TWI723814B - Ceramic composition, ceramic sintered body and laminated ceramic electronic component - Google Patents

Abstract

The present invention provides a ceramic composition, a ceramic sintered body, and a laminated ceramic electronic component, wherein the ceramic composition is a main powder material obtained by firing titanium oxide containing a rutile structure and an anatase structure, The laminated ceramic electronic component including the ceramic sintered body formed by sintering the ceramic composition can have excellent performance of high resistance temperature coefficient and low room temperature resistance value.

Description

Ceramic composition, ceramic sintered body and laminated ceramic electronic component

The present invention relates to a ceramic composition, a sintered ceramic sintered body, and a laminated ceramic electronic component containing the ceramic sintered body, and particularly to a laminated ceramic electronic component applied to a positive temperature coefficient thermistor.

Thermistor (Thermistor) is a variable resistor, that is, its resistance value changes with temperature, and is divided into positive temperature coefficient thermistors, negative temperature coefficient thermistors, and critical temperature thermistors. Because the thermistor has high accuracy in a specific temperature range, it has been widely used today, such as temperature sensors, inrush current limiters, or resettable fuses.

Positive temperature coefficient thermistor (PTC thermistor), referred to as PTC thermistor, its resistance value will increase as the temperature of the resistor body increases, and has a positive temperature coefficient, and reaches the Curie temperature (Curie temperature, After Tc) or the magnetic transition point, the resistance value increases rapidly, which is also called the PTC effect. Therefore, in addition to being used as a heating element, the PTC thermistor also has the function of switching over-current protection, and can simultaneously realize the three functions of heating, sensing and switching, and the latter two are the main applications.

Because electrical appliances used at room temperature such as home appliances or consumer electronics rely on thermistors, for example, as temperature sensors, thermistors with low room temperature resistance will have a wider range of applications. However, even if PTC thermistors have the above-mentioned excellent functions, due to the limitation of suitable raw materials, thermistors with high temperature coefficient of resistance and low room temperature resistance are still to be developed to satisfy the market. demand.

The present invention provides a ceramic composition which can be used in a thermistor, thereby increasing the resistance temperature coefficient of the thermistor and reducing the room temperature resistance value of the thermistor.

To achieve the above objective, the present invention provides a ceramic composition comprising: a main powder material, a first rare earth material, and micro-nanosilicate glass; wherein the main powder material is fired by a main powder mixture containing barium carbonate and titanium oxide The titanium oxide includes a rutile structure and an anatase structure; based on the total weight of the titanium oxide, the content of the rutile structure is 20% to 90% by weight.

Preferably, the titanium oxide consists essentially of a rutile structure and an anatase structure. More preferably, the titanium oxide is composed of a rutile structure and an anatase structure.

Preferably, based on the total weight of the titanium oxide, the content of the rutile structure is 20% to 90% by weight, for example: 25% by weight, 30% by weight, 35% by weight, 36% by weight, 37% by weight, 38% by weight, 39% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight, 60% by weight, 61% by weight Percentage, 62% by weight, 65% by weight, 70% by weight, 75% by weight, 76% by weight, 77% by weight, 78% by weight, 79% by weight, 80% by weight, 81% by weight, 82% by weight, 83% by weight, 84 weight percent, 85 weight percent, 86 weight percent, 87 weight percent, 88 weight percent, 89 weight percent, or 90 weight percent; more preferably, the content of the rutile structure is 55 weight percent to 82 weight percent.

According to the present invention, by adjusting the content ratio of the rutile structure and the anatase structure in the titanium oxide, the temperature coefficient of resistance (that is, the α value) of the ceramic composition after sintering can be improved.

