JPH01120001A - Electric resistor and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an electric resistor having stable resistance value even it is left alone under high moisture for a long time, being obtainable by firing a resistor material in a reducing atmosphere and not damaging an function as a resistor even when high voltage is impressed, by making to have a burned body containing molybdate of an alkaline earth metal and titanate, or the like. CONSTITUTION:It is a thick film resistor having a burned body containing molybdate of an alkaline earth metal and titanate. Further, it is a burned body having agglomerate particles (b), needle particles (c) sticking to agglomerate particles (b) or located near the neighborhood of the agglomerate particles (b) and a glass layer (a) and containing titanate, wherein agglomerate particles (b) contain molybdate of the alkaline earth metal and needle particles (c) contain a reducing product of the molybdate. Then, a resistor material containing molybdate of the alkaline earth metal and at least one kind of its pre-cursors and titanate as the main components is given heat treatment and the resistor material obtained by the heat treatment is used for firing in order to obtain made of a burned body containing molybdate of the alkaline earth metal and titanate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thick film type electrical resistor provided on a fixed chip resistor or a circuit wiring board, etc., and particularly to a thick film type electrical resistor that can be obtained by firing in a non-oxidizing atmosphere. The present invention relates to an electrical resistor that is possible and has improved withstand voltage characteristics, and a method for manufacturing the same.

Conventional technology The electrical circuits of electronic devices are often constructed by mounting various electrical elements such as resistors, capacitors, diodes, and transistors on circuit boards, but as electronic devices become 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 plate-shaped ceramic chip. There are also fixed chip resistors in which the thick film resistor is formed so as to span both electrodes.

Conventionally, in order to provide such a thick film resistor on a circuit board,
For example, 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°C, and after baking, a paste containing RuO□ as a resistor material is applied by screen printing, etc. A common method is to apply the film, then bake it at 750 to 850°C, and then adjust the resistance value by trimming or the like if necessary.

However, in recent years, electronic devices have become lighter, thinner, and smaller.
The demand for lower costs has become even stronger, and efforts are being made to further reduce the size and cost of circuit boards.

As concrete measures to reduce the size of the former, firstly, the circuit board is multilayered, and secondly, the resistor is built inside. Examples of multilayer circuit boards include Ag or A.
Multilayer structure
In addition, as an example of internalizing a resistor, a RuO□-based resistive material and antibody material paste is further applied on a ceramic green sheet printed with the conductive material paste, and then laminated and crimped in the same manner as above. , a resistor-incorporated multilayer wiring board obtained by simultaneous firing, and the like are known.

In addition, as a specific measure to reduce the cost of the latter, in place of expensive noble metal conductor materials such as Ag or Heg-Pd materials, inexpensive base metal conductors such as Ni or Cu are used. These materials are simultaneously treated with green ceramics at 800 to 1100℃ in a neutral or reducing non-oxidizing atmosphere that can avoid high resistance due to oxidation, such as nitrogen gas or nitrogen gas containing hydrogen. Multilayer wiring boards obtained by firing have been put into practical use. Furthermore, as described in Japanese Patent Application Laid-open No. 56-153702, a resistor material made of Mo5iz-TaSit and glass is coated on an alumina substrate having a W4 (Cu) conductor, and the thickness obtained by heat treatment is 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□-based resistance material antibody material gas or green ceramic co-fired in a nitrogen gas atmosphere containing hydrogen must be used. Sometimes a reduction reaction occurs, resulting in a low resistance value and no longer exhibiting properties as a resistor.

Additionally, when a resistor material made of MoSi, -TaSi2, and glass is co-fired with a green ceramic sheet in a non-oxidizing atmosphere, the fired body may warp due to differences in expansion and contraction rates between the two, and Mo5iz- Ta
There is a problem that gas is generated due to the decomposition reaction of Siz, which tends to cause blistering in the fired product. In order to improve this, an example is known in which a resistor material made of Mo5iz-metal fluoride (e.g. calcium fluoride) and glass is used, as described in JP-A-60-198703. , No warping or blistering during firing as mentioned above was observed.

