JP3950760B2 - Wiring board manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a wiring board that forms a pattern on an insulating sheet. In particular, the present invention relates to a method of manufacturing a wiring board made of a ceramic laminate formed by laminating a plurality of ceramic green sheets.
[0002]
[Prior art and problems]
Conventionally, as a method for producing this type of ceramic laminate, a paste containing a solvent is patterned on a ceramic green sheet by screen printing or the like, and then the solvent contained in the paste is volatilized by heating. A method of manufacturing a sheet by forming a sheet and laminating and baking a large number of sheets is known.
[0003]
However, in the above-described manufacturing method, when the solvent of the sheet is heated and dried, a contraction behavior of the sheet occurs, so that a pitch shift between the sheets of each layer is likely to occur. When pitch deviation occurs in the upper and lower layer patterns due to such shrinkage, problems such as poor connection occur, resulting in problems such as a decrease in yield and electrical characteristics. Such a problem occurs not only when the ceramic laminate is laminated in multiple layers but also when an IC or the like is mounted on a single-layer ceramic substrate.
[0004]
In addition, as another conventional technique, a photosensitive paste that is cured by light is applied onto a ceramic green sheet, and after a photosensitive pace is cured by drying and exposure, a development process is performed to form a pattern. A method of performing this is also known (Japanese Patent Laid-Open Nos. 5-0667405 and 5-204151).
[0005]
However, even in the above-described other techniques, after the pattern is formed on the sheet, the sheet is immersed in a developer (solvent, water, etc.), so that the sheet undergoes behavior such as contraction and expansion. For this reason, there are problems such as pitch shift similar to those described above.
[0006]
SUMMARY OF THE INVENTION The present invention solves the above-described problems of the prior art, and an object of the present invention is to provide a method of manufacturing a wiring board that is less likely to cause sheet expansion / contraction and can form a pattern at a desired position. .
[0007]
[Means for solving the problems and their functions and effects]
The present invention made to solve the above problems
A sheet making process for forming an insulating sheet which is a ceramic green sheet before firing;
A pattern forming step of forming a photosensitive paste that is cured by light on the insulating sheet by a screen printing method in a predetermined pattern;
An exposure step of curing the pattern by exposing it to the pattern;
A baking step of simultaneously baking the insulating sheet and the photosensitive paste after the exposure step;
Equipped with a,
The predetermined pattern formed by the screen printing method is a final pattern substantially the same as the pattern obtained after the exposure step and the baking step;
It is characterized by.
[0008]
According to the manufacturing method of the present invention, if a pattern formed with a photosensitive paste by screen printing is exposed on an insulating sheet, the pattern can be cured. No variation occurs. In other words, since processing such as heating and drying that causes behavioral changes such as contraction and expansion of the sheet is not performed, yield and electrical characteristics can be improved without causing positional deviation in the pattern. .
[0009]
Further, since the final pattern is formed on the insulating sheet by the screen printing method, a wet process such as development for removing an unnecessary portion for forming the final pattern becomes unnecessary, and the process becomes simple. Furthermore, since the exposure process has a shorter processing time than the process of drying and curing the pattern, the productivity can be improved.
[0010]
As an aspect of the insulating sheet of the present invention, any substrate that can screen-print a photosensitive paste may be used. For example, an unfired ceramic green sheet formed from Al ₂ O ₃ or nitride can be applied. The green sheet refers to a non-fired ceramic powder formed into a sheet form by using a doctor blade method or the like in a slurry form using an organic solvent, a plasticizer, a solvent, or the like. When a green sheet is used, the shrinkage of the sheet itself can be further suppressed. Further, after the patterning step and the exposure step, the facilities Succoth firing step of co-firing the insulating sheet and the pattern, in this case, to enhance the integrity by the insulating sheet and the pattern is sintered it can.
[0011]
The screen printing method refers to a printing method in which a screen on which a pattern is formed with or without an opening is placed on a substrate to be printed, and paste is attached only to the opening using the opening.
[0012]
Furthermore, as a preferred aspect of the present invention, a step of firing a plurality of insulating sheets on which the pattern is formed can be performed. In this case, since the pattern is cured on the insulating sheet and the unity is improved, pattern misalignment hardly occurs between the layers of the insulating sheet. Therefore, according to this method, it is suitable for manufacture of the laminated substrate which laminated | stacked many insulating sheets.