According to the present invention, by adjusting the proportion of titanium oxide content in the main powder mixture, the temperature coefficient of resistance can be further increased and the resistance value can be reduced. Preferably, the total weight of the main powder mixture is used as a reference. The content is 27.35 weight percent to 28.35 weight percent, for example: 27.40 weight percent, 27.45 weight percent, 27.49 weight percent, 27.50 weight percent, 27.51 weight percent, 27.52 weight percent, 27.53 weight percent, 27.55 weight percent, 27.58 weight percent, 27.59 weight percent Percentage, 27.60% by weight, 27.61% by weight, 27.62% by weight, 27.65% by weight, 27.67% by weight, 27.68% by weight, 27.69% by weight, 27.70% by weight, 27.71% by weight, 27.75% by weight, 27.78% by weight, 27.79% by weight, 27.80% by weight, 27.81% by weight, 27.82% by weight, 27.85% by weight, 27.90% by weight, 27.95% by weight, 27.98% by weight, 27.99% by weight, 28.00% by weight, 28.01% by weight, 28.02% by weight, 28.05% by weight, 28.10% by weight Percentage, 28.15% by weight, 28.17% by weight, 28.18% by weight, 28.19% by weight, 28.20% by weight, 28.21% by weight, 28.22% by weight, 28.25% by weight, 28.27% by weight, 28.28% by weight, 28.29% by weight, 28.30% by weight or 28.31% by weight.

Preferably, based on the total weight of the main powder mixture, the content of the barium carbonate is 71.65 weight percent to 72.65 weight percent.

Preferably, the main powder mixture further includes a first element material, and the first element material is selected from calcium carbonate, strontium carbonate or a combination thereof.

When the main powder mixture contains calcium carbonate, based on the total weight of the main powder mixture, the content of the calcium carbonate is 0.10 wt% to 0.60 wt%, for example: 0.11 wt%, 0.14 wt%, 0.15 wt%, 0.16 Weight percent, 0.20 weight percent, 0.25 weight percent, 0.30 weight percent, 0.35 weight percent, 0.40 weight percent, 0.45 weight percent, 0.50 weight percent, 0.55 weight percent, or 0.59 weight percent. Preferably, the content of the calcium carbonate is 0.10 wt% to 0.30 wt%.

When the main powder mixture contains strontium carbonate, based on the total weight of the main powder mixture, the content of the strontium carbonate is 0.10 wt% to 0.60 wt%, for example: 0.15 wt%, 0.20 wt%, 0.25 wt%, 0.30 Weight percent, 0.35 weight percent, 0.40 weight percent, 0.44 weight percent, 0.45 weight percent, 0.46 weight percent, 0.49 weight percent, 0.50 weight percent, 0.55 weight percent, or 0.59 weight percent. Preferably, the content of the strontium carbonate is 0.30 wt% to 0.60 wt%.

The main powder mixture is calcined to form a main powder material, and the main powder material contains barium titanate and has a perovskite structure.

In some embodiments, when the main powder mixture includes barium carbonate, calcium carbonate, strontium carbonate, and titanium oxide, the foregoing main powder mixture is calcined to form a main powder material, and the main powder material has the general formula A _m BO _{The perovskite structure shown in 3} , wherein the A site is selected from barium, strontium, calcium or a combination thereof, the B site is titanium, and m is the molar ratio of the A site to the B site, and 1.012≦m≦1.078. Therefore, by adjusting the ratio of elements of barium, strontium, calcium or titanium, the main powder material can further adjust the lattice constant of the perovskite structure, thereby obtaining ceramic sintered bodies with different Curie temperatures according to requirements.

For example, the above m value can be 1.013, 1.014, 1.015, 1.016, 1.017, 1.018, 1.019, 1.020, 1.021, 1.022, 1.025, 1.028, 1.029, 1.030, 1.031, 1.032, 1.035, 1.038, 1.039, 1.040, 1.041 , 1.042, 1.045, 1.048, 1.049, 1.050, 1.051, 1.052, 1.055, 1.058, 1.059, 1.060, 1.061, 1.062, 1.065, 1.068, 1.069, 1.070, 1.071, 1.072, or 1.075.

Preferably, the average particle size of the main powder material is 0.2 μm to 3 μm, and the calcining temperature is 800° C. to 1200° C., for example: 850° C., 900° C., 950° C., 1000° C., 1050° C., 1100° C. or 1150°C, more preferably 900°C to 1100°C.

