JPH0429201B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a thick film type electrical resistor provided on a fixed chip resistor or a circuit wiring board, particularly the resistor which can be obtained by firing in a non-oxidizing atmosphere, and the production thereof. Regarding the method. BACKGROUND TECHNOLOGY Electronic equipment and electrical circuits are often constructed by mounting various electrical elements such as resistors, capacitors, diodes, and transistors on circuit boards, but as electronic equipment becomes smaller, these Circuit boards that can further increase the packaging density of electrical elements have come into widespread use. The resistors installed on these circuit boards are either thick-film resistors formed by printing and baking resistor material paste directly onto the circuit, or a pair of electrodes formed at both ends of a square ceramic chip. There is also a fixed chip resistor in which the thick film resistor is formed so as to span both electrodes. Conventionally, in order to install such a thick film resistor on a circuit board, a conductive material paste such as Ag or Ag-Pd is applied to the surface of an alumina substrate obtained by firing at around 1500℃, and after baking, ,for example
A paste containing RuO ₂ as a resistor material is applied by screen printing, and then heated at 750 to 850℃.
The common method is to bake the resistor and then adjust the resistance value by trimming, etc., if necessary. However, in recent years, frivolous and
The demand for shorter, smaller, and lower costs is becoming stronger, and studies are being conducted to further reduce the size and cost of circuit boards. For the former, specific measures for downsizing include:
Firstly, circuit boards are becoming more multi-layered and secondly resistors are being built internally. An example of multi-layered circuit boards is obtained by laminating and pressing ceramic green sheets (raw sheets) printed with conductive material paste such as Ag or Ag-Pd, and then simultaneously firing them in the atmosphere at 800-1100℃. Examples include multilayer wiring boards,
In addition, as an example of internally incorporating a resistor, a _RuO2 -based resistor material paste is further printed on a ceramic green sheet printed with the conductor material paste, laminated and crimped in the same manner as above, and then co-fired. The resulting resistor-incorporated multilayer wiring board and the like are known. In addition, as a specific measure to reduce the cost of the latter, we will use inexpensive Ni to replace expensive noble metal conductor materials such as Ag or Ag-Pd materials.
Alternatively, base metal-based conductive materials such as Cu are used, and they are heated at 800°C in a neutral or reducing non-oxidizing atmosphere such as nitrogen gas or hydrogen-containing nitrogen gas to avoid high resistance due to oxidation. A multilayer wiring board obtained by co-firing with green ceramic at ~1100℃ has been put into practical use. Furthermore, as described in JP-A No. 56-153702, a resistor material made of MoSi ₂ -TaSi ₂ and glass is coated on an alumina substrate having a copper (Cu) conductor and heat-treated. Thick film resistors and the like are also known. Problems to be Solved by the Invention However, in order to reduce the size and cost of circuit boards at the same time, RuO ₂ -based resistor materials have been co-fired with green ceramics in nitrogen gas or hydrogen-containing nitrogen gas atmospheres. Sometimes a reduction reaction occurs, resulting in a low resistance value and no longer exhibiting properties as a resistor. Furthermore, when a resistor material made of MoSi ₂ - TaSi ₂ and glass is co-fired with a green ceramic sheet in a non-oxidizing atmosphere, the fired body may warp due to differences in the expansion and contraction rates of the two, and the MoSi There is a problem in that the decomposition reaction of ₂ -TaSi ₂ generates gas, which tends to cause blistering in the fired product. In order to improve this, there is a known example of using a resistor material made of MoSl ₂ -metal fluoride (e.g. calcium fluoride) and glass, as described in JP-A-60-198703. There is no warping or blistering during firing as mentioned above. However, a thick film resistor obtained by coating a resistor material made of MoSl ₂ -metal fluoride and glass on a green ceramic sheet and co-firing it will show a ~
A 10% increase in resistance value was observed, and the resistor could no longer perform its intended function. An object of the present invention is to provide an electrical resistor that can not only be used in fixed chip resistors or circuit boards in general, but also can be laminated with base metal conductive materials and incorporated into multilayer boards, and which has a stable resistance value. The purpose of the present invention is to provide an electrical resistor. Another object of the present invention is to provide a manufacturing method that can further improve the characteristics of the electrical resistor. Means for Solving the Problems In order to solve the above problems, the present invention aims to solve the following problems.
