JPH113802A - Resistance paste for low temperature firing - Google Patents

Abstract

An object of the present invention is to provide a temperature coefficient (TC) of a resistor that can be used for a DC plasma display panel (PDP).
It is an object of the present invention to provide a low-temperature sintering resistance paste in which R) and the resistance value are small and the antistatic property is extremely stable. SOLUTION: One or more conductive particles selected from lead ruthenate powder, bismuth ruthenate powder, calcium ruthenate powder, strontium ruthenate powder and lanthanum ruthenate powder, and a softening point of 3 or more.
PbO—SiO ₂ —B ₂ O ₃ — at 50 ° C. to 550 ° C.
Al ₂ O ₃ system or _{PbO-SiO 2 -B 2 O 3} -Al 2
A glass powder in which an O ₃ -ZnO-based material is used alone or mixed, and a mixture of a dysprosium oxide powder and a praseodymium oxide powder as a filler, all of the powders are
Dispersed in an organic vehicle to form a resistance paste.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to various resistors and the like.
It mainly relates to a resistive paste capable of forming a film of a fired resistor on the surface of a glass substrate such as a DC plasma display panel, a liquid crystal display panel, and a cathode ray tube, and is used as a current limiting resistor for preventing spattering. The present invention relates to improvement of a low-temperature firing resistance paste that can be fired.

[0002]

2. Description of the Related Art In recent years, the use of noble metal pastes for the electronic industry has been rapidly expanding, and various kinds of noble metals are used singly or in combination. Although it is difficult to accurately define the noble metal paste, noble metal paste is, in short, a noble metal powder or a noble metal resinate as a conductive functional material, a glass frit as an inorganic binder, a metal oxide. An object is mixed and dispersed in a viscous organic vehicle to form a paste.

[0003] These are generally applied to non-conductive substrate materials such as ceramics, for example, by being applied, baked and cured to be used as electronic components that exhibit a conductive and resistive circuit function. I can understand. The metals and noble metals commonly used for them include Pt, Pd, Ir, Rh, Ru, A
u, Ag, Cu, Cr, Ni and the like.

Further, there are wet plating typified by electroplating, and a method of forming a thin film by vacuum deposition, chemical vapor deposition, sputtering or the like as dry plating.

The thick film method is generally 0.2 μm
Noble metal paste, which forms a film of
It is based on organometallic metal (Metal Organic MO). Products obtained by this method are widely used for precision conductor circuits and the like, and the main ones are hybrid ICs, network resistors, various sensors, multilayer ceramic capacitors, tantalum capacitors, thick-film thermal print heads, and the like.

The present invention belongs to the field of application of the above-mentioned metal and noble metal pastes, and is implemented as a part of the applied technology. Among them, those used as thick film hybrid ICs and pastes for resistors are also used as conductors. ,
It is divided into those that become resistors. Silver / palladium occupied the mainstream as the resistance paste used conventionally, but difficult control such as alloying with silver occurred during the oxidation / reduction process of palladium during firing, and an accurate resistance value was obtained. Difficult to use and is now rarely used.

On the other hand, ruthenium oxide, which has attracted attention in recent years, is a stable oxide, and this powder and glass powder are used by being dispersed in an organic vehicle. The resistivity of the oxide is smaller than that of palladium oxide. Since the temperature coefficient (TCR) of the resistor is small, one series has a wide range of effects from low resistance to high resistance.

[0008] Ruthenium oxide pastes usually use RuO ₂ as a conductive material, and Bi ₂ Ru ₂ O ₇
And pyrochlore-type ruthenates such as MnO ₂ , Cu ₂ O, Nb ₂ O _5, etc., and adding a metal oxide or the like to the temperature coefficient, electric power resistance, anti-static property, etc. of the resistor. A method of controlling an electrical characteristic as a resistance of the semiconductor device has been adopted.

At this time, the glass powder used for the paste is
Fillers are added to control the flow during firing, but titanium oxide powder, aluminum oxide powder, zirconium oxide powder, and the like are commonly used.
A few known examples of these resistance pastes are given.

First, JP-B-63-7585 discloses a resistive paint composed of ruthenium oxide, glass, lanthanum oxide and / or neodymium oxide, and an organic vehicle. Or, an invention is disclosed in which neodymium oxide is contained in glass in advance, and ruthenium oxide and lanthanum oxide and / or neodymium oxide are contained in glass in advance, and their quantitative ratios are specified. I have.

[0011] As a resistive paint related thereto, Japanese Patent Publication No. Sho 6
In 3-55844, (a) ruthenium oxide;
There is disclosed a paint comprising (b) glass, (c) praseodymium oxide and / or samarium oxide, and (d) an organic vehicle, and further adding lanthanum oxide and / or neodymium oxide. ing.

Japanese Patent Application Laid-Open No. Sho 62-124164 discloses that
A resistive paint and a resistor formed therefrom are described, and (a) ruthenium oxide,
(B) glass; (c) one or more oxides selected from the group consisting of lanthanum oxide, neodymium oxide, praseodymium oxide, and samarium oxide; (d) copper oxide; A) a resistance paint comprising an organic vehicle, and (a) ruthenium oxide on an insulating substrate;
(B) glass; (c) one or more oxides selected from the group consisting of lanthanum oxide, neodymium oxide, praseodymium oxide, and samarium oxide; and (d) copper oxide A thick film resistor formed by forming a coating is disclosed.

