Tin-plated copper-alloy terminal material and producing method of the same

Patent metadata

Field	Value
Publication number	US-2017298527-A1
Application number	US-201515505174-A
Country	US
Kind code	A1
Filing date	Aug 18, 2015
Priority date	Sep 11, 2014
Publication date	Oct 19, 2017
Grant date	—

Abstract

A tin-plated copper alloy terminal material in which an Sn-based surface layer is formed on a surface of a base material that is made of copper or a copper alloy, and a Cu—Sn alloy layer and an Ni layer or an Ni alloy layer are sequentially formed between the Sn-based surface layer and the base material from the Sn-based surface layer side: the Cu—Sn alloy layer is a layer that is formed only of an intermetallic compound alloy which is obtained by substituting some of Cu in Cu 6 Sn 5 alloy with Ni; and parts of the Cu—Sn alloy layer are exposed from the Sn-based surface layer, thereby forming a plurality of exposed portions; an average thickness of the Sn-based surface layer is from 0.2 μm to 0.6 μm (inclusive); and an area rate of the exposed portions of the Cu—Sn alloy layer relative to a surface area of is 1% to 40% (inclusive).

First claim

1 . A tin-plated copper alloy terminal material wherein a Sn-based surface layer is formed on a surface of a base material made of copper or a copper alloy, and a Cu—Sn alloy layer/an Ni layer or Ni copper layer are formed from the Sn-based surface layer in a sequence, wherein
the Cu—Sn alloy layer consists of an intermetallic compound alloy which is obtained by substituting some of Cu in Cu 6 Sn 5 alloy with Ni,
parts of the Cu—Sn alloy layer are exposed from the Sn-based surface layer and forms exposed portions,
an average thickness of the Sn-based surface layer is 0.2 μm or larger and 0.6 μm or smaller,
an area rate of the exposed portions of the Cu—Sn alloy layer relative to a surface area of a surface layer of the tin-plated copper alloy terminal material is 1% or higher and 40% or lower,
an average circle-equivalent diameter of the exposed portions of the Cu—Sn alloy layer is 0.1 μm or larger and 1.5 μm or smaller,
a reduced peak height Rpk at a surface of the tin-plated copper alloy terminal material is 0.005 μm or larger and 0.03 μm or smaller, and
coefficient of kinetic friction is 0.3 or less.

2 . The tin-plated copper alloy terminal material according to claim 1 , wherein a content percentage of Ni in the Cu—Sn alloy layer is 1 at % or more and 25 at % or less.

3 . A producing method of a tin-plated copper alloy terminal material wherein on a base material made of copper alloy, performing a nickel plating step or a nickel alloy plating step, a copper plating step, and a tin plating step in this sequence, and then performing a reflowing process, so that an Ni layer or an Ni alloy layer/a Cu—Sn alloy layer/an Sn-based surface layer are formed on the base material, wherein
a first plated layer thickness by the nickel plating step or the nickel alloy plating step is 0.05 μm or more and 1.0 μm or less,
a second plated layer thickness by the copper plating step is 0.05 μm or more and 0.20 μm or less,
a third plated layer thickness by the tin plating step is 0.5 μm or more and 1.0 μm or less, and
the reflowing process comprises a heating step heating the respective plated layers to a peak temperature of 240 to 300° C. at a temperature rise rate of 20 to 75° C./second, a first cooling step cooling the respective plated layers at a cooling rate less than 30° C./second for 2 to 15 seconds after reaching the peak temperature, and a second cooling step cooling at a cooling rate of 100 to 300° C./second after the first cooling step.

Assignees

• Mitsubishi Materials Corp

Inventors

• Kato Naoki
• Inoue Yuki
• Nakaya Kiyotaka

Classifications

• C25D3/30

  of tin · CPC title

• Y10T428/12882

  Cu-base component alternative to Ag-, Au-, or Ni-base component · CPC title

• Y10T428/12715

  Next to Group IB metal-base component · CPC title

• Y10T428/12931

  Co-, Fe-, or Ni-base components, alternative to each other · CPC title

• C23C30/00

  Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process (C23C26/00, C23C28/00 take precedence) · CPC title