The present invention provides an electrical resistor characterized by having a fired body containing at least one molybdate from each group selected from at least two groups (A) to (G). (A) Alkaline earth metal molybdate (B) Zinc molybdate (C) Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb,
Molybdates of the elements Dy, Ho, Er, Tm, Yb, Lu, and composite molybdates of multiple of these elements (D) Molybdates of aluminum (E) Molybdates of the elements zirconium, hafnium, and These composite molybdates (F) molybdates of each element such as niobium and tantalum, and these composite molybdates (G) molybdates of manganese. ) heat treating a resistor material containing at least one molybdate of each group selected from at least two groups and at least one of its precursors;
The resistor material obtained by this heat treatment is fired to obtain an electrical resistor consisting of a fired body containing at least one molybdate in each group selected from at least two groups listed below. The present invention provides a method for manufacturing a characteristic electrical resistor. (A) Alkaline earth metal molybdate (B) Zinc molybdate (C) Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb,
Molybdates of the elements Dy, Ho, Er, Tm, Yb, Lu, and composite molybdates of multiple of these elements (D) Molybdates of aluminum (E) Molybdates of the elements zirconium, hafnium, and These composite molybdates (F) molybdates of each element such as niobium and tantalum, and their composite molybdates (G) molybdates of manganese Next, the present invention will be explained in detail. The molybdates belonging to each group (A) to (G) in the present invention include the following. (A) Alkaline earth metal molybdate If Me is an alkaline earth metal, the general formula
_{MeMoO4 , Me3MoO6 , Me2MoO5} , _{Me2Mo7 ,
MeMo4O13 , MeMo7O24 , MeMe3O10 ,}
Those represented by Me ₂ MoO ₅ , Me ₂ Mo ₃ O ₁₁ , etc. are preferred. Specifically, for example, MgMoO ₄ ,
_CaMoO4 , _SrMoO4 , _BaMoO4 , _{BaMo2O7 ,
BaMo4O13 , BaMo7O24 , BaMo3O10 ,}
Ca ₃ MoO ₆ , Sr ₃ MoO ₆ , Ba ₃ MoO ₆ , Ba ₂ MoO ₅ ,
Examples include Mg ₂ Mo ₃ O ₁₁ and the like. Further, the following complex molybdates are also exemplified. (Mg _x Ca _y )MoO ₄ , however, x+y=1, (Ca _x Sr _y )MoO ₄ , however, x+y=1, (Mg _x Ba _y )MoO ₄ , however, x+y=1, (Mg _x Ca _y Ba _z ) MoO ₄ , however, x+y+z
=1, (Ca _x Sr _y Ba _z )MoO ₄ , where x+y+z
=1, MG _x Ca _y Sr _z Ba _w MoO ₄ , however, x+y+
z+z+=1, (Ca _{x Sry} )MoO ₆ , x+y=3, ( _{SryBa y} )MoO ₆ , x+y=3, (B) Zinc molybdate For example, ZnMoO ₄ , ZnMo ₂ O ₇ , Zn ₃ Mo ₂ O ₉ . (C) Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb,
Molybdates of each element Dy, Ho, Er, Tm, Yb, Lu, and composite molybdates of multiple of these elements Examples include the following:

[Table] Also, (Y _x Ce _y ) MoO ₁₂ , however, x+y=6, (Pr _x Eu _y ) MoO ₁₂ , however, x+y=6, (Gd _x Dy _y ) MoO ₁₂ , however, x+y=6, (La _x Nd _y Tb _z ) MoO ₁₂ However, x + y + z
=6 (Ho _x Tm _y Yb _z )MoO _12However , x+y+z
Composite molybdates consisting of multiple elements such as =6 are also included. (D) Aluminum molybdate For example, Al ₂ Mo ₃ O ₁₂ is mentioned. (E) Molybdates of each element such as zirconium and hafnium, and composite molybdates thereof For example, ZrMo ₂ O ₈ , HfMo ₂ O ₈ , (Zr _x H _y )
Mo ₂ O ₈ However, x+y=1 is mentioned. (F) Molybdates of each element such as niobium and tantalum For example, Nb ₂ Mo ₃ O ₁₄ , Ta ₂ Mo ₃ O ₁₄ , (Nb _x
Ta _y ) Mo ₃ O ₁₄ , provided that x+y=1. (G) Manganese molybdate Examples include MnMoO ₄ . Each of these groups contains at least 2 molybdates.