[0013]
For the pattern formed on the insulating sheet, a conductive material may be used, or a magnetic material or a material for forming electrical resistance may be used alone or in combination. The insulating sheet can be applied to, for example, a wiring board on which an IC chip or the like is mounted in a single layer, or can be applied to an electrical component having a capacitor, a coil, or a resistance by laminating a plurality of sheets.
[0014]
The pattern to be formed on the insulating sheet is not only a conductive pattern using a conductive photosensitive paste, but also a resistance pattern using a magnetic material or a material that forms electrical resistance. May be used in combination or in combination. As the insulating sheet, for example, it can be applied as a substrate on which an IC chip or the like is mounted in one layer, or can be applied to an electrical component having a capacitor, a coil, or a resistor by laminating a plurality of sheets.
[0015]
The photosensitive paste not only imparts conductivity by adding a material having conductivity, but also an oxide (for example, RuO ₂ ) for electric resistance or an oxide (for example, CaTiO ₃ ) for dielectric. ) May be prepared as a paste.
[0016]
When the photosensitive paste is a conductive paste, it can be prepared with the following materials and composition.
(1) Conductive material A metallic filler can be added as a conductive material. As the metal filler, a metal such as gold, silver, platinum, palladium, copper, aluminum, nickel, tungsten, or an alloy powder, a metal powder whose surface is coated with another metal, or the like can be used. In particular, gold, silver, platinum, palladium, copper alone or an alloy powder, or copper powder coated with a noble metal such as gold, silver, platinum, or palladium can be preferably used.
The metal filler is preferably used in the range of 70 to 90% by weight when used as wiring. This is because if it is less than 70% by weight, the resistance of the wiring becomes high after firing and it becomes difficult to densify, and if it exceeds 90% by weight, the amount of other materials added becomes small, for example, photosensitivity can be obtained. Because there is no. Moreover, when using as a resistor, the addition amount is suppressed.
[0017]
(2) Inorganic filler As the inorganic filler, alumina, barium titanate, glass or the like can be used, thereby acting as a buffer material that matches the shrinkage behavior with the insulating sheet when co-fired with the insulating sheet. Can do. The amount of the inorganic filler added is preferably 30% by weight or less, although it depends on the amount of the conductive material added.
[0018]
(3) Photosensitive material As the photosensitive material, 5 to 30% by weight of a resin component containing a photocuring agent is added. If it is less than this range, curing by light cannot be obtained, and if it exceeds this range, the wiring becomes high resistance after firing or densification becomes difficult.
(3) -1 Resin Component As the resin component, an acrylate resin, an epoxy resin, or the like can be used.
[0019]
(3) -1-1 Acrylic allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxytriethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2-ethylhexyl acrylate Glycerol acrylate, glycidyl acrylate, heptadecafluorodecyl acrylate, 2-hydroxyethyl acrylate, isobornyl acrylate, 2-hydroxypropyl acrylate, isodecyl acrylate, isooctyl acrylate, lauryl acrylate, 2 -Methoxyethyl acrylate, methoxyethylene glycol acrylate, methoxydiethylene glycol acrylate, octafluoropentyl acrylate, phenol Xylethyl acrylate, stearyl acrylate, trifluoroethyl acrylate, allylated cyclohexyl diacrylate, bisphenol A diacrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, ethylene glycol diacrylate Acrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, ditrimethylolpropane tetraacrylate, glycerol diacrylate, methoxylation Cyclohexyl diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, polypro Examples include lenglycol diacrylate, triglycerol diacrylate, trimethylolpropane triacrylate, and those obtained by replacing the above acrylate with methacrylate, γ-methacryloxypropyltrimethoxysilane, 1-vinyl-2-pyrrolidone, etc. However, it is not limited to these. One or more of these can be used.
[0020]
(3) -1-2 As a cationic reaction resin, a resin composed of one or more selected from an epoxy resin, an aliphatic cyclic epoxy resin, and an oxetane resin, a diglycidyl ether of bisphenol A, and a diglycol of bisphenol F Sidyl ether, phenol novolac diglycidyl ether, diglycidyl orthotoluidine, diglycidyl aniline, 4,4'-di (1,2-epoxymethyl) diphenyl ether, 4,4 '-(1,2-epoxymethyl) biphenyl, Bifunctional epoxy compounds such as 1,6-hexanediol diglycidyl ether, paraaminophenol triglycidyl ether, metaaminophenol triglycidyl ether, 1,3,5-tri (1,2-epoxyethyl) ) Benzene, phenol formal Polyglycidyl ethers of Hidonoborakku, epoxy compound having three or more functional groups such as triglycidyl ether of glycerol is used.
