JP2006120539A - Paste for conductor, wiring board using the same, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductor paste which is stable, even when an acrylic resin is used, and is especially superior in repeat printability, and to provide a wiring board that uses the same and its manufacturing method. <P>SOLUTION: The paste contains a metal powder, acrylic resin and a prescribed aromatic compound containing an oxyalkylene group. Further, the paste contains a metal powder, an acrylic resin and an aromatic compound having three or more ester bonds. The manufacturing method of the wiring board comprises a step of forming an uncalcined conductor, by printing the conductor paste on a ceramic green sheet surface, and a step of calcining the ceramic green sheet in a nonoxidizing atmosphere. The wiring board (1) has a low-temperature calcined porcelain-made base (11), and a conductor (12) formed by calcining the uncalcined conductor composed of the conductor paste, and the low-temperature calcined porcelain-made base (11) and the conductor (12) are calcined, at the same time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a conductor paste, a wiring board using the same, and a method for manufacturing the same. More specifically, the present invention relates to a conductor paste excellent in printability, a wiring board using the same, and a method for manufacturing the same.

  In recent years, with the speeding up of information communication, etc., high frequency response of electronic parts and the like has been urgently required. Especially in the high frequency region, it is necessary to reduce the transmission loss of electrical signals. Therefore, low resistance metals are used for the conductor layers of electronic components. Furthermore, in applications that require high reliability such as packages, migration resistance is also improved. There is a demand for LTCC wiring boards (low temperature co-fired wiring boards) using excellent Cu or the like as a conductor material.

  However, many low resistance metals such as Cu are easily oxidized, and it is necessary to prevent oxidation of the conductor material for simultaneous firing with ceramics. Therefore, a method of firing in a low-oxygen atmosphere or a non-oxidizing atmosphere is taken, but this firing does not sufficiently remove the organic components contained in the green sheet, paste for conductors, etc., and the performance of electronic parts is sufficient. Can not be pulled out. For this reason, the acrylic resin excellent in thermal decomposability is used as a binder (patent document 1 etc. below). Furthermore, when an acrylic resin is used for the conductor paste, stringing is caused and printability is lowered. However, it is known that the stringing property is improved by the method using the specific acrylic resin (Patent Documents 2 to 4 below). It has been.

JP 59-124149 A JP 2002-80675 A JP 2000-248224 A JP 2003-183331 A

When these acrylic resins are used, the above-described stringing property is improved, and printing defects caused by this stringing can be prevented. However, since these acrylic resins have low solubility in a solvent, they are liable to cause undissolved residual acrylic resin and phase separation. That is, it has been found that the paste tends to become unstable, and the viscosity characteristics change with time, so that there is a problem that printing cannot be stably and repeatedly performed.
On the other hand, as a method for suppressing phase separation, Patent Document 2 discloses a method in which an aromatic hydrocarbon-containing alcohol (such as benzyl alcohol) having a boiling point of 200 ° C. or higher is contained in a solvent. This benzyl alcohol or the like has a high effect of simply suppressing phase separation, but is highly soluble, and thus easily affects the screen mask emulsion used during printing. There is also a problem that repeated printing cannot be sufficiently performed. Furthermore, benzyl alcohol has a problem that the odor is strong and the working environment is deteriorated.

  The present invention solves the above-mentioned problems, and even when an acrylic resin is used, a stable conductor paste can be obtained, and in particular, a conductor paste excellent in repetitive printability and this paste are used. It is an object to provide a method for manufacturing a wiring board and a wiring board.

但し、上記一般式２におけるＲ_１はＨ又はＣＨ_３であり、上記一般式１におけるｎ及び上記一般式２におけるｍは各々独立して１又は２である。
（２）更に、２つ以上のエステル結合を有する芳香族化合物を含有する上記（１）記載の導体用ペースト。
（３）上記芳香族化合物は、フタル酸エステル系化合物である上記（２）に記載の導体用ペースト。
（４）上記フタル酸エステル系化合物は、アルキルフタリルアルキルグリコレートである上記（３）に記載の導体用ペースト。
（５）金属粉末と、アクリル系樹脂と、３つ以上のエステル結合を有する芳香族化合物と、を含有することを特徴とする導体用ペースト（以下、単に「本第２発明の導体用ペースト」ともいう）。
（６）上記フタル酸エステル系化合物は、アルキルフタリルアルキルグリコレートである上記（５）に記載の導体用ペースト。
（７）更に、下記一般式３で表されるオキシアルキレン基含有芳香族化合物及び下記一般式２で表されるオキシアルキレン基含有芳香族化合物のうちの少なくとも一方を含有する上記（５）又は（６）に記載の導体用ペースト。

但し、上記一般式３におけるＲ_２及び上記一般式２におけるＲ_１は各々独立してＨ又はＣＨ_３であり、上記一般式３におけるｋ及び上記一般式２におけるｍは各々独立して１又は２である。
（８）低温焼成磁器製基部と、該低温焼成磁器製基部の内部及び／又は表面に形成された導体部と、を備える配線基板の製造方法であって、
上記低温焼成磁器製基部となるセラミックグリーンシートの表面に、上記請求項１乃至７のうちのいずれかに記載の導体用ペーストを印刷し、上記導体部となる未焼成導体部を形成する未焼成導体部形成工程と、
該未焼成導体部を備える該セラミックグリーンシートを非酸化性雰囲気において焼成する焼成工程と、を備えることを特徴とする配線基板の製造方法。
（９）上記焼成工程における焼成は８５０〜１０５０℃で行う上記（８）に記載の配線基板の製造方法。
（１０）低温焼成磁器製基部と、請求項１乃至７のうちのいずれかに記載の導体用ぺーストからなる未焼成導体部が焼成されてなる導体部と、を備え、且つ、該低温焼成磁器製基部と該導体部とは同時焼成されていることを特徴とする配線基板。 The present invention is as follows.
(1) at least one of a metal powder, an acrylic resin, an oxyalkylene group-containing aromatic compound represented by the following general formula 1 and an oxyalkylene group-containing aromatic compound represented by the following general formula 2, A conductor paste (hereinafter also simply referred to as “the conductor paste of the first aspect of the invention”).

However, R ₁ in the general formula 2 is H or CH ₃ , n in the general formula 1 and m in the general formula 2 are each independently 1 or 2.
(2) The conductor paste according to (1), further comprising an aromatic compound having two or more ester bonds.
(3) The conductor paste according to (2), wherein the aromatic compound is a phthalate ester compound.
(4) The conductor paste according to (3), wherein the phthalate ester-based compound is an alkyl phthalyl alkyl glycolate.
(5) A conductor paste containing metal powder, an acrylic resin, and an aromatic compound having three or more ester bonds (hereinafter simply referred to as “conductor paste of the second invention”) Also called).
(6) The conductor paste according to (5), wherein the phthalate ester compound is an alkylphthalylalkyl glycolate.
(7) The above (5) or (5) further containing at least one of an oxyalkylene group-containing aromatic compound represented by the following general formula 3 and an oxyalkylene group-containing aromatic compound represented by the following general formula 2. The paste for conductors as described in 6).

However, R ₂ in the general formula 3 and R ₁ in the general formula 2 are each independently H or CH ₃ , k in the general formula 3 and m in the general formula 2 are each independently 1 or 2 It is.
(8) A method of manufacturing a wiring board comprising a base made of low-temperature fired porcelain and a conductor formed inside and / or on the surface of the base made of low-temperature fired porcelain,
An unsintered conductor is formed by printing the conductor paste according to any one of claims 1 to 7 on the surface of the ceramic green sheet serving as the low-temperature fired porcelain base. A conductor portion forming step;
And a firing step of firing the ceramic green sheet comprising the unfired conductor portion in a non-oxidizing atmosphere.
(9) The method for manufacturing a wiring board according to (8), wherein the baking in the baking step is performed at 850 to 1050 ° C.
(10) A low-temperature fired porcelain base and a conductor part formed by firing an unfired conductor part made of the conductor paste according to any one of claims 1 to 7, and the low-temperature firing A wiring board, wherein the porcelain base and the conductor are fired simultaneously.