At least one molybdate from each group is used, but when more than one molybdate is selected from the corresponding group, single-element molybdates, each or both of multi-element molybdates can be selected. Molybdates belonging to each of the above groups can be synthesized by heat treatment of oxides of the respective elements and molybdenum oxide (MoO ₃ ), but they can also be synthesized by heat treatment using their precursors. . In addition, for example, a molybdate of an alkaline earth metal is prepared by mixing a substance serving as a precursor of each metal oxide of an alkaline earth metal and molybdenum oxide (MoO ₃ ) or its precursor at a predetermined molar ratio. It can be synthesized by heat treatment. For example, calcium carbonate (CaCO ₃ ) or calcium hydroxide (CaO) is a precursor of CaO.
(OH) ₂ ) and molybdenum oxide (MoO ₃ ) or its precursor, such as molybdic acid (H ₂ MoO ₄ ), are mixed in a predetermined molar ratio and heat treated. The heat treatment conditions at this time include 600 to 1000°C for 1 to 3 hours. In the present invention, it is preferable to use a binder, and examples thereof include glass, and this glass may be a commonly known glass, and is not limited to a glass with a specific composition, but may include Pb ₃ Oxides such as O ₄ , Bi ₂ O ₃ , SnO ₂ , and CdO can be reduced and metallized when resistor materials containing them are fired in a non-oxidizing atmosphere; If it is undesirable for this to occur, it is preferable not to contain these oxides since they change the value. Glass components include SiO ₂ , B ₂ O ₃ , ZnO,
CaO, SrO, ZrO ₂ and the like are preferred, and the composition ratio of these oxides is preferably SiO ₂ 12-33% by weight, B ₂ O ₃ 20-35% by weight ZnO or Sr 13-33% by weight, CaO 10-25% by weight. In order to manufacture glass from a composition of these oxides, the respective oxides are weighed and mixed to achieve the above composition ratio. Put this mixture into a crucible,
After maintaining the temperature at 1200 to 1500°C, the melt is poured into water, for example, and rapidly cooled to obtain coarse glass powder.
This coarse powder is crushed into desired granular soil (for example, 10 μm or less) using a crushing means such as a ball mill or a vibration mill.
Glass powder is obtained by grinding until it becomes . In the above, a mixture of pure oxides was used, but the glass is not limited to this, as long as the result is a mixture of each oxide. It may be melted to make glass. For example, CaO (calcium oxide) can be obtained from CaCO ₃ (calcium carbonate) and B ₂ O ₃ (boron oxide) can be obtained by heat treatment of boric acid (H ₃ BO ₃ ), so CaO,
each in place of part or all of B ₂ O ₃
CaCO ₃ and H ₃ BO ₃ can be used. The same applies to oxides of other components. The molybdate of the element of the above element group and the glass powder obtained as described above may be mixed and used as is as a resistor material, but it is also possible to heat-treat and pulverize it and use it as a resistor material. This is preferable in view of the resistance temperature characteristics of a resistor obtained by firing this. The heat treatment temperature is 800℃~1200℃.
℃ is preferable; if it deviates from this range, the resistance value of the finished resistor will be easily affected by slight fluctuations in the composition ratio due to the working conditions of each step of processing the resistor material into an electrical resistor, and the resistance value will be less than the desired value. It is difficult to obtain a stable resistance value. This heat treatment is preferably performed in a non-oxidizing atmosphere, and it is preferable to use nitrogen gas or other inert gas, or a mixed gas containing these gases and hydrogen gas. The composition ratio of each component of the resistor material is the above (A) or
Molybdates of selected elements of group (G) 50-96
% by weight, preferably 4 to 50% by weight of glass powder. If the amount of molybdate of the element falling within this range is too small and the amount of glass is too large, the resistance value of the electrical resistor obtained by firing may become too high, which is undesirable. If there is too much salt and too little glass, the sinterability during firing may deteriorate and it may not be possible to stably hold it on the circuit board. However, when a resistor is embedded in a laminated circuit board, the molybdate content of the element may not only be greater than the above range, but may also be 100%. To create a resistor for a fixed chip resistor or a thick film resistor from the resistor material powder obtained in this way, for example, the resistor material powder is applied to a ceramic green sheet and fired. In order to perform this coating, a vehicle is mixed with these resistor material powders to prepare a coating liquid so that silk screen printing can be performed, for example. This vehicle is preferably one that can be burned out in the pre-firing stage.For this purpose, the resin is dissolved or dispersed in an organic vehicle, that is, an organic solvent, and various additives such as plasticizers and dispersants are added as necessary. Preferably added. Examples of the organic solvent include butyl carbitol acetate, butyl carbitol, turpentine oil, etc., and examples of the resin include cellulose derivatives such as ethyl cellulose and nitrocellulose, and other resins. The ratio of the organic vehicle to the resistor material powder varies depending on the organic solvent, resin, etc. used, but the ratio of the organic solvent to the resin is 20 to 50.
