615 results about "Dielectric ceramics" patented technology

A multilayer ceramic electronic component comprising an element body in which a dielectric layer and an internal electrode layer are stacked. The dielectric layer is constituted from a dielectric ceramic composition including; a compound having a perovskite structure expressed by a formula of ABO₃ (A is at least one selected from Ba, Ca, and Sr; B is at least one selected from Ti, Zr, and Hf); an oxide of Mg; an oxide of rare earth elements including Sc and Y; and an oxide including Si. The dielectric ceramic composition comprises a plurality of dielectric particles and a grain boundary present in between the dielectric particles. In the grain boundary, when content ratios of Mg and Si are set to D(Mg) and D(Si) respectively, D(Mg) is 0.2 to 1.8 wt % in terms of MgO, and D(Si) is 0.4 to 8.0 wt % in terms of SiO₂.

A multilayer ceramic capacitor includes a multilayer body including dielectric ceramic layers and inner electrode layers containing Ni and electrically connected to outer electrodes. The dielectric ceramic layers contain a Ba- and Ti-containing perovskite compound, Ca, Mg, R (at least one rare earth metal selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y), M (at least one selected from Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo, and W), and Si. The number of parts by mole of each element relative to Ti as 100 parts is as follows:

• • Ca, approximately 0.10 to 5.00 parts;
  • Mg, approximately 0.0010 to 0.0098 parts;
  • R in total, approximately 0.50 to 4.00 parts;
  • M in total, approximately 0.10 to 2.00 parts; and
  • Si, approximately 0.5 to 2.0 parts.

A dielectric ceramic includes, in composition, a perovskite-type compound having the general formula ABO₃ containing Ba, Ca and Ti, and an additive component containing Si, R(La or the like), and M (Mn or the like), the additive component not being solid-dissolved and, moreover, the major component existing in at least 90% of the cross-section of each of the crystal grains of which the number is equal to at least 85% of that of all of the crystal grains contained in the dielectric ceramic, at least the Ba, the Ca, the Ti, the Si, the R, and the M being contained at at least 85% of the analytical points in the crystal grain boundaries of the dielectric ceramic.

A thermosetting composite dielectric film characterized in that the film has flexibility and is made of a thermosetting resin such as an epoxy resin having an epoxy equivalent of 150 to 2500 and containing dielectric ceramics having a high dielectric constant and in that the film has a dielectric constant of 25 or more.

The invention discloses conductive silver paste and a method for preparing the same. The conductive silver paste comprises components including, by mass percent, from 70 to 80% of conductive silver powder, from 3 to 9% of glass powder and from 15 to 27% of an organic carrier. The invention further discloses a surface metallization method for microwave dielectric ceramics. The surface metallization method includes precisely grinding, precisely polishing, ultrasonically cleaning and primarily drying the microwave dielectric ceramics; carrying out screen printing by the aid of the conductive silver paste; carrying out secondary drying; sintering a silver skin and the like. The preparation of the conductive silver paste is optimized, the microwave dielectric ceramics are precisely ground and precisely polished before the conductive silver skin is printed, then the conductive silver skin is sintered to form a silver layer by means of controlling a sintering process, surface adhesion of the metallized silver layer on the surface of the microwave dielectric ceramics can be improved, and physiochemical property and production efficiency of a metallized electrode made of the microwave dielectric ceramics are enhanced.

The invention discloses a low temperature sintering niobate high frequency dielectric ceramic used in microwave component and ceramic capacitor or temperature compensating capacitor. The main phase of the ceramic is (Ba_1-xSr _x)₄LiNb_3-yTa_yO₁₂, of which 0.00<=x<=1, 0.00<=y<=2. It is well sintering, low consumption, and high frequency dielectric constant could reach to 40-90.

The invention provides a microwave dielectric ceramic material which can be cofired with a silver or copper electrode at a low temperature and a preparation method thereof. The microwave dielectric ceramic material is prepared from a microwave dielectric ceramic material 1-y-z[(1-x)Mg2SiO4-xCa2SiO4]-yCaTiO3-zCaZrO3, and mixed with a multicomponent glass material Li2O-BaO-SrO-CaO-B2O3-SiO2, wherein x is more than or equal to 0.2 and is less than or equal to 0.7, y is more than or equal to 0.05 and is less than or equal to 0.3, and z is more than or equal to 0.02 and is less than or equal to 0.15. The low-temperature co-fired microwave dielectric ceramic material can be co-fired with silver or copper and other conductive metals at 900-970 DEG C at an atmosphere and inert gas environment. The material has excellent characteristics of low dielectric consumption, high quality factor, low temperature capacitance and the like, and is applicable to multilayer ceramic component manufacture procedure and processing after being fired.

