conductor according to the present invention, a fine and high-density pattern is formed on the conductor films 8 to 11 with a high density. It can be given easily and easily with precision. In particular, since it is easier to form the conductor films 8 to 11 thicker than in the case where a normal screen printing method or the like is applied, it is easy to make the chip coil 1 excellent in high-frequency characteristics.

Further, the photosensitive paste according to the present invention comprises:
Since there is little deterioration over time in the viscosity, it is possible to suppress the occurrence of pattern blurring or the like due to the viscosity deterioration. Therefore, as described above, when the photosensitive paste according to the present invention is used for forming the insulating films 4 to 7, for example, the diameter is less than 150 μm, particularly 50 μm.
An extremely fine hole for via hole connection such as the following can be formed with high precision. Therefore, it is possible to contribute to miniaturization and high density of electronic components such as the chip coil 1.

The present invention is not limited to the above-described chip coil, but includes electronic components for high-frequency circuits such as a chip capacitor and a chip LC filter, and a VCO (Voltage).
Controlled Oscillator) or P
A board for a high-frequency function module such as LL (Phase Locked Loop), a package board for mounting an IC,
It can be advantageously applied to electronic components such as.

[0105]

As described above, according to the photosensitive paste of the present invention, since the internal curing type photopolymerization initiator and the surface curing type photopolymerization initiator are used in combination as the photopolymerization initiator. In addition, a sufficient cured state is achieved by photopolymerization, and a pattern film having a fine pattern can be easily formed.

Therefore, according to the electronic component having the conductor film and the insulator film formed by using such a photosensitive paste, a fine form can be easily given to the conductor film and the insulator film. Since it is possible to contribute to the miniaturization and high-density of such an electronic component and it is easy to increase the thickness of the conductive film, the electronic component can have excellent high-frequency characteristics.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a chip coil 1 as an example of an electronic component manufactured using a photosensitive paste according to the present invention.

FIG. 2 is an exploded perspective view showing a component body 2 provided in the chip coil 1 shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chip coil 4-7 Insulator film 8-11 Conductive film 14-16 Via hole connection part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Michiaki Inami 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto F-term in Murata Manufacturing Co., Ltd. (reference) 2H025 AA01 AA02 AA19 AB15 AB17 AD01 BC43 BC53 CA00 CA02 CA03 CA27 CA35 CC08 CC09 4E351 BB01 BB24 BB31 CC11 CC22 DD04 DD05 DD06 DD17 DD19 DD20 DD52 EE01 EE11 EE21 GG01 4J038 FA111 FA221 HA066 HA486 KA04 KA20 NA18 NA20 PA17 PB09

Claims (12)

[Claims] 1. A photosensitive paste containing an inorganic powder, a photosensitive resin component, and a photopolymerization initiator, wherein the photopolymerization initiator comprises an internal curing type photopolymerization initiator and a surface curing type photopolymerization initiator. A photosensitive paste, comprising: 2. The photosensitive paste according to claim 1, wherein the photosensitive resin component contains a photosensitive polymer or oligomer and a photosensitive monomer. 3. The photosensitive paste according to claim 2, wherein the photosensitive polymer or oligomer includes an acrylic copolymer, and the photosensitive monomer includes a photo-radical polymerizable monomer. 4. The photopolymerization initiator according to claim 1, wherein the photopolymerization initiator is contained in an amount of 0.1 to 5% by weight based on the total amount of the photosensitive paste.
A photosensitive paste according to any one of the above. 5. The photosensitive paste according to claim 1, wherein in the photopolymerization initiator, a ratio of the internal curing type photopolymerization initiator is 10 to 90% by weight. 6. The photosensitive paste according to claim 1, wherein the inorganic powder includes a conductive powder. 7. The conductive powder is made of Ag, Au, Pt,
The photosensitive paste according to claim 6, which is a powder containing at least one selected from Pd, Cu, Ni, W, Al, and Mo. 8. The photosensitive paste according to claim 1, wherein the inorganic powder includes an insulating powder. 9. The method according to claim 9, wherein the insulating powder is glass powder and / or
9. The photosensitive paste according to claim 8, comprising a ceramic powder. 10. An electronic component comprising a functional material film obtained by patterning a paste film formed of the photosensitive paste according to claim 1 by using a photolithography technique. 11. An electronic component, comprising: a conductor film obtained by patterning a paste film formed of the photosensitive paste according to claim 6 using a photolithography technique. 12. A paste film formed from the photosensitive paste according to claim 8 or 9 comprising an insulator film patterned by using a photolithography technique.
Electronic components.