JPH06325618A - Vehicle for paste - Google Patents

Abstract

PURPOSE:To enhance plate releasing performance in printing, printing accuracy and rectangularity of paste by using boric ester as a binder. CONSTITUTION:In the case of boric ester, boric ester of monohydric alcohol and/or polyhyric alcohol is used as a binder. Particularly, at least one kind of ester borate obtained by mutual reaction of one or two or more kinds of a mixture of boric acid or boric anhydride and monohydric or polyhydric alcohol expressed by a formula R1-OH is used. Consequently, it is possible to prepare paste having adequate viscosity and thixotropy and excellent in plate releasing performance in printing, printing accuracy, rectangularity, and evaportranspiration in sintering, and capable of providing an effect of metal corrosion resistance. As a result, it is possible to apply the paste to a micro IC chip, integrated circuit or the like of high performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle suitable for producing a paste, and more specifically, it imparts excellent printing accuracy and rectangularity to a paste printed on a green sheet ceramics or a fired ceramics substrate and sinters it. The present invention relates to a vehicle that is excellent in transpiration property and rust preventive power.

Products using the vehicle of the present invention include IC packages and circuit boards that utilize ceramics, and these are used as electronic parts for electronic products such as personal computers, workstations, computers, automobiles, and mobile phones. It

[0003]

2. Description of the Related Art Conventionally, as a binder for a paste, a polymer such as ethyl cellulose, nitrocellulose, polyvinyl alcohol, polyvinyl butyral or the like is dissolved in a solvent such as diethylene glycol monobutyl ether or diethylene glycol monobutyl ether acetate to adjust the viscosity and the like. This is mixed with metal powder (tungsten, copper, silver, gold, molybdenum, silver-palladium, etc.) or glass powder in an appropriate compounding ratio, kneaded with a ball mill, and then sintered on a green sheet ceramics or with a stainless steel screen. It is printed, dried and sintered on a ceramic substrate and used as a highly integrated precision circuit.

However, IC chips and integrated circuits have become extremely compact,
With the progress of higher performance, conventional binder compositions do not provide satisfactory paste release properties, printing accuracy and rectangularity in printing and sintering processes.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a paste vehicle capable of improving the plate dropout property, the printing accuracy and the rectangularity of the paste during printing.

[0006]

In view of the current state of the art as described above, the present inventors have an appropriate viscosity as a binder at the time of producing a conductive paste or a glass paste, and a metal or glass ( If a binder with excellent wettability with (powder) is used, a paste with an appropriate viscosity, contact angle and thixotropy can be prepared, and printing, drying and sintering can be performed on green sheet ceramics or fired ceramics substrates. Paying attention to the fact that it is possible to improve the plate missing property, printing accuracy, and rectangularity when
As a result of earnest research, it was found that borate ester is suitable as such a binder. If borate ester is used, printing accuracy and rectangularity can be improved and stabilized, which could not be solved by the conventional technology.Borate ester also has excellent debinding property during sintering and also prevents corrosion. It has the advantage that it can contribute. The present invention is
A vehicle for paste is characterized by containing a borate ester.

The boric acid ester is preferably a boric acid ester obtained by reacting boric acid or boric anhydride with one or more of the following compounds (1) to (4). (1) A monohydric alcohol represented by the general formula R ₁ —OH, (2)
A diol represented by the following general formula,

[0008]

[Chemical 1]

(3) Glycerin or a monoester or diester thereof, (4) a polyhydric alcohol other than the above diol and glycerin or an ester or ether thereof.

However, R ₁ is a linear or branched alkyl group having 1 to 22 carbon atoms, an alkoxyalkyl group or an alkenyl group, or an aryl group, an aralkyl group or a cycloalkyl group, and R ₂ , R ₃ , R ₄ and R ₅ represents a hydrogen atom or a linear or branched alkyl group having 1 to 15 carbon atoms, and X represents a single bond or a linear or branched alkylene group having 1 to 20 carbon atoms.

[0011]

The borate used in the present invention is 1
It is a boric acid ester of a polyhydric alcohol and / or a polyhydric alcohol. In particular, boric acid or boric anhydride and the above
It is preferable to use at least one boric acid ester obtained by reacting the monohydric or polyhydric alcohols of (1) to (4) with one type or a mixture of two or more types.