The present invention relates to dielectric ceramics, thin and/or thick layers produced therefrom and a method for the production thereof and the use of the dielectrics and of the thin and/or thick layers.

The invention discloses an X9R ceramic capacitor dielectric material and a preparation method thereof. The material comprises 95 to 98 molar percent of barium titanate-sodium bismuth titanate complex or barium titanate-potassium bismuth titanate complex serving as a main component, and 2 to 5 molar percent of secondary additive consisting of at least one of Nb2O5, CaZrO3 and SrZrO3. According to the preparation method of the invention, the dielectric ceramic material with high property can be obtained, meeting the electronic industries association (EIA) X9R standard; the process is simple, and intermediate temperature sintering can be performed; and the material has the room temperature dielectric constant of 1,500 to 1,700, the room temperature loss of about 2 percent, the room temperature resistivity of more than or equal to 1,013omega.cm, the breakdown voltage of more than or equal to 5kV/mm, and a good industrial prospect.

A dielectric ceramic contains a BaTiO₃-based compound as a main ingredient, and can be represented by the general formula: 100A_mBO₃+aNiO+bRO_n+cMO_v+dMgO+eXO_w where R represents a rare earth element such as Dy, M represents a metal element such as Mn, and X represents a sintering aid component containing Si. Ni is uniformly solid-solved in crystal grains, and the solid-solution region of the rare earth element in the crystal grains is an average 10% or less in terms of a cross section ratio. 0.96≦m≦1.030, 0.05≦a≦3, 0.1≦b≦1.5, 0.1≦c≦1.0, 0.1≦d≦1.5, and 0.05≦e≦3.5 are satisfied. A laminated ceramic capacitor has dielectric layers formed of the dielectric ceramic. As a result, a dielectric ceramic, and a laminated ceramic capacitor having excellent AC voltage characteristics, capable of keeping desired dielectric characteristics and excellent temperature characteristics, and having excellent withstand voltage and capable of ensuring reliability can be realized.

Crystal grains mainly composed of barium titanate have a mean grain size of not more than 0.2 μm. The volume per unit cell V that is represented by a product of lattice constant (a, b, c) figured out from the X-ray diffraction pattern of the crystal grains is not more than 0.0643 nm³. Thereby, a dielectric ceramics having high relative dielectric constant can be obtained. A multilayer ceramic capacitor comprises a capacitor body and an external electrode that is formed at both ends of the capacitor body. The capacitor body comprises dielectric layers composed of the dielectric ceramics, and internal electrode layers. The dielectric layers and the internal electrode layers are alternately laminated.

Disclosed herein is a sol composition for ultrathin dielectric ceramic films, and dielectric ceramic and a multilayered ceramic capacitor manufactured using the same. The sol composition, composed of BaTiO₃ as a main ingredient and an auxiliary ingredient, includes a polymeric sol having a metal precursor solution of BaTiO₃ and an organic solvent, and an organic additive dissolved in the organic solvent to act as the auxiliary ingredient, in which the amount of the organic additive corresponds to the required amount of the auxiliary ingredient of the dielectric ceramic. Further, the ultrathin dielectric ceramic film, which is manufactured by a sol-gel process, includes the auxiliary ingredient, and hence, is advantageous in making low temperature sintering possible, and having a high dielectric constant, a high sintered density, and TCC characteristic meeting the X5R of EIA standard.

The invention discloses a preparation method of microwave dielectric ceramics materials. The preparation method of the microwave dielectric ceramics materials comprises that the mixed powder of strontium carbonate, alumina, lanthanum oxide and titanium oxide are mechanically and evenly mixed in a spherical tank to form powder particles; and first time high energy ball milling is carried out on the powder particles to mill the powder particles evenly. The powder after the first time high energy ball milling is high-temperature calcined in a closed container to form precursor powder; and a second time high energy ball milling is carried out on the precursor powder to further mill the precursor powder evenly so as to form ceramic powder. The preparation method of the microwave dielectric ceramics materials sinters microwave dielectric ceramics materials with high densified mediation electric constant and a high quality factor by adopting low temperature, sintering temperature can be greatly lowered, sintering time can be greatly shortened, high densification is achieved, and therefore production cost and technical difficulty are reduced.

