Source: http://www.google.com/patents/US4709299?ie=ISO-8859-1
Timestamp: 2014-12-20 10:34:07
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Matched Legal Cases: ['in fine', 'in fine', 'in fine', 'Application No. 53', 'in fine', 'in fine']

Patent US4709299 - Low temperature sintered ceramic capacitor with a temperature compensating ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA temperature compensating capacitor of monolithic or multilayered configuration comprising a dielectric ceramic body and at least two electrodes buried therein. The ceramic body is composed of a major ingredient expressed by the formula, (CaO)k.(Zr1-x Tix)O, where k and x are numerals in the ranges...http://www.google.com/patents/US4709299?utm_source=gb-gplus-sharePatent US4709299 - Low temperature sintered ceramic capacitor with a temperature compensating capability, and method of manufactureAdvanced Patent SearchPublication numberUS4709299 APublication typeGrantApplication numberUS 06/934,667Publication dateNov 24, 1987Filing dateNov 25, 1986Priority dateNov 30, 1985Fee statusPaidAlso published asDE3680883D1, EP0226071A2, EP0226071A3, EP0226071B1Publication number06934667, 934667, US 4709299 A, US 4709299A, US-A-4709299, US4709299 A, US4709299AInventorsHiroshi Kishi, Minoru Oshio, Shunji Murai, Takeshi Wada, Masami FukuiOriginal AssigneeTaiyo Yuden Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (6), Referenced by (2), Classifications (12), Legal Events (5) External Links: USPTO, USPTO Assignment, EspacenetLow temperature sintered ceramic capacitor with a temperature compensating capability, and method of manufactureUS 4709299 AAbstract A temperature compensating capacitor of monolithic or multilayered configuration comprising a dielectric ceramic body and at least two electrodes buried therein. The ceramic body is composed of a major ingredient expressed by the formula, (CaO)k.(Zr1-x Tix)O, where k and x are numerals in the ranges of 0.8 to 1.3 inclusive and of zero to 0.3 inclusive, respectively. To this major ingredient is added a minor proportion of a mixture of boric oxide, silicon dioxide, and one or more metal oxides selected from among barium oxide, magnesium oxide, zinc oxide, strontium oxide and calcium oxide. For the fabrication of capacitors the mixture of the above major ingredient and additives in finely divided form are formed into moldings of desired shape and size, each with at least two electrodes buried therein. The moldings and electrodes are cosintered in a reductive or neutral atmosphere and then are reheated at a lower temperature in an oxidative atmosphere. The cosintering temperature can be so low that nickel or like base metal can be employed as the electrode material.
We claim: 1. A low temperature sintered solid dielectric capacitor comprising a dielectric ceramic body and at least two electrodes in contact therewith, the dielectric ceramic body consisting essentially of:100 parts by weight of a major ingredient expressed by the formula, (CaO)k.(Zr1-x Tix)O2, wherek is a numeral in the range of 0.8 to 1.3 inclusive; and x is a numeral in the range of zero to 0.3 inclusive; and from 0.2 to 10.0 parts by weight of an additive mixture of boric oxide, silicon dioxide and at least one metal oxide selected from the group consisting of barium oxide, magnesium oxide, zinc oxide, strontium oxide and calcium oxide, the relative proportions of boric oxide, silicon dioxide and at least one selected metal oxide constituting the additive mixture being in that region of the ternary diagram of FIG. 2 attached hereto which is bounded by the lines sequentially connecting:the point A where the additive mixture consists of 15 mole percent boric oxide, 25 mole percent silicon dioxide, and 60 mole percent metal oxide; the point B where the additive mixture consists of 30 mole percent boric oxide, zero mole percent silicon dioxide, and 70 mole percent metal oxide; the point C where the additive mixture consists of 90 mole percent boric oxide, zero mole percent silicon dioxide, and 10 mole percent metal oxide; the point D where the additive mixture consists of 90 mole percent boric oxide, 10 mole percent silicon dioxide, and zero mole percent metal oxide; and the point E where the additive mixture consists of 25 mole percent boric oxide, 75 mole percent silicon dioxide, and zero mole percent metal oxide. 2. A low temperature sintered solid dielectric capacitor as set forth in claim 1, wherein the electrodes are buried in the dielectric ceramic body.
