JP2006261250A - Resistor paste, resistor and electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain the temperature characteristics (TCR) and the withstand voltage characteristics (STOL) of resistance having small values certainly, and to improve noise characteristics. <P>SOLUTION: The resistor paste is produced by dispersing a conductive material, a glass composition, and an additive into an organic vehicle wherein the additive contains a composite oxide represented by AXO<SB>3</SB>(in the formula, A is at least one selected from Mg, Ca, Sr, and Ba, and X is at least one selected from group IVb elements (excepting Pb and Si)). X is at least one selected from Sn, Ge, and C. Alternatively, in the resistor paste produced by dispersing a conductive material, a glass composition, and an additive into an organic vehicle, the additive contains a composite oxide represented by AZ<SB>2</SB>O<SB>6</SB>(in the formula, A is at least one selected from Mg, Ca, Sr, and Ba, and Z is at least one kind selected from pentavalent elements). Z is at least one selected from Ta, Nb, and V. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resistor paste containing a conductive material, a glass composition and an additive, and further relates to a resistor and an electronic component formed using the resistor paste.

  For example, a resistor paste is generally composed of a glass composition for adjusting a resistance value and imparting bonding properties, a conductive material, and an organic vehicle as main components, and after printing this on a substrate, By baking, a resistor having a thickness of about 5 to 20 μm is formed. In this type of resistor paste (resistor), lead ruthenium oxide or the like is usually used as the conductive material, and lead oxide (PbO) glass or the like is used as the glass composition.

  In recent years, environmental problems have been actively discussed. For example, in solder materials, it is required to exclude lead. Resistor paste and resistor are no exception. Therefore, in consideration of the environment, it is possible to use lead ruthenium oxide as a conductive material as described above, or to use PbO-based glass as a glass composition. Must be avoided.

Under such circumstances, research on lead-free resistor pastes and thick film resistors has been conducted in various fields. For example, Patent Document 1 preferably contains, for example, CaTiO ₃ in an amount of more than 0 vol% and 13 vol% or less, or NiO in an amount of more than 0 vol% and no more than 12 vol%, and further additives such as CuO, ZnO, and MgO It is described that it is preferable to add the two at the same time, which is suitable for obtaining a resistor having a low resistance temperature characteristic (TCR) and withstand voltage characteristic (STOL) while having a high resistance value. It is described that it is possible to provide a lead-free resistor paste.
JP 2003-197405 A

  By the way, as a problem to be improved in the lead-free resistor, there is a deterioration in noise characteristics in addition to the above TCR and STOL. However, Patent Document 1 does not recognize the problem of the noise characteristics of the resistor, and naturally, no measures are taken to improve the noise value.

  Therefore, the present invention has been proposed in view of such a conventional situation, and the temperature characteristic (TCR) and the withstand voltage characteristic (STOL) of the resistance value are surely made small values, and the noise characteristic is improved. An object of the present invention is to provide a resistor paste that can be achieved. It is another object of the present invention to provide a resistor manufactured using the resistor paste, and further an electronic component having the resistor.

In order to achieve the above object, a resistor paste according to the present invention is a resistor paste in which a conductive material, a glass composition, and an additive are dispersed in an organic vehicle, and the additive includes AXO. ₃ (wherein A is at least one selected from Mg, Ca, Sr and Ba, and X is at least one selected from elements of group IVb of the periodic table (excluding Pb and Si)). It is characterized by containing the complex oxide shown. The resistor paste according to the present invention is a resistor paste in which a conductive material, a glass composition and an additive are dispersed in an organic vehicle, and the additive includes AZ ₂ O ₆ (A Is at least one selected from Mg, Ca, Sr, and Ba, and Z is at least one selected from pentavalent elements). Furthermore, the resistor according to the present invention is formed using the resistor paste. Furthermore, an electronic component according to the present invention includes the resistor.

In the present invention, a composite oxide AXO ₃ containing at least one selected from Mg, Ca, Sr, Ba and an element X of group IVb of the periodic table (excluding Pb and Si) and / or Mg, Ca, Sr The resistor paste includes a composite oxide AZ ₂ O ₆ containing at least one selected from Ba and a pentavalent element as an additive. Although the detailed mechanism is unknown, by using AXO ₃ and / or AZ ₂ O ₆ as an additive, the noise characteristics can be improved while ensuring the TCR characteristics and STOL characteristics of the formed resistor. .