Examples of the monohydric alcohol used for producing the borate ester include alcohols represented by the above general formula R ₁ —OH. Here, R ₁ is a linear or branched alkyl group having 1 to 22 carbon atoms, an alkoxyalkyl group or an alkenyl group, an aryl group, an aralkyl group, or a cycloalkyl group. Specific compounds include, for example, n-butanol, iso-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, 2-ethylhexanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol. , Pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, benzyl alcohol, phenol, and phenol to which ethylene oxide or propylene oxide is added in an amount of 1 to 10 mol, or monohydric alcohol with ethylene oxide. 1 to 10 mol added (methyl glycol,
Ethyl glycol, butyl glycol, methyldiglycol, ethyldiglycol, butyldiglycol, methyltriglycol, ethyltriglycol, butyltriglycol, etc.), monohydric alcohol with 1 to 10 mol of propylene oxide added (propylene glycol). Monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, etc.),
Further, cyclohexanol or a compound obtained by adding 1 to 10 mol of ethylene oxide or propylene oxide to it can be mentioned. Preferred monohydric alcohol has 4 carbon atoms
~ 18 monohydric alcohols. The borate ester also functions as a metal wetting improver. When the number of carbon atoms is 3 or less, the boiling point is low and it is easily volatilized, which is not preferable in terms of work environment hygiene. If the carbon number is 19 or more, the melting point and boiling point are high,
Not good for work.

Among the polyhydric alcohols used in the production of borate esters, the dihydric alcohol (diol) is preferably a compound represented by the above general formula (I). here,
R ₂ , R ₃ , R ₄ and R ₅ represent a hydrogen atom or a linear or branched alkyl group having 1 to 15 carbon atoms, and R ₆ represents a single bond or a linear or branched alkylene group having 1 to 20 carbon atoms. . Specific examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol and 2-methyl-2,4.
-Pentanediol, neopentyl glycol, 1,6-
Hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and the like.

Glycerin can be reacted as it is as a trihydric alcohol, or as a mono- or di-substituted form thereof with boric acid or boric anhydride. As the mono- or di-substituted product, a monoester or diester of glycerin and a fatty acid having 8 to 18 carbon atoms is preferable, and representative examples thereof include lauric acid mono and diglycerides, and oleic acid mono and diglycerides.

Examples of polyhydric alcohols other than the above dihydric alcohols and glycerin include trimethylolpropane, pentaerythritol, arabit, sorbit, sorbitan, mannitol and mannitan. As the ester of these polyhydric alcohols, mono-, di-, or triesters with fatty acids having 8 to 18 carbon atoms can be used. Further, ether type obtained by adding 1 to 20 mol, preferably 1 to 10 mol of alkylene oxide (ethylene oxide, propylene oxide) to the polyhydric alcohol or ester can also be used.

When the boric acid ester used in the present invention is produced by reacting boric acid or boric anhydride with at least one of the compounds (1) to (4), the production method is not limited at all. However, for example, the following method can be used.

(I) Production method from boric acid or boric anhydride and the compound of (1) (i) General production method Boric acid or boric anhydride and 3 to 6 equivalents of 1 to 4 carbon atoms
Add the polyhydric alcohol to a reaction vessel equipped with a thermometer, stirrer, and backflow condenser, mix, and mix under normal pressure or reduced pressure.
A dehydration reaction is performed at 0 to 180 ° C. to obtain a trialkylborate.

(Ii) Specific Example 61.8 g (1.0 mol) of boric acid and 2-ethylhexanol 409.
5 g (3.15 mol) was placed in a reactor equipped with a thermometer, a stirrer, and a backflow cooling tube, and the reaction was carried out at 130 to 150 ° C for 5 hours.
It is possible to obtain tri-2-ethylhexyl borate by letting out g (3 mol) of water of reaction and letting unreacted 2-ethylhexanol come out under reduced pressure (for example, 5 mmHg or less).

(B) Production method from boric acid or boric anhydride and the compound of (2) (i) General production method Boric acid or boric anhydride and 1 to 3 equivalents of diol are placed in a thermometer, a stirrer, and a backflow condenser. Put it in the attached reaction container,
After mixing, a dehydration reaction is carried out at 100 to 180 ° C. under normal pressure or reduced pressure to obtain a borate ester.

(Ii) Specific Example 69.6 g (1.0 mol) of boric anhydride and 312 g (3.0 mol) of neopentyl glycol were placed in a reactor equipped with a thermometer, a stirrer, and a backflow condenser, and the mixture was kept at 130 ° C. for 7 hours. A dehydration reaction is performed under normal pressure to obtain a borate ester.

