Sumitomo Electric Industries, Limited

Osaka University

Yasuhisa Yushio

Hirohiko Nakata

Masuhiro Natsuhara

Motoyuki Tanaka

Kazutaka Sasaki

Akira Yamakawa

Masaya Miyake

Hisao Takeuchi

Akira Sasame

Hitoyuki Sakanoue

Yasuhiro Murase

Kiichi Fukui

Tsutomu Kohinata

Satoshi Tabata

Hitoshi Akazawa

Naoki Ikeguchi

Joyce Cartagena

Shunji Nagao

Naoki Wada

Akira Shinkoda

A PPAT polypeptide of SEQ ID NO: 1 derived from, a PPAT polynucleotide of SEQ ID NO: 2 and so on were found. By transformingwith these PPAT polynucleotides, it is possible to overexpress the PPAT polypeptide in comparison with a wild type, and biosynthesis of coenzyme A is promoted by these polypeptides, the metabolic function and viability of the transformedare enhanced, and for example, stress resistance can be significantly improved.

Polynucleotide encoding PPAT derived from jatropha and use thereof

A susceptor for semiconductor manufacturing equipment obtained by laminating plural aluminum nitride (AlN) ceramic substrates with a high melting point metallic layer and an adhesive layer, and in particular, the aluminum nitride (AlN) ceramic substrate contains a compound of a Group 3 element in an amount of from 0.01 to 1% by weight in terms of the element, and the balance consisting essentially of aluminum nitride (AlN), in which the average particle size of an AlN crystal is from 2 to 5 &mgr;m. The susceptor is prepared by obtaining substrates from a mixture of the material powders through the steps of molding, sintering in a non-oxidizing atmosphere at 1,600 to 2,000&deg; C. and forming into a desired substrate shape, and then laminating a plurality of the thus obtained substrate with a high melting point metallic layer and an adhesive layer inserted between the substrates, firing the laminate in a non-oxidizing atmosphere at 1,500 to 1,700&deg; and finishing the fired laminate.

Susceptor for semiconductor manufacturing equipment and process for producing the same

The circumferential edge portion of a ductile rotating body containing abrasive grains is used to polish the surface of a ceramic substrate. The angle &thgr; formed between the polishing direction D of the ceramic substrate and the rotating direction D , of the rotating body is set in the range from 10&deg; to 80&deg; for the polishing step. Alternatively, the polishing process is divided into at least two steps. and the average grain size of abrasive grains is reduced stepwise in the successive steps of the polishing process. According to this method, the surface of a large-area and thin ceramic substrate can be polished without damage, and a smooth polished ceramic surface can be provided. This method is particularly suitable for polishing a ceramic substrate having a thickness of at most 2.0 mm, and the resulting polished ceramic substrate is suitable for a ceramic heater in a thermal fixation device for fixing a toner image.

Method of polishing a ceramic substrate

The circumferential edge portion of a ductile rotating body containing abrasive grains is used to polish the surface of a ceramic substrate. The angle &thgr; formed between the polished direction D of the ceramic substrate and the rotating direction D of the rotating body is set in the range from 10&deg; to 80&deg; for the polishing step. Alternatively, the polishing process is divided into at least two steps, and the average grain size of abrasive grains is reduced stepwise in the successive steps of the polishing process. According to this method, the surface of a large-area and thin ceramic substrate can be polished without damage, and a smooth polished ceramic surface can be provided. This method is particularly suitable for polishing a ceramic substrate having a thickness of at most 2.0 mm, and the resulting polished ceramic substrate is suitable for a ceramic heater in a thermal fixation device for fixing a toner image.

Ceramic substrate and polishing method thereof

Provided is an aluminum nitride sintered body excellent in thermal shock resistance and strength and applicable to a radiating substrate for a power module or a jig for semiconductor equipment employed under a strict heat cycle. An aluminum nitride sintered body obtained with a sintering aid of a rare earth element and an alkaline earth metal element contains 0.01 to 5 percent by weight of an alkaline earth metal element compound in terms of an oxide and 0.01 to 10 percent by weight of a rare earth element compound in terms of an oxide, and the amount of carbon remaining in the sintered body is controlled to 0.005 to 0.1 percent by weight, thereby suppressing grain growth and improving thermal shock resistance and strength of the sintered body.

Aluminum nitride sintered body and method of preparing the same

An aluminum-nitride sintered body that has both high thermal conductivity and high mechanical strength, a fabricating method for the same, and a semiconductor substrate comprising the same. A material powder is prepared by mixing an aluminum-nitride powder, constituting 1 to 95 wt. %, having an average particle diameter of 1.0 &mgr;m or less obtained by chemical vapor deposition, with another type or types of aluminum-nitride powders constituting the remaining part. The material powder is sintered in a non-oxidizing atmosphere to obtain a sintered body having an average grain diameter of 2 &mgr;m or less and a half width of the diffraction peak on the (302) plane, obtained by X-ray diffraction, of 0.24 deg. or less. Formation of a metallized layer on the sintered body yields a semiconductor substrate.