However, a thick film resistor obtained by coating a resistor material made of Mo5iz-metal fluoride and glass on a green ceramic sheet and co-firing it at 1% in 95% relative humidity
If left for 000 hours, the resistance value will increase by 5 to 10%, and the resistor will no longer be able to function as a resistor.

Therefore, the present inventors have developed an alkaline earth metal molybdate that can be obtained by firing at 800 to 1100°C in a non-oxidizing atmosphere together with a ceramic green sheet printed with base metal conductor paste such as Cu and Ni. A thick film resistor containing salt was proposed. This is preferable because almost no increase in resistance value is observed even if it is left in the high humidity environment for a long time as described above.

However, devices and circuit boards on which thick-film resistors containing molybdate of alkaline earth metals are formed, or electronic devices mounted with these devices and circuit boards, must be handled under conditions of low temperature and low humidity. Then, high-voltage static electricity generated by friction between these elements or the friction of the clothes of the workers handling these elements or equipment will be applied to the thick film resistor, and the resistance value of this resistor will decrease. There is a problem in that it significantly reduces the This decrease in resistance is 2
The resistance value can be as high as 0 to 50%, and once it decreases, it does not return to the original resistance value, and an improvement has been desired.

Therefore, the first object of the present invention is that it can be used not only for fixed chip resistors or general circuit boards, but also for
An object of the present invention is to provide an electrical resistor that can be laminated together with a base metal conductor material and incorporated into a multilayer board, and that has a stable resistance value even when left under high humidity under the skin for a long time.

A second object of the present invention is to provide an electrical resistor having excellent characteristics that can also be obtained by firing the resistor material in a reducing atmosphere.

A third object of the present invention is to provide an electrical resistor that does not lose its function as a resistor even when a high voltage is applied.

A fourth object of the present invention is to provide an electrical resistor that satisfies both the miniaturization of circuit boards and cost reduction.

A fifth 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 achieve the above object, the present invention provides a thick film resistor characterized by having a fired body containing an alkaline earth metal molybdate and a titanate. This is what we provide.

The present invention also provides a fired body comprising a titanate having a glass layer, a block particle, an acicular particle attached to the block particle or existing in the vicinity of the block particle, wherein the block particle is The present invention provides an electrical resistor containing a molybdate of an alkaline earth metal, the acicular particles containing a reduction product of the molybdate.

The present invention also provides a resistor material obtained by heat-treating a resistor material containing at least one molybdate of an alkaline earth metal and its precursor as a main component and a titanate. The present invention provides a method for producing an electrical resistor, which is characterized in that the electrical resistor is made of a fired body containing a molybdate and a titanate of an alkaline earth metal.

As shown in FIG. 1, the electrical resistor of the present invention has a structure in which spherical particles and acicular particles C are dispersed in glass a, and in this example, the acicular particles are attached to the spherical particles. Either there is, or there is one nearby. Such a structure allows electrical current to flow through spherical particles and needle-like particles that are in contact with or in close proximity. Such a structure can be formed, for example, by firing bulk particles of the resistor material and growing a product on the surface into a needle shape, which will be described in detail later.

As such a resistor material, alkaline earth metal molybdate can be used, but when Me is an alkaline earth metal, the general formula MeMoOa, Me3MoOa, Me
, MoOs , Me, Mo, , MeMo40+z, Me
MOJz4, MeMoJO+o, MezMoOs, M
Those represented by ezMOaO++ and the like are preferred. Specifically, for example, MgMo0. , CaMoO4, SrMo0
．． , BaMo0a, BaMozOt, BaMo40+
s, 88MO70za, BaMozOtas CaJo
(16, Sr=MoOb-.

BaMo0a, BaMo0a, MgzMO30+
+ etc.

Further, the following complex molybdates are also exemplified.

(Mgx Ca, )MO04% However, X+31=l,
(CaXSr, )MOO4, where X +y = l
, (ML+Ha, )MOO4, where x+y=l,
(Mgx Ca, Bag) Mo04, however, X +
37 +z = 1, (Cax Sr, Bag >M
ova , however, X + y + z −1.

