Kyocera Corporation

Keio University

Yoshitake Terashi

Shinya Kawai

Masahide Akiyama

Hiromi Iwachi

Nobuki Hiramatsu

Takeshi Okamura

Hiroshi Uchimura

Ken Uchida

Akinori Sato

Kazuki Hayata

Hironori Kii

Takashi Shigehisa

Katsuhiko Onitsuka

Yasuhide Tami

Hideto Yonekura

Shoji Yamashita

Masanari Kokubu

Takahiko Makino

Tetsuya Kimura

Hitoshi Kumatabara

Satoru Hamano

Tsutae Iryo

Kazuyoshi Kodama

Masahiro Tomisako

Satoshi Hamano

Shinichi Kazama

Nobuya Kawai

Jiwang Yan

Toshiki Suhara

A resin composition for semiconductor encapsulation, containing (A) an epoxy resin, (B) a phenolic resin-based curing agent, (C) an inorganic filler, and (D) amorphous carbon, wherein the amorphous carbon of the component (D) contains 30 atomic % or more of an SPstructure and 55 atomic % or less of an SPstructure.

Resin composition for semiconductor encapsulation and semiconductor device

[Object] To efficiently recover tungsten from an object containing tungsten by a simple treatment process using a microorganism with reduced environmental load. [Solution] A method for recovering a tungsten compound is provided which includes the step of preparing a tungsten compound solution in which tungsten-containing polyatomic ions are dissolved, by eluting the metal component of an object containing tungsten into an alkaline solution; the adsorption step of adsorbing the tungsten-containing polyatomic ions to a microorganism by introducing the microorganism to the tungsten compound solution and adjusting the tungsten compound solution to an acidic level; and the collecting and washing step of collecting the microorganism to which the tungsten-containing polyatomic ions are adsorbed and washing the microorganism.

Method for recovering tungsten compound

A NRD guide includes a pair of parallel plate conductors opposed to each other at a spacing equal to or shorter than half the wavelength of a high-frequency signal to be transmitted and having opposing inner surfaces whose arithmetic average roughness Ra satisfies 0.1 &mgr;m&lE;Ra&lE;50 &mgr;m, and a dielectric strip arranged between the pair of parallel plate conductors and held in contact with the respective inner surfaces of the parallel plate conductors. The dielectric strip is strongly secured to the inner surfaces to exhibit an excellent durability. The transmission loss of the high-frequency signal can be effectively suppressed.

Nonradiative dielectric waveguide and a millimeter-wave transmitting/receiving apparatus

Ceramics comprising filler crystal particles having an average particle diameter of not smaller than 2.5 &mgr;m and a matrix crystal phase present on the grain boundaries of the filler crystal particles, the filler crystal particles being Al O and the matrix crystal phase being diopside-type oxide crystals precipitated from the crystallized glass. The ceramics has a dielectric loss tangent at 60 to 77 GHz of not higher than 50&times;10 , and can be effectively used as an insulating substrate in a wiring board for transmitting high-frequency signals.

Ceramics having excellent high-frequency characteristics and method of producing the same

Ceramics containing a diopside crystal phase and a cordierite phase, the remainder being a glass phase and/or other ceramic crystal phases, and having an open porosity of not larger than 1%. The ceramics is obtained by firing at from 800 to 1050&deg; C., and exhibits a dielectric constant of not larger than 7 and a small dielectric loss in a high-frequency region, a ceramic strength of not smaller than 250 MPa, and a coefficient of thermal expansion close to those of the chips such as of Si and Ga&mdash;As and of the printed board.

Ceramics and method of preparing the same

The porcelain of the present invention comprises 5 to 70% by weight of a non-oxide ceramic filler and 30 to 95% by weight of a borosilicate glass having a glass transition temperature of 800&deg; C. or lower, wherein a weight loss per unit surface area of said non-oxide ceramics is not more than 0.15 g/cm after dipping said non-oxide ceramic having purity of not less than 96% by weight for five minutes in a glass melt obtained by melting said borosilicate glass with heating at 1200&deg; C. Since the porcelain composition can be fired at a low temperature together with a low-resistance metal, the resulting porcelain has a high thermal conductivity, a low dielectric constant, a high heat dissipation property and a reduced apparent signal delay in a high frequency signal and is suited for use as an insulating board in a wiring board.

Porcelain composition, porcelain and method of producing the same, and wiring board and method of producing the same

Glass ceramic sintered product

High-frequency ceramics containing SiO , Al O , MgO, ZnO and B O as constituent components, said ceramics comprising: 30 to 50% by weight of a crystal phase containing ZnO and Al O ; 5 to 15% by weight of a crystal phase containing SiO and MgO; and 40 to 60% by weight of an amorphous phase comprising substantially SiO or SiO and B O ; wherein the content of the SiO crystal phase is suppressed to be not larger than 6% by weight. The ceramics has a dielectric loss at 60 GHz of not larger than 15&times;10 , exhibiting excellent high-frequency characteristics, and is very useful as an insulating substrate for the wiring boards that deal with high-frequency signals.