5. A process for the manufacture of a low temperature sintered solid dielectric capacitor, which process comprises:providing a mixture of:100 parts by weight of a major ingredient, in finely divided form, that is expressed by the formula, (CaO)k.(Zr1-x Tix)O2, wherek is a numeral in the range of 0.8 to 1.3 inclusive; and x is a numeral in the range of zero to 0.3 inclusive; and from 0.2 to 10.0 parts by weight of an additive mixture, in finely divided form, of boric oxide, silicon dioxide and at least one metal oxide selected from the group consisting of barium oxide, magnesium oxide, zinc oxide, strontium oxide and calcium oxide, the relative proportions of boric oxide, silicon dioxide and at least one selected metal oxide constituting the additive mixture being in that region of the ternary diagram of FIG. 2 attached hereto which is bounded by the lines sequentially connecting:the point A where the additive mixture consists of 15 mole percent boric oxide, 25 mole percent silicon dioxide, and 60 mole percent metal oxide; the point B where the additive mixture consists of 30 mole percent boric oxide, zero mole percent silicon dioxide, and 70 mole percent metal oxide; the point C where the additive mixture consists of 90 mole percent boric oxide, zero mole percent silicon dioxide, and 10 mole percent metal oxide; the point D where the additive mixture consists of 90 mole percent boric oxide, 10 mole percent silicon dioxide, and zero mole percent metal oxide; and the point E where the additive mixture consists of 25 mole percent boric oxide, 75 mole percent silicon dioxide, and zero mole percent metal oxide; molding the mixture into desired shape and size, the molding having at least two electrode portions of an electroconductive material; cosintering the molding and the electrode portions to maturity in a nonoxidative atmosphere; and reheating the cosintered molding and electrode portions in an oxidative atmosphere. 6. A process for the maufacture of a low temperature sintered solid dielectric capacitor as set forth in claim 5, wherein the electrode portions are formed on the molding by coating the same with an electroconductive paste composed principally of a base metal.
Japanese Laid Open Patent Application No. 53-98099 suggests a solution to the above discussed problem, particularly in regard to the manufacture of temperature compensating ceramic capacitors. This patent application teaches ceramic compositions comprising calcium zirconate (CaZrO3) and manganese dioxide (MnO2). In the manufacture of ceraminc capacitors the dielectric bodies of these known compositions are sinterable in a reductive atmosphere, so that electrodes of nickel or like base metal can be employed for cosintering with the dielectric bodies without the danger of oxidation.
Stated briefly in one aspect thereof, our invention provides a low temperature sintered solid dielectric capacitor comprising a dielectric ceramic body and at least two electrodes in contact therewith. The dielectric ceramic body consists essentially of 100 parts by weight of (CaO)k.(Zr1-x Tix)O2, where k is a numeral in the range of 0.8 to 1.3 inclusive, and x a numeral in the range of zero to 0.3 inclusive, and 0.2 to 10.0 parts by weight of an additive mixture of boric oxide (B2 O3), silicon dioxide (SiO2), and at least one metal oxide selected from the group consisting of barium oxide (BaO), magnesium oxide (MgO), zinc oxide (ZnO), strontium oxide (SrO) and calcium oxide (CaO). The relative proportions of B2 O3, SiO2 and at least one selected metal oxide, altogether constituting the additive mixture, will be specifically determined in connection with a ternary diagram attached hereto.
The ceramic capacitor of our invention, having its dielectric body formulated as set forth in the foregoing, has proved to be very well suited for temperature compensating applications in oscillator and other circuits. The test capacitors manufactured in accordance with our invention had specific dielectric constants of over 30 at one magahertz (MHz), temperature coefficients of capacitances of +30 to -700 ppm per degree C., Q factors of over 2000 at 1 MHz, and resistivities of 1�107 megohm-centimeters or more. The Q factor rises to as much as 5000 or more if the dielectric body contains from 0.2 to 5.0 parts by weight of the additive mixture with respect to 100 parts of the major ingredient.
