Hitachi, Ltd.

Other

Hitachi Chemical Company, Ltd.

Masanori Nemoto

Akio Takahashi

Mineo Kawamoto

Hideki Asano

Masao Suzuki

Tokihito Suwa

Satoru Amou

Shiro Kobayashi

Masashi Miyazaki

Mitsuo Yokota

Hiroyuki Fukai

Shuji Eguchi

Toshikazu Narahara

Masatsugu Ogata

Seikichi Tanno

Junichi Katagiri

Yoshiaki Okabe

Noriaki Taketani

Morimichi Umino

Kenichi Hironaka

Yoshinori Kawai

Hirokazu Takasaki

Tetuo Ishikawa

Tuneo Narusawa

Yoshimitsu Mihara

Yukihiko Takada

A multilayer circuit board having a resolution in the range of 25-80 &mgr;m, and blind via-holes between layers, the blind via-holes having an aspect ratio in the range of 2.0-0.6 for effecting access between the layers, wherein an insulating layer having the blind via-holes between the layers has a glass transition temperature in the range of 150-220&deg; C., and an epoxy group photosensitive resin composition is used therefor. A photosensitive resin composition having a preferable resolution and heat resistance is obtained. A multilayer circuit board is provided in which the thermal stress generated in the steps of a reflow process, a gold wire bonding process and a repairing process in a bare chip mounting process are reduced, and peeling off of the conductor wiring and deformation of the multilayer circuit board caused by mechanical stresses during the heating processes are suppressed. Accordingly, a decrease in the size and weight of an electronic apparatus is possible.

Multilayer circuit board having insulating layer with via-holes

A multilayer circuit board having a resolution in the range of 25-80 .mu.m, and blind via-holes having an aspect ratio in the range of 2.0-0.6 for effecting access between the layers, wherein an insulating layer between said layers having the blind via-holes has a glass transition temperature in the range of 150-220.degree. C., and an epoxy group photosensitive resin composition is used therefor. A photosensitive resin composition having a preferable resolution and heat resistance is obtained. A multilayer circuit board is provided in which the thermal stress generated in the steps of a reflow process, a gold wire bonding process and a repairing process in a bare chip mounting process was reduced, and peeling off of the conductor wiring and deformation of the multilayer circuit board caused by mechanical stresses during the heating processes were suppressed. Accordingly, a decrease in the size and weight of an electronic apparatus is possible.

Multilayer circuit board and photosensitive resin composition used

A photosensitive resin composition for use in manufacture of multi-layer circuit boards with connecting holes between layers is disclosed. The resin composition has excellent adhesion with a plating metal, resolution, photo-curing, thermosetting, thermal resistance, and is capable of being developed using an alkaline solution or an aqueous solution containing a non-halogen based organic solvent as the developing solution. The resin composition comprises a photosensitive epoxy resin, a thermosetting epoxy resin, a reactant of a carboxylic acid added to an acrylonitrile-butadiene rubber and an epoxy resin, a photo-polymerization initiator and a thermosetting agent. This reactant facilitates a high density pattern of connecting holes for circuit boards of the layered type.

Photosensitive resin composition and method for using the same in

This invention comprises unifying circuits with a base on which mechanical parts are mounted and relates to a mechanical part mounting chassis provided with a substrate and a circuit buried in the substrate and/or spread out on the substrate surface.

Mechanical part mounting chassis with integrated circuit

A molded part including a metal plate formed with a plurality of through holes, a plurality of resin portions connected to a resin filled in the through holes and protruding on opposite sides of the metal plate, the resin portions having a planar cross section larger than a cross section of the through holes, and a plurality of resin components each integrally formed with one of the resin portions. The resin components are secured in place on the metal plate separate from and independent of each other by virtue of residual thermal stress produced by the difference in the coefficient of thermal expansion between the resin portions and the metal plate in such a manner that a radially oriented residual thermal stress in each resin portion is symmetrical with respect to a center axis of one of the resin components.

Molded part and method of making the same

A chassis for video tape recorder molded integrally with a fiber-reinforced plastic composition is light in weight and can meet the requirements for attainment of high precision. It is possible to obtain a chassis with even higher precision and higher rigidity while preventing deformation with time as well as creep deformation, by properly selecting the components of the composition, the number and the position of the gates, and/or the reinforcing measures. In case of using glass fiber as the reinforcing fiber component of the composition, it is desirable to use the type in which 5% by weight or more of the whole glass fiber component is occupied by those glass fibers which have a length of over 1.0 mm and a diameter of 15 .mu.m or less.

Chassis for video tape recorder

A resin molded stator comprising a stator core and coils as major constituents at least parts of which are molded into one piece by a molding material, said molding material comprising (a) a low-shrink unsaturated polyester resin, (b) a filler having a particle size of 44 .mu. or less, and (c) a fibrous material having a length of 3 mm or less, in proportions of 15 to 40% by weight of the component (a) and 60 to 85% by weight of a total of the components (b) and (c), and a weight ratio of the component (b) to the component (c) being 3/1 to 30/1, is excellent in crack resistance, moisture resistance and insulating properties.

Resin molded stators

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Ibaraki, Japan

Masanori Nemoto