Printed wiring board

摘要

A printed wiring board includes a core insulation layer including a resin and having a via conductor through the core insulation layer, a first conductive layer formed on the core layer and including a copper foil and a plated film, an interlayer insulation layer formed on the first layer and including a resin, the interlayer layer having a via conductor through the interlayer layer, and a second conductive layer formed on the interlayer layer and including a copper foil and a plated film. The first layer includes a conductive circuit, the core and interlayer layers have dielectric constants of 4.0 or lower for signal transmission at frequency of 1 GHz and thermal expansion coefficient of 85 ppm/° C. or lower at or below Tg, and the foil of the first layer has thickness greater than thickness of the foil of the second layer.

主权项

1. A printed wiring board, comprising:
a core insulation layer comprising a resin and having a via conductor comprising a plating material filling a hole formed through the core insulation layer; a first laminated structure formed on a first surface of the core insulation layer and comprising a first conductive layer, an interlayer insulation layer and a second conductive layer; and a second laminated structure formed on a second surface of the core insulation layer on an opposite side of the first surface of the core insulation layer and comprising a first conductive layer, an interlayer insulation layer and a second conductive layer, wherein the first conductive layer of the first laminated structure is formed on the first surface of the core insulation layer, the interlayer insulation layer of the first laminated structure is formed on the first conductive layer of the first laminated structure, comprises a resin and has a via conductor comprising a plating material filling a hole formed through the interlayer insulation layer of the first laminated structure, the second conductive layer of the first laminated structure is formed on the interlayer insulation layer of the first laminated structure, the first conductive layer of the second laminated structure is formed on the second surface of the core insulation layer, the interlayer insulation layer of the second laminated structure is formed on the first conductive layer of the second laminated structure, comprises a resin and has a via conductor comprising a plating material filling a hole formed through the interlayer insulation layer of the second laminated structure, the second conductive layer of the second structure is formed on the interlayer insulation layer of the second laminated structure, each of the first conductive layers of the first and second laminated structures includes a conductive circuit, each of the second conductive layers of the first and second laminated structures has a conductive circuit connected to the conductive circuit in a respective one of the first conductive layers of the first and second laminated structures through the via conductor in a respective one of the interlayer insulation layers of the first and second laminated structures, each of the core insulation layer and the interlayer insulation layers has a dielectric constant of 4.0 or lower at a signal frequency of 1 GHz and a thermal expansion coefficient of 85 ppm/° C. or lower at or below Tg, the via conductor in the interlayer insulation layer of the first laminated structure is positioned such that the via conductor in the interlayer in the interlayer insulation layer of the second laminated structure is positioned such that the via conductor in the interlayer insulation layer of the second laminated structure is stacked on the via conductor in the core insulation layer, and the via conductor in the interlayer insulation layer of the first laminated structure and the via conductor in the core insulation layer are tapered in a direction opposite to a tapering direction of the via conductor in the interlayer insulation layer of the second laminated structure.