Preferably, the calcining time is at least 50 minutes, for example: 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4.0 hours, more preferably 1 hour to 3 hours.

Preferably, based on the total weight of the main powder material, the first rare earth material and the micro-nanosilicate glass, the content of the main powder material is 77 weight percent to 96.9 weight percent; more preferably, the The content of the main powder material is 79 weight percent to 92.9 weight percent.

According to the present invention, the perovskite structure can be semiconducted by adding the above-mentioned first rare earth material, thereby reducing the resistance value of the resulting ceramic sintered body. Preferably, the first rare earth material includes yttrium (Y), samarium (Sm), niobium (Nb), neodymium (Nd), cerium (Ce), alloys or oxides thereof.

More preferably, based on the total weight of the main powder material, the first rare earth material and the micro-nanosilicate glass, the content of the first rare earth material is 0.1% to 3% by weight; for example, The content of the first rare earth material can be 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1.0% by weight, 1.5% by weight, 2.0 Weight percentage or 2.5 weight percentage.

In the present invention, the temperature required for the formation of the liquid phase of the micro-nanosilicate glass is relatively low, so that each element can be more uniformly diffused into the lattice of the perovskite structure to further increase the α value of the resulting porcelain sintered body And reduce its resistance value. Preferably, the micro-nanosilicon glass contains silicon dioxide, and the content of the micro-nanosilicon glass is based on the total weight of the main powder material, the first rare earth material, and the micro-nanosilicon glass From 3 weight percent to 20 weight percent, for example: 4 weight percent, 5 weight percent, 6 weight percent, 7 weight percent, 8 weight percent, 9 weight percent, 10 weight percent, 11 weight percent, 12 weight percent, 13 weight percent , 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight or 19% by weight; more preferably, the content of the micro-nanosilicate glass is 5 to 15% by weight.

Preferably, the micro-nanosilicate glass further includes a second rare earth material and/or a second element; the second rare earth material and/or the second element is sintered together with the silicon dioxide to form the micro-nano Silicon glass. Preferably, the second rare earth material is any one or a combination of yttrium, samarium, niobium, neodymium, and cerium, and the second element includes any one or a combination of barium, strontium, calcium, and titanium.

More preferably, based on the total weight of the micro-nanosilicate glass, the content of the silicon dioxide is 97.3 wt% to 99.4 wt%; the content of the second rare earth material is 0.1 wt% to 0.7 wt%, and/ Or the content of the second element is 0.5 wt% to 2 wt%. In some embodiments, the content of the second rare earth material is 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, or 0.6% by weight; the content of the second element is 0.6% by weight, 0.7% by weight, 0.8% by weight. Weight percent, 0.9 weight percent, 1.0 weight percent, 1.1 weight percent, 1.2 weight percent, 1.3 weight percent, 1.4 weight percent, 1.5 weight percent, 1.6 weight percent, 1.7 weight percent, 1.8 weight percent, or 1.9 weight percent.

Preferably, the average particle size of the micro-nanosilicate glass is 30 nanometers to 3 micrometers.

The present invention also provides a ceramic sintered body, which is formed by sintering the above-mentioned ceramic composition; wherein the ceramic sintered body has a plurality of pores, and the porosity of the ceramic sintered body is 5% to 20%.

According to the present invention, the cavity of the ceramic sintered body is a space formed by the grain boundaries of at least three crystal grains.

According to the present invention, the porosity is obtained by randomly selecting a cross section of the ceramic sintered body and observing and calculating with a scanning electron microscope. The porosity is expressed by the following formula: porosity (%)=VH/VT*100; where VH is the total area of all holes in the section, and VT is the total area of the section.

Since the ceramic sintered body has a plurality of pores, it can provide an oxygen transmission path in the oxidation treatment step of the sintering process. Therefore, an appropriate increase in porosity can increase the oxygen supplement efficiency and further improve the performance of the temperature coefficient of resistance of the ceramic sintered body. Therefore, the present invention can also adjust the porosity by adjusting the content of silica.