Although the softening point of the glass is not described in the above conventional examples, it is not clear, but the softening point is 550 to 850.
It is presumed that the product of C was used alone. A characteristic indispensable for a current limiting resistor used in a DC plasma display panel (DC PDP), that is, the resistance value is 5
Approximately 00 kΩ / □, the variation in resistance is small (CV
5%), the TCR (temperature coefficient of the resistor) is small (within -500 ppm / ° C.), and at the same time, the size is small (within 0.3 mm × 0.3 mm).
000 V) is required (change rate is within 3%), but the conventional example is not satisfactory in all of these characteristics.

Regarding the filler, the first three examples are lanthanum oxide and / or neodymium oxide, praseodymium oxide and / or samarium oxide, lanthanum oxide, neodymium oxide and praseodymium oxide. And samarium oxide, one or more oxides selected from the group consisting of dysprosium oxide powder and praseodymium oxide powder used in the present invention. At the same time, the glass powder used in the present invention differs from the glass powder having a low softening point of 350 to 550 ° C.

[0015]

In the case of a DC plasma display panel, since millions of fine resistors are formed on a single substrate, the variation in the resistance of the current limiting resistor is small. In addition, considering a change in the temperature of the substrate and a change in the ambient environment temperature, it is an important requirement that the temperature coefficient (TCR) be small. Considering that a voltage pulse of 200 to 300 V is applied, it is also important to stabilize the voltage pulse.

Taking the above into consideration, the required characteristics of the resistor applicable to the DC plasma display panel are about 500 kΩ / □, the variation in the resistance value is 5% or less, and the temperature. Coefficient (TCR) is -500
Within ppm / ° C, 0.3mm × 0.3mm size 10
It is an object of the present invention to provide a resistor having a change rate of 5% or less with a 00V pulse.

[0017]

[Means for Solving the Problems]

1 Lead ruthenate powder, bismuth ruthenate powder,
One or more conductive particles selected from calcium ruthenate powder, strontium ruthenate powder, and lanthanum ruthenate powder;
PbO-SiO ₂ is _{50 ℃ -B 2 O 3 -Al 2} O 3
System or _{PbO-SiO 2 -B 2 O 3} -Al 2 O 3 -Zn
A low-temperature firing resistor characterized in that a glass powder in which an O-based powder is used alone or mixed, and a mixture of dysprosium oxide powder and praseodymium oxide powder as a filler, and all of the powders are dispersed in an organic vehicle. paste. 2. The resistance paste for low-temperature firing according to the above item 1, wherein the weight sum of the mixture of the dysprosium oxide powder and the praseodymium oxide powder is in the range of 5% by weight to 35% by weight of the total weight of the conductive particles and the glass powder.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The resistor made according to the present invention can be improved in withstand voltage characteristics by several steps as compared with conventional products. It is worth noting that dysprosium oxide powder and praseodymium oxide powder are used as fillers. Have been used. In addition, the glass powder, which is a component of the resistance paste, having a softening point of 350 to 550 ° C., can be sintered at a low temperature, the fired and fixed resistor has good uniformity, and a glass substrate is used. In addition to being applicable to the direct current type plasma display panel, there is an advantage that it can contribute to energy saving.

The glass composition is 75.0 to 81.0 PbO.
Wt%, SiO ₂ 6.0 to 10.0 wt%, B ₂ O
₃ 3.0 to 5.0 wt%, Al ₂ O ₃ 8.0~12.0
% By weight, or 70.3 to 76.4 of PbO
Wt%, SiO ₂ 0.9 to 3.0 wt%, B ₂ O ₃ 1
4.8 to 18.9 wt%, Al ₂ O ₃ 1.7 to 3.7 wt%, using the following average particle diameter of 1μm consisting ZnO4.1~6.2 wt%.

More specifically, Pb having a softening point of 510 ° C.
O 78.0% by weight, SiO ₂ 8.0% by weight, B ₂ O
₃ 4.0% by weight, glass powder of 10.0% by weight of Al ₂ O ₃ and / or 73.3% by weight of PbO having a softening point of 430 ° C., 2.0% by weight of SiO ₂ , 16.9% by weight of B ₂ O ₃ %,
A glass powder of 2.7% by weight of Al ₂ O ₃ and 5.2% by weight of ZnO is used alone or in combination.

[0021]

[Example] First, PbO73.3 wt%, SiO _{2 2.}
0 wt%, B ₂ O ₃ 16.9 wt%, Al ₂ O ₃ 2.7
% Of ZnO and 5.2% by weight of ZnO were mixed, melted at about 1300 ° C., cooled, and pulverized by a ball mill to prepare glass powder having a softening point of 430 ° C. and an average particle diameter of 1 μm or less. Separately, lead ruthenate powder having an average particle diameter of 1 μm or less as conductive particles, and an average particle diameter of 1 μm as a filler.
A mixture of dysprosium oxide powder and praseodymium oxide powder of m or less was prepared.