Another aspect of our invention is a method of fabricating the above defined ceramic capacitor. The method dictates, first of all, the preparation of a mixture of the above indicated proportions of the major ingredient and additives in finely divided form. This mixture is then molded into a body of desired shape and size, which is provided with at least two electrode portions of an electroconductive material in any convenient manner. Then the molding with the electrode portions is sintered in a nonoxidative (i.e. reductive or neutral) atmosphere and is subsequently reheated in an oxidative atmosphere.
The major ingredient of the ceramic compositions in accordance with our invention has been herein defined as (CaO)k.(Zr1-x Tix)O2, or (CaO)k.(Me)O2, where Me is either Zr or (Zr+Ti). Accordingly, in Table 1, we have given various combinations of the atomic numbers k and x in the formula to indicate the specific major ingredients employed in the various Tests. The ceramic compositions of our invention further include mixtures, in various proportions, of additives B2 O3, SiO2 and MO. Table 1 specifies the amounts, in parts by weight, of the additive mixtures with respect to 100 parts by weight of the major ingredient, as well as the relative proportions, in mole percent, of the additives B2 O3, and MO. Further, since MO can be any one or more of BaO, MgO, ZnO, SrO and CaO, Table 1 gives the relative proportions, in mole percent, of these metal oxides, wherever one or more of them are employed.
TABLE 1__________________________________________________________________________Ceramic CompositionsMajor Ingredient       AdditivesTest   (100 wt. parts)       Amount            Composition (mole %)                       MO (mole %)No.   k   x    (wt. part)            B2 O3                SiO2                   MO  BaO                          MgO                             ZnO                                SrO                                   CaO__________________________________________________________________________ 1 1.0 0.02 3.0  15  25 60  -- -- -- 60 40 2 "   "    "    30   0 70  -- -- -- -- -- 3 "   "    "    90   0 10  -- -- -- -- -- 4 "   "    "    "   10  0  -- -- -- -- -- 5 "   "    "    25  75 "   -- -- -- -- -- 6 "   "    "    35  10 55  -- -- -- 60 40 7 "   "    "    50  15 35  -- -- -- "  " 8 "   "    "    "   45  5  -- -- -- "  " 9 "   "    "    35  30 35  100                          -- -- -- --10 "   "    "    --  -- --  -- 100                             -- -- --11 "   "    "    15  25 60  -- -- 100                                -- --12 "   "    "    "   "  "   -- -- -- 100                                   --13 "   "    "    "   "  "   -- -- -- -- 10014 "   "    "    "   "  "   30 20 50 -- --15 "   "    "    "   "  "   -- 50 20 30 --16 "   "    "    "   "  "   20 20 20 20 2017 "   "    "    25  10 65  10 10 -- 50 3018 "   "    "    50   0 50  20 -- 60 20 --19 "   "    "    20  45 35  10 40 20 10 2020 "   "    "    35  45 20  40 60 -- -- --21 "   "    "    40  60 --  -- -- -- -- --22 "   "    "    70  30 --  -- -- -- -- --23 "   "    "    20  10 70  -- -- -- 60 4024 "   "    "    95   5 --  -- -- -- -- --25 "   "    "    15  75 10  -- -- -- 60 4026 "   "    "    10  50 40  -- -- -- "  "27 "   "    "     5  25 70  -- -- -- "  "28 "   0    "    50  30 20  -- -- -- "  "29 "   0.01 "    "   "  "   -- -- -- "  "30 "   0.03 "    "   "  "   -- -- -- "  "31 "   0.05 "    "   "  "   -- -- -- "  "32 "   0.10 "    "   "  "   -- -- -- "  "33 "   0.15 "    "   "  "   -- -- -- "  "34 "   0.20 "    "   "  "   -- -- -- "  "35 "   0.25 "    "   "  "   -- -- -- "  "36 "   0.30 "    "   "  "   -- -- -- "  "37 "   0.35 "    "   "  "   -- -- -- "  "38 "   0.40 "    "   "  "   -- -- -- "  "39 1.1 0.05 0    25  