(Mgx ca, Srx Batt) MOO4, however, x + y + z + z = 1, (CaX5ry
) MOO6, however, x + y = 3, (Srx Ba
y) MoOa, provided that x+y=3, such an alkaline earth metal molybdate is a mixture of a substance that is a precursor of each metal oxide of an alkaline earth metal and molybdenum oxide (Mood) or its precursor. It can be synthesized by mixing at a predetermined molar ratio and heat-treating the mixture. For example, calcium carbonate (CaC) is a precursor of CaO.
Oi) or calcium hydroxide (Ca (Oll) 2)
and molybdenum oxide (MoOz) or its precursor, for example, molybdic acid (H2MOO4), are mixed in a predetermined molar ratio and heat treated. The heat treatment conditions at this time are:
Examples include 600-1000t and 1-3 hours.

Moreover, the alkaline earth metal molybdate can also be synthesized by heat treating an alkaline earth metal oxide and molybdenum oxide (Mood). For example, CaO and Mo
Calcium molybdate is synthesized by heat-treating b., but in this case, since Mob tends to sublime, it is preferable to heat-treat while pressurizing. The same applies to other alkali metals.

Further, the titanate used in the present invention is represented by the general formula 2MeTiO=, where Me is a metal, and examples of Me include alkaline earth metals. Specifically, perovskite type oxide MgTi0:+, CaTiO2,
5rTiOi and BaTiO1 are preferred.

In the present invention, it is preferable to use glass, and as this glass, commonly known glass is used,
Although not limited to glasses of particular composition, Pb
Oxides such as 3O4, Bizol, 5nOz, and CdO may be reduced and metallized when resistor materials containing them are fired in a non-oxidizing atmosphere, and this metal changes the resistance value. If such occurrence is undesirable, it is preferable not to contain these oxides.

Glass components include 5i02, B204, ZnO,
CaO1SrO% ZrO□, etc. are preferable, and the composition ratio of these oxides is as follows: 5i (h 12-33 wt% 8□0,20-35 wt% ZnO or 5r013-33 wt% CaO10-2
5% by weight ZrO215-45% by weight is preferred.

In order to manufacture glass from a composition of these oxides, the respective oxides are weighed and mixed to achieve the above composition ratio. This mixture is placed in a crucible and melted at a temperature of 1200 to 1500°C, and then the melt is poured into water, for example, and rapidly cooled to obtain coarse glass powder.

Glass powder is obtained by pulverizing this coarse powder to a desired particle size (for example, 10 μm or less) using a pulverizing means such as a ball mill or a vibration mill.

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) is caco:+ (calcium carbonate), BzO
Since :+ (boron oxide) is obtained by heat treatment of boric acid (H:IBO:l), CaC0, H:lBO,l can be used in place of part or all of CaO and BzOz, respectively. The same applies to oxides of other components.

The alkaline earth metal molybdate and glass powder obtained as described above may be mixed, and titanate may be added to this mixed composition and further mixed to be used as a resistor material. It is preferable to use heat-treated and pulverized material as a resistor material in view of the resistance temperature characteristics of a resistor obtained by firing the same. The heat treatment temperature is 80
A temperature of 0°C to 1200°C is preferable; if the temperature is outside this range, the resistance value of the finished resistor will not be affected by slight fluctuations in the composition ratio due to work conditions in each step of processing the resistor material into an electrical resistor. It is difficult to stably obtain a desired resistance value. This heat treatment is preferably carried out in a non-oxidizing atmosphere, and it is preferable to use nitrogen gas, other active gases, or a mixed gas containing these gases and hydrogen gas.

The composition ratio of each component of the resistor material is 0.01 parts by weight of titanate per 100 parts by weight of a composition of 30 to 96% by weight of alkaline earth metal molybdate and 4 to 70% by weight of glass powder.
It is preferable to add up to 5.00 parts by weight.