Dielectric ceramics comprising a diopside oxide crystal phase, at least one kind of crystal phase selected from the group consisting of a quartz crystal phase and a composite oxide crystal phase containing Ti and Mg or Zn, and a glass phase of an amount of not larger than 30% by weight, said dielectric ceramics having a coefficient of thermal expansion of not smaller than 5.5 ppm/&deg; C. at room temperature to 400&deg; C. and a dielectric loss of not larger than 30&times;10,at 60 to 77 GHz. The ceramics can be obtained by the co-firing with a low-resistance metal such as copper or silver, and can be advantageously used for the production of wiring boards to which the signals of particularly high frequencies are applied. The ceramics has a large coefficient of thermal expansion which can be brought close to the coefficient of thermal expansion of the semiconductor element such as of GaAs or of the printed board. The wiring board produced by using the ceramics effectively prevents breakage in the mounting portion of the wiring board that is caused by a difference in the thermal expansion.

Dielectric ceramics

Ceramics for wiring boards having an SiO,crystal phase, a spinel type oxide crystal phase containing Mg or Zn and Al and a composite oxide type crystal phase containing at least Sr, Al and Si, and having a coefficient of thermal expansion of not smaller than 5.5 ppm/&deg; C. at room temperature through up to 400&deg; C., a dielectric constant of not larger than 7, and a dielectric loss of not larger than 50&times;10,at 20 to 30 GHz. The ceramics can be obtained by the co-firing with a low-resistance metal such as copper or silver, and can be advantageously applied for the production of a wiring board for treating, particularly, signals of high frequencies. Furthermore, the ceramics has a coefficient of thermal expansion which is so large as can be brought close to the coefficient of thermal expansion of the semiconductor element such as GaAs or of the printed board. Therefore, the wiring board produced by using the ceramics makes it possible to effectively prevent the mounting portions from being damaged by the difference in the thermal expansion.

Ceramics for wiring boards and method of producing the same

The ceramic sintered body of this invention contains at least 14.9% by weight of Si calculated as SiO.sub.2, 1 to 84.9% by weight of Zn calculated as ZnO, 0.1 to 15% by weight of B calculated as B.sub.2 O.sub.3 and 0.1 to 10% by weight of Li calculated as Li.sub.2 O, and especially, a quartz crystal phase and a willemite crystal phase are precipitated. This sintered body has low dielectric constant and low dielectric loss in a high frequency region, and the thermal expansion coefficient at room temperature to 400.degree. C. can be adjusted to 1.5 to 17 ppm/.degree. C. For this reason, this sintered body is extremely useful as an insulated substrate for use in a wiring board for transmitting high frequency signals.

Ceramic sintered body and a process for its production

The insulated board of this invention is a sintered body of a complex oxide containing Si, Al, Mg, Zn and B as constituent elements. This sintered body contains a spinel crystal phase containing at least ZnO and Al.sub.2 O.sub.3 and a quartz crystal phase. Since the amorphous phase does not substantially contain ZnO, Al.sub.2 O.sub.3 or MgO, the sintered body has a low dielectric loss of 30.times.10.sup.-4 or below and a dielectric constant of 30 or below at a frequency of 15 to 20 GHz. As a result, by forming a wiring layer on the surface or the inside of the insulated board of this invention, the insulated board can transmit high frequency signals at a low loss as the wiring layer.

Insulated board for a wiring board

Dielectric ceramics comprising 85 to 99.95% by weight of a Zn-containing composite oxide of which the composition of constituent metals is represented by the following formula (1) as expressed by atomic ratios:

Electrically conducting ceramics having, as a chief crystalline phase, a perovskite crystalline phase containing La, Cr and Mg and further having, in addition to the chief crystalline phase, an oxide phase containing La, wherein when the atomic ratios among the rare earth element, Mg and Cr in said chief crystalline phase are represented by the following formula,

Electrically conducting ceramics, process for producing the same and

A glass-ceramic sintered body containing Si, Al, Zn, element of Group 2a and Group 4a of the periodic table, and Boron and Oxygen, as constituent elements, and comprising a glass phase and crystalline phases, wherein the crystalline phase comprises a first crystalline phase of a composite oxide containing at least Si, Al and Ca or Sr, or, Si, Al, Ca and Sr, a second crystalline phase of ZrO.sub.2 crystalline and a third crystalline phase of spinel crystalline is presented. The glass-ceramic sintered body has a high dielectric constant of not smaller than 8.5 and have a fracture strength of not smaller than 20 kg/mm.sup.2 and preferred as an insulation substrate of a circuit board, a substrate board for mounting an integrated circuit or an electronic compornent part.

Growing community of inventors

Kokubu, Japan

Yoshitake Terashi