Aluminum-nitride sintered body, method for fabricating the same, and semiconductor substrate comprising the same

An aluminum nitride sintered body has excellent thermal shock resistance and strength, and is applicable to a radiating substrate for a power module or a jig for semiconductor equipment employed under a strict heat cycle. The aluminum nitride sintered body contains 0.01 to 5 percent by weight of an alkaline earth metal element compound in terms of an oxide and 0.01 to 10 percent by weight of a rare earth element compound in terms of an oxide, respectively as sintering aids, and a residual amount of carbon in a range from 0.005 to 0.1 percent by weight, thereby suppressing grain growth and improving thermal shock resistance and strength of the sintered body.

A sintered aluminum nitride body comprising aluminum nitride as the main component and containing a calcium compound, an ytterbium compound, and a neodymium compound. Due to the use of the above calcium-yttrium-neodymium ternary sintering aid, the sintered aluminum nitride body can be obtained by firing a compact of the raw material powder at a low temperature after degreasing the compact without cracking and has evenness of in color, strength and thermal conductivity. The sintered aluminum nitride body provides an inexpensive, high-quality metallized substrate for electronic parts by forming a high-melting metallizing layer of W and/or Mo. Onto the aluminum nitride body, an Ag metallizing layer including oxides of Zn and Cu or an Ag-Pd metallilzing layer including oxides of B, Pb, Cr and Ca and, if necessary, further an insulating vitreous layer may be formed.

Sintered aluminum nitride body and metallized substrate prepared therefrom

A ceramic heater includes a substrate (1) consisting of an aluminum nitride sintered body, and a heating element (2) and a feed electrode (3), mainly composed of silver or a silver alloy, formed on a surface of the substrate (1). The aluminum nitride sintered body contains a group IIa or IIIa element in the periodic table or a compound thereof and silicon or a silicon compound of 0.01 to 0.5 percent by weight in terms of the silicon element, and preferably further contains a group VIII transition element or a compound thereof by 0.01 to 1 percent by weight in terms of the element.

Aluminum nitride heater

A heater for fixing a toner image suffers no cracking of the ceramics substrate, thereof has a high connection reliability between an electrode and a connector thereof, and capable of attaining an improved fixing speed and a size increase of a transfer material. The heater, which is adapted to heat and fix a toner image on a transfer material, comprises a ceramics substrate containing silicon nitride and a heat generator formed on the ceramics substrate. The thermal conductivity and the transverse rupture strength of the silicon nitride forming the ceramics substrate are preferably at least 40 W/mK and at least 50 kg/mm.sup.2 respectively, and the thickness of the ceramics substrate can be reduced to 0.1 to 0.5 mm.

Ceramic fixing heater containing silicon nitride

A connection structure between lead frames and a base plate of aluminum nitride, to be applied as a connection structure between components of a semiconductor apparatus, has a base plate made of a sintered body of aluminum nitride on which a semiconductor device is to be mounted. The lead frames are made of iron alloy containing nickel in 29 wt. % and cobalt in 17 wt. %. A silver solder is used for joining the base plate and the lead frames. A surface of the lead frame to be joined to the base plate is clad with a stress relief layer of oxygen-free copper of a high plastic deformability to relieve, by its plastic deformation, a thermal stress caused by a difference between a thermal expansion coefficient of the aluminum nitride base plate and that of the lead frame in a cooling process at the time of soldering. Preferably, only a portion of each lead frame to be joined to the base plate comprises an inner layer of an iron alloy containing 29 wt. % of nickel and 17 wt. % of cobalt, and an outer layer portion of oxygen-free copper.

Connection structure between components for semiconductor apparatus

A member for a semiconductor apparatus for carrying or holding a semiconductor device, obtained by joining an aluminum nitride substrate and a radiating substrate, comprises an insulating member formed by an aluminum nitride sintered body to be provided thereon with the semiconductor device, a radiating member to be joined to the insulating member, which radiating member is mainly formed of a copper-tungsten alloy or a copper-molybdenum alloy, a stress relieving member interposed between the insulating member and the radiating member and a silver solder member for joining the insulating member, the stress relieving member and the radiating member with each other. The stress relieving member is prepared by copper or a copper alloy, implementing a soft metal or a soft alloy having high plastic deformability, in order to relax, by its own plastic deformation, thermal stress caused by difference in thermal expansion coefficient between the insulating member and the radiating member in a cooling step upon soldering.

Growing community of inventors

Itami, Japan

Yasuhisa Yushio