JP2003257242A - Thick membrane resistor paste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thick membrane resistor paste which is superior in acid resistance by using SiO<SB>2</SB>-Bi<SB>2</SB>O<SB>3</SB>-BaO system non-lead non-alkaline glass having a specific range of bismuth content as a binder glass of the thick membrane resistor paste and in which three layers of the electrode part, resistor part and surface coat part can be fired simultaneously and which can contribute to the earth environment protection. <P>SOLUTION: This is a thick membrane resistor paste made mainly of a conductive powder, glass frit, and an organic vehicle. The glass frit is constituted of a composition in weight ratio of 1% or less alkaline metal, 10-30% Bi<SB>2</SB>O<SB>3</SB>, 25-40% SiO<SB>2</SB>, 30-40% BaO, 5-7% ZnO, 4-7% Al<SB>2</SB>O<SB>3</SB>, and 0.01-8% B<SB>2</SB>O<SB>3</SB>, and does not contain PbO. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thick film resistor paste for obtaining a printing type thick film resistor by printing and firing a predetermined pattern on a ceramic substrate by a screen printing technique, and particularly as an acid resistant glass frit. Excellent in P
The present invention relates to a thick film resistor paste using bismuth-based glass that does not contain bO.

[0002]

_2. Description of the Related Art Thick film resistor pastes that are commonly used are RuO ₂ and pyrochlore type lead ruthenate (Pb _2).
It is prepared by mixing conductive fine powder such as Ru ₂ O _7-x ) and glass frit with an organic vehicle and kneading with a three-roll mill. This pyrochlore-type lead ruthenate (P
b ₂ Ru ₂ O ₇₎ and for use with RuO ₂ is pyrochlore lead ruthenate When using a small amount of temperature coefficient of resistance (TCR) is smaller RuO ₂ as compared to the RuO ₂ alone, the resistance value is unstable It serves to stabilize the process of becoming. As a glass frit which serves as a binder glass of these conventional thick film resistor pastes, lead borosilicate glass containing a large amount of PbO, which has a good compatibility with lead ruthenate and has an extremely large effect of lowering the melting point of the glass. Is mainly used. The lead borosilicate glass is a low-melting glass and has the advantage of excellent chemical resistance such as acid resistance.

[0003]

Nowadays, as the protection of the global environment is being emphasized, energy saving and sustainable economic development are being promoted, the electronics field has reached a stage where steady improvement measures are required. The printed type thick film resistor, which is an electronic component, occupies a large specific weight quantitatively among the components used in electronic devices. The thick film resistor paste is used as the resistor material of the printing type thick film resistor, and lead borosilicate glass frit containing a large amount of PbO is used for most of the paste. On the other hand, recently, lead-free materials and electronic parts have been desired from the viewpoint of global environment protection, and Pb is also used for thick film resistor pastes used for printing type thick film resistors.
There has been a demand for adopting a glass frit that does not contain O. As the glass frit containing no PbO, for example, bismuth borosilicate type glass, zinc borosilicate type glass, borate type glass and the like are known, and the use of these lead-free glass frit has been tried, but the acid resistance Satisfaction was not obtained in the sex test.

On the other hand, in the structure of the printing type thick film resistor, printing, drying and firing are performed for each of the electrode formation, the resistance formation and the protective glass film formation, so that the number of steps is large and energy saving and cost reduction are achieved. There was also a problem from the viewpoint. Therefore, the simultaneous firing method of electrode formation using a thick film resistor paste, resistance formation and protective glass film formation has also been attempted, but in the conventional simultaneous firing method using a thick film resistor paste, especially in the firing step. A crack or the like is generated at the connecting portion between the electrode portion and the resistor portion, which causes a problem in quality. The present invention solves the above-mentioned conventional problems,
The binder glass of the thick film resistor paste, which does not contain PbO and has excellent acid resistance, is used in the global environment in which three layers of the electrode part, the resistor part and the precoat glass part can be simultaneously fired. It is an object of the present invention to provide a thick film resistor paste that can contribute.