According to the conductor paste of the first invention of the present invention, excellent repeated printability can be realized. In particular, it is excellent in repetitive printability of fine circuit patterns. Moreover, there is little residual charcoal and it can exhibit the excellent withstand voltage property.
Furthermore, when it contains the aromatic compound which has two or more ester bonds, it becomes the paste for conductors which was more excellent in printing characteristics, and can improve repetitive printability and fine printability.
When the aromatic compound is a phthalate ester-based compound, it becomes a conductor paste excellent in printing characteristics, and can improve repetitive printability and fine printability.
When the phthalic acid ester compound is an alkyl phthalyl alkyl glycolate, it becomes a conductor paste particularly excellent in printing characteristics, and can improve repetitive printability and fine printability.
According to the conductor paste of the second aspect of the invention, excellent repeatability can be realized. In particular, it is excellent in repetitive printability of fine circuit patterns. Moreover, there is little residual charcoal and it can exhibit the excellent withstand voltage property.
When the phthalic acid ester compound is an alkyl phthalyl alkyl glycolate, it becomes a conductor paste particularly excellent in printing characteristics, and can improve repetitive printability and fine printability.
In the case of containing a predetermined oxyalkylene group-containing aromatic compound, it becomes a conductor paste excellent in printing characteristics, and repeatability and fine printability can be improved.
According to the method for manufacturing a wiring board of the present invention, it is possible to manufacture a highly reliable wiring board which has fine wiring stably and reliably and is excellent in voltage resistance. Moreover, since it has excellent repetitive printability in the manufacturing process, this wiring board can be manufactured at low cost.
When baking is performed at 850 to 1050 ° C., it is possible to obtain a wiring substrate having fine wiring and high reliability at low cost.
According to the wiring board of the present invention, it is possible to have the fine wiring fired simultaneously with the base made of the low-temperature fired porcelain, to further have a high withstand voltage, and to exhibit high reliability.

Hereinafter, the present invention will be described in detail.
The conductor paste of the first invention includes a metal powder, an acrylic resin, an oxyalkylene group-containing aromatic compound represented by the general formula 1 and an oxyalkylene group-containing aromatic compound represented by the general formula 2. And at least one of them.

  The conductor paste of the first invention uses an acrylic resin, and it is difficult for the carbon content to remain after firing. Therefore, the metal electrode is easily fired, and the paste using the acrylic resin by using a specific organic solvent. Even so, the repetitive printability is good.

  The “metal powder” is a powder that becomes a conductor after firing. The metal which comprises this metal powder is not specifically limited, A base metal and a noble metal are mentioned. The type of base metal is not particularly limited. For example, Cu, Al, Ni, Ti, V, Cr, Mn, Fe, Co, Zn, Ga, Zr, Nb, Mo, Tc, In, Sn, Hf, Ta, W , Re, Pb, and the like. Examples of the noble metal include Ag, Au, Pt, Pd, Ir, Ru, Rh, and Os. These base metals and precious metals may use only 1 type and may use 2 or more types together. When using 2 or more types, only a base metal may be used, only a noble metal may be used, and these may be used together. Furthermore, when using 2 or more types, these alloys are also included.

The metal powder is stable regardless of what kind of metal it contains, and can be excellent in repetitive printability, but the acrylic resin contained in the paste is a non-oxidizing atmosphere. Since the remaining charcoal in the firing can be prevented, it is particularly effective in a metal powder containing a base metal that needs to be fired in a non-oxidizing atmosphere.
Therefore, the metal powder can contain a base metal as a main component. That is, for example, a total of 50 mol% or more (may be 100 mol%) of base metals can be contained with respect to 100 mol% of the whole metal powder. Further, among base metals, at least one of Cu, Al, and Ni can be a main component. That is, for example, a total of 50 mol% or more (or 100 mol% may be included) of Cu, Al and Ni with respect to 100 mol% of the entire metal powder. In particular, Cu can be a main component among base metals. That is, for example, a total of 50 mol% or more (or 100 mol%) of Cu can be contained with respect to 100 mol% of the entire metal powder.

  Furthermore, the shape of the powder particle which comprises metal powder is not specifically limited, For example, it can be set as spherical shape, substantially spherical shape, dendritic shape, and flake shape. Of these, spherical and substantially spherical are preferable. Spherical and substantially spherical wiring (for example, it can be used for patterning of a wiring pattern having a line width of 55 μm or less (usually 10 μm or more), and the line width is 40 μm or less (usually 10 μm or more) Patterning with an interval of 40 μm or less (usually 10 μm or more) is possible, and in particular, patterning with a line width of 35 μm or less (usually 10 μm or more) and a line interval of 35 μm or less (usually 10 μm or more)} can be handled. Although the average particle diameter of the particle | grains which comprise metal powder is not specifically limited, 0.1-10 micrometers (especially 0.5-7 micrometers, Furthermore 1-5 micrometers) are preferable. If it is this range, it is suitable for the patterning of fine wiring, and a metal powder can fully be sintered. In addition, the undulation of the base material that occurs because the metal powder starts sintering at an excessively low temperature does not occur.

  The content of the metal powder is not particularly limited, but is usually 60% by mass or more (preferably 65 to 90% by mass, more preferably 70 to 88% by mass, further preferably 100% by mass when the entire conductor paste is 100% by mass. Is 75 to 85% by mass, usually 92% by mass or less). If it is this range, the paste for conductors which is homogeneous and stable and has the excellent repetitive printability will be obtained, and sufficient conductivity will be obtained in the conductor part obtained after firing.

  The “acrylic resin” is a polymer having an acrylic structure and a methacrylic structure. The kind of acrylic resin is not particularly limited, and examples thereof include poly-n-butyl methacrylate resin, polyisobutyl methacrylate resin, poly-2-ethylhexyl methacrylate resin, and polyethyl methacrylate resin. These may use only 1 type and may use 2 or more types together. These are particularly excellent in thermal decomposability and are difficult to remain in an environment where the oxygen concentration is low. Moreover, this acrylic resin is usually thermoplastic.

  Furthermore, the acrylic resin may not have a hydroxyl group in the molecule, but preferably has a hydroxyl group. By having a hydroxyl group, the dispersibility of a metal and an inorganic substance is improved and printability is improved. The hydroxyl group content is not particularly limited, but the hydroxyl group preferably has an OH group value of 10 mgKOH / g or more (usually 50 mgKOH / g or less). If it is this range, the effect containing a hydroxyl group can be acquired.

  Further, the properties of the acrylic resin are not particularly limited, but the total viscosity including the solvent when the acrylic resin is 20% by mass when the total of the acrylic resin and the solvent is 100% by mass. Is preferably 10 Pa · s or more (particularly 20 Pa · s or more, more preferably 40 Pa · s or more, usually 200 Pa · s or less) at 22 ° C. If it is this range, the stringing at the time of printing can be suppressed especially effectively, and this effect can be acquired especially by use of a small amount of acrylic resin.

  The properties of the acrylic resin used in the conductor paste of the first invention (acrylic resin in the state before being contained in the conductor paste) are not particularly limited, but usually an acrylic resin powder in powder form is used. . The average particle diameter of the acrylic resin powder particles constituting the acrylic resin powder is not particularly limited, but is preferably 200 μm or less (particularly 100 μm or less, usually 0.01 μm or more). If it is this range, compared with the case where the acrylic resin powder which remove | deviates from this range is used, a more homogeneous conductor paste is obtained.

  The content of the acrylic resin is not particularly limited, but usually 0.5% by mass or more (preferably 1 to 10% by mass, more preferably 1.5 to 8%) when the entire conductor paste is 100% by mass. Mass%, more preferably 2 to 6 mass%, and usually 12 mass% or less). If it is this range, the paste for conductors which is homogeneous and is stable and has the excellent repetitive printability will be obtained.