[0021]
(3) -1-3 Examples of the aliphatic cyclic epoxy include YL-6663 (made by Japan Epoxy Resin), YL-6653 (made by Japan Epoxy Resin), Araldite CY-184 (made by Ciba Geigy), Araldite CY-192- 1 (Ciba Geigy), Araldite CY-179 (Ciba Geigy), Araldite CY-177 (Ciba Geigy), Celoxide 2021 (Daicel Chemical), Celoxide 2081 (Daicel Chemical), Celoxide 2083 (Daicel Chemical), Celoxide 3000 (Manufactured by Daicel Chemical), epolide GT301 (manufactured by Daicel Chemical), epolide GT302 (manufactured by Daicel Chemical), epolide GT401 (manufactured by Daicel Chemical), epolide GT403 (manufactured by Daicel Chemical), and the like.
[0022]
(3) -1-4 Examples of the oxetane resin include OXT101 (manufactured by Toagosei), OXT121 (manufactured by Toagosei), and the like.
[0023]
(3) -2 As the curing agent curing agent, a photo radical curing agent, a photo acid generator or the like can be used.
[0024]
(3) -2-1 Photoradical curing agent benzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 4,4'-dichlorobenzophenone 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, fluorenone, 2,2'-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, p -T-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzyl, benzyldimethyl ketal, benzyl-β-methoxyethyl acetal, benzoin, benzine Inmethyl ether, benzoin butyl ether, anthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, anthrone, benzanthrone, dibenzosuberone, methyleneanthrone, 4-azidobenzalacetophenone, 2,6-bis (P-azidobenzylidene) cyclohexanone, 6-bis (p-azidobenzylidene) -4-methylcyclohexanone, 1-phenyl-1,2-butanedione-2- (o-methoxycarbonyl) oxime, 1-phenyl-propanedione- 2- (o-ethoxycarbonyl) oxime, 1-phenyl-propanedione-2- (o-benzoyl) oxime, 1,3-diphenyl-propanetrione-2- (o-ethoxycarbonyl) oxime, 1-phenyl- 3-ethoxy-propanetrione-2- (o-benzoyl) oxime, Michler's ketone, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, naphthalenesulfonyl chloride, quinolinesulfonyl chloride, N -Phenylthioacridone, 4,4'-azobisisobutyronitrile, diphenyl disulfide, benzthiazole disulfide, triphenylphosphine, camphorquinone, carbon tetrabromide, tribromophenylsulfone, benzoin peroxide and eosin, methylene blue, etc. A combination of a photoreductive dye and a reducing agent such as ascorbic acid or triethanolamine is not limited thereto. One or more of these can be used.
[0025]
(3) -2-2 Photoacid generator Triphenylphenacylphosphonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, diphenyliodonium salt of tetrafluoroborate, 4,4′-bis [di (β-hydroxyethoxy ) Phenylsulfonio] phenylsulfide-bis-hexafluoroantimonate and the like are included, but the present invention is not particularly limited thereto. One or more of these can be used.
[0026]
(3) -3 Solvent of the paste The solvent of the paste is a high-boiling polyhydric alcohol derivative such as n-methylpyrrolidone, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, Boiling aromatic compounds, ketones, esters and terpenes can be used. The content of the solvent is preferably 0 to 15% by weight. If no solvent is added, there is no effect of shrinkage on the sheet, but if it exceeds 15% by weight, the sheet is greatly shrunk or expanded after screen printing. .
[0027]
DETAILED DESCRIPTION OF THE INVENTION
In order to further clarify the configuration and operation of the present invention described above, preferred embodiments of the present invention will be described below.