20 55  -- -- -- "  "40 "   "    0.2  "   "  "   -- -- -- "  "41 "   "    1.0  "   "  "   -- -- -- "  "42 "   "    5.0  "   "  "   -- -- -- "  "43 "   "    7.0  "   "  "   -- -- -- "  "44 "   "    10.0 "   "  "   -- -- -- "  "45 "   "    12.0 "   "  "   -- -- -- "  "46  0.90  0.15 0    70  15 15  -- -- -- "  "47 "   "    0.2  "   "  "   -- -- -- "  "48 "   "    5.0  "   "  "   -- -- -- "  "49 "   "    10.0 "   "  "   -- -- -- "  "50 "   "    12.0 "   "  "   -- -- -- "  "51 1.0 0.25 0    25  65 10  -- -- -- "  "52 "   "    0.2  "   "  "   -- -- -- "  "53 "   "    5.0  "   "  "   -- -- -- "  "54 "   "    10.0 "   "  "   -- -- -- "  "55 "   "    12.0 "   "  "   -- -- -- "  "56 0.7 0.05 3.0  70   0 30  -- -- -- "  "57 0.8 "    "    "   "  "   -- -- -- "  "58 1.0 "    "    "   "  "   -- -- -- "  "59 1.2 "    "    "   "  "   -- -- -- "  "60 1.3 "    "    "   "  "   -- -- -- "  "61 1.4 "    "    "   "  "   -- -- -- "  "62 0.7 0.20 5.0  55  20 25  -- -- -- "  "63 0.8 "    "    "   "  "   -- -- -- "  "64 1.0 "    "    "   "  "   -- -- -- "  "65 1.2 "    "    "   "  "   -- -- -- "  "66 1.3 "    "    "   "  "   -- -- -- "  "67 1.4 "    "    "   "  "   -- -- -- "  "__________________________________________________________________________
According to Table 1, the major ingredient of the dielectric bodies of the capacitors of Test No. 1 was CaO.(Zr0.98 Ti0.02)O2. One hundred parts of this major ingredient was admixed with 3.0 parts by weight of a mixture of 15 mole percent B2 O3, 25 mole percent SiO2 and 60 mole percent MO. MO was a mixture of 60 mole percent SrO and 40 mole percent CaO. The other additives BaO, MgO and ZnO were not used in this particular Test.
B2 O3 : 10.18 grams (15 mole percent)
SiO2 : 14.64 grams (25 mole percent)
SrCO3 : 51.79 grams (36 mole percent)
CaCO3 : 23.39 grams (24 mole percent).
To these substances we added 300 cubic centimeters of alcohol, and the resulting slurry was stirred for 10 hours in a polyethylene pot with alumina balls. Then the mixture was air fired at 1000� C. for two hours. Then, charged into an alumina pot together with 300 cubic centimeters of water, the fired mixture was pulverized with alumina balls over a period of 15 hours. Then the pulverized mixture was dried at 150� C. for four hours. There was thus obtained in finely divided form the desired additive mixture of 15 mole percent B2 O3, 25 mole percent SiO2 and 60 mole percent MO, with the MO consisting of 36 mole percent SrO and 24 mole percent CaO.
We employ a furnace capable of atmosphere control for cofiring the above prepared green dielectric bodies and, buried therein, the conductive layers which were to become the film electrodes 14 in the completed capacitors 10. The chips were first air heated in this furnace to 600� C. at a rate of 100� C. per hour, thereby driving off the organic binder that had been used for providing the slurry of the powdered major ingredient and additives. Then the furnace atmosphere was changed from air to a reductive (nonoxidative) atmosphere consisting of two percent by volume of molecular hydrogen and 98 percent by volume of molecular nitrogen. In this reductive atmosphere the furnace temperature was raised from 600� C. to 1120� C. at a rate of 100� C. per hour. The maximum temperature of 1120� C., at which the ceramic bodies formulated in accordance with our invention were to be sintered to maturity, was maintained for three hours. Then the furnace temperature was lowered to 600� C. at a rate of 100� C. per hour. Then, with the furnace atmosphere again changed to air (oxidative atmosphere), the temperature of 600� C. was maintained for 30 minutes for the oxidizing heat treatment of the sintered chips. Then the furnace temperature was allowed to drop to room temperature.