Dielectric ceramics include a sintered body comprising a principal ingredient, when represented by:

ABO₃+aRe+bM+Zr oxide

where ABO₃ is a barium titanate-based solid solution having a perovskite structure, Re is at least one oxide of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and/or Y, M is at least one oxide of Mg, Al, Cr, Mn, Fe, Ni, Cu, and/or Zn, a and b each represents a mol number of the oxides per 1 mol of ABO₃ within a range of:

1.100≦Ba/Ti≦1.700, 0.05≦a≦0.25, 0.05≦b≦0.25, Ti:Zr=95:5 to 60:40.

A multi-layer ceramic capacitor capable of being sintered at 1,080° C. or lower in a reducing atmosphere, having a permittivity of 2,000 or more, a temperature characteristic of X7R characteristic or X8R characteristic, and favorable life time property, in which the internal electrodes are formed of Cu or a Cu alloy, the dielectric ceramics are constituted with grains each of an average value for the diameter of 400 nm or less as viewed on the cross section and grain boundaries, the grain comprises a dielectric substance having a domain pattern and shells formed on the surface of the dielectric substance and with t/D from 2% to 10% where D represents an average value for the diameter of the grains as viewed on the cross section and t represents the average value for the thickness of the shells.

Provided is a lead-free dielectric ceramics having a low leakage current value, and a bismuth iron oxide powder as a raw material thereof. The bismuth iron oxide powder includes at least: (A) grains including a bismuth iron oxide having a perovskite-type crystal structure; (B) grains including a bismuth iron oxide having a crystal structure classified to a space group Pbam; and (C) grains including a bismuth iron oxide or a bismuth oxide having a crystal structure that is classified to a space group I23. The dielectric ceramics are made of bismuth iron oxide in which the bismuth iron oxide crystals having the crystal structure classified to the space group Pbam are distributed at a grain boundary of crystal grains of the bismuth iron oxide crystals having the perovskite-type crystal structure.

A method of making a sub-miniature “micro-chip” oxygen sensor is provided where multiple sensor elements are applied to a dielectric ceramic substrate consisting of a heater pattern, followed by a dielectric layer. Intermeshing electrodes are then applied either over the heater pattern/dielectric layers or on the opposite side of the substrate. The space between the intermeshing electrodes is filled with an n-type or p-type high temperature semiconductor which is covered by a porous protection layer. After singulation (dicing), the sensor element is assembled having conductors applied to the contact pads on the element and is packaged in an assembly for introduction to the exhaust stream of a combustion process. A large step-wise change in the resistance of the element takes place as a result of changes in oxygen content in the exhaust whereby one can determine if the exhaust is rich or lean for use in an engine management or combustion management systems for emissions control. A circuit is proposed to convert the change in resistance to a voltage signal to be used for control algorithms in engine or combustion control. Utilizing multiple units of the device for individual cylinder control of multi-cylinder engines is described. A method of using one embodiment of the invention for use as a safety switch is also revealed.

The invention relates to an ion modified titanium dioxide ceramic material with a high dielectric constant and a preparation method thereof, and belongs to the field of environment-friendly dielectric ceramics. The ceramic material disclosed by the invention is as shown in a general formula as follows: (A0.5Nb0.5)xTi(1-x)O2, wherein A is Bi, Al, Ga, Y, Sc, Yb, Dy, Sm, Gd and Pr, and x is not smaller than 0.005 mol content and not larger than 0.150 mol content. The ceramic material is prepared by adopting a traditional solid phase sintering process; the raw materials in the general formula are added with different trivalent A elements and the same pentavalent Nb element; the obtained ceramic material is as high as 10<6> in dielectric constant and as low as 6% in dielectric loss. The ceramic prepared by the method disclosed by the invention has a relatively large practical value in the present age when electronic elements are miniaturized and lightened, and especially the elements prepared from the ceramic have practical application values in various electronic elements such as capacitors and dynamic storage.

A laminated ceramic capacitor which exhibits excellent lifetime characteristics in a high temperature loading test uses a dielectric ceramic constituting the dielectric layers which contains (Ba_1-xCa_x)TiO₃ as its main constituent, and contains a parts by mol of Al, b parts by mol of V, c parts by mol of Mg, and d parts by mol of Re with respect to 100 parts by mol of the (Ba_1-xCa_x)TiO₃. The Re is at least one metal element selected from among Y, La, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, and the x, a, b, c, and d respectively satisfy the conditions of 0.050≦x≦0.150, a≧0.15, 0.05≦b≦0.50, c≦0.50, and d≧1.00.