If the amount of alkaline earth metal molybdate is too small and the amount of glass is too large, the resistance value of the fired electric resistor may become too high, which is undesirable. If the amount of glass is too large and the amount of glass is too small, 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 content of molybdate of the element in question is not limited to more than the above range, but may be 100%, and if the amount of titanate is too large, the temperature The coefficient becomes negative with a large absolute value, and if it is too small, it may be unfavorable in terms of voltage resistance.

In order to create a resistor for a fixed chip resistor or a thick film resistor from the resistor material powder thus obtained, the resistor material powder is applied to, for example, a ceramic green sheet and fired. At this time, it is preferable to use the above-mentioned molybdate, which will form the main body of the electrical resistor, after forming it into bulk particles such as spheres, ellipses, and polygons. This is because it is preferable that . A binder such as glass is used to make this resistor body material into bulk particles.

It can also be used.

In order to apply a resistor material made of molybdate and glass, for example, a vehicle is mixed with the resistor material powder 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. Additions are preferred. Examples of the organic solvent include butyl carbitol acetate, butyl carbitol, and turpentine oil, and examples of the resin include cellulose derivatives such as ethyl cellulose and nitrocellulose, and other resins.

The usage ratio of this organic vehicle and the resistor material powder varies depending on the organic solvent, resin, etc. used, but the usage ratio of the organic solvent and resin is 20 to 50% by weight for the former and 80% for the latter.
~50% by weight is suitable. 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 the method in which a ceramic green sheet is fired in advance, a resistor material and a conductor material are further applied thereto, and then fired, these methods can also be applied to the formation of a laminate.

The ceramic green sheets include, for example, 35 to 45% by weight of aluminum oxide (AlzOs), 25 to 35% by weight of silicon oxide (Sing), and boron oxide (BzOs).
i) lo ~ 15% by weight, calcium oxide (CaO) 7
~13% by weight, magnesium oxide (MgO) 7-10
For example, a slurry prepared by mixing a mixture of oxides of ceramic constituents such as % by weight with an organic vehicle using a ball mill or the like may be formed into a sheet using a doctor blade or the like. At this time, when glass is not used in combination with the alkaline earth metal molybdate, the ceramic green sheet may contain a large amount of glass to produce the same effect as when glass is used in combination. is composed of an acrylic resin such as an acrylic 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.

The resistor material paste is applied to a ceramic green sheet by means such as silk screen printing,
After drying, it is preferable that the resin component is decomposed and burned by heat treatment at 400 to 500°C.

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 or Ag-Pd is also applied to the ceramic green sheet in the same way as the resistor material paste coating film, and the paste is also applied to the ceramic green sheet in the same way as the resistor material paste coating. will be processed.

This base metal conductor material such as Ni or Cu or Ag
Alternatively, a paste composition of Ag-Pd noble metal conductor material is exemplified by adding 2 to 15 weight % of glass flift to 98 to 85 weight % of each metal powder.

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 incorporated, and in the case of a thick film resistor of a multilayer substrate, the resistor material and/or the conductor material are incorporated into the ceramic green sheet. The body material and conductor material assembled in an unfired state are further laminated to form a predetermined circuit, and 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℃~1100℃
, 0.5 hours to 2 hours. As the non-oxidizing atmosphere, nitrogen gas and other active gases, as well as mixed gases containing these gases and hydrogen gas, can be used. Also, Ag or A
When g-Pd noble metal conductor material is used, 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 there may be cracks, distortions, etc. not only between the fired board and the conductor but also between the fired board and the resistor due to firing. In addition to not causing any blistering, the resistance value is suppressed to change within ±10% even when high voltage pulses are applied, and furthermore, the resistance value remains unchanged even after being left in a high temperature, high humidity atmosphere for more than 1000 hours. Changes can be suppressed to within 2% and high reliability can be ensured. This is thought to be due to the good matching of the resistor to the conductor and the fired substrate, and the effect of the addition of titanate, but the details of this mechanism are not clear. Note that molybdate in the resistor can be observed by X-ray diffraction analysis. Furthermore, lumpy particles and needle-like particles can be observed using a transmission electron microscope.

