JPH01168002A - Electric resistor and manufacture thereof - Google Patents

Abstract

PURPOSE:To stably obtain a resistance value even if it is left to stand through high moisture for a long period of time and to reduce the change rate of power operation by providing a sintered material containing molybdate of alkaline earth metal and oxide of at least one element selected from a group consisting of specific rare earth elements. CONSTITUTION:A resistor material containing as main ingredients molybdate of alkaline earth metals, at least one of its precursor, and oxide of at least one element selected from a group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Pm is heat treated. The resistor material obtained by the heat treatment is baked to attain an electric resistor made of the baked material. The composition ratio of the components of the material preferably contains 0.1-20.0 pts.wt. of the oxide of the rare earth element to be added to 100 pts.wt. of a composition having 30-96wt.% of molybdate of the alkaline earth metal, and 4-70wt.% of glass powder.

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 and a method for manufacturing the same that are possible and have a reduced rate of change in power operation, and further to an electrical resistor that has improved withstand voltage characteristics.

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.
Examples include multilayer wiring boards obtained by laminating and crimping ceramic green sheets (green sheets) printed with conductor material paste such as g-Pd, and then simultaneously firing them in the atmosphere at 800 to 1100°C; As an example of internalization, a RuO□ resistance material antibody material paste is further applied on a ceramic green sheet printed with the conductor material paste, laminated and crimped in the same manner as above, and then co-fired to create a resistor body. Multilayer wiring boards 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 8G or Ag-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 MoSi, -TaSiz, 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□-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.

Furthermore, when a resistor material made of Mo5t, -TaSiz, and glass is co-fired with a green ceramic sheet in a non-oxidizing atmosphere, the fired body may warp due to the difference in expansion and contraction rates of the two, and MoSi, -Ta
There is a problem that gas is generated due to the decomposition reaction of St, which tends to cause blisters in the fired body. In order to improve this, an example is known in which a resistor material made of MoS i z-metal fluoride (e.g. calcium fluoride) and glass is used, 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 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 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 a base metal conductor paste such as CuSNi. We have proposed a thick film resistor containing . This is preferable because almost no increase in resistance value is observed even when left for a long time under high humidity as described above.

However, the rated voltage of the thick film resistor containing this alkaline earth metal molybdate at 70±5°C is 1.
When conducting a power operation test for 24 hours with a cycle of 5 hours on and 0.5 hours off, there was a resistance change of ±2% (absolute value greater than 2), indicating that the power operation change was The problem was that it was large.

In addition, 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 20-50
%, and once it decreases, it does not return to its 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 chi-knob 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 with a small rate of change in power operation.

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.

A sixth object of the present invention is to achieve the above object, and
Another object of the present invention is to provide a voltage-resistant electrical resistor that does not lose its function as a resistor even when a high voltage is applied.

Means for Solving the Problems In order to achieve the above object, the present invention provides the following methods: alkaline earth metal molybdate, Y, Laz Ces Pr.
5Nd, Sm, Eus Gds Tbs DV%■
0% Erx Tmx YblLLI%Scs Pll
An object of the present invention is to provide a thick film resistor characterized by having a fired body containing an oxide of at least one element selected from the group of.

In addition, the Y
SLa, Ce5Prs Nd, 5II1% 211
% Gds TbxDy, Ho,, Er, Tm,
A fired body containing an oxide of at least one element selected from the group of Yb, Lu, Sc, and Pm, wherein the massive particles contain molybdate of an alkaline earth metal, and the acicular particles contain the oxide of at least one element selected from the group of Yb, Lu, Sc, and Pm. An object of the present invention is to provide an electrical resistor characterized by containing a reduction product of molybdate.

In addition, alkaline earth metal molybdate and Y SL
a, Ce, Pr, Nd, SMS 211% G
ds Tbs Dy180%Er, Tms Ybs
An object of the present invention is to provide a thick film resistor characterized by having a fired body containing an oxide of at least one element selected from the group of Lus SC5Pm and titanium oxide.

In addition, the main components are at least one of molybdates of alkaline earth metals and their precursors, Y, La, and Ce.
, Prx Nd, Sm, Eu, , Gd5Tb, ,
07% 80, E r -.