[0005]

Means for Solving the Problems The present inventors have conducted various studies in order to achieve the above-mentioned object, and as a result, as a binder glass of a thick film resistor paste, the content of bismuth within a specific range of SiO2- The present inventors have found that the use of a Bi-Ba-based lead-free and alkali-free glass is excellent in acid resistance, and that the electrode part, the resistor part, and the surface coat part can be co-fired, and the present invention has been reached. That is, the present invention provides (1) a thick film resistor paste containing conductive powder, glass frit and an organic vehicle as main components, the glass frit being 1% by weight or less of alkali metal and Bi ₂ O. ₃ 10-30%, SiO ₂ 25-40
%, BaO 30-40%, ZnO 5-7%, Al ₂
A thick film resistor paste, characterized in that it is composed of O ₃ 4 to 7% and B ₂ O ₃ 0.01 to 8% and does not contain PbO, (2) the conductive powder is RuO ₂ and Bi ₂ Ru. _Two
The thick film resistor paste according to claim 1, which is O _7-x .
(3) The conductive powder is RuO ₂ , at least one of Bi ₂ Ru ₂ O _7-x , Ru (OH) ₄ , SrRuO ₃ , and B.
aRuO ₃ , CaRuO ₃ , LiRuO ₃ , Bi ₂ Ir
₂ O ₇ , Bi _1.5 In _0.5 R _u2 O ₇ , NdBiR
1 to ₂ selected from u ₂ O 7 and BiInRu ₂ O ₇
2. The thick film resistor paste according to claim 1, which is more than one kind.
(4) The thick film resistor paste according to claim 1, wherein the softening point of the glass frit is 700 to 900 ° C.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The conductive powder used in the present invention,
For example, RuO ₂ , Ru (OH) ₄ , SrRuO ₃ , B
aRuO ₃ , CaRuO ₃ , LiRuO ₃ , Bi ₂ Ru
₂ O _7-x , Bi ₂ Ir ₂ O ₇ , Bi _1.5 In _0.5
Ru ₂ O ₇ , NdBiRu ₂ O 7 and BiInRu ₂ O
₇ etc. are mentioned. The ratio between the conductive powder and the glass frit is determined by the required resistance value of the resistor. That is, when a high resistance value is required, the amount of conductive powder is reduced, and when a low resistance value is required, the amount is increased. However, if it does not reach 5% by weight, the resistance value of the produced resistor film becomes almost an insulator, and if it exceeds 70% by weight, the resistance value becomes too low, and the function as the resistor is not achieved.

The glass frit used in the present invention means S
iO2-Bi-Ba-based and lead-free non-alkali glass, the glass frit in a weight ratio of alkali metal less than _{1%, Bi 2 O 3 10~30%,} SiO 2 25~40
%, BaO 30-40%, ZnO 5-7%, Al ₂
It is composed of O ₃ 4 to 7% and B ₂ O ₃ 0.01 to 8%, and its softening point is 700 to 900 ° C. Bi ₂ O
_If the content of ₃ is less than 10% and the softening point is less than 700 ° C., the acid resistance decreases, which is not preferable. Also, Bi
_When the content of ₂ O ₃ is 30% or more and the softening point is 900 ° C. or more, the flow during firing of the thick film resistor paste is deteriorated and sintering is unsatisfactory, which is not preferable. The content of the glass frit is 25 to 90% by weight of the thick film resistor paste of the present invention.
When the content is less than 25% by weight, it becomes difficult to obtain a stable electric resistance, and when the content exceeds 90% by weight, the electric resistance becomes high and unstable, and cannot be put to practical use.