  The “oxyalkylene group-containing aromatic compound” is a compound represented by the above general formula 1 or 2. These compounds function as a solvent for the acrylic resin and form a conductor paste as a whole with the metal powder and the acrylic resin.

  Among the oxyalkylene group-containing aromatic compounds, the compound represented by the general formula (1) (hereinafter also simply referred to as “oxyalkylene compound (1)”) is an oxyalkylene group {oxyethylene group, phenoxy group, Is a compound composed of n may be 1 or 2. By having an oxyalkylene group, it is possible to ensure the ease of handling of the conductor paste (does not volatilize excessively while ensuring adequate volatility), and thus a stable and homogeneous conductor paste can be obtained. Moreover, the plate clogging of the screen mask can be effectively suppressed, the erosion of the screen mask can be further suppressed, and the odor can be suppressed.

  Examples of the oxyalkylene compound (1) include 2-phenoxyethanol and 2- (2-phenoxyethoxy) ethanol. Of these, 2-phenoxyethanol is preferred. By being n = 1, it can have sufficient compatibility with acrylic resin, ensuring moderate volatility. These oxyalkylene compounds (1) may be used alone or in combination of two or more.

Of the oxyalkylene group-containing aromatic compounds, the compound represented by the general formula (2) (hereinafter also simply referred to as “oxyalkylene compound (2)”) is an oxyalkylene group {oxyethylene group (R ₁ is H Or an oxyisopropylene group (when R ₁ is CH ₃ )} and a benzylalkoxy group. m may be 1 or 2. Furthermore, when m = 2, the two R ₁ constituting the oxyalkylene group can be independently H or CH ₃ . When m is 1 or 2, that is, by having an oxyalkylene group, it is possible to ensure the ease of handling of the conductor paste (does not volatilize excessively while ensuring adequate volatility), and is stable and A homogeneous conductor paste can be obtained. Moreover, the plate clogging of the screen mask can be effectively suppressed, the erosion of the screen mask can be further suppressed, and the odor can be suppressed.

  As this oxyalkylene compound (2), 2- (benzyloxy) ethanol, 1-benzyloxy-2-propanol, 2-[(benzyloxy) ethoxy] ethanol, 2- (1-benzyloxy-2-propoxy) Examples include ethanol and 1-[(benzyloxy) ethoxy] -2-propanol. Among these, 2- (benzyloxy) ethanol and / or 1-benzyloxy-2-propanol in which n = 1 is preferable. By being n = 1, it can have sufficient compatibility with acrylic resin, ensuring moderate volatility. These oxyalkylene compounds (2) may be used alone or in combination of two or more.

  Of the oxyalkylene compound (1) and the oxyalkylene compound (2), the oxyalkylene compound (1) is more preferable, and 2-phenoxyethanol is more preferable. This is because, in particular, the solubility in the resin is high, the stability of the paste is increased, and clogging of the screen mask can be effectively suppressed.

  The content of the oxyalkylene group-containing aromatic compound {oxyalkylene compound (1) and / or oxyalkylene compound (2)} is not particularly limited, but is usually the sum of the acrylic resin and the oxyalkylene group-containing aromatic compound. Is 100 mass% or more (preferably 65 to 98 mass%, more preferably 70 to 95 mass%, still more preferably 75 to 90 mass%, usually 99 mass% or less). If it is 60% by mass or more, the acrylic resin can be uniformly dissolved, and a conductor paste having excellent repeated printability that is homogeneous and stable can be obtained.

The conductor paste of the first invention can contain other solvent components in addition to the oxyalkylene group-containing aromatic compound, and particularly an aromatic compound having two or more ester bonds (hereinafter simply referred to as “ester”). It is preferable to contain a compound ". By containing the ester compound, it is possible to exhibit excellent printability even in printing a finer pattern as compared with the case where the ester compound is not contained.
The ester compound is not particularly limited as long as it is a compound having two or more ester bonds and a benzene ring structure. The number of ester bonds is not particularly limited as long as it is 2 or more, but is usually 5 or less. The ester bond is preferably 2, 3, or 4, more preferably 2 or 3, and particularly preferably 3.

Examples of such ester compounds include various diester compounds, triester compounds, and tetraester compounds. Among these, various ester compounds having a dicarboxylic acid residue are included. That is, for example, an aromatic diester compound having a dicarboxylic acid residue, an aromatic triester compound having a dicarboxylic acid residue, an aromatic tetraester compound having a dicarboxylic acid residue, and the like.
Examples of the dicarboxylic acid residue include phthalic acid residues (including phthalic acid residues, isophthalic acid residues and terephthalic acid residues), adipic acid residues, and the like.
Of these ester compounds, phthalate ester compounds are preferred. That is, each diester compound, triester compound and tetraester compound having a phthalic acid residue is preferred. Furthermore, each diester compound and triester compound having a phthalic acid residue is more preferable, and an aromatic triester compound having a phthalic acid residue is particularly preferable. This is because a more stable conductor paste can be obtained. These ester compounds may use only 1 type and may use 2 or more types together.

  Examples of aromatic diester compounds having phthalic acid residues include dialkyl phthalates (diethyl phthalate, dibutyl phthalate, dimethyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, dinonyl phthalate, etc.) , Alkylbenzyl phthalate (such as butylbenzyl phthalate), dialkyl isophthalate (such as diethyl isophthalate, dibutyl isophthalate, dimethyl isophthalate, di-n-octyl isophthalate, di-2-ethylhexyl isophthalate, dinonyl isophthalate) Alkyl benzyl isophthalate (such as butyl benzyl isophthalate), dialkyl terephthalate (diethyl terephthalate, dibutyl terephthalate, dimethyl terephthalate, di-n-octyl terephthalate, di-2-ethylhexyl terephthalate, Dinonyl Tal acid), terephthalic acid alkyl benzyl (butyl terephthalate benzyl, etc.) and the like. Of these, diethyl phthalate, dibutyl phthalate, and dimethyl phthalate are more preferable. These diester compounds may use only 1 type and may use 2 or more types together.

但し、上記一般式４におけるＲ_３、Ｒ_４及びＲ_５は各々独立して炭素数が１〜４の炭化水素基である。 As an aromatic triester compound which has a phthalic acid residue, the compound represented by following General formula (4) is mentioned.

However, R ₃ , R ₄ and R ₅ in the above general formula 4 are each independently a hydrocarbon group having 1 to 4 carbon atoms.

Examples of the compound represented by the general formula 4 include alkyl phthalyl alkyl glycolate and alkyl phthalyl alkyl propionate. That is, for example, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, ethyl phthalyl methyl glycolate, propyl phthalyl ethyl glycolate, ethyl phthalyl propyl glycolate, ethyl isophthalyl ethyl glycolate, methyl isophthalyl ethyl Glycolate, ethyl isophthalyl methyl glycolate, propyl isophthalyl ethyl glycolate, ethyl isophthalyl propyl glycolate, ethyl terephthalyl ethyl glycolate, methyl terephthalyl ethyl glycolate, ethyl terephthalyl methyl glycolate, propyl terephthalyl ethyl glycol Rate, ethyl terephthalyl propyl glycolate, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl propionate, methyl phthalyl ethyl Ropioneto, ethyl phthalyl methyl propionate, and the like. Among these, alkyl phthalyl alkyl glycolate is preferable, and ethyl phthalyl ethyl glycolate and methyl phthalyl ethyl glycolate are more preferable. These triester compounds may use only 1 type and may use 2 or more types together.
Examples of the aromatic tetraester compound having a phthalic acid residue include phthalyl di (alkyl glycolate). That is, for example, phthalyl di (ethyl glycolate), phthalyl di (methyl glycolate) and the like can be mentioned. These tetraester compounds may use only 1 type and may use 2 or more types together.
Among ester compounds, in particular, when an ester compound having these three ester bonds is contained, it is possible to exhibit dramatically superior performance in printing a fine pattern.