A resistor material containing an oxide of at least one element selected from the group Tms YbXLLI% S0% pH Molybdate and Y
s Las Ces Prx Nds Srs, Eu
, Gd, Tb, 07% Ilo.

An object of the present invention is to provide a method for producing an electrical resistor, which is characterized by obtaining an electrical resistor made of a fired body containing an oxide of at least one element selected from the group Er, Tms Yb-, LLI% ScSPm0. .

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.

Molybdates of alkaline earth metals can be used as such resistor materials, but when Me is an alkaline earth metal, the general formulas MeMoOa, MeJo06, Mez
MoOs, Me, Mot, MeMO40+i, MeM
oJza, MgMoO4,o, MezMoOs,M
62MO: Those represented by +O+, etc. are preferable. Specifically, for example, MgMoO4, CaMo0as SrM
oO4, BaMoO4, BaMoO47, [18MO4
013, BaMo, 0.4, BaMoO+o, CaMo
0asBaMoO4 The following complex molybdates are also exemplified.

(Mgx Cay) MOO4, however, x + y = 1
, (CaX5ry) MOO4, where x + y = 1
, (Mgz Bay )MOO4, where x + y =
1, (MgXCayBa, )MOO4, where x +
y + z = 1, (Caz Sr, Ba, )MOO
4, However, X + y + z = 1, (MgXCa, S
rz Baw ) MOO,, however, X +y +Z
+z = 1' (Caz Sry ) Moth, however, X +y = 3, (Srx [lay) MOO&
However, x + y-3, such an alkaline earth metal molybdate is obtained by combining a substance that becomes a precursor of each metal oxide of an alkaline earth metal and molybdenum oxide (MoOz) or its precursor in a specified manner. It can be synthesized by mixing at a molar ratio of and heat-treating. For example, a precursor of CaO, such as calcium carbonate (CaCO:+) or calcium hydroxide (Ca (OR) z), and an acid C hismolybdenum (MoOz), or a precursor thereof, such as molybdic acid (11□MOO4) are mixed in a predetermined molar ratio and heat treated. The heat treatment conditions at this time are 600 to 1
000°C for 1 to 3 hours.

Alkaline earth metal molybdates can also be synthesized by heat treatment of alkaline earth metal oxides and molybdenum oxide (MoO3).
Calcium molybdate is synthesized by heat-treating b. However, in this case, since Woo tends to sublime, it is preferable to heat-treat while pressurizing. The same applies to other alkali metals.

Furthermore, Y% Lax Ce, P used in the present invention
r5Nd.

Srm-, Eu, Gdz Tbs Dy, Ho, E
rs Tll1% Yb-, Lus ScsPm element oxides are oxides of Sc, Y, and lanthanoids (element numbers 57 to 71) belonging to subgroup A of genus A of the periodic table, and these rare earth elements are divalent, Although compounds with an oxidation number such as tetravalence are also produced, oxides with an oxidation number of trivalence are generally stable and are preferably used.

Furthermore, the titanium oxide used in the present invention has the general formula Tix
Oy, specifically TiO, Tit(h, Ti0
z etc. 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, Bi2O3, 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 Sing, B201, ZnO%
CaO1SrO1zrO2 and the like are preferable, and the composition ratio of these oxides is as follows: Si0□12-33 wt% [1zOi 20-35 wt% ZnO or Sr0 13-33 wt%Ca0 10
-25% by weight Zr0z 15-45% 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. For example, CaO (calcium oxide), CaC0+ (calcium carbonate), BtO*
Since (boron oxide) is obtained by heat treatment of boric acid (HJO+), CaCO5 and HJO3 can be used in place of part or all of CaO, 8203, respectively. The same applies to oxides of other components.