In the present invention, alkaline earth metal molybdates may be used as described above, but instead of these molybdates, some or all of the precursors that become these molybdates through heat treatment may also be used. can. 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 applying it to
It is also possible to directly create a resistor by firing after heat treatment to remove organic matter.

In addition, the glass may be placed in a state in which the mixed material of the oxides constituting it is fired together with molybdates and titanates of alkaline earth metals, and the precursors of these oxides are A part or all of this oxide together with the earth metal molybdate and/or its precursor and titanate are made into a paste as described above, and this is applied to the substrate to burn out the organic matter and then In any of the firing processes, it becomes a glass consisting of the above glass components, and by firing this with an alkaline earth metal molybdate and/or its precursor, and further a titanate, a resistor can be made. Good. For example, CaO (calcium oxide), which is a component of glass material, is CaC0
5 (calcium carbonate), B2δ3 (boron oxide) can be obtained from heating boric acid (H, BO,), so CaO
, B20. CaC0 instead of part or all of
= , HJ (h can be used. ゛The resistor material in the present invention is a material whose main components are alkaline earth metal molybdate, glass, and titanate as a result of the treatment process. Good.

Example Next, the present invention will be explained in detail.

Each component was weighed and mixed to have the composition shown in Table 1 in terms of oxide.

Table 1 In the table, the unit is weight%.

The mixture for glass was 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 pole for 24 hours to obtain a particle size of 1.
A glass powder of 0 μm or less was obtained.

Further, molybdenum oxide and magnesium carbonate were mixed at a molar ratio of 1, and heat treated at 700° C. for 1 hour to obtain a magnesium molybdate.

Next, the glass A powder obtained above, magnesium molybdate, and titanate were weighed and mixed in the weight parts shown in each column of Table 2.

Each sample in Table 2 was heated to 100% in a gas atmosphere of 98.5 vol. 1% nitrogen (Nz) and 1.5 vol. % hydrogen (llz).
The resultant was heat-treated at 0° C. for 1 hour, then ground with ethanol in a pot mill, and dried to obtain resistor material powder of glass and alkaline earth metal molybdate and titanate heat-treated powder having a size of 10 μm or less.

Next, 25 parts by weight of an organic vehicle (90 parts by weight of butyl carbitol, 10 parts by weight of ethyl cellulose) were 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, 40.0% by weight of 0, 35.0% by weight of 5iOz, 3.0% by weight of BzOd, 7.0% by weight of Ca, M
gO5.0% by weight (ceramic raw material powder 100
1! 8 parts by weight of polyvinyl butyral, 8 parts by weight of diethyl phthalate, 0.5 parts by weight of oleic acid, 1 part by weight of acetone.
0 parts by weight, 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, and after defoaming treatment, a long ceramic green sheet with a thickness of 200 μm was prepared using a doctor blade method. did. From this ceramic green sheet, a green sheet piece with length 911 width 9N, length 9 fins width 9
I cut out a piece of green sheet for the basket.

Next, as shown in FIG. 2, 95 parts by weight of copper powder and 5 parts of glass frit
Butylcarpitol 20 as transport vehicle in parts by weight
parts by weight and 5 parts by weight of ethyl cellulose were added and mixed using a three-roll mill. A conductive material paste 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 l, place the vertical 6fl and horizontal 91
Layer the green sheet pieces 4 of 1 as shown by the chain lines in the figure,
Thermocompression bonding is carried out at 100°C and 150 kg/aJ. Next, this is heated at 400 to 500° C. in an oxidizing atmosphere such as air to decompose and burn the residual organic matter in each of the green sheet pieces 1.4, the conductor material coating 2, and the resistor material coating 3.

After removing organic matter in this way, NZ 98.5v
o1%, Hz 1.5 vo1% mixed gas, 95
After firing at 0° C. for 1 hour, as shown in FIG. Thick film conductor 2a, thick film resistor 3a of fired body of resistor material coating 3
We have completed a multilayer ceramic substrate with In this multilayer ceramic substrate, no warping or blistering as shown in FIGS. 4 and 5, which will be described later, was observed.