  Further, the molecular weight of the ester compound is not particularly limited, but is preferably 500 or less (more preferably 400 or less, more preferably 380 or less, usually 250 or more) for an ester compound having three or more ester bonds, and 350 or less for a diester compound. (More preferably 300 or less, usually 180 or more). If it is within this range, it becomes a stable and homogeneous conductor paste having sufficient solubility with respect to the acrylic resin. Moreover, since it does not volatilize excessively, it is stable and homogeneous, so that a conductor paste excellent in handleability can be obtained. Moreover, the screen clogging of the screen mask can be effectively suppressed.

  In particular, when an ester compound having three or more ester bonds is contained, fine patterning can be more reliably performed. That is, for example, a wiring pattern having a line width of 55 μm or less (usually 10 μm or more) can be accurately patterned, and further, the line width is 40 μm or less (usually 10 μm or more) and the line interval is 40 μm or less (usually 10 μm or more). Thus, it is possible to obtain a conductor paste that can cope with the patterning. Further, excellent repeatability is maintained even in such fine patterning.

  The content of the ester compound is not particularly limited, but is usually 1% by mass or more (preferably 2 to 50% by mass) when the total of the acrylic resin, the oxyalkylene group-containing aromatic compound and the ester compound is 100% by mass. More preferably, it is 5-40 mass%, More preferably, it is 10-30 mass%, Usually 50 mass% or less. If it is 1% by mass or more, it is possible to obtain a conductor paste that is excellent in printability that is homogeneously dissolved and that is particularly suitable for fine patterning.

In addition to the oxyalkylene group-containing aromatic compound and the ester compound, the conductor paste of the first invention can contain other solvent components. Other solvent components include butyl carbitol acetate, butyl carbitol, butyl cellosolve, butyl cellosolve acetate, monoalkyl phthalate, monoalkyl adipate, dialkyl adipate (diethyl adipate, dibutyl adipate, dimethyl adipate, diadipate -N-octyl, di-2-ethylhexyl adipate, dinonyl adipate, etc.), alkylbenzyl adipate (butyl benzyl adipate, etc.) and the like. These may use only 1 type and may use 2 or more types together.
In addition, the content of these other solvent components is not particularly limited. However, when other solvent components are contained, 50% by mass or less (preferably 30% by mass or less, more preferably) when the total solvent component is 100% by mass. It is preferably 20% by mass or less.

Furthermore, the conductor paste of the first invention can contain a sintering control agent. Examples of the sintering control agent include various inorganic oxides, inorganic carbides, inorganic nitrides, and organometallic resinates. Among these, examples of the inorganic oxide include SiO ₂ , TiO ₂ , Fe ₂ O ₃ , Al ₂ O ₃ , CuO, MgO, Bi ₂ O ₃ , and glass frit. These may use only 1 type and may use 2 or more types together. By containing the sintering control agent, it is possible to control the sintering temperature and the sintering speed, and it is possible to prevent warping that occurs in the conductor portion when the base material and the unfired conductor portion are simultaneously fired.
Although content of this sintering control agent is not specifically limited, 0.1-10 mass% is preferable when the paste for conductors is 100 mass%.

  Furthermore, the conductor paste of the first invention can contain other components in addition to the metal powder, acrylic resin, various solvents and sintering control agent. Other components include a thickener, leveling agent, antifoaming agent, dispersant component, lubricant component, surfactant component, antioxidant component, adhesion improving component, firing shrinkage adjusting component, ceramic green described later. Examples include various components contained in the sheet. Each of these may be an inorganic component or an organic component. Moreover, these may use only 1 type and may use 2 or more types together.

  The conductor paste of the second invention contains a metal powder, an acrylic resin, and an aromatic compound having three or more ester bonds.

The conductor paste of the second invention uses an acrylic resin, and it is difficult for the carbon content to remain after firing. Therefore, the metal electrode can be easily fired, and a paste using an acrylic resin by using a specific organic solvent. Even so, the repetitive printability is good.
The “metal powder” and the “acrylic resin” can be applied as they are in the conductor paste of the first invention.

The “aromatic compound having three or more ester bonds” is not particularly limited as long as the number of ester bonds is three or more, but is usually five or less. This ester bond is preferably either three or four, and more preferably three.
When the ester compound having three or more ester bonds is contained, fine patterning can be performed reliably. That is, for example, it can cope with patterning of a wiring pattern having a line width of 55 μm or less (usually 10 μm or more), and further, the line width is 40 μm or less (usually 10 μm or more) and the line interval is 40 μm or less (usually 10 μm or more). In particular, it is possible to obtain a conductor paste that can support patterning with a line width of 35 μm or less (usually 10 μm or more) and a line interval of 35 μm or less (usually 10 μm or more). Further, excellent repeatability is maintained even in such fine patterning.

Examples of such ester compounds include various triester compounds and tetraester compounds. Among these, various ester compounds having a dicarboxylic acid residue are included. That is, for example, an aromatic triester compound having a dicarboxylic acid residue, an aromatic tetraester compound having a dicarboxylic acid residue, and the like.
Examples of the dicarboxylic acid residue include phthalic acid residues (including phthalic acid residues, isophthalic acid residues and terephthalic acid residues), adipic acid residues, and the like.
Of these ester compounds, phthalate ester compounds are preferred. That is, each triester compound and tetraester compound having a phthalic acid residue are preferred. Furthermore, a triester compound having a phthalic acid residue is more preferable. This is because a more stable conductor paste can be obtained. These ester compounds may use only 1 type and may use 2 or more types together.

但し、上記一般式４におけるＲ_３、Ｒ_４及びＲ_５は各々独立して炭素数が１〜４の炭化水素基である。 As an aromatic triester compound which has a phthalic acid residue, the compound represented by following General formula (4) is mentioned.

However, R ₃ , R ₄ and R ₅ in the above general formula 4 are each independently a hydrocarbon group having 1 to 4 carbon atoms.

Examples of the compound represented by the general formula 4 include alkyl phthalyl alkyl glycolate and alkyl phthalyl alkyl propionate. That is, for example, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, ethyl phthalyl methyl glycolate, propyl phthalyl ethyl glycolate, ethyl phthalyl propyl glycolate, ethyl isophthalyl ethyl glycolate, methyl isophthalyl ethyl Glycolate, ethyl isophthalyl methyl glycolate, propyl isophthalyl ethyl glycolate, ethyl isophthalyl propyl glycolate, ethyl terephthalyl ethyl glycolate, methyl terephthalyl ethyl glycolate, ethyl terephthalyl methyl glycolate, propyl terephthalyl ethyl glycol Butyl phthalyl butyl glycolate, ethyl terephthalyl propyl glycolate, ethyl phthalyl ethyl propionate, methyl phthalyl ethyl Ropioneto, ethyl phthalyl methyl propionate and the like. Among these, alkyl phthalyl alkyl glycolate is preferable, and ethyl phthalyl ethyl glycolate and methyl phthalyl ethyl glycolate are more preferable. These triester compounds may use only 1 type and may use 2 or more types together.
Examples of the aromatic tetraester compound having a phthalic acid residue include phthalyl di (alkyl glycolate). That is, for example, phthalyl di (ethyl glycolate), phthalyl di (methyl glycolate) and the like can be mentioned. These tetraester compounds may use only 1 type and may use 2 or more types together.

  Further, the molecular weight of the aromatic compound having three or more ester bonds is not particularly limited, but is preferably 500 or less (more preferably 400 or less, still more preferably 380 or less, usually 250 or more). If it is within this range, it becomes a stable and homogeneous conductor paste having sufficient solubility with respect to the acrylic resin. Moreover, since it does not volatilize excessively, it becomes a paste for conductors that is stable and homogeneous and has excellent handleability. Moreover, the screen clogging of the screen mask can be effectively suppressed.