The alkaline earth metal molybdate and glass powder obtained as described above are mixed, and the above-mentioned rare earth element oxide and/or titanium oxide are added to this mixed composition and further mixed to obtain a resistor material. However, it is preferable to use heat-treated and pulverized material as the resistor material in view of the resistance temperature characteristics of the resistor obtained by firing it. The temperature for this heat treatment is preferably 800°C to 1200°C, and if the temperature is outside this range, the resistance of the finished resistor will increase due to subtle fluctuations in the composition ratio caused by the working conditions of each step of processing the resistor material into an electrical resistor. The resistance value is easily affected and it is difficult to stably obtain the desired 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 as follows: 0.0% of the above rare earth element oxide 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 1 to 20.0 parts by weight, and when titanium oxide is used in combination, it is preferable to add 0.01 to 5.00 parts by weight of titanium oxide.

If the amount of alkaline earth metal molybdate is too small and the amount of glass is too large, the resistance value of the electrical resistor produced by firing may become too high (which may be undesirable); If there is too much salt and too little glass, the sinterability during firing will deteriorate and it may not be possible to stably hold the resistor on the circuit board.However, when the resistor is embedded in a stack of circuit boards, The content of molybdenum and acid salts may not only be greater than the above range, but may also be 100%.Furthermore, if the amount of the rare earth element oxide added is too small, the rate of change in power operation may not be able to be reduced.
If it is too large, the temperature coefficient may become negative with a large absolute value.

Furthermore, if the amount of titanium oxide is too large, there will be the same problem as when the amount of rare earth element oxide is large, and if the amount 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 that the above-mentioned molybdate, which will become the main body of the electrical resistor, be made into bulk particles such as spheres, ellipses, and polygons before use. This is because it is preferable that the original matrix remains during the firing process in which the acicular particles grow. A binder such as glass may also be used to form the resistor body material into bulk particles.

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. Examples of the organic solvent, which is preferably added, 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 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 a 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 can also be applied when forming a laminate.

The ceramic green sheet includes, for example, aluminum oxide (A 1 zOx>35 to 45% by weight, silicon oxide (SiO□) 25 to 35% by weight, boron oxide (BzO
+) to ~15%, calcium oxide (Cab)
7-13 1% by weight, magnesium oxide (MgO) 7-1
A slurry prepared by mixing an oxide mixture of ceramic constituents with an organic vehicle using a ball mill or the like and forming it into a sheet using a doctor blade or the like may be used. 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. The organic vehicle is comprised 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 cracks, distortions, and distortions occur not only between the fired board and the conductor but also between the fired board and the resistor due to firing. Does not cause blistering, etc., and has 7
Even when subjected to a power operation test in which the rated voltage is turned on for 1.5 hours and turned off for 0.5 hours at 0±5℃ for 240 hours, the rate of change can be suppressed to within ±2%. Even if it is left in a humid atmosphere for 1000 hours or more, its resistance value is suppressed to change within ±2%, and its high reliability can be ensured. In addition, when used in combination with titanium oxide, the resistance value decreases by ±10% even when high voltage pulses are applied.
Changes within the range are suppressed. This is thought to be due to the good matching of the resistor with the conductor and the fired substrate, and the effect of addition of the rare earth element oxide and titanium oxide, 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 made of a mixed material of oxides as long as the molybdate of the alkaline earth metal is fired together with the oxide of the rare earth element and titanium oxide. A glass oxide precursor, an alkaline earth metal molybdate and/or its precursor, an oxide of the above-mentioned rare earth element, and further a part or all of this oxide are pasted together with titanium oxide as described above. This is applied to a substrate, and in the process of combustion of the organic matter and subsequent firing, it becomes a glass consisting of the above glass components, and this and the alkaline earth metal molybdate and/or its precursor, the above. Any material that can be used to produce a resistor by firing with rare earth element oxides and titanium oxide may be used. For example, CaO (calcium oxide), which is a component of glass material, is heated by heating CaC0, (calcium carbonate), and th (h (boron oxide) is heated by boric acid (HJ).
Oi), so instead of some or all of CaO, B, O, respectively, CaC0,..., HJOz
can be used. The resistor material according to the present invention is mainly composed of molybdate of alkaline earth metal, oxide of the above-mentioned rare earth element, and glass, and further composed of these and titanium oxide in the process of treatment. It's fine as long as it's something you can do.

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 product was taken out and placed in a bot mill with ethanol, and ground with an alumina ball for 24 hours to obtain a particle size of 1.
A glass powder of 0 μm or less was obtained.