The multilayer ceramic substrate of the fired body thus obtained was polished in the layer direction to expose the resistor layer, and the exposed resistor layer was analyzed by X-ray diffraction (Cu K c X-ray). The obtained results are shown in FIG. 6 for sample No. 5. This enabled confirmation of magnesium molybdate.

Next, we will calculate the resistance value (R*s) of this multilayer ceramic substrate 3a at 25°C and the resistance value (R*s) when heated to 125°C.
ags) was measured using a digital multimeter, and the temperature coefficient of resistance (TCR) was determined using the following equation.

2s Table 2 shows the measured resistance value of Ls and the calculated value of TCR.

In addition, the multilayer ceramic substrate obtained above was heated at 60°C for 9
25℃ after standing for 1ooo hour under 5% relative humidity
Table 2 shows the results of measuring the resistance value and calculating the rate of change.

Further, the results of measuring voltage resistance are shown in Table 2.

Note that this withstand voltage property is based on I
After charging at a voltage of KI/ for 0.8 seconds, the process of discharging the multilayer ceramic substrate for 0.8 seconds was repeated three times, and the rate of change in resistance value after voltage application was calculated.

Examples 2 to 4 Tables 3.4 and 4 are the same as in Example I, except that calcium molybdate, strontium molybdate, and barium molybdate were used instead of magnesium molybdate, respectively. A multilayer ceramic substrate was prepared from the resistor material shown in Example 5, and l? 26, TCP, resistance change rate, and withstand voltage were determined, and these are shown in 3.4.5.

In addition, No. 1 to No. 4 in each table regarding the results of measurements made in the same manner for samples prepared in the same manner as in Examples 1 to 4 above except that titanate was not added.
It was shown to.

Table 2 (continued) Table 3 (vs. θ12) Table 3 (continued) Table 3 (continued) Table 5 (continued) Table 5 (continued) Table 5 (continued) Comparative example 1 (MoSiz-TaSiz glass-based resistor material) MoSiz A mixture of 16 parts by weight of Ta5iz and 9 parts by weight of Ta5iz was heated at 1400° C. in vacuo, and the product was ground with ethanol in an alumina ball in a Bottle mill 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, BaO1B2
03. 75 parts by weight of glass frit consisting of MgO, CaO, 5iOz and 25 parts by weight of organic vehicle (20 parts by weight of butyl rubitol, 5 parts by weight of ethyl cellulose) were added and mixed in a roll mill to obtain a resistor material paste. Ta.

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, the ceramic green sheet was coated with a resistor material coating, heat-treated to remove organic matter, and then fired simultaneously. As shown in Figure 3, warpage is observed,
In addition, in the decomposition reaction of MoSi, Ta5iz, Sin,
Due to the generation of gas, blistering occurred as shown in FIG. 4, making it impossible to put it to practical use. In addition, lla
14a is the ceramic layer N4a, and 13a is the ceramic layer and thick film resistor corresponding to the thick film resistor 3a, respectively.

Comparative Example 2 (MoSiz-BaFz glass-based resistance material antibody material Siz 70 parts by weight, BaFz 20 parts by weight, S
in,,ZnO,,ZrO,,CaO% AlzOx
The resulting powder was mixed with 10 parts by weight of glass frit consisting of
After heat treatment at 200° C., this was ground with ethanol in an alumina ball in a Bot mill for 24 hours and dried to obtain a fine powder of 10 μm or less.

A multilayer ceramic substrate was obtained in the same manner as in Example 1 except that this resistor material paste was used. Table 6 shows the R2S, TCP, 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 6 From the above results, all of the multilayer ceramic substrates of the examples have no warping or blistering, the rate of change in resistance value is within ±2%, and the voltage resistance is also superior to that without adding titanate. On the other hand, it can be seen that the multilayer ceramic substrate of Comparative Example 1 is warped, and the multilayer ceramic substrate of Comparative Example 2 has a rate of change in resistance value that is four times larger.