  The content of the aromatic compound having three or more ester bonds is not particularly limited, but is usually 10% by mass or more (preferably 20 to 80% by mass) when the total of the acrylic resin and the ester compound is 100% by mass. %, More preferably 25 to 75% by mass, still more preferably 30 to 70% by mass, and usually 90% by mass or less). If it is 10 mass% or more, it is excellent in the printability melt | dissolved uniformly, and can obtain the paste for conductors especially suitable for fine patterning.

The conductor paste of the second invention preferably contains other solvent components in addition to the compound having three or more ester bonds. As another solvent component, a solvent component having a boiling point of 150 to 300 ° C. (preferably 170 to 280 ° C., more preferably 180 to 270 ° C.) can be used. By using other solvent components in combination, it is possible to maintain sufficient drying performance while preventing blur due to plate clogging.
Further, the other solvent component is preferably a compound having an oxyalkylene group. By having an oxyalkylene group, more appropriate volatilization performance is exhibited. Examples of the solvent component having an oxyalkylene group include an oxyalkylene group-containing aromatic compound and an oxyalkylene group-containing aliphatic compound.

  As said oxyalkylene group containing aromatic compound, the compound shown by the following general formula 3 or 2 is mentioned. These compounds function as a solvent for the acrylic resin and form a conductor paste as a whole with the metal powder and the acrylic resin.

但し、上記一般式３におけるＲ_２及び上記一般式２におけるＲ_１は各々独立してＨ又はＣＨ_３であり、上記一般式３におけるｋ及び上記一般式２におけるｍは各々独立して１又は２である。

However, R ₂ in the general formula 3 and R ₁ in the general formula 2 are each independently H or CH ₃ , k in the general formula 3 and m in the general formula 2 are each independently 1 or 2 It is.

The general formula of the oxyalkylene group-containing aromatic compound (3) a compound represented by (hereinafter, simply referred to as "oxyalkylene compound (3)"), the oxyalkylene group {oxyethylene group (R ₂ is H Or an oxyisopropylene group (when R ₂ is CH ₃ )} and a phenoxy group. k may be 1 or 2. Furthermore, when k = 2, the two R ₂ constituting the oxyalkylene group can each independently be H or CH ₃ . When k is 1 or 2, that is, by having an oxyalkylene group, it is possible to ensure the ease of handling of the conductor paste (does not volatilize excessively while ensuring adequate volatility), and is stable and A homogeneous conductor paste can be obtained. Moreover, the plate clogging of the screen mask can be effectively suppressed, the erosion of the screen mask can be further suppressed, and the odor can be suppressed.

  As this oxyalkylene compound (3), 2-phenoxyethanol, 1-phenoxy-2-propanol, 2- (2-phenoxyethoxy) ethanol, 2- (1-phenoxy-2-propoxy) ethanol, 1- (2- And phenoxyethoxy) -2-propanol. Among these, 2-phenoxyethanol and / or 1-phenoxy-2-propanol in which k = 1 is preferable. By being k = 1, it can have sufficient compatibility with acrylic resin, ensuring moderate volatility. These oxyalkylene compounds (3) may be used alone or in combination of two or more.

Of the oxyalkylene group-containing aromatic compound, the “oxyalkylene compound (2)” can be applied as it is to the compound represented by the general formula (2).
Of the oxyalkylene compound (3) and the oxyalkylene compound (2), the oxyalkylene compound (3) is more preferable, and 2-phenoxyethanol is more preferable. This is because, in particular, the solubility in the resin is high, the stability of the paste is increased, and clogging of the screen mask can be effectively suppressed.
Moreover, these oxyalkylene compounds (3) and oxyalkylene compounds (2) are considered to be preferable in that both are compounds having a hydroxyl group. Thereby, the thickening of the paste due to the interaction between the acrylic resin and the metal powder in the conductor paste is suppressed, and it is considered that good paste properties can be obtained.

Further, the oxyalkylene group-containing aliphatic compound includes butyl carbitol, butyl cellosolve, carbitol, cellosolve, butyl carbitol acetate, butyl cellosolve acetate, ethylene glycol solvents such as carbitol acetate and cellosolve acetate, propylene glycol monobutyl ether, Examples include propylene glycol solvents such as dipropylene glycol monobutyl ether, propylene glycol monobutyl ether acetate, and dipropylene glycol monobutyl ether acetate.
Furthermore, among these oxyalkylene group-containing aliphatic compounds, compounds having a hydroxyl group are preferred. That is, for example, butyl carbitol, butyl cellosolve, carbitol, cellosolve, propylene glycol monobutyl ether and dipropylene glycol monobutyl ether are preferable. About the effect, it is the same as the effect in an oxyalkylene group containing aromatic compound.

  The content of these oxyalkylene group-containing aromatic compounds and / or oxyalkylene group-containing aliphatic compounds (hereinafter also simply referred to as “oxyalkylene compounds”) is not particularly limited, but is usually an acrylic resin and three or more esters. When the total of the aromatic compound having a bond and the oxyalkylene compound is 100% by mass, it is 10% by mass or more (preferably 10 to 90% by mass, more preferably 20 to 90% by mass, still more preferably 30 to 85% by mass. %, Usually 95% by mass or less). If it is this range, acrylic resin can be melt | dissolved uniformly and the paste for conductors which has the uniform reproducibility which is homogeneous and stable can be obtained.

  The conductor paste of the second invention can further contain a solvent component other than an aromatic compound having three or more ester bonds and an oxyalkylene compound. Examples of the solvent component include high-boiling solvents such as dialkyl phthalate, monoalkyl phthalate, monoalkyl adipate, and dialkyl adipate. These may use only 1 type and may use 2 or more types together. Further, the content of these solvent components is not particularly limited, but may be 50% by mass or less (preferably 30% by mass or less, more preferably 20% by mass or less) when the entire solvent component is 100% by mass. it can.

  The conductor paste of the second invention can contain other components in addition to the metal powder, the acrylic resin and various solvents. Other components include a thickener, leveling agent, antifoaming agent, dispersant component, lubricant component, surfactant component, antioxidant component, adhesion improving component, firing shrinkage adjusting component, ceramic green described later. Examples include inorganic components contained in the sheet. These may use only 1 type and may use 2 or more types together.

The method for manufacturing a wiring board according to the present invention is a method for manufacturing a wiring board comprising a base made of low-temperature fired porcelain and a conductor formed inside and / or on the surface of the base made of low-temperature fired porcelain,
An unsintered conductor is formed by printing the conductor paste according to any one of claims 1 to 7 on the surface of the ceramic green sheet serving as the low-temperature fired porcelain base. A conductor portion forming step;
A firing step of firing the ceramic green sheet having the unfired conductor portion in a non-oxidizing atmosphere.

The “low-temperature fired porcelain base” is a base that functions as an insulating portion with respect to the conductor, and is a portion made of low-temperature fired porcelain. The degree of insulation is not particularly limited, but is usually 1 × 10 ⁸ Ω · cm or more at 25 ° C. The low-temperature fired ceramic is a ceramic obtained at a firing temperature of 1050 ° C. or lower (usually 700 ° C. or higher). However, this firing temperature is the firing temperature of the low-temperature fired porcelain and is not related to the temperature necessary for sintering the material constituting the base. Accordingly, the low-temperature fired porcelain may or may not contain a high-temperature sinterable material as a filler or the like.

The components constituting the low-temperature fired ceramic, the composition thereof, and the like are not limited, and any low-temperature fired ceramic used as a wiring board can be used. That is, it may consist only of ceramic components, may contain glass components (including glass ceramics) in addition to ceramic components, and may further contain other components.
Examples of the composition constituting the low-temperature fired porcelain include alumina, titania, zirconia, quartz, silicon carbide, aluminum nitride, mullite, spinel, cordierite, spodumene, garnite, forsterite, wollastonite, anorthite, enstatite. , Diopsite, akermanite, gehlenite, titanate, niobate, tantalate, zirconate, aluminosilicate, aluminoborosilicate, borosilicate, silicate, part of each of these compositions Examples thereof include substitution products substituted with other elements, solid solutions in which other elements are partly dissolved in each of these compositions, and the like. Only 1 type may contain these and 2 or more types may contain.