The latter is preferably 80 to 50% by weight. These components are made into a paste using a mixing means such as a three-roll mill or a sieve. The resistor material paste obtained in this way is applied to a substrate, which is further processed as described below to create a resistor. In addition to a method in which a ceramic green sheet is fired in advance, a resistor material and a conductor material are further coated on the ceramic green sheet, and then fired. These can also be applied when forming a laminate. The ceramic green sheet includes, for example, 35 to 45% by weight of aluminum oxide (Al ₂ O ₃ ), 25 to 35% by weight of silicon oxide (SiO ₂ ), and boron oxide (B ₂ O ₃ ).
10-15% by weight, calcium oxide (CaO) 7-13% by weight, magnesium oxide (MgO) 7-10% by weight
For example, a slurry prepared by mixing an oxide mixture of ceramic constituents with an organic vehicle using a ball mill or the like is formed into a sheet using a doctor blade or the like. At this time, when glass is not used in combination with the molybdate of the element in the element group, the ceramic green sheet may contain a large amount of glass to produce the same effect as when glass is used in combination. The organic vehicle is comprised of an acrylic resin such as an acarlic acid ester, a resin such as polyvinyl butyral, a plasticizer such as glycerin or diethyl phthalate, a dispersant such as a carboxylic acid salt, and a solvent such as water or an organic solvent. Preferably, the resistor material paste is applied to a ceramic green sheet by means such as silk screen printing, and after drying, it is heat treated at 400 to 500°C to decompose and burn the resin component. At this time, a paste of a base metal conductor material such as Ni or Cu or a noble metal conductor material such as Ag-Pd is simultaneously applied to the ceramic green sheet at the same time as the resistor material paste coating, and is treated in the same manner as the resistor material paste coating. Ru. Examples of paste compositions of base metal conductor materials such as Ni or Cu or noble metal conductor materials such as Ag or Ag-Pd include those in which 2 to 15 weight % of glass frit is added to 98 to 85 weight % of each metal powder. be done. In this way, the resistor material and/or conductor material is incorporated into the ceramic green sheet, but
In the case of a fixed chip resistor, only the surface of this unfired substrate is used, and in the case of a thick film resistor of a multilayer board, the resistor material and conductor material incorporated in the unfired state are further laminated to form a predetermined circuit. It is then fired. By this firing, the conductor material and/or the thick film resistor material can be made into a fired body at the same time as the substrate. In this case, when a base metal conductor material such as Ni or Cu is used as the conductor material, it is preferable to sinter it in a non-oxidizing atmosphere in order to prevent the resistance value from increasing due to oxidation, and the sintering temperature is as follows: For example, 800°C to 1100°C for 0.5 hours to 2 hours. As the non-oxidizing atmosphere, nitrogen gas, other inert gases, and mixed gases containing these gases and hydrogen gas may also be used. Furthermore, when using a noble metal conductor material such as Ag or Ag-Pd, it can also be fired in an oxidizing atmosphere such as air. A circuit wiring board incorporating a conductor and/or a resistor is completed as described above, but cracks, distortions, etc. occur not only between the fired board and the conductor, but also between the fired board and the resistor due to firing. It does not cause any blistering, and the resistance of the resistor is 10 to 90 at 25℃.
