JP2018049900A - Resistance paste and resistor produced by firing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a lead-free thick film resistor having a good electric property with small current noise while having a high resistance value; and a lead-free resistance paste which acts as a material thereof.SOLUTION: A resistance paste substantially comprises: thermally conductive particles made of a ruthenium dioxide; a lead-free glass frit; an organic vehicle; and an additive agent. The resistance paste includes, as the additive agent, an organic titanium compound of 0.1-4.0 mass% in terms of a titanium oxide. The organic titanium compound is suitably di-n-butoxy bis(triethanolaminato) titanium.SELECTED DRAWING: None

Description

  The present invention relates to a resistor paste used as a material for resistors such as thick film chip resistors and hybrid ICs, and more particularly to a resistor paste containing no lead and a resistor produced by firing the paste.

  Conventionally, as a method for forming a resistor film of an electronic component, a thick film method in which a film is formed using a resistance paste containing a film forming material and a thin film method in which a film forming material is formed by sputtering or the like are generally used. Are known. Among them, the thick film method is to form a resistor by printing a resistor paste on a ceramic substrate and then firing it. This method is inexpensive and has high productivity required for film formation. It is widely used for manufacturing resistors included in electronic components such as chip resistors and hybrid ICs.

The resistive paste used in the thick film system is substantially composed of conductive particles and glass frit, and an organic vehicle for making them suitable for printing. As the conductive particles, ruthenium dioxide (RuO ₂ ) or pyrochlore-type ruthenium-based oxides (Pb ₂ Ru ₂ O _7-X , Bi ₂ Ru ₂ O ₇ ) are generally used. The reason why the Ru-based oxide is used as the conductive particles is mainly because the resistance value changes gently with respect to the concentration of the conductive particles.

In addition, as a glass frit, a large amount of lead such as lead borosilicate glass (PbO—SiO ₂ —B ₂ O ₃ ) and lead aluminoborosilicate glass (PbO—SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ ) is used. Including lead borosilicate glass. The reason why the lead borosilicate glass is used for the glass frit in this way is that it has good wettability with the Ru-based oxide, has a thermal expansion coefficient close to that of the substrate, and has a suitable viscosity during firing.

In the above-described resistance paste, various additives have been included for a long time in order to improve the characteristics of the resistor after film formation. For example, Patent Document 1 discloses a composition for forming a resistive film containing a TCR adjusting agent such as Nb ₂ O ₅ or TiO ₂ in order to adjust the temperature coefficient of resistance (TCR).

Japanese Patent Laid-Open No. 04-291901

  In recent years, lead-free electronic components have been promoted in consideration of environmental protection, and lead-free solder pastes are also required. In addition, electronic components made from the above-mentioned resistance paste are becoming smaller and higher performance, and as a result, resistance pastes have low current noise even if the resistance value is increased. There is a demand for a material that can be used.

  The present invention has been made in view of the above situation, and can form a lead-free thick film resistor excellent in electrical characteristics capable of suppressing current noise while having a high resistance value. An object is to provide a lead-free resistance paste.

  As a result of repeated studies on a lead-free resistance paste capable of achieving the above object, the present inventor uses a lead-free oxide containing ruthenium in conductive particles by including a specific additive in the resistance paste. At the same time, it has been found that a resistor having good electrical characteristics can be produced even when a lead-free glass frit is used, and the present invention has been completed.

  That is, the resistance paste provided by the present invention is a resistance paste substantially composed of conductive particles made of ruthenium dioxide, glass frit containing no lead, an organic vehicle, and an additive. It is characterized by containing 0.1 to 4.0% by mass of an organic titanium compound in terms of titanium oxide as an agent.

  According to the present invention, there is provided a resistance paste capable of producing a thick film resistor excellent in electrical characteristics capable of suppressing current noise to a low level while having a high resistance value without causing environmental pollution due to lead. Can do.

  Hereinafter, embodiments of the resistance paste of the present invention will be described. There is no restriction | limiting in particular about the form of ruthenium dioxide used for the resistance paste of this embodiment of this invention, The oxide obtained by a general manufacturing method can be used. However, in order to suppress the variation in resistance value and current noise of the thick film resistor formed by firing as much as possible, it is desirable to make the conductive path in the thick film resistor finer. The average particle diameter by diameter is preferably 1.0 μm or less.

  If the glass frit which comprises the said resistance paste does not contain lead, there will be no restriction | limiting in particular in the composition. For example, borosilicate glass, aluminoborosilicate glass, borosilicate alkaline earth glass, borosilicate alkali glass, borosilicate zinc glass, borosilicate bismuth glass, or the like can be used. As described above, D50 (median diameter) measured by laser diffraction particle size distribution measurement of glass frit to minimize the conductive path in the thick film resistor and suppress variations in resistance value and current noise of the thick film resistor as much as possible. Is preferably 5 μm or less.

  The organic vehicle constituting the resistance paste may be one normally used for the resistance paste, for example, a resin obtained by dissolving a resin such as ethyl cellulose, butyral, or acrylic in a solvent such as terpineol or butyl carbitol acetate. Used for.