  The “conductor portion” is a portion formed by firing an unfired conductor portion formed using the conductor paste of the present invention, and is a portion having conductivity. The conductivity of the conductor portion is not particularly limited, but is usually 5 μΩ · cm or less at 25 ° C. Moreover, the shape of this conductor part is not specifically limited. That is, for example, it may be a wiring pattern formed in a layer form in the base made of low-temperature fired porcelain, and may be a via conductor and a through-hole conductor that connect these wiring patterns. Examples of the wiring pattern include a normal conduction wiring, a resistance wiring, a capacitor wiring (such as a pad shape), an inductance wiring, and a bonding pad. Further, the conductor portion may be formed inside the base made of low-temperature fired porcelain, may be formed on the surface (outer surface) of the base made of low-temperature fired porcelain, or may be formed on both of them. Good.

According to this manufacturing method, since the conductor paste of the present invention is used, a wiring board provided with the fine wiring can be obtained.
In addition, the form, shape, configuration, and the like of the wiring board obtained by this manufacturing method are not particularly limited. That is, the wiring board may be a single layer or a multilayer.
Among these, the single-layer wiring board is a wiring board obtained by using only one layer of ceramic green sheets. For example, the aspect provided with a conductor part (conductor layer) on at least one surface of the front and back surfaces of the low-temperature fired porcelain layer obtained by firing a single ceramic green sheet can be mentioned.

On the other hand, the multilayer wiring board is a wiring board obtained by laminating a plurality of ceramic green sheets. For example, it is obtained by firing an unsintered laminate obtained by laminating a plurality of ceramic green sheets each having an unsintered conductor part (unsintered conductor layer) formed on at least one surface,
The aspect provided with the conductor part baked integrally in the inside of the base made from a low-temperature baking porcelain formed by sintering a ceramic green sheet is mentioned.
In addition, although the conductor part formed in the unfired conductor part formation process mentioned later is a process using the conductor paste of this invention, all the conductor parts with which a wiring board is provided are obtained using the conductor paste of this invention. It need not be

The “unfired conductor portion forming step” is a step of printing the conductor paste of the present invention on the surface of the ceramic green sheet to form an unfired conductor portion.
The “ceramic green sheet” is a part of the base made of low-temperature fired porcelain after firing. This ceramic green sheet usually contains an inorganic component powder that becomes a low-temperature fired ceramic after firing, and a binder component.
As the inorganic component powder, various materials constituting the low-temperature fired ceramic can be used. Furthermore, these materials may be obtained by firing.

The binder component usually contains a resin and a solvent component. Although the kind of resin is not specifically limited, It is preferable to use the acrylic resin contained in the said paste for conductors of this invention. In addition, for example, a cellulose resin, a rubber resin, a polyurethane resin, a polyester resin, a phenol resin, a polyvinyl acetal resin, and the like can be used. These may use only 1 type and may use 2 or more types together.
Moreover, the kind of solvent component is not particularly limited, but the compound having two or more ester bonds may be used. In particular, an aromatic ester compound having a phthalic acid residue is desirable. Examples of aromatic ester compounds having phthalic acid residues include dialkyl phthalates (diethyl phthalate, dibutyl phthalate, dimethyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, dinonyl phthalate, etc.) , Alkylbenzyl phthalate (such as butylbenzyl phthalate), dialkyl isophthalate (such as diethyl isophthalate, dibutyl isophthalate, dimethyl isophthalate, di-n-octyl isophthalate, di-2-ethylhexyl isophthalate, dinonyl isophthalate) , Alkylbenzyl isophthalate (such as butylbenzyl isophthalate), dialkyl terephthalate (diethyl terephthalate, dibutyl terephthalate, dimethyl terephthalate, di-n-octyl terephthalate, di-2-ethylhexyl terephthalate, terephthalate Le dinonyl etc.), terephthalic acid alkylbenzyl (butyl terephthalate benzyl, etc.) and the like. These may use only 1 type and may use 2 or more types together.

Although content of a binder component is not specifically limited, For example, when the whole ceramic green sheet is 100 mass%, it can be 5-40 mass%, and resin is 50-100 mass% among binder components. can do.
Furthermore, the ceramic green sheet can contain other components in addition to the inorganic component and the binder component. Examples of other components include a dispersant component, a leveling agent component, a lubricant component, an antifoaming component, an antioxidant component, and a surfactant component. These may use only 1 type and may use 2 or more types together.

The “printing” is not particularly limited as long as the unfired conductor portion can be formed on the surface of the ceramic green sheet, and the printing conditions are not particularly limited. In other words, various screen printers can be used as the printer. The printing pressure can be 10 to 300 kPa (preferably 20 to 250 kPa, more preferably 20 to 180 kPa). Furthermore, the gap between the screen mask and the printing surface can be 0.5 to 3 mm (preferably 0.8 to 2.5 mm, more preferably 1.0 to 2 mm). The printing speed can be 20 to 200 mm / second (preferably 30 to 200 mm / second, more preferably 40 to 200 mm / second). Each of these printing conditions can be combined.
In this printing, a transfer sheet having an unfired conductor portion obtained by once printing the conductor paste of the present invention on a peelable sheet is used, and the transfer sheet is transferred and printed on the surface of the ceramic green sheet. An unfired conductor portion may be formed.

The “firing step” is a step of firing a ceramic green sheet having an unfired conductor portion in a non-oxidizing atmosphere.
The “non-oxidizing atmosphere” is an atmosphere having a low oxygen partial pressure, and is usually an atmosphere having an oxygen partial pressure of 10 Pa or less (preferably 0.1 Pa or less, usually 0.0001 Pa or more). Moreover, although the gas which comprises non-oxidizing atmosphere is not specifically limited, For example, inert gas, such as noble gases, such as nitrogen and argon, is mentioned. Of these, nitrogen is preferred. Moreover, these inert gases may use only 1 type and may use 2 or more types together. Furthermore, this non-oxidizing atmosphere may or may not contain a reducing gas. Examples of the reducing gas include hydrogen gas and carbon monoxide gas. Of these, hydrogen gas is preferred. These reducing gases may use only 1 type and may use 2 or more types together.
Further, the non-oxidizing atmosphere may be a wet atmosphere or a non-wet atmosphere. The wet atmosphere is an atmosphere in which the dew point is controlled, and is usually an atmosphere in which the dew point is kept at 90 ° C. or lower (preferably 80 ° C. or lower, usually 30 ° C. or higher).
Among these non-oxidizing atmospheres, a nitrogen atmosphere or a wet nitrogen atmosphere is preferable. By using these atmospheres, oxidation of the metal component contained in the conductor paste can be prevented.

In the firing step, firing conditions other than using the non-oxidizing atmosphere are not particularly limited, but the firing temperature is 1050 ° C. or lower. The firing temperature is not particularly limited as long as it is 1050 ° C. or less (temperature for firing a low-temperature fired ceramic), but it is preferably 850 to 1050 ° C. (more preferably 900 to 1050 ° C., particularly preferably 925 to 1000 ° C.). . Within this temperature range, the low-temperature fired porcelain can be sufficiently densified, abnormal grain growth and melting of the metal powder in the unfired conductor portion can be prevented, and fine wiring can be formed in a desired shape.
The firing temperature time (time for maintaining the firing temperature) is not particularly limited, but is usually 0.1 hour or longer (preferably 0.5 hour or longer, usually 5 hours or shorter).

  In this manufacturing method, in addition to the unfired conductor portion forming step and the firing step, other steps can be provided. Examples of other processes include a preliminary firing process, a lamination process, a through hole drilling process, and a cutting process.

Among the other steps, the pre-baking step is a step in which organic components contained in the ceramic green sheet and the conductor paste are removed by heating. This pre-baking process is a process performed before the said baking process. However, the preliminary firing step and the firing step may be performed continuously or may be performed without being continued.
The firing conditions in the preliminary firing step are not particularly limited, but usually the firing atmosphere is a non-oxidizing atmosphere and a wet atmosphere. As for the non-oxidizing atmosphere and the humid atmosphere, each of the above firing steps can be applied as it is. Among these atmospheres, a wet nitrogen atmosphere is preferable.