Also, the molar ratio of molybdenum oxide and magnesium carbonate is 1
:1 and heat treated at 700° C. for 1 hour to obtain magnesium molybdate.

Next, the glass powder obtained above, the magnesium molybdate, and the rare earth element oxide were weighed and mixed so as to have the weight parts shown in each column of Table 2.

Each sample in Table 2 was heated to 1000 ml in a gas atmosphere of 98.5 vol% nitrogen (Nz) and 1.5 vol% hydrogen (H2).
℃ for 1 hour, and then ground with ethanol in a bot mill and dried to obtain a resistor material powder of 10 μm or less of heat-treated powder of glass, magnesium molybdate, and the above-mentioned rare earth element oxide.

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 ioo 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, A It tch 40.0% by weight, SiO□3
5.0% by weight, th(h13.0% by weight, CaO7.0
% by weight, 100 parts by weight of ceramic raw material powder consisting of 5.0% by weight of MgO, 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, and after defoaming treatment, a long ceramic green sheet with a thickness of 200 μm was prepared using a doctor blade method. A green sheet piece measuring 9 cm long and 91 mm wide and a green sheet piece measuring 6 nL long and 9 fins wide were cut out from this ceramic green sheet.

Next, as shown in Figure 2, on top of the green sheet piece L measuring 9 m long and 9 mm wide, 95 parts by weight of copper powder, 5 parts by weight of glass lift, 20 parts by weight of butyl calpitol as an organic vehicle, and 5 parts by weight of ethyl cellulose were added. A conductive material paste was screen printed by mixing these parts using a three-roll mill, and was dried at 125° C. for 10 minutes to form a conductive material coating film 2.

Next, the resistor material paste obtained above was screen printed on the green sheet piece 1 in the same manner as above, and heated at 125°C.
, and was dried for 10 minutes to form a coating film 3 for thick film resistor.

Next, on the green sheet piece l, place the vertical 6 pieces horizontally 91-
Layer the green sheet pieces 4 as shown by the chain lines in the figure, and
00°C and thermocompression bonding at 150Kg/cal. 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, a thick film of the fired conductive material coating 2 is formed between the porcelain 1i1a of the fired body of green sheet piece 1 and the porcelain N4a of the fired body of green sheet piece 4, as shown in FIG. Thick film resistor 3 of fired body of conductor 2a and resistor material coating 3
A multilayer ceramic substrate with a. 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 was polished in the layer direction to expose the resistor layer, and when this exposed resistor layer was analyzed by X-ray diffraction (Cu Kα ray), it was found that the molybdenum of magnesium was I was able to confirm the acid salt.

Next, the resistance value (RZ
S) and the resistance value (R+□5) when heated to 125℃
is measured with a digital multimeter, and the temperature coefficient of resistance (T
CR) was determined by the following formula.

I above? Table 2 shows the measured resistance value of zs and the calculated value of TCP.
It was shown to.

In addition, the multilayer ceramic substrate obtained above was heated at 60°C for 9
25℃ after 1000 hours under 5% relative humidity
Table 2 shows the results of measuring the resistance value and calculating the rate of change.

Further, Table 2 shows the results of measuring the rate of change in power operation when the rated power P was set to 174 watts (-).

This power operation rate of change is determined by calculating the rated voltage E from the following formula, E=5 (where rated type crab P=1/4 watt (W)), and applying this rated voltage E to the thick film resistor 3a by 70± After applying for 245 hours in a cycle of 1.5 hours on and 0.5 hours off at 5 degrees Celsius, the resistance value R' was again increased at 25 degrees Celsius.

was measured, and the rate of change ΔR2, [%] was determined from the following formula.

In Example 1, molybdenum M! of calcium was substituted for molybdate of magnesium! Multilayer ceramic substrates using the resistor materials shown in Table 3.4.5 were prepared in the same manner except that , strontium molybdate, and barium molybdate were used. The results of measurements of thick film resistors in the same manner as in Example 1 are shown in Table 3.4.5.

In addition, in each of the above tables, the results of measurements made in the same manner for samples prepared in the same manner except that the oxide of the rare earth element mentioned above was not added and that titanium oxide was added instead of this oxide are shown in each table. No. 1” No. 4
, and No. 5.6.