If the ceramic sintered body is too dense, the oxygen transmission path will be reduced and the oxygen supplement ability will be reduced, which may make the alpha value perform poorly; on the contrary, if the porosity of the ceramic sintered body is too high, although there are more oxygen supplement paths To increase the value of α, the problem of insufficient structural strength of the ceramic sintered body is likely to occur, and the insufficient density of the ceramic sintered body may also cause failure in the subsequent dielectric performance test. Therefore, preferably, the porosity of the ceramic sintered body is 5% to 20%. For example: the porosity can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19 % Or 20%.

According to the present invention, after the sintering of the ceramic composition is completed, the silicon dioxide component in the micronanosilicate glass will mainly gather in the pores of the ceramic sintered body to form solid particles, which is the glass phase. The glass phase can also be called a solid glass phase or a glass body, which helps to further reduce the resistance value of the ceramic sintered body and increase the α value of the ceramic sintered body.

Preferably, when the content of the micro-nanosilicate glass in the ceramic composition is more than 3% by weight, the resulting ceramic sintered body can obviously form a glass phase due to the sufficient silicon content.

The present invention also provides a laminated ceramic electronic component, which includes: a ceramic body including a plurality of the above-mentioned ceramic sintered bodies and a plurality of internal electrodes; wherein the ceramic sintered bodies and the internal electrodes are formed by overlapping each other. The ceramic body; and two external electrodes, which are respectively arranged on two opposite sides of the ceramic body and are electrically connected to the internal electrodes.

According to the present invention, two adjacent inner electrodes are electrically connected to opposite outer electrodes, respectively.

In the above-mentioned laminated ceramic electronic component, a plurality of internal electrodes are alternately laminated inside the ceramic body in a parallel manner, thereby achieving the function of reducing room temperature resistance.

Preferably, the internal electrodes include nickel (Ni).

Preferably, each of the external electrodes includes any one or a combination of silver (Ag), nickel, and tin (Sn). In some embodiments, each of the external electrodes is an electrode with a multilayer structure. For example, the external electrodes may be external electrodes with a three-layer structure, and the materials of the first to third external electrodes are silver, nickel, and tin in order.

Preferably, each of the inner electrodes and the outer electrodes are approximately perpendicular (90 degrees included).

Preferably, the above-mentioned laminated ceramic electronic component may further include two protective layers, and the protective layers are disposed on two opposite surfaces of the ceramic body, and the surfaces and the internal electrodes are parallel to each other. The protective layer can avoid the problem of over-plating when the laminated ceramic electronic components are electroplated to form external electrodes.

Preferably, the room temperature resistance value of the above-mentioned laminated ceramic electronic component is 1 ohm to 30 ohm, wherein the room temperature refers to 25°C.

According to the present invention, the temperature coefficient of resistance of the multilayer ceramic electronic component can be 3.35 ppm/℃ to 10 ppm/℃; preferably, the temperature coefficient of resistance of the above-mentioned multilayer ceramic electronic component is 3.95 ppm/℃ to 10 ppm/℃ ℃, for example: 4.0 ppm/℃, 4.5 ppm/℃, 5.0 ppm/℃, 5.5 ppm/℃, 6.0 ppm/℃, 6.5 ppm/℃, 7.0 ppm/℃, 7.5 ppm/℃, 8.0 ppm/℃, 8.5 ppm/°C, 9.0 ppm/°C, 9.5 ppm/°C, or 9.9 ppm/°C.

Preferably, the Curie temperature of the above-mentioned laminated ceramic electronic component is 80°C to 110°C. For example, the Curie temperature of the laminated ceramic electronic component can be 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91℃、92℃、93℃、94℃、95℃、96℃、97℃、98℃、99℃、100℃、101℃、102℃、103℃、104℃、105℃、106℃、107℃ , 108°C, 109°C or 110°C, more preferably, the Curie temperature of the above-mentioned laminated ceramic electronic components is 95°C to 100°C.

The present invention further provides an electrical appliance including the above-mentioned laminated ceramic electronic component.