  By using the resistor paste of the present invention, it is possible to form a resistor and an electronic component that are excellent in any of TCR, STOL, and noise characteristics while having a lead-free composition.

  Hereinafter, embodiments of a resistor paste, a resistor, and an electronic component to which the present invention is applied will be described in detail.

The resistor paste of the present invention includes a glass composition, a conductive material, and an additive as AXO ₃ (wherein A is at least one selected from Mg, Ca, Sr, Ba, and X is group IVb of the periodic table). (However, it is at least one selected from the elements of Pb and Si). The resistor composition comprising these components is mixed with an organic vehicle.

In addition, the resistor paste of the present invention includes AZ ₂ O ₆ (wherein A is at least one selected from Mg, Ca, Sr, Ba, and Z is 5) as a glass composition, a conductive material, and an additive. At least one selected from valent elements), and a resistor composition comprising these components is mixed with an organic vehicle.

Here, the conductive material has a role of imparting conductivity to the resistor, which is a structure, by being dispersed in the glass composition that is an insulator. As the conductive material, a lead-free conductive material substantially free of lead is used. Specifically, a conductive material containing Ru, for example, RuO ₂ or a Ru composite oxide is used. As the Ru composite oxide, one or more selected from CaRuO ₃ , SrRuO ₃ , BaRuO ₃ , and Bi ₂ Ru ₂ O ₇ are preferable.

  The composition of the glass composition is not particularly limited, but in the present invention, it is preferable to use a lead-free glass composition that does not substantially contain lead for environmental protection. In the present invention, “substantially free of lead” means not containing lead exceeding the impurity level, and the amount of the impurity level (for example, the content in the glass composition or the conductive material is If it is about 0.05% by mass or less), it may be contained. Lead may be contained in a trace amount as an inevitable impurity.

  When the glass composition is a resistor, it has a role of binding the conductive material and the additive to the substrate in the resistor. As the glass composition, it is possible to use a material obtained by mixing a raw material modified oxide component, a network-forming oxide component, etc., and vitrifying it. In particular, as a main modified oxide component, an alkaline earth metal oxide is used. Specifically, so-called CaO-based glass using one or more selected from CaO, SrO, and BaO is preferable.

But with the other ingredients in the glass composition, as a network-forming oxide component may include B ₂ O ₃ and SiO _2.

In addition to the main modified oxide component, any other metal oxide can be used as another modified oxide component. Specific examples of the metal oxide include ZrO ₂ , Al ₂ O ₃ , ZnO, CuO, NiO, CoO, MnO, Cr ₂ O ₃ , V ₂ O ₅ , MgO, Li ₂ O, Na ₂ O, and K _{2. O,} can be mentioned _{TiO 2, SnO 2, Y 2} O 3, Fe 2 O 3, MnO 2, Mn 3 O 4, ta2O 5, Nb 2 O 5, Sc 2 O 3, In 2 O 3 or the like, One or more selected from these may be used.

  Each component of the glass composition can be selected according to the resistance value of the resistor.

In the present invention, as an additive, AXO ₃ (wherein A is at least one selected from Mg, Ca, Sr, Ba, and X is selected from elements of group IVb of the periodic table (excluding Pb and Si)). At least one compound oxide (hereinafter simply referred to as AXO ₃ ), or AZ ₂ O ₆ (wherein A is at least one selected from Mg, Ca, Sr and Ba, Z Is a composite oxide (hereinafter simply referred to as AZ ₂ O ₆ ), which is a great feature point.

First, AXO ₃ will be described. In the present invention, as X in the formula, it is necessary to use at least one selected from Sn, Ge, and C, which are group IVb of the periodic table. Although belonging to group IVb of the periodic table, Si is contained in a large amount as a network-forming oxide in the glass, which may impair the characteristics of the resistor. In addition, when Si is used as X in the formula, the effect of improving noise characteristics cannot be obtained. The use of Pb is inappropriate from the viewpoint of obtaining a lead-free resistor substantially free of lead. Therefore, in the present invention, the element X needs to be selected from the group consisting of Sn, Ge, and C. Note that the AXO ₃ is an oxide AO of at least one element A selected from Mg, Ca, Sr, and Ba, and an oxide XO ₂ of an element X of group IVb of the periodic table (excluding PbO ₂ and SiO ₂ ). ) And a composite oxide.