Using the above materials, lead ruthenate powder 2
4.1 wt%, glass powder 59.2 wt%, a mixture of dysprosium oxide powder and praseodymium oxide powder (1
5: 5, 10:10, 5:15; see Table 1, Examples 1 to 3) Mix powder at 16.7% by weight with an organic vehicle consisting of 15 parts by weight of ethylcellulose and 85 parts by weight of terpineol. Then, after preliminary kneading with a planetary blender, the three components were uniformly dispersed through three rolls having different rotation ratios to obtain a low-temperature firing resistance paste.

Although a resistor was prepared from the paste thus obtained, a linear common electrode was provided in advance at the center of the glass plate to evaluate the variation in the resistance value. Two evaluation substrates provided with the test electrodes were prepared. Each electrode of these evaluation substrates was fired after screen printing a conductor paste containing silver as a main component on a glass plate in advance. The resistive paste for low-temperature firing according to the present invention was screen-printed so as to bridge the common electrode and the test electrode on the evaluation substrate, and was fired in a firing furnace at 580 ° C. with a peak value of 10 minutes for a total of 1 hour. Body.

0.25 of 32 samples per evaluation substrate
A resistor having a size of mm × 0.25 mm and a thickness of 5.5 μm was formed by firing. When two evaluation substrates were prepared and a total of 64 samples of fired resistors were prepared and evaluated, the average resistance value was 1.17 MΩ, and the resistance value variation coefficient CV = σ / _X × 100 as an index of resistance value variation. As shown in Table 1, (%) (σ is the standard deviation, _X is the average resistance value) was as low as 3.2 in Example 1, 4.4 in Example 2, and 3.8 in Example 3.

[0025]

[Comparative Examples] Except that each filler was used alone, the procedure was the same as in Examples. As shown in Comparative Examples 1 to 7 in Table 2, the variation coefficient of the resistance value is largely varied except for a part, and the variation coefficient of the resistance value is partially praseodymium oxide 4.3.
Titanium oxide 4.2 and close to the example, but on the other hand, temperature coefficient
-313, -2071, Δ at high voltage pulse 1000V
R is -12.5 and -0.1, satisfying the three factors, indicating that the filler mixture of the present invention has an unexpected effect. Some examples are shown in Table 1 as an evaluation result of the next leaf, and Table 2 below shows a comparative example.

In Tables 1 and 2, Ω / □ is the sheet resistance value CV% is the coefficient of variation of the resistance value ppm / ° C. is the rate of change of the resistance value per 1 ° C. ΔR% is the rate of change of the resistance value at the high voltage pulse (R ₂ -R ₁
/ R ₁ × 100) R ₁ : resistance value before test R ₂ : resistance value after test

[0027] In the table, the filler amount is% by weight based on 100% by weight of conductive particles + glass powder.

[0028] In the table, the filler amount is% by weight based on 100% by weight of conductive particles + glass powder.

As is clear from the above-mentioned Example Table 1 and Comparative Example Table 2, the present invention uses a mixture of a dysprosium oxide powder and a praseodymium oxide powder as fillers. Compared to the case where the compound of the above is used, the requirements of the variation of the resistance value, the low temperature coefficient of the resistor, and the withstand voltage characteristics are satisfied. For example, comparing the case of using a mixture of dysprosium oxide powder and praseodymium oxide powder as the filler of Example 2 with the case of using the dysprosium oxide powder of Comparative Example 1 alone, the resistance value and the variation thereof were as in Example 1. Both the comparative examples and the comparative examples show similar values, but there is a remarkable difference in the withstand voltage characteristics, and it can be seen that all of the numerical values are stable in Examples 1 to 3 because the overall balance is kept uniform. .

[0030]

According to the resistance paste for low-temperature firing according to the present invention, since a mixture of dysprosium oxide powder and praseodymium oxide powder is used as a filler, the resistance is as high as about 500 kΩ / □ and 0.3 mm × 0.3
mm or less, the resistance variation and the temperature coefficient of the resistor are small as described above, and are stable against high-voltage pulses. The current limiting resistor has a particularly remarkable effect of being able to cope with it more than enough.

Claims (2)

[Claims] 1. One or more conductive particles selected from lead ruthenate powder, bismuth ruthenate powder, calcium ruthenate powder, strontium ruthenate powder and lanthanum ruthenate powder, and a softening point of 3 or more.
PbO—SiO ₂ —B ₂ O ₃ — at 50 ° C. to 550 ° C.
Al ₂ O ₃ system or _{PbO-SiO 2 -B 2 O 3} -Al 2
A glass powder in which an O ₃ -ZnO-based material is used alone or mixed, and a mixture of a dysprosium oxide powder and a praseodymium oxide powder as a filler, all of the powders are
A low-temperature baking resistance paste characterized by being dispersed in an organic vehicle. 2. The low-temperature firing according to claim 1, wherein the weight sum of the mixture of the dysprosium oxide powder and the praseodymium oxide powder as the filler is in the range of 5% by weight to 35% by weight of the total weight of the conductive particles and the glass powder. For resistance paste.