Next, the organic vehicle used in the present invention is
For example, a vehicle or a methyl (meth) acrylate prepared by dissolving a cellulose ether such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, oxyethyl cellulose, benzyl cellulose, or propyl cellulose in an organic solvent such as terpineol, butyl carbitol acetate, or ethyl carbitol acetate. , Ethyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxyoxymethacrylate, and other acrylic resins as organic solvents such as methyl ethyl ketone, terpineol, butyl carbitol acetate,
Examples thereof include vehicles or rosin-based resins dissolved in ethyl carbitol acetate, etc., such as hydrogenated rosin, polymerized rosin, and rosin ester dissolved in the above organic solvent. The organic vehicle content used in the present invention is 10 to 40% by weight of the thick film resistor paste of the present invention. If it is less than 10% by weight, the viscosity of the paste becomes high and the cutness of the printed matter becomes poor, which is not preferable. On the other hand, 4
When it exceeds 0% by weight, poor dispersion of the conductive material occurs and it becomes difficult to obtain a stable resistance value, which is not preferable.

In the present invention, in addition to the above essential components, various metal oxides can be added in order to adjust the resistance temperature characteristic (TCR). As such a metal oxide,
For example, Nb ₂ O ₅ , Sb ₂ O ₃ , Fe ₂ O ₃ , Ca
O, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , MnO ₂ , Cu
_{O, Bi 2 O 3, Ta} 2 O 5, MoO 3 and MgO,
Etc. The TCR adjuster (metal oxide) is added in an amount of 0. 0 with respect to the solid content of the conductive powder and the glass frit in consideration of stability of resistance value, adhesive strength of paste, stability of glass component and the like. 1-5% by weight is used.

In the present invention, a saturated fatty acid metal salt of stearic acid such as aluminum, calcium, magnesium, strontium, and zinc, a fatty acid amide such as stearic acid amide, oleic acid amide, and erucic acid amide, as a dispersant, in addition to the above components. Waxes such as polyethylene wax, paraffin wax, microcristan wax and carnauba wax, and rosin may be contained.

The resistor paste of the present invention is manufactured by premixing the above-mentioned constituents with a mixer such as a kneader and further kneading with a three-roll mill. As a specific production example, first, ruthenium oxide and bismuth ruthenate having an average particle diameter of 2 μm or less, or the other conductive fine powder described above, and a glass frit having an average particle diameter of 5 μm or less and T are used.
The CR adjuster is mixed at a predetermined ratio, an organic vehicle is added, and premixing is performed with a powerful mixer such as a kneader. Then, this mixture is transferred to a three-roll mill and kneaded at room temperature to obtain a paste. The paste is made to have a desired viscosity by adding an organic vehicle during kneading with a three-roll mill or by adding an organic solvent such as terpineol or butyl carbitol. The mixing ratio of the conductive fine powder and the glass frit is determined by the resistance value required for the thick film resistor layer provided by printing or the like. That is, when a thick film resistor paste having a low resistance value is intended, the compounding ratio of the glass frit is reduced, and conversely, the thick film resistor layer aims at a thick film resistor paste having a high resistance value. In that case, the compounding ratio of the glass frit may be increased.

The average particle diameter of the conductive fine powder is set to 2 μm or less so that the conductive fine powder is bonded to glass in the thick film resistor layer to form a conductive network in which the conductive fine powder is reticulated. Therefore, the finer the particle size, the more stable the conductive network can be obtained. Glass frit average particle size 5μm
The reason for the following is also to prevent clogging of the screen when screen-printing a fine pattern due to poor fluidity when the particle size becomes coarse.

The thick film resistor paste of the present invention is printed in a predetermined shape on an electrode layer provided in advance on an alumina substrate by a screen printing method, and the temperature is 120 to 150 ° C. for 10 to 20.
After pre-drying for minutes, in a firing furnace at 800-900 ° C
Is baked in. The firing time is 30 to 60 minutes,
Hold at peak temperature for 10-15 minutes. The sintering atmosphere can be performed in air. A thick film resistor layer is obtained by such firing. In this case, the thickness of the thick film resistor layer is preferably set within the range of 6 to 25 μm. The thick film resistor paste of the present invention can be printed on the electrode layer that has been touch-dried and can be co-fired together with the electrode layer. In that case, it is preferable to use the same glass frit as that used in the thick film resistor paste of the present invention as the binder glass of the electrode. Simultaneous firing of the electrode and the thick film resistor has the advantage of shortening the working process, and can provide a leadless resistor.

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples. The present invention is not limited to the examples described below.