We have thus completed the fabrication of monolithic, multilayered ceramic test capacitors, each constructed as in FIG. 1, in accordance with the ceramic composition of Test No. 1 of Table 1. The composition of the ceramic bodies 15 of the thus completed capacitors proved substantially akin to that before sintering. It is therefore reasoned that the sintered ceramic bodies 15 are of perovskite structures, with the additives (15 mole percent B2 O3, 25 mole percent SiO2, 36 mole percent SrO and 24 mole percent CaO) uniformly dispersed among the crystal grains of the major ingredient.
As for the other ceramic compositions of Table 1, designated Tests Nos. 2 through 67, we made similar capacitors through exactly the same procedure as that set forth in the foregoing in connection with Test No. 1 composition, except for the temperature of sintering in the reductive atmosphere, which will be referred to presently.
All the capacitors of Test Nos. 1 through 67 were then tested as to their specific dielectric constants, temperature coefficients, Q factors, and resistivities. The following are the methods we employed for the measurement of these properties:
TEMPERATURE COEFFICIENT OF CAPACITANCE The capacitance C85 at 85� C. and capacitance C20 at 20� C. of each test capacitor were first measured. Then the temperature coefficient TC of capacitance was computed by the equation ##EQU1##
Table 2 gives the results of the measurements by the above described methods, as well as the maximum temperatures at which the test capacitors were sintered in the reductive atmosphere during their manufacture. It will be noted from this table that the specific dielectric constants of the Test No. 1 capacitors, for instance, averaged 33, their temperature coefficients -10 ppm per degree C., their Q factors 8200, and their resistivities 2.6�107 megohm-centimeters. The temperature coefficients of the capacitances of the test capacitors were practically constant in the normal range of their operating temperatures, making the capacitors well suited for use as temperature compensating capacitors.
TABLE 2______________________________________Sintering Temperature &amp; Capacitor CharacteristicsSin-      Capacitor Characteristicstering  Specific  TemperatureTest Temp.   Dielectric                  Coefficient                           Q     ResistivityNo.  (�C.)        Constant  (ppm/�C.)                           Factor                                 (megohm-cm)______________________________________ 1   1120    33        -10      8200  2.6 � 107 2   "       "         -15      8300  2.1 � 107 3   1100    "         -20      8900  3.1 � 107 4   "       "         "        8500  3.0 � 107 5   1120    "         -15      7800  2.2 � 107 6   "       "         "        8500  2.4 � 107 7   1100    "         -20      8600  2.5 � 107 8   "       "         -10      8300  " 9   1120    "         "        8200  2.3 � 10710   "       "         "        "     2.1 � 10711   "       "         -15      8000  "12   "       "         "        8300  2.4 � 10713   "       "         "        "     2.3 � 10714   "       "         -10      8200  2.1 � 10715   "       "         "        "     "16   "       "         -15      8300  2.2 � 10717   "       "         -10      8900  "18   1100    "         -15      9200  2.3 � 10719   1120    "         -10      8800  2.2 � 10720   "       "         "        8700  2.3 � 10721   1100    "         -15      9100  2.3 � 10722   "       "         -20      8300  2.2 � 10723   1250    Not coherently bonded on firing.24   "       "25   "       "26   "       "27   "       "28   1120    30        +30      8300  3.1 � 10729   "       33        +10      8400  3.0 � 10730   1100    34        -50      9200  3.2 � 10731   "       35        -100     8800  2.8 � 10732   "       42        -210     8600  2.6 � 10733   "       49        -340     "     2.5 � 10734   "       53        -470     8400  2.3 � 10735   "       60        -560     8200  "36   "       67        -690     8300  2.1 � 10737   "       74        -840     8000  1.5 � 10738   "       82        -980     7700  1.3 � 10739   1300    Not coherently bonded on firing.40   1180    36        -75      8300  2.9 � 10741   1150    "         -80      