Patent classifications
C04B2235/3249
LOW-TEMPERATURE CO-FIRED MICROWAVE DIELECTRIC CERAMIC MATERIAL AND PREPARATION METHOD THEREOF
A low-temperature, high stability co-fired microwave dielectric composite of ceramic and glass, including 85-99 wt % microwave dielectric ceramic of formula [1-y-z[(1−x)Mg.sub.2SiO.sub.4−xCa.sub.2SiO.sub.4]−yCaTiO.sub.3−zCaZrO.sub.3, wherein 0.2≦x≦0.7,0.05≦y≦0.3 and 0.02≦z≦0.15], and 1 to 15 wt % with Li.sub.2O—BaO—SrO—CaO—B.sub.2O.sub.3—SiO.sub.2 glass respectively made at a low sintering temperature of ceramic for co-firing with Ag or Cu electrode, employing eutectic phase of ceramic oxides to reduce its melting temperature, a low melting-point glass material with high chemical stability as a sintering aid added to oxides and raw material powders of Li.sub.2O, BaO, SrO, CaO, B.sub.2O.sub.3 and SiO.sub.2, obtained by combining and melting the ingredients in the temperature range between 1000 to 1300° C., quenching and crashing, and then adding it to the main ceramic oxides to form the final composition. This ceramic/glass composite material may be co-fired with an Ag and Cu electrode at 900° C.-970° C. for 0.5-4 hours in a protective atmosphere. After sintering, this dielectric material possesses efficacious microwave dielectric properties, dielectric constant between middle-K to low-K at 8.sup.−15, high quality factors, low dielectric loss, low temperature-capacitance coefficient and superior chemical stability suitable for manufacture of multilayer ceramic devices.
DIELECTRIC CERAMIC COMPOSITION AND MULTILAYER CERAMIC CAPACITOR
A dielectric ceramic composition has good characteristics even under the high electric field intensity, and particularly good IR characteristic and the high temperature accelerated lifetime. The dielectric ceramic composition has a main component having a perovskite type compound shown by a compositional formula (Ba.sub.1-x-ySr.sub.xCa.sub.y).sub.m(Ti.sub.1-zZr.sub.z)O.sub.3, a first sub component having oxides of a rare earth element R, a second sub component as a sintering agent, wherein the dielectric particles has dielectric particles having high diffusion rate of the rare earth element, preferably of a complete solid solution particle, and when a concentration of Ti atom in the diffusion phase is 100 atom %, then an average concentration of the rare earth element R in the diffusion phase is 5 atom % or more, and an average concentration of Zr in the diffusion phase is 10 atom % or more.
PIEZOELECTRIC ELEMENT
A piezoelectric element includes a piezoelectric body having a main phase configured by lead zirconate titanate and a heterogenous phase configured by a different component to lead zirconate titanate, and a pair of electrodes provided on the piezoelectric body. The piezoelectric body has a surface region within 10 μm of a surface, and an inner region more than 10 μm from the surface. A surface area coverage of the heterogenous phase in a cross section of the surface region is at least 0.75% greater than a surface area coverage of the heterogenous phase in a cross section of the inner region.
DIELECTRIC CERAMIC COMPOSITION AND MULTILAYER CERAMIC CAPACITOR
A dielectric ceramic composition having good characteristic even under high electric field intensity, and particularly good IR characteristic and high temperature accelerated lifetime. The present invention is a dielectric ceramic composition comprising, a main component comprising a perovskite type compound shown by a compositional formula (Ba1-x-ySrxCay)m(Ti1-zZrz)O3, a first sub component comprising oxides of a rare earth element, a second sub component as a sintering agent, wherein said dielectric ceramic composition is a complete solid solution particle wherein the rare earth element is solid dissolved to entire dielectric particle, or a core-shell particle having high ratio of the diffusion phase, and comprises the dielectric particle having 5 to 20 atom % of the average concentration of the rare earth element in the diffusion phase, and having uniform concentration distribution of the rare earth element in the diffusion phase.