Example 1 1.26 parts by weight of ruthenium oxide (RuO ₂ ) and 0.8 of bismuth ruthenate (Bi ₂ Ru ₂ O ₇ ).
4 parts by weight, bismuth-based glass frit (Bi ₂ O ₃ 1
5% by weight, 25% by weight of SiO ₂ , 35% by weight of BaO,
ZnO 5% by weight, Al ₂ O ₃ 7% by weight, B ₂ O ₃ 3
% By weight) and 4.5 parts by weight of an organic vehicle (8% ethyl cellulose in terpineol solution) were well kneaded using a ceramic three-roll mill to obtain a thick film resistor paste. An electrode (Ag electrode prepared by using the bismuth-based glass frit) was printed in advance on the alumina substrate which had been touch-dried, and the paste was screen-printed in a pattern with a width of 2 mm and a length of 6 mm. ℃
After being dried for 15 minutes, it was baked for 30 minutes in a continuous electric furnace set to a peak temperature of 850 ° C. for 10 minutes. After cooling, a glass layer made of the bismuth-based glass frit is provided on the surface of the thick film resistor layer provided as described above.
A resistor was prepared by firing at 50 ° C. and providing a protective glass film on the surface of the thick film resistor layer. The resistor was immersed in a 5% sulfuric acid solution at 50 ° C. for 5 hours, and the change in resistance value was examined. The results are shown in Table 1.

[0015]

Example 2 1.26 parts by weight of ruthenium oxide (RuO ₂ ) and 0.8 of bismuth ruthenate (Bi ₂ Ru ₂ O ₇ ).
4 parts by weight, bismuth-based glass frit (Bi ₂ O ₃ 2
5 wt%, SiO ₂ 29 wt%, BaO 31 wt%, ZnO 6 wt%, Al ₂ O ₃ 6 wt%, B ₂ O
₃ 0.5% by weight) 4.9 parts by weight, organic vehicle (8
% Ethyl cellulose terpineol solution) (4.5 parts by weight) was well kneaded with a three-roll ceramic mill to obtain a thick film resistor paste. An electrode (Ag electrode prepared using the bismuth-based glass frit) was printed in advance on the alumina substrate which had been touch-dried, and the paste was screen-printed in a pattern of width 2 mm and length 6 mm,
After drying at 120 ° C for 15 minutes, peak temperature 850 ° C, 10
Firing was performed for 30 minutes in a continuous electric furnace set to the condition of minute. After cooling, a glass layer made of the bismuth-based glass frit was provided on the surface of the thick film resistor layer formed as described above, followed by firing at 850 ° C., and a protective glass film was provided on the surface of the thick film resistor layer to form a resistor. The resistor was immersed in a 5% sulfuric acid solution at 50 ° C. for 5 hours, and the change in resistance value was examined. The results are shown in Table 1.

[0016]

Example 3 An electrode (Ag electrode prepared by using the bismuth-based glass frit of Example 1) was printed in advance and touch-dried to obtain the space between the electrodes on the alumina substrate obtained in Example 1. The thick film resistor paste is screen-printed on a pattern having a width of 2 mm and a length of 6 mm and dried at 120 ° C. for 15 minutes to form a resistor layer. Then, the surface of the resistor layer is printed in the same pattern with a precoated glass paste-formed using the glass frit used in Example 1,
Drying was performed at 120 ° C. for 15 minutes to form a precoat layer. Further, the above-mentioned three-layer printed and dried alumina substrate was fired for 30 minutes in a continuous electric furnace set at a peak temperature of 850 ° C. for 10 minutes to obtain a fixed resistor. The resistor was immersed in a 5% sulfuric acid solution at 50 ° C. for 5 hours, and the change in resistance value was examined. The results are shown in Table 1.