In the following, those skilled in the art can easily understand the advantages and effects that the present invention can achieve from the following embodiments. Therefore, it should be understood that the description presented herein is only used to illustrate the preferred embodiments and not to limit the scope of the present invention. Various modifications and changes can be made for implementation or application without departing from the spirit and scope of the present invention. Contents of the invention.

"Main powder material"

First, according to the composition ratio of titanium oxide shown in Table 1 (unit is weight percentage, wt%), barium carbonate, strontium carbonate, calcium carbonate and titanium oxide are uniformly mixed to obtain respective main powder mixtures. Wherein, in each main powder mixture, based on the total weight of the main powder mixture, the content of each group of strontium carbonate is 0.45 weight percent, and the content of each group of calcium carbonate is all 0.15 weight percent. Next, the main powder mixtures are each calcined at a temperature of 900°C to 1100°C for 1 to 3 hours, so that the main powder materials 1 to 16 having a perovskite structure can be fired; and, The main powder material 1 to the main powder material 16 are all powders with an average particle size of 0.2 micrometers to 3 micrometers. Among them, the main difference between the main powder material 1 to the main powder material 16 is the content of the rutile structure and the anatase structure contained in the main powder mixture, and the titanium oxide accounts for the total amount of the main powder mixture The content is different.

Table 1: The formula of each main powder mixture of firing main powder materials 1 to 16 and the m value of main powder materials 1 to 16 Main powder material number Titanium oxide The content of titanium oxide in the main powder mixture (wt%) M value of main powder material Content of rutile structure (wt%) The content of anatase structure (wt%) 1 0 100 28.29 1.015 2 15 85 28.29 1.015 3 20 80 28.29 1.015 4 37 63 28.29 1.015 5 58 42 28.29 1.015 6 79 twenty one 28.29 1.015 7 90 10 28.29 1.015 8 100 0 28.29 1.015 9 79 twenty one 28.38 1.010 10 79 twenty one 28.19 1.020 11 79 twenty one 28.00 1.030 12 79 twenty one 27.80 1.040 13 79 twenty one 27.69 1.050 14 79 twenty one 27.60 1.060 15 79 twenty one 27.51 1.070 16 79 twenty one 27.32 1.080

The above-mentioned raw materials are all commercially available products. Among them, the purity of barium carbonate is 99.9%, the purity of strontium carbonate is 99.9%, and the purity of calcium carbonate is 99.9%; and the titanium oxide has a rutile structure and/or anatase structure. The purity of titanium dioxide is 99.5%.

"Ceramic Composition"

The ceramic compositions of the following embodiments and comparative examples respectively include one of the main powder materials 1 to 16 in Table 1, the first rare earth material, and micro-nanosilicate glass; wherein the total weight of each ceramic composition is fixed, and Based on the total weight of the ceramic composition, the content of the main powder material is all 89.5 wt%, the content of the first rare earth material is all 0.5 wt%, and the content of the micro-nanosilicate glass is all 10 wt%. Among them, the ceramic compositions of Comparative Example 1-1, Comparative Example 1-2, Example 1-1 to Example 1-5, Comparative Example 1-3, and Example 2-1 to Example 2-8 are in order Use the main powder materials 1 to 16 in Table 1.

The above-mentioned first rare earth material is also a commercially available product, which is niobium oxide with a purity of 99.9%.

The above-mentioned micro-nanosilica glass is also commercially available, with an average particle size of 30 nanometers to 3 microns, and contains 98.6 weight percent of silicon dioxide, 0.4 weight percent of rare earth elements, and 1 weight percent of barium, strontium, and calcium. , At least one of titanium.

"Ceramic sintered body and laminated ceramic electronic components containing the same"

The preparation methods of the ceramic sintered bodies and laminated ceramic electronic components of the following examples and comparative examples are as follows: prepare the above-mentioned ceramic compositions, use the above-mentioned ceramic compositions as starting materials, and use toluene and alcohol as solvents. The amount of solvent added can be adjusted according to the required degree of dispersion. In addition, a polymer dispersant (product model: BYK-110, 111 and/or 115) of about 0.5 wt% to 0.75 wt% of the total weight of the starting materials is added. ), and add about 25% to 30% by weight of the total weight of the starting materials, polyvinyl butyral resin binder, and put it into the ball mill together with the zirconium balls, and use wet grinding to combine the starting materials and additives Perform thorough mixing to obtain ceramic slurry. Then use the doctor blade method to form the ceramic slurry into a sheet and then dry it at a drying temperature of about 50 to 60°C; the drying time is adjusted according to the actual situation to obtain a roll of thin ribbon.