The change in resistance value is less than ±0.1% with respect to the change in % relative humidity, and even if it is left in a high temperature and high humidity atmosphere for more than 1000 hours, the change in resistance value is suppressed to within ±2%. This is thought to be due to the resistor's good matching with the conductor and the fired substrate, and the unique moisture resistance of the resistor, which is made of a molybdate of an element from the above element group and a fired glass body, but the details are not clear. do not have. Note that molybdate in the resistor can be observed by X-ray diffraction analysis. In the present invention, molybdates of the elements selected as described above may be used, but instead of these molybdates, some or all of the precursors that become these molybdates by heat treatment can also be used. . In any of these cases, it is preferable to mix it with glass and heat treat it, then crush it and use it as a resistor material. However, a paste made by mixing it with the above-mentioned organic vehicle, etc. without performing this heat treatment can be used, for example, as a green ceramic sheet. After coating, it is heated to remove organic matter and then fired. It is also possible to create a resistor directly. Additionally, the glass may be placed in a state where the mixed material of the oxides constituting it is eventually fired together with the molybdates of the selected elements, and the precursors of these oxides are combined with the molybdates of the selected elements. A part or all of this oxide together with salt and/or its precursor is made into a paste state as described above, and this is applied to a substrate, and in the process of burning the organic material and subsequent firing, it is made of the above glass component. Any material may be used as long as it becomes glass and can be baked with a molybdate of a selected element and/or its precursor to produce a resistor. For example, CaO (calcium oxide), a component of glass material,
Heating CaCO ₃ (calcium carbonate), B ₂ O ₃ (boron oxide) is obtained from heating boric acid (H ₂ BO ₃ ), so CaCO ₃ can be used instead of CaO, some or all of B ₂ O ₃ , respectively. , H ₃ BO ₃ can be used. The resistor material in the present invention may be any material whose main components are a molybdate of an element selected as a result of the treatment process and glass. Examples Next, examples of the present invention will be described. Each component was weighed and mixed to have the composition shown in Table 1 in terms of oxide.

[Table] In the table, the unit is weight%.
Each of the mixtures of Glass A and Glass B was individually melted at 1400° C. in an alumina crucible, and the melt was poured into water and rapidly cooled. This quenched material was taken out and put into a pot mill with ethanol, and ground with an alumina ball for 24 hours to a particle size of 10 μm.
The following glass powder was obtained. In addition, each of the molybdates belonging to (A) to (G) above was synthesized from cold molybdenum oxide and oxides of each element. Next, the glass powders of Glass A and Glass B obtained above and the molybdate salts obtained above were weighed and mixed in the proportions shown in each column of Table 2. Each sample in Table 2 was heat-treated at 1000°C for 1 hour in a gas atmosphere containing 98.5 vol% nitrogen (N ₂ ) and 1.5 vol% hydrogen (H ₂ ), then crushed in a pot with ethanol and dried to a size of 10 μm. Resistor material powders of the following glasses and heat-treated powders of molybdates of the corresponding elements were obtained. Next, 25 parts by weight of an organic vehicle (90 parts by weight of butyl carbitol, 10 parts by weight of ethyl cellulose) was added to 100 parts by weight of the resistor material powder of each sample and mixed in a roll mill to obtain a resistor material paste. On the other hand, Al ₂ O ₃ 40.0% by weight, SiO ₂ 35.0% by weight,
_{B2O3 13.0} % by weight, CaO7.0% by weight, MgO5.0% by weight
100 parts by weight of ceramic raw material powder consisting of 8 parts by weight of polyvinyl butyral, 8 parts by weight of diethyl phthalate, 0.5 parts by weight of oleic acid, 10 parts by weight of acetone,
20 parts by weight of isopropyl alcohol and 20 parts by weight of methyl ethyl ketone were added and mixed in a ball mill to prepare a slurry. After defoaming, a long ceramic green sheet with a thickness of 200 μm was prepared by a doctor blade method. A green sheet piece measuring 9 mm in length and 9 mm in width and another green sheet piece measuring 6 mm in length and 9 mm in width were cut out from this ceramic green sheet. Next, as shown in Figure 1, on top of the green sheet piece 1 measuring 9 mm in length and 9 mm in width, 95 parts by weight of copper powder, 5 parts by weight of glass frit, 20 parts by weight of butyl carbitol and 5 parts by weight of ethyl cellulose as an organic vehicle were added. A conductive material paste obtained by mixing these materials using a three-roll mill was silk screen printed and dried at 125° C. for 10 minutes to form a conductive material coating film 2. Next, the resistor material paste obtained above was silk screen printed on the green sheet piece 1 in the same manner as above and dried at 125° C. for 10 minutes to form a thick film resistor coating 3. Next, on the green sheet piece 1, the length 6 mm obtained above was
Green sheet pieces 4 each having a width of 9 mm are stacked as shown by the chain lines in the figure and heat-pressed at 100° C. and 150 kg/cm ² . Next, this is heated at 400 to 500℃ in an oxidizing atmosphere such as air.