[0017]

Comparative Example 1 1.26 parts by weight of ruthenium oxide (RuO ₂ ) and 0.8 of bismuth ruthenate (Bi ₂ Ru ₂ O ₇ ).
4 parts by weight, 4.9 parts by weight of ZnO-B2O3-SiO2 glass frit, and 4.5 parts by weight of an organic vehicle (8% ethylcellulose terpineol solution) were added to ceramic 3
Thorough kneading was performed using this roll mill to obtain a thick film resistor paste. The above paste was applied to the electrode (ZnO-B2
A prepared using O3-SiO2 glass frit
(g electrode) and screen-printed on an alumina substrate which has been dried by touch to give a pattern having a width of 2 mm and a length of 6 mm.
Firing was performed for 30 minutes in a continuous electric furnace set for 10 minutes. After cooling, a glass layer made of the above ZnO-B2O3-SiO2 glass frit is provided on the surface of the thick film resistor layer formed as described above, followed by firing at 850 ° C, and a protective glass film is provided on the surface of the thick film resistor layer to form a resistor. Created. The resistor was immersed in a 5% sulfuric acid solution at 50 ° C. for 5 hours, and the change in resistance value was examined. The results are shown in Table 1.

[0018]

Comparative Example 2 Instead of the bismuth-based glass frit of Example 2, 5% by weight of Bi ₂ O ₃ and SiO ₂ 35 having the following composition were used.
% By weight, 40% by weight of BaO, 7% by weight of ZnO, Al
_{2 O} 3 ₆ wt%) using a glass frit and others in the same manner as in Example 2 to obtain a thick-film resistor paste. The paste was screen-printed in a pattern with a width of 2 mm and a length of 6 mm on an alumina substrate which had been dried by touching with an electrode (Ag electrode prepared using the bismuth-based glass frit) in advance, and 120 ° C. After being dried for 15 minutes, it was baked for 30 minutes in a continuous electric furnace set to a peak temperature of 850 ° C. for 10 minutes. After cooling, a glass layer made of the bismuth-based glass frit was provided on the surface of the thick film resistor layer formed as described above, followed by firing at 850 ° C., and a protective glass film was provided on the surface of the thick film resistor layer to form a resistor. The resistor was immersed in a 5% sulfuric acid solution at 50 ° C. for 5 hours, and the change in resistance value was examined. The results are shown in Table 1.

[0019]

[Table 1]

[0020]

The resistor formed by using the thick film resistor paste of the present invention has a resistance value change rate, T
The CR change rate is low and the appearance is smooth. Moreover, when the thick film resistor paste of the present invention is used,
Since the resistor part and the pre-coated glass part can be formed by simultaneous firing, the process is greatly shortened and the production can be rationalized. Further, since it does not contain PbO, it is also effective from the viewpoint of environmental protection.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masao Iwasaki             337 26 Kashiwara, Sayama City, Saitama Prefecture Kojima Chemical             Within the corporation F term (reference) 5E033 AA18 AA27 BB02 BG02                 5G301 DA23 DA34 DA36 DA37 DA38                       DA39 DA42 DD01

Claims (4)

[Claims] 1. A thick film resistor paste containing conductive powder, glass frit and an organic vehicle as main components, wherein the glass frit is 1% by weight or less of an alkali metal,
Bi ₂ O ₃ 10 to 30%, SiO ₂ 25 to 40%,
BaO 30~40%, ZnO 5~7%, Al 2 O 3
A thick film resistor paste characterized in that it is composed of 4 to 7% and B ₂ O ₃ 0.01 to 8% and does not contain PbO. 2. The conductive powder is RuO ₂ and Bi ₂ RU ₂ O.
The thick film resistor paste according to claim 1, which is _7-x . 3. The conductive powder is RuO ₂ , Bi ₂ Ru ₂ O.
_At least one of _7-x and Ru (OH) ₄ , SrRu
O ₃ , BaRuO ₃ , CaRuO ₃ , LiRuO ₃ , B
i ₂ Ir ₂ O ₇ , Bi _1.5 In _0.5 Ru ₂ O ₇ , N
dBiRu ₂ O7, selected from BiInRu ₂ O ₇ 1
The thick film resistor paste according to claim 1, wherein the thick film resistor paste is one or more kinds. 4. The softening point of the glass frit is 700 to 900.
The thick film resistor paste according to claim 1, which has a temperature of ° C.