The nickel metal powder and the organic binder are dispersed together in an organic solvent to prepare an internal electrode paste, and then the internal electrodes are printed on the thin strip by screen printing to form a thin strip with internal electrodes. Use thin strips without printed internal electrodes as the upper and lower covers, and sandwich the laminated structure formed by multiple thin strips with internal electrodes between the upper and lower covers; then, after the heat equalization step, use it again The cutting machine cuts out the ceramic green embryo. The green ceramic embryo with a laminated structure is subjected to degreasing treatment at about 300°C for 24 hours in a protective atmosphere. The degreased ceramic green body is calcined in a nitrogen/hydrogen reducing atmosphere at 1250°C to 1380°C for about 1 hour to prepare a sintered ceramic body. The sintered ceramic body includes a plurality of sintered ribbons. The ceramic sintered body is formed, and the ceramic sintered body and a plurality of internal electrodes overlap each other, and the number of layers of the ceramic sintered body and the number of internal electrodes can be adjusted according to the thickness of the ribbon. The sintered ceramic body is subjected to piping and corner grinding, and then subjected to an oxidation treatment at 700°C to 900°C in an atmospheric environment to form a ceramic body. Coating the upper and lower surfaces of the ceramic body with a protective layer to form a protective layer parallel to the internal electrodes, and depositing silver on the left and right sides of the ceramic body to form external electrodes to form the laminated ceramic electronics Element, wherein the external electrodes are electrically connected to the internal electrodes.

As shown in FIG. 1, the laminated semiconductor ceramic electronic component 10 has a ceramic body 100, which includes a plurality of ceramic sintered bodies 110 and a plurality of internal electrodes 120, and the ceramic sintered bodies 110 and the internal electrodes 120 are formed by overlapping each other In the ceramic body 100; two external electrodes 200, 300, which are respectively disposed on two opposite sides 130, 140 of the ceramic body 100, and are electrically connected to the internal electrodes 120, and the two external electrodes 200, 300 and the internal The included angle of the electrode 120 is approximately 90 degrees; and two protective layers 400, which are respectively disposed on the upper and lower surfaces 150, 160 of the ceramic body, and are approximately parallel to the inner electrodes 120. In addition, two adjacent internal electrodes 120 are separated by the ceramic sintered body 110, and there is a thickness S between the two adjacent internal electrodes 120, which thickness S is less than 40 microns.

Characteristic analysis :

In experiment 1, the α values of the laminated ceramic electronic components of Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-3 were measured, and the measurement results are listed in Table 2; in experiment 2, In addition to measuring the alpha value of the laminated ceramic electronic components of Examples 1-4 and Examples 2-1 to 2-8 in the same manner as in Experiment 1, the room temperature resistance value and Curie were also measured. The temperature, and observe the microstructure of the ceramic sintered body contained in each laminated ceramic electronic component and calculate the porosity. Among them, the length of the tested sample is 0.933 millimeters (mm), and the cross-sectional area is 2.396 square millimeters (mm ² ). The measurement is performed after the multilayer ceramic electronic component is deposited with silver as the external electrode according to the above steps.

First, the room temperature resistance measurement method is to apply a voltage to the tested sample at room temperature (ie 25°C), and use a multimeter (brand: HIOKI, model: RM3545) to measure its current value to calculate the resistance value.