8400  3.2 � 10742   1100    "         -85      8100  3.1 � 10743   1080    35        "        6800  3.0 � 10744   "       "         -80      3300  1.8 � 10745   1050    33        -120     1050  6.5 � 10646   1300    Not coherently bonded on firing.47   1170    48        -330     8700  2.7 � 10748   1120    49        -340     7800  3.3 � 10749   1060    46        -370     3800  2.2 � 10750   "       42        -390     1050  5.3 � 10651   1300    Not coherently bonded on firing.52   1160    63        -540     6600  3.0 � 10753   1080    61        -550     5700  2.1 � 10754   1050    59        "        3200  1.6 � 10755   "       56        -590     1130  8.2 � 10656   1120    38        -90       120  5.4 � 10357   "       36        -80      3500  1.1 � 10758   "       "         "        7800  2.6 � 10759   1130    35        -90      8100  2.4 � 10760   1170    34        -100     5320  1.6 � 10761   1300    Not coherently bonded on firing.62   1080    55        -480      60   3.6 � 10363   1100    54        -440     8300  1.0 � 10764   "       "         "        8500  2.4 � 10765   1130    53        -450     7300  2.6 � 10766   1170    50        -490     5200  1.3 � 10767   1300    Not coherently bonded on firing.______________________________________
It will be observed from Table 2 that the dielectric bodies of Tests Nos. 23-27, 39, 46, 51, 61 and 67 were not coherently bonded on firing at temperatures as high as 1250� or 1300� C. in the reductive atmosphere. The corresponding ceramic compositions of Table 1 fall outside the scope of our invention. The dielectric bodies of all the other Tests could be sintered to maturity at temperatures less than 1200� C.
Before proceeding further with the examination of the results of Table 2 we will determine the acceptable criteria of the four electrical properties in question for the temperature compensating ceramic capacitors provided by our invention. These cirteria are:
Specific dielectric constant: From 30 to 67.
Temperature coefficient of capacitance: From -690 to +30 ppm per degree C.
Q factor: Not less than 3200.
Resistivity: Not less than 1�107 megohm-centimeters.
A reconsideration of Table 1 in light of the above estabilished criteria of favorable electrical characteristics will reveal that the capacitors of Tests Nos. 37, 38, 45, 50, 55, 56 and 62 do not meet these criteria. Accordingly, the correspondingly ceramic compositions of Table 1 also fall outside the scope of our invention. All the test capacitors but those of Tests Nos. 23-27, 37-39, 45, 46, 50, 51, 55, 56, 61, 62 and 67 satisfy the criteria, so that their ceramic compositions are in accord with our invention.
Now, let us study the ceramic compositions of Table 1 and the corresponding capacitor characteristics, as well as the sintering temperatures, of Table 2 in more detail. The ceramic compositions of Tests Nos. 39, 46 and 51 contained no additive specified by our invention. The dielectric bodies formulated accordingly were not coherently bonded on firing at a temperature as high as 1300� C. Consider the ceramic compositions of Tests Nos. 40, 47 and 52 for comparison. They contained 0.2 part by weight of the additives with respect to 100 parts by weight of the major ingredient. Even though the firing temperature was as low as 1160�-1180� C., the resulting test capacitors possess the desired electrical characteristics. We set, therefore, the lower limit of the possible proportions of the additive mixture at 0.2 part by weight with respect to 100 parts by weight of the major ingredient.
The Tests Nos. 45, 50 and 55 ceramic compositions contained as much as 12 parts by weight of the additives with respect to 100 parts by weight of the major ingredient. The resulting Tests Nos. 45, 50 and 55 capacitors have average Q factors of 1050, 1050 and 1130, respectively, which are all far less than the above established criterion of 3200. When the proportion of the additive mixture was reduced to 10 parts by weight, as in Tests Nos. 44, 49 and 54, the resulting capacitors have all the desired characteristics. Therefore, the upper limit of the possible proportions of the additive mixture is set at 10 parts by weight with respect to 100 parts by weight of the major ingredient.