Effects of the Invention According to the present invention, it is possible to provide an electrical resistor containing alkaline earth metal molybdate and titanate. If a resistor material is formed using a resistor material having a composition such as, for example, a base metal conductor material and a ceramic green sheet in a non-oxidizing atmosphere, the fired product will not warp or bulge. In addition, it is possible not only to reduce the change in the resistor over time, especially under high humidity conditions, but also to improve the voltage resistance.

Furthermore, since it is possible to provide an electrical resistor having a fired body in which needle-like particles are attached to or close to the lump particles, the resistor material containing the lump particles of the electrical resistor main body material can be used together with a base metal conductor material in a non-oxidizing atmosphere. When an electrical resistor is formed by firing the powder together with a ceramic green sheet, acicular particles can be grown from the surface of the lump particles, avoiding excessive reduction and providing an electrical resistor with an appropriate resistance value. can.

As a result, circuit boards incorporating resistors can be made smaller,
It satisfies both requirements for cost reduction and can contribute to further improving the performance of circuit boards.

In addition, if a molybdate of an alkaline earth metal 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, which improves circuit performance. can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the structure of the electrical resistor of the present invention, and FIG. 2 is a diagram showing the formation of a resistor material coating film and a conductive material coating film on a substrate before firing when manufacturing the electrical resistor of the present invention, ``A figure showing an example of a state in which a multilayer structure is to be formed, Fig. 3 is a cross-sectional view of the fired body, Fig. 4 is a cross-sectional view of the fired body when a multilayer structure is formed using conventional resistor material, FIG. 5 is an explanatory diagram showing the state in which gas is further generated in the fired body, and FIG. 6 is an X-ray diffraction diagram showing the detection of magnesium molybdate from the electrical resistor of sample N015 of Example 1 of the present invention. It is a diagram. In the figure, a is glass, b is lumpy particles, C is needle-like particles, 1,
4 is a green sheet piece, 2 is a conductor material coating, 3 is a resistor material coating, 1a, 4a are ceramic layers, 2a is a thick film conductor, 3a
is a thick film resistor. November 2, 1988 Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 X-ray diffraction diagram Brang angle for X-rays of Cu1iα

Claims (7)

[Claims] (1) A thick film resistor characterized by having a fired body containing an alkaline earth metal molybdate and a titanate. (2) The fired body is fired from a resistor material containing at least one molybdate of an alkaline earth metal and its precursor, and a titanate as a main component. Thick film resistor according to item 1. (3) The main component of the resistor material is an alkaline earth metal molybdate and at least one of its precursors, which is 30 to 96% in terms of the alkaline earth metal molybdate.
% by weight and 4 to 70% by weight of glass;
The thick film resistor according to claim 2, characterized in that the titanate is contained in an amount of 0.01 to 5.0 parts by weight based on 100 parts by weight of the composition. (4) A fired body containing a titanate and having a glass layer, lump particles, acicular particles attached to the lump particles or existing in the vicinity of the lump particles, wherein the lump particles are alkaline earth An electrical resistor comprising a metal molybdate, the acicular particles containing a reduction product of the molybdate. (5) The electrical resistor according to claim 4, wherein the acicular particles are a reduction product produced by reducing the surface of the bulk particles. (6) Heat treating a resistor material containing at least one of molybdates of alkaline earth metals and their precursors and titanates as main components, and using the resistor material obtained by this heat treatment. 1. A method for producing an electrical resistor, the method comprising: obtaining an electrical resistor comprising a fired body containing an alkaline earth metal molybdate and titanate. (7) The main component of the resistor material before heat treatment is at least one of an alkaline earth metal molybdate and its precursor in an amount of 30 to 96% by weight in terms of the alkaline earth metal molybdate. , 4 to 70% by weight of glass, and 0.01 to 5% by weight based on 100 parts by weight of the composition.
．． 7. The method for manufacturing an electrical resistor according to claim 6, wherein the titanate is 0 parts by weight.