Sumitomo Electric Industries, Limited

Sumitomo Electric Printed Circuits, Inc.

Masashi Iwamoto

Koji Nitta

Shoichiro Sakai

Junichi Motomura

Mitsutaka Tsubokura

Akira Tsuchiko

Mari Sogabe

A printed wiring board includes a base layer having insulating properties, a first conductive layer directly or indirectly stacked on the base layer front surface, and including a copper foil, a second conductive layer directly or indirectly stacked on the base layer back surface, and including a copper foil, a stacked body for a via hole, the stacked body being stacked on an inner periphery and a bottom of a connection hole that extends through the first conductive layer and the base layer in a thickness direction, and being configured to electrically connect the first conductive layer and the second conductive layer to each other, and having an electroless copper plating layer. Each copper foil contains a copper crystal grain oriented in a plane orientation, and an average crystal grain size of copper of each copper foil is 10 μm or greater, the electroless copper plating layer includes palladium.

Printed wiring board

The printed circuit board includes, a first conductive layer including copper foil, an insulating base layer, and a second conductive layer including copper foil in this order, and includes a via-hole laminate that is stacked on an inner circumference and a bottom of a connection hole extending through the first conductive layer and the base layer in a thickness direction. The via-hole laminate has an electroless copper plating layer stacked on the connection hole and an electrolytic copper plating layer stacked on the electroless copper plating layer. The copper foil has copper crystal grains oriented in a (100) plane orientation, and an average crystal grain size of copper of 10 μm or more. The electroless copper plating layer includes palladium and tin, and an amount of the palladium stacked per unit area of a surface of the copper foil is 0.18 μg/cmor more and 0.40 μg/cmor less.

Printed circuit board

Growing community of inventors

Koka, Japan

Masashi Iwamoto