Specific examples of the pentavalent element Z in AZ ₂ O ₆ include Ta, Nb, and V. The AZ ₂ O ₆ is a composite oxide of an oxide AO of at least one element A selected from Mg, Ca, Sr, and Ba and an oxide Z ₂ O ₅ of a pentavalent element Z. be able to.

The resistor paste preferably includes a metal material as an additive in addition to the AXO ₃ and / or the AZ ₂ O ₆ . As the metal material, fine particles of any conductive metal such as Ag, Pd, Ag—Pd alloy, etc. can be used. In particular, Ag is most suitable from the viewpoint of combination with the composite oxide. . By adding the composite oxide and the metal material to the resistor paste, the heat cycle, thermal stability, and the like of the formed resistor can be improved.

The combined use of the AXO ₃ and / or the AZ ₂ O ₆ and the metal material can sufficiently improve TCR and STOL without using other additives. Things may be included. As the additive, any metal oxide can be mentioned, but in particular, by using CuO in combination, TCR, STOL, reliability and the like can be further improved.

Further, as an additive, with the AXO ₃ and / or the _{AZ 2 O 6, Mg, Ca} , Sr, may be used in combination with complex oxide containing at least one of Ti selected from Ba. The composite oxide containing Ti and at least one selected from Mg, Ca, Sr, and Ba is specifically BaTiO ₃ , SrTiO ₃ , CaTiO ₃ , MgTiO _{3, and the} like.

  The resistor composition described above is made into a resistor paste by being dispersed in an organic vehicle. However, any organic vehicle for resistor paste can be used for this type of resistor paste. Yes, for example, a binder resin such as ethyl cellulose, polyvinyl butyral, methacrylic resin, butyl methacrylate, and a solvent such as terpineol, butyl carbitol, butyl carbitol acetate, acetate, toluene, various alcohols, xylene may be used. it can. At this time, various dispersants, activators, plasticizers, and the like can be appropriately used in accordance with the application.

  Although it is the compounding ratio of the said organic vehicle, the ratio (W2 / W1) of the mass (W1) of a resistor composition and the mass (W2) of an organic vehicle is 0.25-4 (W2: W1 = 1: 0). .25 to 1: 4). More preferably, the ratio (W2 / W1) is 0.5-2. If the ratio is outside the above range, a resistor paste having a viscosity suitable for forming a resistor on, for example, a substrate may not be obtained.

In order to form the resistor, the resistor paste containing the above-described components may be printed (applied) on the substrate by a method such as screen printing and fired at a temperature of about 850 ° C. As the substrate, a dielectric substrate such as an Al ₂ O ₃ substrate or a BaTiO ₃ substrate, a low-temperature fired ceramic substrate, an AlN substrate, or the like can be used. The substrate form may be any of a single layer substrate, a composite substrate, and a multilayer substrate. In the case of a multilayer substrate, the resistor may be formed on the surface or inside. In the formed resistor, the composition of the resistor composition contained in the resistor paste is maintained almost as it is.

  In forming the resistor, a conductive pattern to be an electrode is usually formed on the substrate, and this conductive pattern is printed with a conductive paste containing an Ag-based highly conductive material containing Ag, Pt, Pd, or the like, for example. Can be formed. Further, a protective film (overglaze) such as a glass film may be formed on the surface of the formed resistor.

  The electronic component to which the resistor of the present invention can be applied is not particularly limited. For example, a single-layer or multi-layer circuit board, a resistor such as a chip resistor, an isolator element, a CR composite element, a module element, and a laminated layer Capacitors such as chip capacitors, inductors and the like can be mentioned, and the present invention can also be applied to electrode portions such as capacitors and inductors.

  Hereinafter, specific examples of the present invention will be described based on experimental results.

