According to one embodiment, a metal base circuit board includes a metal base substrate, a first circuit pattern, and a first insulating layer between the metal base substrate and the first circuit pattern. The first insulating layer covers a lower surface of the first circuit pattern and at least part of a side surface of the first circuit pattern, the lower surface facing the metal base substrate, the at least part of the side surface being adjacent to the lower surface.

A method for producing a wired circuit board, including an insulating layer having a first through portion passing through in a thickness direction thereof and a first terminal portion having a second through portion overlapped with the first through portion when projected in the thickness direction, includes the steps of providing a first bonding material at one surface in the thickness direction of the first terminal portion and allowing the first bonding material to flow from the one surface in the thickness direction of the first terminal portion toward the other surface in the thickness direction thereof into the second through portion by allowing the first bonding material to flow.

The thermosetting resin composition, a prepreg containing same, a metal foil-clad laminate and a printed circuit board; the resin composition comprises the following components: a combination of a bismaleimide resin and a benzoxazine resin or a prepolymer of a bismaleimide resin and a benzoxazine resin, an epoxy resin and an active ester. A metal foil-clad laminate prepared by using the resin composition provided by the present invention has a high glass transition temperature, a low thermal expansion coefficient, a high high-temperature modulus, a high peel strength, a low dielectric constant, a low dielectric loss factor, as well as good heat resistance and good processability.

A flexure includes a metal substrate whose front end supports a slider and a wiring part having a base insulating layer and a conductor layer formed on the base insulating layer. The wiring part includes a normal wiring part that is on the metal substrate and an aerial wiring part that is on a space separated from the metal substrate. The base insulating layer of the aerial wiring part is formed to be thinner than that of the normal wiring part. This configuration reduces a rigidity contribution ratio of the wiring part.

A wiring substrate for improving connection reliability with an electronic component, a component embedded substrate that incorporates an embedded component into the wiring substrate, and a package structure including an electronic component mounted on the wiring substrate or the component embedded substrate. The wiring substrate includes a metal plate, and a wiring layer including a plurality of insulating layers and a conductive layer arranged on the plurality of insulating layers arranged on at least one principal surface of the metal plate. The plurality of insulating layers includes a first insulating layer to contact the principal surface of the metal plate and has a larger thermal expansion rate in the planar direction than the metal plate and a second insulating layer which is laminated on the first insulating layer to contact the first insulating layer and has smaller thermal expansion rate in the planar direction than the metal plate.

A dielectric tape suitable for use in an electronic device is provided. A dielectric slip composition comprises an organic vehicle and a dielectric glass composition comprising at least about 20 wt % and no more than about 50 wt % silicon dioxide, based upon 100% total weight of the glass composition, at least about 10 wt % and no more than about 50 wt % alkali metal oxides, based upon 100% total weight of the glass composition, and at least about 1 wt % and no more than about 10 wt % of at least one transition metal oxide. A method of forming an electronic device is also provided. The method includes the steps of applying at least one dielectric tape to at least one non-planar surface of a substrate, and subjecting the at least one dielectric tape to one or more thermal treatment steps to form a dielectric layer.

A three-dimensional molded circuit component, includes: a base member which includes a metal part and a resin part; a circuit pattern which is formed on the resin part; and a mounted component which is mounted on the base member, and is electrically connected to the circuit pattern. The resin part includes a resin thin film as a portion thereof, which includes a thermoplastic resin, of which a thickness is in the range of 0.01 mm to 0.5 mm, and which is formed on the metal part. The mounted component is arranged on the metal part via the resin thin film.

A first insulating layer is formed on a support substrate. The first insulating layer includes a first portion and a second portion. The second portion has a thickness smaller than that of the first portion. A ground layer having electric conductivity higher than that of the support substrate is formed on the second portion of the first insulating layer. The ground layer is electrically connected to the support substrate. A second insulating layer is formed on the first insulating layer to cover the ground layer. A write wiring trace is formed on the second insulating layer to overlap with the first portion and the second portion of the first insulating layer.

Provided is a wiring thin plate capable of suppressing deterioration of an electric characteristic and variation in thickness of an aerial wiring portion while advancing reduction of rigidity of the aerial wiring portion. The wiring thin plate includes an aerial wiring portion including wiring traces and passing over an airspace, aerial base layers provided at the respective wiring traces in the aerial wiring portion and being apart from each other, and an aerial cover layer provided in the aerial wiring portion and spanning from the wiring traces of the aerial wiring portion through the aerial base layers to interspaces between adjacent aerial base layers of said aerial base layers.

The invention is directed to a metal core substrate having high thermal conductivity and high electrical insulating properties; an electrophoretic deposition fluid for use in fabrication of the metal core substrate; and a method for fabricating the metal core substrate. The electrophoretic deposition fluid is used during electrophoretic deposition, and contains ceramic particles for coating a metal substrate, and an organopolysiloxane composition which binds the ceramic particles.