Example 5 Multilayer ceramic substrates were produced in the same manner as in Example 1, except that instead of the resistor materials shown in Table 2, resistor materials with and without titanium oxide shown in Table 6 were used. The R2, TCR, resistance change rate, and power operation change rate were determined for the thick film resistor formed from this resistor material in the same manner as in Example 1, and the results of measuring the voltage resistance are shown. 6.

Note that this withstand voltage property is based on I
After charging for 0.8 seconds at a voltage of KV, the thick film resistor has a voltage of 0.
This was performed by discharging for 8 seconds, repeating this three times, and calculating the rate of change in resistance value after voltage application.

Examples 6 to 8 The same procedure as in Example 5 was repeated except that calcium molybdate, strontium molybdate, and barium molybdate were used instead of magnesium molybdate, respectively.Table 6.7. A multilayer ceramic substrate using the resistor materials shown in 8 was created, and the Rts, TCR, resistance value change rate, and power operation change rate were determined in the same manner as in Example 5 for the thick film resistors formed from each resistor material. In addition, the results of measuring voltage resistance are shown in Table 6.7.8.

Note that the same effect can be obtained even when the above-mentioned rare earth oxide is used in combination with a molybdate of another metal. In addition, even if titanates of alkaline earth metals such as Tints TiC, TiN% Ti5iz, etc. or any mixture containing these and titanium oxide are used in place of the titanium oxide in the above formulation, the pressure resistance will be maintained. , power operation stability is obtained, again with molybdates of other metals alone or in combination.

Table 2 (Example 1) Table 2 (Continued) Table 2 (Continued) (Margins below this page) Table 3 (Example 2) Table 3 (Continued) * 3 (Continued) (Margins below this page) Table 4 (Implementation) Example 3) 3 4 (Continued) Table 4 (Continued) (Margins below this page) Table 5 (Example 4) Table 5 (Continued) Table 5 (Continued) (Margins below this page) Table 6 Compensation Example 5) (Margins below this page) Table 7 (Example 6) (Margins below this page) Table 8 (Example 7) (Margins below this page) Table 9 (Example 8) (White space below Ninomai Jsu) Comparative example 1 (MoSi, -TaSiz glass-based resistor material) A mixture of 16 parts by weight of MoSiz and 9 parts by weight of Ta5iz was heated at 1400°C in vacuum, and the product was ground with ethanol using an alumina ball in a pot mill for 24 hours, and dried. A fine powder of 10 μm or less was obtained. For 25 parts by weight of the fine powder thus obtained, BaQ, B2
75 parts by weight of glass frit consisting of O3, MgO% CaO, Sing, and 25 parts of organic vehicle (1 part of butyl calpitol 2Qiii, 5 ti parts of ethyl cellulose)
A resistor material paste was obtained by adding 1 part of weight and mixing with a roll mill.

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, the decomposition reaction of Mo5iz % Ta5iz results in 5i0
Due to the generation of the two gases, blistering occurred as shown in FIG. 4, making it impossible to put it to practical use. N-o-l
la is the above-mentioned ceramic layer Nla, 14a is the above-mentioned ceramic layer 4a, 1
3a is a ceramic layer corresponding to the thick film resistor 3a, respectively;
It is a thick film resistor.

Comparative Example 2 (MoSiz-111aFz glass-based resistor material) 70 parts by weight of MoSiz, 20 parts by weight of BaFz, and 120 parts of Sing, ZnO, Zr01, CaO, 8. 1-10 parts by weight of glass friso 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. This multilayer ceramic board J! 7- Jl! R2. was also obtained for the resistor in the same manner as in Example 1. , TCP, and the rate of change in resistance value are shown in Table 10.

Table 10 From the above results, all of the multilayer ceramic substrates of Examples have no warping or blistering, the rate of change in resistance value is within ±2%, the rate of change in power operation is within ±2%, and the rare earth elements are oxidized. However, the multilayer ceramic substrate of Comparative Example 1 showed 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.