The green sheet pieces 1 and 4, the conductor material coating film 2, and the resistor material coating film 3 are heated to decompose and sinter the residual organic matter. After removing organic matter in this way, N ₂ 98.5vol
%, H ₂ 1.5 vol% in a mixed gas at 95°C for 1 hour, and as shown in FIG. 4a, a multilayer ceramic substrate having a thick film conductor 2a as a fired body of conductor material coating 2 and a thick film resistor 3a as a fired body of resistor material coating 3 was completed. In this multilayer ceramic substrate, no warping or blistering as shown in FIGS. 3 and 4, which will be described later, was observed. The multilayer ceramic substrate of the fired body thus obtained is polished in the layer direction to expose the resistor layer,
This exposed resistor layer was analyzed by X-ray diffraction (Cu K α
line). The results obtained are shown in FIG. 5 for sample No. 1. As a result, we were able to confirm the molybdate of the corresponding element. Similar confirmation can be made for other samples, but they are omitted here. Next, the resistance value (R ₂₅ ) of this multilayer ceramic substrate 3a at 25°C and the resistance value (R ₁₂₅ ) when heated to 125°C were measured with a digital multimeter.
The temperature coefficient of resistance (TCR) was calculated using the following formula. TCR=R ₁₂₅ −R ₂₅ /R ₂₅ ×1000 (ppm/°C) Table 3 shows the measured resistance value of R ₂₅ and the calculated value of TCR. In addition, the multilayer ceramic substrate obtained above was
After standing for 1000 hours under ℃, 95% relative humidity
Table 3 shows the results of measuring the resistance value at 25°C and determining the rate of change.

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[Table] Comparative Example 1 (MoSi ₂ - TaSi ₂ glass-based resistor material) A mixture of 16 parts by weight of MoSi ₂ and 9 parts by weight of TaSi ₂ was heated at 1400°C in vacuum, and the product was mixed with alumina in a pot mill with ethanol. It was ground with a ball for 24 hours and dried to obtain a fine powder of 10 μm or less. For 25 parts by weight of the fine powder thus obtained, BaO,
75 parts by weight of glass frit consisting of B ₂ O ₃ , MgO, CaO, SiO ₂ and 25 parts by weight of an organic vehicle (20 parts by weight of butyl carbitol, 5 parts by weight of ethyl cellulose) were added and mixed in a roll mill to form a resistor material paste. I got it. A multilayer ceramic substrate was obtained in the same manner as in the example except that this resistor material paste was used. As a result, we formed a resistor material coating on a ceramic green sheet, heat-treated it to remove organic matter, and then fired it simultaneously. As shown in Figure 3, warpage is observed, and MoSi ₂ ,
The decomposition reaction of TaSi ₂ generated SiO ₂ gas, which caused blistering as shown in Figure 4, making it impossible to put it to practical use. Note that 11a is the ceramic layer 1a, 14a is the ceramic layer 4a, and 13a is the ceramic layer and thick film resistor corresponding to the thick film resistor 3a, respectively. Comparative Example 2 (MoSi ₂ -BaF ₂ glass-based resistor material) 70 parts by weight of MoSi ₂ , 20 parts by weight of BaF ₂ , SiO ₂ ,
10 parts by weight of glass frit consisting of ZnO, ZrO ₂ , CaO, and Al ₂ O ₃ are mixed in a ball mill, and the resulting powder is heat-treated at 1200°C in an argon (Ar) gas atmosphere. Grind in a bowl for 24 hours and dry
A fine powder of 10 μm or less was obtained. A multilayer ceramic substrate was obtained in the same manner as in Example 1 except that this resistor material paste was used. Table 4 shows the R ₂₅ , TCR, and rate of change in resistance value obtained for the thick film resistor of this multilayer ceramic substrate in the same manner as in Example 1.

