A multi-layer circuit board is formed by positioning a top sub having traces on at least one side to one or more pairs of composite layers, each composite layer comprising an interposer layer and a sub layer. Each sub layer which is adjacent to an interposer layer having an interconnection aperture, the interconnection aperture positioned adjacent to interconnections having a plated through via or pad on each corresponding sub layer. Each interposer aperture is filled with a conductive paste, and the stack of top sub and one or more pairs of composite layers are placed into a lamination press, the enclosure evacuated, and an elevated temperature and laminated pressure is applied until the conductive paste has melted, connecting the adjacent interconnections, and the boards are laminated together into completed laminated multi-layer circuit board.

A resin sheet that contains one or more kinds of resin materials and a liquid crystal polymer, wherein a weight of the liquid crystal polymer is less than a total weight of the one or more kinds of resin materials. The resin sheet has a thermal expansion coefficient in a plane direction smaller than a thermal expansion coefficient in the plane direction of a comparative resin sheet containing the one or more kinds of resin materials and not containing the liquid crystal polymer.

A wiring board unit capable of reducing the stress inside the wiring board to reduce the risk of a crack being formed from a location where stress is concentrated. To achieve this, the present invention includes a first wiring board and a second wiring board bonded to the first wiring board. A semiconductor element being resin-sealed on a surface side of the second wiring board opposite to a surface for bonding with the first wiring board. A tensile strength of an insulating resin material used for the second wiring board and a width of a Cu pattern formed on the side opposite to the first wiring board give a value smaller than 0.5 when substituted in Formula 1 below.

[00001]$\begin{array}{cc}\begin{array}{c}1/\left(1+\mathrm{Exp}\left(-A\right)\right)\\ A=-15\text{.45}-0.1654?\mathrm{Tensile}\mathrm{strength}+11.31?\log \left(\mathrm{Cu}\mathrm{pattern}\mathrm{width}\right)\end{array}& \left(1\right)\end{array}$

The invention provides transient printed circuit board devices, including active and passive devices that electrically and/or physically transform upon application of at least one internal and/or external stimulus.

An optical module includes a first board that includes a recessed portion and a first conductor layer, a second board accommodated in the recessed portion and includes an optical waveguide and a second conductor layer, a semiconductor element installed across the first board and the second board and coupled to the first conductor layer and the second conductor layer, and a first bonding material disposed between a sidewall and a bottom surface of the recessed portion and the second board so as to bond the first board and the second board to each other.

A multi-layered board includes: a middle conductive layer; a first dielectric layer that is disposed directly on a first surface of the middle conductive layer; a second dielectric layer that is disposed directly on a second surface of the middle conductive layer; a first outer surface conductive layer that is disposed directly on an outer side of the first dielectric layer; and a second outer surface conductive layer that is disposed directly on an outer side of the second dielectric layer. The first outer surface conductive layer serves as a first outer surface of the multi-layered board, and the second outer surface conductive layer serves as a second outer surface of the multi-layered board. The middle conductive layer is solidly formed over an entire planar direction of the multi-layered board. The first dielectric layer and the second dielectric layer each independently have a thickness variation of 15% or less.

A wiring substrate for electronic component inspection apparatus includes a first laminate which is formed by stacking a plurality of ceramic layers and which has a front surface and a back surface, and a plurality of studs joined to the back surface of the first laminate, wherein each of the studs is composed of a flange portion which is circular in bottom view, and a bolt portion which perpendicularly extends from a center portion of an outside surface of the flange portion; and in a vertical cross section along an axial direction of the bolt portion, the outside surface from which the bolt portion protrudes has a curved surface which is convex toward an inside surface of the flange portion facing the back surface of the first laminate.

A wiring substrate for electronic component inspection apparatus includes a first laminate which is formed by stacking a plurality of ceramic layers and which has a front surface and a back surface, and a plurality of studs joined to the back surface of the first laminate, wherein each of the studs is composed of a flange portion which is circular in bottom view, and a bolt portion which perpendicularly extends from a center portion of an outside surface of the flange portion; and the flange portion has a truncated conical shape and the outside surface from which the bolt portion protrudes, such that the outside surface slopes from the proximal end side of the bolt portion toward the peripheral edge of the flange portion and gradually approaches the inside surface of the flange portion.

An object of the present invention is to provide a multilayered printed wiring board provided with split through holes excellent in through-hole formability and co-planarity in inner layer wirings around through holes for providing of a conduction isolation portion. To achieve the object, a copper clad laminate provided with a protective layer for manufacturing of a printed wiring board having a conduction isolation portion electrically isolating a through hole, the copper clad laminate is characterized in that the copper clad laminate is provided with a protective layer on the surface that can be released after forming of the through holes for providing of a conduction isolation portion and filling of the through holes for providing of a conduction isolation portion by a plating resist is employed.

An electronic component includes a multilayer body including insulating base materials laminated on each other and including first and second main surfaces perpendicular or substantially perpendicular to a lamination direction, and an alignment mark is defined by a conductor on one of the insulating base materials. The multilayer body includes a first layer area at a side of the first main surface and a second layer area at a side of the second main surface with respect to the alignment mark. An insulating base material in the first layer area has higher translucency than an insulating base material in the second layer area. The alignment mark is a trapezoidal cross-sectional shape including a first base at the side of the first main surface and a second base at the side of second main surface, the first base being longer than the second base.