[0028]
(1) Structure of Ceramic Multilayer Body FIG. 1 is a cross-sectional view illustrating a wiring board (ceramic multilayer body) on which a ceramic laminate according to an embodiment of the present invention is laminated. In FIG. 1, a ceramic multilayer body 10 includes a ceramic laminate 14 in which a large number of patterns 13 are formed on an insulating sheet 12, and is configured by laminating a large number of these ceramic laminates 14. Vias 16 are formed in the ceramic multilayer body 10, and the layers are connected through conductors filling the vias 16.
[0029]
(2) Manufacturing Process Next, the manufacturing process of the ceramic multilayer body 10 will be described. FIG. 2 is a process diagram for explaining a process for producing a ceramic multilayer body, and FIG. 3 is an explanatory diagram for explaining a process for producing a ceramic laminate.
[0030]
(2) -1 Formation of Green Sheet First, as shown in FIG. 3A, a green sheet 12A to be an insulating sheet is formed by a general-purpose doctor blade method or the like.
[0031]
(2) -2 Pattern Formation Subsequently, as shown in FIG. 3B, a pattern 13 is formed on the green sheet 12A using the photosensitive paste 20 by a screen printing method. As the photosensitive paste, a conductive paste prepared by silver: 70 to 90% by weight, acrylic ester resin: 6 to 22% by weight, diethylene glycol monoethyl ether acetate: 3 to 10% by weight, for example, can be used. Photoresist OK301 (trade name: manufactured by Daiken Chemical Co., Ltd.) can be used.
[0032]
(2) -3 Exposure Curing Step As shown in FIG. 3C, the pattern 13 on the green sheet 12A is exposed. Thereby, the pattern 13 formed of the photosensitive paste is cured, and the creation of the ceramic laminate 14 is completed.
[0033]
(2) -4 Lamination / Hot Press Step A large number of ceramic laminates 14 produced in the above step are laminated and further integrated by hot press to form a laminated green body. At this time, the resin component in the pattern 13 is softened by heat.
[0034]
(2) -5 Debinding process The resin component contained in the green sheet and the photosensitive paste is removed by heating the laminated green body to 250 to 350 ° C.
[0035]
(2) -6 Firing Step The laminated green body is heated to 850 to 1800 ° C. to sinter and integrate the layers. The firing temperature at this time is 850 to 900 ° C. when the metal contained in the photosensitive paste has a low melting point such as silver or gold, and high temperature around 1800 ° C. when the metal is a high melting point metal such as tungsten. Bake with. Thereby, the ceramic multilayer body 10 is completed.
[0036]
(3) Result of Shrinkage Behavior of Ceramic Laminate Next, the shrinkage / expansion behavior of the green sheet by the exposure process was examined. FIG. 4 shows the amount of change between the pitches of the vias 16 (FIG. 1) when the pattern is cured, the solid line shows the case where the exposure process according to this embodiment is performed, and the one-dot chain line shows the thermal drying process according to the conventional example. The case where is given. As a result, it was found that in this example, there was almost no change between via pitches due to the exposure process.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a ceramic multilayer body (wiring board) in which ceramic multilayer bodies according to an embodiment of the present invention are laminated.
FIG. 2 is a process diagram illustrating a process for producing a ceramic multilayer body (laminated body).
FIG. 3 is an explanatory diagram for explaining a process for manufacturing a ceramic laminate.
FIG. 4 is an explanatory diagram illustrating a change amount between via pitches when a pattern is cured;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Ceramic multilayer body 12 ... Insulating sheet 12A ... Green sheet 13 ... Pattern 14 ... Ceramic laminated body 16 ... Via 20 ... Photosensitive paste

Claims (3)

A sheet making process for forming an insulating sheet which is a ceramic green sheet before firing;
A pattern forming step of forming a photosensitive paste that is cured by light on the insulating sheet by a screen printing method in a predetermined pattern;
An exposure step of curing the pattern by exposing it to the pattern;
A baking step of simultaneously baking the insulating sheet and the photosensitive paste after the exposure step;
Equipped with a,
The predetermined pattern formed by the screen printing method is a final pattern substantially the same as the pattern obtained after the exposure step and the baking step;
A method of manufacturing a wiring board characterized by the above. In the manufacturing method of the wiring board of Claim 1,
The said photosensitive paste is a manufacturing method of the wiring board currently formed from the material which has electroconductivity. An insulating sheet formed with the pattern, a plurality, after stacking, manufacturing method of a wiring board according to claim 1 or claim 2, characterized in that firing.

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