[Table] From the above results, the multilayer ceramic substrates of Examples have no warping or blistering, and the rate of change in resistance value is within ±2%, whereas the multilayer ceramic substrate of Comparative Example 1 shows no warping. It can be seen that the multilayer ceramic substrate of Comparative Example 2 has a rate of change in resistance value that is four times larger. In addition, although the above described a mixture of molybdates, the molybdates of each single element and the composite molybdates of multiple elements may be used alone, each of each group may be used individually, or both may be mixed. Of course, similar effects can be obtained in other cases as well. Effects of the Invention According to the present invention, it is possible to provide an electrical resistor containing at least one type of molybdate in each group of at least two groups (A) to (G). If a resistor is formed by using a resistor material whose main component is glass and firing it together with a base metal conductor material and a ceramic grease sheet in a non-oxidizing atmosphere, the fired body will be formed by firing. Warping or blistering does not occur, and changes in the resistor over time, especially under high humidity conditions, can be reduced. This satisfies the demands for both miniaturization and cost reduction of a circuit board incorporating a resistor, and contributes to further improvement in the performance of the circuit board. Furthermore, if the molybdate of the above-mentioned corresponding atoms is heat-treated with glass, for example, and the heat-treated resistor material is fired to make a resistor, the absolute value of the temperature change coefficient of resistance can be reduced, and the circuit Performance can be further improved.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of a state in which a resistor material coating film and a conductor material coating film before firing are formed on a substrate to form a multilayer structure when manufacturing the electrical resistor of the present invention, and Fig. 2 is a cross-sectional view of the fired body, Figure 3 is a cross-sectional view of the fired body when it has a multilayer structure using conventional resistor materials, and Figure 4 is an explanation showing the state in which gas is generated in the fired body. FIG. 5 is an X-ray diffraction diagram when the corresponding molybdate was detected from the electrical resistor of sample No. 1 of the example of the present invention. In the figure, 1 and 4 are green sheet pieces, 2 is a conductor material coating, 3 is a resistor material coating, 1a and 4a are ceramic layers, 2a is a thick film conductor, and 3a is a thick film resistor.

Claims (1)

[Scope of Claims] 1. An electrical resistor characterized by having a fired body containing at least one type of molybdate from each group selected from at least two of the following groups (A) to (G): . (A) Alkaline earth metal molybdate (B) Zinc molybdate (C) Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb,
Molybdates of the elements Dy, Ho, Er, Tm, Yb, and Lu, and composite molybdates of multiple of these elements (D) Molybdates of aluminum (E) Molybdates of the elements zirconium and hafnium, and These composite molybdates (F) Molybdates of each element such as niobium and tantalum, and these composite molybdates (G) Molybdates of manganese 2 The fired product is made of molybdates of the corresponding groups (A) to (G). The electrical resistor according to claim 1, wherein the electrical resistor is fired from a resistor material containing as a main component at least one of the corresponding molybdate and its precursor. 3. The main component of the resistor material is 50 to 96% by weight of at least one of the molybdates and precursors thereof in the relevant groups (A) to (G), calculated as molybdates; The electrical resistor according to claim 2, characterized in that the electrical resistor comprises 4 to 50% by weight of glass. 4 At least two of the following (A) to (G) as the main component
heat-treating a resistor material containing at least one molybdate of each group selected from the three groups and at least one of its precursors, and firing the resistor material obtained by the heat treatment, A method for producing an electrical resistor, which comprises obtaining an electrical resistor comprising a fired body containing at least one molybdate from each group selected from at least two of the following groups. (A) Alkaline earth metal molybdate (B) Zinc molybdate (C) Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb,
Molybdates of the elements Dy, Ho, Er, Tm, Yb, and Lu, and composite molybdates of multiple of these elements (D) Molybdates of aluminum (E) Molybdates of the elements zirconium and hafnium, and These composite molybdates (F) Molybdates of each element such as niobium and tantalum and their composite molybdates (G) Manganese molybdate 5 The main components of the resistor material before heat treatment are (A) or ( G)
A patent characterized in that at least one of the molybdates and precursors thereof in the relevant group is comprised of 50 to 96% by weight in terms of the molybdate, and 4 to 50% by weight of glass. A method for manufacturing an electrical resistor according to claim 4.