  The resistance paste further contains an organic titanium compound as an additive in an amount of 0.1% by mass to 4.0% by mass in terms of titanium oxide. The type of the organic titanium compound as the additive is not particularly limited. For example, di-n-butoxy bis (triethanolaminato) titanium, (2-n-butoxycarbonylbenzoyloxy) tributoxytitanium, or the like may be used. it can. In general, titanium oxide has the function of increasing the resistance value of the resistor formed by firing to reduce current noise, but its function is insufficient only by adding it in the form of titanium oxide powder. Prone. On the other hand, the resistance value can be increased satisfactorily by adding the organic titanium compound as described above. The content of the additive is 0.1% by mass or more and 4.0% by mass or less in terms of titanium oxide with respect to the resistance paste. If the content is less than 0.1% by mass, the effect of reducing current noise is sufficiently obtained. Because there is no. Conversely, if it exceeds 4.0 mass%, the resistance value becomes too high, and there is a possibility that the effect of reducing the current noise cannot be obtained sufficiently.

  The method for producing the resistance paste of the above-described embodiment of the present invention is not particularly limited, and a predetermined amount of the components of the resistance paste described above is weighed into a commercially available kneading apparatus such as a roll mill, and kneaded. Can be produced. At that time, the mixing ratio of the conductive particles and the glass frit is preferably about 5/95 to 50/50 in terms of the ratio of the conductive particles / glass frit on a mass basis. Further, the method for manufacturing the resistor is not particularly limited, and the resistor can be formed by the same method as the conventional one using the resistor paste of the embodiment of the present invention as a material. For example, the above-described resistance paste is applied to a normal substrate such as an alumina substrate by screen printing or the like, dried, and then fired at a peak temperature of about 800 to 900 ° C. using a belt furnace or the like, thereby lead-free. Can be formed.

  In addition to the essential components described above, the resistor paste according to the embodiment of the present invention is conventionally used in various ways such as dispersants and plasticizers that are conventionally used to adjust the electrical characteristics of thick film resistors. You may add an additive as needed.

Conductive particles, glass frit, organic vehicle, and additives are mixed at various blending ratios to prepare multiple resistor paste samples, which are then fired to form thick film resistors and their electrical properties Was evaluated. Specifically, RuO ₂ powder having a BET diameter of 40 nm prepared by roasting ruthenium hydroxide was prepared as the conductive particles. For glass frit, 10 mass% SrO-43 mass% SiO ₂ -16 mass% B ₂ O ₃ -4 mass% Al ₂ O ₃ -20 mass produced by mixing, melting, quenching, and pulverizing by a general method. A glass frit having a composition of% ZnO-7 mass% Na ₂ O and having a D50 of 1.9 μm as measured by laser diffraction particle size distribution was prepared.

Di-n-butoxy bis (triethanolaminato) titanium (organic titanium A), (2-n-butoxycarbonylbenzoyloxy) tributoxytitanium (organic titanium B), and TiO ₂ are prepared as additives. The organic vehicle was prepared based on ethyl cellulose and terpineol. These RuO ₂ powder, glass frit, additive, and organic vehicle were weighed so as to have various blending ratios and kneaded by a three-roll mill. This produced the resistance paste of samples 1-9.

  Next, an alumina substrate on which two electrodes having an interelectrode distance of 1 mm are formed using AgPd paste is prepared for the resistance paste of each sample, and the two electrodes are connected on the alumina substrate. Was screen printed to a width of 1 mm, dried at 150 ° C. for 10 minutes, and then fired in a belt furnace at a peak temperature of 850 ° C. for 9 minutes. The electrical characteristics (resistance value, current noise) of the thick film resistor thus fabricated were measured. The measurement results of the electrical characteristics are shown in Table 1 below together with the composition of the resistance paste used. The resistance value was measured by a four-terminal method using a Model 2001 Multimeter manufactured by KEITHLEY, and the current noise was measured by applying 1/10 W using a noise meter Model 315C manufactured by Quan-Tech.

In Table 1 above, as can be seen by comparing Sample 1 and Sample 5, Samples 2 and 4, Samples 6-8, and Sample 3 and Sample 9 having substantially the same resistance value, each is made of inexpensive RuO _2. Even when a thick film resistor is formed using conductive particles and lead-free glass frit, di-n-butoxy bis (triethanolaminato) titanium or (2-n -Butoxycarbonylbenzoyloxy) tributoxytitanium is added within the range specified by the present invention, so that the organic current is not added or the TiO ₂ used conventionally is added as an additive. It can be seen that noise can be reduced.

Claims (5)

  A resistance paste substantially composed of conductive particles made of ruthenium dioxide, glass frit containing no lead, an organic vehicle, and an additive, wherein the additive is 0.1 to 0.1 in terms of titanium oxide. A resistance paste comprising 4.0% by mass of an organic titanium compound.   The resistance paste according to claim 1, wherein the organic titanium compound is di-n-butoxy bis (triethanolaminato) titanium.   It forms by baking the resistance paste of Claim 1 or 2, The lead-free resistor characterized by the above-mentioned.   An electronic component comprising the resistor according to claim 3. A method for producing a lead-free resistor, wherein the resistor is produced by firing the resistor paste according to claim 1.