Secondly, the method for measuring the value of α is to place the above-mentioned sample under test in a constant temperature bath, and while gradually increasing the temperature from 20°C to 250°C, convert the resistance value corresponding to each temperature according to the above method to obtain The resistance value-temperature curve is used to obtain the temperature at which the resistance value is twice the room temperature resistance value, that is, the double point. Since the double point is the phase transition temperature at which the tested sample begins to exhibit PTC characteristics, and roughly approaches the Curie temperature (Tc), the room temperature (25°C) and double point are respectively T1 and T2. The corresponding resistance values are R1 and R2, and the α value is calculated according to the formula α={ln10×(LogR2-LogR1)/(T2-T1)×100).

Finally, the temperature corresponding to 2 times the room temperature resistance value is the Curie temperature.

The microstructure and porosity calculations were performed by observing the microstructure of the cross-section of the ceramic sintered body formed by the ceramic compositions of each group of experiment 2 with an electron microscope, and then calculating the porosity, and the results are listed in Table 3.

Table 2: Experiment 1: Test results of the alpha value of the laminated ceramic electronic components of Comparative Example 1-1, Comparative Example 1-2, Example 1-1 to Example 1-5, and Comparative Example 1-3 Experiment group number Rutile structure ratio (wt%) α value (ppm/℃) Comparative example 1-1 0 3.51 Comparative example 1-2 15 3.69 Example 1-1 20 4.02 Example 1-2 37 4.23 Example 1-3 58 4.51 Example 1-4 79 4.73 Example 1-5 90 3.97 Comparative example 1-3 100 3.66

It can be seen from Table 2 that the ratio of the rutile structure to the anatase structure in the titanium dioxide raw material will significantly affect the α value; when the types and contents of other components are fixed, the total weight of the titanium dioxide is used as the basis. When the structure ratio is 20% to 90% by weight, the α value of the final laminated ceramic electronic components can reach 3.35 ppm/℃; even as in Examples 1-3 and 1-4, when the rutile type When the ratio of the structure is 55 wt% to 82 wt%, the α value can even reach above 4.5 ppm/℃, and it has better electrical performance.

Table 3: Experiment 2: Test results of laminated ceramic electronic components of Example 1-4 and Example 2-1 to Example 2-8 Experiment 2 group number Titanium dioxide content (wt%) α value (ppm/℃) Room temperature resistance (ohm) Tc (℃) Porosity(%) microstructure Example 2-1 28.38 3.39 103 97 twenty four As shown in Figure 2A Example 1-4 28.29 4.73 11 96 13 As shown in Figure 2B Example 2-2 28.19 5.82 9.17 96 15 As shown in Figure 2C Example 2-3 28.00 5.21 8.03 95 16 As shown in Figure 2D Example 2-4 27.80 5.18 9.97 98 18 As shown in Figure 2E Example 2-5 27.69 5.03 12 97 18 As shown in Figure 2F Example 2-6 27.60 4.87 twenty one 99 20 As shown in Figure 2G Example 2-7 27.51 4.52 26 98 20 As shown in Figure 2H Example 2-8 27.32 4.31 89 97 twenty four As shown in Figure 2I

It can be seen from Table 3 that the α value of each group of laminated ceramic electronic components can reach 3.35 ppm/℃ or more; among them, Example 1-4, Example 2-2 to Example 2-7 Laminated Ceramic The alpha values of the electronic components are all higher than 4.5 ppm/°C, especially the alpha values of the laminated ceramic electronic components of Example 2-2 to Example 2-5 are all higher than 5.0 ppm/°C, the main display adjustment The total content of titanium dioxide in the powder mixture can also further adjust the alpha value and electrical performance of laminated ceramic electronic components. In addition, although the alpha values of Example 2-1 and Example 2-8 are not as good as those of Example 1-4, Example 2-2 to Example 2-7, the laminated ceramic electronic components of Example 2-1 And the α values of Examples 2-8 are still in the ideal range in this technical field, and can also be prepared into thermistors.

Secondly, it can be seen from FIG. 2A to FIG. 2I that the cross section of the ceramic sintered body formed by the ceramic composition shows that the ceramic sintered body has holes 170 to provide an oxygen transmission path.

Finally, from Figures 2A to 2F and Figures 2H to 2I, it can be seen that the cross-section of the ceramic sintered body formed by the ceramic composition of the present invention can clearly observe that the ceramic sintered body has a glass phase 180, which helps to improve Oxygen replenishment efficiency and electrical performance of laminated ceramic electronic components.