As for the major ingredient, (CaO)k.(Zr1-x Tix)O2, the value of x was set at 0.35 and more in Tests Nos. 37 and 38. In the resulting capacitors the temperature coefficient of capacitance is -840 and -980, both outside the desired range of -690 to +30. When the value of x was decreased to not more than 0.30, as in Test No. 36, then the desired electrical characteristics were all obtained. The highest possible value of x is therefore 0.30. Test No. 28 indicates that the desired electrical characteristics are obtainable if the value of x is zero, that is, if the major ingredient does not include titanium. The Q factor becomes relatively high if the value of x is reduced to less than 0.20.
The value of k in the formula of the major ingredient was set at 0.7 in Tests Nos. 56 and 62. The resistivities of the resulting capacitors were 5.4�103 and 3.6�103, both much lower than the desired lower limit of 1�10. The desired value of resistivity was obtained when the value of k was increased to 0.8 as in Test No. 57 and 63. The lowermost possible value of k is therefore 0.8. On the other hand, when the value of k was made as much as 1.4 as in Tests Nos. 61 and 67, the resulting dielectric bodies were not coherently bonded on firing at as high a temperature as 1300� C. The desired electric characteristics were obtained when the value of k was reduced to 1.3 as in Tests Nos. 60 and 66. Accordingly, the greatest possible value of k is 1.3.
We have ascertained from the results of Table 2 that the acceptable range of the relative proportions of B2 O3, SiO3 and MO, the additives of the ceramic compositions in accordance with our invention, can be definitely stated in reference to the ternary diagram of FIG. 2.
6. The ceramic compositions disclosed herein may be employed for capacitors other than those of the multi-layered configuration.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4223369 *Jul 3, 1978Sep 16, 1980Sprague Electric CompanyMonolithic capacitor with low firing zirconate and nickel electrodesUS4482934 *Jul 25, 1983Nov 13, 1984Murata Manufacturing Co., Ltd.Temperature compensating titanate ceramic capacitor with nickel or copper electroless metal electrodesUS4616289 *Dec 20, 1982Oct 7, 1986Matsushita Electric Industrial Co., Ltd.Containing barium and callcium titanate with tantalum oxideUS4626393 *Jul 9, 1985Dec 2, 1986Taiyo Yuden Co., Ltd.Method of manufacturing low temperature sintered ceramic materials for use in solid dielectric capacitors or the likeUS4626396 *Jul 9, 1985Dec 2, 1986Taiyo Yuden Co., Ltd.Method of manufacturing low temperature sintered ceramic materials for use in solid dielectric capacitors of the likeJPS5398099A * Title not available* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS4809131 *Apr 29, 1988Feb 28, 1989Taiyo Yuden Co., Ltd.Low temperature sintered ceramic capacitor having a high resistivity and bending strength, and method of manufactureUS5059566 *Dec 27, 1989Oct 22, 1991Kabushiki Kaisha ToshibaHigh-dielectric constant ceramic composite and ceramic capacitor elements* Cited by examinerClassifications U.S. Classification361/321.4, 264/615International ClassificationC04B35/49, C04B35/47, H01B3/12, H01G4/12Cooperative ClassificationC04B35/47, C04B35/49, H01G4/1245European ClassificationH01G4/12B4C, C04B35/47, C04B35/49Legal EventsDateCodeEventDescriptionFeb 16, 1999FPAYFee paymentYear of fee payment: 12May 15, 1995FPAYFee paymentYear of fee payment: 8Apr 15, 1991FPAYFee paymentYear of fee payment: 4Dec 13, 1988CCCertificate of correctionNov 25, 1986ASAssignmentOwner name: TAIYO YUDEN CO., LTD., 2-12, UENO 1-CHOME, TAITO-KFree format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:KISHI, HIROSHI;OSHIO, MINORU;MURAI, SHUNJI;AND OTHERS;REEL/FRAME:004636/0054Effective date: 19861105Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KISHI, HIROSHI;OSHIO, MINORU;MURAI, SHUNJI;AND OTHERS;REEL/FRAME:004636/0054Owner name: TAIYO YUDEN CO., LTD. A CORP OF JAPAN, JAPANRotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google