Effects of the Invention According to the present invention, it is possible to provide an electric resistor containing an alkaline earth metal molybdate, an oxide of the rare earth element, and further titanium oxide. Using a resistor material with a composition mainly composed of the above-mentioned rare earth element oxides, glass, or even titanium oxide, a resistor is made by firing it with a ceramic green sheet in a non-oxidizing atmosphere together with a base metal conductor material, for example. By forming such a resistor, the fired body will not warp or bulge during firing, and it will not only reduce the aging of the resistor, especially under high humidity conditions, but also reduce the rate of change in power operation. Furthermore, when titanium oxide is used in combination, voltage resistance can also be improved.

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. If an electric resistor is formed by firing the ceramic green sheet in a ceramic green sheet, needle-like particles can be grown from the surface of the lump particles, and excessive reduction can be avoided to form an electric resistor with an appropriate resistance value. Can be provided.

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, when a molybdate of an alkaline earth metal, an oxide of the above-mentioned rare earth element, and titanium oxide are heat-treated with glass, for example, and this heat-treated resistor material is fired to make a resistor, the temperature change in resistance changes. The absolute value of the coefficient can be reduced, and the performance of the circuit 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, Figure 3 is a cross-sectional view of the fired body, and Figure 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 a state in which gas is further generated in the fired body. 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 conductive material coating film, 3 is a resistor material coating film, la, 4a is a ceramic layer, 2a is a thick film conductor, 3a
is a thick film resistor. December 24, 1988 Figure 1 Figure 2 Figure 4

Claims (9)

[Claims] (1) Alkaline earth metal molybdate, Y, La
, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy,
A thick film resistor comprising a fired body containing an oxide of at least one element selected from the group of Ho, Er, Tm, Yb, Lu, Sc, and Pm. (2) The fired body contains at least one molybdate of an alkaline earth metal and its precursor, Y, La, Ce, Pr.
, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er,
The thickness according to claim 1, which is fired from a resistor material containing as a main component an oxide of at least one element selected from the group of Tm, Yb, Lu, Sc, and Pm. membrane resistor. (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;
0.1 to 20.0 parts by weight of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, T based on 100 parts by weight of the composition.
b, Dy, Ho, Er, Tm, Yb, Lu, Sc, Pm
The thick film resistor according to claim 2, characterized in that it contains an oxide of at least one element selected from the group of. (4) having a lumpy particle, an acicular particle attached to the lumpy particle or existing in the vicinity of the lumpy particle, and a glass layer;
La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, D
A fired body containing an oxide of at least one element selected from the group of Y, Ho, Er, Tm, Yb, Lu, Sc, and Pm, wherein the lump particles contain an alkaline earth metal molybdate. an electrical resistor, wherein the acicular particles contain 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) Alkaline earth metal molybdate, Y, La
, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy,
A thick film resistor characterized by having a fired body containing an oxide of at least one element selected from the group of Ho, Er, Tm, Yb, Lu, Sc, and Pm and titanium oxide. (7) The fired body contains at least one molybdate of an alkaline earth metal and its precursor, Y, La, Ce, Pr.
, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er,
Claim No. 1, characterized in that the resistor material is fired from a resistor material containing as main components an oxide of at least one element selected from the group of Tm, Yb, Lu, Sc, and Pm and titanium oxide. Thick film resistor according to item 6. (8) At least one of molybdates of alkaline earth metals and their precursors as main components, Y, La, Ce,
Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, E
Heat treating a resistor material containing an oxide of at least one element selected from the group of r, Tm, Yb, Lu, Sc, and Pm, and firing using the resistor material obtained by this heat treatment, Alkaline earth metal molybdate and Y, La,
Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, H
1. A method for producing an electrical resistor, the method comprising obtaining an electrical resistor comprising a fired body containing an oxide of at least one element selected from the group of O, Er, Tm, Yb, Lu, Sc, and Pm. (9) 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 0.1 to 20% by weight based on 100 parts by weight of the composition.
．． 0 parts by weight of Y, La, Ce, Pr, Nd, Sm, Eu
, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu,
9. The method of manufacturing an electrical resistor according to claim 8, wherein the electrical resistor is made of an oxide of at least one element selected from the group of Sc and Pm.