Showa Aluminum Corporation

Showa Denko K.k.

Other

Showa Denko Packaging Co., Ltd.

Showa Aluminum Kabushiki

Kiyoshi Tada

Kurata Awaya

Kenji Tomita

Tomoya Utashiro

Masashi Sakaguchi

Tadao Fujihira

Kazuyoshi Nishizawa

Takashi Tamura

Satoshi Yamazaki

Eizo Isoyama

Daisuke Hashimoto

Kenji Tsukamoto

Norihiko Miyata

Shigetoshi Jogan

Tatsuo Otsuka

Hisatsugu Nakaya

Shozo Umetsu

Makoto Tanio

The present invention is to provide a positive tab lead capable of being connected with each other with a sufficient connection strength at a low energy cost. It is constituted such that a partial coating layer () made of nickel, tin or solder is formed on at least a part of a region of an aluminum plate () exposed to an outside of an outer cover. It is preferable to form a chitosan layer () containing one or more compounds selected from the group consisting of chitosan and chitosan derivatives on the surface of the tab lead.

Positive electrode tab lead, negative electrode tab lead, and battery

A cooling plate provided with a cooling medium passage therein is formed by integrally joining a plurality of metal plates each having a cooling medium passage forming groove on a joining surface thereof. An anodic oxide film is formed on at least the cooling medium passage forming groove on the joining surface, and the plurality of metal plates are integrally joined each other by a friction agitation joining method. This enhances corrosion resistance of the cooling medium passage, resulting in an improved durability and extended life, which enables uniform cooling performance.

Cooling plate and production method therefor

The present invention provides an abrasive composition for polishing magnetic recording disk substrates that results in a low surface roughness of the magnetic recording disk, allows the attaining of high-density recording without the occurrence of protrusions or polishing scratches, and enables polishing to be performed at an economical speed. The present invention discloses an abrasive composition for polishing magnetic recording disk substrates comprising water, silicon dioxide, antigelling agent, aluminum nitrate and hydrogen peroxide.

Abrasive composition for polishing magnetic recording disk substrates

A magnetic hard disc substrate made of an aluminum alloy for memory devices such as a computer must correspond to an improved structure in which the interval between a head and a medium is made narrower to attain high density recording. In order to prevent head crash, it is required that the magnetic hard disc substrate have a smooth surface and decreased defects. The present invention provides a process for manufacturing a magnetic hard disc substrate made of an aluminum alloy which satisfies the above requirements and also provides a disc substrate which has a surface roughness Ra&lE;0.5 nm and is free from abrasive flaws with a depth of 5 nm or more and from micro-waviness or provides a disc substrate which has a surface roughness Ra&lE;5 angstroms and a surface roughness Rmax&lE;80 angstroms and in which the number of scratches with a depth of 50 angstroms or more is 5 or less and the number of pits with a depth of 50 angstroms or less is 5 or less in the surface.

Magnetic hard disc substrate and process for manufacturing the same

Magnetic disk substrates are produced by subjecting glass substrates to at least steps of degreasing, etching, sensitization with tin chloride, activation and sensitivity-enhancing treatment in that order, then plating the pretreated substrates with a nickel/phosphorus film, and thereafter polishing the plated substrates. In the process, the substrates being processed are washed with hot pure water at a temperature of not lower than 50&deg; C. for a period of from 20 to 90 seconds, after the sensitization step but before the activation step, and heated at a temperature of not lower than 70&deg; C. for a period of from 5 to 100 minutes, after the sensitization step but before the nickel/phosphorus-plating step.

Method for producing magnetic disk substrates

A provision of a magnetic disk substrate using, as a plated substrate, glass with high hardness in place of aluminum. The magnetic disk substrate is small-sized, can stand against an impact when it is carried, and avoids leaving struck damages (head snap) even if it is used for recent note- or mobile-type computers having a head which is located as closely as possible to the substrate. The magnetic disk substrate comprises forming a nickel/phosphorus coating with a film thickness of 8 &mgr;m-20 &mgr;m or less on crystallized glass with a roughness Ra of 0.05 to 0.5 &mgr;m, the roughness being measured by a tracer and contact type roughness meter after the glass is ground (lapped) and polishing the nickel/phosphorus coating to a depth of 3 &mgr;m or more in a polishing process with the thickness of the plating film left unremoved being 5 &mgr;m or more.

Magnetic disk substrate

A magnetic hard disc substrate made of an aluminum alloy for memory devices such as a computer must correspond to an improved structure in which the interval between a head and a medium is made narrower to attain high density recording. In order to prevent head crash, it is required that the magnetic hard disc substrate have a smooth surface and decreased defects. The present invention provides a process for manufacturing a magnetic hard disc substrate made of an aluminum alloy which satisfies the above requirements and also provides a disc substrate which has a surface roughness Ra.ltoreq.0.5 nm and is free from abrasive flaws with a depth of 5 nm or more and from micro-waviness or provides a disc substrate which has a surface roughness Ra.ltoreq.5 angstroms and a surface roughness Rmax.ltoreq.80 angstroms and in which the number of scratches with a depth of 50 angstroms or more is 5 or less and the number of pits with a depth of 50 angstroms or less is 5 or less in the surface.

An aluminum foil to be etched for use as the electrolytic condenser electrodes is composed of a foil body of an aluminum purity of 99.9% or higher, and an oxide layer 20-70 .ANG. thick and formed due to contact of the foil body with an oxidizing atmosphere. At least one etching nuclei-forming element is concentrated in a boundary region and/or in an outermost surface region of the oxide layer, the boundary region being disposed between the foil body and the oxide layer, and both the regions having a thickness of 20 .ANG. or less. The ratio in ion intensity of a maximum concentration of the elements in these regions to a concentration of the elements in the inner layer of the foil body is 1.2-30. There are three patterns in distribution of the elements, so that the maximum concentration is in a predetermined ratio to the concentration in the surface region, the inner layer or a minimum concentration appearing between the regions. The foil will be etched to be ready for use as the electrolytic condenser electrodes.

Aluminum foil as electrolytic condenser electrodes

Aluminum foils used as a material of electrodes in electrolytic capacitors are manufactured by a method which comprises a step of forming at first an initial internal oxide coating 5 to 50 .ANG. thick on the surface of the aluminum foils before they are electrochemically or chemically etched later. The aluminum foils are then subjected to high temperature heat treatment such that the whole thickness of the oxide coating does not exceed 70 .ANG..

Method for manufacturing aluminum foils used as electrolytic capacitor

A substrate for amorphous silicon solar cells comprises an aluminum or aluminum alloy plate which is formed on at least one surface thereof with an oxalic acid anodized film in an unsealed state and having a thickness of 1 to 20 .mu.m. A plurality of amorphous silicon solar cells provided on the substrate include lower electrodes of chrominum or the like which are formed on the anodized film. The lower electrodes are electrically insulated from one another by the anodized film.

Growing community of inventors

Oyama, Japan

Kiyoshi Tada