It can be proved that the main powder material in the ceramic composition of the present invention can make the ceramic sintered body have an appropriate α value by using titanium oxide containing a specific rutile structure ratio as a raw material, and can be obtained by specific The proportion of titanium dioxide content is adjusted to further increase the alpha value, and thus to obtain a laminated ceramic electronic component with better efficiency.

10: Laminated ceramic electronic components

100: ceramic body

110: Ceramic sintered body

120: inner electrode

130,140: side

150, 160: surface

170: hole

180: glass phase

200, 300: External electrode

400: protective layer

S: thickness

FIG. 1 is a schematic diagram of a cross-section of a laminated ceramic electronic component of the present invention.

2A to 2I are electron micrographs of the cross-sections of the ceramic sintered bodies in the laminated ceramic electronic components of each group of experiment two, respectively.

10: Laminated ceramic electronic components

100: ceramic body

110: Ceramic sintered body

120: inner electrode

130,140: side

150, 160: surface

200, 300: External electrode

400: protective layer

S: thickness

Claims (11)

A ceramic composition comprising: a main powder material, which is obtained by firing a main powder mixture containing a first element material, barium carbonate and titanium oxide, wherein the first element material is selected from calcium carbonate, strontium carbonate or The combination is based on the total weight of the main powder mixture. When the main powder mixture contains calcium carbonate, the content of the calcium carbonate is 0.10 wt% to 0.60 wt%; when the main powder mixture contains strontium carbonate, the The content of strontium carbonate is 0.10 wt% to 0.60 wt%, and the titanium oxide includes a rutile structure and an anatase structure, and based on the total weight of the titanium oxide, the content of the rutile structure is 20% to 90% by weight; the first rare earth material; and micro-nanosilicate glass. The ceramic composition according to claim 1, wherein the content of the titanium oxide is 27.35 wt% to 28.35 wt% based on the total weight of the main powder mixture. The ceramic composition according to claim 1 or 2, wherein the main powder material is obtained by calcining the main powder mixture, the calcining temperature is 800°C to 1200°C, and the calcining time is at least 50 Minutes; and the average particle size of the main powder material is 0.2 microns to 3 microns. The ceramic composition according to claim 1, wherein the first rare earth material contains yttrium, samarium, niobium, neodymium, cerium, alloys thereof, or oxides thereof. The ceramic composition according to claim 1, wherein, based on the total weight of the main powder material, the first rare earth material and the micro-nanosilicate glass, the content of the main powder material is 77% by weight to 96.9 weight percent, the content of the first rare earth material is 0.1 weight percent to 3 weight percent, and the content of the micro-nanosilicate glass is 3 weight percent to 20 weight percent. The ceramic composition according to claim 1, wherein the main powder material has a _{perovskite structure represented by the general formula A m} BO ₃ , wherein the A position is selected from barium, strontium, calcium or a combination thereof, and the B position is For titanium, m is the molar ratio between the A site and the B site, and 1.012≦m≦1.078. A ceramic sintered body is formed by sintering the ceramic composition according to any one of claims 1 to 6; wherein the ceramic sintered body has a plurality of pores, and the porosity of the ceramic sintered body is 5% to 20 %. The ceramic sintered body according to claim 7, wherein a glass phase is formed in some of the pores. A laminated ceramic electronic component, comprising: a ceramic body, which comprises a plurality of ceramic sintered bodies as described in claim 7 or 8 and a plurality of internal electrodes; wherein the ceramic sintered bodies and the internal electrodes intersect each other Stacked in the ceramic body; and two external electrodes, which are respectively arranged on two opposite sides of the ceramic body and electrically connected with the internal electrodes. The laminated ceramic electronic component described in claim 9 has a room temperature resistance value of 1 ohm to 30 ohm, and a temperature coefficient of resistance of 3.95 ppm/°C to 10 ppm/°C. The multilayer ceramic electronic component described in claim 9 has a Curie temperature of 80°C to 110°C.

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