(C) Production method from boric acid or boric anhydride and the compound of (3) (i) General production method Boric acid or boric anhydride and 1 to 6 equivalents of glycerin or its derivative (at least one hydroxyl group is (Including) in a reaction vessel equipped with a thermometer, stirrer, and backflow condenser,
After mixing, a dehydration reaction is carried out at 100 to 180 ° C. under normal pressure or reduced pressure to obtain a borate ester.

(Ii) Specific Example Boric acid 61.8 g (1.0 mol), stearic acid monoglyceride 358 g (1.0 mol) and oleic acid diglyceride 620 g
(1.0 mol) is put in a reaction vessel equipped with a thermometer, a stirrer, and a backflow condenser, and dehydration reaction is performed at 150 ° C. for 8 hours under reduced pressure to obtain a borate ester.

(D) Production method from boric acid or boric anhydride and the compound of (4) (i) General production method Boric acid or boric anhydride and 1 to 6 equivalents of a polyhydric alcohol or its derivative (at least one (Containing a hydroxyl group) is placed in a reaction vessel equipped with a thermometer, a stirrer, and a backflow condenser, mixed, and dehydrated at 100 to 180 ° C. under normal pressure or reduced pressure to obtain a borate ester.

(Ii) Specific Example 61.8 g (1.0 mol) of boric acid, 388 g (1.0 mol) of trimethylolpropane monooleate and 386 g (1.0 mol) of trimethylolpropane dicaprylate were thermometered, stirred and refluxed. Put in a reaction vessel equipped with a cooling tube, mix, and dehydrate at 170 ° C for 9 hours under reduced pressure to obtain borate ester.

The alcohol used for producing the borate ester is one kind or a mixture of two or more kinds. When two or more kinds are used, in addition to the same kind of alcohol, different kinds of alcohol, for example, 1 as shown in Comparative Examples 2 to 4 described later.
It may be a mixture of a dihydric alcohol and a dihydric alcohol.

The present invention is characterized in that the borate ester obtained as described above is used as a vehicle for paste. However, a known additive can be appropriately used in combination with the borate ester. For example, conventional binders such as ethyl cellulose, nitrocellulose, polyvinyl butyral, polyvinyl alcohol, etc., octanol, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, terpineol, solvents such as benzyl alcohol, gels such as dibenzyl bensorbitol, tribenzyl bensorbitol, etc. You may use together with an agent.

The vehicle of the present invention comprises tungsten, copper,
It can be suitably used for preparing a paste by mixing with metal powder such as silver, gold, molybdenum, silver-palladium or the like or glass powder. In this case, metal powder or glass powder
Usually, about 5 to 50 parts by weight may be mixed with 100 parts by weight, but it is preferably 15% by weight or less in consideration of economy and evaporation during sintering. If it is less than 5% by weight, the effect as a vehicle is small.

The vehicle of the present invention has an appropriate viscosity, plate release property, printing accuracy, and the like during paste preparation, printing, drying and sintering.
It is a paste vehicle with excellent rectangularity and transpiration. It is possible to obtain superior printing accuracy and rectangularity compared to the commercially available vehicle because boric acid ester coordinates with metal powder or glass powder and acts as a binder / gelling agent. Improve thixotropy,
It is thought that this will lead to improvements in plate missing properties, printing accuracy, and rectangularity. Further, since the addition amount to the metal powder or glass powder can be relatively small as described above, it is also advantageous for improving the debinding property (transpiration property) during firing, and the boron atom easily bonds with oxygen. It is also effective in preventing metal oxidation and improves the metal corrosion prevention effect.

[0029]

EXAMPLES In order to explain the present invention in more detail, the following is given.
Reference examples, which are synthetic examples, are shown, and examples using the synthetic products are shown, but the following synthetic examples and examples do not limit the present invention in any way.

Reference Example 1 61.8 g (1.0 mol) of boric acid and 409.5 g of 2-ethylhexanol were placed in a reactor equipped with a thermometer, a stirrer and a backflow condenser.
(3.15 mol) was added, dehydration reaction was carried out at 130 to 150 ° C. for 5 hours, and unreacted 2-ethylhexanol was removed under reduced pressure (5 mmHg or less) to obtain a borate ester having the following structure.