DIELECTRIC COMPOSITION, DIELECTRIC ELEMENT, ELECTRONIC COMPONENT AND LAMINATED ELECTRONIC COMPONENT
The aim of the present invention lies in providing a dielectric composition which has a relatively high dielectric constant of 800 or greater, and which has relatively low dielectric loss of 4% or less when a DC bias of at least 8 V/ym is applied, and also in providing a dielectric element employing said dielectric composition, an electronic component, and a laminated electronic component. A dielectric composition having a main component represented by (Bi.sub.aNa.sub.bSr.sub.cBa.sub.d) (α.sub.xTi.sub.1-x) O.sub.3, characterized in that a is at least one selected from Zr and Sn; and a, b, c, d and x satisfy the following: 0.140≦a≦0.390, 0.140≦b≦0.390, 0.200≦c≦0.700, 0.020≦d≦0.240, 0.020≦x≦0.240 and 0.950<a+b+c+d≦1.050.
PRECURSOR SOLUTION AND METHOD FOR THE PREPARATION OF A LEAD-FREE PIEZOELECTRIC MATERIAL
The present disclosure relates to a precursor solution for the preparation of a ceramic of the BZT-αBXT type, where X is selected from Ca, Sn, Mn, and Nb, and α is a molar fraction selected in the range between 0.10 and 0.90, said solution comprising: 1) at least one barium precursor compound; 2) a precursor compound selected from the group consisting of at least one calcium compound, at least one tin compound, at least one manganese compound, and at least one niobium compound; 3) at least one anhydrous precursor compound of zirconium; 4) at least one anhydrous precursor compound of titanium; 5) a solvent selected from the group consisting of a polyol and mixtures of a polyol and a secondary solvent selected from the group consisting of alcohols, carboxylic acids, ketones, and mixtures thereof; and 6) a chelating agent, as well as method of using the same.
CHROMIUM OXIDE REFRACTORY OBJECT AND METHODS OF FORMING THEREOF
A refractory object may include a Cr.sub.2O.sub.3 content of at least about 80 wt. % of a total weight of the refractory object, an Al.sub.2O.sub.3 content of at least about 0.7 wt. % and not greater than about 10.0 wt. % of the total weight of the refractory object, a SiO.sub.2 content of at least about 0.3 wt. % and not greater than about 5.0 wt. % of the total weight of the refractory object and a TiO.sub.2 content of at least about 1.0 wt. % and not greater than about 5.6 wt. % TiO.sub.2 of the total weight of the refractory object. The refractory object may further include an MOR of at least about 37 MPa as measured at 1200° C.
COMPOSITION FOR FORMING Mn-DOPED PZT-BASED PIEZOELECTRIC FILM AND Mn-DOPED PZT-BASED PIEZOELECTRIC FILM
A composition for forming a PZT-based piezoelectric film formed of Mn-doped composite metal oxides is provided, the composition including: PZT-based precursors containing metal atoms configuring the composite metal oxides; a diol; and polyvinylpyrrolidone, in which when a metal atom ratio in the composition is shown as Pb:Mn:Zr:Ti, the PZT-based precursors are contained so that a metal atom ratio of Pb is satisfied to be from 1.00 to 1.20, a metal atom ratio of Mn is satisfied to be equal to or greater than 0.002 and less than 0.05, a metal atom ratio of Zr is satisfied to be from 0.40 to 0.55, a metal atom ratio of Ti is satisfied to be from 0.45 to 0.60, and the total of Zr and Ti in a metal atom ratio is 1.
Power module with capacitor configured for improved thermal management
A module having a power semiconductor device and a ceramic capacitor which is configured for cooling the power semiconductor device.
DIELECTRIC CERAMIC COMPOSITION AND ELECTRONIC COMPONENT
A dielectric ceramic composition contains dielectric particles containing a main component represented by a composition formula (Ba.sub.1-x-ySr.sub.xCa.sub.y).sub.m(Ti.sub.1-zZr.sub.z)O.sub.3 and grain boundaries present between the dielectric particles. The values of m, x, y, and z in the composition formula are all molar ratios. In the composition formula, 0.9≤m≤1.4, 0≤x<1.0, 0<y≤1.0, 0.9≤(x+y)≤1.0, and 0.9≤z≤1.0 are satisfied. The dielectric particles contain specific structural particles having a predetermined intragranular structure, and each of the specific structural particles intragranularly includes a first region and a second region having different Ca concentrations from each other. C2/C1 is less than 0.8 in which C1 is an average value of the Ca concentration in the first region and C2 is an average value of the Ca concentration in the second region.