<Preparation of glass composition>
A predetermined amount of a compound such as B ₂ O ₃ , SiO ₂ , CaCO ₃ , SrCO ₃ , BaCO ₃ , ZrO ₂ , Ta ₂ O ₅ was weighed so as to have the composition shown in Table 1, mixed in a ball mill, and then dried. . The obtained powder was heated to 1300 ° C. at a rate of 5 ° C./min, held at that temperature for 1 hour, and then rapidly cooled by being put into water to be vitrified. The obtained vitrified product was pulverized with a ball mill to obtain a glass composition powder. The composition of the obtained glass powder is shown in Table 1 below.

<Conductive materials and additives>
As the conductive material, RuO ₂ , CaRuO ₃ , SrRuO ₃ , and BaRuO ₃ were used. Further, as an _{additive, BaNb 2 O 6, SrNb 2} O 6, CaNb 2 O 6, MgNb 2 O 6, BaSnO 3, SrSnO 3, CaSnO 3, MgSnO 3, BaTa 2 O 6, BaV 2 O 6, BaGeO 3 BaCO ₃ , BaTiO ₃ , SrTiO ₃ , CaTiO ₃ , MgTiO ₃ , CuO and the like were appropriately selected and used. Further, Ag, Pd, and Ag—Pd alloy were appropriately selected and used as additives.

<Preparation of organic vehicle>
Using ethyl cellulose as the binder and terpineol as the organic solvent, the binder was dissolved while heating and stirring the organic solvent to prepare an organic vehicle.

<Preparation of resistor paste>
The conductive material, the glass composition powder, the additive and the organic vehicle were weighed so as to have each composition and kneaded with a three roll mill to obtain a resistor paste. The ratio of the total mass of the conductive material, the glass composition powder, and the additive to the mass of the organic vehicle is 1: 0 in mass ratio so that the obtained resistor paste has a viscosity suitable for screen printing. In the range of 25 to 1: 4, a resistor paste was prepared.

<Fabrication of resistor>
On a 96% alumina substrate, the Ag—Pt conductor paste was screen-printed in a predetermined shape and dried. The Ag ratio in the Ag-Pt conductor paste was 95% by mass, and the Pt ratio was 5% by mass. This alumina substrate was placed in a belt furnace and baked in a pattern of 1 hour from charging to discharging. The baking temperature at this time was 850 ° C., and the holding time at that temperature was 10 minutes.

  On the alumina substrate on which the conductor was formed in this manner, the resistor paste prepared previously was applied in a pattern of a predetermined shape (1 mm × 1 mm square shape) by screen printing and dried. Thereafter, the resistor paste was baked under the same conditions as the conductor baking to obtain a resistor.

<Evaluation of resistor characteristics>
(1) Resistance value
Measurement was performed with Agilent Technologies product number 34401A. The average value of 24 samples was determined.

(2) TCR
The resistance value change rate when the temperature was changed to −55 ° C. and 125 ° C. was obtained based on the room temperature of 25 ° C. The average value of 10 samples. When resistance values of −55 ° C., 25 ° C., and 125 ° C. are R-55, R25, and R125 (Ω / □), CTCR and HTCR are expressed as follows.
CTCR (ppm / ° C) = [(R-55-R25) / R25 / 80] x 1000000
HTCR (ppm / ° C) = [(R125-R25) / R25 / 100] x 1000000
Of CTCR and HTCR, the larger absolute value was taken as the TCR value. TCR ≦ ± 100 ppm / ° C. is a standard for characteristics.

(3) STOL (short-time overload)
A test voltage was applied to the resistor for 5 seconds, and the change rate of the resistance value before and after that was determined. The average value of 10 samples. Test voltage = 2.5 × rated voltage, rated voltage = √ (R / 4), and R is a resistance value (Ω / □). For a resistor having a resistance value with a calculated test voltage exceeding 400V, the test voltage was 400V. STOL ≦ ± 0.1% is a reference for characteristics.

(4) Noise characteristics
Measured with model315c manufactured by Quan-Tech. The average value of 10 samples was determined. At a level of 500 kΩ to 1 MΩ, 15 dB or less is a characteristic reference. In general, the noise value tends to increase as the resistance value increases.

