Matsushita Electric Industrial Co., Ltd.

Gen Itakura

Takayuki Kuroda

Hideyuki Okinaka

Yoshihiro Matsuo

Hideki Kuramitsu

Takashi Iguchi

Kiyoyuki Morita

Tatsuya Wada

Yasuhiro Hioki

Yoshio Irie

Tadayoshi Ushijima

Yamato Takada

Shoichi Ikebe

Kaneomi Nagase

Kenji Kusakabe

A method for selectively and rapidly extracting/removing a plasticizer from a compact such as a green laminate that is produced at a certain point in the process of manufacturing a multilayer ceramic capacitor. Carbon dioxide is introduced into a pressure chamber in which the green laminate has been placed, and the temperature and the pressure of the pressure chamber are set to 40&deg; C. and 10 MPa, respectively, so that the pressure chamber is filled with a supercritical carbon dioxide. The plasticizer is extracted/removed from the green laminate by using the supercritical carbon dioxide. Then, a de-binder step and a baking step are performed in an ordinary manner. By performing the de-plasticizer process of selectively extracting/removing the plasticizer before the de-binder step, it is possible to suppress the formation of a graphite-like substance even if the temperature is increased rapidly in the subsequent de-binder step and the baking step. Therefore, the manufacturing yield or the performance of the product from will not be reduced.

Method and apparatus for manufacturing sinter, method for measuring concentration of plasticizer, evaluation method, and evaluation apparatus

Electronic part and method for producing the same

Ceramic high dielectric composition

This invention relates to a composite function element which includes a high resistance thin film layer containing the constitutional elements of a perovskite type oxide and specified impurity elements at the grain boundary of a sintered body, said sintered body comprises an agglomerate of n type semiconductor particles and to a process for producing said composite function element. The composite function element has a composite function such that it acts as a varistor passing high voltages at a high voltage and as a capacitor passing the currents of abnormal frequency zone at a low voltage, so that the functions of two elements, a varistor and a capacitor, can be fulfilled simultaneously with only one element. Therefore, its extensive application in uses such as, for example, prevention of erroneous operation of microcomputer-controlled instruments can be expected.

Composite function element and process for producing the same

A ceramic composition of a high dielectric constant is provided, which consists of 100 mol parts of barium metatitanate (BaTiO.sub.3), (2/3)(7.+-.1) mol parts of cerium dioxide, and 7.+-.1 mol parts of titanium dioxide (TiO.sub.2), and to which 0.05 to 0.2 mol part of MnO.sub.2 is added. The ceramic composition has a ceramic microstructure in which a grain size is as small as 2 to 3 .mu.m and a pore size is small to be not more than 3 .mu.m. The ceramic composition has a high dielectric constant of about 10,000, a high breakdown voltage, and little dependency on voltage. The ceramic composition is very suitable as a thin dielectric film for a laminated ceramic chip capacitor.

Ceramic composition of high dielectric constant

Grain boundary layer dielectric ceramic compositions comprising semiconductive ceramic grains having a composition of 50.23 to 49.47 mol % of SrO and CaO, 49.72 to 50.23 mol % of TiO.sub.2, 0.05 to 0.3 mol % of Nb.sub.2 O.sub.5, substantially each of said grains being surrounded by grain boundary layer dielectric materials which are formed by grain boundary diffusion of a mixture having a composition of 93.5 to 8.5 mol % of Bi.sub.2 O.sub.3, 4.5 to 45 mol % of Cu.sub.2 O, 0.5 to 4 mol % of MnO.sub.2, 1 to 8.5 mol % of B.sub.2 O.sub.3, 0.5 to 17 mol % of La.sub.2 O.sub.3, and below 17 mol % of TiO.sub.2. These ceramic compositions provide capacitors having a temperature coefficient of capacitance less than .+-.15%, an apparent dielectric constant higher than 35,000, a dielectric loss less than 0.01 and a breakdown voltage higher than 500 V/mm; or capacitors having a temperature coefficient of capacitance less than .+-.10%, an apparent dielectric constant higher than 20,000, a dielectric loss less than 0.01 and a breakdown voltage higher than 700 V/mm; or capacitors having a temperature coefficient of capacitance less than .+-.5%, an apparent dielectric constant higher than 5,000, a dielectric loss less than 0.01 and a breakdown voltage higher than 700 V/mm.

Grain boundary layer dielectric ceramic compositions

Method for manufacturing a ceramic electronic component such as a voltage-dependent non-linear resistor element and a semiconductive ceramic capacitor is disclosed, in which a precisely uniform metal coating is formed on a surface of a ceramic and the metal coating is then heat treated to convert the metal of the metal coating to a metal compound to form a metal compound coating on the surface of the ceramic and/or diffuse a portion of or all of the metal coating into the ceramic, for attaining completely different electric properties than those of untreated ceramic. The present method is particularly useful in the application to a semiconductive ceramic capacitor.

Method for manufacturing a ceramic electronic component by electroless

A composition consisting of 5 to 95 mol% of bismuth oxide (Bi.sub.2 O.sub.3) and 95 to 5 mol% of copper oxide (Cu.sub.2 O), or a composition consisting of 50 to 95 mol% of copper oxide (Cu.sub.2 O) and 50 to 5 mol% of manganese dioxide (MnO.sub.2), or a composition consisting of 5 to 95 mol% of bismuth oxide (Bi.sub.2 O.sub.3) and 95 to 5 mol% of manganese dioxide (MnO.sub.2), is thermally diffused in the grain boundaries of semiconductor ceramics composed mainly of strontium titanate (SrTiO.sub.3) to form highly insulating layers in the grain boundaries to thereby provide semiconductive ceramics wherein the rate of change of dielectric constant with temperature as well as the dielectric loss (tan .delta.) are smaller than in the conventional barium titanate type semiconductor products. Further, the insulation resistance is higher than in the conventional product.

Semiconductive ceramics

Growing community of inventors

Hirakata, Japan

Gen Itakura