[0031]

[Chemical 2]

Reference Example 2 61.8 g (1.0 mol) of boric acid and 104 g of neopentyl glycol were placed in a reactor equipped with a thermometer, a stirrer and a backflow condenser.
(1.0 mol) and benzyl alcohol (108 g, 1.0 mol) were added, and dehydration reaction was carried out at 100 to 170 ° C. for 4.5 hours to obtain a borate ester having the following structure.

[0033]

[Chemical 3]

Reference Example 3 61.8 g (1.0 mol) of boric acid and oleic acid monoglyceride 356. were added to a reactor equipped with a thermometer, a stirrer and a backflow condenser.
1 g (1.0 mol) and 74 g (1.0 mol) of n-butanol were added and dehydration reaction was carried out at 100 to 130 ° C. for 7 hours to obtain a borate ester having the following structure.

[0035]

[Chemical 4]

Reference Example 4 61.8 g (1.0 mol) of boric acid, 244 g (1.0 mol) of pentaerythritol dioctylic acid ester and 2-ethylhexanol were placed in a reactor equipped with a thermometer, a stirrer and a backflow condenser.
130 g (1.0 mol) was added and dehydration reaction was carried out at 150 to 170 ° C. for 12 hours to obtain a borate ester having the following structure.

[0037]

[Chemical 5]

Reference Example 5 61.8 g (1.0 mol) of boric acid and 104 g of neopentyl glycol were placed in a reactor equipped with a thermometer, a stirrer and a backflow condenser.
(1.0 mol) was added and dehydration reaction was carried out at 100 to 130 ° C. for 4 hours to obtain a borate ester having the following structure.

[0039]

[Chemical 6]

Reference Example 6 The compound obtained in Reference Example 5 was further subjected to an intramolecular dehydration reaction at 150 to 170 ° C. to obtain a borate ester having the following structure.

[0041]

[Chemical 7]

Examples 1 to 8 The components shown in Table 1 below were blended in predetermined amounts to obtain a metallization paste binder. However, all the numbers in the table indicate parts by weight.

[0043]

[Table 1]

The results of measuring the transpiration properties of the binders of Examples 2 and 6 are shown in FIG. As Comparative Example 1, a commercial product A containing 6% of ethyl cellulose in a terpene solvent is used, and as Comparative Example 2, an ester-
4% gelling agent and 16% ethyl cellulose in ether solvent
Was used as a commercial product B.

Measurement conditions: Sample 10 to 15 mg Temperature range RT (room temperature) to 900 ° C. Temperature rising rate 5 ° C./min N ₂ gas amount 100 ml / min Each of Examples 2 and 6 and Comparative Examples 1 and 2 above The results of measuring the viscosity of the binder are shown in FIG. E-type viscometer (Toki Sangyo Co., Ltd.)
Was used.

Examples 2 and 6 and Comparative Examples 1 and 2
The results of measuring the contact angles of the respective binders are shown in FIG. Measurement conditions: Goniometer type Elma contact angle measuring instrument G-1
The mold was used.

Substrate: undried green sheet Measurement temperature: 25 ° C. Table 2 shows a formulation example in which a conductive paste was prepared using the binders of Examples 1 to 8 and Comparative Examples 1 and 2. However, all the numbers in the table indicate parts by weight.

[0048]

[Table 2]

The results of measuring the viscosities of the conductive pastes of Examples 9 to 16 and Comparative Examples 3 and 4 are shown in FIGS. 4 and 5. The results of measuring the contact angles of the conductive pastes of Examples 9 to 16 and Comparative Examples 3 and 4 are shown in FIGS. 6 and 7.

The transpiration test results of FIG. 1 show that the binders of Examples 2 and 6 are superior to the Comparative Examples in transpiration. Therefore, it can be seen that the binder of the present invention works predominantly when the conductive paste is actually prepared and printed, dried and sintered.

FIG. 2 shows the viscosity measurement results of the binder, and FIGS. 4 and 5 show the viscosity measurement results of the paste. When the viscosity of the binder is too high, the paste becomes even higher when it is actually used as a paste, resulting in poor plate removal during printing, and a rectangular shape failure is obtained. Further, if the viscosity of the binder is too low, printing accuracy and rectangularity are deteriorated. That is, the predetermined line width and line height cannot be obtained, and a defective product is to be produced. In printing, it is necessary that the binder itself and the paste have thixotropy. That is, it is required to have a property of lowering the viscosity when a force is applied and increasing (returning to the original) the viscosity when a force is not applied. The viscosity shown in FIGS. 2, 4 and 5 is low when the shear rate is high,
It can be seen that the binder of the present invention has the required thixotropy, since the higher the rate, the higher the thixotropy.