<Examination of complex oxide>
In preparing the resistor paste, glass composition powder 1, CaRuO ₃ is used, and BaTiO ₃ , BaNb ₂ O ₆ , BaTa ₂ O ₆ , BaV ₂ O ₆ , BaSnO ₃ , BaGeO ₃ , BaCO ₃ , (Ba, Sr, Ca) (Nb, Ta) ₂ O ₆ , (Ba, Sr, Ca) (Sn, Si) O ₃ , SrTiO ₃ , SrNb ₂ O ₆ , SrSnO ₃ , CaTiO ₃ , CaNb ₂ O ₆ , _{CaSnO 3, MgTiO 3, MgNb 2} O 6, MgSnO 3, Ag, using selected from CuO, to produce a resistor samples 1 18 as described in Preparation section of the resistor. Table 2 shows the composition of the resistor composition in each sample and the results of the characteristic evaluation. In the following table, the same applies, but samples and the like (corresponding to comparative examples) deviating from the range defined in the present invention are marked with *.

From Table 2, Sample 2 to Sample 4 containing a complex oxide AZ ₂ O ₆ containing Ba and a pentavalent element as additives, and Ba and Group IVb group elements (except Pb and Si) and Samples 5 to 7 containing the composite oxide AXO ₃ containing TCR and STOL have good values, and the noise characteristics are better than those of the sample 1 containing BaTiO ₃ as an additive. Yes. In particular, in the samples 2 to 4 containing the complex oxide AZ ₂ O ₆ containing Ba and a pentavalent element, the noise characteristics are greatly improved. Also, as shown in Sample 8 and Sample 9, when multiple types of elements are used as A, X, and Z in the formulas represented by AZ ₂ O ₆ and AXO ₃ , the noise characteristics are improved as in Samples 2 to 7. The effect was able to be acquired.

<Examination of conductive materials, glass compositions and additives>
In preparing the resistor paste, the components shown in Table 3 below were selected and used, and the resistors of Sample 19 to Sample 36 were manufactured according to the description in the section of manufacturing the resistor. Table 3 shows the composition of the resistor composition in each of these samples and the results of characteristic evaluation.

From Table 19 to Sample 24 in Table 3, when RuO ₂ , SrRuO ₃ , and BaRuO ₃ are used as the conductive material, AZ ₂ O _{6 and the} like are contained as an additive in the same manner as when CaRuO ₃ is used. Thus, both TCR and STOL are achieved, and the noise value is improved.

Further, from the sample 25 to sample 30, when changing the modified oxide component such as in the composition (glass composition powder 2 glass composition powder 4), as an additive that contain AZ ₂ O _6, etc. , TCR and STOL are compatible, and an effect of improving noise characteristics is obtained.

Furthermore, when the resistor paste does not contain CuO as a metal material or other additive (sample 31 and sample 34), when Pd and an Ag—Pd alloy are used as an additive instead of Ag (sample 32 and sample 34) 33) In any case where AZ ₂ O ₆ and BaTiO ₃ are used in combination as an additive (sample 35), it was confirmed that the present invention is effective. As shown in Sample 36, it was also effective to use AXO ₃ and AZ ₂ O ₆ in combination as additives.

Claims (6)

A resistor paste in which a conductive material, a glass composition and an additive are dispersed in an organic vehicle,
As the additive, AXO ₃ (wherein A is at least one selected from Mg, Ca, Sr, Ba, and X is at least one selected from elements of group IVb of the periodic table (excluding Pb and Si)). A resistor paste comprising a composite oxide represented by   2. The resistor paste according to claim 1, wherein the X is at least one selected from Sn, Ge, and C. A resistor paste in which a conductive material, a glass composition and an additive are dispersed in an organic vehicle,
As the additive, composite oxidation represented by AZ ₂ O ₆ (wherein A is at least one selected from Mg, Ca, Sr, and Ba, and Z is at least one selected from pentavalent elements). A resistor paste characterized by containing an object.   The resistor paste according to claim 3, wherein Z is at least one selected from Ta, Nb, and V.   A resistor formed using the resistor paste according to claim 1.   An electronic component comprising the resistor according to claim 5.