JPS60169589A - Copper alloy material containing phosphorus coated with tin or tin alloy - Google Patents

Abstract

PURPOSE:To prevent the stripping of an Sn or Sn alloy coating formed on a Cu alloy substrate contg. P by forming a Zn or Zn alloy layer of a specified thickness as an intermediate layer on the substrate before forming the Sn or Sn alloy coating. CONSTITUTION:A Zn or Zn alloy layer of >=0.1mum, especially 0.1-3mum thickness as an intermediate layer is formed on a Cu alloy substrate contg. P. The preferred Zn alloy is Cu-Zn or Sn-Zn. An Sn or Sn alloy coating is then formed on the intermediate layer. The diffusion of P contained in the substrate into the Sn or Sn alloy coating is inhibited by the presence of the intermediate layer contg. Zn, so the stripping of the Sn or Sn alloy coating is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to the improvement of a wood cutting material made by providing a tin or tin alloy nucleation layer on a phosphorus-containing steel alloy base material, typified by phosphor bronze.

[Prior art]

Because phosphor bronze has relatively good conductivity, excellent springiness, and strength, it is widely used as a variety of electrical and electronic materials, such as connectors, various switches, electromagnetic switches, and spring rings. In addition, since phosphorous copper has good corrosion resistance, it is sometimes used as is after processing, or when used for terminals etc., it is soldered with tin or tin alloys (such as solder) to improve soldering properties. ) is often used with regret. Coating with tin or a tin alloy is often done exclusively by electroplating, and is usually plated to a thickness of 0.5 to 3 microns using a 0.1 to 1 micron thick copper as a base plating.

After the above-mentioned plating, a part of the trench may be heated for a short time to smooth the bell or tin alloy on the surface by bath melting, or flow treatment may be applied.

When bonding copper and copper or tin alloy, two types of intermetallic compounds consisting of copper and tin are formed at the interface, namely η' phase (Cu6Sns) on the tin B111 and ε phase (CuaSn) on the rough side.
is known to be formed, but when the copper base material contains phosphorus, further copper in the ε phase (till K,
A phase containing 0.01-0.2% phosphorus is formed.

This phase is extremely brittle, and after long-term use, a phenomenon occurs in which tin shavings or nucleated alloy chips peel off from the copper alloy base material. Moreover, under heating conditions, a similar phenomenon occurs within a short time. If such a phenomenon occurs, it may lead to circuit failures in electrical/electronic equipment, resulting in a significant loss of reliability of the equipment.

[Purpose of the invention]

The purpose of the present invention is to solve the problems of the prior art as described above! It is an object of the present invention to provide a tin or tin alloy coating layer of a phosphorus-containing steel alloy that can prevent the tin or tin alloy coating layer from peeling.

[Structure of the invention]

The phosphorus-containing steel base metal layer or tin alloy coating layer of the present invention that achieves the above object is coated on the phosphorus-containing steel base metal base with a thickness of 01 μm.
The above is preferably 01~:3μ! A tin or Xit pot coating layer is provided through a lead or zinc alloy intermediate layer.

As the zinc alloy, Cu-Zn and Sn-Zn are suitable, but the amount of Ni-Zn, Ni-Co-Zn
Zn-Cd, I! ``Alloys such as e-Zn can also be used.
It depends on the amount of n, but normally O1μ1μ is good. If the eaves are removed, a sufficient peeling prevention effect cannot be obtained. In addition, from the viewpoint of soldering properties, it is preferable that the thickness of this intermediate layer is 3μ or less1.
Although the mechanism by which zinc inhibits phosphorus concentration is not clear, the presence of the zinc-containing intermediate layer also inhibits the development of the Cu-8n intermetallic compound phase, which suggests that phosphorus will diffuse from the copper alloy base material. It is thought that this is due to the fact that zinc suppresses this.

Note that the present invention can be applied not only to phosphorus-containing steel but also to other phosphorus-containing steel base metals or tin alloy coatings.

[Implementation 1911] Real 1" ■ 0.4 mm in speed, 425 mm in diameter (Sn:
7.9%.

P: o, lz section) as profiteers, the next step is to create a thick glaze! II Trowel plating with lead plating as the intermediate layer (thickness 1
μ) A nucleated material was created. In addition, the 8J size of galvanizing is
Adjust by changing liJ during plating, 0.05, 0.1
.

There were 6 types: 0.5, 1.2.4μ.

(1) Cathode delunation j7 NaOH20g/f Current density 10A/dm' Processing time 10 seconds (2) Water (first (3) 13 ml Washing H2804100g/fH202
10g/l Stabilizer 1-Og/Jl Processing time 5 seconds (4) Water washing (5) Zinc plating ZnCN 60 g/fNaCN
40 g/j! Na01-1 80 g/f Current density IA/dm2 (6) Water washing (7) Bright tin plating 5nS0440 g/fH2S
O4 100g/, z Formalin 5cc/1 'Turtle flow rate 2.5 A/dm2 Processing time 50 seconds (8) Water Washing (9) Drying Example 2 Brass plating (Zn approx. 30%
) was used as the middle layer, and the other conditions were kept the same to create the nucleated material of the gods. The conditions for brass plating are as follows.

CuCN 30 g/J Z,, (CN)2 10 g/z NaCN 50 g/J4 Na,, Co3: Og/x Current density I A,/dm2 Bath temperature 40C Example 3 For the zinc plating of Example 1 Alternative So-Zn plating (Z
n 4'l 20%) 1mj Ie in f7,
Other Articles 1 pm 1TTi I created Kiri, the destroyer of the gods. The conditions for Sr+ -Zn plating are as follows.

Na25n03・3f (4067g/lZ+1 (CN
) 210 g/1 NaCN 25 g/, e NaOl-16 g/f Current rating 2 A/dm2 (Valley temperature 60 r Conventional example Instead of the zinc plating in Example 1, bright copper plating with a thickness of 1 μm was used as intermediate JE, A conventional coating material was prepared with other conditions being the same.The conditions for glossy hook plating were as follows.

Cu5O4a5H20220g/f 1 (280455g/working current density 3A/d+n2) For each weight mU created as above,
The origin of peeling due to bending after heating in 150C atmosphere for a predetermined period of time and the area of smearing when immersed in 230C solder for 2 seconds were investigated.

The results are shown in the table below.

Note) 0) + Toru 1. [(Mu7, 1N to 13 is a comparison example.

(2) Peeling evaluation ○: No peeling]: Slightly △: Partially peeled × = Peeling (3) Soldering is rough ○: >90% (Wet surface is blue) Mouth: 8o~90% △: 50 to 80 Alternatively, it is possible to obtain a tin alloy oxidizable material, which contributes to improving the reliability of electrical, electronic, and slave devices.

Patent attorney Hiroshi Wakabayashi is the agent

Claims (1)

[Claims] A tin or tin alloy coating of a phosphorus-containing steel alloy, characterized in that a tin or tin alloy nucleation layer is provided on a phosphorus-containing copper alloy base layer through a zinc or zinc alloy intermediate/Gm' having a thickness of 01μ or more. nuclear layer.