Although the firing temperature in the preliminary firing step is not particularly limited, it is usually lower than the firing temperature by 100 ° C. or more and in the range of 600 to 900 ° C. (more preferably 700 to 875 ° C.). Within this range, the organic component can be sufficiently removed, and the unfired component that becomes the low-temperature fired porcelain is not densified. Further, it is possible to prevent the unsintered conductor portion from being sintered and causing the wiring substrate to swell.
Further, the firing temperature time (time for maintaining the firing temperature) in the preliminary firing step is not particularly limited, but is usually 0.5 hours or longer (preferably 1 hour or longer, usually 24 hours or shorter).

The laminating step is a step of laminating ceramic green sheets and the like. The ceramic green sheets to be laminated in this lamination include at least a ceramic green sheet on which an unfired conductor portion is formed, but may include a ceramic green sheet that does not have an unfired conductor portion.
The lamination conditions in this lamination process are not particularly limited, and there is no limitation on the presence or absence of pressurization and the presence or absence of heating. However, pressurization is preferable, and further, heating is preferably performed in addition to pressurization. The pressure at the time of pressurization is not particularly limited, but can be 200 MPa or less (preferably 150 MPa or less, more preferably 100 MPa or less). Furthermore, although the temperature at the time of heating is not specifically limited, It can be 30-100 degreeC (preferably 30-90 degreeC, More preferably, it is 30-80 degreeC). Furthermore, each time at the time of pressurization and / or heating is not particularly limited, but can be 300 seconds or less (preferably 250 seconds or less, more preferably 200 seconds or less).
In addition, when laminating | stacking, a solvent is normally apply | coated to a lamination surface. Moreover, temporary adhesion can also be performed for the purpose of positioning or the like. In this case, the pressure when performing pressurization is usually 50 MPa or less, the temperature when performing heating is 100 ° C. or less, and the time when performing pressurization and / or heating is 90 seconds or less. is there.

The through hole forming step is a step of forming a through hole in a ceramic green sheet when obtaining a wiring board having a through hole for electrically connecting conductor layers separated by a low-temperature fired ceramic. It is. A through-hole conductor can be obtained by filling the through-hole with a conductor paste in an unfired conductor portion forming step or the like. As described above, the conductor portion includes such a through-hole conductor. That is, each conductor layer and the through-hole conductor connecting each conductor layer behave as an integral conductor in the wiring board.
The cutting step is a step of placing a break line and aligning the panel size.

  The wiring board of the present invention comprises a base made of low-temperature fired porcelain and a conductor formed by firing an unfired conductor made of the paste for conductor of the present invention, and the base made of low-temperature fired porcelain and the conductor The part is characterized by being co-fired.

As the “conductor paste”, the conductor paste of the first invention and the conductor paste of the second invention can be applied as they are. As the conductor paste, the conductor paste of the first invention may be used, the conductor paste of the second invention may be used, or both of them may be used.
Each of the “low temperature fired porcelain base”, the “unfired conductor”, the “fired”, and the “conductor” can be applied as it is in the production method.
The term “co-fired” means that the base made of low-temperature fired porcelain and the conductor are co-fired integrally.

  The reason why the repeated printability is improved in the conductor paste of the present invention is not clear, but is considered as follows. That is, an acrylic resin excellent in printability generally has low solubility in a solvent component, and the acrylic resin is likely to remain undissolved or phase-separated easily. This undissolved residue causes clogging of the screen mask, and phase separation makes the conductive paste unstable, so it is considered that the paste wraps around the back surface of the screen mask and causes blurring. However, if the solvent is selected only by focusing on the low solubility, a solvent component having high erosion with respect to the screen mask is selected. For this reason, the screen mask is eroded, resulting in repeated printability deterioration.

The solvent component used in the present invention contains an aromatic compound having an appropriate oxyalkylene structure and / or an aromatic compound having three or more ester bonds. These compounds have sufficient solubility in acrylic resins and do not cause undissolved or phase separation. Furthermore, the erosion property with respect to a screen mask is low. For this reason, it is considered that printing can be repeated without causing plate clogging or blurring, and further, fine wiring patterning can be performed. Moreover, since these solvent components can moderately adjust volatility by the mixing ratio, they can hold | maintain a paste stably over a long period of time, and can perform printing stably.
Furthermore, since the acrylic resin used for the binder has a hydroxyl group, the paste interacts with the metal to thicken the paste. However, since the predetermined solvent component has a hydroxyl group or a plurality of ester bonds in the molecule, it is considered that the solvent component and metal also interact. For this reason, it is considered that the interaction between the acrylic resin and the metal is reduced, the viscosity is suppressed, the paste property is excellent, and the patterning of fine wiring can be supported.

(1) Production of ceramic green sheet Acrylic resin binder for 100 parts by mass of mixed powder (particle size 2.5 μm) of glass powder (50 parts by mass) and alumina filler (50 parts by mass) having the following composition. (Dai Nippon Ink Chemical Co., Ltd., product name “NCB-732”) 14 parts by mass of solid content, 6 parts by mass of plasticizer (di-2-ethylhexyl phthalate), toluene / isopropyl alcohol mixed solvent (appropriate amount) A slurry was prepared, and a green sheet for low-temperature firing having a thickness of 250 μm was obtained by a doctor blade method.
Glass powder composition SiO ₂ 72.0 (mol%)
B ₂ O ₃ 18.0 (mol%)
Al ₂ O ₃ 4.5 (mol%)
CaO 5.5 (mol%)

(2) Preparation of paste for conductor 100 parts by mass of copper powder having an average particle size of 3 μm, a vehicle having the composition of Table 1 that is 25 parts by mass with respect to this copper powder, 1 part by mass of SiO ₂ powder, and 1 mass Part of TiO ₂ powder and 1 part by mass of Fe ₂ O ₃ powder were mixed by a three-roll mill to obtain pastes for conductors of Examples 1 to 10 and Comparative Examples 1 to 8.
However, each component in Table 1 is as follows.
<resin>
Acrylic resin: Acrylic resin fine powder for printing paste, manufactured by Mitsubishi Rayon Co., Ltd., product name “MB-3088”
<Solvent 1>
EPh: 2-phenoxyethanol PPh: 1-phenoxy-2-propanol EBz: 2- (benzyloxy) ethanol BCA: butyl carbitol acetate BC: butyl carbitol BzA: benzyl acetate BzAl: benzyl alcohol Krs: cresol <solvent 2>
DBP: Dibutyl phthalate DEP: Diethyl phthalate EPEG: Ethyl phthalyl ethyl glycolate MPEG: Methyl phthalyl ethyl glycolate

(3) Printability evaluation Each pattern of line width / inter-line width (L / S) = 30 μm / 30 μm, 50 μm / 50 μm, and 70 μm / 70 μm is formed on one surface of the ceramic green sheet obtained in (1) above. Each conductor paste prepared in the above (2) was printed using each screen mask. In printing, the printing state of the wiring pattern printed at the 10th time is performed 10 times with a printing pressure of 20 kPa, a gap between the screen mask and the printing surface of 1.5 mm, and a printing speed of 80 mm / second. Was observed with a 20 × magnifier. The results were evaluated according to the following criteria, and this evaluation is also shown in Table 1.
“◯”: Conductor paste capable of printing with good edge shape.
“Δ”: A paste for conductors that has blurring or blurring but does not cause short circuit or open defects.
“X”: A paste for a conductor that causes short-circuit failure and open failure due to bleeding or blurring.