FIG. 3 shows the contact angle measurement results of the binder and FIGS. 6 and 7 show the contact angle measurement results of the paste on the green sheet. The contact angle is as high as possible and the change with time is small, which leads to the improvement of printing accuracy and rectangularity. However, as shown in the measurement results of Examples 9 to 16, those using the binder of the present invention are relatively high and stable. is doing.

Application Example of IC Package An application example of the IC package is shown below. Using the substrates and pastes shown in Table 3 and using a screen having the printed line width shown in Table 4, firing was performed at 1550 ° C. for 2 hours in an H ₂ / H ₂ O atmosphere.

[0054]

[Table 3]

[0055]

[Table 4]

FIG. 8 shows the evaluation test items (printing accuracy and rectangularity) and the evaluation method.

The measurement and evaluation results are shown in FIGS. 9, 10 and 11. As is clear from these, when applied to the IC package, the vehicle of the present invention is superior in printing accuracy and rectangularity to the conventional vehicle. Further, Table 5 shows an example of the composition of the binder for glass paste.

[0058]

[Table 5]

The results of measuring the transpiration properties of the binders of Examples 17 and 19 are shown in FIG. In Comparative Example 5, a commercial product C containing terpene-based, ester-based, aliphatic solvent 0.3% nitrocellulose, and in Comparative Example 6 terpene-based, ester-based ether solvent 0.3% nitrocellulose. A commercial product D was used.

Further, the results of measuring the viscosity of the glass pastes compounded as shown in Table 6 are shown in FIG.
Further, the results of measuring the contact angle of the pastes prepared by using the binders of Examples 18 and 19 and Comparative Examples 5 and 6 are shown in FIG.

[0061]

[Table 6]

[0062]

EFFECTS OF THE INVENTION The vehicle of the present invention has an appropriate viscosity and thixotropy, and has excellent plate release property during printing.
A paste having excellent printing accuracy and rectangularity can be produced. In addition, this vehicle has an excellent transpiration property during sintering and also has an effect of preventing metal corrosion. Therefore, it is very useful for application to IC chips, integrated circuits, etc., which are becoming ultra-miniaturized and have higher performance.

[Brief description of drawings]

FIG. 1 is a diagram showing the results of transpiration test.

FIG. 2 is a view showing a result of measuring a viscosity of a binder.

FIG. 3 is a diagram showing a contact angle measurement result of a binder on a green sheet.

FIG. 4 is a diagram showing a result of measuring viscosity of a paste.

FIG. 5 is a diagram showing a viscosity measurement result of a paste.

FIG. 6 is a diagram showing a contact angle measurement result of a paste on a green sheet.

FIG. 7 is a view showing a contact angle measurement result of a paste on a green sheet.

FIG. 8 is a diagram showing test items and evaluation methods.

FIG. 9 is a diagram showing a measurement result of printing accuracy.

FIG. 10 is a diagram showing a measurement result of rectangularity.

FIG. 11 is a schematic diagram showing a wiring cross section after printing.

FIG. 12 is a diagram showing a result of measuring the transpiration property of a binder.

FIG. 13 is a diagram showing a viscosity measurement result of a paste.

FIG. 14 is a diagram showing a contact angle measurement result of a paste.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirokichi Morikawa 1021 Kita-cho, Nukata-gun, Yamato-Koriyama City, Nara Prefecture Daibuka Kagaku Kogyo Co., Ltd. (72) Toru Hibi 1021 Kita-cho, Nukata-gun, Yamato-Koriyama City, Nara Prefecture Industrial Co., Ltd. (72) Inventor Toshihiko Kubo 4-53-3 Kitahama, Chuo-ku, Osaka Sumitomo Metal Industries Co., Ltd. (72) Inventor Kouji Sumida 2701-1, Iwakura, Omine-cho, Mine-shi, Yamaguchi Prefecture Sumitomo Metal Ceramics (72) Inventor Nobuhiro Nishijima 2701-1 Iwakura, East branch, Omine Town, Mine City, Yamaguchi Prefecture Sumitomo Metal Ceramics Co., Ltd.

Claims (1)

[Claims] 1. A vehicle for paste, which comprises a borate ester.