Fujikura Limited

Kunihiro Naoe

Yuu Ishii

Masateru Ichikawa

Shoji Ajimura

Yoshiyasu Isobe

An electronic component mounting board, including: a substrate base made of a flat-plate-like elastic body, the substrate base having a plurality of through-holes in a manner spaced a predetermined distance apart from each other; conductive members, each of which has a main unit portion filled in the through-hole, the main unit portion having a first protrusion portion and a second protrusion portion respectively on a first end and a second end thereof, with the first protrusion portion arranged so as to protrude from a first surface of the substrate base and the second protrusion portion arranged so as to protrude from a second surface of the substrate base; a flexible substrate that is arranged on the first surface of the substrate base and that has first opening portions for penetration of the first protrusion portions; and a plurality of oval electrodes arranged on the substrate, each of which has a second opening portion for penetration of the first protrusion portion, in which the electrodes are arranged in a manner spaced apart from each other, and each of the second opening portions is formed on a first end side of each of the electrodes.

Electronic component mounting board, method for manufacturing the same and electronic circuit unit

In a terminal portion having a copper or a copper alloy wiring according to one embodiment, the terminal portion being of a flexible print circuit board or a flexible flat cable and for connecter-fitting to a connector by being pressed by a connector pin, the copper or the copper alloy wiring having a pure tin or a lead-free tin alloy plating layer formed thereon is thermally treated so as to form an inter-metal compound including copper and tin on the copper or the copper alloy wiring, and a remaining thickness of the pure tin or the lead-free tin alloy plating layer is from 0.2 &#x3bc;m to 1.6 &#x3bc;m, wherein as an initial plating layer, a thickness of the pure tin or the lead-free tin alloy plating layer formed on the copper or the copper alloy wiring is from 1.5 &#x3bc;m to 5.0 &#x3bc;m, and a thickness of the inter-metal compound including copper and tin is from 0.1 &#x3bc;m to 3.5 &#x3bc;m.

Terminal portion of flexible print circuit board or flexible flat cable

Disclosed is a plated flat conductor including a flat conductor of copper or a copper alloy and a plated layer formed on a surface of the flat conductor. The plated layer includes a first intermetallic compound layer of CuSn disposed on the surface of the flat conductor, a second intermetallic compound layer of CuSnformed on the first intermetallic compound, and a superficial layer formed on the second intermetallic compound layer. The superficial layer is plating material of pure tin or a tin alloy and has an average thickness from about 0.3 &#x3bc;m to 1.0 &#x3bc;m and a maximum thickness of about 1.0 &#x3bc;m or less. A volume ratio of the second intermetallic compound layer to the first intermetallic compound layer is about 1.5 or more.

Growing community of inventors

Sakura, Japan

Kunihiro Naoe