From the results shown in Table 1, all of the solvent components used in Comparative Examples 1 to 10 are included in the compounds represented by the general formulas (1) and (2) and the compounds having three or more ester bonds. There is nothing.
In Comparative Example 1, butyl carbitol acetate (BCA) frequently used in a conductor paste was used, but the paste was remarkably thickened, and slickness was generated even at L / S = 70/70.
Comparative Example 2 uses butyl carbitol (BC), which has neither a hydroxyl group nor a plurality of ester bonds in the molecule, but has a poor solubility in acrylic resins and provides a homogeneous vehicle. I could not. For this reason, many pastes wrap around the back side of the screen mask during repeated printing, resulting in blurring.

Further, Comparative Example 3 contains benzyl acetate (BzA) having a benzyloxy group in the molecule but not having a plurality of ester bonds extending to the hydroxyl group. Although the conductor paste of Comparative Example 3 was able to be repeatedly printed at L / S = 70/70, when L / S = 50/50 or less, the screen mask was clogged frequently, resulting in blurring. .
In Comparative Examples 4 and 6 containing either benzyl alcohol (BzAl) or cresol (Krs), bleeding occurs even at L / S = 70/70, and it is difficult to perform repeated printing beyond that. I understand that there is. Furthermore, in Comparative Example 5 containing 1-phenoxy-2-propanol (PPh) alone, blurring occurs at L / S = 50/50, and it is difficult to perform further repeated printing. I understand.
Further, when butyl carbitol is used as the solvent component 1 and dibutyl phthalate (DBP) or diethyl phthalate (DEP) which is an aromatic diester compound having a phthalic acid residue is used as the solvent component 2, L / It can be seen that any wiring of S = 30/30 to 70/70 cannot be repeatedly printed.

On the other hand, Example 1 contains only 2-phenoxyethanol (EPh) represented by the general formula (1) as a solvent component, and Example 2 is represented by 2 represented by the general formula (2). Only-(benzyloxy) ethanol (EBz) is contained as a solvent component, and Example 9 contains both of these. For this reason, it is found that the fine wiring up to L / S = 50/50 can be surely formed repeatedly although the scraping due to the plate clogging occurs at L / S = 30/30 and the open defect occurs.
Furthermore, Examples 3 and 4 contain dibutyl phthalate (DBP) or diethyl phthalate (DEP) having two ester bonds in combination. For this reason, the L / S = 30/30 blur is further reduced as compared with the additive-free Examples 1 and 2, and it can be seen that the printing can be repeated at least 10 times. Further, it can be seen that fine wiring up to L / S = 50/50 can be reliably and repeatedly formed.

In particular, Examples 5 and 6 contain ethyl phthalyl ethyl glycolate (EPEG) or methyl phthalyl ethyl glycolate (MPEG) with three ester linkages, and Example 10 contains both. For this reason, it can be seen that fine wiring up to L / S = 30/30 can be reliably and repeatedly formed, and extremely excellent performance is exhibited.
Further, Examples 7 and 8 are conductor pastes using butyl carbitol as the solvent component 1 and ethyl phthalyl ethyl glycolate (EPEG) or methyl phthalyl ethyl glycolate (MPEG) as the solvent component 2. . In these conductor pastes, in Comparative Examples 7 and 8, any wiring of L / S = 30/30 to 70/70 cannot be repeatedly printed, whereas L / S = 30/30 to 50/50. It can be seen that printing can be repeated well until. That is, it can be seen that even if only EPEG or MPEG is used as the solvent component 2, the printing performance is dramatically improved.

(4) Production of wiring board Through holes were formed at predetermined positions of the ceramic green sheet obtained in (1) above. Then, using the conductor paste of Example 6 prepared in (2) above from one side of this ceramic green sheet, L / S = 30/30 fine wiring was provided, and the through-hole was filled with the conductor paste The formed wiring pattern was printed. Three similar ceramic green sheets were prepared. Then, each was laminated | stacked so that each wiring pattern might oppose the surface opposite to the wiring pattern printing surface of each ceramic green sheet, and the unbaking laminated body was produced.

Degreasing organic components by pre-baking the obtained unfired laminate at 800 ° C. in a wet nitrogen atmosphere with a nitrogen partial pressure of 10,000 Pa, an oxygen partial pressure of 1 Pa or less, and a dew point maintained at 80 ° C. Went. Thereafter, the atmosphere was replaced, and the substrate was baked at 1000 ° C. for 1 hour in a nitrogen atmosphere where nitrogen was 100 MPa and the oxygen partial pressure was 1 Pa or less. A multilayered wiring board (1) having a conductor part (12) made of was obtained.
The obtained wiring board had a fine wiring circuit of L / S = 30/30 μm and exhibited excellent voltage resistance (withstand voltage value of 10 kV) because there was little residual carbon.

In addition, in this invention, it can restrict to what is shown to said specific Example, It can be set as the Example variously changed within the range of this invention according to the objective and the use. Further, although not included in the present invention, in the oxyalkylene group-containing aromatic compound represented by the general formulas 1 to 3, carbon atoms constituting the benzene ring in each compound (excluding carbon atoms that already have a substituent) ) _May be used in which a part of the hydrocarbon group is substituted with a hydrocarbon group having 1 or 2 carbon atoms (that is, —CH ₃ , —C ₂ H ₅ ).

The conductor paste of the present invention is widely used in the field of electronic components. It is used as a conductor paste for forming a conductor portion of any electronic component that requires firing at a low temperature, and is particularly suitable for forming a conductor portion of a wiring board (including a package or the like) using various low-temperature firing ceramics.
The wiring board of the present invention is widely used in the field of electronic components. In particular, various wiring boards (normal wiring boards such as motherboards, flip-chip wiring boards, CSP wiring boards, MCP wiring boards, etc.), various packages (semiconductor elements, crystal elements, etc.) Etc.) and various modules (wiring boards used in various modules such as antenna switches, mixers, PLLs, MCMs, etc.).
The method for manufacturing a wiring board of the present invention is widely used for manufacturing the various wiring boards.

It is typical sectional drawing of an example of the wiring board of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Wiring board, 11: Base made from a low-temperature baking porcelain, 12: Conductor part.

Claims (10)

A metal powder, an acrylic resin, and at least one of an oxyalkylene group-containing aromatic compound represented by the following general formula 1 and an oxyalkylene group-containing aromatic compound represented by the following general formula 2. A conductor paste characterized by that.

However, R ₁ in the general formula 2 is H or CH _3, m in the n and the general formula 2 in the general formula 1 are each independently 1 or 2.   The conductor paste according to claim 1, further comprising an aromatic compound having two or more ester bonds.   The conductor paste according to claim 2, wherein the aromatic compound is a phthalate ester compound.   4. The conductor paste according to claim 3, wherein the phthalate ester compound is an alkyl phthalyl alkyl glycolate.   A conductive paste comprising metal powder, an acrylic resin, and an aromatic compound having three or more ester bonds.   The conductor paste according to claim 5, wherein the phthalate ester compound is an alkylphthalylalkyl glycolate. The conductor according to claim 5 or 6, further comprising at least one of an oxyalkylene group-containing aromatic compound represented by the following general formula 3 and an oxyalkylene group-containing aromatic compound represented by the following general formula 2. For paste.

However, R ₂ in the general formula 3 and R ₁ in the general formula 2 are each independently H or CH ₃ , k in the general formula 3 and m in the general formula 2 are each independently 1 or 2 It is. A method of manufacturing a wiring board comprising: a base made of low-temperature fired porcelain; and a conductor formed inside and / or on the surface of the base made of low-temperature fired porcelain,
An unsintered conductor is formed by printing the conductor paste according to any one of claims 1 to 7 on the surface of the ceramic green sheet serving as the low-temperature fired porcelain base. A conductor portion forming step;
And a firing step of firing the ceramic green sheet comprising the unfired conductor portion in a non-oxidizing atmosphere.   The method for manufacturing a wiring board according to claim 8, wherein the firing in the firing step is performed at 850 to 1050 ° C. 10.   A base made of low-temperature fired porcelain and a conductor made by firing an unfired conductor made of the conductor paste according to any one of claims 1 to 7, and the low-temperature fired porcelain base And the conductor part are fired at the same time.

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